cssi/SciSciGPT-SciSciNet huggingface dataset:
TU‐EE‐A4‐06: Experimental Evaluation of Effective Detective Quantum Efficiency for Digital Radiographic Imaging Systems

Purpose: To develop and evaluate an experimental methodology for measuring the effective detective quantum efficiency (eDQE) of digital radiographicsystems which reflects the actual signal‐to‐noise performance of the system per unit exposure. Method and Materials: A NEXT phantom, simulating the scatter and attenuation properties of an adult human thorax was used to measure the resolution, noise, and scatter performance of a digital radiographicsystem(GE xQi) under conditions approximating those seen in clinical chest radiography. The resolution was measured in terms of the modulation transfer function(MTF) using an edge device placed at the phantom surface closest to the x‐ray tube. The noise was measured in terms of the noise power spectrum (NPS) of the region corresponding to the phantom center, acquired at three exposure levels. The scatter fraction (SF) was evaluated using a beam‐stop technique. These measurements along with measures of phantom attenuation and estimates of x‐ray flux and exposure were incorporated in the computation of the effective Detective Quantum Efficiency (eDQE). Results: The phantom exhibited a broad‐beam transmission fraction of 18.65%. The measuredscatter fraction in the presence of grid and phantom was 33%. The MTF of the system dropped by 25% at 1.0 cycles/mm when the edge was placed at the phantom surface due to scatter and focal spot blurring. The computed eDQE was assessed to be 0.038 and 0.028 at 0.5 and 1.0 cycles/mm, respectively (for E= 5.6 mR). Conclusion: Conventional DQE measurements performed under relatively idealized conditions do not accurately represent the relative performance of digital radiographicimagingsystems in routine clinical use. A more appropriate metric, the eDQE, measured under conditions that reasonably approximate those encountered clinically reflects the additional contributions from scatter, grid, and focal spot blurring, and provides a better estimate of the relative clinical performance of digital radiographicimagingsystems.
Automorphism Groups of Metacirculant Graphs of Order a Product of Two Distinct Primes

Let p and q be distinct primes. We characterize transitive groups G that admit a complete block system of q blocks of size p such that the subgroup of G which fixes each block set-wise has a Sylow p-subgroup of order p. Using this result, we prove that the full automorphism group of a metacirculant graph Γ of order pq such that Aut(Γ) is imprimitive, is contained in one of several families of transitive groups. As the automorphism groups of vertex-transitive graphs of order pq that are primitive have been determined by several authors, this result implies that automorphism groups of vertex-transitive graphs of order pq are known. We also determine all nonnormal Cayley graphs of order pq, and all 1/2-transitive graphs of order pq.
n-particle cross sections in diffraction-production models

We show how a simple ${t}_{min}$ effect can significantly alter the ${\ensuremath{\sigma}}_{n}\ensuremath{\sim}\frac{1}{{n}^{2}}$ rule found in most diffractive models of particle production. Data on $\mathrm{pp}$, ${\ensuremath{\pi}}^{\ensuremath{-}}p$, and ${K}^{\ensuremath{-}}p$ collisions appear consistent with ${n}^{2}{\ensuremath{\sigma}}_{n}\ensuremath{\sim}\mathrm{exp}(\ensuremath{-}\frac{{n}^{4}}{s})$, which implies that (1) double diffraction dissociation is the dominant feature, and (2) $〈n〉\ensuremath{\sim}\mathrm{ln}s$, but correlation functions rise much more slowly than in earlier treatments. Critical comments on diffractive models are given.
Notch Ductile-to-Brittle Transition Due to Localized Inelastic Band

Holes are often drilled in a panel for cooling or fastening. For a panel made of a monolithic ceramic, such a hole concentrates stress, reducing load-carrying capacity of the panel by a factor of 3. By contrast, for a ductile alloy panel, plastic flow relieves stress concentration so that the small hole does not reduce load-carrying capacity. A panel made of ceramic-matrix composite behaves in the middle: matrix cracks permit unbroken fibers to slide against friction, leading to inelastic deformation which partially relieves stress concentration. Load-carrying capacity is studied in this paper as an outcome of the competition between stress concentration due to the notch, and stress relaxation due to inelastic deformation. The inelastic deformation is assumed to be localized as a planar band normal to the applied load, extending like a bridged crack. The basic model is large-scale bridging. A material length, δ0 E/σ0 , scales the size of the inelastic band, where σ0 is the unnotched strength, δ0 the inelastic stretch at the onset of rupture, and E Young’s modulus. Load-carrying capacity is shown to depend on notch size a, measured in units of δ0 E/σ0 . Calculations presented here define the regime of notch ductile-to-brittle transition, where ceramic-matrix composites with typical notch sizes would lie. Both sharp notches and circular holes are considered. The shape of the bridging law, as well as matrix toughness, is shown to be unimportant to load-carrying capacity.
Process engineering, biology and profitability of a new protein biosynthesis method

Abstract A new process for the production of Single Cell Protein is discussed. The new features of the process are mainly: use of 95% pure O 2 rather than air, use of several parallel fermentation units rather than one very large ferment, use of a special vacuum drier. These features result in very low operation cost and high availability of the plant. The yeast produced is of high biological value and may be used for human as well as animal consumption.
Electronic structure of a self-interaction-corrected lithium cluster

