cssi/SciSciGPT-SciSciNet huggingface dataset:
Do Bacterial Membranes Contribute to Calcium Oxalate (Caox) Crystal Deposition

Clinical studies demonstrate the presence of bacteria in as many as one third of calcium oxalate/phosphate stones1. A role for such organisms has not been previously recognized. Bacteria may develop intracellular calcium phosphate crystals (hydroxyapatite) in unique clinical situations (e.g. dental tartar) and when inoculated into calcium phosphate enriched growth media in vitro 2. Previous work in our laboratory suggests that bacteria may form intracellular electron dense deposits containing calcium when inoculated in human urine3. Such bacteria demonstrate x-ray powder diffraction patterns consistent with hydroxyapatite3, 4. Additional in vitro studies suggest that bacteria may form microcolonies on tissue surfaces in urines that demonstrate increased levels of calcium5. The following study was designed to test the hypothesis that bacteria or bacterial membranes (mineralized and non-mineralized) may form a platform for calcium oxalate crystal deposition.
The Future of Teleradiology in Medicine Is Here Today

Teleradiology is transferring of medical images through an Internet provider from a primary system to a remote location. Compressed digital imaging tools and the picture archiving and communication system have helped teleradiology to become more accessible and feasible to physicians. Wireless transmission using portable viewers has the potential to further improve its application and accessibility. In order to protect confidential medical records from being accessible to unauthorized individuals, security measures such as the establishment of a virtual private network between hospitals and receiving locations have been taken. Teleradiology provides students, residents, and even attending physicians with access to a limitless number of images for reference from almost anywhere in the world and helps improve their continued exposure and experience in the health-care setting.
Behavioral Chemicals in the Augmentation of Natural Enemies

The behavioral manipulation of natural enemies of pest insects has been a long standing dream among the biological control practitioners. Recent work concerning the behavior of some natural enemies of pest insects suggests that this dream may become a practical reality. Wright (1964, 1965) recognized the potential for pest management by the behavioral modification of insects through the use of non-toxic agents that modify the insects’ behavior. As stated by Wright (1965) these chemicals may effect control of a pest by inhibiting a correct response or eliciting an incorrect one. He coined the term “metarchon” for the introduced stimulus which includes chemical repellents and attractants as well as physical factors such as light and sound which interfere with the insects ability to communicate. While much effort is underway to develop methods of manipulating the pest insect, a different approach is needed for the manipulation of natural enemies. Instead of attempting to elicit an incorrect response or inhibit a correct one, the goal of entomophagous insect manipulation is to redirect or stimulate the response. The behavioral modification of certain arthropod enemies of insects through the use of chemicals has opened up new opportunities for the manipulation of these arthropods for the benefit of man. However, such an approach requires a working understanding of the behavior of entomophagous arthropods and the role played by chemicals in their behavioral patterns.
Managing Scientists, Leadership Strategies in Science

Effective leadership of science is important from both individual and global perspectives. At an individual level, scientists’ morale and, thus, the quality of their work are influenced by the effectiveness of the leader. At a global level, social and economic welfare can be affected by the quality of output of high technology (i.e., R&D-intensive) organizations. There are numerous challenges facing leaders of R&D, some of which stem from their education and training – especially the emphasis on individual accomplishments. Leaders must be skilled in motivating other scientists and technicians, in communicating and listening actively, and in resolving conflict that arises whenever people work together. And, they must be able to administer R&D effectively, which includes designing the organization of work (structure), determining the right number of people in work groups (size), and setting up formal processes that support work (systems). The purpose of this chapter is to provide a brief overview of how leadership matters in terms of people and the organization of scientific work.
Quest for Rigorous Combining Probabilistic and Fuzzy Logic Approaches for Computing with Words

Lotfi Zadeh initiated three fundamental concepts: (1) the concept of a linguistic variable, (2) the concept of a fuzzy set (with a membership function (MF) for linguistic terms that gradually changes between 0 and 1), and (3) the concept a matrix of linguistic rules that connect linguistic variables. These concepts are outside of the main stream of concepts used in both the probability theory and the control theory. These concepts are critical for the area that Zadeh later denoted as Computing with Words (CWW) [17]. The elegance and intuitiveness of these three concepts deeply impressed me when I learned about them a long time ago.
Tuning the Valency of Heterogeneous Au–Silica Nanostructure via Controlled Ostwald Ripening Process

Morphology control of interfaced heterogeneous nanostructure composed of two different materials is critical for achieving desired properties of the nanostructures. With heterogeneous Au–silica sys...
Canonical Rainfall Distributions in the United States

AbstractThis study identifies five normalized depth-duration functions (NDDFs) that can be used to represent the rainfall characteristics in various regions of the United States. An analysis of the...
The probabilistic and reliable connected power dominating set problems

