cssi/SciSciGPT-SciSciNet huggingface dataset:
Impact of Community Experiences on Student Retention Perceptions and Satisfaction in Higher Education

Understanding student experiences and the ability to predict satisfaction and retention continues to be an important topic in higher education. Among the many variables that have predictive capacit...
La Necesidad de la Convergencia en el Derecho Privado

espanolEl presente articulo describe la discusion entre Gayo y Hume con respecto a la verdadera definicion de “ley natural”, concluyendo que todas leyes que regulan al hombre, con las cuales ha formado no solo el Derecho Civil de cada Estado, sino el Derecho de las Naciones, son siempre convencionales, siendo las verdaderas leyes naturales unicamente las que no han tenido intervencion alguna del hombre para su creacion, sino que existen por si mismas: fisica, quimica y biologia. Una vez definido esto, la investigacion presenta las condiciones en las que el Derecho Privado, el cual regula las actividades cotidianas del ser humano y se ha ido creando poco a poco por la conducta de las acciones ordinarias y sin intervencion de un ser superior, necesita converger con estas leyes naturales, las cuales son inamovibles, intransferibles e invariables. Las condiciones seran aplicadas a las instituciones del Derecho Privado que son parte de los rasgos universales que se comparten entre todos los seres humanos como esencia de su existencia: el matrimonio, la fuerza, la propiedad, el dano y el contrato. EnglishThis article describes the discussion between Gaius and Hume regarding the correct definition of “natural law”. It concludes that all rules that regulate man, through which he has formed not only the Civil Law of each State but also the Law of Nations, are always conventional, being the correct natural laws only those that have not had any intervention by man for their creation but exist by themselves: physics, chemistry, and biology. Once this is defined, the investigation presents the conditions under which Private Law, which regulates the daily activities of the human being and has been created gradually by the conduct of ordinary actions and without the intervention of a superior being, needs to converge with these natural laws, which are immovable, non-transferable, and invariable. The conditions will be applied to the institutions of Private Law that are part of the universal features shared by all human beings as the essence of their existence: marriage, force, property, damage, and contract.
Analysis of COVID-19 virus particles on surfaces in new york city

Purpose : SARS-CoV-2 virus can remain stable on surfaces for several days. This crosssectional analysis sought to determine the presence of SARS-CoV-2 virus on various surfaces that trainees and faculty of an academic eye clinic routinely came into contact with during the pandemic in New York City. Methods : Samples were collected by faculty and trainees from surfaces encountered during daily life. On 4 different days, teams collected at least two samples using sterile swabs (Puritan HydraFlock). Prior to collection, nasal swabs were obtained from all individuals to check for SARS-CoV-2. Collection sites were grouped into four zones depending on proximity and the amount of the time personnel spent there. Zones included: (1) Work microenvironment: Slit lamp;door handles;computers;waiting room;reception;bathrooms (2) Work macroenvironment: ICU, ED, inpatient units;elevators, bathrooms;cafeteria (3) Living microenvironment: Home doorknob;kitchen;car;sitting area (4) Living macroenvironment: Subway station;subway cars;car services;restaurants;bike stations;grocery stores. Samples were transported to the lab in transport medium and RNA extraction was conducted using the QIAamp DSP Viral RNA Mini Kit. Presence of viral RNA was investigated using Luna Universal Probe One-step RT-qPCR. Results : A total of 816 swabs were submitted. Only 2 (0.25%) samples were positive. The first was a sample from a patient bathroom sink handle in the main emergency room and the second was a nasal swab from a staff member who had been assigned to collect samples. Prior to this positive swab result, this staff member had tested positive for COVID-19, quarantined for two weeks, and had then received one prior negative test. Conclusions : Though COVID-19 is currently widespread in the United States, this study shows that the healthcare personnel working in New York City at Edward S. Harkness Eye Institute at the Columbia University Irving Medical Center have a low chance of encountering viral RNA on surfaces they are in close contact with during their daily life. Considering the 1.77-2.39% citywide test positivity during the time this study was conducted, the likelihood of faculty and trainees getting infected from contaminated surfaces is 100 times less likely than acquiring COVID-19 from an infected individual. This result may be a reflection of the efficacy of disinfection protocols or the limited viability of the virus on inorganic surfaces.
Infectious SARS-CoV-2 is emitted in aerosols

Respiratory viruses such as SARS-CoV-2 are transmitted in respiratory droplets and aerosols, which are released during talking, breathing, coughing, and sneezing. Non-contact transmission of SARS-CoV-2 has been demonstrated, suggesting transmission in aerosols. Here we demonstrate that golden Syrian hamsters emit infectious SARS-CoV-2 in aerosols, prior to and concurrent with the onset of mild clinical signs of disease. The average emission rate is 25 infectious virions/hour on days 1 and 2 post-inoculation, with average viral RNA levels 200-fold higher than infectious virus in aerosols. Female hamsters have delayed kinetics of viral shedding in aerosols compared to male hamsters, with peak viral emission for females on dpi 2 and for males on dpi 1. The majority of virus is contained within aerosols <8 {micro}m in size. Thus, we provide direct evidence that, in hamsters, SARS-CoV-2 is an airborne virus.
Hydrogel Films Encapsulating Fully Organic Scintillating Crystalline Colloidal Arrays with Tunable Emission

