cssi/SciSciGPT-SciSciNet huggingface dataset:
The decision process behind inclement‐weather school closings: a case‐study in Maryland, USA

School closings due to inclement weather cause inconvenience for parents, employees, and other affected parties, and such closings have been shown to lower scores on standardized tests. Delaying or closing school is usually a last-minute decision based on current and predicted weather trends. The decision process can also be stressful, as an incorrect decision results in community scorn. Little formal research has been conducted on the procedures used to make an inclement weather closing or delay decision. This research sought to identify the procedures school administrators follow, including the types of weather data used. Statistical analysis of actual closing dates was also carried out to examine if non-meteorological factors, such as day of the week, play a role. Maryland, a mid-Atlantic state in the eastern United States, was chosen for study because there are only 24 school districts but they span a widely-varied physical and socioeconomic landscape. School closing data were collected and assembled and interviews across school districts of varying size were carried out during the autumn and winter of 2010–2011. Overall, three major findings emerged from this study. First, the decision-making process was remarkably similar for districts of all sizes and locations, and largely the same for all types of weather. Second, school transportation directors are well-literate, high-level weather consumers in spite of little or no formal meteorological training. Finally, non-meteorological factors play almost no role in the decision making process, though a slight predilection towards Friday closures was observed. Copyright © 2012 Royal Meteorological Society
Systems Modeling to Inform Drug Policy

Illegal drugs cause substantial harm and raise challenging policy problems. Operations research has made important contributions to modeling drug market operations and the effectiveness of various interventions. This article outlines some of the key contributions. Keywords: drug control; optimal control; resource allocation; criminal justice
Russian “Defectology” Anticipating Perestroika in the Field

Created as a part of the general Russian educational system, special education in Russia has mirrored all the good and bad qualities of that system. It was during the Soviet phase of its existence that Russian remedial education developed its specific and unique character, reflecting the structure and values of the global social environment. Despite the fact that Russian society realized the need to change its general educational system, remedial education remained untouched by reconstructive forces. This article discusses both the background and the current state of treatment of children with disabilities in Russia. The theoretical basis of the modern Russian approach to disability, the current needy population, and the existing system for referral and rehabilitation are described, and emerging trends and new perspectives on the Russian treatment of children with disabilities are presented.
Diffusion of H 2 , D 2 , and T 2 in Single-Crystal Ni and Cu

Diffusion coefficients have been obtained for ${\mathrm{H}}_{2}$, ${\mathrm{D}}_{2}$, and ${\mathrm{T}}_{2}$ as a function of temperature in both Cu and Ni. The absolute-rate-theory formalism as proposed by Vineyard provides an adequate explanation of the results if quantum corrections and anharmonic effects are taken into consideration. The Ni results are especially affected by the failure of the harmonic approximation that apparently holds for Cu.
Gastrointestinal Bleeding From Jejunal Diverticulosis: Report of a Case

HEMORRHAGE from jejunal diverticula is extremely rare. Shackelford1reviewed the literature on this subject in 1960 and found only 21 reported cases, adding 3 of his own to the list. The present case report represents a well-documented example of massive gastrointestinal bleeding from jejunal diverticulosis. Report of a Case The patient (PBBH 1-03-14) was a 67-year-old white single woman who entered the Peter Bent Brigham Hospital on April 23, 1964, with a four-hour history of tarry stools. The patient had a known hiatus hernia and, in addition, took two tablets daily of a buffered aspirin preparation (Bufferin). At 4 AM on the day of admission, the patient awoke with pain in the right upper quadrant of the abdomen which progressed to diffuse abdominal cramps and an urgent need to defecate. During the next four hours the patient had seven tarry bowel movements and the abdominal pain subsided. She came
Scavenger receptor class B type I is expressed in cultured keratinocytes and epidermis. Regulation in response to changes in cholesterol homeostasis and barrier requirements.

Cholesterol is a key lipid in the stratum corneum, where it is critical for permeability barrier homeostasis. The epidermis is an active site of cholesterol synthesis, but inhibition of epidermal cholesterol synthesis with topically applied statins only modestly affects epidermal permeability barrier function, suggesting a possible compensatory role for extraepidermal cholesterol. Scavenger receptor class B type I (SR-BI) is a recently described cell surface receptor for high density lipoproteins (HDL) that mediates the selective uptake of cholesterol esters from circulating HDL. In the present study, we demonstrate that SR-BI is present in cultured human keratinocytes and that calcium-induced differentiation markedly decreases SR-BI levels. Additionally, the cell association of [3H]cholesterol-labeled HDL decreased in differentiated versus undifferentiated keratinocytes. Furthermore, the inhibition of cholesterol synthesis with simvastatin resulted in a 3–4-fold increase in both SR-BI mRNA and protein levels, whereas conversely, addition of 25-hydroxycholesterol suppressed SR-BI levels by approximately 50%. SR-BI mRNA is also expressed in murine epidermis, increasing by 50% in parallel with cholesterol requirements following acute barrier disruption. Because the increase is completely blocked by occlusion with a vapor-impermeable membrane, changes in epidermal SR-BI expression are regulated specifically by barrier requirements. Lastly, using immunofluorescence we demonstrated that SR-BI is present in human epidermis predominantly in the basal layer and increases following barrier disruption. In summary, the present study demonstrates first that SR-BI is expressed in keratinocytes and regulated by cellular cholesterol requirements, suggesting that it plays a role in keratinocyte cholesterol homeostasis. Second, the increase in SR-BI following barrier disruption suggests that SR-BI expression increases to facilitate cholesterol uptake leading to barrier restoration.
Field profile tailoring in a-Si:H radiation detectors

