cssi/SciSciGPT-SciSciNet huggingface dataset:
Size restriction on peptide utilization in Escherichia coli.

It has been shown by measuring the growth response of appropriate amino acid auxotrophs to several series of homologous oligopeptides that higher oligomers were unable to enter Escherichia coli. The exclusion did not always occur at the same chain length of peptide, for the oligomer at which exclusion was first observed varied with the nature of the amino acid residues. To investigate the possibility that over-all size may be important in regulating peptide entry, the relative hydrodynamic volumes of the peptides used in the above studies were measured by gel filtration on Sephadex G-15. These studies suggested that to be able to enter E. coli the hydrodynamic volume of a peptide could not exceed a certain critical value. To test the generality of this observation, the heterogeneous mixture of peptides present in the enzymatic protein hydrolysate Neopeptone was separated according to size on Sephadex G-15. On the basis of the previous measurements it proved possible to exactly predict which of the Neopeptone peptide fractions could enter the cell and which would be excluded. Lack of competition between peptides that can enter and peptides that are excluded, suggests that the exclusion may occur external to the peptide transport system. The speculation is raised that the cell wall may act as a molecular sieve preventing molecules above a certain size from crossing the cell envelope, the critical hydrodynamic volume being some measure of the pore size of such a sieve.
Transient characteristics of dense gas dispersion. Part 1

Abstract A wind-tunnel validated, non-proprietary depth integrated numerical model is developed to calculate the behavior of heavy and cold gas clouds released into the atmosphere at ground level. The model (DENS20) is time dependent, quasi-three dimensional, and permits cloud heating from below and the entrainment of moist air. The model does not depend upon the Boussinesq assumption, but it does require the hydrostatic assumption. Model constants are set to fit a cross-section of data from wind-tunnel experiments on the transient and steady behavior of releases of heavy gases. Plume shape and concentration decay with distance and time are reproduced for comparative cases from the Porton Downs and China Lake field tests and the Colorado State University cold gas laboratory tests on dense gas behavior. T001 . List of symbols B Plume width C Concentration mass fraction C f /2 Surface drag coefficient c p Specific heat capacity E Enthalpy g ′ Gravitational constant Gr Grashof number, g β( T a - T 0 ) H 0 /ν a 2 H Plume height ( HS ) Heavyside operator h s Surface heat transfer coefficient k Von Karman constant K See eqn. (8), section longitudinal momentum l b Bouyancy length scale L h , l H 2 O See eqn. (9), latent heat of vaporization of water vapor M See eqn. (5), section lateral momentum, or molecular weight N See eqn. (6), section mass p Pressure P See eqn. (7), section mass fraction Pr Prandtl number Q See eqn. (9), section enthalpy, or plume source strength R See eqn. (5), plume density Re Reynolds number, ( g ′ 0 H ) 1/2 H /ν a Ri * Richardson number, ( g ′ 0 H 0 )/ u * 2 ( SG ) Specific gravity t Time T Temperature, or time scale T* Dimensionless temperature, ( T-T 0 )/( T a - T 0 ) u, U Velocity, velocity scale u * Friction velocity U T , W T Advection velocities at cloud top υ e , w e Entrainment velocities V g Gravity spread velocity χ Mole fraction concentration x,y,z Coordinates z 0 Surface roughness ν Kinematic viscosity ϱ Density α, β, Re T Constants Subscripts a Ambient air conditions m Maximum 0 Initial value or ground level R Reference value Superscripts Ensemble average
GAMMA-RAY SPECTRA AND VARIABILITY OF THE CRAB NEBULA EMISSION OBSERVED BY BATSE

We report ~600 days of BATSE earth occultation observations of the total gamma-ray (30 keV to 1.7 MeV) emission from the Crab Nebula between 1991 May 24 (TJD 8400) and 1994 October 3 (TJD 9628). Light curves from 35-100, 100-200, 200-300, 300-400, 400-700, and 700-1000 keV show that positive fluxes were detected by BATSE in each of these six energy bands at significances of approximately 31, 20, 9.2, 4.5, 2.6, and 1.3 σ, respectively, per day. We also observed significant flux and spectral variations in the 35-300 keV energy region, with timescales of days to weeks. The spectra below 300 keV, averaged over typical Compton Gamma Ray Observatory viewing periods of 6-13 days, can be well described by a broken power law with average indices of ~2.1 and ~2.4, varying around a spectral break at ~100 keV. Above 300 keV, the long-term averaged spectra, averaged over three 400 day periods (TJD 8400-8800, 8800-9200, and 9200-9628, respectively), are well represented by the same power law with index of ~2.34 up to ~670 keV, plus a hard spectral component extending from ~670 keV to ~1.7 MeV, with a spectral index of ~1.75. The latter component could be related to a complex structure observed by COMPTEL in the 0.7-3 MeV range. Above 3 MeV, the extrapolation of the power-law continuum determined by the low-energy BATSE spectrum is consistent with fluxes measured by COMPTEL in the 3-25 MeV range and by EGRET from 30-50 MeV. We interpret these results as synchrotron emission produced by the interaction of particles ejected from the pulsar with the field in different dynamical regions of the nebula system, as observed recently by the Hubble Space Telescope, XMM-Newton, and Chandra.
cAMP-dependent regulation of gene transcription by cAMP response element-binding protein and cAMP response element modulator.

