cssi/SciSciGPT-SciSciNet huggingface dataset:
Tax: Different, not Exceptional

Tax is different from other fields of law, just as any field of law is different from others. But tax scholarship, judicial opinions in tax litigation, and public attitudes toward taxation have long claimed more than difference in doctrinal details. They have claimed that tax is different in kind from other fields of law— that it is unique, that it is exceptional. Even though the Supreme Court seemed to kill tax exceptionalism in its 2011 decision in Mayo Foundation for Medical Education & Research v. United States, claims of tax exceptionalism have hardly abated. In this article we take on the concept of tax exceptionalism directly. We begin by accepting that scholars, judges, and taxpayers experience tax as different from other fields of law, but we then tackle the question whether these differences add up to tax exceptionalism. Our view is that they do not, and we believe that pragmatism provides a useful framework for identifying just what is mistaken about claims of tax exceptionalism. From a pragmatist perspective, the question is whether it is useful to believe that the accumulation of the various differences between tax and other fields of law makes tax fundamentally different from the others. We conclude and demonstrate that it is not useful to characterize tax as exceptional; questions about the differences between tax and other fields of law can be fully answered by focusing on a specific issue and then deciding whether there is something about tax that requires that particular issue to be treated differently in tax. That is precisely what the Supreme Court did in Mayo. Rather than treat tax as different in kind from other fields of law, the Mayo Court treated the tax issue before it as it would any other issue in any other field, thereby rejecting the vary premise of tax exceptionalism. In prior work we have claimed that tax exceptionalism has had the insidious effect of stunting the growth of a robust tax jurisprudence by insulating tax from other fields of law, disparaging the lessons that tax can learn from careful attention to those other fields, undermining the legitimacy of tax administration, and perhaps even contributing to the relative lack of diversity in the tax bar. But here our focus is different. In light of the persistence of the concept of tax exceptionalism, which we believe is fueled by the salience of the differences between tax and other fields of law, we tackle the effect of those differences directly. We do not minimize them or deny their existence; rather, we show that despite their existence and their number they should not lead to the conclusion that tax is exceptional because the concept of tax exceptionalism is analytically empty. It is useless.
Investigating the Effects of IF Bandwidth and Averaging on Calibrated Scattering-Parameter Measurements

We investigate the effects of IF (intermediate-frequency) bandwidth and averaging on calibrated scattering-parameter measurements made with a vector network analyzer. We begin by examining the sweep times and noise-floor levels for various combinations of the two settings. Then, we study how these settings influence calibrated measurements and compare the results to uncertainties due to systematic and random effects for devices with varying insertion-loss values.
Effect of external compression on femoral retrograde shear and microvascular oxygenation in exercise trained and recreationally active young men.

Retrograde shear causes endothelial damage and is pro-atherogenic. The purpose of our study was to examine the impact of vascular remodeling from habitual exercise training on acute changes in retrograde shear and microvascular oxygenation (SMO2) induced via 30 min of external compression. Participants included 11 exercise trained (ET) men (Division I track athletes; age 20 ± 3 years) and 18 recreationally active (RA) men (age 23 ± 5 years). Near-infrared spectroscopy (NIRS) was used to measure vastus medialis SMO2. Doppler-ultrasound was used to assess SFA intima-media thickness, diameter and flow velocity to derive retrograde shear. Vascular measures were made at baseline (BASELINE), during a sham condition (calf compression to 5 mmHg, SHAM) and during the experimental condition (calf compression to 60 mmHg, EXP). Compared to RA, ET had larger SFA diameters (0.66 ± 0.06 vs 0.58 ± 0.06 cm, p < 0.05) and lower SFA IMT (0.33 ± 0.03 vs 0.36 ± 0.07 mm, p < 0.05). Retrograde shear increased similarly in both groups during EXP (p < 0.05) but ET men had lower overall retrograde shear during the conditions (BASELINE 75.8 ± 26.8 vs EXP 88.2 ± 16.9 s−1) compared to RA men (BASELINE 84.4 ± 23.3 vs EXP 106.4 ± 19.6 s−1p < 0.05). There was a similar increase in SMO2 from BASELINE to SHAM (ET + 8.1 ± 4.8 vs RA + 6.4 ± 9.7%) and BASELINE to EXP (ET + 8.7 ± 6.4 vs RA + 7.1 ± 9.0%) in both groups. Beneficial vascular remodeling in ET men is associated with lower retrograde shear during external compression. Acute increases in retrograde shear with external compression do not detrimentally impact microvascular oxygenation.
Modeling Expected Reaching Error and Behaviors for Motor Adaptation

Motor adaptation studies can provide insight into how the brain handles ascending and descending neural signals during motor tasks, revealing how neural pathologies affect the capacity to learn and adapt to movement errors. Such studies often involve reaches towards prompted target locations, with adaptation and learning quantified according to Euclidean distance between reach endpoint and target location. This paper describes methods to calculate steady-state error using knowledge of the distribution of univariate, bivariate, and multivariate steady-state reaches. Additionally, in cases where steady-state error is known or estimated, it does not fully describe underlying reach distributions that could be observed at steady-state. Thus, this paper also investigates methods to describe univariate, bivariate, and multivariate steady-state reaching behavior using knowledge of the estimated steady-state error. These methods may yield a clearer understanding of adaptation and steady-state reaching behavior, allowing greater opportunities for inter-study comparison and modeling.
The Relationship of Breastfeeding and Infant Eczema: The Role of Reverse Causation

