cssi/SciSciGPT-SciSciNet huggingface dataset:
Global prostate cancer incidence and the migration, settlement, and admixture history of the Northern Europeans

The most salient feature of prostate cancer is its striking ethnic disparity. High incidences of the disease are documented in two ethnic groups: descendents of the Northern Europeans and African Americans. Other groups, including native Africans, are much less susceptible to the disease. Given that many risk factors may contribute to carcinogenesis, an etiological cause for the ethnic disparity remains to be defined. By analyzing the global prostate cancer incidence data, we found that distribution of prostate cancer incidence coincides with the migration and settlement history of Northern Europeans. The incidences in other ethnic groups correlate to the settlement history and extent of admixture of the Europeans. This study suggests that prostate cancer has been spread by the transmission of a genetic susceptibility that resides in the Northern European genome.
Deterministic and Stochastic Characterization of Friction-Induced Vibration in Disc Brakes

The dynamic behavior of a disc brake subjected to a follower frictional force governed by a constant or random friction coefficient is studied. Under a constant frictional load, the circumferential motion is characterized by a quasi-periodic vibration while the transverse deflection exhibits a periodic motion. The numerical simulation indicates that the response amplitude of the circumferential vibration is larger than that of the transverse vibration. Under random frictional load, both transverse and circumferential displacements are found to be essentially non-Gaussian, non-stationary, and narrow-band processes. The energy of the transverse motion considerably concentrates at a dominant frequency. On the other hand, the spectral density of circumferential motion is mainly distributed at two different frequencies.
Theoretical Studies of Cyclic C2SI2H4 Molecules

Calculs ab initio (MP3/6-31G * /3-21G) sur les 13 isomeres cycliques: le silylsilacyclopropenylidene est le plus stable; le disilatetraedrane est situe tres haut sur la surface d'energie; aucun minimum n'existe pour les 2 disila-1,2cyclobutadienes plans; le disila-1,3cyclobutadiene a une structure stable a caractere de diradical
ON THE MECHANISM OF OPSONIN AND BACTERIOTROPIN ACTION : II. CORRELATION BETWEEN CHANGES IN BACTERIAL SURFACE PROPERTIES AND IN PHAGOCYTOSIS CAUSED BY NORMAL AND IMMUNE SERA.

The work reported in this and in previous papers (1, 7) demonstrates the following relations for acid-fast bacteria and rabbit polymorphonudear leucocytes: 1. The combination of a substance or substances present in fresh immune rabbit serum, heated or unheated, or in fresh unheated normal rabbit serum, with a substance or substances in the bacterial surface causes an increase in cohesiveness, decrease in surface potential difference and characteristic alteration in wetting properties of the bacteria, and prepares the bacteria for phagocytosis. 2. (a) The effective substance or substances in the serum may become so altered as the result of heating or aging that combination with the bacterial surface, while causing changes in bacterial surface properties indistinguishable by the present physical-chemical tests from these just mentioned, may not lead to phagocytosis, or may lead to phagocytosis with a prezone not paralleled by a prezone in the changes in surface properties. (b) Sensitization of bacteria with human sera causes changes in surface properties similar to those caused by rabbit sera, but does not lead to phagocytosis by rabbit leucocytes. The spreading requirements of rabbit polymorphonuclear leucocytes are evidently highly selective.
Access to Medical Care is Not the Problem: Low-Income Status and Health Care Needs Among HIV-Positive African-American Women in Urban North Carolina

This essay explores living conditions, health care needs, and psychological vulnerabilities among HIV-positive African-American women living in urban North Carolina to more broadly consider the categorical label "low-income" as assigned by federal poverty guidelines. Specifically, I examine the differences among study participants as a means of teasing out the differential impact of neoliberal economic reform on women who comprise an epidemiological population, but who are nonetheless variably situated in relation to public health care resources and support programs. Central to this analysis is a discussion of women's shared positioning within the contexts of national and regional economies. The Treatment Modernization Act, in particular, provides an important part of the policy context through which women's financial circumstances and health needs are realized. Through the lenses of policy and lived experience, I demonstrate that "low-income" is not self-evident. Rather, I argue that the label refers to ...
Printer model inversion by constrained optimization

This paper describes a novel method for finding colorant amounts for which a printer will produce a requested color appearance based on constrained optimization. An error function defines the gamut mapping method and black replacement method. The constraints limit the feasible solution region to the device gamut and prevent exceeding the maximum total area coverage. Colorant values corresponding to in-gamut colors are found with precision limited only by the accuracy of the device model. Out-of- gamut colors are mapped to colors within the boundary of the device gamut. This general approach, used in conjunction with different types of color difference equations, can perform a wide range of out-of-gamut mappings such as chroma clipping or for finding colors on gamut boundary having specified properties. We present an application of this method to the creation of PostScript color rendering dictionaries and ICC profiles.
Advanced titanium doping of sodium aluminum hydride:: segue to a practical hydrogen storage material?

