cssi/SciSciGPT-SciSciNet huggingface dataset:
1 From Glycerol to the Genome

Seeking a convenient method of collecting myxospores than harvesting fruiting bodies, Dorothy Powelson’s group had explored techniques for converting vegetative cells into myxospores in liquid culture. A more detailed description of the process followed, which demonstrated that glycerol-induced myxospores were able to germinate, were resistant to elevated temperature, UV irradiation, and sonication, and mimicked the sequence of morphological stages during the formation of fruiting body myxospores. While David Zusman pointed out some important differences between glycerol-induced and fruiting body myxospores, glycerol induction quickly became a favorite vehicle for comparing the properties and processes of vegetative cells and myxospores, albeit with careful qualifications. It was suggested that the patchy quality of the peptidoglycan and the changes during glycerol induction were causally related to the shape change during myxospore formation. Despite structural differences between fruiting body and glycerol-induced myxospores, the Tn5lac insertion mutation, Ω7536, simultaneously blocked the development of glycerol-induced spores as well as fruiting body spores as they changed their shape from rod to sphere. By 1976 it had already become clear that a defining feature of myxobacterial behavior was the pervasive tendency of cells to maintain a high cell density. When the animal encounters nutrients and feeds, the package of myxospores may be deposited in the organic matter. The spores would germinate together and instantly create a feeding swarm of myxobacteria. Those experiments would constitute no more than one step in the overall task of understanding the whole organism that is revealed in the M. xanthus genome.
A Comparison of Several Control Algorithms for Activated Sludge Waste Rate

Several algorithms for the control of the waste flow rate of the activated sludge process were compared by computer simulation. The algorithms included: constant waste flow rate; constant proportion of the mass; proportional-integral-derivative (PID) control of the dynamic sludge age (DSA); PID control of mass inventory; and feedforward ratio control based on B.O.D. loading. The study examined the effect of each algorithm on variability in DSA, biomass, and F/M ratio. PID control of DSA minimized variability in sludge age; PID control of biomass minimized variability in biomass; and constant flow rate minimized variability in F/M ratio when mixed liquor was wasted; when return sludge was wasted then constant proportion wasting was significantly better than constant flow wasting in terms of sludge age variability. It is concluded that until the relationship between sludge age, F/M and biomass and effluent quality in an unsteady-state process is better understood, a conservative control strategy is recommended: plants that waste mixed liquor should use constant flow wasting; those that waste return sludge should use constant proportion wasting.
Balanced codes with parallel encoding/decoding

A balanced code with r check bits and k information bits is a code of length k+r and cardinality 2k such that each codeword is balanced. The paper contains simple and efficient parallel encoding/decoding schemes to construct balanced codes. A particular one is described for k=32 and r=6. >
Unsupervised image segmentation using the minimum description length principle

Considers the problem of unsupervised multiband image segmentation specifically, using the MDL criterion, an associated complexity measure. According to the MDL principle, the best estimates are those that result in the most compact encoding of the image. An important advantage of such an approach is that it is virtually free of the need to choose arbitrary thresholds, which are typical of many segmentation techniques, and which, in many cases, need to be interactively adjusted in order to get satisfactory results. >
A Design Theory for Digital Habitats: Building Virtual Communities of Practice

This paper reports on-going research into the design of virtual communities of practice. Using Wenger's work on communities of practice it develops an Information Systems Design Theory (ISDT) for building digital habitats for communities of practice. The researchers use an analytical approach in applying the design theory ontology of Gregor and Jones to the work of Wenger, White, and Smith together with inductive insights gained from several development case studies. An expository example illustrates a design project case study for a virtual conference.
Designing distributed systems using approximate synchrony in data center networks

Distributed systems are traditionally designed independently from the underlying network, making worst-case assumptions (e.g., complete asynchrony) about its behavior. However, many of today's distributed applications are deployed in data centers, where the network is more reliable, predictable, and extensible. In these environments, it is possible to co-design distributed systems with their network layer, and doing so can offer substantial benefits. This paper explores network-level mechanisms for providing Mostly-Ordered Multicast (MOM): a best-effort ordering property for concurrent multicast operations. Using this primitive, we design Speculative Paxos, a state machine replication protocol that relies on the network to order requests in the normal case. This approach leads to substantial performance benefits: under realistic data center conditions, Speculative Paxos can provide 40% lower latency and 2.6× higher throughput than the standard Paxos protocol. It offers lower latency than a latency-optimized protocol (Fast Paxos) with the same throughput as a throughput-optimized protocol (batching).
Fast portscan detection using sequential hypothesis testing