Aim: Although reverse causation is well known in the breastfeeding–allergy arena, only a few studies have used a valid statistical method to test its occurrence. This study aimed to illustrate reve...
Endosomal Wnt signaling proteins control microtubule nucleation in dendrites

Dendrite microtubules are polarized with minus-end-out orientation in Drosophila neurons. Nucleation sites concentrate at dendrite branch points, but how they localize is not known. Using Drosophila, we found that canonical Wnt signaling proteins regulate localization of the core nucleation protein γTubulin (γTub). Reduction of frizzleds (fz), arrow (low-density lipoprotein receptor-related protein [LRP] 5/6), dishevelled (dsh), casein kinase Iγ, G proteins, and Axin reduced γTub-green fluorescent protein (GFP) at branch points, and two functional readouts of dendritic nucleation confirmed a role for Wnt signaling proteins. Both dsh and Axin localized to branch points, with dsh upstream of Axin. Moreover, tethering Axin to mitochondria was sufficient to recruit ectopic γTub-GFP and increase microtubule dynamics in dendrites. At dendrite branch points, Axin and dsh colocalized with early endosomal marker Rab5, and new microtubule growth initiated at puncta marked with fz, dsh, Axin, and Rab5. We propose that in dendrites, canonical Wnt signaling proteins are housed on early endosomes and recruit nucleation sites to branch points.
MinENet: A Dilated CNN for Semantic Segmentation of Eye Features

Fast and accurate eye tracking is a critical task for a range of research in virtual and augmented reality, attention tracking, mobile applications, and medical analysis. While deep neural network models excel at image analysis tasks, existing approaches to segmentation often consider only one class, emphasize classification over segmentation, or come with prohibitively high resource costs. In this work, we propose MinENet, a minimized efficient neural network architecture designed for fast multi-class semantic segmentation. We demonstrate performance of MinENet on the OpenEDS Semantic Segmentation Challenge dataset, against a baseline model as well as standard state-of-the-art neural network architectures - a convolutional neural network (CNN) and a dilated CNN. Our encoder-decoder architecture improves accuracy of multi-class segmentation of eye features in this large-scale high-resolution dataset, while also providing a design that is demonstrably lightweight and efficient.
EUS-directed transgastric endoscopic retrograde cholangiopancreatography versus laparoscopic-assisted ERCP versus deep enteroscopy-assisted ERCP for patients with RYGB.

Background and study aims Endoscopic ultrasound-directed transgastric endoscopic retrograde cholangiopancreatography (ERCP) (EDGE) is a novel technique for managing pancreaticobiliary diseases in patients with a history of Roux-en-Y Gastric Bypass (RYGB). It has shown to have high technical success rates and fewer adverse events as compared to laparoscopic-assisted ERCP (LA-ERCP). We compared the technical success and clinical outcomes of EDGE vs. LA-ERCP vs. E-ERCP. Patients and methods A retrospective chart review was performed for 56 patients, of whom 18 underwent LA-ERCP, 12 underwent E-ERCP, and 26 had EDGE, and a comparison of technical success and complication rates was done. Results Baseline demographic characteristics of patients undergoing these procedures, including age and gender, were comparable. The technical success rate for patients in the EDGE group were 100 % (n = 26), compared with 94 % (n = 17) and 75 % (n = 9) in the LA-ERCP and E-ERCP groups (P = 0.02). In the EDGE group, 8 % of patients (n = 2) had bleeding, and 4 % of patients (n = 1) had lumen-apposing metal stent migration occur during the procedure. In the LA-ERCP group 6 % (n = 1) of patient had bleeding, 6 % (n = 1) post-ERCP pancreatitis and 6 % (n = 1) were diagnosed with an intra-abdominal infection post-procedure. Time to complete the EDGE procedure was significantly shorter at 79 ± 31 mins, compared with 158 ± 50 mins for LA-ERCP and 102 ± 43 mins for E-ERCP (P Conclusion EDGE is a novel procedure with short procedure times and an effective alternative to LA-ERCP and E-ERCP in management of pancreaticobiliary diseases in patients with a history of RYGB.
XMM-Newton Observation of Fe Kα Emission from a Broad Absorption Line Quasar: Markarian 231

We present results from a 20 ks XMM-Newton observation of Mrk 231. The European Photon Imaging Camera (EPIC) spectral data reveal strong line emission due to Fe Kα, which has rarely been detected in this class, as broad absorption line quasars (BAL QSOs) are very faint in the X-ray band. The line energy is consistent with an origin in neutral Fe. The width of the line is equivalent to a velocity dispersion ~18,000 km s-1, and thus the line may be attributed to transmission and/or reflection from a distribution of emitting clouds. If, instead, the line originates in the accretion disk, then the line strength and flat X-ray continuum support some contribution from a reflected component, although the data disfavor a model in which the hard X-ray band is purely reflected X-rays from a disk. The line parameters are similar to those obtained for the Fe Kα line detected in another BAL QSO, H1413+117.
Long-Term Survival and Causes of Death in Children with Trisomy 21 After Congenital Heart Surgery.

