Why does the brain prefer opium to broccoli?

Hemangiomas present at, or soon after birth, proliferate and eventually involute. In spite of this, children may suffer severe psychosocial trauma during the formative years of their lives, and, in a proportion of cases, a cosmetically unacceptable result is left at the end of involution. Since flashlamp pumped dye lasers have been shown to selectively destroy ectatic dermal vascular tissue through intact epidermis, 6 patients with very early superficial cutaneous hemangiomas were treated. All treated areas resolved completely and treatment was completed by 12 months. No complications were encountered apart from mild, temporary post-inflammatory hyperpigmentation which was seen in one patient. This, however, resolved completely within 3 months of treatment. Flashlamp pumped dye lasers are thus able to effect complete resolution of very superficial proliferating cutaneous hemangiomas in neonates and infants without the risk of scarring.     

Survival, developmental and morphogenic deficiencies of Parasarcophaga argyrostoma (Diptera: Sarcophagidae) induced by the biosynthesis inhibitor, chlorfluazuron (IKI-7899)

To evaluate the activity of benzoylphenyl urea chitin biosynthesis inhibitor chlorfluazuron (IKI-7899) against Parasarcophaga argyrostoma, seven doses were topically applied (once) onto early third (last) instar larvae, puparia, or newly formed pupa: 150, 100, 50, 10, 1.0, 0.5, and 0.25 microgram/insect. After topical treatment of last instar larvae, the highest mortality was caused by both higher doses and the lowest mortality was caused by the lowest dose. The lethal activity of IKI-7899 as pronouncedly decreased as the treatment was lately carried out (at the puparial time). IKI-7899 failed to cause cumulative mortality because no pupal or adult mortalities were observed, irrespective of the time of treatment. Treated larvae suffered the action of IKI-7899 because they had decreased weight gain. Except the lowest dose, the weight gain of larvae inversely correlated with the dose-levels. IKI-7899 prolonged not only the larval duration but also the pupal duration after topical treatment of last instar larvae with doses 50-0.25 micrograms/larva. With no exception, all doses topically applied onto puparia or newly formed pupae enhanced pupae to live longer. Topical application onto last instar larvae resulted in different degrees of reduction of pupation rate, but IKI-7899 could not affect the pupal morphogenesis after larval treatment except by its highest dose which led to 8.33% pupal deformities and 7.69% larval-pupal intermediates. The dose 100 micrograms/larva topically applied onto last instar larvae detained 7.69% of what known as "permanent larvae" which suffered the action of the compound along 16 days and eventually perished without any external feature of puparium formation. A metamorphic effect of IKI-7899 pronouncedly appeared in the adult stage. Three higher doses completely arrested the adult flies. Topical application of the compound onto prepupae did not greatly reduce the pupation rate especially at the doses 50, 10 and 1.0 micrograms/puparium. The dose 50 micrograms/puparium was only the dose halting the pupal moulting program because 7.14% of permanent prepupae remained about 12 days and then died. In respect to adult emergence, the highest dose led to zero rate and the lowest dose allowed to all pupae to emerge without malformation.     

Effect of synthesis conditions and surrounding medium on luminescence properties of YVO4:Eu3+nanopowders

Nanocrystalline yttrium vanadate doped with europium ions powders were synthesized via sol-gel method based on decomposition of metal-polymer complex. X-ray diffraction analysis showed that samples had pure tetragonal phase without any impurities. Scanning electron microscopy and static light scattering technique were used to study morphology and size of prepared nanoparticles. Average diameter of the nanoparticles was about 40 nm. The changes in structural and luminescence properties were observed as a function of the first and second calcination temperature. The optimal conditions for synthesis of nanoparticles were determined as Т1=500 °С, t1=1 h; Т2=950 °С, t2=1.5 h. The effect of different media surrounding the nanoparticles on their luminescence properties and lifetime was investigated and discussed in terms of effective refractive index. It was found that the observed lifetime of YVO4:Eu3+ 5 at.% nanophosphor was decreased from 0.64 ms in air(nmed=1) to 0.45 ms in chalcogenide glass As39S61(nmed=2.39).     

Getting the focus right: production constraints for six major food crops in Asian and African farming systems

To determine the most important production constraints and associated yield losses for six major food crops in 13 farming systems with high poverty in Sub-Saharan Africa, South Asia and East Asia, surveys were conducted with 672 experts representing a diversity of backgrounds and experience. Respondents reported large gaps between highest achieved crop yield on smallholder farms and average yield on farm. Yield gaps were smallest for rice (about 60% of current average smallholder farm grain yields), mid size for wheat and cassava, and larger (sometimes double current farm yields) for sorghum, cowpea and chickpea. Gaps were also smaller in the high input and yield farming systems of East Asia and largest in the marginal, drier systems, particularly in Sub-Saharan Africa. Four categories of production constraint (abiotic, biotic, management and socio-economic) were considered important contributors to yield gaps. A diversity of specific constraints was reported for the crops in the different systems. The most severe and widespread specific constraints for wheat involved the deficiency, high cost and poor management of N fertilizer, and problems associated with drought stress at grain filling, mid season drought and irrigation management. Those for rice included N fertilizer problems, soil fertility depletion, various leaf, stem and head pests and diseases, weed competition and inadequate water management. Striga and weed competition, soil resource degradation, poor soil fertility management, and drought were the most severe specific constraints for sorghum. Insect pests of pod, leaf, stem and flower and the high cost of their control dominated the constraint set for cowpea. Helicoverpa pod borer, Botrytis grey mould and control costs were the most severe for chickpea. Unsuitable varieties/poor seed, soil infertility and fertilizer constraints were also widespread with the legumes. Marketing problems and lack of finance were concerns for cassava along with weed competition, African cassava mosaic virus and poor varieties/planting materials. The findings can help to inform priority setting for international agricultural research and development activities on important food crops in major farming systems occupying areas of high poverty.     

