cssi/SciSciGPT-SciSciNet huggingface dataset:
Dominant environmental factors in wetland plant communities invaded by Phragmites australis in East Harbor, Ohio, USA.

Elevation, standing crop, disturbance and soil fertility often emerge from studies of freshwater plant communities as the dominant environmental factors determining both species richness and species composition. Few studies in North America have investigated the relationship between these factors and species abundance (standing crop) and species composition in the context of invasion by Phragmites australis. This study explores the influence of key abiotic and biotic variables on species abundance and composition across three Lake Erie wetlands differing in hydrology and Phragmites abundance in East Harbor, Ohio, USA. Standing crop for 92 species was related to standard sediment analyses, wave exposure, distance to shoreline, elevation, light interference, species density, and Phragmites standing crop in each of 95 1 × 1 m quadrats by using canonical correspondence analysis (CCA). Elevation (Axis I) and Phragmites standing␣crop-soil fertility (Axis II) explained 35.7 and 26.2%, respectively, of the variation in the species–environment relationships. Wave exposure was not a primary component of the first four canonical axes. Axis I was instrumental in describing species composition, separating wet meadow species from marsh species. Axis II was inversely related to species density for both wet meadow and marsh species. These findings generally support prevailing models describing the distribution of wetland plants along environmental gradients. Two discrepancies were noted, however: (1) species density was highest in the most sheltered sites and (2) wave exposure was directly associated with Phragmites standing crop-soil fertility gradient. The structural integrity of Phragmites stems, topographic heterogeneity and differential responses to anthropogenic disturbance may contribute to departure from prevailing multivariate models. This information has direct implications for local and regional wetland managers.
What can be learned from open direct comparative trials in multiple sclerosis

Randomised, placebo-controlled, double-blind clinical trials are considered the "gold standard" for clinical research. A corollary of this is that data from observational open- label studies are viewed as having less validity, and as not providing accurate estimates of treatment effects. However, a number of systematic reviews have shown that well- designed observational studies are quantitatively or qualitatively similar to those measured in randomised controlled trials. Moreover, these observational studies performed under standard conditions of care provide useful reassurance that the findings of randomised controlled trials can be considered as broadly representative of the population at risk. Several such observational studies have been performed in multiple sclerosis in order to compare the effectiveness and tolerability of the different disease-modifying therapies available for the treatment of relapsing remitting disease. One of these was a prospective study conducted in 156 patients that compared the effects of high-dose interferon-beta and glatiramer acetate. This study indicated that the two treatments had similar efficacy on all measures evaluated. The effect sizes observed were very comparable to those observed in the pivotal trials of these two agents. This study predates by a decade a much larger randomised study which also failed to demonstrate a difference between the efficacy of high-dose interferon-beta and that of glatiramer acetate. Observational studies such as this can thus provide useful and reliable information on treatment effects and can be used for preliminary hypothesis testing at a fraction of the cost and constraints of pivotal trials. In the context of the increasing difficulty and expense of conducting randomised, placebo-controlled trials in multiple sclerosis, comparative studies using an open-label design or a rater-blinded design are likely to be increasingly employed in comparing existing and future therapies.
Surface Wave Radiation from a Thick, Semi-Infinite Plane with a Reactive Surface

The idealized surface wave radiator considered here is a thick, semi-infinite plane with a reactive surface. The scattered field is found when symmetrical and unsymmetrical surface waves are radiated at the termination of the plane. Since there are semi-infinite boundary conditions, the Wiener-Hopf technique is used for finding equations describing the scattered field. These equations contain a series of unknown constants which require numerical solution. Field patterns are plotted for different plane thicknesses and surface reactances with even excitation. The scattering of a plane wave by a thick, reactive plane is also discussed briefly.
Potential benefits of the cognitive perspective: expanding entrepreneurship's array of conceptual tools

Abstract Entrepreneurship is a highly complex process influenced by an enormous range of variables. In view of these facts, it seems reasonable to suggest that entrepreneurship, as a field, can benefit greatly from expanding the array of conceptual tools at its disposal. The cognitive perspective provides a potentially rich source of such tools. Consistent with this reasoning, the papers in this special issue focus on concepts, theories, and findings in cognitive science that have not yet been “imported” by entrepreneurship researchers, but which may prove helpful in enhancing our basic understanding of the entrepreneurial process.
Detection of Yersinia pestis using branched DNA.

