cssi/SciSciGPT-SciSciNet huggingface dataset:
Insights into North American Paleogeography and Paleotectonics from U-Pb ages of detrital zircons in Mesozoic strata of the Colorado Plateau, USA

Individual U–Pb ages for 5,655 detrital zircons (DZ) in 61 sandstone samples from Mesozoic strata of the Colorado Plateau and nearby areas provide insights into paleogeographic relations across the interior of North America and the paleotectonic evolution of North American continental margins. Pre-Mesozoic DZ grains derived either directly, or ultimately through sediment recycling, from distant sources in eastern North America are more abundant than DZ grains derived from the nearby Cordilleran magmatic arc of western North America. Sediment dispersal patterns included Triassic fluvial transport of detritus westward from the Ouachita orogen uplifted along the northern flank of rift highlands precursor to the oceanic Gulf of Mexico, Jurassic eolian transport southward into widespread ergs from deflation of floodplains of transcontinental paleorivers with headwaters in pre-Atlantic Appalachian highlands, and Jurassic-Cretaceous recycling of eolianite DZ from retroarc Sevier thrust sheets and from sedimentary cover of the Mogollon paleohighlands flanking the Border rift system.
On the mechanism of the quantitative precipitin reaction

Abstract The types of complexes which constitute antigen-antibody precipitate and supernatant have been computed from a theoretical interpretation of results of quantitative precipitin analyses. It was found that precipitates in the antibody and antigen excess regions are composed primarily of small complexes. For the system under study in the precipitates in far antibody excess the principal complex consists of three antibody molecules and one antigen molecule; in the precipitates in far antigen excess the most abundant complex is composed of four antigen molecules and three antibody molecules. The composition of complexes near equivalence has not yet been determined. The theory seems to have withstood its firts test. It has predicted properly the epxerimentally observed supernatant composition (antibody excess, equivalence and antigen excess).
The U.S. experience with worker cooperation

Abstract This article surveys the U.S. experience with worker cooperation. Worker cooperation is viewed as an alternative mode of production which exists within the capitalist economy. The historical experience is divided into the pre-Civil War era, the period between 1865 and 1930, the Depression years, and the post-World War II era. Reasons for the creation of worker cooperatives are surveyed, as are the determinants of cooperative growth, development, and failure. Generally, worker cooperation has been a heterogeneous movement, both in terms of geographical and industrial dispersion. It has also been mainly a working class phenomenon, and has therefore suffered from a lack of working capital and of management skills. It is argued that cooperative enterprise is a viable strategy for regional economic development and for relieving unemployment due to recessions and plant closings. This requires the establishment of supportive structures that can provide capital and technical assistance.
Erratum: Generation and design of canonic grounded capacitor variable frequency RC-active oscillators

A comprehensive study for generation and design of grounded-capacitor variable-frequency RC-active oscillators using operational amplifiers (OAs) is reported. All the circuits derived are canonic, that is, the number of components (active as well as passive) in them is a minimum. First, a set of eight canonic circuits is found, each using one OA, two capacitors and six resistors. However, these circuits suffer from either a poor start-up property or a limited frequency range of variation. Thus, based on this set of eight circuits, another set of 12 variable-frequency oscillators is derived. This set provides easy tunability and a wider tuning range. Both the sets are shown to be complete. All the variable-frequency oscillators are single resistor controlled. Two of the circuits have their variable resistors grounded which makes them attractive candidates for voltage-controlled oscillators. Design equations for all the oscillator circuits are given. All the circuits have been laboratory tested. Experimental results are found to be in close agreement with the theoretical analysis. Representative test results are included in the article.
Gravity-Induced Wrinkling in Subscale, Singly Curved Parabolic Gossamer Membrane

†‡ In this study, close-range photogrammetry was used to reconstruct the three-dimensional surface contour of a parabolic membrane as a function of local gravity. One of the most persistent challenges involving the deployment of full-scale gossamer structures is the development of predictive numerical models for full-scale, zero-g behavior, which can be verified using sub-scale models at one-g. One step in the development and verification of such models is simply obtaining suitable data at zero-g and one-g that can be used for such purposes. This paper describes a half-scale 76.2-µm thick parabolic membrane, fabricated from Kapton HN, which was flown aboard NASA’s KC-135A and used to obtain surfaceprofile-versus-gravity data. Surface measurement was made using a five-camera photogrammetry system, which allowed non-contact measurement of the lower two-thirds of the membrane to be made. Using this method, it was found that membrane surface wrinkle configuration at zero-g changed as the membrane was accelerated to 1.8-g, but then returned to its initial configuration once weightless conditions were restored. Measurement resolution over the extent of the membrane varied between approximately 0.0001 – 0.001 m, which was not as good as that typically obtained using close-range photogrammetry. This discrepancy was likely due to the non-ideal camera positions and orientations necessitated by the space restrictions aboard the KC-135A.
Evaluation and Initial Treatment of Supraventricular Tachycardia

This article reviews a systematic approach to diagnosis and management of supraventricular tachycardias. Adenosine, which blocks the AV node, is of diagnostic value but should not be used in cases of irregular wide-complex tachycardias, since it may lead to clinical instability.
The four horsemen of tech: Has another bubble burst?