Objective To evaluate long-term transplant-free survival and causes of death in the trisomy 21 (T21) population after surgery for congenital heart disease (CHD) in comparison with patients who are euploidic. Study design This is a retrospective cohort study from the Pediatric Cardiac Care Consortium, enriched with prospectively collected data from the National Death Index and the Organ Procurement and Transplantation Network for patients with sufficient direct identifiers. Kaplan-Meier survival plots were generated and multivariable Cox proportional hazards models were used to examine risk factors for mortality between patients with T21 and 1:1 matched patients with comparable CHD who are euploidic. Results A long-term survival analysis was completed for 3376 patients with T21 (75 155 person-years) who met inclusion criteria. The 30-year survival rate for patients with T21 ranged from 92.1% for ventricular septal defect to 65.3% for complex common atrioventricular canal. Of these, 2185 patients with T21 were successfully matched with a patient who was euploidic. After a median follow-up of 22.86 years (IQR, 19.45-27.14 years), 213 deaths occurred in the T21 group (9.7%) compared with 123 (5.6%) in the euploidic comparators. After adjustment for age, sex, era, CHD complexity, and initial palliation, the hazard ratio of CHD-related mortality was 1.34 times higher in patients with T21 (95% CI, 0.92-1.97; P = .127). Conclusions CHD-related mortality for patients with T21 after cardiac surgical intervention is comparable with euploidic comparators. Children with T21 require lifelong surveillance for co-occurring conditions associated with their chromosomal abnormality.
2020 Sidney Licht lecture: The metabolic syndrome and obesity negatively impact function

There are important connections between metabolic abnormalities and poor function. This is relevant because the World Health Organization and the Centers for Disease Control and Prevention indicate that we are facing an epidemic of obesity and pre-diabetes/diabetes, which present substantial and challenging health-care concerns. Most of these people have metabolic syndrome (MS), including hypertension, hyperglycemia, obesity, hyperlipidemia, and hypertriglyceridemia. The relationships among function and MS seem intuitive and reasonable. One link could include abnormal energy production and mitochondrial efficiency in the generation of adenosine triphosphate(ATP). Another link might result from insulin resistance and its impact on interfering with glucose uptake. Sedentary behavior with increased waist circumference is associated with obesity and fatigue. In addition, there has been a reported association between sarcopenia and obesity, both associated with reduced function. The health implications include increased all-cause mortality and is thought to be mediated through processes that include inflammation of muscle and MS. Human function is likely to be influenced by physiological and anatomical as well as environmental and personal factors. These factors will be discussed in an effort to integrate them and explain why people with MS have significant functional problems. The premise is that fatigue is frequently reported, negatively impacts activity and exercise tolerance, and may explain why this group of people is so sedentary. We have effective treatments for fatigue that is associated with MS and obesity. Unfortunately, at this time in the history of medicine, the best treatments are behavioral and require patience and commitment. Risks are very low, rewards are high but not instantaneous.
Plain Language Summaries Required for Submission to the Space Weather Journal

The Space Weather editorial board is mandating Plain Language Summaries to enhance access and create new ways for the information to be shared.
A Precedent for the Unprecedented: Historical Reflections on Plague, Quarantine, and Islamic Law in Morocco (preprint)

Historical Reflections on Plague, Quarantine, and Islamic Law in Morocco, written as part of the Islamic Law Blog's 2020 Roundtable on pandemics.
Application of Biomedical Molecular Techniques in Environmental Sciences

Biomarkers are chemical or biological markers that are indicators of internal exposures, disease status, or preclinical precursors to the onset of disease. In the last 30 years, major advances have been made in our ability to measure biomarkers that can indicate external exposures to environmental contaminants, track the progress of metabolic processes that convert them to toxins, and to determine the genetic susceptibility of certain populations to the impacts of environmental exposures. The use of biomarkers of exposure and biomarkers of disease in Medical Geology has been briefly disc in Chap. 2 of this book. The use of internal biomarkers in pharmacokinetic models to estimate external exposures is discussed in Chap. 9 by Bowers (2021) in this book. The purpose of this chapter is to introduce the theory and application of current techniques used in research and diagnostic laboratories in order to assess biological impact of environmental exposures. Environmental exposure examples which can be analyzed by each technique will also be discussed. Biomedical techniques are a broad group of scientific methods and assays, which have a wide clinical application across medicine. This chapter is designed to increase your theoretical, conceptual, and practical understanding of biomedical techniques used in Molecular Epidemiology.
Evaluation of Transformer Leakage Inductance Using Magnetic Image Method

