cssi/SciSciGPT-SciSciNet huggingface dataset:
How biofuels policies affect the level of grains and oilseed prices: Theory, models and evidence

Abstract This paper synthesizes and critiques three approaches to the analysis of the recent booms in food grains and oilseeds commodity prices: the ‘perfect storm’; statistical time-series models; and models explaining how biofuels linked the fuel and agricultural markets, thus giving rise to a new era of commodity prices. We find that biofuel policies and corn markets were a key instigator of the sharp food commodities price rise in 2006 onwards. We argue that the price increase in the corn market had a spillover effect on the wheat market and caused policy responses and speculation, including hoarding, which caused rice prices to spike. We conclude that because of the sudden increase in commodity prices, the developing countries were unable to benefit from the higher prices even though they have comparative advantage in biofuels production.
Is Ambulatory Electrocardiography Useful in the Evaluation of Patients With Recent Stroke

This study was designed to determine whether ambulatory electrocardiography in patients with recent stroke would lead to a change in clinical management or outcome and to express these findings in terms of cost benefit. A prospective, consecutive sample of patients (n=100) with recent stroke referred from the neurology or medical services for ambulatory electrocardiography was identified. Ambulatory electrocardiograms were reviewed to identify patients with potentially important bradyarrhythmias, tachyarrhythmias, or atrial fibrillation. Patients were then followed up without interference with ongoing care to determine whether these findings led to changes in clinical management that might influence patient outcome. Of the 100 patients, 16 had an index "important" arrhythmia. No significant bradyarrhythmias were noted. Nonsustained ventricular tachycardia (≥6 complexes) in two patients and supraventricular tachycardia (≥10 complexes) in seven patients did not lead to management changes. Four patients had a history of atrial fibrillation who were in sinus rhythm; anticoagulation had been addressed in three; the fourth patient died before the issue could be addressed. Of three patients in atrial fibrillation, there was a history of atrial fibrillation and a decision regarding anticoagulation in each before monitoring. The cost of these 100 ambulatory electrocardiograms was about $55,000. In conclusion, these findings do not support the routine use of ambulatory electrocardiography in the evaluation of patients with stroke.
Review of ACR hematologic criteria in systemic lupus erythematosus

We have conducted a thorough literature review to evaluate the relative value of the hematologic criterion in making a diagnosis of systemic lupus erythematosus (SLE), its clinical relevance, and its prognostic significance. In the updated 1982 ACR criteria, the presence of one or more of the four elements: 1) hemolytic anemia (with reticulocytosis); 2) leukopenia (<4000/microL on two or more occasions); 3) lymphopenia (< 1500/microL on two or more occasions); or 4) thrombocytopenia (< 100,000/microL in the absence of offending drugs) is now considered as a single hematologic disorder. The sensitivity and specificity of the individual elements of the hematologic criterion range from 18 to 46% and 89 to 99%, respectively. The accuracy of the hematologic criterion requires proper interpretation. For example, many studies reported the presence of anemia that was not clearly defined and likely included anemia from etiologies other than hemolytic anemia, thereby causing an overestimation of the prevalence. In addition, medications such as corticosteroids and cytotoxic agents, and viral infections, can also contribute to a reduction in lymphocyte count. Despite these limitations, the SLICC committee recommends no change in the elements of the hematologic criterion when this criterion is properly interpreted and other causes of cytopenia are excluded.
Solid-State Nanopores: From Fabrication to Application

There are relatively few technologies for measurement at the single-molecule scale. Fluorescent imaging, for example, can be used to directly visualize molecules and their interactions, but diffraction limitations and labeling requirements may push the system from its native state. Although recent advances in super-resolution imaging have been able to break this resolution barrier, important challenges remain. Atomic force microscopy (AFM) is capable of imaging molecules at high resolution and at high speed. However, AFM imaging is a surface technique, requiring sample preparation and some immobilization. Other technologies such as optical tweezers and magnetic tweezers are capable of molecular manipulation and spectroscopy to great effect but require a significant apparatus and have limited inherent analytical capabilities.
Increased efficacy of doxorubicin delivered in multifunctional microparticles for mesothelioma therapy

