cssi/SciSciGPT-SciSciNet huggingface dataset:
Models of spatial spread: A synthesis

I review models describing the dynamics of range expansion (spatial spread) of invading organisms, emphasizing two apparently robust results. First, there appears to be a linear rate of spread with time, and second, this rate is proportional to the per capita growth rate of the population when the invading species is rare. Both results hold for a variety of single-species and two-species models. I then present two models, one stochastic, and one with an Allee effect, that demonstrate that the constant linear rate of spread may only hold after an initial period of slower spread. Finally, I emphasize that the dependence of the rate of spread on the per capita growth rate need only hold when this is maximized when the species is rare. This last observation may have important implications for understanding the rate of spread for precisely those species which are likely to cause the most disruption to the communities they invade.
Adrenergic status in anxiety disorders: Platelet alpha2-adrenergic receptor binding, blood pressure, pulse, and plasma catecholamines in panic and generalized anxiety disorders patients and in normal subjects

Abstract In order to evaluate adrenergic function in anxiety disorders, platelet alpha 2 -adrenergic binding parameters and supine and standing blood pressure, pulse, and venous plasma epinephrine and norepinephrine were determined in patients with panic attacks or generalized anxiety disorder and in normal subjects. The maximum number of binding sites (B max ) for the partial agonist tritiated clonidine was significantly lower for both patient groups than for normal subjects, and the B max for the antagonist tritiated yohimbine was significantly lower for panic patients. There were no other substantive differences across groups. Prior exposure to psychotrophic drugs might account for the results for clonidine binding, but not for yphimbine. The B max for clonodine was correlated with norepinephrine increases upon standing and, for panic patients, with the severity of full unexpected panic attacks. These data provide further evidence of adrenergic receptor abnormalities in people with anxiety disorders.
Breaking through the beaver dam: guiding your customers and staff through a major restructure

Oregon State University's Community Network, a contract-based support service, was established in 1995 to create efficiencies and centralize desktop support services being provided by individual departments. Based on four independent teams, each of which supported a specific group of departments, the Community Network service model had many redundancies, was not scalable with growth, and did not allow for rapid response to critical events.At the SIGUCCS Fall 2005 Conference we presented our proposed plan to move from the "departmental" support model to a new model based on functional teams. Three years later, having revised and refined the plan, the long and sometimes painful process of transition is now complete.This paper will discuss the Community Network support model, as it was in 2005, the plan as it was proposed and as implemented, and the Community Network support model today. We will discuss the factors that drove the need for change, hurdles we encountered, the things that really worked well and the many lessons we learned along the way. We will close with a look toward the future and how we plan to meet new challenges already on the horizon.
Nature of phenotypic masking exhibited by drug-dependent streptomycin A mutants of Escherichia coli.

Abstract A class of drug-dependent mutants that occur at the strA locus in Escherichia coli requires any one of several factors for growth: streptomycin, paromomycin or ethanol. Streptomycin and paromomycin in combination, however, kill these mutants at the same doses and with the same kinetics as they kill the wild type when used individually. Each drug can sensitize the culture to the other by fixation to non-metabolizing cells; four generations of growth are required to completely dilute out the induced sensitivity. This property persists in a class of revertants to drug independence. Dependence on, or resistance to, either streptomycin or paromomycin can thus be phenotypically masked in cells of these strains which have been previously grown in the presence of the other antibiotic. The amount of misreading by ribosomes extracted from strains exhibiting phenotypic masking is small when induced by either streptomycin or paromomycin, but is quite large in the presence of both. Ribosomes from cells grown in one of the drugs are induced by the other to the same high level of misreading as by the drug combination. This phenomenon can be attributed to the binding of drugs by ribosomes during growth in the presence of antibiotics. The association is very stable and two ammonium sulfate precipitations are required to dissociate the drug from the ribosome. These observations demonstrate (1) that exposure of a culture to streptomycin or paromomycin results in firm binding of the antibiotics to the ribosomes; (2) that in vivo the complex between drug and ribosome disappears only through dilution of the bacterial mass by growth; (3) that drug binding results in misreading of the genetic code, at least when the ribosomes are programmed with synthetic messenger RNA; (4) that killing by streptomycin and paromomycin in vivo is related to high levels of misreading in vitro in a strictly parallel way; and (5) that mutation at the strA gene, which codes the structure of a ribosomal protein, affects bacterial response to several antibiotics and not to streptomycin alone.
Protein kinase C-α inhibits the repair of oxidative phosphorylation after S-(1,2-dichlorovinyl)-l-cysteine injury in renal cells

Previously, we showed that physiological functions of renal proximal tubular cells (RPTC) do not recover following S-(1,2-dichlorovinyl)-l-cysteine (DCVC)-induced injury. This study investigated th...
Hormonal regulation of aggression: evidence for a relationship among genotype, receptor-binding, and behavioral sensitivity to androgen and estrogen

