cssi/SciSciGPT-SciSciNet huggingface dataset:
Internal refractive index changes affect light transport in tissue

This investigation explores the effect of index of refraction, as an optical property, on light transport through optically turbid media. We describe a model of light propagation that incorporates the influence of refractive index mismatch at boundaries within a domain. We measure light transmission through turbid cylindrical phantoms with different distributions of refractive index. These distributions approximate the heterogeneous, layered nature of biological tissue. Finite element method model calculations of diffuse transmittance through these phantoms show good agreement with the trends observed experimentally. We see that phase measurements of light that propagates through approximately 90 (mm) of scatter-dominated media may vary by 10 degrees depending upon the values of refractive index of the medium. Amplitude measurements are not as sensitive to this parameter as phase. Model calculations of diffuse reflectance from a semi-infinite slab geometry with different layers also shows good agreement with Monte Carlo simulations. We conclude that incorporating refractive index into light transport models may be worthwhile. Applying such a model in tomographic image reconstruction may improve the estimation of optical properties of biological tissues.
Mutable Protection Domains: Adapting System Fault Isolation for Reliability and Efficiency

As software systems are becoming increasingly complex, the likelihood of faults and unexpected behaviors will naturally increase. Today, mobile devices to large-scale servers feature many millions of lines of code. Compile-time checks and offline verification methods are unlikely to capture all system states and control flow interactions of a running system. For this reason, many researchers have developed methods to contain faults at runtime by using software and hardware-based techniques to define protection domains. However, these approaches tend to impose isolation boundaries on software components that are static, and thus remain intact while the system is running. An unfortunate consequence of statically structured protection domains is that they may impose undue overhead on the communication between separate components. This paper proposes a new runtime technique that trades communication cost for fault isolation. We describe Mutable Protection Domains (MPDs) in the context of our Composite operating system. MPD dynamically adapts hardware isolation between interacting software components, depending on observed communication “hot-paths,” with the purpose of maximizing fault isolation where possible. In this sense, MPD naturally tends toward a system of maximal component isolation, while collapsing protection domains where costs are prohibitive. By increasing isolation for low-cost interacting components, MPD limits the scope of impact of future unexpected faults. We demonstrate the utility of MPD using a webserver, and identify different hot-paths for different workloads that dictate adaptations to system structure. Experiments show up to 40 percent improvement in throughput compared to a statically organized system, while maintaining high-fault isolation.
An estimation study for control of a lattice model of thin film deposition

The deposition of a thin film is a dynamic process that is complex and subject to unmeasured disturbances. When the dynamics and final material properties are dominated by atomic scale phenomena, it is difficult to apply existing optimization and control tools to improve process repeatability and to optimize the resulting material properties. Currently, feedback loops are used to control sensed quantities, and optimization has been applied to macroscopic reactor conditions like fluid flow. Ultimately, one would like to directly control the material properties that determine the performance of an integrated circuit or MEMS device, even when the property of interest is not directly measured. In this simulation study, several estimation strategies are explored to infer surface roughness from a measurement of step density. The dynamics of the growth process are represented by an atomic scale kinetic Monte-Carlo simulation, whose computational demands are then reduced through model reduction. The reduced order model is used in the estimator, which is then applied to the full Monte-Carlo simulation. The surface roughness estimate is used with a feedback controller, which corrects for temperature offset and modeling error in the presence of input and output noise.
Interannual variability of elevation on the Greenland ice sheet: effects of firn densification, and establishment of a multi-century benchmark

In order to interpret measurements of ice-sheet surface elevation changes in terms of climatic or dynamic trends, it is necessary to establish the range of stochastic variability of elevation changes resulting from interannual fluctuations of accumulation rate and firn density. The analyses presented here are intended to facilitate such interpretations by defining benchmarks that characterize elevation-change variability in central Greenland, in the current climate and over the past millennium. We use a time- dependent firn-densification model coupled to an ice- and heat-flow model, forced by annual accumulation rate and temperature reconstructions from the Greenland Ice Sheet Project II (GISP2) ice core, to examine the elevation changes resulting from this climatic forcing. From these results, effective firn densities are calculated. These are factors that convert water-equivalent accumulation-rate variability to surface elevation variability. A current-climate benchmark is defined by applying this conversion to Van der Veen and Bolzan’s water-equivalent statistics, and to a 50 year accumulation variability estimate from the GISP2 core. Elevation-change statistics are compiled for the past millennium to define longer-term benchmarks, which show that multi-century variability has been substantially larger than current variability estimated by Van der Veen and Bolzan. It is estimated here that the standard deviation of net elevation change over 5 and 10 year intervals has been 0.27 and 0.38 m, respectively. An approximate method for applying these quantitative results to other dry-snow sites in Greenland is suggested.
Introduction: Public Policy and the Urbanization of Farmland

Public debate over farmland conversion has focused on the magnitude, the social costs, and whether public land-use policies are appropriate and effective. A review of the problems of farmland protection and equity concludes that the issues are best dealt with at a local level, and that excessive urbanization of good farmland is not the primary problem. 21 references. (DCK)
Channel-forming solvate crystals and isostructural solvent-free powder of 5-hydroxy-6-methyl-2-pyridone.