Leakage inductance is a critical design element of a transformer in a galvanically isolated power converter. For multi-objective optimization-based designs of power converters, analytical leakage inductance models that are computationally efficient and accurate are preferred over the finite element methods (FEMs). In this article, three new analytical models are proposed—triple-2-D, double-2-D, and single-2-D—that are formulated using the magnetic image method. These 2-D models are used to calculate the leakage inductance of a partially filled shell-type transformer having a circular center leg, and the resulting errors are less than 1.25% for each model when compared to the 3-D FEM simulated value of the leakage inductance. Additionally, three different conductor models are considered, and their relative accuracies and computational efficiencies are investigated. Furthermore, a variable inductance transformer (VIT) is designed, whose leakage inductance can be modified by moving one of the windings vertically along the central core leg. The analytically evaluated variable leakage inductances of the VIT are in good agreement with the 3-D FEM simulated and experimentally measured values.
Consistently estimating the selectivity of conjuncts of predicates

Cost-based query optimizers need to estimate the selectivity of conjunctive predicates when comparing alternative query execution plans. To this end, advanced optimizers use multivariate statistics (MVS) to improve information about the joint distribution of attribute values in a table. The joint distribution for all columns is almost always too large to store completely, and the resulting use of partial distribution information raises the possibility that multiple, non-equivalent selectivity estimates may be available for a given predicate. Current optimizers use ad hoc methods to ensure that selectivities are estimated in a consistent manner. These methods ignore valuable information and tend to bias the optimizer toward query plans for which the least information is available, often yielding poor results. In this paper we present a novel method for consistent selectivity estimation based on the principle of maximum entropy (ME). Our method efficiently exploits all available information and avoids the bias problem. In the absence of detailed knowledge, the ME approach reduces to standard uniformity and independence assumptions. Our implementation using a prototype version of DB2 UDB shows that ME improves the optimizer's cardinality estimates by orders of magnitude, resulting in better plan quality and significantly reduced query execution times.
Macromolecular relaxation in the damped torsional oscillator and statistical segment models

Abstract : The damped torsional oscillator models of polymer chain dynamics is compared with that of Rouse and Bueche where the basic responding unit is the statistical segment of approximately ten carbon-carbon links. The monomeric torsional oscillator approach appears to correspond better to physical reality for high frequency dielectric and nuclear magnetic resonance relaxations. Effects of coupling of torsional oscillators in not only one but also three dimensional arrays are discussed. Response of three dimensional quasi-lattices such as might occur with organic glasses is predicted to be much sharper than the one dimensional analog. (Author)
The role of Rab27a in the regulation of neutrophil function

Neutrophils are central regulators of the innate immune response and help shape the adaptive immune response. Malfunction and unregulated neutrophil activation leads to disease and inflammation. During the host response to infection, neutrophils display several mechanisms of defense mediated by their arsenal of granular proteins. Regulation of granular trafficking, docking and fusion is at the core of the neutrophil defense response to pathogens. The small GTPase Rab27a has emerged as a central regulator of the neutrophil response through its tight control of vesicular trafficking and degranulation. This review focuses on the latest research that has led to the characterization of Rab27a as an essential regulator of neutrophil function.
Adrenergic regulation of ileocecal sphincter function in the cat

Abstract The neural control of the ileocecal sphincter (ICS) is poorly understood. The purpose of this study is to evaluate: (a) ICS and blood pressure responses to alpha- and beta-adrenergic agonists and antagonists; and (b) the ICS response to direct stimulation or section of the greater splanchnic nerves. In the anesthetized cat, the ICS is 1.36 ± 0.05 cm (mean ± SEM) in length and maintains a basal pressure of 23.5 ± 1.5 mm Hg. Phenylephrine gave a dose-dependent increase in ICS pressure with a maximal response of 16.0 ± 2.0 mm Hg. Isoproterenol gave a maximum reduction in ICS pressure of 51.2 ± 3.4%. Phentolamine decreased ICS pressure by 61.3 ± 2.8%, but propranolol had no effect. Section of the greater splanchnic nerve had no effect on basal ICS pressure. Electrical stimulation of the cut peripheral end of the nerve produced a maximal increase in sphincter pressure of 16.0 ± 1.5 mm Hg at 10 V, 10 Hz. This response was antagonized by phentolamine, but not by propranolol or atropine. Stimulation of the central end of the splanchnic nerve had no effect on ICS pressure. Adrenergic drugs and splanchnic stimulation did not affect ileal or colonic motility. These studies indicate that: (a) the ICS is a high pressure zone that shows an excitatory response to peripheral splanchnic nerve stimulation and alpha-adrenergic agonists; (b) beta-adrenergic stimulation inhibits ICS pressure, but plays no apparent role in the response to splanchnic stimulation; and (c) the ICS responds differently than the adjacent ileum or colon.
LIGHTNING-a WDM-based distributed shared memory clustering testbed: system architecture and protocols