Gonadectomized male mice from the CF-1, CFW, and CD-1 strains were exposed to different androgens (testosterone, dihydrotestosterone, methyltrienolone) or estrogens (estradiol, diethylstilbestrol) and tested for aggressive behavior. Genetic differences in sensitivity to the aggression-promoting property of the various treatments were found. CF-1 mice responded to either androgenic or estrogenic stimulation, CFW males were most sensitive to the estrogen treatments, while CD-1 males responded to androgen but were relatively insensitive to the aggression-promoting property of estrogens. These data suggest that there may be multiple aggression-activating systems and that the functional pathway varies with genotype. Additional experiments examined whether receptor binding in the hypothalamic-preoptic-septal region was related to the genetic differences in behavioral responsiveness. The binding data suggested that sensitivity to the aggression-promoting property of estrogens was related to either a higher concentration of binding sites or to higher affinity binding between estrogen and its receptor. A systematic relationship between dihydrotestosterone binding and behavioral responsiveness to androgen was not found.
An explanation for the effect of clouds over snow on the top-of-atmosphere bidirectional reflectance

[1] It has been a long-standing puzzle why clouds, which should interact with solar radiation similarly to a thin layer of snow, have such a dramatic effect on the reflectance observed by satellites over snow-covered regions. The presence of a cloud over the snow strongly enhances the anisotropy of the scene, so that a cloud-over-snow scene appears darker than clear sky over snow when observed near nadir, but much brighter when observed at large zenith angles in the forward reflected direction. By contrast, when a plane-parallel cloud is placed above a plane-parallel snow surface in a model, it slightly decreases the anisotropy of the system because of the cloud's smaller particles. Using a parameterization for the directional reflectance from East Antarctic snow, developed from extensive near-surface observations from a tower, we show that the unexpected effect of clouds over snow in this region is due to the non-plane-parallel nature of the snow surface, not to unexpected features of the clouds. The snow surface roughness reduces the anisotropy of the reflected sunlight compared to that from a plane-parallel snow surface. Clouds, by hiding this roughness with a surface that is very smooth in units of optical depth, increase the anisotropy by bringing the system closer to the plane-parallel case. We use the surface parameterization to accurately model reflectance observations made from the tower over a ground fog and from the top of the atmosphere over cloud-covered snow by the MISR satellite instrument.
Advanced Facsimile System And Network Applications

ADVANCED FACSIMILE SYSTEMAND NETWORK APPLICATIONSJohn W. WatkinsHarris Corporation, Electronic Systems DivisionMelbourne, Florida 32901IntroductionLaser, acousto- optics and dry silver material technologies were designed into an advanced facsimile system to achievehigh recording speeds, high copy resolution, and chemical -free operation. The basic system was designed so that its per-formance specifications can be modified over a wide range with minor changes required to enable a broad spectrum ofapplications to be addressed.The technologies that were used and the design features of the facsimile system are reviewed in this report, includinga description of the unique optics bench that was designed to provide electronic control of its performance parameters.These unique features, along with the modular design of the system, provide the versatility required to satisfy a wide rangeof network applications.Laserfax Design ObjectivesFacsimile and hard copy display applications have been found to require a relatively wide range of operational andfunctional specifications. While it would be difficult and expensive, if not impossible, to develop a single system thatwould satisfy all requirements, an approach has been devised by which a significant segment of the applications can beaddressed through a functionally designed system whose specifications can be modified significantly without requiring a
ATTACHED PRIMES UNDER SKEW POLYNOMIAL EXTENSIONS

In the author's work [S. A. Annin, Attached primes over noncommutative rings, J. Pure Appl. Algebra212 (2008) 510–521], a theory of attached prime ideals in noncommutative rings was developed as a natural generalization of the classical notions of attached primes and secondary representations that were first introduced in 1973 as a dual theory to the associated primes and primary decomposition in commutative algebra (see [I. G. Macdonald, Secondary representation of modules over a commutative ring, Sympos. Math.11 (1973) 23–43]). Associated primes over noncommutative rings have been thoroughly studied and developed for a variety of applications, including skew polynomial rings: see [S. A. Annin, Associated primes over skew polynomial rings, Commun. Algebra30(5) (2002) 2511–2528; and S. A. Annin, Associated primes over Ore extension rings, J. Algebra Appl.3(2) (2004) 193–205]. Motivated by this background, the present article addresses the behavior of the attached prime ideals of inverse polynomial modules over skew polynomial rings. The goal is to determine the attached primes of an inverse polynomial module M[x-1] over a skew polynomial ring R[x;σ] in terms of the attached primes of the base module MR. This study was completed in the commutative setting for the class of representable modules in [L. Melkersson, Content and inverse polynomials on artinian modules, Commun. Algebra26(4) (1998) 1141–1145], and the generalization to noncommutative rings turns out to be quite non-trivial in that one must either work with a Bass module MR or a right perfect ring R in order to achieve the desired statement even when no twist is present in the polynomial ring "Let MR be a module over any ring R. If M[x-1]R is a completely σ-compatible Bass module, then Att(M[x-1]S) = {&#x1d52d;[x] : &#x1d52d; ∈ Att(MR)}." The sharpness of the results are illustrated through the use of several illuminating examples.
Design of laminated plates for maximum buckling load