The capability of tailoring the field profile in reverse-biased a-Si:H diodes by doping and/or manipulating electrode shapes opens a way to many interesting device structures. Charge collection in a-Si:H radiation detectors is improved for high LET particle detection by inserting thin doped layers into the i-layer of the usual p-i-n diode. This buried p-i-n structure enables us to apply higher reverse-bias and the electric field is enhanced in the mid i-layer. Field profiles of the new structures are calculated and the improved charge collection process is discussed. Also discussed is the possibility of field profile tailoring by utilizing the fixed space charges in i-layers and/or manipulating electrode shapes of the reverse-biased p-i-n diodes.
Argon isotopic zoning in mantle phlogopite

Incremental-heating and laser-probe /sup 40/Ar//sup 39/Ar analyses were performed on phlogopite extracted from a garnet-lherzolite mantle nodule entrained by the Precambrian (1200 Ma) Premier kimberlite, South Africa. The spatial resolution of the laser probe has enabled the characterization of argon isotopic zoning in a single phlogopite grain. An apparent age contour map records lower ages (1.2 Ga) along grain margins and high apparent ages (up to 2.4 Ga) at the core. The latter ages are caused by excess argon contamination and subsequent partial diffusive loss, and have no age significance. Comparison with step-heating results indicates that argon spatial distributions inferred from in-vacuo step-heating experiments are, at best, grossly approximate. Variations in the laser-probe apparent ages were observed only laterally across the phlogopite cleavage surface, indicating that argon transport occurs preferentially along phlogopite cleavage planes. Age profiles, when modeled using one-dimensional radial geometry (cylindrical coordinates), do not conform to classical Fick's law diffusion, suggesting that the characteristic dimension of diffusion for argon in phlogopite may be highly variable within individual grains.
Food Aid Donor Allocation Decisions After 1990

Bilateral donations of food aid have been criticized for not responding to the need in recipient countries. U.S. food aid programs have attempted to meet humanitarian objectives while providing limited support to domestic agricultural producers and developing overseas markets, so food aid is now being examined in World Trade Organization negotiations on export competition. This paper investigates if significant policy changes in the mid 1990s by the EU, and more modest modifications to U.S. programs, have resulted in a measurable increase in donor responsiveness to need. A new specification of need is developed, and the role of chronic hunger and violent conflict are also tested as proxies for need. Results indicate that most donors are more responsive to severe shortfalls in production. Additionally, donors appear to be increasingly responsive to need over the 1990s, particularly to recipient countries experiencing violent conflict, but not to the needs of least developed countries. Results indicate that food aid is increasingly additional, an important finding for negotiations on disciplines for food aid. L'aide alimentaire bilaterale a ete critiquee parce qu'elle ne repondait pas aux besoins des pays beneficiaires. Les programmes d'aide alimentaire des Etats-Unis ont tente de satisfaire aux objectifs humanitaires tout en apportant un certain soutien aux producteurs agricoles des Etats−Unis et en developpant des marches d'outre-mer, si bien que l'aide alimentaire fait maintenant l'objet d'un examen dans les negociations de l'Organisation mondiale du commerce sur la concurrence a l'exportation. Le present article examine si les importantes modifications de politiques apportees par l'UE au milieu des annees 1990, de meme que les modifications plus modestes apportees aux programmes etatsuniens, ont entraine une hausse mesurable de la sensibilite des donateurs quant aux besoins. Une nouvelle description des besoins est en cours d'elaboration, et le role de la faim chronique et des conflits violents est egalement evalue comme indicateur de besoins. D'apres les resultats, la plupart des donateurs sont davantage influences par un manque a gagner important dans la production. Depuis 1990, les donateurs semblent etre de plus en plus receptifs aux besoins, particulierement a ceux des pays beneficiaires touches par des conflits violents, mais non a ceux des pays les moins avances. Les resultats ont indique que l'aide alimentaire augmente de plus en plus et devient un element important pour les negociations sur les disciplines a l'aide alimentaire.
Analysis and Stability of Orotic Acid in Milk

Abstract A method based on HPLC and ion pairing techniques was used to determine the orotic acid concentrations in cows' milk. Average amounts were 69 to 74 mg/L. Orotic acid in milk was stable to heating but decreased during commercial yogurt fermentation. Correlations were made between the loss of orotic acid and the increase or decrease in pH during fermentation.
Regulatory response to the problem of pathogenic bacteria in the dairy industry.