New and effective treatment strategies are desperately needed for malignant mesothelioma (MM), an aggressive cancer with a poor prognosis. We have shown previously that acid-prepared mesoporous microspheres (APMS) are nontoxic after intrapleural or intraperitoneal (IP) administration to rodents. The purpose here was to evaluate the utility of APMS in delivering chemotherapeutic drugs to human MM cells in vitro and in two mouse xenograft models of MM. Uptake and release of doxorubicin (DOX) alone or loaded in APMS (APMS-DOX) were evaluated in MM cells. MM cell death and gene expression linked to DNA damage/repair were also measured in vitro. In two severe combined immunodeficient mouse xenograft models, mice received saline, APMS, DOX or APMS-DOX injected directly into subcutaneous (SC) MM tumors or injected IP after development of human MMs peritoneally. Other mice received DOX intravenously (IV) via tail vein injections. In comparison to DOX alone, APMS-DOX enhanced intracellular uptake of DOX, MM death and expression of GADD34 and TP73. In the SC MM model, 3× weekly SC injections of APMS-DOX or DOX alone significantly inhibited tumor volumes, and systemic DOX administration was lethal. In mice developing IP MMs, significant (p < 0.05) inhibition of mesenteric tumor numbers, weight and volume was achieved using IP administration of APMS-DOX at one-third the DOX concentration required after IP injections of DOX alone. These results suggest APMS are efficacious for the localized delivery of lower effective DOX concentrations in MM and represent a novel means of treating intracavitary tumors.
Background field formalism for chiral matter and gauge fields conformally coupled to supergravity

Abstract We expand the generic model involving chiral matter, super-Yang–Mills gauge fields, and supergravity to second order in the gravity and gauge prepotentials in a manifestly covariant and conformal way. Such a class of models includes conventional chiral matter coupled to supergravity via a conformal compensator. This is a first step toward calculating one-loop effects in supergravity in a way that does not require a perturbative expansion in the inverse Planck scale or a recourse to component level calculations to handle the coupling of the Kahler potential to the gravity sector. We also consider a more restrictive model involving a linear superfield in the role of the conformal compensator and investigate the similarities it has to the dual chiral model.
Habitual Sleep, Reasoning, and Processing Speed in Older Adults with Sleep Complaints.

The relationship between habitual sleep and cognition in older adults with sleep complaints is poorly understood, because research has focused on younger adults, used experimental or retrospective quasi-experimental designs, and generally produced equivocal results. Prospective studies using sleep diaries are rare, but may provide important insights into this relationship as they offer greater ecological validity and allow for examination of the impact of night-to-night variability in sleep (an often overlooked aspect of sleep) on cognitive performance. Seventy-two older adults (Mage = 70.18 years, SDage = 7.09 years) completed fourteen consecutive days of sleep diaries and paper/pencil self-administered cognitive tasks, including measures of processing speed (Symbol Digit) and reasoning (Letter Series). Regression analyses revealed increased average total wake time (TWT) during the night was associated with higher Symbol Digit scores, β = 0.45, P < 0.05. Night-to-night variability in either total sleep time (TST) or TWT was not associated with either cognitive measure. Implications and potential explanations for these initially counterintuitive findings are discussed.
Cryptosporidium Infection Causes Undernutrition and, Conversely, Weanling Undernutrition Intensifies Infection

Abstract Cryptosporidium parvum is a leading pathogen in children in developing countries. To investigate whether early postnatal malnutrition leads to heavier C. parvum infections, we assessed intestinal adaptation and parasite load in suckling mice during the first 2 wk of life, analogous to the first postnatal yr in humans. Undernutrition was induced by daily C57BL6J pup separation from lactating dams. Half of the pups were separated daily, for 4 hr on day 4, 8 hr on day 5, and for 12 hr from day 6 until day 14. On day 6, each pup received an oral inoculum of 105 to 107 parasites in 10–25 μl of PBS. Littermate controls received PBS alone. Stools were assessed from days 8, 11, and 14 for oocyst counts. Mice were killed on day 14, 8 days postinoculation, at the peak of the infection. Ileal and colon segments were obtained for histology, real-time and reverse transcriptase PCR, and immunoassays. Villus and crypt lengths and cross-sectional areas were also measured. Undernourished and nourished mice infect...
A health literate approach to the prevention of childhood overweight and obesity.

Objective To describe a systematic assessment of patient educational materials for the Growing Right Onto Wellness (GROW) trial, a childhood obesity prevention study targeting a low health literate population.
Raman study of molecular motion in liquid phosphine

Abstract The polarized and depolarized Raman scattering spectra of the v 1 (A 1 ) band at 2306 cm −1 in liquid phosphine were obtained as a function of temperature in the range from 142 to 297°K. The depolarized linewidths were found to be at least an order of magnitude greater than the polarized widths at all temperatures studied. An analysis of the linewidths showed that the reorientational correlation times vary from approximately 0.1 to 0.2 psec, which is a factor of 10 to 50 shorter than the times found in other molecules of similar size. Scattering from the v 4 (E) band at 1110 cm −1 was also measured and a comparison of the polarized and depolarized line shapes afforded the opportunity to check the validity of using the rotational diffusional model to describe the reorientational behavior of this molecule.
Interdependency of spatial structure and spatial behavior: A general field theory formulation

A general field theory, made operational through multivariate analysis, very obviously provides a powerful way of analyzing spatial structure, spatial behavior, and their interdependencies. The essential link is provided by dyadic representation of interaction potentials in structural space, thus drawing into the theory the social physicists' preoccupation with potentials and providing a multivariate generalization of it.
Cu(II) AND Cu(I) COMPLEXES OF A MACROCYCLIC TETRATHIOETHER-INFLUENCE OF THE ANION ON STRUCTURE

