cssi/SciSciGPT-SciSciNet huggingface dataset:
Loss mechanism analysis in single-crystal and polycrystalline silicon MIS solar cells to produce 13% efficiency

Abstract Current mechanism studies have revealed band-to-band tunneling and surface state currents to control chromium MIS solar cell behavior. This information, together with intrinsic and design-related loss analysis, was used to optimize the design of the chromium MIS solar cell. It is shown that a high efficiency can be produced when the interface and grain boundary state densities are below 10 12 cm −2 eV −1 , the interface oxide thickness is 12 – 18 A, the grain size is above 40 μm and the doping density is 10 16 – 10 17 cm −3 . This computer-aided design was used to fabricate a 13.2% experimental solar cell in agreement with the predicted performance.
The structure and chemistry of the TiO(2)-rich surface of SrTiO(3) (001).

Oxide surfaces are important for applications in catalysis and thin film growth. An important frontier in solid-state inorganic chemistry is the prediction of the surface structure of an oxide. Comparatively little is known about atomic arrangements at oxide surfaces at present, and there has been considerable discussion concerning the forces that control such arrangements. For instance, one model suggests that the dominant factor is a reduction of Coulomb forces1; another favours minimization of ‘dangling bonds’ by charge transfer to states below the Fermi energy2. The surface structure and properties of SrTiO3—a standard model for oxides with a perovskite structure—have been studied extensively3,4,5,6,7,8,9,10,11,12,13,14. Here we report a solution of the 2 × 1 SrTiO3 (001) surface structure obtained through a combination of high-resolution electron microscopy and theoretical direct methods. Our results indicate that surface rearrangement of TiO6-x units into edge-sharing blocks determines the SrO-deficient surface structure of SrTiO3. We suggest that this structural concept can be extended to perovskite surfaces in general.
The future of superconducting technology

Abstract As soon as cryogenic engineering problems are convincingly solved, superconducting technology is destined to play a vital role in mining, pollution control, medicine, power generation and transmission, and metallurgy.
Effect of echocardiography on clinical impact and patient outcome in hypertension.

Echocardiography in research. As a research tool, echocardiography has been importantin defining the prevalence and magnitude of the cardiac effects of hypertension. 18 Moreover, it has established its value in determining the effects of antihypertensive therapy on left ventricular (LV) mass, LV hypertrophy (LVH), and LV function. 9~13 Additionally, echocardiographic studies Of normotensive subjects have provided" fundamental insights into the relationship between genetic susceptibility, blood pressure, and LVH. 14"~s Echocardiography for cardiac hypertensive and comorbid disease. Cardiac abnormality in patients with hypertension is often an expression of the interaction of direct effects of hypertension on the heart with coronary heart disease, which in itself may be accelerated by elevated blood pressure. In addition to the presence of comorbid coronary artery disease (CAD), elderly hypertensive patients are prone to degenerative aortic and mitral valve disease. Hence, in hypertension, echocardiography might bc expected to bc a clinically vibrant diagnostic tool with a rich yield of cardiac abnormality related to hypertensive heart disease, as well as comorbid coronary and valvular disease. Impact versus outcome. Because hypertension, present in at least 20 million Americans, is arguably the most common disorder affecting the heart, it is reasonable to consider the impact of cchocardiography on physicians' diagnostic and therapeutic behavior. More important, it is appropriate to determine if echocardiography alters physician behavior in such a way as to affect the clinical outcome of patient care. Moreover, in the current health care climate, with its growing demand for justification of expenditures,
Ecdysteroid activity during oögenesis in the black blowfly, Phormia regina (Meigen)

Abstract Haemolymph and ovarian ecdysteroid titres were measured, using a radioimmunoassay, for adult Phormia regina in relation to their first gonotrophic cycle. Immediately after adult emergence there was about 5.5 pg of ecdysteroids in each microlitre of haemolymph. This amount declined to non-detectable levels at 24 h after eclosion and remained non-detectable if flies were fed only sugar and water. Haemolymph ecdysteroid titre increased rapidly after a replete meal of liver (provided at 72 h after eclosion) and reached a maximum of 27.3 pg/μl, 32 h after the liver meal (i.e. 104 h after eclosion). In ovariectomized, liver-fed females, the haemolymph ecdysteroid titre was greatly reduced but was maintained at detectable levels indicating that the ovaries are the major, but not the only, source of dietary-induced ecdysteroids. A very small quantity of vitellogenin was also detected in the haemolymph of ovariectomized females after they fed on liver, indicating that ecdysteroids from extra-ovarian sources could initiate the synthesis of vitellogenin. If flies were treated with precocene II (20 μg/fly) at
Factor Structure of the DIAL-3: A Test of the Theory-Driven Conceptualization versus an Empirically Driven Conceptualization in a Nationally Representative Sample.