Publisher Summary This chapter discusses cyclic AMP (cAMP)-dependent regulation of gene transcription by cAMP response element-binding protein and cAMP response element modulator. The cAMP signaling pathway is one of the most important intracellular signal transduction pathways in eukaryotic cells. In the absence of cAMP, the inactive protein kinase A (PKA) holoenzyme is a heterotetrameric protein complex consisting of two regulatory subunits (R) and two catalytic subunits (C). Two classes of R subunits, each with two isoforms, and three isoforms of the C subunits are described in the chapter. cAMP binds cooperatively to two sites on the R subunits within the holoenzyme, thereby liberating free active C subunits. Regulation of gene transcription is accomplished by the interaction of DNA-binding proteins with DNA regulatory sequences and with proteins of the general transcription machinery. Variant cAMP response elements (CREs) include asymmetrical or atypical sequences that differ from the consensus motif by single or multiple nucleotide deletions or substitutions. It is found that the interplay between the phosphorylating protein kinases and the dephosphorylating protein phosphatases is critical in determining the relative transactivation potential at any given moment.
Quantifying the Artistic Experience with Perceptive Sketching Tools: Cognitive Technologies to Support Creativity Researchers

Creativity research has gradually moved away from controlled laboratory settings to more naturalistic and real world domains. As a result, new research methods are required to systematically analyze the artistic experience that includes the artist’s perception, behavior, and conception throughout the creative process. We use research findings from the Cognitive Science literature to create a framework called Perceptual Logic to categorize different types of artistic experience. This framework is applicable to open-ended artistic creativity. Empiri- cally validating such a framework requires new tools that provide insight into the naturalistic creative process. We describe the initial design of a set of digital sketching tools that enables creativity researchers to quantitatively analyze the artistic experience. These tools focus spe- cifically on understanding how visual digital artists perceive and interact with their drawings and paintings throughout their creative process.
Fine-scale population structure and riverscape genetics of brook trout (Salvelinus fontinalis) distributed continuously along headwater channel networks

Linear and heterogeneous habitat makes headwater stream networks an ideal ecosystem in which to test the influence of environmental factors on spatial genetic patterns of obligatory aquatic species. We investigated fine-scale population structure and influence of stream habitat on individual-level genetic differentiation in brook trout (Salvelinus fontinalis) by genotyping eight microsatellite loci in 740 individuals in two headwater channel networks (7.7 and 4.4 km) in Connecticut, USA. A weak but statistically significant isolation-by-distance pattern was common in both sites. In the field, many tagged individuals were recaptured in the same 50-m reaches within a single field season (summer to fall). One study site was characterized with a hierarchical population structure, where seasonal barriers (natural falls of 1.5–2.5 m in height during summer base-flow condition) greatly reduced gene flow and perceptible spatial patterns emerged because of the presence of tributaries, each with a group of genetically distinguishable individuals. Genetic differentiation increased when pairs of individuals were separated by high stream gradient (steep channel slope) or warm stream temperature in this site, although the evidence of their influence was equivocal. In a second site, evidence for genetic clusters was weak at best, but genetic differentiation between individuals was positively correlated with number of tributary confluences. We concluded that the population-level movement of brook trout was limited in the study headwater stream networks, resulting in the fine-scale population structure (genetic clusters and clines) even at distances of a few kilometres, and gene flow was mitigated by ‘riverscape’ variables, particularly by physical barriers, waterway distance (i.e. isolation-by-distance) and the presence of tributaries.
Perceptions of Domestic Violence in a Chinese American Community

Thirty-one Chinese adults (16 men and 15 women) were randomly selected using a 1995 telephone directory for the San Gabriel Valley in Los Angeles County. A telephone questionnaire on perceptions of domestic violence was administered. Respondents defined domestic violence as physical or sexual acts of aggression between spouses as opposed to psychological aggression. Chinese men and women did not agree with the use of violence in the home or that hitting is an effective problem-solving strategy. However, they tended to justify it in cases of self-defense and defense of a child. Domestic violence was attributed to individual and environmental factors. Minimal gender differences were found; however, age and length of residence in the United States were significantly related to various perceptions of domestic violence. The cultural context of domestic violence and implications for social work interventions and research are discussed.
An analysis of Artificial Immune System and Genetic Algorithm in urban path planning

Evolutionary Algorithms like Genetic Algorithm (GA) and Artificial Immune System (AIS) are commonly used to find solutions to problems not suitable for traditional optimization approaches. In this study, we compare the results of AIS and GA for path-planning where the objective is to optimize the safety and the travelling distance. Since these algorithms are computationally intensive, we perform offline optimization to generate a list of suboptimal solutions. Results show that the performance of GA and AIS are similar in terms of convergence and optimality. Furthermore, an analysis of AIS revealed that the convergence rate is faster at higher separation threshold; however, the effects of maturity age and percentage of hypermutation had minimal effects in convergence of AIS. Using AIS, we were also able to produce several sub-optimal paths in the form of memory cells, which provide robustness to the optimal path subject to perturbations.
Business Failure in a Developing Town: Pendembu, Sierra Leone