Crystals of 5-hy­droxy-6-methyl-2-pyridone, (I), grown from a variety of solvents, are invariably trigonal (space group R\overline{3}); these are 5-hy­droxy-6-methyl-2-pyridone acetone 0.1667-solvate, C6H7NO2·0.1667C3H6O, (Ia), and 6-methyl-5-hy­droxy-2-pyridone propan-2-ol 0.1667-solvate, C6H7NO2·0.1667C3H8O, (Ib), and the forms from methanol, (Ic), water, (Id), benzonitrile, (Ie), and benzyl alcohol, (If). They incorporate channels running the length of the c axis that contain extensively disordered solvent mol­ecules. A solvent-free sublimed powder of 5-hy­droxy-6-methyl-2-pyridone micro­crystals is essentially isostructural. Inversion-related host mol­ecules inter­act via pairs of N—H⋯O hydrogen bonds to form R22(8) dimers. Six of these dimers form large R126(42) puckered rings, in which the O atom of each N—H⋯O hydrogen bond is also the acceptor in an O—H⋯O hydrogen bond that involves the 5-hy­droxy group. The large R126(42) rings straddle the \overline{3} axes and form stacked columns via π–π inter­actions between inversion-related mol­ecules of (I) [mean inter­planar spacing = 3.254 A and ring centroid–centroid distance = 3.688 (2) A]. The channels are lined by methyl groups, which all point inwards to the centre of the channels.
“It Was Like This, I Think”: Constructing an Adoption Narrative for Chinese Adopted Children

Using qualitative survey data from 35 adoptive parents of children from China, I explore the type of narrative parents construct about their child's “abandonment.” Parents tell the story they know ...
Urban Underclass: The Wayward Travels of a Chaotic Concept

This commentary critically engages with arguments made by Loic Wacquant in his book Urban Outcasts on the nature of public discourse regarding concentrated urban poverty in the United States. In particular, it elaborates a critical reading of the international circulation of social-scientific analyses of urban poverty—in particular the concept of the "urban underclass"—which rose to prominence through research on Chicago neighborhoods. This concept has subsequently influenced scholarly and public policy approaches to characterizing and combating entrenched urban poverty and long-term unemployment in Europe, Asia, and elsewhere. I challenge the appropriateness of the concept as well as the direction of public policymaking that has downplayed, if not ignored, questions of job availability and job quality in urban areas.
The modified Puestow procedure for complicated hereditary pancreatitis in children

Abstract Purpose: The aim of this study was to evaluate the role of longitudinal pancreaticojejunostomy (modified Puestow procedure) in the treatment of complicated hereditary pancreatitis (HP) in children. Methods: The authors reviewed their experience with the modified Puestow procedure for complicated HP in patients less than 18 years of age at a single tertiary care facility between 1973 and 1998. Main study outcomes included surgical morbidity and mortality, pre- and postoperative pancreatic function, number of hospitalizations, and percentile ideal body weight (IBW). Results: Twelve patients (6 boys and 6 girls) with a mean age of 9.3 years were identified. Presenting diagnoses were abdominal pain (n = 10), failure to thrive (n = 4), pancreatic pleural effusion (n = 2), and pancreatic ascites (n = 1). Blood loss was greater in patients who underwent distal pancreatectomy to localize the duct (n = 6) than in those who underwent direct transpancreatic duct localization (n = 6; 29.1 ± 6.8 v 8.3 ± 3.7 mL/kg; P =.03). Other complications in patients who underwent distal pancreatectomy included splenic devascularization requiring splenectomy (n = 1) and postoperative intraabdominal bleeding with subsequent left subphrenic abscess (n = 1). There was no surgical mortality. Five patients had steatorrhea preoperatively that resolved in 4 patients postoperatively and was well controlled in the fifth. Mean number of hospitalizations for pancreatitis in the 5 years after surgery were markedly less than in the 5 years preceding surgery (0.4 ± 0.2 v 3.5 ± 0.5; P =.01, n=9). Percentile ideal body weight tended to increase within the first postoperative year (24.6 ± 6.8 v 45.0 ± 8.3; P =.07, n=9), and by the third year this trend was clearly significant (27.0 ± 7.2 v 60.9 ± 9.5; P =.01, n=8). Conclusions: In children with complicated HP, the modified Puestow procedure improves the quality of life by improving pancreatic function, decreasing hospitalizations, and increasing the percentile ideal body weight. Direct pancreatic duct localization during the procedure had a lower morbidity rate than localization via distal pancreatectomy. It is our impression that surgery performed in the early stage of complicated disease may preserve pancreatic function. J Pediatr Surg 35:343-348. Copyright © 2000 by W.B. Saunders Company.
Dilation and evacuation training in maternal-fetal medicine fellowships.