As a variation of minimum dominating set problem, the power dominating set problem is proposed to achieve the complete observation of a power system by placing the smallest number of PMUs. Under different contingencies consisting line outages or PMU losses, the reliability of observation for each bus should be guaranteed to ensure the security and robustness of the power system. Thus, the probabilistic power dominating set (PPDS) problem is proposed in this paper. Given a pre-specified reliability level for each bus in the power system to be observed and known distribution of random events, an integer programming formulation, with consideration of zero-injection property, is presented for the PPDS problem. Additionally, the reliable connected power dominating set problem is studied to meet two requirements, including the connectivity of the PMU subgraph and the reliability of the connectivity of this subgraph. Numerical experiments based on several IEEE test cases are performed to find the best deployment of PMUs satisfying different requirements.
Robust Distributed Dictionary Learning for In-Network Image Compression

Camera networks are resource-constrained distributed systems that communicate over (wireless) networks to make decisions collaboratively. For surveillance applications, these camera nodes take decisions about an object of interest within incoming videos by coordinating with neighboring nodes, which is a costly process in terms of both time and energy. Datacompression methods can bring significant energy savings in camera nodes while transmitting or storing data in the network. Signal representation using sparse approximations and overcomplete dictionaries have received considerable attention in recent years and have been shown to outperform traditional compression methods. However, distributed dictionary learning itself relies on consensus-building algorithms, which involve communicating with neighboring nodes until convergence is achieved. To this end, we design a novel protocol to enable energy-efficient and robust dictionary learning in distributed camera networks by leveraging the spatial correlation of collected multimedia data. We employ low-computational-complexity metrics to quantify the correlation across cameras nodes. We also present a feasibility study of the parameters of the network that impact the performance of distributed dictionary learning and consensus process in terms of accuracy of the algorithm and energy consumed by the camera nodes. The performance of the proposed approach is validated through extensive simulations using a network simulator and public datasets as well as via real-world experiments on a testbed of Raspberry Pi nodes.
Fractional calculus derivation of a rate-dependent PPR-based cohesive fracture model: theory, implementation, and numerical results

Rate-dependent fracture has been extensively studied using cohesive zone models (CZMs). Some of them use classical viscoelastic material models based on springs and dashpots. However, such viscoelastic models, characterized by relaxation functions with exponential decay, are inadequate to simulate fracture for a wide range of loading rates. To improve the accuracy of existing models, this work presents a mixed-mode rate-dependent CZM that combines the features of the Park–Paulino–Roesler (PPR) cohesive model and a fractional viscoelastic model. This type of viscoelastic model uses differential operators of non-integer order, leading to power-law-type relaxation functions with algebraic decay. We derive the model in the context of damage mechanics, such that undamaged viscoelastic tractions obtained from a fractional viscoelastic model are scaled using two damage parameters. We obtain these parameters from the PPR cohesive model and enforce them to increase monotonically during the entire loading history, which avoids artificial self-healing. We present three examples, two used for validation purposes and one to elucidate the physical meaning of the fractional differential operators. We show that the model is able to predict rate-dependent fracture process of rubber-like materials for a wide range of loading rates and that it can capture rate-dependent mixed-mode fracture processes accurately. Results from the last example indicate that the order of the fractional differential operators acts as a memory-like parameter that allows for the fracture modeling of long- and short-term memory processes. The ability of fractional viscoelastic models to model this type of process suggests that relaxation functions with algebraic decay lead to accurate fracture modeling of materials for a wide range of loading rates.
Longshot enables accurate variant calling in diploid genomes from single-molecule long read sequencing.

Whole-genome sequencing using sequencing technologies such as Illumina enables the accurate detection of small-scale variants but provides limited information about haplotypes and variants in repetitive regions of the human genome. Single-molecule sequencing (SMS) technologies such as Pacific Biosciences and Oxford Nanopore generate long reads that can potentially address the limitations of short-read sequencing. However, the high error rate of SMS reads makes it challenging to detect small-scale variants in diploid genomes. We introduce a variant calling method, Longshot, which leverages the haplotype information present in SMS reads to accurately detect and phase single-nucleotide variants (SNVs) in diploid genomes. We demonstrate that Longshot achieves very high accuracy for SNV detection using whole-genome Pacific Biosciences data, outperforms existing variant calling methods, and enables variant detection in duplicated regions of the genome that cannot be mapped using short reads. Single-molecule sequencing (SMS) such as Pacific Biosciences and Oxford Nanopore generate long reads with high error rate. Here, the authors develop Longshot, a computational method that detects and phases single nucleotide variants (SNV) in diploid genomes using SMS data.
Age Differences in the Subcomponents of Executive Functioning

OBJECTIVES Across the life span, deficits in executive functioning (EF) are associated with poor behavioral control and failure to achieve goals. Though EF is often discussed as one broad construct, a prominent model of EF suggests that it is composed of three subdomains: inhibition, set shifting, and updating. These subdomains are seen in both younger (YA) and older adults (OA), with performance deficits across subdomains in OA. Therefore, our goal was to investigate whether subdomains of EF might be differentially affected by age, and how these differences may relate to broader global age differences in EF. METHODS To assess these age differences, we conducted a meta-analysis at multiple levels, including task level, subdomain level, and of global EF. Based on previous work, we hypothesized that there would be overall differences in EF in OA. RESULTS Using 1,268 effect sizes from 401 articles, we found overall differences in EF with age. Results suggested that differences in performance are not uniform, such that variability in age effects emerged at the task level, and updating was not as affected by age as other subdomains. DISCUSSION These findings advance our understanding of age differences in EF, and stand to inform early detection of EF decline.
Predicting toxicity-related docetaxel discontinuation and survival in metastatic castration-resistant prostate cancer (mCRPC) using open phase III trial data.