After the subprime mortgage bubble burst, people started looking around to see if other disasters were on the horizon. In the high-tech sector, the stocks of four companies—Google, Apple, Research in Motion, and Amazon.com—provided strong market leadership during 2007. But following their steep rise in the second half of 2007, the stocks of these “new four horseman of tech” suffered a sharp correction. Has another bubble burst? If so, what does it mean for the broader market? © 2008 Wiley Periodicals, Inc.
Hydration State Controls Stress Responsiveness and Social Behavior

Life stress frequently occurs within the context of homeostatic challenge, requiring integration of physiological and psychological need into appropriate hormonal, cardiovascular, and behavioral responses. To test neural mechanisms underlying stress integration within the context of homeostatic adversity, we evaluated the impact of a pronounced physiological (hypernatremia) challenge on hypothalamic-pituitary-adrenal (HPA), cardiovascular, and behavioral responses to an acute psychogenic stress. Relative to normonatremic controls, rats rendered mildly hypernatremic had decreased HPA activation in response to physical restraint, a commonly used rodent model of psychogenic stress. In addition, acute hypernatremia attenuated the cardiovascular response to restraint and promoted faster recovery to prestress levels. Subsequent to restraint, hypernatremic rats had significantly more c-Fos expression in oxytocin- and vasopressin-containing neurons within the supraoptic and paraventricular nuclei of the hypothalamus. Hypernatremia also completely eliminated the increased plasma renin activity that accompanied restraint in controls, but greatly elevated circulating levels of oxytocin. The endocrine and cardiovascular profile of hypernatremic rats was predictive of decreased anxiety-like behavior in the social interaction test. Collectively, the results indicate that acute hypernatremia is a potent inhibitor of the HPA, cardiovascular, and behavioral limbs of the stress response. The implications are that the compensatory responses that promote renal-sodium excretion when faced with hypernatremia also act on the nervous system to decrease reactivity to psychogenic stressors and facilitate social behavior, which may suppress the anxiety associated with approaching a communal water source and support the social interactions that may be encountered when engaging in drinking behavior.
Determining the response of nonlinear systems to arbitrary inputs

IF AN ENGINEER is presented with a general linear system, a ?black box,? let us say, having an input and an output, the first question he will usually ask is: What is (or should be) the relationship between its input and output? This is a question which can be answered in many ways. One can determine or prescribe the response of the box to impulses or step functions or sine waves, and from these calculate the response to any input, regardless of its character. The concept here is essentially that of impedance, a term which may be defined in a variety of ways, but the central idea of all the definitions is that, in some fashion, the general relationship between the stimulus and the response of a system is specified.
The Political Economy of Results-Oriented Management in the “Neoadministrative State” Lessons from the MCDHHS Experience

To comply with the precepts of today's neoadministrative state, public managers are routinely pressed by elected officials to become results-oriented, customer-focused, and partnership-seeking service deliverers. The magnitude of the cultural change involved has frequently proved daunting at all levels of government in the United States. Although much remains unclear about the prudence and prospects of such cultural-reform efforts, researchers are gradually discerning the political economy of the efforts and challenges they pose to effectiveness and to public accountability. In the process, they are finding how critical the approaches taken in the early stages of cultural reform are to their ultimate success or failure. To advance practice and research on this topic, this article chronicles and analyzes the first 3 years of a critical case study of results-driven, customer-focused, and partnership-oriented cultural change in the Department of Health and Human Services in Montgomery County, Maryland. Identified are nine critical choices made during those years that sorely complicated progress, the flaws in underlying causal theories that spawned these problems, and the challenges to, and opportunities for advancing, accountability that reformers can expect and that researchers can profitably pursue.
Postoptimality analyses of the transportation problem

We develop here a new approach to postoptimality analyses of the transportation problem (TP) through the use of perturbation analysis. In contrast to the usual sensitivity analysis the proposed methods allow for simultaneous, independent (or dependent) perturbation of the supplies, demands and transportation rates cost from their nominal values whilst preserving the current optimal basis. The essential parts of the calculation involve the same manipulations as the solution algorithm used in solving the parametric perturbed supply-demand version of the nominal TP. Furthermore, the coefficient of the perturbed parameters in the optimal parametric cost function is used to indicate the existence of a cheaper (or equivalent cost) solution than the current optimal one by shipping more total goods. The proposed approach permits computation of the maximal allowable additional units and distribution of these extra units in a systematic manner. The proposed unified procedures are demonstrated by numerical examples.
Noninvasive imaging of transcriptionally restricted transgene expression following intratumoral injection of an adenovirus in which the COX-2 promoter drives a reporter gene.

