bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Reasons for Non-Conformance of the Movable Latch Lock Plunger Releasing Current of Control Rod Drive Mechanism and Improvement Measures
Authors: Lan Yinhui , He Cuizhu , Duan Yuangang , Liu Feihua
Published: December 2017

As one of the most important equipment for reactivity control, Control Rod Drive Mechanism (CRDM), which is widely used in pressurized water reactor (PWR) nuclear power plant, has a series of important security functions. As an important component of the claw part in CRDM, the nonmagnetic shim materials have big influence on the movable latch lock plunger releasing current of CRDM. When cutting off the coil power, the nonmagnetic shim materials can block the magnetic circuit between the pole and latch lock plunger effectively and reduce the remanence suction force between magnetic pole and latch lock plunger, which can promote a quick latch lock plunger’s action and finish the step-jump and rod-release. In this paper, we introduce the background of non-conformance of the movable latch lock plunger releasing current of CRDM of PWR plant simply, and then we analyze the reasons of the non-conformance in detail, including a comprehensive analysis of various factors and a series of retest conclusions. Through specific analysis, the important role of nonmagnetic shims in CRDM and its big influence on movable latch lock plunger releasing current are proved. Based on research and test results, we show our optimized measures on the movable latch lock plunger releasing current in detail, from the perspective of technical specification for raw materials and improved processing technology during production. At last, one latch unit which occurred the movable latch lock plunger releasing current non-conformance and experienced a 1.7 million steps performance test is used in the following performance verification test. Being installed in this latch mechanism, our nonmagnetic shims finished an integral series of cold test, hot test and cold test after hot test. All of the test results meet our design requirements and all of the releasing current under cold condition is better than the results of 1.7 million steps performance test. Especially, the independently developed nonmagnetic shims improved the movable latch lock plunger releasing current significantly. In addition, other current results of hot test are equal to that of 1.7 million steps performance test. In conclusion, these optimized measures may not only provide data for solving the problem completely, but also provide reference for the manufacture of nonmagnetic shim materials in the future nuclear power plant.
New data on oribatid mites (Acari, Oribatida) of Cameroon: results of the Joint German-Cameroonian scientific expedition (April 2016)
Authors: Ermilov Sergey G. , Koehler Hartmut H.
Published: December 2017

The present study is based on oribatid mite material (Acari, Oribatida) collected in 2016 from herbaceous-grassy vegetation from a ReviTec site, University of Ngaoundéré, Cameroon. A list of identified taxa, including 29 species from 23 genera and 12 families, is provided; of these, one species is new to science, one species (Pseudoamerioppia barrancensis) is recorded in the Ethiopian region for the first time, and all other species are recorded in Cameroon for the first time. A new subgenus of the genus Pilizetes Sellnick, 1937 (Galumnidae), Pilizetes (Pseudopilizetes) Ermilov subgen. nov., with type species Pilizetes (Pseudopilizetes) camerunensis Ermilov sp. nov., is described. The new subgenus differs from Pilizetes (Pilizetes) by the presence of setiform notogastral setae, a complete dorsosejugal suture and bothridial setae with unilaterally dilated heads.
The Impact of Physical Activity on Serum Inflammatory Markers in Overweight Pubertal Boys: 24-Month Follow-Up Study
Authors: Remmel Liina , Tillmann Vallo , Mengel Eva , Kool Pille , Purge Priit , Lätt Evelin , Jürimäe Jaak
Published: December 2017

Purpose: To investigate the differences in the pattern of changes in serum inflammatory cytokines measured annually over a 24-month period, between less active and more active overweight boys. Participants/Methods: In total, 25 pubertal overweight boys were divided by their moderate to vigorous physical activity (MVPA) levels into 2 groups: less active group (LAG; n = 10; MVPA < 60 min/d) and more active group (MAG; n = 15; MVPA > 60 min/d). Physical activity was measured by 7-day accelerometry. Serum concentration of 13 inflammatory cytokines [interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, IL-1α, IL-1β, vascular endothelial growth factor, interferon-γ, tumor necrosis factor-α, monocyte chemotactic protein-1, epidermal growth factor, and C-reactive protein] was measured at baseline (T0), after 12 months (T1), and after 24 months (T2) from fasting blood samples. Results: Serum IL-6 level was significantly higher [LAG: 1.27 (0.86, 1.98) pg/mL; MAG: 0.80 (0.52, 0.84) pg/mL] at T0 and IL-8 level [LAG: 10.26 (8.80, 11.64) pg/mL; MAG: 7.42 (6.10, 9.54) pg/mL] at T2 in LAG compared with MAG. The changes over the study period varied between different inflammatory markers. None of the slopes of any measured markers were statistically different between the LAG and MAG, although the slopes of interferon-γ and IL-10 tended to be different between the groups. Conclusions: The pattern of changes over the study period varied between different inflammatory markers, but these changes were not different between the MVPA groups. More longitudinal studies are needed to investigate whether IL-6, IL-8, IL-10, and interferon-γ would be the choice of inflammatory markers to study the associations between obesity and physical activity in future.
Defining Accelerometer Nonwear Time to Maximize Detection of Sedentary Time in Youth
Authors: Cain Kelli L. , Bonilla Edith , Conway Terry L. , Schipperijn Jasper , Geremia Carrie M. , Mignano Alexandra , Kerr Jacqueline , Sallis James F.
Published: December 2017