Thirty-one business failures distributed among six types of enterprise (market woman, hawker, produce middleman, petty shopkeeper, large shopkeeper, and petrol station operator) were studied in the railroad town of Pendembu, Sierra Leone. The combined number of failures due to misuse of capital and overextension of credit equals those due to family obligations. This finding is contrary to previous studies linking entrepreneurial failure to the extended family system. It is concluded that managerial training could be as important a part of economic development as capital input.
The effects of two endotracheal tube cuff inflation pressures on liquid aspiration and tracheal wall damage in horses

Objective To investigate the effect of endotracheal tube cuff inflation pressure on the occurrence of liquid aspiration and tracheal wall damage. Study design Prospective, randomized experimental study. Animals Ten healthy horses, weighing 535 ± 55 kg. Methods Horses were anesthetized, orotracheally intubated, placed in dorsal recumbency, and maintained on isoflurane in oxygen with controlled ventilation for 175 ± 15 minutes. The horses were randomly assigned to an endotracheal cuff pressure of 80–100 or 120 cm H2O. The cuff pressure was continuously monitored and maintained at a constant pressure. Methylene blue in saline was instilled proximal to the cuff. After euthanasia, the trachea was opened distal to the endotracheal tube tip to check for evidence of dye leaking past the cuff. The cervical trachea was then resected and opened longitudinally for gross and histologic examinations. Results No blue staining was found distal to the cuff in any horse. Visual examination of the tracheal mucosa revealed hyperemic and hemorrhagic lesions at the site of the cuff contact. Histologic changes included epithelium attenuation or erosion, submucosal neutrophilic infiltration, and submucosal hemorrhages. Lesions were absent or less extensive in the lower cuff pressure group as compared to the high cuff pressure group. Conclusions The endotracheal tube cuff produced a seal sufficient to prevent leakage in both groups. Tracheal wall damage was more severe and occurred more frequently in the higher cuff pressure group. Clinical relevance Tracheal mucosal damage induced by cuff inflation is pressure-dependent. Cuff pressure monitoring is recommended.
A decision analysis approach to the transaction selection problem in a competitive electric market

Abstract The power industry is presently participating in a changing business environment. While planning to meet future peak demand is still a concern, the efficient utilization of existing generation and transmission resources is fast becoming of primary interest. The electric market is being deregulated to promote competition. In such a situation, the market players will have many choices for power transactions. In this new environment, the transaction selection problem will be complicated to solve because of the risk involved in the economic and reliable operation arising from uncertainties in many factors. This work integrates the economic and reliability aspects of power systems in the new business environment. The approach is based on decision analysis methodology, which involves the use of a set of mathematical techniques to explicitly address risk, uncertainty, and complexity in the transaction selection problem. The methodology successfully finds the best tradeoff between low cost and low risk in the cost based operation of the electric market.
Liver microsomes contain multiple forms of inositol 1,4,5-trisphosphate binding proteins: Identification by nitrocellulose blot overlay

Abstract A group of proteins binding to inositol 1,4,5-trisphosphate (IP3) has been identified in rat liver microsomes by a nitrocellulose blot-overlay technique. Proteins were resolved by SDS-PAGE, blotted on nitrocellulose and incubated with [32P]IP3 followed by autoradiography. Approximately eight IP3-binding polypeptides ranging Mr 23–50 kDA were present exclusively in microsomes; these were absent from plasma membrane and mitochondrial fractions. Binding of [32P]IP3 to these proteins was displaceable to a great extent by 5 μM unlabeled IP3 but not by 10 μM IP1, IP2, IP4, ATP, or GTPγS. These results suggest that liver microsomes contain multiple forms of IP3-binding proteins that can be detected by this new method.
Neonatal Neurological Emergencies

Encephalopathy, or an altered state of consciousness, presents a diagnostic challenge to clinicians involved in the care of neonates. Unlike older age groups where neurological dysfunction almost invariably suggests central nervous system disease, the neonate will present with an acute encephalopathy when severe illness arises within or outside the central nervous system. This article is intended to highlight the various neonatal conditions that may present with disturbed neurological function (seizures and altered states of consciousness) to the emergency department, and emergency physicians must be aware of the extensive differential diagnoses associated with such presentations. It cannot be overemphasized that a detailed history from a caregiver and a thorough physical examination are essential to identify potentially treatable etiologies.
Developing a reliable Senior Walking Environmental Assessment Tool.