Purpose To demonstrate the efficacy of repeated, non-invasive optical imaging of reporter gene expression in monitoring the ability of bi-specific recombinant molecules (i) to “transductionally untarget” adenovirus from Coxsackie and Adenovirus Receptor (CAR)-dependent infection of normal tissue and (ii) to “transductionally retarget” infection to specific target cells. Procedures sCAR-EGF is a recombinant, bi-specific molecule containing the soluble portion of CAR fused to Epidermal Growth Factor. The sCAR moiety binds to the virus and blocks CAR-dependent adenovirus infection. The EGF moity binds to cellular EGF receptors. We used non-invasive optical imaging of firefly luciferase to repeatedly monitor, in living animals, the ability of sCAR-EGF (i) to “transductionally untarget” systemically administered Ad.CMVfLuc, an adenovirus that constitutively expresses luciferase, from normal tissues and (ii) to “transductionally redirect” adenovirus infection in mice to xenograft tumors that express elevated epidermal growth factor (EGF) receptor levels. Results Systemic injection of sCAR-EGF “coated” adenovirus expressing firefly luciferase from the CMV early promoter, reduces expression of the reporter gene in the liver and facilitates expression of the reporter gene in tumor xenografts expressing high levels of the EGF-receptor. Conclusion Both liver “untargeting” and tumor “retargeting” of adenovirus by recombinant sCAR-EGF can be imaged non-invasively using a luciferase reporter gene.
Transmembrane Domain of M2 Protein from Influenza A Virus Studied by Solid-State 15N Polarization Inversion Spin Exchange at Magic Angle NMR

Abstract The M2 protein from the influenza A virus forms a proton channel in the virion that is essential for infection. This tetrameric protein appears to form a four-helix bundle spanning the viral membrane. Here the solid-state NMR method, 2D polarization inversion spin exchange at magic angle (PISEMA), has been used to obtain multiple constraints from specifically amino acid-labeled samples. The improvement of spectral resolution from 2D PISEMA over 1D methods and 2D separated local field methods is substantial. The reliability of the method is validated by comparison of anisotropic chemical shift and heteronuclear dipolar interactions from single site labeled samples. The quantitative interpretation of the high-resolution constraints confirms the helix tilt to be within the range of previous experimental determinations (32°–38°). The binding of the channel inhibitor, amantadine, results in no change in the backbone structure at position Val 27,28 , which is thought to be a potential binding site for the inhibitor.
Role of the CCAAT/enhancer-binding protein NFATc2 transcription factor cascade in the induction of secretory phospholipase A2.

Inflammatory cytokines such as interleukin-1 and tumor necrosis factor-α modulate a transcription factor cascade in the liver to induce and sustain an acute and systemic defense against foreign entities. The transcription factors involved include NF-κB, STAT, and CCAAT/enhancer-binding protein (C/EBP). Whether the NFAT group of transcription factors (which was first characterized as playing an important role in cytokine gene expression in the adaptive response in immune cells) participates in the acute-phase response in hepatocytes is not known. Here, we have investigated whether NFAT is part of the transcription factor cascade in hepatocytes during inflammatory stress. We report that interleukin-1 or tumor necrosis factor-α increases expression of and activates NFATc2. C/EBP-mediated NFATc2 induction is temporally required for expression of type IIA secretory phospholipase A2. NFATc2 is also required for expression of phospholipase D1 and the calcium-binding protein S100A3. Thus, a C/EBP-NFATc2 transcription factor cascade provides an additional means to modulate the acute-phase response upon stimulation with inflammatory cytokines.
Contact dermatitis of the vulva

Vulvar diseases rarely stand alone. They are often caused or worsened by primary irritant or allergic contact dermatitis, and this should be considered when evaluating any vulvar complaint. All irritants should be avoided in all women, and those with vulvar dermatoses should be patch tested to help define or rule out allergens.
Simplified dynamic density based capacity estimation

Methods for estimating constant and variable sector capacity based on an airspace complexity metric, simplified dynamic density, are proposed. Simplified dynamic density is a weighted sum of seven traffic components that contribute to airspace complexity. Constant and variable estimates of maximum sector capacity, based on projected flight tracks, are used to constrain the traffic demand in fast-time simulations. Delays and aircraft counts resulting from these methods are compared with those obtained using the capacities in the current system and based on the “5/3 of average sector flight time” rule. Results show that the simplified dynamic density based capacities produce lower system-wide delays and more throughputs, and indicate more predictable air traffic demands during the peak traffic period.
Secretory leukocyte protease inhibitor binds to Neisseria gonorrhoeae outer membrane opacity protein and is bactericidal.

Problem Secretory leukocyte protease inhibitor (SLPI) is an innate immune peptide present on the genitourinary tract mucosa which has antimicrobial activity. In this study, we investigated the interaction of SLPI with Neisseria gonorrhoeae.
Three chromosome abnormalities (trisomy 21,XXY, and a de novo reciprocal translocation) in a child with 48,XXY,+21,t(6;10)(p22-24;p12)

An infant with chromosomally normal parents was found to have double aneuploidy and a reciprocal translocation between chromosomes number 6 and 10. This cooccurrence may represent a very rare coincidence or may indicate that primary nondisjunction and chromosome rearrangements may be more than coincidentally related.
Endothelium-derived hyperpolarizing factor(s) and the potentiation of kinins by converting enzyme inhibitors

