cssi/SciSciGPT-SciSciNet huggingface dataset:
Surgical management of negative dysphotopsia.

Purpose To evaluate curative and preventative surgical strategies for negative dysphotopsia. Setting Private practice, Los Angeles, California, USA. Design Retrospective case series. Methods Patients with self-reported chronic negative dysphotopsia had corrective surgery as the therapeutic group. Second eye surgery, in cases with negative dysphotopsia in the previously operated eye, comprised the preventative group. Chronologically, several surgical strategies were used, including bag-to-bag intraocular lens (IOL) exchange, reducing posterior chamber depth, piggyback secondary IOL placement, bag-to-sulcus IOL exchange, and reverse optic capture. The primary outcome measure was improvement of negative dysphotopsia by 3 months postoperatively. Results The therapeutic group comprised 40 eyes of 37 patients; 76.6% of causative IOLs were acrylic and 23.4% were silicone and all were bag-fixated. There were 21 eyes in the preventative group of which 11 were second eyes from the therapeutic group; the remaining 10 did not require surgery for the symptomatic eye. Successful outcomes for each surgical strategy were as follows: bag-to-bag IOL exchange (0/5), a reduction in posterior chamber depth with iris suture fixation of the bag–haptic complex (0/1), piggyback secondary IOL (8/11), secondary reverse optic capture (21/22), ciliary sulcus posterior chamber IOL exchange (7/8), and primary reverse optic capture (21/21). Conclusions Negative dysphotopsia was associated with acrylic or silicone IOLs of either square- or round-edge design. Negative dysphotopsia was reduced, eliminated, or prevented when the IOL optic overlaid the anterior capsulotomy rather than when the capsule edge overlaid the optic. Bag-to-sulcus IOL exchange and reverse optic capture were highly successful in managing or preventing negative dysphotopsia.
Practical design approach for trapezoidal modulation of a radio-frequency quadrupole

Trapezoidal modulation of quadrupole electrodes offers additional benefits to the concept of a radio-frequency quadrupole (RFQ). Because of the significant increase of the effective shunt impedance, RFQs with trapezoidal modulation have a reduced interelectrode voltage or resonator length as compared to conventional RFQs with sinusoidal modulation. This feature is especially valuable for RFQs operating in cw mode, since it reduces the required rf power. We develop a detailed procedure for the design of RFQ electrodes with trapezoidal modulation. With our design procedure and by properly choosing the trapezoidal cell parameters, we can easily control the peak surface fields in the RFQ to the same level as for sinusoidal cell modulation. The procedure is applied to the design of the electrodes for the ReA3 RFQ at Michigan State University.
A rapid molecular precursor solid-state route to crystalline Fe2GeS4 nanoparticles

Abstract Iron germanium sulfide (Fe2GeS4) recently emerged as a potential thin film solar photovoltaic absorber. The introduction of the third element—germanium (Ge)—viewed as a solution for overcoming multiple barriers of a photovoltaic pyrite, confers stability to Fe2GeS4 at elevated temperatures, typically required for accomplishing grain growth in Gen 2 thin film PV. A facile synthesis of Fe2GeS4 nanoparticles from molecular precursors, comprising mechanical mixing of starting materials followed by a two-hour annealing in a sulfur-rich atmosphere is presented herein. Further processing of the resulting Fe2GeS4 nanopowders at elevated temperatures demonstrates high thermal stability of Fe2GeS4 (up to 500 °C), in comparison with pyrite, which shows onset of pyrrhotite upon heating above 160 °C. Based on the secondary crystalline phases formed, we propose a mechanism of decomposition of Fe2GeS4 at high temperatures. Films fabricated with Fe2GeS4 were further annealed and revealed that Fe2GeS4 withstands high temperatures in thin film.
Radiation-Accellerated Ions in Hot Star Winds: Heating and “Turbulence” Effects

In the papers by Vilkoviskij (1981), Vilkoviskij and Tambovtzeva (1988) and Springmann and Pauldrach (1992) it was shown that ions can reach velocities \({v_i} \geqslant \bar v_{Tp}\left( {\bar v_{Tp} = {{\left( {2kT/{m_p}} \right)}^{1/2}}} \right)\) relative to the wind plasma when the radiation pressure force exceeds the protons frictional force. The condition for this transition can be estimated as $${v_7} \geqslant 0.7{\dot M_6}z_i^2/\left( {R_1^2{T_4}\phi \left( {{\lambda _i}{T_*}} \right)} \right),$$ (1) where v 7 is the wind velocity in units of 107 cm/s, \({\dot M_6} = dM/dt\) the stellar mass-loss rate in units of 10-6 M ⊙/yr, z i the ion charge, R 1 = R */(10R ⊙), \(\phi \left( {{{\lambda }_{i}}{{T}_{*}}} \right) = {{f}_{i}}\lambda _{5}^{{ - 3}}/{{e}^{{14.4/\left( {{{\lambda }_{5}}{{T}_{4}}} \right) - 1}}},{{\lambda }_{5}} = {{\lambda }_{i}}/{{10}^{3}}{\AA}and{{T}_{4}} = {{T}_{e}}/{{10}^{4}}K \). The ion distribution function consists of two parts: the part DF 1 approximates the “shifted Maxwell” distribution, and the non-Maxwellian part DF 2 is for “runaway” particles: $$DF\left( {{v_i}} \right) = \left( {1 - {q_2}} \right)D{F_{1i}} + {q_2}D{F_{2i}},$$ (2) where q 2 > 0 when condition (1) is fulfilled. The specific heat power, divided by N p 2 is $$H = {N_i}/N_p^2\int_0^\infty {{v_i}} DF\left( {{v_i}} \right){F_{ip}}d{v_i},$$ (3) where N i and N p are the ion and proton densities and F ip is the frictional force. If the “runaway condition” (1) is not fulfilled, the mean velocity of ions relative to the wind plasma \({{\bar{v}}_{i}} \) is less then, \({\bar v_{Tp}}\) but it rises to about the electron thermal velocity \({\bar v_{ep}} \sim 43{\bar v_{Tp}}\) in the opposite case.
Microbiology of Acute, Subacute, and Chronic Rhinosinusitis in Children