Background Research of the effects of the built environment on physical activity often excludes certain segments of the population. The senior population, one segment perhaps most influenced by the physical features of an environment, has been understudied. Developing reliable measures of the environment is important to increase our understanding of the environmental effects on physical activity among seniors. Methods A review of urban planning and health literature helped identify important concepts and theories that were used to inform the development of the Senior Walking Environmental Assessment Tool (SWEAT). Urban planning and health research professionals were consulted and provided feedback on the tool. A total of 355 neighborhood segments were assessed using SWEAT. Thirty-six neighborhood segments were assessed for inter-rater reliability. Results Overall, raters exhibited good-to-excellent agreement on most items included in SWEAT. Items assessing buildings and destinations were less reliable than other categories. Conclusions The development of a reliable senior-specific environmental measurement of detailed street level environmental features that may influence walking among seniors is important to advance this research and engage communities to consider simple environmental changes that encourage walking among seniors.
Prekindergarten Teachers' Verbal References to Print During Classroom-Based, Large-Group Shared Reading

Purpose The frequency with which adults reference print when reading with preschool-age children is associated with growth in children’s print knowledge (e.g., L.M. Justice & H.K. Ezell, 2000, 2002...
Recrystallization of Amorphous or Nanocrystalline NdBa2Cu3O7-x and GdBa2Cu3O7-x

Using a novel melt-spinning technique, we have produced highly disordered NdBa2Cu3O7-x and GdBa2Cu3Oy-x materials. Samples which were melt-spun in an O2 environment consist of nanocrystals with the tetragonal REBa2Cu3O7-x structure: samples which were processed in an N2 environment consist of an amorphous matrix with small amounts of crystalline BaCu2O2, as shown by x-ray diffraction and electron microscopy. High temperature XRD studies indicate that the BaCu2O2 is eliminated during heating to 500°C in O2 and that the REBa2Cu3O7-x Phase recrystallizes directly from the amorphous matrix at temperatures below 800°C. Preliminary magnetization measurements show that higher temperature heat treatments are needed to restore superconductivity.
Giant Myofibroblastoma of the Male Breast

Myofibroblastoma of the breast is a rare, benign neoplasm, seen predominantly in men. The gross appearance is that of a well-circumscribed nodule, characteristically small, seldom exceeding 3 cm. We report a case of giant myofibroblastoma measuring 10 cm and weighing 169 g in the breast of an 83-year-old man. Light microscopic, immunohistochemistry, and electron microscopic features are described. Histologically, these neoplasms may exhibit a varied cellularity that can be misinterpreted as sarcoma. However, they lack marked cellular pleomorphism, tumor necrosis, and mitosis and are characteristically composed of plump and long bipolar, spindly cells arranged in swirling fascicles with intervening broad collagen bands. As we report, immunostaining is strongly positive for vimentin, desmin, and muscle common antigen and negative for cytokeratins and S-100-associated protein. Electron microscopy shows predominantly cells suggestive of myofibroblastic differentiation. The patient has remained free of disease 2 years after mastectomy.
Digital signatures: are they legal for electronic commerce?

In electronic commerce, like elsewhere, certain types of messages are inherently more sensitive than others. For example, a contract acceptance is more sensitive than a notice of goods delivery. One requires more integrity and assurance. One will be retained, the other discarded. In the paper-based world, signatures provide a degree of assurance for the more important messages. The means by which the handwritten signature concept can be translated into the new electronic medium is discussed. Cryptologic techniques (such as "digital signatures") may be employed to obtain similar assurances in an electronic form. The author discusses digital signatures and legal signatures. >
Measuring conformability of probabilities

Given a probability space or a joint distribution, any derived probabilities or marginal distributions will be conformable. The inverse problem is to determine whether a set of fragmentary probabilities or marginal distributions is conformable in the sense that there exists a probability space or joint distribution that yields these fragmentary probabilities or marginal distributions. Because nonconformability or inconsistency may occur in a number of ways, we present a hierarchy of inconsistencies, and provide a linear programming approach designed to uncover different levels of inconsistency.
YOUTH AND SOCIAL ACTION. 1. PERSPECTIVES ON THE STUDENT SIT-IN MOVEMENT.

The motivation and style of student involvement in antisegregation activities are linked to (1) the emergence of a new social character based on older traits in Negro personality as well as on recent sociohistorical developments, and (2) certain psychosocial aspects of late adolescence. A new concept, “prosocial acting out,” is discussed in light of the authors' observations.
The effect of pay-for-performance in nursing homes: evidence from state Medicaid programs.

Objective Pay-for-performance (P4P) is commonly used to improve health care quality in the United States and is expected to be frequently implemented under the Affordable Care Act. However, evidence supporting its use is mixed with few large-scale, rigorous evaluations of P4P. This study tests the effect of P4P on quality of care in a large-scale setting—the implementation of P4P for nursing homes by state Medicaid agencies. Data Sources/Study Setting 2001–2009 nursing home Minimum Data Set and Online Survey, Certification, and Reporting (OSCAR) datasets. Study Design Between 2001 and 2009, eight state Medicaid agencies adopted P4P programs in nursing homes. We use a difference-in-differences approach to test for changes in nursing home quality under P4P, taking advantage of the variation in timing of implementation across these eight states and using nursing homes in the 42 non-P4P states plus Washington, DC as contemporaneous controls. Principal Findings Quality improvement under P4P was inconsistent. While three clinical quality measures (the percent of residents being physically restrained, in moderate to severe pain, and developed pressure sores) improved with the implementation of P4P in states with P4P compared with states without P4P, other targeted quality measures either did not change or worsened. Of the two structural measures of quality that were tied to payment (total number of deficiencies and nurse staffing) deficiency rates worsened slightly under P4P while staffing levels did not change. Conclusions Medicaid-based P4P in nursing homes did not result in consistent improvements in nursing home quality. Expectations for improvement in nursing home care under P4P should be tempered.
Recent Developments Encompassing Non-Isothermal/Isothermal Liquid Composite Molding Process Modeling/Analysis: Physically Accurate, Computationally Effective, and Affordable Simulations and Validations:

The mathematical and associated computational modeling and analysis of mold filling, heat transfer, and polymerization reaction kinetics in Resin Transfer Molding (RTM) are quite complex and not only require accurate computational approaches to capture the process physics during the simulations, but also must permit complex geometric configurations to be effectively analyzed. The process simulations at a macroscopic level require the representative macroscopic constitutive behavior which can be predicted from a microscopic analysis of the representative volume element (RVE) of the fiber preform configurations. This is first presented here for purposes of illustration in reference to determination of the preform flow permeabilities. Next, an effective integrated micro/macro approach and developments including a viable flow solution modeling and analysis methodology with emphasis on providing improved physical accuracy of solutions and computational advantages are described for the transient flow progressio...
Epidemiology, biologic behavior, and natural history of mesothelioma.

Malignant pleural mesothelioma (MPM) is a rare and aggressive malignant disease that is associated with distinct occupational exposures to asbestos. Characterized by a long latency period and relentless local invasion into adjacent mediastinal structures, it presents a unique challenge to physicians in its diagnosis, staging, and treatment. Although reports of the association between MPM and asbestos exposure date back to 1960, it was years before asbestos use was banned in some countries and restricted in the United States [1]. In the developing world, workers continue to be exposed, and in some regions, asbestos use has even expanded. World production of asbestos climbed steadily since its commercial introduction in the late nineteenth century. By the late twentieth century, although asbestos had been banned by many Western societies, the mineral was still mined for use in many nations of the Eastern and Southern hemispheres. The largest mines are located in Russia and China, where asbestos is mined mainly for domestic use, and Canada (especially Quebec), where the product is mined for export to Asia and Africa. In recent decades, however, worldwide production has declined. Most asbestos in the United States currently is found in building and machinery insulation products and older products, such as appliances that are available for resale. Current approved uses of asbestos for new products in the United States include brake pads, roofing material, vinyl tiles, cement pipe and sheeting, gaskets, and garden products (vermiculite). The long latency period between exposure and disease development assures that we will continue to see cases of MPM well into the future. The increasing interest in this disease, fueled by lucrative product liability suits and the decreased rate of reported exposure to asbestos in new cases, has spawned efforts to identify other potential risk factors, including simian virus 40 (SV40), radiation therapy used for other malignant diseases such as lymphoma, and genetic predisposition. This article presents a brief synopsis of the occurrence, distribution, presentation, and natural history of MPM.
Continuous arteriovenous hemofiltration attenuates polymorphonuclear leukocyte phagocytosis in porcine intra-abdominal sepsis**

Background Activation of circulating polymorphonuclear leukocytes (PMN) is a characteristic of systemic inflammation and may contribute to organ malfunction. Continuous arteriovenous hemofiltration (CAVH) has been reported to improve organ malfunction during severe systemic inflammation. This study postulates that the CAVH effects may be linked to alterations in PMN activation. Methods Sixteen pigs that underwent cecal ligation and rupture were randomized to receive CAVH or no CAVH for 24 hours. The PMN phagocytosis of Candida was measured prior to the insult and at 24, 48, and 72 hours. Temperature, total leukocyte count (WBC), hemodynamic, blood gas, microbiologic, and ionized calcium data were also collected. Results All animals developed increased temperature, heart rate, and WBC, and positive blood and peritoneal cultures. Hemodynamic, pulmonary, and ionized calcium changes were not different between the CAVH and no CAVH groups. Phagocytosis of PMN increased in the no CAVH group at 24 hours, but not in the CAVH group. After discontinuing CAVH, phagocytosis increased to the no CAVH rate at 48 and 72 hours. Conclusions Continuous arteriovenous hemofiltration attenuates the upregulation of PMN phagocytosis of Candida ; this effect disappears after CAVH is discontinued. Hemofiltration does not affect many other manifestations of sepsis, which implies that these manifestations may not be related to PMN phagocytosis capacity.
Mass dependence of statistical fission parameters

Abstract Statistical fission parameters Bf and a f a ν are extracted from analyses of recently measured heavy-ion induced fission and evaporation residue excitation functions for medium mass systems using a formalism with spin dependent level densities and multiple particle/fission competition. Results are compared with those of the less rigorous s-wave approximation as treated in the code ALICE.
State dependent predictability: impact of uncertainty dynamics, uncertainty structure and model inadequacies

The implications of state dependent, finite time error growth has been studied using singular values in a chaotic 2-dimensional map. Earlier studies have demonstrated the superiority of the singular values over the Lyapunov number in representing error growth over finite time scales, since they take state dependency into account. In this work, linearized error growth as given by singular values under operational constraints like non-isotropic initial uncertainty and model error is considered. It is demonstrated that the relevant singular values in the case of non-isotropic initial uncertainty are quite different from the isotropic case. The effect of model inadequacy on error growth is delineated.
Subjective fatigue, influencing variables, and consequences in chronic obstructive pulmonary disease.

