cssi/SciSciGPT-SciSciNet huggingface dataset:
TLR agonists and/or IL-15 adjuvanted mucosal SIV-vaccine reduced gut CD4+ memory T cell loss in SIVmac251-challenged rhesus macaques

Adjuvant plays an important role in increasing and directing vaccine-induced immune responses. In a previous study, we found that a mucosal SIV vaccine using a combination of IL-15 and TLR agonists as adjuvant mediated partial protection against SIVmac251 rectal challenge, whereas neither IL-15 nor TLR agonists alone as an adjuvant impacted the plasma viral loads. In this study, dissociation of CD4+ T cell preservation with viral loads was observed in the animals vaccinated with adjuvants. Significantly higher levels of memory CD4+ T cell numbers were preserved after SIVmac251 infection in the colons of the animals vaccinated with vaccine containing any of these adjuvants compared to no adjuvant. When we measured the viral-specific CD8+ tetramer responses in the colon lamina propria, we found significantly higher levels of gag, tat, and pol epitope tetramer+ T cell responses in these animals compared to ones without adjuvant, even if some of the animals had similarly high viral loads. Furthermore, this CD4+ T preservation was positively correlated with increased levels of gag and Tat, but not pol tetramer+ T cell responses, and inversely correlated with beta-chemokine expression. The pre-challenged APOBEC3G expression level, which has previously been shown inversely associated with viral loads, was further found positively correlated with CD4+ T cell number preservation. Overall, these data highlight one unrecognized role of adjuvant in HIV vaccine development, and show that vaccines can produce a surprising discordance between CD4+ T cell levels and SIV viral load.
Estimation of time-varying range-direction target density functions in nonstationary environments

Two different solutions are given to the problem of estimation of time-varying target density functions in arbitrary nonstationary environments via use of one transmitted signal and a distributed sensor (or an array of point sensors). The first one utilizes a wideband signal with a certain bandlimitedness condition on the time variation of the target density function at each point in space. By choosing small successive processing time intervals, bandlimitedness of the time-variation becomes much more realistic than assuming no time-variation or a specific time-variation. The second one does not have this assumption and utilizes a narrowband signal with a continuous spectral content. These provide a general methodology for imaging of nonstationary environments. In addition to nonstationarity, time-varying density functions can also describe nonlinearity of a medium where each point distorts the transmitted wave by multiplying it with a time-varying function during reflection.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Posterior spinal fusion to sacrum in non-ambulatory hypotonic neuromuscular patients: sacral rod/bone graft onlay method

Purpose A retrospective study involving 65 non-ambulatory patients with hypotonic neuromuscular scoliosis has assessed the effectiveness of a sacral rod/bone onlay technique for extending spinal fusion to the sacrum.
A Spectral-Scanning Nuclear Magnetic Resonance Imaging (MRI) Transceiver

An integrated spectral-scanning nuclear magnetic resonance imaging (MRI) transceiver is implemented in a 0.12 mum SiGe BiCMOS process. The MRI transmitter and receiver circuitry is designed specifically for small-scale surface MRI diagnostics applications where creating low (below 1 T) and inhomogeneous magnetic field is more practical. The operation frequency for magnetic resonance detection and analysis is tunable from 1 kHz to 37 MHz, corresponding to 0-0.9 T magnetization for 1H (hydrogen). The concurrent measurement bandwidth is approximately one frequency octave. The chip can also be used for conventional narrowband nuclear magnetic resonance (NMR) spectroscopy from 1 kHz up to 250 MHz. This integrated transceiver consists of both the magnetic resonance transmitter which generates the required excitation pulses for the magnetic dipole excitation, and the receiver which recovers the responses of the dipoles.
The Daya Bay Neutrino Oscillation Experiment

The search for the mixing angle θ 13 , the last unknown angle in the neutrino mixing matrix, is one of the main priorities in the field of neutrino physics. By measuring s i n 2 ( 2 θ 13 ) to better than 0.01 at 90% C.L., the Daya Bay Reactor Neutrino Experiment has the highest sensitivity to this parameter among all the other experiments that are currently operating or under construction. The experiment consists of multiple identical detectors placed underground at different baselines from three groups of reactors, a configuration that minimizes systematic errors and cosmogenic backgrounds. The main aspects of the experiment, as well as its current status and future prospects, are reviewed.
Relative success in college chemistry for students who experienced a high-school course in chemistry and those who had not

A total of 53 high-ability students who had completed the eleventh year in high school enrolled in a standard college chemistry course at the University of Iowa. Half of them had completed a high-school course in chemistry and half had not. After 2 months of instruction during a summer session, there was no difference between groups as to attitude toward chemistry, performance on the ACS-NSTA Chemistry Achievement Examination, final examination for the course, and course grade. There was a great difference in the amount of time required of tutors; the students who had not completed high-school chemistry spent more time in studying and with tutors.
Cellular expression of a leech netrin suggests roles in the formation of longitudinal nerve tracts and in regional innervation of peripheral targets.