Applying a self-consistent, self-interaction-correction (SIC) procedure to a 15-atom lithium cluster results in a lowering of the valence eigenvalues to about 1.5 eV below those of the local density approximation (LDA), with 1s core-state energies dropping to over 18 eV below the LDA. The lowered Fermi level yields a good approximation to the ionization energy as computed by transition-state theory. A significant broadening of the valence energy range to 95% of a bulk LDA calculation is seen, and some migration of valence-electron density into the cluster occurs as a result of the redistribution of orbital density. Application of the SIC with the LDA orbitals yields eigenvalues very close to those obtained with the self-consistent, corrected orbitals, implying that the LDA orbitals are reasonable substitutions for those of the SIC. Simple arguments show that the largest atomic metal clusters amenable to electronic-structure calculation in the LDA retain non-negligible self-energy errors in the eigenvalues of their free-electron-like orbitals.
Lake Stanley, A Low Stage of Lake Huron Indicated by Bottom Sediments

Core samples taken in northwestern Lake Huron, from present depths ranging from 110 to 436 feet, show a sequence of deep-water lake clays which is cut by an unconformity extending down to a present depth of 230 feet. The unconformity is marked by a thin layer of sand and shallow-water fossils, and these are overlain by clay. Allowing for an estimated 160 feet of uplift since the zones below the unconformity were truncated, the unconformity is interpreted as evidence of a low-level lake stage at 190 feet above present sea level. This is the extreme low stage of Lake Huron, inferred by Stanley (1936) and named the Stanley Stage by Hough (1955). A conformable zone of silt occurring within the lake clays and extending from 230 to 338 feet (present depths) is considered a shallow water deposit of the Stanley Stage. Deep-water clays, in depths below the Stanley level, have grain size variations which may correlate with changing depths of water resulting from the combination of changes in lake level and elevation of the bottom.
Molecular flexibility demonstrated by paramagnetic enhancements of nuclear relaxation. Application to alamethicin: a voltage-gated peptide channel

A nitroxide spin label attached to the C-terminus of the channel forming peptide alamethicin produces an enhancement of the nuclear spin-lattice relaxation rates of peptide protons as a result of both intermolecular and intramolecular magnetic dipole-dipole interactions. The intermolecular contribution provides evidence that alamethicin monomers collide preferentially in a C-terminal-to-N-terminal configuration in methanol. From the intramolecular paramagnetic enhancement of nuclear spin-lattice relaxation times, effective distances between the unpaired electron on the nitroxide at the C-terminus of alamethicin and protons along the peptide backbone were calculated. These distances are much shorter than distances based on the reported crystal structure of alamethicin, and cannot be accounted for by motion in the bonds that attach the nitroxide to the peptide. In addition, the differences between distances deduced from the nuclear spin relaxation and the distances seen in the crystal structure increase toward the N-terminal end of the peptide. The simplest explanation for these data is that the alamethicin backbone suffers large structural fluctuations that yield shorter effective distances between the C-terminus and positions along the backbone. This finding can be interpreted in terms of a molecular mechanism for the voltage-gating of the alamethicin channel. When the distances between a paramagnetic center and a nucleus fluctuate, paramagnetic enhancements are expected to yield distances that are weighted by r-6, and distances calculated using the Solomon-Bloembergen equations may more nearly represent a distance of closest approach than a time average distance.(ABSTRACT TRUNCATED AT 250 WORDS)
Study of the Ca2+/Na+ exchange mechanism in vesicles isolated from apical membranes of lens epithelium of spiny dogfish (Squalus acanthias) and bovine eye.

Abstract Apical membrane vesicles of dogfish and bovine lens epithelium were prepared by differential centrifugation and Mg2+ precipitation. Enrichment of the apical enzyme markers, for Na+, K+-ATPase was achieved. Na+, K+-ATPase was enriched 25·9-fold and 23·6-fold for dogfish and bovine lens epithelia, respectively, and acid phosphatase was enriched 10·4-fold and 12·6-fold, respectively. There was no enrichment of the cytoplasmic marker, NADH reductase. The majority of the apical membrane vesicles isolated from both dogfish and bovine lens epithelia were oriented right-side out. Electron micrographs of the purified vesicles show the presence of circular sealed vesicles with an average size of approximately 0·2–0·5 μm. Incubation of the vesicles with either the acetoxymethyl ester of SBFI, a new indicator for sodium, or with Fura-2, the calcium-specific indicator, leads to a large accumulation of the de-esterified SBFI or Fura-2 in the lens epithelial apical vesicles as determined by fluorescence measurements. When an outwardly direct Ca2+ gradient is formed across the vesicular membranes, the influx of Na+ is stimulated 77·8 and 63·0% for dogfish and bovine lens epithelia, respectively. When an outwardly directed Na+ gradient is formed across the vesicular membranes, the Ca2+ influx is also greatly enhanced. Both cases indicate that there is a bidirectional Ca2+/Na+ exchanger present in the apical side of the lens epithelial cell. The exchanger is inhibited by 50 μ m bepridil or by 200 μ m La3+. The stimulatory effects are also observed in membrane vesicles that are ‘short-circuited’ with valinomycin and high concentrations of K+. Hydrogen peroxide (H2O2), at a concentration of 100 μ m ; has a stimulatory effect on the Ca2+/Na+ exchange; however, the stimulation is totally blocked by either reduced glutathione (GSH) or catalase.
Heat generated by ultrasound in an absorbing medium