Radioluminescent copolymer nanoparticles that self-assembled into a crystalline colloidal array due to electrostatic repulsion were encapsulated within hydrogels. The rejection wavelength of the gels was tuned through drying and swelling the system.
A Review of “World City”

This special issue addresses the construction and use of place in education. Rather than draw further attention to how place is constructed in and though education, this book review uses World City...
Siting Transmission Lines in a Changed Milieu: Evolving Notions of the 'Public Interest' in Balancing State and Regional Considerations

This Article discusses how state public utility law presents a barrier to the siting of new high voltage transmission lines to serve renewable resources, and how states could approach its evolution in order to preserve a role for state regulators in a new energy economy in which renewable energy will play a significant role. The traditional approach to determining the "public interest" in siting transmission lines is well on its way to obsolescence. Two developments over the past fifteen years have begun to challenge this paradigm. First, policies at the federal level and in many states have encouraged increased competition in generation, contributing to de-monopolization of the bulk power side of the industry. Second, the increased emphasis on environmental, energy independence, and other public policy objectives, has resulted in a dramatically increased demand for renewable energy, particularly given heightened attention to climate change. Given that wind power -- the most economically viable renewable resource on a bulk power basis -- is feasible predominantly in locations far removed from, load centers, the demand for new multistate transmission facilities has been brought clearly into focus. After an introduction in Part I, Part II describes the existing arrangements in several resource rich Western states for siting new transmission lines, and the coexistence of those arrangements with a conventional understanding of the public interest in determining need and addressing environmental concerns under traditional state transmission siting laws. Part III discusses transmission issues related to the competitive wholesale market and increased attention to climate change and highlights how federal law has expanded to accommodate some of these concerns. Part IV emphasizes the need for a new definition of the public interest which might better reflect these new market circumstances and opportunities, and highlights the two main barriers to this: 1) legislative and/or regulatory inertia and 2) an outdated cost-allocation model. The public interest under most state siting statutes is sufficiently capacious to give regulators some flexibility to evolve, but in other instances legislative action may be needed. In addition, the state cost-of-service ratemaking model must evolve to a more regional approach to allocating the costs of new transmission.
Effects of social reinforcement, subject sex, and experimenter sex on children's motor performance.

Abstract The effects of positive, negative, and conversation-control social reinforcement were examined on a gross motor accuracy task for 48 boys and 48 girls of primary school age. Subjects were randomly assigned to one of the treatments in which reinforcement was administered on every trial. Results indicated that male subjects in the positive and negative social reinforcement treatments performed significantly better than males in the conversation-control condition. Subjects' heart rate deviations from basal heart rates significantly differed as a function of social reinforcement, experimenter sex, and subject sex. These heart rate differences partially supported the obtained performance differences.
A constant approximation algorithm for the a priori traveling salesman problem

One of the interesting recent developments in the design and analysis of approximation algorithms has been in the area of algorithms for discrete stochastic optimization problems. In this domain, one is given not just one input, but rather a probability distribution over inputs, and yet the aim is to design an algorithm that has provably good worst-case performance, that is, for any probability distribution over inputs, the objective function value of the solution found by the algorithm must be within a specified factor of the optimal value. The a priori traveling salesman problem is a prime example of such a stochastic optimization problem. One starts with the standard traveling salesman problem (in which one wishes to find the shortest tour through a given set of points N), and then considers the possibility that only a subset A of the entire set of points is active. The active set is given probabilistically; that is, there is a probability distribution over the subsets of N, which is given as part of the input. The aim is still to compute a tour through all points in N, but in order to evaluate its cost, we instead compute the expectation of the length of this tour after shortcutting it to include only those points in the active set A (where the expectation is computed with respect to the given probability distribution). The goal is to compute a "master tour" for which this expectation is minimized. This problem was introduced in the doctoral theses of Jaillet and Bertsimas, who gave asymptotic analyses when the distances between points in the input set are also given probabilistically. In this paper, we restrict attention to the so-called "independent activation" model in which we assume that each point j is active with a given probability pj, and that these independent random events. For this setting, we give a 8-approximation algorithm, a polynomial-time algorithm that computes a tour whose a priori TSP objective function value is guaranteed to be within a factor of 8 of optimal (and a randomized 4-approximation algorithm, which produces a tour of expected cost within a factor of 4 of optimal). This is the first constant approximation algorithm for this model.
Sparse models by iteratively reweighted feature scaling: a framework for wavelength and sample selection

