cssi/SciSciGPT-SciSciNet huggingface dataset:
The One-Way Road of Aging: On Jean Améry's Essay Über das Altern

My article approaches Amery's complex essay via an interpretation of its five subtitles, which refer to a number of paratexts (Heidegger, Sartre, Freud, etc.) and at the same time expose the conceptual inaccessibility of aging: All five can be understood without referring to aging. Second, I try to explore how the essay on aging relates to the traumatizing events in Amery's life, and why he characterizes the inescapable process of aging as a long Todesmarsch. Third, I explain how Amery bridges the abyss between the factual experience of aging and the impossibility to conceptualize this continuous process, which begins with our birth. Aging is experienced in moments of sudden, frightening insights. The analysis of these sudden experiences leads Amery finally to a convincing rethinking of the Cartesian split between mind and body. La souffrance vecue mediates between aging as a concept and its experience. By means of fully exposing himself to aging, Amery thus rejuvenates philosophy.
A perturbation technique for improving the design of a planar slot array

We present a perturbation technique for improving the design parameters of a waveguide-fed planar slot array consisting of longitudinal radiating slots and centered-inclined coupling slots. Initial design is performed using the well-known Elliott technique. Subsequently a method-of-moments solution to the pertinent coupled integral equations of the aperture electric field of all slots in the array is employed to perturb the slot parameters. This process improves the slot aperture distribution and the return loss.
A Continuous Infusion Fascia Iliaca Compartment Block in Hip Fracture Patients: A Pilot Study

Background : Hip fractures account for 350,000 fractures annually and the projected incidence is expected to exceed 6.3 million by 2050. As the number of hip fractures continues to increase as a result of the aging American population, the importance of limiting and preventing complications is magnified. Methods : This study demonstrated the clinical effects of a continuous fascia iliaca compartment block placed pre-operatively when combined with a comprehensive pain protocol. All patients who presented to our institution with a hip fracture were given the option of having a continuous fascia iliaca compartment block for pain control versus usual pain management (non-opioids, opioids, and ice therapy). The block was monitored by the pain service until the day of discharge from the hospital. Data was collected regarding mean pain scores, average length of stay and opioid medication use. Results : There were eighteen males and twenty four females. The pain score on post-operative day zero was reduced from a 2010 annual average of 4.1 to 1.7 in the pilot study group on the visual analog score. On post-operative day one, the 2010 annual average was 2.9 compared to 1.4 in the pilot study group. The length of stay was decreased from the 2010 annual average of 5.9 days to 4.8 days in the pilot study group. The patients used an average of 18mg of morphine equivalent medications during the average infusion time of 40.7 hours. There were no falls or infections noted within our pilot study group. Conclusions : Overall, it has been noticed that the reduction in opioid usage in this elderly patient population, with an average age of seventy five years, has produced alert and mobile patients often as early as post-operative day one. The length of stay has decreased along with the average pain score in the pilot sample of forty two patients. doi:10.4021/jocmr724w
Nontemplate Polymerization of Free Nucleotides Into Genetic Elements by Thermophilic DNA Polymerase in vitro

DNA synthesis is the cornerstone of all life forms and is required to replicate and restore the genetic information. Usually, DNA synthesis is carried out only by DNA polymerases semiconservatively to copy preexisting DNA templates. We report here that DNA strands were synthesized ab initio in the absence of any DNA or RNA template by thermophilic DNA polymerases at (a) a constant high temperature (74°C), (b) alternating temperatures (94°C/60°C/74°C), or (c) physiological temperatures (37°C). The majority of the ab initio synthesized DNA represented short sequence blocks, repeated sequences, intergenic spacers, and other unknown genetic elements. These results suggest that novel DNA elements could be synthesized in the absence of a nucleic acid template by thermophilic DNA polymerases in vitro. Biogenesis of genetic information by thermophilic DNA polymerase-mediated nontemplate DNA synthesis may explain the origin of genetic information and could serve as a new way of biosynthesis of genetic information that may have facilitated the evolution of life.
In Defence of Neo‐Classical Neo‐Populism

This paper is a response to the discussion in the special issue of this Journal on Redistributive Land Reform Today (Vol. 4, Nos. 1 and 2). We begin by attempting to clarify the methodological debate, differentiating our approach, which our critics call neo-classical neo-populism, from mainstream neo-classical economics and historical materialism. We then distinguish between land tenure reforms and redistributive land reforms, and argue that it is the latter that really matter. Next, we address the issue of the inverse relationship between farm size and productivity. Fourth, we discuss cases in which systems of labour control are used to transform the peasantry into a landless rural proletariat and challenge the view that systems of labour control can usefully be reduced to a problem of transaction costs. We end with discussions of reform in the transition economies, China and Bangladesh, where we defend the view that it is the distribution of landownership rather than operational holdings that largely determines the extent of poverty.
Effects of complex or isolated environments on cortical dendrites of middle-aged rats.

