cssi/SciSciGPT-SciSciNet huggingface dataset:
Epoxy Resin with Carbon Nanotube Additives for Lightning Strike Damage Mitigation of Carbon Fiber Composite Laminates

Carbon fiber composites are paving the way for light weight, high strength structures in the aerospace industry. While the benefits of carbon fiber composites are undeniable, they also have their drawbacks. Crippling damage due to lightning strikes is one of them. The current solutions to reducing the damage due to lightning includes adding expensive and heavy copper mesh into the laminate. A potential solution to this problem would be to add a lightweight conductive additive to the epoxy resin instead of a copper mesh. Carbon nanotubes are chosen as the additive to create an electrically conductive resin matrix and hence increase the overall electrical conductivity of the composite. Increasing the conductivity will decrease the damage owing to a faster dissipation of lightning-strike-induced Joule heating, and more importantly increase the residual strength. In this work, we quantified the increase in conductivity through measuring the electrical resistance using the four-probe method. Results showed that the electrical resistance of the sample with carbon nanotube additives is 31% lower than the one with no additives when the same resin system is used. In addition, lightning strike tests have also been carried out with both samples using an artificially generated waveform A impulse current with a peak of 100 kA. The current results showed no visible damage to both the samples with and without CNT additives in the epoxy. Time-resolved camera images taken for the lightning strike tests showed that
The Impact of Race, Ethnicity and Insurance Status on Surgery Rates for Benign Prostatic Hyperplasia.

Abstract Objective To determine whether patient race/ethnicity are associated with differences in likelihood of undergoing surgical treatment for LUTS/BPH. Methods Queried hospital network database between 1/2011 and 10/2018. Men over age 40 on medical therapy for LUTS (selective alpha blockade and/or 5-alpha-reductase inhibitor), with 2+ provider visits, and without bladder/prostate malignancy were included. Ethnicity/race determined by self-identification. Insurance status classified as public (Medicare/Medicaid/Tricare), private, self-pay, or other. Multivariable backwards step-wise logistic regression was performed to compare odds of undergoing a surgical procedure by race/ethnicity, controlling for patient age, insurance status, comorbidities, and type of medical therapy. Results 30,466 patients included, with White (n=24,443, 80.2%), Hispanic (n=2,715, 8.9%), Black (n=1,245, 4.1%), and other race/ethnicity (2,073, 6.8%) identified within the study population. After adjusting for age, insurance status, major comorbidities, and type of medical therapy, Black patients were less likely to undergo surgery than White patients (OR 0.57, 95% CI 0.37 – 0.88, P = .011), as were patients of other race/ethnicity (OR 0.67, 95% CI 0.49 – 0.92, P = .013). Conclusions Adjusting for age, insurance status, major comorbidities and type of LUTS medication, men categorized as Black were significantly less likely to undergo surgical treatment for LUTS/BPH than White patients. It is unknown whether this difference results from differences in counseling, access, or other bias in therapy. Efforts to understand and respond to this disparity are necessary. Limitations include lack of IPSS data, additional comorbidity data, limited geographic area, and retrospective nature.
White pine blister rust resistance in North American, Asian and European species - results from artificial inoculation trials in Oregon

Dorena Genetic Resource Center (DGRC) has used artificial inoculation trials to evaluate progenies of thousands of Pinus monticola and P. lambertiana selections from Oregon and Washington for resistance to white pine blister rust caused by Cronartium ribicola. In addition, early results are now available for P. albicaulis and P. strobiformis. DGRC has also recently evaluated seed orchard progenies of P. strobus, as well as bulked seedlots from P. armandii and P. peuce. The majority of P. monticola, P. lambertiana, P. albicaulis, and P. strobus progenies are very susceptible to blister rust. However, resistance exists in all these species. P. strobiformis showed relatively high levels of resistance for the eight progenies tested. Resistance in P. armandii was mainly reflected in the very low percentage of cankered seedlings; for P. peuce, the high percentage of cankered seedlings alive three years after inoculation was notable. R-genes are present in some of the North American five-needle pine species, but partial resistance traits (e.g. bark reaction) will play a major role in breeding activities for P. monticola and P. lambertiana and will likely be the key to developing durable resistance.
The valorization of non-patent intellectual property in academic medical centers.

Turning university research output into useful products such as drugs, devices and diagnostics requires skills, knowledge, and resources traditionally attributed to private industry. When it comes to intangibles such as care delivery models, informatics and algorithms, and the software behind smart wearables, the commercialization challenges are even greater. With notable exceptions, Academic Medical Centers have typically not excelled in advancing commercialization of such non-patent intellectual property (IP). We believe that this is in part because the traditional closed form university IP policy, formulated since Bayh–Dole (1980), is ill-suited to non-patent IP. In this paper, we reflect on the evolving challenges that new forms of healthcare-related discoveries, specifically non-patent IP, are placing on the traditional university intellectual property and technology transfer regime, and to offer suggestions on how universities can begin to modernize their IP policies to support the valorization of non-patent IP.
Optical Parametric Oscillation in Dielectric Multipolar Nanostructures

We present a theoretical framework using time-domain slowly-varying envelope approximation to study optical parametric oscillators (OPOs) in nanostructures with multipolar Mie resonances. We show feasibility of wavelength-scale OPOs which can be useful for numerous applications.
Linking armed conflict to malnutrition during pregnancy, breastfeeding, and childhood.