Objective Many maternal-fetal medicine (MFM) specialists provide dilation and evacuation (DE 95% confidence interval, 1.8–30). Conclusion MFM physicians are in a unique position to provide termination services for their patients with pregnancy complications. Many MFM subspecialists provide DE therefore, D&E training opportunities should be offered as a part of MFM fellowship.
Characterization of medium- and long-range structure with the connectivity matrix

Abstract The connectivity matrix is presented as a formalism for characterizing the medium-and-long range structure of noncrystalline solids. First, it is defined relative to the linkage of structural building blocks. The connectivity matrix has the advantage (in comparison to the radial distribution function) of not involving structural averaging. Second, the connectivity matrix for interstices is defined. There is a duality between the matrices for building blocks and interstices. The building block connectivity matrix is attractive for automated structural model building. The interstitial connectivity matrix is attractive for diffusional modeling.
A Simple System of Evolutionary Operation Subject to Empirical Feedback

Experimentation can lead to progress through empirical feedback or through scientific (technical) feedback; or more usually by some combination of both [Box and Jenkins, 19621. Empirical feedback is typical of the “try it and see” or Edisonian approach. Here information fed back from the experiment triggers a simple reaction like “accept a modification which increases yield.” By contrast scientific feedback occurs as an interaction between the data and the knowledge, experience, and imagination of the experimenter. It may result in reactions to data which are quite unpredictable by consideration of the data alone. An example would be the decision to vary in further experimentation certain specific factors not even considered in the previous stages of the work. In this paper an empirical feedback model for an elementary form of evolutionary operation is considered. From this investigation it is clear that the strategy necessary to achieve optimal empirical feedback might give very poor scientific feedback ...
Interactions of charged Langmuir monolayers with dissolved ions

Dissociation of protons from fatty acid Langmuir monolayers causes competitive adsorption of other counterions and partial charge neutralization. A new equilibrium model incorporating surface electrochemical and thermodynamic features is presented. The Stern–Gouy–Chapman equations are used, along with a modified Langmuir isotherm in which ion activities in the mixed surface monolayer instead of concentrations are employed. A two‐dimensional lattice model with Flory–Huggins interaction parameters χij is invoked to obtain the activities of the ions in the monolayer. The competitive adsorption of ions to fatty acid monolayers is either ‘‘ideal’’ (χij=0), or nonideal, depending on the ions mixing behavior with protons. Previous electrochemical models apply only for ideal adsorption, which appears to occur for Cd2+ and Ca2+. The nonideal adsorption is characterized successfully by the use of the above interaction parameters. Ba2+ ions show negative deviations from ideal adsorption, i.e., they adsorb less than ...
Cytogenetic Low-Dose Hyperradiosensitivity Is Observed in Human Peripheral Blood Lymphocytes

Purpose The shape of the ionizing radiation response curve at very low doses has been the subject of considerable debate. Linear-no-threshold (LNT) models are widely used to estimate risks associated with low-dose exposures. However, the low-dose hyperradiosensitivity (HRS) phenomenon, in which cells are especially sensitive at low doses but then show increased radioresistance at higher doses, provides evidence of nonlinearity in the low-dose region. HRS is more prominent in the G2 phase of the cell cycle than in the G0/G1 or S phases. Here we provide the first cytogenetic mechanistic evidence of low-dose HRS in human peripheral blood lymphocytes using structural chromosomal aberrations. Methods and Materials Human peripheral blood lymphocytes from 2 normal healthy female donors were acutely exposed to cobalt 60 γ rays in either G0 or G2 using closely spaced doses ranging from 0 to 1.5 Gy. Structural chromosomal aberrations were enumerated, and the slopes of the regression lines at low doses (0-0.4 Gy) were compared with doses of 0.5 Gy and above. Results HRS was clearly evident in both donors for cells irradiated in G2. No HRS was observed in cells irradiated in G0. The radiation effect per unit dose was 2.5- to 3.5-fold higher for doses ≤0.4 Gy than for doses >0.5 Gy. Conclusions These data provide the first cytogenetic evidence for the existence of HRS in human cells irradiated in G2 and suggest that LNT models may not always be optimal for making radiation risk assessments at low doses.
Is the Job Burning Me Out? An Exploratory Test of the Job Characteristics Model on the Emotional Burnout of Prison Staff:

Although emotional burnout of prison staff is costly to all involved, it has not received the kind of research attention that is warranted. This exploratory study focused on the impact of job characteristics on the emotional exhaustion dimension of burnout of prison staff. Using data from 272 staff members at a Midwestern state prison, this study found that both job feedback and job autonomy had negative effects on the index of emotional exhaustion burnout; however, both supervision and job variety had nonsignificant effects. The study further discussed possible reasons for both the significant and nonsignificant relationships.
A 3′-Untranslated Region of Catalase Messenger-RNA Composed of a Stem-Loop and Dinucleotide Repeat Elements Binds a 69-kDa Redox-Sensitive Protein

