cssi/SciSciGPT-SciSciNet huggingface dataset:
Variable-Width Pulse Generation Using Avalanche Transistors

The extremely fast ionization process in semiconductors offers a means of generating pulses that have subnanosecond rise times and high peak powers. There are several important applications of these pulses which require the duration of the generated pulse to be variable. This report investigates three methods of producing variable-width pulses using transistors operating in the avalanche mode. The first circuit studied is used with a capacitor as the collector load. It produces pulse rise times of less than one nanosecond but has the disadvantage of a relatively slow RC discharge fall time. Distributed and lumped parameter delay lines were used in the second form of circuits studied. With the artificial delay line the pulse width can be controlled by opening the line at different sections whereas, with the cable, the length must be altered to change the pulse width. These circuits produced fast rise, flat top, and fast fall pulses. In the third method studied, a composite circuit is used in which the fast rise of an avalanche pulse is added to a slower rise, but variable duration pulse, generated by a saturating transistor. This method is shown to produce fast rise, variable-width pulses with overshoot and ringing easily held to less than five per cent.
Selective gonadotrophin uptake by mouse ovarian carcinoma.

Bei Mausen mit Granulosa- oder Theca-Tumoren wurde die Bindung von125I-HCG untersucht. Im Vergleich zur Bindung an andere Gewebe derselben Tiere konnte eine zellspezifische Bindung im Bereich der Tumoren festgestellt werden. Die Befunde werden im Zusammenhang mit der Zweizelltheorie der ovariellen Steroidgenese diskutiert.
Spin relaxation due to magnetic-field inhomogeneities: Quartic dependence and diffusion-constant measurements

Extension de la theorie perturbative de la relaxation de spin dans des champs magnetiques inhomogenes. Mesures en utilisant la relaxation de spin, des constantes de diffusion du xenon dans 760 torr de He et de N 2 a 80°C; elles sont respectivement 0,791±0,032 et 0,21±0,03 cm 2 /sec. En utilisant ces constantes de diffusion, on montre que la theorie decrit bien les effets quantiques observes
A rationale for the use of the hearing-aid metronome in a program of therapy for stuttering.

A stutterer can be taught to reduce the severity of his stuttering by pacing his speech with a metronome built into the housing of a behind-the-ear hearing aid (e.g., Brady, 1968). One rationale2 for using this device as a therapy for stuttering, which to my knowledge has not been mentioned in the literature, is similar to one that has been suggested in the literature for using Van Riper's speech controls (Bloodstein, 1969, p. 249), i.e., to "reverse" the vicious circle responsible for the maintenance of stuttering by progressively reducing the fear of stuttering and hence the desire to avoid stuttering. According to this rationale, the following process is responsible for the "reversal" of the vicious circle. As a stutterer learns that he can lessen the severity of individual moments of stuttering by pacing his speech with a metronome, it is probable that he will not fear stuttering as much as he previously did and for this reason his desire to avoid it will be reduced. According to most contemporary theories of stuttering, including Wendell Johnson's (Bloodstein, 1969, p. 3 2 ) , the less a stutterer fears stuttering and desires to avoid it the less he will probably stutter. Hence, a reduction in fear of stuttering would be expected to result in a reduction in frequency of stuttering. Once a stutterer realizes that he is stuttering less frequently than he did when he first began pacing his speech with a metronome, his fear of stuttering will probably be diminished even more and he will be even less anxious to avoid it which, in turn, should result in a further reduction in his stuttering frequency, et cetera Assuming i t is possible to rauonalize the use of the hearing-aid metronome and speech controls in the same manner, why might the former be the method of choice for some stutterers? This is one of a series of questions concerning the hearingad metronome that we are currently artempung to answer. The data collected thus far suggest that a partial answer to this question is "efficiency": it would probably take some sturrerers (especially, severe ones) much less time to learn to reduce the severity of their stuttering through the use of the metronome than through the use of speech controls.
Seabird and fur seal responses to vertically migrating winter krill swarms in Antarctica

The foraging behaviour of fur seals and two species of surface feeding seabirds was observed over swarms of vertically migrating krill along the Antarctic Peninsula in July 1987. Fur Seal haul out patterns were correlated with krill in the upper 30 m of the water column. Krill moved to the surface at night; seals subsequently foraged from 1400-0700 hours before returning to floes. Foraging was continuous through the night. Dive duration decreased as krill moved up to the surface; shorter dives may have been more successful than longer ones. It is possible that very deep dives, which occur early in a foraging bout, represent more of an attempt to assess krill depth and distribution rather than being a genuine foraging effort. Seabirds responded to the presence of a surface krill swarm by circling over it and foraging; krill at depths greater than 30 m elicited directional flight and low frequencies of prey capture attempts. Both Snow Petrels and Antarctic Terns preyed on krill, but each species approached the swarms from different habitats. Snow Petrels primarily overflew areas covered by ice; terns preferred open water. This suggested that prey encounters are essentially opportunistic, although the search for prey is limited to rather specific marine habitats. This feature may be important to our understanding of the factors that determine the pelagic distribution of seabirds.
Digoxin, hypercalcaemia, and cardiac conduction