Netrins are secreted, diffusible proteins that direct axonal growth. To study the functions of netrins in the relatively simple and easily accessible nervous system of the leech Hirudo medicinalis, we have cloned a leech netrin and have characterized its expression during embryogenesis. By probing a leech cDNA library at low stringency with chick netrin probes, we have identified a complete cDNA clone that bears significant sequence similarity to netrins of other species. In situ hybridization and dye filling of individual neurons show that this leech netrin is expressed by several identifiable central neurons in every segmental ganglionic primordium during early stages of embryogenesis. Some of these neurons, including the bipolar cells which are thought to be involved in setting up longitudinal tracts, express this gene only transiently during embryogenesis, while others continue to express it in the adult. In addition, leech netrin is expressed by ventral but not dorsal longitudinal muscle cells in each segment before central neurons project their axons to the periphery. These highly specific expression patterns are consistent with the hypothesis that leech netrin plays a role in forming the major interganglionic neuronal tracts and in defining ventral versus dorsal domains of peripheral innervation.
The remember response: subject to bias, graded, and not a process-pure indicator of recollection.

Recognition memory judgments have long been assumed to depend on the contributions of two underlying processes: recollection and familiarity. We measured recollection with receiver-operating characteristic (ROC) data and remember-know judgments. Under standard remember-know instructions, the two estimates of recollection diverged. When subjects were told they might need to justify theirremember responses to the experimenter, the two estimates were more likely to agree. The data support the conclusion thatremember responses are generally based on a continuous underlying process but that specific task instructions can produce data that appear consistent with a high-threshold recollective process. Models based on signal detection theory provide a better account of these data than does the dual-process model (Yonelinas, 1994) or process-pure interpretations.
Minimum rock bolt force and minimum static acceleration in tetrahedral wedge stability: A probabilistic study

ABSTRACT An investigation of effect of variability of strength and orientation on stability of tetrahedral wedges with two free surfaces is presented. Study was limited to potential sliding along the line of intersection of the two joint planes. Minimum rock bolt force and minimum static acceleration were considered as output stability parameters in this study. An analytical procedure which combines a deterministic analytical method and Monte-Carlo simulation technique was used to perform this study. Variability of orientations of the joint planes was modeled by the hemispherical normal distribution. Shear strength of the joint planes was modeled by the Mohr Coulomb criterion. Variability of shear strength parameters of the joint planes was modeled by the bivariate normal distributions. Effect of variability of orientation was found to be more pronounced than the effect of variability of strength on both output parameters. Variability of the magnitudes of the output parameters increased with decreasing co...
Heat-Sink Modeling and Design With Dipole Moments Representing IC Excitation

Electromagnetic field coupling and radiation from a heat sink is a challenging issue in the electromagnetic compatibility design of high-speed circuits. In order to accurately predict the fields excited by a heat sink, an approach is proposed in this paper to include the equivalent excitation of the heat sink, which is described by some dipole moments constructed from the near-field scanning of the integrated circuit beneath the heat sink. With both the dipole moments and the passive heat-sink structure incorporated in a full-wave model, near-field coupling and far-field radiation can be estimated, and the heat-sink structure can be optimized for mitigating unintentional interferences. Two examples are used to validate and demonstrate the proposed approach.
The induction of chromosome aberrations by restriction endonucleases that produce blunt-end or cohesive-end double-strand breaks.

Abstract Restriction endonucleases have been used to study the involvement of specific types of DNA damages in the production of chromosome aberrations. In this study restriction endonucleases were introduced into viable CHO cells using osmolytic shock of pinocytic vesicles. We compared two cohesive-end cutters, Msp I (C▾CGG-2-base overlap) and Sau2A I (▾GATC-4-base overlap) with two blunt-end cutters, Alu I (AG▾CT) and Rsa I (GT▾AC). All 4 enzymes were effective at inducing aberrations. The 4-base overlap cohesive-end cutter Sau3A I was approximately was as effective as the blunt-end cutter Alu I. We present evidence that cutting frequency rather than cut end-structure is important in determining efficiency of aberration induction. There is over-dispersion of the distribution of dicentrics and rings among cells, and the data could be fitted to a Neyman Type A distribution, a modified Poisson, that indicates that there is a probability distribution both for the entry of the enzyme into a cell nucleus and for the induction of aberrations once the enzyme has entered a cell nucleus. In addition, we used Alu I to determine the sensitivity of cells to aberration induction in the different stages of the cell cycle. Alu I induced aberrations in all stages of the cycle, chromatid-type in S/G2 and chromosome-type in G1. In agreement with data of others, there were variations in sensitivity with cycle stage, and changes in the proportions of the different aberration classes for chromatid-type aberrations.
Visual masking following transient adaptation.

