cssi/SciSciGPT-SciSciNet huggingface dataset:
Selective fluorescence quenching of polynuclear aromatic hydrocarbons in microcolumn liquid chromatography

Abstract A selective fluorescence quenching method using nitromethane as the quenching agent is systematically studied in the absence and presence of absorption effects. Nitromethane is found to quench the emission intensity of polynuclear aromatic hydrocarbons (PAHs) with six-membered rings, while the emission of PAHs with five-membered rings is essentially unaltered. However, fluorescence attenuation caused by primary and secondary absorption may result in errors in the determination of dynamic quenching constants. In this work, a modified Stern-Volmer relationship is developed to distinguish and to compensate mathematically for absorption effects. Utilizing this expression, the Stern-Volmer quenching constant ( K q ) is determined to be 125 and 0.15 M −1 for pyrene and fluoranthene, respectively, using nitromethane as the quenching agent in methanol at ambient temperature. Because of the large difference in quenching constants, this analytical methodology is applied for the class-selective identification of PAHs in coal-derived fluids by microcolumn liquid chromatography with laser fluorescence detection.
Comment on "Absence of impurity bands in conjugated polymers"

A Comment on the Letter by K. Harigaya, Y. Wada, and K. Fesser, Phys. Rev. Lett. 63, 2401 (1989).
Relationships Among Antioxidant Activity, Total Phenolic Content and Specific Gravity in Several Potato ( Solanum tuberosum L.) Cultivars Grown in Different Environments

Environmental conditions influence crop productivity and quality, making breeding for improvement of a particular trait challenging. Similarly, relationships among traits may make trait improvement difficult, especially if selection for high levels of one trait results in low levels of the other(s). Therefore, understanding the influence of environment and relationships among traits is necessary in trait selection and crop improvement. The objective of this study was to investigate the variability and correlations among antioxidant activity (AOA), total phenolic content (TP), and specific gravity (SPG) in potato cultivars and advanced breeding selections. This research included investigation of genotype x environment (GxE), using four cultivars (Atlantic, Red LaSoda, Russet Norkotah, and Yukon Gold) grown for 3 years (2005, 2006, and 2007) in nine states (CA, ID, MI, MN, NJ, NC, OR, TX, and WI), and two broader genotype studies using 15 advanced breeding selections grown in Texas in 2005 and 60 advanced selections and five cultivars grown in Texas in 2009. Two methods, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS), were used to evaluate AOA, and total phenolic (TP) content was determined using the Folin-Ciocalteau method. Significant effects of cultivar, year, location and their interactions on AOA, TP, and SPG were observed, as well as significant trait differences among cultivars within and between locations. The correlations between AOA and TP were significantly positive, while between AOA and SPG, and between TP and SPG were weak and negative in the GxE study. Correlations between AOA and SPG, and between TP and SPG in the two genotype studies were not significant. The weak relationships observed in the GxE study between AOA and SPG, and between TP and SPG may have been due to the small sample size and/or the cultivar Atlantic consistently exhibiting the lowest values of AOA and TP, and highest SPG in all locations. Results from the genotype studies suggest that breeding for high AOA and TP to increase the nutritional value of potato cultivars can be done without compromising tuber quality in terms of specific gravity.
Hematology Grants K08 and K23

The first National Institutes of Health (NIH) grant awarded to physician scientists is often a K08 or K23 award. This chapter is designed for the Hematology Fellow who is preparing for an independent faculty position in 3-5 years. The topics covered include deciding which award to apply for, advice about planning and writing the application, as well as a description of the review process and how candidates can make their application stand out.
The sterol response element binding protein regulates cyclooxygenase-2 gene expression in endothelial cells

We previously demonstrated that cholesterol deprivation increases endothelial cyclooxygenase-2 (COX-2)-dependent prostacyclin [prostaglandin I2 (PGI2)] production in vitro. Cholesterol directly regulates gene transcription through the sterol response element binding protein (SREBP). In this work, we demonstrate that SREBP directly regulates COX-2 expression. Cholesterol reduces human COX-2 promoter-luciferase reporter construct activity in transiently transfected endothelial cells. Conversely, cotransfection with a constitutively active mutant SREBP increases COX-2 promoter activity. SREBP-1a and -2 specifically bind a putative sterol response element (SRE) sequence in the COX-2 promoter. This sequence competes for SREBP binding to a low density lipoprotein receptor consensus sequence in an electromobility-shift assay. These data indicate that endothelial COX-2 is regulated by cholesterol via the SREBP pathway. The present study identifies COX-2 as the first vascular gene without a clear role in lipid metabolism transactivated by SREBP, and suggests that enhanced production of PGI2 through this pathway may be an additional benefit of cholesterol-lowering therapies.
On trees of a graph and their generation

Abstract The efficiency with which a complex electrical network may be analyzed by a digital computer depends, largely, upon the efficiency with which the trees of the corresponding graph are generated. This paper is a presentation of those properties of a set of trees that aid us in generating the trees of a given graph. Two different methods for generating trees of a graph are described. Both these methods are extremely efficient for graphs whose nullities are small in comparison to their ranks, especially if the computer is supplied with bit-wise logical instructions. An important theoretical question, that of testing a given set of trees for “completeness,” is also considered.
The nuances of cognition and depression in older adults: the need for a comprehensive assessment

