cssi/SciSciGPT-SciSciNet huggingface dataset:
Teaching Physics to Radiology Residents

OBJECTIVE. The complexity of diagnostic imaging has expanded dramatically over the past two decades. Over the same period, the time and effort devoted to teaching physics (the science and technology of the discipline) have diminished. This paradox compromises the ability of future radiologists to master imaging technologies so that they are used in an efficient, safe, and cost-effective manner. This article addresses these issues.CONCLUSION. Efforts involving many professional organizations are under way to resolve the paradox of the expanding complexity of medical imaging contrasted with the declining emphasis on physics in radiology residency programs. These efforts should help to reestablish physics education as a core value in radiology residency programs.
Word Recognition by Second Graders: The Unit of Perception and Interrelationships among Accuracy, Latency, and Comprehension

Two issues were investigated: the first examined the relationships among accuracy and latency of word recognition and comprehension by non-fluent readers, and the second examined whether component letter or holistic processing was used in word recognition by these same readers. Speed and accuracy of word recognition were measured on individual words, Literal comprehension was measured for the same words presented in meaningful context. The unit of perception was measured by the relationship between latency of word recognition and word length. If students were using component processing, latency would increase with word length, but if holistic processing were used, there would be no increase in latency with length. Results of this study indicated that accuracy and latency were each significantly related to comprehension for both first- and second-grade words, with evidence for latency influencing comprehension scores to a greater extent on the first-grade words. With regard to the unit of perception, in general there was evidence of com- ponent letter processing for all subjects with the highly accurate readers showing a tendency towards more holistic processing. This research investigates two problems in reading. One problem undertaken in this study pertains to the relationships among word recognition latency, word recognition accuracy and literal comprehension by beginning readers. The second problem pertains to the size of the perceptual unit used by beginning readers in word recognition. This question focuses on the component letter-holistic processing con- troversy which has been with us for nearly a century (Cattell, 1947). Under compo- nent letter processing it is assumed that the perceptual unit may be as small as the let- ter; under holistic processing it is assumed that the unit is considerably larger, perhaps as large as the word itself. We have chosen to study these two seemingly disparate problems—the question of the unit of perception for beginning readers and the relationships among word recognition speed, accuracy and literal comprehension in these same readers—because both may be examined using word recognition laten- cy.
Geometrically uniform codes

A signal space code C is defined as geometrically uniform if, for any two code sequences in C, there exists an isometry that maps one sequence into the other while leaving the code C invariant. Geometrical uniformity, a strong kind of symmetry, implies such properties as a) the distance profiles from code sequences in C to all other code sequences are all the same, and b) all Voronoi regions of code sequences in C have the same shape. It is stronger than Ungerboeck Zehavi-Wolf symmetry or Calderbank-Sloane regularity. Nonetheless, most known good classes of signal space codes are shown to be generalized coset codes, and therefore geometrically uniform, including (a) lattice-type trellis codes based on lattice partitions Lambda / Lambda ' such that Z/sup N// Lambda / Lambda '/4Z/sup N/ is a lattice partition chain, and (b) phase-shift-keying (PSK)-type trellis codes based on up to four-way partitions of a 2/sup n/-PSK signal set. >
Molecular Imaging of Alzheimer Disease Pathology

Development of molecular imaging agents for fibrillar β-amyloid positron-emission tomography during the past decade has brought molecular imaging of Alzheimer disease pathology into the spotlight. Large cohort studies with longitudinal follow-up in cognitively normal individuals and patients with mild cognitive impairment and Alzheimer disease indicate that β-amyloid deposition can be detected many years before the onset of symptoms with molecular imaging, and its progression can be followed longitudinally. The utility of β-amyloid PET in the differential diagnosis of Alzheimer disease is greatest when there is no pathologic overlap between 2 dementia syndromes, such as in frontotemporal lobar degeneration and Alzheimer disease. However β-amyloid PET alone may be insufficient in distinguishing dementia syndromes that commonly have overlapping β-amyloid pathology, such as dementia with Lewy bodies and vascular dementia, which represent the 2 most common dementia pathologies after Alzheimer disease. The role of molecular imaging in Alzheimer disease clinical trials is growing rapidly, especially in an era when preventive interventions are designed to eradicate the pathology targeted by molecular imaging agents.
Housekeeping sortase facilitates the cell wall anchoring of pilus polymers in Corynebacterium diphtheriae

