cssi/SciSciGPT-SciSciNet huggingface dataset:
Asymmetric Regulation of Bipolar Single-stranded DNA Translocation by the Two Motors within Escherichia coli RecBCD Helicase

Repair of double-stranded DNA breaks in Escherichia coli is initiated by the RecBCD helicase that possesses two superfamily-1 motors, RecB (3' to 5' translocase) and RecD (5' to 3' translocase), that operate on the complementary DNA strands to unwind duplex DNA. However, it is not known whether the RecB and RecD motors act independently or are functionally coupled. Here we show by directly monitoring ATP-driven single-stranded DNA translocation of RecBCD that the 5' to 3' rate is always faster than the 3' to 5' rate on DNA without a crossover hotspot instigator site and that the translocation rates are coupled asymmetrically. That is, RecB regulates both 3' to 5' and 5' to 3' translocation, whereas RecD only regulates 5' to 3' translocation. We show that the recently identified RecBC secondary translocase activity functions within RecBCD and that this contributes to the coupling. This coupling has implications for how RecBCD activity is regulated after it recognizes a crossover hotspot instigator sequence during DNA unwinding.
Correlation of ash-flow tuffs.

Discrimination and correlation of ash-flow sheets is important in structurally complex, long-lived volcanic fields where such sheets provide the best keys to the regional stratigraphic framework. Three-dimensional complexities resulting from pulsatory eruptions, sectorial emplacement, mechanical sorting during outflow, thermal and compositional zoning of magmas, the physical zoning of cooling units, and structural and erosional disruption can make such correlation and discrimination difficult. When lithologic, magnetic, petrographic, chemical, and isotopic criteria for correlating ash-flow sheets are critically evaluated, many problems and pitfalls can be identified. Distinctive phenocrysts, pumice clasts, and lithic fragments are among the more reliable criteria, as are high-precision K-Ar ages and thermal remanent magnetization (TRM) directions in unaltered welded tuff. Chemical correlation methods should rely principally upon welded or nonwelded pumice blocks, not upon the ash-flow matrix, which is subject to fractionation, mixing, and contamination during emplacement. Compositional zoning of most large sheets requires that many samples be analyzed before phenocryst, glass, or whole-rock chemical trends can be used confidently as correlation criteria.
Propranolol and its potential inhibition of positive post-traumatic growth.

Henry et al. (2007), in their discussion of the pharmacological manipulation of memory, present a sensible rejoinder to the frequent fanciful hypotheticals of the President's Council on Bioethics (...
Molecular mechanisms of multiple toxin–antitoxin systems are coordinated to govern the persister phenotype

Toxin–antitoxin systems are ubiquitous and have been implicated in persistence, the multidrug tolerance of bacteria, biofilms, and, by extension, most chronic infections. However, their purpose, apparent redundancy, and coordination remain topics of debate. Our model relates molecular mechanisms to population dynamics for a large class of toxin–antitoxin systems and suggests answers to several of the open questions. The generic architecture of toxin–antitoxin systems provides the potential for bistability, and even when the systems do not exhibit bistability alone, they can be coupled to create a strongly bistable, hysteretic switch between normal and toxic states. Stochastic fluctuations can spontaneously switch the system to the toxic state, creating a heterogeneous population of growing and nongrowing cells, or persisters, that exist under normal conditions, rather than as an induced response. Multiple toxin–antitoxin systems can be cooperatively marshaled for greater effect, with the dilution determined by growth rate serving as the coordinating signal. The model predicts and elucidates experimental results that show a characteristic correlation between persister frequency and the number of toxin–antitoxin systems.
Comparison of Algorithms for Haptic Interaction With Isosurfaces Extracted From Volumetric Datasets.

Volumetric datasets have become essential in virtual reality and haptics simulation for medical and surgical training. Technologies such as computed tomography (CT) and magnetic resonance imaging provide 3D scans of patient anatomy, from which 3D models can be generated to represent highly detailed and complex anatomical structures such as bone, organs, or muscle. Traditionally, 3D models have been represented as polygonal meshes, i.e., surfaces in 3D space consisting of multiple triangles. From the volumetric data, polygonal meshes are constructed using an isosurface extraction algorithm such as Marching Cubes [1]. Furthermore, mesh processing may be required in order to reduce the number of triangles in each model (decimation) and to obtain smooth surfaces. All these preprocessing stages often demand a fair amount of time to generate high quality models. Although methods to automate the segmentation and isosurface creation processes have been discussed in the literature [2], they still require considerable human intervention. Alternatively, anatomical 3D models can be displayed using direct volume rendering, which requires less human participation and minimum data preprocessing, generally at the expense of lower graphics frame rates. Combinations of scene graph managers [3,4] and haptics libraries [5] have been used in surgical simulations for graphics and haptics rendering of 3D models [6,7]. The goals of these simulations are simultaneous visualization of complex 3D models and tactile interaction with anatomy at interactive frame rates. While frame rates in the order of 30–60 Hz are acceptable for graphics rendering, the minimum required rate of 1 kHz for haptics rendering makes it a nontrivial problem when dealing with complex and highly detailed polygonal models. On the other hand, volume-based haptics techniques have proven themselves capable of generating force feedback from complex anatomies at interactive frame rates [8,9]. This paper presents a comparison of haptics rendering algorithms combined with polygonal graphics rendering within the framework of medical simulation. This evaluation seeks to assess the quality of the haptic feedback provided as well as identifying the best algorithm in terms of rendering time.
Observed variations of tropical convective available potential energy

