Computer Simulation of a Living Cell: Metabolic Control System Experiments

Abstract

This paper reports on some interesting experiments performed on a simulated model of a living cell. The basic model is that of Weinberg [35] and the underlying techniques employed are described by Zeigler and Weinberg [41]. The cell was subjected to step changes in its nutrient environment.     

Increased sensitivity for the diagnosis of Taenia saginata cysticercus infection by additional heart examination compared to the EU-approved routine meat inspection

In spite of the statutory meat inspection at abattoirs, Taenia saginata cysticercus infection in cattle remains an economically important parasitic disease for the livestock industry by affecting food safety. The routinely performed standard meat inspection protocol has a low diagnostic sensitivity for the detection of T. saginata cysticerci infections. Therefore, an abattoir trial aiming to increase the detection level was undertaken. In three EU-approved abattoirs, several additional heart incisions were performed in a total of 1088 slaughtered cattle originating from 832 farms throughout Switzerland. Cysticerci as putative parasitic lesions were classified by visual examination during meat inspection and confirmed microscopically and/or by molecular analyses. With the EU-approved routine meat inspection, bovine cysticercosis was diagnosed in 1.8% (20/1088) of the slaughtered animals. Additional incisions into the heart muscle revealed a further 29 cases, indicating that the prevalence was at least 4.5%. All infected animals originated from individual farms. This straightforward technique had a significantly higher sensitivity and is feasible for routine practice. It also confirms that the prevalence of this zoonotic parasite in the cattle population is underestimated based on the routine abattoir reports.     

Efficient Non-Malleable Commitment Schemes

Non-malleability protects against man-in-the middle attacks on cryptographic protocols. Non-malleable commitment schemes, for example, assure that a commitment of a message does not help to produce a commitment of a related message. Here we present efficient constructions of such commitment schemes in the common reference string model based on standard assumptions such as RSA, factoring, or discrete logarithm. Our protocols require only three rounds and a few modular exponentiations, and provide statistical or even perfect secrecy of committed values.     

Learning psychotherapy in the digital age.

There is substantial literature documenting the process factors that lead to effective psychotherapy. Similarly, there is now a wealth of data attesting to the effectiveness of several psychotherapy brands. Little is known about the elements that facilitate learning how to be an effective clinician. One important step, after reading about a treatment model and seeing techniques demonstrated, is having the chance to practice the approach and receiving feedback and coaching from an experienced, knowledgeable supervisor. To accomplish this efficiently, most programs rely not only on trainee accounts of what went on in their therapy sessions, but also on recordings and videos of therapeutic encounters. This article describes our experience over a 5-year period in developing the use of Webcams for training psychology interns and psychiatric residents in the delivery of psychotherapy services. Pragmatic and technical details are given about how we went about establishing a recording system that is easy to use and provides secure, confidential storage of information at a reasonable cost. Discussion addresses both the weighing of choices that need to be made and overcoming the hesitation of trainees to reveal their work during treatment sessions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The history of broad and general education in scientific psychology: The foundation for professional psychology education and training.

The article provides the historical roots and rationale for providing professional psychologists with knowledge of the underpinnings in core scientific areas of psychology with two goals–knowledge of those scientific areas themselves and as the basis for further understanding the integration of science and practice to improve professional service delivery. This article discusses the early roots of the applied areas within psychology and the changes in curricular expectations in accreditation to the current provisions for the accreditation of doctoral programs in professional psychology. After the historical introduction, the article discusses the current use of the concept of broad and general training as the basis for current practice in accreditation of programs in professional psychology and for the practice as a licensed psychologist. Finally, the article provides some initial discussion of the different perspectives in the rest of the section regarding how best to provide students with appropriate knowledge for competence in scientific underpinnings of professional psychology. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Transverse wakefield suppression using cell detuning assisted by manifold damping for high gradient linear colliders

Transverse wakefields excited by multiple bunches in ultra-relativistic charged particle beams in a linear collider must be adequately damped in order to preserve the luminosity of the colliding beams and to prevent a beam break up instability developing. Means of achieving this wakefield suppression are discussed in detail for high gradient normal conducting linacs. In particular the features of a damped and detuned series of structures (DDS) are described. Analytical expressions for the wakefield on short time scales are presented together with the circuit analysis required to rapidly analyse the general long-range behaviour in these linacs. A conspectus of experimental results along with theoretical predictions for this series of accelerating structures developed for the NLC/GLC is presented together with recent results on wakefield suppression for CLIC.     