The dehydrogenation kinetics of NaAlH4 have been enhanced far beyond those previously achieved upon titanium doping of the host hydride. Homogenization of NaAlH4 with 2 mole % Ti (OBun) 4 under an atmosphere of argon produces a novel material which contains only traces of carbon. TPD measurements show that the dehydrogenation of this material occurs about 30°C lower than that previously found for NaAlH4 doped with titanium through wet chemistry methods. The novel titanium containing material can be rehydrided under 1600 psi of hydrogen pressure at 200°C. In further contrast to wet doped NaAlH4, the dehydrogenation kinetics observed for the novel material are undiminished over several dehydriding/hydriding cycles. © 1999 International Association for Hydrogen Energy.
13C chemical shielding anisotropies of metal acetates

Abstract The 13C chemical shielding anisotropies are reported for a series of common diamagnetic acetates. Neither the carboxyl nor the methyl tensors are axially symmetric in all compounds studied and the values measured are in reasonable agreement with previous measurements. The CP-MAS spectra of calcium and lead acetate give three or more lines in the carboxyl region and were not analyzed. The lithium, aluminum, sodium, and lanthanum acetate spectra are considerably broadened by the metal-carbon dipole-dipole interaction which may be suppressed by slow magic-angle spinning. Use of high magnetic fields to suppress the relative importance of the metal-carbon dipolar interaction and to accentuate the chemical-shift anisotropy is also illustrated.
Superstring theory: Information transfer in an emerging field

This paper traced an individual paper through the literature as it garnered citations. This paper was chosen because of its seminal nature in a highly controversial area of theoretical physics. The distribution of citations was tested against models suggested byPrice andKuhn as well as compared to other studies which also examined benchmark papers. The results indicate that the paper chosen behaved in a significantly different way from most of the prior models. The suggestion is made that further study of this and papers like it will add much to the theory of information transfer in science.
Agrin Is a Chimeric Proteoglycan with the Attachment Sites for Heparan Sulfate/Chondroitin Sulfate Located in Two Multiple Serine-Glycine Clusters

Agrin is a large extracellular matrix protein that plays a key role in the formation and maintenance of the vertebrate neuromuscular junction. The amino acid sequence of agrin encodes a protein with a molecular size of 220 kDa, whereas SDS-PAGE shows a diffuse band around 400 kDa. Further studies showed that agrin is highly glycosylated and belongs to the family of heparan sulfate proteoglycans. By expressing different protein fragments, we localized the glycosaminoglycan (GAG) attachment sites to two locations within the agrin molecule. One site that is located between the seventh and eight follistatin-like domain includes 3 closely spaced serine-glycine (SG) consensus sequences and carries exclusively heparan sulfate side chains. The second site is located further downstream in the centrally located serine-threonine-rich domain and contains a cluster of 4 closely packed SG consensus sequences. This site predominantly carries chondroitin sulfate side chains. Investigating the contribution of individual serines in GAG priming by site-directed mutagenesis showed that each serine of the two SG clusters has the potential to carry GAGs. In accordance with the mixed GAG glycosylation of agrin peptide fragments, it was found that recombinant and in vivo-derived full-length agrin are not exclusively heparan sulfate proteoglycans but also carry chondroitin sulfate side chains.
Mycorrhizas and secondary succession in aspen–conifer forests: Light limitation differentially affects a dominant early and late successional species

Plant succession and mycorrhizal fungi both play crucial roles in shaping the development of forest ecosystems. However, despite the strong potential for interactions between them, few studies have examined how patterns of forest succession affect mycorrhizal associations that a majority of plant species depend on to alleviate soil resource constraints. Fire suppression in subalpine forests over the last century has changed successional patterns in ways that may have important implications for mycorrhizal associations of forest tree species. To better understand these relationships we conducted a field and greenhouse study in which we examined mycorrhizal infection along gradients of light intensity and soil nutrient availability that develop as aspen becomes seral to conifers under longer fire return intervals. We examined whether ectomycorrhizal associations of quaking aspen (Populus tremuloides), a shade intolerant, early succession species, were more sensitive to light and soil resource limitations than subalpine fir (Abies lasiocarpa), a shade tolerant, late succession species. In the field study, ectomycorrhizal infection of aspen roots was reduced by 50% in conifer dominated stands relative to aspen stands. In contrast, subalpine fir maintained its EM associations regardless of the successional status of the stand. The greenhouse results were consistent with field results and indicated that light limitation was the driving force behind reductions in EM infection of aspen roots in later stages of succession. These results suggest that nutrient limitations constraining early successional species may be exacerbated by losses in EM associations via light limitations created by late successional species. This is one potential mechanism by which climax forest species create a competitive advantage over early successional species and these results suggest that it is likely exacerbated by longer fire return intervals.
Aeroacoustic predictions in complex geometries

