cssi/SciSciGPT-SciSciNet huggingface dataset:
Utilizing Google Trends to Track Online Interest in Elective Hand Surgery During the COVID-19 Pandemic

Introduction Elective hand surgery encompasses a large volume of orthopaedic cases annually. Carpal tunnel syndrome, ganglion cysts, and trigger digits are some of the most common pathologies treated by hand surgeons. In the midst of the COVID-19 pandemic, patient's interest in elective hand surgery for these conditions is uncertain. The objective of this study is to use Google Trends to track online interest in elective hand surgery in the United States during the COVID-19 pandemic. Methods Online search trends regarding elective orthopaedic hand surgery were obtained via Google Trends from November 2019 to November 2020. Three common hand pathologies in lay terms ("carpal tunnel," "‘ganglion cyst’ + ‘wrist cyst,’" and "trigger finger") and three hand surgery-specific keywords ("hand surgery," "carpal tunnel surgery," and "trigger finger surgery") were used as search terms. The search volume index (SVI) graphs for the United States for both sets of search terms were then generated from the Google Trends data and compared to the seven-day average of new COVID-19 cases per day as reported by the CDC. A separate SVI graph was then created for the search term "coronavirus” and was compared against both sets of search terms as above. Results Search trends for all elective hand pathologies and surgery-specific keywords remained constant from November 2019 to the beginning of March 2020 and then decreased significantly within a one-month period following the peak in COVID-19 cases the week of March 15, 2020. Search trends for these keywords increased to baseline levels over the next few months. The search trend for "coronavirus" demonstrated a small search volume index peak of 13 during January 2020 followed by the maximum peak of 100 during the week of March 15, 2020, corresponding to the decrease in search trends of elective hand surgery at that time. Conclusions Online interest in elective hand surgery remained constant prior to the COVID-19 pandemic; however, there was a marked decrease in search trends of elective hand surgery with the rise in daily reported COVID-19 cases, suggesting that patient's interest in elective hand surgery decreased with the onset of the pandemic.
Inhibitory hippocampo-septal projection controls locomotion and exploratory behavior

Abstract Although the hippocampus is generally considered a cognitive center for spatial representation, learning and memory, increasing evidence supports its roles in regulation of locomotion. However, the neuronal mechanisms of hippocampal regulation of locomotion and exploratory behavior remain unclear. Here we found that the inhibitory hippocampo-septal projection bi-directionally controls locomotion speed of mice. Pharmacogenetic activation of these septum-projecting interneurons decreased locomotion and exploratory behavior. Similarly, activation of the hippocampus-originated inhibitory terminal in the medial septum reduced locomotion. On the other hand, inhibition of the hippocampus-originated inhibitory terminal increased locomotion. The locomotion-regulative roles were specific to the septal projecting interneurons as activation of hippocampal interneurons projecting to the retrosplenial cortex did not change animal locomotion. Therefore, this study reveals a specific long-range inhibitory output from the hippocampus in the regulation of animal locomotion.
A Look at Communication-Intensive Performance in Julia

The Julia programming language continues to gain popularity both for its potential for programmer productivity and for its impressive performance on scientific code. It thus holds potential for large-scale HPC, but we have not yet seen this potential fully realized. While Julia certainly has the machinery to run at scale, and while others have done so for embarrassingly parallel workloads, we have yet to see an analysis of Julia's performance on communication-intensive codes that are so common in the HPC domain. In this paper we investigate Julia's performance in this light, first with a suite of microbenchmarks within and without the node, and then using the first Julia port of a standard, HPC benchmarking code, high-performance conjugate gradient (HPCG). We show that if programmers properly balance the computation to communication ratio, Julia can actually outperform C/MPI in a cluster computing environment.
Vulnerability Disclosure and Management for AI/ML Systems: A Working Paper with Policy Recommendations

Artificial intelligence systems, especially those dependent on machine learning (ML), can be vulnerable to intentional attacks that involve evasion, data poisoning, model replication, and exploitation of traditional software flaws to deceive, manipulate, compromise, and render them ineffective. Yet too many organizations adopting AI/ML systems are oblivious to their vulnerabilities. Applying the cybersecurity policies of vulnerability disclosure and management to AI/ML can heighten appreciation of the technologies’ vulnerabilities in real-world contexts and inform strategies to manage cybersecurity risk associated with AI/ML systems. Federal policies and programs to improve cybersecurity should expressly address the unique vulnerabilities of AI-based systems, and policies and structures under development for AI governance should expressly include a cybersecurity component.
A Path Criterion for Deformation Plasticity Theory