Using data from the standardization sample of the Developmental Indicators for the Assessment of Learning—Third Edition (DIAL-3), this study compared the usefulness of an empirically derived factor structure introduced by Anthony, Assel, and Williams with the author's theoretical conceptualization. Confirmatory factor analyses (CFAs) were conducted on three age groups of children (i.e., 831 3- and 4-year-olds, 729 5- and 6-year-olds, and 1,560 3- to 6-year-olds). Both models explained the younger group of children's performances reasonably well (e.g., Comparative Fit Indices [CFIs] = .93) and yielded equivalent standardized fits. The two models explained the older children's performances reasonably well (e.g., CFIs = .93), and their fits were also equivalent. Finally, the two models characterized performances of the standardization sample quite well (e.g., CFIs = .96), and their fits were also equivalent. Results are discussed in terms of how assessments are standardized and validated and how this is rele...
Microscopic Theory of Rabi Flopping, Photon Echo, and Resonant Pulse Propagation in Semiconductors

The phenomena of Rabi oscillations, resonant pulse propagation, and photon echo in semiconductors are investigated by numerically solving the full semiconductor Bloch equations for the example of bulk CdSe. The calculations are done for resonant femtosecond excitation at the exciton resonance. The many-body modifications of Rabi Dopping and semicooductor photon echo are discussed for a thin medium, whereas the propagation of weak and strong pulses is 'analyzed for an extended material. Rabi Dopping of the density can lead to field reamplification and thus to long propagation distances of sufficiently strong pulses and to pulse break-up
1732 RESPIRATORY DYSRHYTHMIA: A NEW CAUSE OF CENTRAL ALVEOLAR HYPOVENTILATION (CAH)

Normal mammalian breathing is characterized by the rhythmic, alternating activation of inspiratory and expiratory muscles. In previously described patients with CAH, neural output to respiratory muscles during sleep has been characterized by an inadequate rate or depth of breathing. In the present case, CAH appeared to result from a disorganization of neural output to inspiratory and expiratory muscles. SB was a normal infant until he developed aseptic meningitis at age five months. Persistent brainstem dysfunction at 16 months was indicated by inability to suck and swallow, diminished gag reflex and CAH requiring continuous mechanical ventilation. Polygraphic recordings during sleep demonstrated severe central hypoventilation (PACO2 > 76mmHg), writhing truncal movements, and marked though disorganized respiratory muscle activation with a tonic or right-left pattern rather than the normal inspiratory-expiratory phase switching. Marked respiratory muscle electromyographic activity indicated quantitatively adequate central neural output. Fluoroscopy confirmed dyssynchronous diaphragmatic movements; only rarely did the right and left hemidiaphragms contract simultaneously. Phrenic nerve stimulation ruled out diaphragmatic paralysis. We conclude that injury to the brainstem respiratory pattern generator can result in CAH when normal inspiratory-expiratory switching mechanisms are damaged.
The influence of active electrode placement on CMAP amplitude

The compound muscle action potential (CMAP) is a measure of the number of axons in a nerve. Placement of the active recording electrode over the motor point of a muscle is thought to give the maximal response, but there is considerable variation in amplitude among initially negative CMAP wave forms. Ten examiners of varied training backgrounds and experience placed the active electrode as they usually do over the thenar, hypothenar, abductor hallucis, and extensor digitorum brevis muscles in the same normal subject. There was variability of the CMAP amplitude recorded over each muscle; the lowest value recorded from a muscle was 57% of the maximum value, and the lowest median value was 77%. There was no relation between examiner background or level of training and recording the maximal response. Higher amplitude CMAPs were associated with steeper wave form slopes, but the range of correlations between amplitude and slope was 0.42 to 0.92. We conclude that when it is important to record the maximal CMAP response, empirical assessment by moving the active electrode is necessary.
Dire and Sequestered Meetings: The Work of Game Wardens

Game wardens are law enforcement agents responsible for enforcing fish and wildlife laws. Based on data from extensive interviews with game wardens the authors describe dangerous situations faced by wardens in their work. Comparisons with the dangers experienced by other types of police officers are made. Temporal, spatial, and situational factors shape the uniqueness of the law enforcement experiences of the game warden. Specific factors found which increase dangerousness were: isolation of area, being outnumbered, being alone, mistakes like not wearing hunter’s orange, and not being aware an offender is under the influence. In addition, most if not all individuals encountered are armed and skilled in the use of deadly weapons.
Impingement Cooling in Rotating Two-Pass Rectangular Channels with Ribbed Walls

Impingementcooling wasstudiedonribbed wallsinrotatingtwo-passrectangularchannelswith asharp 180-deg turn. Two rows of circular jets impinged opposite to the direction of rotation in one channel and in the same direction of rotation in the other channel. Square cross-sectioned ribs were periodically attached to the target walls and inclined at a 45-deg angle to the direction of spent aire ow. Rib pitch to height and rib height to channel hydraulicdiameterratiosweree xed at10 and0.125,respectively. Afterimpingement,spent air (crosseow)traveled radially outward and inward in the e rst and the second impingement channel, respectively. Jet Reynolds numbers and rotation numbers varied from 4 £ 10 3 to 1 £ 10 4 and 0 to 0.0133, respectively. As the jet Reynolds number increased from 4 ££ 10 3 to 1 £ 10 4 , the ratios of channel-averaged ribbed to smooth surface Nusselt numbers increased from 13 to 47% for the nonrotating test. For the rotating test, however, these ratios changed from 9 to 44% as the jet Reynolds number increased. Rotation-induced Coriolis and centrifugal forces altered the pressure distribution, but the jet velocity distribution was not signie cantly affected. However, those rotation-induced forces decreased the Nusselt number values up to 20% in the ribbed impingement channels.
Changes in long bone diaphyseal strength with horticultural intensification in west-central Illinois.