Objectives This study aimed to examine the confluence of depression, cognitive impairment, and vascular risk factors in older individuals. Methods The study uses baseline data from the National Alzheimer's Coordinating Center. Data were collected across Alzheimer's Disease Centers in the USA. The sample included 12,634 individuals (cognitive intact = 8022; amnestic mild cognitive impairment [aMCI] = 3652; nonamnestic MCI [nonaMCI] = 960). The Geriatric Depression Scale assessed depression; the Trail Making Test assessed executive function. Results The proportion of participants with depression was higher in the aMCI (18%) and nonaMCI group (21%) as compared with that in the cognitively intact group (8%); there was no difference in rates of depression between aMCI and nonaMCI groups. The proportion of participants with executive dysfunction differed between nondepressed and depressed individuals for the cognitively intact (8% vs. 12%) and aMCI groups (28% vs. 35%), but not for the nonaMCI group (37% vs. 41%). Nine percent of the cognitively intact group had executive dysfunction compared with 31% of the aMCI group and 40% of the nonaMCI group. The proportion of participants with hypertension was greater in individuals with executive dysfunction compared with those with no executive deficits; the presence of hypertension was not associated with depression severity. Conclusions The confluence of vascular risk factors, episodic memory impairment, and depression and executive dysfunction highlights the need for comprehensive assessment of depressed older adults that can aid clinicians in the formulation of treatment planning and inform clinicians and researchers about long-term prognosis. Copyright © 2013 John Wiley & Sons, Ltd.
Insulin-like growth factor-1 receptors mediate infragenicular vascular smooth muscle cell proliferation in response to glucose and insulin not by insulin receptors.

PURPOSE: Vascular smooth muscle cell (VSMC) proliferation is an early event in the pathogenesis of atherosclerosis. Insulin and glucose are known to stimulate the growth of VSMC. Cell membrane receptors play an important role in the proliferation of VSMC in response to growth factors. Insulin and insulin-like growth factor-1 (IGF-1) have demonstrated a cross reactivity for receptor binding and function. By using monoclonal antibodies directed against insulin (IRA) and IGF-1 (IGF-1RA) receptors, we attempt to further delineate the mechanism for the proliferation of VSMC in response to insulin and glucose. METHODS: Human infragenicular VSMC isolated from diabetic patients undergoing below-knee amputations were used. Cells from passages 3 to 6 were grown in serum-free media with a glucose concentrations of 0.1% or 0.2%, both with and without insulin (100 ng/mL). The baseline cell density was 4,635 ± 329 cells/mL. IRA or IGF-1RA was added to the media, with the control group receiving neither antibody. Cells were grown in 5% CO 2 at 37°C for 6 days. Analysis of variance was used for statistical analysis, with P <0.05 considered significant. In addition, DNA synthesis was measured using thymidine incorporation assays in the same groups of cells receiving IRA, IGF-1RA, and no antibody. RESULTS: IGF-1RA prevented the proliferation of VSMC in response to insulin and glucose, while IRA had no effect on cell growth. There was no significant growth when IGF-1RA was added to the media, while the control group and the group receiving IRA demonstrated significant growth compared with the baseline concentration of 4,635 ± 329 cells/mL at all concentrations of insulin and glucose. [ 3 H]thymidine incorporation assays confirmed the cell count results. CONCLUSIONS: These results suggest that the mitogenic effects of insulin and glucose on infragenicular VSMC are due to stimulation of the IGF-1 receptor. VSMC antiproliferative strategies employing receptor blockade should be directed against the IGF-1 receptor, not the insulin receptor.
Mate Value Discrepancy as Predictor of Forgiveness and Jealousy in Romantic Relationships

Mate value discrepancy (MVD), the perceived difference in resource value between self and partner in romantic relationships, may impact both forgiveness and jealousy. One hundred seventy-nine participants rated their own and their partner’s mate value, and self-reported forgiveness and jealousy. MVD was associated with forgiveness in romantic relationships in that the higher the value of one’s mate in relation to self, the more likely an individual would forgive that partner’s transgression. Similarly, MVD played a role with jealousy in that the higher the value of the partner, the more likely an individual experienced jealousy. Additionally, individuals were more likely to forgive transgressions when their partners had higher mate values than theirs, even when jealousy is experienced.
Stratified motion planning on nonsmooth domains with robotic applications

This paper presents an extension of stratified motion planning results to the case where the base manifold upon which the motion planning occurs is not smooth. Robotic applications of this work include motion planning for legged robots over known, nonsmooth terrain and manipulation of nonsmooth objects with multiple robotic manipulators.
Reconciling estimates of the free surface height in Lagrangian vertical coordinate ocean models with mode-split time stepping

