cssi/SciSciGPT-SciSciNet huggingface dataset:
Time Comparison of Intensive Care Units With and Without Digital Viewing Systems

As hospital radiology departments and intensive care units (ICUs) make plans to use or expand the usage of digital data outside of the radiology department, the need to assess the requirements of the potential recipients in the ICUs has become more important. The present operations in an ICU that uses digital viewing instead of film has been compared with a unit that does not. The difference in time between x-ray exposure and final image viewing was determined in both settings and compared. In this preliminary study, significant differences were found between the two units. The odds of having examination results actually accessed by the ordering physician in an hour or less were 9.5 times greater for the unit with digital viewing capability than for the one without it.
Identification with Resource-Based Occupations and Desire for Tourism: Are the Two Necessarily Inconsistent?

Occupational identity is frequently used to explain why rural residents traditionally involved in natural resource-based occupations have no interest in tourism activities as a form of economic development, with researchers arguing these residents view tourism as inconsistent with the cultural traditions associated with more traditional rural occupations such as logging, mining, or agriculture. However, the link between resource-based occupational identity and attitudes about tourism development has not been systematically tested. Using survey data from three Western communities undergoing social and economic changes, this article examines this relationship and assesses the influence of other variables that may impact the relationship. Results show that while resource-based occupational identity is associated with attitudes toward tourism, perception of the local economic condition is a stronger predictor of such attitudes.
Lattice sums and the two-dimensional, periodic Green's function for the Helmholtz equation

Many algorithms that are currently used for the solution of the Helmholtz equation in periodic domains require the evaluation of the Green's function, G(x,x0). The fact that the natural representat...
Suture Growth Modulated by the Oscillatory Component of Micromechanical Strain

Sutures are fibrous connective tissue articulations between intramembranous craniofacial bones. Sutures are composed of fibroblastic cells with their matrices in the center and osteogenic cells in the periphery producing a matrix that is mineralized during skeletal growth. Whether oscillatory forces stimulate sutural growth is unknown. In the present work, we applied static and cyclic forces with the same peak magnitude of 5N to the maxilla in growing rabbits and quantified (1) acute in vivo sutural bone strain responses and (2) chronic growth responses in the premaxillomaxillary suture (PMS) and nasofrontal suture (NFS). Bone strain recordings showed that the waveforms of static force and 1-Hz cyclic force were expressed as corresponding static and cyclic sutural strain patterns in both the PMS and NFS, with the mean peak PMS strain (−1451 ± 137 μe for the cyclic and −1572 ± 138 μe for the static) approximately 10-fold higher than the mean peak NFS strain (124 ± 9 μe for the cyclic and 134 ± 9 μe for the static). Strain polarity was the opposite: compressive for the PMS but tensile for the NFS. However, on application of repetitive 5N cyclic and static forces in vivo for 10 minutes/day over 12 days, cyclic loading induced significantly greater sutural widths for the compressed PMS (95.1 ± 8.3 μm) than sham control (69.8 ± 8.2 μm) and static loading (58.9 ± 2.8 μm; p < 0.01). Interestingly, the same trend was true for the NFS under tensile strain: significantly greater sutural width for cyclic loading (267.4 ± 64.2 μm) than sham control (196.0 ± 10.1 μm) and static loading (169.9 ± 11.4 μm). Cell counting in 110 × 110 μm grids laid over sutures disclosed significantly more sutural cells on repetitive cyclic loading than sham control and static loading (p < 0.05) for both the PMS and NFS. Fluorescent labeling of newly formed sutural bone demonstrated more osteogenesis on cyclic loading in comparison with sham control and static loading. Thus, the oscillatory component of cyclic force or more precisely the resulting cyclic strain experienced in sutures is a potent stimulus for sutural growth. The increased sutural growth by cyclic mechanical strain in the tensed NFS and compressed PMS suggests that both microscale tension and compression induce anabolic sutural growth response.
A clinical trial of propofol vs midazolam for procedural sedation in a pediatric emergency department.

Objective: To compare the effectiveness, recovery time from sedation, and complication rate of propofol with those of midazolam when used for pro- cedural sedation in the pediatric emergency depart- ment (PED). Methods: A prospective, blinded, ran- domized, clinical trial comparing propofol and midazolam was conducted in the PED of a tertiary pediatric center. Eligible patients were aged 2-18 years with isolated extremity injuries necessitating closed reduction. All patients received morphine for pain, then were randomized to receive propofol or midazolam for sedation. Vital signs, pulse oximetry, and sedation scores were recorded prior to sedation and every 5 minutes thereafter until recovery. Recov- ery time, time from cast completion to discharge, and other time intervals during the PED course and all sedation-related complications were also recorded. Results: Between August 1996 and October 1997, 91 patients were enrolled. Demographic data, morphine doses, and sedation scores were similar between the propofol and midazolam groups. Mean 6 SD recovery time for the propofol group was 14.9 6 11.1 minutes, compared with 76.4 6 47.5 minutes for the midazo- lam group, p < 0.001. Mild transient hypoxemia was the most significant complication, occurring in 5 of 43 (11.6%) patients given propofol and 5 of 46 (10.9%) patients given midazolam (odds ratio 1.08, 95% CI = 0.24 to 4.76). Conclusion: In this study, propofol in- duced sedation as effectively as midazolam but with a shorter recovery time. Complication rates for pro- pofol and midazolam were comparable, though the small study population limits the power of this com- parison. Propofol may be an appropriate agent for se- dation in the PED; however, further study is neces- sary before routine use can be recommended. Key words: propofol; procedural sedation; closed ortho- pedic reduction; pediatric emergency department. ACADEMIC EMERGENCY MEDICINE 1999; 6: 989-997
Clostridium difficile-associated disease in long-term care facilities.

