Measuring cellular structure at submicrometer scale with lightscattering spectroscopy

We present a novel instrument for imaging the angular distributions of light backscattered by biological cells and tissues. The intensities in different regions of the image are due to scatterers of different sizes. We exploit this to study scattering from particles smaller than the wavelength of light used, even when they are mixed with larger particles. We show that the scattering from subcellular structure in both normal and cancerous human cells is best fitted to inverse power-law distributions for the sizes of the scattering objects, and propose that the distribution of scattering objects may be different in normal versus cancerous cells     

Nutritional status of rural women in relation to their participation in mixed farming in the Tafresh area of Iran

This study was conducted in the Tafresh area of Iran to assess the dietary patterns, time allocation, and nutritional status of rural women in relation to their participation in mixed farming activities. We selected 75 women from 40 villages by applying a stratified random-sampling technique. Cereals and grains were the major source of energy intake. According to the recommended dietary allowance (RDA) tables of India, the United States, the United Kingdom, and the Food and Agriculture Organization (FAO), the respondents seemed to have no micronutrient and energy deficiencies during the spring season. They spent most of their time and energy on household, animal husbandry, and crop farming activities. According to measurements of body mass index (BMI), the respondents were well nourished. However, despite the high level of BMI, analysis suggested a negative energy balance. Nevertheless, analysis indicated that rural women with negative energy balance spent more time and energy in mixed farming and had a higher level of participation in related activities. Hence, it is evident from the results that the physical contribution of rural women in mixed farming activities has a detrimental effect on their nutritional status, at least during some parts of the year (e.g., spring or summer). Therefore, there is a need to adjust nutritional interventions to improve the sustainability of their food intake and to develop appropriate technologies in mixed farming to alleviate their work burdens.     

Binding of organic anions by synthetic supramolecular metallopores with internal Mg2+-aspartate complexes

We report that cation-selective transmembrane pores formed by synthetic p-octiphenyl beta barrels with internal aspartate residues can be transformed into anion-permeable metallopores with internal Mg(2+)-aspartate complexes. These metallopores are shown to be useful for fluorimetric sensing of a broad variety of organic anions of biological relevance such as phytate, heparin, thiamine phosphates, and adenosine triphosphate. The negligible flippase activity measurable for Mg(2+)-free pores indicates that transmembrane p-octiphenyl beta barrels do not disturb the lipid bilayer suprastructure, in other words, they form barrel-stave rather than toroidal pores.     

Secure electronic markets for private information

Technological advances in the collection, storage, and analysis of data have increased the ease with which businesses can make profitable use of information about individuals. Some of this information is private, and individuals are simultaneously becoming more aware of the value of the information and how the loss of control over this information impacts their personal privacy. As a partial solution to these concerns, this paper presents a mechanism that serves two purposes. The first enables the use of private, numerical data in the answering of queries while simultaneously providing a security feature that protects the data owners from a loss of privacy that could result from an unauthorized access. The second develops a compensation model for the use of the data that allows individuals to dynamically redefine their security requirements. The compensation model is built on the information-security mechanism to create the foundation of a market for private information. This paper illustrates how compensation models like the one presented here could be used in a self-regulating market for private information. Additionally, the compensation component of an intermediated market for private information is developed and extensively analyzed. Finally, this paper provides insights and draws several important conclusions on markets for private information.     

Enhanced layered segment trees: a pragmatic data structure for real-time processing of geometric objects

The data structure that is probably most used in the pattern recognition and image processing of geometric objects is the segment tree and its optimized variant, the “layered segment tree”. In all the versions currently known, except the work of Vaishnavi and Wood described later, these data structures do not operate in real time. Even in the latter scheme, although the structure can be implemented in real time and in an on-line fashion, the operation of insertion involves the sorting of the representations of the line segments in the tree. In essence, for all the reported algorithms, there is no known strategy to insert the segments one by one, other than the trivial strategy of processing them all together as in a batched-mode. In this paper, we present a strategy in which all the operations done on the tree can be done efficiently. Indeed, by improving the bottleneck, we prove that an arbitrary horizontal segment can be inserted into this data structure without invoking an expensive sorting process. We show that while this is accomplished by maintaining the same space and query complexity of the best-known algorithm, the version presented here is applicable to on-line real-time processing of line segments. The paper thus has applications in all areas of pattern recognition and image processing involving geometric objects.     

Characterization of laser and laser/thermal annealed semiconducting iron silicide thin films

-FeSi₂ is an important semiconducting silicide which is being studied extensively. In this paper, we report our results of the effect of laser and laser-thermal annealing on the properties of -FeSi₂. 5N purity Fe was deposited on Si substrate and was subsequently irradiated by CW and pulsed laser separately followed by thermal annealing to reduce the laser induced damage. The samples were then characterized by sheet resistance, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), optical reflectance and absorption studies. Lastly, -FeSi₂/n-Si heterojunctions were fabricated and the effect of laser treatment on the junction ideality factor was investigated. All these characterizations indicated the formation of good quality -FeSi₂, particularly after pulsed laser followed by thermal treatment.     

Kinetics of oxygen dissolution in molten lead

An electromotive force cell employing the ZrO₂-CaO solid electrolyte has been set up to investigate the kinetics of dissolution of oxygen in molten lead under various oxidizing conditions. The cell may be written as The cell has been so designed that the electrode chambers are completely isolated from each other. The oxygen in lead is first reduced to a very low value by bubbling hydrogen. subsequently, oxygen dissolution is achieved through gas diffusion across the free surface or through bubble metal interaction. During all these reactions the electromotive force of the cell changes continuously and is automatically recorded. The diffusion coefficient of oxygen in lead, as calculated from the experimental data, is 1.29×10⁻⁵ sq cm per sec and the liquid phase mass transfer coefficient is estimated to be 0.035 cm per sec at 750°C.     

Characterization of information improvement due to N revisions and its generalization by a functional equation

The idea of information improvement was introduced by Thiel [3]. This idea was further extended by the first author to information improvement due to 2 and N revisions and specifically states that different experimenters (a finite number) are required to proceed with given distributions P and U and are permitted to choose a suitable revision. We attempted to provide a measure of information corresponding to Theil's measure which reflected the effect of all revisions. In this paper, the authors have studied a joint characterization of information improvement of N revisions and its generalization by considering a suitable functional equation.     

Growth characteristics of two interacting cracks

This paper deals with the growth characteristics of two interacting cracks in a mixed mode condition. The problem considered is that of two cracks of different lengths, arbitrarily placed in a plane. A uniform load is applied in the plane at a large distance away from the cracks. The objectives of this study are threefold: (1) Solve the mixed boundary value problem described in the foregoing; (2) Predict the most vulnerable crack tip where the instability would first occur as the load is increased; (3) Determine the directions in which the cracks may grow. The numerical results given are only for the specific case of one crack lying along a radial line which emanates from the tip of the other crack at an arbitrary angle.