Abstract Rat lung extract contains protein that forms redox-sensitive, specific complexes with a 1130-base catalase cRNA ( J. Biol. Chem . 267, 2853-2855, 1992). The present paper reports studies aimed at delimiting the site of protein binding on the RNA and characterizing the protein. A 240-base sequence was identified as the 3′ untranslated region of catalase mRNA that binds lung protein in a redox-sensitive manner. Two elements within this 240-base region bind protein; one is a 36-base element that has a computer-predicted stem-loop secondary structure and the other is a CA dinucleotide repeat. Competition studies indicate that both elements are required for specific binding. Cross-competition experiments demonstrated that catalase RNA-binding protein (CAT-BP) is not the iron-responsive element-binding protein. Ultraviolet light-induced cross-linking and two-dimensional electrophoresis showed that CAT-BP has an apparent molecular mass of 69 kDa and appears to be composed of four isoforms. Competition studies indicate the stem-loop cis element is directly involved in binding CAT-BP. In addition to rat, the 69-kDa catalase RNA-binding protein is present in mouse and human fibroblast cell lines.
Ostwald ripening in non-spherical morphologies

A statistical theory of Ostwald ripening has been extended to describe the diffusion-limited coarsening of non-spherical convex interfaces. Distributional analysis is performed on a series of interfacial patches, where the patches and adjacent isopotential surfaces have a common fixed ratio of principal curvatures. Results of this analysis are expressed in terms of a dimensionless shape factor that ranges from zero for spherical interfaces to unity for cylindrical surfaces. Coarsening rate constants are calculated as a function of both the precipitate volume fraction and this geometric shape factor. Application of these results to ripening of ellipsoidal precipitates and other morphologies are discussed.
Determination of Phenyl Isocyanate in a Flow-Injection System With Infrared Spectrometric Detection

Summary A flow-injection system for the determination of isocyanate moiety, as an example of organic functional groups, is described; infrared detection is used in the transmittance mode. Absorption is measured at 4.40 lim with carbon tetrachloride as the solvent and carrier stream. Injections (25µ) of 0.100–16.0 mM phenyl isocyanate solutions provide a useful calibration curve with a linear response up to about 1.5 mM. The detection limit for phenyl isocyanate at a signal-to-noise ratio of 2 is about 4 µg ml−1 in the sample injected.
Differential Localization and Development-dependent Expression of G-protein Subunits, Goα and Gβ, in Rabbit Heart

Among various G-protein subunits identified in atrial and ventricular membranes from newborn and adult rabbits, the most remarkable developmental and tissue-specific differences were observed in the amounts of the alpha-subunit of Go (Go alpha) and the beta-subunit (G beta). Go alpha was abundant in atrial membranes especially from newborn rabbits but was barely detectable in ventricles. In contrast, G beta was present in both atrial and ventricular membranes. In both tissues the level of G beta-2 was much higher than that of G beta-1. Starting just after birth, the high levels of Go alpha in atria at term decreased gradually to about half of the amount in term animals, at 30 days of age, while the amount of G beta remained relatively constant until 26 days after birth. The levels of G beta in ventricles slowly declined during neonatal development. Similar developmental patterns were also observed when these parameters were studied in membranes isolated from cultured myocytes. Northern blot analysis showed the presence of mRNA for Go alpha-1A isoform in RNA samples from atria but not those from ventricles. The developmental expression of Go alpha-1A mRNA was somewhat different from that of Go alpha protein, whereas the time course of G beta mRNA expression was similar to that of G beta protein. Among other G-protein subunits tested, the amount of the splice variant of Gs protein, Gs alpha-1, in atrial as well as ventricular membranes increased with age of animals, while the amounts of Gs alpha-2, Gi alpha 2 and G alpha q/11 did not change significantly during development. These results indicate differential localization and tissue-specific developmental expression of G-protein subunits in rabbit heart.
MicroRNA targeting in mammalian genomes: genes and mechanisms

We briefly review the history of microRNA (miRNA) research and some of the lessons learnt. To provide some insights as to how and why miRNAs came into existence, we consider the evolution of the RNA interference machinery, miRNA genes, and their targets. We highlight the importance of systems biology approaches to integrate miRNAs as an essential subnetwork for modulating gene expression programs. Building accurate computational models that can simulate highly complex cell-specific gene expression patterns in mammals will lead to a better understanding of miRNAs and their targets in physiological and pathological situations. The impact of miRNAs on medicine, either as potential disease predisposing factors, biomarkers, or therapeutics, is highly anticipated and has started to reveal itself. Copyright © 2010 John Wiley & Sons, Inc. For further resources related to this article, please visit the WIREs website.
BILATERAL ROBOTIC ASSISTED LAPAROSCOPIC HEMINEPHROURETERECTOMY

