cssi/SciSciGPT-SciSciNet huggingface dataset:
Collective ratings for online labor markets

In online labor markets, experts sell their expertise to buyers. Despite the success and the perceived promise of online labor markets, they face a serious practical challenge: providing appropriate incentives for experts to participate and exert effort to accurately (successfully) complete tasks. Personal rating schemes have been proposed to address this challenge: they provide differentiated reward/punishment to experts in order to incentivize them to cooperate (i.e. to their best to complete tasks). However, when the transactions in a market are subject to errors, the experts are wrongly punished frequently whenever personal rating schemes are deployed. This not only reduces the experts' incentives to cooperate, but also it harms the market performance such as the obtained social welfare or revenue. To mitigate the problem of wrong punishments, we develop a novel game-theoretic formalism based on collective ratings. We formalize an online labor market as a two-sided trading platform where buyers and experts interact repeatedly. The market designer's problem is to create a market policy that maximizes the market's revenue subject to the constraints imposed by the characteristics of the market and the incentives of the participants. We propose to organize such markets by dividing experts into groups for which a collective rating is created and maintained based on the buyers' aggregated feedback. We analyze how the group size and the adopted rating scheme affect the market's revenue and the social welfare of the participants in the market, and determine the optimal design of the market policy. We show that collective ratings are surprisingly more effective and more robust than personal rating for a wide variety of online labor markets.
Observables in 2+1 dimensional gravity

Abstract We study some aspects of gauge invariant observables in Witten's new approach to canonical 2+1 dimensional gravity as a Chern-Simons gauge theory. We derive the Poisson brackets of the Wilson line observables in the case that space is topologically the plane with N isolated points removed. The infinitely many Wilson line observables provide a complete but highly redundant description of the physical phase space. We eliminate this redundancy by showing how to write any Wilson line as a function of a finite set of observables. The Poisson brackets of this finite set of observables from a non-trivial closed algebra which has an interesting structure. We solve the quantum operator ordering problem and thus convert the classical Poisson bracket algebra into a quantum mechanical commutator algebra. We argue that this algebra could serve as an alternative starting point for 2+1 dimensional gravity.
Mass spectrometry and the environmental sciences

Abstract Research in environmental mass spectrometry focuses on two broad areas: development of new methods for a wide range of pollutants; and using existing methods to understand the fate of pollutants in nature. This paper will present examples of both types of research. In some environmental settings it is important to have rapid analytical turnaround, which suggests that samples should be analyzed in the field rather than in a remote laboratory. Thus, there has been considerable interest in “fieldable” mass spectrometers. Volatile and water soluble analytes can be introduced into a mass spectrometer by passing the water sample over a semi-permeable membrane. The analytes of interest pass through the membrane, but the water does not. This method may be useful in situations that require a continuous readout of concentration. Like mass spectrometrists everywhere, environmental scientists have explored the many facets of liquid chromatographic mass spectrometry. Work in our laboratory has centered on continuous flow fast atom bombardment (CF-FAB) as the LC MS interface. In addition, flow injection analysis is possible using CF-FAB. By avoiding chromatographic separation, the throughput of the analytical system is increased. Frequently, tandem mass spectrometry is necessary to unscramble the chemical signals produced by this technique. Electron capture negative ionization mass spectrometry can achieve sensitivities of a few attomoles for selected compounds; furthermore, the technique can be remarkably specific. These features make it ideal for the analysis of highly chlorinated environmental contaminants such as chlorinated dioxins. Such an application will be presented in detail.
A simple contact–friction interface element with applications to buried culverts

A simple friction–contact interface element is introduced which simulates frictional slippage, separation, and re-bonding of two bodies initially mating at a common interface and subsequently deforming with an arbitrary static loading schedule. Constraint equations between initially mating node pairs and the general principle of virtual work are used to formulate the interface element for a finite element solution procedure. Some advantages of the interface element include; easy implementation intostandard finite element programs, direct determination of interface forces without round-off problems, and the generality afforded by the virtual work formulation to include other non-conservative models in the system. The application of the interface element to an idealized buried culvert problem illustrates that the model behaves properly. A second application, for a long-span culvert installation with incremental soil loading, demonstrates the importance of modelling slippage at the culvert–soil interface in order to conform with experimental observations.
DYMOS: a dynamic modification system

Programs are frequently modified during their lifetime. Furthermore, modifications to some systems have to be made on the fly; that is, without stopping their execution. For example, changes to airline reservation systems, telephone switching systems, and on-line banking systems have to performed dynamically. Other continuously running systems, such as operating systems, may be modified on the fly to increase their availability.DYMOS is a programming system that supports a programmer modifying a StarMod program dynamically. StarMod [2] is an extension of Modula [3]. To modify procedures dynamically, the programmer modifies and recompiles the source code of the procedures to be replaced and then requests the system to change the current core image to incorporate new code and data.
Energy performance of advanced stripper configurations