Abstract Female rats were placed into complex (EC) or isolated (IC) environments for 45 days, beginning at 450 days of age. Golgi-Cox stained layer IV stellate and layer III occipital cortical pyramidal neurons were analyzed for numbers and lengths of dendritic branches and the amount and location of dendritic material with respect to the soma. In both cell populations, neurons from EC had significantly more dendritic material, with differences occurring throughout the dendritic field. In the stellate population, EC neurons had significantly longer terminating (non-bifurcating) branches, and more second and fifth order branches. In pyramidal cells, EC neurons had significantly more branches at each of orders 2–5 as well as significantly longer terminating branches. This report is the first to describe substantial dendritic alterations subsequent to differential housing in middle-aged rats. These results, taken with previous work, suggest that experience may affect neuronal structure over much of an animal's lifespan.
Investigation and Development of Protective Ointments IV.: The influence of active fillers on the permeability of semisolids

The permeability of protective barriers containing adsorbent type fillers has been studied. It has been shown that the time for the nonstationary state permeation of these barriers can be significantly increased by the incorporation of small quantities of an active filler into the ointment base. The theoretical considerations of permeation through filled ointments have been presented with particular emphasis placed on the theory pertaining to barriers containing a filler with a high affinity for the penetrant. An equation relating the lag time to the concentration and maximum adsorptive capacity of this type filler and to the initial concentration of the chemical agent has been derived and verified by experimental procedures.
Recovery of standard 125I-peptides at the picogram asnd femtogram level by reversed-phase high-perofrmance liquid chromatogrphy

Abstract Average recoveries of standard [ 125 I]angiotensin II are 92–103% when amounts of this peptide ranging from 10 pg to 50 fg are analyzed by reversed-phase high-performance liquid chromatography (RP-HPLC) employing a C 8 -bonded silica packing, whether an “old” (one year of prior use) or previously unused column is employed. In one case this recovery is 68% on a column giving a ten-fold higher retention of this peptide with the usual mobile phase of acetonitrile—aqueous 0.01 M sodium perchlorate (40:60); the same mobile phase except 0.1 M sodium perchlorate shortens the retention ten-fold on this column and gives an average recovery of 103%. Similar recoveries are obtained for [ 125 I]brdykinin (105%) and [ 125 I]luteinizing hormone releasing hormone (107%), tested at the 1 -pg level. Although two commercial preparations of [ 125 I]vasoactive intestinal peptide are recovered only to the extent of 75 and 85%, the HPLC chromatograms also display several peaks. Aside from the potential for complications in the analysis of real samples, this work establishes that RP-HPLC is a viable technique for sample clean-up/characterization in the ultratrace analysis of at least some peptides.
Development of autoimmunity after skin graft rejection via an indirect alloresponse.

Background. T cell allorecognition occurs through direct contact with donor peptide: MHC complexes on graft cells and through indirect recognition of donor-derived determinants expressed by recipient MHC molecules. As both indirect allorecognition and autoantigen recognition are self-restricted, we hypothesized that chronic activation of indirectly primed T cells might result in determinant spreading to involve autoantigens, analogous to that which occurs during chronic autoimmune diseases. Methods. We placed C57BL/6 MHC II knockout (B6 II-/-) skin grafts onto BALB/c SCID mice reconstituted with wild-type (WT) CD4 + T cells. Under these conditions the CD4 + cells could not recognize any antigen on the graft, but could respond through the indirect pathway. CD4 + cell-mediated rejection of WT B6 skin was studied to determine if autoreactivity was induced after direct allorecognition. Recall immune responses against donor- and self-stimulator cells were determined by ELISPOT and animals were tested for their ability to reject second isografts. Results. WT allografts were rejected by day 14 although B6 II-/- grafts underwent delayed rejection over 4-5 weeks. CD4 + cells reisolated from the recipients of the MHC II-/- grafts, but not from the recipients of WT grafts, vigorously produced interferon-y and interleukin-2 in response to self, BALB/c stimulators. These autoreactive CD4 + T cells mediated rejection of a second isogenic BALB/c skin graft, demonstrating that the autoimmune response was pathogenic. Conclusion. Autoreactivity can develop after transplant rejection via the indirect pathway. Although the direct alloresponse is likely to be the driving force in acute graft rejection, posttransplantation induced autoimmune responses may be important elements of delayed or chronic rejection.
SFR with once-through depleted uranium breed & burn blanket

This paper assesses the feasibility of Sodium-cooled Fast Reactor (SFR) cores that have TRU recycled seeds and once-through depleted uranium blankets. The design objective of these Seed-and-Blanket (SB the blanket batches are gradually shuffled inward, while one third of the fuel batches in the seed are recycled. The preliminary study found that it is possible to design the seed to accommodate a wide range of TRU conversion ratios (CR) without significantly penalizing the burnup reactivity swing. The relatively small burnup reactivity swing enables to design the SB this fraction increases when the seed is designed to have a smaller CR. These features are expected to improve the economics of SFR.
Impact of network resource constraints on the performance of wireless sensor relay networks

This work studies the impact of the network resource constraints on the performance of wireless sensor multi-hop relay networks. A differential space-time coding and the cooperative relay scheme for cross layer design is introduced in multi-hop wireless sensor networks. To analyze the network performance of such a system, the relay system from source to destination is simplified as a virtual bit pipe line, and a Markov chain model as well as an M/G/1 queueing system are used. The closed form expression for throughput and delay are derived in the infinite buffer case. A truncated Markov chain model and an M/G/1/K queueing system are used to model the finite buffer situation. Moreover, the system drop probability and the go through delay are studied based on the models.
Surgical resident allocation: an art or a mathematical formula?