Acute, subacute, and chronic rhinosinusitis may involve an infectious etiology. Knowledge of the microbiology of sinusitis is necessary because it impacts the choice of antibiotic therapy. The sinus aspirate is the most reliable source of microbiological data in sinusitis in children. However, sinus aspirates are rarely done in cases of patients with rhinosinusitis; the last time one was done in a child was in 1984. When they are done, sinus aspirate studies of children showed the presence of Streptococcus pneumoniae (S. pneumoniae), Haemophilus influenzae, and Moraxella catarrhalis (M. catarrhalis). Unlike sinus aspirates, nasopharyngeal and middle meatal cultures are not reliable in determining the bacteriology of children with acute sinusitis. The observation of an increase in the proportion of cases of acute otitis media caused by H. influenzae may reflect that in acute sinusitis as well. Staphylococcus aureus does not play a significant role in uncomplicated acute bacterial sinusitis. The microbiology of acute otitis media can be used as a surrogate for that of acute bacterial sinusitis in children. In contrast to bacteria, the contribution of viruses to the pathogenesis of acute bacterial sinusitis has not been studied systematically. The pathogenesis of chronic sinusitis may be related to bacterial biofilms as a stimulant of chronic inflammation.
Quantum light sources based on individual carbon nanotubes

Abstract: Single-walled carbon nanotubes (SWCNTs) have recently attracted tremendous interest as a nanomaterial for photonics and quantum photonics devices. Here we shall review recent work with a focus on quantum light properties such as blinking and spectral diffusion, and in particular, methods and techniques to suppress these detrimental effects with the goal of enhancing optical emission. Furthermore, we shall review recent work on the generation and detection of nonclassical light emissions from individual SWCNTs embedded in polymer cavities, and discuss the role of spatial exciton localization along the tube.
Learning Multiclassifiers with Predictive Features that Vary with Data Distribution

In many real-world big data applications, the data distribution is not homogeneous over entire data, but instead varies across groups/clusters of data samples. Although a model’s predictive performance remains vital, there is also a need to learn succinct sets of features that evolve and capture smooth variations in data distribution. These small sets of features not only lead to high prediction accuracy, but also discover the important underlying processes. We investigate this challenging problem by developing a novel multi-task learning paradigm that trains multiple support vector machine (SVM) classifiers over a set of related data clusters, and directly imposes smoothness constraints on adjacent classifiers. We show that such patterns can be effectively learned in the dual form of the classical SVM, and further show that a parsimonious solution can be achieved in the primal form. Although a solution can be effectively optimized via gradient descent, the technical development is not straightforward, requiring a relaxation over the loss function of SVMs. We demonstrate the performance of our algorithm in two practical application domains: team performance and road traffic prediction. Empirical results show our model not only achieves competitive prediction accuracy, but its discovered patterns truly capture and give intuition about the variation in the data distribution across multiple data clusters.
Statistical Methods To Explore The Phenotypic Consequences Of Gene Regulation

Abstract Background Over the last 15 years, enormous advances have been made in the technology to interrogate the genome, which in turn has allowed us to discover thousands of genetic variants robustly associated with complex traits including psychiatric disorders. However, most of these variants are not located in coding regions making their interpretation challenging. It is generally accepted that an important mechanism that mediate the genotype phenotype relationship is the regulation of gene expression levels as well as alternative splicing of mRNAs. Methods We will describe a method (PrediXcan) to integrate large scale of genome wide association studies (GWAS) with reference transcriptome studies in order to investigate the underlying mechanism behind these discoveries. PrediXcan imputes the transcriptome and computes the correlation between the genetically determined component and the phenotype to prioritize genes that are likely to be causal. Results We will show the results of applying PrediXcan to several large scale GWAS studies using prediction models of 44 human tissues. We find that most associations are tissue specific and that because of sharing between tissues, we increase our chances to discover the mediating genes when we scan across a broad set of tissues. Conclusions To take full advantage of the large amounts of genomic data that are being generated, methods that integrate multiple sources of high throughput data are needed. Here we present PrediXcan and its extension that addresses this need. Application to a broad set of phenotypes allows us to explore the phenotypic consequences of gene regulatory variation.
Species-specific patterns in corallivory and spongivory among Caribbean parrotfishes