Abstract This study determines the energy benefit of advanced stripper configurations for 8 m PZ, 7 m MDEA/2 m PZ, and 5 m MDEA/5 m PZ. Three novel configurations were tested: (1) interheated stripper, (2) two-stage flash with cold rich bypass, and (3) two-stage flash with cold rich bypass and a low temperature adiabatic flash. Generally, increasing the complexity improved process performance, but in some cases the improvements were too marginal to justify the additional capital cost. Configuration 3 has the added benefit of removing entrained oxygen before feeding the solvent to the high temperature flash vessels, but its energy performance is very sensitive to operating conditions. This paper also describes the creation of a thermodynamic, hydraulic, and kinetic model in Aspen Plus® that predicts experimental data for 8 m PZ, 7 m MDEA/2 m PZ, and 5 m MDEA/5 m PZ over operationally significant temperature and loading ranges. The next step in this work will include conducting techno-economic studies to quantify the capital and operating cost tradeoffs associated with these novel configurations.
Accelerating smolt development and downstream movement in yearling chinook salmon with advanced photoperiod and increased temperature

Abstract To accelerate smolt development and downstream migration in yearling spring chinook salmon ( Oncorhynchus tshawytscha ), treatment groups at Dworshak National Fish Hatchery (Idaho) were exposed to 3-month advanced photoperiod and ambient temperature (4–6°C). In each of 3 years, photoperiod treatment began in late December or January and continued for 13 to 18 weeks until release between 29 March and 5 April into the Clearwater River. Additional groups exposed to either the advanced photoperiod or ambient light were reared at an elevated water temperature (11–12°C) for 10 to 14 days preceding release. Downstream movement and recovery proportions were evaluated using passive-integrated-transponder (PIT) tags. Photoperiod treatment increased gill Na + K + ATPase levels significantly at the time of release in 2 of the 3 study years and in all 3 years resulted in significantly faster travel times to Lower Granite Dam, 117 km downstream. The combination of photoperiod and increased temperature treatment resulted in the highest gill Na + K + ATPase levels at release, the fastest downstream movement, and significantly higher recovery proportions downstream. Temperature treatment alone had no effect on gill Na + K + ATPase level or recovery proportion and resulted in significantly slower travel time to Lower Granite Dam. Treatment groups exhibiting faster travel time to Lower Granite Dam also passed McNary Dam (343 km downstream) sooner, although the differences were not as great.
Cervical spine MRI in abused infants

Abstract Objective: To determine clinical utility of screening with cervical spine MRI to detect unsuspected cord injury in children with head injury from child abuse. Design: Prospectively collected case series. Setting—Tertiary care children's hospital and county medical examiner's office. Patients: Twelve children with intracranial injury secondary to child abuse. None was clinically suspected to have cord injury. Includes all eligible children whose attending felt: (a) needed follow-up cranial imaging; (b) could be safely imaged; and (c) whose caretakers consented between November, 1991 and September, 1994. Interventions: MRI scans of the cervical spine were obtained either more than 3 days after clinical presentation or postmortem. Main Outcome Measures: Clinical observations by neurologist, child protection team pediatrician and medical examiners by prospective protocol. MRI scans evaluated by prospective radiology protocol with emphasis on cervical cord injury. Results: Four of the five autopsied children had small subdural or subarachnoid hemorrhages at the level of the cervical spine; MRI scan did not identify them. MRI did not identify cord injury in any child studied. Conclusion: Routine cervical spine MRI scans are probably not warranted in children with head injury secondary to child abuse without clinical symptoms of cervical cord injury.
Reliability of physiological and subjective responses to physical and psychosocial exposures during a simulated manufacturing task

Abstract Responses to physical and psychosocial exposures can be measured using diverse methods, but their reliability, particularly under multiple exposures, is largely unknown. Five classes of methods were used to assess physiological and subjective responses among 24 participants to four combinations of physical and psychosocial exposures while performing two identical sessions of a simulated overhead manufacturing task. As an exploratory analysis, test–retest reliability was quantified using intraclass correlation coefficients (ICC) and coefficients of variation (CV). Discomfort ratings were reliable under less favorable exposures, and ratings of the psychosocial environment were most reliable under favorable social support. Workload ratings were most reliable with high physical exposure and favorable social support, and task performance was reliable overall. EMG and heart rate had relatively low reliability. Slightly less than half of the variables were considered reliable, but reliability depended on exposure conditions. Relevance to industry: The study provides information on the reliability of commonly used exposure measurement methods. The results can guide the selection of physiological and psychological work outcome measurements in future studies and work evaluations.
Studies on the irreversible adsorption of T1 bacteriophage.