Laparoscopic surgery has an increasingly important role in pediatric urology. It has emerged as an alternative means of performing nephrectomy and heminephroureterectomy in the pediatric population.1 To our knowledge we report the first case of bilateral laparoscopic heminephroureterectomy. CASE REPORT A 4-year-old girl presented with recurrent urinary tract infections and persistent urinary incontinence. Diagnostic evaluation included ultrasonography (fig. 1) and computerized tomography (fig. 2) which revealed bilateral duplicated collecting systems, left upper pole hydroureteronephrosis and right upper pole hydronephrosis. A renal scan demonstrated bilateral nonfunctioning upper pole moieties and cystoscopy revealed an opening below the bladder neck where 2 ectopic ureters entered. Cystoscopy was performed before the procedure and ureteral catheters were inserted in the 2 lower pole systems. A 6 port transperitoneal approach was used. The patient was placed in the right lateral decubitus position. A pure laparoscopic approach was used to reflect the colon medially, and isolate and dissect the upper pole ureter downward toward the bladder and upward toward the kidney. The lower end of the ureter was clipped and divided. We switched to the daVinci robotic system (Intuitive Surgical, Mountain View, California) to dissect the renal hilum and upper pole vessels, and isolate the upper pole segment. The upper pole segment was excised using the Harmonic scalpel (Ethicon, Somerville, New Jersey) and the argon beam coagulator was used to fulgurate the base of the upper pole segment. The patient was then repositioned to the left lateral decubitus position, and a similar procedure was performed on the right side. A pure laparoscopic method was used initially to reflect the colon medially, perform the Kocher maneuver on the duodenum, and isolate and divide the upper pole ureter. The daVinci robotic system was then used to isolate and excise the upper pole segment, and facilitate fulguration of the base of the upper pole with the argon beam coagulator. There were no intraoperative or postoperative complications. The overall surgical time was 7 hours and 20 minutes. Estimated blood loss was 15 cc. The patient was placed on ketorolac postoperatively and required only 2 doses of supplemental narcotic analgesia. She was discharged home on postoperative day 2 and returned to full activity in 2 weeks. DISCUSSION
Infrared absorption spectra of deuterated polyisoprenes

Abstract The infrared spectra of high- cis forms of polyisoprene-3,4,4- d 3 , polyisoprene-1,1,4,4- d 4 and poly(2-methyl- d 3 -1,3, butadiene-1,1- d 2 ) are presented and discussed in the light of previously presented spectra of high- cis forms of polyisoprene- d 0 , -3- d and - d 8 . The major new assignments are out-of-plane deformation vibrations associated with the 1,4 units: -C(CH 3 )CH-, as in the d 4 polymer, 815 cm −1 (counterpart of the well-known 840 cm −1 band in the d 0 polymer); -C(CH 3 )CD-, in the d 3 polymer, 685 cm −1 (same as in the d 1 polymer); and -C(CD 3 )CH-, in the d 5 polymer, 805 cm −1 . The corresponding band associated with the remaining isotopic variation of the 1,4 unit, -C(CD 3 )CD-, at 650 cm −1 in the d 3 polymer, was noted previously and its assignment confirmed. Replacement of both the CH 3 by CD 3 and an adjacent CH 2 by CD 2 results in the out-of-plane CH or CD deformation being shifted by ~35 cm −1 to lower frequencies.
Mass and heat transfer modeling of a physical vapor deposition effusion source

The effusion sources modeled in this article are part of a continuous process for production of thin-film photovoltaic modules. Industrial production requires tight control of the vapor flow rates during long run times. A dynamic model is developed to provide physical insight, facilitate simulation studies, and to be incorporated into model-based control schemes. Prediction of the vapor flow rate requires both the mass and energy balance to be solved. Model parameters are estimated based on literature and experimental data, and the entire model is shown to be consistent with independent experimental data. © 2005 American Institute of Chemical Engineers AIChE J, 51: 878–894, 2005
IMPACT OF THE DECLINE OF RAW SILK ON TWO MAJOR COCOON‐PRODUCING REGIONS IN JAPAN1

Both sericultural and manufacturing branches of Japan's once highly important raw silk industry suffered severe dislocations following peak production about 1930. World economic depression, synthetic fiber development, and World War II were fundamental causes. Reeling mill closures stemmed from bankruptcies, governmental readjustment programs, conversions into defense plants, bombings, and post-war business rationalization. Mulberry acreage shrank principally owing to wartime food shortages and profitable post-war alternatives, particularly orcharding. This paper contrasts changes observed in two of the most specialized Japanese cocoon-producing regions, Gumma Prefecture, on the Kanto lowlands where sweet potatoes and upland rice characteristically followed mulberry, and the Nagano Basin, representative of highland basins in central and northern Honshu, where orchards commonly replaced mulberry. Proportional losses in both reeling capacity, measured in number of reeling machines, and in mulberry acreage were above the national average in the Nagano Basin and below it in Gumma. Governmental policies and local factors caused these differences.
Empirical orthogonal function analysis of the diurnal cycle of precipitation in a multi‐scale climate model

[1] Long-term variability in the hydrologic cycle is poorly simulated by current generation global climate models (GCMs), partly due to known climatological biases at shorter timescales. We demonstrate that a prototype Multi-scale Modeling Framework (MMF) provides a superior representation of the spatial and temporal structure of precipitation at diurnal timescales than a GCM. Results from empirical orthogonal function (EOF) decomposition of the boreal summer climatological composite diurnal cycle of precipitation in an MMF are compared to a GCM and satellite data from the Tropical Rainfall Measuring Mission. The eigenspectrum, principal component time series, and the spatial structure of leading EOFs in an eigenmode decomposition of the MMF composite day are a much better match to observations than the GCM. Regional deficiencies in the MMF diurnal cycle are manifest as localized anomalies in the spatial structures of the first two leading EOFs.
Percutaneous management of chronic deep venous reflux: review of experimental work and early clinical experience with bioprosthetic valve.