This presentation describes a hierarchical optical structure for high-performance processor clustering. The architecture is based on wavelength division multiplexing (WDM) which enables multiple multi-access channels to be realized on a single optical fiber. The objective of the hierarchical architecture is to achieve scalability yet avoid the requirement of multiple wavelength tunable devices per node. Furthermore, single-hop all-optical communication is achieved: a packet remains in the optical form from source to destination and does not require intermediate routing or o/e conversion. The wavelength multiplexed hierarchical structure features wavelength channel re-use at each level, allowing scalability to very large system sizes. It partitions the traffic between different levels of the hierarchy without electronic intervention in a combination of wavelength- and space-division multiplexing. A significant advantage of the proposed structure is its ability to dynamically vary the bandwidth provided to different levels of the hierarchy.
Who's Guarding the Henhouse? How the American Prosecutor Came to Devour Those He is Sworn to Protect

Every day, all across America, prosecutors charge people with crimes that the criminal justice system is not sufficiently funded to handle. Most of the accused are indigent citizens forced to rely on the services of over-burdened public defenders. In a system that lacks the resources to resolve these cases at trial, or even to spend the requisite capital at the pre-trial stage, prosecutors have found creative ways to process the vast majority of these cases without the expense associated with providing the accused actual justice. With an ever-expanding list of behaviors and actions deemed criminal, and increasingly harsh sentencing options for these offenses, prosecutors are able to put pressure on most criminal defendants to give up many of their most fundamental Constitutional rights and plead guilty to avoid potentially draconian outcomes. While many prosecutors see this as a cheap and effective way to justly punish wrongdoers, this course of action has largely replaced our reliance on principles of justice such as the right to counsel, the right to trial by jury, and the role of an independent judiciary determining a punishment that fits the crime. By undermining basic principles of justice so crucial to our legal system, one might ask whether this way of handling criminal cases is antithetical to the prosecutor’s critical role as minister of justice. This article argues that when a prosecutor charges more cases than he knows the system can justly resolve due to resource limitations, he violates his ethical obligation to seek justice. It further argues that many prosecutors fail to appreciate how they violate their duty to justice because of a culture that promotes this behavior. Finally, it suggests that prosecutors must be trained to resist these systemic pressures, and to act in accordance with values consistent with justice, if they are to fulfill their intended role in the criminal justice system.
Studying the effect of aspect ratio and core displacement on the resonance wavelengths of a nanoegg in the quasistatic regime

In this paper we use an efficient formulation for the problem of scattering by a nanoegg to study the effect of the aspect ratio and the core displacement on the nanoegg resonance properties. The formulation is in the quasistatic regime and utilizes the spherical harmonic translation relations in order to arrive at system of equations in the spherical harmonic expansion coefficients of the potential function that can be efficiently and accurately solved.
Cutting Edge Technology in Breast Imaging: PACS

The integration of picture archiving and communications systems (PACS) into our private practice in order to create a more efficient workflow and office environment has been a challenging and time-consuming work-in-progress affair. While transitioning to a digital environment, we began to incorporate PACS into our daily practice. Since 2005, we have been working with our PACS vendor to continue to change our PACS to suit our needs. We worked through initial connectivity and technical issues, and these problems were resolved through the combined efforts of our PACS vendor, the imaging vendors, and our dedicated homegrown IT and PACS departments. As time has progressed, over the last 4 years so has the role PACS has played in our office. We continually make innovations within our facility to create more efficient workflow and office environment, but also continue to provide excellent patient care, and our PACS continue to play a major role.
Sequential Induction of Phenylalanine Ammonia-lyase and a Lyase-inactivating System in Potato Tuber Disks

The light induced synthesis of phenylalanine ammonia-lyase in disks cut from potato tubers is very sensitive to cycloheximide. Synthesis is inhibited 50% in disks cultured on 5 mum cycloheximide instead of water and almost completely in disks aged in the presence of 10 mum inhibitor. Inhibition is irreversible. Fresh disks exposed only 1 hour to 10 mum cycloheximide do not synthesize enzyme during the subsequent 24 hours.Normally a maximal enzyme activity develops in disks about 24 hours after being cut from the tuber. Thereafter enzyme activity declines. The disappearance of enzyme is not affected by concentrations of cycloheximide sufficient to inhibit the synthesis of enzyme initially. No disappearance of enzyme is noted during the initial phase of induction if enzyme synthesis is inhibited by cycloheximide. However, enzyme does disappear from the tissue if more than half the maximal enzyme content is allowed to form before synthesis is inhibited. If cycloheximide at a concentration 10-fold that needed to inhibit synthesis completely is added to disks after they have attained a maximal enzyme level, then subsequent loss of enzyme activity from the tissue is prevented. The initial stability of the enzyme in the absence of further synthesis and the inhibition of enzyme disappearance by high concentrations of cycloheximide suggest A) that early phases of induction involve synthesis of enzyme protein in the absence of turnover, B) that a system capable of degrading or inactivating the lyase subsequently forms in the tissue, and C) that the formation of the degrading or inactivating system requires protein synthesis.The effect of cycloheximide on uptake and incorporation of l-isoleucine-U-(14)C into soluble and insoluble proteins of tuber disks was also examined. During induction the rate of uptake increased 3 to 4-fold, and the rate of incorporation into protein, corrected for change in uptake, increased 25-fold. Cycloheximide inhibited incorporation of isoleucine-(14)C into proteins of fresh disks more than 80%. It did not prevent activation of general protein synthesis during induction and inhibited incorporation in induced disks only 20%. At all times incorporation of amino acid into the soluble, lyase-rich, protein fraction was more sensitive to cycloheximide than the insoluble fraction.
Evidence for sinking of small particles into substrates and implications for heterogeneous catalysis

