cssi/SciSciGPT-SciSciNet huggingface dataset:
Complément de Schur et sous-différentiel du second ordre d'une fonction convexe

The Schur complement relative to the linear mappingA of a functionf is denotedAf and defined as the image off underA. In this paper we give some estimates for the second-order differential ofAf whenf is either a partially quadratic convex function or aC2 convex function with a nonsingular second-order differential. We then consider an arbitrary convex functionf and study the second-order differentiability ofAf in a more general sense.
Chemical changes in the blood during operative hysteroscopy using 5.0% mannitol versus 1.5% glycine

This study compared the changes in blood chemistry that occur during operative hysteroscopy when either 5.0% mannitol or 1.5% glycine is used as a distention medium. Blood values of both groups were measured immediately before and after surgery. Only 1.5% glycine was used until December 1992, and then 5.0% mannitol was used exclusively.
Evaluating Model Performance of an Ensemble-based Chemical Data Assimilation System During INTEX-B Field Mission

Abstract. We present a global chemical data assimilation system using a global atmosphere model, the Community Atmosphere Model (CAM3) with simplified chemistry and the Data Assimilation Research Testbed (DART) assimilation package. DART is a community software facility for assimilation studies using the ensemble Kalman filter approach. Here, we apply the assimilation system to constrain global tropospheric carbon monoxide (CO) by assimilating meteorological observations of temperature and horizontal wind velocity and satellite CO retrievals from the Measurement of Pollution in the Troposphere (MOPITT) satellite instrument. We verify the system performance using independent CO observations taken on board the NSF/NCAR C-130 and NASA DC-8 aircrafts during the April 2006 part of the Intercontinental Chemical Transport Experiment (INTEX-B). Our evaluations show that MOPITT data assimilation provides significant improvements in terms of capturing the observed CO variability relative to no MOPITT assimilation (i.e. the correlation improves from 0.62 to 0.71, significant at 99% confidence). The assimilation provides evidence of median CO loading of about 150 ppbv at 700 hPa over the NE Pacific during April 2006. This is marginally higher than the modeled CO with no MOPITT assimilation (~140 ppbv). Our ensemble-based estimates of model uncertainty also show model overprediction over the source region (i.e. China) and underprediction over the NE Pacific, suggesting model errors that cannot be readily explained by emissions alone. These results have important implications for improving regional chemical forecasts and for inverse modeling of CO sources and further demonstrate the utility of the assimilation system in comparing non-coincident measurements, e.g. comparing satellite retrievals of CO with in-situ aircraft measurements.
Obliquely Crossed, Differential Thermal Lens Measurements under Conditions of High Background Absorbance:

A differential thermal lens spectrometer based on the oblique crossing of separate pump and probe beams is described. This arrangement utilizes the differential response of the thermal lens to compensate for the intensity noise in the pump source while maintaining the intrinsic sensitivity of photothermal measurements. Thus, this design is ideally suited for absorbance measurements in the presence of a large background, such as might be encountered in circular dichroism or indirect photometry. The theory describing the thermal lens signal observed with this configuration will be developed and experimentally verified. The experimental conditions mandating differential TL measurements will also be investigated. Absorbance changes of 2 × 10−7 are demonstrated. Application of this arrangement to indirect HPLC detection is also discussed.
Airway manifestations in childhood granulomatosis with polyangiitis (Wegener's).

Objective Granulomatosis with polyangiitis (Wegener's) (GPA) is a necrotizing granulomatous vasculitis affecting the upper and lower respiratory tract, kidneys, and other small vessels throughout multiple organ systems. Recently, classification criteria for childhood GPA have been proposed and include the addition of airway stenosis. Airway inflammation occurs more frequently in children than adults and often proves difficult to diagnose and treat. Our objectives were to 1) determine the frequency of airway involvement in a cohort of children with GPA as defined by the European League Against Rheumatism/Paediatric Rheumatology International Trials Organisation/Pediatric Rheumatology European Society (EULAR/PRINTO/PRES) criteria, 2) document the frequency of specific airway findings, and 3) review our treatment approach to children with GPA-related airway disease. Methods A retrospective chart review was performed on patients ages <18 years with a diagnosis of vasculitis evaluated at the Cleveland Clinic between 2004 and 2010. Results Twenty-eight patients fulfilling the EULAR/PRINTO/PRES classification criteria for the diagnosis of childhood GPA were included in the analysis. There was a mean followup time of 3.1 years. The overall prevalence of any airway disease was 86%, with upper airway involvement in 86% and laryngotracheobronchial (LTB) disease in 50% of patients. LTB disease was present at diagnosis in 36%, while in the remaining 14% it developed on immunosuppressive therapy. Ten patients underwent a successful endoscopic intervention. Conclusion Airway manifestations frequently occur in childhood GPA. Inflammatory changes can occur at any point in the disease course, necessitating diligent surveillance. Endoscopic interventions for LTB stenotic lesions represent a safe and effective therapeutic option.
Up‐Regulation in Vascular Endothelial Cells of Binding Sites of High Density Lipoppppprotein Induced by 25‐Hydroxycholesterol