In contrast to target amplification methods, e.g. polymerase chain reaction, the branched DNA (bDNA) signal amplification method quantitates target nucleic acid at physiological levels, involving a series of hybridization reactions without thermal cycling. In this report, we describe a modification of the bDNA assay in which a > preamplifier oligonucleotide (206 mer) is used in concert with ELISA and light addressable potentiometric sensor (LAPS) formats to detect the plasminogen activator (pla) gene of Yersinia pestis, the etiological agent of plague. Pla is encoded by a 9.6-kb plasmid pPCP, which is essential for virulence. The detection limit of the bDNA-ELISA and LAPS assays is less than 10 000 and 1000 molecules of Y. pestis plasmid DNA, respectively.
Surface enhanced raman scattering at electrodes: A status report

Progress during the first decade of surface enhanced Raman scattering (SERS) is briefly reviewed. Examples of SERS of adsorbed H2O. OH−, and H3O+ on Ag electrodes which have undergone an oxidation-reduction cycle (ORC) are discussed in some detail in order to bring out the unique and general features of SERS in an electrochemical system. Experimental techniques to further enhance the SERS signal, as well as to decrease the SERS signal after an ORC, are reviewed as such results can provide clues to possible surface enhancement mechanisms. The two enhancement mechanisms (electromagnetic and charge transfer) are presented in a unified but simplistic picture which involves the nearly free s,p-electron band and the more localized d-electron band for the noble metals (Ag, Cu, and Au). The role of the intraband transitions in the electromagnetic and charge transfer enhancement processes is discussed in terms of the wave-vector uncertainty associated with the Raman dipole located on or near the surface and with the localized metal clusters which are often referred to as SERS-active sites. Several examples are cited in which experiments initially designed to prove the presence of one enhancement mechanism end up proving the existence of both enhancement mechanisms. Progress expected in the SERS field during the next decade is also suggested.
A classification of h-connected 2-complexes

Abstract The finite regular 2-complexes that have the property that every finite sheeted cover has total space homeomorphic to the base space are classified.
Origin of rhyolite by crustal melting and the nature of parental magmas in the Oligocene Conejos Formation, San Juan Mountains, Colorado, USA

Abstract Four closely spaced volcanoes (Summer Coon; Twin Mountains; Del Norte; Carnero Creek) form the east-central cluster of Conejos volcanic centers. These Conejos rocks range from high-K basaltic andesite to rhyolite, with andesite volumetrically the most abundant. Summer Coon and Twin Mountains are composite volcanoes. The Del Norte and Carnero Creek volcanoes are deeply eroded dacite shields. Rhyolite (10% of our Conejos analyses but a much smaller percentage by volume) is only known from Summer Coon and Twin Mountains volcanoes, although high-SiO2 dacite occurs in the Del Norte volcano. The younger Hinsdale Formation contains a related series ranging from transitional basalt to high-K andesite; we use Hinsdale Formation analyses to represent Conejos parental magmas. Conejos and Hinsdale magmas evolved through AFC processes: Basalt, after interacting with lower crust, assimilated low K/Rb crust, similar in some ways to Taylor and McLennan (Taylor, S.R., and McLennan, S.M., 1985, The continental crust: its composition and evolution. Oxford, Blackwell Scientific.) model upper crust; main series basaltic andesite fractionated to high-K andesite; rhyolite was produced by melting of high K/Ba upper crustal rocks similar to granite gneiss known from inclusions and basement outcrops. Some rhyolite may have been back-mixed into fractionating andesite and dacite. Field evidence for assimilation includes sanidinite-facies, partially melted, gneiss blocks up to 1 m in diameter. Temperature estimates (1100–900 ° C) from two-pyroxene equilibria are consistent with this interpretation, as are the sparsely porphyritic nature of the most-evolved rhyolites and the absence of phenocrystic alkali feldspar. Our study supports the conclusions of previous workers on AFC processes in similar, but generally more mafic, Conejos magmas of the southeastern San Juan Mountains. Our results, however, emphasize the importance of crustal melting in the generation of Conejos rhyolite. We further speculate that Conejos magmatism, and the San Juan Volcanic Field (SJVF) in general, may represent an early phase of Rio Grande rift magmatism, the orogenic geochemical signature of the series having been generated through multi-level and extensive assimilation of varied Precambrian orogenic and anorogenic rocks.
Stability indicating validated HPLC method for quantification of levothyroxine with eight degradation peaks in the presence of excipients

A simple, sensitive, accurate, and robust stability indicating analytical method is presented for identification, separation, and quantitation of l-thyroxine and eight degradation impurities with an internal standard. The method was used in the presence of commonly used formulation excipients such as butylated hydroxyanisole, povidone, crospovidone, croscarmellose sodium, mannitol, sucrose, acacia, lactose monohydrate, confectionary sugar, microcrystalline cellulose, sodium laurel sulfate, magnesium stearate, talc, and silicon dioxide. The two active thyroid hormones: 3,3',5,5'-tetra-iodo-l-thyronine (l-thyroxine-T4) and 3,3',5-tri-iodo-l-thyronine (T3) and degradation products including di-iodothyronine (T2), thyronine (T0), tyrosine (Tyr), di-iodotyrosine (DIT), mono-iodotyrosine (MIT), 3,3',5,5'-tetra-iodothyroacetic acid (T4AA) and 3,3',5-tri-iodothyroacetic acid (T3AA) were assayed by the current method. The separation of l-thyroxine and eight metabolites along with theophylline (internal standard) was achieved using a C18 column (25 degrees C) with a mobile phase of trifluoroacetic acid (0.1%, v/v, pH 3)-acetonitrile in gradient elution at 0.8 ml/min at 223 nm. The sample diluent was 0.01 M methanolic NaOH. Method was validated according to FDA, USP, and ICH guidelines for inter-day accuracy, precision, and robustness after checking performance with system suitability. Tyr (4.97 min), theophylline (9.09 min), MIT (9.55 min), DIT (11.37 min), T0 (11.63 min), T2 (14.47 min), T3 (16.29 min), T4 (17.60 min), T3AA (22.71 min), and T4AA (24.83 min) separated in a single chromatographic run. Linear relationship (r2>0.99) was observed between the peak area ratio and the concentrations for all of the compounds within the range of 2-20 microg/ml. The total time for analysis, equilibration and recovery was 40 min. The method was shown to separate well from commonly employed formulation excipients. Accuracy ranged from 95 to 105% for T4 and 90 to 110% for all other compounds. Precision was <2% for all the compounds. The method was found to be robust with minor changes in injection volume, flow rate, column temperature, and gradient ratio. Validation results indicated that the method shows satisfactory linearity, precision, accuracy, and ruggedness and also stress degradation studies indicated that the method can be used as stability indicating method for l-thyroxine in the presence of excipients.
Biomechanics of stair walking and jumping.