Abstract The simulation of sound generating flows in complex geometries requires accurate numerical methods that are non-dissipative and stable, and well-posed boundary conditions. A structured mesh approach is often desired for a higher-order discretization that better uses the provided grids, but at the expense complex geometry capabilities. One solution is to use an overset mesh based discretization where locally structured meshes are globally assembled in an unstructured manner. This article discusses recent advancements in overset, also called Chimera, methods concerning boundary conditions, parallel methods for overset grid management, and stable and accurate interpolation between grids. Several examples are given, some of which include moving grids.
Texture Changes on Heating Spray‐Dried Egg White

Computerized texture profile analysis and a computer-simulated model of protein monomer complexation were used to study egg white gelation. The results showed that the parameter Kn, an association equilibrium constant, was large so that the monomer to monomer complex reaction essentially went to completion. Approximately 8 to 10 protein monomer units combined to form the egg white gel. The monomer complex primarily contributed to the hardness of egg white.
Biologically motivated composite image sensor for deep-field target tracking

The present work addresses the design of an image acquisition front-end for target detection and tracking within a wide range of distances. Inspired by raptor bird's vision, a novel design for a visual sensor is proposed. The sensor consists of two parts, each originating from the studies of biological vision systems of different species. The front end is comprised of a set of video cameras imitating a falconiform eye, in particular its optics and retina [1]. The back end is a software remapper that uses a popular in machine vision log-polar model of retino-cortical projection in primates [2], [3], [4]. The output of this sensor is a composite log-polar image incorporating both near and far visual fields into a single homogeneous image space. In such space it is easier to perform target detection and tracking for those applications that deal with targets moving along the camera axis. The target object preserves its shape and size being handled seamlessly between cameras regardless of distance to the composite sensor. The prototype of proposed composite sensor has been created and is used as a front-end in experimental mobile vehicle detection and tracking system. Its has been tested inside a driving simulator and results are presented.
Poroelastic-plastic consolidation - analytical solution

Consolidation of a poroelastic material that yields according to Drucker–Prager or Mohr–Coulomb criteria leads to a Stefan problem for time-dependent pore fluid pressure. The solution to the Stefan problem for a column of infinite depth is known and is adapted to poroelastic/plastic consolidation of a weightless material under a uniform surface load applied instantaneously and subsequently maintained constant. In this approach, the plastic potential and yield criterion need not be the same. If yielding occurs concurrently with application of load, then collapse is instantaneous. Otherwise, yielding may occur during the consolidation period. If so, then the elastic–plastic zone first appears at the surface and subsequently moves down the column. Depth to the elastic–plastic boundary is given by the simple expression Z = 2β√t where β is a constant determined from continuity conditions at the elastic–plastic boundary. Time-dependent surface displacement that occurs during consolidation is directly proportional to Z. There is little difference between elastic–plastic and purely elastic results in a numerical example because there is little difference in the respective consolidation coefficients. Elastic–plastic finite element results obtained from a column of finite depth are in close agreement with analytical results as long as the pore pressure at the bottom of the column does not change significantly from the value induced by application of the surface load. The analytical solution provides for: (1) efficient evaluation of material properties effects on consolidation, including strength and fluid compressibility, and (2) an accurate way of validating poroelastic/plastic computer codes that are based on Drucker–Prager and Mohr–Coulomb criteria. Copyright © 1999 John Wiley & Sons, Ltd.
Biodegradation of petroleum hydrocarbons in continental shelf regions of the Bering Sea

Rates of petroleum hydrocarbon biodegradation were measured in water and sediment samples collected from the Bering Sea. Radiolabelled hydrocarbons, hexadecane, pristane, 9-methyl anthracene, and benz(a)anthracene were used to measure most probable numbers of hydrocarbon degraders and biodegradation potentials for various classes of hydrocarbons. Additionally, a six week flow through experiment in the laboratory was conducted to determine biodegradative capacities of sediment microorganisms for alipathic and aromatic components of Cook Inlet crude oil. Results indicated low populations of hydrocarbon degraders in both waters and sediments of the Bering Sea, low mineralization of hydrocarbons, but some modification of the composition of crude oil exposed to the indiginous microorganisms of the Bering Sea. Some differences were observed between ice covered and ice free areas with higher rates of microbial oil degradation associated with ice covered areas. Flow-through experiments demonstrated very low biodegradation of crude oil by sediment microorganisms even when supplied with nutrients. For trajectory modelling purposes our studies indicate that conservation of hydrocarbons must be assumed for at least three weeks, providing sufficient time for oil spilt into the Bering Sea to impact coastal regions.
Totaro’s question for simply connected groups of low rank

