cssi/SciSciGPT-SciSciNet huggingface dataset:
Density-functional theory models of xanthine oxidoreductase activity: comparison of substrate tautomerization and protonation

The hydroxylation mechanism of the molybdoprotein xanthine oxidoreductase (XOR) has been modelled using density-functional theory. High activation barriers are often obtained for models of this enzyme due to the absence of factors that stabilize the accumulation of charge on the substrate at the transition state. Xanthine provides much lower barriers than small model substrates such as formamide or imidazole due to charge delocalization to centers which appear to interact with key residues in the protein. Of the two mechanisms of stabilization discussed in the literature—tautomerization and protonation of xanthine—density-functional theory calculations suggest that proton transfer from Glu1261 to N9 reduces the activation barrier by ∼30 kcal mol−1 and leads to an intuitive product complex. Further, similar values for the activation barriers of methyl xanthine isomers lead to the conclusion that the wide variation in rates for substituted purines is due to interactions with key residues in the active site. In addition, the transition state for oxidation of xanthine can be superimposed over the X-ray structure of inhibitor-bound XO with high correlation suggesting that the enzyme active site orients the substrate into the ideal position for reaction. The activation barriers for models of a hypothetical tungsten-substituted XO are predicted to be ∼10 kcal mol−1 higher in energy due to the higher reduction potential of the metal and unfavourable electrostatic interactions for the hydride transfer.
An experiment with design formalism in introductory courses

(This paper has been accepted for publication in the Proceedings, but the photo-ready from was not delivered in time. Copies of the paper should be available upon request at the presentation.)
Factors associated with nonparticipation among registrants for a self-help, community-based smoking cessation intervention

Abstract Smokers (n = 96) who registered for but did not participate in a televised smoking cessation intervention based on the American Lung Association's self-help manual, Freedom From Smoking in 20 Days, were compared with participants (n = 1.035). Nonparticipants were more likely to be male, employed, and have a higher annual household income. At preintervention, nonparticipants expressed weaker desire to quit smoking, less confidence in their ability to quit, and less determination to quit. At post-program, 92% of nonparticipants smoked, but 93% planned to quit someday, with 82% planning to quit within the next 12 months. Additionally, nonparticipants were asked about their impressions of the manual, reasons for not reading the manual, and reasons for not watching the televised segments. Nonparticipants expressed positive initial impressions of the manual and mentioned time demands and conflicts with other commitments most often as reasons for not reading the manual and not watching the televised segments. Besides motivating smokers to try to quit, smoking cessation programs should help smokers to prepare to act. Also, nonparticipants are good candidates for recycling into subsequent programs.
Relationship between disordered c(2×2) structure and diffracted intensity: the 5-site filling model and the hard-square lattice gas

The relationship between the size of disordered c(2 × 2) domains on a square lattice, and the associated diffracted intensity, is investigated for two specific models. The hard-square model describes an equilibrium lattice gas with infinitely repulsive nearest-neighbor (NN) interactions. A transition from short-range to long-range c(2 × 2) order occurs at θc = 0.368 monolayers mimicking Cl/Ag(100) behavior. Here the singular (12, 12)-beam diffracted intensity behavior matches that of the average size (number of atoms) and radius of gyration of suitably defined c(2 × 2) domains. In the non-equilibrium 5-site filling model, empty sites fill irreversibly, at random, provided that all four NN sites are empty. A saturation state occurs at θs = 0.364 monolayers modelling metastable disordered c(2 × 2) O/Fe(001). Here the (12, 12)-beam behavior does not match rapid increases in average domain size and radius of gyration near θs, but correlates better with domain chord length behavior. This difference between equilibrium and non-equilibrium behavior is a general phenomenum.
Withdrawal of cylinders from non-newtonian fluids

The cylinder withdrawal theory for power-law fluids proposed by Tallmadge has been compared with continuous withdrawal data in this work. Calculated withdrawal speeds differ greatly from measured values, although Tallmadge's gravity-corrected theory for Newtonian fluids is in agreement with the present data on Newtonian fluids. Correlations similar to that of Goucher and Ward have been developed with the experimental data over a 400-fold range of dimensionless withdrawal speeds. These correlations are applicable for prediction of non-Newtonian liquid film thicknesses on vertical wires and also apparently for viscoelastic fluids like CMC solutions, but are not applicable for inelastic fluids like Carbopol 934. On a compare, avec les resultats d'un retrait continu, la theorie de retrait des cylindres proposee par Tallmadge pour les fluides obessant a la loi d'energie. Les vitesses de retrait calculees ont differe beaucoup des valeurs mesurees, bien que la theorie de gravite corrigee de Tallmadge pour les fluides newtoniens se soit averee en accord avec les resultats actuels sur les dits fluides. On a mis au point des correlations semblables a celle de Goucher et Ward, en utilisant les resultats experimentaux sur une echelle de vitesses 400 fois plus etendue que celles du retrait sans dimensions. On peut employer les dites correlations pour predire les epaisseurs de pellicules de liquides non newtoniens sur des fils verticaux et apparemment aussi dans le cas de fluides visco-elastiques (tels que des solutions de carboxy-methylcellulose), mais elles ne s'appliquent pas aux fluides non-elastiques tels que le Carbopol 934.
Neuronal compartmentation of ionic cobalt in rat cerebral cortex during initiation of epileptiform activity.