Over the past few years, pasteurized fluid milk and milk products have been demonstrated to contain pathogenic microorganisms and to have caused outbreaks of human illness. The most recent significant outbreaks have been Yersiniosis in Tennessee, Arkansas, and Mississippi in 1982; Listeriosis in Massachusetts in 1983 and California in 1985; Salmonetlosis in Illinois in 1985; and staphylococcal enterotoxins in Kentucky in 1985. These incidents seemed to be occurring with greater frequency and affecting larger numbers of people. Deaths have been associated with some of these outbreaks. The FDA has the responsibility under the Food, Drug and Cosmetic Act (FD&C Act) and the Public Health Service Act of assuring the public that nation's milk supply is uniformly safe and wholesome. The FDA fulfills its responsibilities for Grade A dairy plants through a signed Memorandum of Understanding with the National Conference on Interstate Milk Shipments, which comprises all 50 states. Under this program, responsibilities for assuring the wholesomeness of Grade A milk products are shared cooperatively between the states, and FDA responsibilities for non-Grade A products such as ice cream and cheese are undertaken separately by FDA and the states under the regulatory provisions of FD&C Act and state statutes. As a result of the outbreaks mentioned, FDA increased surveillance for the nation's dairy industry to provide assurance that there were no generic public health control weaknesses in the industry and to prevent further disease outbreaks. The primary purposes of this
Anomalous origin of the sural nerve in a patient with tibial—common peroneal nerve anastamosis

Recognition of anomalous innervation patterns may be important in dealing with peripheral nerve injuries. We describe a patient who suffered injury to the common peroneal nerve (CPN) at the knee when he laterally dislocated his knee. Intraoperative nerve conduction studies during surgical exploration revealed that nerve fibers from the tibial nerve crossed over to join the CPN immediately distal to a neuroma incontinuity. The sural nerve was also found to arise totally from the CPN. © 1993 John Wiley & Sons, Inc.
Anticoagulant activity of pectic acid derivatives

Abstract Pectic acid propionate is reduced with gaseous diborane to yield a series of polysaccharides having different carboxyl group content. Sulfation of the reduced polymers with various molar ratios of sulfur trioxide-N,N-dimethylformamide complex yields a series of polysaccharides having different carboxyl and O-sulfate group contents. Treatment of the reduced polymers with ethylenimine prior to sulfation yields a second series of polysaccharides having various levels of carboxyl and N- and O-sulfate groups. All of the sulfated polysaccharide preparations show activity in delaying the clotting time of recalcified human plasma. The anticoagulant activity of the reduced and sulfated polysaccharides increases with increasing degree of substitution of sulfate groups and with decreasing amounts of carboxyl groups. Activities of 44 and 43 units/mg are observed for preparations reduced to 7.7 and 4.9% carboxyl content and having degrees of sulfate substitution of 1.55 and 1.46, respectively. An increase in anticoagulant activity with decreasing carboxyl group content is also observed for preparations containing both N- and O-sulfate groups. The amount of nitrogen present, however, representing N-sulfate groups has little, if any, effect on the anticoagulant activity.
Mitochondrial oxidative DNA damage in experimental autoimmune uveitis.

PURPOSE. In experimental autoimmune uveitis (EAU), recent work has demonstrated that retinal damage involves oxidative stress early in uveitis, before macrophage cellular infiltration. The purpose of this study was to determine whether oxidative mitochondrial DNA damage occurs early in EAU, before leukocyte infiltration. METHODS. Lewis rats were immunized with S-antigen mixed with complete Freund adjuvant (CFA) to induce EAU. Nonimmunized animals and animals injected with CFA served as controls. Animals were killed on days 3, 4, 7, and 12 after immunization. Damage to mitochondrial DNA and nuclear DNA was assessed using a novel long quantitative polymerase chain reaction technique. TUNEL staining to detect apoptosis and immunohistochemical detection of leukocyte infiltration in EAU retinas were also performed at these times. RESULTS. Mitochondrial DNA damage occurred early in EAU, from day 4 to day 12. In the early phase of EAU (days 4‐7), there was no inflammatory cell infiltration. On day 12 inflammatory cells infiltrated the retina and uvea. Nuclear DNA damage occurred later in EAU at day 12. Neither mitochondrial nor nuclear DNA damage was detected in the controls. TUNELpositive staining for apoptosis was detected only at day 12 in EAU retina. CONCLUSIONS. Oxidative mitochondrial DNA damage begins at day 4 in EAU, supporting the view that oxidative stress selectively occurs in the mitochondria in the early phase of EAU, before leukocyte infiltration. Such oxidative damage in the mitochondria may be the initial event leading to retinal degeneration in EAU. (Invest Ophthalmol Vis Sci. 2008;49: 3299‐3304) DOI:10.1167/iovs.07-1607
Crystal growth and properties of pyroelectric Li2GeO3

Abstract The growth of single crystal pyroelectric Li 2 GeO 3 by the Czochralski technique is described and measurements of several of its piezoelectric and acoustic properties reported. The electromechanical coupling factor k 2 t in c-cut Li 2 GeO 3 is approximately five times that of α-quartz.
Problem of imbalance in risk factors in clinical trials: logistic regression is the answer.

Abstract Readers are encouraged to write letters to the editor concerning articles that have been published in Gastroenterology. Short, general comments are also considered, but use of the Correspondence section for publication of original data in preliminary form is not encouraged. Letters should be typewritten double-spaced and submitted in triplicate.
Removal of beta III isotype enhances taxol induced microtubule assembly.