Inhibitors of angiotensin converting-enzyme (ACE) enhance the endothelium-dependent relaxation to bradykinin and cause the accumulation of kinins in the vascular wall. Bradykinin elicits the production of vasodilator prostanoids and nitric oxide by endothelial cells. However, there is an additional component to the dilator actions of bradykinin, which is mediated by a diffusible endothelium-derived hyperpolarizing factor (EDHF). The knowledge gathered on the nature of EDHF and its mechanism of action are reviewed briefly. EDHF causes hyperpolarization and relaxation of arterial smooth muscle by activating K(+)-channel, the nature of which varies between species. During the inhibition of both cyclooxygenase and nitric oxide synthase, concentration-response relationships of the hyperpolarization and relaxation elicited by bradykinin overlap in canine coronary arteries. Both effects are enhanced equally by the ACE inhibitor perindoprilat. They are inhibited by membrane depolarization that is obtained by raising the extracellular concentrations of potassium ions. Likewise, in the human coronary artery, the hyperpolarization elicited by bradykinin, which is also mediated by EDHF, is augmented in the presence of perindoprilat and prevented by potassium-induced depolarization. In this blood vessel, contrary to the canine coronary artery, the EDHF-mediated responses occur at concentrations comparable to those initiating the nitric oxide-dependent component. Therefore, the increased production of EDHF, which is induced by kinins, may contribute to the cardiovascular effects of perindoprilat, together with an enhanced production of nitric oxide and vasodilator prostanoids.
Performance of large-eddy breakup devices at post-transitional Reynolds numbers

Large-eddy alteration techniques were used to modify the drag characteristics of the turbulent boundary layer. Local skin-friction coefficients were measured for single and multi-element arrays of thin plates suspended in a fully turbulent, flat plate, boundary layer at R(theta) = 3,000. Effects of these devices were measured more than 300 boundary-layer thicknesses downstream to R(theta) = 17,000. It was found that although most of the devices reduced the local skin friction immediately downstream, this reduced skin-friction region persisted for only 100-120 delta-0, after which a rapid rise in skin-friction coefficient occurred, often exceeding flat plate values. Net drag reductions were obtained only for tandem configurations and these reductions were sensitive to device spacing and height. The maximum net drag reduction reported was approximately 7 percent with a device spacing of 10 delta-0 at a height of 0.8 delta-0.
|[ldquo]|NEAR-MISS|[rdquo]| SUDDEN INFANT DEATH SYNDROME |[lpar]|SIDS|[rpar]| WITH I-ACTIC ACIDOSIS

A healthy 5 mo. old male had six apneic spells with cyanosis and loss of tone, lasting up to 60 seconds, within two days. Although monitored and free of further apneic episodes, hyperlactatemia (46 mg%) was present two and four days later, pyruvate 2.2 mg%, arterial and CSF lactate 43 and 20 mg%; uric acid 11 mg%, plasma alanine increased, urine screen by GC for organic acids normal. Multiple FBS determinations, glucose tolerance and alanine loads were normal and not associated with lactate elevation. Conversion of I-14C pyruvate to 14CO2, measured in WBC and cultured fibroblasts was normal. BMR was normal. On anticonvulaants and thiamine there were 7 more episodes in 6 weeks. Multiple EEC's were normal except for one episode of seizure discharges following 10 second apnea. Spontaneous panting episodes occurred prior to and throughout observation. Following a ketogenic diet with medium chain triglycerides, serum lactate declined gradually to 8.5 mg% and lactate pyruvate ratio normalized: 11. The patient who excretes large amounts of medium chain dlcarboxylic acids, has been asymptomatic for 5 months. A causal relationship with the apparent recovery is possible. The above tests do not suggest defective gluconeogenesis; defective pyruvate dehydrogenase complex in brain is unlikely in view of normal pyruvate metabolism in WBC and fibroblasts, and lower lactate levels in CSF than blood. Lactate, which may be elevated due to dysregulation of respiratory drive, should be monitored in infants at risk for SIDS.
THE EFFECT OF INGESTION OF DIATOMACEOUS EARTH IN WHITE RATS: A SUBACUTE TOXICITY TEST.

Abstract The effects of 5% diatomaceous earth in the diet fed to white rats over a 90-day period indicated no mechanical or chemical damage to the tissues. There was no significant increase in the percentage of residual silica in liver, kidneys, and spleens of the test animals. Comparison of weight changes in the 5% group with the control showed a greater weight gain in the 5% test group. Histologic sections of animals fed 3% and 1% diatomaceous earth also showed no damage.
Two cases of thyroid storm-associated cholestatic jaundice.

Objective: To describe the association of the rare and serious complication of jaundice with severe thyrotoxicosis, a potentially lethal endocrine disorder.Methods: We report the clinical, laboratory, and pathologic findings of 2 cases of severe jaundice (total biliru-bin levels: 35.2 mg/dL in case 1 and 42 mg/dL in case 2) associated with thyroid storm in the absence of a history of liver disease, thionamide exposure, or congestive heart failure. We also present other relevant reports available in the literature.Results: Case 1 was a 38-year-old woman who presented with nausea, vomiting, fatigue, pruritus, and frequent nonbloody diarrhea. She was transferred to our institution because of worsening hyperbilirubinemia. Case 2 was a 35-year-old woman admitted to a community hospital with thyroid storm and jaundice. Upon transfer to our institution, the patient was unconscious, mechanically ventilated, and in atrial fibrillation. In case 2, liver biopsy results revealed diffuse hepatocellular ballooning with...
Photosynthetic responses of Zostera marina L. (Eelgrass) to in situ manipulations of light intensity