Abstract The macrocycle S4-propano [16] (1,3,5,9–13-tetrathiacyclohexadecane) acts as a tetradentate ligand with copper(I) and copper(II) tetrafluoroborate but as two bidentate ligands in the presence of chloride.
Mass spectral fragmentation of ethene and propene dithioketals of cyclobutanone

A detailed analysis of the electron impact induced fragmentation of ethene and propene dithioketals of cyclobutanone is presented. The tetradeuterio analog of the cyclic dithioketals was prepared as an aid in analyzing the fragmentation patterns. Cleavage of the 1,3-dithiolane ring system is favored at 15 eV, whereas cyclobutane ring cleavage is favored at 70 eV. Thus, the primary fragmentation pathway seems to be dependent upon the ionization energy.
Responses of cultured heart cells to procainamide and lignocaine.

The effects of procainamide and lignocaine, in concentrations from 10(-6) to 10(-2) mol.litre(-1), on the Na influx and contraction frequency of cultured heart cells were studied. Both drugs produced a prompt, dose-dependent reduction in Na influx which was significant (P less than 0.01) for all concentrations tested. Lignocaine affected only that portion of the Na influx which was also verapamil-sensitive, whereas procainamide suppressed in addition, the verapamil-insensitive influx. In addition both drugs produced a concomitant decrease in the spontaneous contraction frequency of the cells. A close linear correlation (r = 0.99) between verapamil-sensitive Na influx and contraction frequency, in the presence of both procainamide and lignocaine was found. From this, and previous studies indicating a dependency of contraction frequency on the inward verapamil-sensitive Na influx, it is suggested that the drugs modify the automaticity of this preparation by a primary influence on membrane Na exchange.
MicroRNA regulation in Ames dwarf mouse liver may contribute to delayed aging

The Ames dwarf mouse is well known for its remarkable propensity to delay the onset of aging. Although significant advances have been made demonstrating that this aging phenotype results primarily from an endocrine imbalance, the posttranscriptional regulation of gene expression and its impact on longevity remains to be explored. Towards this end, we present the first comprehensive study by microRNA microarray screening to identify dwarf-specific lead microRNAs, and investigate their roles as pivotal molecular regulators directing the long-lived phenotype. Mapping the signature microRNAs to the inversely expressed putative target genes, followed by in situ immunohistochemical staining and in vitro correlation assays, reveal that dwarf mice posttranscriptionally regulate key proteins of intermediate metabolism, most importantly the biosynthetic pathway involving ornithine decarboxylase and spermidine synthase. Functional assays using 3′UTR reporter constructs in co-transfection experiments confirm that microRNA-27a indeed suppresses the expression of both of these proteins, marking them as probable targets of this microRNA in vivo. Moreover, the putative repressed action of this microRNA on ornithine decarboxylase is identified in dwarf mouse liver as early as two months of age. Taken together, our results show that among the altered aspects of intermediate metabolism detected in the dwarf mouse liver — glutathione metabolism, the urea cycle, and polyamine biosynthesis — microRNA-27a is a key posttranscriptional control. Furthermore, compared to its normal siblings, the dwarf mouse exhibits a head start in regulating these pathways to control their normality, which may ultimately contribute to its extended healthspan and longevity.
The families of origin of adolescent drug abusers: Perceived autonomy and intimacy

The Family-of-Origin scale is a 40-item self-report inventory based on the concepts of autonomy and intimacy and comprised of 10 subscales which assess issues such as conflict resolution, respect for individuality, and affective expression. It was administered to 40 adolescents undergoing treatment for substance abuse. A MANOVA was performed to compare substance abusers' scores with those of a non-clinical sample of adolescents. Substance abusing adolescents scored significantly lower on the total FOS score and on five subscales. Discriminant analysis provided further support for the scale's ability to classify subjects into drug abusing and non-clinical groups. Results are discussed in the context of previous clinical descriptions of family of adolescent substance abusers. These preliminary data suggest that the FOS may be of value for assessing family dynamics among adolescents.
Selective Sorption of Alkali-Metal Cations by Carboxylic Acid Resins Containing Acyclic or Cyclic Polyether Units

Novel ion-exchange resins have been prepared by condensation polymerization with formaldehyde in formic acid of three polyether carboxylic acids which possess two benzo group substituents. The selectivities and efficiencies of competitive alkali-metal cation sorption from aqueous solutions by these polyether carboxylic acid resins are strongly influenced by (1) the pH of the aqueous solution, (2) the acyclic or cyclic nature of the polyether unit, and (3) the conformational positioning of the carboxylic acid group in the resins derived from cyclic polyether (crown ether) compounds. Good sorption selectivity for Na{sup +} was observed for dibenzo-16-crown-5 resin 3 in which the pendant carboxylic acid group is oriented over the polyether cavity. Resin 3 was utilized as a stationary phase for selective column concentration of Na{sup +} from dilute aqueous solution.
Experimental Evaluation of the Probe Test for Measuring Thin Film Adhesion