[1] Data from selected tropical radiosonde stations (located between 25°S and 25°N) are used to compute multidecadal trends in convective available potential energy (CAPE). Positive trends slightly outnumber negative trends, with the greatest concentration of positive trends occurring in the western Pacific Ocean and the Caribbean Sea. Analysis shows that positive and negative CAPE trends are primarily driven by same-signed trends in low-level moisture, while lapse rate trends play a secondary role and may either increase or decrease the magnitude of the CAPE trends. Monthly CAPE anomalies are generally positively correlated with sounding-derived precipitable water (PW) and lapse rate as well as with Special Sensor Microwave Imager (SSMI)-derived PW for retrievals located over the sounding location. Sounding-derived PW estimates for island and coastal locations were averaged and compared to tropical SSMI PW estimates, which are available only over the oceans. The two time series are poorly correlated, suggesting that the limited number of sounding stations considered herein does not adequately capture tropical-wide variability. The relationship of CAPE changes to PW and lapse rate changes is examined on a variety of timescales for evidence of quasi-equilibrium (QE) behavior, in which convection acts to maintain an approximately moist adiabatic temperature profile. Strict QE, in which convection maintains an exactly moist adiabatic temperature profile, is assumed in the convective parameterizations of many general circulation models. PW and lapse rate anomalies are negatively correlated on multidecadal timescales and on monthly timescales in heavily raining regions, in support of QE theory. However, no such negative correlation is seen over the course of the seasonal cycle or for monthly timescales in low-rain areas. CAPE anomalies were compared to nearest-grid-point monthly precipitation anomalies derived from surface-based rain gauges. Correlations are small and centered at about zero. Mean tropical rainfall estimates, based on a combination of satellite and surface gauge data, are uncorrelated with the mean tropical SSMI PW estimates.
MSH activity in pituitaries of rats treated with hypothalamic extracts from various animals.

Abstract Hypothalamic extracts from frog, rabbit, kitten, sheep, pig, and man were found to increase the melanocyte-stimulating hormone (MSH) content of rat pituitary glands. Frog hypothalamic extracts also lightened frogs previously darkened by removal of the hypothalamic region. The results indicate the presence of MSH-release inhibiting factor (MIF) in the hypothalami of frogs and several mammals.
Molecular computational investigation of electron-transfer kinetics across cytochrome - Iron oxide interfaces

The interface between electron-transfer proteins such as cytochromes and solid-phase mineral oxides is central to the activity of dissimilatory-metal reducing bacteria. A combination of potential-based molecular dynamics simulations and ab initio electronic structure calculations are used in the framework of Marcus's electron-transfer theory to compute elementary electron-transfer rates from a well-defined cytochrome model, namely, the small tetraheme cytochrome (STC) from Shewanella oneidensis, to surfaces of the iron oxide mineral hematite (α-Fe2O3). Room-temperature molecular dynamics simulations show that an isolated STC molecule favors surface attachment via direct contact of hemes I and IV at the poles of the elongated axis, with electron-transfer distances as small as 9 A. The cytochrome remains attached to the mineral surface in the presence of water and shows limited surface diffusion at the interface. Ab initio electronic coupling matrix element (VAB) calculations of configurations excised from ...
Imaging neutral particle detector

Abstract With the support of NASA's Innovative Research Program (IRP), we undertook the definition and initial development of an imaging neutral particle detector, a new instrument for global imaging of planetary magnetospheres. This instrument carries out remote sensing of magnetospheric plasmas by imaging and analyzing charge exchange neutrals, which are energetic neutral atoms (ENAs) created by charge exchange reactions between ambient neutrals and energetic ions. The imaging neutral particle detector can determine the composition of the charge exchange neutrals and therefore also the composition of the original hot plasma. Such an instrument, the Ion‐Neutral Camera of the Magnetospheric Imaging Instrument (MIMI), has been selected for flight on the NASA/ESA Cassini mission to Saturn and Titan, and a similar instrument is part of the baseline payload for the proposed Inner Magnetosphere Imager (IMI) mission to carry out remote sensing of Earth's magnetosphere. Remote sensing of charge exchange neutrals...
Decentralization or privatization of environmental governance? Forest conflict and bioregional assessment in Australia