Algorithmic issues for three-invariant hyperplastic Critical State models

Implicit stress integration and the consistent tangents are presented for Critical State hyperplasticity models which include a dependence on the third invariant of stress. An elliptical deviatoric yielding criterion [43] is incorporated within the family of geotechnical models first proposed by Collins and Hilder [8]. An alternative expression for the yield function is proposed and the consequences of different forms of that function are revealed in terms of the stability and efficiency of the stress return algorithm. Errors associated with the integration scheme are presented. It is shown how calibration of the two new material constants is achieved through examining one-dimesional consolidation tests and undrained triaxial compression data. Material point simulations of drained triaxial compression tests are then compared with established experimental results. Strain probe analyses are used to demonstrate the concepts of energy dissipation and stored plastic work along with the robustness of the integration method. Over twenty finite element boundary value problems are then simulated. These include single three-dimensional element tests, plane strain footing analyses and cavity expansion tests. The rapid convergence of the global Newton–Raphson procedure using the consistent tangent is demonstrated in small strain and finite deformation simulations.     

Characterizing executive functioning in older special populations: From cognitively elite to cognitively impaired.

The authors examined the structure and invariance of executive functions (EF) across (a) a continuum of cognitive status in 3 groups of older adults (cognitively elite [CE], cognitively normal [CN], and cognitively impaired [CI]) and (b) a 3-year longitudinal interval. Using latent variable analyses (LISREL 8.80), the authors tested 3-factor models (“Inhibition”: Hayling [Burgess & Shallice, 1997], Stroop [Regard, 1981]; “Shifting”: Brixton [Burgess & Shallice, 1997], Color Trails [D’Elia et al., 1996]; and “Updating”: Reading and Computational Span [Salthouse & Babcock, 1991]) and 1-factor models within each group. Participants (initial N = 570; 53–90 years) were from the Victoria Longitudinal Study (Sample 3, Waves 1 and 2). Cross-sectionally, the authors observed a 3-factor EF structure especially for the CE group and 1-factor solutions for all 3 groups. Longitudinally, temporal invariance was supported for the 3-factor model (CE and CN groups) and the 1-factor model (CI and CN groups). Subgroups with higher cognitive status and greater 3-year stability performed better on EF factors than corresponding groups with lower cognitive status and less stability. Studies of EF structure, performance, dedifferentiation, and dysfunction will benefit from considering initial cognitive status and longitudinal stability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Copper accumulation in soils from two different‐aged apricot orchards in Central Otago,New Zealand

In recent years there has been a move in New Zealand to convert small, uneconomic orchards to other agricultural uses. Overseas research has demonstrated that copper from fungicide sprays often accumulates in the soils of orchards and can cause certain problems for plant growth and livestock. To date, no assessments appear to have been made of the degree of copper accumulation in such older orchards in New Zealand. This study presents the results of an assessment of two well‐established apricot orchards in the Central Otago region of South Island, New Zealand.

Two aspects of the results are surprising. The first is the relatively low levels of copper in the soil when compared with results from another orchard in the region. That orchard is 18 years old and mean soil copper has already reached 100.0 μg/g, indicating a much faster rate of accumulation than in the two orchards in the current study. The second unexpected result is that the younger orchard has a significantly higher level of copper than the older orchard. Reasons for these findings are discussed in relation to apparent differences in soil properties.