Abstract Physical activities such as stair walking and jumping result in increased dynamic loading on the human musculoskeletal system. Use of light weight, externally attached accelerometers allows for in‐vivo monitoring of the shock waves invading the human musculoskeletal system during those activities. Shock waves were measured in four subjects performing stair walking up and down, jumping in place and jumping off a fixed elevation. The results obtained show that walking down a staircase induced shock waves with amplitude of 130% of that observed in walking up stairs and 250% of the shock waves experienced in level gait. The jumping test revealed levels of the shock waves nearly eight times higher than that in level walking. It was also shown that the shock waves invading the human musculoskeletal system may be generated not only by the heel strike, but also by the metatarsal strike. To moderate the risk of degenerative joint disorders four types of viscoelastic insoles were utilized to reduce the imp...
Augmented Calcium Currents in Mesenteric Artery Branches of the Spontaneously Hypertensive Rat

Abstract The greater efficacy of organic channel blockers in lowering peripheral resistance and blood pressure in hypertensive subjects has been suggested to be the result of augmented calcium influx through L-type calcium channels in arterial smooth muscle. These studies were performed to determine whether differences exist in voltage-gated calcium channels of mesenteric artery branches from 20-week-old spontaneously hypertensive rats (SHR) compared with Wistar-Kyoto rats (WKY). Single myocytes were acutely isolated by collagenase and elastase treatment and studied at room temperature (≈20°C) with the use of whole-cell, patch-clamp methods. Maximum values of calcium current measured at 0 mV from a holding potential of −90 mV were larger in SHR myocytes (105±11 versus 149±15 pA). Values of cell capacitance were smaller in SHR (29.5±1.3 pF) compared with WKY (35.0±1.5 pF) myocytes. Cell capacitance measures surface membrane area and, when used to normalize calcium currents, magnified the difference between WKY and SHR to approximately 47%. There was a larger percent reduction of maximum calcium current at holding potentials of −60 and −40 mV in SHR compared with WKY myocytes: for example, at −40 mV calcium current was reduced from values at −90 mV by −73±2% in SHR compared with −58±1% in WKY. When divided by the maximum current for each holding potential, the voltage dependence of normalized calcium currents for the two groups was completely superimposed. Difference currents were calculated by subtracting currents measured from holding potentials of −90 and −40 mV. The voltage dependence of difference currents was identical to that of the calcium currents measured from the two values of holding potential. The results of this study indicate that (1) only L-type calcium currents are present in freshly isolated mesenteric artery myocytes from 20-week-old WKY and SHR, and (2) these currents are larger in SHR. These differences in calcium currents may contribute to augmented contractile responses that have been previously reported.
Recurrent Population II X-ray transients — similarities to SU UMa cataclysmic variables

Quasi-periodic outburst activity is not uncommon among Population II X-ray binaries. This paper reports observations of such activity in several sources, made by the Vela 5B X-ray monitor. Typical periods are 1/2–2 years with an r.m.s. scatter in interval time of ∼10%. This activity is reminiscent of the superoutburst cycles of SU UMa CV's with respect to mean recurrence times, the variation of the recurrence times about their mean, and the total mass transferred during outburst. However, the outbursts in the X-ray sources have a substantially longer duration, 50–100 days instead of ∼10 days. I suggest that SU UMa and X-ray transient outbursts may be caused by similar mass-transfer instabilities.
Serological detection of multiple retroviral infections in cattle: Bovine leukemia virus, bovine syncytial virus and bovine visna virus

Abstract Individual experimental animals used in our studies on bovine leukemia virus (BLV) are routinely screened for the presence of antibodies to the three bovine lymphotropic retroviruses. We utilized these screening methods to examine frozen sera from eight herds for antibodies to BLV, bovine visna virus (BVV) and bovine syncytial virus (BSV). Serum samples from 235 animals in four dairy and four beef herds were analyzed. Detection methods used included indirect fluorescent antibody tests of virus-infected cell cultures (BLV, BSV, BVV) and agar gel immunodiffusion (BLV). Sera from the BLV-infected animals in the dairy herds showed the highest single (50%, 49 97 ) and multiple (30%, 29 97 ) infections compared with 5% ( 7 138 ) and 1 138 ), respectively in the beef herds. Single BVV infections were not detected in the dairy herds, but 11% ( 11 97 ) of the sera contained antibodies to BVV plus BLV or BSV. Five sera from beef cattle had antibodies only to BVV and four were obtained from one herd. Only one beef serum of the 138 tested demonstrated multiple antibodies (BLV, BVV).
Clostridial Bacteremia During the First Year of Life: an Analysis of 53 Patients Including Two New Cases

