cssi/SciSciGPT-SciSciNet huggingface dataset:
Optical phase conjugation using DX centers

Optical phase conjugation is measured in a doped semiconductor containing DX centers. This is to our knowledge the first observation of a steady-state optical nonlinearity in these materials. Phase-conjugate reflectivities of 0.3% result from four-wave mixing in AlGaAs:Te at intensities of the order of 1 mW/cm2. The measured nonlinear-optical sensitivity of ∼0.4 cm2/J is 2 orders of magnitude larger than that in ferroelectric photorefractive crystals.
Sol-Gel Synthesis of Nanostructured TiO2 Films for Water Purification

Sol gel method is an important technology for the synthesis of TiO2 films for water treatment. In this chapter, we will discuss the critical issues on the sol gel synthesis of TiO2 films with high photocatalytic activity and good long-term mechanical stability. The aspects will mainly include the following: (1) design of film structure for increasing the number of electron-hole pairs generated and number of hydroxyl radicals produced, (2) tailor-design of the film pore structure for increasing adsorption of treated contaminants and enhancing mass transfer between the contaminants and catalyst active sites, and (3) improvements in the long-term mechanical stability of the TiO2 films by achieving good adhesion of immobilized TiO2 films on the support (substrate). Important achievements of our research works related to sol gel synthesis of TiO2 films and membranes and the application of these TiO2 photocatalysts in promising photocatalytic reactors are summarized. Current challenges and future directions on the sol gel synthesis of TiO2 films for water purification are also discussed.
The Role of the Mitochondria in the Evolution of Stem Cells, Including MUSE Stem Cells and Their Biology.

From the transition of single-cell organisms to multicellularity of metazoans, evolutionary pressures selected new genes and phenotypes to cope with the oxygenation of the Earth’s environment, especially via the symbiotic acquisition of the mitochondrial organelle. There were many new genes and phenotypes that appeared, namely, stem cells, low-oxygen-micro-environments to house these genes (“niches”), new epigenetic mechanisms to regulate , selectively, the gene repertoire to control proliferation, differentiation, apoptosis, senescence and DNA protection mechanisms, including antioxidant genes and DNA repair. This transition required a critical regulation of the metabolism of glucose to produce energy for both the stem cell quiescent state and the energy-requiring differentiated state. While the totipotent-, embryonic-, pluripotent-, and a few adult organ-specific stem cells were recognized, only relatively recently, because of the isolation of somatic cell nuclear transfer (SCNT) stem cells and “induced pluripotent stem” cells, challenges to the origin of these “iPS” cells have been made. The isolation and characterization of human MUSE stem cells and more adult organ-specific adult stem cells have indicated that these MUSE cells have many shared characteristics of the “iPS” cells, yet they do not form teratomas but can give rise to the trigeminal cell layers. While the MUSE cells are a subset of human fibroblastic cells, they have not been characterized, yet, for the mitochondrial metabolic genes, either in the stem cell state or during their differentiation processes. A description of other human adult stem cells will be made to set future studies of how the MUSE stem cells compare to all other stem cells.
Atheroprotective roles of smooth muscle cell phenotypic modulation and the TCF21 disease gene as revealed by single-cell analysis

In response to various stimuli, vascular smooth muscle cells (SMCs) can de-differentiate, proliferate and migrate in a process known as phenotypic modulation. However, the phenotype of modulated SMCs in vivo during atherosclerosis and the influence of this process on coronary artery disease (CAD) risk have not been clearly established. Using single-cell RNA sequencing, we comprehensively characterized the transcriptomic phenotype of modulated SMCs in vivo in atherosclerotic lesions of both mouse and human arteries and found that these cells transform into unique fibroblast-like cells, termed 'fibromyocytes', rather than into a classical macrophage phenotype. SMC-specific knockout of TCF21-a causal CAD gene-markedly inhibited SMC phenotypic modulation in mice, leading to the presence of fewer fibromyocytes within lesions as well as within the protective fibrous cap of the lesions. Moreover, TCF21 expression was strongly associated with SMC phenotypic modulation in diseased human coronary arteries, and higher levels of TCF21 expression were associated with decreased CAD risk in human CAD-relevant tissues. These results establish a protective role for both TCF21 and SMC phenotypic modulation in this disease.
NAT8L mRNA oxidation is linked to neurodegeneration in multiple sclerosis

Abstract RNA oxidation has been implicated in neurodegeneration, but the underlying mechanism for such effects is unclear. Recently, we demonstrated extensive RNA oxidation within the neurons in multiple sclerosis (MS) brain. In this report we identified selectively oxidized mRNAs in neuronal cells that pertained to neuropathological pathways. N-acetyl aspartate transferase 8 like (NAT8L) mRNA is one such transcript, whose translated product enzymatically synthesizes N-acetyl aspartic acid (NAA), a neuronal metabolite important for myelin synthesis. We reasoned that impediment of translation of an oxidized NAT8L mRNA will result in reduction in its cognate protein, thus lowering NAA level. This assertion is directly supported by our studies on a model cellular system, an MS animal model and postmortem human MS brain. Reduced NAA level in the brain hampers myelin integrity making neuronal axons more susceptible to damage, which contributes in MS neurodegeneration. Overall, this work provides a framework for mechanistic understanding of the link between RNA oxidation and neurodegenerative diseases.
The genesis of carbon-supported Fe-Mn and K-Fe-Mn catalysts from stoichiometric metal carbonyl clusters. III: Characterization by chemisorption, calorimetry, and kinetic analysis

