cssi/SciSciGPT-SciSciNet huggingface dataset:
Comparison of small-intestinal submucosa and expanded polytetrafluoroethylene as a vascular conduit in the presence of gram-positive contamination.

Despite intensive research efforts, the ideal vascular graft has yet to be developed. Mechanical stability, biocompatibility, nonthrombogenicity, infection resistance, and availability are desired characteristics of a vascular bypass graft. Refinements in conduit fabrication have led to improvements in mechanical stability and patency rates of large-diameter vascular grafts in recent years; however, the use of synthetic conduits for small-diameter (<6 mm) arterial reconstruction is complicated by poor long-term patency rates ranging from 40% to 60% at 5 years.1–3 Synthetic conduits are also susceptible to infection, which is a devastating complication of vascular reconstruction. Individualized treatment modalities, including debridement and evacuation of surrounding infection with muscle-flap coverage, long-term antibiotic therapy, and partial graft excision with in situ prosthetic reconstruction, have been described with varying degrees of success.4–6 The most reliable and comprehensive approach to eradicate infection and restore distal perfusion involves total graft excision with extra-anatomic bypass. ePTFE (expanded polytetrafluoroethylene) is a commonly used synthetic conduit. However, ePTFE is susceptible to infection since its microporous structure provides a “safe haven” for bacteria to survive and proliferate. Staphylococcus and mucin-producing Staphylococcus are the most common infecting organisms and result in chronic infection, lack of graft incorporation, pseudoaneurysm formation, leading to potential graft failure and major morbidity. In addition, an excessive neointimal response due to a persistent inflammatory process and a compliance mismatch with the native artery are significant causes of late graft failure. Thus, a readily available conduit that is resistant to bacterial colonization, mechanically stable, and elicits a favorable host response upon implantation would be superior for elective vascular reconstruction. Advances in tissue engineering technology have resulted in the clinical application of a variety of biomaterials. Porcine small-intestinal submucosa (SIS) is an acellular collagen matrix, which provides a scaffold for site-specific host tissue remodeling.7,8 It has been successfully used in herniorrhaphy, chronic wound healing, bladder reconstruction, dural repair, and as a tendon and ligament substitute.9–14 It has previously been shown that, when used as a vascular patch, SIS is resistant to infection following fecal contamination and is remodeled into host artery.15 In the present study, we constructed a small-diameter conduit of SIS and compared it to ePTFE in the presence of Gram-positive contamination to evaluate infection resistance, incorporation and remodeling, morphometry, graft patency, and the neointimal response.
Simple technique for measuring the injection current-induced frequency deviation of semiconductor lasers.

A simple but reliable method for measuring the injection-current induced frequency deviation of semiconductor lasers is presented. This technique can be used for modulation frequencies of the order of several hundred megahertz.(AIP)
Psoriasis and hypertension severity: results from a case-control study.

Background Epidemiologic studies have provided new insights into the association between psoriasis and cardiovascular diseases. Previous population studies have examined hypertension frequency in psoriasis patients. However, the relationship between severity of hypertension and psoriasis has not been characterized. Objective We sought to investigate whether patients with psoriasis have more difficult-to-manage hypertension compared to non-psoriatic hypertensive patients. Approach We performed a case-control study using the University of California Davis electronic medical records. The cases were defined as patients diagnosed with both psoriasis and hypertension, and controls were defined as patients with hypertension and without psoriasis. In this identified population, 835 cases were matched on age, sex, and body mass index (BMI) to 2418 control patients. Key Results Treatment with multiple anti-hypertensives was significantly associated with the presence of psoriasis using univariate (p<0.0001) and multivariable analysis, after adjusting for diabetes, hyperlipidemia, and race (p<0.0001). Compared to hypertensive patients without psoriasis, psoriasis patients with hypertension were 5 times more likely to be on a monotherapy antihypertensive regimen (95% CI 3.607.05), 9.5 times more likely to be on dual antihypertensive therapy (95% CI 6.68–13.65), 16.5 times more likely to be on triple antihypertensive regimen (95% CI 11.01–24.84), and 19.9 times more likely to be on quadruple therapy or centrally-acting agent (95% CI 10.58–37.33) in multivariable analysis after adjusting for traditional cardiac risk factors. Conclusions Psoriasis patients appear to have more difficult-to-control hypertension compared to non-psoriatic, hypertensive patients.
Small Hospitality Business Involvement in Environmentally Friendly Initiatives

Complex contemporary economic and political environments are increasingly pressurising businesses to follow environmentally conscious principles, particularly in view of the constant increase of landfill from solid waste, pollution and other environmental issues. Environmental sustainability is a key issue for the hospitality industry in terms of water, power consumption and waste production. However, how important is environmental sustainability for operators, particularly for small operators that because of their size may not have the means and support to be “environmentally friendly”? This study explores this question from the perspective of 21 small hospitality entrepreneurs (SHEs) located in a traditional college town in the South-eastern United States. While there is acknowledgement of the importance of being environmentally friendly, only a small number of operators were actively involved in environmentally sustainable practices. A common concern was the lack of support from local authorities (city...
Soil structural interfaces in some Texas Vertisols and their impact on solute transport