Abstract In ocean models that use a mode splitting algorithm for time-stepping the internal- and external-gravity modes, the external and internal solutions each can be used to provide an estimate of the free surface height evolution. In models with time-invariant vertical coordinate spacing, it is standard to force the internal solutions for the free surface height to agree with the external solution by specifying the appropriate vertically averaged velocities; because this is a linear problem, it is relatively straightforward. However, in Lagrangian vertical coordinate ocean models with potentially vanishing layers, nonlinear discretizations of the continuity equations must be used for each interior layer. This paper discusses the options for enforcing agreement between the internal and external estimates of the free surface height, along with the consequences of each choice, and suggests an optimal, essentially exact, approach.
The design and field evaluation of a repeatable collaborative software code inspection process

The use of software products in today's world has increased dramatically making quality an important aspect of software development. There is a continuous need to develop processes to control and increase software quality. Software code inspection is one way to pursue this goal. This paper presents a collaborative code inspection process that was designed during an action research study using Collaboration Engineering principles and techniques. Our inspection process was implemented as a sequence of thinkLets, chunks of facilitation skill, that were subsequently field tested in a traditional paper-based and Group Support System (GSS)-based environment. It was found to be successful in uncovering many major, minor as well as false-positive defects in inspected pieces of code. Results illustrate the process' efficiency in identifying duplicate defects thereby reducing follow-up time to correct each defect. The inspection process' flexibility was observed as it was successfully applied to inspect both pieces of code or an entire module. Overall the collaborative inspection process was considered to be productive for code inspection and was satisfactory for the inspectors involved.
The effect of iron in MRI and transverse relaxation of amyloid‐beta plaques in Alzheimer's disease

Dysregulation of neural iron is known to occur during the progression of Alzheimer's disease. The visualization of amyloid-beta (Aβ) plaques with MRI has largely been credited to rapid proton relaxation in the vicinity of plaques as a result of focal iron deposition. The goal of this work was to determine the relationship between local relaxation and related focal iron content associated with Aβ plaques. Alzheimer's disease (n=5) and control tissue (n=3) sample slices from the entorhinal cortex were treated overnight with the iron chelator deferoxamine or saline, and microscopic gradient-echo MRI datasets were taken. Subsequent to imaging, the same slices were stained for Aβ and iron, and then compared with regard to parametric R2 * relaxation maps and gradient-echo-weighted MR images. Aβ plaques in both chelated and unchelated tissue generated MR hypo-intensities and showed relaxation rates significantly greater than the surrounding tissue. The transverse relaxation rate associated with amyloid plaques was determined not to be solely a result of iron load, as much of the relaxation associated with Aβ plaques remained following iron chelation. The data indicate a dual relaxation mechanism associated with Aβ plaques, such that iron and plaque composition synergistically produce transverse relaxation.
Living Donor Pancreas Transplantation

The pancreas was the first extrarenal organ to be successfully transplanted with use of a living donor. The goal at that time, in the azathioprine and cyclosporine eras, was to improve graft survival rates after solitary pancreas transplants. But today, in the tacrolimus era, most living donor pancreas transplants are with a simultaneous living donor kidney transplant because of the cadaver kidney donor shortage. The evolution of stringent selection criteria for living pancreas donors has significantly reduced the incidence of surgical complications and adverse metabolic changes. In contrast to kidney and liver transplants with use of living donors, the donor mortality rate after more than 140 living donor pancreas transplants has remained 0%. The introduction of laparoscopic donor hemipancreatectomy, with its rapid recovery time, makes living pancreas donation more attractive. Patient and graft survival rates for living donor pancreas recipients are now greater than 85%. Living donor pancreas (with or without a simultaneous living donor kidney) transplants decrease the number of deaths of diabetic patients on dialysis and on the waiting list, help overcome the organ shortage, reduce morbidity, and improve the quality of life for patients formerly on dialysis or with debilitating side effects of diabetes. Meticulous donor workup remains key to a low metabolic and surgical complication rate.
Growth of the endometrial adenocarcinoma cell line AN3 CA is modulated by tumor necrosis factor and its receptor is up-regulated by estrogen in vitro.

We demonstrate that tumor necrosis factor (TNF) has a biphasic effect on the growth of the human endometrial adenocarcinoma cell line AN3 CA in vitro. Low levels (0.2-5 pg/ml) of TNF were moderately growth stimulatory (up to 20% enhancement), while levels over 100 pg were growth inhibitory (up to 45% inhibition). Northern blot analysis showed expression of the 75-kilodalton (kDa) TNF receptor mRNA, but no expression of the 55-kDa TNF receptor mRNA or TNF mRNA. The growth of these cells was not directly affected by physiological concentrations (10(-7)-10(-9) M) of 17 beta-estradiol (E2). However, [125I]TNF binding studies and Scatchard analysis showed that 18-h coculture with 10(-8) M E2 increased the number of TNF receptors expressed on these cells 3-fold. Quantitative mRNA analysis confirmed that 75-kDa TNF receptor mRNA expression increased within 4 h of incubation with E2. These observations suggest an interaction between the endocrine and the immune systems, with an important implication for the homeo...
Effects of elastin degradation and surrounding matrix support on artery stability