Nyborg’s [J. Acoust. Soc. Am. 70, 310–312 (1981)] derivation of heat generation density has been examined. An alternative approach has been developed to yield the same expression by assuming a complex wavenumber with the linear acoustic equations.
What is the Value of Incorporating Tear Osmolarity Measurement in Assessing Patient Response to Therapy in Dry Eye Disease

Purpose To evaluate the correlation between changes in tear osmolarity, symptoms, and corneal fluorescein staining in patients with dry eye disease (DED). Design Retrospective, clinic-based cohort study. Methods In this single-institution study, we reviewed the charts of 186 patients with DED from whom we had data on tear osmolarity, symptoms, and corneal fluorescein staining from 2 separate visits. Main outcomes included the correlation of the changes between the 2 visits for tear osmolarity (TearLab system), symptoms (Ocular Surface Disease Index), and corneal fluorescein staining (modified Oxford scheme). For tear osmolarity and corneal fluorescein staining the scores from the eye with highest readings were analyzed. The correlations were repeated on subgroups based on proposed cutoffs for DED severity and on patients' treatment. Results We found a modest, though statistically significant, correlation between changes in corneal fluorescein staining and symptoms of DED ( R = 0.31; P R = −0.091; P = .38) or between changes in tear osmolarity and corneal fluorescein staining ( R = −0.02; P = .80). This lack of correlation was consistent in all the subgroups studied. A multivariate analysis revealed that changes in corneal fluorescein staining had predictive value on symptom changes, whereas tear osmolarity changes did not. Conclusions Changes in tear osmolarity do not correlate significantly with changes in patient symptoms or corneal fluorescein staining in dry eye disease.
The Rise of the Russian Khalifat: The View from the Jihadist Side

Russia, similar to many other parts of the globe, continues to be affected by terrorism, mostly since the beginning of the conflicts in the Caucasus. While started by the Chechens after the beginning of the First Chechen War (1994-1996), terrorism and resistance to Moscow in general soon moved outside Chechen borders, absorbing representatives from other ethnic groups of the Caucasus and beyond. As a result, what originally had been mostly a Chechen nationalist movement finally transformed itself into a multi-ethnic force where the liberation of Chechnya from Russian rule became just one aspect of the struggle. Moreover, nationalist-minded Chechens seemed to have moved to the margins of the resistance, for increasing numbers of the resistance members could well go to the official Chechen leadership. While nationalistic and, in a way, a moderate model of the Chechen resistance became increasingly unworkable, jihadism provided an increasingly acceptable modus operandi . To start with, jihadism emphasises an ideological, Muslim identity and discards any sense of ethnicity, nationalism in general, that separates Muslims from each other. Secondly, jihadism promulgates the creation of a universal Khalifat as the final goal. Khalifat is seen as the ideal society, in a way similar to that of the “thousand-year rule of Christ” and/or communism, each of which actually transcends history as it is known. All of this has led to the increasing influence of jihadists among the members of the Chechen resistance, and a final split between them and the nationalist-minded members of the resistance. This paper presents a detailed analytic account of the recent developments within the Chechen resistance, as well as the jihadist ideology, and terrorism in the North Caucasus and Russia in general.
Evaluating rescaled range analysis for time series

Rescaled range analysis is a means of characterizing a time series or a one-dimensional (1-D) spatial signal that provides simultaneously a measure of variance and of the long-term correlation or "memory," The trend-corrected method is based on the statistical self-similarity in the signal: in the standard approach one measures the ratio R/S on the range R of the sum of the deviations from the local mean divided by the standard deviation S from the mean. For fractal signals R/S is a power law function of the length tau of each segment of the set of segments into which the data set has been divided. Over a wide range of tau's the relationship is: R/S = a tau H, where kappa is a scalar and the H is the Hurst exponent. (For a 1-D signal f(t), the exponent H = 2 - D, with D being the fractal dimension.) The method has been tested extensively on fractional Brownian signals of known H to determine its accuracy, bias, and limitations. R/S tends to give biased estimates of H, too low for H > 0.72, and too high for H or = 0.5, that is, for signals with positive correlations between neighboring elements. Rescaled range analysis has poor convergence properties, requiring about 2,000 points for 5% accuracy and 200 for 10% accuracy. Empirical corrections to the estimates of H can be made by graphical interpolation to remove bias in the estimates. Hurst's 1951 conclusion that many natural phenomena exhibit not random but correlated time series is strongly affirmed.
Acute and chronic dose/response effect of benzene inhalation on the peripheral blood, bone marrow, and spleen cells of CD-1 male mice.