Many surface proteins in Gram-positive bacteria are covalently linked to the cell wall through a transpeptidation reaction catalysed by the enzyme sortase. Corynebacterium diphtheriae encodes six sortases, five of which are devoted to the assembly of three distinct types of pilus fibres--SrtA for the SpaA-type pilus, SrtB/SrtC for the SpaD-type pilus, and SrtD/SrtE for the SpaH-type pilus. We demonstrate here the function of SrtF, the so-called housekeeping sortase, in the cell wall anchoring of pili. We show that a multiple deletion mutant strain expressing only SrtA secretes a large portion of SpaA polymers into the culture medium, with concomitant decrease in the cell wall-linked pili. The same phenotype is observed with the mutant that is missing SrtF alone. By contrast, a strain that expresses only SrtF displays surface-linked pilins but no polymers. Therefore, SrtF can catalyse the cell wall anchoring of pilin monomers as well as pili, but it does not polymerize pilins. We show that SrtA and SrtF together generate wild-type levels of the SpaA-type pilus on the bacterial surface. Furthermore, by regulating the expression of SpaA in the cell, we demonstrate that the SrtF function becomes critical when the SpaA level is sufficiently high. Together, these findings provide key evidence for a two-stage model of pilus assembly: pilins are first polymerized by a pilus-specific sortase, and the resulting fibre is then attached to the cell wall by either the cognate sortase or the housekeeping sortase.
Material reflector for cellular/PCS array applications

A material reflector composed of a metallic ground plane, resistive sheets and, if necessary, elongated rails along the edges of the sheet reflector is presented. The optimized design achieves a front-to-back ratio greater than 30 dB with minimal change in pattern beamwidth. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1890–1894, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21793
Hydrodynamic Shear Regulates the Kinetics and Receptor Specificity of Polymorphonuclear Leukocyte-Colon Carcinoma Cell Adhesive Interactions

The ability of tumor cells to metastasize hematogenously is regulated by their interactions with polymorphonuclear leukocytes (PMNs). However, the mechanisms mediating PMN binding to tumor cells under physiological shear forces remain largely unknown. This study was designed to characterize the molecular interactions between PMNs and tumor cells as a function of the dynamic shear environment, using two human colon adenocarcinoma cell lines (LS174T and HCT-8) as models. PMN and colon carcinoma cell suspensions, labeled with distinct fluorophores, were sheared in a cone-and-plate rheometer in the presence of the PMN activator fMLP. The size distribution and cellular composition of formed aggregates were determined by flow cytometry. PMN binding to LS174T cells was maximal at 100 s(-1) and decreased with increasing shear. At low shear (100 s(-1)) PMN CD11b alone mediates PMN-LS174T heteroaggregation. However, L-selectin, CD11a, and CD11b are all required for PMN binding to sialyl Lewis(x)-bearing LS174T cells at high shear (800 s(-1)). In contrast, sialyl Lewis(x)-low HCT-8 cells fail to aggregate with PMNs at high shear conditions, despite extensive adhesive interactions at low shear. Taken together, our data suggest that PMN L-selectin initiates LS174T cell tethering at high shear by binding to sialylated moieties on the carcinoma cell surface, whereas the subsequent involvement of CD11a and CD11b converts these transient tethers into stable adhesion. This study demonstrates that the shear environment of the vasculature modulates the dynamics and molecular constituents mediating PMN-tumor cell adhesion.
Ongoing electrical activity of superior cervical ganglion cells in mammals of different size

The ongoing synaptic activity of superior cervical ganglion cells in adult mammals was examined in situ by intracellular recording in anesthetized mice, hamsters, rats, guinea pigs, and rabbits. The proportion of neurons exhibiting subthreshold and suprathreshold synaptic activity during a standard period of observation was least in a small mammal like the mouse (30%), intermediate among neurons of mammals of intermediate size such as the hamster and rat (48% and 45%, respectively), and greatest in the largest animals in the series, the guinea pig (89%) and rabbit (91%). Ganglion cells in all species fell silent after transection of the cervical trunk. The average frequency of synaptic activity among tonically active cells also increased with animal size, being least in the mouse (1.0/second) and greatest in the rabbit (6.4/second). This variation of ongoing synaptic activity in sympathetic ganglion cells may reflect the demands of progressively larger peripheral targets on relatively fixed populations of autonomic neurons.
Heterozygote advantage and the evolution of a dominant diploid phase

The life cycle of eukaryotic, sexual species is divided into haploid and diploid phases. In multicellular animals and seed plants, the diploid phase is dominant, and the haploid phase is reduced to one, or a very few cells, which are dependent on the diploid form. In other eukaryotic species, however, the haploid phase may dominate or the phases may be equally developed. Even though an alternation between haploid and diploid forms is fundamental to sexual reproduction in eukaryotes, relatively little is known about the evolutionary forces that influence the dominance of haploidy or diploidy. An obvious genetic factor that might result in selection for a dominant diploid phase is heterozygote advantage, since only the diploid phase can be heterozygous. In this paper, I analyze a model designed to determine whether heterozygote advantage could lead to the evolution of a dominant diploid phase. The main result is that heterozygote advantage can lead to an increase in the dominance of the diploid phase, but only if the diploid phase is already sufficiently dominant. Because the diploid phase is unlikely to be increased in organisms that are primarily haploid, I conclude that heterozygote advantage is not a sufficient explanation of the dominance of the diploid phase in higher plants and animals.
Adaptive modulation for multi-antenna transmissions with channel mean feedback