A probe test is proposed to quantify the adhesion of thin films and coatings. Using a micromanipulator, a tungsten probe is advanced into the edge of a polymeric coating. Debonds initiate at the loading point and propagate into semicircular cracks at the interface as the probe slides under the coating. The size of the debond is related to the interfacial fracture energy; poorer adhesion results in larger debonds for a given probe displacement. Approximate closed-form and finite element analyses of the geometry have been conducted, along with a significant number of experiments on as-produced and environmentally-conditioned specimens. The technique is showing considerable promise for characterizing coating adhesion, and has certain advantages over existing techniques for certain application.Copyright © 2003 by ASME
Spatial contrast sensitivity changes after subcortical visual system lesions in the rat

Spatial contrast sensitivity functions were determined in hooded rats after lesions involving the pretectum (PRT), rostral pretectum and adjacent medial thalamus (PRT +), posterior thalamus (PT), or ventral lateral geniculate nucleus (LGv). PRT and PRT + lesions depressed sensitivity at both high and low spatial frequencies but the high frequency loss was much greater in the latter group. PT lesions depressed sensitivity to frequencies of 0.45 cycles/deg. and above but had no detectable effect upon low frequencies while LGv lesions depressed sensitivity to both high and low frequencies. The discussion relates these results to previous reports of discrimination learning impairments after comparable lesions.
The strategic defense initiative: An innovative science and technology perspective that's much more than “star wars”

The Strategic Defense Initiative (SDI) proposed by President Reagan immediately caught the fancy of the news media who dubbed it the “Star Wars Program.” However, only in the fantasy world of films can the tasks envisioned by the program be accomplished by a few swashbuckling space heroes who take on all the technological might of an evil empire and succeed. By contrast, the SDI program goals will require a major commitment of scientific assets, money, and people just to establish feasibility of the concepts.
Modeling the Impact of Failed Members for Progressive Collapse Analysis of Frame Structures

During the past decade, increasing attention has been focused on the design of buildings to resist progressive collapse. Previously, the authors presented a nonlinear solution procedure for progressive collapse analysis of planar frame structures. In the current study, a modeling strategy to account for the impact of failed members against other structural components is developed to extend the capabilities of the initial models. Assumptions made in approximating the effects of impact on the overall behavior of frame structures are discussed. An example illustrating the importance of accounting for the effects of impact on predicting progressive collapse is also given. Results indicate that the impact velocity plays the most significant role in causing failure of intact beam elements.
Fate of lesion-related side branches after coronary artery stenting

Abstract Objectives. The aim of this study was to assess the immediate and long-term patency of lesion-associated side branches after coronary artery stenting. Background. The possible adverse effects related to implantation of coronary stents are not completely known. An important potential complication of stenting is side branch occlusion due to mechanical obstruction or thrombosis. Methods. Serial coronary angiography was performed in 153 patients (167 lesions) at baseline, after conventional balloon angioplasty, immediately after Palmaz-Schatz stent placement and at 6 months. The patency of side branches, where present, was analysed at each of these points. Results. Of 167 lesions stented, 57 stent placements spanned 66 side branches with a diameter ≥1 mm. Twenty-seven (41%) of these side branches had ≥50% ostial stenosis before standard balloon angioplasty. Six side branches became occluded after standard balloon angioplasty and remained occluded after stenting. Of the 60 side branches patent after conventional angioplasty, 57 (95%) remained patent immediately after stenting. All three side branches that became occluded after stenting had ≥50% ostial stenosis at baseline. All 60 side branches, including the 3 initially occluded after stenting, were patent at 6-month follow-up. Conclusions. These findings demonstrate that 1) acute side branch occlusion due to coronary stenting occurs infrequently; 2) when side branch occlusion occurs, it is associated with intrinsic ostial disease; and 3) the patency of side branch ostia is well maintained at long-term follow-up.
Bayesian process-identification in bacteria transport in porous media.