Abstract Inhaled benzene hematotoxicity to recognize stem cell progeny was studied in male CD-1 mice exposed for 6 hr/day × 5 days to one of the following mean benzene concentrations: 1.1, 9.9, 103, 306, 603, 1276, 2416, and 4862 ppm. Additional groups of mice were exposed for 6 hr/day × 5 days/week × 10 weeks to 9.6 ppm, or 6 hr/day × 5 days/week × 26 weeks to 302 ppm. Following the 5-day exposures, granulocytopenia and lymphocytopenia were observed at levels ≥ 103 ppm with no change in WBC differential. RBC counts were depressed only at the two highest exposure levels while hematocrits were variably affected and showed no clear dose/response effect. Marrow and splenic cellularities were reduced at all levels ≥ 103 ppm. Marrow lymphocytes, splenic lymphocytes, and marrow granulocytes were reduced in accordance with the reduction in total cellularity, however, splenic granulocytes and spleen weights were depressed at almost all exposure levels. Nucleated RBCs in the marrow and spleen were depressed at almost all levels ≥ 103 ppm. Exposure for 50 days to 9.6 ppm benzene, a total dose equivalent to that delivered over 5 days at 103 ppm, induced no detectable changes in the peripheral blood or bone marrow, however, increases in splenic weight and cellularity were observed. Twenty-six weeks of exposure to 302 ppm benzene resulted in lymphocytopenia and anemia. Marrow cellularity was reduced to 32% of control and was due primarily to a reduction in lymphocytes and granulocytes. Spleen cellularity and weight were reduced to 17 and 67% of control, respectively. Decreased spleen cellularity was due primarily to a reduction in lymphocytes to 5% of control. These extended exposures to 302 ppm benzene resulted in atypical cell morphology in the peripheral blood, bone marrow, and spleen.
Fishing and Farming at Lake Chad: Responses to Lake‐level Fluctuations

Lake Chad lies at the southern extreme of the Sahara Desert and is well known for large fluctuations in its surface area this century. Seasonal fluctuations, however, have received much less attention. This paper presents the results of two complimentary research efforts on the south-west shore of the lake. These illustrate how important both inter and intra-annual fluctuations in the level of the lake are, both in terms of their impact on the environment and in the response of the communities living on the lake shore. The paper compares a time series of the fluctuations in the level of Lake Chad as monitored by the TOPEX/POSEIDON satellite with findings from participatory research with the communities of the south-west lake shore. It shows how the communities of the lake have responded to lake-level fluctuations with their livelihood choices. These results are used to show that although vastly different in scope, a high degree of complimentarity exists between remotely-sensed information and community-based research and that they are of potentially great value to development initiatives on the shores of Lake Chad.
Operant Procedures to Eliminate Drooling Behavior in a Cerebral Palsied Adolescent

SUMMARY A 14-year-old male with cerebral palsy was subjected to operant conditioning procedures to eliminate drooling behavior. Positive reinforcement through the implementation of a penny reward system was the selected operant conditioning procedure used to increase non-drooling (swallowing) behavior. Statistical analysis of baseline and conditioning recordings indicated a significant decrease in drooling behavior beyond the .01 level of confidence. It is believed that, in some cases, operant procedures can be effective in eliminating or decreasing deviant behavior secondary to organic involvement. RESUME Utilisation de conditionnement instrumental pour eliminer le bavage chez un adolescent IMC Un garcon IMC de 14 ans a ete soumis a un conditionnement instrumental dans le but deliminer le bavage. Un renforcement positif par un systeme de recompense sous forme de petites pieces de monnaie a constitue le conditionnement instrumental choisi pour accroitre le conditionnement anti-bavage (deglutition). L'analyse statistique de 'etat de base et des resultats du conditionnement indique une diminution du bavage, significative a un seuil meilleur que 0,01. L'auteur pense que dans quelques cas, le conditionnement peut etre efficace pour eliminer ou decroitre un comportement anormal secondaire a une modification organique. ZUSAMMENFASSUNG Der Gebrauch von Steuerungsma βnahmen zum Ausschalten der Gewohnheit zu sabbem bei einem Jungling mit cerebraler Lahmung Ein 14 jahriger Jungling mit cerebraler Lahmung wurde den Prozeduren eines Reglersystems unterzogen, um die Gewohnheit zu sabbern auszuschalten. Als positive Bestarkung wurde ein Pfennig-Lohn-System entwickelt und als Reglersystem gewahlt, um die Gewohnung, nicht zu sabbern (also zu schlucken) zu bestarken. Die statistische Auswertung der Ausgangswerte und der Werte wahrend der Steuerungsmasnahmen zeigte einen signifikanten Ruckgang der Gewohnheit zu sabbern mit p weniger als 0, 01. Es wird angenommen, das in manchen Fallen Steuerungs—masnahmen bei der Ausschaltung oder Verminderung schlechter Gewohnheiten bei organischen Erkrankungen wirksam sein konnen. RESUMEN La utilizacion de procedimientos operantes para eliminar el comportamiento con sialorrea en un adolescente con paralisis cerebral Un muchacho de 14 anos con paralisis cerebral due sometido a procedimientos condicionantes para eliminar su sialorrea. El procedimiento elegido para aumentar el comportamiento sin sialorrea (deglucion) fue el de refuerzo positivo consistente en la recompensa a base de una pequena moneda. El analisis estadistico del comportamiento sin y con el condicionamiento indico una disminucion significativa del babeo mas alla de un nivel de confianza de 0, 01. Se cree que en algunos casos los procedimientos operantes pueden ser efectivos para eliminar o disminuir un comportamiento desviado secundario a una alteracion organica.
Prognostic Value of Cardiac Troponin in Patients With Chronic Kidney Disease Without Suspected Acute Coronary Syndrome: A Systematic Review and Meta-analysis