This is an interesting support tool advocated to help move residents through academic residency programs in all disciplines. Its most important functions are to decide how many interns to recruit and how to advance the residents within the program. In attempting to apply this “macro” to surgical residencies, there are significant limitations. First, the authors have described a 3.4%-3.8% attrition rate across-the-board for all residency programs. It is well-known that the attrition rate in general surgery residencies is higher than for any other specialty (approximately 20%) and usually occurs after the first or second year. Thus, I do not think any general surgery residency program director would advocate limiting the number of interns to recruit each year as has been suggested by the authors. Second, as residents get further along in the program, some may develop health issues, become pregnant, or require a year of remediation. The authors admit that this system was originally devised for residencies with mandatory research requirements. Thus, it
Adaptive clustering of hypermedia documents

A hypermedia system connects various types of information into a network where related nodes of information (text, audio, video) are connected by links. Clustering these nodes is an effective way to reduce information-overhead, allowing the user to browse through the clusters as well as the individual nodes. In this paper, we compare the use of two adaptive algorithms (genetic algorithms, and neural networks) in clustering hypermedia documents. These clusters allow the user to index into this overwhelming number of nodes and find needed information quickly. We base the clustering on the user's paths through the hypermedia document and not on the content of the nodes or the structure of the links in the document, thus the clustering reflects the unique relationships each user sees among the nodes. The original hypermedia document remains untouched, however each user will now have a personalized index into this document.
Variable quadratic propagator for quantum Monte Carlo simulations

Abstract A new propagator for the Monte Carlo evaluation of path integrals is proposed. The propagator has a quadratic form which varies with position The variable quadratic propagator (VQP) approximation combines features of Taylor series and quasiharmonic expression; it is constructed to interpolate between the low-and high-temperature limit for the anharmonic propagator. Using two model potentials, the quartic and Morse ocillators, we demonstrate the accuracy that may be achieved with a simple diagonal approximation to the propagator.
Temporary droplet-size hysteresis in immiscible polymer blends

The droplet size distribution during steady shearing of model polymer blends is examined in situ by optical microscopy. The volume-average steady-state droplet size during shear is essentially inversely proportional to shear rate, as expected. When the shear rate is increased suddenly, the droplets break up, through a process that involves the transient formation of threads, and rapidly establish a new steady state, comprising ellipsoidal droplets that are extended slightly in the direction of shear. When the shear is stopped, the droplets quickly relax to a spherical shape, but virtually no coalescence is observed, because neither Brownian nor buoyant forces are significant and the volume fraction of the dispersed phase is low. Slow shear, however, induces droplet collisions that lead to coalescence. The coalescence process is much slower than breakup. In contrast to some predictions, however, there is no permanent droplet size hysteresis. The steady-state size produced by breakup of initially larger droplets is eventually produced at large strain by coalescence of initially smaller droplets. The lack of permanent hysteresis has implications concerning appropriate mathematical models of coalescence behavior.
Cultural Relativism and the Theory of Value: The Educational Implications

. The philosophy of science developed by John Dewey in Logic: The Theory of Inquiry should be applied in the study of philosophy and the social sciences as it has come to be applied in the physical sciences. Dewey's methodology prescribes the use of both reason and observation in problem-solving, that is, both theory (hypothesis making) and practice (fact-gathering), with movement back and forth between the two, revising the theory and gathering new facts until a conclusion is reached. The rightness of a conclusion should be evaluated in terms of its consequences and is always subject to modification in the light of later evidence. This philosophy means that a scientific criterion of judgment is possible, in this case Dewey's instrumental theory of value. Higher education should incorporate value theory explicitly into its curriculum and thereby help society to make choices about the good, the true, and the beautiful.
The Children And Parents Service (CAPS): A Multi-Agency Early Intervention Initiative for Young Children and their Families

Behaviour problems make up approximately 30–50% of all referrals to child and adolescent mental health services. Behavioural parent training is one of the most effective interventions for young children. However, those families most at risk of difficulties fail to access services. This paper outlines the Children And Parents Service (CAPS), a citywide multi-agency, early intervention service to young children and their families. The intervention includes parent training groups, multi-agency training and liaison in community settings. The model of service delivery is outlined and the obstacles to service implementation and the strategies used to overcome them are discussed. The service has adopted a well validated evidence-based model of parent training, monitoring of outcomes and user involvement, and is delivered in the wider context of multi-agency systems. A thorough evaluation of service delivery models, including CAPS, would be beneficial. Whilst research trials examine the efficacy of treatments, the effective delivery of treatments within clinical services requires clarity about the place of the intervention within wider systems. The CAPS model proposes a framework for delivering interventions within these systems.
Calcium phosphate-induced renal epithelial injury and stone formation: involvement of reactive oxygen species.