Adaptive modulation has the potential to increase the system throughput significantly by matching transmitter parameters to time-varying channel conditions. However, adaptive modulation assuming perfect channel state information (CSI) is sensitive to CSI imperfections induced by estimation errors and feedback delays. In this paper, we design adaptive modulation schemes for multi-antenna transmission based on partial CSI, that models the spatial fading channels as Gaussian random variables with non-zero mean and white covariance, conditioned on feedback information. Based on a two-directional beamformer, our proposed transmitter optimally adapts the beam directions, the power allocation between two beams, and the signal constellation, to maximize the transmission rate while maintaining a target bit error rate (BER). Numerical results demonstrate the rate improvement, and illustrate an interesting tradeoff that emerges between feedback quality and hardware complexity.
Diagnosis and Metamodeling of System Failures

In this chapter, we apply the metamodeling approach to the identification and diagnosis of system failures. The chapter is based on the author’s previous work.1,2 In the spirit of the present text, reducing the possibility of system failures requires effort at three system levels. Failures in systems are actual, concrete events which occur at the implementation level of systems. In all probability, some of the failures occurring at this level can be attributed to difficulties in properly carrying out operating procedures.
Real-Time Value Chain Management

Value creation in the digital economy of the 21 st century is characterized by the instantaneous processing and coordination of value chain activities across extended enterprises. Value chain management has evolved from automation and integration to the optimization of the entire value chain in real-time. Realtime value chain management enables organizations to be agile and responsive in a complex and rapidly changing global environment. This paper examines the real-time characteristics for each of the activities in the demand and supply value chains. A model is presented for real-time value chain management enabled by technologies in e-business, knowledge management and business intelligence.
TV Transmitting Antenna Selection

In the selection of a transmitting antenna, factors such as power gain, height above terrain, horizontal pattern directivity, amount of null fill, and beam tilt of the vertical pattern have to be taken into consideration to best satisfy the equipment availability and intended market coverage. A critical analysis of all these factors with possible tradeoffs is presented and the station coverage is computed based on the present available FCC (50, 50) curves and a computer program. A new variable, the maximum possible antenna gain to guarantee a minimum signal level over a certain area, is introduced. A set of curves relating the maximum possible antenna gain to distance, maximum radiated power, antenna height, and signal level is developed for the three TV bands.
Toxicity of coal-tar pavement sealants and ultraviolet radiation to Ambystoma Maculatum

Polycyclic aromatic hydrocarbons (PAHs) can affect amphibians in lethal and many sublethal ways. There are many natural and anthropogenic sources of PAHs in aquatic environments. One potentially significant source is run off from surfaces of parking lots and roads that are protected with coal tar sealants. Coal tar is 50% or more PAH by wet weight and is used in emulsions to treat these surfaces. Break down of sealants can result in contamination of nearby waters. The toxicity of PAHs can be greatly altered by simultaneous exposure to ultraviolet radiation. This study exposes larvae of the spotted salamander (Ambystoma maculatum) to determine if coal tar sealant can have negative effects on aquatic amphibians and if coal tar toxicity is influenced by ultraviolet radiation. Spotted salamanders were exposed to 0, 60, 280 and 1500 mg coal tar sealant/kg sediment for 28 days. Half of the animals were exposed to conventional fluorescent lighting only and half were exposed to fluorescent lighting plus ultraviolet radiation. No significant mortality occurred during the experiment. Exposure to sealants resulted in slower rates of growth, and diminished ability to swim in a dose-dependent fashion. Exposure to ultraviolet radiation affected the frequencies of leukocytes and increased the incidence of micronucleated erythrocytes. There was an interactive effect of sealant and radiation on swimming behavior. We conclude that coal-tar sealant and ultraviolet radiation increased sublethal effects in salamanders, and may be a risk to salamanders under field conditions.
Responding to Sex Offenders Empirical Findings, Judicial Decision Making, and Legal Moralism

The science examining institutional and community-based responses to sexual offending has been well documented. The responses to this form of criminal behavior include penal incarceration followed by civil commitment, community notification, and sex offender registration. To date, evidence-based findings report that these correctives and/or curatives yield limited effectiveness sufficient to justify their continued maintenance as statewide or even national criminal justice and mental health policy prescription. One official systems-level way that policy receives legitimacy is through the Courts. Interestingly, the precedent-setting sex offender case law indicates that current policy prescriptions are constitutionally permissible and therefore justifiable as regulatory practices, notwithstanding the empirical evidence that challenges their soundness. This article summarizes the science regarding sex offender policy from the point of imprisonment to reentry, recounts the relevant case law that judicially sanctions such institutional and community practices, and explains how the driver for sex offender law and policy is legal moralism grounded in and advanced by utilitarian reasoning and duty-based logic. This article concludes by suggesting how judicial reliance on legal moralism could further the interests of public safety and civil liberties if insights from virtue jurisprudence informed the analysis. Language: en
Shape from texture using the Wigner distribution