The cardiac effects of hypercalcaemia are usually manifest as a shortening of the QT-interval. Hypercalcaemia is infrequently associated with a clinically manifest arrhythmia. However, concomitant therapy with digoxin or underlying cardiac disease can potentiate the arrhythmogenic effects of hypercalcaemia, leading to a symptomatic rhythm disorder. We describe a symptomatic arrhythmia, which developed in a patient with hypercalcaemia secondary to squamous cell carcinoma of the bronchus. The patient was on digoxin therapy at the time. The arrhythmia did not recur after discontinuation of digoxin therapy and correction of the hypercalcaemia. Because of its effect on cardiac conduction, hypercalcaemia should be considered in the evaluation of any patient with an unexplained bradyarrhythmia. Conversely, patients with hypercalcaemia should discontinue digoxin therapy and be evaluated for the presence of rhythm disorders while receiving appropriate treatment for hypercalcaemia.
Alignment and composition of laminin-polycaprolactone nanofiber blends enhance peripheral nerve regeneration.

Peripheral nerve transection occurs commonly in traumatic injury, causing deficits distal to the injury site. Conduits for repair currently on the market are hollow tubes; however, they often fail due to slow regeneration over long gaps. To facilitate increased regeneration speed and functional recovery, the ideal conduit should provide biochemically relevant signals and physical guidance cues, thus playing an active role in regeneration. To that end, laminin and laminin–polycaprolactone (PCL) blend nanofibers were fabricated to mimic peripheral nerve basement membrane. In vitro assays established 10% (wt) laminin content is sufficient to retain neurite-promoting effects of laminin. In addition, modified collector plate design to introduce an insulating gap enabled the fabrication of aligned nanofibers. The effects of laminin content and fiber orientation were evaluated in rat tibial nerve defect model. The lumens of conduits were filled with nanofiber meshes of varying laminin content and alignment to assess changes in motor and sensory recovery. Retrograde nerve conduction speed at 6 weeks was significantly faster in animals receiving aligned nanofiber conduits than in those receiving random nanofiber conduits. Animals receiving nanofiber-filled conduits showed some conduction in both anterograde and retrograde directions, whereas in animals receiving hollow conduits, no impulse conduction was detected. Aligned PCL nanofibers significantly improved motor function; aligned laminin blend nanofibers yielded the best sensory function recovery. In both cases, nanofiber-filled conduits resulted in better functional recovery than hollow conduits. These studies provide a firm foundation for the use of natural–synthetic blend electrospun nanofibers to enhance existing hollow nerve guidance conduits.
Estimation for jump processes in the tangent bundle of a Riemann manifold

A stochastic process is formulated in the tangent bundle of a Riemann manifold where the vector fibre portion of the process is a jump process. Since the tangent spaces change as the process in the base manifold evolves, it is necessary to define a jump process in the fibres of the tangent bundle with respect to the process in the base manifold. An estimation problem is formulated and solved for a process obtained from the jump process in the fibres of the tangent bundle where the observations include the process in the base manifold and the jump times. Since each fibre of the tangent bundle is a linear space, a suitable modification of some results for estimation in linear spaces can be used to solve the aforementioned estimation problem.
Challenging the validity of the association between oversleeping and overeating in atypical depression.

Abstract Objective In this study, we used a strict definition of hypersomnia and tested if the association between overeating–hypersomnia remained positive and significant. Hypersomnia was present if the total sleep time was close to 10 h per day or was at least 2 h longer than in normothymic periods. Methods Cross-sectional study using the adult general population of California and New York. The sample was composed of 6694 individuals aged between 18 and 96 years. Participants were interviewed by telephone using the Sleep-EVAL system. The interviews included various sleep and health topics and the assessment of DSM-IV sleep and psychiatric disorders. Results The one-month prevalence of major depressive episode was 6.1%, including a one-month prevalence of atypical depression of 1.6%, in this sample. Atypical depression subjects had a greater number of depressive symptoms and a longer duration of the current depressive episode than the other depressive subjects. Depressive subjects with hypersomnia slept longer (8 h, 29 min) than the other depressive subjects (6 h, 36 min) and longer than the subjects “getting too much sleep” (6 h, 48 min). Furthermore, hypersomnia was not associated with overeating while “getting too much sleep” showed a positive association with overeating. Conclusions Hypersomnia needs to be evaluated using a strict definition. Otherwise, it leads to an overestimation of this symptom in major depressive episode subjects and to a false association with overeating.
Computer-aided classification techniques for biological taxonomy

A computer-aided classification algorithm is basically a procedure for clustering a large number of objects into subsets representing similar "types." The cluster analysis technique is used to select objects which have similar characteristics and is distinct from such techniques as discriminant analysis and other more recently developed pattern recognition methods in the sense that it is not assumed a priori which objects belong to specific groups or what probability distributions characterize the different groups. The primary value of cluster analysis is in the classification of objects into "natural" groups as suggested by the data itself. This paper discusses recently developed approaches to three fundamental problems associated with the creation of computer-aided classification techniques for taxonomic studies of biological populations: 1) Data Characterization; 2) Clustering Procedure, and 3) Statistical Significance of Clustering Results, A brief presentation of biological applications is included.
Oxygen isotopic compositions of individual minerals in Antarctic micrometeorites: Further links to carbonaceous chondrites