Abstract Structural surfaces and slickensides have been reported to be important features impacting sorption–desorption of chemicals and bypass flow of pollutants to shallow groundwater aquifers. This study provides visible, microscopic and submicroscopic characteristics of slickenside features in two Texas Vertisols of different geomorphological age. Transport of visible anionic dye and CaBr is studied as related to soil structural surfaces, root channels and slickenside planes. Macromorphic observations were coupled with thin section microscopy, scanning electron microscopy and electron microprobe analyses. Slickenside surfaces differed from subjacent micromass of the ped interiors by stronger preferred orientation of clay particles and reduction in macropores with corresponding increase in micropores. Such characteristics could make slickensides act as semi-permeable barriers to solute transport, but this phenomenon could not be confirmed from CaBr studies herein. The majority of the solute bypass flow in both soils was conducted through root channels and ped interfaces. Slickenside surfaces in these Vertisols conducted less than 1% of the flow. It was observed primarily when the dye solution was delivered to the surface of the slickenside via the adjacent root channel. In spite of the preferential orientation of clay particles along slickenside planes, the penetration of Br into the aggregate interior was not retarded like the larger organic anion dye. These results may reflect specific moisture conditions, which should be considered in future works.
Effects of moisture adsorption on laboratory wear measurements of brake friction materials

As is the case for tribological systems in general, the wear of brake friction materials, sliding against brake discs or drums, is influenced by many factors. This dependency requires very complicated test matrices in order to characterize the range of lining wear properties. Furthermore, the wear rate is very low under normal operating conditions, and thus a substantial amount of test time is needed before the wear progresses to reach a measurable amount. One way to reduce the test time is to use small brake material samples and to measure their weight change with an accurate electronic balance. A laboratory-scale, block-on-disc brake testing machine was used to measure the wear rate of two brake friction materials against cast iron. While conducting these tests, the lining specimen weight changes caused by moisture adsorption were found to be similar in magnitude to the weight change caused by wear. These effects were studied using weight change experiments with both desiccants and heating. Gravimetric methods for wear measurement in porous materials like brake linings are problematic. Several alternatives are offered for mitigating this problem.
Crystal gazing in optical microscopy.

For most of the three centuries after Hooke introduced optical microscopy, refinement of the instrumentation and approach made microscopes more convenient than anything else. A modern reader of Hooke's classic treatise Micrographia (ca. 1655) has no problem in visualizing the instrument employed; as in modern microscopes, a light source, an objective lens and an eyepiece were used to project an image magnified a 100-fold to a 1,000-fold into a human eye. This range of magnifications and resolution (~200 nm) has brought cellular morphology and tissue structure into view and made optical microscopy the perfect partner for biological investigation.
A Characterization Of Volatile Organic Compounds And Secondary Organic Aerosol At A Mountain Site In The Southeastern United States

Mean temperature anomalies in the Southeastern United States (SEUS) over the past century have reflected regional cooling hypothesized to be a result of an enhancement of warm season aerosol optical thickness caused by the oxidation of biogenic volatile organic compounds (VOCs). Aerosol and gas-phase VOC measurements were made at the Appalachian Atmospheric Interdisciplinary Research (AppalAIR) site in the southern Appalachian mountains of North Carolina during the summer of 2013 in an effort to characterize warm season chemistry. Organic aerosol (OA) chemistry was characterized through a positive matrix factorization analysis resolving a low-volatility, semi-volatile, and isoprene oxidation factor contributing 34 ± 15, 24 ± 12, and 42 ± 17 %, respectively to the total observed OA. Volatile organic compound characterization described chemistry that was typical of rural background levels with periods of elevated hydrocarbon and urban tracer loading that varied with synoptic flow. Chemical, meteorological, and aerosol optical property data suggested that measurements made at the AppalAIR site are representative of background atmospheric chemistry in the SEUS. Annual background secondary organic aerosol (SOA) production in the SEUS was estimated to be 0.15–0.50 GgC yr−1. Estimates of total and background SOA from this study provide evidence that the SEUS is a region of global significance in the context of global SOA budgets, and can be useful in understanding the extent of anthropogenic enhancement of summertime SOA compared to background levels.
Substitution of Bi and Nb Ions in Lead Zirconate‐Titanate

Solid-state substitution of Bi and Nb ions in the perovskite crystal structure of Pb(Ti0.47Zr0.53)O3 was investigated by sample weight changes at 1150°C in an “equilibrium” PbO atmosphere. A model is discussed that includes the effect of charge neutralization, requiring weight losses for A-site substitutions and weight gains for B-site substitutions. Experiments support the substitution of Bi as Bi3+ on the Pb2+ A site and Nb as Nb5+ on the (Ti,Zr)4+ B site of lead zirconate-titanate. For each mole of BiO1.5 added to a specimen, 1.5 moles of PbO are lost; for each mole of NbO2.5 added, 0.5 moles of PbO are gained. These results agree with the proposed model and with ionic size arguments. The weight changes were time-dependent during the first 30 to 40 h at 1150°C. This behavior is accounted for by the presence of transient second phases.
Well-being in the context of workplace ethnic diversity