Lower extremity chronic deep venous insufficiency (CDVI) is common and remains a major health problem worldwide. Selected patients benefited from direct deep vein valve surgical repair or valve transplantation. A major limitation of this approach is that most of the patients are not candidates for these procedures due to obstructions or residual thrombus throughout the vein. The past 15 years have wit- nessed experimental efforts at catheter-based management of CDVI. This review describes the initial designs and experimental evolution of a mechanical and biopros- thetic venous valve that can be implanted by using a transcatheter technique. These valves consisted of single, double, or triple cusp leaflets made of synthetic or biologi- cal materials attached to a carrier or frame. All described devices for percutaneous transcatheter valve placement rely on some form of a vascular stent for valve attachment.
Novel Cause of Spurious Mode Switching in Dual‐Chamber Pacemakers: Atrioventricular Desynchronization Arrhythmia

Spurious Mode Switching. Spurious mode switching is a common problem in DDDR pacing and implantable cardioverter defibrillator systems. It may produce symptoms indistinguishable from classic pacemaker syndrome or paroxysmal atrial arrhythmias due to loss of AV synchrony. The dominant cause of spurious mode switching is oversensing of far-field R waves. This report describes a novel cause of spurious mode switching, AV desynchronization arrhythmia. Clinical manifestations, recognition, and management are discussed.
Atypical Cushing's Syndrome in Dogs: Arguments For and Against

In the past 5 to 10 years, much interest has arisen in the syndrome of occult hyperadrenocorticism. Patients with occult hyperadrenocorticism purportedly have many clinical signs and routine laboratory abnormalities suggestive of the presence of typical hyperadrenocorticism, or Cushing's syndrome (ie, hypercortisolism either due to a pituitary or adrenal tumor). However, the standard diagnostic tests-corticotropin (ACTH) stimulation and low-dose dexamethasone suppression tests-are normal. A theory has arisen that the clinical signs of occult hyperadrenocorticism are due to excess adrenal secretion of sex hormones rather than cortisol. The authors believe that the role of sex hormones has not been proven. The article reviews the evidence both for and against the importance of sex hormones in creating occult hyperadrenocorticism.
Information Retrieval, Information Structure, and Information Agents

This paper presents a customizable architecture for software agents that capture and access information in large, heterogeneous, distributed electronic repositories. The key idea is to exploit underlying structure at various levels of granularity to build high-level indices with task-specific interpretations. Information agents construct such indices and are configured as a network of reusable modules called structure detectors and segmenters. We illustrate our architecture with the design and implementation of smart information filters in two contexts: retrieving stock market data from Internet newsgroups, and retrieving technical reports from Internet ftp sites.
Open string fields and D-branes

These lecture notes review some modern developments in open string field theory. We begin with a discussion of the physical motivations and general framework of open SFT. We then briefly introduce and contrast the two basic formalisms, Boundary SFT and cubic SFT, and summarize the main results about tachyon condensation obtained with both approaches. Next, we review the Vacuum SFT conjecture, according to which D-brane solutions correspond to string fields that are projectors of Witten's *-algebra. We describe the Boundary CFT technique to compute *-products and construct projector solutions. We argue that VSFT accounts precisely for the expected moduli space of D-branes.
Synaptic and Network Mechanisms of Sparse and Reliable Visual Cortical Activity during Nonclassical Receptive Field Stimulation

SUMMARY During natural vision, the entire visual field is stimulated by images rich in spatiotemporal structure. Although many visual system studies restrict stimuli to the classical receptive field (CRF), it is known that costimulation of the CRF and the surrounding nonclassical receptive field (nCRF) increases neuronal response sparseness. The cellular and network mechanisms underlying increased response sparseness remain largely unexplored. Here we show that combined CRF + nCRF stimulation increases the sparseness, reliability, and precision of spiking and membrane potential responses in classical regular spiking (RSC) pyramidal neurons of cat primary visual cortex. Conversely, fast-spiking interneurons exhibit increased activity and decreased selectivity during CRF + nCRF stimulation. The increased sparseness and reliability of RSC neuron spiking is associated with increased inhibitory barrages and narrower visually evoked synaptic potentials. Our experimental observations were replicated with a simple computational model, suggesting that network interactions among neuronalsubtypes ultimately sharpen recurrent excitation, producing specific and reliable visual responses.
Avalanches at the core-mantle boundary