Abstract We report in situ measurements of oxygen isotopic abundances in individual silicate and oxide minerals from 16 Antarctic micrometeorites (AMMs). The oxygen isotopic compositions of 10 olivine and 11 pyroxene grains are enriched in 16 O relative to terrestrial minerals, and on an oxygen three-isotope diagram they plot on the low δ 18 O side of the 16 O mixing line defined by calcium-aluminum-rich inclusions (CAI) from chondritic meteorites. AMM olivine and pyroxene δ 18 O values range from –9.9‰ to +8.0‰ and δ 17 O ranges from –11.3‰ to +5.5‰, similar to values measured in individual olivine grains and whole chondrules from carbonaceous chondrites. These data indicate that the mineral grains preserve their pre-terrestrial oxygen isotopic compositions, and provide another link between AMMs and carbonaceous chondrites. However, no clear relationship with one single subgroup of carbonaceous chondrite can be established. Based on their textures, crystal chemistries, and oxygen isotopes, some coarse-grained crystalline AMMs could originate from chondrule fragmentation. Whether the remaining mineral grains were formed by igneous or condensation processes is unclear. No clear correlation is observed between isotopic compositions and mineral compositions of AMM olivine grains, suggesting that the FeO- and 16 O-enrichment processes are not coupled in a simple way. Nor are any relatively large 16 O enrichments measured in any of the olivine grains, however two Mg-Al spinels and a melilite grain are 16 O enriched at the level of δ 18 O ∼ δ 17 O ∼ –40‰. The discovery of an 16 O-enriched melilite grain in AMMs supports the hypothesis that refractory minerals throughout the solar nebula formed from a relatively uniformly 16 O-enriched reservoir. This unique 16 O-rich signature of refractory minerals in primitive solar system materials suggests that they either formed from a widespread 16 O-rich reservoir in the solar nebula, or that an efficient mechanism (such as bipolar outflows) was acting to spread them from a highly localized 16 O-rich region over the early solar nebula.
The ongoing development of a problem-based surgery clerkship: year three.

The third-year clerkship at one college of medicine was modified to reflect an emphasis on adult learning principles and life-long learning habits. Problem-based learning was selected as the educational method, and the development of a cognitive knowledge base, clinical problem-solving skills, and appropriate clinical skills was stressed. At a yearly faculty education retreat, strengths and weaknesses of the clerkship were discussed. As a result of this meeting, several changes were made in the clerkship, including additional stress on students' usage of the medical library and computerized databases, a tutor development program, the addition of expert resource sessions, and more emphasis on students' development of clinical skills through a preceptor program. A comprehensive evaluation program designed to support the educational goals of the clerkship is in place. The major challenge of the program remains the proper synchronization of curricular, clinical, and student self-study activities essential for...
Plastic-deformati on mechanisms in quartz: The effect of water

Abstract High-temperature and pressure-deformation experiments indicate that small amounts of water strongly affect the plastic-deformation mechanisms that operate in quartz. Inherently dry natural quartz crystals exhibit a transition from T = (0001), t = 〈11 2 0〉 to T = {10 1 0} , t = [0001] glide at approximately 700° C at a strain rate of 8 · 10−6 sec−1. The transition temperature decreases with decreasing strain rate. When water is diffused into dry natural crystals at high temperature, duplex slip occurs on the systems (0001), 〈1120〉and either {1120}, [0001] or {1010}, [0001] depending on which of the latter systems is most highly stressed. Hydrothermally grown synthetic quartz crystals contain relatively large amounts of structurally bound water. In these crystals, a transition occurs from (0001), 〈1120〉 to dominantly pencil glide in the [0001] and possibly 〈1123〉 directions. The transition temperature is strongly dependent on the water content of the crystals, and coincides with the hydrolytic weakening temperature defined by Griggs and Blacic for these crystals. Inhomogeneous distribution of water in the synthetic crystals controls the distribution of plastic strain and may, in part, control the orientation of subbasal deformation lamellae in these. It is suggested that anisotropic diffusion of H-OH in quartz may be responsible for the operation of the [0001] pencil-glide system in the hydrolytic weakening regime. Crystal structure anisotropy may also play a role in the slip-system transition through its influence on the Peierls stress, and this is most likely the dominant factor in the dry crystals.
Sustained stimulation shifts the mechanism of endocytosis from dynamin-1-dependent rapid endocytosis to clathrin- and dynamin-2-mediated slow endocytosis in chromaffin cells