Parrotfishes are key herbivores on Caribbean reefs but also feed on other benthic taxa such as corals and sponges. Here, we used in situ behavioral observations to show that Caribbean parrotfishes have species-specific feeding patterns of corallivory and spongivory. Overall, Scarus guacamaia, Scarus taeniopterus, and Sparisoma viride were the most frequent corallivores while Scarus coeruleus and Sparisoma chrysopterum never fed on corals. There were differences between the two genera in the corals targeted with Sparisoma parrotfishes preying on Colpophyllia natans and Orbicella faveolata more frequently while Scarus parrotfishes were more likely to prey on Porites astreoides and Siderastrea siderea. The most frequent spongivores were Sc. guacamaia, Sc. taeniopterus, Sparisoma aurofrenatum, and Sparisoma rubripinne. Scarus guacamaia fed across multiple sponge genera while other parrotfishes primarily fed on Agelas spp. sponges. Together, our data suggest that understanding patterns in corallivory and spongivory for Caribbean parrotfishes reveal other axes of functional diversification in these important herbivorous fishes.
Taming the Problems of Hypermobility Through Synergy

Our interest in space and time has existential roots. It stems from a need to bring meaning and order into a world of events and action. Modern concepts of time and space are expressed through the desire to achieve higher mobility and increased accessibility, and this in turn is associated with social progress. To meet this modern-day demand, an extensive transport system was created, developed, expanded, and persistently "improved" in this century, in the hope of integrating society in time and space, all in the name of enhancing economic and social "progress".
Differences in Pulmonary and Systemic Flow Measurements by Cardiac Magnetic Resonance vs Cardiac Catheterization and Relation to Collateral Flow in Single Ventricle Patients

Both cardiac magnetic resonance (CMR) and cardiac catheterization (cath) may assess patients with single ventricle physiology prior to stage II or Fontan palliation. However, development of significant aortopulmonary collaterals may invalidate assumptions of the Fick method. We compared CMR and cath flow measurements and evaluated the relation to collateral flow. This single-center study included all pre-stage II and pre-Fontan patients between 2010 and 2017 with CMR and cath within 1 month. Pulmonary (Qp) and systemic flow (Qs) by cath were calculated by Fick method. CMR Qp was calculated by total pulmonary venous flow, and Qs by total vena caval flow. Collateral flow by CMR was the difference of pulmonary vein and pulmonary artery flow. In 26 studies (16 pre-stage II and 10 pre-Fontan) in 21 patients, collateral flow was higher in pre-Fontan patients (1.8 ± 0.6 vs 0.9 ± 0.8 L/min/m2, p = 0.01). Overall, CMR and cath had good agreement for Qs and Qp:Qs, with moderate correlation (r = 0.44, p = 0.02 for Qs, r = 0.48, p = 0.02 for Qp:Qs). In pre-Fontan but not in pre-stage II patients, CMR had higher Qp (mean difference − 1.71 L/min/m2) and Qp:Qs (mean difference − 0.36). The underestimation of cath Qp correlated with amount of collateral flow (r = − 0.47, p = 0.02). Neither cath nor CMR flow measurements correlated with outcomes in this small cohort. In conclusion, collaterals lead to systematically higher Qp and Qp:Qs measurements by CMR vs cath in single ventricle patients. Measurements may not be used interchangeably, with potential clinical significance in estimating pulmonary vascular resistance. Further study is necessary to evaluate possible relation to clinical outcomes.
Congenital lung abnormalities

Congenital lung anomalies(CLA) are a group of malformations that include bronchopulmonary anomalies, vascular anomalies, and combined lung and vascular anomalies.With the advances in fetal ultrasonography and magnetic resonance imaging, and multi-detector computer tomography, CLA are increasingly being detected during both antenatal and postnatal periods, in turn influence patient counselling and management stratification.This paper focus on congenital lung abnormalities and congenital lobar emphysema. Key words: Congenital lung abnormalities; Lung agenesis; Lung aplasia; Lung hypoplasia; Congenital lobar emphysema
Application of Vehicle-Based Sensing Technology in Monitoring Vibration Response of Pavement Conditions

AbstractThe technique of using vibration sensors to monitor the pavement roughness has been expanding in pavement engineering. In addition to the currently used automated pavement sensing method an...
Investigations of Dimethylglycine, Glycine Betaine, and Ectoine Uptake by a Betaine-Carnitine-Choline Transporter Family Transporter with Diverse Substrate Specificity in Vibrio Species.

ABSTRACT Fluctuations in osmolarity are one of the most prevalent stresses to which bacteria must adapt, both hypo- and hyperosmotic conditions. Most bacteria cope with high osmolarity by accumulating compatible solutes (osmolytes) in the cytoplasm to maintain the turgor pressure of the cell. Vibrio parahaemolyticus, a halophile, utilizes at least six compatible solute transporters for the uptake of osmolytes: two ABC family ProU transporters and four betaine-carnitine-choline transporter (BCCT) family transporters. The full range of compatible solutes transported by this species has yet to be determined. Using an osmolyte phenotypic microarray plate for growth analyses, we expanded the known osmolytes used by V. parahaemolyticus to include N,N-dimethylglycine (DMG), among others. Growth pattern analysis of four triple-bccT mutants, possessing only one functional BCCT, indicated that BccT1 (VP1456), BccT2 (VP1723), and BccT3 (VP1905) transported DMG. BccT1 was unusual in that it could take up both compounds with methylated head groups (glycine betaine [GB], choline, and DMG) and cyclic compounds (ectoine and proline). Bioinformatics analysis identified the four coordinating amino acid residues for GB in the BccT1 protein. In silico modeling analysis demonstrated that GB, DMG, and ectoine docked in the same binding pocket in BccT1. Using site-directed mutagenesis, we showed that a strain with all four residues mutated resulted in the loss of uptake of GB, DMG, and ectoine. We showed that three of the four residues were essential for ectoine uptake, whereas only one of the residues was important for GB uptake. Overall, we have demonstrated that DMG is a highly effective compatible solute for Vibrio species and have elucidated the amino acid residues in BccT1 that are important for the coordination of GB, DMG, and ectoine transport. IMPORTANCEVibrio parahaemolyticus possesses at least six osmolyte transporters, which allow the bacterium to adapt to high-salinity conditions. In this study, we identified several additional osmolytes that were utilized by V. parahaemolyticus. We demonstrated that the compound DMG, which is present in the marine environment, was a highly effective osmolyte for Vibrio species. We determined that DMG is transported via BCCT family carriers, which have not been shown previously to take up this compound. BccT1 was a carrier for GB, DMG, and ectoine, and we identified the amino acid residues essential for the coordination of these compounds. The data suggest that for BccT1, GB is more easily accommodated than ectoine in the transporter binding pocket.
Sanctioning Genocide: To What Effect?:

Although economic sanctions have become a prominent response to mass atrocity, there has been relatively little scholarship assessing the impact of economic sanctions on genocidal violence. This ar...
Fractional Landau Inequalities of Riemann–Liouville Type

We present uniform Riemann–Liouville left and right fractional Landau inequalities over \(\mathbb {R}_{+}\) and \(\mathbb {R}_{-}\), respectively, of fractional orders \(1 0\), \(\nu \notin \mathbb {N}.\) It follows [1].
The Rx-HEART Framework to Address Health Equity and Racism Within Pharmacy Education.

Objectives. The objectives of this paper are to summarize the inclusion of health equity and anti-racism education in published literature and use it to identify current gaps across the pharmacy curriculum, define the key health equity and anti-racism concepts that are suggested to be included across the pharmacy curriculum, and recommend a framework with steps to integrate health equity and anti-racism education across the pharmacy curriculum. Findings. Other professions such as social work, nursing, and medicine have taken steps to address social injustice by integrating anti-racism into their curriculum. The National Association of Social Worker (NASW) advocates for “social justice, and social change with and on behalf of clients”, and included racism and health equity in its mission to eradicate “discrimination, oppression, poverty, and other forms of social injustice.” The American Association of Colleges of Nursing (AACN) curricular standards for baccalaureate nursing education provided four key changes for immediate change in the curriculum to overcome structural, individual, and ideological racism (SIIR). In October 2020, the Association of American Medical Colleges (AAMC) released a four-pillar framework to address racism. Summary. The pharmacy profession must follow suit in the efforts to eradicate social injustices by incorporating into its curriculum topics that would result in the graduation of culturally and linguistically sensitive, and structurally competent pharmacists. This five-phased framework, Rx-HEART (Pharmacy Health Equity Anti-Racism Training) aims to provide guidance to the pharmacy academy on how to accomplish the set objectives of this paper and of the themed issue on social injustice.
p-type AlN based heteroepitaxial diodes with Schottky, Pin, and junction barrier Schottky character achieving significant breakdown performance

The recent achievement of p-type AlN films via Be doping was utilized to achieve novel heteroepitaxial diodes with Schottky, Pin, and junction barrier Schottky (JBS) electrical behavior. Although the heteroepitaxial structures were quasi-vertical, which is subject to many issues lowering the breakdown voltage, the Pin diode achieved a breakdown voltage of ∼25 V for a 200 nm thick unintentionally doped intrinsic layer indicating ∼50% of the theoretical breakdown voltage performance for a similar homoepitaxial GaN pin diode. JBS and Schottky diodes were implemented using the inherent and intentional stress cracking properties of AlN grown on GaN films avoiding regrowth and plasma etching, both known to be technology impediments. The density of the intentional cracks and crystalline quality of the p-AlN films was controlled via Be doping and the total metal dose supplied during the metal modulated epitaxy shutter cycle resulting in differing degrees of grown stress. Since the intentional crack density determines the surface area ratio of the Schottky diode to the Pin diode, it is a key design parameter in optimizing device performance. Furthermore, a novel current spreading layer was implemented to improve the current uniformity in these devices. The high breakdown voltage and good forward voltage characteristics of these devices shows potential to enable high-performance III-nitride high-power devices.
Application of Large-Scale Analysis Techniques to a Man-Portable Limited-Scope Environment

New computer-assisted ultrasonic inspection techniques are occurring on both small PC-based and larger minicomputer/workstation-based systems. The bigger systems can address large-scale inspection problems through the acquisition of multigigabytes of data and the use of sophisticated analysis and visualization techniques [1,2]. With these benefits, however, come greater bulk, complexity, and cost. Smaller systems excel in applications requiring man portability. Optimally a combination of the two technologies would provide the sophisticated analysis techniques of the large systems with the smaller size and lower cost PC. The EDAS Model 100 ultrasonic inspection system, described in this paper, achieves this synthesis.
Surgical Management of Hyperparathyroidism