Test-stimulus thresholds were determined as a function of the interval separating the masking- and test-stimuli onsets as a darkened area in the visual field was exposed binocularly once each 750±5 ms for a duration of 21, 42, or 188 ms. Increased test-stimulus thresholds were observed following the onset of the masking stimulus and were directly related to the duration of the dark interval. These results demonstrated that when the eyes are briefly exposed to a dark interval, transient fluctuations in visual sensitivity occur. Such sensitivity changes, which are likely of neural origin, affect the magnitude of masking effects.
Diagnosis of breast cancer by MRI: a 3D computer visualization and analysis system

The conventional diagnosis of breast cancer by a combination of mammography and physical examination has limited efficacy. Only 20 - 30% of the suspicious breast lesions biopsied are actually malignant. Breast MRI (BMRI), using intravenous contrast injection to detect and characterize breast lesions, has shown promise in several studies. We are developing a 3D image visualization and analysis system to assist radiologists to detect breast cancer in BMRI. Dynamic contrast-enhanced MRI has emerged to become an effective procedure in BMRI for the diagnosis and management of breast carcinoma. A 3D image visualization and analysis system that allows a radiologist to rapidly search through BMRI images and visualize three- dimensional volume of a whole breast has been developed. Three dimensional breast images were constructed from 2D slices. The system can register and subtract a pre-contrast image from each of the time sequenced post-contrast images. The dynamic time sequences of the breast before and after the contrast administration can be visualized. Suspicious lesions can be detected based on the dynamic time-sequence changes in images. The system also allows interactive manipulation of images for viewing from different angles and examination of 2D projections at specific locations. The developed 3D image visualization and analysis system provided radiologists an efficient way to analyze MR breast images. Our automated detection scheme has the potential to accurately detect suspicious lesions and can be an effective tool to facilitate the clinical application of MRI for breast imaging.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Kinetic analysis and mechanical properties of nanoclay reinforced unsaturated polyester (UP) resins cured at low temperatures

The reaction between unsaturated polyester (UP) resin and styrene (St) is a heterogeneous free-radical chain-growth cross-linking copolymerization. Curing of the UP/St system in the presence of organically-modified nanoclay was studied by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. A mechanistic kinetic model based on the free radical copolymerization mechanism was developed to simulate the reaction rate and conversion profiles of UP/St resin mixtures with various nanoclay contents cured at low temperatures. The model parameters were determined from several DSC experiments under isothermal conditions. The model, in conjunction with heat transfer analysis, was able to successfully predict the temperature and conversion profiles during curing in two vacuum-infusion liquid composite molding (e.g., the Seemann composite resin infusion molding process [SCRIMP]) experiments. The presence of nanoclay particles enhanced the tensile modulus, but reduced the tensile strength of the UP nanocomposites. The fracture toughness parameter KIC was improved by 30% with the addition of 5 wt% nanoclay. The system with mixed nanoclay and calcium carbonate was found to possess the highest KIC without sacrificing the tensile strength. POLYM. ENG. SCI., 45:496–509, 2005. © 2005 Society of Plastics Engineers
In vitro synthesis and secretion of glycoprotein by human mammary tissue.

Organ cultures of human surgical specimens can be used to investigate glycoprotein production in vitro under conditions in which three-dimensional tissue structures and cell-cell interactions resemble those present in vivo. In this report, an organ-culture system is used to investigate the synthesis, transport and release of glycoprotein by normal and benign hyperplastic human mammary epithelium. Autoradiography of explants pulse-labeled with individual glycoprotein precursors ([3H]glucosamine, [3H]fucose, [3H]acetylmanosamine) and maintained in organ culture for intervals up to 72hr revealed that glycoprotein is synthesized and then secreted by mammary epithelium. Incorporation of each isotope took place in the Golgi apparatus. Most of the newly synthesized glycoprotein, labeled with each of the three precursors, then was transported to apical cell surfaces and secreted into gland lumina. Observations were indistinguishable in normal and benign hyperplastic glands. Thus nonlactating human mammary epithelium exhibits a glycoprotein secretory activity. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of [3H]glucosamine-labeled macromolecules released into the medium showed a group of glycoproteins with a molecular weight of 48,000±6,000 daltons plus high-molecular-weight glycosylated components at the top of gels. The nature of gp48 is not known, but similar molecular-weight glycoproteins also are released by surgical specimens of human mammary cancer maintained in organ culture.
Full-dose irradiation for invasive bladder cancer: prognostic factors and techniques.

Modern megavoltage irradiation (XRT) can be curative treatment for a minority of patients with invasive bladder cancer while preserving bladder function. \Vith recent improvements in urologic equipment and techniques, XRT is now often combined with transurethral resection (TUR) which may remove 80 % to 90 % or more of the tumor. When the intent is cure without planned cystectomy, the amount of XRT administered is the full or maximum dose that the patient's pelvis can tolerate without loss of bladder function or other radiation injury. This XRT dose by fractionated external beam treatment has ranged from 4,500 to 5,000 rads given in four weeks to 7,000 rads or more given in seven to nine weeks. Because the description "definitive XRT" does not seem to acknowledge the very important contribution to cure of a TUR that may remove 90 % or more of the cancer, "full-dose XRT" or "fulltolerance-dose XRT" seems a more accurate and preferrable description. Reports of treatment results for XRT, surgery, or combined therapy from retrospective series vary widely in success rates for patients with invasive carcinoma. This is the combined result of inaccuracies of clinical staging and variations in patient selection, in patient exclusions, in the treatments used and their quality, and in the heterogeneity of the subtypes among tumors treated. Prospective randomized trials of alternative treatments (which in theory should control for variations in clinical staging, patient selection, and exclusion) have likewise failed to give specific guidelines to the best management of all patients with invasive (of muscle) bladder cancer. Four randomized trials have been reported.!" but only one, and, ironically, the smallest, gave a statistically significant result-favoring 5,000
The effect of lung α-tocopherol content on the acute toxicity of nitrogen dioxide