Abstract Carbon-supported Fe, FeMn, and KFeMn catalysts derived from stoichiometric mixedmetal carbonyl clusters were pretreated at either 473 or 673 K in H 2 after which their chemisorption behavior and catalytic properties for CO hydrogenation were determined. The iron remained welldispersed at all times except after high temperature reduction when potassium was present. The single promotion by either Mn or K increased the olefin/paraffin ratio, and the doubly promoted catalyst gave very high selectivity to light olefins. Integral CO heats of adsorption at 300 K were measured, and they increased from 15 kcal/mole on the Fe C catalysts to nearly 17 kcal/mole on each singly promoted sample to 21 kcal/mole on the doubly promoted catalyst. A model for the decomposition of these carbonyl clusters is proposed based on these results combined with previous studies utilizing Mossbauer effect spectroscopy, transmission election microscopy/energy dispersive spectroscopy, and diffuse reflectance Fourier transform infrared spectroscopy. The state of the MnO x , and K phases on the iron surface, as well as Fe crystallite size, appears to play a dominant role in determining catalytic behavior.
OpenFPGA: An Open-Source Framework for Agile Prototyping Customizable FPGAs

Demanded by ever-evolving data processing algorithms, field-programmable gate arrays (FPGAs) have become essential components of modern computing systems, thanks to their reconfigurable and distributed computing capabilities. However, FPGAs are among the very few integrated chips that still require long development cycles and high human efforts, even for industrial vendors. In this article, we introduce OpenFPGA, an open-source framework that can automate and significantly accelerate the development cycle of customizable FPGA architectures. OpenFPGA allows users to customize their FPGA architectures down to circuit-level details using a high-level architecture description language and autogenerate associated Verilog netlists which can be used in a backend flow to generate production-ready layouts. A generic Verilog-to-Bitstream generator is also provided, allowing end-users to implement practical applications on any FPGAs that OpenFPGA can support. Using OpenFPGA, we demonstrate less than 24-h layout generation of two FPGA fabrics, which are based on a Stratix-like architecture built with a commercial 12-nm standard cell library and 40-nm custom cells, respectively.
Urologic oncology practice during COVID-19 pandemic: A systematic review on what can be deferrable vs. nondeferrable.

Abstract Purpose To provide a review of high-risk urologic cancers and the feasibility of delaying surgery without impacting oncologic or mortality outcomes. Materials and Methods A thorough literature review was performed using PubMed and Google Scholar to identify articles pertaining to surgical delay and genitourinary oncology. We reviewed all relevant articles pertaining to kidney, upper tract urothelial cell (UTUC), bladder, prostate, penile, and testicular cancer in regard to diagnostic, surgical, or treatment delay. Results The majority of urologic cancers rely on surgery as primary treatment. Treatment of unfavorable intermediate or high-risk prostate cancer, can likely be delayed for 3-6 months without affecting oncologic outcomes. Muscle-invasive bladder cancer (MIBC) and testicular cancer can be treated initially with chemotherapy. Surgical management of T3 renal masses, high-grade upper tract urothelial carcinoma, and penile cancer should not be delayed. Conclusion The majority of urologic oncologic surgeries can be safely deferred without impacting long-term cancer specific or overall survival. Notable exceptions are MIBC, high-grade UTUC, large renal masses, testicular and penile cancer. Joint decision making among providers and patients should be encouraged. Clinicians must manage emotional anxiety and stress when decisions around treatment delays are necessary as a result of a pandemic.
Data-Inspired and Physics-Driven Model Reduction for Dissociation: Application to the O2 + O System

This work presents an in-depth discussion on the nonequilibrium dissociation of O2 molecules colliding with O atoms, combining quasi-classical trajectory calculations, master equation, and dimensionality reduction. A rovibrationally resolved database for all of the elementary collisional processes is constructed by including all nine adiabatic electronic states of O3 in the QCT calculations. A detailed analysis of the ab initio data set reveals that for a rovibrational level, the probability of dissociating is mostly dictated by its deficit in internal energy compared to the centrifugal barrier. Because of the assumption of rotational equilibrium, the conventional vibrational-specific calculations fail to characterize such a dependence. Based on this observation, a new physics-based grouping strategy for application to coarse-grained models is proposed. By relying on a hybrid technique made of rovibrationally resolved excitation coupled to coarse-grained dissociation, the new approach is compared to the vibrational-specific model and the direct solution of the rovibrational state-to-state master equation. Simulations are performed in a zero-dimensional isothermal and isochoric chemical reactor for a wide range of temperatures (1500-20,000 K). The study shows that the main contribution to the model inadequacy of vibrational-specific approaches originates from the incapability of characterizing dissociation, rather than the energy transfers. Even when constructed with only twenty groups, the new reduced-order model outperforms the vibrational-specific one in predicting all of the QoIs related to dissociation kinetics. At the highest temperature, the accuracy in the mole fraction is improved by 2000%.
DRRGenerator: A Three-dimensional Slicer Extension for the Rapid and Easy Development of Digitally Reconstructed Radiographs