75Background: Docetaxel (D) is widely used in mCRPC, however its optimal use remains unclear in the current treatment (tx) landscape. Biomarkers to predict D toxicity may help inform tx selection. ...
Generic, growing, green?: The changing political economy of the global pesticide complex

Agriculture is now more dependent on pesticides than ever. The value of global pesticide imports increased 3x faster in the 2000s than in the 1990s. Structural transformations in the industry – inc...
Deriving a De-Identified Dataset from EPIC-Derived Data for Use in Clinical Research: Pearls and Pitfalls in Database Creation and Analysis

Background: Given the ubiquity and amount of information available through EHRs, there is treasure trove of data available for research purposes if we can gather and analyze this information in a systematic way. In 2018, EPIC announced plans for Cosmos, a large scale collaborative research database pooling EHR data from multiple institutions likely to be widely adopted for research purposes1. Pediatrics is a field where it often difficult to obtain high power studies and enroll patients for prospective trials. Through our institutional database we compared the efficacy of lactate, CRP, procalcitonin in predicting mortality among adults in an effort to …
[Equivalence of Kramer and Shannon sampling Theorems]The Equivalence of Kramer and Shannon sampling Theorems Revisited

It is known that Kramer’s sampling theorem is a generalization of the Whittaker-Shannon-Kotel’nikov (WSK) sampling theorem. However, if Kramer’s theorem arises from a self-adjoint boundary-value problem with a regular, first order differential operator, the two theorems are equivalent, while, as L. Campbell showed, if Kramer’s theorem arises from regular Sturm-Liouville problems, Kramer’s theorem does not enlarge the class of functions to which sampling theorems can be applied. This class of functions has never been explicitly defined in the literature. In this paper we use the theory of transformation operators developed by Gelfand and Levitan to define this class of functions and then refine results previously obtained by L. Campbell and A. Jerri. We show that the class of functions to which the Kramer’s theorem can be applied depends on the boundary conditions of the associated boundary-value problems. This dependency on the boundary conditions seems to have passed unnoticed for many years. Furthermore, we discuss the equivalence of the WSK and Kramer sampling theorems when the latter arises from singular Sturm-Liouville problems.
Assignment Algorithms for Grocery Bill Reduction

This paper focuses on identifying an algorithm that can be utilized in grocery cost reduction within the consumer space. The algorithm produces the combination of grocery products to stores that net the lowest overall grocery cost for the consumer. This is often referred to as a combinatorial optimization problem, and is commonly used by many industries for resource or task assignment. To identify a solution for grocery cost reduction, the Kuhn-Munkres algorithm (often referred to as the Hungarian algorithm) and the Deepest Hole algorithm are explored in depth. After comparing the algorithms based on their implementation and performance, a third solution combining ideas from the Kuhn-Munkres algorithm and Deepest Hole algorithm was created to solve for the specific needs of this problem. This solution will be referred to as the KMDH Hybrid algorithm. Modifications include the ability for users to select the number of stores they wish to shop at, the ability to use a rectangular grid, and allowing for one-to-many assignments. All three algorithms were developed in Python, and tested on a dataset with a predefined list of stores, products, and prices. It is apparent that the proposed hybrid algorithm can be applied to the assignment problem, and has the potential to be applied to other similar applications.
Abstract 2134: Bioinformatic analysis of the tumor biomarker thymidine kinase 1: Elucidating its cancer gene network and membrane expression across all cancers