The buckling load of laminated plates having midplane symmetry is maximized for a given total thickness. The thicknesses of the layers are taken as the design variables. Buckling analysis is carried out using the finite element method. The optimality equations are solved by a homotopy method which permits tracing optima as a function of total thickness. It is shown that for any design with a given stacking sequence of ply orientations, there exists a design associated with any other stacking sequence which possesses the same bending stiffness matrix and same total thickness. Hence, from the optimum design for a given stacking sequence, one can directly determine the optimum design for any rearrangement of the ply orientations, and the optimum buckling load is independent of the stacking sequence.
Egg Production, Larval Development, and Adult Longevity of Cat Fleas (Siphonaptera: Pulicidae) Exposed to Ultrasound

Adult cat fleas, Ctenocephalides felis felis (Bouche), on cats (Felis catus) were exposed to emissions from an ultrasonic flea collar worn by the cat. No significant differences were found in total numbers of eggs produced per day (mean = 524 control, 614 treatment), in length of larval development time (mean = 7.7 d control, 7.7 d treatment), or in total daily pupal production (mean = 485 control, 445 treatment) between the treatment and the control groups. Tests off the host were conducted to determine whether ultrasonic exposure caused mortality in adult fleas; no significant differences were found in daily mortality between the treated and control fleas during 1 wk of exposure.
Thoracic epidural anesthesia for treatment of angina: Pro: The anesthesiologist should provide epidural anesthesia in the coronary care unit for patients with severe angina

PPER THORACIC epidural anesthesia (TEA) is a lowrisk technique I that can be performed on almost any patient with myocardial ischemia to improve analgesia and myocardial perfusion, decrease the incidence and severity of arrhythmias, and decrease the size of myocardial infarction. TEA is grossly underused and should be considered for patients with status angina as well as patients with end-stage multivessel disease not amenable to revascularization. Catheters should be placed by physicians with a knowledge of spinal anatomy, epidural analgesia, and cardiac pathophysiology. Although the risk/benefit ratio of placing and managing a patient with an epidural catheter for status angina needs to be considered, it is a very safe procedure in experienced hands. MAXIMIZING SUPPLY AND DEMAND
Tribological Study Comparing PAG and POE Lubricants Used in Air-Conditioning Compressors Under the Presence of CO2

Polyalkylene glycol (PAG) and polyolester (POE) synthetic lubricants are good candidates for air-conditioning systems that work with alternative refrigerants such as carbon dioxide (CO2). Both synthetic lubricants are widely used in air-conditioning compressors and have been optimized for use with hydrofluorocarbon (HFC) refrigerants. However, it is still not clear which lubricant is more suitable for use in compressors operating with CO2 as a refrigerant. This study compares the performance of PAG and POE lubricants of the same viscosity (ISO VG 68) used in air-conditioning compressors. The materials used were Al390-T6 disks and hardened steel SAE 52100 pins. The tests were performed using a high pressure tribometer (pin-on-disk configuration) in the presence of CO2. The results showed that scuffing and wear resistance of Al390-T6 tested with PAG were superior compared to the samples tested with the POE lubricant. Chemical analysis using X-ray photoelectron spectroscopy showed that PAG tends to promote t...
Fine needle aspiration biopsy of pediatric head and neck masses.

Abstract Objective: To determine if fine needle aspiration (FNA) can preclude the requirement for diagnostic open biopsy in suspicious pediatric head and neck masses. Methods: The records of 40 children presenting to an inner city tertiary care hospital who underwent a total of 50 FNA biopsies during the years 1988–1999 were reviewed. From these 40 patients, 17 children, aged 3 months to 18 years, underwent both clinically indicated FNA biopsy and subsequent open surgical biopsy or excision. Outcome measurements included clinical resolution or surgical pathologic diagnosis. Results: The 17 patients who underwent open surgical biopsy subsequent to the FNA had a total of 21 FNAs performed. Three of these patients had more than one needle biopsy prior to surgery. The histologic diagnosis of the surgical excision confirmed the FNA biopsy cytologic diagnosis in all but two cases. FNA cytologic diagnostic categories included reactive lymph node/non-specific inflammation (25 biopsies), benign cystic process (four), granulomatous disease (eight), malignant neoplasm (three), and benign neoplasm (one). Eight of nine FNAs initially non-diagnostic had either complete resolution of the mass or a diagnosis obtained by subsequent FNA or open biopsy. Conclusions: FNA is a valuable diagnostic tool in the management of children with the clinical presentation of a suspicious neck mass. The technique reduces the need for more invasive and costly procedures. Early surgical biopsy, however, should be considered in rapidly enlarging masses, in the presence of persistent systemic symptoms, and when repeated FNA cytology is non-diagnostic.
Canonical transformations and graph theory

