一种高灵敏性钢包下渣检测装置的研究与应用

在钢水浇铸过程中,需要严格控制钢包到中间包的钢渣量.通过对国外多种下渣检测技术的调研分析及国内多个钢厂的现场试验,提出了一种高灵敏性的钢包下渣检测装置,从硬件上改变了传统采集的单一检测方式,同时在软件上简化了下渣特征提取的算法.通过在现场使用,取得了较好的检测效果,有效控制了进入中间包内的钢渣量,提高了钢厂的经济效益.     

System Dynamics Urban Sustainability Model for Puerto Aura in Puebla, Mexico

This paper reports on an on-going project on urban sustainability, the Puerto Aura in the region of the Valsequillo Lake in Puebla, Mexico. As part of the project, a simulation model was built to explore the dynamic interaction of the dimensions inherent in sustainable urban development. After reviewing literature on sustainable urban development (SUD) frameworks and tools, we identify key variables that intervene in SUD. We propose a System Dynamics model to simulate the dimensions that intervene in a sustainable development and to anticipate the consequences of the decision making process. The structure and inter-relationships of four sectors in the proposed model are described, the sustainability indicators in each sector explained. Preliminary conclusions are drawn stating that a complete run of the model simulating a 20 years horizon in monthly periods is expected when the full data from the Puerto Aura master plan becomes available.

Mutations in kelch-like 3 and cullin 3 cause hypertension and electrolyte abnormalities

Hypertension affects one billion people and is a principal reversible risk factor for cardiovascular disease. Pseudohypoaldosteronism type II (PHAII), a rare Mendelian syndrome featuring hypertension, hyperkalaemia and metabolic acidosis, has revealed previously unrecognized physiology orchestrating the balance between renal salt reabsorption and K(+) and H(+) excretion. Here we used exome sequencing to identify mutations in kelch-like 3 (KLHL3) or cullin 3 (CUL3) in PHAII patients from 41 unrelated families. KLHL3 mutations are either recessive or dominant, whereas CUL3 mutations are dominant and predominantly de novo. CUL3 and BTB-domain-containing kelch proteins such as KLHL3 are components of cullin-RING E3 ligase complexes that ubiquitinate substrates bound to kelch propeller domains. Dominant KLHL3 mutations are clustered in short segments within the kelch propeller and BTB domains implicated in substrate and cullin binding, respectively. Diverse CUL3 mutations all result in skipping of exon 9, producing an in-frame deletion. Because dominant KLHL3 and CUL3 mutations both phenocopy recessive loss-of-function KLHL3 mutations, they may abrogate ubiquitination of KLHL3 substrates. Disease features are reversed by thiazide diuretics, which inhibit the Na-Cl cotransporter in the distal nephron of the kidney; KLHL3 and CUL3 are expressed in this location, suggesting a mechanistic link between KLHL3 and CUL3 mutations, increased Na-Cl reabsorption, and disease pathogenesis. These findings demonstrate the utility of exome sequencing in disease gene identification despite the combined complexities of locus heterogeneity, mixed models of transmission and frequent de novo mutation, and establish a fundamental role for KLHL3 and CUL3 in blood pressure, K(+) and pH homeostasis.     

On Jacobi’s transformation theory of elliptic functions

The main interpretative challenge set by the Fundamenta Nova Theoriae Functionum Ellipticarum lies in Jacobi’s transformation theory upon which the entire theoretical edifice of the treatise depends. Unfortunately, Jacobi did not convey any indication of how he attained his general formulae for rational transformations of elliptic functions. He limited himself to providing a posteriori verification of the validity of his claims. The aim of this paper is precisely to describe the heuristic path by which in 1827 Jacobi succeeded in finding these transformation formulae. The proposed historical reconstruction will hopefully shed new light upon the emergence in Jacobi’s work of the inversion process of elliptic integrals of the first kind and thus of the elliptic function sinam \(u\) itself.     

Antipredator defence mechanism in the amphidromous shrimp Xiphocaris elongata (Decapoda: Xiphocarididae): rostrum length

Predators may affect prey through inducible defences that can alter prey phenotype. The shrimp Xiphocaris elongata exhibits a short rostrum (SR) in the absence of fish predators and a long rostrum (LR) in their presence. The long rostrum in X. elongata is inducible by the predatory fish Agonostomus monticola (mountain mullet). Our objective was to test whether the long rostrum is an effective antipredator defence against A. monticola in different stages of predator–prey interactions (i.e. choice, attacks, bites, rejections, handling time and survival). We conducted behavioural experiments in fish tanks in which we fed A. monticola simultaneously with (1) one LR shrimp and one SR shrimp, or (2) one LR shrimp and one shrimp which originally had a long rostrum but whose rostrum was cut (LR[S]). We scored the fish behaviours in terms of choice, unsuccessful attacks, bites, rejections and handling time. We also conducted mortality experiments in closed artificial pools in which we exposed (1) 10 LR and 10 SR shrimp or (2) 10 LR and 10 LR[S] shrimp to A. monticola, and quantified shrimp survival after 24 h. In the trials with LR and SR shrimp, A. monticola tended to attack SR shrimp first. LR shrimp were unsuccessfully attacked, bitten and rejected more than SR individuals. Handling time was higher for LR shrimp. The mortality experiments show higher survival of LR shrimp. In the trials with LR and LR[S] shrimp, A. monticola tended to attack LR[S] shrimp first. Unsuccessful attacks were similar for LR and LR[S]. There were more bites and rejections and longer handling time for LR shrimp. Survival was similar for LR and LR[S] shrimp in the mortality experiments. This study provides evidence in support of the hypothesis that the long rostrum in X. elongata is an effective antipredator defence against A. monticola by conferring benefits in most stages of the predator–prey interactions.