The interaction of βIII-depleted tubulin with taxol was investigated. A monoclonal antibody against the βIII tubulin isotype was immobilized on a sepharose 4B column and used to remove the βIII tubulin isotype from unfractionated tubulin. The assembly of βIII-depleted tubulin in the presence of taxol was enhanced compared to unfractionated tubulin. The critical concentration of unfractionated tubulin in the presence of 10 μM taxol is 0.4 mg/ml, while the critical concentration of βIII-depleted tubulin is 0.16 mg/ml. At different concentrations of taxol, the assembly of βIII-depleted tubulin is increased relative to that of un fractionated tubulin and reaches the maximumat about a 1 : 1 ratio of tubulin and taxol. The assembly of un fractionated tubulin and βIII-depleted tubulin has also been studied by electron microscopy. After 2 minutes at 37°C, unfractionated tubulin assembly in the presence of 10 μM taxol results only in ribbon-like and ring structures; there are no visible microtubules. By 5 minutes, microtubules appear and increase in length. The assembly of βIII-depleted tubulin in the presence of 10 μM taxol occurs more quickly. In contrast to the case with un fractionated tubulin, βIII-depleted tubulin assembles within 2 minutes into microtubules which increase in length with time. At 30 minutes, microtubules assembled from βIII-depleted tubulin are shorter than the microtubules assembled from unfractionated tubulin. There is no visible difference between the microtubules assembled from unfractionated tubulin and βIII-depleted tubulin. Taxol-induced βIII-depleted tubulin assembly is more resistant to the inhibiting effect of podophyllotoxin and colchicine. It is also less sensitive to the inhibiting effect of cold temperature.
Leukotriene B4 receptor BLT1 mediates early effector T cell recruitment.

Leukotriene B4 (LTB4) was originally described as a potent lipid myeloid cell chemoattractant, rapidly generated from innate immune cells, that activates leukocytes through the G protein–coupled receptor BLT1. We report here that BLT1 is expressed on effector CD4+ T cells generated in vitro as well as in vivo when effector T cells migrate out of the lymphoid compartment and are recruited into peripheral tissues. BLT1 mediated LTB4-induced T helper type 1 (TH1) and TH2 cell chemotaxis and firm adhesion to endothelial cells under flow, as well as early CD4+ and CD8+ T cell recruitment into the airway in an asthma model. Our findings show that the LTB4-BLT1 pathway is involved in linking early immune system activation and early effector T cell recruitment.
Encapsulation of NF-κB decoy oligonucleotides within echogenic liposomes and ultrasound-triggered release

Abstract Echogenic liposomes (ELIP) have additional promise, beyond diagnostic agents, as vehicles for delivering oligonucleotides (ODN), especially if the release of the agent can be triggered and its uptake can be enhanced by ultrasound application at a specific site. The purpose of this study was to co-encapsulate air and NF-κB decoy ODN within ELIP allowing ultrasound to release encapsulated ODN from ELIP, and to accurately quantify release of encapsulated ODN from ELIP upon ultrasound application. FITC-labeled sense ODN (2 mM) was incorporated within ELIP using freeze/thaw method. Encapsulation efficiency of FITC–ODN was spectrofluorometrically analyzed by quenching fluorescence of unencapsulated FITC–ODN using a complementary strand tagged with Iowa Black FQ–ODN. Quenching of FITC–ODN (0.05 μM) with Iowa Black FQ–ODN (0.1 µM) was found to be efficient (92.4 ± 0.2%), allowing accurate determination of encapsulated ODN. Encapsulation efficiency of ODN was 14.2 ± 2.5% in DPPC/DOPC/DPPG/CH liposomes and 29.6 ± 1.5% in DPPC/DOPE/DPPG/CH liposomes. Application of ultrasound (1 MHz continuous wave, 0.26 MPa peak-to-peak pressure amplitude, 60 s.) to the latter formulation triggered 41.6 ± 4.3% release of ODN from ODN–containing ELIP. We have thus demonstrated that ODN can be encapsulated into ELIP and released efficiently upon ultrasound application. These findings suggest potential applications to gene therapy for atherosclerosis as well as a variety of other diseases.
Bers-ERK Schwann Cells Coordinate Nerve Regeneration

In this issue of Neuron, Napoli et al. (2012) demonstrate that elevated ERK/MAPK signaling in Schwann cells is a crucial trigger for Schwann cell dedifferentiation in vivo. Moreover, the authors show that dedifferentiated Schwann cells have the potential to coordinate much of the peripheral nerve response to injury.
H2O2 Generation by bacillus Calmette-Guérin Induces the Cellular Oxidative Stress Response Required for bacillus Calmette-Guérin Direct Effects on Urothelial Carcinoma Biology

Purpose: Exposure of urothelial carcinoma cells to bacillus Calmette-Guerin affects cellular redox status and tumor cell biology but the mechanism(s) remain unclear. We examined free radical production by bacillus Calmette-Guerin in tumor cells in response to the bacillus using global profiling of reactive oxygen species/reactive nitrogen species. The relationship between free radical generation and downstream cellular events was evaluated.Materials and Methods: Using fluorescent probes we performed global profiling of reactive oxygen species/reactive nitrogen species in heat killed and viable bacillus Calmette-Guerin, and in the 253J and T24 urothelial carcinoma cell lines after exposure to the bacillus. Inhibition of bacillus Calmette-Guerin internalization and H2O2 pharmacological scavenging were studied for their effect on cellular reactive oxygen species/reactive nitrogen species generation and various physiological end points.Results: Viable bacillus Calmette-Guerin produced H2O2 and O2– but nitric ...
Inhibition of mitogen and immune blastogenesis by two distinct populations of suppressor cells present in the spleens of fibrosarcoma-bearing mice: Adoptive transfer of suppression