Parathyroidectomy is the only curative treatment for patients with primary hyperparathyroidism. Although care must be individualized, parathyroidectomy should be considered in all patients with biochemically confirmed primary hyperparathyroidism, irrespective of symptoms. Subtotal parathyroidectomy or total parathyroidectomy with transplant is indicated in secondary hyperparathyroidism with renal osteodystrophy, calciphylaxis, or when medical therapy fails or cannot be tolerated. Parathyroid surgery can achieve superb cure rates with minimal morbidity when performed by experienced surgeons. The best surgical approach to parathyroidectomy incorporates strategic exploration guided by anatomic relationships in a bloodless field. Although bilateral neck exploration is an acceptable approach for parathyroid adenomas, minimally invasive parathyroidectomy with intraoperative hormone monitoring can achieve similar cure rates.
The Effects of Ethnicity and Income on the Reported Importance of Selected Retail Store Evaluative Criteria

The marketer's ability to precisely segment his target market is an important determinant of his success. The challenge facing the marketing strategist lies in identifying stable human characteristics which can be used for segmentation (McDaniel and Burnett 1990). Delener (1990) suggests that differences in cultural heritage partially explain differing consumption patterns among groups, and that marketplace behaviors aid in defining culture.
Viscoelastic Response in Shear

In the classical linearized theory of elasticity, the stress in a sheared body is taken to be proportional to the amount of shear. The Navier-Stokes theory of viscosity takes the shearing stress to be proportional to the rate of shear. In most materials, under appropriate circumstances effects of both elasticity and viscosity are noticeable. If these effects are not further complicated by behavior that is unlike either elasticity or viscosity, we call the material viscoelastic.
System Architectures for Functional Programming Languages: Problems and Solutions

This paper considers various approaches to the solving the problems of implementing functional programming languages. Emphasis has been put on the basic problems, their solution in terms of abstract machines and their realizations. No claim is made with respect to an exhaustive enumeration of all current machine projects and functional languages.
Tipping Pointedly Colder

Data from multiple ocean basins elucidate an ancient climate transition from greenhouse to icehouse.
A modified needle-inside-needle technique for the ganglion impar block.

Purpose The ganglion impar is the fused terminus of the paired sympathetic chain located at the level of the sacrococcygeal junction. It has been blocked using a bent and a curved spinal needle via the anococcygeal ligament. It has also been approached through the sacrococcygeal disc using a straight spinal needle. We describe a neede-inside-needle modification of the latter approach.
Luttinger-liquid instability in the one-dimensional t-J model.

We study the t-J model in one dimension by numerically projecting the true ground state from a Luttinger-liquid trial wave function. We find the model exhibits Luttinger-liquid behavior for most of the phase diagram in which interaction strength and density are varied. However, at small densities and high interaction strengths a new phase with a gap to spin excitations and enhanced superconducting correlations is found. We show that this phase is a Luther-Emery liquid and study its correlation functions.
Optimal R&D policy for a patent race with uncertain duration

Abstract We analyze a model with rival firms in a winner-take-all patent race in which the time of success is a random variable directly related to level of effort, a firm decision variable. At the symmetric Nash equilibrium, R&D effort varies directly with patent life, with benefits accruing to the successful firm, and with a change in the number of rivals. A cost-sharing subsidy induces an increase in effort, including the subsidy, but may result in a decrease in effort net of subsidy. In the centralized socially optimal version of the model the number of firms and the level of per firm effort are chosen optimally. We derive the characteristics of optimal patent life, fee for entry, and cost-sharing subsidy so that the competitive free-entry Nash equilibrium will replicate the socially optimal solution with respect to level of R&D effort and number of rival firms.
SIGACT news complexity theory column 35

I was surprised and delighted at a recent conference when the complexity class Θ2p suddenly popped up in a talk (by Markus Holzer on work by him and Pierre McKenzie) where it is was not exactly something one would have before-hand expected to come into play. After hearing the rest of Markus's remarkable talk (which he illustrated using toys from his daughter), I was much hoping that the authors would be so kind as to write a guest column; they very generously agreed to, and that column appears below.So, what is Θ2p? Θ2p is the class of languages acceptable via parallel access to NP, and has many equivalent alternate definitions and characterizations (see [KSW87, Hem89, Wag90]), such as the one used in the paper below. This class was first studied by Papadimitriou and and Zachos in 1983 [PZ83] (though in a form that at that time was not known to be equivalent to the definition just mentioned), and has played an important role in complexity theory, e.g., Kadin [Kad89] proved that the polynomial-time hierarchy collapses to Θ2p if NP has sparse Turing-complete sets. Recently, the class has turned out to play other surprising roles, such as in analyzing the complexity of electoral systems (see the survey [HH00]) and in understanding the performance of greedy algorithms [HR98, HRS01]. In fact, a survey column a few years ago was devoted to overviewing such raised-to-Θ2p lower bounds [HHR97].Bill Gasarch and SIGACT News need YOU! That is, the next issue will contain a guest column edited by Bill Gasarch, which will collection opinions on the future of the P-versus-NP question. Bill very much wants a broad range of opinions, and will be setting up a web page (http://www.cs.umd.edu/~gasarch/pnp/) describing how you can get your opinions to him. He may even put up a series of polling questions there, so please go there, vote early, and vote often!And in the issues following that will be articles by M. Schaeffer and C. Umans on complete sets at and beyond the polynomial hierarchy's second level, by A. Nickelsen and T. Tantau on partial information classes, and by R. Paturi on the complexity of k-SAT.
Social Work and Social Presence in an Online World