Attackers routinely perform random portscans of IP addresses to find vulnerable servers to compromise. Network intrusion detection systems (NIDS) attempt to detect such behavior and flag these portscanners as malicious. An important need in such systems is prompt response: the sooner a NIDS detects malice, the lower the resulting damage. At the same time, a NIDS should not falsely implicate benign remote hosts as malicious. Balancing the goals of promptness and accuracy in detecting malicious scanners is a delicate and difficult task. We develop a connection between this problem and the theory of sequential hypothesis testing and show that one can model accesses to local IP addresses as a random walk on one of two stochastic processes, corresponding respectively to the access patterns of benign remote hosts and malicious ones. The detection problem then becomes one of observing a particular trajectory and inferring from it the most likely classification for the remote host. We use this insight to develop TRW (Threshold Random Walk), an online detection algorithm that identifies malicious remote hosts. Using an analysis of traces from two qualitatively different sites, we show that TRW requires a much smaller number of connection attempts (4 or 5 in practice) to detect malicious activity compared to previous schemes, while also providing theoretical bounds on the low (and configurable) probabilities of missed detection and false alarms. In summary, TRW performs significantly faster and also more accurately than other current solutions.
A New Approach to Linear Filtering and Prediction Problems

The clssical filleting and prediclion problem is re-examined using the Bode-Shannon representation of random processes and the ?stat-tran-sition? method of analysis of dynamic systems. New result are: (1) The formulation and Methods of solution of the problm apply, without modification to stationary and nonstationary stalistics end to growing-memory and infinile -memory filters. (2) A nonlinear difference (or differential) equalion is dericed for the covariance matrix of the optimal estimalion error. From the solution of this equation the coefficients of the difference, (or differential) equation of the optimal linear filter are obtained without further caleulations. (3) Tke fillering problem is shoum to be the dual of the nois-free regulator problem. The new method developed here, is applied to do well-known problems, confirming and extending, earlier results. The discussion is largely, self-contatained, and proceeds from first principles; basic concepts of the theory of random processes are reviewed in the Appendix.
Distinct domains of antizyme required for binding and proteolysis of ornithine decarboxylase

Selective degradation by proteasomes of ornithine decarboxylase, the initial enzyme in polyamine biosynthesis, is mediated by the polyamine-inducible protein antizyme. Antizyme binds to a region near the N terminus of ornithine decarboxylase (X. Li and P. Coffino, Mol. Cell. Biol. 12:3556-3562, 1992). This interaction induces a conformational change in ornithine decarboxylase that exposes its C terminus and inactivates the enzyme (X. Li and P. Coffino, Mol. Cell. Biol. 13:1487-1492, 1993). Here we show that the C-terminal half of antizyme alone can inactivate ornithine decarboxylase and alter its conformation, but it cannot direct degradation of the enzyme, either in vitro or in vivo. A portion of the N-terminal half of antizyme must be present to promote degradation.
Interacting Social and Environmental Predictors for the Spatial Distribution of Conservation Lands

Conservation decisions should be evaluated for how they meet conservation goals at multiple spatial extents. Conservation easements are land use decisions resulting from a combination of social and environmental conditions. An emerging area of research is the evaluation of spatial distribution of easements and their spatial correlates. We tested the relative influence of interacting social and environmental variables on the spatial distribution of conservation easements by ownership category and conservation status. For the Appalachian region of the United States, an area with a long history of human occupation and complex land uses including public-private conservation, we found that settlement, economic, topographic, and environmental data associated with spatial distribution of easements (N = 4813). Compared to random locations, easements were more likely to be found in lower elevations, in areas of greater agricultural productivity, farther from public protected areas, and nearer other human features. Analysis of ownership and conservation status revealed sources of variation, with important differences between local and state government ownerships relative to non-governmental organizations (NGOs), and among U.S. Geological Survey (USGS) GAP program status levels. NGOs were more likely to have easements nearer protected areas, and higher conservation status, while local governments held easements closer to settlement, and on lands of greater agricultural potential. Logistic interactions revealed environmental variables having effects modified by social correlates, and the strongest predictors overall were social (distance to urban area, median household income, housing density, distance to land trust office). Spatial distribution of conservation lands may be affected by geographic area of influence of conservation groups, suggesting that multi-scale conservation planning strategies may be necessary to satisfy local and regional needs for reserve networks. Our results support previous findings and provide an ecoregion-scale view that conservation easements may provide, at local scales, conservation functions on productive, more developable lands. Conservation easements may complement functions of public protected areas but more research should examine relative landscape-level ecological functions of both forms of protection.
The effect of regioisomerism on the crystal packing and device performance of desymmetrized anthradithiophenes

Anthradithiophenes (ADTs) are typically synthesized as inseparable mixtures of regioisomers. In this paper, we describe the synthesis of desymmetrized anthradithiophenes containing one trialkylsilylethyne solubilizing group, which allowed chromatographic separation of the three resulting isomers. Cyclic voltammograms, as well as absorption and emission spectra for all isomers, were nearly identical. However, X-ray crystallography revealed that the positions of the sulfur atoms in each isomer strongly influence crystal packing, corroborating calculations that show the S–π interaction to be less stabilizing than the C–H–π interaction. Isomer 3c packs in a pseudo 1-D fashion while isomers 3a and 3b pack as isolated π-stacked pairs. Isomer 3c shows a field-effect mobility four orders of magnitude higher than isomers 3a and 3b, presumably due to this difference in packing motif.
Time delay in triggered vacuum gap

