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Mechanistic pathways relevant to mineralization are not well-understood fundamentally, let alone in the context of their biological and geological environments. Through quantitative analysis of ion association at near-neutral pH, we identify the involvement of HCO3− ions in CaCO3 nucleation. Incorporation of HCO3− ions into the structure of amorphous intermediates is corroborated by solid-state nuclear magnetic resonance spectroscopy, complemented by quantum mechanical calculations and molecular dynamics simulations. We identify the roles of HCO3− ions as being through (i) competition for ion association during the formation of ion pairs and ion clusters prior to nucleation and (ii) incorporation as a significant structural component of amorphous mineral particles. The roles of HCO3− ions as active soluble species and structural constituents in CaCO3 formation are of fundamental importance and provide a basis for a better understanding of physiological and geological mineralization.

[EN] This paper explores the possibility that perishable goods can be ordered several times in a single period after considering the cost of Marginal contribution, Marginal loss, Shortage, and Purchasing under stochastic demand. In order to determine the optimal ordering quantity to improve the traditional newsvendor and maximize the total expected profits, and then sensitivity analysis is taken to realize the influence of the parameters on total expected profits and decision variables respectively. In addition, this paper designed a multi-order computerized system with Monte Carlo method to solve the optimal solution under stochastic demand. Based on numerical examples, this paper verified the feasibility and efficiency of the proposed model. Finally, several specific conclusions are drawn for practical applications and future studies.

[EN] This paper explores the possibility that perishable goods can be ordered several times in a single period after considering the cost of Marginal contribution, Marginal loss, Shortage, and Purchasing under stochastic demand. In order to determine the optimal ordering quantity to improve the traditional newsvendor and maximize the total expected profits, and then sensitivity analysis is taken to realize the influence of the parameters on total expected profits and decision variables respectively. In addition, this paper designed a multi-order computerized system with Monte Carlo method to solve the optimal solution under stochastic demand. Based on numerical examples, this paper verified the feasibility and efficiency of the proposed model. Finally, several specific conclusions are drawn for practical applications and future studies.

[EN] This paper explores the possibility that perishable goods can be ordered several times in a single period after considering the cost of Marginal contribution, Marginal loss, Shortage, and Purchasing under stochastic demand. In order to determine the optimal ordering quantity to improve the traditional newsvendor and maximize the total expected profits, and then sensitivity analysis is taken to realize the influence of the parameters on total expected profits and decision variables respectively. In addition, this paper designed a multi-order computerized system with Monte Carlo method to solve the optimal solution under stochastic demand. Based on numerical examples, this paper verified the feasibility and efficiency of the proposed model. Finally, several specific conclusions are drawn for practical applications and future studies.

[EN] This paper explores the possibility that perishable goods can be ordered several times in a single period after considering the cost of Marginal contribution, Marginal loss, Shortage, and Purchasing under stochastic demand. In order to determine the optimal ordering quantity to improve the traditional newsvendor and maximize the total expected profits, and then sensitivity analysis is taken to realize the influence of the parameters on total expected profits and decision variables respectively. In addition, this paper designed a multi-order computerized system with Monte Carlo method to solve the optimal solution under stochastic demand. Based on numerical examples, this paper verified the feasibility and efficiency of the proposed model. Finally, several specific conclusions are drawn for practical applications and future studies.

[EN] This paper explores the possibility that perishable goods can be ordered several times in a single period after considering the cost of Marginal contribution, Marginal loss, Shortage, and Purchasing under stochastic demand. In order to determine the optimal ordering quantity to improve the traditional newsvendor and maximize the total expected profits, and then sensitivity analysis is taken to realize the influence of the parameters on total expected profits and decision variables respectively. In addition, this paper designed a multi-order computerized system with Monte Carlo method to solve the optimal solution under stochastic demand. Based on numerical examples, this paper verified the feasibility and efficiency of the proposed model. Finally, several specific conclusions are drawn for practical applications and future studies.