Abstract Background Women in LMICs are important agricultural actors; however, these same women, and with their children, suffer high rates of acute malnutrition during armed conflicts. Methods and Fidings A review was undertaken of peer-reviewed literature to describe how armed conflict drives acute malnutrition in pregnant and breastfeeding women and their children. Armed conflict factors driving malnutrition were conceptualized as belonging to one of eight overarching drivers. Conclusion Future research must examine the effect of specific drivers on acute malnutrition in order to improve predictive models; emphasize inclusion of pregnant and breastfeeding participants in studies; elucidate the role of peacekeepers in mitigating the risk of acute malnutrition; explore how to support breastfeeding women living in armed conflict situations; and explore how displaced populations affect host communities’ food systems.
Black-Box Optimization: Methods and Applications

Black-box optimization (BBO) is a rapidly growing field of optimization and a topic of critical importance in many areas including complex systems engineering, energy and the environment, materials design, drug discovery, chemical process synthesis, and computational biology. In this chapter, we present an overview of theoretical advancements, algorithmic developments, implementations, and several applications of BBO. Lastly, we point to open problems and provide future research directions.
DEPICTING EXODUS IN TIMES OF EMERGENCY: BEATRIZ GONZÁLEZ’S ZULIA, ZULIA, ZULIA

Este articulo analiza como Zulia, Zulia, Zulia (2015), un oleo sobre lienzo en el que la artista colombiana Beatriz Gonzalez retrata la experiencia de cientos de miles de inmigrantes anonimos que c...
Epigenetic treatment of behavioral and physiological deficits in a tauopathy mouse model.

Epigenetic abnormality is implicated in neurodegenerative diseases associated with cognitive deficits, such as Alzheimer's disease (AD). A common feature of AD is the accumulation of neurofibrillary tangles composed of hyperphosphorylated tau. Transgenic mice expressing mutant P301S human tau protein develop AD-like progressive tau pathology and cognitive impairment. Here, we show that the euchromatic histone-lysine N-methyltransferase 2 (EHMT2) is significantly elevated in the prefrontal cortex (PFC) of P301S Tau mice (5-7 months old), leading to the increased repressive histone mark, H3K9me2, which is reversed by treatment with the selective EHMT inhibitor UNC0642. Behavioral assays show that UNC0642 treatment induces the robust rescue of spatial and recognition memory deficits in P301S Tau mice. Concomitantly, the diminished PFC neuronal excitability and glutamatergic synaptic transmission in P301S Tau mice are also normalized by UNC0642 treatment. In addition, EHMT inhibition dramatically attenuates the hyperphosphorylated tau level in PFC of P301S Tau mice. Transcriptomic analysis reveals that UNC0642 treatment of P301S Tau mice has normalized a number of dysregulated genes in PFC, which are enriched in cytoskeleton and extracellular matrix organization, ion channels and transporters, receptor signaling, and stress responses. Together, these data suggest that targeting histone methylation enzymes to adjust gene expression could be used to treat cognitive and synaptic deficits in neurodegenerative diseases linked to tauopathies.
Development of C13-norisoprenoids, carotenoids and other volatile compounds in Vitis vinifera L. Cv. Pinot noir grapes.

Developmental changes in the carotenoids and volatile compounds of Pinot noir grape berries were investigated in this study from pea size to harvest during 2012. HPLC analysis showed continued decrease of lutein, β-carotene, neochrome a and neoxanthin continued to decrease during berry development, with rapid decrease of lutein and (9'z)-neoxanthin occurred two weeks before veraison. Neochrome b and violaxanthin accumulated at early development and started to decrease two weeks before veraison. Volatile analysis demonstrated that total β-damascenone, TDN and vitispirane all increased dramatically, especially at later stage of ripening, whereas the changes for α-ionone and β-ionone were not obvious. The correlation between carotenoids and C13-norisoprenoids in the grape berries was compound-dependent, suggesting dependency on enzyme activity and specificity. In addition, C6-alcohols accumulated before veraison and decreased towards maturation, and 3-isobutyl-2-methoxyprazine decreased with increasing maturity.
Experimental Techniques for Cross-Section Measurements

Instrumentation and experimental techniques for electron-impact crosssection measurements have improved significantly in recent years. This progress has been motivated by the need for electron collision data in connection with the modeling of many practical systems (lasers, plasma devices, planetary ionospheres, chemical systems under the influence of particle bombardment, and so on) and has been aided by advances in vacuum techniques, charged and neutral particle beam technology, progress in electron energy analysis and detection, and computer developments. On one hand the reliability and accuracy of crosssection measurement techniques have reached a stage where a large body of highly accurate (few %) cross sections can now be determined with moderate efforts. On the other hand refinements and sophistication in the experimental techniques make it possible to study and distinguish individual processes which have been averaged over in previous measurements (e.g., individual vibrational— rotational transitions, competing and overlapping dissociation and ionization processes, magnetic sublevel excitation amplitudes, etc.).
CELL-WALL LYSINS OF STAPHYLOCOCCUS AUREUS STRAINS INDUCED BY SPECIFIC TYPING PHAGES