Tortuous arteries are often associated with aging, hypertension, atherosclerosis, and degenerative vascular diseases, but the mechanisms are poorly understood. Our recent theoretical analysis suggested that mechanical instability (buckling) may lead to tortuous blood vessels. The objectives of this study were to determine the critical pressure of artery buckling and the effects of elastin degradation and surrounding matrix support on the mechanical stability of arteries. The mechanical properties and critical buckling pressures, at which arteries become unstable and deform into tortuous shapes, were determined for a group of five normal arteries using pressurized inflation and buckling tests. Another group of nine porcine arteries were treated with elastase (8 U/ml), and the mechanical stiffness and critical pressure were obtained before and after treatment. The effect of surrounding tissue support was simulated using a gelatin gel. The critical pressures of the five normal arteries were 9.52 kPa (SD 1.53) and 17.10 kPa (SD 5.11) at axial stretch ratios of 1.3 and 1.5, respectively, while model predicted critical pressures were 10.11 kPa (SD 3.12) and 17.86 kPa (SD 5.21), respectively. Elastase treatment significantly reduced the critical buckling pressure (P < 0.01). Arteries with surrounding matrix support buckled into multiple waves at a higher critical pressure. We concluded that artery buckling under luminal pressure can be predicted by a buckling equation. Elastin degradation weakens the arterial wall and reduces the critical pressure, which thus leads to tortuous vessels. These results shed light on the mechanisms of the development of tortuous vessels due to elastin deficiency.
Progressive Degradation and Subsequent Refinement of Acoustic Representations in the Adult Auditory Cortex

Correlated neuronal activity is believed to play an important role in refining and maintaining cortical circuitry during early development. Here we provide evidence that globally and locally correlated activity mediate different forms of adult plasticity. Pulses of broad-spectrum noise were used to activate time-locked responses across large areas of the rat auditory cortex, globally synchronizing cortical activity. Brief tone pips were used to activate relatively small groups of neurons, generating locally correlated activity. Pairing pulsed noises with nucleus basalis (NB) stimulation in awake rats for 4 weeks broadened spectral tuning, disrupted tonotopic maps, and reduced spontaneous discharge correlation in the primary auditory cortex (AI), as examined under anesthesia. Those effects caused AI neurons to appear qualitatively similar to neurons in nonprimary auditory fields of naive animals. Subsequent pairing of tone pips with NB stimulation for a period of 4 weeks completely reversed these effects induced by previous noise-NB pairing. These findings further demonstrate that the adult auditory cortex retains a substantial capacity for receptive field plasticity and tonotopic map reorganization and that locally correlated activity plays an important role in plasticity in the adult, as in the developing cortex.
Ride Quality Flight Testing

The ride quality experienced by passengers is a function of airframe rigid-body, elastic dynamic responses, autopilot, and stability augmentation system control inputs. A frequency response method has been developed to select sinusoidal elevator input time histories yielding vertical load factor distributions, within a given limit, as a function of fuselage station. The numerical technique is illustrated by applying two-degree-of-freedom short-period and first symmetric mode equations of motion to a B-1 aircraft at Mach 0.85 during sea level flight conditions.
Species-specific and transgenerational responses to increasing salinity in sympatric freshwater gastropods

Freshwater salinization is a global concern partly attributable to anthropogenic salt contamination. The authors examined the effects of increased salinity (as NaCl, 250–4,000 µS/cm, specific conductance) on two sympatric freshwater gastropods (Helisoma trivolvis and Physa pomillia). Life stage sensitivities were determined by exposing naive eggs or naive juveniles (through adulthood and reproduction). Additionally, progeny eggs from the juvenile-adult exposures were maintained at their respective parental salinities to examine transgenerational effects. Naive H. trivolvis eggs experienced delayed development at specific conductance > 250 µS/cm; reduced survivorship and reproduction were also seen in juvenile H. trivolvis at 4,000 µS/cm. Survival and growth of P. pomilia were not affected by increased salinity following egg or juvenile exposures. Interestingly, the progeny of H. trivolvis exposed to higher salinity may have gained tolerance to increased salinity whereas P. pomilia progeny may have experienced negative transgenerational effects. The present study demonstrates that freshwater snail species vary in their tolerance to salinization and also highlights the importance of multigenerational studies, as stressor impacts may not be readily apparent from shorter term exposures. Environ. Toxicol. Chem. 2012; 31: 2517–2524. © 2012 SETAC
Study of PET Detector Performance With Varying SiPM Parameters and Readout Schemes