THE shapes and structures of small metal particles (1–10 nm in size) supported on oxide substrates and the effect of substrate-particle interactions in such systems are of substantial importance for heterogeneous catalysis. Here we present, for the first time, experimental evidence using atomic-resolution electron microscopy of gold clusters on MgO smoke particles, which shows that a small particle sitting on a substrate may be thermodynamically unstable and can 'sink' into the substrate. A simple theoretical model is proposed to explain this effect. The results may be of importance in small-particle catalyst systems. The stability of the particle with respect to sinking, and hence reactivity, can be changed by chemisorption of impurities, which will change the surface free energies. A plausible model of catalyst deactivation is that the particle sinks diffusively into the substrate in the course of time. Regeneration of the catalyst could require changing the surface free energy by chemisorption, causing the particle to float back onto the substrate surface.
Simultaneous Cooperative Exploration and Networking based on Voronoi Diagrams

Abstract We develop a strategy that enables multiple intelligent vehicles to cooperatively explore complex territories. Every vehicle deploys communication devices and expands an information network while constructing a topological map based on Voronoi diagrams. As the information network weaved by each vehicle grows, intersections eventually happen so that the topological maps are shared. This allows for distributed vehicles to share information with other vehicles that have also deployed communication devices. Our exploration algorithms are provably complete under mild technical assumptions. A performance analysis of the algorithms shows that in a bounded workspace, the time spent to complete the exploration decreases as the number of vehicles increases. We further provide an analytical formula for this relationship. Time efficiency of the algorithms is demonstrated in MATLAB simulation.
Inhibition of homogeneous angiotensin-converting enzyme of rabbit lung by synthetic venom peptides of Bothrops jararaca.

Abstract Seven synthetic peptides, identical to those found in the venom of Bothrops jararaca, inhibited the peptidolytic activity of homogeneous (275-fold purified) angiotensin-converting enzyme from rabbit lung on [Ile5]-angiotensin I (angiotensin I), and on hippuryl- l -histidyl- l -leucine (Hip-His-Leu), with I50 values ranging from 0.06 to 76 μM. The nonapeptide, SQ 20 88 i (Pyr-Trp-Pro-Arg-Pro-Gln-Ile-Pro-Pro), and decapeptide, SQ 20 858 (Pyr-Asn-Trp-Pro-His-Pro-Gln-Ile-Pro-Pro), were competitive with both substrates (angiotensin I and Hip-His-Leu), but the pentapeptide, SQ 20 475 ∗∗ (Pyr-Lys-Trp-Ala-Pro) was a “mixed” competitive and noncompetitive inhibitor. The Ki values (enzyme-inhibitor dissociation constants) calculated for SQ 20 881, SQ 20 858 and SQ 20 475 did not depend significantly on the substrate employed, but were altered by differences in pH. At pH 7.5, with angiotensin I as substrate, the Ki values were: SQ 20 475, 0.09 μM; SQ 20 881, 0.8 μM; and SQ 20 858, 4.3 μM. At pH 8.3, with Hip-His-Leu as substrate, the corresponding values were lower: 0.06, 0.10 and 0.74 μM. The most potent of the inhibitors in vitro, SQ 20 475, could be cleaved and inactivated when incubated with homogeneous angiotensin-converting enzyme in the absence of other substrates and of the activator, Cl−; the other six peptides could not serve as substrates for the enzyme. The nonapeptide, SQ 20 881, appears to be the best of the synthetic venom peptides for use in studying the role of the renin (EC 3.4.4.15)-angiotensin system in physiological and pathological processes.
1,25-dihydroxyvitamin D reduces parathyroid hormone receptor number in ROS 17/2.8 cells and prevents the glucocorticoid-induced increase in these receptors: relationship to adenylate cyclase activation.