Ralston, Doris J. (University of California, Berkeley), and Mary McIvor. Cell-wall lysins of Staphylococcus aureus strains induced by specific typing phages. J. Bacteriol. 88:667-675. 1964.-At least 12 different phages induced the formation of soluble lysins (separable from the phages by ultracentrifugation). The lysins caused rapid clearing of heat-killed cells of all strains of Staphylococcus aureus tested, irrespective of the capacity of the phage to form plaques on living cells of the strain. The uninfected cells of the 12 strains contained a second lysin, an autolysin, released upon cellular autolysis. The autolysin preparations differed from the phage-induced lysins, in that they exhibited relatively high activity for lysing Micrococcus lysodeikticus and low activity for strain S. aureus K(1N), and were each specifically inhibited by antiserum prepared against purified autolysin from strain K(1). A third kind of lysin, virolysin, induced by polyvalent phage K, was differentiated from the lysins of the specific phages on the basis of its antigenic specificity and lack of action on M. lysodeikticus. All three kinds of lysins digested the mucopeptide portion of staphylococcal cell walls. No evidence was found that any of these lysins possessed specific host ranges which could be correlated with the lytic host range of the inducing phage.
Glomerular Deposition of Immune Complexes Made with IgG2a Monoclonal Antibodies

The factors that determine whether immune complexes (IC) are cleared safely from the circulation or are deposited in vulnerable tissues such as glomeruli are not well defined. To better understand how IC are handled, the present study examined the fate in vivo of three model IC preparations with different immunochemical characteristics. Radiolabeled IC were constructed with murine IgG1, IgG2a, or IgG3 anti-DNP mAbs bound to DNP-BSA, designated IgG1 IC, IgG2a IC, and IgG3 IC, respectively. The IC were infused i.v. into BALB/c mice, and clearance and tissue localization of the three IC probes were compared. The results indicate that the major portion of each IC preparation was cleared from the circulation by the liver. However, compared with the other two probes, IgG2a IC were preferentially deposited in the kidney. Histologic examination revealed the presence of IgG2a IC in glomeruli. The enhanced renal uptake of IgG2a IC could not be attributed solely to such characteristics as IC size, Ag/Ab ratio, Ab charge, or affinity. However, the preferential renal deposition of IgG2a IC was abrogated by complement depletion. Thus, enhanced renal uptake in normal mice was complement dependent. These data suggest that interactions between IC and the complement system can influence the propensity of IC to deposit in tissues susceptible to IC-mediated injury.
Attenuated cerebral vasodilatory capacity in response to hypercapnia in college-aged African Americans.

African Americans (AAs) have increased risk for cardiovascular, cerebral vascular and metabolic disease, including hypertension, stroke, coronary artery disease, metabolic syndrome and type II diabetes, relative to Caucasian Americans (CAs). While it is accepted that endothelial function is impaired in AAs, less is known regarding their cerebral vasodilatory capacity in response to hypercapnia. We hypothesized that AAs have a reduction in the total range of change in cerebral blood flow velocity (CBFV) measured in the middle cerebral artery and an index of cerebral vascular conductance (CVCI) in response to changes in the partial pressure of end-tidal carbon dioxide () during rebreathing-induced hypercapnia when compared with CAs. Twenty-one healthy, college-aged AA (10 male) and 21 age- and sex-matched CA (10 male) subjects participated in this study. A four-parameter logistic regression was used for curve fitting the responses of CBFV and CVCI relative to changes in . The total ranges of change in CBFV (101 ± 18 versus 69 ± 23%; P < 0.001) and CVCI (83 ± 21 versus 58 ± 21%; P < 0.001) as well as the maximal increase in CBFV (205 ± 24 versus 169 ± 24%; P < 0.001) and CVCI (188 ± 30 versus 154 ± 19%; P < 0.001) were reduced during hypercapnia in AAs relative to CAs despite a similar increase in (change, 15 ± 3 versus 15 ± 3 mmHg; P = 0.65). In conclusion, these data indicate that AAs have attenuated cerebral vascular capacity to respond to hypercapnia when compared with CAs.
Epidemiology of Stroke

Stroke is a major cause of death and disability in developed countries. The incidence of stroke increases exponentially with age, yet, traditionally, many medical practitioners have been reluctant to treat hypertension in older patients. Since 1991, the results of 3 major trials — the British Medical Research Council (MRC) trial of treatment in older adults, the Swedish Trial in Old Patients with Hypertension (STOP-Hypertension) and the Systolic Hypertension in the Elderly Program (SHEP) — have conclusively established the benefits of treating older patients (> 60 years) with both diastolic and isolated systolic hypertension. International guidelines for the management of hypertension — including the Fifth Report of the Joint National Committee, the 1993 report of the World Health Organization and the International Society of Hypertension and the second report of the British Hypertension Society Working Party — have all been modified to reflect the emerging evidence concerning the benefits of treating older patients. Cost-effectiveness data are similarly in accord with giving high priority to the treatment of older individuals with hypertension.
An introduction to smoothing spline ANOVA models in RKHS, with examples in geographical data, medicine, atmospheric sciences and machine learning