Background Clinicians face uncertainty about the prognostic value of troponin testing in patients with chronic kidney disease (CKD) without suspected acute coronary syndrome (ACS). Purpose To systematically review the literature on troponin testing in patients with CKD without ACS. Data sources MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials through May 2014. Study selection Studies examining elevated versus normal troponin levels in patients with CKD without ACS. Data extraction Paired reviewers selected articles for inclusion, extracted data, and graded strength of evidence (SOE). Meta-analyses were conducted when studies had sufficient homogeneity of key variables. Data synthesis Ninety-eight studies met inclusion criteria. Elevated troponin levels were associated with all-cause and cardiovascular mortality among patients receiving dialysis (moderate SOE). Pooled hazard ratios (HRs) for all-cause mortality from studies that adjusted for age and coronary artery disease or a risk equivalent were 3.0 (95% CI, 2.4 to 4.3) for troponin T and 2.7 (CI, 1.9 to 4.6) for troponin I. The pooled adjusted HRs for cardiovascular mortality were 3.3 (CI, 1.8 to 5.4) for troponin T and 4.2 (CI, 2.0 to 9.2) for troponin I. Findings were similar for patients with CKD who were not receiving dialysis, but there were fewer studies. No study tested treatment strategies by troponin cut points. Limitation Studies were heterogeneous regarding assays, troponin cut points, covariate adjustment, and follow-up. Conclusion In patients with CKD without suspected ACS, elevated troponin levels were associated with worse prognosis. Future studies should focus on whether this biomarker is more appropriate than clinical models for reclassifying risk of patients with CKD and whether such classification can help guide treatment in those at highest risk for death. Primary funding source Agency for Healthcare Research and Quality.
Quantitative assay for mutation in diploid human lymphoblasts using microtiter plates

We describe a microtiter plating technique which eliminates the need for soft agar and fibroblast feeder layers to determine the colony-forming ability of diploid human lymphoblast lines. The calculation of cloning efficiency is based on the Poisson distribution, and we present a statistical method for calculating confidence intervals. We have applied this technique to the comcomitant examination of induced mutation at the putative loci for hypoxanthine guanine phosphoribosyl transferase, thymidine, kinase, and Na+/K+ adenosine triphosphatase.
Long-term risk preference and suboptimal decision making following adolescent alcohol use

Individuals who abused alcohol at an early age show decision-making impairments. However, the question of whether maladaptive choice constitutes a predisposing factor to, or a consequence resulting from, alcohol exposure remains open. To examine whether a causal link exists between voluntary alcohol consumption during adolescence and adult decision making the present studies used a rodent model. High levels of voluntary alcohol intake were promoted by providing adolescent rats with access to alcohol in a palatable gel matrix under nondeprivation conditions. A probability-discounting instrumental response task offered a choice between large but uncertain rewards and small but certain rewards to assess risk-based choice in adulthood either 3 weeks or 3 months following alcohol exposure. While control animals' performance on this task closely conformed to a predictive model of risk-neutral value matching, rats that consumed high levels of alcohol during adolescence violated this model, demonstrating greater risk preference. Evidence of significant risk bias was still present when choice was assessed 3 months following discontinuation of alcohol access. These findings provide evidence that adolescent alcohol exposure may lead to altered decision making during adulthood and this model offers a promising approach to the investigation of the neurobiological underpinnings of this link.
Step trajectory analysis of spinal cord injured rats trained with neuromuscular electrical stimulation coordinated with robotic treadmill training

Applying neuromuscular electrical stimulation (NMES) during treadmill training (TT) has been shown to improve functional outcomes, such as gait speed and walking distance, in spinal cord injury (SCI) patients. However, ways to improve this combined NMES+TT therapy have not been investigated. We have developed NMES system for a rodent model of SCI to investigate whether and how more precisely timing the stimulation to robotically assisted hindlimb position might achieve rehabilitation of independent stepping after SCI. In our therapy (NMES+RTT), rodent ankle flexor muscles are stimulated while the hindlimbs are robotically driven through pre-programmed trajectories during treadmill training. The objectives of the work presented here were to quantify changes in step trajectory resulting from our combined NMES+RTT therapy and compare those effects with those induced by robotic treadmill training (RTT) alone. Animals were spinally contused to model severe SCI, and either received 2 weeks of NMES+RTT followed by 2 weeks of RTT (n=6) or 2 weeks of RTT followed by 2 weeks of NMES+RTT (n=7). Changes in step trajectories after training were analyzed. According to a deviation measure we developed, the step trajectories improved after either NMES+RTT or RTT training but more closely matched the desired pre-programmed trajectories after NMES+RTT than after RTT only. The step trajectories are also more consistent, as indicated by a coefficient of variation measure, after training and more so after NMES+RTT than after RTT only. These preliminary results from our NMES+RTT vs. RTT study are consistent with the hypothesis that appropriately timing NMES with hindlimb movements during stepping is an effective therapy for restoring the ability to step after spinal cord injury.
Molecular weights of arginase from different species.