We have previously shown that 1,25-dihydroxyvitamin D [1,25-(OH)2D3] and glucocorticoid modulate adenylate cyclase activation by PTH in osteoblast-like cells. Here we examine whether steroid effects on PTH receptor density explain the modulation of PTH action. Receptor assays were performed on late logarithmicphase monolayers of ROS 17/2.8 cells using human PTH-like peptide (hPLP) as radioligand. Kd and receptor density were computed from competition of tracer amounts of [125I-Tyr36]hPLP-(1–36) with unlabeled hPLP-(1–36) (0.1–30 nM). Steroid treatment had little or no effect on affinity for ligand. Pretreating cells with 10 nM 1,25-(OH)2D3 for 48 h decreased PTH receptor number to 17% of control values. Treating cells with 10 nM of the glucocorticoid triamcinolone acetonide (TRM) increased receptor number 10-fold, but simultaneous treatment with 1,25-(OH)2D3 (10 nM) completely prevented this receptor increase. Steroid effects required 13–18 h of treatment. Dose-response relationships for steroid modulation, determined from binding at 0.17 nM radioligand, indicated an EC50 of 0.3 nM for glucocorticoid augmentation of PTH receptor number and 0.02 nM for 1,25-(OH)2D3 reduction of receptor number in the presence or absence of the maximum TRM effect. The initial rate of cAMP production by receptor-saturating concentrations of PTH was 11,500 molecules per receptor per minute in untreated cells, comparable to reported turnover numbers for mammalian adenylate cyclase. Control experiments were validated measuring cAMP in intact cells as an indicator of adenylate cyclase activity. Cyclic AMP production was reduced 63% by 1,25-(OH)2D3 (10 nM) treatment. Glucocorticoid (10 nM) enhanced cAMP production twofold but reduced cAMP generation per receptor by 80%. We conclude that 1,25-(OH)2D3 reduction of PTH receptor number modulates ROS cell responses to PTH and prevents glucocorticoid-enhanced PTH action. The data also suggest that other components of the adenylate cyclase complex limit amplification of the PTH signal when PTH receptor number is elevated by glucocorticoid treatment.
Variational methods for crack intensity factors and plastic regions of dugdale model

Abstract The mixed boundary value problems for cracks can be reduced to Fredholm integral equations. In general, these integral equations have complicated kernels and have to be solved by approximate methods. In this paper variational methods are presented to obtain approximate solutions of the integral equations. The classical variational principle is used to find the stress intensity factors while Noble's modified variational method gives the plastic regions of Dugdale cracks. A straight crack in an infinite plate and a penny-shaped crack in an infinite medium are taken as examples to illustrate the variational methods. The approximate results are fairly close to the exact ones. The method is simple and quite general.
Rare earth metals: A strategic concern

Rare earth metals are important inputs into the development and manufacturing of many green and high-tech products. It is an international strategic concern that much of the supply chain for rare earth metals is based in China. This paper looks at issues involving the availability of rare earth metals, its use, China’s involvement, and pricing to better understand the strategic issues and their impact. It is concluded that the major need is to develop rare earth metal processing and use capacity outside of China. However, this will not be easy to do because of economic and social factors.
Once is Enough: N400 Indexes Semantic Integration of Novel Word Meanings from a Single Exposure in Context.

We investigated the impact of contextual constraint on the integration of novel word meanings into semantic memory. Adults read strongly or weakly constraining sentences ending in known or unknown (novel) words as scalp-recorded electrical brain activity was recorded. Word knowledge was assessed via a lexical decision task in which recently seen known and unknown word sentence endings served as primes for semantically related, unrelated, and synonym/identical target words. As expected, N400 amplitudes to target words preceded by known word primes were reduced by prime-target relatedness. Critically, N400 amplitudes to targets preceded by novel primes also varied with prime-target relatedness, but only when they had initially appeared in highly constraining sentences. This demonstrates for the first time that fast-mapped word representations can develop strong associations with semantically related word meanings and reveals a rapid neural process that can integrate information about word meanings into the ...
Professor Mills on the Calling of Sociology

Prosperity brings its own disorders. When American sociology, unregarded and undemanding, was pleased to be allowed an academic existence, it suffered from lack of self-confidence. The other academic disciplines thought little of it and it was unknown to the outside world. Its rustic naivete and its simple enthusiasm aroused no antipathies within its own parochial confines. When, however, it began to thrive—when its output became more interesting intellectually, as it did in the i930's, and the attention of the great world, of foundations, governments, and publicists, was drawn toward it—it also began to suffer the malaise of the prosperous. Professor Robert Lynd was probably the first of those who found that the subject they had fostered had not kept pace with their own political development toward the radical populism which was one trend in the leftward movement of the 1930's. In Knowledge for What? he accused his sociological colleagues of the evasion of the responsibilities implicit in the potentialities of their discipline. He was strongly for planning, for equality, and above all for radical political engagement; American sociologists—indeed, American social scientists in general—were charged with indifference, academic triviality, and subservience to the reigning authorities of state and economy.
Good Practice With Multiply Vulnerable Young Families: Challenges and Principles

Abstract What has served in the literature as the paradigm of highest risk family life—chronic financial and material hardship, vulnerable and overwhelmed parents, overburdened social support networks, and an unsupportive community context—is rapidly becoming the norm for young families in urban poverty. When present together, these risk factors create a variety of special challenges to those who would provide formal help and support around parenting and other dimensions of family life. In this article I examine the challenges of work with multiply vulnerable young families; discuss helping principles responsive to them; and suggest how these principles can be supported in frontline practice.
Monitoring nutrient loss in runoff from dairy cattle lots