This research examined the relation between the effects of workplace diversity (defined as the proportion of coworkers of same ethnicity as the respondent) and psychosomatic complaints, psychological well-being, life satisfaction, and job satisfaction. A sample of 648 African American and Latino workers was surveyed in Chicago and New York City. A nonlinear (inverted U-shaped) relationship between co-ethnicity and the outcomes was found, such that poorer psychological functioning was observed among workers with a very small or a very high proportion of co-ethnic coworkers. The importance of disentangling the meaning of diversity in light of occupational segregation issues is discussed. © 2006 Wiley Periodicals, Inc.
The Solution Structure of the Sac7d/DNA Complex: A Small-Angle X-ray Scattering Study†

Small-angle X-ray scattering has been used to study the structure of the multimeric complexes that form between double-stranded DNA and the archaeal chromatin protein Sac7d from Sulfolobus acidocaldarius. Scattering data from complexes of Sac7d with a defined 32-mer oligonucleotide, with poly[d(GC)], and with E. coli DNA indicate that the protein binds along the surface of an extended DNA structure. Molecular models of fully saturated Sac7d/DNA complexes were constructed using constraints from crystal structure and solution binding data. Conformational space was searched systematically by varying the parameters of the models within the constrained set to find the best fits between the X-ray scattering data and simulated scattering curves. The best fits were obtained for models composed of repeating segments of B-DNA with sharp kinks at contiguous protein binding sites. The results are consistent with extrapolation of the X-ray crystal structure of a 1:1 Sac7d/octanucleotide complex [Robinson, H., et al. (1998) Nature 392, 202-205] to polymeric DNA. The DNA conformation in our multimeric Sac7d/DNA model has the base pairs tilted by about 35 degrees and displaced 3 A from the helix axis. There is a large roll between two base pairs at the protein-induced kink site, resulting in an overall bending angle of about 70 degrees for Sac7d binding. Regularly repeating bends in the fully saturated complex result in a zigzag structure with negligible compaction of DNA. The Sac7d molecules in the model form a unique structure with two left-handed helical ribbons winding around the outside of the right-handed duplex DNA.
Long‐term survival and prognostic factors in breast cancer patients with localized (no skin, muscle, or chest wall attachment) disease with and without positive lymph nodes

Uncertainty exists regarding the magnitude of excess mortality from localized breast cancer at long follow-up times (>15 years) since diagnosis and regarding the effects of race and age as prognostic factors at all follow-up times. Long-term survival was determined in 1141 patients (311 white, 830 black) diagnosed as having localized breast cancer with and without positive axillary lymph nodes, but without any signs of complete or incomplete skin, muscle, or chest wall attachment. Survival curves were estimated by means of actuarial methods; prognostic factors were evaluated with the Cox's regression analysis. Survival from all causes was 62%, 43%, 33%, 25%, and 18% at 5, 10, 15, 20, and 30 years, respectively. Breast cancer-specific survival was 76%, 65%, 63%, 61%, and 59% at 5, 10, 15, 20, and 30 years, respectively. Breast cancer-specific hazard rates exceeded those expected in the general population by 119 times, 53 times, 12 times, and 6 times at 0 to 5, 5 to 10, 10 to 20, and 20 to 25 years, respectively. Of the 395 patients enrolled after 1968 who had modified radical or radical surgery, 338 had known number of positive nodes and size of tumor. Breast cancer-specific survival was significantly increased with: (1) a decreasing number of positive lymph nodes, 0, 1 to 3, and 4 or more (P = 0.000); (2) later year of diagnosis (1974 or before versus 1975 or later) (P = 0.000); and (3), possibly, tumor size of 7.0 cm or less (P = 0.09). When these variables were controlled, no significant association of age at diagnosis or race with breast cancer-specific survival was found. These data suggest that the number of nodes, year of diagnosis and, possibly, tumor size are important prognostic factors for survival, but race and age are not. Also, excess mortality may exist at late intervals; however, it is small in relation to other causes.
Threshold voltage stability comparison in AlGaN/GaN FLASH MOS-HFETs utilizing charge trap or floating gate charge storage

Enhancement mode operation of AlGaN/GaN devices with breakdown voltage over 700 V is achieved by threshold shifting in a FLASH metal oxide semiconductor heterojunction field effect transistor. Charge stored during a programming step in either a charge trap or metal floating gate charge storage layer is responsible for this shift. Threshold stability for charge trap and floating gate memories is compared with charge trap devices losing <10% of initial threshold voltage shift after 104 seconds. Charge trap and floating gate devices maintain enhancement mode operation after 4 × 104 s. Threshold voltage as a function of drain bias for each storage method is compared. The most stable threshold voltage is observed when utilizing charge trap storage due to the discrete nature of the traps. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Reforma de Salud en Chile: Evaluación Garantía Explícita en Salud Oral en Población de 60 Años