Calcium phosphate–induced renal epithelial injury and stone formation: Involvement of reactive oxygen species. Background Crystal formation and retention are critical events for the formation of kidney stones. Oxalate and calcium oxalate (CaOx) crystals are injurious to renal epithelium, and membranes of injured cells promote crystal adherence and retention. Calcium phosphate (CaP) is the most common crystal in both urine and stones, most likely to form in the early segments of the nephron and can nucleate CaOx in a metastable solution. We hypothesized that CaP can also injure the renal epithelial cells. Methods We exposed proximal tubular origin line derived from pig proximal tubules (LLC-PK 1 ), and collecting duct origin Madin-Darby canine kidney (MDCK) cell lines to various concentrations of Brushite (Br) crystals and investigated staining with Trypan Blue and the release of lactate dehydrogenase (LDH) into the medium as an indicator of injury. In order to determine the involvement of reactive oxygen species, we also measured LDH release in the presence of superoxide dismutase (SOD) and production of hydrogen peroxide (H 2 O 2 ) and 8-isoprostane (8-IP) in the presence of the catalase. Results Exposure to Br crystals was associated with LDH release by both cell types, induced the production of H 2 O 2 and 8-IP. Presence of SOD and catalase reduced LDH release as well as staining with trypan blue. Catalase was also associated with reduced production of H 2 O 2 and 8-IP. Conclusion Brushite crystals are injurious to cells of both the proximal tubules as well as collecting ducts. Injury is mediated by reactive oxygen species. We propose that CaP crystals can independently interact with renal epithelium, promote sites for crystal attachment, and then either grow into mature CaP stones or create sites for CaOx crystal nucleation, retention, and stone development.
Location Of Hole And Electron Traps On Nanocrystalline Anatase TiO2

The defect photoluminescence from TiO2 nanoparticles in the anatase phase is reported for nanosheets which expose predominantly (001) surfaces and compared to that from conventional anatase nanoparticles which expose mostly (101) surfaces. Also reported is the weak defect photoluminescence of TiO2 nanotubes, which we find using electron backscattered diffraction to consist of walls which expose (110) and (100) facets. The nanotubes exhibit photoluminescence that is blue-shifted and much weaker than that from conventional TiO2 nanoparticles. Despite the preponderance of (001) surfaces in the nanosheet samples, they exhibit photoluminescence similar to that of conventional nanoparticles. We assign the broad visible photoluminescence of anatase nanoparticles to two overlapping distributions: hole trap emission associated with oxygen vacancies on (101) exposed surfaces, which peaks in the green, and a broader emission extending into the red which results from electron traps on undercoordinated titanium atoms,...
Assessment of RANS-Based Turbulent Combustion Models for Prediction of Emissions from Lean Premixed Combustion of Methane

Reynolds-Averaged Navier-Stokes (RANS) simulations of Lean Premixed Combustion (LPC) of methane–air in a bluff-body stabilized combustor were performed with several widely used turbulent combustion methodologies in order to assess their prediction capabilities. The methods employed are the Eddy Dissipation Concept (EDC), the Composition Probability Density Function (CPDF) and the Joint Velocity–Frequency-Composition PDF (VFCPDF) models. Where needed, two different models were employed for turbulent transport closure, namely the Renormalization Group (RNG) k-ϵ and Reynolds Stress Transport (RSM) models. The combustion chemistry was represented by two separate augmented reduced mechanisms (ARM9 and ARM19) in order to assess the influence of chemical mechanisms on calculations. Mean temperature and major species predictions of all of the employed methodologies compared well with the experimental data. Intermediate and emission species predictions were sensitive to the resolution of turbulence viscosity, whic...
The Relationship of Mammographic Density and Age: Implications for Breast Cancer Screening

OBJECTIVE. Breast density is increasingly recognized as an independent risk factor for the development of breast cancer, because it has been shown to be associated with a four- to sixfold increase in a woman’s risk of malignant breast disease. Increased breast density as identified on mammography is also known to decrease the diagnostic sensitivity of the examination, which is of great concern to women at increased risk for breast cancer. Dense tissue has generally been associated with younger age and premenopausal status, with the assumption that breast density gradually decreases after menopause. However, the actual proportion of older women with dense breasts is unknown. The purpose of this study was to examine the relationship between age and breast density, particularly focusing on postmenopausal women. MATERIALS AND METHODS. All screening mammograms completed at the New York University Langone Medical Center in 2008 were retrospectively reviewed. Analysis of variance and descriptive analyses were us...
Expanding the Benefits of Implantable Cardioverter-Defibrillator Therapy: "Is Less More"?