A loading path criterion is presented for total strain (or deformation) theory of plasticity based upon the associated loading function of Sanders. The considered state of stress is that corresponding to three-dimensional axisymmetric or plane strain problems. A simple geometric transformation of the yield surfaces enables the establishment of an analytic condition for determining the acceptability of stress paths predicted by the Hencky-Nadai total strain equations. The criterion is shown to be satisfied throughout the loading history of a longitudinally constrained, thermally loaded bar. A stiffness matrix iteration method is employed in the numerical solution.
Preliminary Report Using the Contact Endoprobes and the Laser Scalpel with the Neodymium: YAG Laser in Gastrointestinal Surgery

Application of the neodymium: YAG laser in gastroenterology have increased from being used by 12 centers in 1981 to over 300 installations as of May 1985 in the USA. Sales of medical lasers are expected to reach $600 million by 1990 and between $1.2 and 2.5 billion by 1995. The continuous wave neodymium:YAG laser will account for most of these sales based on it’s multidisciplinary applications(1) and increased endoscopic and therapeutic options. In major acute upper gastrointestinal (GI) bleeding the neodymium: YAG laser has been found to significantly decrease the rebleeding rate, requirement for emergency surgery, and reduces mortality (2). Results of a questionnaire presented in Washington D.C. (USA) in April 1985 found that 3190 patients with acute upper GI bleeding (26 reponders) and 967 patients with upper GI carcinoma predominantly of the esophagus (25 responders) have been treated endoscopically with the neodymium: YAG laser using the non-contact method (Fleischer 1985, Personal Communication).
Tax Implications of Housing Allowances and Purchase of a Residence Abroad

A U. S. citizen employed abroad may solve his residence needs in the host country by renting premises or buying a house. In order to defray residence costs, a U. S. expatriate may receive a housing allowance from the American employer. This study deals with the tax treatment of such allowance from the employee's viewpoint and from the payor company's viewpoint, in each of the 18 Latin American countries.
Three-Dimensional Vortex Dynamics near a Wall

The three-dimensional deformation of an artificially generated line vortex near a flat wall is examined by means of flow visualization and quantitative conditioned sampling of a hot-wire anemometer. The vortex is observed to undergo a very rapid deformation from the rectilinear form to a hairpinlike shape. Similar shapes have been observed in the case of driven flows in laminar boundary layers and during the transition to turbulent flow. In the present case the vortices are driven by a rotor configuration of larger scale than the boundary layer thickness.
Real-time nonlinear optimal control using neural networks

In this paper, a neural network based controller which optimizes a finite horizon quadratic cost function is developed for a class of nonlinear systems. The controller converges to its optimal value real-time eliminating the need for a priori knowledge of the nonlinearity and the initial conditions. The method makes use of the optimality conditions obtained from the Hamiltonian directly. These conditions are realized by a series of neural networks which converge to the optimal control iteratively in real-time. A nonlinear system to demonstrate its applicability is also included.
Low-power, high-speed InGaAs/InP photoreceiver for highly-parallel optical data links

Low-power photoreceivers based on InGaAs/InP heterojunction bipolar transistors (HBTs) and p-i-n diodes for highly-parallel optical data links have been designed, fabricated and characterized. The receivers are designed to operate from 980 nm to over 1.3 /spl mu/m and interface directly with 3.3 V CMOS. SPICE was utilized to investigate circuit topographies that minimize power dissipation while maintaining large signal operation required to interface directly with CMOS. Low-power dissipation of /spl sim/10 mW/channel has been achieved at bit rates up to 800 Mbits/sec. Performance characteristics of discrete HBTs and of low-power photoreceivers fabricated with p-i-n/HBT circuits are reported.
The jacobian of a cyclic quotient of a fermat curve

Fix a positive integer m . Let F m denote the Fermat curve over Q of degree m, given by the projective equation
Range policy of adaptive cruise control for improved flow stability and string stability

This paper presents the problem of designing a range policy for adaptive cruise control systems and a companion control algorithm for improved traffic flow stability and string stability. A nonlinear range policy is proposed and its performance is compared against a constant time-headway policy and the range policy employed by human drivers, with special attention on traffic flow stability. The proposed range policy is obtained from the solution of an optimization problem under traffic flow requirements. A sliding mode controller is then designed to work with the range policy. Simulation results show that higher and sustainable (stable) traffic flow is achieved by the proposed method.
Chromosome replication in Salmonella typhimurium.