Abstract An understanding of the mechanisms responsible for chronic epileptiform discharge induced by topical application of metallic cobalt to the cerebral cortex of the rat has been complicated by the progressive inflammation and necrosis of cortical tissue. In this study, ionic cobalt was transferred from a pipette on the pial surface into rat sensorimotor isocortex at a rate of 4 μg/min using an iontophoretic current of 3 μamp. Bilateral discharges of high voltage associated with brief bursts of ictal spike and polyspike activity were observed after transfer of 100 μg of cobalt. No histologic evidence of tissue damage was found by light microscopy. Quantitative and qualitative histochemical analysis revealed that cobalt was confined to the upper three cortical layers, occupying a circular area 1 mm in diameter on the pial surface. Although 75% of the heavy metal was found in layer I, neurons and their processes were intensely stained in layers II, and III. Hence, epileptiform discharge originated from neuronal aggregates which have a selective affinity for ionic cobalt and occupy a focal site in upper layers of sensorimotor cortex.
Fast VQ codebook search algorithm for grayscale image coding

In this paper, a fast codebook search algorithm that is equivalent to the full search algorithm for image vector quantization is proposed. The image encoding procedure of VQ needs to find the closest codewords in the codebook for image blocks. A great deal of computational cost is consumed in the image encoding procedure. The proposed algorithm employs two test conditions to speedup the image encoding procedure without incurring any extra image distortion. According to the results, an average 95.23% reduction of execution time can be achieved when the codebook of 256 codewords is used in the proposed algorithm.
Polyphasic feedback enables tunable cellular timers

Cellular ‘timers’ provide an important function in living cells [1]. Timers help cells defer their responses to stimuli, often for time intervals extending over multiple cell cycles (Figure 1A, left). For example, mammalian oligodendrocyte precursors typically proliferate for ∼7 divisions before differentiating during neural development [2]. The bacterium Bacillus subtilis can respond to sudden nutrient limitation by transforming into a dormant spore after ∼5 cell cycles [3]. Timers can balance proliferation with differentiation to control the sizes of various cell populations. Some timers appear to operate in a largely cell-autonomous fashion, but the underlying genetic circuit mechanisms that enable this remain poorly understood. Protein dilution poses stringent challenges to timer circuits by continually diluting out timer components in proliferating cells ( Figure 1A, right). Recent work suggests that pulsatile or oscillatory dynamics can facilitate timer functions 3 and 4. Here, we show how polyphasic positive feedback — a pulsed architecture that breaks a feedback signal into temporally distinct phases — counteracts protein dilution to facilitate timer behavior.
A proposed grading system for standardizing tumor consistency of intracranial meningiomas.

Object Tumor consistency plays an important and underrecognized role in the surgeon's ability to resect meningiomas, especially with evolving trends toward minimally invasive and keyhole surgical approaches. Aside from descriptors such as “hard” or “soft,” no objective criteria exist for grading, studying, and conveying the consistency of meningiomas. Methods The authors designed a practical 5-point scale for intraoperative grading of meningiomas based on the surgeon's ability to internally debulk the tumor and on the subsequent resistance to folding of the tumor capsule. Tumor consistency grades and features are as follows: 1) extremely soft tumor, internal debulking with suction only; 2) soft tumor, internal debulking mostly with suction, and remaining fibrous strands resected with easily folded capsule; 3) average consistency, tumor cannot be freely suctioned and requires mechanical debulking, and the capsule then folds with relative ease; 4) firm tumor, high degree of mechanical debulking required, an...
Hypertonic saline destruction of multiple glomus tumors.

background. Multiple glomus tumors are uncommon cutaneous neoplasms. Therapeutic destructive alternatives include excision, argon or CO2 laser treatment, and sclerotherapy with sodium tetradecyl sulphate. objective. A case report is presented using a previously unreported technique of therapy, specifically hypertonic saline. methods. 23.4% NaCl was injected intraluminally in four sessions over a 6-month period. conclusion. Serial hypertonic saline injections should be added to the list of effective treatment alternatives for multiple glomus tumors.
Observations on Echinostoma revolutum and Echinostoma trivolvis in single and concurrent infections in domestic chicks.

Studies were done to determine specific differences between adults of Echinostoma revolutum and Echinostoma trivolvis grown singly and concurrently in domestic chicks. Worm recovery at 10-21 days post-infection (p.i.) of E. revolutum and E. trivolvis in singly infected chicks was 21 and 17%, respectively; in concurrent infections, worm recovery for E. revolutum and E. trivolvis was 21 and 16%, respectively. The body area of E. trivolvis was 1.5-2.0 times greater than that of E. revolutum at 10-21 days p.i. Most body organ measurements of the suckers and gonads at 10, 14 and 21 days p.i. were significantly greater in E. trivolvis compared with those of E. revolutum. The mean dry weight/worm at 14 days p.i. was 2.5 mg for E. trivolvis and 1.0 mg for E. revolutum. In single infections, E. revolutum was found only in the rectum and E. trivolvis mainly in the lower ileum, and in concurrent infections worms of both species were found in the rectum. Contrary to a previous report that stated that the body size of adult worms is not a reliable taxonomic indicator between E. revolutum and E. trivolvis, the findings reported here show that body area and organ size can be used to distinguish these closely related species.
A CRISPR approach to gene targeting.