In the past decade, there has been an increase in the use of sparse multivariate calibration methods in chemometrics. Sparsity describes a parsimonious state of model complexity and can be defined in terms of a subset of samples or covariates (e.g., wavelengths) that are used to define the calibration model. With respect to their classical counterparts such as principal component regression or partial least squares, sparse models are more easily interpretable and have been shown to exhibit non-inferior prediction performance. However, sparse methods are still not as fast as the classical methods in spite of recent numerical advances. In addition, for many chemometricians, sparse methods are still “black-box” algorithms whose internal workings are not well understood. In this paper, we describe a simple framework whereby classical multivariate calibration methods can be iteratively used to generate sparse models. Moreover, this approach allows for either wavelength or sample sparsity. We demonstrate the effectiveness of this approach on two spectroscopic data sets. Copyright © 2013 John Wiley & Sons, Ltd.
Addressing Alcohol and Drug Addiction Among People With Mental Retardation in Nonaddiction Settings: A Need for Cross-System Collaboration

People with mental retardation (MR) and addiction are an especially vulnerable population, yet evidence-based approaches to substance abuse (SA) treatment for this group are limited. Research suggests that SA-related services for this population are most likely received in nonaddiction settings that are generally focused on provision of mental health services to populations with MR and that might be unequipped for this work. This fact, combined with documented challenges to cross-system collaboration, suggests the potential for discontinuities in care for people with MR and SA. Recommendations for SA screening and a framework for cross-system collaboration are presented with specific recommendations for the ways in which social workers in both MR and SA service settings can promote positive client outcomes.
Estimation of Forest Canopy Nitrogen Concentration

The ability to detect patterns of carbon assimilation by vegetation is a key component of the North American Carbon Program. Because photosynthetic potential is strongly related to biochemical constituents such as nitrogen and chloro- phyll concentrations in foliage, the ability to incorporate canopy chemistry into landscape- to regional-scale carbon cycling research represents an important contri- bution to NACP research goals. Here, we summarize the functional basis for using foliar N as a scalar of C uptake and recommend a practical, field-based approach for canopy N measurement that can be efficiently scaled using currently available remote sensing technology and ecosystem process modeling.
Perinatal Influences on the Behavior and Learning Problems of Children

For more than a century there has been speculation that the antecedents of mental retardation, learning disabilities, personality disorders, and similar educational and behavioral problems may be associated with anomalies of pregnancy, birth, and infancy. While most of the substantive research in this area has taken place during the past 25 years, its antecedents can be directly traced to the late 19th century. Systematic observation appears to have begun in 1862 with Little, who maintained that birth difficulties—specifically asphyxia, prematurity, and abnormal labor—were directly related to mental deficiency and cerebral palsy.
Multi-dimensional Virtual Values and Second-degree Price Discrimination

We consider a multi-dimensional screening problem of selling a product with multiple quality levels and design virtual value functions to derive conditions that imply optimality of only selling highest quality. A challenge of designing virtual values for multi-dimensional agents is that a mechanism that pointwise optimizes virtual values resulting from a general application of integration by parts is not incentive compatible, and no general methodology is known for selecting the right paths for integration by parts. We resolve this issue by first uniquely solving for paths that satisfy certain necessary conditions that the pointwise optimality of the mechanism imposes on virtual values, and then identifying distributions that ensure the resulting virtual surplus is indeed pointwise optimized by the mechanism. Our method of solving for virtual values is general, and as a second application we use it to derive conditions of optimality for selling only the grand bundle of items to an agent with additive preferences.
Discovering the feasibility of using the radiation forces for recovering rare earth elements from coal power plant by-products

Abstract The feasibility of using laser separation for rare earth recovery from coal ashes was explored. To do so, laser-induced motion and travel distances of some rare earth and rare earth oxides (Lu 2 O 3 , Yb 2 O 3 , HfO 2 , Dy 2 O 3 , Ta 2 O 5 , Tm, Lu, Ho, TeO 2 , La 2 O 3 , Ho, TiO 2 , Fe 2 O 3 Y 2 O 3 , GeO 2 , Sc 2 O 3 ) and mineral compounds (MgO, CaO, Al 2 O 3 , SiO 2 , KCl) that are commonly found is coal ashes were numerically investigated. The investigations were carried out for particles in quiescent air, ( T = 300 K, μ = 18.46 × 10 −6 N s/m 2 , ρ = 1.177 kg/m 3 ) exposing to a CW laser beam of 6 mm in diameter and it was focused by a 500 mm focal length lens. The results showed that the separation distances between these elements varied from few micrometers to several millimeters and it became widened as the laser power increased. The important result presented here is that all rare earth oxides were separated and concentrated in a small area located near the beam waist while all other mineral compounds traveled further and concentrated in a small area far from the beam waist.
On cubic graphs which are irreducible for nonorientable surfaces

Let ∑n denote the nonorientable surface of nonorientable genus n. A graph G is irreducible for ∑n if G does not embed in ∑n but any proper subgraph does embed. Let I3∑n) denote the set of cubic irreducible graphs for ∑n. This note proves Theorem. I3(∑n) is finite for each n.
SU‐FF‐J‐103: A Robust Marker Registration Algorithm