La reforma chilena creo el Programa de Garantias Explicitas en Salud (GES) para salvaguardar la atencion bajo condiciones garantizadas de acceso, oportunidad, proteccion financiera y calidad para situaciones prioritarias como la salud oral del adulto de 60 anos. Objetivo: Comparar la salud bucodental y satisfaccion entre pacientes beneficiarios del GES salud oral integral 60 anos y no beneficiarios. Estudio caso-control. Los participantes se dividieron en casos (n=48) y grupo control (n=28). Examen clinico recogiendo las variables: sexo, edad, enfermedades sistemicas declaradas, nivel educacional, uso de protesis, indices COPD, CPITN y O'Leary. Para medir satisfaccion se utilizo la escala multidimensional SERVPERF no ponderado. Analisis inferencial mediante test de significancia (pruebas de Pearson, Exacto de Fisher, Mann-Whitney, Medianas de Mood y Kolmogorov-Smirnov con un nivel de confianza del 95%) en los software SPSS19, Stata-SE 10.1 y Minitab 15. En las mediciones bucodentales se encontraron diferencias significativas solo en cariados y COPD. No hubo diferencias en las necesidades de tratamiento periodontal entre los grupos (p-valor=0.615). La presencia de protesis removible es estadisticamente mayor en el grupo de casos (OR=4,4 [1,6­12,5]); p-valor=0,006). La reforma en salud a traves del GES Salud Oral Integral de 60 anos, demuestra variar los parametros clinicos de los pacientes beneficiarios, enfocado a la restauracion con un aumento significativo de protesis y una disminucion de las caries, pero no logra mantener la salud periodontal ni el manejo de los factores de riesgo. La satisfaccion del usuario es buena en los beneficiarios del GES.
Optical charge carrier generation by charge-transfer excitation in pentacene crystals

Abstract Charge-transfer spectra and activation energies for charge carrier generation in pentacene crystals, recently reported by different authors, are related via a model originally developed for anthracene
Merging content analysis and the policy sciences: A system to discern policy-specific trends from news media reports

In this article we set out to bridge a surprising methodological gap between two time-honored research traditions – news media content analysis and the policy sciences analytic framework. Lasswell, a recognized pioneer of both the method and the framework, discussed the mutual benefits of each decades ago. But few researchers, if any, have formally linked the two. To that end, in this article we (1) make the case for using news media content analysis to inform research studies using the policy sciences analytic framework; (2) introduce an original content analysis categorical system for that purpose; (3) demonstrate that system with a study of 90 national news articles about the stratospheric ozone hole; and (4) compare our system to others used to examine news content. We report that our system, used by human coders, is well geared to describing and mapping trends in the social process surrounding the development of the Montreal Protocol ozone treaty during the intelligence gathering and promotion phases encompassed by our data sample. We argue that other content analysis systems fall short – in structure and purpose – of meeting the promise ours holds to the policy scientist.
Infection Control Issues in Older Adults

Older adults receive care from various settings, including acute care hospitals, skilled nursing facilities, nursing homes, group homes, outpatient primary care, specialty clinics, and home. In these various settings, older adults are exposed to pathogens, which makes them "vectors" that transport pathogens from one setting to another and makes them vulnerable to care fragmentation. These health care settings face unique challenges that require individualized infection control programs. Infection control programs should address: surveillance for infections and antimicrobial resistance, outbreak investigation and a control plan for epidemics, isolation precautions, hand hygiene, staff education, and employee and resident health programs.
Hyperfinite Von Neumann games

Abstract Let ∗ [V( R )] be an ω1-saturated enlargement in the sense of Keisler (1977) and let F be a hyperfinite finite set in ∗ N . Following the suggestion of Wesley (1971) we define a class of hyperfinite games of the form: Γ F ( ∗ υ)=〈Φ, A ( F ), ∗ υ〉 , and show that measure-theoretic analogues of the kernel and bargaining set exist in this nonstandard setting such that their standard parts Loeb-measurable measurable on the Loeb space generated by the internal ∗finitely additive measure u F : A ( F )→ ∗ R + .
Angular momentum and ballistic tracking

The correlation and tracking problem for ballistic objects is a major concern for the Strategic Defense Initiative (SDI). In this presentation, the use of angular momentum for gating and assignment of reports and tracks of ballistic objects is proposed. The various errors and appropriate statistical tests that could be used on angular momentum to potentially improve the tracking and correlation, multi-track hypothesis and Kalman filters are studied. The investigation is performed in earth centered inertial Cartesian coordinates for position, velocity, and acceleration in tracking, gating, and assignment. A discussion is given of a brief investigation, the theory developed, the results of numerical test, and the conclusions.
The transmembrane domain of the E5 oncoprotein contains functionally discrete helical faces.