It is getting easier and easier to determine complete genome sequences—of model organisms, animals and plants of commercial importance, and humans: Craig Venter, Jim Watson, the 1000 Genome Project, soon you and me. Now that researchers have all this information at hand, the focus has shifted in many cases to manipulating particular sequences to determine their function or to alter their impact. A new study by Jinek et al.1 proposes a new approach—based on the oldest of DNA recognition principles—to the design of reagents that can target specific genomic sequences.
Impact of Respiratory Symptoms and Pulmonary Function on Quality of Life of Long-term Survivors of Non-Small Cell Lung Cancer

Purpose To describe respiratory symptoms and pulmonary function among long-term survivors of non-small cell lung cancer (NSCLC), and their relationship to quality of life (QOL). Methods Cross-sectional survey of disease-free, 5-year minimum survivors of NSCLC (n = 142; 54% women; average age, 71 years); the majority (74%) had received a lobectomy. Analysis included frequency of self-reported respiratory symptoms (cough, phlegm, wheezing, breathlessness) as measured by the American Thoracic Society questionnaire, pulmonary function findings from hand-held spirometry, and QOL (Short Form-36). Results Two thirds of survivors reported at least one respiratory symptom (mean, 1.3; SD, 1.2): 25% cough, 28% phlegm, 31% wheezing, and 39% dyspnea. Twenty-one percent reported that they spent most of the day in bed in the past 12 months because of respiratory symptoms. Average FEV 1 percentage predicted was 68% (SD, 23); 21% had 1 . Based on spirometry results, 36% had a moderate/severe obstructive and/or restrictive ventilatory disorder. Survivors exposed to second-hand smoke (28%) were more than three times as likely to report respiratory symptoms. Respiratory symptom burden contributed to diminished QOL in several domains. Conclusions The majority of these survivors experienced respiratory symptoms, and more than one third reported dyspnea, including one of five patients with seriously diminished pulmonary function. Symptom burden, rather than ventilatory impairment, contributed to diminished QOL. Further study is needed to determine the patterns and effective management of posttreatment respiratory symptoms on survivors of lung cancer.
Fast and reliable methods for determining the evolution of uncertain parameters in differential equations

A very common problem in science and engineering is the determination of the effects of uncertainty or variation in parameters and data on the output of a deterministic nonlinear operator. For example, such variations may describe the effect of experimental error or may arise as part of a sensitivity analysis of the model. The Monte-Carlo Method is a justifiably popular tool for analyzing such effects. It does, however, require many evaluations of the operator and it is difficult to extract precise information about the accuracy of any particular result. In this paper, we borrow techniques from a posteriori error analysis for finite element methods to compute information about the derivative of an operator with respect to its parameters. These techniques employ the generalized Green's function to describe how variation propagates into the solution around localized points in the parameter space. We show how this derivative information can be used either to create a higher order method or produce an error estimate for information computed from a given representation. In the latter case, this provides the basis for adaptive sampling according to the variation in the output values. Both the higher order method and the adaptive sampling method are generally orders of magnitude faster than Monte-Carlo methods in the case that the parameter space is not too high dimensional.
Use of spectroscopic imager for the assessment of optical properties and 3-D reconstruction of biological media

We introduce an imaging system consisting of a modulated source and a spectroscopic imager. A Carre's algorithm was used for the reconstruction of the material's optical properties and 3-D shape.
Selection of active member locations in adaptive structures

The effective use of multiple passive and active members in adaptive structures necessitates that these members be optimally distributed throughout the structure. In truss structures, the problem falls into the class of combinatorial optimization for which the solution becomes exceedingly intractable as the problem size increases. This is overcome by using the simulated annealing algorithm to obtain near optimal locations for passive and/or active members. The maximization of the rate of energy dissipation over a finite time period as the measure of optimality is adopted. The selection of optimal locations for both passive and active members is consistently treated through the use of the energy dissipation rate criterion within the simulated annealing algorithm. Numerical examples are used to illustrate the effectiveness of the methodology for large truss structures.
Examination of Homalometron elongatum Manter, 1947 and Description of a New Congener from Eucinostomus currani Zahuranec, 1980 in the Pacific Ocean off Costa Rica