Exposure of bovine vascular endothelial cell cultures to 25-hydroxycholesterol (50-100 μg/ml) result in a 5-10-fold increase in cell surface binding sites of high density lipoprotein (HDL). This increase in HDL- binding sites was dependent on time and temperature. After a 48-h exposure to the oxygenated sterol, a maximal increase in HDL. Binding could be observed, and newly induced binding sites disappeared rapidly once 25-hydroxycholesterol was removed from the medium. No increase in HDL-binding sites was observed when cells were maintained at 4 °C. In contrast, cultures maintained at 37 °C did show an increase in HDL-binding sites when exposed to 25-judrpxycholesterol. Since simulataneous exposure of the cells to 25-hydroxycholesterol and cyclotheximide resulted in an inhibition of HDL binding to the cells, it is suggested the denovo synthesis of HDL-binding sites is induced by 25-hydroxycholesterol. When the abilities of HDL2 and HDL3 to bind to newly synthesized HDL-binding sites were compared, HDL3 was found to bind more efficiently than HDL2 It is therefore unlikely that apoprotein E plays a major role in the binding of HDL to newly synthesized HDL bind sites were analyzed, they were found to have a high affinity for HDL, since half-maximal binding was reached at a concentration as low as 5 μg HDL protein/ml, and were saturable. Such HDL-binding sites had a relaxed specificity, since they were capable of binding low density liprotein (LDL). However, when LDL bound to newly synthesized HDL binding sites, it was no longer internalized, as reflected by a 90% reduction of LDL degradation, and instead of being cytotoxic it became mitogenic.
An Algorithm for Grey-Level Transformations in Digitized Images

Grey-level transformations on digitized images are variously used to minimize storage requirements or to enhance low-level contrast information. A graph-theoretic approach is proposed to implement these transformations. In particular, an efficient algorithm is given for transformation leading to almost uniform grey-level distribution.
Comparison between skin-mounted fiducials and bone-implanted fiducials for image-guided neurosurgery

Point-based registration for image-guided neurosurgery has become the industry standard. While the use of intrinsic points is appealing because of its retrospective nature, affixing extrinsic objects to the head prior to scanning has been demonstrated to provide much more accurate registrations. Points of reference between image space and physical space are called fiducials. The extrinsic objects which generate those points are fiducial markers. The markers can be broken down into two classifications: skin-mounted and bone-implanted. Each has distinct advantages and disadvantages. Skin-mounted fiducials require simply sticking them on the patient in locations suggested by the manufacturer, however, they can move with tractions placed on the skin, fall off and perhaps the most dangerous problem, they can be replaced by the patient. Bone implanted markers being rigidly affixed to the skull do not present such problems. However, a minor surgical intervention (analogous to dental work) must be performed to implant the markers prior to surgery. Therefore marker type and use has become a decision point for image-guided surgery. We have performed a series of experiments in an attempt to better quantify aspects of the two types of markers so that better informed decisions can be made. We have created a phantom composed of a full-size plastic skull [Wards Scientific Supply] with a 500 ml bag of saline placed in the brain cavity. The skull was then sealed. A skin mimicking material, DragonSkinTM [SmoothOn Company] was painted onto the surface and allowed to dry. Skin mounted fiducials [Medtronic-SNT] and bone-implanted markers [Z-Kat]were placed on the phantom. In addition, three additional bone-implanted markers were placed (two on the base of the skull and one in the eye socket for use as targets). The markers were imaged in CT and 4 MRI sequences (T1-weighted, T2 weighted, SPGR, and a functional series.) The markers were also located in physical space using an Optotrak 3020 [Northern Digital Inc]. Registrations between image space and physical space were performed and fiducial and target registration errors were determined. Finally the 5 bone-implanted makers which penetrated the skin were removed and a traction equivalent to 25% of the weight of the average human head was applied to the “skin” surface. Target and fiducial registrations were again performed.
Survey of maneuvering target tracking: decision-based methods

This is the fourth part of a series of papers that provide a comprehensive survey of techniques for tracking maneuvering targets without addressing the so-called measurement-origin uncertainty. Part I and Part II deal with target motion models. Part III covers the measurement models and the associated techniques. This part surveys tracking techniques that are based on decisions regarding target maneuver. Three classes of techniques are identified and described: equivalent noise, input detection and estimation, and switching model. Maneuver detection methods are also included.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
COLLEGE PROXIMITY EFFECTS IN FLORIDA: RESEARCH EVIDENCE

Using published articulation reports from high school principals for the year 1974, the author found that having any type of institution of higher education within one's county of residence (1) significantly (.005) increases the probability that one will go to college somewhere; (2) significantly (.01) increases the chances that one will attend the same kind of institution as is located in one's county of high school completion; and (3) significantly (.05) increases attendance at public junior colleges in that very same county.
Time-dependent mode of immunization augments suppressed antibody responses in spleen cell cultures from mice experimentally infected with Trypanosoma cruzi