Purpose: We present a novel marker registration algorithm for rigid‐body transformations that minimizes sum of least squares between two point sets, and requires no user intervention to handle missing markers. Method and Materials: The novel registration algorithm computes the sum of squared distances by finding the minimum weighted matching of a dense bipartite graph (DPG). The space of rigid‐body transforms (3 translations and 3 rotations) is explored using a branch‐and‐bound method. The minimum weighted bipartite match is calculated using a modified Dijkstra's algorithm[1]. The branch‐and‐bound method is an extension to 3D of the method in [2]. Unlike conventional singular value decomposition (SVD), i) DPG works with point sets with different cardinalities; and ii) no homology or correspondence has to be defined between reference and target point sets. These advantages provide our algorithm with greater robustness for automatic marker detection, and handling missing markers. Though DPG is not limited by number of markers (N), here N=3 to 7 was used to simulate clinical conditions. Results: DPG yielded an accuracy of <0.1mm translational and <0.1° rotational errors, which are within the precision of back projection errors. It was validated using simulated portalimages and a high precision table. It was tested on clinical portalimaging data to validate robustness for missing markers. Conclusion: DPG provides an accurate and robust point based registration that works with missing markers and different cardinalities, which can be used in conjunction with automatic marker detection.
Gas phase studies of substituted methylperoxy radicals: the UV absorption spectrum and self-reaction kinetics of CH3OCH2O2 ― the reaction of CF2ClO2 with Cl atoms

Abstract A flash photolysis technique has been used to measure the gas phase UV absorption cross-sections for the methoxy-methylperoxy radical, CH 3 OCH 2 O 2 , over the wavelength range 210 – 290 nm. Reaction (1) was then studied by kinetic absorption spectroscopy and the rate constant, defined as —d[CH 3 OCH 2 O 2 ]/d t = 2 k 1 [CH 3 OCH 2 O 2 ] 2 , was derived using σ CH 3 OCH 2 O 2 (240 nm) = (3.65 ± 0.35) × 10 −18 cm 2 molecule −1 . The self-reaction rate constants were observed to be in the fall-off region over the temperature range 228 – 380 K at pressures between 25 and 800 Torr (using N 2 ) and were fit using the formulation developed by Troe for association reactions. Attempts at similar studies for CF 2 ClO 2 radicals were hindered by the apparent secondary formation of ClO. An interpretation of the experimental observations in this radical formation system is offered which is consistent with the occurrence of a rapid reaction between CF 2 ClO 2 and Cl yielding ClO
Effect of donor selection on the early outcome of heart transplant recipients.

Recipients receiving heart transplants from 83 donors from 1995 to 2002 were analyzed to evaluate the effect of various donor factors on recipient outcomes. The 83 donors (13 women and 70 men; 2-51 years old) had cold ischemic times ranging between 55 and 287 minutes. Donor age, cause of death, inotropic support, and cold ischemic times of the hearts were compared to 1-year left ventricular ejection fraction, permanent pacemaker dependency, 30-day mortality, and 1-year survival in the recipients. Donors receiving low-dose inotropic support resulted in recipients with permanent pacemaker dependency in 14.8%, and 30-day mortality and 1-year survival rates of 7.4% and 70.3%, respectively. Donors not receiving inotropic support resulted in recipients with permanent pacemaker dependency in 3.5%, and 30-day mortality and 1-year survival of 3.5% and 83.9%, respectively. Cold ischemic times less than or equal to 120 minutes showed 30-day mortality and 1-year survival rates of 0% and 90.9%, respectively. Cold isch...
Nationalism and the moral psychology of community

Monarchies often start with highly competent individuals or war leaders, but their descendants then often fall into the caretaker category. Without adequate checks and balances in society, which re...
An evaluation of Secchi disk visibility for estimating plankton density in Fish ponds

Correlation coefficients between Secchi disk visibility (X) in fish ponds and concentrations of chlorophyll a and particulate organic matter were −0.79 (P< 0.01) and −0.83 (P< 0.01), respectively. Different observers may obtain different values for Secchi disk visibility and measurements by the same observer differ with the time of day. Nevertheless, Secchi disk visibility provides a suitable estimate of plankton density for management purposes in ponds were plankton is the primary source of turbidity
Typical and Atypical Electrocardiograms in Myocardial Infarction Caused by Acute Coronary Occlusion and Coronary Insufficiency

When an acute coronary episode occurs, if the initial electrocardiogram does not indicate a coronary occlusion, it may be difficult at first to determine the exact nature of the attack. The electrocardiogram may remain normal for a variable period or may indicate coronary insufficiency and myocardial ischemia. In the cases going on to coronary thrombosis and massive infarction, the electrocardiogram may show various rapidly changing patterns before the appearance of RS-T elevation and Q-waves. In coronary occlusion the electrocardiogram often shows involvement of more than one surface and variations of the typical patterns are frequent. The changes may be present in only a few of the 12 routine leads or only in special chest positions. In an acute coronary episode it is essential to keep the patient at rest until the extent of myocardial involvement has been determined. Not infrequently the electrocardiogram shows temporary improvement or actual return of RS-T and T to normal between the third and 10th days following myocardial infarction.
Carbon Doping of InGaAs for Device Applications