Adolescent smoking trajectories and nicotine dependence.

The present study correlates empirically constructed prospective adolescent smoking trajectories with indicators of nicotine dependence assessed in adolescence and in adulthood. Excluding individuals who reported no smoking during repeat assessment (nonadopters), we identified five smoking trajectory groups: experimenters (n=116, 48.5%), late increasers (n=39, 16.3%), early increasers (n=37, 15.5%), quitters (n=22, 9.2%), and persistent smokers (n=25, 10.5%). Higher frequency of nicotine dependence symptoms in adolescence occurred in the quitters and persistent smokers groups, who smoked at higher levels relative to the experimenters, late increasers, and early increasers groups, who reported a similar frequency of nicotine dependence symptoms and smoked at low levels. Lifetime nicotine dependence was assessed in adulthood in lifetime daily smokers using the Fagerstr?m Test for Nicotine Dependence (FTND) and the Nicotine Dependence Scale (NDS). Lifetime FTND levels were similar across trajectory groups. Relative to experimenters, all remaining smoking trajectory groups had higher NDS levels that were similar to one another. These results suggest that higher levels of adolescent nicotine dependence were associated with heavier smoking trajectory groups, and that regardless of trajectory group membership, smoking more than a few cigarettes per week throughout adolescence resulted in similar levels of lifetime nicotine dependence as measured by the FTND and NDS.     

Quantitative method of assessing the effectiveness of radiotherapy of malignant neoplasms based on computerized tomography data

Computed tomography assesses the linear coefficient of X-ray radiation decrease in the tissue and hence determines changes in its density thus allowing one to control the destruction of tumor cells and tissues during treatment. The paper proposes a procedure for determining the sizes and density of a tumor along the chosen linear direction crossing the image of a pathological focus. The whole procedure is performed by the special computer programme "Diaglmag". The equations that characterize the dynamics of using the parameters used before, during, and after treatment are presented. Baseline information on the optic image densities on a computer tomogram is obtained with a graphic scanner. The examples presented in the paper show it feasible to solve a difficult task to determine the effect of treatment. This enables a treatment regimen to be corrected in time or modified.     

The effect of inner products for discrete vector fields on the accuracy of mimetic finite difference methods

The support operators method of discretizing partial differential equations produces discrete analogs of continuum initial boundary value problems that exactly satisfy discrete conservation laws analogous to those satisfied by the continuum system. Thus, the stability of the method is assured, but currently there is no theory that predicts the accuracy of the method on nonuniform grids. In this paper, we numerically investigate how the accuracy, particularly the accuracy of the fluxes, depends on the definition of the inner product for discrete vector fields. We introduce two different discrete inner products, the standard inner product that we have used previously and a new more accurate inner product. The definitions of these inner products are based on interpolation of the fluxes of vector fields. The derivation of the new inner product is closely related to the use of the Piola transform in mixed finite elements. Computing the formulas for the new accurate inner product requires a nontrivial use of computer algebra. From the results of our numerical experiments, we can conclude that using more accurate inner product produces a method with the same order of convergence as the standard inner product, but the constant in error estimate is about three times less. However, the method based on the standard inner product is easier to compute with and less sensitive to grid irregularities, so we recommend its use for rough grids.     

Computer arithmetic for probability distribution variables

The uncertainty in the variables and functions in computer simulations can be quantified by probability distributions and the correlations between the variables. We augment the standard computer arithmetic operations and the interval arithmetic approach to include probability distribution variable (PDV) as a basic data type. Probability distribution variable is a random variable that is usually characterized by generalized probabilistic discretization. The correlations or dependencies between PDVs that arise in a computation are automatically calculated and tracked. These correlations are used by the computer arithmetic rules to achieve the convergent approximation of the probability distribution function of a PDV and to guarantee that the derived bounds include the true solution. In many calculations, the calculated uncertainty bounds for PDVs are much tighter than they would have been had the dependencies been ignored. We describe the new PDV Arithmetic and verify the effectiveness of the approach to account for the creation and propagation of uncertainties in a computer program due to uncertainties in the initial data.     

Suggested guidelines for rating cardiac disability in workers' compensation. Medical and Chiropractic Advisory Committee to the Administrative Director of the California Division of Industrial Accidents

Cardiac disability ratings in workers' compensation cases currently lack any consistent scientific basis, with varying medical evidence used by different examiners in the same case. Opinions about the extent of disability may differ with the same patient, delaying resolution and the delivery of benefits. We describe guidelines for determining cardiac impairment and suggest a schedule for rating disability based on evidence. Our experience is in California, but arriving at equitable ratings for disability purposes is a nationwide challenge. Exercise stress testing provides the best reproducible data to test the heart's ability to do work. When exercise stress testing is not possible or adequate, alternative or supplemental testing is necessary. Certain conditions, such as hypertension, arrhythmias, coronary artery spasm, and a history of coronary artery operations or myocardial infarction, may affect "cardiac disability" but may not necessarily be reflected in exercise testing.