Photosynthetic responses of the temperate seagrass, Zostera marina L., were examined by manipulations of photon flux density in an eelgrass bed in Great Harbor, Woods Hole, MA during August 1981. Sun reflectors and light shading screens were placed at shallow (1.3 m) and deep (5.5 m) stations in the eelgrass bed to increase (+35% to +40%) and decrease (-55%) ambient photon flux densities. The portion of the day that light intensities exceeding the light compensation point for Z. marina (H comp) and the light saturation point (H sat) were determined to assess the impact of the reflectors and shades. The H comp and H sat periods at the deep station shading screen were most strongly affected; H comp was reduced by 11% and H sat was reduced by 52%. Light-saturated photosynthetic rates, dark respiration rates, leaf chlorophyll content, chlorophyll a/b, PSUO 2 size, PSU density, leaf area, specific leaf area, leaf turnover times and leaf production rates were determined at the end of three sets of 1- to 2-week experiments. None of the measured parameters were affected by the photon flux density manipulations at the shallow station; however, at the deep station leaf production rates were significantly reduced under the shading screen and chlorophyll a/b ratios were higher at the reflector. These results indicate that adjustment to short-term changes in light regime in Z. marina is largely by leaf production rates. Further, the most dramatic changes in the periods of compensating or saturating photon flux densities had the greatest impact on the measured photosynthetic responses.
RF power amplifier's nonlinear modelling with memory effect

Theoretically, memoryless nonlinear effect is the main concern for RF power amplifier (PA) modelling and analysis. However, the latest generation wireless communication systems, such as Wi-Fi, WiMAX and LTE, using wider bandwidth, add new problems for the analysis of RF PAs, which is the memory effect associated with the bandwidth. The memory effect causes additional distortion to the PA and affects the performance of digital predistortion (DPD) design. Previously, we predicted the memoryless spectrum regrowth of a PA related to its intercept points up to arbitrary high order for a few of wireless communication signals, such as TDMA, CMDA and OFDM. In this letter, we propose a simplified Hammerstein structure-based method to consider the memory effect as well in order to analyse the nonlinear characteristic of PAs more precisely and completely. The simplification greatly reduced the complexity of classic Hammerstein system identification for PAs. The result will be useful in the analysis of RF PAs with me...
Coordinated and conserved expression of alphoid repeat and alphoid repeat-tagged coding sequences.

We have found an alpha-like simple-sequence DNA repeat that is differentially expressed during early embryogenesis in both chick and zebrafish. Before and during the primitive streak stage, transcripts of the alphoid repeat sequence were ubiquitously expressed throughout zebrafish and chick embryos. After headfold formation, expression was limited to the cardiac neural crest, the head, and the heart. Two types of alphoid repeat sequence transcripts were identified: alphoid repeat RNA and alphoid repeat-tagged mRNA (ESalphaT). Several of the ESalphaTs were identified by (1) searching expressed sequence tag databases, (2) arbitrary rapid amplification of cDNA ends (RACE), and (3) screening embryonic cDNA libraries. The alphoid element was located in the 3' untranslated region of one ESalphaT that was obtained by RACE. The ESalphaT sequences encoded a variety of different types of proteins, but all were expressed within tissues that were positive for the alphoid repeat RNA. The presence of two types of coordinately expressed alphoid-like repeat transcripts in maternal RNA with subsequent restriction to the head and heart, and the conservation of these features in disparate vertebrate embryos, suggest that the alphoid repeat sequence may serve as a control element in the gene regulation network.
Morphology and ultrastructure of the Malpighian tubules of the Chilean common tarantula (Araneae: Theraphosidae).

Relatively little is known about the morphology and ultrastructure of the Malpighian tubules of spiders (Arachnida: Araneae). Our study represents the first investigation of the Malpighian tubules of a theraphosid spider and is the only study to examine the living Malpighian tubules using confocal laser scanning microscopy. In theraphosid spiders, the Malpighian tubules originate from the stercoral pocket in the posterior portion of the opisthosoma and extend forward toward the prosoma in a dendritic pattern. There are three distinct segments (initial, main, and terminal), all dark brown in appearance. Each segment has distinctive ultrastructural features. Both the terminal and the main segment appear to be composed of at least two cell types with finger-like cytoplasmic protrusions associated with one of these types. The terminal segment, which is most proximal to the stercoral pocket, is the largest in diameter. It is composed of large, cuboidal cells containing many mitochondria and lipid inclusions. The main segment is intermediate in diameter with many mitochondria and secretory vesicles present. The initial segment is relatively thin in comparison to the other segments and is intimately associated with the digestive gland. The cells of the initial segment contain very little cytoplasm, fewer mitochondria, secretory vesicles, and prominent inclusions. J. Morphol. 251:73–82, 2002. © 2002 Wiley-Liss, Inc.
The Appropriateness of Imaging: A Comprehensive Conceptual Framework

