Environmental sustainability and information systems: The similarity

Application of information technology and environmental planning share two very important characteristics: they are both concerned with planning, evaluating, and directing human activity in a wider context, and this activity is multiaspectual, multimodal, and multidisciplinary in scope. Further, the ideal in both cases is sustainable, long-term activity that brings overall good rather than harm. This paper discusses the multiaspectual nature of environmental sustainability and shows briefly how this understanding can be translated to the field of information systems.     

No communication without manipulation: A causal-deflationary view of information

In this paper, we shall describe a new account of information in communicational contexts, namely, a causal-deflationary one. Our approach draws from Timpson's deflationary view and supplies the field of philosophy of information with new tools that will help to clarify the underlying structure of communication: information is an abstract entity that must be involved in a causal link in order to achieve communication. In light of our account, communication is not merely the existence of statistical correlations between source and receiver, as usually understood from a purely formal view. Instead, communication is an asymmetric phenomenon involving causal notions: the destination system must be able to be causally manipulated by intervening on the source for successful communication. In a nutshell, we shall support the following lemma: no communication without manipulation.     

Evidence for polarization of plasma membrane domains in pancreatic endocrine cells

Polarization of plasma membrane domains is an essential feature of secretory epithelial cells from exocrine glands. The surface of exocrine cells (a typical example is the acinar cell of the pancreas) is separated into an apical domain, where secretion occurs by exocytosis, and a basolateral domain, which senses variations of the internal milieu and is enriched with receptors for various hormones and secretagogues. It is unknown whether secretion is polarized in endocrine cells (except for thyroid follicular cells, which are organized into cavitary structures). To determine whether distinct plasma membrane domains exist in endocrine cells, we infected monolayer cultures of pancreatic endocrine cells with enveloped RNA viruses known to bud selectively from either the apical or basolateral domain in polarized epithelial cells. This asymmetrical budding is thought to reflect the polarized nature of the infected cells, as in non-polarized cells such as fibroblasts, the same viruses bud nonselectively from the entire cell surface. We show here that influenza virus and vesicular stomatitis virus (VSV) emerge asymmetrically from cultured pancreatic islet cells; this represents the first evidence for polarization of plasma membrane domains in pancreatic endocrine cells.     

A locus for familial early-onset Alzheimer's disease on the long arm of chromosome 14, proximal to the alpha 1-antichymotrypsin gene.

Although mutations in the beta-amyloid precursor protein gene (APP) on chromosome 21 cause some cases of early-onset Alzheimer's disease (AD), most cases evidently do not have mutations in APP. We analysed ten early-onset families for linkage to APP and markers elsewhere in the genome. One family (F172) was consistent with linkage to chromosome 21 and was subsequently found to have an APP Val to Ile mutation. Of the others, all but one were consistent with linkage to markers in the middle long arm of chromosome 14. However, no family showed independent evidence of linkage with two point analysis and only one showed independent evidence of linkage on multipoint analysis. Therefore, we cannot rule out heterogeneity at these loci although tests for heterogeneity were not significant.     

The modal-Hamiltonian interpretation and the Galilean covariance of quantum mechanics

The aim of this paper is to analyze the modal-Hamiltonian interpretation of quantum mechanics in the light of the Galilean group. In particular, it is shown that the rule of definite-value assignment proposed by that interpretation has the same properties of Galilean covariance and invariance as the Schrödinger equation. Moreover, it is argued that, when the Schrödinger equation is invariant, the rule can be reformulated in an explicitly invariant form in terms of the Casimir operators of the Galilean group. Finally, the possibility of extrapolating the rule to quantum field theory is considered.     

The myosin motor in muscle generates a smaller and slower working stroke at higher load

Muscle contraction is driven by the motor protein myosin II, which binds transiently to an actin filament, generates a unitary filament displacement or 'working stroke', then detaches and repeats the cycle. The stroke size has been measured previously using isolated myosin II molecules at low load, with rather variable results, but not at the higher loads that the motor works against during muscle contraction. Here we used a novel X-ray-interference technique to measure the working stroke of myosin II at constant load in an intact muscle cell, preserving the native structure and function of the motor. We show that the stroke is smaller and slower at higher load. The stroke size at low load is likely to be set by a structural limit; at higher loads, the motor detaches from actin before reaching this limit. The load dependence of the myosin II stroke is the primary molecular determinant of the mechanical performance and efficiency of skeletal muscle.     

制造单元设计中瓶颈问题的处理

近几年来，不少文章提出了在制造单元设计中评价机床利用率的不同方法，多数论文是假设按带有单元间输送作为预定参数的网络模型来处理的，从这一观点出发，为消除所谓瓶颈因素的其他经济的方法可以重复配置机床成将某些工序扩散到单元外加工，本文分析了在处理瓶颈问题时单元间输送的作用，集中分析了它的非独立性性质，因而较大地简化了解决这一问题方法的复杂性，此外，文中还讨论了在处理瓶颈问题时将某些工序扩散到单元外加工的