The purpose of this study was to develop a loop-mediated isothermal amplification (LAMP) method for rapid, sensitive, and simple detection of Streptococcus agalactiae in farmed fish. A set of four primers, two outer and two inner, was designed from the fibrinogen-binding (fbsB) proteins gene sequence of S. agalactiae, and conditions for LAMP were optimized as incubation of all reagents for 60 min at 64°C. LAMP products were judged by agar gel electrophoresis as well as the naked eye after development by Synergy Brands Green I (SYBR Green I). Sensitivity of the assay was 2.8 × 103 CFU/ml (2.8 CFU per reaction) and no positive amplification was detected for other related bacteria. This LAMP method can be used to detect S. agalactiae infection in the laboratory and the field.

The purpose of this study was to develop a loop-mediated isothermal amplification (LAMP) method for rapid, sensitive, and simple detection of Streptococcus agalactiae in farmed fish. A set of four primers, two outer and two inner, was designed from the fibrinogen-binding (fbsB) proteins gene sequence of S. agalactiae, and conditions for LAMP were optimized as incubation of all reagents for 60 min at 64°C. LAMP products were judged by agar gel electrophoresis as well as the naked eye after development by Synergy Brands Green I (SYBR Green I). Sensitivity of the assay was 2.8 × 103 CFU/ml (2.8 CFU per reaction) and no positive amplification was detected for other related bacteria. This LAMP method can be used to detect S. agalactiae infection in the laboratory and the field.

The purpose of this study was to develop a loop-mediated isothermal amplification (LAMP) method for rapid, sensitive, and simple detection of Streptococcus agalactiae in farmed fish. A set of four primers, two outer and two inner, was designed from the fibrinogen-binding (fbsB) proteins gene sequence of S. agalactiae, and conditions for LAMP were optimized as incubation of all reagents for 60 min at 64°C. LAMP products were judged by agar gel electrophoresis as well as the naked eye after development by Synergy Brands Green I (SYBR Green I). Sensitivity of the assay was 2.8 × 103 CFU/ml (2.8 CFU per reaction) and no positive amplification was detected for other related bacteria. This LAMP method can be used to detect S. agalactiae infection in the laboratory and the field.

A small number of clonal lineages dominates the global population structure of methicillin-resistant Staphylococcus aureus (MRSA), resulting in the concept that MRSA has emerged on a few occasions after penicillinase-stable beta-lactam antibiotics were introduced to clinical practice, followed by intercontinental spread of individual clones. We investigated the evolutionary history of an MRSA clone (ST5) by mutation discovery at 108 loci (46 kb) within a global collection of 135 isolates. The SNPs that were ascertained define a radial phylogenetic structure within ST5 consisting of at least 5 chains of mutational steps that define geographically associated clades. These clades are not concordant with previously described groupings based on staphylococcal protein A gene (spa) typing. By mapping the number of independent imports of the staphylococcal cassette chromosome methicillin-resistance island, we also show that import has occurred on at least 23 occasions within this single sequence type and that the progeny of such recombinant strains usually are distributed locally rather than globally. These results provide strong evidence that geographical spread of MRSA over long distances and across cultural borders is a rare event compared with the frequency with which the staphylococcal cassette chromosome island has been imported Udgivelsesdato: 2008/9/16

A small number of clonal lineages dominates the global population structure of methicillin-resistant Staphylococcus aureus (MRSA), resulting in the concept that MRSA has emerged on a few occasions after penicillinase-stable beta-lactam antibiotics were introduced to clinical practice, followed by intercontinental spread of individual clones. We investigated the evolutionary history of an MRSA clone (ST5) by mutation discovery at 108 loci (46 kb) within a global collection of 135 isolates. The SNPs that were ascertained define a radial phylogenetic structure within ST5 consisting of at least 5 chains of mutational steps that define geographically associated clades. These clades are not concordant with previously described groupings based on staphylococcal protein A gene (spa) typing. By mapping the number of independent imports of the staphylococcal cassette chromosome methicillin-resistance island, we also show that import has occurred on at least 23 occasions within this single sequence type and that the progeny of such recombinant strains usually are distributed locally rather than globally. These results provide strong evidence that geographical spread of MRSA over long distances and across cultural borders is a rare event compared with the frequency with which the staphylococcal cassette chromosome island has been imported Udgivelsesdato: 2008/9/16