This review seeks to clarify and explicate an elusive concept: the appropriateness of diagnostic imaging. To ensure a common basis for discussion, several key components are articulated and defined. These include the diagnostic imaging procedure (DIP) itself, the subject (a patient), and the setting (a clinical scenario) in which the DIP is being considered. A review of the literature shows that appropriateness is a logical extension of empiric research, which has revealed substantial variation in the type and intensity of health services delivered to otherwise similar populations and communities in the United States. Against this background, the appropriate rate of a service in a population is transformed into appropriateness for an individual patient, which, when defined in terms of expected net health outcome, provides a conceptual link with the denominator of cost-effectiveness analysis. The complementary roles of clinical trials, technology assessment, decision-analytic modeling, and consensus methods in estimating appropriateness are compared and contrasted.
Degree ramsey numbers of graphs

Let H G mean that every s-colouring of E(H) produces a monochromatic copy of G in some colour class. Let the s-colour degree Ramsey number of a graph G, written RΔ(G; s), be min{Δ(H): H G}. If T is a tree in which one vertex has degree at most k and all others have degree at most âk/2â, then RΔ(T; s) = s(k-1) + Iµ, where Iµ = 1 when k is odd and Iµ = 0 when k is even. For general trees, RΔ(T; s) â¤ 2s(Δ(T)-1). To study sharpness of the upper bound, consider the double-starSa,b, the tree whose two non-leaf vertices have degrees a and b. If a â¤ b, then RΔ(Sa,b; 2) is 2b-2 when a <b and b is even; it is 2b-1 otherwise. If s is fixed and at least 3, then RΔ(Sb,b;s) = f(s)(b-1)-o(b), where f(s) = 2s-3.5-O(s-1). We prove several results about edge-colourings of bounded-degree graphs that are related to degree Ramsey numbers of paths. Finally, for cycles we show that RΔ(C2k + 1; s) â¥ 2s + 1, that RΔ(C2k; s) â¥ 2s, and that RΔ(C4;2) = 5. For the latter we prove the stronger statement that every graph with maximum degree at most 4 has a 2-edge-colouring such that the subgraph in each colour class has girth at least 5.
Reputational Signals and Capital Acquisition When Insurance Companies Go Public

We analyse reputational signals and decisions surrounding capital acquisition by examining 76 insurance firms going public from 1996 to 2006. We first explore the relationship between proxies for insurance firm reputation and initial public offering (IPO) underwriter reputation. In general, we find that more reputable underwriters market IPOs of more reputable insurers—insurers that are less risky, more likely to be life insurers and that have higher franchise value. These results suggest that underwriter and insurer reputations are aligned and send consistent signals. Second, we show that the market requires a higher return from riskier/less reputable insurers when they go public. When we compare the performance of our insurance company sample to a matched sample of non-insurance firms, we find that the greater reputational transparency of insurers allows the market to do a better job of determining future performance. Last, we conclude by showing empirically that franchise value and the reputational posture of the insurance firms are positively related. These results contribute to the growing body of knowledge on reputational risk management and should enhance capital acquisition strategies of insurance company managers.
Effect of vent opening area and arrangement on gas flow field as gas propelled cylinder exits a flow tube

The effects of auxiliary flow tube vent opening area and arrangement on the gas flow field as a gas propelled cylinder exits a flow tube were studied numerically. Configurations with a single opening of increasing size and multiple opening arrangements with equivalent opening area were considered for comparison to a baseline no-opening system. The openings are positioned near the end of the flow tube. The intended use of the openings is to reduce the pressures of the gases escaping to the surroundings and thus to reduce the intensity and size of the gas expansion zone in the surroundings. The results indicated that increasing the opening flow area decreased the pressure at the axial end of the flow tube and the radial extent of the end of flow tube exit plume. However, the radially directed flow streams leaving through the side vent openings could increase the overall radial spread of the gas expansion into the surroundings. The single opening arrangement produced as much as a 95% decrease in the pressure at the end of the flow tube and a 37% decrease in the recoil force at a given time with about 95% of the exiting flow leaving through the opening. For the parameters considered, the multiple opening arrangement produced up to a 93% decrease in the pressure at the end of the flow tube and a 90% decrease in the recoil force at a given time with about 93% of the exiting flow leaving through the openings. The results showed larger single openings to be more effective at reducing end of flow tube pressure, while the multiple openings to be more conducive to a reduced recoil force.
Estimation of Corrosion Damage in Steel Reinforced Mortar Using Guided Waves

Corrosion of reinforced concrete is a chronic infrastructure problem, particularly in areas with deicing salt and marine exposure. To maintain structural integrity, a testing method is needed to identify areas of corroding reinforcement. For purposes of rehabilitation, the method must also be able to evaluate the degree, rate, and location of damage. Toward the development of a wireless embedded sensor system to monitor and assess corrosion damage in reinforced concrete, reinforced mortar specimens were manufactured with seeded defects to simulate corrosion damage. Taking advantage of waveguide effects of the reinforcing bars, these specimens were then tested using an ultrasonic approach. Using the same ultrasonic approach, specimens without seeded defects were also monitored during accelerated corrosion tests. Both the ultrasonic sending and the receiving transducers were mounted on the steel rebar. Advantage was taken of the lower frequency (<250 kHz) fundamental flexural propagation mode because of its relatively large displacements at the interface between the reinforcing steel and the surrounding mortar. Waveform energy (indicative of attenuation) is presented and discussed in terms of corrosion damage. Current results indicate that the loss of bond strength between the reinforcing steel and the surrounding concrete can be detected and evaluated.
Research and reform in community policing