Carbon has gained wide acceptance as a p-type dopant for GaAs-based device structures due to its low atomic diffusivity. Carbon doping of InGaAs, however, is complicated by the amphoteric nature of C and difficulty in incorporating C efficiently during epitaxial growth. We have achieved hole concentrations as high as 7×1019 cm−3 in CCl4-doped InGaAs grown at low temperature by MOCVD. Growth-related issues include the effect of CCl4 on the alloy composition due to etching during growth, and the incorporation of hydrogen, which passivates the C acceptor and reduces the hole concentration during growth and during the post-growth cool-down. The effect of H passivation on minority carrier transport has been characterized by the zero-field time-of-flight technique. High frequency InP/InGaAs HBTs with a C-doped base have been demonstrated with ft = 62 GHz and fmax = 42 GHz, which is comparable to the best performance reported for MOCVD-grown InP/InGaAs HBTs.
Two-Dimensional Piston Ring Lubrication—Part I: Rigid Ring and Liner Solution

A two-dimensional elastohydrodynamic cavitation algorithm is developed for piston ring lubrication. The nonlinear governing equation derived from the Reynolds equation to include cavitation and elastohydrodynamics is linearized for numerical efficiency. An elliptic cylinder liner and rigid ring are considered to investigate circumferencial flow effects which have been ignored in previous studies. The hydrodynamic pressure distribution and film thickness at various crank angles are determined. Results for a typical automotive engine show that the elliptic liner causes a dramatic drop in the hydrodynamic pressure and reduces the film thickness. It is found that the pressure reformation effect cannot be neglected when the piston ring moves away from the top dead center (TDC). Presented at the 50th Annual Meeting in Chicago, Illinois May 14–19, 1995
The Influence of Flooring on Standing Balance among Older Persons

This study investigated the effects of flooring on balance during quiet standing in healthy young and older participants. Seven flooring conditions were examined, including a hard tile floor and combinations of low-pile and high-pile carpet with urethane foam and rubber padding. The resulting floors provided a variety of compliant surfaces, ranging from very soft to hard. Participants stood during three separate visual conditions: eyes open, eyes closed, and looking at a moving visual surround. Three measures of postural sway were calculated using center of pressure recordings during the trails. The results showed that the amplitude of sway was higher in the older than in the younger participants, particularly in the moving visual surround condition. Flooring compliance was found to have an effect on sway during moving visual environments, with the largest effects found among the older participants. Softer floors increased the amount of sway in the older participants. These results suggest that floor compliance influences standing postural stability in older people, particularly in destabilizing visual environments.
HIV-Tat elicits microglial glutamate release: Role of NAPDH oxidase and the cystine–glutamate antiporter

Excitotoxicity and/or microglial reactivity might underlie neurologic dysfunction in HIV patients. The HIV regulatory protein Tat is both neurotoxic and pro-inflammatory, suggesting that Tat might participate in the pathogenesis of HIV-associated neurocognitive disorders (HAND). The present study was undertaken to evaluate if Tat can increase extracellular glutamate, and was specifically designed to determine the degree to which, and the mechanisms by which Tat could drive microglial glutamate release. Data show that application of Tat to cultured primary microglia caused dose-dependent increases in extracellular glutamate that were exacerbated by morphine, which is known to worsen Tat cytotoxicity. Tat-induced glutamate release was decreased by inhibitors of p38 and p42/44 MAPK, and by inhibitors of NADPH oxidase and the x(c)(-) cystine-glutamate antiporter. Furthermore, Tat increased expression of the catalytic subunit of x(c)(-) (xCT), but Tat-induced increases in xCT mRNA were not affected by inhibition of NADPH oxidase or x(c)(-) activity. Together, these data describe a specific and biologically significant signaling component of the microglial response to Tat, and suggest that excitotoxic neuropathology associated with HIV infection might originate in part with Tat-induced activation of microglial glutamate release.
A Differential Molecular Connectivity Index

A differential molecular connectivity index, ΔmX, has been defined which is the difference between the simple and the valence connectivity indexes of the same order, m, is ΔmX = mX — mXv. The information contained in this index is largely electronic with contributions from adjacent alkyl fragments amounting to the size of m. The electronic information is a quantitation of the pi and lone pair electrons on that part of the fragment defined by m. The index is capable of modeling selected physical properties which are regiospecific within a molecule. Examples include NMR chemical shifts, gas phase basicities, ionization potentials and chromatographic retention indexes.
Atmospheric trace gases - Possibility of sources in the Southern Hemisphere

When measurements of globally distributed trace gases establish their existence in the Southern Hemisphere, it is not always clear whether their presence is due to transport from the Northern Hemisphere or partly from significant sources in the Southern Hemisphere. In this paper a simple criterion is developed whereby one can determine if significant Southern Hemisphere sources exist for a given trace gas. Despite the limitations of the model, there are strong indications that C2 hydrocarbons (C2H2, C2H4, C2H6), CO and CH4 have significant Southern Hemisphere sources.
The Effect Of CT Reconstruction Time Upon Patient Throughput In A University Setting