Let k be a field and let G be a connected linear algebraic group over k. In a 2004 paper, Totaro asked whether a torsor X under G and over k which admits a zero cycle of degree d also admits a closed etale point of degree dividing d. We consider this question in the setting where G is a simply connected, semisimple group of rank at most 2 and k is of characteristic different from 2.
Normal beam spin asymmetries during the G0 forward angle measurement

The vector analyzing power measured in elastic scattering of transversely polarized electrons from an unpolarized nucleon is directly proportional to the imaginary part of the two photon exchange amplitude. There has been recent interest in explorations of the two photon exchange amplitude, as the real part has been proposed as a possible resolution of the discrepancy between Rosenbluth separation and polarization observable measurements of the ratio of the electric to magnetic proton form factor. The vector analyzing power appears in the experiment as an azimuthal asymmetry. It has been measured previously in the SAMPLE and A4 experiment with different kinematics than those achievable with the G0 apparatus. As part of the systematic checks for the G0 forward angle measurement at TJNAF, the normal beam spin asymmetry in the G0 detector array was measured with a 3 GeV beam incident upon a liquid hydrogen target. The experimental configuration was identical to the standard G0 forward angle running except that the beam was transversely polarized in the plane of the accelerator. The data collected cover a range in center of mass angle from 19° to 37°, with an eight-fold azimuthal symmetry. About 30 hours of data were taken in this configuration, resulting in an extracted vector analyzing power with a precision of a few ppm, which may already be able to provide some constraint on model predictions.
Protein folding and chart parsing

How can proteins fold so quickly into their unique native structures? We show here that there is a natural analogy between parsing and the protein folding problem, and demonstrate that CKY can find the native structures of a simplified lattice model of proteins with high accuracy.
An examination of the relation between combat experiences and combat-related posttraumatic stress disorder in a sample of Connecticut OEF-OIF Veterans.

Abstract Background Combat exposure is an important risk factor for posttraumatic stress disorder (PTSD). However, little research has examined specific combat experiences associated with PTSD and confirmatory factor analytically (CFA)-derived re-experiencing, avoidance, dysphoria, and hyperarousal symptom clusters. Methods A total of 285 predominantly older National Guard/Reservist OEF–OIF Veterans completed an anonymous mail survey that assessed demographics and deployment history, a broad range of combat experiences, PTSD, and unit and postdeployment social support. Results Personally witnessing someone from one’s unit or an ally unit being seriously wounded or killed ( β = 0.22), and being exposed to “friendly” fire ( β = 0.14) and land mines/traps ( β = 0.13) were the only three combat experiences associated with severity of combat-related PTSD symptoms, after adjustment for age, relationship status, unit support, postdeployment social support, and other combat experiences. Differential patterns of associations were observed for specific combat experiences in relation to CFA-derived symptom clusters (e.g., experiencing “friendly” fire was associated with re-experiencing and dysphoria symptoms, but not avoidance and hyperarousal symptoms). Personally witnessing someone from one’s unit or an ally unit being seriously wounded or killed (odds ratio [OR] = 4.34; 95% confidence interval [CI] = 1.62–11.61) and being exposed to “friendly” fire (OR = 2.94; 95%CI = 1.16–7.47) emerged as independent predictors of a positive screen for probable PTSD. Conclusions Results of this study suggest that witnessing someone in one’s unit or ally unit being seriously wounded or killed while in a combat zone and being exposed to “friendly” fire are most strongly associated with combat-related PTSD in this sample of OEF/OIF Veterans. Examination of the relation between specific combat experiences and combat-related PTSD in OEF/OIF Veterans may help inform etiologic models of PTSD, and guide prevention and treatment approaches in this population.
Milling Cutter Data Structures for Use in Force Models

In this study we present a new general representation for describing a milling cutter and an internal data structure that systematically stores the cutting edge segment properties of the milling cutter. The intention of this effort is to enable commercial milling simulation software packages to communicate and store complicated cutter information, and thus enable them to include improved models developed in academic research. Examples with various milling cutters are given, and the versatility of the structures is demonstrated by using two different cutting force models with three different milling cutters. Force calculation time was decreased by a factor of four by using the internal data structure to store pre-calculated trigonometric functions.Copyright © 2009 by ASME
Note on an anomaly in paging

In [1] the authors use a lemma to prove their Theorem 1 (pp. 352-353). While the lemma is true, there is a defect in its proof, for one cannot assume that each of the symbols appearing as a type IV reference is in t(Ek , s). Using their example (p. 350) as a reference string with k = 12, t(E12 , 3) is 534 and lacks the two symbols (1 and 2) which appear as type IV references.
The supraclavicular artery flap for lateral skull and scalp defects: effective and efficient alternative to free tissue transfer.