Abstract 1. 1. Normal E. coli, strain K12, adsorb T1 phage irreversibly at 37 °C., somewhat better in the presence than in the absence of glucose. 2. 2. If normal cells are “starved” of glucose for periods of 2–6 hr., their ability to bind phage irreversibly is considerably reduced. 3. 3. The addition of glucose or pyruvate to “starved” glucose-grown cells and of glucose or acetate to “starved” acetate-grown cells restores their ability to effect irreversible attachment. 4. 4. Dinitrophenol, azide, and fluoride interfere with the process of irreversible attachment to normal cells and with the restoration of “starved” cells. 5. 5. The experimental evidence is interpreted to suggest that energy is required for the step of irreversible attachment of phage to bacteria.
Historical perspectives of The American Association for Thoracic Surgery: Craig R. Smith

Craig Richey Smith, Jr, the 92nd president of The American Association for Thoracic Surgery (AATS), was born in Cleveland, Ohio, on November 17, 1948, several days after incumbent Harry S. Truman defeated heavily favored Thomas E. Dewey. He was the second of 4 children born to 22-year-old parents, his namesake Craig Smith and Mary Glover Smith, a first-grade teacher. Smith’s father started at the bottom rung of management in a Cleveland machine tool company while serving in the Navy Reserve. Smith spent much of his childhood on the move, and he quickly learned to adapt to change. In later years, the ease with which he embraced progress became a hallmark of his career as a leader and pioneer. During the Korean War, the family bounced across the continent, finally settling in Philadelphia, where he finished his senior year of high school at Harrington High. Smith excelled at football and was versatile playing multiple positions, including quarterback, running back, and safety. He also was accomplished at lacrosse, wrestling, and the long-jump. In his early years, Smith’s most influential role models were his grandparents. His grandfather, Donald Mitchell Glover, was a Harvey Cushing trainee and accomplished pediatric plastic surgeon, deeply revered by the family and community. He instilled in Smith the energy, love, and passion for patient care and hard work. His grandmother, Leona van Gorder Glover, was one of the first women of her generation to become a doctor. She was charismatic, lively, and independently wealthy because of the family-owned McKesson & Robbins company. She introduced Smith and his brother to the outdoors, teaching them the art of fly-fishing and horseback riding. In high school, Smith had a lackluster academic performance and was mislabeled an underachiever. Eventually, he was accepted to Williams College, where he was convinced that he was the ‘‘last student to be accepted.’’ Worried about not graduating, Smith refused to buy mugs, T-shirts, or other collegiate memorabilia until after the first
Largely detuned injection-locked semiconductor lasers

The equations for a semiconductor laser subject to injection are examined numerically and analytically for large values of the detuning parameter. Our analysis is motivated by recent experimental studies using either distributed feedback laser diodes or vertical-cavity surface-emitting lasers. For negative detuning, we show that a pulsating intensity regime may coexist with a stable steady state. Transitions between time-periodic and steady states as the injection rate is progressively increased or decreased appear through sudden jumps. Of particular interest is the fact that the upper locking point corresponds to a bifurcation point to quasiperiodic intensity oscillations. For positive detuning, the pulsating intensity regime is the only stable state until steady state locking smoothly occurs through a Hopf bifurcation point. Our analysis is based on a new asymptotic analysis of the semiconductor laser equations which allows analytical expressions for all bifurcation points.
Spatial organization and signal transduction at intercellular junctions

The coordinated organization of cell membrane receptors into diverse micrometre-scale spatial patterns is emerging as an important theme of intercellular signalling, as exemplified by immunological synapses. Key characteristics of these patterns are that they transcend direct protein-protein interactions, emerge transiently and modulate signal transduction. Such cooperativity over multiple length scales presents new and intriguing challenges for the study and ultimate understanding of cellular signalling. As a result, new experimental strategies have emerged to manipulate the spatial organization of molecules inside living cells. The resulting spatial mutations yield insights into the interweaving of the spatial, mechanical and chemical aspects of intercellular signalling.
Mallet finger treatment

The mallet finger deformity is easy to diagnose because the patient is unable to extend the distal phalanx of a finger. A lateral radiograph of the finger usually shows whether this is a fracture-type mallet or a purely tendinous disruption. These injuries are commonly the result of a work-or sports-related injury. The vast majority of these injuries can be treated with splinting with very few long-term sequelae or negative side effects. For those fracturetype injuries that cannot be properly reduced or maintained with an external splint, the Ishiguru technique described in this article is versatile and reliable. Although the majority of mallet fingers can be treated with an external splinting technique, this buttress pinning technique is extremely valuable to the armamentarium of the practicing hand surgeon.
Relaxing Global Decrescence Conditions in Lyapunov Theorems for Hybrid Systems

Abstract Lyapunov methods have been successfully applied to compute the Region of Attraction (ROA) of a system, i.e. the set of states that remain invariant for all time. A popular method for constructing Lyapunov functions is the Sum of Squares (SOS) approach. Current methods for determining stability of hybrid systems using SOS require either stability over the entire hybrid guard or knowledge of the switching times, limiting the types of systems that can be analyzed. In this paper, we introduce a new method to relax these constraints by only requiring decrescence properties over the 'active' subsections of each guard. We introduce our new formulation, explore useful modeling techniques, then apply them to five examples.
Effect of Oxide Scale Compositions on Metal Dusting Corrosion of Fe-Based Alloys