A proposed theory of metal vapor arcs in vacuum, based on the assumption of field emission of electrons, has been used to calculate the time delay of Lafferty's Triggered Vacuum Gap, with excellent agreement with experiment.
Biopolitics, trauma and the public fetus: An analysis of preconception care

In 2006, the US Center for Disease Control rolled out guidelines for ‘preconception care,’ institutionalizing the use of the public fetus as a fetish object in relation to which the cultural body can disavow and contain the post 9/11 contagion of annihilation anxiety. Integrating Bergson's ideas of duration with cultural and psychoanalytic theories of time and subjectivity, this article will examine these guidelines and the ways in which they become alluring as forms of traumatic repetition instilling hypervigilance as normality. The preconception care guidelines are a perfect example of Clarke's ideas of biomedicalization, as women's bodies emerge through practices of self and biomedical surveillance and risk management strategies in relation to the future fetus. This future orientation functions not only to disavow, displace and contain vulnerability, but also creates a future in order to attempt to go on being in the face of trauma and humiliation.
Application of scanning tunneling microscopy to a superconducting surface

Abstract It is shown that the scanning tunneling microscope as developed by Binnig and Rohrer can be expected to resolve the spatial variations of the superconducting order parameter in inhomogeneous superconductors.
Disposition of short-chain aliphatic alcohols in rabbit vitreous by ocular microdialysis.

Abstract Anatomic and physiological barriers limit drug delivery to the posterior segment of the eye via topical or systemic administration. Intravitreal administration has proven to be a safe and effective means of treating various posterior segment diseases. Elimination of a compound from the vitreous chamber may depend on lipophilicity, diffusivity, and aqueous solubility. This information is critical for optimizing intravitreal dosing which in turn can aid in the design of drug delivery systems. The purpose of this study is to determine the vitreous disposition of an ascending homologous series of short chain aliphatic alcohols ranging from hydrophilic methanol to lipophilic 1-heptanol by microdialysis. Radiolabelled 14C-methanol, 14C-1-propanol, 14C-1-pentanol, and 14C-1-heptanol with log partition coefficient values ranging from −0·77 to 2·7 were studied. Microdialysis probes were implanted in both anterior and vitreous chamber of the rabbit eye to sample aqueous and vitreous humors simultaneously. Concentric probe was implanted in vitreous chamber about 3 mm below the cornealscleral limbus. Linear probe was implanted in the anterior chamber using a 25-guage needle. Isotonic phosphate buffer saline (IPBS) (pH 7·4) was perfused through the probe with a flow rate of 2 μl ml−1. Alcohols (2·0 μg–130·72 μg) were injected into the vitreous body. In vitro recovery for the probes was calculated using respective alcohols in IPBS. Pharmacokinetic parameters were determined by non-compartmental analysis. Vitreal elimination half-lives of methanol, 1-propanol, 1-pentanol and 1-heptanol are 52·0±5·7, 58·5±5·8, 72·9±5·8 and 153·7±21·6 min, respectively. Dose normalized area under the aqueous concentration time curve values of methanol, 1-propanol and 1-pentanol are 33·8±13·4, 28·3±11·9 and 29·2±4·9 μg min ml−1 μg−1 10−2, respectively. Time taken to reach maximum concentration in the anterior chamber for methanol, 1-propanol and 1-pentanol is 120±42, 160±26, and 260±26 min, respectively. The maximum concentration of methanol, 1-propanol and 1-pentanol achieved in the anterior chamber is 18·6±10·3, 9·4±3·2, and 5·9±1·3 μg ml−1 10−4 respectively. Detectable 1-heptanol levels were not observed in the anterior chamber with the intravitreal dose administered. The shorter vitreal elimination half-lives of the alcohols studied suggest retina as major route of elimination from the vitreous body. The elimination rate constants of alcohols from the vitreous appear to be progressively decreasing with ascending chain length and lipophilicity (methanol to 1-heptanol). Among the alcohols studied, methanol produced the highest concentration in the anterior chamber following vitreal administration.
Nanosecond Flash Photolysis Studies of Intersystem Crossing Rate Constants in Biradicals: Structural Effects Brought About by Spin-Orbit Coupling

On montre que le couplage spin-orbite est renforce dans les diradicaux ayant un groupe acyle terminal. Effet de la longueur de la chaine et de la conformation
Interactive Transparent Networking: Protocol meta modeling based on EFSM

The extensibility and evolution of network services and protocols had become a major research issue in recent years. The 'programmable' and 'active' network paradigms have been trying to solve the problems emanating from the immutable organization of network software layers by allowing arbitrary custom codes to be embedded inside network layers. In this work, we propose a new approach for building extensible network systems to support cross-layer optimization. The fundamental idea is to perform a simple, light-weight meta-engineering on the classical OSI protocols' organization to make it interactive and transparent. The protocols become (interactive) since they can provide event notification to service subscribers, and they become (transparent) since they also allow controlled access to their state information. Actual protocol extensions (or modifications) can then be performed at the application space by what we call Transientware Modules. This organization provides the infrastructure needed for easy and practical extensions of the current network services and it becomes much easier to address other difficult issues like security and flexibility. We call this mechanism Interactive Transparent Networking (InTraN) and we call the extended kernel InTraN-enabled. We have realized a FreeBSD implementation of the extensible InTraN-enabled kernel. In this paper, we present a formal EFSM-based model for the proposed meta-engineering and illustrate the principles through a real example of TCP extension. Then, we demonstrate how it can be used to realize equivalents of other protocol modifications by showing the InTraN model of 'Snoop' [H. Balakrishnan, S. Seshan, R. Katz, Improving reliable transport and handoff performance in cellular wireless networks, ACM Wireless Networks 1 (1995)].
Defending Literature in Early Modern England: Renaissance Literary Theory in Social Context