Examines the opportunities provided by problem‐oriented community policing to combine research with reform. Advocates the involvement of workers as researchers in this action research. Points out that outcomes which at first appear to be negative can be a tool for change, e.g., an increase in client callbacks after family crisis intervention was an indication of the improved image of police as service‐providers, rather than failure by police to reduce crises. Considers ways of establishing evaluation criteria. Explains the value of exploratory action research whereby the object of the exercise is revised as the data is being gathered. Lists the desiderata for participatory action research.
Distinguishing Hope and Optimism: Two Sides of a Coin, or Two Separate Coins?

Abstract Structural equation modeling was used to test hypotheses about (a) the dimensionality of measures of dispositional hope (the Adult Hope Scale, AHS) and dispositional optimism (the Life Orientation Test, LOT), (b) the extent and source of conceptual overlap and divergence between hope and optimism, and (c) patterns of discriminant validity for each trait. Separate two-factor models best fit the hope (Agency and Pathways, r = .68) and optimism (Optimism and Pessimism, r = -.63) data. Analyzing the combined AHS and LOT data, a measurement model with separate, correlated second-order factors of Hope and Optimism ( r = .80) provided a better fit than did a higher-order model with a single second-order factor. Optimism correlated equally with both Agency and Pathways, whereas Pessimism was more strongly correlated with Agency than with Pathways. Confirming hypotheses, second-order Optimism had a stronger influence on the use of positive reappraisal as a coping strategy than did second-order Hope, where...
Colonic fermentation : metabolic and clinical implications

Colonic SCFA formation from fermentable carbohydrate is important for the maintenance of morphologic and functional integrity of the colonic epithelium. Carbohydrate-induced diarrhea occurs when the amount of carbohydrate entering the colon exceeds its fermentation capacity. Deficient availability or utilization of SCFA, mainly of n-butyrate, is the cause of diversion colitis and may play important roles in colonic carcinogenesis, in starvation and enterotoxigenic diarrhea, and in idiopathic UC.
Site-directed chemical cross-linking demonstrates that helix IV is close to helices VII and XI in the lactose permease.

The N-terminal six transmenbrane helices (N6) and the C-terminal six transmembrane helices (C6) of the lactose permease, each containing a single-Cys residue, were coexpressed, and proximity was studied. Paired Cys residues in helices IV (positions 114, 116, 119, 122, 125, or 129) and VII (227, 231, 232, 234, 235, 238, 239, 242, 243, 245, or 246) or XI (350, 353, 354, 357, 361, or 364) were tested for cross-linking in the presence of two rigid homobifunctional thiol-specific cross-linkers, N,N‘-o-phenylenedimaleimide (o-PDM; 6 A) and N,N‘-p-phenylenedimaleimide (p-PDM; 10 A). Cys residues in the middle of helix IV (position 119 or 122) cross-link to Cys residues in the middle of helix VII (position 238, 239, 242, or 243). In contrast, no cross-linking is evident with paired Cys residues at either end of helix IV (position 114, 116, 125, or 129) or helix VII (position 227, 231, 232, 234, 235, 245, or 246). On the other hand, Cys residues in the cytoplasmic half of helix IV (position 125 or 129) cross-link ...
Effects of zinc on the cytoskeletal proteins in the central nervous system of the rat.

Summary To test for in vivo zinc neurotoxicity on the cytoskeleton of neurotubules and intermediate filaments, Zn wires were implanted into the brains of adult Lewes rats for periods of 1–35 weeks. After 16 weeks of implant, some neurons showed bundles of intermediate filaments which were often localized in the perinuclear area. At the same time, occasional 200 nm tubular-like structures were seen in swollen dendrites. These structures were morphologically similar to Zn ion-induced aggregates of pure tubulin and structures found in ZnSO 4 -treated dorsal root ganglion organotypic cultures. The 200 nm structures in dendrites and the intermediate filaments in neurons increased in frequency with time. After 35 weeks of Zn wire implant, few microtubules could be found in the lesion. All the animals showed an astrocyte and glial filament proliferation with axoglial membrane specialization. Other wires studied: Pt, Ni, Co, Mg, demonstrate that Zn wires have a specific effect on cytoskeletal proteins in the CNS of the rat and many of the effects can be explained by an interaction between Zn and tubulin.
Optimal characterization of myocardial perfusion with AngioMARK.