Abstract Oxide scales on the surface of Fe-based alloys play an important role in prevention of metal dusting corrosion. Phase composition of oxide scales was studied by Raman spectroscopy, x-ray d...
Characterization of the Viscoelastic Behavior of Polyaniline Solutions for Fiber Spinning

Solutions of emeraldine base(EB) in DMPU have been successfully spun into fibers and characterized according to their morphology, mechanical and electrical properties. This study presents results for as-spun (undrawn) fibers. The viscoelastic behavior of EB spin solutions have been investigated with dynamic measurements of the complex moduli, first normal stress coefficient, and complex viscosity. A knowledge of the viscoelastic behavior of emeraldine base solutions is crucial for effective processing into fibers and films.
Uncoupled and coupled approaches to predict macrocrack initiation in fiber reinforced ceramic matrix composites

Abstract Localized fiber pull-out is one of the fracture features of fiber reinforced ceramic matrix composites. The onset of this mechanism is predicted by using Continuum Damage Mechanics, and corresponds to a localization of the deformations. After deriving two damage models from a uni-axial bundle approach, and criteria at localization, different axisymmetric configurations are analyzed through two different approaches to predict macrocrack initiation.
The Role of T cell PPAR γ in mice with experimental inflammatory bowel disease

Peroxisome proliferator-activated receptor γ (PPAR γ) is a nuclear receptor whose activation has been shown to modulate macrophage and T cell-mediated inflammation. The objective of this study was to investigate the mechanisms by which the deletion of PPAR γ in T cells modulates immune cell distribution and colonic gene expression and the severity of experimental IBD. PPAR γ flfl; CD4 Cre+ (CD4cre) or Cre- (WT) mice were challenged with 2.5% dextran sodium sulfate in their drinking water for 0, 2, or 7 days. Mice were scored on disease severity both clinically and histopathologically. Flow cytometry was used to assess lymphocyte and macrophage populations in the blood, spleen, and mesenteric lymph nodes (MLN). Global gene expression in colonic mucosa was profiled using Affymetrix microarrays. The deficiency of PPAR γ in T cells accelerated the onset of disease and body weight loss. Examination of colon histopathology revealed significantly greater epithelial erosion, leukocyte infiltration, and mucosal thickening in the CD4cre mice on day 7. CD4cre mice had more CD8+ T cells than WT mice and fewer CD4+FoxP3+ regulatory T cells (Treg) and IL10+CD4+ T cells in blood and MLN, respectively. Transcriptomic profiling revealed around 3000 genes being transcriptionally altered as a result of DSS challenge in CD4cre mice. These included up-regulated mRNA expression of adhesion molecules, proinflammatory cytokines interleukin-6 (IL-6) and IL-1β, and suppressor of cytokine signaling 3 (SOCS-3) on day 7. Gene set enrichment analysis (GSEA) showed that the ribosome and Krebs cycle pathways were downregulated while the apoptosis pathway was upregulated in colons of mice lacking PPAR γ in T cells. The expression of PPAR γ in T cells is involved in preventing gut inflammation by regulating colonic expression of adhesion molecules and inflammatory mediators at later stages of disease while favoring the recruitment of Treg to the mucosal inductive sites.
Electron-phonon bound states and impurity band formation in quantum wells

A generalized propagation matrix method is used to study how scattering from local Einstein phonons affects resonant electron transmission through quantum wells. In particular, the parity and the number of the phonon mediated satellite resonances are found to depend on the available scattering channels. For a large number of phonon channels, the formation of low-energy impurity bands is observed. Furthermore, an effective theory is developed which accurately describes the phonon-generated sidebands for sufficiently small electron-phonon coupling. Finally, the current-voltage characteristics caused by phonon-assisted transmission satellites are discussed for a specific double-barrier geometry.
A Cell Wall-associated, Receptor-like Protein Kinase

Physical connections between higher plant cell walls and the plasma membrane have been identified visually, but the molecules involved in the contact are unknown. We describe here an Arabidopsis thaliana protein kinase, designated Wak1 for wall-associated kinase, whose predicted extracytoplasmic domain contains several epidermal growth factor repeats and identity with a viral movement protein. Wak1 fractionates with insoluble material when plant tissue is ground in a variety of buffers and detergents, suggesting a tight association with the plant extracellular matrix. Immunocytochemistry confirms that Wak1 is associated with the cell wall. Enzymatic digestion of the cell wall allows the release of Wak1 from the insoluble cell wall fraction, and protease experiments indicate that Wak1 likely has a cytoplasmic kinase domain, and the EGF containing domain is extracellular. Wak1 is found in all vegetative tissues of Arabidopsis, and has relatives in other angiosperms, but not Chlamydomonas. We suggest that Wak1 is a good candidate for a physical continuum between the cell wall and the cytoplasm, and since the kinase is cytoplasmic, it also has the potential to mediate signals to the cytoplasm from the cell wall.
MIXING POLYMERS OF DIFFERENT VISCOSITIES