Transient stimulation of secretion in calf chromaffin cells is invariably followed by rapid endocytosis (RE), a clathrin- and K+-independent process with a half time of several seconds. Here we show that when exocytosis is triggered in a more sustained manner, a much slower form of endocytosis (SE) replaces RE. SE is complete within 10 min and is abolished when anticlathrin antibodies are introduced into the cell or when intracellular K+ is removed. RE, but not SE, is blocked by intracellular administration of antidynamin-1 antibodies; the inverse specificity was found for antidynamin-2 antibodies. Replacement of extracellular Ca2+ by Ba2+ or Sr2+ completely blocked RE but had little effect on SE. Thus chromaffin cells exhibit two kinetically and mechanistically distinct forms of endocytosis that are coupled to different extents of exocytosis and are mediated by different isoforms of dynamin. We surmise that RE is associated with the transient fusion (“kiss-and-run”) mechanism of transmitter release and is the prevalent means of vesicle recapture and recycling under normal physiological conditions, whereas the clathrin-based SE mechanism comes into play only at higher levels of stimulation and may be associated with complete fusion of vesicles with the plasma membrane.
Geochemical Evolution of a High Arsenic, Alkaline Pit-Lake in the Mother Lode Gold District, California

The Harvard orebody at the Jamestown gold mine, located along the Melones fault zone in the southern Mother Lode gold district, California, was mined in an open-pit operation from 1987 to 1994. Dewatering during mining produced a hydrologic cone of depression; recovery toward the premining ground-water configuration produced a monomictic pit lake with alkaline Ca-Mg-HCO3-SO4–type pit water, concentrations of As up to 1,200 μ g/L, and total dissolved solids (TDS) up to 2,000 mg/L. In this study, pit-wall rocks were mapped and chemically analyzed to provide a context for evaluating observed variability in the composition of the pit-lake waters in relationship to seasonal weather patterns. An integrated hydrogeochemical model of pit-lake evolution based on observations of pit-lake volume, water composition (samples collected between 1998–2000, 2004), and processes occurring on pit walls was developed in three stages using the computer code PHREEQC. Stage 1 takes account of seasonally variable water fluxes from precipitation, evaporation, springs, and ground water, as well as lake stratification and mixing processes. Stage 2 adds CO2 fluxes and wall-rock interactions, and stage 3 assesses the predictive capability of the model. Two major geologic units in fault contact comprise the pit walls. The hanging wall is composed of interlayered slate, metavolcanic and metavolcaniclastic rocks, and schists; the footwall rocks are chlorite-actinolite and talc-tremolite schists generated by metasomatism of greenschist-facies mafic and ultramafic igneous rocks. Alteration in the ore zone provides evidence for mineralizing fluids that introduced CO2, S, and K2O, and redistributed SiO2. Arsenian pyrite associated with the alteration weathers to produce goethite and jarosite on pit walls and in joints, as well as copiapite and hexahydrite efflorescences that accumulate on wall-rock faces during dry California summers. All of these pyrite weathering products incorporate arsenic at concentrations from <100 up to 1,200 ppm. In the pit lake, pH and TDS reach seasonal highs in the summer epilimnion; pH is lowest in the summer hypolimnion. Arsenic and bicarbonate covary in the hypolimnion, rising as stratification proceeds and declining during winter rains. The computational model suggests that water fluxes alone do not account for this seasonal variability. Loss of CO2 to the atmosphere, interaction with pit walls including washoff of efflorescent salts during the first flush and seasonal rainfall, and arsenic sorption appear to contribute to the observed pit-lake characteristics.
A survey for unknown diabetics in a mental hospital. I. Men under age fifty.

A 100 gm. two-hour oral glucose tolerance test was administered to an institutional group of 213 mentally ill men who were fifty to eighty-eight years old and without known diabetes. Thereafter, the test was selectively repeated. In thirty-two cases results were interpreted, in association with other data, as consistent with previously unknown, unsuspected diabetes — an incidence of 15 per cent. Discovery of this high incidence is attributed to universal employment of the glucose tolerance test. The influence of phenothiazine therapy on carbohydrate metabolism was partially examined with inconclusive results and requires further study.
Physicochemical Characteristics of Active and Arrested Carious Lesions of Dentin

SYNOPSIS IN INTERLINGUACHARACTERISTICAS PHYSIO-CHIMIC DE ACTIVE E ARRESTATE LESIONES CAEIOSE.—Le duo plus obvie differentias clinic inter dentinas a cariositate arrestate e active es le augmentos del duritate superficial e del pigmentation in le lesiones arrestate. Analyses per medio de un specialmente disveloppate technica a absorption infrarubie monstrava un augmento del contento organic e un declino del contento inorganic in dentina cariose, sed le methodo provideva nulle information relative al natura del pigmento in le dentina a cariositate arrestate. Analyses spectral a flamma revelava in dentina a cariositate arrestate in comparation con dentina a cariositate active un augmento de Ca++ per un factor de 1,64. Le mesme methodo monstrava que le dentina a cariositate arrestate habeva minus Ca++- que dentina normal.
ARTIFICIAL INTELLIGENCE AND EXPERT SYSTEMS RESEARCH AND THEIR POSSIBLE IMPACT ON INFORMATION SCIENCE EDUCATION