As the interest in image-guided medical interventions has increased, so too has the necessity for open-source software tools to provide the required capabilities without exorbitant costs. A common issue encountered in these procedures is the need to compare computed tomography (CT) data with X-ray data, for example, to compare pre-operative CT imaging with intraoperative X-rays. A software approach to solve this dilemma is the production of digitally reconstructed radiographs (DRRs) which computationally simulate an X-ray-type image from CT data. The resultant image can be easily compared to an X-ray image and can provide valuable clinical information, such as small anatomical changes that have occurred between the pre-operative and operative imaging (i.e., vertebral positioning). To provide an easy way for clinicians to make their own DRRs, we propose DRR generator, a customizable extension for the open-source medical imaging application three-dimensional (3D) Slicer. DRR generator provides rapid computation of DRRs through a highly customizable user interface. This extension provides end-users a free, open-source, and reliable way of generating DRRs. This program is integrated within 3D Slicer and thus can utilize its powerful imaging tools to provide a comprehensive segmentation and registration application for clinicians and researchers. DRR generator is available for download through 3D Slicer’s in-app extension manager and requires no additional software.
Improving the biogas yield of manure: Effect of pretreatment on anaerobic digestion of the recalcitrant fraction of manure.

Abstract Anaerobic digestion of animal manure show a maximum of ca. 50% conversion of volatile solids due to recalcitrance of lignin and crystalline cellulose under anaerobic conditions. The aim of this study is to evaluate different pretreatments on anaerobic digestion of manure fibers after anaerobic digestion. Physical, chemical, thermal, and thermal combined with alkaline pretreatments using sodium hydroxide were tested on manure fiber fraction separated out after anaerobic digestion of cow manure. The anaerobic digestion after pretreatment along with untreated controls were done in semi-continuous anaerobic bioreactors. All pretreatments showed positive effect and the highest increase in VS conversion (42.4%) and methane yield (ca. 127%) was found for 3% NaOH pretreated sample at 180 °C. Composition analysis showed that cellulose, hemicellulose and lignin in digested manure fibers were optimally reduced by 24.8, 29.1 and 9.5% respectively during pretreatment and 76.5% of cellulose and 84.9% of hemicellulose was converted to methane during AD.
Using DRG weight as a tool to assess comorbidities and complexity associated with twins

Background: Diagnosis related groups (DRG) describe the complexity of a patient’s care at the end of the hospital stay for billing purposes. Coding of the DRG can be complicated, but there are only seven DRG codes for newborns. Each DRG has a numeric weight which increases with increased morbidity and lower gestational age. DRG weights range from 0.1771 for a normal newborn to 5.2692 for an infant with respiratory distress syndrome (RDS) or < 26 weeks. DRG weight may also be used to clinically …
Sales and Rank on Amazon.com

In this note we provide a method for converting sales rank data into sales quantity. We show how sales quantity data can be extracted from product inventories on Amazon for a subset of products. We collect a large dataset using this method and then generalize results from Chevalier & Goolsbee (2003) by estimating the fit of a Pareto distribution model of sales rank for a large number of categories. We provide the outputs necessary to convert rank to quantity for these categories as well as a method for conducting inference on quantities.
Confidence, ability to meet return to sport criteria, and second ACL injury risk associations after ACL-reconstruction.

This study tested the hypotheses that participants with high knee-related confidence at the time of return to sport (RTS) after anterior cruciate ligament (ACL) reconstruction (ACLR) would have a greater likelihood of meeting RTS criteria and would have a higher likelihood of second ACL injury. Participants completed RTS testing when cleared to RTS. Success was defined as an IKDC score more than or equal to 90 and all limb symmetry index (LSI) scores more than or equal to 90%. Confidence groups were created based on response to the KOOS Quality of Life subscale. Incidence of second ACL injury was tracked for 24 months after RTS. Associations among confidence, success in meeting RTS criteria, and second ACL injury were evaluated. At RTS, 37.7% were classified with high knee-related confidence, 26.4% met RTS criteria and 22.0% sustained a second ACL injury post-RTS. A higher proportion of confident participants met all RTS criteria (p = 0.001). Confident participants were over two times more likely to suffer a second ACL injury (odds ratio [OR] = 2.40; 95% confidence interval [CI]:1.21-5.20) (p = 0.02) and participants who were both confident and met all RTS criteria were 10 times more likely to suffer a second ACL injury (OR = 9.6; 95% CI:1.1, 84.2) (p = 0.02) than those who passed all RTS criteria but lacked knee-related confidence. Clinical significance: Confident, young athletes at the time of RTS after ACLR are more likely to meet all RTS criteria and more likely to sustain a second ACL injury after RTS. Future work must consider how the inclusion of additional factors into RTS criteria may better identify those at high risk for poor outcome after ACLR.
Mental Illness and the Second Amendment