Mice infected with Trypanosoma cruzi develop immunosuppressed responses to heterologous antigens. Experiments were performed using infected mice in the acute stage of infection to assess immunoregulatory activities during induction of direct plaque-forming cells (DPFC) to sheep erythrocytes (SRBC). After normal or infected mice were primed with SRBC, their spleen cells were restimulated 4 days later with SRBC in Mishell-Dutton cultures and found to mount hyperaugmented IgM anti-SRBC responses. It was also demonstrated that T-cells derived from normal mice primed in vivo 4 days previously with SRBC, and subsequently added to cultures of spleen cells from T. cruzi-infected mice, enhanced anti-SRBC DPFC responses in a dose-dependent fashion. These results show that functional help provided by T-cells activated during an in vivo priming and exposed to an in vitro challenge dose of antigen (SRBC) in a time-dependent mode can overcome the effect of immunosuppression in the spleen cell cultures from T. cruzi-infected mice.
H-spaces analogous to E~8 mod 3

Let p be an odd prime. Let X0 be a finite, p-local, simply connected homotopy associative H-space. Suppose H*(X0;ℤ p ) contains the subalgebra satisfying The only known examples occur for p=3 and involve the Lie group E8. In this note we prove that if X0 exists, then p must be 3.
Market power and welfare effects in DC power flow electricity models with thermal line losses

A nodal electric power network with Cournot-Nash interaction among power generators is formulated as a mixed complementarity problem. The model incorporates a direct current (DC) power flow approximation with thermal line losses to model real-time flows. We include constant wheeling rate and variable congestion charges for transmission of electricity. Market power and welfare effects are measured in an aggregated Indiana electric grid model. We find that imposing DC power flow constraints in a model results in significant changes in social welfare estimates. Line losses are also an important factor affecting market power and welfare of market participants in the case study.
Grain Contact Adhesion Hysteresis: A Mechanism For Attenuation of Seismic Waves In Sedimentary Granular Media

Attenuation is observed experimentally in dry sedimentary rock samples at low frequency and high overburden stress. Currently well established attenuation mechanisms such as frictional sliding, squirt flow and viscous dissipation can not adequately explain the observed attenuation. We propose a new mechanism for attenuation of seismic waves in sedimentary granular rocks. The origin of this mechanism lies in grain contact adhesion hysteresis. The propagation of seismic waves causes the gap width at grain contacts to vary. At high frequencies Hz), in liquid saturated rocks this leads to attenuation due to squirt flow. However in dry rocks at low frequency Hz) this periodic oscillation in gap width (h) leads to energy dissipation due to hysteresis on a surface force vs. separation distance (h) diagram. The path taken when h is decreasing is different than when h is increasing (grains are being pulled apart). Surface forces and applied load play an important role in the magnitude of the calculated attenuation. The trends obtained from the proposed grain contact adhesion hysteresis mechanism are consistent with experimental observations. We show here that grain contact adhesion hysteresis causes energy dissipation without frictional sliding at grain contacts and gives rise to frequency independent attenuation that increases with strain amplitude and decreases with overburden stress. The conclusions obtained from the calculations are qualitative since they do not account for the complex distribution of asperity sizes and separations that would exist in a rock. However, they provide a qualitative explanation for some hitherto unexplained experimental observations.
Evidence for plastic deformation in the natural polycrystalline diamond, framesite☆

Abstract Relief-polished striations have been found within grains in polished sections of framesite, a naturally occurring polycrystalline diamond. Because the narrow zones represented by these surface striations are harder than any orientation of the matrix (as revealed by abrasion resistance) and because they etch preferentially, they have been interpreted as representing oriented deformation bands within the grains. It is concluded that the microstructure of framesite is the result of plastic deformation of diamond grains probably under conditions such that brittle fracture was inhibited.
Path-integral formulation of the Langer modification and its applications to the hydrogen atom

Abstract The Larger transformation is performed in the path integral for the radial propagator. The semiclassical calculation of the transformed propagator results in the exact energy spectrum of the hydrogen atom and the semiclassical Coulomb phase shifts with the correct angular modification.
Coupling between the helix–coil transition and nematic–isotropic transitions in polypeptide solutions

The lattice model of Flory has been extended in order to consider equilibrium between isotropic and nematic phases containing helix–coil type chains. Nearly complete exclusion of coil sequences from the lyotropic nematic phase produces an enhanced cooperativity in the helix–coil transition. In poor solvents this enhancement begins to occur at concentrations typical of some experiments.
SU-E-T-452: Impact of Abdominal Compression on the Tumor Motion in the Treatment of NSCLC Using Stereotactic Body Radiosurgery.