The effect of lung vitamin E content on early direct damage to lung by NO2 was studied by exposing three groups of rats differing in lung vitamin E content to 0, 10, 20, 30, and 40 ppm NO2 for 4 hr. Lung vitamin E contents of 3.24, 17.4, and 87.7 micrograms/lung were obtained by maintaining animals on semipurified diets containing 0, 10, or 1000 mg/kg of d-alpha-tocopherol acetate. Animals were sacrificed immediately after the 4-hr exposure and lung damage was assessed by assaying the lung lavage content of protein, sialic acid, lactate dehydrogenase (LDH), malate dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (GDH), acid phosphatase (AP), and aryl sulfatase (AS), all of which increase in lavage fluid in a concentration-dependent manner over the range of NO2 concentrations used. Increases in lavagable protein, sialic acid, AP, and AS were not affected by the different vitamin E contents, while the increases in LDH, MDH, and GDH were significantly attenuated in the 1000-mg/kg diet group relative to the 0- and 10-mg/kg diet groups. Lipid peroxidation was not detectable in NO2-exposed lungs by either conjugated diene measurement or thiobarbituric-acid-reactive materials, with the exception of a slight increase in thiobarbituric-acid-reactive material in free cells. These results suggest two mechanisms of NO2 damage to lung. The attenuation of the appearance of some lavage parameters by high vitamin E is consistent with lipid peroxidation as a necessary event in the damage responsible for their appearance, although the lack of change in indicators of lipid peroxidation in the whole lung suggests that peroxidation occurs to only a very limited extent. The lavage parameters which are unaffected by lung vitamin E content apparently appear in airways as a result of events not involving lipid peroxidation.
Finding Dostoevsky's “Idiot” in Carson McCullers's The Heart Is a Lonely Hunter

The books of Dostoevski—The Brothers Karamazov, Crime and Punishment, and The Idiot—opened the door to an immense and marvelous new world. For years I had seen these books on the shelves of the pub...
MSH-6: extending the reliability of immunohistochemistry as a screening tool in Muir–Torre syndrome

The subtype of Muir-Torre syndrome, allelic to hereditary nonpolyposis colorectal cancer is typically associated with germline mutations in the mismatch repair proteins MSH-2 and/or MLH-1. More recently, mutation in an additional mismatch repair protein MSH-6 has been documented in a patient with Muir-Torre syndrome. Given this, the aim of the present study was to ascertain the frequency of the same in unselected sebaceous gland neoplasms. Overall, we found that 59% of sebaceous neoplasms exhibited a mutation in at least one mismatch repair protein gene -- a prevalence rate similar to that reported previously by others. Of interest, we found MSH-6 to be the mismatch repair protein most commonly lost 17/41 (41%), followed by MSH-2 14/41 (34%) and MLH-18/41 (20%) and the positive predictive value of each were as follows: MLH-1 88%, MSH-6 67% and MSH-2 55%. The frequency of a MSH-6 germline mutation in our cohort indicates that it is not a rare finding. Evidence indicating microsatellite stability in three of 17 patients with a clinical history indicative of Muir-Torre syndrome and a mutation in only MSH-6 suggests that the phenotype of a germline MSH-6 mutation differs from that of MLH-1 and MSH-2 mutations and further supports the use of immunohistochemistry as a screening tool in patients with Muir-Torre syndrome with an extended panel that includes MSH-6.
Zinc increases the activity of vitamin D-dependent promoters in osteoblasts.

Zinc modulates the structure and binding of the DNA binding domain of the 1alpha,25-dihydroxyvitamin D(3) receptor to specific vitamin D response element DNA (Nature Biotechnology 16, 262-266, 1998). To determine whether zinc alters 1alpha,25-dihydroxyvitamin D(3)-regulated genes in cells, we permanently transfected rat osteoblasts with two vitamin D-dependent promoter-reporter systems and examined their responses to 1alpha,25-dihydroxyvitamin D(3) in the presence of increasing amounts of extracellular zinc. When extracellular zinc concentrations were increased in the presence of 1alpha,25-dihydroxyvitamin D(3), there was an increase in the activity of 1alpha,25-dihydroxyvitamin D(3)-dependent promoters with increasing concentrations of zinc. The effect was specific for zinc since metals such as copper failed to increase the activity of 1alpha,25-dihydroxyvitamin D(3)-dependent promoters. The concentration of the vitamin D receptor within the cell and the affinity of 1alpha,25-dihydroxyvitamin D(3) for its receptor remained unchanged with added zinc. Our results show that zinc increases the activity of 1alpha,25-dihydroxyvitamin D(3)-dependent promoters in osteoblasts.
Invariance of linearity of regression and related characterizations of some classical discrete distributions