The replication of the Salmonella typhimurium chromosome was studied. As with E. coli 15T−, replication was sequential. After amino acid starvation, replication proceeded from a unique and heritable region of the chromosome. 5-Bromouracil, when substituted for thymine, did not disturb the sequence of replication nor did it initiate extra replication cycles. By labeling the origin and the terminus of the chromosome with 3H- and 14C-thymine, respectively, it was possible to determine that the rate of chain elongation decreases as the growth rate decreases. No gap in the replication cycle could be observed.
Structural glass on a lattice in the limit of infinite dimensions

We construct a mean-field theory for the lattice model of a structural glass and solve it using the replica method and one-step replica symmetry breaking ansatz; this theory becomes exact in the limit of infinite dimensions. Analyzing the stability of this solution we conclude that the metastable states remain uncorrelated in a finite temperature range below the transition, but become correlated at a certain low temperature; below this temperature metastable states bifurcate and the one step replica symmetry breaking solution fails. We find dynamic and thermodynamic transition temperatures as functions of the density, and construct a full thermodynamic description of a typical physical process in which the system is trapped in one metastable state when cooled below the vitrification temperature. We find that for such physical process the entropy and pressure at the glass transition are continuous across the transition, while their temperature derivatives have jumps.
Deposition and diagenesis of Mammoth Hot Springs travertine, Yellowstone National Park, Wyoming, U.S.A.

Strata forming a 113 m long core through Mammoth Hot Springs record the Holocene evolution of this travertine accumulation from deposition as part of a lacustrine to a terraced mound environment. The deposit is readily divided into four intervals: 11367 m, carbonate-cemented volcaniclastic with intercalated layers of travertine; 6760 m, moderately pure travertine with some volcaniclastics; 6050 m, carbonate-cemented volcaniclastic-rich interval; and 500 m, essentially pure travertine. Lithologic composition, sedimentary structures, and the rare ostracode fossils indicate that the lower 67 m predominantly accumulated in a lacustrine environment, whereas the upper 40 m are terraced mound deposits. All of the travertine is calcite, some after aragonite. Layers of shrubs, oncoids, and peloids, all bacterial in origin, form the dominant allochems within the travertine. Stable isotopic carbon and oxygen values (n = 128) are strongly positively correlated and decrease up-core ~4 and 8, respectively, reflec...
Regulation of the G2/M Transition in Xenopus Oocytes by the cAMP-dependent Protein Kinase

Vertebrate oocytes are arrested in G2 phase of the cell cycle at the prophase border of meiosis I. Progesterone treatment of Xenopus oocytes releases the G2 block and promotes entry into the M phases of meiosis I and II. Substantial evidence indicates that the release of the G2 arrest requires a decrease in cAMP and reduced activity of the cAMP-dependent protein kinase (PKAc). It has been reported and we confirm here that microinjection of either wild type or kinase-dead K72R PKAc inhibits progesterone-dependent release of the G2 arrest with equal potency and that inhibition can be reversed by a second injection of the heat-stable inhibitor of PKAc, PKI. However, a mutant enzyme predicted to be completely kinase-dead from the crystal structure of PKAc, K72H PKAc, was much less inhibitory when carrying additional mutations that block interaction with either type I or type II regulatory subunit. Moreover, inhibition by K72H PKAc was reversed by PKI at a 30-fold lower concentration and with more rapid kinetics compared with wild type PKAc. K72R PKAc was found to have low but detectable activity after incubation in an oocyte extract. These results indicate that inhibition of the progesterone-dependent G2/M transition in oocytes after microinjection of dead PKAc reflects either low residual activity or binding to regulatory subunits with a resulting net increase in the level of endogenous wild type PKAc. Consistent with this hypothesis, the induction of mitosis in Xenopus egg extracts by the addition of cyclin B was blocked by wild type PKAc but not by K72H PKAc. The identification of substrates for PKAc that maintain cell cycle arrest in G2 remains an important goal for future work.
“Providing for the Common Defense?” The Outsourcing of America's National Security through the Commercial Sale of Arms and Arms Production

How can a democracy and the tenets of democratic society be preserved and protected amid the contemporary security challenges that pose a threat to democracy and its tenets? As democracies fashion their new security strategies to deal with these new threats, what are the chances that some of these cures might pose more harm than good? This paper describes what has emerged over the past decade as perhaps the greatest unintended consequence facing the United States and global security: the globalization of the conventional arms market and the commercialization and “foreignization” of the US military-industrial complex. President Eisenhower's 1961 warning has come home to roost in the early 2000s, now representing an “outsourcing of national security” at risk of escalating as much as deflating the security challenges facing American democracy today.
Exploring modal worlds

Abstract Modal idempotent semirings cover a large set of different applications. The paper presents a small collection of these, ranging from algebraic logics for program correctness over bisimulation refinement, formal concept analysis, database preferences to feature oriented software development. We provide new results and/or views on these domains; the modal semiring setting allows a concise and unified treatment, while being more general than, e.g., standard relation algebra.
Anger dysregulation: driver of violent offending

Anger has had insufficient priority in the forensic field. From classical scholarship to contemporary neuroscience, anger has been known for its dynamic bearing on violence risk and for its involvement in psychiatric disorders. Anger is intrinsically and reciprocally related to threat perception, and it impels violent behavior in the absence of self-regulatory controls. Focus is given to what has been learned in forensic domains about anger as an impetus for the violent behavior of offenders. Issues bearing on anger assessment in forensic settings are discussed. Topics for further engagement in forensic research on anger are presented, including offender readiness, transdiagnostic processes, and female offender specificity. While anger treatment is not covered, interfacing discussion is provided throughout.
A note concerning non-uniform pool labeling.