Abstract This paper is concerned with the democratic governance of public environmental resources. The paper examines the use of bioregional assessment in Australia as a means of resolving long-term, multilateral, and acrimonious conflict over native forest use and management. Reflecting on recent theorizing in environmental management that has pivoted on concepts of democracy, including representations of the public interest and mechanisms to promote public deliberation, the paper identifies the anti-democratic implications of decentralized environmental governance. In particular, the paper demonstrates how uncritical engagement of civic actors can lead to development of privatized, corporatist style agreements that fail to reflect diverse values and interests. It concludes by arguing that calls for decentralization and devolution of many areas of state responsibility fail to acknowledge the potential for powerful actors in a diverse civil society to subvert, rather than promote, democratic processes and outcomes.
Structural changes accompanying human serum albumin's binding of fatty acids are concerted

Long chain fatty acids (LCFAs), a major source of cellular energy, are solubilized and transported in the blood by binding to serum albumin. Changes in human serum albumin's (HSA's) UV absorption and characteristic reactivity with pyridoxal-5'-phosphate appear to reflect a concerted change in its structure upon binding five equivalents of myristate. Isothermal titrations with myristate and other LCFA anions are also consistent with the presence of five strong, interacting, binding sites. Although HSA is usually thought to have many independent LCFA anion binding sites, just five interacting sites appear to account for the changes in structure that accompany its binding of myristate.
Exchange Rates and the Effectiveness of Actual and Oral Official Interventions: A Survey on Findings, Issues and Policy Implications

Monetary authorities of many open economies have been regularly intervening in foreign exchange markets for years to limit volatility in exchange rates and/or push exchange rates back to some desir...
Perturbation of periodic boundary conditions. II. Bifurcation and symmetry

Abstract We continue our study (SIAM J. Math. Anal., 15, No. 4 (1984)) of perturbations of the problem (∗) − x ″ + bx = λax, x(0) − x(1) = 0, x′(0) − x′(1) = 0 both by changes of boundary conditions and by addition of nonlinear terms. We assume that for λ = λ0 there are two linearly independent solutions of (∗). The method of Liapunov and Schmidt is used to analyze the full nonlinear problem. For three examples we do the thorough local bifurcation analysis of determining the bifurcation set and bifurcation diagrams. These examples are endowed with varying amounts of the symmetry of (∗), and we see that the examples are amenable to varying methods: (1) When the perturbed problem loses all symmetry, one can use the generic methods of Chow, Hale, and Mallet-Paret, (2) when the perturbed problem retains some of the symmetry and is not too degenerate, one can use results of Shearer and basic group-theoretical techniques, (3) when the perturbed problem retains much symmetry but is degenerate, one can use some of the same methods as for (2), Vanderbauwhede's generalization of the simple eigenvalue idea, and some ad hoc methods.
The dopamine β-hydroxylase inhibitor, nepicastat, suppresses chocolate self-administration and reinstatement of chocolate seeking in rats

Craving for chocolate is a common phenomenon, which may evolve to an addictive-like behaviour and contribute to obesity. Nepicastat is a selective dopamine β-hydroxylase (DBH) inhibitor that suppresses cocaine-primed reinstatement of cocaine seeking in rats. We verified whether nepicastat was able to modify the reinforcing and motivational properties of a chocolate solution and to prevent the reinstatement of chocolate seeking in rats. Nepicastat (25, 50 and 100 mg/kg, intraperitoneal) produced a dose-related inhibition of operant self-administration of the chocolate solution in rats under fixed-ratio 10 (FR10) and progressive-ratio schedules of reinforcement, measures of the reinforcing and motivational properties of the chocolate solution, respectively. The effect of nepicastat on the reinstatement of chocolate seeking was studied in rats in which lever-responding had been extinguished by removing the chocolate solution for approximately 8 d. Nepicastat dose-dependently suppressed the reinstatement of lever-responding triggered by a 'priming' of the chocolate solution together with cues previously associated with the availability of the reward. In a separate group of food-restricted rats trained to lever-respond for regular food pellets, nepicastat reduced FR10 lever-responding with the same potency as for the chocolate solution. Spontaneous locomotor activity was not modified by nepicastat doses that reduced self-administration of the chocolate solution and regular food pellets and suppressed the reinstatement of chocolate seeking. The results indicate that nepicastat reduces motivation to food consumption sustained by appetite or palatability. Moreover, the results suggest that DBH inhibitors may be a new class of pharmacological agents potentially useful in the prevention of relapse to food seeking in human dieters.
A young pregnant woman with shortness of breath.

She is 12 weeks pregnant, has had no prenatal care, and has lost 20 pounds due to nausea and vomiting. What could be the cause?
Bidirectional Electron Transfer in Photosystem I: Direct Evidence from High-Frequency Time-Resolved EPR Spectroscopy

Efficient charge separation occurring within membrane-bound reaction center proteins is the most important step of photosynthetic solar energy conversion. All reaction centers are classified into two types, I and II. X-ray crystal structures reveal that both types bind two symmetric membrane-spanning branches of potential electron-transfer cofactors. Determination of the functional roles of these pairs of branches is of fundamental importance. While it is established that in type II reaction centers only one branch functions in electron transfer, we present the first direct spectroscopic evidence that both cofactor branches are active in the type I reaction center, photosystem I.
Respiratory effects on cardiac related impedance indices measured under voluntary cardio-respiratory synchronisation (VCRS).