Abstract Implantable cardioverter-defibrillator (ICD) therapy improves survival in patients with significant left ventricular systolic dysfunction. Although this lifesaving therapy has many benefits, inappropriate ICD shocks may increase morbidity and mortality. With rates of inappropriate therapy quoted as high as 35% at 3 years after device implantation, numerous strategies have been evaluated to decrease the overall incidence of inappropriate therapy. Changes in programming algorithms, which allow for longer detection windows for rhythm analysis, extended the use of antitachycardia pacing, and improved supraventricular tachycardia discriminators, hold promise for decreasing inappropriate ICD therapy. In this review, we discuss the data summarizing the adverse effects of ICD shocks on outcomes, clinical trial–based programming algorithms to decrease inappropriate shocks, and the expanded role of antitachycardia pacing in ventricular arrhythmia management.
Ventral tegmental self-stimulation selectively induces opioid peptide release in rat CNS.

Intracranial self-stimulation (ICS) is thought to activate neuronal systems involved in processing natural reinforcing agents. Metabolic mapping studies have previously demonstrated a subset of CNS structures specifically engaged by ICS in animals receiving stimulation actively vs. passively. Since opiates are known to enhance ICS behavior and presumably its reinforcing properties, the current study addressed the question of the role of opioid peptides as mediators of ICS. Rats were trained on a fixed ration (FR) 20 schedule of responding maintained by ICS. Following response stabilization, rats were assigned either to an active or a corresponding yoked stimulation group at 1 of 2 schedules of reinforcement (i.e., FR1-YFR1, FR20-YFR20, or sedentary control), and opioid peptide release was inferred from in vivo receptor occupancy. Autoradiographic analyses identified 3 groups of structures. Treatment-induced alterations in occupancy were seen in the medial dorsal nucleus of the thalamus, basolateral amygdala, ventral pallidum, medial habenula, dorsal raphe, posterior hypothalamus, substantia nigra pars compacta, agranular preinsular cortex, and zona incerta. Depending upon the structure, peptide release was dependent upon stimulus contingency (active vs. yoked) and/or schedule (FR1 vs. FR20). Evidence for ICS-induced inhibition of peptide release was found in the habenula and preinsular cortex. Nine additional structures, all components of, or receiving projections from, the limbic system, revealed complex interactions between ICS treatment and the electrode side. Finally, a widespread ipsilateral increase in receptor binding was seen rostrally from the cingulate, olfactory tubercle, and nucleus accumbens, along the lateral hypothalamus and hippocampus, and extending caudally to the substantia nigra and ventral tegmentum. These later effects appear to be related to stimulation-induced changes in blood flow and subsequent ligant presentation increases. Collectively, these data point towards the ability of rewarding brain stimulation to activate discrete neuronal opioid systems contingent upon specific behavioral as well as stimulus conditions.
Local Delivery of Protease-Resistant Stromal Cell Derived Factor-1 for Stem Cell Recruitment After Myocardial Infarction

Background— Local delivery of chemotactic factors represents a novel approach to tissue regeneration. However, successful chemokine protein delivery is challenged by barriers including the rapid diffusion of chemokines and cleavage of chemokines by proteases that are activated in injured tissues. Stromal cell–derived factor-1 (SDF-1) is a well-characterized chemokine for attracting stem cells and thus a strong candidate for promoting regeneration. However, SDF-1 is cleaved by exopeptidases and matrix metalloproteinase-2, generating a neurotoxin implicated in some forms of dementia. Methods and Results— We designed a new chemokine called S-SDF-1(S4V) that is resistant to matrix metalloproteinase-2 and exopeptidase cleavage but retains chemotactic bioactivity, reducing the neurotoxic potential of native SDF-1. To deliver S-SDF-1(S4V), we expressed and purified fusion proteins to tether the chemokine to self-assembling peptides, which form nanofibers and allow local delivery. Intramyocardial delivery of S-SD...
On an inverse boundary value problem

This paper is a reprint of the original work by A. P. Calderon published by the Brazilian Mathematical Society (SBM) in ATAS of SBM (Rio de Janeiro), pp. 65-73, 1980. The original paper had no abstract, so this reprint to be truthful to the original work is published with no abstract.
Comparison of algorithms for computing the two-dimensional discrete Hartley transform

Three methods have been described for computing the two-dimensional discrete Hartley transform. Two of these employ a separable transform, the third method, the vector-radix algorithm, does not require separability. In-place computation of the vector-radix method is described. Operation counts and execution times indicate that the vector-radix method is fastest.
Wrinkling control in aluminum sheet hydroforming