Abstract The E5 protein of bovine papillomavirus is a 44-amino acid, Golgi-resident, type II transmembrane protein that efficiently transforms immortalized mouse fibroblasts. The transmembrane (TM) domain of E5 is not only critical for biological activity, it also regulates interactions with cellular targets including the platelet derived growth factor receptor (PDGF-R) and the 16-kDa subunit of the vacuolar proton ATPase (V-ATPase). In order to define the specific TM amino acids essential for E5 biological and biochemical activity, we performed scanning alanine mutagenesis on 25 of the 30 potential TM residues and genetically mapped discrete α-helical domains which separately regulated the ability of E5 to bind PDGF-R, activate PDGF-R, and to form oligomers. Alanine substitutions at positions 17, 21, and 24 (which lie on the same helical face) greatly inhibited E5 association with the PDGF-R, suggesting that this region comprises the receptor binding site. PDGF-R activation also mapped to a specific but broader domain in E5; mutant proteins with alanines on one helical face (positions 8, 9, 11, 16, 19, 22, and 23) continued to induce PDGF-R tyrosine phosphorylation, whereas mutant proteins with alanines on the opposite helical face (positions 7, 10, 13, 17, 18, 21, 24, and 25) did not, indicating that the latter helical face was critical for mediating receptor transphosphorylation. Interestingly, these “activation-defective” mutants segregated into two classes: 1) those that were unable to form dimers but that could still form higher order oligomers and transform cells, and 2) those that were defective for PDGF-R binding and were transformation-incompetent. These findings suggest that the ability of E5 to dimerize and to bind PDGF-R is important for receptor activation. However, since several transformation-competent E5 mutants were defective for binding and/or activating PDGF-R, it is apparent that E5 must have additional activities to mediate cell transformation. Finally, alanine substitutions also defined two separate helical faces critical for E5/E5 interactions (homodimer formation). Thus, our data identify distinct E5 helical faces that regulate homologous and heterologous intramembrane interactions and define two new classes of biologically active TM mutants.
Perineuronal satellitosis in the human hippocampal formation

A previously unreported example of perineuronal satellitosis in the medial CA1 and adjacent subiculum in the human hippocampal formation is described. This phenomenon is characterized by a clustering of glial cells in relation to the perikarya of a subpopulation of neurons in the deep pyramidal layer and around most neurons scattered in the stratum oriens and subcortical white matter. Most of the perineuronal satellite glia were identified as oligodendrocytes based on their nuclear chromatin patterns and antigenic properties. Satellite oligodendrocytes were mostly of the medium dense variety. A type of satellite glia with nuclear features of the dark oligodendrocyte could not be identified unequivocally using the antigenic criteria employed in this study.
The lateral fluidity of erythrocyte membranes. Temperature and pressure dependence.

Abstract The pressure and temperature dependence of the lateral and rotational fluidity of erythrocyte membranes was investigated by inserting the excimeric membrane probe 1′-pyrenedodecanoic acid (PDA) into the membranes of intact cells and measuring the probe excimer formation rate and the steady-state polarization of the monomer at pressures up to 2000 atm (2 kbar). At that pressure the lateral diffusivity of PDA was found to decrease by a factor of 10 and its emission anisotropy by a factor of 5 at 22° C. At atmospheric pressure, the local lateral diffusion coefficient of PDA at 2 and 33° C is 1.5 and 4.3 × 10 −8 cm 2 s −1 , respectively. The activation energy for probe translation was found to decrease from 6 to 3 kcal M −1 in going from atmospheric pressure to 2 kbar, while the entropy decreased by approx. 15 cal M −1 K −1 , indicating greater lipid order at the high pressure. The experimental data are consistent with a ‘free-area’ model for the membrane, analogous to the free-volume model for nonassociated liquids. The lateral diffusivity of PDA was found to be proportional to the free membrane area and linear extrapolation to zero diffusivity indicates that at atmospheric pressure, the fractional free area of the erythrocyte membrane is 6%.
The Academic Journal Review Process as a Framework for Student Developmental Peer Feedback

Developmental peer feedback has been suggested as a method for providing students with individual feedback critical to the learning process. However, many faculty members are reluctant to employ peer feedback citing fear of student responses, student feedback capabilities, unfamiliarity with the process, and time constraints in and outside of class. Addressing faculty concerns, this article describes a peer feedback intervention, which adapts the academic journal review process and creates mutually beneficial outcomes for both faculty and students. Students build feedback capacity while improving project quality. Faculty members share the responsibility for providing feedback while enhancing student learning.
Synthesizing Parallel Flexures That Mimic the Kinematics of Serial Flexures Using Freedom and Constraint Topologies

The principles of the freedom and constraint topologies (FACT) synthesis approach are adapted and applied to the design of parallel flexure systems that mimic degrees of freedom (DOFs) primarily achievable by serial flexure systems. FACT provides designers with a comprehensive library of geometric shapes. These shapes enable designers to visualize the regions wherein compliant flexure elements may be placed for achieving desired DOFs. By displacing these shapes far from the point of interest of the stage of a flexure system, designers can compare a multiplicity of concepts that utilizes the advantages of both parallel and serial systems. A complete list of which FACT shapes mimic which DOFs when displaced far from the point of interest of the flexure system's stage is provided as well as an intuitive approach for verifying the completeness of this list. The proposed work intends to cater to the design of precision motion stages, optical mounts, microscopy stages, and general purpose flexure bearings. Two case studies are provided to demonstrate the application of the developed procedure.
A Single-Step Method for Estimation of Local Cerebral Blood Volume from Susceptibility Contrast MRI Images