Acknowledgments 1. Introduction: 'aut prodesse ... aut delectare' 2. Recreating reading: Elyot's Boke Named the Governour 3. Heroic diversions: Sidney's Defence of Poetry 4. A 'gentle discipline': Spenser's Faerie Queene 5. Epilogue: from text to work? Notes Bibliography Index.
Likelihood Ratio Derivative Estimators For Stochastic Systems

This paper discusses Iikelihood--ratio--derivative estimation techniques for stochastic systems. After a brief review of the basic concepts, likelihood-ratio-derivative estimators are presented for the following classes of stochastic processes: time homogeneous discrete-time Markov chains, non-time-homogeneous discrete-time Markov chains, time-homogeneous continuous-time Markov chains, semi-Markov processes, non-time-homogeneous continuous-time Markov chains, and generalized semi-Markov processes.
Aaron Lerner's Legacy at Yale University.

The Yale Department of Dermatology is the “house that Aaron built.” That rewording of the age-old description of Yankee Stadium as the “house that [Babe] Ruth built” is quite fitting, because his most enduring legacy at Yale is the creation of a culture in which students, residents, fellows, and faculty are encouraged to “swing for the fences,” striving to follow his example of tackling big ideas and expansive goals. Along with many, I have been deeply affected by Aaron through four decades, dating from my days as a Yale Medical School student performing research in the dermatology department to my research fellowship in the dermatology branch of the National Cancer Institute when he served as scientific advisor, to my faculty years at Columbia when he kept close watch over me, to my past 21 years as his successor as chair of Yale's dermatology department. Running toward and then behind someone for so long, across all grades of terrain, gives me a cherished view of his comfortable gait and the giant steps that he took for and through the field.
Primary and secondary structure of U2 snRNA

Abstract With the improved rapid sequencing techniques, the earlier sequence of U2 RNA of Novikoff hepatoma (Shibata et al, J. Biol. Chem. 250, 3909-3920, 1975) was reanalyzed and modified. The improved sequence of U2 RNA is 188 (or 189) nucleotides long and is in register with a characterized U2 RNA pseudogene (Denison et al, PNAS 78, 810-814, 1981) except for an 11 nucleotide sequence (nucleotides 147-157) which is absent from the pseudogene. From these results, a secondary structure of U2 RNA is proposed which is supported by the preferred cleavage sites with T1-RNase, RNase A and S1 nuclease. Isolated U2 RNA was cleaved by T1-RNase preferentially at positions 64 and 164, whereas U2 RNA in U2-snRNP was cleaved only at position 64, indicating that position 164 is protected in U2-snRNP. As with U1 RNA (Epstein et al, PNAS 78, 1562-1566, 1981) the 5'-end of isolated U2 RNA was not preferentially cleaved by T1-RNase.
Time series of chaparral live fuel moisture maps derived from MODIS satellite data

Wildfires in chaparral shrublands of southern California are a major hazard and important ecological disturbance agent. Fire managers typically monitor fuel moisture of chaparral shrublands to assess the risk of wildfires, using field-based sampling methods for a few small study areas located sparsely throughout southern California. Remote sensing provides the potential for deriving spatially explicit and temporally frequent data on live fuel moisture (LFM) conditions. The objective of this present study was to explore the potential for monitoring LFM with maps derived from Moderate Resolution Imaging Spectroradiometer (MODIS) data on the National Aeronautics and Space Administration (NASA) Terra Earth-observing satellite. A time series of MODIS surface reflectance data (MOD-09_A1) for San Diego County, California from Fall 2000 through 2003 was used to derive normalized difference indices, which were regressed against LFM data. A high degree of temporal co-variability was found, with three MODIS indices providing similar predictability. Regression relationships were inverted and applied to MODIS images to map LFM interval classes for chaparral areas of San Diego County. The spatial–temporal patterns of LFM maps suggest that, at a minimum, the MODIS can provide spatially explicit information that extends the utility of ground-based measurements of LFM data at a few sites.
Accelerated chromatographic analysis of amino acids commonly found in physiological fluids on a spherical resin of specific design.