Rao (1963) introduced what we call an additive damage model. In this model, original observation is subjected to damage according to a specified probability law by the survival distribution. In this paper, we consider a bivariate observation with second component subjected to damage. Using the invariance of linearity of regression of the first component on the second under the transition of the second component from the original to the damaged state, we obtain the characterizations of the Poisson, binomial and negative binomial distributions within the framework of the additive damage model.
The critical importance of epidemiology in public health and professional education.

The author discusses the uses of epidemiology in identifying underserved populations and the positive impact of preventive health care on poverty and social distress. The U.S. Public Health Service document, Healthy People 2000, and its recommendations regarding eye care, are discussed
Hazus-MH earthquake modeling in the central USA

This investigation was undertaken to assess the sensitivity of the Hazus-MH (v2.0) earthquake model to model parameters and to guide the selection of these parameters for realistic earthquake-loss assessment in the central USA. To accomplish these goals, we performed several sensitivity analyses and a validation assessment using earthquake damage surveys from the 2008 M5.2 Mt. Carmel, Illinois earthquake. We evaluated the sensitivity of the Hazus-MH earthquake model to the selection of seismic hazard data, attenuation function, soils data, liquefaction data, and structural fragility curves. These sensitivity analyses revealed that earthquake damage, loss, and casualty estimates are most sensitive to the seismic hazard data and selection of the attenuation function. The selection of the seismic hazard data and attenuation function varied earthquake damages and capital-stock losses by ±68 % and casualty estimates by ±84 %. The validation assessment revealed that Hazus-MH overpredicted observed damages by 68–221 % depending on the model parameters employed. The model run using region-specific soils, liquefaction, and structure fragility curves produced the most realistic damage estimate (within 68 % of actual damages). Damage estimates using default Hazus-MH parameters were overpredicted by 155 %. The uncertainties identified here are similar to uncertainties recognized in other Hazus-MH validation assessments. Despite uncertainties in Hazus-MH earthquake-loss estimates, such estimates are still useful for planning and response so long as the limitations of the results are properly conveyed to planners, decision makers, emergency responders, and the public.
The effect of desynchronization on meal patterns of humans living in time isolation.

Abstract We analyzed the timing of meals in nine subjects who lived for several weeks in a time isolation environment and whose free-running sleep-wake cycles lengthened markedly and lost synchrony with the body temperature rhythm for part of the study. The long sleep-wake periods (SWP) in free-running desynchrony (mean=34±3 hours) as compared to free-running synchrony (25±1 hours) enabled us to compare meal timing in two distinct temporal frameworks and to relate them to the two major oscillators presumed to underlie circadian rhythms in man. We found that when the SWP lengthened in desynchrony, the intermeal interval (IMI) increased significantly. In half the subjects, the increase in IMI was approximately proportional to the increase in the SWP—the IMI “stretched” along with the SWP. Analysis of prelunch and postlunch IMIs indicated that the lengthening of the IMI during desynchrony was comparable in early and later parts of the subjective day. The increase in meal spacing was not due to increased caloric content of meals. The findings support an interpretation of dual regulation of meal timing. Proportional increases in IMI and SWP suggest that the mechanism governing the timing of the sleep-wake cycle also governs meal timing. The less than proportional increase in some cases suggests that an additional, probably metabolic, mechanism tends to limit the intervals between meals.
To Clot or Not To Clot: Are there Predictors of Clinically Significant Thrombus Formation in Patients with Gastroparesis and Prolonged IV Access?

Some patients with gastroparesis (GP) require sustained central intravenous access for hydration, medication and/or nutrition, leaving them at risk for venous thrombosis. We studied a group of 53 patients with gastroparesis for identifiable risk factors of clinically significant thrombosis. Patients requiring prolonged central IV access fell into two groups: those who had clinical incidence of IV catheter-related thrombosis confirmed radiologically (CLOT, n = 14), and those who did not form IV catheter thrombosis (NOCLOT, n = 39). We analyzed and compared clinical symptoms, serum/plasma coagulation studies, and autoimmune antibodies in the CLOT and NOCLOT groups. Patients in the CLOT group had statistically more Scl 70 antibodies than did the NOCLOT group, and another autoantibody, Ku 66, was found in higher titers in the NOCLOT group than the CLOT group. Other autoimmune and coagulation factors were not statistically different between the two groups, although a sub-group of CLOT patients had lower plasma Protein S levels. We conclude that the presence of Scl 70 autoantibodies is associated with increased clotting risk in this group of GP patients, and that the Ku 66 antibody may be associated with decreased risk of thrombosis in patients with GP. These findings, coupled with lower Protein S levels in some CLOT patients, suggests that autoimmune factors may be associated with GP patients who thrombose IV access versus patients who do not.
Regression modelling strategies for improved prognostic prediction.