Clostridium difficile is a major cause of gastrointestinal infections. In 1978, Bartlett and colleagues identified C difficile and its toxin as the cause of the antibiotic-associated pseudomembranous colitis (PMC). Within a few years, there was the development of a diagnostic assay, a description of a clinical and pathological spectrum of the disease, a definition of risk factors and characterization of the two toxins that account for the pathological event. Additional information regarding the microbiology, pathogenesis, clinical manifestations, diagnosis and treatment has rapidly developed. These features are beyond the scope of this report, and the reader is referred to several recent reviews.
Beryllium mirror-polishing optimization for minimum cost

This paper compares the manufacturing effort and estimated relative cost of traditionally finished surfaces and single point, precision machined beryllium surfaces which have been subsequently polished by loose abrasive polishing techniques. The study includes O50 optical grade beryllium and a preliminary look at a new sputter deposited beryllium cladding showing both of their characteristics. The study was done in a manner which has allowed optimization of the polishing process for any specific desired, final mirror quality allowing determination of the minimum cost process. The objective of this study has been to establish both a 'baseline' of quality and costs while assisting optimization. The study co-addresses quality, effectiveness, and effort when producing low scatter optical surfaces from the single point turned beryllium surface. The results are useful in selecting minimum cost beryllium mirror manufacturing processes while mapping the latitude that is available. Optimized polishing is shown to reduce polishing times by 70 to 90 percent below that normally needed.
Accumulation and release of methane from clathrates below the Laurentide and Cordilleran ice sheets

Abstract Ice-age cycles are associated with large fluctuations in the concentration of atmospheric methane. These fluctuations are commonly attributed to changes in wetlands, although clathrates have also been proposed as a potential source. We examine the possibility that methane clathrates accumulate below continental ice sheets during an ice age. The source of methane is due to microbial decomposition of organic material below the ice sheet. Methane is stored in clathrate when the pressure and temperature conditions permit thermodynamic stability. Deglaciation releases methane from clathrate into the atmosphere. We use a numerical model for the Laurentide–Cordilleran ice sheet [Marshall, S.J., Tarasov, L., Clarke, G.K.C., Peltier, W.R., 2000. Glaciological reconstruction of the Laurentide ice sheet: physical processes and modeling challenges, Can. J. Earth Sci. 37, 769–793.] to assess the aerial extent, thickness, and the thermal conditions at the base of the ice sheet as a function of time. Both low and high inventories of the organic carbon below the ice sheet are considered, based on soil carbon estimates for tundra and for the present potential vegetation. We model the spatial distribution of clathrate as the ice sheet grows and quantify the amplitude and timing of methane releases as the ice sheet retreats. The predicted fluctuations in atmospheric methane are 80–200 ppbv, which are comparable to fluctuations recorded in ice cores from Greenland and Antarctica. However, clathrates cannot explain the entire atmospheric methane record because there is insufficient methane in clathrate to sustain the elevated atmospheric concentration for more than 1 kyr.
Redox Behavior of Gold Species in Zeolite NaY: Characterization by Infrared Spectroscopy of Adsorbed CO

The state of gold on a Au/NaY zeolite sample prepared from Au(CH3)2(C5H7O2) and subjected to various treatments was monitored by infrared spectroscopy of adsorbed CO as a probe molecule. Spectra of...
The first harmonic as a known source for wavefront correction

It is demonstrated that distortion of a non-linearly generated first harmonic transmit beam due to a near-field aberrator is reduced as transmit pressure is increased. The first harmonic transmit beam is then used as a source for correction of aberration. In the first experiment, pieces of Lucite 11 mm and 24 mm thick were used as near-field aberrators. Beam plots of the fundamental and first harmonic were measured in a water tank with and without the aberrators present at multiple transmit voltages. The Lucite aberrator was then removed and an electronic aberrator with RMS delay error of 138 ns was applied to the transmit and receive apertures. The first harmonic reflected from the tip of a hydrophone was measured, and correcting delays were determined using a multi-lag least-means-squares cross-correlation method. Corrections were applied to an imaging beam transmitted at twice the frequency of the fundamental beam, the same frequency as the generated first-harmonic. Results from the Lucite experiments showed a -6 dB beam width improvement of 1.8 degrees when transmit voltage was increased from 20 volts to 80 volts. Results from first harmonic based correction of the electronic aberrator resulted in significant improvement in beam width and showed an average improvement of 16.8 dB in transmit beam signal level and 31.9 dB improvement in transmit-receive beam signal level.
Seed germination and life history syndromes in the California chaparral