The respiratory effects on impedance-determined cardiac indices ((dZ/dt)min, stroke volume (SV), the Heather index (HI) and the O-wave) were measured at 100 kHz on ten normal males in the supine and sitting positions. The respiration was synchronised to 1/5th of the heart rate using voluntary cardiorespiratory synchronisation (VCRS). Digital filtering was used to eliminate breathing artefacts in the impedance signals, SV, (dZ/dt)min and HI were statistically higher during inspiration than expiration. Ensemble-averaging of (dZ/dt) signals using the R spike of the ECG as reference will lose beat-to-beat information and statistically reduce (dZ/dt)min because of the variation of RZ intervals during respiration Zo increased with inspiration and decreased in expiration delayed by one heart beat. The ratio of the O-wave height to (dZ/dt)min changed by 48 per cent from the beginning of inspiration to the end of expiration. Based on the timing and direction of the changes, the data imply that the traditional band impedance measurement is more closely related to the right heart event than to that of the left heart.
Depressive Symptoms in Third‐Grade Teachers: Relations to Classroom Quality and Student Achievement

This study investigated associations among third-grade teachers' (N = 27) symptoms of depression, quality of the classroom-learning environment (CLE), and students' (N = 523, Mage = 8.6 years) math and literacy performance. teachers' depressive symptoms in the winter negatively predicted students' spring mathematics achievement. This depended on students' fall mathematics scores; students who began the year with weaker math skills and were in classrooms where teachers reported more depressive symptoms achieved smaller gains than did peers whose teachers reported fewer symptoms. teachers' depressive symptoms were negatively associated with quality of CLE, and quality of CLE mediated the association between depressive symptoms and student achievement. The findings point to the importance of teachers' mental health, with implications for policy and practice.
Some Evidence on English and American Wage Rates, 1790–1830

It is a widely held belief that significant wage rate differentials existed between Britain and the United States during the period 1790–1830. Indeed, the existence of such differentials is a pivotal factor in at least one theory of the nature and rate of growth of American and British technology and in the explanation of relative factor combinations in the two countries during the nineteenth century.
The Theory of Culture-Specific Total Quality Management: Quality Management in Chinese Regions

The article reviews the book “The Theory of Culture-Specific Total Quality Management: Quality Management in Chinese Regions,” by Carlos Noronha.
Management of ventral incisional hernias in large horses: a surgical challenge

The report by Elce et al. (2005) in this issue describes some critical but previously undescribed problems with mesh hernioplasty in horses, which makes it a valuable contribution to the veterinary literature. Incisional complications can develop in 40% of horses that have had intestinal surgery through a ventral median incision (Wilson et al. 1995), with incisional drainage in 32–36% of horses, dehiscence in 3–5% and hernia formation in 6–17% (Gibson et al. 1989; Kobluk et al. 1989; Wilson et al. 1995). Odds of incisional hernia are 62.5 times greater for horses that had incisional drainage, and incisional drainage and herniation can have a negative association with survival (Ingle-Fehr et al. 1997). As discussed by Elce et al. (2005), an important factor associated with incisional complications is the size of the horse (Wilson et al. 1995). Hernias of ventral midline incisions typically appear months after the initial surgery as a well defined abdominal wall protrusion (Fig 1) or, more commonly, as scattered areas of attenuation along the healed body wall. The latter can be more evident on palpation than on visual inspection, do not require repair and can withstand full athletic activity and foaling. If hernia repair is indicated, it should be postponed for approximately 3–4 months after the initial surgery to allow inflammation and infection to fully resolve and the hernial ring to become firm and well organised. Timing of hernia formation in a broodmare might not allow for repair before foaling, but mares can foal uneventfully with very large hernias. However, the concern exists for conversion of a large hernia to a more complete rupture of the abdominal wall, and assisted delivery is encouraged to reduce this risk. Despite the obvious cosmetic defect, a horse can perform successfully in athletic activities, such as high-level dressage, with a large incisional hernia. Despite attempts to follow recommended guidelines for patient selection, surgical timing, technique and aftercare, the high complication and fatality rates described by Elce et al. (2005) after this procedure draw particular attention to the following observations:
Defining and Managing Imatinib Resistance

While imatinib is highly effective therapy, with improving prospects over time for sustained remission and potential to severely limit or eliminate disease progression and transformation, a minority of patients either fail or respond suboptimally to imatinib; as well, disease eradication may not be possible with imatinib. Distinct patterns of resistance have evolved with the use of imatinib, and Abl kinase mutations, which alter imatinib binding or favor kinase conformations inaccessible to imatinib, are a common finding associated with clinical resistance. Dasatinib and nilotinib, alternate Abl kinase inhibitors, restore hematologic and cytogenetic remission in the majority of patients with primary failure or acquired resistance in chronic phase disease; in advanced disease and Philadelphia chromosome (Ph)(+) ALL, responses are more limited and relapse is common. Future studies with these agents will focus on further optimizing imatinib response, reduction of minimal residual disease, and prevention of resistance. Still newer inhibitors active against T315I mutant BCR-ABL may overcome primary and secondary resistance to dasatinib and nilotinib.
Gastric adenomas in familial adenomatous polyposis are common, but subtle, and have a benign course