A method is presented for estimating the orientation of a textured surface as a descriptor of surface shape. It is based on the analysis of local spectrum information of the texture in an image. The local spectrum representation is computed by the two-dimensional Wigner distribution, which gives the spatial-frequency information as a function of location. The change in texture density, or the so-called texture gradient, caused by the perspective projection of a surface in the three dimensional world onto the two-dimensional image plane, is computed from this space-frequency representation by measuring the high-frequency energy distribution at each location of the image. The surface orientation is then estimated from the texture gradient. This method was implemented for the limited case of planar surfaces. Simulations were performed and results were analyzed to address issues related to the method's estimation accuracy, implementation, and limitations. >
Interactive Effects of Jasmonic Acid, Salicylic Acid, and Gibberellin on Induction of Trichomes in Arabidopsis

Leaf trichomes protect plants from attack by insect herbivores and are often induced following damage. Hormonal regulation of this plant induction response has not been previously studied. In a series of experiments, we addressed the effects of artificial damage, jasmonic acid, salicylic acid, and gibberellin on induction of trichomes in Arabidopsis. Artificial damage and jasmonic acid caused significant increases in trichome production of leaves. The jar1-1 mutant exhibited normal trichome induction following treatment with jasmonic acid, suggesting that adenylation of jasmonic acid is not necessary. Salicylic acid had a negative effect on trichome production and consistently reduced the effect of jasmonic acid, suggesting negative cross-talk between the jasmonate and salicylate-dependent defense pathways. Interestingly, the effect of salicylic acid persisted in the nim1-1 mutant, suggesting that the Npr1/Nim1 gene is not downstream of salicylic acid in the negative regulation of trichome production. Last, we found that gibberellin and jasmonic acid had a synergistic effect on the induction of trichomes, suggesting important interactions between these two compounds.
EFFECTS OF FRAGMENTATION AND INVASION ON NATIVE ANT COMMUNITIES IN COASTAL SOUTHERN CALIFORNIA

We investigated the roles of habitat fragmentation and the invasion of an exotic species on the structure of ground-foraging ant communities in 40 scrub habitat fragments in coastal southern California. In particular, we asked: how do fragment age, fragment size, amount of urban edge, percentage of native vegetation, degree of isolation, and the relative abundance of an exotic species, the Argentine ant (Linepithema humile) affect native ants? Within these fragments, Argentine ants were more abundant near developed edges and in areas dominated by exotic vegetation. The number of native ground-foraging ant species at any point declined from an average of >7 to <2 species in the presence of the Argentine ant. Among fragments, a stepwise multiple regression revealed that the abundance of Argentine ants, the size of the fragment, and the number of years since it was isolated from larger continuous areas of scrub habitat best predict the number of remaining native ant species. The Argentine ant was found in every fragment surveyed as well as around the edges of larger unfragmented areas. Fragments had fewer native ant species than similar-sized plots within large unfragmented areas, and fragments with Argentine ant-free refugia had more native ant species than those without refugia. The relative vulnerability of native ants to habitat fragmentation and the subsequent presence of Argentine ants vary among species. The most sensitive species include army ants (Neivamyrmex spp.) and harvester ants (genera Messor and Pogonomyrmex), both of which are important to ecosystem-level processes. Our surveys suggest that the Argentine ant is widespread in fragmented coastal scrub habitats in southern California and strongly affects native ant communities.
An online introductory computer programming course using Matlab: Design steps and what to expect

The usefulness of online and hybrid delivery methods in education has long been realized and with the advancement of computer and communication technologies and the Web based authoring tools, their effectiveness have been further extended. We are at a point that online and hybrid course offerings for undergraduates are quickly becoming an integrated and regular part of engineering departments' course offerings. Many institutions are offering online courses, as part of their regular schedule. In this paper, based on our experience that started with hybrid delivery and ultimately extended to a full online offering, we will present a set of recommended steps that can be used as a guide by those who are interested in designing an online introductory computer-programming course. We will then present a set of observations that we feel needs to be considered and discussed by the research community. The paper will include examples of students' comments, which were received in teaching evaluations, for hybrid and online offerings.
Comment on Robert C. Post's Community and the First Amendment

This article responds to Professor Robert C. Post’s article, Community and the First Amendment, 29 Ariz. St. L.J. 473 (1997). Both this paper and Professor Post’s article are part of a symposium which arose out of the Conference on Free Speech and Community sponsored by the Arizona Humanities Council and Arizona State University College of Law.Post's discussion of the relationship between community and the First Amendment uses the concepts “public discourse” and “civility rules.” Post defines “public discourse” as “the speech necessary for the formation of public opinion.” “Civility rules,” he says, are “community norms that involve speech” and that “receive legal enforcement.” Post's “most important ” conclusion is that “the First Amendment suspends the enforcement of civility rules within public discourse, but not elsewhere.” This article argues that there is no area of so-called “public discourse” in which some or all laws involving speech are completely suspended. There is absolutely no warrant for such an exclusion in either the text or the purpose of the First Amendment. “Public discourse” is a part of the realm of constitutionally protected expression. But public discourse, however defined, is not the entire realm of constitutionally protected free expression. The Constitution is best read as according protection to all expression, except where cognizable harm is culpably caused or threatened to the rights of others, and read, as well, as prohibiting speech to be labeled as “harmful” simply because it is wrongheaded, or because it stirs the intellect or the emotions of its recipients.
Positional Information and Cell Fate Determination in the Early Drosophila Embryo