Purpose: The present study examined various accelerometer nonwear definitions and their impact on detection of sedentary time using different ActiGraph models, filters, and axes. Methods: In total, 61 youth (34 children and 27 adolescents; aged 5–17 y) wore a 7164 and GT3X+ ActiGraph on a hip-worn belt during a 90-minute structured sedentary activity. Data from GT3X+ were downloaded using the Normal filter (N) and low-frequency extension (LFE), and vertical axis (V) and vector magnitude (VM) counts were examined. Nine nonwear definitions were applied to the 7164 model (V), GT3X+LFE (V and VM), and GT3X+N (V and VM), and sedentary estimates were computed. Results: The GT3X+LFE-VM was most sensitive to movement and could accurately detect observed sedentary time with the shortest nonwear definition of 20 minutes of consecutive “0” counts for children and 40 minutes for adolescents. The GT3X+N-V was least sensitive to movement and required longer definitions to detect observed sedentary time (40 min for children and 90 min for adolescents). VM definitions were 10 minutes shorter than V definitions. LFE definitions were 40 minutes shorter than N definitions in adolescents. Conclusion: Different nonwear definitions are needed for children and adolescents and for different model-filter-axis types. Authors need to consider nonwear definitions when comparing prevalence rates of sedentary behavior across studies.
Assessing Differences in Cardiorespiratory Fitness With Respect to Maturity Status in Highly Trained Youth Soccer Players
Authors: Doncaster Greg , Iga John , Unnithan Viswanath
Published: December 2017

Purpose: The purpose of the study was to examine differences in measures of cardiorespiratory fitness and determinants of running economy with respect to maturity status in a group of highly trained youth soccer players. Methods: A total of 21 highly trained youth soccer players participated in this study. On separate visits, players’ peak oxygen uptake (VO2peak), running economy at 3 different speeds [8 km·h−1, 80% gaseous exchange threshold (GET), and 95% GET], and pulmonary oxygen uptake (VO2) kinetics were determined. Players also performed a Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1). Players were categorized as either “pre-PHV” (peak height velocity) or “mid-PHV” group using the measure of maturity offset. Independent t tests and Cohen’s d effect sizes were then used to assess differences between groups. Results: The mid-PHV group was significantly taller, heavier, and advanced in maturity status. Absolute measures of VO2peak were greater in the mid-PHV group; however, when expressed relative to body mass, fat-free mass, and theoretically derived exponents, VO2peak values were similar between groups. Pre-PHV group presented a significantly reduced VO2 response, during relative submaximal running speeds, when theoretically derived exponents were used, or expressed as %VO2peak. VO2 kinetics (tau) were faster during a low (standing) to moderate (95% GET) transition in the pre-PHV group. Yo-Yo IR1 performance was similar between groups. Conclusion: Although measures of VO2peak and Yo-Yo IR1 performance are shown to be similar between groups, those categorized as pre-PHV group display a superior running economy at relative submaximal running speeds and faster taus during a low to moderate exercise transition than their more mature counterparts.
A Delphi developed syllabus for the medical specialty of sport and exercise medicine
Authors: Humphries David , Jaques Rod , Dijkstra Hendrik Paulus
Published: December 2017

Training in the medical specialty of sport and exercise medicine is now available in many, but not all countries. Lack of resources may be a barrier to the development of this important specialty field and the International Syllabus in Sport and Exercise Medicine Group was convened to reduce one potential barrier, the need to develop a syllabus. The group is composed of 17 sport and exercise medicine specialists residing in 12 countries (Australia, Canada, India, Ireland, Malaysia, the Netherlands, Qatar, South Africa, Sweden, Switzerland, the UK and USA). This paper presents the first phase of this project covering the domains and general learning areas of a specialist training syllabus in sport and exercise medicine.
Newborn in cardiogenic shock
Authors: Wagner Franziska , Gebauer Roman A , Paech Christian
Published: December 2017

Clinical introduction

A 2-month-old baby boy was referred to our centre due to tachycardia and acute heart failure. The ECG showed a narrow complex tachycardia with a heart rate of 300 beats per minute (Figure 1). Echocardiographically, a patent foramen ovale and a parachute mitral valve with mild regurgitation were diagnosed; cardiac function was highly impaired.

