Role of midwives

Dr. Alfano (New England Journal of Medicine 296: 1126, 1977) is certainly entitled to his personal opinions, but when they appear in a major publication in a setting that calls for factual information, they cannot go unchallenged. Midwives have played and continue to play a major part in maternal-infant services in many advanced European countries. Combined midwife-physician services in Sweden, Finland, Japan, Netherlands, Denmark, Norway, and Switzerland produced infant mortality rates in 1972 superior to those reported by Dr. Alfano for the Commonwealth of Massachusetts in 1974. Even in 1967 Sweden and the Netherlands (where most infants are delivered by midwives) had infant mortality rates, respectively, of 12.9 and 13.4/100 live births. These numbers, of course, do not mean that midwives are superior to doctors, but they do not seem to prove them inferior when they are employed in an appropriate setting. In Oregon (where certified nurse-midwives have been employed for some years) the professional midwife is found mainly in the "expensive" practices, so that if there is a "3rd-level of care," it is delivered to the well-to-do rather than the indigent. It is a little early to tell, but the impression around here is that although the quality of the birth experience may be changed by addition of midwives to an upper-middle-class practice, the outcome in terms of numbers of live babies is no different. This finding may not apply when 1 is dealing with the economically disadvantaged. A striking study from California demonstrated a definite improvement in fetal outcome when certified midwives were added to an established program and a tendency for the infant mortality rate to rise again when their services were discontinued for lack of funds. A similar program is under way in Oregon, but it is much too early for results to be apparent. This letter is not written in defense of midwives - it is a plea for balance and rationality. Medicine is no place for a territorial imperative. Only by calling on the expertise of all qualified members of a society can one hope to progress and to improve the human condition.     

Concept-based near-duplicate video clip detection for novelty re-ranking of web video search results

State-of-the-art near-duplicate video clip (NDVC) detection for novelty re-ranking uses non-semantic low-level features (color/texture) to detect and eliminate “content-based NDVC” and increases content level novelty in the top results. However, humans may perceive a video as near duplicate from a semantic perspective as well. In this paper, we propose concept-based near-duplicate video clip (CBNDVC) detection technique for novelty re-ranking. We identify “semantic NDVC”, making use of the semantic features (events/concepts) and re-rank the top results to increase the content as well as semantic novelty. Videos are represented as a multivariate time series of confidence values of relevant concepts and thereafter discovery of CBNDVC clusters is achieved by conceptual clustering. Obtained results show higher precision and recall from the user’s perspective.     

Nano and micro structural studies of thin films of ZnO

Zinc oxide thin films grown by sol–gel and RF sputtering methods have been characterized. The characterization techniques used involve ellipsometry, optical absorption, scanning tunneling microscopy, scanning and transmission electron microscopy. The films grown by sol–gel spin method which followed zinc acetate route exhibited a smoother texture than the films, which were deposited by using zinc nitrate route. The later type of films showed a dendritic character. Nano-structured fine grains of size ranging from 20 to 60 nm were observed with zinc nitrate precursor film. Individual grains show a sharp contrast with different facets and boundaries. Crystal planes and lattice parameters calculated by electron diffraction and X-ray diffraction are quite close and in agreement with the reported values in literature. Scanning tunneling microscopy has been used for measuring the average roughness of the surface and estimating the lattice constants. The STM studies of RF sputtered films, although showing a ZnO structure, exhibited a disturbed lattice. This was presumably due to the fact that after deposition the films were not annealed. Nanographs of 2D and 3D view of atomic positions of ZnO have been presented by using scanning tunneling microscopy.     

Comments on the limitation of the Reynolds equation for porous thrust bearings

Fractographic studies have been conducted on fretting fatigue test specimens made of 7075-T7351 aluminum alloy. Growth rates of fretting fatigue cracks as determined from striation spacings were much higher than would be expected for this alloy based on the cyclic stresses alone. The results indicate that in the early stages of crack growth fretting acts to increase the effective stress intensity factor range, thus greatly accelerating crack propagation rates. However, a full understanding of the early stages of fretting crack growth will also depend upon knowledge of the behavior of short (about 100 μm) fatigue cracks in general.     