Syndromes are life history responses that are correlated to environmental regimes and are shared by a group of species (Stebbins, 1974). In the California chaparral there are two syndromes contrasted by the timing of seedling recruitment relative to wildfires. One syndrome, here called the fire-recruiter or refractory seed syndrome, includes species (both resprouting and non-resprouting) which share the feature that the timing of seedling establishment is specialized to the first rainy season after fire. Included are woody, suffrutescent and annual life forms but no geophytes have this syndrome. These species are linked by the characteristic that their seeds have a dormancy which is readily broken by environmental stimuli such as intense heat shock or chemicals leached from charred wood. Such seeds are referred to as “refractory” and dormancy, in some cases, is due to seed coat impermeability (such seeds are commonly called hardseeded), but in other cases the mechanism is unknown. Seeds of some may require cold stratification and/or light in addition to fire related stimuli. In the absence of fire related cues, a portion or all of a species’ seed pool remains dormant. Most have locally dispersed seeds that persist in the soil seed bank until the site burns. Dispersal of propagules is largely during spring and summer which facilitates the avoidance of flowering and fruiting during the summer and fall drought. Within a life form (e.g., shrub, suffrutescent, etc.), the seeds of these species have less mass than those of species with non-refractory seeds and this possibly reflects the environmental favorableness of the postfire environment for seedling establishment. Regardless of when fire occurs, germination is normally delayed until late winter or early spring. In the absence of fire, or other disturbance, opportunities for population expansion are largely lacking for species with this syndrome.
Wealth, Status, and Reproductive Success among the Mukogodo of Kenya

Fieldwork conducted in 1985-87 among the Mukogodo a pastoralist population in north-central Kenya provided support for Irons hypothesis that culturally defined values are proximate to the ultimate goal of reproductive success. In this society the accumulation of livestock remains a central value. To obtain a measure of livestock wealth a livestock census was conducted of all Mukogodo males over 20 years of age; in addition reproductive histories were obtained from 142 women. A positive correlation was found between total number of livestock units and number of live births. This correlation was even stronger when small stock--shorter-lived and less valued for bridewealth payments and loans--were excluded and only cattle were counted. Possible confounding variables--age education wage employment and differential access to medical care--could be ruled out. The correlation between wealth and reproductive success appeared to be largely attributable to the greater incidence of polygyny among wealthier men and to a lesser extent to the tendency for wealthy men to marry at an earlier age because of their greater ease in accruing the bridewealth payment. Also observed was a correlation between mens livestock holdings and their wives reproductive success but the correlation was nonsignificant. There was no indication that the correlation revealed in this study was related to the bridewealths obtained when daughters marry or the productivity of wives and children. As wage employment becomes more prevalent among the Mukogodo it may constitute an alternative strategy for accumulating bridewealth and supporting families.
Calcium effects on calmodulin lysine reactivities

Abstract The differential reactivities of individual lysines on porcine testicular calmodulin were determined by trace labeling with high specific activity [ 3 H]acetic anhydride as a function of the molar ratio of Ca 2+ to calmodulin. In progressing from the Ca 2+ -depleted form of the protein to a Ca 2+ :calmodulin molar ratio of 5:1, six of the seven lysyl residues exhibited a modest 1.5- to 3.0-fold increase in reactivity. Lys 75, in contrast, was enhanced in reactivity greater than 20-fold. When the change in reactivity of each lysine was normalized as a percentage of the maximum change, most of the residues were found to fall into two distinct classes. One class, comprising lysines 94 and 148 from the two carboxy terminal Ca 2+ -binding domains 3 and 4, respectively, exhibited about 90% of their reactivity change when the Ca 2+ :calmodulin molar ratio was 2:1, and these residues were perturbed very little upon further addition of Ca 2+ . The other class, encompassing lysines 13, 21, and 30 from the amino terminal domain 1 and Lys 75 from the extended helix connecting the two globular lobes of calmodulin, underwent most of their overall reactivity change (55–70%) between 2 and 5 equivalents of Ca 2+ per mol of calmodulin. Lys 77 was distinct in its pattern of change, undergoing approximately equal changes with each Ca 2+ increment. These results are consistent with a model where Ca 2+ first binds to the two carboxy terminal sites of calmodulin with no apparent preference, concomitant with minor alterations in the microenvironments of lysines in the unoccupied amino terminal domains. The third and fourth Ca 2+ ions then bind to these latter two domains, again with no evidence of preference, with little change in the lysine reactivities at the carboxy terminus of the molecule. The environments of groups in the central helix appear to undergo changes in a manner that reflects their proximity to the amino and carboxy terminal domains. In the course of this work, it was found that Lys 94 in apocalmodulin is specifically perturbed by the addition of EGTA, suggesting that the chelating agent may interact with calmodulin at or near the third Ca 2+ -binding domain.
Separation and characterization of the complexes constituting the cellulolytic enzyme system of Clostridium thermocellum