Anaerobic bacteremias, and more specifically clostridial bacteremias, appear to be quite uncommon in infants. This report includes a detailed analysis of 53 infant pediatric patients with clostridial bacteremia, including 51 previously reported cases and two new cases. There were 54 clostridial cultures from these 53 patients;Clostridium perfringens (50%) and C. butyricum (25.9%) together accounted for nearly 76% of clostridia isolated. Only eight of the 54 blood cultures (14.8%) were also positive for one or more non-clostridial bacteria. Patient age, available for 43 of 53 infants, ranged from 1 to 182 days (mean 21 days, median 5 days). Among patients for whom information on each of multiple clinical parameters was available, the following were identified: male to female ratio 2.0; presence of underlying gastrointestinal disease (usually necrotizing enterocolitis) seen in 66% of infants; administration of antibiotic therapy in 80.4%; and patient survival of 56.9%. No statistically significant differences (P<0.05) were noted when survival was assessed against: gender, age at onset of bacteremia (18 days or less vs. greater than 18 days), and birth weight (less than 1500 g vs. greater than 1500 g). The presence of underlying gastrointestinal disease did have a statistically significant negative impact upon survival (P<0.025). Unexpectedly, the use of antibiotic therapy was associated with a statistically significant negative impact upon survival, which disappeared when the 14 C. butyricum cases were dropped from statistical consideration. The significance of clostridial bacteremia during infancy and its associated antibiotic therapy are reviewed and summarized in this report.
Relative timing of crustal plateau magmatism and tectonism at Tellus Regio, Venus

Crustal plateaus, subcontinent-sized regions of thickened crust that stand 1–4 km above surrounding low-lying plains, define a major physiographic province of Venus. Thus their mode of emplacement plays a fundamental part in the evolution of the entire planet. Local topographic lows up to several hundred kilometers across filled with radar-dark volcanic flows, termed intratessera floodlava basins (ITBs), are common within crustal plateaus. ITBs record abundant crustal plateau volcanism and have implications for crustal plateau emplacement and evolution. We ask the fundamental question: Did ITBs develop before, during, or after crustal plateau development? To address this question, we mapped in detail the geology a particular ITB in Tellus Regio to determine temporal relationships between ITB volcanic flows and local crustal plateau tectonism. Mechanical arguments and crosscutting relationships indicate that ITB volcanism occurred during crustal plateau formation. Extending the timing relationships resolved at this basin, we suggest that ITB magmatism played a major role in crustal plateau genesis. The geologic history discerned is consistent with the upwelling model for crustal plateau evolution in which early surface extension and volcanism would be expected in a hotspot environment. Conversely, early widespread extension and volcanism would not be expected if crustal plateaus formed above a mantle downwelling because (1) predicted horizontal and radial convergence would obstruct early surface extension and (2) lower than normal geothermal gradients would impede, rather than enhance, volcanism.
Role of renal metabolism in risk to toxic chemicals

The kidneys are capable of carrying out extensive oxidation, reduction, hydrolysis, and conjugation reactions. Renal cortex has high activities of cytochrome P450 and glutathione (GSH) S-transferas...
Reliability Estimation for Time-Dependent Problems Using a Niching Genetic Algorithm

A reliability analysis method is presented for time-dependent systems under uncertainty. The system response is modeled as a parameterized random process. A double-loop optimization algorithm is used. The inner loop calculates the maximum response in time using a global-local search method, and transforms a time-dependent problem into a time-independent one. The outer loop calculates multiple most probable points (MPPs) which are commonly encountered in vibration problems. The dominant MPPs with the highest contribution to the probability of failure are identified. A niching genetic algorithm is used because of its ability to simultaneously identify multiple solutions. All potential MPPs are initially identified approximately and their location is efficiently refined using a gradient-based optimizer with local metamodels. Among all MPPs, the significant ones are identified using a correlation analysis. Approximate limit states are built at the identified MPPs, and the system failure probability is estimated using bi-modal bounds. The vibration response of a cantilever plate under random oscillating pressure load and a point load illustrates the proposed method. The finite-element model is used to calculate the response.Copyright © 2007 by ASME
Spatial and temporal variability of SeaWiFS chlorophyll a distributions west of the Antarctic Peninsula: Implications for krill production