The purpose of this study was to analyze the regulatory gene cancer network of the tumor biomarker Thymidine Kinase 1 (TK1) across all cancers and identify the genes with meaningful correlations that interact and drive tumorigenesis along with TK1. In addition, we sought to find a feasible mechanism for TK1 membrane expression in cancer cells. Using data from The Cancer Genome Atlas (TCGA), the pathway commons protein interaction database, the Biogrid database and the R graphite library, we analyzed the correlation of mRNA expression levels of all proteins that were involved in TK1 metabolic pathways or physically interacted with TK1. By searching the pathway commons protein interaction database and data drawn from the graphite library in R, we found that 1495 proteins were involved with TK1 metabolism. Using Dijkstra9s algorithm we found that 294 proteins had 1-2 degrees of interaction with TK1. Analysis of the Biogrid database showed that 191 proteins physically interact with TK1. The genes with higher average Pearson9s correlation values across all 25 cancers had the following functions: cell cycle regulation, DNA synthesis, replication and repair, transcription factors (E2F family), transport of mono and dicarboxylate for energy production pathways, transport of nucleosides, pyrimidine metabolism, DNA methylation of tumor suppressor genes, mRNA stabilization, aging, regulation of cell proliferation, control of cyclin kinases, apoptosis, and formation of channels on cell membranes. Among the genes that had significant correlation values with TK1 (P Citation Format: Edwin J. Velazquez, David M. Bellini, Rachel A. Skabelund, Tyler B. Humpherys, Jonathan R. Skidmore, Brett E. Pickett, Stephen R. Piccolo, Kim L. O9Neill. Bioinformatic analysis of the tumor biomarker thymidine kinase 1: Elucidating its cancer gene network and membrane expression across all cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2134.
Consolidation properties and structural alteration of Old Alluvium

We present experimental observations and a conceptual model for understanding the compression and swelling characteristics of Old Alluvium (OA) from San Juan, Puerto Rico. Prior studies have classified OA as a transported, in situ weathered tropical soil whose intact macrostructure comprises a cemented, pseudo-silt with a mixture of quartz grains and aggregated clay particles. The aggregates include mixtures of kaolinite and smectite coated by Fe-oxides. The Fe-oxides also act as cementing agents between the particles. This study describes results from a series of high-pressure (up to 63 MPa) incremental consolidation tests. Breakdown of the clay aggregates and cemented structure is observed through changes in the compression properties, significant swelling during unloading, and an extraordinary reduction (i.e., by three orders of magnitude) in the coefficient of consolidation. These experimental observations are explained by a combination of mechanical processes, comminution and breakdown of cementing bonds, and physicochemical changes linking pore fluid in the intra- and inter-aggregate pore space. These processes alter the fundamental particle size distribution and macro-porosity of the soil and activate the swelling potential of the smectites concealed by the Fe-oxides coating in the intact material. The experimental observations provide the basis for the formulation of a constitutive model to describe macroscopic compression and swelling behavior of Old Alluvium and offer a framework to understand the response of piedmont transported residual soils found elsewhere.
Development of health literacy in persons and caregivers living with dementia: A qualitative directed content analysis.

BackgroundPersons living with dementia and their caregivers need health information to understand and manage daily life. Previous studies focused on the associations of health literacy and cognitiv...
Dynamic implicit cost and Discount Window borrowing. An empirical investigation

Abstract This paper investigates dynamic implicit cost in aggregate Discount Window borrowing. We utilize Goodfriend's formulation, with nonprice rationing based upon the bank's current request and its past borrowing record. Estimation by Generalized-Method-of-Moments reveals a positive, systematic implicit cost structure which dampens over time. Significance extends back to nine biweekly reserve maintenance intervals. We also specify implicit cost as a geometrically declining distributed lag of past borrowing and derive a semi-reduced form for borrowed reserve demand. Empirical results support this specification as well.
Hardy-Littlewood theorems for $A$-harmonic tensors

Conjugate $A$-harmonic tensors are generalizations of conjugate harmonic functions to differential forms. They share common analytical properties such as integrability and Holder continuity. Applications to quasiregular mappings follow.
Following molecular transitions with single residue spatial and millisecond time resolution.

'Footprinting' describes assays in which ligand binding or structure formation protects polymers such as nucleic acids and proteins from either cleavage or modification; footprinting allows the accessibility of individual residues to be mapped in solution. Equilibrium and time-dependent footprinting links site-specific structural information with thermodynamic and kinetic transitions, respectively. The hydroxyl radical ({center_dot}OH) is a uniquely insightful footprinting probe by virtue of it being among the most reactive chemical oxidants; it reports the solvent accessibility of reactive sites on macromolecules with as fine as a single residue resolution. A novel method of millisecond time-resolved {center_dot}OH footprinting is presented based on the Fenton reaction, Fe(II) + H2O2 {yields} Fe(III) + {center_dot}OH + OH-. It is implemented using a standard three-syringe quench-flow mixer. The utility of this method is demonstrated by its application to the studies on RNA folding. Its applicability to a broad range of biological questions involving the function of DNA, RNA, and proteins is discussed.
Exploring Students’ Integration of Learning After Four Years of College

This chapter uses findings on integration of learning from the qualitative portion of the WNS to discuss how students make connections between skills, ideas, and knowledge across contexts.
Cardinals or Clerics? Congressional Committees and the Distribution of Pork

Journalistic and academic accounts of Congress suggest that important committee positions allow members to procure more federal funds for their constituents, but existing evidence on this topic is limited in scope and has failed to distinguish the effects of committee membership from selection onto committees. We bring together decades of data on federal outlays and congressional committee and subcommittee assignments to provide a comprehensive analysis of committee positions and distributive politics across all policy domains. Using a within-member research design, we find that seats on key committees produce little additional spending. The chairs of the Appropriations subcommittees—the so called “cardinals” of Congress—are an exception to the rule. These leadership positions do generate more funding for constituents, but only from programs under the jurisdiction of their subcommittee. Our results paint a new picture of distributive politics and call for a reexamination of its canonical theories.
Observable particle motions