The spatial resolution performance characteristics of a monolithic crystal PET detector utilizing a sensor on the entrance surface (SES) design is reported. To facilitate this design, we propose to utilize a 2D silicon photomultiplier (SiPM) array device. Using a multi-step simulation process, we investigated the performance of a monolithic crystal PET detector with different data readout schemes and different SiPM parameters. The detector simulated was a 49.2 mm by 49.2 mm by 15 mm LYSO crystal readout by a 12 by 12 array of 3.8 mm by 3.8 mm SiPM elements. A statistics based positioning (SBP) method was used for event positioning and depth of interaction (DOI) decoding. Although individual channel readout provided better spatial resolution, row-column summing is proposed to reduce the number of readout channels. The SiPM parameters investigated include photon detection efficiency (PDE) and gain variability between different channels; PDE and gain instability and dark count noise. Of the variables investigated, the PDE shift of -3.2±0.7% and gain shift of -4±0.9% between detector testing and detector calibration had the most obvious impact on the detector performance, since it not only degraded the spatial resolution but also led to bias in positioning, especially at the edges of the crystal. The dark count noise also had an impact on the intrinsic spatial resolution. No data normalization is required for PDE variability of up to 12% FWHM and gain variability of up to 15% FWHM between SiPM channels. Based upon these results, a row-column summing readout scheme without data normalization will be used. Further, we plan to cool our detectors below room temperature to reduce dark count noise and to actively control the temperature of the SiPMs to reduce drifts in PDE and gain.
Electromagnetic cave-to-surface mapping system

This paper presents the principle, design, construction, and methodology for an electromagnetic (EM) system to be used in the detection/location and mapping of underground cavities using surface measurements. The EM instrument consists of a loop-loop transmitter/receiver system with the transmitter placed inside the cavity. The transmitter's position and depth are determined by analyzing the shape and distribution of the transmitted field on the surface. From the perspective of a cylindrical coordinate system, the vertical component of the through rock transmitted magnetic field peaks at the point where the transmitter and receiver are vertically collinear. On the other hand, the horizontal component reaches a minimum at this point. Based on these observations, a procedure is presented and tested that efficiently locates the position as well as the depth of the transmitter. A physical model for the system was developed and compared to the results of calibration experiments, with very good agreement. The model allows the study of different responses for EM waves/fields propagating through a homogenous Earth of different electrical characteristics and therefore enables several type-curves to be generated that aid in the development of an optimal system.
Mobile code security by Java bytecode instrumentation

Mobile code provides significant opportunities and risks. Java bytecode is used to provide executable content to Web pages and is the basis for dynamic service configuration in the Jini framework. While the Java Virtual Machine includes a bytecode verifier that checks bytecode programs before execution, and a bytecode interpreter that performs run-time tests, mobile code may still behave in ways that are harmful to users. We present techniques that insert run-time tests into Java code, illustrating them for Java applets and Jini proxy bytecodes. These techniques may be used to contain mobile code behavior or, potentially, insert code that is appropriate to profiling or other monitoring efforts. The main techniques are class modification, involving subclassing non-final classes, and method-level modifications that may be used when control over objects from final classes is desired.
Distribution and severity of hypoxic-ischaemic lesions on brain MRI following therapeutic cooling: selective head versus whole body cooling.

Background Whole body cooling (WBC) cools different parts of the brain uniformly, and selective head cooling (SHC) cools the superficial brain more than the deeper brain structures. In this study, the authors hypothesised that the hypoxic–ischaemic lesions on brain MRI following cooling would differ between modalities of cooling. Aim To compare the frequency, distribution and severity of hypoxic–ischaemic lesions on brain MRI between SHC or WBC. Methods In a single centre retrospective study, 83 infants consecutively cooled using either SHC (n=34) or WBC (n=49) underwent brain MRI. MRI images were evaluated by a neuroradiologist, who was masked to clinical parameters and outcomes, using a basal ganglia/watershed (BG/W) scoring system. Higher scores (on a scale of 0 to 4) were given for more extensive injury. The score has been reported to be predictive of neuromotor and cognitive outcome at 12 months. Results The two groups were similar for severity of depression as assessed by a history of an intrapartum sentinel event, Apgar scores, initial blood pH and base deficit and early neurological examination. However, abnormal MRI was more frequent in the SHC group (SHC 25 of 34, 74% vs WBC 22 of 49, 45%; p=0.0132, OR 3.4, 95% CI 1.3 to 8.8). Infants from the SHC group also had more severe hypoxic–ischaemic lesions (median BG/W score: SHC 2 vs WBC 0, p=0.0014). Conclusions Hypoxic–ischaemic lesions on brain MRI following therapeutic cooling were more frequent and more severe with SHC compared with WBC.
Transcranial Magnetic Stimulation Disrupts Eye-Hand Interactions in the Posterior Parietal Cortex

Recent neurophysiological studies have started to shed some light on the cortical areas that contribute to eye-hand coordination. In the present study we investigated the role of the posterior parietal cortex (PPC) in this process in normal, healthy subjects. This was accomplished by delivering single pulses of transcranial magnetic stimulation (TMS) over the PPC to transiently disrupt the putative contribution of this area to the processing of information related to eye-hand coordination. Subjects made open-loop pointing movements accompanied by saccades of the same required amplitude or by saccades that were substantially larger. Without TMS the hand movement amplitude was influenced by the amplitude of the corresponding saccade; hand movements accompanied by larger saccades were larger than those accompanied by smaller saccades. When TMS was applied over the left PPC just prior to the onset of the saccade, a marked reduction in the saccadic influence on manual motor output was observed. TMS delivered at earlier or later periods during the response had no effect. Taken together, these data suggest that the PPC integrates signals related to saccade amplitude with limb movement information just prior to the onset of the saccade.
Multiscale Modeling of Two Dimensional Rough Surface Contacts

