cssi/SciSciGPT-SciSciNet huggingface dataset:
A Francisella tularensis Schu S4 Purine Auxotroph Is Highly Attenuated in Mice but Offers Limited Protection against Homologous Intranasal Challenge

BACKGROUND Francisella tularensis is a gram-negative coccobacillus that causes the febrile illness tularemia. Subspecies that are pathogenic for humans include those comprising the type A (subspecies tularensis) or type B (subspecies holarctica) biovars. An attenuated live vaccine strain (LVS) developed from a type B isolate has previously been used to vaccinate at-risk individuals, but offers limited protection against high dose (>1000 CFUs) challenge with type A strains delivered by the respiratory route. Due to differences between type A and type B F. tularensis strains at the genetic level, it has been speculated that utilization of an attenuated type A strain as a live vaccine might offer better protection against homologous respiratory challenge compared with LVS. Here, we report the construction and characterization of an unmarked Delta purMCD mutant in the highly virulent type A strain Schu S4. METHODOLOGY/PRINCIPAL FINDINGS Growth of Schu S4 Delta purMCD was severely attenuated in primary human peripheral blood monocyte-derived macrophages and in the A549 human lung epithelial cell line. The Schu S4 Delta purMCD mutant was also highly attenuated in mice when delivered via either the intranasal or intradermal infection route. Mice vaccinated intranasally with Schu S4 Delta purMCD were well protected against high dose intradermal challenge with virulent type A or type B strains of F. tularensis. However, intranasal vaccination with Schu S4 Delta purMCD induced tissue damage in the lungs, and conferred only limited protection against high dose Schu S4 challenge delivered by the same route. The level of protection observed was similar to that conferred following vaccination with wild-type LVS or the analogous LVS Delta purMCD mutant. CONCLUSIONS/SIGNIFICANCE Collectively, these results argue that development of the next generation live attenuated vaccine for Francisella should be based on use of the less pathogenic type B biovar rather than the more reactogenic type A biovar.
The Development of Personnel Management in the United States

Personnel management as we know it today grew out of welfare work, on the one hand, and Scientific Management on the other. It came to embrace added functions and concepts, the most important of which was that idealism and realism were compatible in dealing efficiently with human beings.
Childhood myelofibrosis and osteosclerosis without myeloid metaplasia

R E F E R E N C E S 1. Berdon, W. E., Baker, D. H., and James, L. S.: The ductus bump. A transient physiologic mass in chest roentgenograms of newborn infants, Am. J. Roentgenol. 95: 91, 1965. 2. Heikkinen, E. S., and Simila, S.: Aneurysm of the ductus arteriosus in infancy: Report of two surgically treated cases, J. Pediatr. Surg. 7: 392, 1972. 3. Heymann, M. A., and Rudolph, A. M.: Effects of congenital heart disease on fetal and neonatal circulation, Progr. Cardiovasc. Dis. 15: 115, 1972. 4. Moss, A. J., Emmanoulides, G., and Duffle, E. R.: Closure of the ductus arteriosus in the newborn infant, Pediatrics 32: 25, 1963.
Proximity relationships among the 30 S ribosomal proteins during assembly in vitro.

Abstract Previous studies (Craven et al. , 1974) demonstrated that the capacity of ribosomal proteins to be chemically modified by iodine is extensively reduced when they are members of an intact ribosome. We have attempted to exploit this observation by analyzing in detail the alterations in the iodine accessibility of the individual 30 S ribosomal proteins. We have prepared a total of 38 different complexes between 16 S RNA and mixtures of individual purified 30 S ribosomal proteins. Eighteen of the 21 30 S proteins were used in the formation of these complexes. Comparison of the iodination patterns obtained for the various proteins derived from different complexes has revealed that sometimes a specific protein can selectively alter the chemical reactivity of another protein in the complex. We have found 30 different examples of protein pairs in which one protein effectively protects another protein from chemical iodination.
SVEC responds to the call of the final frontier

Abstract Bridging the gap between basic research and applied research is a difficult challenge for many university based research laboratories. Navigating these turbulent cross currents is the Space Vacuum Epitaxy Center (SVEC) at the University of Houston.
High-order W-methods

Implicit methods are the natural choice for solving stiff systems of ODEs. Rosenbrock methods are a class of linear implicit methods for solving such stiff systems of ODEs. In the Rosenbrock methods the exact Jacobian must be evaluated at every step. These evaluations can make the computations costly. By contrast, W-methods use occasional calculations of the Jacobian matrix. This makes the W-methods popular among the class of linear implicit methods for numerical solution of stiff ODEs. However, the design of high-order W-methods is not easy, because as the order of the W-methods increases, the number of order conditions of the W-methods increases very fast. In this paper, we describe an approach to constructing high-order W-methods.
Thermal conduction and heating by nonthermal electrons in the x-ray halo of M87

A hydrostatic model for the X-ray halo around the giant elliptical galaxy M87 is presented. It is shown that by taking into account the processes of thermal conduction, and nonthermal heating by relativistic electrons in the radio lobes, a self-consistent hydrostatic model can be constructed. There is no need to invoke radiative accretion or the suppression of thermal conductivity.
Effect of lysophosphatidylcholine on renal hemodynamics and excretory function in anesthetized rats.