An analytical relation is suggested, which in certain cases may permit the labeling pattern of a cellular compartment to be computed from the labeling pattern of cells in a precursor compartment.
Simulation of directional solidification with steep thermal gradients

The convection and macrosegregation predicted by a simulation of a directionally solidified binary alloy (Pb - 23.2 wt%Sn) are presented, and the simulated macrosegregation is compared with the macrosegregation in an experimental casting. The casting was solidified at a rate of and a thermal gradient of approximately ; such thermal gradients are much greater than those previously simulated. The calculated results showed channels at the vertical casting surfaces and segregated internal pockets in the mushy zone, in agreement with the observation of freckles in the experimental casting.
Illite equilibria in solutions: II. Phase relationships in the system K2OMgOAl2O3SiO2H2O

The stability of the Marblehead illite has been investigated in the five-component system K2O-MgO-Al2O3-SiO2-H2O in the presence of kaolinite and microcline. The mica-like solubility-controlling phases [Kx(MgyAl2−y)(Alx−ySi4−(x−y)) O10(OH)2]identified include (i) smectite x = 0.29 ± 0.04, y = 0.26 ± 0.02; (ii) illite x = 0.50 ± 0.05, y = 0.22 ± 0.14; (iii) illite x = 0.69 ± 0.08, y = 0.16 ± 0.03; (iv) illite x = 0.85 ± 0.05, y = 0.12 ± 0.04; and (v) muscovite. Possible stability regions have been defined for these solubility-controlling phases using isothermal isobaric log aMg12+2/2aH+ vs. log aH+ diagrams. When illite stability is referred to the quaternary system K2O-Al2O3-SiO2-H2O, the effect of (R+2)VI substitution is neglected. The error inherent in this simplification has been estimated. Inasmuch as a four-fold increase in aMg2+ shifts the illite-smectite-kaolinite-solution invariant point by less than 0.3 log units, stability relationships in the quaternary system provide an adequate representation of illite solution equilibria, to a first approximation. However, the error caused by neglecting Mg+2 is close to or within experimental error. Thus, a more precise determination of the effect of Mg+2 on illite solution equilibria may not be possible using the solution equilibration method.
Research note: A thirteen-day assay for use in pigmentation evaluation of egg yolks.

Abstract An experiment was conducted to compare 13-day and 42-day assays for egg yolk pigmentation in the laying hen. Birds previously fed a commercial-type diet were fed experimental diets with white corn meal (replacing yellow corn) and varying levels of canthaxanthin. Egg yolks were evaluated for dominant wavelength (DWL) and excitation purity (EP) at various intervals for 21 days using a MC-1010® Reflectance Colorimeter. These data were then compared with similar data obtained from eggs from hens that were fed the same experimental diets but that were allowed to deplete the eggs of pigment on a xanthophyll-free diet for 21 days and then replete the eggs with pigment on the experimental diets for 21 days. The data indicated that it was possible to obtain accurate and consistent pigmentation values for DWL and EP in 13 days by allowing hens to deplete and replete xanthophyll stores simultaneously. This results in savings in both time and expense in collecting egg yolk pigmentation data.
Ad-atom interactions with III-V semiconductor surfaces

Abstract Photoemission techniques (core level, valence band and partial yield spectroscopies) using synchrotron radiation as the excitation source have been applied to study the changes in the surface electronic structure of the (110) cleavage face of III-V semiconductor surfaces as a function of different ad-atom coverages. In this paper we concentrate on Au overlayers on GaSb and in particular address the problem of the mechanism for Fermi level pinning and the formation of Schottky barrier heights. It appears that the Fermi level pinning is fully established at a small fraction of a monolayer coverage. Core level spectroscopy gives evidence for a strong metal-semiconductor interaction leading to decomposition of GaSb at the interface. The experimental results form the basis for proposing a new model for the Schottky barrier based on defect states at the interface.
Effects of noise on transfer entropy estimation for damage detection