Mitogen and immune blastogenic responses were progressively impaired in the spleens of mice with transplanted fibrosarcomas. Spleen cells from tumour-bearing BALB/c mice were shown to suppress in vitro phytohemagglutinin (PHA) and immune blastogenesis of normal syngeneic spleen cells. Nylon wool column and other depletion techniques were utilized to characterize the cellular source of suppressive activity in tumour-bearing host (TBH) spleens. Evidence is presented for two distinct suppressor cell systems operating in the spleens, but not lymph nodes, of TBH BALB/c mice. Both normal and TBH splenic macrophages were shown to suppress in vitro PHA and immune blastogenesis at high in vitro concentrations. No functional difference was detected between normal and TBH splenic macrophages. Suppressor T cells, detected in a macrophage-depleted culture system, significantly suppressed normal spleen cell blastogenesis at low in vitro concentrations. Anti-Thy 1 serum-sensitive suppressor T cells elaborated an immunosuppressive material that could also mediate inhibition of blastogenesis. Tumour-bearing host thymocytes also elaborated such a material. No soluble inhibitor(s) was released by macrophages or TBH lymph-node cells. The suppressor T cell was tentatively defined as a spleen-seeking, mildly nylon-wool-adherent, and anti-Thy 1 serum and hydrocortisone succinate-sensitive T lymphocyte. Adoptive transfer studies revealed that both macrophages (normal or TBH) and suppressor T cells were inhibitory. The data suggest that suppressor T cells may significantly affect blastogenesis at low in vitro and in vivo concentrations, whereas macrophage-mediated suppression requires higher concentrations.
Metabolism of thyroxine during prolonged kidney cortex incubation.

A study has been carried out of the metabolic changes in thyroxine, as the hormone maintained the oxygen consumption of rat kidney cortex slices incubated for three days at 5°C. Tetraiodothyroacetic acid (Tetrac) and iodide were rapidly produced, with triiodothyroacetic acid (Triac) and small amounts of a thyroxine conjugate appearing later. When Tetrac was added instead of thyroxine, conjugation was more rapid, but no Triac was formed. Addition of Triiodothyronine (Trit) resulted in Triac formation, as well as maximal production of both glucuronic and sulfuric acid conjugates. No Trit was encountered, even with careful bidimensional chromatography; thus, renal deamination and decarboxylation of Trit must dispose of it as fast as it is produced from thyroxine. No correlation could be obtained between production of any metabolite of thyroxine and its effect on kidney cortex metabolic rate. These results suggest that there is a response of some labile factor in the cell rather than production of an “active”...
An x‐ray photoelectron spectroscopy study of the thermal nitridation of SiO2/Si

The dependence of the nitrogen distribution in thermally nitrided SiO2 films on the nitridation time and temperature has been studied by means of X-ray photoelectron spectroscopy (XPS). The photoelectron peak intensities were measured by fitting Voigt profiles to the XPS spectra and were used to calculate the film composition as a function of film depth, applying an analytical method described in detail. The times of appearance of the maxima in interfacial nitrogen concentration are shown for 800, 1000, and 1150 C, and the data are related to a kinetic model of Vasquez and Madhukar (1985), which considers the effect of interfacial strain on the nitridation kinetics. In addition, the intensity of a fluorine marker (from the HF used in the etching step) was found to correlate with the nitrogen concentration. It is postulated that the F bonds preferentially to defects. This hypothesis and the measured F intensities are consistent with the proposed strain-dependent energy of defect formation.
Congenital Lobar Emphysema The Roles of CT and V/Q Scan

An infant with congenital lobar emphysema of the left upper lobe presented with unusually severe mediastinal shift and underwent computed tomography (CT) and radionuclide V/Q scans. The V/Q scan confirmed the non-functioning nature of the hyperinflated lobe while the CT scan depicted the abnormal anatomy as well as the normal morphologic characteristics of the remaining lung thus allowing for safe and appropriate surgical management.
Reduced lens development in lid-suture myopia.

Abstract The possibility that lens growth may be modulated by physical forces transmitted through the suspensory ligament has been examined by comparing lens weights in the eyes of tree shrews which matured with the lids of one eye closed. Tree shrew eyes which are deprived of pattern vision from infancy develop severe myopia and, therefore, a monocularly deprived animal matures with one myopic eye and one emmetropic mate which serves as a genetically identical control. Relative to normal, the myopic eyes are axially elongated and have poorly developed ciliary zonules which appear incapable of providing normal tensile stress to the lens. In this paper it is shown that lenses from myopic eyes weigh approximately 5·5% less than their normal controls, suggesting decreased growth as a result of subnormal tension. Experimental evidence that lid-sutured myopic eyes suffer from axial elongation, zonular dysplasia, and lens hypoplasia supports the hypothesis that excessive accommodation during development contributes to acquired myopia.
The focusing DIRC with waveform digitizing electronics