The method of Gordon is used to remove the zitterbewegung from the expectation values of the velocity and spin operators in the Dirac and Kemmer theories. To terms of first order in the electromagnetic-field gradients, these expectation values obey Good's classical Lorentz-covariant equations of motion, with coefficients characteristic of spin one-half and one respectively.
Dynamic Web File Format Transformations with Grace

Web accessible content stored in obscure, unpopular or ob- solete formats represents a significant problem for digital preservation. The file formats that encode web content represent the implicit and ex- plicit choices of web site maintainers at a particular point in time. Older file formats that have fallen out of favor are obviously a problem, but so are new file formats that have not yet been fully supported by browsers. Often browsers use plug-in software for displaying old and new formats, but plug-ins can be difficult to find, install and replicate across all envi- ronments that one may use. We introduce Grace, an http proxy server that transparently converts browser-incompatible and obsolete web con- tent into web content that a browser is able to display without the use of plug-ins. Grace is configurable on a per user basis and can be expanded to provide an array of conversion services. We illustrate how the Grace prototype transforms several image formats (XBM, PNG with various alpha channels, and JPEG 2000) so they are viewable in Internet Ex- plorer.
A Current Activated on Depletion of Intracellular Ca2+ Stores Can Regulate Exocytosis in Adrenal Chromaffin Cells

Exocytosis in excitable cells is strongly coupled to Ca2+ entry through voltage-gated channels but can be evoked by activation of membrane receptors that release Ca2+ from inositol 1,4,5-trisphosphate-sensitive internal stores. In many cell types, depletion of Ca2+ stores activates Ca2+ influx across the plasma membrane, a process known as capacitative or store-operated Ca2+ entry. This influx is mediated by a number of voltage-independent, Ca2+-selective currents. In addition to replenishing Ca2+ stores, these currents are hypothesized to play an important role in agonist-evoked secretion in nonexcitable cells, although this has not been confirmed experimentally. The existence and physiological function of such currents in excitable cells is not known. Using the capacitance detection technique to monitor exocytosis, we provide direct experimental evidence that a similar mechanism exists in bovine adrenal chromaffin cells. Depletion of intracellular Ca2+stores with thapsigargin, a SERCA pump inhibitor, or with BAPTA, an exogenous Ca2+ chelator, activates a small-amplitude, voltage-independent current that is carried by Ca2+ and Na+ ions. Ca2+ entry through this pathway is sufficient to stimulate exocytosis at negative membrane potentials. In addition, depolarization-evoked exocytosis is markedly facilitated on activation of the current. These data suggest that excitable cells possess a store-operated Ca2+ influx mechanism that may both directly trigger exocytosis and modulate excitation–secretion coupling.
The Tobacco Diaries: Lessons Learned and Applied to Regulation of Dietary Supplements

Little is known about adverse reactions to dietary supplements because these events are underreported. The Food and Drug Administration’s ability to regulate dietary supplements has a long and complicated history and the battle over regulation continues. On a simple level, the debate over regulation of dietary supplements boils down to manufacturers’ desire not to be regulated and personal autonomy to make decisions about what supplements to take versus the FDA’s charge to protect the public from harmful drugs and devices. At present, dietary supplements are regulated as food, not drugs. The arguments surrounding this debate fall along a spectrum. These arguments, however, are reminiscent of the debates surrounding the regulation of tobacco. The tobacco companies fought hard to keep the FDA out of regulation, some members of the public argued that they should be allowed to take personal responsibility, and the FDA fought to bring tobacco within its regulatory authority. This article seeks to re-examine the debate over dietary supplement regulation through the lens of lessons learned from the tobacco industry. This article proposes new approaches and concerns regarding the future of the FDA and its role in regulating the dietary supplement industry.
Bivalve grazing causes substantial mortality to an estuarine copepod population

Abstract The escape responses of planktonic copepods to grazing by introduced clams in the San Francisco Estuary were estimated for several copepod species, and resulting loss rates were compared with overall mortality for one species. Experiments were conducted to determine the escape responses of both nauplii and copepodites to entrainment in the siphons of clams ( Potamocorbula amurensis ) and artificial siphons. Copepod nauplii escaped both classes of siphon about 75% of the time and copepodites were more capable of escaping than were nauplii. Escape probabilities were combined with field-based data on clam grazing rates to estimate the impact of clam grazing on copepod survival in the low-salinity region of the San Francisco Estuary. Clams removed nauplii of Eurytemora affinis at a rate of ~ 10% d − 1 with a seasonal pattern from 5% d − 1 in spring to 20% d − 1 in summer–fall and considerable interannual variability. This range of loss rates was similar to the estimated range of total mortality rates for nauplii. Furthermore, the annual estimates of loss rate were negatively correlated with an index of decline in the annual cycle of the copepod population. By combining an understanding of copepod escape capabilities with extensive data on copepod abundance and clam grazing, this paper shows that clam grazing has persisted as a dominant control on the estuarine ecosystem and is implicated in the long-term depression in abundance of food organisms for several fish species that are also in decline.
Effect of dichlorodifluoromethane on the appearance, viability, and integrity of Escherichia coli.