Abstract SeaWiFS chlorophyll a distributions between 1997 and 2004 were investigated in relation to sea-ice dynamics for waters west of the Antarctic Peninsula (55–75°S, 50–80°W) in order to better understand the reproductive patterns and recruitment success of the Antarctic krill, Euphausia superba . Climatology patterns showed that the Bellingshausen Sea and Marguerite Bay region usually had higher chlorophyll a concentrations, which persisted throughout austral spring and summer, compared with more northern regions along the Antarctic Peninsula and the western Scotia Sea. These predictable and long-lasting phytoplankton accumulations could provide krill with the food levels required for successful reproduction and larval survival. Unusually high krill reproduction in 2000/2001 was coincident with above-average chlorophyll a concentrations throughout most of the study area and resulted in the largest juvenile recruitment (in 2001/2002) since 1981. High larval densities (up to 132 ind m −3 ) at the shelf break along the Antarctic Peninsula may have resulted, in part, from krill spawning in the Bellingshausen Sea. In general, ice-edge blooms were only a significant feature in the southern sectors of our study area, particularly in the Bellingshausen Sea and, thus, may not support krill reproduction in the northern Peninsula region as previously believed. Instead, phytoplankton blooms during spring in the northern region appeared to be governed by shelf-break processes, such as upwelling of iron-rich deep water. Interannual differences in sea ice also probably contributed to the variability in larval krill abundances observed in Marguerite Bay. Sea ice melted early in 2000/2001, allowing elevated phytoplankton blooms to develop. In contrast, sea ice persisted throughout spring and summer 2001/2002 limiting phytoplankton accumulation, particularly in southern Marguerite Bay. Thus, the early and extended availability of elevated chlorophyll a concentrations during spring and summer 2000/2001, particularly in the vicinity of Marguerite Bay and to the south in the Bellingshausen Sea, as well as reduced sea ice in coastal areas, likely supported the unusually high densities of larval krill observed during fall in waters west of the Antarctic Peninsula.
Origin of radiation emission induced by fusion reaction products

Abstract The excitation of collective modes at the harmonics of the cyclotron frequency of the 4 He population produced in D-T fusing plasmas has been predicted by a detailed analysis that includes the important effects of the confinement geometry and confirmed by the first experiments on D-T plasmas. These modes are shown to be spatially localized in a narrow layer centered around a surface near the edge of the plasma column that is consistent with that inferred from the value of the magnetic field corresponding to the observed cyclotron frequency. The radial width of the layer is compatible with the relatively narrow width of the peaks of radiation emission. The outermost edge of the plasma column is reached by the α-particles having magnetically trapped orbits of relatively large amplitude and a distribution anisotropy in velocity space of the type needed to drive the considered modes unstable. The relevance of the proposed interpretation to both analyze and interfere with the α-particle distribution is pointed out.
Wildlife responses to thinning and burning treatments in southwestern conifer forests: A meta-analysis

After a century of fire suppression, conifer forests in the western United States have dramatically departed from conditions that existed prior to Euro-American settlement, with heavy fuel loads and an increased incidence of wildfire. To reduce this threat and improve overall forest health, land managers are designing landscape-scale treatments that strategically locate thinning and burning treatments to disrupt fuel continuity, allowing managed wildfires to burn the remaining area. A necessary step in designing and evaluating these treatments is understanding their ecological effects on wildlife. We used meta-analysis to compare effects of small-diameter removal (thinnings and shelterwoods) and burning treatments, selective harvesting, overstory removal (including clearcutting), and wildfire on wildlife species in southwestern conifer forests. We hypothesized that small-diameter removal and burning treatments would have minimal effects on wildlife compared to other treatments. We found 33 studies that met our criteria by (1) comparing density or reproductive output for wildlife species, (2) using forest management or wildfire treatments, (3) implementing control-impact or before-after control-impact design using unmanaged stands as controls, and (4) occurring in Arizona or New Mexico ponderosa pine (Pinus ponderosa) or mixed conifer (Abies/Picea/Pinus) forest. The 22 studies suitable for meta-analysis occurred ≤20 years post-treatment on sites <400 ha. Small-diameter harvest and burning treatments had positive effects but thin/burn and selective harvest treatments had no detectable effect on most small mammals and passerine bird species reported in studies; overstory removal and wildfire resulted in an overall negative response. We examined foraging guild responses to treatments; ground-foraging birds and rodents had no strong response. Aerial-, tree-, and bole-foraging birds had positive or neutral responses to the small-diameter removal and burning treatments, but negative responses to overstory removal and wildfire. Small-diameter removal and burning treatments as currently being implemented in the Southwest do not negatively impact most of the wildlife species in the studies we examined in the short-term (≤10 years). We believe a combination of treatments in a patchy arrangement across the landscape will result in the highest diversity and density. We recommend that managers implement thinning and burning treatments, but that future research efforts focus on long-term responses of species at larger spatial scales, use reproductive output as a more informative response variable, and target species for which there is a paucity of data.
Pancreatic cancer screening: identifying premalignant disease

Evaluation of: Canto MI, Goggins M, Yeo CJ et al.: Screening for pancreatic neoplasia in high-risk individuals: an EUS-based approach. Clin. Gastroenterol. Hepatol. 2(7), 606–621 (2004). Endoscopic ultrasound was utilized in the screening of individuals at high risk for pancreatic cancer. Patients with abnormal endoscopic ultrasound findings were further evaluated with fine-needle biopsy, endoscopic retrograde cholangipancreatography, and computerized tomography scanning. A total of 38 patients were enrolled in this prospective screening program. A total of seven patients were identified with suspicious neoplastic lesions and underwent pancreatic resection. No significant morbidity or mortality resulted from the screening tests or subsequent intervention including surgery. Surgical pathology revealed two neoplastic masses (invasive carcinoma and intraductal pancreatic mucinous neoplasm), three pancreatic intraepithelial neoplastic lesions, and two benign lesions for a diagnostic yield of 13.1% (five of 38...
Abdominal aortic aneurysms: cost-effectiveness of elective endovascular and open surgical repair.