This study examines changes in long bone diaphyseal strength in west-central Illinois from the Middle Woodland through the Mississippian periods. Significant differences occur between the Middle Woodland and the Late Woodland periods, at the time when use of native seed crops intensifies. In females, both humeral and femoral strength increases, which may be related to their role in growing and processing these crops. In males, right arm strength declines, which may be tied in part to the replacement of the atlatl by the bow. Fewer significant changes occur between the earlier and later Late Woodland periods, at the time when maize is introduced as a dietary staple, possibly because maize is at first grown as only one of a series of other starchy seeds. Finally, in the Mississippian period, when maize use intensifies, female left arm strength declines. This may be because maize is easier to process than native seeds, or it may reflect innovations in processing technology in the Mississippian period. External dimensions and shape indices, in part, reflect the trends seen in biomechanical strength. Comparisons are made to similar studies in other regions.
Beta tricalcium phosphate: observation of use in 100 posterolateral lumbar instrumented fusions

Abstract Background Beta tricalcium phosphate (B-TCP) is increasingly used to supplement lamina autograft to perform posterolateral lumbar-instrumented arthrodesis. Purpose To determine the radiographic arthrodesis and pseudarthrosis rates after multisegment lumbar laminectomies and one- or two-segment posterolateral instrumented fusion using lamina autograft and an artificial bone graft expander B-TCP (Vitoss; Orthovita, Malvern, PA, USA). Study design/setting To document radiographic arthrodesis/pseudarthrosis rates using lamina autograft and B-TCP. Patient sample One hundred patients with lumbar spinal stenosis underwent multisegment laminectomies (average 3.6 segments) and one- (78 patients) or two- (22 patients) segment posterolateral instrumented arthrodesis. Outcome measures Two-year postoperative outcomes were assessed using Short-Form 36 questionnaires. Methods The arthrodesis mass consisted of lamina autograft and B-TCP. Two independent neuroradiologists, using both dynamic X-rays and 2D-CT studies performed 3, 4.5, 6, and up to 12 months postoperatively, documented radiographic arthrodesis progression. Results One-segment arthrodesis was performed in 79 patients; 74 (93.7%) were radiographically fused “early” (6.5 postoperative months), 2 (2.5%) fused “late” (6.5–12 months), and 3 (3.8%) exhibited pseudarthrosis. Two-segment arthrodesis was performed in 21 patients; 14 (66.7%) radiographically fused “early,” 5 (23.8%) fused “late,” and 2 (9.5%) exhibited pseudarthrosis. Although chi-square analyses revealed a significant increase in the number of “late” radiographic fusions occurring for patients undergoing two-level arthrodesis, no significant difference in radiographic pseudarthrosis rates was noted between the two patient populations. In both groups, Short-Form 36 questionnaires revealed nearly comparable maximal improvement on seven of eight Health Scales by the second postoperative year. Conclusions At 6.5 months after multisegment lumbar laminectomies with posterolateral instrumented lumbar arthrodesis using lamina autograft/B-TCP, more one-segment (93.7%) versus two-segment (66.7%) radiographic arthrodesis occurred. By 1 year after operation, there was no significant difference in fusion rates between one- and two-segment radiographic arthrodeses.
Elevated complement C5a receptor expression on neurons and glia in astrocyte-targeted interleukin-3 transgenic mice

Evidence from several central nervous system (CNS) inflammatory disease models suggests that intrathecal complement synthesis may contribute to early inflammatory events in the brain. In this study, we examined the expression of the receptor for C5a (C5aR), a potent inflammatory and chemotactic factor, in the brains of transgenic mice with constitutive astrocyte expression of interleukin-3 (IL-3), a hematopoietic and immunomodulatory cytokine. By in situ hybridization, we demonstrated that cells infiltrating the cerebellar meninges, the cerebellum, and demyelinating lesions in the cerebellum were strongly positive for C5aR mRNA. By immunohistochemistry, the infiltrating cells expressing the C5aR were identified as macrophages based on staining with antibodies to the complement receptor type 3 and F4/80, a mouse macrophage-specific marker. In addition, some of the cells in cerebellar lesions were positive for the astrocyte-specific marker, glial fibrillary acidic protein, suggesting that a subpopulation of astrocytes in these lesions express elevated levels of the C5aR. Increased C5aR expression was also observed in cortical neurons in the occipital cortex and in pyramidal neurons in the cornu ammonis and subiculum of the hippocampus, at both the protein and mRNA levels. These data suggest that IL-3 may play an immunomodulatory role in C5aR expression on several cell types in the brain and that increased C5aR expression correlates with the pathology seen in this model. The transgenic mice used in this study provide a useful tool for characterizing the mechanism of regulation of the C5aR expression and for examining the functions of this chemotactic receptor in CNS inflammation.
Optimizing the salt-induced activation of enzymes in organic solvents: effects of lyophilization time and water content.