Abstract The effect of myristoyl-lysophosphatidylcholine (myristoyl-LPC) on renal hemodynamics, electrolyte and water excretion was examined over a 90 min period in sodium pentobarbital anesthetized male Sprague Dawley rats. Intravenous infusion of myristoyl-LPC at 13 ± 3 pmol/min resulted in a small fall in systemic blood pressure, a 13% decrease in renal plasma flow without significantly altering glomerular filtration rate and produced a slightly greater excretion of sodium and water than vehicle controls. These results suggest that short term myristoyl-LPC administration can significantly alter renal function producing a weak natriuresis and diuresis which is not dependent on systemic blood pressure and renal hemodynamic changes.
Quenching of the 2 $sup 1$S$sub 0$ metastable state of helium by an electric field

A time-of-flight technique has been used to measure the quenching of the $2^{1}S_{0}$ metastable state of helium by a static electric field. Neutral ground-state helium atoms effusing from a cooled source slit are immediately excited to the $2^{1}S_{0}$ and $2^{3}S_{1}$ metastable states by a pulse of antiparallel magnetically focused electrons. The metastable beam is collimated before passing through a uniform electric field region 0.5 m long and is then preferentially detected at the end of the time-of-flight region, 1.825 m from the electron gun. The time-of-flight distribution for the $2^{1}S_{0}$ state is separated from that of the $2^{3}S_{1}$ state by illuminating the beam before the electric field region with an rf-discharge helium lamp. The $2^{1}S_{0}$ state is quenched by resonant absorption of a 20 581-\AA{} photon, raising the atom to the $2^{1}P_{1}$ state, which then decays to the $^{1}S_{0}$ ground state; the $2^{3}S_{1}$ state remains unaffected because it is the ground state for the triplet system. The $2^{1}S_{0}$ time-of-flight distribution is therefore obtained from the difference between the full beam and the quenched beam. The number of $2^{1}S_{0}$ atoms arriving at the detector in specific velocity intervals with the electric field off is compared to the number with the field on to determine the quenching rate ($=k{E}^{2}$). The result for the quenching constant $k$ for both ${\mathrm{He}}^{3}$ and ${\mathrm{He}}^{4}$ with $E$ in kV/cm is $k=0.933\ifmmode\pm\else\textpm\fi{}0.005$; this value is in good agreement with theory and with an earlier less accurate experiment. The error in the present experiment arises from a 0.5% uncertainty in the effective length of the electric field region.
β-Adrenergic stimulation evokes a rapid, Ca2+-dependent stimulation of endocytosis, hexose and amino acid transport associated with increased Ca2+ fluxes in mouse kidney cortex

The β-adrenergic agonist 1-isoproterenol evokes an acute (<5 min) stimulation of endocytosis, hexose transport and amino acid transport, measured by the temperature-sensitive uptake of HRP, 3H-DG and 14C-AIB, in mouse kidney cortex slices. This stimulation is concentration dependent and is maximal at 10−8 – 10−7 M isoproterenol. Peroxidase cytochemistry showed that the hormonal increase in HRP uptake is confined to proximal tubules. The rapid membrane response is abolished in a calcium-free medium and by the β-adrenergic antagonist propranolol, indicating Ca2+- and β-adrenoreceptor-dependence. Isoproterenol (1 μM) rapidly (<30 sec) stimulates the influx and efflux of 45Ca in cortex slices. Isoproterenol also decreased mitochondrial 45Ca and increased soluble 45Ca. These results indicate that β-adrenergic stimulation of membrane transport functions involves an increased influx of extracellular calcium and a mobilization of intracellular (mitochondrial) calcium. An increase in cytosolic Ca2+ concentration appears to be the regulatory signal for these membrane transport processes.
Inspection of the cylindrical surface feature after turning using coordinate metrology

Abstract The aim of the study is to derive a model for cylindricity that is based on turning process variables. A mathematical model was defined for the helical geometry based on feed rate, radius of the bar and rake angle. Additionally, radial and tangential cutting forces result in the deflection on the workpiece, and change the nominal depth of cut. Hence, a deflection model was added to the above mathematical model. An experiment with four different work pieces was performed to analyze model efficiency. The cutting forces were measured and the amount of deflection for each point on the surface was calculated based on the deflection model. The surfaces of these four different work pieces were measured with two different sampling strategies with same sample size. Each non-linear function was solved using software, and feed rate, workpiece radius, residuals and minimum zone of error obtained from the model and compared against the theoretical results. The results showed that the developed model calculations compared well with theoretical results.
A quantitative in vitro study of antacids

The tablet antacids tested have been found to exhibit a rather wide range of neutralizing efficiency. Of the two types of antacids, the physical-mixture and the more nearly true chemical type, the latter are not, a priori, superior antacids, but of those tested two such compounds showed clearly a more rapid dissolving rate and maintained thepH at a range of 3–4: hydrated magnesium aluminate and dihydroxy aluminum aminoacetate.
Constructing Seasonal Climograph Overlap Envelopes from Holocene Packrat Midden Contents, Dinosaur National Monument, Colorado