Abstract This paper is a brief introduction to smoothing spline ANOVA (SS-ANOVA) models in reproducing kernel Hilbert spaces (RKHS) and some of their applications. These models decompose a function of several variables as sums of functions of one variable plus sums of functions of two variables and so forth, analogous to the ordinary analysis of variance decomposition familiar to students in elementary Statistics classes. This is done in such a way that the individual terms are projections onto orthogonal subspaces in RKHS, and the relevant reproducing kernels may be found in many examples. Given the appropriate RKHS, various kinds of estimation and model fitting problems in several variables given observational data can be solved.
The Effect of Technological Innovation on Organizational Structure Two Case Studies of the Effects of the Introduction of a New Technology on Informal Organizational Structures

This article looks at how two offices changed their informal work relationships and patterns in response to a major technological innovation in their field. This inductive study involves a cross-ca...
A standard for transfer of digital neurophysiological data

A Standard Specification for Transferring Digital Neurophysiological Data Between Independent Computer Systems (Designation E 1467–92) has been developed through ASTM (American Society for Testing and Materials), a recognized American voluntary consensus standards organization. This represents a cooperative effort among medical specialty societies, instrumentation vendors, and academic institutions. The specification defines a common representation of all of the data associated with a complete clinical study, including digitized neurophysiological waveforms, textual annotations and interpretive reports. Data formatted using this standard can be interchanged between neurophysiological instruments, computer systems in the neurophysiology department or hospital, and healthcare facilities or research laboratories.
The propagation speed of a positive lightning return stroke

The first direct determination of the propagation speed of a lightning return stroke lowering positive charge to ground has been made. This stroke was the third of eight otherwise negative strokes in a triggered lightning flash initiated at the Kennedy Space Center, FL. Two independent optical systems, one photographic and the other photoelectric, yielded common recordings for the third and fourth strokes; the respective two-dimensional return stroke propagation speeds were 1.0 vs 0.93 x 10 to the 8th m/s for the positive (third) stroke and 1.0 vs 1.0 x 10 to the 8th m/s for the fourth stroke. Using fast electric-field data, the positive stroke peak current was estimated to be 21 kA. Photoelectric data only yielded propagation speeds of 1.4, 1.6, 1.2, 1.3, 1.0 and 0.90 x 10 to the 8th m/s for the first, second and fifth through eighth return strokes, respectively.
Extrusion foaming of polystyrene/carbon particles using carbon dioxide and water as co-blowing agents

Abstract Carbon particles such as platelet-like graphite (GR), spherically shaped activated carbon (AC), and tubular carbon nanofiber (CNF) were used as additives in extruded polystyrene (PS) foams with carbon dioxide (CO2) and water as co-blowing agents. It was found that GR is the best additive for improving the thermal insulation performance of CO2 based foam samples because of GR’s good absorption and reflectivity of infrared (IR) radiation. However, when the GR concentration was higher than 0.5 wt.%, the extruded foams exhibited large bubbles in the center of the foam and the extrusion line became unstable. By adding water carried by AC as a co-blowing agent, it was able to decrease the temperature in the center of the extruded foam, which successfully eliminated the bubble problem and achieved stable foam extrusion with good control of the foam density and cell morphology. Moreover, water carried by AC could also improve the mechanical performance of extruded foams containing CNF or GR. Water was not found in the extruded foams and the presence of water during extrusion did not affect the molecular weight and glass transition temperature of PS. Our results showed that a combination of AC as a water carrier and GR as an absorber and reflector of IR radiation can produce CO2 based PS foams with good thermal insulation and mechanical properties, particularly with the presence of a small amount of CNF nanoparticles.
Transsternal Thymectomy for Myasthenia Gravis

A consistent, planned approach to thymectomy for patients with myasthenia gravis has been used at the University of North Carolina since 1977. This involves a sternotomy, with excision of the entire thymus and adjacent fatty tissues from the thyroid to the diaphragm and laterally to 1 cm from each phrenic nerve. Between 1977 and 1993, 100 consecutive patients were treated in this manner with no mortality. Eight-four percent of patients were extubated in the operating room or within 1 hour of surgery, and no patients experienced postoperative respiratory difficulty. After a mean follow-up of 65 months, 78% of all patients improved by at least one modified Osserman classification, and 69% of patients with preoperative class I, II, or III disease (maximal preoperative severity) are in pharmacological remission. We conclude that transsternal thymectomy is associated with minimal morbidity and no mortality, and results in long-term improvement in symptoms for patients with myasthenia gravis.
Surgical treatment of pneumopericardium in the neonate