The addition of simple inorganic salts to aqueous enzyme solutions prior to lyophilization results in a dramatic activation of the dried powder in organic media relative to enzyme with no added salt. Activation of both the serine protease subtilisin Carlsberg and lipase from Mucor javanicus resulting from lyophilization in the presence of KCl was highly sensitive to the lyophilization time and water content of the sample. Specifically, for a preparation containing 98% (w/w) KCl, 1% (w/w) phosphate buffer, and 1% (w/w) enzyme, varying the lyophilization time showed a direct correlation between water content and activity up to an optimum, beyond which the activity decreased with increasing lyophilization time. The catalytic efficiency in hexane varied as much as 13-fold for subtilisin Carlsberg and 11-fold for lipase depending on the lyophilization time. This dependence was apparently a consequence of including the salt, as a similar result was not observed for the enzyme freeze-dried without KCl. In the case of subtilisin Carlsberg, the salt-induced optimum value of kcat/Km for transesterification in hexane was over 20,000-fold higher than that for salt-free enzyme, a substantial improvement over the previously reported enhancement of 3750-fold (Khmelnitsky, 1994). As was found previously for pure enzyme, the salt-activated enzyme exhibited greatest activity when lyophilized from a solution of pH equal to the pH for optimal activity in water. The active-site content of the lyophilized enzyme samples also depended upon lyophilization time and inclusion of salt, with opposite trends in this dependence observed for the solvents hexane and tetrahydrofuran. Finally, substrate selectivity experiments suggested that mechanism(s) other than selective partitioning of substrate into the enzyme-salt matrix are responsible for salt-induced activation of enzymes in organic solvents.
The evaluation of matrix elements in the analysis of anharmonic molecular vibrations: Optimized expansions and quadratures

This article presents methods for computing matrix elements with Cartesian Gaussian wave functions of potential energy operators that depend on functions of the form (r−r0)n exp[−a(r − r0)] as well as matrix elements of the class of polynomial many-body potentials developed by Murrell et al. The matrix elements arise in the analyses of anharmonic vibrations in molecules. © 1995 John Wiley & Sons, Inc.
Efficient pseudopotentials for plane-wave calculations. II. Operators for fast iterative diagonalization

We present an investigation of the computational requirements for the pseudopotential plane-wave method as a function of the number of atoms per unit cell. For systems containing a large number of atoms the computational load can be reduced if the pseudopotential operator is of a suitable form, such that it can be efficiently calculated in the position representation. The pseudopotentials examined here include local pseudopotentials, position-dependent electron-mass pseudopotentials, and separable nonlocal pseudopotentials.
A rare case of vulvar endometriosis in an adolescent girl.

Objective To describe a case of vulvar endometriosis in a teenager after a history of vulvar ulcers in the same location. Design Case report. Setting University medical center. Patient(s) A 13-year-old girl with a history of vulvar ulcers. Main Outcome Measure(s) None Result(s) A 13-yr-old female presented with painful, open vulvar ulcerations on the inner side of her labia minora. Biopsy revealed dermatitis with ulceration. One year later she noted an ulcer and blood in her undergarments. Biopsy results were consistent with endometriosis. Five years later, the lesions persisted and bled during menses. A bilateral labial excision was performed. Pathology again revealed endometriosis. Conclusion(s) Vulvar endometriosis is extremely unusual. This rare case of vulvar endometriosis in the same location as a previous vulvar ulcer is most likely due to ectopic transplantation of endometrial cells during a menstrual cycle. Excision is considered definitive treatment.
Role of Tissue Factor in Atherothrombosis

Tissue factor (TF) is abundantly present in atherosclerotic plaques and it is the primary source of TF that triggers the rapid activation of the coagulation cascade after plaque rupture. While much of this TF is associated with monocyte/macrophages and vascular smooth muscle cells, recent studies suggests TF-positive microparticles (MPs) are the most abundant source in plaques. Further, while intravascular TF is largely absent in healthy patients, cardiovascular disease patients have increased TF expression in circulating monocytes, which can result in increased levels of TF-positive MPs. This brief review describes how TF is the primary initiator of atherothrombosis and how TF-positive MPs may serve as a biomarker to identify patients at greater risk of forming an occlusive thrombus. In addition, currently used therapeutics, such as statins and inhibitors of the renin angiotensin system, may have additional benefits by reducing TF expression and subsequent thrombosis.
“…Death and Taxes.”. and CD‐ROMs?