This study was undertaken to assess the effect of reconstruction time upon computed tomography (CT) patient throughput. Time studies were performed to analyze patient throughput and the distribution of examination time on a Pfizer 0450 and a Siemens DR3 CT scanners. Analyses were performed for both head and body examinations. An overall reduction in examination time of about 32% was observed for the DR3, owing primarily to the nearly instant image reconstruction available on this scanner. Our initial time study on the 0450 scanner proved to be useful in predicting the increase in patient throughput on the DR3. Hence the time study approach was felt to be valuable in both its predictive use as well as a tool to analyze current operating characteristics.
A measurement of the polarizability of sodium clusters

The static electric dipole polarizabilities of sodium clusters ${\mathrm{Na}}_{n}$ for a series of sizes in the range $7l~nl~93$ were measured by electric field deflection of a supersonic cluster beam. Results for the smaller clusters are in overall good agreement with previous experiments. Polarizabilities of the larger clusters continue the downward trend with increasing size, but remain considerably above the bulk limit. There is a degree of correlation between the polarizability values and electronic shell structure. Furthermore, there is an indication that the polarizability is sensitive to the source conditions, possibly reflecting the influence of internal cluster temperature.
Effect of Boll Age and Mercerization on Cotton Fiber Properties

Samples of six cotton cultivars grown in three environments in 1977 and 1978 were harvested 26 days postanthesis and at 6-day intervals thereafter until boll opening to obtain samples of four boll ...
Prospective Evaluation of a Clinical Pathway for Suspected Appendicitis

OBJECTIVE: To evaluate the diagnostic accuracy of a clinical pathway for suspected appendicitis combining the Samuel’s pediatric appendicitis score (PAS) and selective use of ultrasonography (US) as the primary imaging modality. METHODS: Prospective, observational cohort study conducted at an urban, academic pediatric emergency department. After initial evaluation, patients were determined to be at low (PAS 1–3), intermediate (PAS 4–7), or high (PAS 8–10) risk for appendicitis. Low-risk patients were discharged with telephone follow-up. High-risk patients received immediate surgical consultation. Patients at intermediate risk for appendicitis underwent US. RESULTS: Of the 196 patients enrolled, 65 (33.2%) had appendicitis. An initial PAS of 1–3 was noted in 44 (22.4%), 4–7 in 119 (60.7%), and 8–10 in 33 (16.9%) patients. Ultrasonography was performed in 128 (65.3%) patients, and 48 (37.5%) were positive. An abdominal computed tomography scan was requested by the surgical consultants in 13 (6.6%) patients. The negative appendectomy rate was 3 of 68 (4.4%). Follow-up was established on 190 of 196 (96.9%) patients. Overall diagnostic accuracy of the pathway was 94% (95% confidence interval [CI] 91%–97%) with a sensitivity of 92.3% (95% CI 83.0%–97.5%), specificity of 94.7% (95% CI 89.3%–97.8%), likelihood ratio (+) 17.3 (95% CI 8.4–35.6) and likelihood ratio (−) 0.08 (95% CI 0.04–0.19). CONCLUSIONS: Our protocol demonstrates high sensitivity and specificity for diagnosis of appendicitis in children. Institutions should consider investing in resources that increase the availability of expertise in pediatric US. Standardization of care may decrease radiation exposure associated with use of computed tomography scans.
Importance of partially unfolded conformations for Mg2+-induced folding of RNA tertiary structure: Structural models and free energies of Mg2+ interactions

RNA molecules in monovalent salt solutions generally adopt a set of partially folded conformations containing only secondary structure, the intermediate or I state. Addition of Mg2+ strongly stabilizes the native tertiary structure (N state) relative to the I state. In this paper, a combination of experimental and computational approaches is used to estimate the free energy of the interaction of Mg2+ with partially folded I state RNAs and to consider the possibility that Mg2+ favors "compaction" of the I state to a set of conformations with a higher average charge density. A sequence variant with a drastically destabilized tertiary structure was used as a mimic of I state RNA; as measured by small-angle X-ray scattering, it adopted a progressively more compact conformation over a wide Mg2+ concentration range. Average free energies of the interaction of Mg2+ with the I state mimic were obtained by a fluorescence titration method. To interpret these experimental data further, we generated molecular models of the I state and used them in calculations with the nonlinear Poisson-Boltzmann equation to estimate the change in Mg2+-RNA interaction free energy as the average I state dimensions decrease from expanded to compact. The same models were also used to reproduce quantitatively the experimental difference in excess Mg2+ between N and I states. On the basis of these experiments and calculations, I state compaction appears to enhance Mg2+-I state interaction free energies by 10-20%, but this enhancement is at most 5% of the overall Mg2+-associated stabilization free energy for this rRNA fragment.
A preliminary clinical scale to predict the risk of in-hospital death after carotid endarterectomy