Recent research has shown that transfer entropy can be effectively employed as a feature for nonlinearity detection and linear damage identification. However, computation of transfer entropy requires the estimation of non-parametric one-, two-, and three-dimensional probability density functions. Therefore, small random perturbations caused by noise could lead to large variances in transfer entropy estimates. In this paper, we evaluate the effect of input and output noise on estimation of transfer entropy, and how noise, in turn, affects the capability of transfer entropy as a damage detector in a structural health monitoring (SHM) application. A damage index from the transfer entropy is computed from the response of a simulated multi-degree-of-freedom oscillator subject to linear and nonlinear stiffness changes in the presence of various noise influences. Damage indices are also evaluated for an experimental frame structure. Based on the computational study, we find that input noise lessens the sensitivity of the damage feature by diminishing the ability of the non-parametric density estimators to produce low variance transfer entropy estimations. Despite this reduced capability, an input that has no deterministic component can still detect a 25% stiffness loss in the computational example employed. Output noise has a greater impact on the feature's ability to accurately estimate the transfer entropy, such that a signal-to-noise threshold of approximately 30 dB leads to a greatly diminished ability to detect damage. Despite these noise effects, all damage cases tested on an experimental frame structure were detectable using the transfer entropy damage index.
Variable Radiobiological Responses of Spheroids

Several techniques are now available for the growth of mammalian cells in culture as three-dimensional spheroids. Use of these spheroids as in vitro models of solid tumors is increasing, yet little characterization of most systems, other than histological appearance, has been forthcoming. Data are presented here which indicate that spheroids produced with different sublines of V79 Chinese hamster cells can exhibit vastly different radiobiological properties, despite having a similar histological appearance. Quantitative characterization of the radiation response of these spheroids indicates that the responses are highly dependent upon cell type, whether spheroids are irradiated in stirred or unstirred cultures, and the techniques used to recover cells from spheroids. Further, the extent and/or degree of hypoxia within spheroids does not always correlate with spheroid radiosensitivity or development of central necrosis. These results clearly indicate the necessity of adequately characterizing such model systems, and thus suggest, that results obtained with one spheroid system cannot be used as a baseline for another.
The distribution of neurons projecting from the retina and visual cortex to the thalamus and tectum opticum of the barn owl, Tyto alba, and the burrowing owl, Speotyto cunicularia.

Using the HRP retrograde transport technique in two different genera of owls (Speotyto and Tyto), we have studied the distribution of neurons projecting to the optic tectum and the visual thalamus. Small injections of HRP were made into these structures from the pial surface after they had been visualized directly by dissection of the overlying bone. In contrast to the findings in mammals, retinal ganglion cells were labeled only in the eye contralateral to the injection site, whether this was in the thalamus or tectum, and the labeled ganglion cells were found on both nasal and temporal sides of the vertical retinal meridian through the fovea. After thalamic injection, labeling was prominent in temporal retina representing the binocular field, temporal to the optic nerve head. Retinothalamic ganglion cells formed roughly concentric lines of isodensity centered on the fovea (Speotyto) or area centralis (Tyto); labeling form thalamic injections involved both large and medium-sized neurons, but did not involve the smallest nor a conspicuous class of very large neurons. Tectal injections led to prominent labeling along the horizontal streak region, with horizontally elongated isodensity contours in both Tyto and Speotyto; retinotectal ganglion cells were heterogeneous and included a group of very large neurons and another group of small neurons, neither of which was labeled from the thalamus. In the visual Wulst, labeled neurons were confined to the supragranular layers after both tectal and thalamic injections. Corticotectal neurons were found in both ipsilateral and contralateral visual Wulst. They were characterized by large cell bodies and prominent dendrites. Corticotectal neurons were distributed throughout the mediolateal extent of the ipsilateral Wulst and therefore involved both the monocular and binocular representations of the visual field. Corticothalamic neurons, found only in the ipsilateral Wulst, were characterized by smaller cell bodies and fine dendrites. They were confined to the monocular crescent on the extreme medial edge of the Wulst.
Experimental Study of Effects of Non-Condensable on Condensation in a Vertical Tube Bundle

One of the engineered safety systems in the advanced boiling water reactor is a passive containment cooling system (PCCS) which is composed of a number of vertical heat exchanger. After a loss of coolant accident, the pressurized steam discharged from the reactor and the noncondensable (NC) gases mixture flows into the PCCS condenser tube. The PCCS condenser must be able to remove sufficient energy from the reactor containment to prevent containment from exceeding its design pressure. The efficient performance of the PCCS condenser is thus vital to the safety of the reactor. In PCCS condenser tube three flow conditions are expected namely the forced flow, cyclic venting and complete condensation modes. The PCCS test facility consists of steam generator (SG), instrumented condenser with secondary pool boiling section, condensation tank, suppression pool, storage tank, air supply line, and associated piping and instrumentation. The specific design of condensing tube is based on scaling analysis from the PCCS design of ESBWR. The scaled PCCS is made of four tubes of diameter 52.5mm and height 1.8 m arranged in square pitch. Steam air mixture condensation tests were carried out in a through flow mode of operation where the mixture flows through the condenser tube with some steam condensation. Data on condensation heat transfer were obtained for two nominal pressures, 225 kPa and 275 kPa and for air concentration fraction from 0 to 13%. Test results showed that with increase in pressure the condensation heat transfer increased. The presence of the air in the steam decreased the condensation heat transfer coefficient from 10 to 45% depending on air fraction in the steam.Copyright © 2009 by ASME
Autonomy in Space Exploration: Current Capabilities and Future Challenges