Abstract The mixing of viscous polymers of dissimilar viscosities undergoing an overall shear is considered. Data are presented to illustrate the effects of component viscosity ratio and relative volume fraction on the quality of mixing. Experiments and analysis are based upon the geometry suggested by a tumbled mixture of polyethylene pellets in the hopper of an extruder. For a system in which the viscosity of the initially disperse phase exceeds that of the major component, deformation is modelled as the elongation of circular cylinders resulting from heightened shear stresses and discontinuous normal stresses at the component interface. In fluids as viscous as the polymers considered, these stresses are strongly dependent upon the cross-sectional area of the mixing channel, and the interaction between elongating drops is modelled as a decreasing effective cross-sectional area. 1t is shown that the interaction between neighboring drops is sufficiently strong that at a certain drop length the disperse ph...
Perturbation of Cope's Rearrangement: 1,3,5-Triphenylhexa-l,5-diene. Chameleonic or Centauric Transition Region?

Two types of perturbations of Cope's rearrangement are distinguished by their occupancy of sets of four “active” and two “nodal” positions. A “chameleonic” model of a continuum of chair-like transition regions is defined as extending from two noninteracting allyl radicals at one extreme to cyclohexa-1,4-diyl diradical at the other. Perturbations are analyzed quantitatively in terms of obligatory corrections for conjugative interaction in the educt, and a model of the transition region that specifies transference of stabilization energies of the perturbing substituents on allyl radicals if occupying active positions, and on secondary radicals if occupying nodal positions. When this model is applied to the chameleonic 2,5- (nodal) and 1,4- (active) diphenylhexa-l,5-dienes, good agreement with empirical lowering of enthalpies of activation per phenyl group of −8.7 and −4.4 kcal mol-1, respectively, is obtained. In a perturbation of mixed type, 1,3,5-triphenylhexa-1,5-diene (1,3-diphenyl-active; 5-phenyl-noda...
Enhancing Learning While Creating a Library Presence in Course Management Systems

Web 2.0 has made information more accessible and offers opportunities to make library resources more visible. This article presents several strategies for incorporating libraries and library resources into Web sites and course management systems. The tools presented are appropriate for many types of libraries and work with most Web-based systems. Readers who are exploring ways to integrate resources into other sites will find a convenient list of ideas.
Animal mitochondrial DNA as a genetic marker in population and evolutionary biology

Animal mitochondrial DNA (mtDNA) is playing an increasingly important role as a genetic marker in population and evolutionary biology. The popularity of this molecule derives, in part, from the relative ease with which clearly homologous sequences can be isolated and compared. Simple sequence organization, maternal inheritance and absence of recombination make mtDNA an ideal marker for tracing maternal genealogies. Rapid rate of sequence divergence (at least in vertebrates) allows discrimination of recently diverged lineages. Studies of mtDNAs from a diversity of animal groups have revealed significant variation among taxa in mtDNA sequence dynamics, gene order and genome size. They have also provided important insights into population structure, geographic variation, zoogeography and phylogeny.
Differential phase optical coherence probe for depth-resolved detection of photothermal response in tissue

We describe a differential phase low-coherence interferometric probe for non-invasive, quantitative imaging of photothermal phenomena in biological materials. Our detection method utilizes principles of optical coherence tomography with differential phase measurement of interference fringe signals. A dual-channel optical low-coherence probe is used to analyse laser-induced thermoelastic and thermorefractive effects in tissue with micrometre axial resolution and nanometre sensitivity. We demonstrate an application of the technique using tissue phantoms and ex-vivo tissue specimens of rodent dorsal skin.
The influence of suppository bases upon the rectal absorption of acetylsalicylic acid

Plasma levels of acetylsalicylic acid were administered rectally in three different types of suppository bases and were compared to plasma levels of aspirin administered orally. Statistically no significant difference existed between the absorption of acetylsalicylic acid from the Carbowax®, type base given rectally and acetylsalicylic acid administered orally. Irritation studies conducted reveal that little or no irritation results from administration of acetylsalicylic acid suppositories of both the cocoa butter and Carbowax®, types, while glycerinated gelatin causes a high incidence of irritation.
Java nano patterns: a set of reusable objects

Software patterns are used in many applications and domains. They reduce time, effort and cost as they increase reliability, reusability and testability when used for developing software systems. Although they have been criticized for their high level of abstraction, design patterns are the most commonplace patterns used. Furthermore, micro patterns are introduced in the literature. They have a lower level of abstraction and deal with Java software programs at the level of a class while design patterns describe the system design in general. In this paper, I am introducing a lower level of abstraction for Java patterns. Nano patterns are a group of reusable methods that are frequently used in Java software development. Sixteen nano patterns are defined into five groups, according to their privileges, nature and functionality. Additionally, I provide experimentation and initial results and conclude that nano patterns reduce more time, effort and cost for a Java-based software project.
Modeling and analysis of middleware design for streaming power grid applications