Clostridium thermocellum, strain JW20 (ATCC 31449) when growing in cellulose produces a cellulolytic enzyme system, that at the early stage of the fermentation is largely bound to the substrate. As cellulose is consumed the bound enzyme is released as free enzyme to the culture fluid. The bound enzyme fraction extracted with distilled water from the cellulose contains two major components, a large complex (Mr≃100×106) and a small complex Mr≃4.5×106) which were separated by gel filtration and sucrose solved by affinity chromatography into a complex that binds to the column and into a non-bindable mixture of proteins. All four fractions have endo-β-glucanase activity but only the two bound complexes and the free bindable complex hydrolyze crystalline cellulose with cellobiose as the main product. These three complexes are qualitatively similar in that they each contain about 20 different polypeptides (Mr values from 45,000 to 200,000) of which about ten are major components. However, the relative amounts of some of the peptides in the complexes differ. At least four polypeptides of the complexes have endo-β-glucanase activity.
High bandwidth SOI photonic wire ring resonators using MMI couplers.

A ring resonator in SOI photonic wire waveguides is demonstrated using a compact MMI coupler with 3μm × 9 μm footprint as the coupling element. We achieved high bandwidth of 0.25 nm, and a quality factor Q of ∼ 6000 for rings with a radius of 50 μm. Unlike directional coupler based rings, these resonators have a wavelength independent Q and extinction ratio over more than 30 nm wavelength range, and there is no loss penalty for increasing the bandwidth. Compared to their directional coupler based counterparts, these resonators also have less demanding fabrication requirements and are compatible with high speed signal processing and optical delay lines.
Assessing spatial patterns of crime in Lima, Ohio

Abstract Police departments, city officials and policy makers all recognize the importance of a better understanding of the dynamics of crime. Both theoretical and applied approaches, or combinations of the two, which provide insight into why and where crime takes place are much in demand. Macrolevel analysis helps to identify problem neighborhoods. Microlevel analysis helps to isolate precise trouble spots within neighborhoods and, as a result, allows for better evaluation of crime and specific socioeconomic, demographic, land use and environmental characteristics associated with these trouble spots. This paper details a framework for better understanding the spatial characteristics of crime based upon the use of geographical information systems (GIS) and quantitative techniques. Lima, Ohio, provides a case study for a number of reasons. Many smaller communities have serious crime problems, so the study of crime in these communities is much needed. Lima (population 40,263) has violent crime rates well above average for its size, experiencing rates of violent crime equal to or above larger cities such as Columbus, Cincinnati and Toledo. Also, crime has an inordinately strong influence in the social and economic performance of small cities and hinders economic recovery efforts. The establishment of an analytical and theoretical framework for evaluating the relationship between aspects of place and the clustering of crime will undoubtedly lead to enhanced crime prevention strategies.
Mariner 1969 television image processing

Abstract Mariners 6 and 7 sent back approximately two hundred photographs of Mars, taken from distances ranging between one million and three thousand km relative to the planet surface. These images contain true object space information distorted, to one extent or another, by the signature of the imaging system itself. In order to maximize the scientific yield of the television data, the natures of the distortions introduced by the imaging system must be quantitatively determined, and techniques developed whereby they can be accurately removed. Television systems typically exhibit photometric nonuniformities and nonlinearities, geometric distortions, both optical and electronic, image retention and spatial frequency response limitations. In addition, Mariner 1969 specific problems were introduced in the course of on-board processing applied in the interest of data compression and efficient bandwidth utilization. A cubing amplifier and an automatic gain control circuit were employed, with photometric “DC reference” supplied in the form of a separately encoded, under sampled raw signal. The effects of on-board processing can in principle be removed by means of combining these separate data streams. Digital image processing techniques have been developed at the Jet Propulsion Laboratory which enable us to characterize these various distortions using calibration data, and to remove them from images returned by the two Mariner spacecraft. This paper will provide brief descriptions of some of these techniques and illustrations of their application to Mariner 1969 image data.
Jobs and Chocolate: Samuelsonian Surpluses in Dynamic Models of Unemployment

In dynamic models of unemployment in which the employed consume more than the unemployed, workers are finitely lived, and jobs are lasting, employment transfers consumption from future generations to those currently alive, resulting in a social surplus. That is, these transfers allow the current generation to consume more than its share of the output produced during its lifetime, without the increased consumption coming at the expense of future generations. Moreover, due to these intergenerational transfers, the allocation that maximizes steady-state output is Pareto dominated by another feasible allocation with a higher level of steady-state employment.
Human breast cancers respond to growth factors in vivo but not in vitro