Homalometron elongatum is reexamined using heat-killed material that was not subjected to pressure during fixation from Gerres cinereus collected from San Juan Harbor, Puerto Rico, U.S.A. The new material is compared with some paratype specimens and differs by having a much less variable forebody length, and a median rather than submedian genital pore. Tegumental spines reportedly cover the anterior end of the body but we observed tegumental spines covering the entire body surface in both the paratype and new material. Homalometron lesliorum n. sp. is described from Eucinostomus currani from the Pacific coasts of Costa Rica and Nicaragua. The new species has 3 pairs of oral papillae surrounding the mouth and thus resembles 3 other congeners: H. elongatum, Homalometron carapevae ,a ndHomalometron papilliferum. Homalometron lesliorum n. sp. is distinguished from the 3 species by having the anterior extent of the vitelline follicles at or above the base of the ventral sucker, compared with posterior to the ventral sucker at the level of the seminal vesicle (H. elongatum) or further posterior at the posterior margin of the ovary (H. carapevae and H. papilliferum). The 4 species are further differentiated from one another by sucker width ratio, tegumental spine size and distribution, egg size, host preference, and biogeography. Comparison of nuclear ribosomal DNA (39 end of 18S, internal transcribed spacer (ITS)1, ITS2, and 59 end of 28S) between H. elongatum and H. lesliorum n. sp. revealed 1 variable base (n 5 162) at the 39 end of 18S, 12 variable bases (n 5 476) at ITS1, 10 variable bases (n 5 310) at ITS2, and 11 variable bases (n 5 1,325) at the 59 end fragment of 28S. Nuclear ribosomal DNA from Homalometron pallidum and Homalometron armatum are included for
First-Generation Megacopta cribraria (Hemiptera: Plataspidae) Can Develop on Soybeans

ABSTRACT Megacopta cribraria (F.) (Hemiptera: Plataspidae) was first reported in 2009 near Atlanta, GA. The insect undergoes two generations per year. The first-generation is reported mainly in kudzu during May and June, with the second establishing on both kudzu and soybean during July and August. A greenhouse study was conducted to determine the suitability of two legumes as hosts for first generation M. cribraria. First generation M. cribraria successfully developed on caged potted soybean plants. Conversely, snap beans were not a suitable host under the conditions of this study. A range of 45–50 d was needed to transition from the egg to adult on soybean plants. Although this study was limited to the greenhouse, kudzu may not be an obligate host for the development of first-generation M. cribraria. An important implication of this finding is the establishment for this pest on spring-planted soybean and for the possible expanded geographic range for this pest beyond that of kudzu.
Attitude Content, Intensity, and the Neutral Point on a Likert Scale

(1963). Attitude Content, Intensity, and the Neutral Point on a Likert Scale. The Journal of Social Psychology: Vol. 61, No. 2, pp. 327-334.
USP dissolution IV: Comparison of methods

The hydrodynamics of four dissolution apparatus—viz., the USP basket, the USP paddle, the stationary basket–spinning filter, and the USP disintegration apparatus, were characterized. At higher velocities, the relationship between the intrinsic dissolution rate constant and linear velocity was parabolic rather than linear.
Scattering loss of multi-slot silicon light emission device: Theory and experiment

Ever since slot waveguide was first proposed [1][2], its unique photon confinement characteristic has attracted a lot of interest. Its applications in several areas such as silicon light emission device, nonlinear optical device, and optical bio detection have been proposed and experimentally verified [3][4][5]. Different merit functions for device design have also been proposed for some specific applications [6]. We have recently demonstrated the significant advantages of multi-slot waveguide structures, including the very high photon confinement in the lower index material [7], which could make this structure ideal for a laser structures in which electrical pumping takes place in thin Si layers and light is emitted, after energy transfer, from Er atoms located in the thin SiO 2 layers. However, scattering losses due to multiple interfaces has not yet been investigated. While low loss single-slot waveguides have been reported [8], no information on loss is available for multi-slot waveguide.
Power-dissipation driven FPGA place and route under timing constraints

In this paper we address the problem of field programmable gate arrays (FPGAs) place and route for low power dissipation with critical path delay constraints. The presence of a large number of unprogrammed antifuses in the routing architecture adds to the capacitive loading of each net. Hence, a considerable amount of power is dissipated in the routing architecture, due to signal transitions occurring at the output of logic modules. Based on primary input signal distributions, signal activities at the internal nodes of a circuit are estimated. Placement and routing are then carried out, based on the signal activity measure so as to achieve routability with low power dissipation and required timing. Results show that a more than 40% reduction in power dissipation due to routing capacitances can be achieved, compared to a layout based only on area and timing.
Emergence (Unpredictability) and the Evolution of Novel Designs

Strategies for developing innovative designs are discussed, first from a philosophical viewpoint and then in detail with specific examples. The goal is to speed and simplify enginnering design.
High-frequency propagation statistics in a shallow water environment

A high frequency acoustic propagation and bottom scattering experiment was conducted by the Naval Research Laboratory in the Baltic Sea near Eckernforde Bucht, Germany during May 1993. Bottom and surface back, forward, and bistatic scatter, acoustic bottom penetration, and direct path data were collected using the NRL high frequency acoustic data collection system. This paper is concerned with the statistics of direct path propagation signals, and includes amplitude variations, means, variances, coefficients of variation, and probability distributions for several receiving hydrophones over the frequency range from 20 to 150 kHz. >
Ciprofloxacin-resistant Aeromonas hydrophila cellulitis following leech therapy