Objectives Describe the use of the supraclavicular artery flap for reconstruction of lateral skull and scalp defects. Discuss advantages and potential limitations of the supraclavicular artery flap. Design Case series. Setting Tertiary care academic medical center. Participants Patients undergoing lateral scalp and skull base resections. Main Outcome Measures Effectiveness in reconstructing lateral skull base defects and complications. Results All three patients reconstructed with the supraclavicular artery flap had excellent reconstructive outcomes. There were no flap losses, either complete or partial. There were no major complications, but one patient had a significant donor site dehiscence requiring local wound care. Referred sensation to the shoulder was alleviated by division of the sensory innervations into the flap. Conclusions The supraclavicular artery flap is an excellent option for lateral skull and scalp defects, and donor site morbidity is limited. It should be considered as an alternative to free tissue transfer.
The changing vision of marine minerals

Abstract Non-fuel marine minerals are reviewed from the perspective of resources and their value as active analogs that can advance understanding of types of ancient ore deposits that formed in marine settings. The theory of plate tectonics is the largest influence in expanding our vision of marine minerals and in developing our understanding of geologic controls of mineralization in space and time. Prior to the advent of plate tectonics, we viewed the ocean basins as passive sinks that served as containers for particulate and dissolved material eroded from land. This view adequately explained marine placer deposits (heavy minerals and gems), aggregates (sand and gravel), and precipitates (phosphorites and manganese nodules). Although numerous sites of placer mineral deposits are known on continental shelves worldwide, current activity pertains to diamond mining off southwestern Africa, tin mining off southeastern Asia, and intermittent gold mining off northwestern North America, which are all surpassed economically by worldwide recovery of marine sand and gravel, in turn dwarfed by offshore oil and gas. With the advent of plate tectonics, plate boundaries in ocean basins are recognized as active sources of mineralization in the form of hydrothermal massive sulfide deposits and proximal lower-temperature deposits hosted in oceanic crust (mafic at ocean ridges and felsic at volcanic island arcs), and of magmatic Ni–Cu sulfide, chromite and PGE deposits inferred to be present in the oceanic upper mantle–lower crust based on their occurrence in ophiolites. Some 300 sites of hydrothermal active and relict mineralization, most of them minor, are known at this early stage of seafloor exploration on ocean ridges, in fore-arc volcanoes, at back-arc spreading axes, and in arc rifts; deposits formed at spreading axes and transported off-axis by spreading are present in oceanic lithosphere but are virtually unknown. The TAG (Trans-Atlantic Geotraverse) hydrothermal field in the axial valley of the Mid-Atlantic Ridge (latitude 26° N) is considered to exemplify a major Volcanogenic Massive Sulfide (VMS) deposit forming at a spreading axis. The most prospective of these occurrences lie within the 200 nautical mile (370 km)-wide Exclusive Economic Zone (EEZ) of the nations of the volcanic island arcs of the western Pacific where metal content of massive sulfides (Ag, Au, Ba, Cu, Pb, Sb, Zn) exceeds that at ocean ridges. Plate tectonics early provided a framework for mineralization on the scale of global plate boundaries and is providing guidance to gradually converge on sites of mineralization through regional scales of plate reorganization, with the potential to elucidate the occurrence of individual deposits (e.g., Eocene Carlin-type gold deposits). Investigation of the spectrum of marine minerals as active analogs of types of ancient mineral deposits is contributing to this convergence. Consideration of questions posed by Brian Skinner (1997) of what we do and do not know about ancient hydrothermal mineral deposits demonstrates the ongoing advances in understanding driven by investigation of marine minerals.
Tales from the tail: Robust estimation of moments of environmental data with one-sided detection limits

Estimating the means and standard deviations of environmental data remains a great challenge because a substantial percentage of observations lies below or above detection limits. The inadequacy of several common, ad hoc estimation procedures is clear; this study instead proposes a robust moment estimation procedure for environmental data with a one-sided detection limit. The procedure assumes that the tails of the underlying distribution of the (transformed) data are symmetric, and censoring only occurs on one side. Through an application of the Renyi representation theorem, it is possible to use observations from the other side to learn the shape of the distribution below the detection limit, without specifying any particular parametric model, and consequently, derive the moment estimates of the distribution. A simulation provides a comparison of estimation performance between the proposed procedure and several existing estimators, and several real-life samples offer a good illustration.
Centroid-moment tensor solutions for July–September 1993

Abstract Centroid-moment tensor solutions are presented for 186 earthquakes that occurred during the third quarter of 1993. The solutions are obtained using corrections for aspherical earth structure represented by a whole mantle shear velocity model SH8/U4L8 of Dziewonski and Woodward
Three-phase wattmeter connections

FOR the past 15 years or more there have occured recurrently in technical literature articles giving methods of checking the connections of three-phase wattmeters. In February 1916 Prof. W. B. Kouwenhoven presented a long and detailed paper to the American Institute on the subject. (Vol. 35, Part I, page 183). Practically all these writings point out the frequency with which misconnections occur and their difficulty of detection. In fact this constant recurrence of the subject itself vouches for its importance but it might seem, particularly after Prof. Kouwenhoven's treatment, that another discussion of the subject would be a little superfluous. The writer feels, however, that this is not the case for the reason that all of the existing discussions of the subject which have come to his notice are either incomplete or contain serious errors.
Portable 4.6 Micrometers Laser Absorption Spectrometer for Carbon Monoxide Monitoring and Fire Detection