Abstract Cultures of Escherichia coli H52 were treated with liquid dichlorodifluoromethane (fluorocarbon-12 [f-12]) for 2 h at 22 C and then examined microscopically. Treated cells tended to clump, and their cytoplasms were generally less dense and less uniform in appearance than those of control cells. E. coli ML30 was exposed to f-12 at a concentration of 1.25 × saturation for times up to 1,200 min at 22 C. Cells were examined for changes in viability (plate count), permeability (as measured by exit of α-[14C]methylglucoside or uptake of o-nitrophenyl-β-D-galactopyranoside), release of compounds absorbing at 260 nm, and lysis (changes in absorbance at 420 nm). Large losses of α-methylglucoside and of percentage of viability occurred after brief exposure to f-12. Release of compounds absorbing at 260 nm occurred more slowly than the aforementioned events, possibly because these molecules are larger than α-methylglucoside. During 1,200-min exposure to f-12, the number of survivors decreased from 109 to 104 organisms/ml, the loss of compounds absorbing at 260 nm amounted to 50% and 32% lysis occurred. Most of these changes occurred during the first 300 min of treatment. Loss of α-methylglucoside was almost complete after 1-min exposure to f-12. These results suggest that death of the cell involves several stages, with a change of permeability occurring first, followed by leakage of compounds of increasing size and, finally, lysis.
Water soluble products of UV-irradiated autoxidized linoleic and linolenic acids.

The water-soluble products of the UV-initiated autoxidation of linoleic and linolenic acids emulsified in water were separated into volatile and relatively involatile components, each of which reacted with both thiobarbituric acid (TBA) and peroxidase. The volatile TBA-reactive compound is probably malonaldehyde and the volatile peroxidase-reactive compound is hydrogen peroxide. Additional compounds which absorb UV light were present in the volatile fraction. After thin-layer chromatography of the involatile fraction, reactivity toward TBA and peroxidase was found in the same spot. Approximate molar yields of hydrogen peroxide, malonaldehyde, ``hydroperoxides'', and other TBA-reactive compounds were estimated. The ratio of ``hydroperoxide'' to TBA reactivity was lower for linoleic than for linolenic acid. The mass of relatively involatile compounds was about 20 times greater than that predicted from either peroxidase or TBA assays of water extracts of oxidized linolenic acid. The properties of the water extract were similar to those shown by others for the products of prolonged autoxidation (without UV-irradiation) of emulsified methyl linoleate.
A new strategy for directed protein cleavage

Abstract Attachment of a Ni(II)-glyglyhis chelate to trifluoperazine results in a molecule capable of cleaving calmodulin at a single locus upon activation with a peracid.
Political instability and Nuclear dangers in Eastern Europe

The Number Four reactor at Chernobyl exploded during a routine power test in April 1986. Radioactive contaminants fell on northern Ukraine and several neighbouring countries, reaching as far as Japan and the United States. Six years later the G-7 committed considerable resources to improve the safety of Soviet-designed nuclear power plants in five East European countries. They conditioned further assistance on strict commitments to close all first-generation reactors lacking solid containment structures regardless of their technical end-of-lifetime dates. Each country agreed despite the heavy economic and political costs. However, the past ten years have shown wide variations in compliance and political stability in those countries. Ukraine and Armenia, specifically, have experienced extreme hardships in the post-communist era, greater than the other nuclear-powered East European states; each has a distinct trajectory in compliance, and together they dramatically illustrate the effect of political instabi...
Evidence that Blastocladiella emersonii zoospore chitin synthetase is located at the plasma membrane

Abstract Blastocladiella emersonii zoospores are not encased by a cell wall and do not detectably synthesize or contain chitin; accompanying de novo cell wall formation during zoospore encystment, chitin rapidly accumulates and is incorporated into the cell wall. Essential for understanding this abrupt change in chitin synthesis is the location of zoospore chitin synthetase. The enzyme has previously been reported to the sequestered with distinctive cytoplasmic organelles (gamma particles) characteristic for the zoospore cell type. Using similar differential and equilibrium density centrifugation procedures to those reported previously, we have observed the vast majority of zoospore homogenate chitin synthetase activity in fractions distinct from the gamma particle-enriched fractions. Over 90% of the homogenate enzyme activity could be recovered in a sucrose buoyant density region (1.14–1.18 g/ml) containing membranous elements and well separated from the region enriched for gamma particles (1.30–1.34 g/ml). When zoospores were surface-labelled with [ 3 H]concanavalin A prior to homogenization, the buoyant density regions of radioactivity and of chitin synthetase activity exhibited nearly complete coincidence. At least the bulk of zoospore chitin synthetase appears to be located at the plasma membrane, rather than in gamma particles.
Tokamak reactors and structural materials