We report a case of surgical site infection with ciprofloxacin-resistant Aeromonas hydrophila following leech therapy. Antimicrobial and genetic analyses of leech and patient isolates demonstrated that the resistant isolates originated from the leech gut microbiota. These data suggest that ciprofloxacin monotherapy as a prophylaxis regimen prior to leech therapy may not be effective in preventing infection.
Shot type classification by dominant color for sports video segmentation and summarization

This paper introduces a novel generic framework for sports video processing by using the common feature of most sports: the dominant color of the field. This dominant field color is automatically detected and updated to compensate for the lighting and weather changes by a robust dominant color region detection algorithm. We also introduce new shot type classification algorithms for soccer and basketball. Finally, we use shot-based low-level features for domain-specific high-level applications. Specifically, the system detects soccer goals and summarizes soccer games in real-time, and it enables basketball fans to skip fouls, free throws, and time-out events by segmenting a basketball game into plays and breaks.
Quadrature-quadrature phase-shift keying

Quadrature-quadrature phase-shift keying (Q/sup 2/PSK) is a spectrally efficient modulation scheme which utilizes available signal space dimensions in a more efficient way than two-dimensional schemes such as QPSK and MSK (minimum-shift keying). It uses two date shaping pulses and two carriers, which are pairwise quadrature in phase, to create a four-dimensional signal space and increases the transmission rate by a factor of two over QPSK and MSK. However, the bit error rate performance depends on the choice of pulse pair. With simple sinusoidal and cosinusoidal data pulses, the E/sub b//N/sub 0/ requirement for P/sub b/(E)=10/sup -5/ is approximately 1.6 dB higher than that of MSK. Without additional constraints, Q/sup 2/PSK does not maintain a constant envelope, however, a simple block coding can provide a constant envelope. This coded signal substantially outperforms MSK and TFM (time-frequency multiplexing) in bandwidth efficiency. Like MSK, Q/sup 2/PSK also has self-clocking and self-synchronizing ability. An optimum class of pulse shapes for use in Q/sup 2/PSK format is presented. One suboptimum realization achieves the Nyquist rate of 2 b/s/Hz using binary detection. >
CO Oxidation on Au/FePO4 Catalyst: Reaction Pathways and Nature of Au Sites

Abstract In situ FTIR spectroscopy coupled with downstream mass spectrometry has been used to clarify the pathways for room temperature (rt) CO oxidation over iron phosphate-supported Au catalyst. The charge state of Au on Au/FePO4 after calcination, reduction, or under reaction conditions was assessed by both FTIR spectroscopy (CO probing) and X-ray absorption near edge spectroscopy (XANES). Results from both approaches show that cationic gold species dominate the surface after pretreatment in O2 at 200 °C. A portion of the cationic gold on Au/FePO4 can be reduced by the initial CO adsorption at rt, and subsequently repeated CO exposures do not reduce the remaining cationic Au. FTIR and Raman results from cycled CO reduction and O2 reoxidation of Au/FePO4 indicate that there are active structural oxygen species on the surface of Au/FePO4that can be consumed by CO and then replenished by gaseous O2 at rt. Au activates both CO and O2 so that the FePO4 support can undergo reduction (by CO) and reoxidation (by O2) cycles. The results of CO oxidation with labeled 18O2 suggest the operation of two parallel reaction pathways at rt: (1) a redox pathway in which FePO4 supplies active oxygen and (2) a direct pathway on metallic Au, via either Langmuir–Hinshelwood or Eley–Rideal mechanism, in which gas phase O2 provides the active oxygen.
Real-time packet loss prediction based on end-to-end delay variation

The effect of packet loss on the quality of real-time audio is significant. Nevertheless, Internet measurement experiments continue to show a considerable variation of packet loss, which makes audio error recovery and concealment challenging. We propose a novel framework to predict packet loss and congestion, based on measurements of end-to-end delay variation and trend, enabling proactive error recovery and congestion avoidance. Our preliminary simulation and experimentation results with various sites on the Internet show the effectiveness and the accuracy of the Loss Predictor technique.
Central Nervous System Infections Due to Stomatococcus mucilaginosus in Immunocompromised Hosts

We present a case of central nervous system (CNS) infection due to Stomatococcus mucilaginosus involving a patient with leukemia and summarize 12 additional published reports of CNS infection due to this organism in immunocompromised hosts. The infection was diagnosed most commonly in the setting of hematologic malignancy accompanied by chemotherapy-induced neutropenia. S. mucilaginosus was recovered from blood prior to discovery of the CNS infection in 62% of cases. Signs or symptoms of CNS infection were observed in all patients. Although a number of patients responded to regimens containing intravenous vancomycin, the addition of intrathecal vancomycin appeared to be of benefit in some cases.
Grating lobes suppression in stepped-frequency pulse train