Objective Carotid endarterectomy (CEA) remains the gold standard for the treatment of carotid disease, with mortality rates generally at 0.4% to 1.7%. Controversy remains with regards to its role in the treatment of the high-risk surgical population. We developed a new clinical scale incorporating weighted risk factors into a single numerical score that correlates with the risk of in-hospital death after CEA. We propose that this tool may serve to prospectively identify the high-risk patient. Methods We performed a retrospective analysis of 10 years (1994 to 2003) of the Maryland hospital discharge database. Included in the analysis were patients with (1) International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) procedure code 38.12 (endarterectomy of the vessels of the head and neck other than intracranial vessels) in the primary coding position but not in any secondary position, or (2) Diagnosis Code 433.00 to 433.91 (occlusion/stenosis, precerebral artery), or (3) the Diagnosis-Related Group 5 (extracranial vascular procedure). ICD codes representing preoperative conditions of the patients were identified and evaluated with stepwise regression modeling techniques for association with in-hospital deaths. Different regression models were evaluated and compared by discriminative power as measured by receiver operating characteristics (ROC) and goodness-of-fit to data as measured by r 2 and the Hosmer-Lemeshow statistic. A numeric index correlating with the risk of in-hospital death was constructed by rounding the correlation coefficients for the statistically significant variables from the logistic regression. Results We identified 23,237 cases. The mean age of patients was 70.6 years, with 54.7% male patients. There were 125 in-hospital deaths (0.54%). Patient age and four patient medical conditions emerged with significant associations with in-hospital deaths after CEA, and their relationships can be summarized in a single diagnostic scale: 1 point for age ≥75, 2 points for atherosclerosis (ICD code 440), 3 points for cardiomyopathy (ICD code 425), 4 points for iron-deficiency anemia (ICD code 280), and 5 points for cerebral degeneration (ICD code 331). This scale has moderate discriminative power (ROC = 0.67). On average, each point increase on this scale is associated with a 1.58-times increase in mortality risk, with score of 6 on the scale carrying a mortality risk >5%. Conclusions This new 5-item scale, based on patient age and past medical history, correlates moderately with the rate of in-hospital death after CEA. This clinical index may serve to identify high-risk patients. Future improvements to this diagnostic scale should focus on the diagnostic values of additional laboratory and demographic data.
From the Great Depression to the Great Inflation: Path dependence and monetary policy

Abstract There is substantial narrative evidence that the shadow of the Great Depression may have influenced the conduct of U.S. monetary policy during the 1970s. In this paper, we estimate central bank reaction functions for the United States and 12 other countries over the 1970s to examine the relationship between the magnitude of the Great Depression and the response of central banks to output gaps and inflation during the Great Inflation. The main finding is that countries which suffered the most during the 1930s had monetary policy reaction functions that responded substantially more aggressively to output gaps during the 1970s.
Three ulnar nerve conduction studies in patients with ulnar neuropathy at the elbow

Abstract Objective: Ulnar neuropathy at the elbow is often difficult to localize by standard electrophysiologic testing. This study compared three ulnar nerve conduction studies to determine which was more sensitive in localizing ulnar neuropathy at the elbow. Methods: Motor studies to the first dorsal interosseous and the abductor digiti quinti and a mixed ulnar nerve sensory study across the elbow. Results: Motor studies to the first dorsal interosseous and abductor digiti quinti were abnormal in 81% and 71% of patients, respectively. The ulnar mixed sensory study across the elbow was abnormal in 57%. In 38%, all three tests were abnormal. Conclusion: Motor studies were more sensitive than the ulnar mixed sensory study across the elbow in localizing ulnar neuropathy of the elbow.
Microcontact Printing With Octadecanethiol

We investigate various alkanethiol self-assembled monolayer inks for microcontact printing patterns on gold substrates. Our research compares hexadecanethiol with an alkanethiol of higher molecular weight, octadecanethiol. Transport mechanisms of alkanethiols along the gold surface and through the ambient are highly dependant upon the molecular weight of the thiols used, and thus are of particular importance when patterning submicron features. Monolayers of octadecanethiol are well suited for patterning such features on gold. The quality of transferred patterns printed with octadecanethiol and hexadecanethiol are examined. The gold patterns fabricated in this work were analyzed via scanning electron microscopy.
Energy demand and the composition of output growth

Abstract Using the theory of the firm, the effects of unbalanced rates of output growth on aggregate energy demand are examined. Theoretical results show that failure to consider unbalanced growth leads to bias in aggregate price elasticity estimates. Empirically, differential output growth rates are important contributors to the overall growth of energy and other inputs; they can be as important as net price effects in explaining input growth. Unbalanced growth effects help to explain changes in labor's productivity growth and have increased in importance since the Arab oil embargo. They are quite significant relative to other sources of change during business cycle downturns.
Diet and host–microbial crosstalk in postnatal intestinal immune homeostasis