A hybrid simulation method is used to study non-adhesive contact between two-dimensional self-affine rough surfaces. We find strong scale dependence as the contact dimensions decrease to the atomic scale. Both purely elastic and plastic materials are considered, and show different trends with system size. In all cases the contact area rises linearly with applied load, but the slope is substantially different from continuum predictions. We also examine the effect of commensurability between contacting surfaces. Contact area and frictional forces can be very different for commensurate and incommensurate surfaces, particularly for plastic materials.
Pension Plans 2014

Pension Plans 2014 discusses the popular cash balance plan, floor offset plan and cross tested plan from an actuarial viewpoint. Many retirement plan could be upgraded to take into account benefits from a pension plan if they were understood. Contributions to these plans are made on a "benefits" basis as opposed to a "contribution" basis. The plan will favor older highly compensated employees with less time to fund for retirement. These plans are popular with professionals who understand them even though they are not as simple as a 401(k) plan.
Structure and functional characterization of a bile acid 7α dehydratase BaiE in secondary bile acid synthesis

Conversion of the primary bile acids cholic acid (CA) and chenodeoxycholic acid (CDCA) to the secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA) is performed by a few species of intestinal bacteria in the genus Clostridium through a multistep biochemical pathway that removes a 7α-hydroxyl group. The rate-determining enzyme in this pathway is bile acid 7α-dehydratase (baiE). In this study, crystal structures of apo-BaiE and its putative product-bound [3-oxo-Δ(4,6) -lithocholyl-Coenzyme A (CoA)] complex are reported. BaiE is a trimer with a twisted α + β barrel fold with similarity to the Nuclear Transport Factor 2 (NTF2) superfamily. Tyr30, Asp35, and His83 form a catalytic triad that is conserved across this family. Site-directed mutagenesis of BaiE from Clostridium scindens VPI 12708 confirm that these residues are essential for catalysis and also the importance of other conserved residues, Tyr54 and Arg146, which are involved in substrate binding and affect catalytic turnover. Steady-state kinetic studies reveal that the BaiE homologs are able to turn over 3-oxo-Δ(4) -bile acid and CoA-conjugated 3-oxo-Δ(4) -bile acid substrates with comparable efficiency questioning the role of CoA-conjugation in the bile acid metabolism pathway.
Direct Measurement of Combustion Efficiency of a Dual-Mode Scramjet via TDLAT and SPIV (Invited)

The combustion efficiency of a scramjet is a metric that evaluates the overall performance of the engine. Until recently, combustion efficiency was measured using indirect approaches such as a 1-D control volume calculation or calorimeter and wall pressure tap measurements. A non-intrusive direct approach for the measurement of combustion efficiency is presented which combines the optical diagnostic techniques tunable diode laser absorption tomography (TDLAT) and stereoscopic particle image velocimetry (SPIV). Experimental results are presented for measurements on the University of Virginia’s supersonic combustion facility (UVaSCF) in both the scramand ram-modes of operation. The TDLAT/SPIV method directly measures the flux of water vapor exiting the dual-mode scramjet and compares this to the facility-measured injected H2 fuel flux. A complementary computational fluid dynamics (CFD) study was performed and results were available for only the scram-mode operating condition. The results reported show excellent agreement between the TDLAT/SPIV measured combustion efficiency and the CFD predicted combustion efficiency for the scram-mode of operation, both near 99%. The TDLAT/SPIV measured combustion efficiency for the ram-mode of operation is shown to be lower than that of the scram-mode operation, at 79%.
Does Alcohol Stimulate Gastric Secretion by Liberating Histamine

The stimulation of gastric secretion by alcohol is similar to the stimulation by histamine in a number of ways. They both stimulate the secretion of a juice that is highly acid but relatively low in peptic power.1 The stimulating effect of alcohol, like that of histamine, is much more resistant to the inhibitory effect of atropine than is the usual meal stimulus.2, 3 Similarly the stimulating effect of alcohol, like that of histamine, is more resistant to the inhibitory effect of fat feeding than is the usual meal stimulus.3 Such similarities suggest the possibility that these two substances, alcohol and histamine, act upon the stomach by a similar mechanism. There is no known reason to suppose that histamine acts through the mediation of alcohol, while there are some reasons to suppose that alcohol may act through the mediation of histamine. In the first place the general nature of the pharmacological action of alcohol is that of a depressant, so that a bona fide stimulation of gastric secretion is not c...
Anemia and malaria in a Yanomami Amerindian population from the southern Venezuelan Amazon