Abstract A Bayesian parameter estimation approach is developed for the estimation of joint probability distribution functions for colloid and bacterial fate and transport model parameters describing breakthrough curves (BTCs) obtained through porous media column studies, and is applied to data involving different ionic strength solutions to fit models of differing complexity. Our approach focuses on the simultaneous fitting of a number of BTCs representing different conditions, and it provides a measure of the goodness of model structure, namely Deviance Information Criteria (DIC). Comparison of DIC per model fit enables the evaluation of the significance of various processes through step-wise increases in complexity due to the addition of process model components. We use the method to investigate the transport of both flagellated and non-flagellated strains of Azotobacter vinelandii in a simulated porous media under three ionic strengths. Three different model structures are considered: one without a detachment process and with Langmuirian blocking function, one with detachment, and one with detachment and a second-order blocking function based on random sequential adsorption. First, the model was applied separately to each single BTC. Next, the model was applied comprehensively to the experiments under various ionic strengths, whereas some transport parameters including dispersivity, detachment coefficient, the fraction of cells undergoing irreversible attachment, and the coefficient of the second-order blocking term were assumed to be the same under different ionic strengths. In most cases, including detachment substantially improved the DIC as expected, whereas using the second-order blocking improved DIC for most of the cases when the method was applied to separate BTCs but not when the method was applied collectively to the three BTCs obtained under various ionic strengths. Also, comparing the outcomes of the separate applications of the parameter estimation algorithm versus the collective application indicates that the uncertainty associated with the estimated parameters is substantially smaller when the collective approach is used and also that the estimated parameters are more consistent with the expectations based on the underlying physical processes.
What management needs to know: a research-based model for management education in information systems

The subject of user involvement in computer-based information systems (CBIS) development is one that continues to be addressed with concern in both management and information systems literature. The problem of obtaining an effective degree of user-community involvement in the CBIS development process is one that has been recognized in the literature for some time. (7) Current writings on the subject reflect a clear consensus of opinion on the part of writers with academic and practitioner backgrounds that active and knowledgeable user-community involvement is a key determinant in the development of successful information systems in a modern business environment. It is further recognized that an active interest and initiative on the part of business management is a necessary pre-condition to achieving an effective level of user-involvement.
The Pathology of Shingles: Head and Campbell's 1900 Monograph

Shingles (herpes zoster) and postherpetic neuralgia, a chronic neuropathic pain syndrome that can persist after the shingles lesions heal, were studied by eminent neurologists of the 19th century. Autopsy studies were used to establish sensory neural pathways in the peripheral and central nervous systems. More recently, zoster and postherpetic neuralgia have served as models for the study of the pathogenesis and treatment of neuropathic pain. Postherpetic neuralgia has the cardinal clinical features of all neuropathic pain syndromes, including sensory abnormalities, ongoing pain, and allodynia (touch-induced pain). Unlike most other neuropathic pain syndromes, such as trigeminal neuralgia or nerve root compressions, shingles has a well-defined pathogenesis and onset, as well as visible lesions, and is therefore uniquely suitable for study.
Critical Success Factors for Electronic Services: Challenges for Developing Countries

AbstractDeveloping countries are at a distinct disadvantage when competing with developed countries in the electronic commerce domain. Electronic services hold both peril and promise for developing countries as a means to expedite their entry into the world of cyber commerce, create value-added jobs within their economies, and attract much needed foreign investment. This paper examines critical success factors (CSFs) developing countries encounter as they develop their cyber economy and explains challenges and potential solutions. Anecdotal evidence and "lessons learned" from developed and developing countries are investigated as well as implications from the World Trade Organization's (WTO) General Agreement on Trade in Services (GATS) negotiations and Organization for Economic Cooperation and Development (OECD) proceedings. The study develops a framework of technical and societal CSFs whose synergy can expedite the entrance of developing countries into the cyber economy.
Investing in a Robotic Milking System: A Monte Carlo Simulation Analysis

This paper uses Monte Carlo simulation methods to estimate the breakeven value for a robotic milking system (RMS) on a dairy farm in the United States. The breakeven value indicates the maximum amount that could be paid for the robots given the costs of alternative milking equipment and other important factors (e.g., milk yields, prices, length of useful life of technologies). The analysis simulates several scenarios under three herd sizes, 60, 120, and 180 cows. The base-case results indicate that the mean breakeven values are $192,056, $374,538, and $553,671 for each of the three progressively larger herd sizes. These must be compared to the per-unit RMS cost (about $125,000 to $150,000) and the cost of any construction or installation of other equipment that accompanies the RMS. Sensitivity analysis shows that each additional dollar spent on milking labor in the parlor increases the breakeven value by $4.10 to $4.30. Each dollar increase in parlor costs increases the breakeven value by $0.45 to $0.56. Also, each additional kilogram of initial milk production (under a 2x system in the parlor) decreases the breakeven by $9.91 to $10.64. Finally, each additional year of useful life for the RMS increases the per-unit breakeven by about $16,000 while increasing the life of the parlor by 1 yr decreases the breakeven value by between $5,000 and $6,000.
Cell cycle variations in chromosomal proteins of the lens epithelium.