Abstract Chromatographic analysis and improved resolution of the amino acids commonly found in physiological fluids have been accelerated by improved resin technology. The acidic and neutral amino acids are analyzed on a 55.5 × 0.9 cm resin column and the basic amino acids on a 22.0 × 0.9 cm resin column. Buffer flow rates of 50 ml/hr (79 linear cm/hr) are pumped through both columns under pressures of 240 psi and 210 psi for the long and short columns, respectively. This system reduces the analysis time from the previously reported 44 hr of a physiological-type amino acid mixture, urine, or blood plasma to 11 hr, 10 min (5 hr, 25 min, for the acidic and neutral amino acids and 5 hr, 45 min, for the basic amino acids). Two complete physiological fluid analyses are possible in a 24-hr day.
Measuring similarity in feature space of knowledge entailed by two separate rule sets

This paper addresses the task of comparing two rule sets induced within the same feature space for measuring the knowledge entailed jointly by the two. A procedure that quantifies the similarity of knowledge entailed by two separate rule sets in a given feature space is proposed. A formalized description of the proposed procedure along with its computational complexity analysis, applicability and utility is presented. Application of the proposed procedure is demonstrated using two rule sets from the computer security domain.
Screening wheat and sorghum cultivars for aluminum sensitivity at low aluminum levels

Abstract Screening cultivars for aluminum (Al) tolerance is often conducted in acid soils or in complete nutrient solutions. The former method lacks precise measurements of Al, and the second requires high Al concentrations because of precipitation and chelation of the Al and is less representative of the actual environmental stresses to which plants must adapt. These experiments were designed to determine Al tolerance of wheat (Triticum aestivum L. em Thell) and sorghum (Sorghum bicolor L. Moench) using incomplete solutions with very low Al concentrations. Six wheat and five sorghum cultivars were screened for Al tolerance in solution culture with 0 to 10 μM Al and only Ca, K, Mg, NO3, and Cl in the solutions. Plants were subjected to the solutions for 4 d, and the change in relative root length was measured. Solution Al levels and pH were measured after the termination of the experiments. ‘Atlas’ 66 and ‘Stacy’ were the most tolerant wheat cultivars ('Atlas 66’ = ‘Stacy’ ≥ ‘Monon’ ≥ ‘Scout 66’ ≥ ‘Arthur...
Computer science via digital sound and music: a hands-on introduction to open source tools and new curriculum material to introduce computer science concepts (abstract only)

In this workshop, participants will create and manipulate digital audio using open source software (Audacity, PureData, Processing's Minim Beta, Octave, and C/C++). The cross-disciplinary digital audio content links music, engineering, physics, mathematics, and computer science and was developed for and test-taught in computer science courses. Additionally, participants will access and use the freely available online videos, tutorials, and textbook that can be incorporated into their classrooms. The online content's development was funded by the National Science Foundation CCLI Grant, "Linking Science, Art, and Practice Through Digital Sound." Exercises that engage students in creative computational problem solving for sound and music applications will also be discussed. Laptops equipped with the open source applications mentioned above are strongly recommended but not required.
The Yoneda Algebra of a &#x1d4a6;2 Algebra Need not be Another &#x1d4a6;2 Algebra

The Yoneda algebra of a Koszul algebra or a D-Koszul algebra is Koszul. &#x1d4a6;2 algebras are a natural generalization of Koszul algebras, and one would hope that the Yoneda algebra of a &#x1d4a6;2 algebra would be another &#x1d4a6;2 algebra. We show that this is not necessarily the case by constructing a monomial &#x1d4a6;2 algebra for which the corresponding Yoneda algebra is not &#x1d4a6;2.
Hemodynamic response profile predicts susceptibility to cocaine-induced toxicity.

Cocaine evokes pressor responses due either to a large increase in systemic vascular resistance despite a decrease (>8%) in cardiac output (vascular responders) or to small increases in both cardiac output and vascular resistance (mixed responders) in conscious rats. These studies were designed to determine (1) if the hemodynamic response pattern to cocaine correlates with relative sensitivity to toxicity and (2) if altering the hemodynamic response pattern to cocaine using propranolol enhances toxicity. Rats were instrumented for determination of cardiac output and arterial pressure. After recovery, rats were classified as vascular or mixed responders to cocaine (5 mg/kg, i.v., four to six trials). Two weeks later, cocaine was infused (1.5 mg/kg/min) until death after pretreatment with saline or propranolol (1 mg/kg). Saline-pretreated mixed responders (n=6) had greater tolerance to cocaine toxicity compared to vascular responders (n=11). Furthermore, saline-pretreated vascular responders were less sensitive than propranolol-pretreated vascular responders (n=9) to cocaine toxicity. Therefore, we propose that the initial hemodynamic response pattern to cocaine predicts sensitivity to cocaine toxicity. In addition, propranolol, a drug that enhances the increase in vascular resistance to cocaine, also increases toxicity to cocaine in vascular responders.
Cloning of mammalian cells by a simplified capillary technique.