High quality, high throughput sensor devices in the power distribution network are driving an increase in the volume and the rate of data streams available to monitor and control the power grid. Middleware support is essential to coordinate data streams with distributed power models and adapt to situations with data communication failures and errors in the sensor measurements. One challenge in designing this middleware support is scalability. In particular, the number of sensor devices and their intercommunications is a significant factor in determining temporal and functional properties of power models such as distributed state estimation. In this paper, we present our experience modeling the entire data flow from sensor devices to distributed state estimators using middleware. This model helps to analyze the middleware's behavior and its scalability in coordinating data streams.
The new policy environment for food aid: the challenge of sub-Saharan Africa.

Abstract Food-aid decisions are being made in a new policy environment and implemented under changing institutional arrangements and guidelines. Constrained budgets and changing US agricultural policies, as well as economic and policy reform in developing countries, affect food-aid decision-making and implementation at the national level. Global forces — trade liberalization, WTO negotiations and the outcome of the recent World Food Summit — create both constraints and opportunities for food aid's role in a more complicated and dynamic world.
Self-irradiation and annealing of plutonium and plutonium-aluminum alloys

Abstract The electrical resistivity of single-phase alpha and delta plutonium at 20°K increases with time. The initial rate of increase in resistivity of unalloyed alpha is greater than in alloyed delta by a factor of approximately 6. This increase in resistivity is attributed to radiation damage caused by the alpha activity in plutonium, and is believed to have its origin in lattice defects produced by the α-particles and their accompanying recoil nuclei. An appreciable fraction of these lattice defects are removed by annealing in the temperature range below 100°K. The self irradiation behavior of two-phase alloys consisting of alpha-plus-delta phase mixtures is also discussed.
Effect of Acetylsalicylic Acid on the Liver Response to Endotoxin

SummaryGeneral responses of the dog to a lethal intravenous injection of endotoxin have been previously reported. The present investigation was devised to study the mechanism of the canine liver response to endotoxin. Experiments were carried out on an in situ liver preparation with controlled hepatic arterial and portal venous blood flows. Fifty mg acetylsalicylic acid/kg administered intravenously prior to endotoxin injection prevented the decrease in mean systemic arterial pressure and obliterated the constriction observed in both hepatic artery and hepatic vein in animals given endotoxin alone. The mechanism of action of acetylsalicylic acid is unknown.
The Increasing Racial Disparity in Infant Mortality: Respiratory Distress Syndrome and Other Causes

Although substantial declines in infant mortality rates have occurred across racial/ethnic groups, there has been a marked increase in relative black-white disparity in the risk of infant death over the past two decades. The objective of our analysis was to gain insight into the reasons for this growing inequality on the basis of data from linked cohort files for 1989-1990 and 1995-1998. We found a nationwide reversal from a survival advantage to a survival disadvantage for blacks with respect to respiratory distress syndrome over this period. The results are consistent with the view that the potential for a widening of the relative racial gap in infant mortality is high when innovations in health care occur in a continuing context of social inequality. As expected, the results for other causes of infant mortality, although similar, are less striking. Models of absolute change demonstrate that among low-weight births, absolute declines in mortality were greater for white infants than for black infants.
Training models of anatomic shape variability

Learning probability distributions of the shape of anatomic structures requires fitting shape representations to human expert segmentations from training sets of medical images. The quality of statistical segmentation and registration methods is directly related to the quality of this initial shape fitting, yet the subject is largely overlooked or described in an ad hoc way. This article presents a set of general principles to guide such training. Our novel method is to jointly estimate both the best geometric model for any given image and the shape distribution for the entire population of training images by iteratively relaxing purely geometric constraints in favor of the converging shape probabilities as the fitted objects converge to their target segmentations. The geometric constraints are carefully crafted both to obtain legal, nonself-interpenetrating shapes and to impose the model-to-model correspondences required for useful statistical analysis. The paper closes with example applications of the method to synthetic and real patient CT image sets, including same patient male pelvis and head and neck images, and cross patient kidney and brain images. Finally, we outline how this shape training serves as the basis for our approach to IGRT/ART.
Therapy of systemic fungal infections

The incidence of both community-acquired and nosocomial fungal infections has significantly increased over the past several decades. The major factors for this increase are a heightened use of antibiotics, a growing population of the elderly and of immunocompromised patients as a result of HIV, cancer, and organ transplantation. In this article, we will review the indications, efficacy, and safety of the polyenes, imidazoles, triazoles, and other systemic antifungals in development that are used for systemic fungal infections.
One-step purification of a recombinant protein from a whole cell extract by reversed-phase high-performance liquid chromatography