PURPOSE: To evaluate the cost-effectiveness of elective endovascular and open surgical repair of infrarenal abdominal aortic aneurysms (AAAs) by taking into account short- and long-term outcomes. MATERIALS AND METHODS: A Markov decision model was developed to evaluate quality-adjusted life-years (QALYs) and lifetime costs of endovascular and open surgical repair. The incremental cost-effectiveness ratio (CER) was calculated for endovascular repair relative to open surgery in a cohort of 70-year-old men with an AAA between 5 and 6 cm in diameter. Clinically effectiveness data were derived from the literature. Cost data were derived from Medicare reimbursement rates, the hospital database, and the literature. One- and multiple-way sensitivity analyses were performed on uncertain model parameters. Costs were converted to year 2000 U.S. dollars; future costs and outcomes were discounted at 3%. RESULTS: The incremental CER of endovascular repair was $9,905 per QALY. QALYs and lifetime costs were higher for end...
Planned versus actual outcomes as a result of animal feeding operation decisions for managing phosphorus

The paper explores how decisions made on animal feeding operations (AFOs) influence the management of manure and phosphorus. Variability among these decisions from operation to operation and from field to field can influence the validity of nutrient loss risk assessments. These assessments are based on assumptions that the decision outcomes regarding manure distribution will occur as they are planned. The discrepancy between planned versus actual outcomes in phosphorus management was explored on nine AFOs managing a contiguous set of 210 fields in south-central Wisconsin. A total of 2611 soil samples were collected and multiple interviews conducted to assign phosphorus index (PI) ratings to the fields. Spearman's rank correlation coefficients (r(S)) indicated that PI ratings were less sensitive to soil test phosphorus (STP) levels (r(S) = 0.378), universal soil loss equation (USLE) (r(S) = 0.261), ratings for chemical fertilizer application (r(S) = 0.185), and runoff class (r(S) = -0.089), and more sensitive to ratings for manure application (r(S) = 0.854). One-way ANOVA indicated that mean field STP levels were more homogenous than field PI ratings between AFOs. Kolmogorov-Smirnov (K-S) tests displayed several nonsignificant comparisons for cumulative distribution functions, S(x), of mean STP levels on AFO fields. On the other hand, the K-S tests of S(x) for PI ratings indicated that the majority of these S(x) functions were significantly different between AFOs at or greater than the 0.05 significance level. Interviews suggested multiple reasons for divergence between planned and actual outcomes in managing phosphorus, and that this divergence arises at the strategic, tactical, and operational levels of decision-making.
Monomeric Gallium(III) Compounds Containing Three Different Ligands. Crystal and Molecular Structures of GaMeCl(acac) and GaCl[N(SiMe3)2](acac)

Five monomeric gallium(III) compounds, each containing three different ligands, have been prepared by metathetical and/or ligand redistribution reactions and identified as single compounds in benzene solution and in the solid phase, as appropriate. These compounds include GaRCl(acac) (R = Me, Et, Mes (mesityl, C6H2Me3); acac = 2,4-pentanedionato), GaCl[N(SiMe3)2](acac), and GaMe[N(SiMe3)2](acac). X-ray structural studies of GaMeCl(acac) and GaCl[N(SiMe3)2](acac) confirmed the presence of the three different ligands bonded to gallium in these monomeric molecules. The related derivatives GaMeCl(hfac) and GaMesCl(hfac) (hfac = 1,1,1,5,5,5-hexafluoropentanedionato) were also prepared and characterized, but these compounds slowly decomposed at room temperature.
Age-period-cohort analysis of renal cell carcinoma in United States adults.