Patients with familial adenomatous polyposis (FAP) are known to have an increased risk for gastric adenomas. The clinical features of gastric adenomas in FAP have not been well characterized, and there is a lack of standardized approaches to the management of these lesions. To study the endoscopic appearance, risk factors, clinical course, and response to therapy of gastric adenomas in patients with FAP. We retrospectively reviewed the records of 97 patients with FAP who underwent esophagogastroduodenoscopy (EGD) at Mayo Clinic (Florida, Rochester and Arizona) between 2004 and 2013. Nine patients (9%) had biopsy-proven gastric adenomas. Adenomas were located in the antrum (five patients), in the body and fundus in the setting of background fundic gland polyps (FGP) (three patients), and in the body not associated with FGP (one patient). Adenoma size was 3–40 mm and the number of adenomas per patient ranged from one to 20. Adenomas in the antrum were flat and subtle, whereas those in the gastric body or fundus were polypoid and difficult to differentiate from the cystic FGPs seen in patients with FAP. The performing endoscopists reported difficulty with identifying adenomas, and six patients had at least one EGD within the previous three years where gastric adenomas were not reported. Adenomas were classified as tubular in eight patients and tubulovillous in one patient. High grade dysplasia was noted in one patient. After a median follow-up of 63 months (interquartile range: 20–149 months), no patient in our entire cohort (with or without gastric adenomas) developed gastric cancer. The patients in whom gastric adenoma developed, compared to those without gastric adenoma, were more likely to be younger [36 ± 12 vs. 48 ± 15 years, p = 0.02], have concomitant chronic gastritis [22% vs. 0%, p = 0.008], and have desmoid tumors [5 (56%) vs. 19 (22%), p = 0.04]. Gastric adenomas are not uncommon in patients with FAP and are often difficult to identify endoscopically. Endoscopists should have a high degree of suspicion for gastric adenomas in these patients and a low threshold to biopsy. Given the benign clinical course, recommended initial management is conservative with endoscopic therapy and periodic surveillance.
Doing “Tuesday Lunch” at Lyndon Johnson's White House: New Archival Evidence on Vietnam Decisionmaking

Over the past decade, a number of political scientists have employed presidential papers and other archival materials in order to test various hypotheses regarding American politics. This has been particularly true concerning the Vietnam War and the American presidency (Kahin 1986; Burke and Greenstein 1989; Berman 1982, 1989; Kolko 1985; Hatcher 1990), as scholars have explored the interconnections between ideology, political style, presidential character, and other variables which may explain America's participation in that war. Thus, while some in the profession may have disdained the use of traditional historical research and methodology, there clearly has been a modest resurgence of archival research for the purposes of theory building. While I am among those who see real possibilities for illuminating political processes by drawing on archival sources, their usefulness should not be overstated: even rich archival collections-may not “solve” debates over causation of political phenomena.
How do entrepreneurs hone their pitches?: analyzing how pitch presentations develop in a technology commercialization competition

Technology innovators must pitch their technology and its business value to potential buyers, partners, and distributors: to make claims that will create interest in the appropriate audiences and offer evidence that those audiences recognize as credible and applicable. Such pitches typically involve a spoken presentation and a slide deck, both of which must persuade stakeholders. The pitch represents a rhetorically complex argument backed by many interconnected genres.We examine how innovators in an entrepreneurship development program, structured as a competition, developed pitches in response to feedback. We examine pitch changes in terms of overall structure, individual claims and evidence, and engagement tactics. Our findings suggest that presenters found this task of adjusting their pitches to be difficult, partly because the training program's current feedback does not separate out these different aspects. We recommend developing a heuristic to better structure arguments.
Particle Rotation in Early Sintering

Shrinkage and rearrangement during the early stages of sintering are considered. In such rearrangement the sintering particles can experience both additional center-to-center stresses and bending moments arising from multiparticle interactions and asymmetrical neck formation. The response of a particle pair to the simultaneous action of these stresses is solved analytically in a cylindrical geometry.
Experimental Verification of Wilson's Derivation of the Principle of the Ventricular Gradient

The concept of the ventricular gradient is based upon the theoretical representation of the electrogram of a myocardial fiber as the sum of two monophasic action potential (M.A.P.) curves, each of which represents the electrical activity of one-half of the fiber. Wilson showed that from this premise certain mathematical deductions are possible: (1) that the area of the electrogram is equal to the sum of the areas of the two MAP. curves; (2) that this area is independent of the rela tion of the two M.A.P. curves with respect to time and, therefore, that it is independent of the path of excitation; and (3) that as a corol lary of the latter, the measurement of the area of the electrogram may be used as a measure of the net electrical effect of local differences in repolarization. The present paper reports the results of experiments in which the electrical effects of a segment of a strip of turtle heart muscle were recorded as biphasic complexes and as two M.A.P. curves. Accurate measurement of the areas by means of an electronic integrator supports Wilson's premise. These observations furnish experimental confirmation of the theo retical basis of the concept of the ventricular gradient.
Rechnen mit Potenzreihen