Regression models such as the Cox proportional hazards model have had increasing use in modelling and estimating the prognosis of patients with a variety of diseases. Many applications involve a large number of variables to be modelled using a relatively small patient sample. Problems of overfitting and of identifying important covariates are exacerbated in analysing prognosis because the accuracy of a model is more a function of the number of events than of the sample size. We used a general index of predictive discrimination to measure the ability of a model developed on training samples of varying sizes to predict survival in an independent test sample of patients suspected of having coronary artery disease. We compared three methods of model fitting: (1) standard ‘step-up’ variable selection, (2) incomplete principal components regression, and (3) Cox model regression after developing clinical indices from variable clusters. We found regression using principal components to offer superior predictions in the test sample, whereas regression using indices offers easily interpretable models nearly as good as the principal components models. Standard variable selection has a number of deficiencies.
Obstructive sleep disorders in Prader–Willi syndrome: The role of surgery and growth hormone

Abstract Objective To review the effectiveness and safety of surgical intervention for obstructive sleep apnea in Prader–Willi syndrome. Background The muscle hypotonia and obesity associated with Prader–Willi syndrome (PWS) result in a high rate of obstructive sleep apnea (OSA). The use of growth hormone therapy in these patients has been associated with sudden death, raising concerns that such treatment may exacerbate obstructive sleep apnea. As a result, it has been suggested that children with PWS be evaluated for OSA and indications for adenotonsillectomy prior to instituting growth hormone therapy. The true effectiveness of surgical intervention in these cases, however, remains in doubt. Methods Retrospective review of patients with a diagnosis of PWS who underwent adenoidectomy or adenotonsillectomy from January 2001 to July 2009 at a regional, tertiary care children's hospital. Patients underwent pre-operative and post-operative polysomnography. Differences between pre-operative and post-operative body-mass index (BMI), apnea-hypopnea index (AHI), and median oxygen saturation and oxygen saturation nadir were analyzed. Results Five patients were identified during the study period. Three patients underwent adenotonsillectomy, 1 patient adenoidectomy alone, and another adenotonsillectomy with uvulopalatopharyngoplasty (UPPP). While median AHI was found to have decreased from 16.4 to 4.4, no statistically significant change could be demonstrated (p = 0.274). Mean O2 and nadir O2 saturation also improved, but without reaching statistical significance. No intra-operative complications were noted. Conclusions Our series, and other small case series, have demonstrated that complete resolution of sleep apnea in PWS patients is difficult to obtain with upper airway surgery alone. It is suggested that children with PWS being considered for growth hormone therapy undergo assessment for OSA by polysomnography. Patients identified with OSA should be referred for management by tonsillectomy and/or continuous positive airway pressure (CPAP) and then reassessed for residual airway obstruction prior to instituting hormonal therapy.
Coplanar Integration of Lattice-Mismatched Semiconductors with Silicon by Wafer Bonding Ge / Si1 − x Ge x / Si Virtual Substrates

We have demonstrated a general process which could be used for the integration of lattice-mismatched semiconductors onto large, Si-sized wafers by wafer bonding Ge/Si 1-x Ge x /Si virtual substrates. The challenges for implementing this procedure for large diameter Ge-on-insulator (GOI) have been identified and solved, resulting in the transfer of epitaxial Ge/SiO 2 to a Si wafer. We found that planarization of Ge virtual substrates was a key limiting factor in the transfer process. To circumvent this problem, an oxide layer was first deposited on the Ge film before planarization using a standard oxide chemical mechanical planarization process. The GOI structure was created using H 2 -induced layer exfoliation (Smartcut) and a buried Si 0.4 Ge 0/6 etch-stop layer, which was used to subsequently remove the surface damage with a hydrogen peroxide selective etch. After selective etching, the crosshatched surface morphology of the original virtual substrate was preserved with roughness of <15 nm rms as measured on a 25 X 25 μm scale and a 1 × 1 μm scale roughness of < 1.4 nm. Using an etch-stop layer, the transferred device layer thickness is defined epitaxially allowing for future fabrication of ultrathin GOI as well as III-V films directly on large-diameter Si wafers.
Missing the Trees for the Forest?: Learning Environments Versus Learning Techniques in Simulations

Institutions of higher learning are increasingly asked to defend curricular and pedagogical outcomes. Faculty must demonstrate that simulations are productive tools for learning, but a review of the literature shows that the evidence of their effectiveness is inconclusive, despite their popularity in the classroom. Simulations may in fact help students learn, but the pedagogical benefits of simulations may be being attributed too generally to the learning environments that they supposedly produce, rather than the specific learning modalities that occur within them. The article concludes with a recommendation that educators choose particular learning techniques first and then build simulations around these techniques, rather than the reverse.
Trapezius osteomyocutaneous island flap for reconstruction of the anterior floor of the mouth and the mandible

The anterior mandible defect following cancer excision presents a formidable reconstructive challenge. A trapezius osteomyocutaneous island flap based on the transverse cervical vessels is described which allows immediated reconstruction of the entire defect. The various classes of bone flaps retaining an intact vascular pedicle are discussed. The osseous extension of the trapezius island flap appears to be adequately perfused. The anatomy involved and the orthopedic sequelae of using this flap are discussed.
Rational approximations to Gaunt factors.