Until surprisingly recent times, American laws seldom attempted to regulate the possession of firearms by the mentally ill. Since then, a series of highly publicized mass murders by persons who were, before the crime, identifiably mentally ill have focused attention on the question of how a free society should handle the conflict between the Second Amendment’s “right of the people” and the needs of public safety. This paper examines why regulation suddenly became necessary, the conflicts between civil liberties and public safety, and suggests some strategies to deal with these conflicts.
Dissemination of foot-and-mouth disease virus through animal products:

In summary, any and all products from animals infected with FMD may be possible sources of the virus and a means whereby the disease can be transported from one country to another. Some animal products may be imported; however, the procedures which are followed must be exacting, based on sound knowledge about the product and closely controlled. One means of handling these materials is to permit their entry only under special conditions which provide for transport, quarantine, and processing, all of which must be under official supervision and which must be done in such a way to assure that the processing inactivates the virus and that the virus does not escape by way of a byproduct of the manufacturing process.
Historical Aspects of DDH

Little was known about developmental dysplasia of the hip (DDH) in the early historical era. Symptoms such as limping were caused by a variety of disease processes, many of which were life threatening. It was not until the discovery of X-ray in 1896 that clear understanding of childhood hip conditions, including DDH, could evolve. We reviewed available literature and distilled it into this summary of the history of our understanding of DDH. The development of non-operative methods relied on plaster of Paris cast reductions and later splints and harness systems leading to the Pavlik harness (1950’s). The development of ultrasound as a diagnostic technique made early diagnosis and treatment possible. Surgical approaches to DDH treatment required several key discoveries: invention of general anesthesia (1840s); development of sterilization techniques (1860–1880); discovery of X-ray (1890s); development of stainless steel (1920s); and the discovery of antibiotics (1930s). These surgical advances allowed the development of a remarkable variety of operations to treat DDH including open reduction techniques, and osteotomies of the acetabulum and proximal femur. The path to accurate diagnosis and predictable treatment of DDH parallels the many advances that application of the scientific method has allowed in the specialty of orthopedic surgery. The development of academic centers that focus on research and education in childhood hip disorders, as well as a growing number of centers that focus on hip problems in adolescents and young adults, assure a continuous and changing “history” of this common childhood hip condition.
Algorithms for Combining Airspace Sectors

A heuristic algorithm for combining under-utilized airspace sectors to conserve air traffic control resources is described and analyzed. Simulations and analysis using historical air traffic data a...
Competitive interactions between developing cholinergic neurones.

Publisher Summary This chapter discusses the studies carried out on the chick ciliary ganglion to document critical interactions with the target tissue, which are necessary for survival and full maturation of cholinergic ganglion cells. Early ablation of the peripheral targets for these cholinergic parasympathetic neurons altered their development in several ways: (1) All neurons extended axons the number of axons colaterals was considerably reduced. (2) The ganglion cell somal complement of ribosomes retained an immature appearance. (3) All neurons died during a critical developmental period. In addition, data are presented that suggest that some interactions with periphery may trigger the ganglion cells to increase their synthesis of enzymes involved in cholinergic transmission. During the normal development in this, as well as in many other neural systems, a large proportion of neurons die. Such neurons differentiate to a considerable degree and do not appear to be grossly defective. A large number of cells can be rescued from cell death by experimentally reducing the number of ganglion cells just prior to the critical period. This suggests that ganglion cells normally compete among themselves for some aspect of the peripheral target, resulting in the death of many of them.
WHO SHOULD DECIDE DRIVING COMPETENCE

Comment on: J Am Geriatr Soc 2005; 53(1):94-8. Author reply: J Am Geriatr Soc 2005; 53(9): 1637-8.
GONADOTROP IN MEDIATED REGULATION OF mRNAs FOR INSULIN LIKE GROWTH FACTOR II (IGF-II) AND MULLERIAN-INHIBITORY FACTOR (MIF) IN HUMAN OVARIAN GRANULOSA CELLS

GONADOTROP IN MEDIATED REGULATION OF mRNAs FOR INSULIN LIKE GROWTH FACTOR II (IGF-II) AND MULLERIAN-INHIBITORY FACTOR (MIF) IN HUMAN OVARIAN GRANULOSA CELLS
Semidefinite Relaxations of Fractional Programs via Novel Convexification Techniques

In a recent work, we introduced the concept of convex extensions for lower semi-continuous functions and studied their properties. In this work, we present new techniques for constructing convex and concave envelopes of nonlinear functions using the theory of convex extensions. In particular, we develop the convex envelope and concave envelope of z=x/y over a hypercube. We show that the convex envelope is strictly tighter than previously known convex underestimators of x/y. We then propose a new relaxation technique for fractional programs which includes the derived envelopes. The resulting relaxation is shown to be a semidefinite program. Finally, we derive the convex envelope for a class of functions of the type f(x,y) over a hypercube under the assumption that f is concave in x and convex in y.
Update on Invasive Candidiasis