Abstract Five Neotoma spp. (packrat) middens are analyzed from Sand Canyon Alcove, Dinosaur National Monument, Colorado. Plant remains in middens dated at approximately 9870, 9050, 8460, 3000, and 0 14C yr B.P. are used to estimate Holocene seasonal temperature and precipitation values based on modern plant tolerances published by Thompson et al. (1999a, 1999b). Early Holocene vegetation at the alcove shows a transition from a cool/mesic to a warmer, more xeric community between 9050 and 8460 14C yr B.P. Picea pungens, Pinus flexilis, and Juniperus communis exhibit an average minimum elevational displacement of 215 m. Picea pungens and Pinus flexilis are no longer found in the monument. Estimates based on modern plant parameters (Thompson et al., 1999a) suggest that average temperatures at 9870 14C yr B.P. may have been at least 1° to 3°C colder in January and no greater than 3° to 10°C colder in July than modern at this site. Precipitation during this time may have been at least 2 times modern in January and 2 to 3 times modern in July. Discrepancies in estimated temperature and precipitation tolerances between last occurrence and first occurrence taxa in the midden record suggest that midden assemblages may include persisting relict vegetation.
Discrete symmetries of Petrov type-I space-times

The arbitrariness in the definition of the canonical frame in a Petrov type-I space-time is examined and shown to imply that the Newman-Penrose formalism is invariant under a 24-element discrete symmetry group. The transformations of the N-P scalars under the operations of the group are obtained, and conditions are formulated which characterize space-times that maintain this symmetry globally.
A historical perspective of atmospheric chemicals deposited on a mountain top peat bog in Pennsylvania

Abstract A chronology of a mountain top peat bog in Pennsylvania has been developed using 210 Pb techniques, checked with fallout 137 Cs from nuclear weapons tests, and applied to measurements of the deposition of sulfur, nitrogen, bromine, and trace metals. The local wind, precipitation patterns and vegetation at the bog increased the deposition of materials two to five times more than expected. The trace metals, nutrients and magnetic materials found in the core profiles originate regionally as well as from across the Great Plains of North America and illustrate the history of industrial and domestic activities since 1800. Land use changes from virgin forest to clear cutting to reforestation are recorded by the development of the bog; the rate of mass and specific element deposition increased during the logging operation to a maximum at the time of clear cutting, 1909, and then decreased to the present. The deposition of refractory elements also increased to a maximum and then decreased. However, the deposition of volatile elements and iron showed a steady increase from 1830 to 1983. Annual sulfur and bromine deposition appears to have increased some 20 times and nitrogen some 45 times since 1817.
The “Wild Indians” of Andros Island

Andros Island, Bahamas, served as a refuge for freedom-seeking Black Seminoles who escaped from Florida. They began landing secretly on the island in 1821 after the British in Nassau reneged on their promise to help the Seminole Indians and Black Seminoles fight against White aggressors in Florida. While conducting research on Andros Island in 1937, anthropologist John Goggin met Felix MacNeil, a descendant of the Florida Black Seminole refugees. His encounters with MacNeil and others led Goggin to conclude that he had positively identified the legendary “Wild Indians” of Andros Island as descendants of the Florida Black Seminoles. The majority of residents in the present-day settlement of Red Bays on Andros Island are descended from those original exiles from Florida. This article provides an ethnohistorical perspective of the Black Seminole legacy in Florida and the Bahamas that focuses on the oral history and lives of Felix MacNeil and other descendants.
Young Arab Muslim Women’s Agency Challenging Western Feminism

In a phenomenological study with 16 American and French Arab Muslim women attending college in the United States and France, all self-declared as religious and half of them wearing the hijab, participants express strong arguments against stereotypes of oppression and submission. They affirm agency and personal choice with respect to veiling, in a context of ambient skepticism that is often endorsed by Western feminism. Attention to intersectional experiences of Muslim women and reference to feminist models centered on non-Western women may help understand how second-generation Arab Muslim women experience and express agency.
GABA immunoreactive axons and growth cones in the developing chicken optic nerve and tract.

Abstract Immunohistochemical studies of the chicken embryo optic tract using an antibody to γ-aminobutyric acid (GABA) reveal that the tract is initially free of GABA immunoreactive axons. During the second week of incubation, GABA + axons appear in the tract, chiasm, and optic nerve. The number of GABA + axons in the optic nerve increases through E18, although few are recognizable after hatching. Detailed staining of GABA + growth cones confirmed that virtually all the GABA + axons in the optic nerve were growing toward the retina. Taken together, the findings suggest that the GABA + axons in the chiasm and nerve are largely a transient extension of the GABA + optic tract cells, the tectogeniculate projection, or both.
Imaging and characterization of film coating using scanning acoustic microscopy