Frequency stepping is one of the known techniques employed by modern radars to achieve high range resolution. The main advantage of this approach is that the actual instantaneous bandwidth of a radar is quite small compared with the total processing bandwidth. This allows the transmission of waveforms with extremely wide overall bandwidth (and, as a consequence, the attainment of high range resolution) without the usage of the expensive hardware needed to support wide instantaneous bandwidth. Unfortunately, the autocorrelation function of uniform frequency stepped pulse trains can have undesirable peaks, known as "grating lobes." We address this issue, using an approach which allows us to suppress grating lobes below a desired threshold level in the case of appropriately chosen stepped frequency waveforms. We discuss in detail how to choose relevant parameters in order to produce such waveforms with small grating lobes, and give examples of waveforms with small overlap ratio. We also discuss the issue of high sidelobes in the vicinity of the mainlobe, which are inevitable in a stepped frequency train of linear frequency modulated (LFM) waveforms with small overlap ratio, and show that it is possible to suppress these, as well as the grating lobes, by means of nonlinear frequency modulation (NLFM).
Human Immunodeficiency Virus-Specific Circulating CD8 T Lymphocytes Have Down-Modulated CD3ζ and CD28, Key Signaling Molecules for T-Cell Activation

Although human immunodeficiency virus (HIV)-infected subjects without AIDS have a high frequency of HIV-specific CD8 T lymphocytes, cellular immunity is unable to control infection. Freshly isolated lymphocytes often do not lyse HIV-infected targets in 4-h cytotoxicity assays. A large fraction of circulating CD8 T cells from HIV-infected donors down-modulate CD3ζ, the signaling component of the T-cell receptor complex, which is reexpressed in vitro coincident with the return of cytotoxic function. To investigate further the link between CD3ζ down-modulation and possible CD8 T-cell functional defects, we used flow cytometry to characterize further the properties of the CD3ζ-down-modulated subset. HIV-specific CD8 T cells, identified by tetramer staining, are CD3ζ−. CD8 T cells with down-modulated CD3ζ also do not express the key costimulatory receptor CD28 and have the cell surface phenotype of activated or memory T cells (HLA-DR+ CD62L−). After T-cell activation, CD3ζ-down-modulated cells express the activation marker CD69 but not the high-affinity interleukin 2 (IL-2) receptor α-chain CD25 and produce gamma interferon but not IL-2. Therefore HIV-specific CD8 T cells have down-modulated key signaling molecules for T-cell activation and costimulation and require exogenous cytokine stimulation. The typical impairment of HIV-specific CD4 T helper cells, which would normally provide specific CD8 T-cell stimulation, means that in vivo CTL function in vivo is compromised in most HIV-infected individuals. In AIDS patients, the functional defect is more severe, since CD3ζ is not reexpressed even after IL-2 exposure.
Hospital Differences in Short-Term Outcomes for Uncomplicated Pediatric Patients With Gallbladder Disease

Purpose To examine the differences in short-term outcomes and laparoscopic cholecystectomy rates between children's hospitals and non-children's hospitals for uncomplicated pediatric gallbladder disease. Methods A retrospective study was performed of cholecystectomy patients aged 4 to 12 years in 2003 from the Kid's In-Patient Database. Patients with significant comorbidities were excluded. We compared length of hospitalization, complication rates, and laparoscopic cholecystectomy utilization between hospital types. Results Five-hundred fifty-six cholecystectomies were performed for children aged 4 to 12 years in 2003 after exclusion. Children's hospital patients had longer hospitalizations (3.34 versus 2.52 days, P versus 0.9%, P = 0.05) despite fewer emergency admissions. Utilization of laparoscopic cholecystectomy was lower at children's hospitals (91 versus 97% P versus 97%, P versus 2.44 days, P P Conclusion Children without significant comorbidities have longer hospitalizations when treated at children's hospitals for cholecystectomies compared with those at non-children's hospitals. Laparoscopic cholecystectomy use was lower at children's hospitals and similar differences in outcomes remained when comparing only laparoscopic cholecystectomy patients.
Calcium Supplement Ingestion May Alter Lumbar Spine Bone Mineral Density Measurement

Densitometry centers commonly request patients abstain from ingesting calcium supplements prior to dual-energy X-ray absorptiometry (DXA) examination to avoid interference with bone mineral density (BMD) measurement. However, it is not clear that this practice is necessary. This study assessed the impact of recent calcium supplement intake on lumbar spine BMD measurement. The phase 1 experiment demonstrated BMD differences when placing a supplement over various areas of two encapsulated phantoms. To determine whether these results were clinically relevant, the phase 2 study enrolled 36 subjects who received spine scans before and after random assignment to ingest one Citracal, OsCal or People's Choice tablet providing 315, 500, and 600 mg of elemental calcium, respectively. The phase 3 study evaluated 15 subjects that had three spine scans with repositioning between to establish BMD precision, and then ingested a calcium carbonate tablet. Post-dosing scans were performed 15 and 30 minutes after tablet ingestion. The difference in L1-L4 BMD on subsequent scans was compared with the study derived least significant change (LSC) of 0.028 g/cm(2). In phase 2, L1-L4 BMD changes outside the LSC occurred in 36% of subjects with 47% having visualized tablets. Similarly, 33% of the phase 3 subjects demonstrated changes outside the LSC after calcium ingestion and 53% of the subjects in phase 3 had tablets visualized. Visualization of calcium tablets was not associated with BMD changes. In conclusion, calcium tablet intake may affect measured L1-L4 BMD within 30 minutes of ingestion. As such, it is appropriate to request patients abstain from calcium tablet ingestion prior to a spine DXA examination.
Alignment, Orientation, and the Beam-Foil Interaction