During early development in Drosophila, the spatial information of maternal gradients is translated into discrete transcriptional states determining cell fate. Information transfer depends on reproducibility of the gradients themselves, as well as the ability of cells to accurately measure and utilize morphogen concentrations in biologically meaning ways. In the following essay, these issues are discussed in context of the Bicoid gradient.
Toward an Understanding of Energetic Healing, Part 1 Energetic Structures

The purpose of this article is to describe one understanding of structures involved in energetic healing, which is defined as healing occurring at the quantum and electromagnetic levels of a person, plant, or animal. Characteristics of electromagnets, direct electric currents, Fourier analyzers, and L-C circuits are discussed and applied to the human being. Human electromagnetic characteristics are compared to descriptions of auras, meridians, and chakras. Quantum and chaos theories are presented and applied to the question of the mechanism of energetic healing.
Experimental Studies of Optical Negative-Index Materials

Experimental techniques to verify the negative refractive index of an array of paired gold nanorods are discussed. The results agree with simulations which give a refractive index of -0.3 at the resonance wavelength around 1μm.
A Kinetic Model for Metalorganic Chemical Vapor Deposition of GaAs from Trimethylgallium and Arsine

A kinetic model for metalorganic chemical vapor deposition (MOCVD) of GaAs from trimethylgallium and arsine is presented. The proposed mechanism includes 15 gas-phase species, 17 gas-phase reactions, 9 surface species and 29 surface reactions. The surface reactions take into account different crystallographic orientations of the GaAs substrate. Sensitivity analysis and existing experimental observations have been used to develop the reduced mechanism from the large number of reactions that might in principle occur. Rate constants are estimated by using thermochemical methods and reported experimental data. The kinetic mechanism is combined with a two-dimensional transport model of a hot-wall tubular reactor used in experimental studies. Model predictions of gas-phase composition and GaAs growth rates show good agreement with published experimental studies. In addition, the model predicts reported trends in carbon incorporation.
Abstract 1059: Neuroendocrine-derived peptides stimulate IGF-1R signaling to promote prostate cancer cell survival

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC A common feature of the most aggressive hormone-refractory prostate cancers is the accumulation of cells with neuroendocrine characteristics that produce paracrine growth factors, and may provide a proliferative advantage to cancer cells during disease progression. We have previously shown that neuroendocrine-derived peptides transactivate EGFR and Src signaling to promote growth of prostate cancer cells under low concentrations of androgen. In this study we demonstrate that in addition to the transactivation of EGFR family of receptors, neuroendocrine-derived factors enhance IGF-1R signaling through the transcriptional regulation of downstream components of the pathway to promote cell survival. cDNA microarray analysis to compare the gene expression profile of LNCaP cells in the presence or absence of neuroendocrine-derived conditioned medium (NE-CM) revealed differential regulation of multiple IGF-1R pathway signaling components including the receptor protein tyrosine phosphatase (PTP-RF) and Akt. Quantitative RT-PCR confirmed the downregulation of PTP-RF upon treatment of LNCaP cells with NE-CM for 24 hours that was associated with a reduction in protein levels. IGF1-R and Akt phosphorylation levels were enhanced and sustained over the 24 hour period. Statistically significant changes in cell survival, cell death, and apoptosis were observed with various experimental approaches for both LNCaP and PC3 cells treated with NE-CM. In addition, NE-CM was able to protect the prostate cancer cells from docetaxel-induced apoptosis. The pro-survival effects of NE-CM were abrogated in part by specific antagonists of the neuropeptides neurotensin, bombesin, and PTHrP, as well as selective inhibitors of IGF-1R, EGFR and Src. These data support the hypothesis that neuroendocrine-like cells secrete factors that act upon PC cells to stimulate pro-survival signaling mediated in part by IGF-1R, EGFR, and c-Src. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1059.
Photo-initiated Thiol-ene Click Reactions as a Potential Strategy for Incorporation of [MI(CO)3]+ (M = Re, 99mTc) Complexes

Click reactions offer a rapid technique to covalently assemble two molecules. In radiopharmaceutical construction, these reactions can be utilized to combine a radioactive metal complex with a biological targeting molecule to yield a potent tool for imaging or therapy applications. The photo-initiated radical thiol-ene click reaction between a thiol and an alkene was examined for the incorporation of [MI(CO)3]+ (M = Re, 99mTc) systems for conjugating biologically active targeting molecules containing a thiol. In this strategy, a potent chelate system, 2,2′-dipicolylamine (DPA), for [MI(CO)3]+ was functionalized at the central amine with a terminal alkene linker that was explored with two synthetic approaches, click then chelate and chelate then click, to determine the flexibility and applicability of the thiol-ene click reaction to specifically incorporate ligand systems and metal complexes with a thiol containing molecule. In the click then chelate approach, the thiol-ene click reaction was carried out w...
Comparison of effects of uroguanylin, guanylin, and Escherichia coli heat-stable enterotoxin STa in mouse intestine and kidney: evidence that uroguanylin is an intestinal natriuretic hormone.