Abstract Nitrogen (N) and phosphorus (P) loss from agriculture persists as a water quality issue. For dairy farms, nutrients can be lost from cropland, pastures, barnyards, and outdoor cattle lots. We monitored nutrient runoff for 3.5 years from plots representing cattle lots of differing stocking densities and corn silage cropland. About 5–10% of annual precipitation became runoff for cattle lot and corn silage treatment plots. Sediment loss was low for cattle plots, with loss proportional to stocking density, and was greatest for corn silage plots. Runoff NO3-N was consistent over time, with ∼80% of samples less than 5 mg L−1. Runoff NH4-N and particulate N were also consistent through time, but high concentrations occurred soon after manure application. Sediment P loss was related to sediment loss, while dissolved P loss was more influenced by manure. Soil P and runoff dissolved P increased in cattle plots over time in proportion to stocking density. There were no similar P increases in corn silage plots because P inputs and outputs were well balanced. High dissolved P concentrations occurred soon after manure application, but decreased again as a function of cumulative precipitation. Cattle lots can be significant sources of P in runoff, but may constitute only about 3% of total annual P loss from a dairy farm where they represent 15% of total farm area.
Stability Yields a PTAS for k-Median and k-Means Clustering

We consider $k$-median clustering in finite metric spaces and $k$-means clustering in Euclidean spaces, in the setting where $k$ is part of the input (not a constant). For the $k$-means problem, Ostrovsky et al. show that if the optimal $(k-1)$-means clustering of the input is more expensive than the optimal $k$-means clustering by a factor of $1/\epsilon^2$, then one can achieve a $(1+f(\epsilon))$-approximation to the $k$-means optimal in time polynomial in $n$ and $k$ by using a variant of Lloyd's algorithm. In this work we substantially improve this approximation guarantee. We show that given only the condition that the $(k-1)$-means optimal is more expensive than the $k$-means optimal by a factor $1+\alpha$ for {\em some} constant $\alpha>0$, we can obtain a PTAS. In particular, under this assumption, for any $\eps>0$ we achieve a $(1+\eps)$-approximation to the $k$-means optimal in time polynomial in $n$ and $k$, and exponential in $1/\eps$ and $1/\alpha$. We thus decouple the strength of the assumption from the quality of the approximation ratio. We also give a PTAS for the $k$-median problem in finite metrics under the analogous assumption as well. For $k$-means, we in addition give a randomized algorithm with improved running time of $n^{O(1)}(k \log n)^{\poly(1/\epsilon,1/\alpha)}$. Our technique also obtains a PTAS under the assumption of Balcan et al. that all $(1+\alpha)$ approximations are $\delta$-close to a desired target clustering, in the case that all target clusters have size greater than $\delta n$ and $\alpha>0$ is constant. Note that the motivation of Balcan et al. is that for many clustering problems, the objective function is only a proxy for the true goal of getting close to the target. From this perspective, our improvement is that for $k$-means in Euclidean spaces we reduce the distance of the clustering found to the target from $O(\delta)$ to $\delta$ when all target clusters are large, and for $k$-median we improve the ``largeness'' condition needed in the work of Balcan et al. to get exactly $\delta$-close from $O(\delta n)$ to $\delta n$. Our results are based on a new notion of clustering stability.
Membership privacy: a unifying framework for privacy definitions

We introduce a novel privacy framework that we call Membership Privacy. The framework includes positive membership privacy, which prevents the adversary from significantly increasing its ability to conclude that an entity is in the input dataset, and negative membership privacy, which prevents leaking of non-membership. These notions are parameterized by a family of distributions that captures the adversary's prior knowledge. The power and flexibility of the proposed framework lies in the ability to choose different distribution families to instantiate membership privacy. Many privacy notions in the literature are equivalent to membership privacy with interesting distribution families, including differential privacy, differential identifiability, and differential privacy under sampling. Casting these notions into the framework leads to deeper understanding of the strengthes and weaknesses of these notions, as well as their relationships to each other. The framework also provides a principled approach to developing new privacy notions under which better utility can be achieved than what is possible under differential privacy.
Elastic scattering of 6Li by 39K at 28 and 34 MeV

Abstract Complete elastic scattering angular distributions have been measured for 6 Li + 39 K at 28 and 34 MeV to determine whether the large-angle enhancements reported earlier for 6 Li + 40 Ca are observed also for 39 K. At 34 MeV the angular distribution data for 39 K are almost identical to those previously reported for 40 Ca over the entire angular range. Rather poor descriptions of the data are obtained with the standard Woods-Saxon optical potential, especially in the interference region between 90° and 120°. A better reproduction of the data was obtained with a double folded microscopic real potential and an imaginary Woods-Saxon potential. A real force normalization of about 0.6 was found for 39 K just as for 6 Li scattering by 40 Ca.
Mediation of Classical Conditioning in Aplysia californica by Long-Term Potentiation of Sensorimotor Synapses

Long-term potentiation (LTP) is considered an important neuronal mechanism of learning and memory. Currently, however, there is no direct experimental link between LTP of an identified synapse and learning. A cellular analog of classical conditioning inAplysia was used to determine whether this form of invertebrate learning involvesN-methyl-d-aspartate (NMDA)–type LTP. The NMDA receptor-antagonist dl-2-amino-5-phosphonovalerate significantly disrupted synaptic enhancement after associative training but did not disrupt synaptic enhancement after nonassociative training. Thus, classical conditioning in Aplysia appears to be mediated, in part, by LTP due to activation of NMDA-related receptors.