Abstract The qualities of thin and thick film coatings are closely related to their mechanical parameters such as mass density, acoustic velocity and film thicness, and the defects at the interface. Simultaneous measurements of these three parameters was carried out using a wide-band acoustic microscope operating in reflection mode at the frequency range of 50–250 MHz. This simultaneous measurement was achieved by first identifying the resonant frequency at which the film thickness was equal to one-quarter of the acoustic wavelength and the subsequent determination of the amplitude and phase of the signal reflected from the specimen. Several film coatings have been characterized and the results agree well with both the published data and the data obtained by other techniques. The adhesion of the film coating is greatly affected by the voids and defects at the film-substrate interface. The same acoustic microscope operating in transmission mode was used to detect these voids and defects. Specifically, it was employed to image an AuSn eutectic layer which was melted on a gold-coated alumina substrate, and a similar eutectic layer that was used to bond a GaAs chip and an alumina substrate. Voids and defects were clearly observed and identified. These experiments have demonstrated that the scanning acoustic microscope is a useful instrument for non-destructive characterization of film materials and detection of voids and defects that occur at the film-substrate interfaces.
Corrections to the Glauber theory and nucleon-nucleus scattering

Abstract The leading corrections to the Glauber approximation are evaluated for a wide range of target nuclei. Near 1 GeV the corrections are small enough that the uncorrected theory should be quite reliable for determining the nucleon density distributions in target nuclei from proton scattering data. Effects arising from Pauli correlations and isospin dependence (charge exchange) are also considered.
Hydration at the membrane protein-lipid interface.

Evidence has been found for the existence water at the protein-lipid hydrophobic interface of the membrane proteins, gramicidin and apocytochrome C, using two related fluorescence spectroscopic approaches. The first approach exploited the fact that the presence of water in the excited state solvent cage of a fluorophore increases the rate of decay. For 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-palmitoyl-2-[[2-[4-(6-phenyl-trans-1,3,5- hexatrienyl)phenyl]ethyl]carbonyl]-3-sn-PC (DPH-PC), where the fluorophores are located in the hydrophobic core of the lipid bilayer, the introduction of gramicidin reduced the fluorescence lifetime, indicative of an increased presence of water in the bilayer. Since a high protein:lipid ratio was used, the fluorophores were forced to be adjacent to the protein hydrophobic surface, hence the presence of water in this region could be inferred. Cholesterol is known to reduce the water content of lipid bilayers and this effect was maintained at the protein-lipid interface with both gramicidin and apocytochrome C, again suggesting hydration in this region. The second approach was to use the fluorescence enhancement induced by exchanging deuterium oxide (D2O) for H2O. Both the fluorescence intensities of trimethylammonium-DPH, located in the lipid head group region, and of the gramicidin intrinsic tryptophans were greater in a D2O buffer compared with H2O, showing that the fluorophores were exposed to water in the bilayer at the protein-lipid interface. In the presence of cholesterol the fluorescence intensity ratio of D2O to H2O decreased, indicating a removal of water by the cholesterol, in keeping with the lifetime data.(ABSTRACT TRUNCATED AT 250 WORDS)
Statewide investigation of the role of pyrethroid pesticides in sediment toxicity in California's urban waterways.

A statewide investigation of urban creek sediment toxicity was conducted in California in recognition of increased incidences of toxicity linked to pyrethroid pesticides. The goals were to examine the spatial occurrence and magnitude of sediment toxicity in California urban creeks, and to examine the role of pyrethroids in toxic urban creek sediment samples. After a preliminary screening of 90 sites, 30 creeks were sampled in eight geographical regions. Sediment toxicity was assessed using 10 day bioassays with the resident amphipod Hyalella azteca. Bioassays were conducted at two test temperatures of 23 °C and at 15 °C to provide evidence of the cause of toxicity, and to more accurately reflect ambient environmental temperatures. Twenty-five of 30 samples were toxic when tested at 23 °C, and all 30 samples were toxic when tested at 15 °C. The magnitude of toxicity increased in samples tested at 15 °C suggesting the influence of pyrethroids, which are more toxic at colder temperatures. Pyrethroids were pr...
Radiology education needs an urgent overhaul.

In 3 years, the ABR will be changing the oral board format to a computer-based examination. In anticipation of this, residency training programs must be proactive and optimize the learning environment to maximize residents’ preparation for this examination and their subsequent careers. Undoubtedly, it is vital that training programs provide education to residents to make good clinical judgments rather than using residents for their work product. The optimal residency program provides graduated levels of responsibility such that residents are engaged in active leaning. Unfortunately, radiology residency training programs fall short of providing the optimal “adult” learning as a result of Socratic and didactic lecture style constraints. The problem with the didactic lecture, in which slides are shown one after another with the presenter providing a narrative (typically read from the slide), is that listeners succumb to an insidious mental numbness. In the large lecture halls with the lights low, some residents have actually fallen asleep, as have some attending physicians. Who hasn’t let their mind wander in a long lecture? The attention span of an adult is limited to 20 minutes, and further accumulation of knowledge is not improved by more of the same. Lectures using the Socratic method are lauded for an interactive experience in which an expert guides an individual through a series of questions with the purpose of stimulating critical thinking and illuminating ideas. Here, the reasoning process is considered more important than preconceived facts or beliefs. Unfortunately, the Socratic lecture format is dependent on an expert with a high level of knowledge who corrects erroneous responses before they become “black pearls.” Another problem with the Socratic method is that it can easily degenerate into a pimping session whereby residents recite pertinent facts by rote memory without any thoughtful discourse. An additional issue is the variable application of questions that lead, divert, or even mislead residents. Using these techniques, an examiner can easily make a poor resident look good or a good resident look bad—so not everyone likes the spotlight. The current residency education system using the Socratic method and didactic lecture styles is limited by the inability to incorporate new technologies that maximize decision support. For example, a multiplanar
Handling of Thermal Receipts as a Source of Exposure to Bisphenol A