BACKGROUND: Uroguanylin and guanylin are intestinal peptides that activate a receptor-guanylate cyclase, which is also a receptor for Escherichia coli heat-stable enterotoxin (STa). These peptides may have a role in the body's regulation of fluid and electrolytes. METHODS: STa, bioactive guanylin, and bioactive uroguanylin were evaluated for effects in: 1) the suckling mouse intestinal fluid secretion assay; 2) an in vitro suckling mouse intestinal loop assay; 3) an intestinal receptor autoradiography assay; 4) a control or agonist-stimulated assay for cGMP response in T84 cells; and 5) an in vivo renal function assay in mice. RESULTS: In vivo, orally administered uroguanylin and STa but not guanylin, stimulated intestinal fluid secretion. All three peptides activated intestinal guanylate cyclase and had common intestinal receptors. In vitro, after pretreatment with chymotrypsin, only uroguanylin and STa retained agoinst activity. Chymostatin preserved guanylin activity. STa and uroguanylin induced diuresis, natriuresis, and kaliuresis. Guanylin was less potent than uroguanylin and STa. CONCLUSIONS: The results suggest that the endogenous intestinal peptides, uroguanylin and guanylin, regulate water and electrolyte homeostasis both through local effects on intestinal epithelia and endocrine effects on the kidney.
Modeling and simulation of 3-D virtual cell as a game

Virtual worlds, especially Second Life, play an increasingly important role in the development of innovative and effective teaching and learning strategies. In this paper we use Second Life as a modeling tool and platform to design, build and simulate a virtual 3- D cell, and laboratory setting. A cell is a highly complex factory that organizes thousands of different molecules to perform specialized functions. Advances in biological sciences have allowed biologists to catalog a wealth of data on the structure of cells and cellular components such as mitochondria, nucleus and so on. There are many animations and digital movies that show these structures and activities. However there is no 3- D virtual cell that would allow the user to enter the cell and observe the arrangements and organization of organelles, stop by any organelle, ask questions and interact with the organelle as one would do in a video game. This paper will also discuss how objects were created, textures were mapped and video streams were implemented to enhance the learning process.
Assessing Conceptions of the Youth User in UX Design

This proposal describes a preliminary outline of a current work-in-progress, exploring the concept of the youth user in the field of user experience design and the perception of the youth user and associated application of the concept among user experience design professionals. Of particular interest to this project is the area of social media design, for the purposes of discussing its potential use in establishing social support for youth technology users. Through a thorough analysis of an available body of literature in design studies and adjacent fields, conceptualizations of the user will be identified. Following this stage, willing staff members of 4 separate design and technology firms will be interviewed in a semi-structural fashion to assess the concept of the user in practice. This project has the potential to inform areas of design studies and human-computer interaction, especially regarding the increasing need to incorporate and serve diverse individuals and communities.
The mesozooplankton of the Patos Lagoon Estuary, Brazil: trends in community structure and secondary production

ABSTRACTThe zooplankton abundance and composition of the Patos Lagoon Estuary (PLE) reflects the local hydrological regime with alternating periods of flood, freshwater run-off and mixing of water. However, little is known about the interannual zooplankton variations and secondary productivity of this community. We sampled zooplankton monthly at two stations within the estuary from April 2009 to March 2013. The brackish/marine calanoid copepod Acartia tonsa was found to play an important role in the PLE, with secondary production values of 1.17 mg C m−3 day−1 being comparable with the high values achieved in other estuaries worldwide. During the study period, the greatest change in the community structure was observed in the spring-summer under El Nino influence when the prolonged terrestrial run-off combined with higher temperatures allowed the establishment of a freshwater community that was largely composed of the calanoid copepod Notodiaptomus incompositus, cyclopoids and cladocerans. The freshwater c...
Falsification of combined invariance and reachability specifications in hybrid control systems

We propose an abstraction-based method that can be applied to falsify a class of computation tree logic (CTL) specifications that combine invariance and reachability requirements in terms of the discrete state of a hybrid control system. The fragment of CTL that we address is not expressible in ACTLź (which includes LTL). The method involves applying supervisory control to a finite abstraction of the hybrid system to falsify the specification. For the class of systems that we consider, falsification of the specification implies a flaw in the design of the control and automation logic.
Stellate ganglion blockade and bilateral cardiac sympathetic denervation in patients with life-threatening ventricular arrhythmias

Autonomic modulation is being increasingly employed as a strategy to treat ventricular arrhythmias refractory to beta-blockers, antiarrhythmic drugs, and catheter-based ablation procedures. We report 6 patients with refractory ventricular tachycardia (VT) or ventricular fibrillation (VF) treated with stellate ganglion blockade (SGB) and/or bilateral cardiac sympathetic denervation (CSD). Our case series emphasizes the concept that the cardiac sympathetic nerves are important targets in the management of ventricular arrhythmias. SGB and CSD can be effective in suppressing VT/VF and can be offered to patients with refractory ventricular arrhythmias as an adjunct to conventional therapy.
Motor Vehicle Crash Risk Among Adolescents and Young Adults With Attention-Deficit/Hyperactivity Disorder.