Abstract 1. 1. Gel filtration and density gradinet centrifugation were used to estimate the mol. wt. of arginase from the land planarian Bipalium kewense , the land snail Helix aspersa and the laughing gull Larus atricilla . The mol. wt. of arginase from the land planarian and from the land snail was ∼240,000, while that from the gull was ∼120,000. 2. 2. A considertion of the known molecular weights of arginases from different species indicates there is no general correlation between the mol. wt. of arginase from a given species and that species' excretory nitrogen metabolism.
Supporting reflection on dementia care using proximity sensors

Dementia care requires care home staff to constantly balance daily duties and ad hoc demands. Reflection on the resulting patterns could help carers to improve their care practices. In this paper we describe the evaluation of new low-power proximity sensors in a care home to track and measure these patterns. Carers and residents wear sensors which broadcast a unique ID within a limited range, listen for other sensors, and store all received IDs to measure the co-location of other sensors. Using the sensors, on average 44% of a carer's shift could be matched to a specific resident or a documentation task. When the results were visualized to carers after the shift, carers could recognize behavior from the raw data and started to discuss care practices. The added value was more important to carers than their privacy.
Fast enzymatic preparation of L-dopa from tyrosine and molecular oxygen: a potential method for preparing [15O]L-dopa.

Abstract A fast, simple and inexpensive enzymatic preparation of 3,4-dihydroxyphenyl- l -alanine ( l -DOPA) from molecular oxygen and tyrosine using mushroom tyrosinase is described. The theoretical incubation time for production of [ 15 O] l -DOPA with maximal specific activity from [ 15 O]O 2 can be calculated to be about 3 min. In practice, using a specially-designed glass reaction chamber to facilitate the incorporation of gaseous molecular oxygen into l -DOPA with zero lag-time, a 3 min reaction with 1% oxygen in nitrogen results in the formation of approx. 3.9 μmol of l -DOPA, representing conversion of about 14% of the tyrosine substrate. Given access to a supply of [ 15 O]O 2 , the method should be applicable to the preparation of [ 15 O] l -DOPA for use as a PET tracer.
The calvinist cortex: Penetrating evolutionary predestination commentary on cortex, countercurrent context, and dimensional integration of lifetime memory by Bjorn Merker

Theories of everything can expect to encounter a high rate of skepticism. The “everything” that includes evolution of the brain, the fundamental connectivity, physiology and expandability of the cortex and all of personal experience is certainly in that class, but Merker’s “Cortex, countercurrent context, and dimensional integration of lifetime memory” counters skepticism surprisingly well. This paper opens up an organizational level of the brain to consideration in an evolutionary context in a way I have not seen before. I will address my commentary principally to the first part of the paper, which discusses the proliferation of the cortex and to lesser extent the hippocampus; the correlation of relative cortex size with longevity, and the central notion of the cortex as the storage site of long-term memory. Merker concentrates on the cortex, and the utility of its pattern of connectivity in long term storage in terms of contextualized personal history. The complementary work of my colleagues and myself has focused on developmental structure in the pattern of brain size changes, and the push-pull relationship of the relative size of the limbic system and isocortex in primates. Primates have somewhat altered a highly-conserved mammalian developmental schedule in order to increase the relative size of the
Four new species of Chusquea (Poaceae: Bambusoideae) from Brazil and Ecuador

Four new species ofChusquea—C. bahiana, C. bradei, C. leonardiorum, andC. loxensis—are described and illustrated.Chusquea bahiana andC. bradei, classified within subg.Rettbergia withinChusquea based on their infravaginal, geniculate branching and spatheate, often contracted inflorescences, are endemic to the Atlantic forests of Bahia and Espirito Santo, Brazil, where they are relatively uncommon.Chusquea leonardiorum andC. loxensis are native to the paramos of southern Ecuador;C. leonardiorum is moderately widespread, butC. loxensis is known from only two populations in the Parque Nacional Podocarpus in the province of Loja. These two species are allied withChusquea sect.Chusquea based on their erect to arching or scandent habit, extravaginal branching, and relatively numerous subsidiary branches per node.
Age-Related Smoking Progression among Adolescents in China

Abstract Purpose This study examined the differences in smoking progression between middle and upper school students. Methods The China Seven Cities Study (CSCS) is a longitudinal cohort study. The current sample consists of subjects with both baseline and one-year follow-up measures collected between October 2002 and December 2003. There were 4842 students from 62 middle schools and 5806 students from 83 upper schools. Multilevel random-coefficient modeling techniques were applied. Results Among male never or lifetime ever smokers, middle school students were susceptible to transitioning more rapidly than upper school students (never - RR: 1.272, 95% confidence interval [CI]: .985–1.642; lifetime ever - RR: 1.497, 95% CI: .979–2.290). Among female lifetime ever smokers, middle school students were more likely to progress than upper school students (RR: 1.353, 95% CI: 1.038–1.763). Conclusion This longitudinal study is the first to explore differences in smoking progression among adolescents in China. The results revealed that over a one-year interval, there was greater progression across smoking trajectories during early adolescence (corresponding to middle school) than later adolescence (upper school). This is consistent with the neurological development hypothesis, but does not rule out alternative explanations. These findings are important to consider relative to the content and timing of prevention interventions in China where smoking rates approach 70% in adult males and are increasing rapidly in women.
Inversion of Soil Conductivity Profiles from Electromagnetic Induction Measurements