Pneumopericardium occurred in 28 neonates with respiratory distress syndrome at the University of Minnesota Hospitals and St. Paul Children's Hospital from July 1, 1972 through June 30, 1976. All patients developed this complication while on mechanical ventilatory support with positive end-expiratory pressure (2–12 cm water). In 23 patients, pneumopericardium resulted in clinical pericardial tamponade that necessitated cardiac resuscitation. The clinical presentation of pericardial tamponade consisted of muffled, distant heart sounds, hypotension, bradycardia, and hypoxia with cyanosis. The diagnosis was confirmed by chest x-ray. Pneumothorax, pneumomediastinum, and/or pneumoperitoneum were associated with the appearance of pneumopericardium in 93% of the cases. Treatment consisted of: (a) needle pericardial aspiration in 7 patients, of which 5 survived; (b) pericardial tube placement with application of suction in 10 patients, of which 8 survived; (c) no treatment in 16 patients, of which 5 survived. Overall, 13 patients (46%) survived pneumopericardium and 15 patients (54%) died. Complications of treatment developed in 5 patients; 3 developed pneumothorax and 2 developed myocardial lacerations from percutaneous placement of a plastic drainage catheter. Of 5 asymptomatic patients, 2 (40%) died as a result of pneumopericardium. Based on our experience, it is recommended that pneumopericardium be evacuated whenever it is diagnosed. Initially, needle aspiration of the pericardial sac should be performed to manage the acute episode and stabilize the patient, and then a chest catheter of No. 10 Fr. caliber should be placed under direct vision into the pericardial sac and maintained on suction until positive end-expiratory pressure ventilation has been discontinued.
Seasonal crawling activity of adult root-feeding insect pests (Coleoptera: Curculionidae; Scolytidae) of red clover.

Pitfall traps located between red clover, Trifolium pratense L., stands and adjacent pasture and woods were used to monitor seasonal and directional crawling activity by adults of four species of root-feeding insect pests of red clover: Hylastinus obscures (Marsham), Calomycterus setarius Roelofs, Sitona flavescens Marsham, and Sitona hispidulus (F.). Trapping was conducted at a site in Monongalia County, West Virginia, from May to November 1990, March to December 1991, and April to June 1992. Peak crawling activity by H. obscurus occurred in June. Peak C. setarius activity was from June to September. Peak S. flavescens activity occurred from April to May and from September to November. S. hispidulus had three periods of peak activity: in the spring (April–May), summer (mid-June–mid-July), and fall (September–mid-November). Few directional trends in movement were apparent for H. obscures and S. flavescens , indicating that their movement by crawling is limited to short distances within or between red clover stands. Most C. setarius were caught in traps located between the red clover and adjacent woods. Movement into the red clover was primarily from the direction of the woods. During its period of summer activity, S. hispidulus movement from the red clover was directed toward adjacent woods. During spring and fall, greater numbers of S. hispidulus adults moved toward the red clover from adjacent woods than from the red clover toward the woods, and movement from the red clover was toward adjacent pasture.
Compensating for sink effects in emissions test chambers by mathematical modeling

Abstract Evidence is presented that interior surfaces of a state-of-the-art emissions test chamber can act as a transient sink for organic emissions. The major contribution of this paper is to present a class of mechanistic, mathematical models which accounts for this phenomenon as well as the effect of increasing chamber concentration on the emission rate of the source. A key point is that the effect of the chamber sink can be adjusted out simply by first fitting the appropriate model, then setting to zero the rate constant which governs sink adsorption-absorption. As a consequence of this mathematical development, a source emission rate as a function of time and a steady-state emission rate factor are given precise definitions. Applications involve modeling 1,4-dichlorobenzene emission from moth crystal cake, and mixed emissions from latex caulk. In the first case, at a low air exchange rate and low humidity, the repressive effect of increasing vapor pressure tends to overshadow the sink effect. Increased humidity tends to offset the increase in emission rate which otherwise would occur with increased air exchange. Temperature is the principal determinant of the steady-state emission rate. For the latex caulk, the effect of a sink is to retard the apparent emission rate but lengthen the period of emissions.
Structural characterization of bimetallic nanomaterials with overlapping x-ray absorption edges

We describe a data analysis method for extended x-ray absorption fine structure spectroscopy suitable for use with compounds of diverse form that contain overlapping absorption edges. This method employs direct concurrent analysis of the data—demonstrated here for cases involving two interfering metal edges—and does not utilize subtractive or data filtering strategies that have been previously used to address this challenge. Its generality and precision are demonstrated in analyses made on two model nanoscale samples: 1 a Ir-Pt nanoparticle system supported on -Al2O3 and 2 a hybrid system of Pt nanowires on which Au nanoparticles have been nucleated and grown at the nanowire tips, stacking faults, and twinning boundaries. The results obtained demonstrate the unique compositional and structural qualities of these two systems as well as the broader utility of the new x-ray absorption spectroscopy based protocol used to characterize them.
Diffuse reflection from smooth dielectric surfaces