BACKGROUND: Fatigue is a common symptom of chronic obstructive pulmonary disease (COPD), but little is known about the specific nature of COPD-related fatigue and its impact on daily life. OBJECTIVES: To (a) describe characteristics of fatigue in people with COPD and (b) test a theoretically and empirically supported model of the relationships among subjective fatigue, dyspnea, functional performance, anxious and depressed moods, and sleep quality in people with COPD. METHODS: A cross-sectional descriptive study was conducted with 130 people with moderate to severe COPD. Measures included the following: a Numerical Rating Scale (NRS) for frequency, intensity, and distress of fatigue and dyspnea; Fatigue Assessment Instrument (FAI); Chronic Respiratory Disease Questionnaire (CRQ); Profile of Mood States (POMS); Pittsburgh Sleep Quality Index (PSQI); Functional Performance Inventory (FPI); and spirometry. Path analysis was used to examine the relationships among variables. RESULTS: Participants reported moderate amounts of fatigue, which was described as situation-specific, had considerable consequences, and was responsive to rest and sleep. Dyspnea was slightly greater than fatigue, as measured by the NRSs (p <.001), and there was a strong relationship between fatigue and dyspnea (r =.74, p < .001). Dyspnea, depressed mood, and sleep quality accounted for 42% of the variance in subjective fatigue. Fatigue, dyspnea, airflow obstruction, and anxious mood accounted for 36% of the variance in functional performance. CONCLUSIONS: Fatigue is an important problem that affects performance of daily activities in people with COPD. The relationships or interactions that exist among fatigue and other symptoms are complex.
The role of histamine in control of gastric mucosal blood flow in dogs.

Abstract The role of the histamine receptors in the control of gastric mucosal blood flow was evaluated in dogs utilizing [ 14 C]aminopyrine ([ 14 C]AP) clearance techniques. Because of the importance of maintaining a low intragastric pH to prevent dissociation of AP and back diffusion through the gastric mucosa, AP was traped in the stomach lumen by intragastric perfusion of a marker solution with a pH of 1.16. Results obtained utilizing a marker to determine gastric secretory volume and gastric juice [ 14 C]AP concentration correlated well with those values obtained from direct measurements from fluid collected from a gastric fistula. Histamine base administration increased [ 14 C]AP clearance. Cimetidine, an H 2 receptor antagonist, did not significantly change basal [ 14 C]AP clearance and inhibited [ 14 C]AP clearance at low doses of histamine administration. An H 2 receptor agonist (4-methylhistamine) and an H 1 receptor agonist (2-methylhistamine) each increased mucosal blood flow approximately 30% and 70%, respectively, of the response produced by histamine base. Blood flow stimulated by 2-methylhistamine was inhibited by the H 1 receptor antagonist diphenhydramine. The results suggest that histamine H 1 and H 2 receptors are involved in the control of canine gastric mucosal blood flow.
Organization of Vomeronasal Sensory Coding Revealed by Fast Volumetric Calcium Imaging

A long-standing goal in neuroscience is to perform exhaustive recording of each neuron in a functional local circuit. To achieve this goal, one promising approach is optical imaging of fluorescent calcium indicators, but typically the tens or hundreds of cells imaged simultaneously comprise only a tiny percentage of the neurons in an intact circuit. Here, we show that a recent innovation, objective-coupled planar illumination (OCPI) microscopy, permits simultaneous recording from three-dimensional volumes containing many thousand neurons. We used OCPI microscopy to record chemosensory responses in the mouse vomeronasal epithelium, for which expression of hundreds of receptor types implies high functional diversity. The implications of this diversity for sensory coding were examined using several classes of previously reported vomeronasal ligands, including sulfated steroids. A collection of just 12 sulfated steroids activated more than a quarter of the neurons in the apical vomeronasal epithelium; unexpectedly, responses were functionally organized into a modest number of classes with characteristic spatial distribution. Recording from a whole sensory system thus revealed new organizational principles.
Production of Proinflammatory Cytokines and Chemokines During Neuroinflammation: Novel Roles for Estrogen Receptors α and β