Abstract Growth response of human breast cancer cells to epidermal growth factor (EGF) and transforming growth factoralpha (TGF-α) was tested both in culture and in vivo in nude mice. Human breast cancer cells were obtained from palpable tumors resulting from xenografted primary breast cancers in nude mice. In collagen gel culture, the breast cancer cells grew autonomously as expanding spherical masses of loosely adherent cells in the basal medium and the supplementation of growth factors had no additional stimulatory effect. To determine whether this in vitro response is reflected in vivo, the collagen gel embedded human breast cancer cells were transplanted into athymic nude mice and the growth response to EGF was studied in vivo. In contrast to the situation in vitro, exogenous EGF was growth promoting in vivo. Our results demonstrate the importance of the combined in vitro-in vivo approach in studying physiologically relevant growth regulation. In addition, the use of collagen gel embedded human breast cancer cells for transplantation studies may more closely model the clinical situation in view of the close histopathological resemblance of the recovered gels to the surgical breast specimens.
Resonance raman scattering from metastable O2 molecules in γ-irradiated NaClO3

Abstract Resonance Raman scattering has been observed from metastable O 2 molecules produced in single crystals of NaClO 3 by γ-irradiation at 300 K. Evidence that the observed bands are due to O 2 is provided by the Raman spectrum of irradiated 18 O enriched NaClO 3 in which bands due to 16 O 2 , 16 O 18 O, and 18 O 2 were identified. The Raman band at 1544 cm −1 ascribed to metastable O 2 disappears on bleaching with intense 4880 A radiation enabling the identification of a weaker band at 1557 cm −1 that is assigned to the stable form of O 2 .
TGF-|[beta]|1 Modulates Epithelial Cell Differentiation in Cultured Human Fetal Lung. |[bull]| 300

TGF-β1 is associated with pulmonary fibrosis in various lung injury models and with development of chronic lung disease of prematurity. We examined the effect of exogenously administered TGF-β1 on surfactant protein (SP) expression and lung morphology in a cultured human fetal lung model. Explants prepared from 19-24 wk gestation lungs were cultured for 5 d with or without dexamethasone (dex, 10 nM), TGF, or dex and TGF (added on day 1, 3 or 4). To study synthesis of SP-C, explants cultured with dex were labeled on day 5 of culture with 35S-met for 4h and immunoprecipitated with anti-NPROSP-C antiserum. Dex alone increased SP-C21 expression by 6.8±0.8-fold compared to untreated control. TGF induced a dose and time dependent inhibition of SP-C21 expression with maximal inhibition after 5 d at 100 ng/ml (31±10% of 5 d control) and a Ki of ≈30 ng/ml. There was no change in 35S-met incorporation into total protein in any of the treatment groups vs controls. ELISA analysis of samples cultured for 5 d in TGF revealed a dose dependent inhibition of SP-A protein accumulation with 53% inhibition occurring at 10 ng/ml and a Ki of ≈1 ng/ml. Commensurate with the inhibition of protein content, TGF (100 ng/ml) decreased mRNA content to 17%, 39% and 23% of control for SP-A, SP-B and SP-C, respectively. Transcription rates were similarly reduced vs control to 28% for SP-A, 7% for SP-B and 46% for SP-C. Light microscopy of tissue treated for 5 d with TGF (100 ng/ml) plus dex revealed markedly increased interstitial deposition of extracellular matrix compared to dex alone. We conclude that TGF-β1 disrupts culture- and dex-induced maturation of fetal lung epithelial cells by a mechanism involving transcriptional down-regulation of SP gene expression. We speculate that excessive TGF-β1 contributes to the pathogenesis of chronic lung disease of prematurity in part through modulation of epithelial cell function.
A morphometric analysis of mygalomorph spider carapace shape and its efficacy as a phylogenetic character (Araneae)

Shape features are often used as characters in cladistic analyses, yet states of these characters are seldom delineated in an objective, repeatable fashion. Carapace shape is one such character that is often used in analyses of mygalomorph spider relationships. For example, most analyses have used cephalic region morphology (e.g. steeply arched v. flat or sloping) as a key feature that delineates some major clades. In practice, carapace shapes at the extremes are relatively easy to identify; however, intermediate carapace shapes have proven to be much more difficult to objectively score in one of three shape categories. In this study, carapace shape is used as an exemplar characteristic to evaluate the utility of shape features in phylogenetic analyses and to evaluate our ability to effectively score discrete character states. Carapaces from 178 spider specimens sampled across 13 of the 15 nominal mygalomorph families were digitally photographed and their outlines were traced and pseudo-landmarks plotted. An elliptical Fourier analysis was then employed in an attempt to both delineate and assess character states. It is concluded that landmark analyses are inappropriate for carapace shape delineation as a result of difficulties in scoring precision and, thus, outline analyses are the preferred method given the morphology. Carapace shape is not a very useful character for broad-level systematic studies of mygalomorph relationships owing to the variable nature of the feature and our inability to detect discrete discernable shapes.
A halide-initiated aza-Baylis–Hillman reaction: generation of unnatural amino acids

Abstract A series of allenic ketones react with a glyoxylate-derived imine in the presence of MgBr 2 through an aza-Morita–Baylis–Hillman (MBH) reaction. The isolation of a variety of unnatural amino acids with unique allene-containing functional groups provides a conceptually new application of the aza-MBH. The reaction scope and preliminary mechanistic investigations are discussed.
Aging facial skin: infrared broad band light technologies.