Purpose: Involuntary motion of the tumor during the treatment of NSCLC using stereotactic body radiosurgery presents its own unique challenges. In this study, we quantify the impact of abdominal compression technique to minimize tumor motion as a function of location of tumor in a patient. Methods: 25 patients (5 in each lung lobe viz. RUL, RML, RLL, LUL and LLL) were retrospectively analyzed. A 4DCT study encompassing the tumor was used on a 16 slice GECT scanner along with Varian RPM gating system. The images were retrospectively binned in 10 phases. The motion of tumor was analyzed phase by phase in transverse, sagittal & coronal projections of the 3D image. This gave us 2 values for anterior‐posterior, superior‐inferior and lateral‐medial motions each and was averaged out. Results:Analysis of data reveals that the motion (mean ± 1SD) in the superior‐inferior direction was 1.8 ± 0.9, 4.2±2.8, 7.4±2.3, 1.5±0.8, 3.1±2.8 mm for tumors located in RUL, RML, RLL, LUL and LLL, respectively. Along the anterior‐posterior direction the respective values were 2.5 ± 1.9, 2.4 ± 1.1, 2.7 ± 1.3, 1.4 ± 0.2 and 1.8 ± 1 mm. Similarly, along the lateral direction, the respective values were 2.1 ± 1.1, 1.9 ± 1.1, 1.6 ± 1.3, 1.1 ± 0.3 and 1.8 ± 0.7 mm. When the data was analyzed removing the location of the tumor in the thorax, the median displacement along the superior‐inferior, anterior‐posterior, lateral direction was 2.3, 1.6 and 1.5 mm, respectively while the respective maximum value were 9.2, 5 & 3.8 mm. Conclusions: The use of abdominal compression provides a simple inexpensive yet easily tolerable device to control the motion of the tumor in the management of NSCLC for SBRT treatments. This will allows the treatment of the tumor without resorting to complex and time consuming gated treatments.
Impact of male obesity on infertility: a critical review of the current literature

Objective To evaluate the current understanding of the effects and potential mechanisms of obesity on male fertility. Design Literature review of articles pertaining to obesity and male infertility. Result(s) Recent population-based studies suggest an elevated risk for subfertility among couples in which the male partner is obese and an increased likelihood of abnormal semen parameters among heavier men. Male factor infertility is associated with a higher incidence of obesity in the male partner. Obese men exhibit reduced androgen and SHBG levels accompanied by elevated estrogen levels. Reduced inhibin B levels correlate with degree of obesity and are not accompanied by compensatory increases in FSH. This complexly altered reproductive hormonal profile suggests that endocrine dysregulation in obese men may explain the increased risk of altered semen parameters and infertility. Additional features of male obesity that may contribute to an increased risk for infertility are altered retention and metabolism of environmental toxins, altered lifestyle factors, and increased risks for sexual dysfunction. Neither reversibility of obesity-associated male infertility with weight loss nor effective therapeutic interventions have been studied yet. Conclusion(s) The increasing prevalence of obesity calls for greater clinician awareness of its effects on fertility, better understanding of underlying mechanisms, and eventually avenues for mitigation or treatment.
Thin shell dynamics and equations of state

A relation between stress-energy and motion is derived for accelerated Israel layers. The relation, for layers between two Schwarzschild manifolds, generalizes the equation of state for geodesic collapse. A set of linked layers is discussed.
An Integrated Molecular Analysis of Lung Adenocarcinomas Identifies Potential Therapeutic Targets among TTF1-Negative Tumors, Including DNA Repair Proteins and Nrf2

Purpose: Thyroid transcription factor-1 (TTF1) immunohistochemistry (IHC) is used clinically to differentiate primary lung adenocarcinomas (LUAD) from squamous lung cancers and metastatic adenocarcinomas from other primary sites. However, a subset of LUAD (15-20%) does not express TTF1 and TTF1-negative patients have worse clinical outcomes. As there are no established targeted agents with activity in TTF1-negative LUAD, we performed an integrated molecular analysis to identify potential therapeutic targets. Experimental Design:: Using two clinical LUAD cohorts (274 tumors), one from our institution (PROSPECT) and the TCGA, we interrogated proteomic profiles (by reverse-phase protein array (RPPA)), gene expression, and mutational data. Drug response data from 74 cell lines were used to validate potential therapeutic agents. Results: Strong correlations were observed between TTF1 IHC and TTF1 measurements by RPPA (Rho=0.57, p<0.001) and gene expression (NKX2-1, Rho=0.61, p<0.001). Established driver mutations (e.g. BRAF and EGFR) were associated with high TTF1 expression. In contrast, TTF1-negative LUAD had a higher frequency of inactivating KEAP1 mutations (p=0.001). Proteomic profiling identified increased expression of DNA repair proteins (e.g., Chk1 and the DNA repair score) and suppressed PI3K/MAPK signaling among TTF1-negative tumors, with differences in total proteins confirmed at the mRNA level. Cell line analysis showed drugs targeting DNA repair to be more active in TTF1-low cell lines. Conclusions: Combined genomic and proteomic analyses demonstrated infrequent alteration of validated lung cancer targets (including the absence of BRAF mutations in TTF1-negative LUAD), but identified novel potential targets for TTF1-negative LUAD including KEAP1/Nrf2 and DNA repair pathways.
Tillich's One Nonsymbolic Statement: A Propos of a Recent Study by Rowe