Importance Attention-deficit/hyperactivity disorder (ADHD) often persists into adolescence, when motor vehicle crash risk peaks. We know little about when adolescents with ADHD get licensed and, once they do, the extent to which they have increased crash risk compared with adolescents without ADHD. Objectives To examine the association between ADHD and both driver licensing and crash involvement and whether it varies by sex, licensing age, and/or being prescribed ADHD medication at licensure. Design, Setting, and Participants This retrospective cohort study was conducted at 6 primary care practices of the Children’s Hospital of Philadelphia, a large pediatric health care network in southeastern Pennsylvania and southern New Jersey. Using electronic health records, we defined a cohort of 2479 adolescents and young adults with ADHD and 15 865 without ADHD who were (1) born from 1987 to 1997; (2) residents of New Jersey and patients at 1 of 6 New Jersey primary care practices at age 12 years or older; and (3) age-eligible to obtain a driver’s license from 2004 through 2014. Electronic health records data were then linked with New Jersey’s statewide driver licensing and crash databases for 2004 through 2014. Main Outcomes and Measures Acquisition of a driver’s license and first involvement as a driver in a police-reported crash. Survival analysis was used to estimate adjusted hazard ratios for licensing and crash outcomes through age 25 years. Results The median age of individuals at the end of the study was 22.2 years (interquartile range, 19.7-24.8). Compared with individuals without ADHD, the licensing probability of individuals with ADHD 6 months after eligibility was 35% lower (for males: adjusted hazard ratio, 0.65; 95% CI, 0.61-0.70; females: adjusted hazard ratio, 0.64; 95% CI, 0.58-0.70). Among individuals with a driver’s license, 764 of 1785 with ADHD (42.8%) and 4715 of 13 221 without ADHD (35.7%) crashed during the study period. The adjusted risk for first crash among licensed drivers with ADHD was 1.36 times higher than for those without ADHD (95% CI, 1.25-1.48) and did not vary by sex, licensing age, or over time. Only 129 individuals with ADHD (12.1%) were prescribed medication in the 30 days before licensure. Conclusions and Relevance Adolescents with ADHD get licensed less often and at an older age. Once licensed, this cohort has a greater risk of crashing. Additional research is needed to understand the specific mechanisms by which ADHD influences crash risk.
Fracture Table Application for Pediatric Femur Fractures: Incidence and Risk Factors Associated With Adverse Outcomes.

Background Flexible elastic nails, submuscular plating, and rigid locked intramedullary nails are common methods of fixation for pediatric femur fractures (PFF) in which the fracture table is used to aid reduction. Little is known about complications associated with fracture table application in PFF. The purpose of this study was to determine the incidence and risk factors associated with adverse outcomes related to fracture table application for the treatment of PFF. Methods A retrospective chart review of all children (younger than 18 y) treated for a femur fracture with the use of the fracture table between 2004 and 2015 at a single tertiary pediatric hospital was performed. Data on demographics, mechanism of injury, treatment modality, radiographic characteristics, and fracture table-related complications were gathered. Complications of interest included nerve palsy, skin breakdown/ulceration, vascular injury, and compartment syndrome. Penalized likelihood logistic regression was used to determine risk factors associated with adverse outcomes. Results In total, 260 patients were included. There were 8 patients with nerve palsies related to positioning and traction on the fracture table (1 bilateral and 6 ipsilateral peroneal nerve palsies, 1 contralateral tibial nerve palsy; incidence of 3.1%). No other fracture table-related complications were recorded. Patients who developed a nerve palsy were significantly heavier (78.7 vs. 44.3 kg, P Conclusions Nerve palsy related to the use of the fracture table during the fixation of PFF occurred in 3.1% of patients in our series. Patients who developed nerve palsies were significantly heavier and had significantly longer surgical times. Although the use of the fracture table for fixation of PFF is safe, every effort should be made to minimize time in traction to avoid iatrogenic nerve palsy, particularly in heavier children (>80 kg). Level of evidence Level III.
Post-prostatectomy radiation therapy for locally recurrent prostate cancer.