One of the most common assumptions for recovering object features in computer vision and rendering objects in computer graphics is that the radiance distribution of diffuse reflection from materials is Lambertian. We propose a reflectance model for diffuse reflection from smooth inhomogeneous dielectric surfaces that is empirically shown to be significantly more accurate than the Lambertian model. The resulting reflected diffuse radiance distribution has a simple mathematical form. The proposed model for diffuse reflection utilizes results of radiative transfer theory for subsurface multiple scattering. For an optically smooth surface boundary this subsurface intensity distribution becomes altered by Fresnel attenuation and Snell refraction making it become significantly non-Lambertian. The reflectance model derived in this paper accurately predicts the dependence of diffuse reflection from smooth dielectric surfaces on viewing angle, always falling off to zero as viewing approaches grazing. This model also accurately shows that diffuse reflection falls off faster than predicted by Lambert's law as a function of angle of incidence, particularly as angle of incidence approaches close to 90 degree(s). We present diffuse reflection effects near occluding contours of dielectric objects that are strikingly deviant from Lambertian behavior, and yet are precisely explained by our diffuse reflection model. An additional feature of our diffuse reflection model is that is predicts the diffuse albedo purely in terms of the physical parameters of a smooth dielectric surface, allowing rigorous derivation of the relative brightness of specular and diffuse reflection.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Ultrasonic vocalization production of preweanling rats: Effects of central and peripheral administration of α2-adrenoceptor agonists

Abstract Stimulation of α 2 -adrenoceptors increases the ultrasonic vocalization production of preweanling rats, however it is not known whether these critical α 2 -adrenoceptors are located peripherally or centrally. In a series of three experiments, ultrasonic vocalizations were measured after 11-day-old rats had been administered clonidine or 2-[2,6-diethylphenylamino]-2-imidazole (ST-91) either systemically (i.p.) or into the third ventricle (i.c.v.). These particular α 2 -adrenoceptor agonists were chosen because clonidine is lipophilic and enters the central nervous system, while ST-91 is hydrophilic and does not readily cross the blood–brain barrier. In the third experiment, clonidine- (1 μg, i.c.v.) and ST-91-induced (15 μg, i.c.v.) ultrasonic vocalizations were measured after systemic injection of the α 2 -adrenoceptor antagonist yohimbine (0.5 or 1 mg/kg, i.p.). Results showed that central administration of both clonidine and ST-91 increased the ultrasonic vocalization production of 11-day-old rats, whereas peripheral administration of only clonidine, and not ST-91, increased ultrasonic vocalizations. These results indicate that the α 2 -adrenoceptors mediating ultrasonic vocalization production are located in the central nervous system. Yohimbine fully attenuated clonidine-induced ultrasonic vocalizations but only partially attenuated ST-91-induced vocalizations. This pattern of results may have been due to the differential selectivity of clonidine and ST-91 for α 2 -adrenoceptor subtypes (α 2A , α 2B , and α 2C ) or imidazoline receptors. When combined with past research, the present results are consistent with the hypothesis that centrally located α 2 -adrenoceptors are a component of a neural system that mediates ultrasonic vocalization production.
Fetal nucleated erythrocytes (NRBCS) in chorionic villus sample supernatant fluids: an additional source of fetal material for karyotype confirmation

Fetal erythrocytes leak from the fetal capillaries at the time of chorionic villus removal. The purpose of this study was to determine if fetal nucleated erythrocytes (NRBCs) could be isolated from the chorionic villus sampling (CVS) supernatant fluid and used as an additional source of fetal material in order to confirm the fetal karyotype in cases of CVS mosaicism. One hundred CVS supernatant fluids were studied by simultaneous immunophenotyping, using a mouse antifetal haemoglobin antibody, UCH gamma, combined with fluorescent in situ hybridization (FISH) analysis using X- and Y-specific DNA probes. A chromosome 18 probe was also used in the case of a known male fetus with trisomy 18. Fetal haemoglobin (HbF)-positive cells were identified in 73 supernatant fluids and HbF-positive nucleated cells were present in 60 samples. The number of cells detected per sample showed great variation among the individual samples. FISH analysis was performed in 41 cases. FISH prediction of the fetal gender was concordant with the CVS karyotype in all cases, and the fetal trisomy 18 was correctly verified. In five cases in which Y sequences were detected, a small number of HbF-positive cells with two X signals were also identified; interestingly, in three of the five cases, the mother was a beta-thalassaemia carrier. This technique can be used as a quick and accurate method for the immediate verification of CVS results in cases of mosaicism, thus avoiding second-trimester amniocentesis.
The Effect of Heterogeneity on In-situ Combustion: The Propagation of Combustion Fronts in Layered Porous Media

This report extend the approach to heterogeneous systems, by considering the simpler case of in-situ combustion in layered porous media (and particularly to a two-layer model). Analytical models were developed to delineate the combined elects of fluid flow, reaction and heat transfer on the dynamics of combustion fronts in layered porous media, using as parameters the thermal coupling between the layers, the heat transfer to the surroundings and the permeability contrast.
A survey of critical care training amongst surgical residents: will they be ready?