Neuroinflammation is a common feature of many neurological disorders, and it is often accompanied by the release of proinflammatory cytokines and chemokines. Estradiol-17β (E2) exhibits antiinflammatory properties, including the suppression of proinflammatory cytokines, in the central nervous system. However, the mechanisms employed by E2 and the role(s) of estrogen receptors (ERs) ERα and ERβ are unclear. To investigate these mechanisms, we employed an in vivo lipopolysaccharide (LPS) model of systemic inflammation in ovariectomized (OVX) and OVX and E2-treated (OVX+E2) mice. Brain levels of proinflammatory cytokines (IL-1β, IL-6, and IL-12p40) and chemokines (CCL2/MCP-1, CCL3/MIP-1α, CCL5/RANTES, and CXCL1/KC) were quantified in mice at 0 (sham), 3, 6, 12, and 24 h after infection using multiplex protein analysis. E2 treatment inhibited LPS-induced increases in all cytokines. In contrast, E2 treatment only suppressed CCL/RANTES chemokine concentrations. To determine whether ERα and ERβ regulate brain cytokine and chemokine levels, parallel experiments were conducted using ERα knockout and ERβ knockout mice. Our results revealed that both ERα and ERβ regulated proinflammatory cytokine and chemokine production through E2-dependent and E2-independent mechanisms. To assess whether breakdown of the blood-brain barrier is an additional target of E2 against LPS-induced neuroinflammation, we measured Evan’s blue extravasation and identified distinct roles for ERα and ERβ. Taken together, these studies identify a dramatic cytokine- and chemokine-mediated neuroinflammatory response that is regulated through ERα- and ERβ-mediated ligand-dependent and ligand-independent mechanisms.
Endoscopic ultrasound-guided fine-needle aspiration in 179 cases: the M. D. Anderson Cancer Center experience.

BACKGROUND Recently, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has emerged as a diagnostic adjunct for small pancreatic lesions and abdominal and mediastinal lymph node diseases. DESIGN. During a 21-month period, we performed 179 EUS-FNAs in 166 consecutive patients; these data are the subject of this study. An average of 2.6 needle passes were obtained and aspiration was performed most commonly in the pancreas (162 cases, 91%). The FNA smears were reviewed using six diagnostic categories (negative for malignancy/nondiagnostic [NND], atypia, suspicious for malignancy, benign tumor/cyst, neuroendocrine neoplasm [NEN], and carcinoma). The review diagnosis was correlated with the histologic diagnosis made on resection or surgical biopsy specimens in 70 cases. Up to 17 months of clinical follow-up were sought for the cases with a negative or inconclusive FNA diagnosis and no diagnostic tissue confirmation (81 cases). RESULTS The review FNA diagnoses were as follows: NND (49 cases), atypia (17 cases), suspicious for malignancy (12 cases), benign tumor/cyst excluding NEN (10 cases), NEN (6 cases), carcinoma (85 cases). Follow-up methods included resection (49 cases), surgical biopsy (21 cases), repeat FNA or brushing cytology (28 cases), and clinical follow-up only (81 cases). Of the 49 NND cases, 23 (47%) had positive follow-up results (i.e., false-negative diagnosis) that were confirmed by tissue diagnosis (resection/surgical biopsy in 11 cases [48%] and repeat FNA/brushing in 12 cases [52%]). These included pancreatic/ampullary adenocarcinoma in 20 cases, esophageal squamous carcinoma in 1 case, and NEN in 2 cases. Follow-up also revealed carcinoma in all 12 suspicious cases and 13 pancreatic adenocarcinomas and 1 microcystic adenoma in 14 of the 17 atypical cases. Overall, repeat computed tomography (CT)-guided FNA samples yielded a definite diagnosis in four atypical and seven NND cases, whereas EUS-FNA results provided a definite diagnosis in three cases in which CT-guided FNA failed and in two cases in which ampullary biopsy failed. No false-positive cases were identified. The false-negative rate due to inadequate sampling was 13.2%. Sensitivity (including cases with inadequate cellularity and nondiagnsotic aspirates) was 81.7% and specificity was 100%. None of the factors evaluated (lesion characteristics, aspiration site, and tumor type) significantly influenced diagnostic results. CONCLUSION EUS-FNA is a valuable diagnostic and staging tool with high specificity and sensitivity. Negative or nondiagnostic cases on EUS-FNA require further diagnostic work for a definitive diagnosis when clinical or radiographic findings do not correlate with the FNA results. Cancer (Cancer Cytopathol) 2002. © 2002 American Cancer Society.
Pulpal response to tricalcium phosphate as a capping agent.

Abstract The purpose of this study was to evaluate tricalcium phosphate (TCP) as a pulp-capping agent. Two adult male beagle dogs were used for this investigation. Class I cavities were prepared in the posterior teeth and Class V cavities in the anterior teeth. With the use of a rubber dam and high speed with water coolant, minimal pulp exposures were created in both the experimental and control teeth, by means of a ½ round bur. Zinc oxide-eugenol was the temporary filling material used to restore all cavities. In each dog, five teeth served as control and were capped with the use of calcium hydroxide. In one dog, 10 teeth from two quadrants were capped with the tested material (TCP). In the other dog, 11 teeth were capped with TCP. Four teeth from the fourth quadrant in each dog were capped with a mixture of calcium hydroxide and TCP in a ratio of 1:1 by weight (50/50 group.) The two dogs were killed after 70 days. The histologic evaluation of the response to the capping agents and at the exposure site was recorded. A total of 39 teeth were evaluated in this study. It was found that TCP as a capping agent precipitated the highest mean inflammatory response and also demonstrated the highest percentage of reparative dentin formation.
Proposals: Write to win

Knowing ahead of time what a proposal evaluator looks for will help increase your chance of writing a winning proposal. Winning proposals contain (1) a proposed line of investigation, (2) a method of approach to the problem, (3) recommended changes (if appropriate), (4) logical work units, and (5) estimated completion time. Other tips include writing directly and specifically and making the proposal complete and easy to read.
Dose-sensitive excitation and inhibition of spontaneous amygdala activity by propranolol.