The air quality aboard manned spacecraft must be continuously monitored to ensure crew safety and identify equipment malfunctions. In particular, accurate real-time monitoring of carbon monoxide (CO) levels helps to prevent chronic exposure and can also provide early detection of combustion-related hazards. For long-duration missions, environmental monitoring grows in importance, but the mass and volume of monitoring instruments must be minimized. Furthermore, environmental analysis beyond low-Earth orbit must be performed in-situ, as sample return becomes impractical. Due to their small size, low power draw, and performance reliability, semiconductor-laser-based absorption spectrometers are viable candidates for this purpose. To reduce instrument form factor and complexity, the emission wavelength of the laser source should coincide with strong fundamental absorption lines of the target gases, which occur in the 3 to 5 micrometers wavelength range for most combustion products of interest, thereby reducing the absorption path length required for low-level concentration measurements. To address the needs of current and future NASA missions, we have developed a prototype absorption spectrometer using a semiconductor quantum cascade laser source operating near 4.6 micrometers that can be used to detect low concentrations of CO with a compact single-pass absorption cell. In this study, we present the design of the prototype instrument and report on measurements of CO emissions from the combustion of a variety of aerospace plastics.
Data-driven modeling and analysis of online social networks

With hundreds of millions of users worldwide, social networks provide incredible opportunities for social connection, learning, political and social change, and individual entertainment and enhancement in a wide variety of forms. In light of these notable outcomes, understanding information diffusion over online social networks is a critical research goal. Because many social interactions currently take place in online networks, we now have have access to unprecedented amounts of information about social interaction. Prior to the advent of such online networks, investigations about social behavior required resource-intensive activities such as random trials, surveys, and manual data collection to gather even small data sets. Now, massive amounts of information about social networks and social interactions are recorded. This wealth of data can allow us to study social interactions on a scale and at a level of detail that has never before been possible. We present an integrated approach to information diffusion in online social networks focusing on three key problems: (1) Querying and analysis of online social network datasets; (2) Modeling and analysis of social networks; and (3) Analysis of social media and social interactions in the contemporary media environment. The overarching goals are to generate a greater understanding of social interactions in online networks through data analysis, to develop reliable and scalable models that can predict outcomes of these social processes, and ultimately to create applications that can shape the outcome of these processes. We start by developing and refining models of information diffusion based on realworld data sets. We next address the problem of finding influential users in this data-driven framework. It is equally important to identify techniques that can slow or prevent the spread of misinformation, and hence algorithms are explored to address this question. A third interest is the process by which a social group forms opinions about an idea or product, and we therefore describe preliminary approaches to create models that accurately capture the opinion formation process in online social networks. While questions relating to the propagation of a single news item or idea are important, these information campaigns do not exist in isolation. Therefore, our proposed approach also addresses the interplay of the many information diffusion processes that take place simultaneously in a network and the relative importance of different topics or trends over multiple spatial and temporal resolutions.
An Epidemiological Model of the Natural History of a Disease Within a Multilevel Care System

Detailed epidemiological data on the entire course and treatment of illnesses requiring a variety of forms of management and various levels of institutionalization are scarce, probably due to the difficulty of assembling such data from a multiplicity of sources, particularly within complex and fragmented health care delivery systems. This paper described several analytic approaches to, and applications of, such a body of data, taken from a retrospective cohort study of 552 fractured hip cases incident in one year in an upstate New York county. Examples of six analytic applications of the data are presented, and emphasis is placed on the potential for practical use of some of the results.
Anterior corneal optical aberrations induced by laser in situ keratomileusis for hyperopia

Abstract Purpose To evaluate the effects of hyperopic laser in situ keratomileusis (LASIK) on anterior corneal higher-order aberrations (HOAs) (3rd to 6th orders). Setting Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. Methods In a retrospective study, 3rd-order to 6th-order HOAs from preoperative and 3-month postoperative corneal topographic maps of eyes that had hyperopic LASIK using the Visx Star S2 and Visx Star S3 laser systems were calculated. There were 20 eyes of 14 patients in each group; the optical and transition zones were 6.0 mm and 9.0 mm, respectively. The surgically induced changes in anterior corneal HOAs and the differences between the HOA changes in corneas treated with and without active eye tracking were analyzed. Results In both groups, hyperopic LASIK induced a significant reduction in 4th-order spherical aberration (SA) coefficients ( Z 4 0 ) in the 3.0 mm and the 6.0 mm central zones, and the decrease was significantly correlated with increasing hyperopic correction (except in the Visx S3 group's central 3.0 mm zone). In the 6.0 mm zone in both groups, the root-mean-square (RMS) of the SA ( Z 4 0 and Z 6 0 ) decreased significantly, whereas there were no significant changes in the total HOAs. By excluding Z 4 0 , the mean RMS values for the remaining 21 Zernike terms increased by more than 30% (both P Conclusions Hyperopic LASIK decreased SAs and reduced the magnitude of the SA increase that occurred with pupil dilation. Higher-order aberrations excluding the 4th-order SA increased significantly.
Effect of lesions of the ventrolateral preoptic nucleus on NREM and REM sleep.