Background Residents' duty-hour limitations and the trends towards closed-staffing for surgical critical care (SCC) have reshaped educational paradigms. No study has yet addressed the impact of these changes on resident SCC training. In our study, we investigated residents' experiences and perceptions of SCC education and practice. Methods At the end of the academic year 2007–2008, we distributed anonymous surveys to categorical general surgery residents in a large, university-based residency. All dedicated SCC rotations are currently completed by the end of PGY3. The survey measured residents' ratings of teaching, experiences, satisfaction, and self-assessed comfort with common SCC diseases and procedures. Results The response rate was 78% ( n = 52/67). At the time of the survey, the 52 respondents had completed 9.3 ± 4.5 wk of SCC rotations. Despite no rotations beyond PGY3, senior residents (PGYs 4/5) reported significantly greater SCC training time (13.1 versus 7.8 wk) and comfort managing SCC diseases and procedures than juniors (PGY 3). Attendings were rated the most effective didactic teachers, and senior residents the most effective procedural teachers. The mean education satisfaction score was 3.9 ± 0.9 (5 = extremely satisfied). Residents anticipated performing minimal SCC management of their own patients, but most felt that SCC-trained surgeons should manage critically ill surgery patients. Seniors reported greater SCC fellowship interest (19% versus 0%). The addition of acute care surgery increased interest in 30% of respondents. Conclusions Senior residents reported greater comfort with SCC management despite the lack of senior SCC rotations, whilst dedicated training time for junior residents appears to be declining. Residents wish subspecialist care for their critically ill patients, but the low interest in SCC fellowships suggests future physician shortages in this subspecialty.
A control algorithm for automated pursuit

This paper presents an algorithm for controlling a nonholonomic automated vehicle following a moving target using only range and azimuth information. The automated vehicle is controlled dynamically by torque and steering rate -second and first order processes respectively. Obstacle avoidance is incorporated via a harmonic potential model of the world. Errors in range and azimuth are considered, as is data acquisition latency. A bicycle model simulation is presented. Position errors are important, but latency is not. Obstacles show a tendency to destabilize the current version of the algorithm.
Horizontal and vertical cylinders in waves

Abstract The present investigation examines a vertical cylinder and a horizontal cylinder in progressive waves. The physical differences between the flows are explored and experimental results are compared to previous planar harmonic flow measurements. It is found that modifications to the usual Morison approach are required in some cases to adequately account for the orbital motions of the fluid and to account for the orientation of the orbits with respect to the cylinder axis. The axial variations of the wave force on vertical cylinders are considered in order to evaluate the common practice of assuming constant values of C m and C D over the entire span. Lastly, the methods of computing force transfer coefficients from a force record are examined and several sources of error are identified and briefly discussed.
Non-extremal charged rotating black holes in seven-dimensional gauged supergravity

Abstract We obtain the solution for non-extremal charged rotating black holes in seven-dimensional gauged supergravity, in the case where the three rotation parameters are set equal. There are two independent charges, corresponding to gauge fields in the U ( 1 ) × U ( 1 ) Abelian subgroup of the SO ( 5 ) gauge group. A new feature in these solutions, not seen previously in lower-dimensional examples, is that the first-order “odd-dimensional self-duality” equation for the 4-form field strength plays a non-trivial role. We also study the BPS limit of our solutions where the black holes become supersymmetric. Our results are of significance for the AdS7/CFT6 correspondence in M-theory.
Image Manifolds which are Isometric to Euclidean Space

Recently, the Isomap procedure [10] was proposed as a new way to recover a low-dimensional parametrization of data lying on a low-dimensional submanifold in high-dimensional space. The method assumes that the submanifold, viewed as a Riemannian submanifold of the ambient high-dimensional space, is isometric to a convex subset of Euclidean space. This naturally raises the question: what datasets can reasonably be modeled by this condition? In this paper, we consider a special kind of image data: families of images generated by articulation of one or several objects in a scene--for example, images of a black disk on a white background with center placed at a range of locations. The collection of all images in such an articulation family, as the parameters of the articulation vary, makes up an articulation manifold, a submanifold of L2. We study the properties of such articulation manifolds, in particular, their lack of differentiability when the images have edges. Under these conditions, we show that there exists a natural renormalization of geodesic distance which yields a well-defined metric. We exhibit a list of articulation models where the corresponding manifold equipped with this new metric is indeed isometric to a convex subset of Euclidean space. Examples include translations of a symmetric object, rotations of a closed set, articulations of a horizon, and expressions of a cartoon face. The theoretical predictions from our study are borne out by empirical experiments with published Isomap code. We also note that in the case where several components of the image articulate independently, isometry may fail; for example, with several disks in an image avoiding contact, the underlying Riemannian manifold is locally isometric to an open, connected, but not convex subset of Euclidean space. Such a situation matches the assumptions of our recently-proposed Hessian Eigenmaps procedure, but not the original Isomap procedure.
Balancing service and education : Improving internal medicine residencies in the managed care era