Human exposure to bisphenol A (BPA) has been associated with adverse health outcomes, including reproductive function in adults1 and neurodevelopment in children exposed perinatally.2 Exposure to BPA is primarily through dietary ingestion, including consumption of canned foods.3 A less-studied source of exposure is thermal receipt paper,4 handled daily by many people at supermarkets, ATM machines, gas stations, and other settings. We hypothesized that handling of thermal receipts significantly increases BPA exposure, but use of gloves during handling minimizes exposure.
Epidemiology Investigations of the Health Effects of Particulate Air Pollution: Strengths and Limitations

Abstract Many epidemiological studies have investigated health effects of particulate air pollution. This article provides a simple framework to categorize the basic study designs of most of the currently available studies of the health effects of particulate air pollution and briefly discusses the common methods of statistical analysis. Within this framework it outlines basic strengths and limitations associated with currently available epidemiological evidence. Both the strengths and limitations of the epidemiological studies stem largely from the use of people who are living in uncontrolled environments and who are exposed to complex mixtures of particulate air pollution. Inherent to these studies are at least four basic limitations, including: (1) limited information about biological mechanisms, (2) relatively meager information regarding linkages between ambient and personal exposures, (3) difficulty of disentangling independent effects or potential interactions between highly correlated risk factors...
Rural hospitals and the provision of agricultural occupational health and safety services

Agriculture is one of the most dangerous work environments in the United States. Ironically, there is a near-total absence of occupational health and safety services being provided to agricultural workers. While many of the agricultural occupational hazards could be addressed through health and safety services provided by rural hospitals, the absence of dedicated funds to pay for these services is a major barrier. The ability of rural hospitals to provide these services and specific issues related to the unique character and problems in implementing agricultural occupational health and safety services are discussed.
Parental reports of community activity patterns: A comparison between young children with disabilities and their nondisabled peers

The extent and nature of community activities of families of children with disabilities in comparison with their nondisabled peers were examined. Parents of 82 children with disabilities and 132 children without disabilities, ages 2 through 5 years, completed a Demographic Questionnaire, Community Activities Questionnaire (CAQ), and Parent Experience Survey (PES). The CAQ assessed frequency of child participation in age-appropriate community activities, and the PES was a retrospective self-evaluation by parents of the experience of introducing the child to common community settings. Both groups of parents reported highly similar experiences when shopping with their children, although parents of children with disabilities reported more fear and risk associated with public settings. Overall, parents of children with disabilities reported participation in fewer community activities than parents of children without disabilities. This difference was largely accounted for by a lower level of participation by families having children with disabilities in a subset of activities that reflect opportunities for family enrichment.
Morbidity and mortality of Staphylococcal bacteremia in children.

Background Staphylococcal aureus bacteremia (SAB) is a major problem in adult patients with a significant mortality. Less is known about SAB in children. The present study was designed to review a 5-year experience with SAB in a children's hospital. Methods We conducted a retrospective chart review from 2000-2004. Results Thirty-six children experienced 42 episodes of SAB and ranged in age from 1 week to 16.7 years with a mean age of 30.5 months. Thirty-two (89%) of the 36 children had preexisting medical conditions. Thirty-six (86%) of 42 episodes of SAB were due to hospital-acquired infections, and 22 (61%) of these 36 episodes occurred in premature infants in the neonatal intensive care unit. Only 3 episodes (7%) of endocarditis were identified, and 2 were community-acquired infections. Fourteen (39%) episodes of SAB were due to methicillin-resistant strains. There were only 3 (8%) deaths, and all were unrelated to SAB. Conclusion SAB occurred most often as a hospital-acquired infection in the neonatal intensive care unit, and methicillin-resistant Staphylococcal aureus accounted for one third of the episodes. Complications such as endocarditis or other metastatic infections and death because of SAB were infrequent.
Doping evolution of the absolute value of the London penetration depth and superfluid density in single crystals of Ba ( Fe 1 − x Co x ) 2 As 2

The zero-temperature value of the in-plane London penetration depth, ${\ensuremath{\lambda}}_{ab}(0)$, has been measured in single crystals of $\text{Ba}{({\text{Fe}}_{1\ensuremath{-}x}{\text{Co}}_{x})}_{2}{\text{As}}_{2}$ as a function of the Co concentration, $x$, across both the underdoped and overdoped superconducting regions of the phase diagram. For $x\ensuremath{\gtrsim}0.047$, ${\ensuremath{\lambda}}_{ab}(0)$ has been found to have values between $120\ifmmode\pm\else\textpm\fi{}50$ and $300\ifmmode\pm\else\textpm\fi{}50\text{ }\text{nm}$. A pronounced increase in ${\ensuremath{\lambda}}_{ab}(0)$, to a value as high as $950\ifmmode\pm\else\textpm\fi{}50\text{ }\text{nm}$, has been observed for $x\ensuremath{\lesssim}0.047$, corresponding to the region of the phase diagram where the itinerant antiferromagnetic and superconducting phases coexist and compete. Direct determination of the doping-dependent ${\ensuremath{\lambda}}_{ab}(0)$ has allowed us to track the evolution of the temperature-dependent superfluid density, from which we infer the development of a pronounced superconducting gap anisotropy at the edges of the superconducting dome.
Influence of firm size on export planning and performance