Deep space exploration requires vehicles with appropriate autonomous capabilities. In order to accomplish their missions, spacecraft need to respond to potential hazards while seeking to expand human knowledge of deep space. This paper provides an overview of the role of autonomy for space exploration. First, we explore the range of autonomous behavior that is useful in space exploration. Second, three core requirements are defined for autonomous space systems. Fourth, we identify the decision-making capabilities that will ensure the effectiveness and safety of autonomous systems. Fifth, we describe architectures for integrating capabilities into an autonomous system. Finally, we discuss the challenges that are faced currently in developing and deploying autonomy technologies for space.
Distribution and Survival of Eggs of Summerform Pear Psylla (Homoptera: Psyllidae) Affected by Leaf Midvein

Distribution of pear psylla eggs on pear seedlings and cues affecting oviposition were monitored. Most eggs were deposited on the youngest foliage; few eggs were placed on the oldest, leathery leaves. Highest densities occurred adjacent to the midvein or in leaf serrations. Densities were very low on the leaf blade away from the midvein. Oviposition was induced in areas normally avoided (e.g., leaf blade) by providing strips of tape as artificial structures resembling midveins. Masking of particularly prominent midveins with strips of tape resulted in reduction of oviposition in these normally preferred sites. These results suggest that the midvein provided positive mechanical cues to ovipositing females. Effects of egg location on survival and development of eggs was quantified. Survival rates of eggs were higher for eggs deposited along the midvein than those deposited on the leaf blade. Survival decreased with increasing plant water stress. Development rates of eggs were not affected by location or stress.
In Vitro Study of α-Synuclein Protofibrils by Cryo-EM Suggests a Cu2+-Dependent Aggregation Pathway

The aggregation of α-synuclein is thought to play a role in the death of dopamine neurons in Parkinson’s disease (PD). Alpha-synuclein transitions itself through an aggregation pathway consisting of pathogenic species referred to as protofibrils (or oligomer), which ultimately convert to mature fibrils. The structural heterogeneity and instability of protofibrils has significantly impeded advance related to the understanding of their structural characteristics and the amyloid aggregation mystery. Here, we report, to our knowledge for the first time, on α-synuclein protofibril structural characteristics with cryo-electron microscopy. Statistical analysis of annular protofibrils revealed a constant wall thickness as a common feature. The visualization of the assembly steps enabled us to propose a novel, to our knowledge, mechanisms for α-synuclein aggregation involving ring-opening and protofibril-protofibril interaction events. The ion channel-like protofibrils and their membrane permeability have also been found in other amyloid diseases, suggesting a common molecular mechanism of pathological aggregation. Our direct visualization of the aggregation pathway of α-synuclein opens up fresh opportunities to advance the understanding of protein aggregation mechanisms relevant to many amyloid diseases. In turn, this information would enable the development of additional therapeutic strategies aimed at suppressing toxic protofibrils of amyloid proteins involved in neurological disorders.
Deformation of drawn, annealed polyethylene

Abstract The deformation of drawn and annealed polyethylene film was examined by electron microscopy and small-and wide-angle x-ray diffraction, and is compared with that of oriented, annealed thin films redrawn on Mylar film. Although the detailed results obtained with redrawn thin film can not be directly compared with the thick films, in both cases the observed kabob structure first undergoes separation and tilting of the lamellae followed by breakage of the lamellae into blocks and probable unfolding of the molecules in the blocks to form extended-chain fibrils. The results are similar to those that have been reported for the deformation of solution grown polyethylene shish-kabobs.
Electrocoagulation pretreatment of seawater prior to ultrafiltration: Bench-scale applications for military water purification systems

The objectives were to investigate the performance of a pilot-scale electrocoagulation (EC) reactor and to determine the feasibility of using in-line EC as a pretreatment to ultrafiltration (UF) of seawater. Work was conducted at Port Hueneme, CA, using components of a U.S. military water purification system. Ferric chloride in-line coagulation was also tested. Both the EC and ferric chloride pretreatments improved UF membrane performance compared to UF without in-line coagulation. EC resulted in slightly greater increases in transmembrane pressure (TMP) than observed following ferric chloride pretreatment during sub-critical flux UF. Substantial accumulation of precipitates developed on the EC electrodes during the testing period. X-ray diffraction identified magnetite, maghemite, lepidocrocite, and akaganeite phases. Accumulation of these precipitates was due in part to conservative hydraulic design of the EC unit. It is recommended that EC units should be designed with short hydraulic retention times and higher electrode current density in order to increase upflow (scour) velocity and thus inhibit accumulation on the electrodes. Progressively longer cycling times for polarity reversal are also recommended. This research indicates that EC offers the potential for a feasible and effective pretreatment strategy for mobile water production facilities.
Real-time portal monitoring to estimate dose to skin of patients from high dose fluoroscopy

