Budding and Domain Shape Transformations in Mixed Lipid Films and Bilayer Membranes

We study the stability and shapes of domains with spontaneous curvature in fluid films and membranes, embedded in a surrounding membrane with zero spontaneous curvature. These domains can result from the inclusion of an impurity in a fluid membrane, or from phase separation within the membrane. We show that for small but finite line and surface tensions and for finite spontaneous curvatures, an equilibrium phase of protruding circular domains is obtained at low impurity concentrations. At higher concentrations, we predict a transition from circular domains, or "caplets", to stripes. In both cases, we calculate the shapes of these domains within the Monge representation for the membrane shape. With increasing line tension, we show numerically that there is a budding transformation from stable protruding circular domains to spherical buds. We calculate the full phase diagram, and demonstrate a two triple points, of respectively bud-flat-caplet and flat-stripe-caplet coexistence.Comment: 14 pages, to appear in Phys Rev

Disaggregating the Relative Influence of Genetic, Environmental and Individual Factors on LCL and HDL Cholesterols and BMI for a Sample of African American (AA) Mothers and Daughters

There are many reports about the associations between blood lipids, body mass index (BMI) and dietary cholesterol intakes both within the individual and between related individuals. The purpose of this descriptive research project was to investigate the relationships between LDL and HDL cholesterols, body mass index and dietary cholesterol intakes for a sample of African American (AA) mothers and their daughters and to attempt to separate the contribution of genetic versus environmental factors. Mother and daughter participants (n =42 and 66, respectively) were 12-14-hours fasted when blood samples were drawn, heights and weights measured, and 24 hour food recalls completed

Teachers' ideas versus experts' descriptions of 'the good teacher' in postgraduate medical education: implications for implementation. A qualitative study

Contains fulltext : 96394.pdf (publisher's version ) (Open Access)BACKGROUND: When innovations are introduced in medical education, teachers often have to adapt to a new concept of what being a good teacher includes. These new concepts do not necessarily match medical teachers' own, often strong beliefs about what it means to be a good teacher.Recently, a new competency-based description of the good teacher was developed and introduced in all the Departments of Postgraduate Medical Education for Family Physicians in the Netherlands. We compared the views reflected in the new description with the views of teachers who were required to adopt the new framework. METHODS: Qualitative study. We interviewed teachers in two Departments of Postgraduate Medical Education for Family Physicians in the Netherlands. The transcripts of the interviews were analysed independently by two researchers, who coded and categorised relevant fragments until consensus was reached on six themes. We investigated to what extent these themes matched the new description. RESULTS: Comparing the teachers' views with the concepts described in the new competency-based framework is like looking into two mirrors that reflect clearly dissimilar images. At least two of the themes we found are important in relation to the implementation of new educational methods: the teachers' identification and organisational culture. The latter plays an important role in the development of teachers' ideas about good teaching. CONCLUSIONS: The main finding of this study is the key role played by the teachers' feelings regarding their professional identity and by the local teaching culture in shaping teachers' views and expectations regarding their work. This suggests that in implementing a new teaching framework and in faculty development programmes, careful attention should be paid to teachers' existing identification model and the culture that fostered it

Stock speculation on the New York exchange from 1890–1896

Abstract not availabl

Discrete Step-Sifting Theorems For Signal And System Analyses

Generalized step sifting theorems (GSSTs) that can be used to sift unfolded and folded step functions through the summation sign are presented. The theorems are shown to result in an unsegmented answer that contains step function multipliers that turn the terms on or off at the proper times. The simplified step sifting theorem for unfolded functions (SSST-UF), together with the step sifting theorem for convolution (SST-C) and the identify δ1(-n) = 1 - δ1(n - 1), can be used to solve all piecewise convolution problems easily without the need for sketches. The GSST-UF is easiest to remember and can be used for folded functions by using the above identity. The SSST-UF proves to be the most useful (applicable about 90% of the time). These theorems can greatly reduce the labor involved in signal and system analysis and lead to more meaningful insight and solutions

Optimized Program For Factoring Higher Order Polynomials On The Hp - 41.

The key program for linear system analysis and/or synthesis is a program for factoring higher order polynomials. To meet this need with hand-held computers, the authors present a program derived from an optimized algorithmic formulation of Newton\u27s complex method. Optimization is achieved by minimizing memory and processing requirements

System Analysis Polynomial Algorithms Optimized For Speed And Minimum Memory.

Polynomial evaluation subroutines are the key to fast efficient dynamic system analysis programs. Yet, an examination of the latest software will reveal that the polynomial subroutines use the old standard techniques consisting of either a direct evaluation or Horner\u27s method with complex arithmetic. This report contains new algorithms which are used to design subroutines that will execute in the order of 10-to-1 faster than most subroutines presently used

The complete family of convolution forms for linear time invariant systems

The most common convolution technique for evaluating the output of linear time invariant systems is to convolve the system h(t) impulse response with the input x(t). A major extension of these concepts is presented whereby the convolution of the n th derivative (or integral) of the input x(t) can be convolved respectively with the n th integral (or derivative) of the h(t) impulse-response to yield the output. This extension of convolution theory not only leads to more powerful techniques for system analytical analyses, it also provides the basis for an elegant mathematical interpretation of representing x(t) signal models as expansion of x(t) into an infinite sum of infinitesimal singularity functions