Applications from artificial intelligence and expert systems research will most likely be incorporated in future information services to improve decision making, to solve problems normally thought to require human intelligence, and to achieve levels of performance previously obtainable only by human experts. Expert systems are creating new methods of replicating and multiplying the value of human expertise while preserving this knowledge in computer storage. The successes achieved by these early systems have been modest, but they hold great promise, and they are attracting widespread interest. Information scientists are exploring potential applications of artificial intelligence as guidance for the development of new information services such as aids in formulating search requests, as general problem treatment schemes, and as expert systems for library management, cataloguing, and reference. The role of the library is changing, and schools need to modify their programmes to prepare students for new roles and new careers in information transfer.
Nondestructive Viscoelastic Analysis of Anisotropy in Compressed Tablets

A nondestructive procedure for determining anisotropy levels in compressed tablets was developed based on dynamic stress/strain measurements of viscoelasticity in the axial and radial directions. An instrument was designed and built capable of 10 nm resolution of strain and operating over the frequency range 1–64 Hz. Tablets of 11 pharmaceutical excipients and drugs, representing both plastic and brittle materials, were found to behave as three-parameter viscoelastic solids in both the axial and radial directions. Elastic and viscous parameters were computed, based on frequency dependence over the range studied, and were found to differ greatly in the axial and radial directions. Degrees of anisotropy, defined as the ratio of the uncoupled spring parameters in the radial vs the axial direction, were found to range from 2- to 12-fold over the materials studied. These levels of anisotropy are thought to be typical of tablets manufactured in a rotary press under normal conditions. Measurements of this type can be easily made routinely as a further means of quality control and reflect an important feature of the internal structure of compressed tablets.
African American Adolescents and Skin Color

This study examines skin color in the lives of African American adolescents and explores the relationship to self-esteem and dating relationships. Adolescents between the ages of 11 and 19 years were recruited through schools, churches, and informal networks. A questionnaire was developed by the researchers to explore the meaning of skin color in the lives of African American adolescents and its effect on self-esteem. Primary studyfindings were that (a) a relationship existed between satisfaction with skin color and self-esteem; (b) students self-reported as "lighter" or "darker" had lower levels of satisfaction with their skin color than did students whose skin color was classified as "somewhere in between"; (c) although the difference was nonsignificant, a greater proportion of men than women expresseda desirefor lighterskin; and (d) a gender difference was noted on the dating variable, "Skin color makes a difference to guys when they date girls." Implications of thefindings are discussed.
Perceived work and family conflict among African American nurses in college.

Purpose: This article describes the perceptions of African American nurses regarding the interaction between work—family conflict, job satisfaction, and psychological well-being. Design and methods: A qualitative descriptive design was employed to conduct six focus group sessions with 23 nurses at three universities in the southeastern United States. Findings: Stressors such as racism or lack of teamwork and supervisor support caused the nurses to contemplate leaving a workplace or the profession. Family stressors, such as an ill family member, also influenced any decision regarding career longevity. Implications: Future studies examining work—family interface, especially positive spillover and psychological well-being are warranted.
Caenorhabditis elegans Decapping Proteins: Localization and Functional Analysis of Dcp1, Dcp2, and DcpS during Embryogenesis

Though posttranscriptional regulation is important for early embryogenesis, little is understood regarding control of mRNA decay during development. Previous work defined two major pathways by which normal transcripts are degraded in eukaryotes. However it is not known which pathways are key in mRNA decay during early patterning or whether developmental transcripts are turned over via specific pathways. Here we show that Caenorhabditis elegans Dcp2 is localized to distinct foci during embryogenesis, reminiscent of P-bodies, the sites of mRNA degradation in yeast and mammals. However the decapping enzyme of the 3′ to 5′ transcript decay system (DcpS) localizes throughout the cytoplasm, suggesting this degradation pathway is not highly organized. In addition we find that Dcp2 is localized to P-granules, showing that Dcp2 is stored and/or active in these structures. However RNAi of these decapping enzymes has no obvious effect on embryogenesis. In contrast we find that nuclear cap binding proteins (CBP-20 and 80), eIF4G, and PAB-1 are absolutely required for development. Together our data provides further evidence that pathways of general mRNA metabolism can be remarkably organized during development, with two different decapping enzymes localized in distinct cytoplasmic domains.
The complex dynamics of stroke onset and progression.