As a confessing theologian of the Christian church, Paul Tillich achieved a remarkable synthesis of the interaction of the basic symbols of this religious tradition, exhibiting their revelatory significance for the existential plight of contemporary man. David H. Kelsey has shown us what a systematic and comprehensive picture of Tillich's activity emerges if we view him strictly from this vantage point.' Yet Tillich was also a philosopher who analyzed the structures of finite being in terms of a cluster of ontological polarities ultimately grounded in being-itself. This side of Tillich has in turn been recently scrutinized by William L. Rowe, particularly his theory of being-itself and his theory of symbolic predication.2 Both monographs focus their attention upon the same two central issues in Tillich's thought, the nature of God and the character of our symbols pointing to God, but they do so from such widely divergent angles of vision that there is practically no overlap between their treatments. Together they show how Tillich's dynamic unity of theology and philosophy could be shattered in either direction. Most comprehensively, however, Tillich sought to be neither a confessional theologian nor a philosopher but a philosophical theologian, combining his ontological analysis of being-itself with the fundamental symbol of western religious faith in the central affirmation, "God is being-itself" (ST I 238),3 the one nonsymbolic statement that can be made about God. While Rowe offers us three careful
Competitive reactions of peroxynitrite with 2′-deoxyguanosine and 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxodG): Relevance to the formation of 8-oxodG in DNA exposed to peroxynitrite

Abstract We have examined the formation of 7,8-dihydro-8-oxo-2′-deoxyguanosine (8-oxodG) in reactions of peroxynitrite with 2′-deoxyguanosine (dG) and calf-thymus DNA. Peroxynitrite reacts with dG at neutral pH, but this reaction does not result in the buildup of 8-oxodG. We also do not find any evidence for the formation of 8-oxodG in calf-thymus DNA upon exposure to peroxynitrite. When 8-oxodG is mixed with 1000-fold excess dG and then allowed to react with peroxynitrite, about 50% of the 8-oxodG is destroyed. The preferential reaction of 8-oxodG is also evident when dG in calf-thymus DNA is partially oxidized in an Udenfriend system and then allowed to react with peroxynitrite. We suggest that 8-oxodG is not produced in peroxynitrite-mediated oxidations of dG and DNA or that it is produced but then is rapidly consumed in further reactions with peroxynitrite. Oxidized DNA bases frequently can be more oxidation sensitive than their corresponding progenitors and, therefore, may be present at low steady-state concentrations and not represent stable markers of oxidative stress status. The importance of the 8-oxodG/peroxynitrite reaction is discussed in relation to the formation of more stable, secondary oxidation products that might be more useful markers of DNA damage.
THE EFFECTS OF HYPOPHYSECTOMY AND OF THYROXINE ON THE RADIATION-INDUCED CHANGES IN THE RAT THYROID1

CELLULAR hypertrophy and nuclear changes are impressive histologic features of the thyroid of the rat previously irradiated by the administration of I131 (Maloof, et al., 1952). These findings have been observed as early as one month and have persisted for as long as 18 months after a total radiation dose of only 5800 roentgen equivalents physical (5 μc, of I131) in spite of an abundant supply of iodine (3 μg./gm. food) in the diet. Not all the cells are equally affected; the abnormal nuclei are scattered, but the cellular hypertrophy is constant and intense. These changes vary, depending upon the initial dose of I131. It has not been clear whether the cellular hypertrophy and nuclear changes are direct results of the ionizing radiation upon the cells themselves, or whether the cells are conditioned by the radiation, the subsequent changes arising secondarily from increased thyrotropic hormone stimulation resulting from a reduced rate of hormone synthesis by the irradiated thyroid gland.
Testing Goodness of Fit for Proportional Hazards Model with Censored Observations

Abstract A numerical omnibus test of fit for the two-sample proportional hazards model is proposed for randomly censored observations. The test is derived from Cox's partial likelihood and does not need a dummy time-dependent covariate or any partition of the time-axis. Consistency of the test is established. Examples are provided for illustration.
A Study of the Transition Between Lean Conventional Diesel Combustion and Lean, Premixed, Low-Temperature Diesel Combustion

New diesel combustion modes face difficult challenges with respect to engine-out emissions and transient behavior. Transitions between lean conventional diesel combustion and lean, premixed, low-temperature diesel combustion are investigated with an automotive diesel engine. Effects of fuel pressure on transitional cycles are investigated. Cycle-by-cycle heat release analysis is performed and an exhaust mass flow model is used to obtain cycle-averaged NO concentrations. The behavior of combustion progression and NO emissions during the transitions is discussed. Observed cool-flame behavior is identified and explained.
The value of cognitive foundations for dynamic social theory

It is possible to develop models of social behavior that are predicated on detailed mechanical models of cognition. Cognitively based social models are potentially unified theoretical frameworks that can be used to explain a wide variety of social phenomena. Moreover, if a knowledge representation scheme and a knowledge acquisition scheme are specified in the underlying cognitive model then it is possible to produce a dynamic social model. The resulting social model can thus be used to predict and explain not only conditions for specific behaviors but changes in those behaviors over time. Constructuralism is a theory of social behavior that rests on a cognitive model. The cognitive model specified has a knowledge representation scheme, knowledge acquisition procedures, and control procedures for shifting cognitive attention. The resulting social model is a dynamic model that can be used to explain both conditions for the occurrence of a behavior and social and individual changes that accrue do to a series...
The effects of positive and negative imagery on motor skill performance