Publisher Summary The increasing frequency of infection of Candida spp.—a previously uncommon pathogen—is in large part a consequence of medical progress, and this chapter reviews the available diagnostic and therapeutic approaches to invasive Candida infections. In general, infections because of Candida spp. can be classified as either rnucocutaneous or deep, invasive infections. The chapter focuses on the deep or invasive Candida infections. Although there is substantial overlap, the deep syndromes are divided into those that primarily involve the bloodstream (hematogenous candidiasis) and those that, although generally spread via the bloodstream, occur primarily because of involvement of specific organs (deep organ candidiasis). Diagnosis of invasive candidiasis continues to require integration of clinical intuition and laboratory data. A firm diagnosis of invasive candidiasis is frequently elusive. Two principal scenarios for empiric therapy are considered. First, the potential for invasive candidiasis in critically ill nonneutropenic medical and surgical patients is discussed in the chapter. Although no firm guidelines for therapy exist, such patients are treated when candida colonization, multiple risk factors, and an unexplained, persistent fever are present. Second, given the high incidence and mortality of fungal infections in febrile neutropenic patients, the empiric use of amphotericin B for those patients who do not respond to broad-spectrum antibiotics has been recommended. Although fluconazole might be considered as an alternative therapy in this setting, its lack of activity against Aspergillus and other molds makes it less attractive than amphotericin B. Further, the frequent prophylactic use of fluconazole in cancer patients also makes use of amphotericin B the rational next step.
Dynamics and deposits generated by the Kos Plateau Tuff eruption: Controls of basal particle loss on pyroclastic flow transport

The explosive eruption of voluminous silicic magmas often produces widespread and massive deposits formed from pyroclastic density currents. While these punctuated events dramatically alter the landscape and have potential climate-altering impact, our understanding of the internal structure and transport dynamics of these eruptions is hampered by a lack of direct observations. We utilize the natural boundary conditions encountered by the eruption of the Kos Plateau Tuff to probe its internal structure as well as constrain the neotectonic activity in the region and eruption duration of this moderate to large (>60 km3) event. At the time of the eruption, 161 ka, the lower sea level in the Mediterranean may have resulted in flows that traversed mostly land to the north of the eruptive vent, while flows to the south may have encountered an expanse of water. Steep topography and overwater transport can impede the transport of the dense basal portions of the flow where particles make multiple or sustained contact with the bed. We use an Eulerian-Eulerian-Lagrangian computational approach coupled with overwater and overland boundary conditions, including topography, to determine the role of bed load versus suspended load in the transport of these flows. We find that a ring vent structure and eruptive fluxes greater than ∼2 × 106 m3/s are required for the spatial distribution of the KPT. The maximum grain size and deposit locations of the first voluminous ignimbrite unit (D) can be explained by suspended flow to the south, consistent with overwater transport, and bed load and suspended load transport to the north, consistent with overland transport. However, the maximum lithic size for the largest and last ignimbrite unit (E) requires some bed load transport in all directions. We propose that the boundary conditions were significantly altered during the course of the eruption, through either the in-filling of a shallow sea to the south or the development of a thick pumice raft to aid saltation. On the basis of the inferred eruptive flux, we estimate that the duration of the eruption climax, in which most of the material was erupted, likely only lasted from a few hours to a day.
Effect of Diluent and Relative Humidity on Apparent Viability of Airborne Pasteurella pestis

Airborne Pasteurella pestis (A-1122) at low humidities [20 to 50% relative humidity (RH)] exhibited exponential decay when either 1% peptone or Heart Infusion Broth (HIB) was used as the diluent in the viable assay system. At higher RH values (65 and 87%), however, the 1% peptone diluent adversely affected the viability assay. In contrast, HIB as diluent was remarkably effective in demonstrating a higher number of viable cells in aerosols held at high RH values. Similarly, with HIB as diluent, aerosols were shown to contain viable cells during 90 min of observation; with 1% peptone, viability was not detectable after 20 min in the airborne state.
Background subtraction uncertainty from submillimetre to millimetre wavelengths

Photometric observations of galaxies at submillimetre to millimetre wavelengths (50 - 1000 GHz) are susceptible to spatial variations in both the background CMB temperature and CIB emission that can be comparable to the flux from the target galaxy. We quantify the residual uncertainty when background emission inside a circular aperture is estimated by the mean flux in a surrounding annular region, assumed to have no contribution from the source of interest. We present simple formulae to calculate this uncertainty as a function of wavelength and aperture size. Drawing on examples from the literature, we illustrate the use of our formalism in practice and highlight cases in which uncertainty in the background subtraction needs to be considered in the error analysis. We make the code used to calculate the uncertainties publicly available on the web.
Retaining New Dentists in Iowa: A Role for Dental Schools in Facilitating Graduates’ Connections to Practice Opportunities in Underserved Areas