Noninvasive electromagnetic (EM) induction techniques are used for salinity monitoring of agricultural lands and contaminant detection in soils and shallow aquifers. This study has four objectives. The first objective is to summarize an earlier linear model of the response of the EM38 ground conductivity meter and to discuss a more accurate nonlinear response model. The second objective is to verify experimentally whether the linear and nonlinear models derived for homogeneous media are valid in heterogeneous soil profiles. The third objective is to present an inverse procedure that combines the nonlinear model with Tikhonov regularization. The fourth objective is the experimental verification of inverse procedures with the linear and nonlinear models for inversion of soil conductivity profiles using aboveground electromagnetic induction measurements on fourteen saline Californian soil profiles. The linear and nonlinear models derived for homogeneous media are indeed valid in heterogeneous soil profiles. However, since the errors of the linear model are approximately double those of the nonlinear model, the latter is the preferred one. A small difference was found in the errors of the inverse procedures between the linear and nonlinear models. In this study, the inverse procedures with the linear model and with the nonlinear model produce equally good solutions at EM38 measurements below 100 mS m -1 , while at higher electrical conductivities the inverse procedure with the nonlinear model appears to yield slightly better results. The inverse procedure with the linear model is preferred for all conductivities since it needs considerably less computer resources.
Affective Neuroscience: Tracing the Trace of Fear

The trace of fear has been elusive and difficult to discern in the human brain. Researchers have come up with a clever new way to track it down.
Kinetics of Enzymes with Iso-Mechanisms: Solvent Isotope Effects

Abstract Kinetic isotope effects on enzymatic reactions which employ general acid or general base catalytic mechanisms may arise during reprotonations of free enzyme. These effects reveal kinetically significant isomerizations of the free enzyme, or iso-mechanisms. The effects are expressed kinetically at high concentrations of substrate, on V max or k cat , but only thermodynamically at low substrate, on V max / K m . The effects are also expressed on the noncompetitive inhibition constant of product inhibition, K iip , because this parameter is dependent upon the steady-state concentration of the product form of free enzyme. A normal isotope effect on isomerization will decrease V max and K iip , but not necessarily to the same degree. Which is greater will depend upon how rate-limiting the isomerization is to a complete turnover. Together they are related to the full effect on isomerization, D k iso , by their product: D k iso = D V max D K iip . Moreover, precisely how rate-limiting the isomerization is to a turnover can be shown to be numerically equal to ( D V max − 1)/( D K iip D V max − 1), which surprisingly, holds whether there are other isotope effects present or not. The new relationships applied to published data on bovine carbonic anhydrase II reveal an intrinsic solvent isotope effect of D k = 9 ± 4, and an iso step that is less than 80% rate-limiting. Applied to porcine pepsin, a significant D V is accompanied by excessive standard error on D K iip , precluding the calculation of a definitive intrinsic solvent isotope effect.
The fine structure of prokaryotic-eukaryotic cell junctions

The fine structural characteristics of junctional complexes formed between endemic colon bacteria and mucosal epithelial cells are presented. The attachments are permanent and do not precede invasion of the mucosa by the bacteria. The mucosal cells do not exhibit inflammatory or degenerative responses which characterize similar junctions in the intestinal mucosa of other mammals. The morphological features of the junctional complexes closely resemble attachments between symbiotic bacteria and the surface of host protozoans. A highly organized arrangement of filaments in the junctional complex may originate from mucopolysaccharide filaments associated with the mucosal cell surface or from capsular material surrounding the bacterial cell.
Concentric Tube Robots as Steerable Needles: Achieving Follow-the-Leader Deployment

Concentric tube robots can enable new clinical interventions if they are able to pass through soft tissue, deploy along desired paths through open cavities, or travel along winding lumens. These behaviors require the robot to deploy in such a way that the curved shape of its shaft remains unchanged as the tip progresses forward (i.e., “follow-the-leader” deployment). Follow-the-leader deployment is challenging for concentric tube robots due to elastic (and particularly torsional) coupling between the tubes that form the robot. However, as we show in this paper, follow-the-leader deployment is possible, provided that tube precurvatures and deployment sequences are appropriately selected. We begin by defining follow-the-leader deployment and providing conditions that must be satisfied for a concentric tube robot to achieve it. We then examine several useful special cases of follow-the-leader deployment, showing that both circular and helical precurvatures can be employed, and provide an experimental illustration of the helical case. We also explore approximate follow-the-leader behavior and provide a metric for the similarity of a general deployment to a follow-the-leader deployment. Finally, we consider access to the hippocampus in the brain to treat epilepsy, as a motivating clinical example for follow-the-leader deployment.
Cochlear N1 depression produced by the new "loop" diuretic, bumetanide, in cats.