We present the results of a number of recent measurements of alignment and orientation for a variety of atomic systems. The significance of these results in understanding the ion-foil interaction process is discussed.
Cerebral arteriovenous malformation in three successive generations

We report a kindred with cerebral arteriovenous malformations in three generations, suggesting autosomal dominant inheritance in this family. Screening asymptomatic persons with a family history for cerebral arteriovenous malformations is discussed.
The Curious Image: Husserlian Thoughts on Photography

This paper develops a Husserlian analysis of photography. Based on Husserl’s account of the constitution of images and image-consciousness, the photograph can likewise be understood as constituted according to the tripartite distinction image-thing, image-object, and image-subject. As this essay argues, however, the mechanical production of (traditional) photography is a mirror of memory that enjoys a special phenomenological relation to the past.
Land Banking in a 'Post-Racial' Society: Philadelphia, Pa a Year Later

In December of 2013, Philadelphia, Pennsylvania became the largest city in the United States to pass land bank legislation. In January of 2014, the city officially began its quest to implement land banks. The aim of this study is to exam the progress that the city has made in implementing land banks in its critical first year. Special attention will be played to the following items: (1) the role that land banking plays in a major city under the leadership of a “post-racial” mayor; (2) the impact land banks have on the low income and working class black population of the city; and (3) whether or not the land banks help and/or hurt the city’s ability to deal with gentrification and globalization.
Atmospheric Correction with the Bayesian Empirical Line

Atmospheric correction of visible/infrared spectra traditionally involves either (1) physics-based methods using Radiative Transfer Models (RTMs), or (2) empirical methods using in situ measurements. Here a more general probabilistic formulation unifies the approaches and enables combined solutions. The technique is simple to implement and provides stable results from one or more reference spectra. This makes empirical corrections practical for large or remote environments where it is difficult to acquire coincident field data. First, we use a physics-based solution to define a prior distribution over reflectances and their correction coefficients. We then incorporate reference measurements via Bayesian inference, leading to a Maximum A Posteriori estimate which is generally more accurate than pure physics-based methods yet more stable than pure empirical methods. Gaussian assumptions enable a closed form solution based on Tikhonov regularization. We demonstrate performance in atmospheric simulations and historical data from the "Classic" Airborne Visible Infrared Imaging Spectrometer (AVIRIS-C) acquired during the HyspIRI mission preparatory campaign.
Preparation of Cell-free Solutions of Hydrogenase:

SummaryStable dry powders and cell-free solutions that possess hydrogenase activity have been prepared from cultures of B. coli communior.
Applied Longitudinal Analysis, Second Edition, by G. M. Fitzmaurice, N. M. Laird, and J. H. Ware

This book provides very broad coverage of modern methods for longitudinal data analysis from an applied perspective. The book is grouped into five parts: Introduction to Longitudinal and Clustered ...
Cytomegalovirus in immunocompromised children.

Purpose of review The purpose of this study is to explore the latest developments in the risk factors, prevention and treatment of cytomegalovirus (CMV) infection in immunocompromised children, including those with congenital immunodeficiency or iatrogenic immune suppression related to solid organ transplantation (SOT) or haematopoietic cell transplantation (HCT). Recent findings CMV viral load measurements now have international standards, allowing for more reliable comparison across sites and within individuals. Preemptive and prophylactic therapy with routine CMV monitoring in transplant patients has yielded significant reduction in CMV morbidity and mortality in these patients. The majority of U.S. states have adopted routine newborn screening for severe combined immunodeficiency (SCID). Viral infections, including CMV, are a major obstacle preventing optimal curative transplantation in these patients. Several new antiviral agents are currently being investigated for CMV infection in immunocompromised patients. Knowledge on CMV drug resistance in children is emerging and requires further study. Summary Conditions that diminish cell-mediated immunity impact the development of CMV infection and disease. These conditions include certain congenital immunodeficiencies and SOT and HCT. Infants identified as having SCID should be screened for CMV risk factors. A preemptive or prophylactic strategy should be chosen for CMV management in children who are high risk posttransplantation. In those who develop disease, viral loads should be monitored and resistance testing considered if response is not deemed adequate. Oral valganciclovir is being used as an alternative to ganciclovir in children, although pharmacokinetic data are limited. Other oral antiviral agents under development are promising future options for paediatric CMV therapy.
Adjunctive and Alternative Treatment of Circadian Rhythm Sleep Disorders

Circadian rhythm sleep disorders (CRSDs) are caused by a misalignment between the endogenous circadian timing system and the desired/required sleep–wake schedule. Treatment usually focuses on shifting the circadian system to align with the desired sleep–wake schedule or on ways to alleviate sleep impairment during sleep periods and decreased alertness during wake periods. Bright light and melatonin are the dominant therapies used in treating CRSDs. Alternative methods to shifting the circadian system involve the manipulation of the sleep–wake schedule and the use of nonphotic cues such as exercise, food timing, and arousal. However, little is known regarding the proper timing of these stimuli for shifting the circadian system, and there has been minimal investigation of their use with specific CRSDs. As a result, most specific treatment recommendations for CRSDs involve combinations of bright light, melatonin, and/or sleep–wake manipulations.
Barrier Metal–Dielectric Interfaces