Neonates face unique challenges in the period following birth. The postnatal immune system is in the early stages of development and has a range of functional capabilities that are distinct from the mature adult immune system. Bidirectional immune-microbial interactions regulate the development of mucosal immunity and alter the composition of the microbiota, which contributes to overall host well-being. In the past few years, nutrition has been highlighted as a third element in this interaction that governs host health by modulating microbial composition and the function of the immune system. Dietary changes and imbalances can disturb the immune-microbiota homeostasis, which might alter susceptibility to several autoimmune and metabolic diseases. Major changes in cultural traditions, socioeconomic status and agriculture are affecting the nutritional status of humans worldwide, which is altering core intestinal microbial communities. This phenomenon is especially relevant to the neonatal and paediatric populations, in which the microbiota and immune system are extremely sensitive to dietary influences. In this Review, we discuss the current state of knowledge regarding early-life nutrition, its effects on the microbiota and the consequences of diet-induced perturbation of the structure of the microbial community on mucosal immunity and disease susceptibility.
On statistical mechanics of small systems: accurate analytical equation of state for confined fluids

Some relations are derived using statistical mechanics to describe the effects of surroundings on the properties of systems for sizes below the thermodynamic limit. A general expression for the free energy of closed, small systems is derived and then used to obtain the dependence of the thermal properties on density and temperature, including general expressions for equations of state and internal energies. Comparisons between predictions of the current theory and the results of molecular dynamics (MD) simulations are made for 3D hard-sphere and Lennard-Jones fluids for which the surroundings are modelled as reflecting hard walls that confine the system along one direction. The analytical predictions are in excellent agreement with the MD results.
Separated Oscillatory Field Measurement of the Lamb Shift in H, n=2

This paper reports a precision measurement of the Lamb shift in the n=2 state of hydrogen using separated oscillatory fields in conjunction with a fast atomic beam. Atoms in the 22S1/2 metastable state are produced through charge capture by protons in a gas target. The atoms pass thrugh two separated oscillatory fields whose relative phase is switched between 0 and π. A rf quenching field and a solar blind photomultiplier tube provide a monitor of the number of atoms in the 22S1/2 state that pass through the spectroscopy fields. The procedure used to take and correct the data is described and the major sources of residual error are discussed. The result of the measurement is compared with the current theoretical value. An experiment for further improvement in the measurement of the Lamb shift is outlined.
Prenatal exposure to electroconvulsive seizures and phenytoin: Development of benzodiazepine binding sites, reflex behaviors and seizure thresholds in exposed offspring

Abstract Electroconvulsive seizures administered during the period of fetal benzodiazepine (BZ) binding site proliferation (days 16, 18 and 20 in gestation) significantly the decreased density of cerebral cortical benzodiazepine binding sites in exposed pups up to 21 days postnatal age. Significant decreases in seizure threshold were also found in exposed offspring. However, decreases in BZ sites were not accompanied by significant alterations in RO5-4864-displaceable benzodiazepine binding as seen after in utero exposure to phenytoin (DPH). Neither prenatal treatment affected the ability of GABA to enhance BZ binding in vitro. Prenatal exposure to electroshock delayed the onset of acoustic startle and eye-opening during postnatal development; similar effects were not seen following in utero exposure to DPH. These data suggest that prenatal exposure to seizures and DPH decrease postnatal BZ site proliferation by different mechanisms.
A new mechanism of failure in polymers

Transparent laminates containing imbedded crystals of various ionic and nonionic substances were prepared and their swelling in distilled water was observed. It was found that under certain conditions, disk-shaped cracks formed around the swollen pockets containing a dissolving crystal. Such cracks can form before equilibrium swelling is reached and may severely damage the elastomer.
Reversible Diaphragmatic Eventration Following Chest Tube Thoracostomy

Abstract This report describes a case of acquired eventration of a hemidiaphragm after insertion of a chest tube for treatment of an iatrogenic pneumothorax. Partial withdrawal of the chest tube resulted in immediate return of the hemidiaphragm to its original position. This is believed to be the first report of the resolution of this diaphragmatic functional defect. [Salon JE: Reversible diaphragmatic eventration following chest tube thoracostomy. Ann Emerg Med April 1995;25:556-558.]
Effect of inhaled nitric oxide on cerebrospinal fluid and blood nitrite concentrations in newborn lambs.

Inhaled nitric oxide (iNO) has many extrapulmonary effects. As the half-life of nitric oxide (NO) in blood is orders of magnitude less than the circulation time from lungs to the brain, the mediator of systemic effects of iNO is unknown. We hypothesized that concentrations of nitrite, a circulating byproduct of NO with demonstrated NO bioactivity, would increase in blood and cerebrospinal fluid (CSF) during iNO therapy. iNO (80 ppm) was given to six newborn lambs and results compared with six control lambs. Blood and CSF nitrite concentrations increased 2-fold in response to iNO. cGMP increased in blood but not CSF suggesting brain guanylate cyclase activity was not increased. When sodium nitrite was infused i.v. blood and CSF nitrite levels increased within 10 min and reached similar levels of 14.6 ± 1.5 μM after 40 min. The reactivity of nitrite in Hb-free brain homogenates was investigated, with the findings that nitrite did not disappear nor did measurable amounts of s-nitroso, n-nitroso, or iron-nitrosyl-species appear. We conclude that although nitrite diffuses freely between blood and CSF, due to its lack of reactivity in the brain, nitrite's putative role as the mediator of the systemic effects of iNO is limited to intravascular reactions.