Nanomaterials based biofuel cells: A review

Biofuel cells (BFCs) are the devices made to transform the chemical energy of organic matter to electrical energy utilizing metabolic reactions occurring in microorganisms during degradation of organic contaminants. In spite of having many applications such as waste water treatment, biosensors and portable uses of BFCs, promoting the uses of BFCs is very challenging because of short life-time and low-power density. Most of the BFC developed till date is only capable to fulfill energy needs of biomedical short-term implanted devices. Use of materials with nano dimensions in the construction of BFCs has been studied extensively and reported as a worthwhile strategy to increase its efficiency. Usually, it is difficult to achieve efficient electron transfer on planar electrode from biocatalyst due to its non-specific orientational the interface. Nonmaterials provide close wiring for the electron transfer between biocatalyst and electrode. Use of various nanomaterials is the most effective way to decrease the gap between active sites (electron producing area)deep inside the enzyme or proteins and the electrodes to achieve better electron transfer. Also, various nanomaterials are utilized to improve the membrane materials for better electron barrier. Many carbon nanostructures, conducting polymers, metal and metal oxides are promising nonmaterials to enhance the current output from BFC. This review highlights recent progress registered in the development of various nanomaterials for construction of electrode and membranes of biofuel cells for better efficiency. It also emphasized the utilization of different metallic nanomaterials, inorganic nanomaterials, conducting polymer-based nanomaterials and carbon-based nanomaterials such as graphene, fullerenes, and carbon nanotubes.     

Effect of Duplex Ageing on the Properties of A356 Alloy Containing Rare Earth Elements

Reduced weight of automobiles for the purpose of fuel economy has encouraged the use of light metals especially aluminium alloys. A356 Al alloy containing 7% Si and 0.3% Mg is widely used in automobile and aircraft industries due to excellent castability, good corrosion resistance and good pressure tightness. A356 is age hardenable alloy and there is appreciable improvement in strength and hardness achievable due to precipitation of intermetallic compound Mg₂Si. In the present investigation, aluminium alloy A356 with and without rare earth (RE) addition (0.5 wt%) was subjected to single ageing as well as double aging treatment. The results were compared for mechanical properties like hardness and ultimate tensile strength with the material not containing RE additions.     

A novel leukodepletion filter from electrospun poly(ethylene-vinyl alcohol) membranes and evaluation of its efficiency

The authors describe the fabrication and evaluation of a novel leukodepletion filter using novel poly(ethylene-vinyl alcohol) membranes through electrospinning. The membranes were biocompatible and nonhemolytic. A prototype of the filter was developed by stacking the membranes in a poly(methyl methacrylate) case. Upon whole blood filtration, the filter could achieve 100% leukodepletion while capturing 8% red blood cells and 91% platelets. The length of filtration through the developed filter was high when compared to that of marketed filter while overall performance of the filter was comparable to that of the marketed filter.     

Structural development and magnetic phenomenon in Zn–Cr–Fe multi oxide nano-crystals

The Cr³⁺ ions doped multi-oxide ZnFe_2−xCr_xO₄ ferrite nanoparticles have been synthesized by chemical co-precipitation method. Site occupancies of Zn²⁺, Cr³⁺ and Fe³⁺ ions were analyzed using X-ray diffraction data and Buerger's method. The effect of the constituent phase variation on the magnetic hysteresis behavior was examined by saturation magnetization which decreases with the increase in Cr³⁺ content in place of Fe³⁺ ions at octahedral B-site. Typical blocking temperature (T_B) around 90 K was observed by zero field cooling and field cooling magnetization study. Room temperature Mössbauer spectra show two paramagnetic doublets (tetrahedral and octahedral sites). The isomer shifts of both doublets decrease whereas quadrupole splitting and relative area of tetrahedral A-site increases with increasing Cr³⁺ substitution. The dielectric constant (measured on compositions x=0, 0.4, 0.8 and 1.0) increases when the temperature increases as in the semiconductor. This behavior is attributed to the hopping of electrons between Fe²⁺ and Fe³⁺ ions with a thermal activation.