Introduction: Approximately 15–30% of men with localized prostate cancer will experience biochemical recurrence (BCR) after radical prostatectomy. Postoperative radiation therapy is used in men wit...
A New Outlook for Alzheimer’s Disease

Within decades, Alzheimer’s disease has transformed from a rare disorder to one of the most common and economically and socially important diseases of the aging population. Failure to find an effective treatment to alter the course of the disease has pressured researchers in the field to retreat towards basics in order to create a lifestyle that will become an answer to this disorder and lead to greater survival of the aged. Perhaps, like many other diseases of the era, we are looking at the outcomes of the modern lifestyle not only to decrease mortality but also to lead to unintended consequences on our health. Pollution, refined foods, and low levels of physical activity are all contributors to the observed shift in many diseases and increasing evidence links these same features to Alzheimer’s disease. Where once most illnesses were caused by pathogens and lack of sanitation, today’s diseases tend to center around the role certain lifestyle choices have on the function of cellular processes. Deviations from the original environment of man where our genes adapted to have altered the body’s ability to carry out standard metabolic procedure.
Internal Deformation and Thermal Anomalies in Lower Blue Glacier, Mount Olympus, Washington, U.S.A.*

In 1957 through 1962 six deep holes were drilled by means of specially developed electrically powered hotpoints, 4 cm diameter aluminum pipes were placed in them, and annual inclinometer surveys were made to investigate the deformation field and flow law of the ice at depth. Although a strongly maritime climate with moderate temperatures implies that lower Blue Glacier should be temperate, freezing at depths as great as 200 m, sometimes even in summer, seriously hindered inclinometer surveys. This freezing cannot be due solely to chilling by winter cold and to leakage into initially dry pipes, but may also be due to wintertime changes of water Table in the glacier and to contamination of the ice by antifreeze. Another possibility, residual subfreezing zones carried down from the ice fall, seems unlikely. Because the relatively inextensible pipe slips lengthwise in the deforming hole, observations of pipe motion at best give only the two components of ice velocity perpendicular to the hole. Thus, a single hole gives two independent equations connecting the nine unknown derivatives of the velocity components; two holes give four equations: and three or more give at most six. Incompressibility of the ice, when applicable gives another. The remaining unknowns must be either neglected or estimated from assumptions about the flow field. At the Blue Glacier holes the longitudinal strain-rate is less than about 0.01 per year, becoming more extensional down-glacier and more compressional at depth, because the holes were moving through a reach in which the surface steepens and the bed becomes more steep-sided and flat-bottomed. Although the effective strain-rates are only about 0.01 to 0.1 per year, so that errors are relatively large, they are in reasonable agreement with flow laws deduced from laboratory experiments by Glen, from tunnel contraction by Nye, and from deformation of Athabasca Glacier bore holes by Paterson and Savage, except that in the range of strain-rates covered the viscosities found for Blue Glacier are about half those derived from the other studies.
Electrophysiology and Bioinstrumentation

Fundamental to intraoperative monitoring are the principles of electrical recording and stimulation of neural tissue. The monitoring clinician in the surgical suite will record neural activity that is both spontaneous and evoked by electrical stimulation in order to monitor and map the nervous system and ensure intact neural pathways. A conceptual understanding of these processes is one of the main pillars upon which the field of intraoperative monitoring is based. In the early history of intraoperative monitoring, neurophysiologists conceived of and built their own systems for electrically interfacing with the patient’s nervous system. Today, the equipment is purchased from companies that manufacture advanced monitoring devices. These devices automate many of the calculations that had to be performed manually in the past. Nevertheless, the monitoring clinician in the surgical suite must have a working understanding of bioinstrumentation and electrical stimulation and recording techniques in order to ensure valid testing of neural function.
Hymenoxys ambigens var. wagneri (Asteraceae: Helenieae: Tetraneurinae), a New Variety in Hymenoxys Subgenus Plummera from Arizona

Hymenoxys ambigens var. wagneri is a new variety endemic to the Dragoon Mountains of Cochise County, Arizona.
Valuing attributes of forest restoration in a semi-arid watershed

Abstract Approximately 1.5 M residents of the Phoenix metropolitan area rely upon the Salt Verde River watershed in central Arizona, USA, to meet their water demands. However, the health of the semi-arid watershed is at risk. Densely populated forests increase the probability of catastrophic wildfire and threaten the watershed’s integrity. Restoration reduces the risk of catastrophic wildfire and improves the health and productivity of the watershed. While current research indicates public support of watershed restoration, little guidance exists for land managers regarding the relative benefits of restoration projects. We estimate benefits of watershed restoration projects in the Salt-Verde River watershed using a choice experiment. The survey focuses on residents of the Phoenix metropolitan area as beneficiaries of watershed restoration and includes public access, surface water quality, groundwater recharge, critical habitat, and cultural significance as attributes. Willingness to pay estimates are obtained using a Bayesian mixed logit model. Respondents have a positive and statistically significant willingness to pay for all attributes. The highest willingness to pay is a one-time fee of $41.92 for restoration projects that protect critical habitats for endangered and threatened species. Our results also provide one of the first estimates for groundwater recharge as an attribute of watershed restoration. The benefit estimates obtained can directly inform land managers regarding restoration in semi-arid landscapes and assist in clearly delineating difficult to quantify environmental benefits in cost-benefit analyses of proposed future projects.