Abstract The nature and impact of export planning and related activities in small and large U.S. exporting firms is the focus of interest in this study. The findings indicate a pattern of significant differences between small and large exporters in the areas of export planning activity, organizational and attitudinal variables, and information-gathering activity. In the case of the export planning-performance relationship, the data show that export planning activity and export intensity are related. Export profitability, however, does not appear to be a correlate of planning activity in either small or large firms.
Power and the rhetoric of social intervention

Relating rhetoric to power, this essay offers a view of power as communication medium, i.e., communication through power. Logically prior, however, is power through communication by which the rules for power are rhetorically derived. Case studies show (1) a conception of rhetoric‐as‐power being complementary to rhetoric‐as‐epistemic; (2) the development of the power medium as a cultural code dependent on hierarchical interdependency; and (3) the formal strategies, tactics, and maneuvers of rhetoric‐as‐power for social intervention.
Design and analysis for interferometric measurements of the GMT primary mirror segments

The Giant Magellan Telescope (GMT) uses seven 8.4-m diameter segments to create a giant primary mirror, 25 meters across with focal ratio f /0.7. The off-axis segments will be difficult to measure accurately, as they have 14.5 mm departure from the nearest fitting sphere! The test configuration adopted uses a large 3.75-m powered mirror to fold the light path and provide most of the aspheric correction, with a smaller mirror and computer generated hologram (CGH) providing the additional correction. These optics will be aligned to a vibration-insensitive interferometer using a combination of optical references created by the CGH and metrology with a laser tracker. Some key challenges for this system are presented here including, the system alignment, the large fold mirror, and the mechanical structure. Analysis of the optical test shows that it will meet GMT specifications, including the difficult requirement that the separate segments have matching radius of curvature. Additional corroborative testing will be performed to assure that the mirror segments are correctly figured.
Characteristics of spontaneously produced and of virus-induced human LuKII cell interferons.

Several human lymphoblastoid cell lines produced significant levels of interferon (IFN) activity in the absence of any IFN inducees. We have partially purified spontaneous IFN (SpIFN) from LuKII cells and compared it with the IFN activity produced by the same cells following Sendai virus induction. Virus-induced LuKII IFN reached maximum titers of 1000–6000 reference units/ml at 12 to 15 houts post-induction and produced a heterogeneous electrophoretic profile with major (18,500 dalton) and minor (23,500 dalton) species. Spontaneous LuKII IFN was produced very slowly over several days and reached maximum titers of 100–1000 reference units/ml. Crude SpIFN (25–100 ref. units/ml) was purified to 1–6×105 ref. units/ml with a 53–80 percent overall recovery, and it consistently migrated as a homogeneous 20,000 dalton band upon SDS gel electrophoresis. Although spontaneously produced and virus-induced lymphoblastoid IFNs differed in their ability to be neutralized by anti-mouse IFN antiserum (18), both types of IFN were only 1 percent cross-reactive on heterologous mouse L cells. We conclude that IFN definitely can be produced by many human lymphoblastoid cell lines in the absence of inducers, and that LuKII SpIFN has different characteristics than the IFNs produced by the same cell line following viral induction. Since it is now known that there are many IFN-α genes (3, 10), it seems likely that these cell lines may provide a system for studying the selective expression of one or more of these genes.
Investigations of Pulsed Second Sound in Liquid Helium II

Pulse methods are applied to the case of second sound in liquid helium II. Both transmitter and receiver consist of thermal elements and d.c. pulses are used throughout. The advantages of pulsing are enumerated for the particular case of second sound. The analagous electrical circuit is formulated for the geometry involved. Data is recorded photographically and examples for several cases presented. Velocity of second sound is given as a function of temperature; both the high temperature and low temperature ranges are extended past those of previous investigators employing standing wave methods. Attenuation of these d.c. pulses is given as a function of temperature. The "filtering in time" inherent to the pulse method permits the investigation of several forms of coupling between second sound and ordinary sound. The previously known conversion between second sound and classical sound in helium vapor is examined quantitatively. In addition, conversion of second sound to first sound within the liquid is induced by exceeding critical intensities and observed by means of a classical detector. A third conversion, probably occurring upon reflection from a boundary, is illustrated.
Canalith repositioning variations for benign paroxysmal positional vertigo.