Abstract In this paper, the wrinkling behavior of 6111-T4 aluminum alloys during sheet hydroforming process was numerically and experimentally investigated. In sheet hydroforming, one or both surfaces of the sheet metal are supported with a pressurized viscous fluid, while a punch forms the part. In sheet hydroforming the use of a matching female die is not needed. The use of the pressurized fluid delays the onset of material rupture (International Journal of Mechanical Science 2003;45:1815–48) and also acts as an active blank-holding force to control wrinkling in the flange area. To form a wrinkle-free deep-drawn hemispherical cup with sheet hydroforming, a theoretical analysis based on the work of Lo et al. (Journal of Materials Processing Technology 1993;37:225–39) was initially used to predict the optimum fluid pressure profile. Simplifying geometrical assumptions and Tresca material model used in the theoretical analysis provided a fluid pressure profile that resulted in premature rupture of the sheet metal. However, an optimum fluid pressure profile generated by the finite element method, using Barlat's anisotropic yield function (Journal of Mechanical Physics and Solids 1997;45(11/12):1727–63), was successfully applied in sheet hydroforming to make the deep-drawn hemispherical cup without tearing and with minimal wrinkling in the flange area. The finite element model was also capable of accurately predicting the location of the material rupture in pure stretch, and wrinkling characteristics of the aluminum alloy sheet in the draw-in process.
On which grids can tomographic equivalence of binary pictures be characterized in terms of elementary switching operations

It is a well-known result, due to Ryser, that if a binary picture on the square grid has the same x and y projections as another such picture, then the first picture can be transformed into the second by a series of switching operations, each of which changes the picture at just four grid points and preserves both projections. In this article, we show that if a grid [such as a two-dimensional (2D) hexagonal grid or the 3D cubic grid] has three or more directions of projection, then Ryser's result has no analog for that grid. Specifically, we show that on any grid with three or more directions of projection there cannot exist any constant L such that every binary picture can be transformed to any other binary picture with the same projections by a series of projection-preserving changes, each of which involves at most L grid points. This is proved for a very general concept of “grid” that encompasses virtually all practical grids in Euclidean n-space, and even some grids in higher-dimensional analogs of cylindrical and toroidal surfaces. (In fact, the set of grid points can be any finitely generated Abelian group of rank ≥ 2.) © 1998 John Wiley & Sons, Inc. Int J Imaging Syst Technol, 9, 118–125, 1998
Isolated familial somatotropinoma.

The great majority of growth hormone (GH)-secreting pituitary tumors are sporadic, though a few occur with a familial aggregation, either as a component of multiple endocrine neoplasia, type 1 (MEN1) or Carney Complex, or when unassociated with other tumors, as isolated familial somatotropinomas (IFS). This report reviews the clinical and genetic information available from the 46 families reported to date with the latter syndrome. In contrast to sporadic tumors, GH-secreting tumors in IFS occur at an earlier age, especially when all affected family members are from a single generation. The IFS gene is believed to be a tumor suppressor gene, based on the presence of loss of heterozygosity. Although the gene still remains to be identified there is strong evidence for linkage to a locus of less than 10 Mb on chromosome 11q13.1–13.3.
Estimation of the minimum detectable activity of preclinical PET imaging systems with an analytical method

Purpose: The traditional figures of merit used in the evaluation of positron emission tomography(PET)systems, including system sensitivity and spatial resolution, do not directly reflect the minimum detectable activity (MDA) performance, despite the fact that it is one of the most important tasks for a PETsystem. MDA, as a combination of the more traditional PETsystem parameters, is directly related to lesion detection. However, MDA evaluation is task specific and cannot be done by a single measurement. Therefore, a simple method to evaluate system detectability needs to be developed. Methods: In this work, an analytical method of MDA estimation was developed, taking into account system sensitivity, spatial resolution, source properties, and noise propagation in image reconstruction by using the Rose criterion and/or the Curie equation as the detection standard. In the implementation, the source background, as well as the intrinsic activity background from the scintillation material of the system, was also taken into consideration. The accuracy of this method was evaluated in two commercially available preclinical PETsystems, with phantom experiments that were designed to closely mimicin vivo tumor uptake without introducing finite boundaries between the source and the background. Results: The lesion contrast-to-noise ratio calculated by the analytical evaluation showed good agreement with that obtained from the experiments. Visual assessment of the reconstructed images at the detection limit (based on analytical evaluation) also was in agreement with the Rose criterion. The MDA performance was quantitatively compared between the two preclinical PETsystems and showed different detection limits under different imaging conditions, suggesting that the detection limit of a PETsystem strongly depends on the lesion properties and acquisition settings. Conclusions: An analytical method of evaluating the PETsystem detectability was developed and validated by experiments. Overall, the analytical MDA calculation provides a simple way to evaluate the signal detectability of a PETsystem and can be used for comparing different systems. It also provides guidelines for designing new PET tomographs as well as optimizing data acquisition protocols.
Myocardial Mucormycosis With Emboli in a Hemodialysis Patient

A 32-year-old man was found to have disseminated mucormycosis. Echocardiogram demonstrated bilateral ventricular thrombi, but there were no segmental wall motion abnormalities. At autopsy, it was found that these thrombi originated from a myocardial abscess and that death had been caused by septic embolization to the brain. The patient had been on maintenance hemodialysis for 9 years. Two transplants, 7 and 8 years previously, had been unsuccessful and had involved only 3 weeks of immunosuppressive treatment. No factor predisposing to fungal infection could be identified, with the possible exception of chronic uremia.
Escherichia coli DnaA Protein Loads a Single DnaB Helicase at a DnaA Box Hairpin