[1] The partial collapse of topographic structure at the core-mantle boundary (CMB) in avalanches, slumps or turbidity flows, would cause sudden temperature changes in both the upper core and the lower mantle. Although such collapses are hypothetical, it is interesting to investigate the potential consequences. Downwelling from such events could disrupt core convection cells and trigger geomagnetic excursions and reversals. Buoyant sediment from the freezing of the inner core is hypothesized to rebuild the avalanched structures. Large avalanches could trigger mantle plumes. Oblique extraterrestrial impacts impart high shear to the CMB, and can trigger one or more simultaneous avalanches, yielding observed coincidences between craters, tektite fields and reversals. A triggered avalanche can explain the coincidence between the formation of the largest known volcanic province (the Ontong-Java Plateau), the start of the 35 Myr Cretaceous geomagnetic quiet period, and reported coincidences between large flood basalts and extinctions.
Feedback control of the spatiotemporal firing pattern of a basal ganglia microcircuit model

One of the fundamental objectives in systems neuroscience is to precisely control the spatiotemporal firing patterns of cortical neurons to elicit a desired pattern of activity. In this work, we study the effects of intracortical micro-stimulation on the dynamics of a basal ganglia microcircuit model, and explore the feasibility of controlling the spatiotemporal firing patterns of the modeled population in the presence of unobserved inputs. Results from the simulation study suggest that properly designed Multiple-Input-Multiple-Output (MIMO) feedback control paradigm can force a subpopulation of observed output neurons to follow a prescribed spatiotemporal firing pattern despite the presence of unobserved inputs. The accuracy of the spike timing of the controlled neural firing with respect to the reference spike trains is in the order of tens of milliseconds.
Role of metalloproteins in the clinical management of head and neck squamous cell carcinoma

Metalloproteins are a group of catalytic proteins, which play significant roles in cell cycle and death. Matrix metalloproteinases (MMPs) are a family of endopeptidases that are capable of digesting extracellular matrix components. They have been implicated in carcinogenesis and recent developments have been made to use MMPs clinically to predict outcomes. In the future, selective inhibition of these proteins and their regulatory pathways may prove useful in anticancer therapeutics. We present a review article on the clinical applications of metalloproteins in head and neck squamous cell carcinoma (HNSCC). Metalopanstimulin is highlighted as a putative metalloprotein of interest for those treating HNSCC. Expression of particular metalloproteins has correlation with lymph node metastasis, tumor invasiveness, and overall prognosis in HNSCC.
Localization accuracy and immobilization effectiveness of a stereotactic body frame for a variety of treatment sites.

Purpose The purpose of this study was to analyze the pretreatment setup errors and intrafraction motion using cone beam computed tomography (CBCT) for stereotactic body radiation therapy patients immobilized and localized with a stereotactic body frame for a variety of treatment sites. Methods and Materials Localization errors were recorded for patients receiving SBRT for 141 lung, 29 liver, 48 prostate, and 45 spine tumors representing 1005 total localization sessions. All patients were treated in a stereotactic body frame with a large custom-molded vacuum pillow. Patients were first localized to the frame using tattoos placed during simulation. Subsequently, the frame was aligned to the room lasers according to the stereotactic coordinates determined from the treatment plan. Every patient received a pretreatment and an intrafraction CBCT. Abdominal compression was used for all liver patients and for approximately 40% of the lung patients to reduce tumor motion due to respiration. Results The mean ± standard deviation pretreatment setup errors from all localizations were −2.44 ± 3.85, 1.31 ± 5.84, and 0.11 ± 3.76 mm in the anteroposterior, superoinferior, and lateral directions, respectively. The mean pretreatment localization results among all treatment sites were not significantly different (F test, P P Conclusions Despite the varied tumor locations, the pretreatment mean localization errors for all sites were found to be consistent among the treatment sites and not significantly different, indicating that the body frame is a suitable immobilization and localization device for a variety of tumor sites. Our pretreatment localization errors and intrafraction shifts compare favorably with those reported in other studies using different types of immobilization devices.
Template Adaptation based Fingerprint Verification

This paper proposes a minutiae-based template adaptation algorithm which can be applied after the fingerprint authentication process. The algorithm updates a template by using a query fingerprint, which is successfully verified by the fingerprint matcher as a high quality genuine input. This algorithm generates an updated minutiae set by using not only the minutiae but also local fingerprint quality information and utilizes a successive Bayesian estimation to evaluate the credibility of minutiae and their types. The proposed algorithm updates fingerprint minutiae information in the template as well as appends new minutiae from the query fingerprint. Preliminary experiments show an average 32.7% EER reduction and an even higher matching accuracy improvement at low false accept rates.
Prevalence and mortality of acute lung injury and ARDS after lung resection