Objective To determine the extent to which the year of diagnosis, year of birth, and age at diagnosis influence the incidence trends of kidney cancer in the United States. Methods Cancer registry data from the National Cancer Institute's Surveillance, Epidemiology, and End-Results (SEER) program were obtained for 64,041 patients with kidney cancer diagnosed between 1973 and 2008. Overall and age-specific incidence rates were calculated and adjustments were made for birth cohort and period effects. Results were stratified by race and sex. Age-period-cohort analysis was used to examine the effects of age, year of diagnosis (period), and year of birth (cohort) on incidence trends. Results The overall age-standardized annual incidence per 100,000 increased during the study period (1973 to 2008) by race, from 6.75 (95% confidence interval, 6.18-7.36) to 19.56 (18.85-20.20) among whites, from 5.31 (3.50-7.71) to 25.38 (23.00-27.92) among blacks, and from 5.61 (3.50-8.50) to 13.98 (12.41-15.71) among other races; and by sex, from 9.44 (8.49-10.47) to 26.48 (25.39-27.60) among men and from 4.21 (3.65-4.84) to 13.38 (12.64-14.11) among women. Age-period-cohort analysis revealed a strong influence from period and cohort effects. The 1983 birth cohort, for example, had a 2-fold increase in kidney cancer (incidence rate ratio, 1.93 [1.63-2.25]) compared with the referent 1948 cohort. Conclusion From 1973 to 2008, the incidence rate of kidney cancer increased for each sex and race across all age groups. Age-period-cohort models revealed that period-related factors, although significant, cannot alone account for these unfavorable temporal trends.
Cross-functional analysis of the Microviridae internal scaffolding protein

The assembly of the viral structural proteins into infectious virions is often mediated by scaffolding proteins. These proteins are transiently associated with morphogenetic intermediates but not found in the mature particle. The genes encoding three Microviridae (phiX174, G4 and alpha3) internal scaffolding proteins (B proteins) have been cloned, expressed in vivo and assayed for the ability to complement null mutations of different Microviridae species. Despite divergence as great as 70% in amino acid sequence over the aligned length, cross-complementation was observed, indicating that these proteins are capable of directing the assembly of foreign structural proteins into infectious particles. These results suggest that the Microviridae internal scaffolding proteins may be inherently flexible. There was one condition in which a B protein could not cross-function. The phiX174 B protein cannot productively direct the assembly of the G4 capsid at temperatures above 21 degreesC. Under these conditions, assembly is arrested early in the morphogenetic pathway, before the first B protein mediated reaction. Two G4 mutants, which can productively utilize the phiX174 B protein at elevated temperatures, were isolated. Both mutations confer amino acid substitutions in the viral coat protein but differ in their relative abilities to utilize the foreign scaffolding protein. The more efficient substitution is located in a region where coat-scaffolding interactions have been observed in the atomic structure and may emphasize the importance of interactions in this region.
SCF and correlated level determination of the molecular and vibrational structure of orthosilicic acid, Si (OH)4

Abstract The focus of this investigation was to determine the relevance of electron correlation corrections in predicting the geometry and molecular spectra of model compounds for silicate materials. We have performed a series of ab initio molecular orbital calculations on various isomers of Si(OH)4 at the self-consistent field (SCF) and second-order many-body perturbation theory (MBPT(2)) levels using double-zeta polarized (DZP) quality basis sets. Electron correlation affects both the molecular and vibrational structure of these compounds. The use of a single scaling factor to account for electron correlation and anharmonic effects does not lead to consistent prediction of MBPT(2) properties.
Aging and Primary Relations

After listing all consanguinal and affinal kin, our sample of 800 respondents forty-five and older identified those with whom they felt very close and who among these were confidants. A parallel procedure was used to identify very close friends and confidant friends. These four types (primary relatives, confidant relatives, primary friends, confidant friends) were seen as constituting the primary-group resource of our respondents. Thirty of the 800 individuals lacked primary ties with kin, compared to 118 of 800 without primary ties with friends. While very few of the respondents were without very close ties of any kind, those with extensive primary-group resources were more likely to be women rather than men, younger rather than older, married rather than single, and in high rather than low-status occupations.
Experimental and Computational Studies Indicate Specific Binding of pVHL Protein to Aurora-A Kinase

Overexpression of Aurora-A kinase is commonly detected in many cancers, whereas the von Hippel−Lindau protein (pVHL) is frequently mutated or absent in renal cell carcinoma and is involved in the Ub proteasome complex, an important degradation pathway. In order to establish a link between Aurora-A overexpression and lack of pVHL protein, we hypothesized that pVHL regulates Aurora-A expression through a physical interaction. We present the first evidence, from both biological assays and computational biology techniques, that human pVHL binds strongly to Aurora-A kinase. Extensive molecular modeling, docking, and dynamic simulations demonstrate that the structure of the pVHL protein would allow it to bind to the TPX2 binding region of Aurora-A. In view of Aurora-A’s importance as a therapeutic target for the treatment of cancer, this observation provides novel insights into the Aurora-A/pVHL pathway. In addition, the detailed Aurora-A/pVHL binding structure obtained will be valuable for the design of future...
A quantitative model for bacterial growth and decline

A model for microbial growth is proposed that includes lag, growth and decline phases. The model assumes that germination, repair or lag and the death processes are all first-order. It assumes that growth is inhibited and eventually stopped by an accumulation of toxic metabolites or depletion of a limiting substrate from cell growth and metabolism. Parameters for the model are computed by trial and error using spreadsheet software. Examples of the model fitted to select growth curves are presented. A comparison of the parameters from this model is made with those from the Gompertz equation.
A simple fluorometric assay for the determination of cell numbers