Abstract We have tested a novel Cherenkov imaging detector called the Focusing DIRC (FDIRC) with waveform digitizing electronics. The prototype's concept is based on the BaBar DIRC with several important improvements: (a) much faster, pixelated photon detectors, (b) a mirror that makes the photon detector smaller and less sensitive to background in future applications, and (c) electronics capable of measuring single photon resolution to σ ≈ 150 ps , which allows for correction due to chromatic error. In this test, the prototype has been instrumented with seven Hamamatsu H-8500 MaPMTs. Waveforms from ∼ 450 pixels are digitized with waveform sampling electronics based on the BLAB2 ASIC, operating at a sampling speed of ∼ 2.5 GSa / s . This version of the FDIRC prototype was tested in a large cosmic ray telescope providing muon tracks with ∼ 1 mrad angular resolution and a muon momentum cutoff of ≥ 1.6 GeV / c .
Characterization of the Hydrodynamically Developing Flow in a Microtube Using MTV

Micro-molecular tagging velocimetry (μMTV) has been used to characterize the hydrodynamic developing flow in a microtube inlet with a nominal inner diameter of 180 μm. Velocity profile data at 11 axial locations within the hydrodynamic developing region were acquired using the μMTV approach and the results represent the first characterization of hydrodynamically developing pipe flow at the microscale. The uncertainty in measurements of time-averaged velocity profiles ranged from 6% to 7% of the centerline velocity. The uncertainty in instantaneous measurements is in the range 8%-16% of the peak maximum velocity. Data were taken at Reynolds numbers of 60, 100, 140, 290, and 350. The data suggest the formation of a vena contracta with either locally turbulent flower unsteady laminar flow separation early in the tube for the larger Reynolds (Re) numbers, which is quite different from macroscale experiment or numerical simulation where a vena-contracta is not observed for Re < 500. The velocity profiles obtained very near the tube entrance exhibited a uniform velocity core flow surrounded by regions of relatively stagnant fluid in the near wall regions
Homologous recombination and maintenance of genome integrity: Cancer and aging through the prism of human RecQ helicases

Abstract Homologous recombination (HR) is a genetic mechanism in somatic cells that repairs DNA double-strand breaks and restores productive DNA synthesis following disruption of replication forks. Although HR is indispensable for maintaining genome integrity, it must be tightly regulated to avoid harmful outcomes. HR-associated genomic instabilities arise in three human genetic disorders, Bloom syndrome (BS), Werner syndrome (WS), and Rothmund–Thomson syndrome (RTS), which are caused by defects in three individual proteins of the RecQ family of helicases, BLM, WRN, and RECQL4, respectively. Cells derived from persons with these syndromes display varying types of genomic instability as evidenced by the presence of different kinds of chromosomal abnormalities and different sensitivities to DNA damaging agents. Persons with these syndromes exhibit a variety of developmental defects and are predisposed to a wide range of cancers. WS and RTS are further characterized by premature aging. Recent research has shown many connections between all three proteins and the regulation of excess HR. Here, we illustrate the elaborate networks of BLM, WRN, and RECQL4 in regulating HR, and the potential mechanistic linkages to cancer and aging.
Electrically Symmetric Poly(Phenylene Acetylene) Diodes

Abstract A diode has been fabricated with poly(phenylene acetylene) [PPA] as the electroluminescent polymer. The device exhibited an unusual symmetric (positive and negative bias) I-V characteristic and electroluminescent output. These experimental results are discussed in terms of tunneling of electrons and holes via localized states.
Preliminary description of focal segmental glomerulosclerosis in patients with renovascular disease

Abstract Summary Background Primary and secondary forms of focal segmental glomerulosclerosis (FSGS) are common causes of glomerular proteinuria. Secondary forms of FSGS seem to be the result of adaptive changes that follow a reduction in renal mass. We saw an elderly patient with severe bilateral renal vascular disease (RVD) who had FSGS on percutaneous biopsy. To find out whether elderly patients with atherosclerotic RVD are predisposed to the development of FSGS, we reviewed all cases of FSGS at our institution between 1990 and 1995. Methods We identified 59 cases of biopsy-proven FSGS and examined clinical, histological, and radiographic records. Findings Of the 59 patients, 24 were older than 50 years; eight of these had RVD. No patient under the age of 50 had RVD. Seven of the eight patients with RVD and FSGS had substantial proteinuria at presentation. All had typical glomerular lesions with focal segmental tuft collapse and synechiae; other glomeruli were hypertrophic. All patients showed further decline in renal function on follow-up. Interpretation The association of FSGS and RVD may represent an under-recognised aetiology of significant proteinuria in elderly patients.
Race versus belief about race as determinants of attraction: Belief prejudice and two kinds of race prejudice ☆

Abstract An experiment was conducted to assess the effects of actual racial membership versus similarity of beliefs about racial issues on interpersonal evaluations. Prejudiced and unprejudiced White male students observed a videotaped interaction of two Black and two White male actors discussing racial issues and then evaluated the actors on several scales. One White and one Black actor took a conservative stand on racial issues, and the other White and Black pair of actors took a liberal position. Results from the ratings showed strong belief prejudice effects. Prejudiced subjects were attracted to conservative actors while unprejudiced subjects were attracted to liberal actors. Additionally, there were two kinds of race effects. Prejudiced subjects preferred White to Black actors, but unprejudiced subjects showed a reverse bias, preferring Black to White actors. A tentative explanation for this unusual finding was proposed.
Influence of optical absorption on urinary calculus threshold fluence and ablation efficiency during infrared laser ablation