Will CD‐ROM technology radically change the way libraries do business or is the CD reader just another peripheral? It depends on whether this new technology finally delivers satisfactory solutions to the information needs of libraries and their users. From the Library of Congress to Sardinia, OH (see p. 16), compact discs are becoming another tool to enable librarians to do more for their users and to do it more effectively and at a cost savings.
Optical Detection of Spectral Diffusion of the Triplet State Zerofield Transition Energy

Abstract Pulsed EEDOR experiments using optical detection have been developed and utilized to study spectral diffusion within the inhomogeneously broadened zerofield spin transition of a photoexcited triplet molecule. Two distinct spectral diffusion processes have been observed. One is very fast and is the source of the rapid loss of spin coherence previously observed in spin echo experiments of photoexcited triplet molecules. This rapid spectral diffusion seems to be limited to a narrow range of frequencies within the inhomogeneous profile of the spin transition. The second phase is considerably slower. but can sample a greater range of frequencies within the inhomogeneous profile. This second spin diffusion process determines the minimum hole width which can be observed in a steady state EEDOR experiment.
Blockade of Rapid Axonal Transport: Effect of Intraocular Pressure Elevation in Primate Optic Nerve

• After acute intraocular pressure (IOP) elevation, an induced disturbance of rapid axonal transport at the optic nerve head began within three hours at the IOP levels tested. The accumulation of radioactive label at the scleral lamina cribrosa increased with time of IOP elevation. There was a 60% decrease in the amount of transported material in the optic nerve, tract, and lateral geniculate body (LGN). Detailed analysis suggests that this decrease is not due to a simple slowdown of transport, but results from a total block of rapid transport in some axons, with no impairment in other axons. This total blockade of rapid transport by elevated IOP in involved axons differs from the apparent slowdown of transport in experimental papilledema, and the difference may explain the response of ganglion cells to the two conditions.
How Does Self-Complexity of Identity Moderate the Relationship between Strain and Crime?

Studies are inconclusive as to which characteristics exacerbate or inhibit criminal reactions to strain. This study examines how self-complexity of identity conditions the relationship between strain and crime. Those who are lower in self-complexity, or those with few overlapping identities, should be more likely to respond to strain with crime than those who are higher in self-complexity. This proposition was tested through analyzing a cross-sectional survey of 357 undergraduates at a Southeastern university. Strong support was found for the conditioning effect of self-complexity on serious crime while partial support was found for this effect on property crime.
The Fermi beam solution generalized to oblique incidence

Abstract We consider the time-independent, monoenergetic searchlight problem for a purely scattering, homogeneous slab of finite thickness. This problem corresponds to a pencil beam of radiation impinging upon one surface of a source-free slab at an arbitrary oblique angle of incidence. The scattering process is assumed sufficiently peaked in the forward direction so that the Fokker-Planck differential scattering operator can be used. Further, the slab is assumed sufficiently thin so that radiation backscattering is negligibly small. Under these assumptions, we obtain the full three-dimensional solution for the angular flux of radiation. This solution is a generalization of the classic Fermi solution, obtained in the special case of perpendicular beam incidence.
The equivalence principle

Abstract The experimental basis of the equivalence principle is reviewed, and the implications for the gravitational interactions of elementary particles are studied within a special relativistic framework. The gravitational red shift is treated in detail and is used to show that antiparticles also obey the equivalence principle. The profound consequences of a violation of the equivalence principle are discussed.
Oxygen impurity in the Chevrel-phase SnMo6S8

Abstract The occurrence of intrinsic defects in Sn and PbMo6S8 has previously been proposed to explain the variation in stoichiometry, lattice constants, superconducting transition temperature and upper critical fields observed by various investigators. We have found that the incorporation of oxygen in SnMo6S8 leads to a decrease in Tc and the c/a (hexagonal lattice constants) ratio. The variation in these two parameters, which we can produce only by the addition of oxygen, covers the entire range of values reported in the literature. We conclude that there is no large intrinsic defect population. The sample-to-sample variation in the superconducting properties of this material is due to the inadvertent incorporation of varying amounts of oxygen.
MIMO throughput optimisation via quantised rate control

The problem of throughput maximisation in a wireless multiple-input multiple-output (MIMO) system using a quantised feedback, which is an appropriate model for practical systems with limited feedback capacity, is considered. Unlike the ergodic capacity that can be achieved through power control only, maximising the throughput in the block fading channels is based on appropriate rate control strategy. The optimal quantised rate control design for general MIMO systems is formulated and a gradient descent search algorithm to find the optimal solution is employed. It is seen that the proposed quantised rate control scheme with only a few bits of feedback considerably improves the throughput of a MIMO system. With the same amount of feedback overhead, the proposed quantised rate control with constant power is compared with the optimal quantised power control strategy with an optimised constant rate, and the result demonstrates the importance of rate control in throughput maximisation. The effect of quantised rate control in MIMO systems employing different automatic repeat request schemes is also investigated.
Application of Lamb Waves for Evaluation of Lap-Shear Adhesive Joints

Methods for nondestructive evaluation of adhesive joints have been extensively discussed in the literature because of the technological importance of the problem and the extreme difficulty of evaluation of interphasial properties [1]. Several methods have been proposed for adhesive joint interphase evaluation: ultilization of interphase [2,3] or guided [4–8] waves in the bonded plates or use of obliquely incident ultrasonic waves analyzing signals in the time or frequency domains [9–14]. Most of the above studies (except [5]) have evaluated the adhesive bond in bonded areas away from the sample edges. Even when the configuration of the experimental samples included the edges [2–7] wave scattering and transformation on the edges was neglected. The edge effect and the transformation of Lamb waves at the edges are the main topics of this work. Some preliminary results in this direction were reported in our previous work [5].
Decaying states of perturbed wave equations