Neurons in the ventrolateral preoptic nucleus (VLPO) in rats show c-fos activation after sleep and provide GABAergic innervation of the major monoamine arousal systems, suggesting that they may be a necessary part of the brain circuitry that produces sleep. We examined the effects on sleep behavior in rats of cell-specific damage to the VLPO by microinjection of ibotenic acid. Severe lesions of the central cell cluster of the VLPO ( approximately 80-90% cell loss bilaterally) caused a 60-70% decrease in delta power and a 50-60% decrease in nonrapid-eye-movement (NREM) sleep time (p 0.10). Lesions in the region containing scattered VLPO neurons medial or dorsal to the cell cluster caused smaller changes in NREM sleep time (24.5 or 15%, respectively) but were more closely associated with loss of REM sleep (r = 0.74; p < 0.01). The insomnia caused by bilateral VLPO lesions persisted for at least 3 weeks. Lesions of the VLPO caused no change in mean body temperature or its circadian variation; after small lesions of the ventromedial preoptic nucleus, body temperature showed normal circadian variation but a wider temperature range, and sleep behavior was not affected. These experiments delineate distinct preoptic sites with primary effects on the regulation of NREM sleep, REM sleep, and body temperature.
The purification of DNA from the genones of Paramecium aurelia and Tetrahymena pyriformis.

SYNOPSIS. Methods are described for the recovery of highly purified DNA from Paramecium aurelia and Tetrahymena pyriformis in high yields. Our DNA is only slightly contaminated with RNA and carbohydrate, and little or no protein can be detected. We could not reduce the RNA (orcinol-positive material) by further treatment (sephadex or hydroxyapatite chromatography and preparative CsCl gradients). At the extreme our DNA is contaminated with 15-20% RNA but the real value is most likely considerably lower than this. The DNA we have prepared from Paramecium and Tetrahymena shows all the properties of double-stranded, high molecular weight DNA when characterized by temperature melting, CsCl density gradient centrifugation and hydroxyapatite and sephadex chromatography. When deE have been investigating the DNA of the ciliated W protozoa Paramecium aurelia and Tetrahymena pyriformis, with the ultimate aim of characterizing the DNA of the micronucleus and macronucleus of these cells in qualitative terms. We have presented elsewhere our detailed reasons for comparing the organization of the DNA molecules of these nuclei ( 1, 2). We hope to correlate genetic studies (1) which have shown that the macronuclear genotype causes cells within a clone to have different phenotypes with differences in the populations of DNA molecules present in macronuclei. In order to isolate DNA or specific fractions of DNA and to characterize the molecules in terms of their renaturation properties following denaturation, it is essential to prepare DNA which is uncontaminated by RNA, protein, carbohydrates, lipids, etc. It is also important to be certain that this DNA is derived from only the protozoan genome and not contaminated with DNA from bacterial sources. We believe that some of the earlier studies did not suficiently eliminate such contamination nor indeed did they record the recovery of DNA from the cells. In such studies it is thus possible that only selected fractions of DNA were being examined and that contaminant molecules interfered in some of the qualitative and quantitative work. In the case of Paramecium DNA a potential source of contamination is the presence of DNA contributed from the food which in most cases is a single type of bacterium. This problem can be eliminated if Paramecium, like Tetrahymena, is grown under axenic conditions. In this report we will describe our methods for the preparation of DNA from Paramecium and Tetrahymena grown under axenic conditions. This DNA will then be characterized in terms of its purity, size, secondary structure, and base composition. We will also show the effects
Modeling Groundwater Upwelling as a Control on River Ice Thickness