Objective To determine if variations in common treatments for benign paroxysmal positional vertigo (BPPV) affected efficacy.
Concentration-dependent hydrogen diffusion in hydrogenation and dehydrogenation of vanadium-coated magnesium nanoblades

Abstract We carry out a computational investigation to show how the exponential concentration dependence of hydrogen diffusion, which was recently verified in a combined experimental and analytical study, could affect the characteristics of hydrogenation and dehydrogenation of a vanadium-coated magnesium nanoblade. A reaction model is built that separates hydrogen surface sorption and interior diffusion during the hydrogenation/dehydrogenation process. For the hydrogenation process, the hydrogen surface adsorption is much faster than the hydrogen diffusion, resulting in high hydrogen concentration buildup at the surface at a relatively low temperature. With increasing temperature, the hydrogen diffusion time decreases more rapidly than the hydrogen surface adsorption time. This leads to a relatively low-gradient diffusion field in the nanoblade during most time of the hydrogenation process, and no shell–core structure with a finite hydride layer is observed. However, for the dehydrogenation process, when hydrogen molecules are released at the surface, a hydride core is formed inside the nanoblade and the interface recedes gradually. The receding rate of the hydride core is determined by the hydrogen molecule release rate. In a two-dimensional simulation with decorated vanadium catalyst islands on the surface, isolated interior hydride islands are sometimes observed before the hydride core entirely fades away. The hydride core boundary is sharper at lower temperature when the surface reaction rate is high relative to the interior diffusion rate.
Intraprocedural cleansing work during colonoscopy and achievable rates of adequate preparation in an open-access endoscopy unit

Background Rates of adequate bowel preparation in the 60% to 80% range continue to be reported for colonoscopy. Objective To describe the rate of adequate bowel preparation and intraprocedural work needed to achieve this rate in an open-access endoscopy unit. Universal split dosing and regimens tailored to medical predictors of inadequate preparation were used. Design Prospective observational study. Setting Academic hospital outpatient endoscopy unit and ambulatory surgery center. Patients Outpatients undergoing colonoscopy. Interventions Prospective assessment of preparation quality for colonoscopy during insertion and after intraprocedural cleansing in 525 patients. Main Outcome Measurements Rates of adequate preparation and work required to improve cleansing quality. Work time for cleaning was measured with a stopwatch. Results Adequate preparation to allow recommendation of standard screening or surveillance intervals was achieved in 96% of patients, including 6% for whom preparation was adequate only after intraprocedural cleansing work. The mean time for intraprocedural cleaning was 4.1 minutes and constituted 17% of total procedure time. Work time for cleaning and fluid volume injected increased when worse preparation grades were identified before cleaning. Limitations Single-center study with low percentage (4%) of patients receiving Medicaid. Conclusion An open-access unit using split-dose bowel cleansing preparations can achieve high rates of adequate bowel preparation for colonoscopy. Intraprocedural cleansing accounts for a substantial fraction of the total procedure time in colonoscopy and is an important contributor to high rates of adequate preparation.
Effects of dietary roxarsone supplementation, lighting program, and season on the incidence of leg abnormalities in broiler chickens

Two 4 x 2 factorial experiments were designed to test the effects of four diets, differing in anticoccidial programs and roxarsone (3-nitro-4-hydroxyphenylarsonic acid) content, and two lighting programs on the incidence of leg abnormalities in 56-d-old male and female broiler chickens. The four diets were: A) basal diet + salinomycin (60.0 g/ton); B) basal diet + salinomycin (60.0 g/ton) + roxarsone (45.4 g/ton); C) basal diet + roxarsone (45.4 g/ton) + live coccidial vaccine; and D) basal diet + live coccidial vaccine. The light treatments were: 1) restricted (R) [18 h light (L): 6 h dark (D)] and 2) standard (S) [23L:1D]. The respective experiments were conducted during winter (Experiment 1, November to January) and summer (Experiment 2, June to August) growing conditions in the southeastern U.S. Light treatment had no significant (P > 0.10) effect on the incidence of leg abnormalities in either experiment. However, in Experiment 1, there was a light treatment by sex interaction; leg abnormalities were greater for males on Treatment R than Treatment S. In Experiment 2, females had a higher incidence of leg abnormalities than males (8.29 vs 4.73%). There was a diet by sex interaction for the incidence of leg abnormalities in Experiment 2; females had a greater incidence of leg abnormalities than males on Treatment A. In both experiments, the incidence was greater with dietary treatments containing roxarsone (P < 0.10). The percentage of leg abnormalities was greater in Experiment 2 than Experiment 1. Leg abnormalities were primarily due to fibrosis of the gastrocnemius tendons and tendon sheaths.
Ground ice on Mars: Inventory, distribution, and resulting landforms