Abstract A summary is given of the status of the tokamak as a reactor concept and the relationship between first wall and blanket materials behavior and reactor design.
Protecting Student Labs from Computer Viruses

Abstract This article explains the effects that computer viruses may have on computers and computer files, discusses how computers usually become infected with viruses, and suggests techniques that users should follow to reduce the incidence of computer virus attacks occurring primarily in educational computer labs. Drawing from personal experience, the author emphasizes nine safeguards that instructors, computer lab managers, and students should follow to protect personal computers in heavily used educational computer labs. An additional seven suggestions are outlined for users for protection of their single-user stations. Recommended antivirus software packages for IBM-compatibles and the Macintosh are identifed.
The role of the siderophore pyridine-2,6-bis (thiocarboxylic acid) (PDTC) in zinc utilization by Pseudomonas putida DSM 3601

Previous work had suggested that in addition to serving the function of a siderophore, pyridine-2,6-bis(thiocarboxylic acid) (PDTC) may also provide producing organisms with the ability to assimilate other divalent transition metals. This was tested further by examining regulation of siderophore production, expression of pdt genes, and growth in response to added zinc. In media containing 10–50 μM ZnCl2, the production of PDTC was found to be differentially repressed, as compared with the production of pyoverdine. The expression of PdtK, the outer membrane receptor involved in PDTC transport, was also reduced in response to added zinc whereas other iron-regulated outer membrane proteins were not. Expression of a chromosomal pdtI:: xylE fusion was repressed to a similar extent in response to zinc or iron. Mutants that cannot produce PDTC did not show a growth enhancement with micromolar concentrations of zinc as seen in the wild type strain. The phenotype of the mutant strains was suppressed by the addition of PDTC. The outer membrane receptor and inner membrane permease components of PDTC utilization were necessary for relief of chelator (1,10-phenanthroline)-induced growth inhibition by Zn:PDTC. Iron uptake from 55Fe:PDTC was not affected by a 32-fold molar excess of Zn:PDTC. The data indicate that zinc present as Zn:PDTC can be utilized by strains possessing PDTC utilization functions but that transport is much less efficient than for Fe:PDTC.
Foam Rubber Modeling of the Lotung Large-Scale Seismic Experiment

Abstract Results from a layered foam‐rubber model of the Lotung Large‐Scale Seismic Experiment are compared with the observed data. A Forced Vibration Test of the model predicts a peak response frequency at 4.0‐4.1 hz. The actual peak response frequency of the 1/4‐scale structure is 3.8 hz. Data from five earthquakes (designated, by EPRI, as events 6, 7, 8, 14, and 16) are used in this study. Events 7 and 16 are mainshocks and high‐strain events; event 8 is the aftershock of event 7. Transfer functions from downhole stations to the surface for events 6, 7, 8, and 16 are compared with the corresponding transfer functions in the foam‐rubber model. The foam‐rubber results agree well with the observed data except for event 7 (the largest event). Transfer functions from the control motion to the top of the 1/4‐scale containment for events 6, 7, 8, 14, and 16 are compared with the corresponding transfer functions in the foam‐rubber model. For events 6, and 14, results of modeling using a low‐strain assumption a...
Hall coefficients of dilute copper alloys

Abstract The Hall coefficients of dilute alloys of Mn, Fe, Co, Ni, Zn, Sn, Si and Ge in copper have been measured as a function of composition at room temperature and 77°K with fields up to 10 kG. Two sets of Cu-Mn alloys have been prepared from purified manganese. In one set, special efforts were made to reduce the impurity oxygen content of the manganese. The dependence of the Hall coefficient on composition is different for the two sets, although both have a minimum near 4 per cent manganese. For all these dilute substitutional alloys, the Hall coefficients are independent of magnetic field.
Robust adaptive photon tracing using photon path visibility

We present a new adaptive photon tracing algorithm which can handle illumination settings that are considered difficult for photon tracing approaches such as outdoor scenes, close-ups of a small part of an illuminated region, and illumination coming through a small gap. The key contribution in our algorithm is the use of visibility of photon path as the importance function which ensures that our sampling algorithm focuses on paths that are visible from the given viewpoint. Our sampling algorithm builds on two recent developments in Markov chain Monte Carlo methods: adaptive Markov chain sampling and replica exchange. Using these techniques, each photon path is adaptively mutated and it explores the sampling space efficiently without being stuck at a local peak of the importance function. We have implemented this sampling approach in the progressive photon mapping algorithm which provides visibility information in a natural way when a photon path contributes to a measurement point. We demonstrate that the final algorithm is strikingly simple, yet effective at sampling photons under lighting conditions that would be difficult for existing Monte Carlo ray tracing-based methods.
Antibody perturbation analysis of gap-junction permeability in rat cardiac myocytes.