An investigation was carried out into the effect of imagery instructions on a simple motor skill accuracy task (putting a golf ball). Thirty college students were blocked on their putting ability and randomly assigned within blocks to one of three experimental conditions: (a) positive imagery, (b) negative imagery, and (c) control. Subjects in the two imagery conditions were given the identical instructions for imagining the backswing and putting stroke. In the positive imagery group, subjects imagined the ball going into the cup, while subjects using negative imagery visualized the ball narrowly missing the cup. Subjects in the control group putted without instructions. On each of 6 consecutive days a 10-putt trial was conducted for each subject. There was a significant main effect on performance improvement for the experimental manipulation. Post hoc analyses showed significant differences among all groups, with positive imagery producing the most improvement, the control condition producing less, and negative imagery resulting in performance deterioration. Results are discussed in relation to the existing literature, and future research directions are delineated.
Ultrastructural localization of peroxidase in atherosclerotic lesions of pigeons.

Abstract Atherosclerotic lesions are known to have metabolic alterations which are associated with progressive lipid accumulation. Among the changes, lysosomal enzyme activity has been extensively characterized and at the ultrastructural level has been correlated with the amount of foam cell lipid. In a fashion paralleling lysosomal change, artery wall peroxidase activity is also altered during disease progression. The present study focuses upon the ultrastructural localization of peroxidase activity in atherosclerotic lesions of the aorta and coronary arteries from White Carneau pigeons fed a cholesterol-supplemented (0.3%) diet for 3 years. This resulted in fibrous lesions, rich in smooth muscle cells. The birds were necropsied by perfusion fixation, and peroxidase cytochemistry was carried out using the diaminobenzidine reaction. Peroxidase activity was found within endothelial cells and smooth muscle cells in both the media and intima, but cytochemically demonstrable activity was not found in macrophage foam cells. Peroxidase was localized within the nuclear envelope and endoplasmic reticulum, especially within cells that had lipid inclusions. The degree of peroxidase positivity varied within and among the arteries. In nonlesion regions of the aorta 20% of medial smooth muscle cells was peroxidase positive; the value for coronary artery smooth muscle cells was less. The peroxidase activity within aortic lesions was increased with 44% of intimal smooth muscle cells being positive. Notably, 85–90% of the lipid-containing intimal smooth muscle cells were positive. In contrast, intimal smooth muscle cells in the coronary artery lacked peroxidase reaction product, even in cells containing lipid. We conclude from these studies that aortic lesions contain a cytochemically differentiated subset of lipid-containing, peroxidase-positive smooth muscle cells; but coronary lesions lack a comparable subset of smooth muscle cells.
Ecosystem structure and growth of the African savanna

Abstract Ecosystems are highly structured, interlocking sets of organismic and environmental interactions. Particular ecosystems reappear in the geological record, structured similarly regardless of their evolutionary history. Ulanowicz has hypothesized that energy throughput and compartmentalization are an important part of the evolutionary growth and development of ecosystems, and that redundancy within compartments can shield an ecosystem from perturbation. The compartments studied in this paper are mammalian guilds and redundancy has been interpreted as guild depth, defined as the number of genera within a particular guild. The fossil history and paleocology of the African savanna ecosystem, from potential precursor systems in the Early Miocene, through the protosavanna, the flowering of the savanna, and the severe depletion of this system about 1.5 Ma, show that redundancy and compartmentalization in this ecosystem did increase with time, and that redundancy did, at 1.5 Ma, protect the system's survival. A similarly redundant savanna system in North America destructure and restructured to prairie at about 5 Ma, apparently due to even more extreme climatic perturbations.
Effect of Task Mental Models on Software Developer's Performance: An Experimental Investigation

This study provides some preliminary results on the efficacy of mental models in software development. Specifically, based on results from a controlled laboratory experiment, it shows that a software developer's mental model quality is a determinant of software quality performance, regardless of whether the task is performed individually or in pairs. Further, this effect is found to be consistent across software tasks of varying complexity.
When the Methodological Shoe is on the Other Foot: African American Interviewer and White Interviewees

Some scholars engaging in the insider/outsider debate have argued that the pairing of researcher and subjects based on racial similarity—i.e., “race matching”—is the most effective means for conducting qualitative research. Although insider/outsider status has been discussed with respect to white researchers' studies of African Americans, I explore the heretofore rarely discussed situation in which an African American is the researcher and whites are the subjects. I argue that insider status with respect to race continues to be based on a presumed connectedness linked to phenotypical characteristics—like skin color or hair texture. Yet, rather than experiencing a solely insider or outsider status, researchers and subjects experience what I call “insider moments” wherein their interests converge and they are able to share in the kinds of interactions that yield important insights. I conclude by evaluating the utility of insider/outsider status in qualitative research.
The ex-post behavior of firms offering optimal employment contracts