Abstract Coefficients for calculating hydrogenic photoionization Gaunt factors by a rational approximation are given.
Production in vitro of a neurotropic substance from proliferative neurolemma-like cells

Abstract The objective of this study was to better define the biological and chemical properties of a neurotropic substance capable of mediating recognition between neurolemma-like cells and neurites during growth. Using in vitro methods, we showed that it was a macromolecular protein apparently synthesized by proliferative cells and was responsible for attracting and promoting neurite outgrowth from chick embryo dorsal root ganglia. The substance appeared to be a normal component of the cell coat during the proliferative phase, and was secreted into the tissue culture medium. Fractionation of the culture fluid by gel filtration chromatography yielded three major fractions containing the biologically active component. The fraction that had the greatest nerve-growth-stimulating activity appeared in a small molecular fraction (mol. wt., 10,000 to 20,000), and was biologically similar to the mouse salivary gland nerve growth factor (NGF). The neurotropic substance appeared to play a central role in promoting and guiding axonal growth during normal development and regeneration of the peripheral nerve.
Singular extremals on Lie groups

We investigate the space of singular curves associated to a distribution ofk-planes, or, what is the same thing, a nonlinear deterministic control system linear in controls. A singular curve is one for which the associated linearized system is not controllable. If a quadratic positive-definite cost function is introduced, then the corresponding optimal control problem is known as the sub-Riemannian geodesic problem. The original motivation for our work was the question “Are all sub-Riemannian minimizers smooth?” which is equivalent to the question “Are singular minimizers necessarily smooth?” Our main result concerns the singular curves for a class of homogeneous systems whose state spaces are compact Lie groups. We prove that for this class each singular curve lies in a lower-dimensional subgroup within which it is regular and we use this result to prove that all sub-Riemannian minimizers are smooth. A central ingredient of our proof is a symplectic-geometric characterization of singular curves formulated by Hsu. We extend this characterization to nonsmooth singular curves. We find that the symplectic point of view clarifies the situation and simplifies calculations.
Modeling the spectral shape of short-arc pulsed xenon flashlamps

Short-arc pulsed xenon flashlamps are used as the source of optical radiation in many analytical and life science instruments. They provide useable energy from below 150nm to over 1100nm. However, the distribution of spectral energy within the arc discharge is not uniform. This non-uniformity can lead to problems when attempting to model the arc in software. This paper will look at the shape of the arc in short-arc pulsed xenon flashlamps in different spectral regions and use the data collected to generate a more complete model of the arc. Possible ways of using this information in optical modeling software will also be discussed.
Photoluminescent and electroluminescent properties of Cd0.95Mn0.05Se electrodes

Abstract Quenching of photoluminescence (PL) and initiation of electroluminescence (EL) from n-type Cd 0.95 Mn 0.05 Se electrodes is used to map the electric field in these solids, grown by a modified Bridgman method.
The repertory grid technique: path to teacher description or teacher potential?

Teachers' decisions are based on certain criteria which teachers believe can justify what happens in their classes. Identifying and measuring those criteria requires multiple approaches in order to triangulate the data as thoroughly as possible. In one case study of a fourth grade teacher, a repertory grid technique was used as the format for a series of in-depth interviews to supplement classroom observations and other interview data. Each subsequent interview generated an increasingly evolved description of teaching that revealed interesting and new associations when the same information was presented to the teacher in a different format. A variety of explanations for the new perspectives are presented, along with recommendations for future research.
Digital multiple wavelength phase shifting algorithm

ABSTRACT This paper presents a digital multiple-wavelength phase-shifting technique for three-dimensional shape measurement. Theprojected phase-shifted fringe images have wavelengths of k = W2 k 1 (k = 1,2,3...). The phase unwrapping is not neededfor the longest wavelength because a single fringe covers the whole area. The shorter wavelength phase, k (x,y),isunwrappedbyreferringtothepreviouslyunwrappedlongerwavelengthphase, k 1 (x,y), pixelbypixelwithoutaccessingits neighborhood pixels. Experiments demonstrate that this technique has low noise and less sensitivity to motion. It canbe used to measure arbitrary step height and multiple objects simultaneously.Keywords: 3D shape measurement; phase shifting; step height; multiple wavelength. 1. INTRODUCTION High-resolution, accurate 3D shape measurement is increasingly important in the last several decades, with applications inmanufacturing, medical sciences, computer sciences, etc.Traditionally, laser interferometries are widely used because of their accuracy and stability. A variety of phase-shiftingalgorithms have been proposed for high resolution and high accuracy measurement.
Onwards with the Evolution of Imagery Research in Sport Psychology