Abstract A method is described for the critical isolation of clones from single mammalian tissue cells in culture. Early attempts to isolate and grow single cells and various cloning methods are reviewed.
Molecular cloning and characterization of the renal diuretic-sensitive electroneutral sodium-(potassium)-chloride cotransporters

cDNAs encoding the two major electroneutral sodium-chloride transporters present in the mammalian kidney, the bumetanide-sensitive Na+-K+-Cl− symporter and thiazide-sensitive Na+-Cl− cotransporter, were isolated and their functional activity characterized in Xenopus laevis oocytes [2]. Although they differ in sensitivities to bumetanide and thiazides and have different requirements for potassium, these approximately 115-kDa proteins share about 60% sequence similarity and exhibit a topology featuring 12 potential membrane-spanning helices flanked by large hydrophilic domains at the NH2- and COOH-termini. These molecules, together with the Na-Cl cotransporter from the flounder urinary bladder, which exhibits a significant homology suggestive of common ancestry, define a new family of electroneutral Na+-(K+)-Cl− cotransporters. Northern blot analysis and in situ hybridization indicate that these transporters are expressed predominantly in kidney with an intrarenal distribution consistent with their recognized functional localization. The kidney-specific distribution of transcripts encoding these cotransporters suggest that other, probably related, genes encode non-renal Na+-(K+)-Cl− cotransporters.
Chest pain in children and adolescents

The focus of this article is to explore chest pain in children and adolescents. Common causes of chest pain and the approach to its evaluation are reviewed. Special emphasis is given to the cardiac causes of pediatric chest pain and how it can be differentiated from more common benign etiologies.
Explanation in Classical Population Genetics

The recent literature in philosophy of biology has drawn attention to the different sorts of explanations proffered in the biological sciences—we have molecular, biomedical, and evolutionary explanations. Do these explanations all have a common structure or relation that they seek to capture? This paper will answer in the negative. I defend a pluralistic and pragmatic approach to explanation. Using examples from classical population genetics, I argue that formal demonstrations, and even strictly “mathematical truths,” may serve as explanatory in different historical contexts.
A paperless environment for group effort in documentation development

Research into the effect of word processing on writing and a paperless environment for the submission and grading of student assignments has led to considerations for new technology to support the development of system documentation. We assert that a relatively paperless system which integrates the concepts of word processing, electronic mail, computer conferencing and the HANDIN paperless system for student assignments (Cross and Wolfe, 1985) has potential for facilitating the process of developing system documentation. A conceptual framework and specific system features are presented. Research goals and methodologies are briefly considered.
Stress Analysis of the Double‐Torsion Specimen

The double-torsion specimen was analyzed with a 3-dimensional elastic finite-element stress analysis. A crack-front configuration where the stress intensity is constant over ≅ 1/2 of the specimen thickness was determined. That value of the stress intensity is nearly equal to the “strength-of-materials” value. The stress intensity is nearly constant for crack lengths > 0.55 × specimen width (W) and ligament lengths > 0.65W.
Impaired natural killer cell activity during bereavement

Natural killer (NK) cell activity, a component of the immune surveillance system, was compared in women whose husbands had recently died with that found in age-matched women who had not experienced recent adverse life events. Bereaved women had significantly lower NK activity than women whose husbands were healthy. In a second study, depressive symptoms and NK activity were measured longitudinally in women before and after the death of their husbands. Our results suggest that depressive symptoms, not merely the death of the spouse, are related to a reduction in NK activity during bereavement.
Redox regulation of mitophagy in the lung during murine Staphylococcus aureus sepsis

Oxidative mitochondrial damage is closely linked to inflammation and cell death, but low levels of reactive oxygen and nitrogen species serve as signals that involve mitochondrial repair and resolution of inflammation. More specifically, cytoprotection relies on the elimination of damaged mitochondria by selective autophagy (mitophagy) during mitochondrial quality control. This aim of this study was to identify and localize mitophagy in the mouse lung as a potentially upregulatable redox response to Staphylococcus aureus sepsis. Fibrin clots loaded with S. aureus (1×10(7) CFU) were implanted abdominally into anesthetized C57BL/6 and B6.129X1-Nfe2l2tm1Ywk/J (Nrf2(-/-)) mice. At the time of implantation, mice were given vancomycin (6mg/kg) and fluid resuscitation. Mouse lungs were harvested at 0, 6, 24, and 48h for bronchoalveolar lavage (BAL), Western blot analysis, and qRT-PCR. To localize mitochondria with autophagy protein LC3, we used lung immunofluorescence staining in LC3-GFP transgenic mice. In C57BL/6 mice, sepsis-induced pulmonary inflammation was detected by significant increases in mRNA for the inflammatory markers IL-1β and TNF-α at 6 and 24h, respectively. BAL cell count and protein also increased. Sepsis suppressed lung Beclin-1 protein, but not mRNA, suggesting activation of canonical autophagy. Notably sepsis also increased the LC3-II autophagosome marker, as well as the lung׳s noncanonical autophagy pathway as evidenced by loss of p62, a redox-regulated scaffolding protein of the autophagosome. In LC3-GFP mouse lungs, immunofluorescence staining showed colocalization of LC3-II to mitochondria, mainly in type 2 epithelium and alveolar macrophages. In contrast, marked accumulation of p62, as well as attenuation of LC3-II in Nrf2-knockout mice supported an overall decrease in autophagic turnover. The downregulation of canonical autophagy during sepsis may contribute to lung inflammation, whereas the switch to noncanonical autophagy selectively removes damaged mitochondria and accompanies tissue repair and cell survival. Furthermore, mitophagy in the alveolar region appears to depend on activation of Nrf2. Thus, efforts to promote mitophagy may be a useful therapeutic adjunct for acute lung injury in sepsis.
Uptake and translocation of ethofumesate in sugar-beet plants†