Abstract A method has been developed for the isolation and electrophoretic separation of chromosomal proteins from rabbit lens epithelium. We have analysed these proteins at a number of times after explantation of the lens into serum containing culture media. Under these conditions, the G1-arrested lens cells are induced to undergo DNA synthesis and mitosis. Qualitatively, the electrophoretic banding pattern for all the chromosomal proteins was remarkably constant throughout the times studied. The chromosomal protein labeling patterns obtained from lenses exposed to a 1 h pulse of tritiated amino acids showed increased incorporation into non-histone chromosomal proteins (NHCPs) during the latter part of the prereplicative and S phase. Histone labeling was confined to the S phase. Absorbance scanning of the stained gels reveals characteristic ratio changes between the total stainable NHCPs and histones during the cell cycle. A 62% inhibition of DNA synthesis does not seem to decrease the incorporation of [ 3 H]leucine into histones or NHCPs.
Calculated Ångströim's Turbidity Coefficients for Fairbanks, Alaska

Angstrom`s turbidity coefficient, {beta}, was determined from measurements of direct normal solar irradiance (broadband) at Fairbanks, Alaska (latitude, 64.82). The frequency distribution and seasonal changes of derived values were similar to those reported for rural sites in other parts of the world, whereas magnitudes were at the lower end of the reported range. The method was sensitive enough to detect a seasonal pattern along with annual deviations associated with hemispheric scale disturbance created by the El Chicon volcanic eruptions of 1982. Daily deviations from the seasonal pattern were associated with antecedent precipitation events and the occurrence of local or regional forest fires in summer and possible episodes of Arctic haze in winter. Knowledge of Angstrom turbidity values will improve representations of solar irradiance in micro- and mesoscale ecological and weather models. 38 refs., 3 figs., 1 tab.
Optimum plane diffusers in laminar flow

The problem of determining the profile of a plane diffuser (of given upstream width and length) that provides the maximum static pressure rise is solved. Two-dimensional, incompressible, laminar flow governed by the steady-state Navier-Stokes equations is assumed through the diffuser. Recent advances in computational resources and algorithms have made it possible to solve the ‘direct’ problem of determining such a flow through a body of known geometry. In this paper, a set of ‘adjoint’ equations is obtained, the solution to which permits the calculation of the direction and relative magnitude of change in the diffuser profile that leads to a higher pressure rise. The direct as well as the adjoint set of partial differential equations are obtained for Dirichlet-type inflow and outflow conditions. Repeatedly modifying the diffuser geometry with each solution to these two sets of equations with the above boundary conditions would in principle lead to a diffuser with the maximum static pressure rise, also called the optimum diffuser. The optimality condition, that the shear stress all along the wall must vanish for the optimum diffuser, is also recovered from the analysis. It is postulated that the adjoint set of equations continues to hold even if the computationally inconvenient Dirichlet-type outflow boundary condition is replaced by Neumann-type conditions. It is shown that numerical solutions obtained in this fashion do satisfy the optimality condition.
Residual Effects of Fall Deep Tillage on Soybean Yields and Net Returns on Tunica Clay Soil

Seed yield of monocrop soybean [Glycine max (L.) Merr.] grown on nonirrigated clay soils in the Mississippi River alluvial flood plain has been consistently low and marginally profitable. Deep tillage (subsoiling) of certain clayey soils in the fall when the soil profile is dry significantly increases yields and net returns from this production system. Yields and net returns were evaluated for seven deep-till treatments and a conventional-till treatment that was disked annually (C). The deep-till treatments included subsoiling annually and once every second, third, fourth, and fifth year (DT1, DT2, DT3, DT4, and DT5, respectively), Paratill annually (PT1), and profile modification every fifth year (MP). Over the 5-yr study, DT1 produced the greatest yield (3452 kg ha -1 ), which was 1016 kg ha -1 (42%) above the average yield from C (2436 kg ha -1 ). Yields from DT2, DT3, and PT1 were virtually identical and averaged only 198 kg ha -1 (5-6%) less than the average yield from DT1, whereas yields from DT4 and DT5 averaged 291 kg ha -1 (9%) and 613 kg ha -1 (18%) less. Net returns from DT1 ($436 ha -1 ) averaged the highest, whereas returns from C ($220 ha -1 ) were the lowest. Net returns from DT2 and DT3 were within 5% of the net returns from DT1, whereas net returns from the DT4, DT5, PT1, and MP treatments respectively averaged 9, 26, 9, and 31% less than returns from DT1. Thus, fall deep tillage should be performed at least once every 3 yr to maximize and sustain higher yields and net returns from soybean grown on nonirrigated Tunica clay (clayey over loamy, smectitic, nonacid, thermic Vertic Haplaquept).
Action spectra and estimation of biologically effective UV radiation

The use of action spectra in calculating biologically effective ultraviolet radiation fluence is reviewed. In predicting biological damage due to ozone depletion, the most reliable action spectra are those derived from experiments utilizing polychromatic irradiation filtered by sharp cut-off UV filters. A new method is presented for optimum estimation of an action spectrum from data obtained in such experiments. Details of the mathematical procedures are discussed, and examples of their use on data from both plant and animal objects are given.
Subtrochanteric Femoral Fractures