PURPOSE OF REVIEW The aim of this article is to discuss the dynamic nature of cerebrovascular ischemia. RECENT FINDINGS Acute risk factors are superimposed on chronic risk factors to precipitate plaque rupture in myocardial infarction. The interaction between external triggers, such as stress, with internal triggers, such as vasoconstriction, is mediated to a large part by the autonomic nervous system. Numerous algorithms have been developed to describe physiological time-series data, for example heartbeat variability, and reveal complex structure that has diagnostic and prognostic significance. Much of this structure is mediated by the autonomic nervous system. Recent data on stroke triggers, carotid stenosis, transient ischemic attack, and infarct expansion suggest a similar need for detailed physiological measurement and non-linear dynamics in order to understand stroke onset and progression. SUMMARY The picture emerging is that stroke arises as a result of multiple processes with different time constants. The nature and timing of interventions should be tailored to these complex interacting processes. This will require more frequent and varied physiological measurement accompanied by non-linear analytical methods. This new approach, which stresses complex within-subject measurements, will likely make 'one size fits all' solutions to stroke care untenable.
Apparent Life-threatening Events (ALTEs) and the Role of Home Monitors

1. Linda Y. Fu, MD, MSc* 2. Rachel Y. Moon, MD† 1. *Assistant Professor of Pediatrics, Goldberg Center for Community Pediatric Health, Children's National Medical Center, Washington, DC 2. †Director, Academic Development, Goldberg Center for Community Pediatric Health, Children's National Medical Center, Washington, DC After completing this article, readers should be able to: 1. Recognize a child who has an apparent life-threatening event (ALTE). 2. Know the differential diagnosis of ALTE. 3. Discuss the appropriate management of ALTE. 4. Describe the role of home monitoring in the care of children who have ALTE. 5. List the limitations of home monitoring in following children who have ALTE. 6. Characterize the psychosocial issues surrounding the use of home monitors. A previously healthy 1-month-old boy who was born at term is brought to the emergency department by ambulance. His mother reports that he stopped breathing for 20 seconds and appeared limp and blue around his lips. Once she picked him up, he began to cry and breathe normally. On physical examination, the baby is well-perfused and in no apparent distress. The infant is admitted for observation and evaluation for an apparent life-threatening event (ALTE). The evaluation includes a complete blood count, urine culture, computed tomography scan of the head, cardiorespiratory monitoring, and pH probe. The pH probe results demonstrate significant gastroesophageal reflux; other findings are unremarkable. The child has no additional episodes after 48 hours in the hospital. After his mother is given information for basic life support courses and educated on sudden infant death syndrome (SIDS) prevention, the child is discharged on antireflux medications. He has no more concerning episodes . ALTE refers to a constellation of unexpected physiologic events in an infant that is witnessed by and distressing to a caregiver. In 1986, an expert panel sponsored by the National Institutes of Health developed the now widely accepted definition of ALTE as “an episode that is frightening to the observer and that is characterized by some combination of apnea (central or occasionally obstructive), color change (usually cyanotic or pallid but occasionally erythematous or plethoric), marked change in muscle tone (usually marked …
Heterogeneous functional Ty1 elements are abundant in the Saccharomyces cerevisiae genome

Despite the abundance of Ty1 RNA in Saccharomyces cerevisiae, Ty1 retrotransposition is a rare event. To determine whether transpositional dormancy is the result of defective Ty1 elements, functional and defective alleles of the retrotransposon in the yeast genome were quantitated. Genomic Ty1 elements were isolated by gap repair-mediated recombination of pGTy1-H3(delta 475-3944) HIS3, a multicopy plasmid containing a GAL1/Ty1-H3 fusion element lacking most of the gag domain (TYA) and the protease (PR) and integrase (IN) domains. Of 39 independent gap repaired pGTyHIS3 elements isolated, 29 (74%) transposed at high levels following galactose induction. The presence of restriction site polymorphisms within the gap repaired region of the 29 functional pGTyHIS3 elements indicated that they were derived from at least eight different genomic Ty1 elements and one Ty2 element. Of the 10 defective pGTyHIS3 elements, one was a partial gap repair event while the other nine were derived from at least six different genomic Ty1 elements. These results suggest that most genomic Ty1 elements encode functional TYA, PR and IN proteins. To understand how functional Ty1 elements are regulated, we tested the hypothesis that a TYB protein associates preferentially in cis with the RNA template that encodes it, thereby promoting transposition of its own element. A genomic Ty1 mhis3AI element containing either an in-frame insertion in PR or a deletion in TYB transposed at the same rate as a wild-type Ty1mhis3AI allele, indicating that TYB proteins act efficiently in trans. This result suggests in principle that defective genomic Ty1 elements could encode trans-acting repressors of transposition; however, expression of only one of the nine defective pGTy1 isolates had a negative effect on genomic Ty1 mhis3AI element transposition in trans, and this effect was modest. Therefore, the few defective Ty1 elements in the genome are not responsible for transpositional dormancy.
Successful treatment of oral lichen planus-like chronic graft-versus-host disease with topical tacrolimus: a case report.