The uptake and translocation of 14C-labelled ethofumesate [(±)-2-ethoxy-2,3-dihydro-3,3-dimethylbenzofuran-5-yl methanesulphonate] was studied in sugar-beet seedlings following soil and foliar applications. After soil applications, the roots absorbed and translocated to the foliage more ethofumesate or its metabolites than did the emerging hypocotyls. Ethofumesate or its metabolites did not accumulate in either roots or hypocotyls after exposure to treated soil. When sugar-beet leaves were treated with the herbicide at the two-leaf stage, acropetal translocation was rapid but there was no translocation out of the treated leaves. Furthermore, ethofumesate or its metabolites were not translocated basipetally after either soil or foliar application.
Confidence sets and the stein effect

The problem of improving upon the usual set estimator of a multivariate normal mean has only recently seen significant advances. Improved sets that take advantage of the Stein effect have been constructed. It is shown here that the Stein effect is so powerful that one can construct improved confidence sets that can have zero radius on a set of positive probability. Other, somewhat more sensible, sets which attain arbitrarily small radius are also constructed, and it is argued that one way to eliminate unreasonable confidence sets is through a conditional evaluation.
TU-G-217BCD-08: The Relationship of Image Noise and Organ Dose as a Function of Patient Size for Abdominal CT Exams at 5 Different Dose Levels When Tube Current Modulation Is Used

Purpose: To investigate the relationship of imagenoise and organ dose as a function of patient size for abdominal CT exams at a 5 different dose levels when tube current modulation is used. Methods: This IRB approved study selected 20 patients scanned by a Siemens Sensation64 CT scanner with CareDose4D turned on. Images at lower dose levels (20%, 30%, 50%, and 70%) were simulated for each patient. Noise for each image set was obtained by drawing an ROI in a homogeneous region in the liver. Radiation dose to liver was obtained using a previously validated Monte Carlo simulation package. The perimeter of the patient at the liver level was also obtained. Results:Noise and liver dose were plotted as a function of patient size for the 100% dose level image sets. Noise behaves roughly as a linearly function of patient perimeter. This is consistent to the principle of CareDose4D: higher noise is acceptable in larger patients due to the intrinsic better contrast from extra fat tissue. As patient size increase, liver dose also increases in a nearly linear fashion, except for two extra large patients. In addition, noise was plotted as function of liver dose for all the image sets (including all 5 dose levels). For each patient, the noise approximately decreases in an inverse square root relationship as the dose increases, as expected. Larger patients' images have higher noise at the same liver dose. Therefore higher organ dose is required to achieve a similar noise level. Conclusions: This study investigated the relationship between imagenoise,organ dose and patient size. The results showed that with CareDose4D: (a) both noise and liver dose increases as patient size increases; (b) larger patients require a higher organ dose in order to have a similar noise level as a smaller patient. For Michael McNitt‐Gray: Institutional research agreement, Siemens AG Recipient research support Siemens AG
POPULAR CULTURAL PRACTICES IN THE “POSTMODERN CITY”

Contemporary interpretations of the city decry what Fredric Jameson calls "a mutation in built space itself," a postmodern urban fabric in which the traditional economic and political foundations of city life are overwhelmed by the cultural, and the city is reduced to a gigantic shopping mall or theme park, its residents powerless to do anything but consume. The focus on cultural processes as fundamental to the character of today's cities leads to an intriguing point of intersection between urban and cultural geography; it also calls into question the soundness of formulations of cultural practice that underlie many "postmodern" interpretations. This paper argues that recent work in cultural geography, with both its rich engagement with culture theory and its enthusiasm for empirical study of everyday life, can shed new light on our understanding of the city. A brief tour of the quintessential expression of the "postmodern" city, Disneyland, demonstrates that contemporary urban landscapes are complicated ...
Use of Bremsstrahlung in the Measurement of the Efficiency of Solid State Detectors below 5 keV

Atomic-field bremsstrahlung produced by the bombardment of atoms by an electron beam of 5-10 keV energy provides a continuous x-ray source which is suitable for the measurement of the relative efficiency of solid state detectors in the energy region below 5 keV. The relative efficiency as a function of photon energy can be obtained by normalizing the observed spectrum to the theoretical bremsstrahlung cross section. In this paper we will present an example of this technique using a thin film target and a gas beam target to illustrate some of the problems and to demonstrate the potential of this technique.
The Factorial Validity of the Dimensions of Self-Concept (DOSC) Measure for a Sample of Eighth-Grade Children and for One of Community College Adults