The molecular engine that drives bidirectional replication fork movement from the Escherichia coli replication origin (oriC) is the replicative helicase, DnaB. At oriC, two and only two helicase molecules are loaded, one for each replication fork. DnaA participates in helicase loading; DnaC is also involved, because it must be in a complex with DnaB for delivery of the helicase. Since DnaA induces a local unwinding of oriC, one model is that the limited availability of single-stranded DNA at oriC restricts the number of DnaB molecules that can bind. In this report, we determined that one DnaB helicase or one DnaB-DnaC complex is bound to a single-stranded DNA in a biologically relevant DNA replication system. These results indicate that the availability of single-stranded DNA is not a limiting factor and support a model in which the site of entry for DnaB is altered so that it cannot be reused. We also show that 2-4 DnaA monomers are bound on the single-stranded DNA at a specific site that carries a DnaA box sequence in a hairpin structure.
The origin of a derived superkingdom: how a gram-positive bacterium crossed the desert to become an archaeon

The tree of life is usually rooted between archaea and bacteria. We have previously presented three arguments that support placing the root of the tree of life in bacteria. The data have been dismissed because those who support the canonical rooting between the prokaryotic superkingdoms cannot imagine how the vast divide between the prokaryotic superkingdoms could be crossed. We review the evidence that archaea are derived, as well as their biggest differences with bacteria. We argue that using novel data the gap between the superkingdoms is not insurmountable. We consider whether archaea are holophyletic or paraphyletic; essential to understanding their origin. Finally, we review several hypotheses on the origins of archaea and, where possible, evaluate each hypothesis using bioinformatics tools. As a result we argue for a firmicute ancestry for archaea over proposals for an actinobacterial ancestry. We believe a synthesis of the hypotheses of Lake, Gupta, and Cavalier-Smith is possible where a combination of antibiotic warfare and viral endosymbiosis in the bacilli led to dramatic changes in a bacterium that resulted in the birth of archaea and eukaryotes. This article was reviewed by Patrick Forterre, Eugene Koonin, and Gaspar Jekely
Fibrous pseudotumor of the scrotum.

Afibrous pseudotumor of the scrotal contents is a relatively rare nonneoplastic condition characterized by usually nodular, probably reactive proliferation of fibrous tissue and inflammatory cells, most often involving the tunica vaginalis. Although benign, this often clinically mimics testicular malignancy and is usually not diagnosed preoperatively, with radical orchiectomy often performed. We present a case of a fibrous pseudotumor involving the tunica vaginalis and epididymis with previously unreported early postoperative clinical recurrence, which was shown on pathologic examination to instead represent a postoperative nodular proliferative reaction.
Nucleolin Is a Second Component of the CD154 mRNA Stability Complex That Regulates mRNA Turnover in Activated T Cells

CD154 (CD40L) mRNA turnover is regulated in part at the posttranscriptional level by a protein complex (termed Complex I) that binds to a highly CU-rich region of the 3'UTR. Polypyrimidine tract-binding protein (PTB) has previously been identified as a major RNA-binding protein in Complex I. Nondenaturing gel filtration of total extract from Jurkat T cells demonstrated that the CD154 mRNA-binding activity migrates as a approximately 200-kDa complex, indicating the presence of multiple complex-associated proteins. We have currently undertaken a biochemical approach to further characterize Complex I and observed that it segregates over DEAE-Sepharose into two subcomplexes (termed I-L and I-U). Furthermore, nucleolin was identified as a component of both subcomplexes and was shown that it is the major RNA-binding protein in I-U. To directly demonstrate the biological significance of Complex I binding to the CD154 transcript, cytoplasm from human Jurkat cells was fractionated over a sucrose gradient and the different cellular fractions subjected to immunoprecipitation with anti-PTB and anti-nucleolin Abs. RT-PCR of the immunoprecipitated products using CD154-specific primers clearly demonstrated that nucleolin and PTB are associated with CD154 mRNA in both the ribonucleoprotein and polysome fractions. These data strongly support a model whereby nucleolin and PTB are integral to the stability of CD154 mRNA and are components of the CD154 ribonucleoprotein particle associated with actively translating ribosomes.
Implementation of competency-based medical education: are we addressing the concerns and challenges?

Context Competency-based medical education (CBME) has emerged as a core strategy to educate and assess the next generation of physicians. Advantages of CBME include: a focus on outcomes and learner achievement; requirements for multifaceted assessment that embraces formative and summative approaches; support of a flexible, time-independent trajectory through the curriculum; and increased accountability to stakeholders with a shared set of expectations and a common language for education, assessment and regulation. Objectives Despite the advantages of CBME, numerous concerns and challenges to the implementation of CBME frameworks have been described, including: increased administrative requirements; the need for faculty development; the lack of models for flexible curricula, and inconsistencies in terms and definitions. Additionally, there are concerns about reductionist approaches to assessment in CBME, lack of good assessments for some competencies, and whether CBME frameworks include domains of current importance. This study will outline these issues and discuss the responses of the medical education community. Methods The concerns and challenges expressed are primarily categorised as: (i) those related to practical, administrative and logistical challenges in implementing CBME frameworks, and (ii) those with more conceptual or theoretical bases. The responses of the education community to these issues are then summarised. Conclusions The education community has begun to address the challenges involved in implementing CBME. Models and guidance exist to inform implementation strategies across the continuum of education, and focus on the more efficient use of resources and technology, and the use of milestones and entrustable professional activities-based frameworks. Inconsistencies in CBME definitions and frameworks remain a significant obstacle. Evolution in assessment approaches from in vitro task-based methods to in vivo integrated approaches is responsive to many of the theoretical and conceptual concerns about CBME, but much work remains to be done to bring rigour and quality to work-based assessment.
Determination of renal molar concentrations of phosphorus-containing metabolites in vivo using 31P NMR.