We have developed a one-step facile, flexible and readily scalable purification method for a recombinant protein, TM 1-99 (113 amino acid residues; 12,837 Da) based on reversed-phase high-performance liquid chromatography (RP-HPLC) from an E. coli cell lysate. Following cell lysis, the cell contents were extracted with 0.1% aqueous trifluoroacetic acid (TFA), applied directly under conditions of high sample load to a narrow bore RP-HPLC C(8) column (150 mm x 2.1 mm I.D.) and eluted by a shallow gradient of acetonitrile (0.1%/min). Loads of 23 and 48 mg of lyophilized crude cell extract produced 2.4 and 4.2mg of purified product (>94% pure), respectively, at >94% recovery. Our results show the excellent potential of one-step RP-HPLC for purification of recombinant proteins from cell lysates, where high yields of purified product and greater purity are achieved compared to affinity chromatography. Such an approach was also successful in purifying just trace levels (<0.1% of total contents of crude sample) of TM 1-99 from a cell lysate.
The Impact of Macroeconomic Performance on Alternative Poverty Measures

Abstract This article studies how aggregate economic conditions affect alternative poverty indexes. The different indexes include the official headcount rate, and others based on improved methods for both identifying and aggregating individuals deemed poor. The empirical analysis uses March Current Population Survey state-level data for the 1990s to estimate cross-section/time-series models of the alternative poverty indexes. Resulting estimates indicate that the measured effects of aggregate activity on poverty turn critically on the procedures for gauging poverty. Based on some theoretically preferred alternatives, the powerful economy of the past decade has had much less of an impact than is suggested by the official headcount rate. The findings thus provide an important caveat for researchers trying to identify the links between economic conditions and poverty, and for policy-makers seeking to understand how best to reduce poverty.
Development of the rat thalamus: V. The posterior lobule of the thalamic neuroepithelium and the time and site of origin and settling pattern of neurons of the medial geniculate body

Long-survival, sequential, and short-survival thymidine radiograms of rat embryos, fetuses, and young pups were analyzed in order to examine the time of origin, site of origin, migratory route, and settling pattern of neurons of the medial geniculate body (MG). Quantitative evaluation of long-survival radiograms established that the bulk of MG neurons are generated between embryonic (E) days E13 and E15, with a pronounced peak on day E14. There is an overall lateral-to-medial and caudal-to-rostral chronological gradient in MG neurogenesis. On the basis of significant regional differences in the birth dates of neurons, the MG was divided into several chronoarchitectonic areas. The earliest-generated neurons (with close to 20% of the cells produced on day E13 and a negligible proportion on day E15) form the dorsal and ventral clusters far laterally. Next in sequential order are the neurons of the lateral shell, intermediate shell, and medial shell of the MG. The medial shell with it latest-generated neurons (with over 30% produced rostrally on day E15) corresponds to the medial (magnocellular) subnucleus of the MG. There were no neurogenetic differences between the traditional dorsal and ventral divisions of the MG. Examination of sequential radiograms in rats labeled with 3H-thymidine on day E14 or E15 and killed on successive days brought supportive evidence for our earlier identification, in short-survival radiograms, of a posteroventral thalamic neuropithelial evagination as the putative source, or committed cell line, of MG neurons. Wave fronts of apparently migrating unlabeled and labeled cells could be traced from this sublobule in a posterolateral direction to the future site of the MG.
Hybrid Heat Engines: The Power Generation Systems of the Future

A hybrid heat engine results from the fusion of a heat engine with a non-heat-engine based cycle (unlike systems). The term combined cycle, which refers to similar arrangements, is reserved for the combination of two or more heat engines (like systems). The resulting product of the integration of a gas turbine and a fuel cell is referred to here as a hybrid heat engine or “Hybrid” for short.The intent of this paper is to provide, to the gas turbine community, a review of the present status of hybrid heat engine technologies. Current and projected activities associated with this emerging concept are also presented. The National Energy Technology Laboratory (NETL) is collaborating with other sponsors and the private sector to develop a Hybrid Program. This program will address the issues of technology development, integration, and ultimately the demonstration of what may be the most efficient of power plants in the world — the Hybrid System.Analyses of several Hybrid concepts have indicated the potential of ultra-high efficiencies (approaching 80%). In the Hybrid, the synergism between the gas turbine and fuel cell provides higher efficiencies and lower costs than either system can alone.Testing of the first Hybrid concept has been initiated at the National Fuel Cell Research Center (NFCRC).© 2000 ASME
The RNA-Binding Protein DDX1 Promotes Primary MicroRNA Maturation and Inhibits Ovarian Tumor Progression