Fast magnetic resonance (MR) scanning techniques are necessary to detect perfusion deficits from coronary stenosis using currently available extracellular contrast agents. In these experiments, typically conducted under conditions of pharmacologic stress, physiologically significant stenoses may be visualized as transient areas of decreased myocardial signal after intravenous (IV) injection of a T1 contrast agent. Because of the demands for rapid imaging, complete imaging evaluation of the entire myocardium is technically challenging. Also, transient susceptibility artifacts have been observed that may occasionally mimic hypoperfusion defects. AngioMARK (MS-325; EPIX Medical, Cambridge, Mass) is a novel T1 contrast agent that binds to albumin after injection, resulting in prolonged retention in the blood pool. The purposes of this study were (a) to determine the utility of this intravascular contrast agent in detecting perfusion abnormalities in a model of coronary artery stenosis, (b) to assess the time course of these perfusion defects, and (c) to determine the contrast dose necessary to visualize these perfusion defects.
MISMATCHED BONE MARROW TRANSPLANTATION (BMT) USING SOYBEAN AGGLUTININ (SBA) NEGATIVE MARROW CELLS

The limitation of mismatched BMT is fatal graft vs. host disease (GVHD). We processed haplotype mismatched parental marrow with SBA to enrich for stem cells and reduce GVHD and successfully treated 6 patients with severe combined immune deficiency disease. HLA chimerism was found within 3 weeks post BMT. All the patients demonstrate T cell and 2 have evidence of B cell engraftment. T cell numbers and responses to phytohemagglutinin (PHA) and alloantigen pre and post BMT are: In #2,5,6 who required pre BMT immunosuppression for maternal GVHD, neutrophil, RBC, and platelet engraftment occurred by days 11,26,32 respectively. No immunosuppression was given post BMT. 2 patients had no GVHD, 3 had transient rash/fever, and only 1 developed persistent rash. Patients are now 3 to 17mo. post BMT. These results demonstrate that treated mismatched BMT can result in engraftment without significant GVHD and can be used for patients who otherwise have limited hope for survival.
Hardness, elastic modulus, and fracture toughness bulk properties in Corning calcium fluoride

Knoop and Vickers hardness, Young's Modulus, and fracture toughness measurements were performed on Corning's Code 9575 calcium fluoride in various orientations. Other commercially available sources of calcium fluoride were also measured for comparison of properties. Knoop hardness and elastic properties exhibited a dependence on orientation while no such dependence was observed for Vickers hardness and fracture toughness. The results also indicated that these physical properties were not dependent on the source of the material
Indomethacin and the cardiopulmonary adaptations of transition.

Summary: The present investigation examines the biochemical and physiologic changes produced in fetal rabbit lungs by adding a prostaglandin synthetase inhibitor, sodium indomethacin trihydrate, to the pulmonary perfusate. A control group was similarly perfused without adding indomethacin. The ductus arteriosus was ligated and perfusion was then continued for 2 h while pulmonary artery pressures were monitored. At the end of this period, with perfusion continuing, the lungs were inflated with air at 5 cm H2O increments. Volume changes were recorded. After deflation, the lungs were lavaged with normal saline. Phospholipids were extracted from lung homogenates and lavage. Total lipid phosphorus was determined. Pulmonary vascular resistances in both groups manifested a sharp increase in pressure with ligation of the ductus. After 2 h of perfusion, pulmonary pressures in the control groups had returned very nearly to preligation levels, while in the indomethacin-treated group, pulmonary pressures remained significantly elevated. The first full inflation produced a slight fall in pulmonary vascular resistance in all control animals and a slight rise in all the treated rabbits. Perfused but untreated lungs had higher volumes during inflation as compared to both indomethacin-perfused lungs and unperfused untreated lungs. In this model, prostaglandins appear to have a significant role at two key points in transition: 1) the gradual accommodation to mechanically or hemodynamically mediated increases in pulmonary vascular resistance and 2) the drop in pulmonary vascular resistance which occurs with the first inflation of the lungs. No direct effect of prostaglandin inhibition on surfactant production was documented.
Structural and functional properties of two types of horizontal cell in the skate retina.

Two morphologically distinct types of horizontal cell have been identified in the all-rod skate retina by light- and electron-microscopy as well as after isolation by enzymatic dissociation. The external horizontal cell is more distally positioned in the retina and has a much larger cell body than does the internal horizontal cell. However, both external and internal horizontal cells extend processes to the photoreceptor terminals where they end as lateral elements adjacent to the synaptic ribbons within the terminal invaginations. Whole-cell voltage-clamp studies on isolated cells similar in appearance to those seen in situ showed that both types displayed five separate voltage-sensitive conductances: a TTX-sensitive sodium conductance, a calcium current, and three potassium-mediated conductances (an anomalous rectifier, a transient outward current resembling an A current, and a delayed rectifier). There was, however, a striking difference between external and internal horizontal cells in the magnitude of the current carried by the anomalous rectifier. Even after compensating for differences in the surface areas of the two cell types, the sustained inward current elicited by hyperpolarizing voltage steps was a significantly greater component of the current profile of external horizontal cells. A difference between external and internal horizontal cells was seen also in the magnitudes of their TEA-sensitive currents; larger currents were usually obtained in recordings from internal horizontal cells. However, the currents through these K+ channels were quite small, the TEA block was often judged to be incomplete, and except for depolarizing potentials greater than or equal to +20 mV (i.e., outside the normal operating range of horizontal cells), this current did not provide a reliable indicator of cell type. The fact that two classes of horizontal cell can be distinguished by their electrophysiological responses, as well as by their morphological appearance and spatial distribution in the retina, suggests that they may play different roles in the processing of visual information within the retina.