The Tanana River flows through Interior Alaska, a region characterized by discontinuous permafrost. Studies link degrading permafrost to increased winter river discharge due to increasing groundwater input. In winter, Interior Alaska rivers are exclusively fed by groundwater, which serves as an external source of heat. In fact, some portions of rivers fed by groundwater maintain thin ice throughout the winter, or remain altogether ice-free, despite very cold air tempe ratures. These ice conditions represent a significant danger to winter travellers that use rivers fo r wintertime travel, particularly in this largely roadless area. We developed a determinist ic model to explore how fluctuations in groundwater discharge control ice thickness on the Tanana River. The model allows us to examine how local changes in groundwater characteristics affect ice dynamics by addressing two questions: What are the dominant factors controlling seasonal ice dynamics on the Tanana River? What are the rates of change in ice thickness resulting from observed and projected changes in these factors? Ice melt is amplified by increa sed hydraulic gradient, increased groundwater upwelling, increased air temperature, increased groundwater temperature, or increased snow depth. A warming c limate in regions with discontinuous permafrost is expected to increase groundwater input into rivers, decrease the temperature gradient between the atmosphere and the ice/water interface, and increase snow depths. All these changes contribute to decreased ice thickness and thus more hazardous conditions for winter travellers. The model illustrates the physical mechanisms, which corroborate s reports from Alaskans that ice conditions have become more dangerous in the spring, and further suggests that permafrost degradation could contribute to the degradation of river ice in a warming climate.
Expression of Endogenously Activated Secreted or Cell Surface Carboxypeptidase A Sensitizes Tumor Cells to Methotrexate-α-Peptide Prodrugs

Methotrexate (MTX) is one of the most commonly used agents in the treatment of solid malignancies; however, the toxicities of MTX to bone marrow and gastrointestinal tract complicate this therapy. We, therefore, propose a gene-dependent enzyme prodrug therapy to limit these toxicities by localizing the production of MTX to the site of the tumor. The combination of MTX-α-peptide prodrugs, which cannot be internalized by the cellular reduced folate carrier, with carboxypeptidase A (CPA), which can remove the blocking peptide, has been demonstrated previously in vitro using antibody-dependent enzyme prodrug therapy. CPA is normally synthesized as a zymogen that is inactive without proteolytic removal of its propeptide by trypsin. Therefore, to adapt this system to gene-dependent enzyme prodrug therapy, a mutant form of CPA was engineered, CPAST3, that does not require trypsin-dependent zymogen cleavage but is instead activated by ubiquitously expressed intracellular propeptidases. Purification, peptide sequencing, and kinetic analysis indicated that mature CPAST3 is structurally and functionally similar to the trypsin-activated, wild-type enzyme. In addition, CPAST3-expressing tumors cells were sensitized to MTX prodrugs in a dose- and time-dependent manner. To limit diffusion of CPA, a cell surface localized form was generated by constructing a fusion protein between CPAST3 and the phosphatidylinositol linkage domain from decay accelerating factor. SDS-PAGE and flow cytometric analysis of infected tumor cells indicated that CPADAF was cell surface localized. Finally, after retroviral transduction, this enzyme/prodrug strategy exhibited a potent bystander effect, even when <10% of the cells were transduced, because extracellular production of MTX sensitized both transduced and nontransduced cells.
Ideal and Nonideal Reasoning in Educational Theory

The terms “ideal theory” and “nonideal theory” are used in contemporary Anglophone political philosophy to identify alternative methodological approaches for justifying normative claims. Each term is used in multiple ways. In this article Alison M. Jaggar disentangles several versions of ideal and nonideal theory with a view to determining which elements may be helpful in designing models of real-world justice that are contextually relevant, morally plausible, and practically feasible.
A novel approach for on-line testable reversible logic circuit design

Two testable reversible logic gates are proposed in this paper. These gates can be used to implement reversible digital circuits with various levels of complexity. The major feature of these gates is that they provide online-testability for circuits implemented using these gates. The application of these gates in testable ripple carry, carry-skip adders and MCNC benchmark circuits have been illustrated.
Effects of Ad Libitum and Restricted Feeding on Semen Quantity and Quality, Body Composition, and Blood Chemistry of Caged Broiler Breeder Males

One hundred eighty, 16-wk-old, caged broiler breeder males were randomly assigned to one of three feeding treatments: 1) restricted feeding (RES), breeder-recommended levels minus 25%; 2) control feeding (CON), breeder-recommended levels; 3) full-fed (FF), ad libitum feeding. Each group received the same corn-soybean diet, with 15.5% CP and 2,878 kcal ME/kg feed. The males were ejaculated twice weekly, and BW, semen characteristics, hematocrits (HCT), and serum testosterone (T) were determined every 4 wk. At 17, 35, and 56 wk of age males were killed for body composition determination of percentages of protein, moisture, and fat. The FF males were heavier throughout the experiment than either CON or RES males. The FF group had a higher percentage of males in semen production than CON, which had a higher percentage of males in production than RES. Males of the FF group produced more semen with a higher spermatozoa concentration (SC) than CON, which males had higher spermatozoan concentrations than RES. The FF males had a higher level of T overall than CON or RES males. Hematocrits of FF were higher than those of CON birds, which were higher than those of RES birds. Body compositions were not significantly different among treatments at 17 wk; however, at 35 and 56 wk, FF males had a higher percentage of fat and a lower percentage of protein than birds in the other two groups. Significant positive correlations were found between body fat and the variables HCT, BW, semen weight (SW), and SC. Body weight was positively correlated with SW, and T was correlated with HCT.