A technique to determine absolute metabolite concentrations of the kidney in vivo using 31P NMR is described. The technique is based on the use of methylphosphonic acid (MPA), which gives rise to a well-resolved peak upfield from in vivo phosphorous metabolite resonances, as an “internal standard.” The method involves acquisition of a fully relaxed kidney spectrum with an implanted coil followed by intravenous infusion of MPA (4 ml of 150 mM) for a period of 30 min. The animal is then sacrificed to insure a steady state level of renal MPA and another spectrum is obtained. From these two spectra the ratio of intensities of MPA to β-ATP was derived. In the method used here, no significant contribution from tissues outside the kidney was observed. In addition, a relatively homogenous distribution of MPA throughout the kidney was achieved. The amount of MPA per gram wet weight of kidney was also obtained through NMR methods by placing the excised organ in a phosphate-calibrated solenoidal coil. The calibration spectra along with the ratio of intensities for MPA/β-ATP were used to calculate the number of micromoles of ATP per gram wet weight of kidney. Infusion of a higher concentration of MPA (1.25 M) produced a visible MPA resonance in other organs besides the kidney. Thus, MPA could be useful in determining phosphate metabolite concentrations in other tissues. © 1987 Academic Press, Inc.
Electronic compensation of fiber nonlinearity for 40 Gb/s WDM transmission systems

We propose and analyze a novel signal processing technique to compensate fiber nonlinearity in 40G b/s long-haul WDM transmission systems. Our analysis shows that our technique can increase the overall system margin by ≫1.0 dB.
Radio interferential measurements of sea level oscillations with large tidal amplitude

A tide height measurement technique using S -band radio waves in an oblique incidence interferometer is reviewed. Generalization of the technique is described which reduces the required bandwidth of the radio frequency adjustment and increases its efficiency. This generalization, however, introduces an ambiguity in the height determination and also requires specification of the phase shift of the radio waves specularly reflected from the sea surface. The ambiguity is shown to be easily removable given coarse information about the expected time derivative of tidal height. The influence of the phase shift which contains sea-wave information is studied analytically and requirement in its specification is evaluated to have an accuracy of \pm1\deg . This corresponds to a tide height determination accuracy of \pm1 cm. The method is designed for coastal regions where a bistatic experiment geometry is feasible.
Electron-impact-induced transitions in molybdenum and their use in modelling of a moly-oxide discharge lamp

Theoretical results from multi-state non-relativistic R-matrix (close-coupling) calculations are presented for electron-impact-induced transitions between excited states of molybdenum. The results are then used in modelling a low-pressure mercury-free Ar-MoO3 discharge lamp. Despite the complexity in the structure description of such an open-shell target and the resulting challenges in subsequent collision calculations, it is shown that an ab initio calculation can predict the most important kinetic pathways leading to the emission of visible and ultraviolet radiation. Satisfactory quantitative agreement, within approximately a factor of 2, is obtained between the measured and modelled spectra of the molybdenum-oxide discharge lamp.
Requirement of upstream Hfq-binding (ARN)x elements in glmS and the Hfq C-terminal region for GlmS upregulation by sRNAs GlmZ and GlmY

Hfq is an important RNA-binding protein that helps bacteria adapt to stress. Its primary function is to promote pairing between trans-acting small non-coding RNAs (sRNAs) and their target mRNAs. Identification of essential Hfq-binding motifs in up-stream regions of rpoS and fhlA led us to ask the question whether these elements are a common occurrence among other Hfq-dependent mRNAs as well. Here, we confirm the presence of a similar (ARN)x motif in glmS RNA, a gene controlled by two sRNAs (GlmZ and GlmY) in an Hfq-dependent manner. GlmZ represents a canonical sRNA:mRNA pairing system, whereas GlmY is non-canonical, interfacing with the RNA processing protein YhbJ. We show that glmS interacts with both Hfq-binding surfaces in the absence of sRNAs. Even though two (ARN)x motifs are present, using a glmS:gfp fusion system, we determined that only one specific (ARN)x element is essential for regulation. Furthermore, we show that residues 66–72 in the C-terminal extension of Escherichia coli Hfq are essential for activation of GlmS expression by GlmY, but not with GlmZ. This result shows that the C-terminal extension of Hfq may be required for some forms of non-canonical sRNA regulation involving ancillary components such as additional RNAs or proteins.