Study objectives To describe the frequency and outcome of patients with acute lung injury (ALI) and ARDS who require mechanical ventilation (MV) after lung resection, and to analyze preoperative and perioperative variables associated with mortality. Methods We retrospectively reviewed the case records of all patients who underwent lung resection and acquired ALI and/or ARDS and required invasive MV and ICU admission at a tertiary-care cancer center from January 1, 2002, to December 31, 2004. Preoperative and perioperative information including ICU-specific variables and outcome data were analyzed. Data are presented as median (range). Results During the study period, 2,039 patients underwent a total of 2,192 lung resections. ALI/ARDS developed in 50 patients (2.45%). The prevalence of ALI/ARDS by procedure was as follows: pneumonectomy, 7.9% (10 cases in 126 procedures); lobectomy/bilobectomy, 2.96% (31 cases in 1,047 procedures); and sublobar resection, 0.88% (9 cases in 1,019 procedures). There were 28 men (56%) and 22 women (44%). Median age was 68.5 years (range, 44 to 88 days). Median time of presentation to the ICU with ALI/ARDS following surgery was 4 days (range, 1 to 22 days). Median ICU length of stay was 10 days (range, 2 to 43 days), and median hospital LOS was 26.5 days (range, 6 to 93 days). During hospitalization, 20 of the 50 patients (40%) died: 16 in the ICU and 4 after ICU discharge. The mortality rate was highest after pneumonectomy (50%), followed by lobectomy (42%) and sublobar resections (22%). Although increased age was associated with a higher ICU mortality, none of the preoperative and perioperative variables were significantly associated with hospital mortality. There was a marginally significant association between mortality and time of presentation to the ICU after surgery (p = 0.06). Conclusions Our results confirm that ALI/ARDS after lung resection is associated with a high mortality in patients who require invasive MV and ICU care.
Hollow‐fiber membrane‐based rapid pressure swing absorption

A novel gas purification technique called rapid pressure swing absorption (RAPSAB) was developed by integrating the best features of membrane contacting, gas-liquid absorption, and pressure swing adsorption (PSA). In this cyclic separation process, a well-packed microporous hydrophobic hollow-fiber module was used to achieve nondispersive gas absorption from a high-pressure feed gas into a stationary absorbent liquid on the module shell side during a certain part of the cycle followed by desorption of absorbed gases from the liquid in the rest of the cycle. The total cycle time varies between 20 s and upwards. Separation of mixtures of N{sub 2} and CO{sub 2} (around 10%) where CO{sub 2} is the impurity to be removed was studied using absorbent liquids such as pure water and a 19.5% aqueous solution of diethanolamine (DEA). Three RAPSAB cycles studied differ in the absorption part. Virtually pure N{sub 2} streams were obtained with DEA as absorbent demonstrating the capability of bulk separation to very high levels of purification. Numerical models developed predict the extent of purification for pure water and the DEA solution for one of the simpler cycles. Model simulations describe the observed behavior well.
Assortative flocking in crossbills and implications for ecological speciation

How reproductive isolation is related to divergent natural selection is a central question in speciation. Here, we focus on several ecologically specialized taxa or ‘call types’ of red crossbills (Loxia curvirostra complex), one of the few groups of birds providing much evidence for ecological speciation. Call types differ in bill sizes and feeding capabilities, and also differ in vocalizations, such that contact calls provide information on crossbill phenotype. We found that two call types of red crossbills were more likely to approach playbacks of their own call type than those of heterotypics, and that their propensity to approach heterotypics decreased with increasing divergence in bill size. Although call similarity also decreased with increasing divergence in bill size, comparisons of responses to familiar versus unfamiliar call types indicate that the decrease in the propensity to approach heterotypics with increasing divergence in bill size was a learned response, and not a by-product of calls diverging pleiotropically as bill size diverged. Because crossbills choose mates while in flocks, assortative flocking could lead indirectly to assortative mating as a by-product. These patterns of association therefore provide a mechanism by which increasing divergent selection can lead to increasing reproductive isolation.
The Developmental Genetics of Microevolution

What is the relationship between variation that segregates within natural populations and the differences that distinguish species? Many studies over the past century have demonstrated that most of the genetic variation within natural populations that contributes to quantitative traits causes relatively small phenotypic effects. In contrast, the genetic causes of quantitative differences between species are at least sometimes caused by few loci of relatively large effect. In addition, most of the results from evolutionary developmental biology are often discussed as though changes at just a few important 'molecular toolbox' genes provide the key clues to morphological evolution. On the face of it, these divergent results seem incompatible and call into question the neo-Darwinian view that differences between species emerge from precisely the same kinds of variants that segregate much of the time in natural populations. One prediction from the classical model is that many different genes can evolve to generate similar phenotypes. I discuss our studies that demonstrate that similar phenotypes have evolved in multiple lineages of Drosophila by evolution of the same gene, shavenbaby/ovo. This evidence for parallel evolution suggests that svb occupies a privileged position in the developmental network patterning larval trichomes that makes it a favourable target of evolutionary change.
Exploring the Metabolic and Genetic Control of Gene Expression on a Genomic Scale

DNA microarrays containing virtually every gene of Saccharomyces cerevisiae were used to carry out a comprehensive investigation of the temporal program of gene expression accompanying the metabolic shift from fermentation to respiration. The expression profiles observed for genes with known metabolic functions pointed to features of the metabolic reprogramming that occur during the diauxic shift, and the expression patterns of many previously uncharacterized genes provided clues to their possible functions. The same DNA microarrays were also used to identify genes whose expression was affected by deletion of the transcriptional co-repressor TUP1 or overexpression of the transcriptional activator YAP1. These results demonstrate the feasibility and utility of this approach to genomewide exploration of gene expression patterns.