The prevalence and age distribution of anemia and malaria among Yanomami Amerindians undergoing sociocultural assimilation are described. Anemia and malaria proportions were determined in 103 individuals randomly selected from 515 villagers in Mavaca in the southern Venezuelan Amazon. The age and sex distribution reflected that of the entire village cluster. Anemia (hematocrit less than World Health Organization/Centers for Disease Control and Prevention reference values) was found in 91% of the study population. As a group, adults (> or = 15 years old) had the highest proportion of anemia (P=0.037). Adult females had lower mean hematocrit values than adult males (P=0.013). The anemia was predominantly hypochromic and microcytic (62%), a finding that could suggest a diagnosis of iron deficiency in the absence of known hereditary hemoglobinopathies in these Amerindians. Malaria was diagnosed in 14% overall. Children (< 10 years old) displayed the highest proportion of Plasmodium falciparum (17%) and P. vivax (14%) parasitemia, splenomegaly (94%), and fever (34%) (P=0.059, 0.039, 0.005, and 0.008, respectively). The high proportions of anemia and splenomegaly observed in the survey may be used as indicators of inadequately controlled malaria in this community. Further studies to assess the epidemiology of risk factors for the high prevalence of anemia, and predominance of P. falciparum infections in the area are urgently needed.
Reconstructing fish movements between coastal wetland and nearshore habitats of the Great Lakes

The use of resources from multiple habitats has been shown to be important to the production of aquatic consumers. To quantify the support of Great Lakes coastal wetland (WL) and nearshore (NS) habitats to yellow perch, we used otolith microchemistry to trace movements between the habitats. WL and NS water and fish samples were collected from lakes Huron and Michigan for water and otolith trace element analysis. Recently deposited otolith-edge Sr : Ca and Ba : Ca from otoliths were strongly correlated with the chemistry of the water in which fish were caught. In general, Sr : Ca and Ba : Ca in otoliths were significantly greater for individuals collected from WL areas. Because of these observed chemical differences between WL and NS habitats, quadratic discriminant function analysis (QDFA) was used to classify individuals with high accuracy to the habitat from which they were collected. We then combined the predictive abilities of QDFA with the otolith chemistry transect data that represents an individuals' entire life, to classify habitat use through each fish's life. Our results suggest larval use of WL habitats as well as three life histories for adult yellow perch. These strategies include (1) fish utilizing WL once annually (2) WL residents (3) WL residence as juveniles followed by movement to nearshore as adults. This application represents a novel use of transect otolith microchemistry to reconstruct fish movements between freshwater environments across entire life spans at fine scales. These results suggest that regular movements of fish may facilitate the production of coastal fishes in the Great Lakes.
Technical Aspects of Prone Dependent-Breast Scintimammography

Objective: We describe the technical aspects of scintimammography for detecting breast cancer in patients with positive mammography or positive clinical findings. Methods: Prone dependent-breast scintimammography was performed on 390 patients evaluated for the presence of breast cancer. Planar images were acquired beginning 5 min following intravenous injection of 20 mCi of 99mTc-sestamibi. Complementary imaging by SPECT was performed in 29 selected cases. Results: The prone dependent-breast position was well tolerated by patients, and resulted in high-quality images with easily identifiable anatomic landmarks. The sensitivity of scintimammography was 96% and specificity was 85% in 62 lesions with pathologic correlation. Interobserver agreement was 96% and intraobserver diagnostic variability was Conclusion: The high ratio of lesion-to-background sestamibi activity and excellent separation of breast tissue from the heart and liver and anterior chest wall provides a reliable noninvasive means of breast cancer detection.
Why Are the Gergonne and Soddy Lines Perpendicular? A Synthetic Approach

In any scalene triangle the three points of tangency of the incircle together with the three vertices can be used to define three new points which are, remarkably, always collinear. This line is called the Gergonne Line. Moreover cevians through these tan gent points are always concurrent at a common point that, together with the incen ter, defines a second line, the Soddy Line. Why should these lines be perpendicular? Beauregard and Suryanarayan [1] used Eucildean coordinates to establish these results, whereas Oldknow [2] used trilinear coordinates. But such a geometric gem deserves a synthetic geometric proof. We shall use the classical theorems of Ceva and Menelaus to define these lines and then establish their perpendicularity by using a certain inver sion. Let ABC be a scalene triangle. Let Q and / be its incircle and incenter, respectively. Circle Q touches sides AB, BC, and CA at Cx, Ax, and Bx, respectively. Lines AXBX and AB meet at C2, and points A2 and B2 are defined analogously. As usual, we set AB = c,BC = a, CA = b, and s = q?j??. Then it is well known that ABX = ACX = s ? a, BAi = BC\ = s ? b, and CAX = CBX ? s ? c.
E15. From Squares in a Square to Clones in Convex Figures

As I thought about Paul Erdős’s problem, it appeared natural for me to pose a “dual” problem, and thus give birth to the New Squares in a Square Problem.
Stereotactic Body Radiation Therapy and the Influence of Chemotherapy on Overall Survival for Large (≥5 Centimeter) Non-Small Cell Lung Cancer