Abstract In the class of symplectic matrices, two infinite subsets are generated by binary spanning trees. For given N, the procedure begins with the complete graph, KN to which N-1 virtual vertices are added in well-defined ways. Then spanning binary trees that connect the 2N-1 vertices are obtained and from these trees, explicit formulae give the symplectic matrices. These matrices define linear canonical transformations for N-body problems in vortex dynamics, plasma physics as well as celestial mechanics.
Endoscopic valvuloplasty for GERD

Abstract Background: The transoral, endoscopic route has been suggested as a possible approach for the correction of severe gastroesophageal reflux. Such a procedure would involve no mobilization of the cardia or other structures. The optimal placement, number, and configuration of sutures remains undefined. Methods: With the use of a previously developed endoscopic sewing machine, this study was undertaken in baboons with two suture arrangements immediately below the lower esophageal sphincter. A linear arrangement (group I) and a circular arrangement (group II) were compared. During the 6 months after the procedure, the animals were evaluated using manometry, fluoroscopic barium swallow, upper gastrointestinal endoscopy, and a pressure volume test. Results: A significant increase in lower esophageal sphincter length was demonstrated only in group II (p = 0.010). A significant increase in lower esophageal sphincter pressure was demonstrated only in group I animals (p = 0.008). The abdominal length increased in group I (p = 0.004) and group II (p = 0.004). The yield pressure and yield volume did not differ significantly from those measured previously in control animals. No evidence of reflux, stricture formation, esophagitis, or other pathology was noted. Conclusions: Some manometric parameters associated with gastroesophageal reflux are altered by the endoscopic placement of sutures below the gastroesophageal junction, with no associated serious complications.
Pressor responsiveness to endothelin is not attenuated in gravid rats

Abstract The aim of this study was to evaluate the effect of synthetic human/ porcine endothelin (ET-1) on mean arterial blood pressure (MAP) in pregnant and non-pregnant rats and to compare this to the effects of two well characterized agonists, angiotensin II (AII), and vasopressin (VP). On day 14 of gestation (parturition day 22) polyethylene catheters were chronically implanted in the abdominal aorta for monitoring of MAP and in the vena cava for administration of drugs. Pressor responsiveness was measured in conscious freely moving animals on day 20 and again on the 7th day post-partum. All three agonists increased MAP in a dose related manner. However, whereas the sensitivity of pregnant rats (P) to AII and VP was significantly blunted compared to postpartal (PP) measurements, the MAP responses to ET-1 were the same in both groups. Moreover, the combined administration of ET-1 at a subpressor dose (0.05 pmol/100 g bw) and AII or VP at effective doses significantly potentiated (particularly in P) the pressor effects of AII and VP. These results demonstrate that ET-1 and possibly other vasoactive substances of endothelial origin, override the compensatory mechanism of normal pregnancy with respect to the blunted responsiveness to AII and VP. Such a mechanism may be of particular relevance in the evolution of pregnancy-induced hypertension.
Preliminary Design and Piping Diagram for a Combined Heat and Power System: For the College of Engineering at the University of Louisiana Lafayette Using Donated Equipment

ABSTRACT Combined heat and power (CHP) systems have many different factors in design procedures. The configuration of a CHP system can be changed to affect different factors of the design and to meet specific needs of the system. Before the design process can begin, product specifications, such as steam or water pressures and temperatures, and equipment, such as absorption chillers and heat exchangers, need to be identified and defined. The objective of this paper is to lay out a preliminary design of the CHP system at the College of Engineering at the University of Louisiana, Lafayette. First, a flow chart is presented depicting a broad scope model of the whole system. Then, the specifications of the absorption chiller and the heat exchanger to be used in the system are calculated by working out the flow rates of the water circuits and the temperature of the exhaust gas. Once these are determined, a piping and instrumentation diagram is shown, based on these calculations. Most of the equipment was donate...
The Roots of Terrorist Motivation: Shame, Rage, and Violence in The Brothers Karamazov

Dostoevsky's most famous novel dealing with terrorism is his work The Demons. In this first-ever novel about terrorism, he carefully analyzed the various factors that contributed to the rise of modern terrorism. This article argues that Dostoevsky's subsequent novel, The Brothers Karamazov, is equally important in understanding the motivations of individual terrorists. The author argues that The Brothers Karamazov is fundamentally a novel about the rage and violence that are the byproducts of shame and humiliation. If modern counterterrorism policymakers, analysts, and operatives are serious about understanding the fundamental motivations of modern terrorists, it may benefit them to read (or reread) The Brothers Karazamov in this light.
Investigation of ring rolling by pseudo plane-strain FEM analysis

Abstract The metal flow in ring rolling has been studied by using a pseudo plane-strain scheme which was incorporated into a finite element method-based model. The average deformation of a ring during each rolling revolution is approximated by a kinematically steady state deformation process. The 3-D deformation is decomposed mathematically into a 2-D in-plane flow and a 1-D out-plane flow (in rolling direction). The out-plane deformation is solved semi-analytically while the in-plane deformation is solved by the rigid-plastic finite element method. Calculated results were compared with the available experimental data as well as other theoretical calculations.
An invitro characterization of interstrand cross-links in DNA exposed to the antitumor drug cis-dichlorodiammineplatinum(II)