Background: Bone marrow transplantation (BMT) is a common treatment used for deficiencies of host marrow or in the control of blood malignancies. Post-allogeneic BMT complications include graft-versus-host disease (GVHD). GVHD occurs when immunologically active T lymphocytes are transplanted into an immunosuppressed recipient who is genetically disparate from the donor. In this case report we describe the occurrence of oral lichen planus-like lesions as the first manifestation of chronic GVHD (c-GVHD) and the subsequent management of this disease with topical tacrolimus. Methods: Diagnostic aids included routine histology and direct immunofluorescence studies to rule out immunobullous diseases and to confirm the c-GVHD. Treatment consisted of topical application of 0.1% tacrolimus ointment three times a day. Results: Routine histology confirmed the clinical diagnosis of oral lichen planus-like c-GVHD. Treatment with tacrolimus ointment completely resolved the oral lesions after 2 months of therapy. Conclu...
Operators for Expensive Functions in Continuous Queries

Many analysis and monitoring applications require the repeated execution of expensive functions over streams of rapidly changing data. These applications appear in fields as varied as finance, supply chain management, and power utility monitoring.While many of these applications can be expressed declaratively, current continuous query processors are not designed to optimize queries with expensive user-defined functions. Such optimizations are hindered by "black box" function interfaces, where the operator has no control over the processing inside each invocation. We are currently developing VAOs (Variable Accuracy Operators), a new class of operators that allow the query processor to speed up individual function calls. VAOs use a new function interface that exposes the trade-off between work and accuracy inherent inmany functions. Using this new interface, VAOs can eliminate unneeded work by running each function call to only the accuracy needed by the query. VAOs play a key role in our larger research agenda of optimizing queries with expensive functions, and we briefly describe this larger agenda as well.
Adaptation of modulation and coding for fading channels based on a block demodulation algorithm

Mobile communication systems can benefit greatly from the use of adaptive signaling. Adaptive signaling can provide a higher data rate than fixed-rate signaling techniques while maintaining an acceptable bit error rate (BER). This paper explores the use of a block demodulation algorithm for providing the basis for adaptation in fading channels. The modulation parameters are adjusted based the receiver's implicit estimate of the reliability of the current block. An adaptation algorithm has been analyzed in which the receiver estimates the current fading rate, adjusts decision thresholds correspondingly and compares them to reliability information generated by the receiver. The adaptive algorithm has shown greatly improved performance compared to fixed-rate schemes over a wide range of channel parameters.
Non-specific effects of diphtheria–tetanus–pertussis vaccination on child mortality in Cebu, The Philippines

The objective was to determine the non-specific effects of diphtheria tetanus and pertussis (DTP) vaccination and sex on mortality before 30 months of age among those who received Bacille Calmette Guerin (BCG) vaccine in a high mortality area. This analysis used a longitudinal study of child survival monitoring the use of primary care services morbidity and mortality in Metro Cebu The Philippines. Participants included 14 537 children under 30 months of age who received a BCG vaccination from July 1988 to January 1991. The main outcome measure was all-cause mortality. Mortality before 30 months of age was 57% lower among BCG-vaccinated children who received DTP vaccination than BCG-vaccinated children who did not receive DTP vaccination {hazard ratio (HR) for vaccinated vs unvaccinated 0.43 [95% confidence interval (CI) 0.21-0.88]}. Females had lower mortality rates [HR=0.19 (0.04-0.86) P=0.03] than males among DTP-unvaccinated children. The protective effect of DTP vaccination was more pronounced in males [HR 0.32 (0.14-0.73)] than in females [HR 0.86 (0.18-4.23)]. DTP vaccination increased (interaction term P=0.08) the female-to-male mortality ratio to 0.76 (0.52-1.12). Among BCG-vaccinated children under 30 months of age DTP vaccination is associated with improved survival. The increased female-male mortality ratio is associated with reduced mortality among males following DTP vaccination rather than increased mortality among female children. (authors)
Photoacoustic optical properties at UV, VIS, and near IR wavelengths for laboratory generated and winter time ambient urban aerosols

Abstract. We present the laboratory and ambient photoacoustic (PA) measurement of aerosol light absorption coefficients at ultraviolet wavelength (i.e., 355 nm) and compare with measurements at 405, 532, 870, and 1047 nm. Simultaneous measurements of aerosol light scattering coefficients were achieved by the integrating reciprocal nephelometer within the PA's acoustic resonator. Absorption and scattering measurements were carried out for various laboratory-generated aerosols, including salt, incense, and kerosene soot to evaluate the instrument calibration and gain insight on the spectral dependence of aerosol light absorption and scattering. Ambient measurements were obtained in Reno, Nevada, between 18 December 2009 and 18 January 2010. The measurement period included days with and without strong ground level temperature inversions, corresponding to highly polluted (freshly emitted aerosols) and relatively clean (aged aerosols) conditions. Particulate matter (PM) concentrations were measured and analyzed with other tracers of traffic emissions. The temperature inversion episodes caused very high concentration of PM2.5 and PM10 (particulate matter with aerodynamic diameters less than 2.5 μm and 10 μm, respectively) and gaseous pollutants: carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NO2). The diurnal change of absorption and scattering coefficients during the polluted (inversion) days increased approximately by a factor of two for all wavelengths compared to the clean days. The spectral variation in aerosol absorption coefficients indicated a significant amount of absorbing aerosol from traffic emissions and residential wood burning. The analysis of single scattering albedo (SSA), Angstrom exponent of absorption (AEA), and Angstrom exponent of scattering (AES) for clean and polluted days provides evidences that the aerosol aging and coating process is suppressed by strong temperature inversion under cloudy conditions. In general, measured UV absorption coefficients were found to be much larger for biomass burning aerosol than for typical ambient aerosols.
PPARδ-mediated macrophage activation: a matter of fat