Abstract Bumetanide is a new “loop” diuretic. The other clinically used “loop” diuretics, ethacrynic acid and furosemide, are ototoxic; ethacrynic acid having the greater ototoxic liability. Therefore, it was of interest to determine if bumetanide was also ototoxic. The effect of intravenous bumetanide on the cochlear N 1 potentials of 22 cats was investigated and compared with the effects produced by sodium ethacrynate, its cysteine adduct and furosemide. The dose-response and dose-time to maximal effect curves of all these drugs are parallel, indicating that they may be producing ototoxicity by acting on the same cochlear site(s) and by way of the same mechanism(s) of action. The absolute ototoxic potency of bumetanide is approximately 6.5 times that furosemide. However, since the absolute diuretic potency of bumetanide is 40–60 times that of furosemide, its relative ototoxic potency is only 0.11–0.16 that of furosemide, when clinical dosages of the two drugs are considered. In addition, the duration of ototoxic action of bumetanide is similar to that of furosemide (and much less than that of ethacrynic acid). Therefore, it can be predicted from these studies that bumetanide will have even less ototoxic liability associated with its clinical use than does furosemide.
Ex‐Situ forced aeration of soil piles: A physical model

This paper presents a physical model of a technology in its early stages of development, which is here referred to as [open quotes]ex-situ forced aeration of soil piles,[close quotes] or, briefly, [open quotes]soil pile aeration.[close quotes] The model can be used in a dual capacity. First, it can be used to screen the technology; that is, to determine if, based on soil characteristics and contamination levels, the technology is at all applicable. Second, if the technology is deemed applicable, the model can be used as a design tool to optimize the basic design parameters, which are the pile radius and length, and the vacuum blower characteristics. The physical model presented in this paper provides a useful framework for understanding the influence that the design and soil parameters have on the effectiveness and/or viability of the technology, and can be a useful tool for preliminary design of aeration piles. 9 refs., 9 figs., 3 tabs.
The effects of endotoxin on cell detachment in vitro

Abstract The effects of endotoxin from E. coli and F. polymorphum on cell detachment was studied in vitro . L929 mouse fibroblasts or Ehrlich ascites carcinoma cells, cultured adherent to glass surfaces, were incubated with doses of endotoxin ranging from 5 to 200 μg/ml in serum-free media for 30 min. Cell detachment was assessed following exposure of cells to a known shearing force. Statistically significant facilitation of cell detachment was detected with doses of endotoxin of 10 μg/ml and higher. This detachment occurred in absence of demonstrable complement.
Peptostreptococcus infective endocarditis and bacteremia. Analysis of cases at a tertiary medical center and review of the literature

Peptostreptococcus infective endocarditis is rare but associated with high morbidity. We report two cases and evaluate all positive blood cultures for Peptostreptococcus at our institution, followed by a review of the literature. This organism causes a subacute presentation and cardiac valve pathology is a risk factor. Penicillin remains the treatment of choice.
Amylin, food intake, and obesity

Amylin, also known as islet amyloid polypeptide, identified in 1987, is a naturally occurring hormone, released by the beta cells of the pancreas and consists of 37 amino acids. Amylin seems to decrease food intake through both central and peripheral mechanisms and indirectly by slowing gastric emptying. The mean basal amylin concentration is higher in obese than in lean human subjects. The amylin response to oral glucose is also greater in obese subjects, whether or not they have impaired glucose tolerance. The elevated amylin levels in obesity may lead to down-regulation of amylin receptors and lessen the impact of postprandial amylin secretion on satiety and gastric emptying. Amylin administration may overcome resistance at target tissues, delay gastric emptying, and have potential for inducing weight loss in obese individuals.
Response to Open Peer Commentaries on “Withdrawal of Nonfutile Life Support After Attempted Suicide”

We are grateful for the careful reading and insightful responses of the several peer commentaries to our proposed approach to requests to withhold or withdraw life support therapies among patients ...
Earthquake swarms on transform faults

SUMMARY Swarm-like earthquake sequences are commonly observed in a diverse range of geological settings including volcanic and geothermal regions as well as along transform plate boundaries. They typically lack a clear mainshock, cover an unusually large spatial area relative to their total seismic moment release, and fail to decay in time according to standard aftershock scaling laws. Swarms often result from a clear driving phenomenon, such as a magma intrusion, but most lack the necessary geophysical data to constrain their driving process. To identify the mechanisms that cause swarms on strike-slip faults, we use relative earthquake locations to quantify the spatial and temporal characteristics of swarms along Southern California and East Pacific Rise transform faults. Swarms in these regions exhibit distinctive characteristics, including a relatively narrow range of hypocentral migration velocities, on the order of a kilometre per hour. This rate corresponds to the rupture propagation velocity of shallow creep transients that are sometimes observed geodetically in conjunction with swarms, and is significantly faster than the earthquake migration rates typically associated with fluid diffusion. The uniformity of migration rates and low effective stress drops observed here suggest that shallow aseismic creep transients are the primary process driving swarms on strike-slip faults. Moreover, the migration rates are consistent with laboratory values of the rate-state friction parameter b (0.01) as long as the Salton Trough faults fail under hydrostatic conditions.