Abstract The cis -isomer of the antitumor drug dichlorodiammineplatinum(II) [ cis -Pt(II)] was tested for its abilty to introduce nicks (single-strand breaks) into supercoiled PM2 DNA. Whereas incubations up to 24 h show no indication of cis -Pt(II)-treated DNA having single-strand breaks, DNA interstrand cross-links were detected in the first 15 min of incubation. Furthermore, the formation of DNA interstrand cross-links was both inhibited and fully reversed after incubation with 2 mM thiourea.
Internal Rotation in Enaminonitriles: Investigation by Dynamic NMR Spectroscopy and Molecular Modeling

Rotational isomerism in enaminonitriles was studied using dynamic NMR spectroscopy and molecular modeling. It was found that the barrier to rotation about Cvinyl-NH bond was higher for enaminonitriles derived from aliphatic amines than that of enaminonitriles derived from aromatic amines. It was also found that the rotational isomerism about the Car-Cvinyl bond also exists in enaminonitriles.
Valence-bond model for silicon force fields.

We propose a new type of classical force-field model for silicon in which the form is based on a valence-bond approach. The results of quantum-mechanical calculations on small clusters, together with bulk experimental data are used to obtain the parameters of the force field. The importance of including a description of bent and long bonds in the potential is discussed. It is shown that a description of such bonds not only accounts for the general compactness of cluster geometries found from electronic structure calculations but also provides reasonable surface reconstructions. Details of cluster geometries are not accounted for in the present potential because a number of effects found in the quantum-mechanical calculations are not included in the present force-field model. Likewise, effects important for describing the high-pressure solid-state phases of silicon are also not included in the present potential. The approach used here is to incorporate very specific and well controlled effects in the potential and determine their consequences for clusters and surfaces.
Developing weed-suppressive soils through improved soil quality management

Manipulating soil microbial communities using soil and crop management practices is a basic strategy in developing sustainable agricultural systems. Sustainable farming is based, in part, on the efficient management of soil microorganisms to improve soil quality. However, the identification of biological indicators of soil quality that can be used to predict weed suppression in soils has received little attention. We investigated differences in soil microbial activity among various crop and soil management systems to assess: (i) the microbiological characteristics of these soils; (ii) determine whether any relationships existed that might be used in the development of weed suppression. Soil enzyme activity, water-stable aggregates, and the proportions of weed-suppressive bacteria were compared among seven cropping systems and one native-prairie ecosystem in mid-Missouri, USA. Assays of soil enzymes (fluorescein diacetate hydrolase, dehydrogenase, phosphatase) revealed that organic and integrated cropping systems, and the native-prairie ecosystem had the highest levels of soil activity. Weed rhizospheres from these same ecosystems also had greater proportions of bacterial isolates characterized as “growth suppressive” to green foxtail (Setaria viridis [L.] Beauv.) and field bindweed (Convolvulus arvensis L.): 15 and 10%, respectively. The proportion of water-stable soil aggregates was the greatest in soils with the highest organic matter and was found to be related to higher enzyme and weed-suppressive activity. Selected biological indicators of soil quality were associated with potential weed-suppressive activity in soil when that soil was managed for high organic matter content under reduced tillage systems. This research study provides further evidence that soil quality and sustainable agricultural practices may be linked to integrated weed management systems for the biological suppression of weeds.
Distinct Saturable Pathways for the Endocytosis of Different Tyrosine Motifs

Endocytosis of surface proteins through clathrin-coated pits requires an internalization signal in the cytoplasmic domain. Two types of internalization signal have been described: one requiring a tyrosine as the critical residue (tyrosine-based motif), and the other consisting of either two consecutive leucines or an isoleucine and leucine (dileucine motif). Although it seems that these signals are necessary and sufficient for endocytic targeting, the mechanism of recognition is not well understood. To examine this question, tetracycline-repressible cell lines were used to overexpress one of several receptors bearing a tyrosine-based internalization signal. By measuring the rates of endocytosis for either the overexpressed receptor, or that of other endogenous receptors, we were able to show that the endocytosis of identical receptors could be saturated, but a complete lack of competition exists between the transferrin receptor (TfR), the low-density lipoprotein receptor, and the epidermal growth factor receptor. Overexpression of any one of these receptors resulted in its redistribution toward the cell surface, implying that entry into coated pits is limited. During high levels of TfR expression, however, a significant increase in the amount of surface Lamp1, but not low-density lipoprotein receptor, epidermal growth factor receptor, or Lamp2, is detected. This suggests that Lamp1 and TfR compete for the same endocytic sites. Together, these results support the idea that there are at least three distinct saturable components involved in clathrin-mediated endocytosis.
Measuring transfer of 14C-PCB from maternal diet to milk in a goat model using an accelerator mass spectrometer (AMS)