Like many other states, Iowa has an aging dental workforce. As this aging population of dentists retires and communities are unable to find new dentists to take over their practices, more small and rural communities lack easy access to oral health care. The University of Iowa College of Dentistry and Dental Clinics established the Office of Iowa Practice Opportunities in 2006 to promote dental practice opportunities in Iowa for its graduates. With this office, an infrastructure connecting the college with practices and communities across the state has been developed. The Office of Iowa Practice Opportunities is the first place many students go to decide what they will do after graduation and to identify practice opportunities in Iowa. The office has exceeded the college’s initial expectations and has provided significant assistance in retaining recently graduated dentists in the state of Iowa and ensuring access to oral health care in the state. This article will show that facilitating connections to practice opportunities has a place in a college of dentistry.
Pertussis Toxin Blocks the Inhibitory Effects of Calcitonin on Cyclic AMP Accumulation in Stimulated Cultured Human Monocytes

Surface stimulation of fresh or cultured human mononuclear cells by latex particles causes an increase in the accumulation of cyclic AMP that is inhibited by preincubation with calcitonin (CT). Preincubation of cultured monocytes with 500 ng/ml pertussis toxin totally blocks the inhibitory effects of CT at low concentrations of this hormone. The effects of pertussis toxin are dose-related and eliminated by boiling the toxin. Similar preincubations with cholera toxin have no significant effects on subsequent inhibition of surface-stimulated cyclic AMP by CT. Membranes prepared from cultured human monocytes contain a 41,000-dalton protein that is ADP-ribosylated by pertussis toxin and may be the inhibitory guanine nucleotide regulatory protein (Ni) mediating this inhibition.
Very Narrow Base Diode

Techniques have been developed to fabricate semiconductor diodes with rectifying junction to ohmic contact distances of the order of microns. The current-voltage relationship of such a diode is a function of the degree of imperfection of the ohmic contact. If it were possible to make ideal ohmic contacts, the diode would exhibit extremely poor rectification. The rectification ratio of germanium diodes for practical ohmic contacts, however, is of the order of 105 to 106. The current-voltage relationship, the small-signal frequency response, and the switching characteristics of the very narrow base diode are analyzed using the appropriate boundary condition at the ohmic contact. The alloy junction current-voltage characteristics follow very closely the (eqV/akT-1) relationship with values of a between 1.02 and the theoretical value 1.00. Because of the narrow base width, the series bulk resistance for typical designs is between 0.3 and 3 ohms. Thus the entire range of forward currents can be obtained at low forward voltages. The diode is a high-frequency device both for small-signal applications and for switching applications, although the ultimate high-frequency capability is reduced because of the imperfection of the ohmic contact. In switching applications, the reverse recovery time may be limited as much by junction capacitance as by hole storage. A method of fabrication is described and small-signal applications at uhf are discussed. A computer diode design that switches at speeds up to 5 mc is described. This diode has the advantageous combination of low forward-voltage drop and high-frequency capability.
Data collection routines on the polycorder for use with infrared thermometers and multiband radiometers

Abstract Two programs have been developed for the Polycorder (Omnidata International) which collect, process, and store analog data from hand-held infrared thermometer and hand-held multiband spectral radiometer. These programs are constructed from subroutines, which serve a number of main programs. Two main segments are used in each program, one for hand-keying of ancillary data associated with the data set and the other for the sampling of the instrument and data processing. These programs allow the user to specify the number of experimental plots and whether the standard deviation or coefficient of variation is to be calculated. Both programs are efficient and all sampling is under direct control of the user.
Mechanisms and dynamics of mechanical strengthening in ligament-equivalent fibroblast-populated collagen matrices

We have measured the dynamics of extracellular matrix consolidation and strengthening by human dermal fibroblasts in hydrated collagen gels. Constraining matrix consolidation between two porous polyethylene posts held rigidly apart set up the mechanical stress which led to the formation of uniaxially oriented fibroblast-populated collagen matrices with a histology resembling a ligament. We measured the mechanical stiffness and tensile strength of these ligament equivalents (LEs) as a function of age at biweekly intervals up to 12 weeks in culture using a mechanical spectrometer customized for performing experiments under physiologic conditions. The LE load-strain curve changed as a function of LE age, increasing in stiffness and exhibiting less plastic-like behavior. At 12 weeks, LEs had acquired up to 30 times the breaking strength of 1-week-old LEs. Matrix strengthening occurred primarily through the formation of BAPN-sensitive, lysyl oxidase catalyzed crosslinks. Sulfated glycosaminoglycan (GAG) content increased monotonically with LE age, reaching levels that are characteristic of ligaments. Cells in the LEs actively incorporated [3H]proline and [35S]sulfate into the extracellular matrix. Over the first three weeks, DNA content increased rapidly but thereafter remained constant. This data represent the first documentation of strengthening kinetics for cell-assembled biopolymer gels and the results suggest that this LE tissue may be a valuable model for studying the cellular processes responsible for tissue growth, repair, and remodeling.
The Use of Artificial Impoundments by Two Amphibian Species in the Delaware Water Gap National Recreation Area

Abstract We compared breeding activity of Ambystoma maculatum (Spotted Salamander) and Rana sylvatica (Wood Frog) in artificial impoundments to patterns in natural wetlands over a three-year period in the Delaware Water Gap National Recreation Area. Rana sylvatica were 5.6 times more likely to use natural bodies of water for breeding than artificial impoundments, while A. maculatum were 2.7 times more likely to use natural bodies of water. Both species were approximately 9 times more likely to breed in fishless bodies of water than in waters with predatory fish. Ambystoma maculatum were 6 times more likely to breed in wetlands with more stable seasonal hydroperiods, while R. sylvatica were only 2 times more likely to do so. We conclude that the high likelihood of fish presence in impoundments was the primary explanation for why both species were less likely to use impoundments than natural wetlands, while the tendency of A. maculatum to avoid natural wetlands with shorter hydroperiods explained why differ...
Near-threshold photoionization spectrum of aligned Ca 4s5p 1P1.