Abstract We study the solutions of perturbed wave equations that represent free wave motion outside some ball. When there are no trapped rays, it is shown that every solution whose total energy decays to zero must be smooth. This extends results of Rauch to the even-dimensional case and to systems having more than one sound speed. In these results, obstacles are not considered. We show that, even allowing obstacles, waves with compact spatial support cannot decay, assuming a unique continuation hypothesis. An example with obstacle is given where nonsmooth, compactly supported, decaying waves exist.
Collection and organization of written information by social scientists and humanists: a review and exploratory study

The literature on the information needs and uses of social scientists and humanists tends to ignore the stage of research in which the scholar collects and organizes written informa tion, i.e., the period between locating information and using it. This article reviews literature on information storage in the humanities and social sciences and describes an exploratory study of the content and organization of personal files. In the study, thirty-six professors in a major private university were each interviewed twice during a five month period. During the interview sessions, the scholars were asked to describe the way in which they organize their files. In addition, certain measure ments were taken in their offices: the linear feet of books, journals and other printed material on shelves; the number of filing drawers maintained; and the number of stacks of printed material on surfaces within the office. The findings are de scribed and discussed in the light of previous research. Finally, the article identif...
Parity violation and flavor selection rules in charmed-baryon decays.

The Cabibbo-allowed two body nonleptonic decays of charmed baryons are studied. The kinematics of the vector-meson final state is worked out and flavor-SU(3) and nonet selection rules for all the amplitudes are given. A simple dynamical model is used to predict asymmetries and branching ratios for the decay modes ${\ensuremath{\Lambda}}_{c}^{+}\ensuremath{\rightarrow}\ensuremath{\Lambda}_{\ensuremath{\rho}}^{}{}_{}{}^{+}$ and ${\ensuremath{\Lambda}}_{c}^{+}\ensuremath{\rightarrow}p{\overline{K}}^{*0}$.
A new way to start: nanoRNA-mediated priming of transcription initiation

A recent study provides evidence that RNA polymerase uses 2- to ~4-nt RNAs, species termed “nanoRNAs,” to prime transcription initiation in Escherichia coli. Priming of transcription initiation with nanoRNAs represents a previously undocumented component of transcription start site selection and gene expression.
Partners in a community of learners: Student and academic affairs at small colleges

The successful small college dean of students must develop and maintain an effective partnership between student and academic affairs, built on a shared educational philosophy, a mutual commitment to collaboration, and common linking issues and tasks.
Resonant cavity enhancement of polycrystalline PbTe films for IR detectors on Si-ROICs

In this paper, we demonstrate high optical quantum efficiency (90%) resonant-cavity-enhanced mid-infrared photodetectors fabricated monolithically on a silicon platform. High quality photoconductive polycrystalline PbTe film is thermally evaporated, oxygen-sensitized at room temperature and acts as the infrared absorber. The cavity-enhanced detector operates in the critical coupling regime and shows a peak responsivity of 100 V/W at the resonant wavelength of 3.5 μm, 13.4 times higher compared to blanket PbTe film of the same thickness. Detectivity as high as 0.72 × 109cmHz1/2W1 has been measured, comparable with commercial polycrystalline mid-infrared photodetectors. As low temperature processing (< 160 °C) is implemented in the entire fabrication process, our detector is promising for monolithic integration with Si readout integrated circuits.
Gravitation and mass decrease

Consequences in physical theory of assuming the general relativistic time transformation for the de Broglie frequencies of matter, v = E/h = mc2/h, are investigated in this paper. Experimentally it is known that electromagnetic waves from a source in a gravitational field are decreased in frequency, in accordance with the Einstein general relativity time transformation. An extension to de Broglie frequencies implies mass decrease in a gravitational field. Such a decrease gives an otherwise missing energy conservation for some processes; also, a physical alteration is then associated with change in gravitational potential. Further, the general relativity time transformation that is the source of gravitational action in the weak field (Newtonian) approximation then has a physical correlate in the proposed gravitational mass loss. Rotational motion and the associated equivalent gravitational-field mass loss are considered; an essential formal difference between metric (gravitational) mass loss and special relativity mass increase is discussed. For a spherical, nonrotating mass collapsed to its Schwarzschild radius the postulated mass loss is found to give a 25% decrease in the mass acting as origin of an external gravitational field.
A Task‐Based Approach to User Interface Design for a Web‐Based Hydrologic Information Systems