Abstract Environmental pollutants pose a substantial risk to nursing infants. Many of these toxicants (i.e. PCBs, PBDEs, mercury) are passed from the maternal diet to the nursing infant in breast milk. Determining the toxicokinetics has been difficult to measure due to ethical limitations. Since extremely small amounts of 14 C can be measured using Accelerator Mass Spectrometry (AMS), a goat model was used to establish a minimum oral dose of 14 C-labeled PCB (2,2′,4,4′,5,5′-hexachlorobiphenyl-UL- 14 C) that could be given to a lactating animal and traced into the milk. An oral dose of 66 nCi/kg body weight (1.84 μg PCB/kg bw) was administered. Plasma and milk samples were collected for 2 months after dosing. The concentration of 14 C label reached a peak value of 1.71 ng/ml PCB equivalents in the milk on day 2 and then declined to about 135 pg/ml PCB equivalents in the milk at 3 weeks. A second goat was administered a smaller dose (22 nCi/kg bw; 616 ng PCB/kg bw). A peak concentration of 485 pg PCB equivalents/ml milk occurred at 3 days and declined to 77.6 pg PCB equivalents/ml milk by 3 weeks. Our results indicated that an even lower dosage of labeled-PCB could be used due to the extreme sensitivity of AMS measurement. Extrapolating from current data it is estimated that the dose could be reduced by a factor of 20 (31 ng PCB/kg bw; 1.1 nCi/kg bw) and still be detectable after 2 months. Thus, the potential exists for developing protocols for studying toxicokinetics in humans using radiologically- and toxicologically-benign doses of labeled environmental toxicants.
Light-induced single electron-transfer reactions between chlorophyll α and quinones in solution II. Some effects of non-quinonoid donors and acceptors: Riboflavin, thioctic acid and NADH

1. 1. Light-induced single electron-transfer reactions have been observed in two-component systems involving chlorophyll and riboflavin or thioctic acid and in three-component systems involving NADH, chlorophyll, and benzoquinone or riboflavin. 2. 2. In the chlorophyll-riboflavin system, illumination of acidic solutions leads to the formation of the semiquinone of riboflavin and, via a side reaction, to the destruction of chlorophyll. 3. 3. In the chlorophyll-thioctic acid system, excitation of thioctic acid produces a species (perhaps the biradical resulting from sulfur-sulfur bond cleavage) capable of forming free radicals upon interaction with an electronically excited chlorophyll molecule. 4. 4. In the three-component systems, from 2- to 8-fold enhancements in steady-state radical concentrations can be achieved by adding NADH to solutions of chlorophyll and acceptors.
Influence of the polymorphic fetal interleukin-1 receptor antagonist (IL-1RA) genotype on pregnancy history

RECEPTOR ANTAGONIST (IL-1RA) GENOTYPE ON PREGNANCY HISTORY SRIRAM C. PERNI, SANTOSH VARDHANA, SARA L. TUTTLE, ROBIN B. KALISH, STEPHEN T. CHASEN, STEVEN S. WITKIN, Weill Medical College of Cornell University, Obstetrics & Gynecology, New York, NY OBJECTIVE: To determine whether fetal carriage of the different IL-1ra genotypes is associated with past pregnancy outcomes. STUDY DESIGN: Fetal cells in midtrimester amniotic fluid samples from 139 women were blindly tested for IL-1ra intron 2 length polymorphisms. Pregnancy data were subsequently obtained. RESULTS: A higher prevalence of the 1,2 genotype was detected in fetuses fromwomenwhose prior pregnancies resulted in termbirths (17/41, 41.5%), or who had a combination of term births and spontaneous abortions (10/22, 45.5%), as compared to fetuses from women whose only pregnancies resulted in a spontaneous abortion (1/15, 6.7%) (P = 0.01). A similar relationship was observed when only the fetuses from the 81 white women in the study were analyzed (45.8% 1,2 genotype in term births only vs 11.1% in spontaneous abortions only, P = 0.04).Medianmidtrimester amniotic fluid concentrations of interleukin-1b (IL-1b) and IL-1ra were reduced in women with only prior spontaneous abortions as compared to those with only prior term births (IL-1b: 7.0 pg/mL vs 18.2 pg/mL, P = 0.02; IL-1ra: 4.1 ng/mL vs 6.6 ng/mL, P = 0.03). Lastly, the fetal IL-1ra genotypewas related to the amniotic fluid IL-1b and IL-1ra levels. Fetal carriage of the 1,2 genotype was associated with elevated median IL1b (18.3 pg/mL) as compared to fetal carriage of the 1,1 genotype (10.1 pg/mL, P = 0.01). Similarly, homozygous carriage of the 2 allele was associated with elevated median IL-1ra levels (7.0 ng/mL vs 4.7 ng/mL in allele 1 homozygotes). In contrast to the results with IL-1b, there was no relationship between amniotic fluid concentrations of tumor necrosis factor-a, interleukin-4, or interleukin-6 and pregnancy history. CONCLUSION:Elevated fetal production of IL-1b, related at least in part to carriage of the IL-1ra 1,2 genotype, is associated with a reduced occurrence of spontaneous abortion and an increased likelihood of a term birth.
Laparoscopic techniques for fecal diversion.