ABSTRACT The objectives of this study were to determine if the optical absorption properties of urinary calculi affect thethreshold fluence for ablation or fragmentation and the ablation efficiency due to laser irradiation. The Vanderbiltfree electron laser (FEL) was tuned to selected wavelengths based on the absorption spectrum of various types ofurinary calculi. The threshold fluences for ablation of the calculi were measured at different wavelengths. Apreliminary study of the ablation efficiency (ablation depth per unit incidence fluence) was performed. The resultswere found to be in agreement with a thermal ablation model for which the threshold fluences were proportional to 1/J.ta. The ablation efficiencies were higher in regions of the infrared spectra in which absorption was higher. For afixed laser irradiation, the lower threshold fluences within regions of high optical absorption allowed more energy toenhance calculus ablation. This study provided insight into determining the optimum wavelengths for ablation andlaser lithotripsy.Keywords: ablation efficiency, absorption coefficient, fragmentation efficiency, free electron laser, infrared, kidneystone, optimum wavelength, threshold radiant exposure, tissue ablation.
Influences on the Size and Scope of Networks for Social Service Delivery

Local social service agencies throughout the world have begun encouraging or requiring social service providers to form community-based networks for the delivery of publicly funded social services. Little is known, however, about the nature of the resulting networks. In this article we develop a model of organizational, programmatic, and community influences on the size and scope of interorganizational networks for social service delivery. We then apply this theoretical framework to an empirical study of service delivery networks in the Family Preservation Program in Los Angeles County. Our findings suggest that the availability of potential partners in the community, the scope of required services, and the ethnic homogeneity of the client population are key determinants of network size. We develop the implications of the results for theories of partnership formation and for more effective management of network formation processes.
Carbon nanotube (CNT) fins for enhanced cooling of shape memory alloy wire

A commonly noted disadvantage of shape memory alloys is their frequency response which is limited by how fast the material can be cooled. This paper presents a feasibility study of using vertically aligned carbon nanotubes (CNT) as microscopic cooling fins to improve convective heat transfer. Using DC plasma enhanced chemical vapor deposition (PECVD), aligned CNT's were successfully grown directly on ½ of the surface of a 0.38 mm diameter SMA wire, achieving desirable thermal contact. Cooling speeds were measured with a thermal imaging camera, and the effective convective coefficient was extracted from the temperature profiles using a basic cooling model of the wire. From this model, the effective convective coefficient was estimated to have increased by 24% (from 50 W/m2K for untreated SMA wire to 62 W/m2K for the nanotube treated wire), indicating that the deposition of CNT's indeed increased performance. By extrapolating these results to full wire coverage, up to a 46% improvement in frequency response with zero weight or volumetric penalties is predicted. Further improvements in cooling performance are likely to occur with higher CNT densities and longer nanotube lengths, allowing further developments of this technology to benefit many future applications utilizing high-speed miniature/micro-scale SMA actuators.
Cerebrospinal fluid norepinephrine concentrations and dynamics in depressed patients and normal volunteers

Abnormalities in central nervous system (CNS) noradrenergic concentrations or dynamics have been postulated to occur in major depression, although direct measurements of norepinephrine concentrations in single samples of lumbar cerebrospinal fluid (CSF) have failed to find significant differences between depressed patients and normal or neurological controls. However, the study of CNS noradrenergic dynamics under physiologic conditions has not been achieved because of the technical limitations of lumbar puncture. In the present study, we used a serial sampling technique in order to longitudinally assess CSF norepinephrine concentrations in ten healthy volunteers and ten depressed patients, smokers as well as non-smokers, while fasting and after the physiologic perturbation of eating. We continuously sampled CSF via indwelling subarachnoid catheters from 1100 to 1700 h and measured norepinephrine at 10 min intervals. A standardized mixed liquid meal was administered at 1300 h, breaking a 17 h fast. We found wide inter-individual variability in CSF norepinephrine concentrations in both groups, but no difference in CSF norepinephrine concentration between depressed patients (1.20 ± 0.85 pmol/ml, mean ± SD) and normal subjects (1.07 ± 0.15 pmol/ml). Significant intra-individual concentration variability over time was observed, which did not differ between healthy subjects and depressed patients. Hourly plasma norepinephrine concentrations were similar in normal volunteers and depressed patients. Mean plasma norepinephrine levels tended to correlate modestly with mean CSF norepinephrine concentrations. Body mass index was inversely correlated with CSF norepinephrine concentration but showed no significant relationship to plasma norepinephrine. Elevated CSF and plasma norepinephrine concentrations were, however, seen in depressed cigarette smokers compared to non-smokers. A rise in CSF norepinephrine was observed during the experiment in all subjects combined, suggesting either a response to a meal or a normal circadian rhythm. These data indicate that CSF norepinephrine concentrations do not distinguish between depressed patients and normal volunteers. Depression 1:149–155 (1993). © 1993 Wiley-Liss, Inc.
Medical Advances in Child Sexual Abuse.