Auf wieviel Arten last sich ein Franken in Kleingeld umwechseln? Als Kleingeld kommen (in der Schweiz) in Betracht: 1-, 2-, 5-, 10-, 20- und 50-Rappenstucke (1 Franken = 100 Rappen).
Slowing the translocation of double-stranded DNA using a nanopore smaller than the double helix

It is now possible to slow and trap a single molecule of double-stranded DNA (dsDNA), by stretching it using a nanopore, smaller in diameter than the double helix, in a solid-state membrane. By applying an electric force larger than the threshold for stretching, dsDNA can be impelled through the pore. Once a current blockade associated with a translocating molecule is detected, the electric field in the pore is switched in an interval less than the translocation time to a value below the threshold for stretching. According to molecular dynamics (MD) simulations, this leaves the dsDNA stretched in the pore constriction with the base-pairs tilted, while the B-form canonical structure is preserved outside the pore. In this configuration, the translocation velocity is substantially reduced from 1 bp/10 ns to approximately 1 bp/2 ms in the extreme, potentially facilitating high fidelity reads for sequencing, precise sorting, and high resolution (force) spectroscopy.
Harmonic diffractive lenses

The harmonic diffractive lens is a diffractive imaging lens for which the optical path-length transition between adjacent facets is an integer multiple m of the design wavelength λ(o). The total lens thickness in air is mλ(o)/(n - 1), which is m times thicker than the so-called modulo 2π diffractive lens. Lenses constructed in this way have hybrid properties of both refractive and diffractive lenses. Such a lens will have a diffraction-limited, common focus for a number of discrete wavelengths across the visible spectrum. A 34.75-diopter, 6-mm-diameter lens is diamond turned in aluminum and replicated in optical materials. The sag of the lens is 23 µm. Modulation transfer function measurements in both monochromatic and white light verify the performance of the lens. The lens approaches the diffraction limit for 10 discrete wavelengths across the visible spectrum.
Natural language processing: an introduction.

Objectives To provide an overview and tutorial of natural language processing (NLP) and modern NLP-system design. Target audience This tutorial targets the medical informatics generalist who has limited acquaintance with the principles behind NLP and/or limited knowledge of the current state of the art. Scope We describe the historical evolution of NLP, and summarize common NLP sub-problems in this extensive field. We then provide a synopsis of selected highlights of medical NLP efforts. After providing a brief description of common machine-learning approaches that are being used for diverse NLP sub-problems, we discuss how modern NLP architectures are designed, with a summary of the Apache Foundation’s Unstructured Information Management Architecture. We finally consider possible future directions for NLP, and reflect on the possible impact of IBM Watson on the medical field.
Queueing Analysis in TK Solver (QTK)

The inherent heavy use of computer-based numerical methods in stochastic modeling has given rise to the natural application of mathematical computer packages to queueing analyses. We present a summary of how our queueing package, QTK, was built up from the well-established TK Solver tool kit of mathematical problemsolving routines. The rule-based, interactive TK software is especially well suited for easy access from the desktop, and, with the queueing modules added, it now permits queueing analyses that include complex “what if?” exercises; comprehensive, stochastic sensitivity analyses; the natural adaptation of standard modules to problems very different than those in the package; and the establishment of cost models and their optimization.
Duke Power Company: Equity-for-Debt Swap (Abridged)

This case regards the analysis of debt/equity swaps. The case presents the swap from a managerial perspective and invites the analysis of the swap in light of Duke's financial strategy. It also presents information from the investment banker's perspective and details the mechanics. See the A, B, and C cases (F-0561, F-0562, and F-0563).
On the mechanism of reactions of oncogenic n-acyloxypurines—III

Abstract UV irradiation of a model “activated ester” of the oncogen 3-hydroxyxanthine induced homolytic cleavage of the N-O bond and gave products arising by reduction of as well as by recombination of the solvent caged amidyl radical intermediate. Identification of the latter product constitutes the first evidence that a distinct product associated specifically with a radical from an acyloxypurine can be formed. The absence of this product among those formed spontaneously from 3-acetoxyxanthine provides the first indication that an amidyl radical is not an intermediate in the spontaneous reactions of N-acyloxy purines.
Abstract 2496: Inhibition of IL-6 signaling induces radiosensitivity in head and neck squamous cell carcinoma (HNSCC)