In this investigation attention was directed toward whether the five hypothesized constructs of Level of Aspiration, Anxiety, Academic Interest and Satisfaction, Leadership and Initiative, and Identification vs. Alienation that have been translated into five subscales of a secondary school version (Form S) of the Dimensions of Self-Concept (DOSC) scale, a measure of academic self-concept, could be identified for a college sample of adults as well as for a sample of eighth-grade students. Factor analyses of the intercorrelations of the same 20 subtests of the DOSC (four subtests of three to four items per factor subscale) revealed a relatively high degree of factorial invariance (congruence) across the two samples. It was concluded that the DOSC measured essentially the same constructs for the two samples and that it showed at least limited promise as a valid indicator of the hypothesized dimensions of academic self-concept for college-level students.
Nijmegen breakage syndrome: Clinical characteristics and mutation analysis in eight unrelated Russian families

Abstract Objective: The purpose of the study was to ascertain patients with Nijmegen breakage syndrome (NBS) in the Russian population and characterize the clinical phenotype and molecular genotype of these patients. Study design: Eight unrelated Russian patients with possible diagnoses of NBS were identified. Family histories were collected and clinical and laboratory analyses were carried out. Mutation screening of the NBS1 gene was carried out to confirm the diagnosis in 7 cases. Results: All patients had the key diagnostic features of NBS. One patient had acute myeloblastic leukemia (AML). Two patients had bone marrow aplasia, not previously described as a feature of NBS. Mutation screening of the NBS1 gene revealed that 6 patients were homozygous for the 657del5 mutation, whereas a seventh patient was a compound heterozygote, having the 657del5 mutation and an additional novel mutation, 681delT. Conclusions: Molecular analyses confirmed the diagnosis of NBS in 7 of the patients. The surprising finding of bone marrow aplasia or AML in 3 of 7 patients raises the possibility of a connection between NBS and another DNA damage disorder, Fanconi anemia. (J Pediatr 2002;140:355-61)
Judges' Use of Examinee Performance Data in an Angoff Standard-Setting Exercise for a Medical Licensing Examination: An Experimental Study

Although the Angoff procedure is among the most widely used standard setting procedures for tests comprising multiple-choice items, research has shown that subject matter experts have considerable difficulty accurately making the required judgments in the absence of examinee performance data. Some authors have viewed the need to provide performance data as a fatal flaw for the procedure; others have considered it appropriate for experts to integrate performance data into their judgments but have been concerned that experts may rely too heavily on the data. There have, however, been relatively few studies examining how experts use the data. This article reports on two studies that examine how experts modify their judgments after reviewing data. In both studies, data for some items were accurate and data for other items had been manipulated. Judges in both studies substantially modified their judgments whether the data were accurate or not.
Ligand interactions with lactose repressor protein and the repressor-operator complex: The effects of ionization and oligomerization on binding

Abstract Specific interactions between proteins and ligands that modify their functions are crucial in biology. Here, we examine sugars that bind the lactose repressor protein (LacI) and modify repressor affinity for operator DNA using isothermal titration calorimetry and equilibrium DNA binding experiments. High affinity binding of the commonly-used inducer isopropyl-β, d -thiogalactoside is strongly driven by enthalpic forces, whereas inducer 2-phenylethyl-β, d -galactoside has weaker affinity with low enthalpic contributions. Perturbing the dimer interface with either pH or oligomeric state shows that weak inducer binding is sensitive to changes in this distant region. Effects of the neutral compound o-nitrophenyl-β, d -galactoside are sensitive to oligomerization, and at elevated pH this compound converts to an anti-inducer ligand with slightly enhanced enthalpic contributions to the binding energy. Anti-inducer o-nitrophenyl-β, d -fucoside exhibits slightly enhanced affinity and increased enthalpic contributions at elevated pH. Collectively, these results both demonstrate the range of energetic consequences that occur with LacI binding to structurally-similar ligands and expand our insight into the link between effector binding and structural changes at the subunit interface.
Invariant differental forms on compact nilmanifolds

Let N=G/Г be a compact nilmanifold, G a connected, simply connected, nilpotent Lie group with its discrete subgroup Г and Lie algebra \(\mathcal{G}\). Let I* (\(\mathcal{G}\)) denote the invariant differential forms on \(\mathcal{G}\).
Maternal gesture use and language development in infant siblings of children with autism spectrum disorder.

Impairments in language and communication are an early-appearing feature of autism spectrum disorders (ASD), with delays in language and gesture evident as early as the first year of life. Research with typically developing populations highlights the importance of both infant and maternal gesture use in infants’ early language development. The current study explores the gesture production of infants at risk for autism and their mothers at 12 months of age, and the association between these early maternal and infant gestures and between these early gestures and infants’ language at 18 months. Gestures were scored from both a caregiver-infant interaction (both infants and mothers) and from a semi-structured task (infants only). Mothers of non-diagnosed high risk infant siblings gestured more frequently than mothers of low risk infants. Infant and maternal gesture use at 12 months was associated with infants’ language scores at 18 months in both low risk and non-diagnosed high risk infants. These results demonstrate the impact of risk status on maternal behavior and the importance of considering the role of social and contextual factors on the language development of infants at risk for autism. Results from the subset of infants who meet preliminary criteria for ASD are also discussed.