A new single-step method is described for estimation of local cerebral blood volume (CBV) from multiple rapidly acquired T2- or T2*-weighted MRI images after bolus administration of a susceptibility contrast agent. This method improves on existing methods in three ways. First, the method includes the baseline scan intensity value as a fitted parameter. Second, the model is fitted directly to the original scan intensity values instead of to transformed concentration curves, avoiding the propagation of errors that occurs in the transformation. Third, the equations are reparameterized with CBV fitted directly as a model parameter. Parameter estimation methods are compared by Monte Carlo simulation. The direct method described here yields more precise parameter estimates, with smaller mean absolute deviations from the true parameter values, than the existing method when compared using simulated data. Implementation is discussed and numerical evaluation of the Digamma or Psi function is described.
Computer-aided geometric design of legs for a walking vehicle

Abstract A legged vehicle is potentially more energy efficient and mobile than conventional vehicles in rough terrain. The performance of such a legged vehicle is strongly dependent on the leg geometry. In general, a leg linkage which possesses three-degree-of-freedom foot motion is adequate. A preliminary design of the leg with a view to good energy efficiency resulted in a four-bar leg. This was described by S. M. Song et al. [Mech. Mach. Theory19, 17–24 (1984)]. In the present paper, the mobility of the legged vehicle is brought into consideration in the leg design. A study of the mobility of a six-legged vehicle shows that a large walking envelope is required for each leg linkage. In order to satisfy this requirement, the original four-bar leg was modified into a seven-bar leg by mounting another four-bar linkage on the coupler of the original four-bar linkage. Also, a different type of leg linkage based on pantograph mechanism was designed. A comparison of the leg performance of both types of leg is made in this paper and the pantograph leg is found to be more effective.
The Paradise Garden Murals of Malinalco: Utopia and Empire in Sixteenth-Century Mexico

Examines in detail the murals painted on the vault walls of the Augustinian monastery at Malinalco, southwest of Mexico City, which have been progressively uncovered from layers of whitewash and restored since the 1970s. Shows how the combination of motives promoted the political and religious agendas of the Spanish conquerors, but also preserved a
Biomass and leaf-area index maps derived from SPOT images for Toolik Lake and Imnavait Creek areas, Alaska

A new emphasis on understanding natural systems at large spatial scales has led to an interest in deriving ecological variables from satellite reflectance images. The normalized difference vegetation index (NDVI) is a measure of canopy greenness that can be derived from reflectances at near-infrared and red wavelengths. For this study we investigated the relationships between NDVI and leaf-area index (LAI), intercepted photosynthetically active radiation (IPAR), and biomass in an Arctic tundra ecosystem. Reflectance spectra from a portable field spectrometer, LAI, IPAR, and biomass data were collected for 180 vegetation samples near Toolik Lake and Imnavait Creek, Alaska, during July and August 1993. NDVI values were calculated from red and near-infrared reflectances of the field spectrometer spectra. Strong linear relationships are seen between mean NDVI for major vegetation categories and mean LAI and biomass. The relationship between mean NDVI and mean IPAR for these categories is not significant. Average NDVI values for major vegetation categories calculated from a SPOT image of the study area were found to be highly linearly correlated to average field NDVI measurements for the same categories. This indicates that in this case it is appropriate to apply equations derived for field-based NDVI measurements to NDVI images. Using the regression equations for those relationships, biomass and LAI images were calculated from the SPOT NDVI image. The resulting images show expected trends in LAI and biomass across the landscape.
Fault Injection in Virtualized Systems—Challenges and Applications

We analyze the interaction between system virtualization and fault injection: (i) use of virtualization to facilitate fault injection into non-virtualized systems, and (ii) use of fault injection to evaluate the dependability of virtualized systems. We explore the benefits of using virtualization for fault injection and discuss the challenges of implementing fault injection in virtualized systems along with resolutions to those challenges. For experimental evaluation, we use a test platform that consists of the Gigan fault injector, that we have developed, with the Xen virtual machine monitor. We evaluate the degree to which fault injection results obtained from running the target system in a virtual machine are comparable to running the target system on bare hardware. We compare results when injection is done from within the target system versus from the hosting hypervisor. We evaluate the performance benefits of leveraging system virtualization for fault injection. Finally, we demonstrate the capabilities of our injector and highlight the benefits of leveraging system virtualization for fault injection by describing deployments of Gigan to evaluate both non-virtualized and virtualized systems.
A Tale of Two Cases: Lessons for Education From the Study of Two Boys Living With Half Their Brains