Human presence is a fundamental consideration of social work practices. The argument in this article is not to undermine such notions but to elaborate on them based on research into social presence, a type of presence projected when a person is associating with others. Communication and information technologies support applications that develop social presence and enable sociality. Such forms of presence are not confined to face-to-face encounters but are necessarily relational. Underlying such a realization is the conviction that all flows of social presence must and can be connected and directed in the conduct of social work practices.
Analysis of positron annihilation lifetime data by numerical laplace inversion with the program CONTIN

Abstract The performance of the program CONTIN [Stephen W. Provencher, Comput. Phys. Commun. 27 (1982) 229], modified to solve Fredholm integral equations with convoluted kernels of the type that occur in the deconvolution and analysis of positron annihilation lifetime data, is investigated with computer-simulated test data. The method avoids direct determination of the instrument resolution function by employing the decay curve of a reference material with a well-known single lifetime. CONTIN employs a constrained, regularized least-squares analysis to calculate a continuous annihilation-rate probability density function (pdf) which is the most parsimonious solution that is consistent with the experimental data and prior knowledge. The performance of the algorithm for extracting positron annihilation lifetime information was evaluated by using several measures of the information content of the data described by Schrader and Usmar [in: Positron Annihilation Studies of Fluids, ed. S. Sharma (World Scientific, Singapore, 1988) p. 215]. The quality of the CONTIN reconstruction of the annihilation-rate pdf is strongly dependent on the information content of the data and is greatly improved as the total number of counts in the data set is increased. Nevertheless, the method provides excellent estimates of the intensities and mean lifetimes of peaks in the annihilation-rate pdf, even when the total counts in the data set are relatively low (105–106). The sensitivity of the algorithm to systematic errors in the data, including errors in the instrument resolution function, shifts in the positron of the zero-time channel of the sample and reference data and contamination of the reference decay by additional lifetime components was also evaluated. Errors in the FWHM of the instrument resolution function and shifts in the zero time channel as small as 1 10 to 1 5 of the channel width of the instrument generate additional spurious peaks in the annihilation-rate pdf and introduce errors in the lifetime parameters of the short-lived components.
WE-C-103-07: Standardization of CT Scanner Performance in Routine Clinical Exams: A Pilot Survey

PurposeThe goal of this project is to standardize CT scanner performance across scanner models, software versions, and patient sizes. In this pilot study, we measured image quality and radiation dose for several CT systems for 3 patient sizes to determine the amount of variation that exists within our practice for our routine abdomen/pelvis scan protocol parameters. Methods4 CT scanners used in a single practice were studied. A wire phantom was used to measure the modulation transfer function (MTF), a foil phantom to measure section sensitivity profile (SSP), and semi‐anthropomorphic abdomen phantoms of three sizes (15 year old, medium and large adults) to measure noise and assess automatic exposure control (AEC) performance. Scans of the abdomen phantom were performed by a clinical technologist as if the phantom were a patient, with all parameters per our clinical protocols. Wire and foil phantoms were scanned with AEC off using overlapping thin images, but with the same reconstruction kernel. ResultsThe 10% values of MTFs were 6.6, 6.4, 6.8 and 6.6 lp/cm and full‐widths‐at‐half‐maximum of SSP were 4.9, 5.0, 5.0 and 5.3 mm. The coefficients of variation of recorded CTDIvol were 18%, 20% and 24% for 15 year old, medium adult and large adult phantoms across the four scanners, with noise coefficients of variation of 11%, 6% and 19%.ConclusionFor routine abdomen scans performed in a single practice using different scanners, there were negligible differences in spatial resolution (MTF or SSP). For a 15 yo and medium adult phantoms, variations of dose and noise were present, but modest. For a large adult, a factor of 1.8 in dose and 1.6 in noise were observed between the lowest and highest dose or noise values, demonstrating an opportunity to adjust our AEC settings to make the dose and noise more consistent across scanners. This work was supported in part by NIH grant R01 EB071095 from the National Institute of Biomedical Imaging and Bioengineering.
Exactly solvable many-fermion independent-boson systems

Generalized many-fermion versions of the independent-boson model with fixed or variable fermion number are solved exactly. In particular, the linear-response characteristics of these systems are discussed. Exact results for physical quantities, such as the partition function and the two-time correlation function for single-fermion operators, as needed in the Kubo formula, are given and discussed. These nontrivial models may serve as simple model systems for interacting many-particle systems and as a testing ground for approximation schemes for more complex coupled many-particle systems.
KNOCK-INS AND CONDITIONAL KNOCKOUTS: IN VIVO ANALYSIS OF GLUCOCORTICOID RECEPTOR REGULATION AND FUNCTION

To determine the cellular targets for glucocorticoid (GC) action, we have generated mice in which a green fluorescent protein-glucocorticoid receptor (GFP-GR) fusion gene is knocked into the endoge...
αCAMKII AUTOPHOSPHORYLATION LEVELS DIFFER DEPENDING ON SUBCELLULAR LOCALIZATION