Abstract The effect of systemically administered propranolol was determined on spontaneous activity of neurons in the central nucleus (CeA) of the amygdala, a brain site implicated in fear-related learning and memory. Extracellular recordings of single units in the CeA were obtained in vivo from rats administered saline or the centrally and peripherally acting β-adrenergic receptor blocker propranolol (4, 7, 10 mg/kg ip). The high dose (10 mg/kg) of propranolol markedly increased spontaneous activity of CeA neurons. In contrast, the low (4 mg/kg) and intermediate (7 mg/kg) doses of propranolol significantly decreased spontaneous CeA activity, with the suppressant effect of propranolol on CeA firing rates weakening as the dosage increased from 4 to 7 mg/kg. These results suggest that (1) spontaneous activity of CeA neurons is tonically influenced by competing excitatory and inhibitory modulatory circuits, and (2) propranolol's effect on the two modulatory circuits is dose dependent: the high dose increasing spontaneous CeA activity by preferentially blocking an inhibitory circuit, the low dose decreasing spontaneous CeA activity by preferentially blocking an excitatory circuit, and the intermediate dose weakly suppressing CeA activity by blocking both the excitatory and inhibitory modulatory circuits. Disinhibition of CeA activity by the high dose of propranolol may explain the enhancement of retention observed in the passive-avoidance task when this dose of the drug is administered systemically, and may have implications for the use of propranolol clinically in treating aversive-memory-related anxiety disorders such as posttraumatic stress syndrome.
18 μm replication units of chromosomal DNA fibers of differentiated cells of Pea (Pisum sativum)

Explants of stelar and cortical mature pea root tissues were cultured on solid agar synthetic medium for up to 6 d. On the 3rd and 6th day the tissue was pulsed with 3H-thymidine from 15 up to 180 min to label the DNA. Subsequently the nuclei were isolated, lysed, and the DNA spread on microscope slides. The autoradiograms of labeled DNA fibers showed that the average replication fork traveled at 9 μm/h, and that an average of 18 μm of DNA separated activated origins. Nearly identical parameters were obtained from DNA of all callus independent of tissue source and independent of the presence or absence of kinetin in the medium.
U.S. insurance trade

The U.S. has had significant trade deficits in insurance for several years. This paper examines the reasons for such big annual deficits. A large home market, a low reinsurance capacity, and the conservative attitude of U.S. insurers toward foreign markets are identified as the primary contributors to such deficits. The paper also addresses the issue of how U.S. insurers can improve their international competitive position. By expanding their operations abroad, particularly in Mexico and Latin America, and by actively participating in the fast-growing Asian markets, American insurers have their greatest chance to accomplish that objective.
I.Q.-I Question: Teacher and Student Questioning in an Online Environment

Teaching is a complex activity that involves careful preparation, delivery, and reflection. As an educator, it is essential to create a sense of community in which students feel significant and are truly engaged as learners. A central focus of the educator is to maximize the capacity of each learner. How does this happen in an online learning environment? This article addresses the needs of learners for a learning community that promotes effective discussion; specifically, the practice of questioning that lies at the heart of classroom practice. Just as in a face-to-face classroom, questioning occurs in a variety of ways for online learners. The article shares ideas for using the I.Q.â€”I Question strategy in an online environment.
The Single-stranded DNA-binding Proteins, Purα, Purβ, and MSY1 Specifically Interact with an Exon 3-derived Mouse Vascular Smooth Muscle α-Actin Messenger RNA Sequence

Amino acids 44–53 of mouse vascular smooth muscle α-actin are encoded by a region of exon 3 that bears structural similarity to an essential MCAT enhancer element in the 5′ promoter of the gene. The single-stranded DNA-binding proteins, Purα, Purβ, and MSY1, interact with each other and with opposite strands of the enhancer to repress transcription in fibroblasts (Sun, S., Stoflet, E. S., Cogan, J. G., Strauch, A. R., and Getz, M. J. (1995) Mol. Cell. Biol. 15, 2429–2436; Kelm, R. J., Jr., Cogan, J. G., Elder, P. K., Strauch, A. R., and Getz, M. J. (1999) J. Biol. Chem. 274, 14238–14245). In this study, we employed both recombinant and fibroblast-derived proteins to demonstrate that all three proteins specifically interact with the mRNA counterpart of the exon 3 sequence in cell-free binding assays. When placed in the 5′-untranslated region of a reporter mRNA, the exon 3-derived sequence suppressed mRNA translation in transfected fibroblasts. Translational efficiency was restored by mutations that impaired mRNA binding of Purα, Purβ, and MSY1, implying that these proteins can also participate in messenger ribonucleoprotein formation in living cells. Additionally, primary structure determinants required for interaction of Purβ with single-stranded DNA, mRNA, and protein ligands were mapped by deletion mutagenesis. These experiments reveal highly specific protein-mRNA interactions that are potentially important in regulating expression of the vascular smooth muscle α-actin gene in fibroblasts.