In recent years, educators have been looking in- creasingly to neuroscience to inform their understanding of how children ' s brain and cognitive development are shaped by their learning experiences. However, while this new inter- disciplinary approach presents an unprecedented opportu- nity to explore and debate the educational implications of neuropsychological research, a good model for this dialogue is lacking. This is in part because relatively little is known about the relationships between cognitive, emotional, and neuro- logical development, in part because of a dearth of research methods designed to rigorously connect issues of learning and development to neuropsychological strengths and weak- nesses, and in part because neuropsychological studies are rarely presented in a format that is conducive to meaningful cross-disciplinary dialogue with educators. To begin to address these issues, in this article, I present the complementary cases of Nico and Brooke, two high-functioning adolescents, who have suffered the removal of an entire brain hemisphere (Nico his right and Brooke his left) to control severe epilepsy. Through presenting a neuropsychological study of these rare boys ' emotion and affective prosody (vocal intonation) through the developmental lens of an educator, I reinterpret the neuropsychological fi ndings for what they reveal about how the boys leveraged their emotional and cognitive strengths to learn important skills for which they were each missing half of the normally recruited neural hardware. While Nico ' s and Brooke ' s results seem on the surface to contradict expectations based on neuropsychological fi ndings with adults, they combine to reveal a compensatory logic that begins to elucidate the active role of the learner as well as the organizing role of emotion in brain development, providing a jumping-off point for discussion between educators and neu- roscientists and a model for connecting neuropsychological strengths and weaknesses to learning.
Scattering by a Cavity in an Exponentially Graded Half-Space

An inhomogeneous half-space containing a cavity is bonded to a homogeneous half-space. Waves are incident on the interface and the problem is to calculate the scattered waves. For a circular cavity in an exponentially graded half-space, it is shown how to solve the problem by constructing an appropriate set of multipole functions. These functions are singular on the axis of the cavity, they satisfy the governing differential equation in each half-space, and they satisfy the continuity conditions across the interface between the two half-spaces. Seven recent publications are criticized: They do not take proper account of the interface between the two half-spaces.
Gamma-Globulin Factors (Gm and Inv) in New Guinea: Anthropological Significance

Analysis of the hereditary Gm and Inv gamma-globulin factors of 1669 New Guineans from the Morobe and Eastern Highlands districts and Bougainville Island demonstrates thatthe frequencies of the three Gm alleles present (Gm(a), GM(ab), and Gm(ax)) are similar in general to those in Mongoloids and in particular to those in Southeast Asians and Micronesians. The New Guinea frequencies are distinct from those in other populations, including Australian aborigines. Highly significant differences in frequencies of Gm and Inv alleles occur between Melanesian-and non-Austronesian-speaking New Guineans.
Computation of Bethe Logarithms and Other Matrix Elements of Analytic Functions of Operators

Abstract A general method is given for the calculation of a matrix element 〈φ| ƒ(A) |ψ〉 of an analytic function ƒ of an operator A. The method begins by writing 〈φ| ƒ(A) |ψ〉 as a contour integral of the corresponding matrix element 〈φ| (ζ − A)−1 |ψ〉 of the resolvent (ζ − A)−1, where the contour surrounds the spectrum of A. The contour is then deformed to obtain 〈φ| ƒ(A) |ψ〉 as a sum of contributions from branch points and poles of f. The numerical evaluation of the Bethe logarithm, which is the dominant contribution to the Lamb shift, is used as an example. The difficulties which arise when the resolvent matrix element 〈φ| (ζ − A)−1 |ψ〉 must be evaluated by approximate methods are discussed.
Gene therapy with extracellular superoxide dismutase attenuates myocardial stunning in conscious rabbits

Background —Administration of Cu/Zn superoxide dismutase (SOD) without catalase fails to alleviate myocardial stunning, but extracellular SOD (Ec-SOD) may be more effective because it binds to heparan sulfate proteoglycans on the cellular glycocalyx. We therefore used in vivo gene transfer to increase systemic levels of Ec-SOD and determined whether this gene therapy protects against myocardial stunning. Methods and Results —The cDNA for human Ec-SOD was cloned behind the cytomegalovirus (CMV) promoter and incorporated into a replication-deficient adenovirus (Ad5/CMV/Ec-SOD). Injection of this virus (2×108 pfu/kg IV) produced high levels of Ec-SOD in the liver, which could be redistributed to the heart and other organs by injection of heparin. Conscious rabbits underwent a sequence of six 4-minute coronary occlusion/4-minute reperfusion cycles for 3 consecutive days starting 3 days after intravenous injection of Ad5/CMV/Ec-SOD or Ad5/CMV/nls/LacZ (negative control). Both groups were given heparin (2000 U/kg IV) 2 hours before the first sequence of occlusions. The severity of myocardial stunning was measured as the total deficit of LV wall thickening after the last reperfusion. On day 1, the total deficit of wall thickening was markedly decreased in Ad5/CMV/Ec-SOD rabbits versus controls and similar to that seen on days 2 and 3 in controls. Conclusions —The results demonstrate that in vivo gene transfer of the cDNA encoding Ec-SOD provides the heart with substantial protection against myocardial stunning without the need for concomitant administration of catalase. The present observations provide the basis for controlling gene therapy at the posttranslational level and for simultaneously protecting multiple organs from oxidant stress.
In Appreciation of an Outstanding Surgeon-in-Chief