The relative cross section for photoionization from the 4s5p $^{1}$${\mathit{P}}_{1}$ excited level of neutral calcium has been measured using pulsed laser excitation and ionization of Ca atoms in an atomic beam. Photoelectrons are counted as a function of ionizing photon energy and polarization. Measurements cover the energy range from 51 300 to 51 700 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ above the Ca $^{1}$${\mathit{S}}_{0}$ ground state at a resolution of approximately 0.15 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$. The shapes and relative peak heights of resonances corresponding to the previously identified $^{3}$${\mathit{S}}_{1}$ and $^{3}$${\mathit{D}}_{1,2}$ autoionizing levels from the 3d4d configuration have been determined. A new, extremely strong resonance is also evident at 51 467 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$, and it has been tentatively identified with the 3d4d $^{1}$${\mathit{P}}_{1}$ level. This is an experimental identification of a doubly excited even-parity singlet level in calcium.
Effect of waiting time on renal transplant outcome

Effect of waiting time on renal transplant outcome. Background Numerous factors are known to impact on patient survival after renal transplantation. Recent studies have confirmed a survival advantage for renal transplant patients over those waiting on dialysis. We aimed to investigate the hypothesis that longer waiting times are more deleterious than shorter waiting times, that is, to detect a "dose effect" for waiting time. Methods We analyzed 73,103 primary adult renal transplants registered at the United States Renal Data System Registry from 1988 to 1997 for the primary endpoints of death with functioning graft and death-censored graft failure by Cox proportional hazard models. All models were corrected for donor and recipient demographics and other factors known to affect outcome after kidney transplantation. Results A longer waiting time on dialysis is a significant risk factor for death-censored graft survival and patient death with functioning graft after renal transplantation ( P Conclusions Longer waiting times on dialysis negatively impact on post-transplant graft and patient survival. These data strongly support the hypothesis that patients who reach end-stage renal disease should receive a renal transplant as early as possible in order to enhance their chances of long-term survival.
Immunity to West Nile virus

Over the past five years, West Nile (WN) virus has emerged as an important public health concern in the United States. Recent studies from experimental models of WN virus infection have increased our understanding of its pathogenesis and immunity. These include the demonstration that the gene encoding 2'-5'oligoadenylate synthetase is responsible for murine susceptibility to WN virus, the elucidation of the contributions of B, CD8(+) and gamma T cells in the control of murine WN virus infection, and the use of active immunization with envelope protein and passive transfer of immunoglobulin for immunotherapy. These efforts will facilitate the development of effective vaccines and therapies to combat WN virus.
Ondansetron quells drug-resistant emesis in theophylline poisoning

Theophylline toxicity is frequently complicated by nausea and vomiting that may be severe, protracted, and resistant to standard antiemetics.’ Adverse effects of continued emesis include severe patient anxiety, hypovolemia, hypokalemia, and gastrointestinal (GI) bleeding.2 Vomiting also hampers the patient’s abilities to retain oral activated charcoal, an agent that binds unabsorbed theophylline in the GI tract and increases the serum clearance of already absorbed theophylline.3*4 Recently, Ondansetron hydrochloride (Zofran, Glaxo Pharmaceuticals, Research Triangle Park, NC) has been available to treat nausea and vomiting associated with emetogenic cancer chemotherapy and its effectiveness for this indication is established.5 Ondansetron has not been prospectively evaluated for the treatment of theophyllineinduced nausea and vomiting. Two case reports that document the successful use of Ondansetron to control persistent vomiting associated with theophylline toxicity after aggressive standard antiemetic regimens had failed are presented.
The secret is at the crossways: Hodotopic organization and nonlinear dynamics of brain neural networks

By integrating the classic psychological principles of ancient art of memory (AAOM) with the most recent paradigms in cognitive neuroscience (i.e., the concepts of hodotopic organization and nonlinear dynamics of brain neural networks), Llewellyn provides an up-to-date model of the complex psychological relationships between memory, imagination, and dreams in accordance with current state-of-the-art principles in neuroscience.
Optimization of ventilation system design and operation in office environment, Part I: Methodology

Ventilation principles that integrate flexible and responsive elements have grown in popularity in office buildings due to increasing concerns about the impact of indoor environment quality on office workers' well-being and productivity, as well as concerns over the rising energy costs for space heating and cooling in the office building sector. Such advanced elements as underfloor air distribution (UFAD), passive swirl diffusers, and demand controlled ventilation have posed challenges to system design and operation. This paper is concerned with the development and implementation of a practical and robust optimization scheme, aiming to assist office building designers and operators to enhance thermal comfort and indoor air quality (IAQ) without sacrificing energy costs of ventilation. The objective function was constructed in a way attempting to aggregate and weight indices (for thermal comfort, IAQ, and ventilation energy usage assessment) into one indicator. The path taken was a simulation-based optimization approach by using computational fluid dynamics (CFD) techniques in conjunction with genetic algorithm (GA), with the integration of an artificial neural network (ANN) for response surface approximation (RSA) and for speeding up fitness evaluations inside GA loop.
Pediatric endocrine surgery: a 20-year experience at the Mayo Clinic.