Purpose Stereotactic body radiation therapy (SBRT) for ≥5 cm lesions is poorly defined, largely owing to the low sample sizes in existing studies. The present analysis examined the SBRT outcomes and assessed the effect of chemotherapy in this population. Methods and Materials The National Cancer Data Base was queried for primary non-small cell lung cancer ≥5 cm treated with SBRT (≤10 fractions). Patient, tumor, and treatment parameters were extracted. The primary outcome was overall survival (OS). Statistical methods involved Kaplan-Meier analysis and multivariable Cox proportional hazards modeling. Results From 2004 to 2012, data from 201 patients were analyzed. The median follow-up was 41.1 months. The median tumor size was 5.5 cm (interquartile range 5.0-6.0), with cT2a, cT2b, and cT3 disease in 24.9%, 53.2%, and 21.9%, respectively. The median total SBRT dose and fractionation was 50 Gy in 4 fractions, and 92.5% of the patients underwent SBRT with ≤5 fractions. The median OS was 25.1 months. Of the 201 patients, 15% received chemotherapy. The receipt of chemotherapy was associated with longer OS (median 30.6 vs 23.4 months; P =.027). On multivariable analysis, worse OS was seen with increasing age (hazard ratio [HR] 1.03; P =.012), poorly differentiated tumors (HR 2.06; P =.049), and T3 classification (HR 2.13; P =.005). On multivariable analysis, chemotherapy remained independently associated with improved OS (HR 0.57; P =.039). Conclusions SBRT has utility in the setting of tumors ≥5 cm, with chemotherapy associated with improved OS in this subset. These hypothesis-generating data now raise the necessity of performing prospective analyses to determine whether chemotherapy confers outcome benefits after SBRT.
A 10ns Bipolar Memory, Working with 18 I/O Bus

A double 576 bits random access memory organized as 2×32 words by 18 bits has been designed, completely tested, and qualified from a functionality and reliability point of view. The two major advantages of this memory are a good speedpower trade off for this particular type of organization and its ability to work with two independant 18 bits I/O busses.
In Situ X-ray Absorption Spectroscopy Studies of Discharge Reactions in a Thick Cathode of a Lithium Sulfur Battery

Lithium sulfur (Li-S) batteries are well known for their high theoretical specific capacities, but are plagued with scientific obstacles that make practical implementation of the technology impossible. The success of Li-S batteries will likely necessitate the use of thick sulfur cathodes that enable high specific energy densities. However, little is known about the fundamental reaction mechanisms and chemical processes that take place in thick cathodes, as most research has focused on studying thinner cathodes that enable high performance. In this work, in situ X-ray absorption spectroscopy at the sulfur K-edge is used to examine the back of a 115 μm thick Li-S cathode during discharge. Our results show that in such systems, where electrochemical reactions between sulfur and lithium are likely to proceed preferentially toward the front of the cathode, lithium polysulfide dianions formed in this region diffuse to the back of the cathode during discharge. We show that high conversion of elemental sulfur is achieved by chemical reactions between elemental sulfur and polysulfide dianions of intermediate chain length (Li2Sx, 4 ≤ x ≤ 6). Our work suggests that controlling the formation and diffusion of intermediate chain length polysulfide dianions is crucial for insuring full utilization of thick sulfur cathodes.
How Anxious Do You Think I Am? Relationship between State and Trait Anxiety in Children with and without ASD during Social Tasks.

Individuals with autism spectrum disorder (ASD) often exhibit increased anxiety, even in non-stressful situations. We investigate general anxiousness (anxiety trait) and responses to stressful situations (anxiety state) in 22 adolescents with ASD and 32 typically developing controls. We measured trait anxiety with standardized self- and parent-reported questionnaires. We used a Biopac system to capture state anxiety via skin conductance responses, mean heart rate and heart rate variability during high- and low-anxiety tasks. Results reveal higher trait anxiety in adolescents with ASD (p < 0.05) and no group difference in state anxiety. Increased parent-reported trait anxiety may predict decreased state anxiety during high-stress conditions. Together, these findings suggest that higher trait anxiety may result in dampened physical responses to stress.
Concerted and mosaic evolution of functional modules in songbird brains

Vertebrate brains differ in overall size, composition and functional capacities, but the evolutionary processes linking these traits are unclear. Two leading models offer opposing views: the concerted model ascribes major dimensions of covariation in brain structures to developmental events, whereas the mosaic model relates divergent structures to functional capabilities. The models are often cast as incompatible, but they must be unified to explain how adaptive changes in brain structure arise from pre-existing architectures and developmental mechanisms. Here we show that variation in the sizes of discrete neural systems in songbirds, a species-rich group exhibiting diverse behavioural and ecological specializations, supports major elements of both models. In accordance with the concerted model, most variation in nucleus volumes is shared across functional domains and allometry is related to developmental sequence. Per the mosaic model, residual variation in nucleus volumes is correlated within functional systems and predicts specific behavioural capabilities. These comparisons indicate that oscine brains evolved primarily as a coordinated whole but also experienced significant, independent modifications to dedicated systems from specific selection pressures. Finally, patterns of covariation between species and brain areas hint at underlying developmental mechanisms.