Hydroinformatics is a new and rapidly developing field that integrates knowledge and understanding of water resources with the latest developments in information technology to improve decision-making in many critical applications. It encompasses methods for data capture, storage, processing, analysis and visualization, and the use of advanced modeling, simulation, optimization and knowledge-based tools and systems infrastructure. Three types of hydrological data are most commonly used: flow rate in major rivers and streams, height of water in wells, and precipitation. To get a complete view of the state of water at a given point in space and time, one must analyze many different types of hydrological data together to derive information using an online GIS tool. To help use these disparate data sources more effectively and efficiently, we have built an online interface called the IJEDI WebCenter for Hydroinformatics using a task-based approach. In this design, we first identify the tasks that users perform to study water-related issues, then organize data for each task, and build task-specific tools to present and analyze data and information. In a study involving both novices and experts in hydrology, we found that the both groups performed water-related studies more effectively and efficiently than they would have without the WebCenter.
Learning effect of dark adaptation among normal subjects

To examine and quantify any change in the dark adaptation (DA) function of normal subjects due to learning effect on test–retest. Sixteen normal subjects (12 women, four men) whose ages ranged between 24 and 52 years (mean 34.6 ± 6.7 years) were studied. The interval period between test and retest ranged between 0.92 and 2.37 months (mean 1.38 ± 0.40 months). DA was measured with a Goldmann–Weekers (GW) dark adaptometer, and subjects were pre-adapted using a light intensity of 2,700 cd/m2 Ganzfeld background for 5 minutes. Exponential non-linear regression analysis was used to determine seven parameters of DA function. These were time of cone–rod break, cone and rod final thresholds, and magnitude of change and time constant of the cone and rod limbs. The mean cone–rod break time with 95% confidence intervals (CI) was 0.098 (CI: −0.527, 0.330) minutes faster on retest (p = 0.630)). Fourteen of the 16 subjects demonstrated an increase or 'worsening' of their final cone and rod thresholds on the second visit. The mean final threshold differences on retest for the cone limb was 0.105 (CI: 0.032, 0.179) log cd/m2 (p = 0.008) and 0.093 (CI: −0.039, 0.225,) log cd/m2 (p = 0.155) for the rod limb. The magnitude of change for the cone limb was 0.016 (CI: −0.122, 0.155) log cd/m2 (p = 0.805) and −0.196 (CI: −0.435, 0.827) log cd/m2 (p = 0.518) for the rod limb, while the time constant on retest for the cone limb was −0.021 (CI: -0.128, 0.169) minutes, (p = 0.770) and 0.276 (CI: -0.424, 0.976) minutes (p = 0.410) for the rod limb. None of the DA parameters that were examined demonstrated a learning effect of clinical significance between test and retest. None of the changes in mean from test to retest for the seven parameters were found to be statistically significant, and the changes were clinically negligible. Therefore, any change among patients that may occur in dark adaptation between a visit interval may be considered real, and not due to the effect of learning.
Developmental expression patterns of Arabidopsis XTH genes reported by transgenes and Genevestigator

The plant cell wall is the structural basis of cellular form and thus forms a foundation on which morphogenesis builds organs and tissues. Enzymes capable of modifying major wall components are prominent candidates for regulating wall form and function. Xyloglucan endotransglucosylases/hydrolases (XTHs) are predicted to participate in xyloglucan integration and/or restructuring. XTHs are encoded by large gene families in plants; the Arabidopsis genome encodes 33 XTHs. To gain insight into the potential physiological relevance of the distinct members of this family, GUS reporter fusion genes were constructed, and plants expressing these transgenes were characterized to reveal spatial and temporal patterns of expression. In addition, Genevestigator sources were mined for comprehensive and comparative XTH expression regulation analysis. These data reveal that the Arabidopsis XTHs are likely expressed in every developmental stage from seed germination through flowering. All organs show XTH::GUS expression and most, if not all, are found to express multiple XTH::GUS genes. These data suggest that XTHs may contribute to morphogenesis at every developmental stage and in every plant organ. Different XTHs have remarkably diverse and distinct expression patterns indicating that paralogous genes have evolved differential expression regulation perhaps contributing to the maintenance of the large gene family. Extensive overlap in XTH expression patterns is evident; thus, XTHs may act combinatorially in determining wall properties of specific tissues or organs. Knowledge of gene-specific expression among family members yields evidence of where and when gene products may function and provides insights to guide rational approaches to investigate function through reverse genetics.
Are Auditors Compromised by Nonaudit Services? Assessing the Evidence*

Ruddock, Taylor, and Taylor (2006) use an earnings conservatism framework to investigate the effects of nonaudit services (NAS) on earnings conservatism, and to test whether audit quality was impaired by NAS in Australia during the 1990s. They find no evidence of differential conservatism conditional on the level of NAS fees paid to auditors, and thus conclude that NAS have no adverse effect on audit quality. While this result may not extrapolate to the U.S. setting due to institutional difference between the two countries, the study does add to a growing body of empirical evidence that questions whether there is any logical rationale for restricting the scope of the services that auditors provide to their audit clients. In reviewing the NAS research literature over the past 40 years, one has to conclude that there is no “smoking gun” evidence linking the provision of nonaudit services with audit failures. However, the literature also finds that NAS can adversely affect the appearance of auditor independence, and this may be more than a “mere perception” problem, because there is also evidence that stock prices are significantly lower for companies that pay their auditors large fees for nonaudit services.
Evolution and Structure of Tropical Squall Line Elements within a Moderate CAPE and Strong Low-Level Jet Environment