This volume is the first of a two-part special issue detailing state of the art practice in medical issues around child sexual abuse. The six articles in this issue explore methods for medical history evaluation, the rationale for when sexual examinations should take place, specific hymenal findings that suggest a child has been sexually abused, the healing of genital injuries, approaches to interpretation of medical findings, and the neurological harm of sexual abuse. From the initial history to the process of the medical examination, the mechanics of what a genital examination might show, and the neurobiological consequences, it is demonstrated that the harm of sexual abuse is has more effect on the brain than the genital area.
Simulated supercritical fluid chromatography mobile phase introduction to a helium microwave-induced plasma : effects on nonmetal emission and spectral behavior

The effects of the introduction of capillary supercritical fluid chromatography mobile phases, CO2 and N2O, into a helium microwave-induced plasma (He-MIP) are investigated. The plasma and mobile-phase flow rates are maintained at conditions comparable to those typically used for these systems. Spectral characteristics are monitored in both the ultraviolet-visible and near-infrared regions. Molecular bands from these "foreign" gases are assigned and their relative intensities are noted as a function of the doping gas flow rate. Possible molecular band interferences are noted for nonmetal atomic emission determinations with He-MIPs. Nonmetal atomic emission reduction by these gases is studied with the use of chlorine atom and ion lines as test signals. Decreases in chlorine atom and ion emission are seen as CO2 and N2O flow rates are increased. It is found that ion line emission intensity is reduced more significantly than atom line emission. Reduction of both atom and ion line emission is more pronounced with CO2 than with N2O. The electron density of the plasma does not change as the CO2 flow rate is increased from 0 to 0.25 mL (STP)/min.
Monocular vision SLAM for indoor aerial vehicles

This paper presents a novel indoor navigation and ranging strategy by using a monocular camera. The proposed algorithms are integrated with simultaneous localization and mapping (SLAM) with a focus on indoor aerial vehicle applications. We experimentally validate the proposed algorithms by using a fully self-contained micro aerial vehicle (MAV) with on-board image processing and SLAM capabilities. The range measurement strategy is inspired by the key adaptive mechanisms for depth perception and pattern recognition found in humans and intelligent animals. The navigation strategy assumes an unknown, GPS-denied environment, which is representable via corner-like feature points and straight architectural lines. Experimental results show that the system is only limited by the capabilities of the camera and the availability of good corners.
Three-dimensional laser radar with APD arrays

MIT Lincoln Laboratory is actively developing laser and detector technologies that make it possible to build a 3D laser radar with several attractive features, including capture of an entire 3D image on a single laser pulse, tens of thousands of pixels, few-centimeter range resolution, and small size, weight, and power requirements. The laser technology is base don diode-pumped solid-state microchip lasers that are passively Q-switched. The detector technology is based on Lincoln-built arrays of avalanche photodiodes operating in the Geiger mode, with integrated timing circuitry for each pixel. The advantage of these technologies is that they offer the potential for small, compact, rugged, high-performance systems which are critical for many applications.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Involvement of Proteasomes in Regulating Jak-STAT Pathways upon Interleukin-2 Stimulation

Interleukin-2 (IL-2) activates the receptor-associated Janus family tyrosine kinases, Jak1 and Jak3, which in turn phosphorylate and activate specific STAT proteins (signal transducers and activators of transcription), such as STAT5. Activation of Jak and STAT proteins by IL-2 is transient and the mechanism for the subsequent down-regulation of their activity is largely unknown. We report here that IL-2-induced DNA-binding activity and tyrosine phosphorylation of STAT5 are stabilized by a proteasome inhibitor MG132; however, no detectable ubiquitination of the STAT proteins is observed. This sustained STAT5 activation can be blocked by protein kinase inhibitors, which is consistent with the ability of the proteasome inhibitor to stabilize IL-2-induced tyrosine phosphorylation of Jak1 and Jak3. These results suggest that proteasome-mediated protein degradation modulates protein-tyrosine phosphatase activity that negatively regulates the Jak-STAT signaling pathways.
Performance of identification techniques applied to uncertain dynamic systems

Abstract When the mathematical model is not a faithful representation of the real system such as when the model contains structural errors, complete specification of the model cannot be achieved unless these errors are compensated for. Two identification techniques ; the classical least squares method and the smoothed least squares method are presented and discussed. A simulated mixing tank system and a pilot-plant vaporizer system whose dynamic models contain structural uncertainties are used to investigate the performance of the two techniques. The ability of the smoothed least squares technique to improve the parameter estimates yielded by the classical least square method is reviewed.
Dispersing Behavior of Hydroxyapatite Powders Produced by Wet‐Chemical Synthesis

Three hydroxyapatite powders with different surface properties were produced by wet-chemical synthesis and characterized. The electrokinetic properties of powders dispersed in water were investigated by electroacoustic spectroscopy measurements. The different surface reactivity (pHiep and ζ potential versus pH curves) was related to the interplay of dissolution and adsorption of Ca2+ ions. With a view toward the preparation of porous bodies by sponge impregnation, the behavior of powder suspensions was studied. Four deflocculants were tested, and the optimum dispersing conditions for each powder were found. Anionic polyelectrolytes resulted in the best effective dispersing agent, with different optimum amounts added to the suspensions.