Posttranscriptional maturation is a critical step in microRNA (miRNA) biogenesis that determines mature miRNA levels. In addition to core components (Drosha and DGCR8 [DiGeorge syndrome critical region gene 8]) in the microprocessor, regulatory RNA-binding proteins may confer the specificity for recruiting and processing of individual primary miRNAs (pri-miRNAs). Here, we identify DDX1 as a regulatory protein that promotes the expression of a subset of miRNAs, including five members in the microRNA-200 (miR-200) family and four miRNAs in an eight-miRNA signature of a mesenchymal ovarian cancer subtype. A majority of DDX1-dependent miRNAs are induced after DNA damage. This induction is facilitated by the ataxia telangiectasia mutated (ATM)-mediated phosphorylation of DDX1. Inhibiting DDX1 promotes ovarian tumor growth and metastasis in a syngeneic mouse model. Analysis of The Cancer Genome Atlas (TCGA) reveals that low DDX1 levels are associated with poor clinical outcome in patients with serous ovarian cancer. These findings suggest that DDX1 is a key modulator in miRNA maturation and ovarian tumor suppression.
Private sector initiative: The Solar Electric Light Fund

The Solar Electric Light Fund (SELF) is a U.S.-based development organization founded in 1990 to address the issue of how 70% of the people in the developing world are going to get electricity. The projects for Vietnam, India, China and Sri Lanka are presented and their financing
Preference for condensed tannins by sheep in response to challenge infection with Haemonchus contortus.

Abstract Herbivores prefer feeds that supply required nutrients and avoid those with excess nutrients and plant secondary compounds (PSC). Nevertheless, PSC such as condensed tannins can provide beneficial medicinal effects to herbivores as they act against infective diseases such as parasitism. The objectives of this study were to determine: (1) if parasitized lambs increased preference for a tannin-rich feed after they experienced the beneficial antiparasitic effects of condensed tannins relative to parasitized lambs that did not experience such benefits, and (2) if preference for the tannin-rich feed in the former group decreased when parasite burdens subsided. Twenty two lambs were familiarized with beet pulp and beet pulp + 8% quebracho tannins (beet pulp + tannins) and choices were given between the two feeds (initial preference tests). Subsequently, all animals were dosed with 10,000 L3 stage larvae of Haemonchus contortus. Twenty-two days later, animals were exposed to beet pulp (Control group; n = 11) or beet pulp + tannins (Treatment group; n = 11) during 24 d. After exposure (during a parasitic infection) animals in both groups were given choices between the two feeds. Lastly, animals in both groups received an antiparasitic drench and were again given a choice between both feeds (after a parasitic infection). Lambs preferred beet pulp to beet pulp + tannins throughout the study (P 0.05). However, during a parasitic infection, intake of and preference for the tannin-rich feed was higher for lambs that experienced the beneficial effects of condensed tannins while parasitized (Treatment) than for lambs that did not (Control) (P 0.05). Preference by the Treatment group for the tannin-rich feed was lower after than during a parasite infection (P 0.05). Lambs in the Treatment group displayed lower FEC than lambs in the Control group (Group × Sampling Date; P
A heuristic parameter estimation procedure for a binary dependent variable regression model

Abstract This paper presents a heuristic constraint reduction procedure for parameter estimation for a regression model with a binary dependent variable. While the expected value of the binary dependent variable represents a probability, ordinary least squares does not guarantee estimates constrained to the interval [0,1]. The proposed algorithm, which formulates the above problem as a quadratic programming problem, guarantees that the estimates will be between 0 and 1, and has clearly demonstrated its efficiency through numerical examples. The proposed quadratic programming estimator is also superior to the least squares estimator in view of some statistical properties examined. Detailed results and comparisons are given.
Methylation pharmacogenetics: Thiopurine methyltransferase as a model system

1. Methyl conjugation is an important pathway in the biotransformation of many drugs and xenobiotic compounds. 'Pharmacogenetic' variation exists in the activities of many methyltransferase enzymes, and experiments with the drug-metabolizing enzyme thiopurine methyltransferase (TPMT) offer a model for one approach that has proven useful in the study of methyltransferase pharmacogenetics. 2. TPMT catalyzes the S-methylation of thiopurine drugs such as 6-mercaptopurine. This enzyme activity is present in the human red blood cell (RBC), and RBC TPMT activity is controlled by a common genetic polymorphism that regulates also the enzyme activity in all other human tissues that have been studied. 3. Subjects with inherited low levels of TPMT activity are at increased risk for thiopurine drug-induced myelotoxicity, while patients with high TPMT activities may be 'undertreated' with these drugs. 4. TPMT activity in tissue from selected strains of inbred mice also is regulated by a genetic polymorphism. These mice provide an animal model for use in the study of pharmacological or toxicological consequences of inherited differences in TPMT activity. 4. Other methyltransferase enzymes including thiol methyltransferase, catechol O-methyltransferase, and histamine N-methyltransferase also are present in the human RBC, are regulated by inheritance, and are responsible for individual variation in drug metabolism. Enhanced understanding of the pharmacogenetics of methylation may make it possible to understand and predict individual variation in the biotransformation, toxicity and therapeutic effect of compounds that undergo methyl conjugation.