The application of infrared broadband light is the more recent addition of nonsurgical laser and light-based treatment for skin laxity and rhytids. Infrared broadband light, when used with the mobile technique, offers a painless, safe, nonsurgical alternative treatment option for treatment of skin laxity on the face and neck. Multiple clinical studies have demonstrated improvements in skin laxity correlated histologically with neocollagenesis and neoelastogenesis over a 6-12 month period. The consistency of clinical improvement in skin laxity supports the use of this approach for moderate skin laxity.
A social network analysis of treatment discoveries in cancer.

Controlled clinical trials are widely considered to be the vehicle to treatment discovery in cancer that leads to significant improvements in health outcomes including an increase in life expectancy. We have previously shown that the pattern of therapeutic discovery in randomized controlled trials (RCTs) can be described by a power law distribution. However, the mechanism generating this pattern is unknown. Here, we propose an explanation in terms of the social relations between researchers in RCTs. We use social network analysis to study the impact of interactions between RCTs on treatment success. Our dataset consists of 280 phase III RCTs conducted by the NCI from 1955 to 2006. The RCT networks are formed through trial interactions formed i) at random, ii) based on common characteristics, or iii) based on treatment success. We analyze treatment success in terms of survival hazard ratio as a function of the network structures. Our results show that the discovery process displays power law if there are preferential interactions between trials that may stem from researchers' tendency to interact selectively with established and successful peers. Furthermore, the RCT networks are “small worlds”: trials are connected through a small number of ties, yet there is much clustering among subsets of trials. We also find that treatment success (improved survival) is proportional to the network centrality measures of closeness and betweenness. Negative correlation exists between survival and the extent to which trials operate within a limited scope of information. Finally, the trials testing curative treatments in solid tumors showed the highest centrality and the most influential group was the ECOG. We conclude that the chances of discovering life-saving treatments are directly related to the richness of social interactions between researchers inherent in a preferential interaction model.
Limitations to the room temperature mobility of two- and three-dimensional electron liquids in SrTiO3

We analyze and compare the temperature dependence of the electron mobility of two- and three-dimensional electron liquids in SrTiO3. The contributions of electron-electron scattering must be taken into account to accurately describe the mobility in both cases. For uniformly doped, three-dimensional electron liquids, the room temperature mobility crosses over from longitudinal optical (LO) phonon-scattering-limited to electron-electron-scattering-limited as a function of carrier density. In high-density, two-dimensional electron liquids, LO phonon scattering is completely screened and the mobility is dominated by electron-electron scattering up to room temperature. The possible origins of the observed behavior and the consequences for approaches to improve the mobility are discussed.
EDUCATIONAL INTERVENTION FOR A HUNTINGTON'S DISEASE CAREGIVER

A lack of knowledge has been linked to increased stress for caregivers. Educational programs are an inexpensive intervention with potential to improve caregivers' provision of care and to reduce the associated stress. The present description is of a Huntington's disease caregiver's participation in a training program for at-home care of a physically dependent, demented person. Care knowledge was deficient prior to participation and increased with participation. Collaterally, confidence in providing assistance increased and stressfulness of care fell. While increased knowledge remained at follow-up, confidence and stressfulness returned to pre-intervention levels. Measures of affect mirrored the pattern of change in confidence and stressfulness. This suggests that education increased knowledge but this gain was not associated with longer term improvement in the caregiver's affect, stressfulness of continuing to provide care, and confidence in providing care. Implications for such programs are discussed.
A communication system for the severely dysarthric speaker with an intact language system.

Two severely dysarthric speakers who had previously spelled entire messages oh an alphabet board were taught a system in which they pointed to the first letter of each word as they spoke. Rate and ...
WRF-Chem model estimates of equatorial Atlantic Ocean tropospheric ozone increases via June 2006 African biomass burning ozone precursor transport

Long-range horizontal and local vertical transport of biomass burning ozone precursors (i.e. carbon monoxide and nitrogen oxides) from Central Africa are simulated for June 2006. Twenty-kilometer resolution combined meteorological and chemical simulations examine transport pathways, spatial distribution, and quantities of ozone precursors and ozone. Results suggest that due to biomass burning, ozone mixing ratios increase by 28–33 parts per billion by volume in the lower troposphere (850 hecto-Pascals) over the Atlantic Ocean west of Central Africa during June. The inter-hemispheric transport of biomass burning emissions from Central Africa subsides over the Gulf of Guinea with a northward extent of approximately 2–5°N. In the lower troposphere, ozone mixing ratio increases decrease from 28 parts per billion by volume in the southern Gulf of Guinea to 2–3 parts per billion by volume on the Gulf of Guinea Coast. There is middle and upper tropospheric ozone enhancement of 6–12 parts per billion over the Equatorial Atlantic Ocean which is the result of convective detrainment of ozone precursors from deep convection on the Gulf of Guinea Coast followed by transport that propagates around a broad anticyclone. The model ozone produced by biomass burning emissions is less than the observed implying that lightning-induced nitrogen oxide emissions, which are not included in this simulation, are a significant tropospheric ozone source for the eastern Equatorial Atlantic Ocean.
Determinants of growth in non-farm proprietor densities in the US, 1990–2000