Squamous cell carcinoma of the head and neck (HNSCC) is the sixth most common cancer worldwide. One of the primary modalities used to treat HNSCC is external radiotherapy, however many tumors are resistant to this treatment. Several studies have noted increased expression of IL-6 and IL-6 receptor in a variety of tumors. Furthermore, inhibition of IL-6 using a monoclonal antibody, tocilizumab, as a monotherapy has been shown to decrease tumor growth of HNSCC in pre-clinical models. However the effect of IL-6 signaling on radiosensitivity has not been well characterized. In this study we have found that baseline radioresistance, determined using a standard clonogenic assay, was significantly higher in HNSCC cell lines expressing high levels of IL-6 receptor (IL-6R) compared to those expressing low levels or IL6R as measured by RT-PCR (Surviving fraction at 2Gy (SF2) 65%% vs. 45%, p=0.028). In HN 31 and PCI 15B cell lines, which express high levels of IL-6 receptor, the addition of tocilizumab potentiated radiosensitivity, with a decrease in SF2 of 15% (p Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2496. doi:10.1158/1538-7445.AM2011-2496
On countability of point-finite families of sets

It is well known that in a separable topological space every point-finite family of open subsets is countable. In the following we are going to show that both in σ-finite measure-spaces and in topological spaces satisfying the countable chain condition, point-finite families consisting of “large” subsets are countable. Notation and terminology. Let A be a set. The family consisting of all (finite) subsets of A is denoted by . Let be a family of subsets of A. The sets and are denoted by and , respectively. We say that the family is point-finite (disjoint) if for each a ∈ A , the family has at most finitely many members (at most one member).
Strong Charge-Transfer Doping of 1 to 10 Layer Graphene by NO2

We use resonance Raman and optical reflection contrast methods to study charge transfer in 1–10 layer (1L–10L) thick graphene samples on which NO2 has adsorbed. Electrons transfer from the graphene to NO2, leaving the graphene layers doped with mobile delocalized holes. Doping follows a Langmuir-type isotherm as a function of NO2 pressure. Raman and optical contrast spectra provide independent, self-consistent measures of the hole density and distribution as a function of the number of layers (N). At high doping, as the Fermi level shift EF reaches half the laser photon energy, a resonance in the graphene G mode Raman intensity is observed. We observe a decrease of graphene optical absorption in the near-IR that is due to hole-doping. Highly doped graphene is more optically transparent and much more electrically conductive than intrinsic graphene. In thicker samples, holes are effectively confined near the surface, and in these samples, a small band gap opens near the surface. We discuss the properties an...
Study on utility of real-time fluorescent quantitative PCR for rapid pathogens′ screening in respiratory infectious disease

Objective:To establish a method of fluorescent quantitative PCR and examine its utility for rapid pathogens′ screening in respiratory infectious disease.Methods:232 specimens of 10 respiratory infectious disease outbreak events occurred in Lishui during the year of 2007-2009 were detected by culture method of national standards and compared with the method of fluorescent quantitative PCR.The results of different methods were compared and the sensitivity,specificity and accuracy of fluorescent quantitative PCR method was obtained.Results:The detective result of fluorescent quantitative PCR was 62.50% in accordance to that of common bacterial culture during 166 samples.6 specimens were detected negative by bacterial culture were positive by fluorescent quantitative PCR method.The detective result of fluorescent quantitative PCR was 88.89% accordance to that of viral culture during 166 samples.Conclusion:Real-time fluorescent quantitative PCR is an ideal method for rapid pathogens′ screening in respiratory infectious disease with high accuracy and sensitivity.
Separation and analysis of pilocarpine, isopilocarpine, and pilocarpic acid by reverse phase liquid chromatography: collaborative study

A method for separating and determining pilocarpine and 2 degradation products was developed and subjected to collaborative study. Pilocarpine, isopilocarpine, and pilocarpic acid were isolated on a reverse phase liquid chromatographic phenyl bonded column and detected by UV spectrophotometry at 220 nm. Nine collaborators received commercial samples labeled to contain 2, 1, and 0.5% pilocarpine and a 2% practice sample. The collaborative results for pilocarpine were excellent; coefficients of variation ranged from 3.20 to 4.10%. The method was adopted official first action for determination of the active component, pilocarpine, in the presence of isopilocarpine and pilocarpic acid. Although quantitative results for the degradation products were not as good, the method is suitable as a limits test for these substances.
Single-Nucleotide Polymorphism Genotyping for Disease Association Studies

The Human Genome Project has led to the discovery of millions of DNA sequence variants in the human genome. The majority of these variants are single-nucleotide polymorphisms (SNPs). Availability of an ultra-high-density SNP map, combined with improvement in genotyping technologies and efficient analytical approaches, opens the possibility of fulfilling the promise of SNP association studies to reveal why some individuals are more susceptible to common chronic diseases such as hypertension and stroke. With millions of SNPs spread throughout the human genome, it is neither practical nor necessary to genotype every single SNP in population samples for association studies. Linkage disequilibrium between sites suggests that it is possible to detect disease association using a relatively sparse collection of SNPs. While the cost associated with assaying a comprehensive set of SNPs is still significant, several technologies show great promise for high-efficiency SNP genotyping. This chapter focuses on two of them: the 5'-nuclease assay and mass spectrometry genotyping.
People-centric computing and communications in smart cities