Chronic inflammation is increasingly recognized as an underlying factor in the development of several pathological disorders including obesity-associated metabolic disease, heart disease, atherosclerosis and rheumatoid arthritis. Macrophages, which are key sentinels of the innate immune system, play
The battered apple: An application of stressor-emotion-control/support theory to teachers’ experience of violence and bullying

This study looked at factors that moderate responses to violence, bullying, and other stressors among public school teachers in the US. Grounded in stressor-emotion-control/ support (SEC/S) theory, the study emphasized the relevance of specific forms of control and support to specific stressors in analyzing moderation effects. A total of 779 teachers completed an online survey of their perceptions of their work environments. Pervasive bullying and violent acts were associated with strains in zero-order correlations, but when regressed, pervasive bullying rather than violence was associated with strains. Relations between violent acts and strains were moderated by satisfaction with the administrations’ handling of violent acts.This has important implications for the development of public and educational policy. Finally, co-worker social support interacted with supervisory/principal bullying, but, contrary to expectations, showed a reverse buffering effect.
Incidence of surgically treated uveal melanoma by race and ethnicity.

Abstract Objective The purpose of the study was to determine the race- and ethnicity-specific incidence of histologically confirmed uveal melanoma. Design The study design was a retrospective study of histologically confirmed cases of primary uveal melanoma submitted to the Florida Cancer Data System (FCDS). Main outcome measures Race-, gender-, and Hispanic-specific incidence rates of uveal melanoma were measured. Calculations are based on Florida census data and Hispanic population estimates from the University of Florida Bureau of Economic and Business Research. Results From 1981 through 1993, 873 histologically confirmed uveal melanomas were reported to the FCDS. Four melanomas occurred in black non-Hispanics, 47 in white Hispanics, and none in black Hispanics. The relative risk of uveal melanoma for blacks compared to non-Hispanic whites was 0.03 (95% confidence interval, 0.01–0.08). Non-Hispanic white men had 72 times the risk of uveal melanoma compared to black men; non-Hispanic white women experienced a 22-fold risk compared to black women. White Hispanics were less likely to develop uveal melanoma than white non-Hispanics (relative risk, 0.36; 95% confidence interval, 0.27–0.48). Conclusion The risk of uveal melanoma in blacks is exceptionally low. The reason for lower risk of uveal melanoma in white Hispanics than in white non-Hispanics is not known but could be related to the protective effects associated with dark skin pigmentation or may be because of unknown cultural-environmental exposures or socioeconomic factors.
WireLisp: combining graphics and procedures in a circuit specification language

WireLisp is a language that incorporates both procedural and graphic constructs for describing the structure of complex circuits. This combination provides both the clarity of a graphic representation and the expressiveness of a procedural description. A description is given of how this is done in a conceptually simple way be representing procedural information graphically. WireLisp is built on Lisp which allows the designer to extend the language with arbitrary functions. WireLisp can be used to generate a variety of different target output descriptions, and allows the incorporation of other kinds of descriptions such as behavioral and physical descriptions. WireLisp is implemented in T Lisp and has been used to describe complex (130000 transistor) VLSI chip design. >
Negation and the left periphery in Finnish

This paper investigates the effects of negation and contrast on Finnish word order. It is well known that prosodically focused, contrastive constituents only occur in certain syntactic positions in Finnish. However, many of these patterns are reversed in negative sentences when negation is preposed from its canonical post-subject position to a sentence-initial location. Corpus examples show that preposed negation is used to negate propositions which are old/known information to the discourse participants. I present a detailed analysis of the structure of the Finnish left periphery which makes use of this information-structural property in order to account for the seemingly surprising changes concerning the positions where contrastive constituents can occur.
The miracle of vaccination

SUMMARY Among all medical procedures, vaccination ranks at the forefront in lives saved and disabling illnesses prevented. Jenner's first experiments with vaccination, 200 years ago, culminated in the eradication of smallpox at the conclusion of a ten-year World Health Organization programme begun in 1967. Two million lives were saved each year and tens of thousand of blindness cases. In 1974, the smallpox campaign was expanded to include six additional vaccines (poliomyelitis, measles, diphtheria, tetanus, pertussis and tuberculosis). By 1990, global vaccination coverage had risen from less than 5% to 80%; poliomyelitis was eradicated from the Americas; and a global eradication campaign was launched. Prospects for more dramatic achievements are bright. Research and development in new vaccines is gaining momentum. More than 150 new vaccines are now in human testing and vaccines against such as malaria, dengue fever and AIDS can be foreseen. Challenges remain in assuring adequate research funds for diseases of the developing world and in supplying needed quantities of assured, high quality vaccines. However, the threat of new and emerging infections and the fact that vaccines are the front line of defense reinforce the need for further strengthening of vaccine research, development and production.