Calcium/calmodulin-dependent protein kinase II (CaMKII) has important roles in many processes in the central nervous system. It is enriched at the post-synaptic density (PSD), a localization which is thought to be critical for many of its proposed neuronal functions. In order to better understand the mechanisms that regulate association of CaMKII with the PSD, we compared the levels of autophosphorylation between PSD-associated kinase and kinase in other parts of the neuron. We were surprised to find that αCaMKII in a PSD-enriched fraction prepared from recovered hippocampal CA1-minislices had a relatively low level of threonine 286 (T286) phosphorylation and a relatively high level of threonine 305 (T305) phosphorylation. Furthermore, when the minislices were subjected to a treatment that mimics ischemic conditions, there was a significant translocation of αCaMKII to the PSD-enriched fraction accompanied with a dramatic reduction in T286 phosphorylation levels throughout the neuron. These findings have important implications for our understanding of the role of autophosphorylation in the localization of CaMKII.
Vanadate in structural biology

Abstract The rapidly growing number of protein structures in the protein data bank (PDB) provides opportunities to obtain biological insights from those that share common features. We used the information available in the PDB to survey the structural features that are common among proteins, which bind to vanadate. The ability of vanadate to mimic phosphate and vice versa is presumably due to the structural similarity vanadate shares with phosphate. We analyze the geometries of the bound vanadate and the nature of its binding interfaces. We also compared structures of enzyme groups bound to both ligands. This data improves our understanding of vanadate recognition and will be useful in not only the evaluation of new structures but also in the development of new therapeutic agents based on structural recognition.
Beating the System: Course Structure and Student Strategies in a Traditional Introductory Undergraduate Physics Course for Nonmajors

The purpose of this study was to describe relationships among instructor and student goals, course design, and student strategies for learning physics in a traditional introductory undergraduate physics course for nonmajors. The procedures included 16 hours ofnonparticipant observation, during which detailed field notes and photographs were taken and documents were collected. Audiotaped open-ended interviews were given to instructors and students, and all students participated in a limited survey. The data were analyzed using qualitative methods of the Chicago School. Results indicated that both differing goals of students and instructors and the structure of the course inhibited the understanding of physics and were conducive to students engaging in unexpected behaviors designed to help them successfully pass the course. The consequences of the structure of the course and subsequent student behaviors inhibited their understanding and appreciation of physics and deterred them from enrolling in further science courses. The paper includes implications for teaching introductory college physics.
COMMUNITY CONTROL, YES! DECENTRALIZATION, NO

(1975). COMMUNITY CONTROL, YES! DECENTRALIZATION, NO. The Review of Education: Vol. 1, No. 1, pp. 78-83.
Highly Reactive Porphyrin-Iron-Oxo Derivatives Produced by Photolyses of Metastable Porphyrin-Iron(IV) Diperchlorates

Photolyses of metastable porphyrin−iron(IV) diperchlorates in laser flash photolysis reactions gave highly reactive transients. The systems studied were 5,10,15,20-tetraphenylporphyrin (TPP), 5,10,15,20-tetramesitylporphyrin (TMP), and 2,3,7,8,12,13,17,18-octaethylporphyrin (OEP). The new species, which decayed within milliseconds in acetonitrile solutions, were shown to react with organic substrates by oxo-transfer reactions involving insertions into carbon−carbon double bonds of alkenes and styrenes or benzylic carbon−hydrogen bonds of arenes. The order of reactivity was OEP > TPP > TMP. Second-order rate constants for reactions with several substrates at 22 °C were determined; representative values of rate constants for the TPP derivative were k = 8.6 × 105 M−1 s−1 for styrene, k = 2.5 × 106 M−1 s−1 for cyclohexene, and k = 7.7 × 104 M−1 s−1 for ethylbenzene. These porphyrin−iron−oxo transients reacted 4−5 orders of magnitude faster than the corresponding iron(IV)−oxo porphyrin radical cations with rat...
Fabrication of Two-Dimensional Assemblies of Ag Nanoparticles and Nanocavities in Poly(dimethylsiloxane) Resin

Silver nanoparticles, self-assembled in two-dimensional arrays on quartz and silicon surfaces, were coated with poly(dimethylsiloxane) (PDMS). After peeling off the surface, resin films contained embedded nanoparticles in their original arrangement. Films with nanoparticles are transparent, flexible, and mechanically stable. The embedded nanoparticles were etched away, producing nanocavities in PDMS. The described method can be used to produce highly robust assemblies of metal, semiconductor, and dielectric nanoparticles on flexible substrates.
Computational microscopy, sensing, and diagnostics (presentation video)

My research focuses on the use of computation/algorithms to create new optical microscopy, sensing, and diagnostic techniques, significantly improving existing tools for probing micro- and nano-objects while also simplifying the designs of these analysis tools. In this presentation, I will introduce a new set of computational microscopes which use lens-free on-chip imaging to replace traditional lenses with holographic reconstruction algorithms. Basically, 3D images of specimens are reconstructed from their “shadows” providing considerably improved field-of-view (FOV) and depth-of-field, thus enabling large sample volumes to be rapidly imaged, even at nanoscale. These new computational microscopes routinely generate <1–2 billion pixels (giga-pixels), where even single viruses can be detected with a FOV that is <100 fold wider than other techniques. At the heart of this leapfrog performance lie self-assembled liquid nano-lenses that are computationally imaged on a chip. These self-assembled nano-lenses are stable for <1 hour at room temperature, and are composed of a biocompatible buffer that prevents nano-particle aggregation while also acting as a spatial “phase mask.” The field-of-view of these computational microscopes is equal to the active-area of the sensor-array, easily reaching, for example, <20 mm2 or <10 cm2 by employing state-of-the-art CMOS or CCD imaging chips, respectively. In addition to this remarkable increase in throughput, another major benefit of this technology is that it lends itself to field-portable and cost-effective designs which easily integrate with smartphones to conduct giga-pixel tele-pathology and microscopy even in resource-poor and remote settings where traditional techniques are difficult to implement and sustain, thus opening the door to various telemedicine applications in global health. Some other examples of these smartphone-based biomedical tools that I will describe include imaging flow cytometers, immunochromatographic diagnostic test readers, bacteria/pathogen sensors, blood analyzers for complete blood count, and allergen detectors. Through the development of similar computational imagers, I will also report the discovery of new 3D swimming patterns observed in human and animal sperm. One of this newly discovered and extremely rare motion is in the form of “chiral ribbons” where the planar swings of the sperm head occur on an osculating plane creating in some cases a helical ribbon and in some others a twisted ribbon. Shedding light onto the statistics and biophysics of various micro-swimmers’ 3D motion, these results provide an important example of how biomedical imaging significantly benefits from emerging computational algorithms/theories, revolutionizing existing tools for observing various micro- and nano-scale phenomena in innovative, high-throughput, and yet cost-effective ways.
Absence of bisulfite mutagenesis in the lacI gene of Escherichia coli.