Abstract The influential papers of Azariadas (1975) and Baily (1974) have clearly demonstrated that with imperfect labor mobility expected profit maximizing firms will offer employment contracts that will not result in profit maximizing behavior once the ‘state of nature’ is disclosed. This Letter shows that such firms will behave as if their objective were to maximize the expected utility of each individual worker subject to a profit target. The rule that emerges when there is unemployment will be shown to be formally equivalent to Meade's Rule for optimal population [Meade (1955, ch. 6)].
Investigating the Impacts of Wind Generation Participation in Interconnection Frequency Response

The electrical frequency of an interconnection must be maintained very close to its nominal level at all times. Excessive frequency deviations can lead to load shedding, instability, machine damage, and even blackouts. There is rising concern in the power industry in recent years about the declining amount of inertia and primary frequency response (PFR) in many interconnections. This decline may continue due to increasing penetrations of inverter-coupled generation and the planned retirements of conventional thermal plants. Inverter-coupled variable wind generation is capable of contributing to PFR and inertia; however, wind generation PFR and inertia responses differ from those of conventional generators, and it is not entirely understood how this will affect the system at different wind power penetration levels. The simulation work presented in this paper evaluates the impact of the wind generation provision of these active power control strategies on a large, synchronous interconnection. All simulations were conducted on the U.S. Western Interconnection with different levels of wind power penetration levels. The ability of wind power plants to provide PFRand a combination of synthetic inertial response and PFRsignificantly improved the frequency response performance of the system. The simulation results provide insight to designing and operating wind generation active power controls to facilitate adequate frequency response performance of an interconnection.
Comparison of Fracture Mechanics and Nominal Stress Analyses in Stress Corrosion Cracking

Abstract Since the development of the fatigue cracked cantilever beam stress corrosion specimen, the fracture mechanics approach has been widely used to analyze the stress corrosion behavior of mat...
Scenario-based robust optimization of a water supply system under risk of facility failure

In this paper, we propose a scenario-based robust optimization model for the design of a water supply system considering the risk of facility failure, which is represented as an uncertainty set generated by a finite set of scenarios. New facilities are planned to be built to hedge against the possible failure of existing system facilities that would potentially damage the capacity of the system to meet given user demands. The goal is to build facilities that are both cost-effective and make the system robust. The system robustness is defined as the ability to satisfy user demands for every data realization in the uncertainty set. The proposed model is shown to be equivalent to a large-scale mixed-integer linear program that is solved by a Benders decomposition algorithm. Computational results demonstrate the efficiency of the proposed algorithm, and show that substantial improvement in system robustness can be achieved with minimal increase in system cost. The risk of facility failure is modeled by a scenario-generated uncertainty set.A robust optimization model is formulated for water supply system planning.The Benders decomposition algorithm is proposed to solve the model.The proposed algorithm is demonstrated to outperform CPLEX.System robustness can be greatly improved with little increase in system cost.
Coaction of intercellular adhesion and cortical tension specifies tissue surface tension

In the course of animal morphogenesis, large-scale cell movements occur, which involve the rearrangement, mutual spreading, and compartmentalization of cell populations in specific configurations. Morphogenetic cell rearrangements such as cell sorting and mutual tissue spreading have been compared with the behaviors of immiscible liquids, which they closely resemble. Based on this similarity, it has been proposed that tissues behave as liquids and possess a characteristic surface tension, which arises as a collective, macroscopic property of groups of mobile, cohering cells. But how are tissue surface tensions generated? Different theories have been proposed to explain how mesoscopic cell properties such as cell–cell adhesion and contractility of cell interfaces may underlie tissue surface tensions. Although recent work suggests that both may be contributors, an explicit model for the dependence of tissue surface tension on these mesoscopic parameters has been missing. Here we show explicitly that the ratio of adhesion to cortical tension determines tissue surface tension. Our minimal model successfully explains the available experimental data and makes predictions, based on the feedback between mechanical energy and geometry, about the shapes of aggregate surface cells, which we verify experimentally. This model indicates that there is a crossover from adhesion dominated to cortical-tension dominated behavior as a function of the ratio between these two quantities.
Diving and foraging energetics of the smallest marine mammal, the sea otter (Enhydra lutris)

As the smallest and one of the most recently evolved marine mammals, sea otters face physiological challenges rarely encountered by larger, more derived aquatic species. To examine the effect of these challenges on foraging costs and resultant daily energy budgets, we measured the energetics of resting, grooming, diving and foraging for adult, male sea otters. The energy expended for these different behaviors as determined from open flow respirometry was then standardized across activity budgets measured for wild sea otters to estimate field metabolic rates (FMR). We found that the metabolic rate of captive otters performing single dives ranging in duration from 40 to 192 s was 17.6±0.5 ml O2 kg–1 min–1 and only 1.3 times resting rates. This rate increased significantly if the animals foraged during submergence. The cost of a foraging dive for sea otters was nearly twice that predicted for phocid seals, which was attributed in part to elevated locomotor costs associated with buoyancy and swimming style. Our behavioral studies indicate that wild sea otters spend the greatest proportion of the day feeding and resting, with the largest daily energy expenditure (6.1±1.1 MJ day–1) associated with foraging. The resulting mean FMR for wild sea otters based on the energy expended for all behaviors was 15.7±2.7 MJ day–1 and matched predicted FMR values based upon a regression of known FMR values for other marine mammals across a range of body sizes. This was achieved by counterbalancing elevated foraging costs with prolonged periods of rest on the water surface.
295 mW CW maximum output of AlGaInP laser diode with windows grown on facets