Although the role of laparoscopic techniques in performing major colorectal resections is unclear, laparoscopy may be well suited for fecal diversion procedures because no resection and minimal tissue dissection is required. PURPOSE: This report reviews our initial experience with laparoscopic stoma procedures to assess safety and efficacy. METHODS: Using a simple two-cannula technique, 24 such procedures (16 loop ileostomies, 6 end sigmoid colostomies, 1 transverse, and 1 sigmoid loop colostomy) were attempted. Indications for diversion were rectovaginal fistula (7), perianal sepsis (7), incontinence (4), advanced rectal or colon carcinoma (4), and complicated pelvic infection (2). There were 15 females and 9 males with a median age of 44 (range, 25–88) years. RESULTS: Median operative time was 60 (range, 20–120) minutes, and median blood loss was 50 (range, 0–150) ml. There were no intraoperative complications. One case was converted to a laparotomy because of dense adhesions. Median time to passage of both flatus and stool was one (range, 1–3) day for ileostomy patients, two (range, 2–4) days for flatus, and 3 (range, 2–6) days for stool after colostomy. Median time to discharge was 6 (range, 2–28) days and was often delayed by the primary disease process or ostomy teaching. One major postoperative complication, a pulmonary embolism, occurred eight days after operation in a patient with near obstructing, widely metastatic colon carcinoma. This patient later died of pulmonary failure. All stomas have functioned well, with no revisions required. CONCLUSIONS: Laparoscopic fecal diversion procedures can be performed safely, simply, and effectively. Apparent advantages over standard techniques are avoidance of a laparotomy, while maintaining the ability to precisely identify and orient the pertinent bowel segment and rapid return of bowel function.
Mechanisms to reduce hospital stays

Background. The present era of medicine is concerned to a large measure with cost containment and the advent of managed care. For these reasons the concept of reducing hospital stays with a concomitant reduction in hospital cost is very attractive. The role of fast track is to ensure that we are not placing the patient at any additional risk and in fact are improving recovery and patient well-being. Methods. Fast track is based on a specific protocol that is followed for each patient. Intensive preoperative education of patient and family familarize them with early discharge. Anesthetic technique is modified to effect early (4 to 8 hours) postoperative extubation. Steroids are administered perioperatively to improve myocardial function and reduce the release of inflammatory mediators. Digoxin is given prophylactically as are the bowelmediating drugs metoclopramide, docusate, and ranitidine. The fast-track protocol is associated with aggressive ambulation of the patients and cardiac rehabilitation, so that the patient is out of bed the first day after operation, walking in the hall the second day, and up a flight of stairs the third day. Results. A shift to fast track in 1992 permitted comparison between 282 non-fast-track patients and 280 fasttrack patients undergoing coronary artery bypass grafting. The results showed no adverse consequences of fast track. Forty-eight percent of fast-track patients were discharged at 3 to 5 days compared with 26% of non-fasttrack patients. No significant differences were found between the two groups with respect to infection (1%), operative mortality (approximately 4%), and 30-day hospital readmission (7% non-fast-track and 8% fast-track). A postdischarge questionnaire addressed issues of patient and family satisfaction. The early discharge patient had a 77% comfort level, whereas their family members felt satisfied with a 3- to 5-day hospital stay in only 54% of cases. These data suggest the need for better communication, education, and additional postdischarge support systems. Conclusions. A fast-track protocol allows faster recovery and earlier discharge from both the intensive care unit and the hospital without apparent increased risk. Complicated patients can also be fast tracked, and the desire to do so may actually expedite recovery.
Outdoor weathering of selected polymeric materials under marine exposure conditions

Abstract Several types of thermoplastic and latex rubber materials commonly encountered in marine plastic debris were weathered in air and while floating in sea water, under North Carolina climatic conditions. The degradation of the different samples was monitored by tensile property determination. In general, the various materials tested tended to weather at a slower rate when exposed in sea water compared to that in air. This retardation of weathering is probably a result of lack of heat build-up in samples exposed at sea.
The positive influence of maternal identification on body image, eating attitudes, and self-esteem of Hispanic and Anglo girls

Objective The role of maternal identification in the development of girls' body image, eating attitudes, and self-esteem was examined. Method Hispanic and Anglo girls (n = 410) ages 8–13 were surveyed using the Body Esteem Scale (BES), the Children's Eating Attitudes Test, the Piers-Harris Children's Self-Concept Scale, and the Child Figure Drawing task. From this sample, normal-weight girls with high or low scores on the BES were selected for the main study. Ninety-two mother-daughter pairs participated in this second phase in which mothers completed similar questionnaires and girls performed a Q-sort task measuring maternal identification. Results Maternal identification was positively correlated with girls' self-esteem and negatively correlated with eating problems and body dissatisfaction. Also, mothers with high self-esteem tended to have daughters with high self-esteem. The mothers of girls with low BES scores found a significantly greater discrepancy than the mothers of girls with high BES scores when contrasting their daughters' current shape with either the ideal figure for their daughter or the figure they believed boys would find attractive. Discussion Girls who aspired to be like their mothers in terms of personality traits felt better about themselves and their bodies compared with girls with low maternal identification. © 2001 by John Wiley & Sons, Inc. Int J Eat Disord 29: 429–440, 2001.
Hematoma-Directed Ultrasound-Guided Breast Biopsy