A three-dimensional cloud model is used to simulate the early development and propagation of an arc-shaped line element similar to that found in the GARP (Global Atmospheric Research Program) Tropical Atlantic Experiment (GATE) 4‐5 September 1974 squall line system. The simulated squall line element forms in a relatively unexplored environment with moderate convective available potential energy and a strong low-level jet (bulk Richardson number 5 37) associated with an easterly wave. The simulated line element develops in a large-scale convergence region from an initial cell that splits and elongates in a manner reminiscent of some midlatitude lines. Simulation features compare favorably with observed characteristics of some of the line elements including line orientation (approximately perpendicular to the average wind shear below the low-level jet), propagation speed (11 m s21 to the southwest), length (75 km), and maximum precipitation rate (187 mm h21). In addition, the simulated line merges with cells that form ahead as observed. The simulated arc-shaped line element consists of four regions several hours after its initiation. The northern region or right flank of the line contains a long-lived cell exhibiting three-dimensional characteristics similar to midlatitude supercells including long-lasting and steady updrafts with midlevel cyclonic rotation and movement to the right of the mean winds. Although the simulated supercell characteristics cannot be confirmed because of insufficient data from the limited GATE 4‐5 September observations, updrafts with strong vertical vorticity have been observed to occur in other GATE rainbands where waterspouts have been seen. The region just to the south of this cell is the site where a cell that formed out ahead of the line segment merges with the line and also develops supercell-like characteristics. Farther to the south, convection develops with quasi twodimensional characteristics below 3‐4 km but breaking into several multicells above. A rear-inflow jet does not accompany these features and the winds in the downdraft are oblique too and nonuniform along the associated gust front. Finally, on the southernmost or left flank of the line element, cells with both long and short lifetimes develop. Sensitivity tests indicate that once the early line structure has developed, its evolution and structure are not seriously altered by the removal of large-scale forcing. Further, the formation of the cold pool and gust front between the initial separating (splitting) cells is crucial to the filling in of the line. Changes in the thermodynamic profile consistent with nonsquall observations one-half day earlier result in only modest differences. Changes in the wind profile (based on the same observations) led to significant differences, such as the lack of convection between the initial separating cells and the merger taking place to the north of the right flank creating a convective complex in this region.
Pressure development in the melting zone of a single‐screw extruder

An analysis is given of the pressure generation mechanism in the tapered channel of a single-screw extruder. It is shown that when increasing the throughput the pressure build-up capacity of the melting zone tends to decrease. As a result, severe pressure drops may occur in the tapered sections. A relationship between the pressure profile and the melting mechanism (solid bed/melt pool configuration) is described in terms of the cross-channel melt circulation.
Postural Risks Associated with Laptop Use on a Bed

Laptop use is associated with a number of musculoskeletal risk factors, however there is a deficit of research pertaining to their use in any context other than a traditional desk and chair. Because laptops are designed to be portable, they are utilized in a wide variety of configurations, some of which may place the user at risk of injury. The current study examines the postural risks associated with three configurations females frequently report employing while using a laptop computer while on a bed. Differences in both posture and choice of configuration are examined as potential explanations for previously noted differences in the prevalence of discomfort associated with laptop use between males and females.
Development of hyperplastic polyps following argon plasma coagulation of gastric antral vascular ectasia

The etiology of gastric antral vascular ectasia (GAVE) syndrome or gastric hyperplastic polyps (HPs) is not fully understood. We report a case of gastric HP arising in a patient treated with argon plasma coagulation (APC) for GAVE syndrome. Despite unclear etiologic progression, this and previously reported cases suggest a temporal relationship between the treatment of GAVE and HP. A 68-year-old male with a history of coronary artery disease, congestive heart failure and diabetes type II who initially presented with symptomatic anemia 2 weeks after starting aspirin and clopidogrel therapy. Diagnostic esophagogastroduodenoscopy (EGD) demonstrated diffuse GAVE. He was treated with 5 APC treatments, at 6-week intervals, over a 30 weeks period. 16 months after the initial APC treatment, an EGD performed secondary to persistent anemia demonstrated innumerable, large, bleeding polyps in the gastric antrum. Biopsy performed at that time confirmed hyperplastic gastric polyps. It has been proposed that HPs are regenerative lesions that arise at sites of severe mucosal injury. Our patient's treatment of GAVE with APC created significant mucosal injury, resulting in HP. Technique and genetic factors may have promoted hyperplastic changes during the regeneration of mucosa, at sites previously treated with APC. This case highlights the potential progression of GAVE to HP in a patient with persistent anemia after APC therapy.
Trace Copper and Nickel Chelate Detection by Electron Capture Gas Chromatography

Abstract The range of volatile metal chelates whose chemical form and gas chromatographic characteristics enable their elution and determination to picogram levels by electron capture detection has been extended to fluorinated tetradentate beta-ketoamine chelates of divalent transition metals. These complexes, notably of copper, nickel and palladium exhibit high electron capture sensitivities due both to the presence of fluorine atoms and to the presence of three chelate rings per molecule. High thermal and gas chromatographic stabilities enable the quantitative elution of