The number of non-farm proprietorships in the US has expanded significantly in past decades, but this expansion has not occurred evenly over space. Regression analysis correcting for spatial autocorrelation reveals that proprietors respond rationally to economic incentives. Parameter estimates for variables measuring collateral, age, ethnic mix, government policy, female labor force participation, and natural amenities, each have the expected signs. A few options are available to policymakers for influencing growth in self-employment densities over time.
Exploring Biotic Impacts from Carcinus maenas Predation and Didemnum vexillum Epibiosis on Mytilus edulis in the Gulf of Maine

Abstract Mytilus edulis (Blue Mussel) is an ecologically important species in the Gulf of Maine. However, many introduced species that have a direct negative impact on the Blue Mussel have entered this system, some as predators (e.g., Carcinus maenas [Green Crab]) and others as aggressive epibionts (e.g., Didemnum vexillum [Carpet Sea Squirt]). Didemnum vexillum has been increasing in abundance throughout the Gulf for the past 10 years and form large mat-like growths on mussel beds, covering individual mussels completely. The first part of our study used a predator-exclusion experiment to determine the impact of predators on the plantigrade stage of the Blue Mussel life cycle. During this stage, no epibiosis occurs due to a protective periostracum layer on the mussel shell. The second part of our study used laboratory trials to assess how overgrowth by D.vexillum impacts predator choice, handling time, and consumption of mussels. There were a significantly greater number of Blue Mussel plantigrades on exc...
Basin and Range rifting in northern Nevada: Clues from a mid-Miocene rift and its subsequent offsets

A linear rift composed of dike swarms and graben-filling volcanic rocks marks the inception of Basin and Range rifting in northern Nevada 17 to 14 m.y. ago. This mid-Miocene rift, with its associated aeromagnetic anomaly, indicates S68/sup 0/W-N68/sup 0/E (+-5/sup 0/) extension. A small strike-slip (transform) fault at Sawtooth dike, one short element of the rift, confirms the mid-Miocene extension direction. The present extension, based on data throughout the Basin and Range province, is N65/sup 0/W-S65/sup 0/E (+-20/sup 0/), which is consistent with younger fault offsets of the rift. In the Sawtooth dike region this 45/sup 0/ change in direction of extension took place between 15 and 6 m.y. B.P. The Nevada rift is thought to be a part of a linear rift zone roughly 700 km long, which includes feeder dikes of Columbia River basalts and the mid-Miocene location of the Yellowstone hot spot. Extension in this zone was probably perpendicular to a then-active trench along the western plate margin. The clockwise change in extension direction is consistent with a superposition of right-lateral shear along the plate margin when the San Andreas fault was activated.
Modernizing the net present value model

Abstract Accounting courses typically emphasize discrete rather than the more realistic continuous discounting and compounding approaches for computing net present values, assume that the reinvestment rate is also the same as the discount rate, and ignore intermediate net present values which can alter the capital budgeting decision. This note presents different techniques for computing net present values by using continuous discounting combined with terminal values. In addition, a bailout payback technique contrasting a “conservative” and “liberal” approach to computing intermediate net present values is presented.
OBSERVATION OF DYNAMIC E2 MIXING VIA KAONIC X-RAY INTENSITIES

Abstract We have observed a nuclear resonance effect between a kaonic atom and a nuclear transition in 98 Mo. Our measurement gave 98 Mo (n=6→5) 92 Mo (n=6→5) = 0.16 ± 0.16 instead of the no-mixing value of 1. Dynamic E2 mixing caused kaons to be strongly absorbed from the 98 Mo atomic state n =6, l =5 in agreement with theoretical predictions.
Wounds incurred in routine cell culture prolong the duration of the life cycle ofAcetabularia acetabulum and require K+ to heal

We have examined the pressure-wound healing response inAcetabularia acetabulum (L.) Silva (Chlorophyta). Commonly incurred in routine cell culture, these wounds induce disruption of the vacuole and translocation of the cytoplasm away from the wound site. Daily wounding of individual cells retarded cytoplasmic healing over time, but had no effect on the rate of membrane healing. The position of the wound along the cell stalk also affected the ability of the cell to heal: cells wounded near the rhizoid healed at least 1.9 times more slowly and were only half as likely to achieve reproduction as were cells wounded either near the apex or at mid-stalk. The 50% mortality of cells wounded at the rhizoid suggests the existence of a physical structure near the primary nucleus which is important to cell viability. The impact of wounding on reproductive potential and time to heal differed with the phase of cell development: juvenile and early adult cells healed 2–2.5 times more quickly but were less likely to achieve reproduction than late adult or reproductive cells. Growth at very high population densities (2.5 cells/ml) impaired the ability of the cells to heal. Growth of cells in seawater containing a range of potassium concentrations revealed that healing depends on potassium and is optimal at a concentration of — 1.51ogM potassium.
Comparative study of the sealing ability of light-cured versus chemically cured materials placed into furcation perforations

