Reaction of lysozyme with dithiothreitol and with other mercaptans

Riassunto Sono misurate le velocità di reazione della lisozima con 0.05M ditiotreitolo, HSCH₂CH₂OH, (HSCH₂CH₂COO^–) e H₂SCH₂CH₂NH₂ in tampone borace di pH 10 e in alcune altre concentrazioni e pH. La cinetica della reazione col ditiotreitolo è differente da quella con HSCH₂CH₂OH e viene data una interpretazione di questo fenomeno.

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This work was aided by a grant and a Career Development Award (to G.G.) from the National Institutes of Health, U.S. Public Health Service.     

Playing with molecules

Recent philosophy of science has seen a number of attempts to understand scientific models by looking to theories of fiction. In previous work, I have offered an account of models that draws on Kendall Walton’s ‘make-believe’ theory of art. According to this account, models function as ‘props’ in games of make-believe, like children’s dolls or toy trucks. In this paper, I assess the make-believe view through an empirical study of molecular models. I suggest that the view gains support when we look at the way that these models are used and the attitude that users take towards them. Users’ interaction with molecular models suggests that they do imagine the models to be molecules, in much the same way that children imagine a doll to be a baby. Furthermore, I argue, users of molecular models imagine themselves viewing and manipulating molecules, just as children playing with a doll might imagine themselves looking at a baby or feeding it. Recognising this ‘participation’ in modelling, I suggest, points towards a new account of how models are used to learn about the world, and helps us to understand the value that scientists sometimes place on three-dimensional, physical models over other forms of representation.     

交通信号PLC控制触摸屏动态显示系统

本文基于可编程逻辑控制器（PLC）和触摸屏,设计了一个城市道路交通信号动态显示系统。该系统的特点是组合应用了PLC和触摸屏,栗用PLC对交通信号进行控制,同时将交通信号的实时状态显示在触摸屏上,并具有在线修改信号配时参数的功能。该系统能对不同相位的信号交叉口的信号进行控制,同时具有信号的协调控制功能。文章介绍了系统的设计过程,论述了交通信号PLC控制程序的设计步骤以及相应的触摸屏界面的制作方法,并给出了典型的PLC控制子程序。     

Nitrothiophenes with schistosomicidal activity

Summary A series of nitrothiophene compounds, with activity against Schistosoma mansoni in mice, is described and shown to be more effective than the corresponding nitrofurans.     

Forecasting with panel data

This paper gives a brief survey of forecasting with panel data. It begins with a simple error component regression model and surveys the best linear unbiased prediction under various assumptions of the disturbance term. This includes various ARMA models as well as spatial autoregressive models. The paper also surveys how these forecasts have been used in panel data applications, running horse races between heterogeneous and homogeneous panel data models using out‐of‐sample forecasts. Copyright © 2008 John Wiley & Sons, Ltd.     

Experiments with interactional expertise

‘Interactional expertise’ is developed through linguistic interaction without full scale practical immersion in a culture. Interactional expertise is the medium of communication in peer review in science, in review committees, and in interdisciplinary projects. It is also the medium of specialist journalists and of interpretative methods in the social sciences. We describe imitation game experiments designed to make concrete the idea of interactional expertise. The experiments show that the linguistic performance of those well socialized in the language of a specialist group is indistinguishable from those with full blown practical socialization but distinguishable from those who are not well socialized. The imitation game can also be used to indicate whether an individual can enter an esoteric domain and master the interactional expertise, a skill required by interpretative sociologists of science, anthropologists, ethnographers, and the like.     

Fooling around with tenses

What, exactly, is the relation between statements about future contingents and statements concerning the spacelike? This question may be answered by transferring Thomasonian supervaluations for future tense statements to statements about the spacelike past, present and future, endorsing present contingents and past contingents. For this task, a language is described semantically which contains (frame-relative versions of) the usual quantifier-like tense operators, operators for (frame-relative) “somewhere”/“everywhere”, the operators “for every reference frame”/“for some reference frame” and three different “necessity” operators with their “possibility” counterparts. Technically, special attention is paid to interaction laws between the different kinds of operators. The “necessity” operators differ in the area on which alternatives must coincide in order to count as accessible. Supervaluations are discussed for past light-cone coincidence. Metaphysically, this approach points towards a distinction between two kinds of determinateness which were undistinguishable pre-relativistically: deictic determinateness (past light-cone) and narrative determinateness (frame-relative present-plus-past). An indeterministic solution to the problem of the “wings” is proposed which, without accepting a frame-independent spatially extended present, solves the problem of “massive coincidence” by carefully analysing the famous tunnel example as a story of decisions and by distinguishing between “whether” and “that”-clauses.     

A life with lectins

No Abstract. .Received 18 February 2005; accepted 18 February 2005     

Forecasting with preliminary data

This paper examines several methods to forecast revised US trade balance figures by incorporating preliminary data. Two benchmark forecasts are considered: one ignoring the preliminary data and the other applying a combination approach; with the second outperforming the first. Competing models include a bivariate AR error-correction model and a bivariate AR error-correction model with GARCH effects. The forecasts from the latter model outperforms the combination benchmark for the one-step forecast case only. A restricted AR error-correction model with GARCH effects is discovered to provide the best forecasts. © 1997 John Wiley & Sons, Ltd.     

Cross-reactivity of autoantibodies from patients with epidermolysis bullosa acquisita with murine collagen VII

The pathomechanism of antibody-mediated tissue damage in autoimmune diseases can be best studied in experimental models by passively transferring specific autoantibodies into animals. The reproduction of the disease in animals depends on several factors, including the cross-reactivity of patient autoantibodies with the animal tissue. Here, we show that autoantibodies from patients with epidermolysis bullosa acquisita (EBA), a subepidermal autoimmune blistering disease, recognize multiple epitopes on murine collagen VII. Indirect immunofluorescence microscopy revealed that EBA patients’ IgG cross-reacts with mouse skin. Overlapping, recombinant fragments of murine collagen VII were used to characterize the reactivity of EBA sera and to map the epitopes on the murine antigen by ELISA and immunoblotting. The patients’ autoantibody binding to murine collagen VII triggered pathogenic events as demonstrated by a complement fixing and an ex vivo granulocyte-dependent dermal–epidermal separation assay. These findings should greatly facilitate the development of improved disease models and novel therapeutic strategies.     

A state-dependent linear recurrent formula with application to time series with structural breaks

An underlying assumption in Multivariate Singular Spectrum Analysis (MSSA) is that the time series are governed by a linear recurrent continuation. However, in the presence of a structural break, multiple series can be transferred from one homogeneous state to another over a comparatively short time breaking this assumption. As a consequence, forecasting performance can degrade significantly. In this paper, we propose a state-dependent model to incorporate the movement of states in the linear recurrent formula called a State-Dependent Multivariate SSA (SD-MSSA) model. The proposed model is examined for its reliability in the presence of a structural break by conducting an empirical analysis covering both synthetic and real data. Comparison with standard MSSA, BVAR, VAR and VECM models shows the proposed model outperforms all three models significantly.