The extremely pervasive nature of mobile technologies, together with the user's need to continuously interact with her personal devices and to be always connected, strengthen the user-centric approach to design and develop new communication and computing solutions. Nowadays users not only represent the final utilizers of the technology, but they actively contribute to its evolution by assuming different roles: they act as humans, by sharing contents and experiences through social networks, and as virtual sensors, by moving freely in the environment with their sensing devices. Smart cities represent an important reference scenario for the active participation of users through mobile technologies. It involves multiple application domains and defines different levels of user engagement. Participatory sensing, opportunistic sensing, and mobile social networks (MSNs) currently represent some of the most promising people-centric paradigms. In addition, their integration can further improve the user involvement through new services and applications. In this article we present SmartCitizen app, an MSN application designed in the framework of a smart city project to stimulate the active participation of citizens in generating and sharing useful contents related to the quality of life in their city. The app has been developed on top of a context- and social-aware middleware platform (CAMEO) able to integrate the main features of people-centric computing paradigms, lightening the app developer's effort. Existing middleware platforms generally focus on a single people-centric paradigm, exporting a limited set of features to mobile applications. CAMEO overcomes these limitations and, through Smart- Citizen, we highlight the advantages of implementing this type of mobile application in a smart city scenario. Experimental results shown in this article can also represent the technical guidelines for the development of heterogeneous people-centric mobile applications embracing different application domains.
Statistical fatigue of unnotched composite laminates

A general analytical, phenomenological model is developed for characterizing fatigue damage accumulation in unnotched composite laminates, and experimental results are used to evaluate the model. The fatigue model, which is developed for various types of cyclic loadings, is based on the assumption that the residual strength reduction is a monotonically decreasing function of the fatigue life. Parameters are determined from baseline test data consisting of one set of residual strength data, one set of static strength data, and one set of constant amplitude fatigue life data. Once the parameters are determined, the model is able to predict: (1) the statistical distribution of the fatigue life, and the residual strength under constant and variable amplitude loads, and (2) the effect of periodic proof tests, without any additional experimental data. Experimental test results show that predictions made from the present model agree quite well with the experimental results. The model is also applicable to fatigue of bonded or bolted composite joints.
Implications of Innovative Engineering Design on Closed Loop Supply Chain Coordination: Incentives for Input Material Reduction vs. Enhanced Recycling

Motivated by interactions with a major player in the aerospace industry, we consider the relationship between a supplier of specialty material forgings and a buyer that manufactures fabricated airplane components by extensively machining down these forgings as per complex design specifications. Due to high material removal costs, the buyer prefers these forgings to be as similar in geometry and size to the final component as possible, i.e., near-net-shape. The supplier, by default, does not have the capabilities to deliver such near-net-shape forgings as per technological constraints, but can utilize costly effort and/or invest in the required technologies to achieve forging size reduction. By taking into account uncertainty regarding the correspondence between supplier's effort and resulting output (i.e., reduction in forging size), and potential information asymmetry issues due to supplier's private information regarding costly effort, we assess the implications of two innovative approaches our study firm considers for improving supply chain performance: (i) The buyer can partially subsidize the supplier to induce forging size reduction efforts, and/or (ii) the supply chain can facilitate a higher rate recycling of scrap material to reduce input material costs.We find that the supplier's input reduction efforts and enhanced recycling across the supply chain interact in non-intuitive ways, thus inflicting a non-monotone effect on supply chain performance; in other words, an increased recycling rate may misalign incentives, and not reduce decentralization cost. We find that enhanced recycling deteriorates supply chain performance the most especially when the recycling rate is moderate, which suggests that our study firm should participate in a supply chain with either superb or insufficient recycling capabilities. Furthermore, when agency issues arise, we find that the buyer should subsidize supplier's forging size reduction efforts only when the recycling level is above a threshold, which helps improve supply chain performance. In contrast, when the recycling level is below the same threshold, as the buyer bets on the possibility on contracting with an efficient supplier, the buyer withholds any compensation at equilibrium, and thus, enhanced recycling yields a higher decentralization cost.
The Effect of Emotional Content and Support on Trust in Internet Forum Posts: A Pilot Study

Many people now use internet forums for gathering and sharing information on diverse topics, raising questions about the quality and credibility of content on these forums. Although anyone can present questions or advice to online forums regardless of their level of expertise, research shows that internet users do not judge credibility stringently when searching for information online (Flanagin & Metzger, 2000). Factors that influence credibility judgements may include star ratings, length of responses, and the presence of emotional support within the information. We conducted a pilot study that tested the presence of emotional content in questions and emotional support in replies on a hypothetical travel forum. We found that neither the presence of emotional content nor the presence of emotional support influenced user ratings of trust or advice quality. Some limitations of the present study include reply length, salience of the emotional support, and the number of questions presented to each participant...