Since Cu can easily penetrate into SiO2 and low-k dielectrics, it is necessary to have barriers to prevent both Cu-atom diffusion and ion generation and drift into interlayer dielectrics. These barriers can also block oxygen/moisture penetration from the dielectrics into the Cu lines, preventing the oxidation of Cu, which can be the source of Cu ions.
Triumph over Racism

Like my father, Ramanujan dealt with racial prejudice. Japanese-Americans like my parents suffered the effects of racism in America largely because of World War II. Ramanujan suffered as a dark-skinned Indian living under British imperialism. Both men were able to overcome prejudice through their important mathematical contributions.
On characteristic $p$ zeta functions

We show that in contrast to the various known analogies, the orders of vanishing of the characteristic p zeta functions introduced by Goss sometimes follow interesting pattems involving base q-digits, providing a challenge to understand them in a general framework as in the classical case. We answer some questions raised by Goss about the connection of the zeta values and periods. We also generalize and simplify the proofs of some results.
Evolution of LeTID Defects in p-Type Multicrystalline Silicon During Degradation and Regeneration

While progress has been made in developing engineering solutions and understanding light- and elevated temperature-induced degradation (LeTID) in p -type multicrystalline silicon (mc-Si), open questions remain regarding the root cause of LeTID. Previously, lifetime spectroscopy of multicrystalline silicon (mc-Si) passivated emitter and rear cell semifabricates in the unaffected and the degraded states enabled identification of the effective recombination parameters of the responsible defect. To gain further insight into the root cause of LeTID, in this paper, we measure the injection-dependent lifetime throughout degradation and regeneration and perform lifetime spectroscopy at several time points. Our analysis indicates that the change in lifetime during most of the process can be described by a corresponding change in the concentration of a single responsible defect. We also explore further exposure to light and temperature after nearly complete regeneration and a subsequent dark anneal to demonstrate that the behavior is no longer consistent with LeTID and the same defect is not detected by lifetime spectroscopy at maximum degradation. We consider our results in the context of the proposed hypotheses for LeTID and conclude that both hydrogenation and precipitate dissolution during firing are consistent with our results.
Alterations of the adrenal cortex of rats treated with progesterone.

Sprague-Dawley rats were treated with 1000 μg/kg body weight of progesterone daily for six days. Ultrastructural changes in the adrenal cortex of these animals consisted of increased polysomes, increased vesicular smooth endoplasmic reticulum, decreased microtubular smooth endoplasmic reticulum, increased number of mitochondria and mitochondrial cristae, hypertrophy of the Golgi apparatus, and the occurrence of numerous, small dense bodies. These changes are consistent with hyperactivity and were present in the fasciculata-reticularis and glomerulosa. These results presumably occur in the face of reduced secretion of ACTH and are considered to reflect the stimulation of corticosterone and aldosterone synthesizing enzyme systems beyond progesterone. The results are compatible with the occurrence of the 21-hydroxylating system in vesicular smooth endoplasmic reticulum and the 11β-hydroxylating and 18-hydroxylating systems in the mitochondria. Small dense bodies as sociated with the hypertrophied Golgi membranes and the cytoplasmic membranes may represent packaged corticosterone and aldosterone secretory granules.
Beyond Citation Rates: A Real-Time Impact Analysis of Health Professions Education Research Using Altmetrics.

PurposeTo complement traditional citation-based metrics, which take years to accrue and indicate only academic attention, academia has begun considering altmetrics or alternative metrics, which provide timely feedback on an article’s impact by tracking its dissemination via nontraditional outlets, s
Detection and Mitigation of Congestion in SDN Enabled Data Center Networks: A Survey

Large-scale data centers play a vital role in supporting the ever growing demand for computation and storage. These data centers often employ commodity hardware switches with shallow buffers arranged in a multi-rooted tree topology. Many-to-one traffic communication pattern is often observed in a data center whereby many servers simultaneously send requested data to an aggregation server. This may result in excessive congestion on the bottleneck switch, overwhelming the shallow switch buffer and resulting in large number of packet drops. Legacy transmission control protocol (TCP) treats a packet drop as an indication of severe congestion in the path and forces the sender to drastically reduce its sending rate. This leads to the phenomena of TCP incast resulting in severe throughput collapse deteriorating the performance of the data center. Many solutions have been proposed in literature that addresses the TCP incast issue by either tweaking TCP parameters or proposing a modified/custom version of TCP to be used in data centers. Recently, software-defined networking (SDN) has gained the attention of researchers due to the ease of centralized control and programmability of the network. The centralized nature of SDN presents an opportunity to address the TCP incast issue in data center networks in an efficient manner. This paper provides a snapshot of research efforts that leverage the capabilities of SDN to mitigate the effect of congestion in data centers. We provide a taxonomy of the existing solutions, discuss complementary concepts and highlight their relative strengths along with their shortcomings.