Welcome to the tenth volume of HSS Journal®. In reflection, 2013 was a notable year for the HSS community. Not only did we celebrate the 150th anniversary of the founding of the hospital but also the 100th anniversary of the founding of our alumni association. Thomas Sculco, MD, our current surgeon-in-chief, announced that after 10 years of service, he will be stepping down. A search for his replacement is currently underway. At the 2013 Alumni Association meeting, in his presidential address, Daniel Rich, MD chronicled many of Dr. Sculco's contributions as surgeon-in-chief. Among these was his leadership in establishing the International Society of Orthopedic Centers also known as ISOC. It was Dr. Sculco's vision to create a society of the best orthopedic centers from throughout the world to collaborate on issues of innovation in clinical care, research, and education. Currently, 17 leading orthopedic academic centers participate with meetings taking place every 18 months. Within the mission of ISOC is the charge to collaborate and build consensus around complex issues in clinical care. We are excited that ISOC has chosen the HSS Journal® as a forum for the publication of two of these consensus-building initiatives. Benjamin Ricciardi, MD and his coauthors report on two studies, which establish a consensus for practice, which is aimed at the prevention and treatment of prosthetic joint infection. The most commonly employed methods for the prevention of surgical site infection are reviewed, and the approaches to clinical management of the infected arthroplasty are described. Although these topics have been described in other studies, these reports provide the consensus of the most active orthopedic centers in Europe and North and South America. ISOC is an impressive accomplishment, and success is largely due to the leadership and vision of Dr. Sculco. One of his other great contributions is the HSS Journal®. Without his support, the journal would not have become a reality. I am sure, and I join with every member of the HSS community and readers around the world in extending our congratulations and appreciation to Dr. Sculco for his 10 years of extraordinary service. Join me in extending best wishes for his future endeavors.
Comparative Spatial Filtering in Regression Analysis

One approach to dealing with spatial autocorrelation in regression analysis involves the filtering of variables in order to separate spatial effects from the variables' total effects. In this paper we compare two filtering approaches, both of which allow spatial statistical analysts to use conventional linear regression models. Getis' filtering approach is based on the autocorrelation observed with the use of the Gi local statistic. Griffith's approach uses an eigenfunction decomposition based on the geographic connectivity matrix used to compute a Moran's I statistic. Economic data are used to compare the workings of the two approaches. A final comparison with an autoregressive model strengthens the conclusion that both techniques are effective filtering devices, and that they yield similar regression models. We do note, however, that each technique should be used in its appropriate context.
Necessary and sufficient condition for crosstalk attack localization in all-optical networks

Although All-Optical Network (AON) are a viable technology for future telecommunication and data networks, it creates many security vulnerabilities that do not exist in traditional networks. Transparency and non regeneration features make attack detection and localization difficult, because the effects of an attack connection can propagate quickly to different parts of a transparent All-Optical Network. Among all attack types in AON, crosstalk attack's propagation capability is second to none. Quick detection and localization of such attack source can avoid losing large amounts of data in an All-Optical Network. However, to detect attack sources, it is not necessary to put monitors on all nodes. Since those connections affected by the attack connection would provide valuable information for diagnosis, we show that placing a relatively small number of monitors on a selected set of nodes in a network is sufficient to achieve the required level of performance. This paper introduces crosstalk attack model and monitor-segment concept. After showing a necessary and sufficient condition for one-OAF diagnosable AON, a new sparse monitor placement method is proposed.
Efficacy of a Secondary Adolescent Pregnancy Prevention Program: An Ecological Study Before, during and after Implementation of the Second Chance Club

Teen mothers are at increased risk of subsequent adolescent births. Interventions to reduce secondary teen pregnancies are expensive and difficult to evaluate. An ecological evaluation compared change in the repeat teen birth rate in an intervention community in Charleston South Carolina over time to state birth certificate data to determine the efficacy of a school-based pregnancy prevention program. Evaluation included comparison of birth rates for multigravida teens in the programs school catchment area (intervention zip codes) to selected state and community data before during and after program implementation. The intervention community demonstrated a decrease in repeat teen births during the intervention period of the program with a rebound after it was discontinued. This trend differed from a 50% linear decrease across these time periods in the state. This low cost evaluation method may be useful for evaluation of teen pregnancy prevention programs with limited resources for program evaluation. (authors)
On the Skew Incidence Diffraction by an Impedance Wedge with Arbitrary Face Impedances

ABSTRACT New diffraction coefficients are derived for an impedance wedge at skew incidence. These are based on the solution of a new set of difference equations, yielding a single expression which recovers ail known skew incidence impedance wedge diffraction coefficients. An. important aspect of the derived expression is that a single computer code can be written for all wedge angles (with arbitrary face impedances) for which an exact solution is possible and furthermore it opens the possibility of deriving approximate solutions for other wedge angles.
Psychological ramifications of pediatric pain

Abstract The pediatric patients experience of pain occurs in a matrix of constitutional, temperamental, familial, and environmental factors, Children's coping and adaptation have long-term implications for their physical and emotional functioning, adjustment and quality of life, adherence with treatment recommendations, and a host of other factors pertinent to health maintenance. Nonpharmacologic approaches to pain management and the inpact of pant on children's phychological adjustment are reviewed from n systemic and developmental perspective.