We have used site-directed antibodies against various segments of the connexin43 (Cx43) gap-junction protein in an attempt to explore the role of different portions of this molecule in regulating junctional permeability. The antibodies used in the present study were raised against epitopes exposed at the cytoplasmic face of the junctions, specifically the amino (AT-2) and carboxy (CT-360) termini and the cytoplasmic loop (CL-100) of Cx43. Neonatal rat cardiac myocytes, which are known to express Cx43, were microinjected with a series of anti-Cx43 antibodies, followed by Lucifer yellow. The extent of cell coupling was quantified as the percentage of instances of intercellular transfer of the dye. The effectiveness of the AT-2 and CT-360 antibodies varied strongly and differentially with the external calcium concentration. In the absence of antibody, the dye permeability was unaffected by calcium. In medium containing physiological concentrations of calcium, the antibodies inhibited dye transfer to different degrees: AT-2 and CT-360 antibodies inhibited well while the CL-100 antibody had very little effect on dye permeability. Our results indicate that several highly conserved cytoplasmic domains of Cx43 could be involved in regulating junctional permeability, and that calcium modulates the effect of antibodies on junctional permeability.
Case report 443

This 20-year-old Hispano male " b r e a k d a n c e r " presented to the clinic with a 3 -month history of pain in the right thigh and left ankle. He described the pain as aching, but tolerable. Physical examinat ion was u n r e m a r k a b l e . Blood chemical studies were within normal limits. N o other abnormal history relevant to the skeleton was obtained. Roen tgenograms o f the right thigh and left calcaneus were obtained. The roen tgenogram of the right femur showed localized exuberant cortical thickening with interspersed, lytic areas within the zone o f cortical sclerosis. The cortical thickening was solid and presented an appearance o f a benign disorder. The roen tgenogram of the left heel showed sclerotic changes in the lower hal f o f the calcaneus, part icular ly in the cancellous bone associated with a periosteal react ion on the plantar aspect o f the calcaneus (Figs I and 2). A technet iumphospha te bone scan demons t ra ted increased activity in the right femur (proximal hal0, the left calcaneus (Fig. 3) and the left patella. The pat ient was lost to fol low-up for 2 years. He subsequently presented again with unchanged clinical and radiographic data. Biopsy of the right femur was performed.
Morphological changes in heart and lungs of broilers experiencing pulmonary hypertension syndrome caused by Enterococcus faecalis

Abstract In a previous report, a method of identification of birds experiencing early symptoms of pulmonary hypertension syndrome (PHS) caused by challenge with Enterococcus faecalis was delineated. This method involved subjective heart scores based on visual observation of a cavity on the external surface of the right ventricular wall (RVW), as well as tonicity and thickness of this wall. Accuracy in identifying birds 48 h postchallenge with E. faecalis was acceptable. However, this method did not attempt to offer other morphological or physiological characteristics for further understanding the etiology of PHS. In the present study, three trials were conducted to establish morphological characteristics of the heart from birds challenged with E. faecalis. In Trials 1 and 2, discrepancies were found in heart length (HL) and thickness of the RVW. In Trial 3, the dry weight of the right ventricle (RV) increased after challenge with E. faecalis, as was the ratio of the mass of the RV to the mass of the total ventricle (TV). Histopathological evidence of hearts and especially lungs of birds challenged with E. faecalis were suggestive of PHS. Results indicated that RV, RV:TV ratio, and histopatholgical evaluation of heart and lungs are complementary to diagnosis of PHS.
Production of poly-β-hydroxyalkanoates from soy molasses oligosaccharides by new, rapidly growing Bacillus species

Aims: To isolate and characterize bacteria from nature capable of producing poly-β-hydroxyalkanoates in high yields from soy molasses oligosaccharides. Methods and Results: Several strains of bacteria were obtained from enrichment cultures employing raffinose as major carbon source and inoculated with soybean field soil, lake sediment, or lake water. Many of the isolates were Bacillus species and produced polyhydroxyalkanoates (PHAs) to high yield. The raffinose-degrading isolates produced endospores, were highly saccharolytic, and both respired and fermented a variety of mono-, di-, tri- and tetrasaccharides. Strain CL1 produced 90% of cell dry mass as PHA from various sugars, including raffinose, and did so without requiring a nutrient limitation. Conclusions: Strain CL1 could be the catalyst for an industrial fermentation converting soy molasses and other waste carbohydrates to PHAs. The properties of this organism that make it ideally suited for such a fermentation include (i) its ability to use a wide variety of plant-associated carbohydrates as PHA feedstocks; (ii) its rapid growth; (iii) its ability to grow under anoxic conditions; and (iv) its ability to produce spores. Significance and Impact of the Study: This is the first report of bacteria capable of making biodegradable plastics to high yield from soy molasses oligosaccharides.