Since doses to skin of patients from fluoroscopically-guided interventional procedures can be very high, real-time monitoring of skin dose is important for both patient management and quality control. The use of a scintillation detector, placed on the X-ray port to measure potential skin dose, was investigated, focusing on the uncertainties related to the technique. Sources of uncertainty include performance characteristics of the dosemeter, errors in calibration, patient set-up and changes during the procedure. Some of the largest sources of error include uncertainty in source-to-skin distance, heel effect, difficulty in identifying the area of skin principally exposed, calibration error, energy dependence of the dosemeter and the dose rate dependence of the monitor. This technique is found to be beneficial for radiation management, but users must be cognizant of the potential errors of the method and the limitations that these place on quality control and patient management. Knowing the limitations and minimizing the sources of error enhance the utility of the technique.
An apparatus for the flask combustion of organic compounds adaptable to carbon determination

Abstract An apparatus for flask combustion of organic compounds is described. The combustion is conducted with an electrically heated device. The flask combustion technique is adaptable to the microdetermination of carbon or hydrogen in organic compounds.
Estradiol and incubation temperature modulate regulation of steroidogenic factor 1 in the developing gonad of the red-eared slider turtle.

Red-eared slider turtles are genetically bipotential for sex determination, with incubation temperature of the egg determining gonadal sex. At higher incubation temperatures, females are produced, possibly due to increased biosynthesis of estrogen. Exogenous estrogen causes the formation of ovaries, and prevention of estrogen biosynthesis results in the development of testes. In mammals, steroidogenic factor 1 (SF-1) regulates most genes required for estrogen biosynthesis from cholesterol. In mammals as well as red-eared slider turtles, SF-1 is differentially expressed in males and females during gonadogenesis. To examine a possible role for SF-1 in temperature-dependent sex determination, we assayed its expression in red-eared slider turtles after treatments that alter sex development during gonadogenesis of the wild-type organism. We examined gonadal SF-1 expression in embryos 1) incubating at three different temperatures, 2) after treating eggs with estrogen at a male-producing temperature, and 3) afte...
Femtosecond probing of persistent wave packet motion in dissociative reactions: up to 40 ps

Femtosecond probing of nuclear motion in an alkali halide (NaI) reaction reveals a persistent wave packet, recurring at long times up to 40 ps. The detection of both “free” Na atoms and “transient” [Na…I]^(≠*) indicates non-exponential dynamics through the crossing zone of the covalent and ionic potential energy curves. These observations are related to the nature of the motion, and the level structure making the packet.
Cloning, expression and sequence analysis of the SphI restriction-modification system

SphI, a type II restriction-modification (R-M) system from the bacterium Streptomyces phaeochromogenes, recognizes the sequence 5'-GCATGC. The SphI methyltransferase (MTase)-encoding gene, sphIM, was cloned into Escherichia coli using MTase selection to isolate the clone. However, none of these clones contained the restriction endonuclease (ENase) gene. Repeated attempts to clone the complete ENase gene along with sphIM in one step failed, presumably due to expression of SphI ENase gene, sphIR, in the presence of inadequate expression of sphIM. The complete sphIR was finally cloned using a two-step process. PCR was used to isolate the 3' end of sphIR from a library. The intact sphIR, reconstructed under control of an inducible promoter, was introduced into an E. coli strain containing a plasmid with the NlaIII MTase-encoding gene (nlaIIIM). The nucleotide sequence of the SphI system was determined, analyzed and compared to previously sequenced R-M systems. The sequence was also examined for features which would help explain why sphIR unlike other actinomycete ENase genes seemed to be expressed in E. coli.
Trading relations in speech and nonspeech

Two acoustic variables that correlate with the distinction between intervocalic [b] and [p] are closure duration and presence or absence of low-frequency glottal pulsing during the closure interval. These variables may be considered to exhibit a trading relation (Repp, 1982), to the extent that a longer closure is required to perceive the consonant as voiceless when glottal pulsing is present than when it is not. Such trading relations have been interpreted as reflecting a special speech mode of perception. In the present experiments, we demonstrated a trading relation between closure duration and closure pulsing for a set of [aba]-[apa] stimuli. Next we showed that a similar effect could be obtained with square-wave analogue stimuli that mimicked the segment durations and peak amplitudes of the speech stimuli but that were not phonetically categorizable. This nonspeech trading relation depended on the degree of spectral continuity between the low-frequency pulsing and the adjacent portions of the square wave. The implications of these results for the speech mode hypothesis are discussed.
Reactive ion etching of gallium nitride films