Bisulfite is used widely as an antimicrobial agent in a variety of foods and beverages and as an antioxidant in certain pharmaceuticals. In vitro bisulfite, at high concentration (1 M) and pH between 5 and 6, deaminates cytosine to uracil via bisulfite-adduct intermediates. Under other conditions bisulfite may cause transaminations that crosslink proteins with nucleic acids, it may add to uracil or thymine or it may provoke free-radical damage of DNA (for reviews see Fishbein, 1976; Hayatsu, 1976; Shapiro, 1977). On the basis of the deamination reaction, it was predicted that at slightly acidic pH and high concentration, bisulfite would induce G:C ~ A:T transitions in vivo. Mutations attributed to such events were detected in Escherichia coli and bacteriophage T4 (Mukai et al., 1970; Summers and Drake, 1971). Other investigators also reported that bisulfite was mutagenic but due to varying treatment conditions the chemical mechanisms responsible remain obscure (Hayatsu and Miura, 1970; Iida et al., 1974; Sussmuth and Lingens, 1976; Khoudokormoff, 1978). In spite of these positive findings, the mutagenicity of bisulfite in vivo has not been established unequivocally. Bisulfite was not found to be mutagenic in a number of studies (Szybalski, 1958; Dorange and Dupuy, 1972; Newell and Maxwell, 1974; Kimball and Hirsch, 1975; Mallon and Rossman, 1981) and was reported recently to be antimutagenic in the Salmonella plate assay (Suwa et al., 1982). Moreover, the previous results with bacteriophage T4 have been irreproducible (J.W. Drake, personal communication). In view of these conflicting reports, we decided to test the mutagenicity of bisulfite in the E. coli lacI system (Miller et al., 1977; Coulondre and Miller, 1977). This system permits the detection of amber and ochre mutations at 65 individual sites within the lacI gene. Since the DNA sequence and location of each nonsense mutation have been determined, each mutation can be attributed to a specific base change by a combination of deletion mapping and suppression pattern analysis. Of the 65 possible alterations, 26 can arise by G:C ~ A:T transitions, thereby providing a substantial number of detectable potential targets for bisulfite mutagenesis.
Photodynamic action of bilirubin on the inner mitochondrial membrane. Implications for the organization of the mitochondrial ATPase

Abstract Bilirubin in the presence of O 2 and light catalyzes the photodynamic modification of the proteins of the inner mitochondrial membrane as monitored by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Numerous polypeptide bands become streaked towards higher apparent molecular weight and decrease in staining intensity while other bands remain largely unchanged. The loss in staining intensity which occurs is at least partially due to apparent cross-linking of the polypeptides to produce aggregates which cannot penetrate into the gel. The α and β bands of the mitochondrial ATPase differ markedly in their susceptibility to modification. The β subunit is rapidly modified while the α subunit is largely inert. This differential susceptibility is a consequence of the binding of the soluble F 1 ATPase to the membrane. When submitochondrial particles with their normal complement of bound F 1 are mixed with free F 1 and are photolyzed together in the presence of bilirubin and O 2 , it is found that the β subunit of the membrane-bound F 1 , but not the α subunit, has been modified while neither subunit of the free F 1 has been modified. This increased susceptibility of the β subunit in the membrane state may represent cross-linking to membrane components and is consistent with the β subunit making more extensive contacts with membrane components than does the α subunit.
Preservation of high-moisture maize — A comparison of gaseous and liquid anhydrous ammonia with methylene-bis-propionate☆

Abstract Freshly harvested maize (22–24% moisture) was treated with either gaseous ammonia (0.9% dry basis), liquid anhydrous ammonia (1.3% dry basis), or methylene- bis -propionate (0.8% dry basis) and stored in metal bins. All treatments initially decreased the counts of bacteria and moulds. Growth of these microorganisms was prevented throughout the 6-month storage period by methylene- bis -propionate and for 5 months by gaseous anhydrous ammonia. Liquid anhydrous ammonia prevented mould growth for 4 months, while bacterial counts increased to pretreatment numbers after 1 month but did not increase further until after 5 months' storage. In feeding trials with steers, more efficient weight gains were obtained from the ammonia-preserved maize than from the methylene- bis -propionate preserved maize.