Background Methods We changed the structure of our program from a system in which the hospitalized patients' primary physicians were responsible for daily inpatient management, while teaching was assigned to a defined teaching rounder, to a method in which the rounding attending was responsible for both teaching and patient care. Measurements before and after the change in the rounding system included: the McGill University clinical tutor evaluations, time-motion observations of house staff, patient satisfaction surveys, average length of stay data, and physician focus groups to assess physician satisfaction. Results The rounding attendings consistently received excellent to superior ratings by the house staff both before and after the implemented change. Compared to time-motion observations performed before the change, observations recorded after the change suggested that a greater percent of house staff time was spent on educational activities. The responses of patient satisfaction surveys indicated that the perception of quality of care remained high after the system change. Lastly, the average length of stay for patients on the general internal medicine and subspecialty services was reduced from 7.6 days before the change to 6.6 days after the change, a difference of 0.92 day (95% confidence interval 1.3 to 0.6, P
Causation, Counterfactuals, and Critical Reading in the Active Classroom

Identifying causal claims may be second nature to a seasoned scholar, but the logic of causality is not always so obvious to the undergraduates in our classrooms. In this article I describe the essential features of a reading assignment designed to hone critical thinking skills, especially as they pertain to cause and effect and the associated logic of counterfactual reasoning. The “Critical Reading Exercise” (or CRE) is a brief, highly structured assignment that calls upon the student to read a scholarly article or book chapter and identify the major thesis and key causal relationships presented by the author as well as develop a plausible counterfactual implied by the argument. Among the advantages of the CRE are the incentive it provides to do careful, critical reading of genuine scholarly work and lay the foundation for fruitful discussion in an active learning classroom. Common pitfalls associated with this assignment are also identified. Ultimately the assignment reflects an appropriate way to engage students with both the substance and the methodological foundation of our discipline.
Analysis of Sb-based resonant interband tunnel diodes for circuit modeling

Abstract Sb-based resonant interband tunneling diodes are an alternative to the more commonly used InP-based resonant tunneling diodes. Potential advantages include higher speed and lower power operation due to its lower characteristic voltages. This fundamental difference is caused by the Type II band alignment of the emitter and quantum well semiconductors as compared to the Type I band alignment in the InP-based system. A simple theoretical framework is provided that exhibits and provides qualitative understanding of the influence on device behavior. A SPICE compatible analytic form for the current versus voltage characteristic is derived.
Learning to live together on a small planet

International understanding, once a humanitarian virtue, is now a dramatic, urgent necessity: the interdependence of the different regions and countries of the world and the strain on limited resources are such that without understanding leading to co-operation there will be disaster. The following article by Lester Brown, head of the Worldwatch Institute, should serve to remind our readers that unless we all become educated to the grave problems facing humanity, the technical skills and general knowledge imparted by our shool and university systems may well become superfluous. [Ed.]
Isolation and characterization of CYP6B4, a furanocoumarin-inducible cytochrome P450 from a polyphagous caterpillar (Lepidoptera: Papilionidae)

Papilio glaucus (tiger swallowtail) is a generalist that rarely encounters plants containing furanocoumarins yet is constitutively capable of metabolizing low levels of these highly toxic allelochemicals. In larvae of this species, metabolism of linear (xanthotoxin, bergapten), and angular (angelicin, sphondin), furanocoumarins can be induced up to 30-fold by the presence of xanthotoxin in their diet. Degenerate primers corresponding to conserved amino acid sequences in three insect P450s, Musca domestica (CYP6A1), Drosophila melanogaster (CYP6A2) and Papilio polyxenes (CYP6B1), were used to clone xanthotoxin-induced P450 transcripts from P. glaucus larvae by a reverse transcription-polymerase chain reaction (RT-PCR) strategy. Positive clones encoding the highly conserved F--G-R-C-G P450 signature motif were used to isolate a full-length CYP6B4v1 cDNA from a P. glaucus xanthotoxin-induced cDNA library. Sequence comparisons indicate the P. glaucus CYP6B4v1 protein sequence is 63% and 61% identical, respectively, to the P. polyxenes furanocoumarin-inducible CYP6B1v1 and CYP6B3v1 proteins. Northern analysis indicates that CYP6B4 and related transcripts are highly induced in response to xanthotoxin. Baculovirus-mediated expression of the CYP6B4v1 protein in lepidopteran cell lines demonstrates that this P450 isozyme metabolizes isopimpinellin, imperatorin, and bergapten at high rates, xanthotoxin and psoralen at intermediate rates and angelicin, sphondin, and trioxsalen only at very low rates.
Water quality characteristics associated with Southern Plains Grasslands

Water quality information regarding grasslands in the Southern Plains of Oklahoma and Texas in sparse. The objective of this study was to determine the extent to which the area's surface and ground-water quality is influenced by native and introduced grass management practices. Concentrations and amounts of sediment, N, and P in surface runoff water were determined for 14,1-to 6-ha watersheds in the Reddish Prairie and Rolling Red Plain land resource areas for periods of 3 to 13 yr []
The Education of Booker T. Washington: American Democracy and the Idea of Race Relations

Michael Rudolph West New York: Columbia University Press, 2006 320 pp., ISBN 9780 231130 486 ($29.50) Booker T. Washington loomed so large over the late 1800s and early 1900s, that no gathering or ...