Summary and Conclusion As noted, Paivio’s (1985) framework, the corresponding SIQ, and the applied model all revolutionized imagery research in sport psychology. However, we are at a time where imagery research must evolve. Researchers must acknowledge the limitations of the SIQ and move their research into new areas. Clearly this is a more desirable path compared to simply conducting replication studies that raise the same criticisms and limitations in the discussion sections. To this end, we outline five statements that summarize our current position on imagery research, each with suggestions for future research. 1. Imagery researchers must differentiate between imagery content and functions and understand that the SIQ measures the former, not the latter. Studies could be conducted that examine what types of images are associated with specific imagery functions (e.g., the image content used for building, maintaining, and regaining confidence). 2. Imagery researchers should consider taking an item-level approach when using the SIQ. Determining which image on the SIQ is the most “powerful” for a specific function for a majority of athletes and testing the effects of this single image on various outcomes would be fascinating. 3. Imagery researchers interested in scale development and validation should consider revising specific items, extending its subscales, and the response scale on the SIQ. In addition, more types of imagery could be added. 57
Desensitization of experimental contact sensitivity.

Historically, the concept that eczematous inflammatory skin reactions to various chemicals was due to an increased sensitivity to the substances rather than to their toxic properties was initiated in 1895 by J. Jadassohn.’ Along with other early investigators, he established that the reaction observed upon exposure to a chemical (i.e., poison ivy, nickel, and so forth) was not merely a result of their toxic properties per se. Rather, the host recognized these substances as foreign and reacted against them. Since then, CS has been extensively studied in humans and experimental animals and has been clearly established as a form of antigen-specific DTH.’ Numerous species, including monkeys, rabbits, dogs, rats, and others, had all been used to investigate hypersensitivity to contactants. However, upon epicutaneous exposure to the contactant, the guinea pig produced a reaction histologically and morphologically similar to that observed in humans. Once considered to be a relatively simple model of DTH, CS has in the last 15 years been shown to be an extremely complex phenomenon. Furthermore, the increasing interest in the endogenous regulation of immune processes has prompted detailed studies of the ways in which CS is controlled.3,’ This article will review work done in our laboratory and others on contact hypersensitivity to DNFB and related chemicals in experimental animals. We will be primarily concerned with regulatory and suppressive mechanisms that have been shown to control the contact allergic reaction.
The Caulobacter crescentus flagellar gene, fliX, encodes a novel trans-acting factor that couples flagellar assembly to transcription.

The first flagellar assembly checkpoint of Caulobacter crescentus couples assembly of the early class II components of the basal body complex to the expression of class III and IV genes, which encode extracytoplasmic structures of the flagellum. The transcription of class III/IV flagellar genes is activated by the response regulator factor, FlbD. Gain of function mutations in flbD, termed bfa, can bypass the transcriptional requirement for the assembly of class II flagellar structures. Here we show that the class II flagellar gene fliX encodes a trans-acting factor that couples flagellar assembly to FlbD-dependent transcription. We show that the overexpression of fliX can suppress class III/IV gene expression in both wild-type and flbD-bfa cells. Introduction of a bfa allele of flbD into cells possessing a deletion in fliX restores motility indicating that FliX is not a structural component of the flagellum, but rather a trans-acting factor. Furthermore, extragenic motile suppressors which arise in ΔfliX cells map to the flbD locus. These results indicate that FlbD functions downstream of FliX in activating class III/IV transcription. β-Lactamase fusions to FliX and analysis of cellular fractions demonstrate that FliX is a cytosolic protein that demonstrates some peripheral association with the cytoplasmic membrane. In addition, we have isolated a mutant allele of fliX that exhibits a bfa-like phenotype, restoring flbD-dependent class III/IV transcription in strains that contain mutations in class II flagellar structural genes. Taken together, these results indicated both a positive and negative regulatory function for FliX in coupling the assembly of class II basal body components to gene expression.
EVA, refined EVA, MVA, or traditional performance measures for the hospitality industry?

Abstract Stewart (1991) proposed economic value added (EVA) as a true measurement of a firm's performance and an executive's evaluation tool because EVA reflects only incremental values added to a firm after considering cost of capital. Kim [Kim, W.G., 2006. EVA and traditional accounting measures: which metric is a better predictor of market value of hospitality companies? Journal of Hospitality & Tourism Research 30(1), 34–39] examined EVA in the hospitality setting and concluded that EVA is not superior to other available measurements for accounting. However, this study contributes several improvements to Kim's (2006) study and compares the incremental explanatory power of six firm performance measures including EVA, refined EVA (REVA), market value added (MVA), and three traditional accounting performance measures for market adjusted returns. According to the findings, REVA and MVA are, apparently, valuable performance measures for evaluating hospitality firms.
Noise in passive FET mixers: a simple physical model

White and flicker noise mechanisms in passive FET mixers are explained in intuitive terms, and simple expressions for circuit design are derived. The analysis is validated against simulations and measurement.