Reactive ion etching (RIE) was performed on gallium nitride (GaN) films grown by electron cyclotron resonance (ECR) plasma assisted molecular beam epitaxy (MBE). Etching was carried out using trifluoromethane (CHF3) and chloropentafluoroethane (C2ClF5) plasmas with Ar gas. A conventional rf plasma discharge RIE system without ECR or Ar ion gun was used. The effects of chamber pressure, plasma power, and gas flow rate on the etch rates were investigated. The etch rate increased linearly with the ratio of plasma power to chamber pressure. The etching rate varied between 60 and 500A/min, with plasma power of 100 to 500W, chamber pressure of 60 to 300 mTorr, and gas flow rate of 20 to 50 seem. Single crystalline GaN films on sapphire showed a slightly lower etch rate than domain-structured GaN films on GaAs. The surface morphology quality after etching was examined by atomic force microscopy and scanning electron microscopy.
Altered GABA Signaling in Early Life Epilepsies

The incidence of seizures is particularly high in the early ages of life. The immaturity of inhibitory systems, such as GABA, during normal brain development and its further dysregulation under pathological conditions that predispose to seizures have been speculated to play a major role in facilitating seizures. Seizures can further impair or disrupt GABAA signaling by reshuffling the subunit composition of its receptors or causing aberrant reappearance of depolarizing or hyperpolarizing GABAA receptor currents. Such effects may not result in epileptogenesis as frequently as they do in adults. Given the central role of GABAA signaling in brain function and development, perturbation of its physiological role may interfere with neuronal morphology, differentiation, and connectivity, manifesting as cognitive or neurodevelopmental deficits. The current GABAergic antiepileptic drugs, while often effective for adults, are not always capable of stopping seizures and preventing their sequelae in neonates. Recent studies have explored the therapeutic potential of chloride cotransporter inhibitors, such as bumetanide, as adjunctive therapies of neonatal seizures. However, more needs to be known so as to develop therapies capable of stopping seizures while preserving the age- and sex-appropriate development of the brain.
Treaty-Making and Partisan Politics: Arms Control and the U.S. Senate, 1960–2001

Because the impact of domestic politics and institutions is increasingly important to understanding foreign policy, the motivations and interests of individual members of Congress are even more important for understanding American foreign policy. Contrasting the well-known thesis that “politics stops at the water's edge” with a “politics past the edge” thesis, we examine an issue arena typically considered immune from the intrusion of domestic politics. Set against the context of previous studies concluding that partisanship exerts a growing impact of congressional behavior in foreign policy, this paper extends current studies to examine the impact of partisanship and other variables on Senate voting on arms control treaties on weapons of mass destruction. With a data set of votes that spans the 1960–2001 period, we employ logit regression to gauge the relative importance of three determinants of congressional voting emphasized in theory and roll call vote analyses—partisanship, ideology, and electoral concerns—while also controlling for a variety of other factors. Our results indicate that partisanship becomes an increasingly important factor in Senate votes on arms control treaties in the post-Vietnam and post-Cold War eras.
Structural shifts in urban population density gradients: an empirical investigation.

Abstract This study investigates the structural shifts in urban population density gradients by first using the shifting regression technique of Farley, Hinich, and McGuire to detect the possible change in the structure of an urban area. Secondly, a generalized random coefficient technique is used to simultaneously detect the possible structural change and stochastic behavior of density gradients. Data for 50 United States SMSA's are used to do the empirical analyses.
Dynamics of tunneling to and from small metal particles

The charge-transfer process between a small metal particle and a nearby electrode is investigated with electron tunneling experiments. The small particles are produced as an island film embedded in a capacitor, separated from one plate by a thin tunnel barrier and from the other by a thick insulator. The device properties reflect an ensemble average of independent particle-electrode tunneling systems. A significant property of the small-particle capacitor is that the potential change e/c associated with the transfer of a single electron is a non-negligible quantity. The experiments investigate the dynamics of the charge transfer process between particle and electrode by measuring the device capacitance C and dissipation constant D as a function of frequency \ensuremath{\omega}, temperature T, and ac voltage amplitude V. Experiments are carried out in the regime kT/e, Vle/c so that at most one electron transfer to or from a particle is induced during a cycle of the applied voltage. A model for the suppression of the tunneling rate by the Coulomb charging energy is presented which predicts C and D should scale as \ensuremath{\omega}/T in the zero-voltage limit and \ensuremath{\omega}/V in the zero-temperature limit. Experimental results verify these scaling laws. It is shown that at low temperature and voltages, a quantum size effect may cause the results to deviate from these scaling laws. Experimental results are presented which qualitatively support this prediction. Additional experiments investigate the transport between a small particle and a superconductor.