Two light-cured materials, Vitrebond and Prisma VLC Dycal, were compared with two chemically cured materials, Ketac Fil and Dycal, for ability to seal furcation perforations. Access openings and furcation perforations were prepared in 60 teeth and randomly divided into four equal groups. Furcation perforations were repaired with each of the tested materials, and the access openings were filled with composite resin. After teeth were immersed in 2% erythrocin B dye solution for 10 days, they were sectioned longitudinally and dye penetration was measured. The light-cured materials allowed statistically significant less dye leakage than did the chemically cured materials.
Basic studies of ductile failure processes and implications for fracture prediction

Fracture of ductile materials has frequently been observed to result from the nucleation, growth and coalescence of microscopic voids. Experimental and analytical studies have shown that both the stress constraint factor and the effective plastic strain play a significant role in the ductile failure process. Experimental results also suggest that these two param- eters are not independent of each other at failure initiation. In this study, a methodology for characterizing the effect of stress constraint Am (which is defined to be the ratio of the mean stress and the effective stress Am = σ m/σ e) on ductile failure is proposed. This methodology is based on experimental evidence that shows the effective plastic strain at failure initiation has a one-to-one relationship with stress constraint. Numerical analyses based on plane strain and three-dimensional unit-cell models have been carried out to investigate failure initiation of the unit cell under different constraint conditions. Results from the numerical studies indicate (a) for each void volume fraction, there exists a local failure locus in terms of mesoscopic quantities, σ m and σ e, that adequately predict incipi- ent local micro-void link-up, (b) the results are fully consistent with a failure criterion that maximizes mesoscopic effective stress for a constant level of stress constraint Am, (c) for high to moderate constraint Am, the link-up envelope values for σ m and σ e are consistent with limit load conditions where the critical principal stress σ 1c corresponds to the maxi- mum principal stress in the loading history and (d) for low constraint, the link-up envelope values for σ m and σ e correspond to link-up conditions having high levels of plastic strain and a principal stress σ 1 that is lower than the maximum value for this loading history. Thus, the results suggest that a two-parameter ductile fracture criterion is plausible, such as critical crack opening displacement (COD) and stress constraint Am, for predicting the process of stable tearing in materials undergoing ductile void growth during the fracture process.
Regulation of μ-opioid receptor in neural cells by extracellular sodium

SH-SY5Y neural cells expressing μ- and δ-opi-oid receptors were maintained viable in isotonic, sodium-free buffer in vitro. Intracellular sodium levels were manipulated by various methods, and ligand binding to intact cells was studied. In physiological buffer containing 118 mM sodium, [3H]Tyr-D-Ala-Gly-(Me)Phe-Gly-ol ([ 3 H]-DAMGO) and [ 3 H]naltrexone bound to μ receptor with K D values of 3.1 and 0.32 nM and B max values of 94 and 264 fmol/mg of protein, respectively. Replacement of sodium by choline decreased the affinity of the antagonist and increased B max for [ 3 H]DAMGO, without significantly affecting the other corresponding binding parameters. Depolarizing concentrations of KCI (34 mM) in physiological buffer decreased the intracellular sodium levels by 67%, but this did not decrease the [ 3 H]DAMGO binding to the cells. Incubation of cells with monensin and ouabain increased the intracellular sodium levels dramatically (from 78 to 250 and 300 nmol/mg, respectively), with no changes in agonist binding parameters. Ethylisopropylamiloride inhibited [ 3 H]DAMGO and [ 3 H]naloxone binding to intact cells with EC 50 values of 24 and 3,600 nM, respectively. Adenylyl cyclase activities measured in intact cells, at different concentrations of sodium, showed the physiological significance of this ion in signal transduction. Potency of DAMGO in inhibiting the forskolin-stimulated adenylyl cyclase activity was significantly higher at lower concentrations of sodium. However, inhibition reached the maximal level only at 50 mM sodium, and typical sigmoidal dose-response curves were obtained only in the presence of 118 mM sodium. Furthermore, even at low or high intracellular sodium levels, DAMGO inhibition of cyclic AMP levels was normal. These results support a role for extracellular sodium in regulating not only the ligand interactions with the receptor, but also the signal transduction through the μ receptor.
Sensitization to the Psychosis-Inducing Effects of Cocaine Compared with Measures of Cocaine Craving and Cue Reactivity

A previous study has suggested that sensitization to the psychosis-inducing effects of cocaine may be a marker of vulnerability to relapse in cocaine addiction. In this report, cocaine-dependent subjects participating in a study on naturally occurring and cue-induced cocaine craving were interviewed about prior experience of cocaine-induced psychosis and the degree to which this effect had become more frequent or severe or had occurred at lower cumulative doses. Sensitization to cocaine-induced psychosis was negatively correlated with baseline measures of drug dependence severity and indices of cocaine craving over the preceding 24 hours but not with measures of cocaine cue reactivity.