Fractures in the subtrochanteric zone of the proximal femur present complex treatment challenges. These treatment difficulties are related to the anatomic and biomechanic features that are unique to this area. These fractures occur in older patients from low-energy trauma and in younger patients with high-energy trauma, with separate diagnostic and treatment significance. Intramedullary fixation with standard centromedullary nails, as well as cephalomedullary nails, are commonly employed as fixation methods to treat this fracture. The techniques and results of this will be reviewed.
Verbal Coding Strategies Used by Hearing-Impaired Individuals

A paired-associate verbal learning task was used to determine the type of perceptual coding strategies hearing-impaired persons use in auditory perceptual processing of language. Four lists of word pairs were devised, whereby the word pairs in each list were characterized as sharing either similar sign-similar meaning, dissimilar sign-similar meaning, similar sign-dissimilar meaning, or dissimilar sign-dissimilar meaning. Severely hearing-impaired subjects were required to replace the missing word associated with the word pairs. The results showed that, while the subjects were able to code the verbal material on both a sign basis and a semantic basis, the semantic coding strategy appeared to be more efficient than the sign coding strategy. The findings are related to earlier investigations and are explained according to a theoretical model of perception.
Input-Output Analysis of an IPFM Neural Model: Effects of Spike Regularity and Record Length

This paper analyzes a model neural modulating system in which the input is a continuous sinusoid and the output is a point process modulated (integral pulse frequency modulation or IPFM) by the output of a linear system. Analytical expressions for the spectrum of the output point process are used to evaluate transfer function estimation procedures. The detectability of the spectral peak at the modulation frequency depends on the record length and upon the bias and variance contributed by the underlying point process. Detectability is found to increase with regularity of the underlying point process when stimulus frequency is much lower than spike rate, decreases with regularity when the stimulus frequency is about equal to spike rate, and be nearly independent of regularity at high frequencies. These results suggest certain procedures for evaluating the transfer function: 1) at low stimulus frequencies direct estimate of the spectrum is appropriate, 2) at middle frequencies, close to the spike rate, an estimate of the period point density may improve the detectabiity of the spectral peak, and 3) at middle frequencies, broad-band noise added to the sinusoidal stimulus may improve the estimate by decreasing the regularity of the underlying point process. Evaluation of the transfer function using broad-band rather than sinusoidal stimulus may have the advantage of decreasing bias and variance due to regularity of the underlying process, but may introduce a bias of unknown spectral character due to the response of the linear system itself and contribute a nonuniform spectral density at high frequencies.
Dietary cholesterol provided by eggs and plasma lipoproteins in healthy populations.

Purpose of reviewExtensive research has not clearly established a link between egg consumption and risk for coronary heart disease. The effects of egg intake on plasma lipids and low-density lipoprotein (LDL) atherogenicity in healthy populations need to be addressed.Recent findingsThe lack of conne
IMPENDING CONFLICT IN COLOR GUIDELINES FOR MAPS OF STATISTICAL SURFACES

Whereas psychological literature provides only indirect and sometimes contradictory guidelines for colors on quantitative maps, limited map testing t o date indicates that nonhypsometric quantitative maps should be regarded as a family with the guideline of darker and more saturated colors on areas of greater amounts. Because of the tendency of lighter colors to advance toward the viewer, it is probable that three-dimensional surfaces, such as topographic surfaces, are best portrayed by maps with lighter colors on the higher areas. The inconsistency of these two guidelines is tolerable because the two map families are distinct; however, it will not be tolerable if all quantitative maps are regarded as representing three-dimensional statistical surfaces. Alors que les textes de caractere psychologique ne fournissent que des conseils indirects, voire contradictoires pour l'emploi des couleurs dans les cartes quantitatives' les experiences limitees de controle effectuees jusqu'a present sur ces cartes, montr...
A stitch in time saves nine

ABSTRACT:Producing a fair and flexible rota quickly and efficiently is a daunting prospect for anyone responsible for arranging staff work patterns, but new technology can help.
A model for the onset of motion of a sessile liquid drop on a rotating disk

Abstract Small liquid droplets which sit upon a rotating smooth solid surface will detach from the surface when the centrifugal force exceeds the force that arises from surface tension. A simple model for estimating the force due to surface tension is presented. Data for the critical rotational speed above which a drop leaves the surface are obtained over a range of relevant parameters and found to be qualitatively represented by the simple model. A quantitative model, due to Dussan V., can be used to predict the critical rotational speed, but requires measurements of the advanced and receded contact angles. A set of such measurements for static drops subject to gravity on vertical surfaces is applied to the rotating drop results. The theory of Dussan V. is in good quantitative agreement with our data for maximum drop size in both the gravitational and centrifugal force fields.
Selective Epitaxial Deposition of Silicon

EPITAXIAL layers of silicon have been prepared by the hydrogen reduction of silicon tetrachloride at raised temperatures1,2. The rate of deposition of silicon is dependent on the total gas flow-rate, the molecular percentage of silicon tetrachloride in the hydrogen and on the silicon substrate temperature.
Contralateral Prophylactic Mastectomy: Perceptions Versus Reality

In this issue, Rosenberg and colleagues evaluated preferences, knowledge, decision making, and experiences of young women with breast cancer who chose contralateral prophylactic mastectomy and foun...
Optimization of immobilized enzyme hydrolysis combined with high-performance liquid chromatography/thermospray mass spectrometry for the determination of neuropeptides.