Up to 295 mW kink-free CW maximum output, about twice as much as the conventional one, was achieved by implementing the WGF (windows grown on facets) structure to AlGaInP laser diode.
Faces of Internationalism in a Transitional Environment

In the post-Vietnam Cold War environment, two dimensions—cooperative internationalism and militant internationalism—came to characterize the foreign policy beliefs of American leaders and the mass public. Although grounded in Cold War concepts and challenges, evidence from opinion polls in the transitional period to a post-Cold War world suggests that the cooperative and militant faces of internationalism persist. Furthermore, because they parallel realism and idealism, as competing orientations toward global problems, the two dimensions and the fourfold typology of foreign policy beliefs they define may help to understand the intersection of attitudes toward traditional security issues and the welfare issues that may dominate future global and national agendas. Preliminary evidence is used to probe the argument that hard-liners on national security issues will evince nationalistic and protectionist sentiments on environmental and trade issues. Contrariwise, accommodationists on security issues are hypoth...
A monomolecular pseudostationary phase for micellar electrokinetic capillary chromatography

A highly stable pseudostationary phase has been synthesized and evaluated for use in micellar electrokinetic capillary chromatography (MECC). Sodium 10-undecylenate has been oligomerized to form a micelle-like structure following the procedure of Durairaj et al. [1].The stability of this structure renders it suitable for use with mobile phases containing relatively high percentages of organic modifiers, enabling the separation and detection of hydrophobic analytes such as alkyl phthalates and polynuclear aromatic hydrocarbons (PAHs) which are difficult to analyze by conventional micellar electrokinetic chromatography. In addition to demonstrating the utility of this structure for the analysis of hydrophobic analytes, the electrophoretic and chromatographic properties of the new phase have been investigated.
A computational sensor system for particle detection applications

This paper presents the design and testing results of a computational radiation sensor. The design utilizes a dedicated microcontroller to perform computation and data aggregation on the sensor head to reduce the information bit rate. A low-power charge sensitive amplifier and ADC complete the design. The design was implemented in a 0.35 µm CMOS technology with field tests demonstrating the validity of the approaches taken.
Tetrahymena thermophila and Candida albicans Group I Intron-Derived Ribozymes Can Catalyze the Trans-Excision-Splicing Reaction

Group I intron-derived ribozymes can catalyze a variety of non-native reactions. For the trans-excision-splicing (TES) reaction, an intron-derived ribozyme from the opportunistic pathogen Pneumocystis carinii catalyzes the excision of a predefined region from within an RNA substrate with subsequent ligation of the flanking regions. To establish TES as a general ribozyme-mediated reaction, intron-derived ribozymes from Tetrahymena thermophila and Candida albicans, which are similar to but not the same as that from Pneumocystis, were investigated for their propensity to catalyze the TES reaction. We now report that the Tetrahymena and Candida ribozymes can catalyze the excision of a single nucleotide from within their ribozyme-specific substrates. Under the conditions studied, the Tetrahymena and Candida ribozymes, however, catalyze the TES reaction with lower yields and rates [Tetrahymena (kobs) = 0.14/min and Candida (kobs) = 0.34/min] than the Pneumocystis ribozyme (kobs = 3.2/min). The lower yields are likely partially due to the fact that the Tetrahymena and Candida catalyze additional reactions, separate from TES. The differences in rates are likely partially due to the individual ribozymes ability to effectively bind their 3′ terminal guanosines as intramolecular nucleophiles. Nevertheless, our results demonstrate that group I intron-derived ribozymes are inherently able to catalyze the TES reaction.
Plasma Arc Welding of TiB2–20 vol% TiC

Ceramics consisting of titanium diboride with titanium carbide additions were fusion welded to produce continuous joins. A welding current of 135 A, welding speed of 8 cm/min, and plasma flow rate of 0.75 L/min were combined with a preheat temperature of ~1450°C to fusion weld coupons of TiB2 containing 20 vol% TiC with a thickness of 4 mm. The resulting fusion zone (FZ) was 3.9 mm deep at the center of the joint and 10.4 mm wide. During cooling of the melt pool, four distinct regions of crystal growth and nucleation were observed due to thermal gradients. Regions at the top and bottom of the FZ exhibited smaller TiB2 crystals due to higher nucleation rates whereas regions in the middle of the FZ showed higher growth rates, with TiB2 crystals up to 1.2 mm in length. Thermal gradients also affected cooling of the eutectic phase, causing a cellular structure to appear in the cooled eutectic. Plasma arc welding was a viable method for joining diboride-based ceramics.