Traditionally, nonpalpable breast lesions have been excised using needle localization breast biopsy (NLBB). Magnetic resonance imaging (MRI) of the breast has allowed the appreciation of lesions previously undetected by mammography. Despite the availability of MRI-guided needle localization techniques at ours as well as other institutions, the patient is still subjected to the disadvantages and complications inherent to this method of biopsy. Although NLBB most often results in the successful removal of the targeted lesion in mammographically detected lesions, the miss rate varies from 0% to 22%. 1–4 The rate is unknown for MRI NLBB, where even thinner wires are used and where the technology is not universally available. Specimen mammography is used to confirm excision of the targeted lesion after NLBB. In contrast, “specimen MRI” is not possible because MRI requires living tissue with a blood supply to demonstrate areas of enhancement of the targeted lesion. Confirmation of removal requires a separate MRI of the remaining breast tissue in the patient on a separate day. Although NLBB is considered the standard for removal of mammographically detected, nonpalpable breast lesions, disadvantages include the possibility of significant vasovagal reactions, which occur in 10% to 20% of patients, the discomfort of the wire, and the possibility of wire transection or migration. 2,4 We therefore sought to develop an alternative method that could be used to excise MRI-detected lesions. Because traumatic hematomas can often be visualized by ultrasound, we hypothesized that iatrogenically induced hematomas could similarly be visualized. Hematomas could then be placed in the breast to identify nonpalpable lesions previously seen only with MRI and could similarly be used to guide their excision and confirm their removal by intraoperative ultrasound.
What Free Schools Teach

Alternative schools are no more, and often less effective in teaching academic skills than are traditional schools. Alternative schools do, however, teach a “hidden curriculum,” a set of norms nearly the inverse of those traditional schools teach. Using the work of Dreeben, On What Is Learned in School (1968), and contrasting his findings with those from a two-year study of two alternative high schools, it is argued that in place of the values of individualism and achievement, alternative schools teach group skills. Students do not learn to cope with the stress of evaluation and the risk of failure; instead they are encouraged to develop autonomy, self-direction, and emotional openness. In contrast to the universalistic, specific norms of traditional schooling, free schools stress diffuse, particularistic, intimate relations between teachers and students and within the student peer group. The paper concludes with an analysis of the social class implications of the norms which free schools teach.
How institutional factors influence the creation of scientific metadata

Access to high volumes of digital data offer researchers in all disciplines the possibility to ask new kinds of questions using computational methods. Burgeoning digital data collections, however, challenge established data management and analysis methods. Data management is a multi-pronged institutionalized effort, spanning technology, policies, metadata, and everyday data practices. In this paper, we focus on the last two components: metadata and everyday data practices. We demonstrate how "frictions" arise in creating and managing metadata. These include standardization frictions, temporal frictions, data sharing frictions, and frictions related to the availability of human support. Through an illustration of these frictions in case studies of three large, distributed, collaborative science projects, we show how the degree of metadata institutionalization can strongly influence data management needs and practices.
Calculation of lateral distribution of interface traps along MIS channel

The lateral distribution of interface traps, averaged over the semiconductor band gap, is calculated in an MIS structure. The calculation is based on the well known charge-pumping technique. The calculation has been applied to p-channel MOSFETs.
Medical complications after stroke

Patients who have had a stroke are susceptible to many complications. These individuals commonly have comorbidities such as hypertension, diabetes, heart disease, or other ailments that increase the risks of systemic medical complications during stroke recovery. However, several complications can arise as a direct consequence of the brain injury itself, from the ensuing disabilities or immobility, or from stroke-related treatments. These events have a substantial effect on the final outcome of patients with stroke and often impede neurological recovery. Cardiac complications, pneumonias, venous thromboembolism, fever, pain, dysphagia, incontinence, and depression are particularly common after a stroke and usually require specific interventions for their prevention and treatment. However, there are few data to guide the management of these complications. Systematic investigations are therefore needed to further study the effects of medical complications on stroke recovery and to improve interventions for the prevention and treatment of these events.
On Hamming Product Codes With Type-II Hybrid ARQ for On-Chip Interconnects

We present hardware performance analyses of Hamming product codes combined with type-II hybrid automatic repeat request (HARQ), for on-chip interconnects. Input flit width and the number of rows in the product code message are investigated for their impact on the number of wires in the link, codec delay, reliability, and energy consumption. Analytical models are presented to estimate codec delay and residual flit error rate. The analyses are validated by comparison with simulation results. In a case study using H.264 video encoder in a network-on-chip environment, the method of combining Hamming product codes with type-II HARQ achieves several orders of magnitude improvement in residual flit error rate. For a given residual flit error rate requirement (e.g., 10-20), this method yields up to 50% energy improvement over other error control methods in high-noise conditions.