A sensitive fluorometric assay was developed for the enumeration of cells in microtiter plates. This assay is based on the fluorescence enhancement of propidium iodide (PI) upon binding with double-stranded nucleic acids. This fluorochrome is compatible with a wide range of reagents commonly used in the laboratory, thus washing the cells before staining is not necessary. PI, together with Triton-X 100 and EDTA, was added directly to the cell culture. After 16-18 h incubation at room temperature, intensity of fluorescence was determined with a micro-plate fluorometer. This quick and simple method is sensitive for as little as 1.95 x 10(3) mononuclear leukocytes, and provides a linear correlation (r = 0.999) between cell number and fluorescence up to 1 x 10(6) cells. Since PI has a large Stokes shift with excitation wavelength at common visible range and emission wavelength far out in the red region of the spectrum, it allows simultaneous detection of DNA and other fluorescent compounds such as calcein and fluorescein. This assay may prove to be a valuable alternative for cell number determination.
Increases in the phosphorylation of cyclic AMP response element binding protein (CREB) and decreases in the content of calcineurin accompany thermal hyperalgesia following chronic constriction injury in rats.

Abstract Plasticity in the spinal dorsal horn may underlie the development of chronic pain following peripheral nerve injury or inflammation. In this study, we examined whether chronic constriction injury of the sciatic nerve was associated with changes in the immunoreactive content of cyclic AMP response element binding protein (CREB), protein kinase A (PKA), and calcineurin Aα and Aβ in the spinal dorsal horn. In animals exhibiting thermal hyperalgesia as a behavioral sign of neuropathic pain 7 days after loose ligation of the sciatic nerve (chronic constriction injury), there was a significant increase in the content of phosphorylated (activated) CREB (pCREB). In contrast, following the typical disappearance of thermal hyperalgesia 28 days after loose ligation surgery, there were no differences in pCREB content between control and sciatic ligation animals. The increased CREB activation associated with thermal hyperalgesia was accompanied by significant decreases in the content of both calcineurin Aα and Aβ. In contrast, there were no differences in the content of non-phosphorylated CREB, and phosphorylated or non-phosphorylated PKA between control and sciatic ligation animals either 7 or 28 days after surgery. These data established a close association in the expression of thermal hyperalgesia with CREB activation and decreased calcineurin content in the spinal dorsal horn. The data revealed a significant but reversible shift in the manner in which spinal neurons processed sensory information following peripheral nerve injury, and lent further support to the notion that plasticity in the spinal dorsal horn may have contributed to the development of chronic pain.
Detection of osteoporosis by morphological granulometries

Local morphological granulometries are generated by opening an image successively by an increasing family of structuring elements and, at each pixel, keeping an image area count in a fixed-size window about the pixel. After normalization there is at each pixel a probability density, called a `local pattern spectrum,' and the moments of this density are used to classify the pixel according to surrounding texture. The method having been developed for binary images, the present paper applies a gray-scale version of the methodology to detect osteoporosis in magnetic resonance (MR) images of the wrist. Maximum-likelihood classification is used to apply the local-pattern-spectra moment information. Owing to the presence of a continuous intertwined network of bone fibers called trabeculae, when imaged by an MR imaging system a normal region of bone tissue possesses a coarse, grainy texture resulting in characteristic granulometric features. Osteoporosis is a metabolic bone disease typified by a gradual loss of trabecular bone, and this loss is revealed by significant changes in the granulometric features, thereby leading to detection.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Prosper Ménière and his disease.

In 1861, Prosper Meniere presented a paper before the French Academy of Medicine in which he described a series of patients with episodic vertigo and hearing loss. He also mentioned the postmortem examination of a young girl who experienced vertigo after a hemorrhage into the inner ear. Prior to that time, vertigo was thought to be a cerebral symptom similar to epileptic seizures. Meniere pointed out that vertigo frequently had a benign course and that common treatments, such as bleeding, often did more harm than good. He was not attempting to define a disease or syndrome but rather to emphasize that vertigo could originate from damage to the inner ear. Confusion regarding the clinical and pathologic features of Meniere disease persisted well into the 20th century.
General pediatrician's role in high-risk deliveries.

Fortunately, most infants make the transition to extrauterine existence well, even when a number of highrisk factors are present. In those few instances in which the pediatrician and his or her team are called upon to use knowledge, experience, and skill to respond to a delivery room emergency, the need is great. It is the responsibility of pediatricians who attend high-risk deliveries to maintain their skills at the highest level and to promote the education and preparedness of the other team members. The pediatrician must work to assure that every delivery room, regardless of the size of the hospital or the level of care in the nurseries, offers resuscitative and stabilization skills of the highest possible caliber.
Characterization of a ubiquitin-fusion gene from the tobacco hawkmoth, Manduca sexta

A gene encoding a ubiquitin-fusion protein was isolated from a cDNA library made from the intersegmental muscles (ISM) of the moth, Manduca sexta. The predicted amino acid sequence of this fusion protein is highly conserved when compared to the sequence of homologous proteins from diverse species. The Manduca clone encoding this ubiquitin fusion gene hybridized with a single, abundantly expressed transcript in all tissues examined. In the ISM, the transcript was present at high levels, independent of the developmental stage or hormonal treatment of these muscles. Data from other species indicate that ubiquitin-fusion genes participate in ribosome biogenesis.