Context: Surgically managed endocrinopathies are rare in children. Most surgeons have limited experience in this field. Herein we report our operative experience with pediatric patients, performed over two decades by high-volume endocrine surgeons. Setting: The study was conducted at the Mayo Clinic (a tertiary referral center). Patients: Patients were <19 years old and underwent an endocrine operation (1993–2012). Main Outcome Measures: Demographics, surgical procedure, diagnoses, morbidity, and mortality were retrospectively reviewed. Results: A total of 241 primary cases included 177 thyroid procedures, 13 neck dissections, 24 parathyroidectomies, 14 adrenalectomies, 7 paragangliomas, and 6 pancreatic procedures. Average age of patients was 14.2 years. There were 133 total thyroidectomies and 40 hemithyroidectomies. Fifty-three cases underwent a central or lateral neck dissection. Six-month follow-up was available for 98 total thyroidectomy patients. There were four cases of permanent hypoparathyroidis...
What's going on in mathematics?

The Problems of Mathematics. By Ian Stewart. Oxford University Press:1987. Pp.257. Hbk £17.50, $24.95; pbk £5.95, $9.95.
“The wild doe”: Augusta Maywood in Philadelphia and Paris, 1837–1840

Augusta Maywood began her professional career at the age of twelve on December 30, 1837, at Philadelphia's Chestnut Street Theatre. The young girl had had only two years' formal study with the former Paris Opera dancer Paul Hazard, but her success was such that her stepfather was encouraged to send her to Paris for ballet lessons with the great Jean Coralli, known today as the creator of Giselle. Her Paris career opened shortly thereafter with a triumphant debut performance at the Opera on November 11, 1839, but a year later ended abruptly in scandal when she eloped with her dancing partner, Charles Mabille. Undaunted, Augusta continued her stage career elsewhere in Europe, which culminated in achieving the honored title of celebrita danzante e mimia assoluta"celebrated ballerina and mime without peer" as she came to be known throughout Italy. Augusta Maywood was the first American ballerina to reverse the flow of French ballerinas inundating the United States, a trend that had begun in 1791 with Susanne Douvillier (also known as Mme Placide), who was apparently the first Opera danseuse to perform on American shores. By the time Augusta was born in New York City on March 5, 1825,1 American stages were staffed by touring French dancers who grandly announced their origins as "From the Paris Opera"
Numerical study of the interactions between droplets at intermediate Reynolds numbers

Effects of droplet interactions on drag, evaporation, and combustion of a planar droplet array oriented perpendicular to the approaching flow are studied numerically. The three-dimensional Navier-Stokes equations, with variable thermophysical properties, are solved using finite-difference techniques. Parameters investigated include the droplet spacing, droplet Reynolds number, approaching stream oxygen concentration, and fuel type. Results are obtained for a Reynolds number range of 5 to 100, droplet spacings from 2 to 24 diameters, oxygen concentrations of 0.1 and 0.2, and methanol and n-butanol fuels. The calculations show that gasification rates of interacting droplets decrease as droplet spacings decrease. The reduction in gasification rates is significant only at small spacings and low Reynolds numbers. The effects of adjacent droplets on drag are shown to be small for the present array orientation.
Novel variable selection quantitative structure--property relationship approach based on the k-nearest-neighbor principle

A novel automated variable selection quantitative structure−activity relationship (QSAR) method, based on the K-nearest neighbor principle (kNN-QSAR) has been developed. The kNN-QSAR method explore...
On the distribution of Dickey–Fuller unit root statistics when there is a break in the innovation variance

Abstract We show that Dickey & Fuller's [Distribution of the estimator for autoregressive time series with a unit root. J. Amer. Statist. Assoc. 74, 427–431; Likelihood ratio statistics for autoregressive time series with a unit root. Econometrica 49, 1057–1072] normalized estimator and F -statistics for the unit root null hypothesis will spuriously reject the null hypothesis if there is a break in the innovation variance relatively early in the sample.
Multi-sample cluster analysis using Akaike's Information Criterion

Multi-sample cluster analysis, the problem of grouping samples, is studied from an information-theoretic viewpoint via Akaike's Information Criterion (AIC). This criterion combines the maximum value of the likelihood with the number of parameters used in achieving that value. The multi-sample cluster problem is defined, and AIC is developed for this problem. The form of AIC is derived in both the multivariate analysis of variance (MANOVA) model and in the multivariate model with varying mean vectors and variance-covariance matrices. Numerical examples are presented for AIC and another criterion calledw-square. The results demonstrate the utility of AIC in identifying the best clustering alternatives.