Abstract Peptidases, including chymotrypsin, thermolysin, trypsin, V 8 protease, and carboxypeptidases A, B, and Y, were immobilized for use in conjunction with HPLC/thermospray MS for the analysis of neuropeptides. The optimal operating conditions for each immobilized enzyme bioreactor were determined. Optimal hydrolysis usually occurred at the highest percentage of aqueous solution in the mobile phase at pH 7–8 and 40–50°C. Often post-HPLC column addition of aqueous solutions before the bioreactor could improve activity and thermospray sensitivity without changing the HPLC separation. Enzymatic hydrolysis requirements were compatible under conditions for HPLC separation and thermospray MS detection of the selected neuropeptides. Synthetic α-, β-, and γ-endorphins were the primary neuropeptides used to evaluate on-line immobilized enzyme bioreactor/MS. HPLC followed by peptidase hydrolysis produced characteristic hydrolysis products for confirming the peptides' identity using thermospray MS detection. Furthermore, the peptide formed from enzymatic hydrolysis resulted in a MS ion current 10–40 times higher than that of the [M + 2H] 2+ ion for unhydrolyzed β-endorphin. The increased sensitivity achieved for detecting the hydrolysis products permits detection and quantitation of synthetic peptides down to 800 fmol.
An integrated bi-directional power electronic converter with multi-level AC-DC/DC-AC converter and non-inverted buck-boost converter for PHEVs with minimal grid level disruptions

In order to increase energy independency and decrease harmful vehicle emissions, plug-in hybrid electric vehicles (PHEVs) have been suggested as viable replacements for conventional internal combustion (IC) vehicles. In the event that PHEVs do command a large market share, their interactions with the grid could either become a large asset or a large burden for the grid, depending on the interface used and how it is implemented. This paper will present a bi-directional converter that not only enables beneficial vehicle-to-grid (V2G) interactions, but also ensures that all power delivered to and from the grid has good power factor and near zero current harmonics. To accomplish this task, a multi-level bi-directional AC-DC converter is combined with an integrated bi-directional DC-DC converter. The proposed converter has four different modes of operation that allows it to supply power to or from the battery to either the grid or the high voltage bus of the PHEV. These capabilities make this topology an ideal candidate for HEV to V2G equipped PHEV conversions.
Seamless authentication across heterogeneous networks using Generic Bootstrapping systems

With the increasing demand for mobile data services and increased availability of multimode devices with multiple wireless interfaces, seamless mobility and service continuity across heterogeneous networks has become a differentiating service for Operators to offer users an enhanced mobile experience. In recent years, the Federated Identity Management (IdM) standards and technologies have rapidly evolved to address security, user experience, and privacy needs from an application layer perspective or as seen from the end user. As a result of these Federated IdM activities, a Single Sign-On (SSO) concept has been created in which a user may use a single set of authentication credentials to gain access to multiple independent Application Services. This paper provides an overview of the various layers of security in a communications protocol stack and then presents an approach to achieve seamless mobility across heterogeneous networks based on Federated Identity systems. By leveraging a pre-established application layer security association, access layer authentication credentials may be generated using a bootstrapping mechanism to enable authentication and setup of a secure channel in an on-demand, automated and seamless manner may be carried out whilst roaming across disparate networks. A comparison of the proposed scheme and state-of-the-art techniques is included.
Experimental Induction of Altered Nonmicrofibrillar Cellulose

Cellulose produced by Acetobacter xylinum was experimentally modified during its biosynthesis. In the presence of fluorescent brightening agents, such as Calcofluor White M2R or Tinopal LPW, nonmicrofibrillar sheets of cellulose were synthesized by the bacteria. These sheets could then be converted to fibrils by washing with distilled water. Possible mechanisms for these modifications of cellulose assembly are disscussed.
The social maladjustment exclusion in educational policy: Implications for multiagency coordination of services

Educational policy within Public Law 94-142 dictates exclusion of socially maladjusted children from eligibility as seriously emotionally disturbed. The history of this exclusion, various state education agency attempts to serve or exclude children with behavioral problems, and major assessment issues surrounding interpretation of the exclusion are described. Substructural issues involving the conceptualization of disability and related funding exigencies are also presented. The differences between P.L.94-142 and Section 504 of the Rehabilitation Act, in terms of the definition of handicap, and the implications of these differences for the exclusion are explored. Major approaches to serving the burgeoning numbers of children in need of mental health services through multiagency collaboration are reviewed with respect to a proposal for a paradigmatic shift in redefining the role of education.