A model is presented for the distribution of ground ice on Mars, and model predictions are compared with Viking Orbiter photographs of landforms possibly related to ground ice. Estimates of the amount of water originally outgassed on Mars and the amount of water presently on Mars are presented which show that approximately 90% of the estimated outgassed volume may be stored in the Martian subsurface as ground ice. The extent of the Martian cryosphere, the zone in which the temperature is below the freezing point of water and in which ground ice can exist, is examined, and it is shown that, in the presence of a protective surface layer approximately 10 m thick, ground ice may occur beneath the entire Martian surface. Observed features on the Martian surface considered most likely to reflect the presence of ground ice are discussed, including thermokarst-like pits and debris flows, and possibly polygonally patterned ground, curvilinear features and pingo-like mounds, and the geographic distributions of these features as seen in Viking photographs are examined. It is found that the possibly ice-related features are concentrated in the northern midlatitudes, the equatorial zone near Olympus Mons, and the Southern Hemisphere near the edge of the plains, indicating that subsurface ice may be present over the entire planet. The origin of the ice-related landforms is explained by a combination of volcanic heating and variations in insolation.
Expression of bvgAS of Bordetella pertussis represses flagellar biosynthesis of Escherichia coli

BvgAS is a two-component system of Bordetella pertussis involved in the reciprocal regulation of the virulence genes and the flagellar biosynthesis. In this study, we found that expression of bvgAS in Escherichia coli also results in reduced motility. The repression was relieved by the addition of known chemical modulators of BvgAS such as MgSO4 and nicotinic acid, indicating that functional BvgAS proteins are required for the negative control of E. coli motility. In addition, BvgAS repressed the transcription of the flhDC master operon of E. coli, which consequently caused non-flagellation on the cell surface. However, expression of BvgAS had no effect on stress-resistant motile mutants of E. coli. These data suggest that E. coli may have BvgA-like protein(s) involved in the regulatory interactions between the stress response and the flagellar biosynthesis.
Instrumental variable quantile regression : A robust inference approach

Abstract In this paper, we develop robust inference procedures for an instrumental variables model defined by Y = D ′ α ( U ) where D ′ α ( U ) is strictly increasing in U and U is a uniform variable that may depend on D but is independent of a set of instrumental variables Z. The proposed inferential procedures are computationally convenient in typical applications and can be carried out using software available for ordinary quantile regression. Our inferential procedure arises naturally from an estimation algorithm and has the important feature of being robust to weak and partial identification and remains valid even in cases where identification fails completely. The use of the proposed procedures is illustrated through two empirical examples.
Statistical uncertainty in estimates of an effective scatterer number density for ultrasound.

In a previous paper [J. Acoust. Soc. Am. 95, 77–85 (1994)], a method for determining an effective scatterer number density in ultrasonography was presented. This is the actual number density multiplied by a frequency‐dependent factor that depends on the differential scattering cross sections of all scatterers. This method involves evaluating the ratio of the fourth moment to the square of the second moment of echo signals scattered from the sample. The random processes involved in forming these echo signals give rise to an uncertainty in the estimated effective scatterer number density. This uncertainty is evaluated here using error propagation. The statistical uncertainty depends on the effective number of scatterers contributing to the segmented echo signal; it increases when the effective number of scatterers increases. Tests of the statistical uncertainty estimator were in good agreement with uncertainties computed from experimental data.
NumChecker: detecting kernel control-flow modifying rootkits by using hardware performance counters

This paper presents NumChecker, a new Virtual Machine Monitor (VMM) based framework to detect control-flow modifying kernel rootkits in a guest Virtual Machine (VM). NumChecker detects malicious modifications to a system call in the guest VM by checking the number of certain hardware events that occur during the system call's execution. To automatically count these events, NumChecker leverages the Hardware Performance Counters (HPCs), which exist in most modern processors. By using HPCs, the checking cost is significantly reduced and the tamper-resistance is enhanced. We implement a prototype of NumChecker on Linux with the Kernel-based Virtual Machine (KVM). Our evaluation demonstrates its practicality and effectiveness.
Partisanship and Participation in Political Campaign Activities, 1952-1996:

In 1972, Verba and Nie identified a “puzzle” of Republican “hyperactivity” in political participation over the 1952-1968 period. Verba and Nie argue that higher levels of Republican participation (...
In search of learning and knowing

The supportive arguments for hypermedia and hypertext learning environments typically assert that as the systems permit individuals to self-select content based on needs, to control the pace and content, and/or provide a measure of control otherwise missing in traditional, linear texts and lectures, learning and knowing outcomes increase. There are two difficulties with this argument and some of the resultant empirical literature. The first is that knowing is a complex phenomenon which can be variously defined and measured. However, the literature often focuses on a narrow range of definitions and measures and doesn't exploit the full range of theory. This, in turn, may lead to the second difficulty, that of very limited outcomes. A cognitive model of learning and knowing is presented and contrasted with a sample of empirical research. This model provides a solid theoretical basis for research into cognitively engaging hypermedia systems.
New culture media to suppress exopolysaccharide production by Rhizobium japonicum

Secretion of exopolysaccharide by Rhizobium japonicum strain USDA 110 ws measured during growth on media comprising 12.5 mM MES [2-(N-morpholino)ethanesulfonic acid] buffer, pH 5.9; 5 mM NH4Cl; trace elements; and 25 or 100 mM of one of 23 different carbon sources. Significant amounts of exopolysaccharide were produced on all aldopentoses, polyols, organic acids, and sugar acids tested, but little or none was secreted during growth on aldohexoses or amino acids. Media suitable for routine slime-free culture of several. R. japonicum strains were made by using 100 mM d-galactose or 25 mM l-aspartate as the carbon source.