Figure 1

ECG (50 mm/s) showing the small complex tachycardia.

Question

Which of the following is the most likely diagnosis?

Ectopic atrial tachycardia

Atrial flutter

Chaotic atrial tachycardia

Focal micro re-entrant tachycardia

Atrial fibrillation
Diagnosing and managing footrot in sheep: an update
Authors: Green Laura , Clifton Rachel
Published: December 2017

In 2011, the Farm Animal Welfare Council proposed that by 2021 the prevalence of lameness in a flock of sheep should average less than 2 per cent. This has been made possible using the considerable amount of UK research into lameness, and footrot in particular, that has occurred since 2000. The average prevalence of lameness has already fallen as farmers adopt new recommended management practices: in 2004 the average prevalence of lameness was 10.2 per cent. By 2013 this had fallen to 3.5 per cent. This article summarises the current recommended approaches to diagnosis, treatment and control of footrot in sheep. It highlights that routine foot trimming is an unnecessary and potentially harmful procedure that contributes to the prevalence of lameness in some flocks. Where farmers practise the recommended management techniques the prevalence of lameness has been shown to fall to 2 per cent.
Chern–Simons theory in aether superspace
Authors: Ganai Prince A. , Mir Mudasir Ahmad , Rafiqi Ideed , Ul Islam Nadeem
Published: December 2017

In this paper, we will analyze the breaking of Lorentz symmetry using aether superspace. We will analyze the aether deformation of a Chern–Simons theory using this deformed superspace. As this theory, will have gauge symmetry, we will add gauge and ghost terms to the original action. We will analyze the nonlinear BRST symmetry for this theory. We also analyze the quantum BRST symmetry in BV formalism.
Status of a minimal composite Higgs theory
Authors: Fodor Zoltan , Holland Kieran , Kuti Julius , Mondal Santanu , Nogradi Daniel , Wong Chik Him
Published: December 2017

We analyze three sets of gauge ensembles in our extended physics program of a particularly important BSM gauge theory with a fermion doublet in the two-index symmetric (sextet) representation of the SU(3) BSM color gauge group. Our investigations include chiral symmetry breaking [Formula: see text] in the p-regime and [Formula: see text]-regime, the mass of the composite [Formula: see text] scalar, resonance spectroscopy, new physics from gauge anomaly constraints, and the role of stable sextet BSM baryons with Electroweak interactions in dark matter searches. Important new goals include studies of the [Formula: see text] scalar entangled with Goldstone dynamics in the p-regime and the [Formula: see text]-regime, the resonance spectrum with particular attention to emerging LHC signals, like recent hints for diphoton excess at 750 GeV or diboson anomalies in the 2 TeV range. All results reported here are preliminary before journal publication including some post-conference material for the discussion.
Recent results from SU(2) with one adjoint Dirac fermion
Authors: Athenodorou A. , Bennett E. , Bergner G. , Lucini B.
Published: December 2017

We present some results for SU(2) with one adjoint Dirac flavour from the lattice studies. Data for the spectroscopy, the static potential, topological charge, and the anomalous dimension of the fermionic condensate are included. Our findings are found to be inconsistent with conventional confining behaviour, instead pointing tentatively towards a theory lying within or very near the onset of the conformal window, with an anomalous dimension of the fermionic condensate of almost 1. Implications of these findings on the building of models of strongly-interacting dynamics beyond the standard model are discussed.
Dynamical origin of the electroweak scale and a 125 GeV boson
Authors: Tuominen K.
Published: December 2017

A fully dynamical origin for the masses of weak gauge bosons and heavy quarks of the Standard Model is considered. Electroweak symmetry breaking and the gauge boson masses arise from new strong dynamics, which leads to the appearance of a composite scalar in the spectrum of excitations. In order to generate mass for the Standard Model fermions, we consider extended gauge dynamics, effectively represented by four fermion interactions at presently accessible energies. By systematically treating these interactions, we show that they lead to a large reduction of the mass of the scalar resonance. Therefore, interpreting the scalar as the recently observed 125 GeV state, implies that the mass originating solely from new strong dynamics can be much heavier, of the order of 1 TeV. The couplings of the scalar resonance with the Standard Model gauge bosons and fermions are evaluated, and found to be compatible with the current LHC results.
Top-Mode pseudo-Nambu–Goldstone Boson Higgs model
Authors: Fukano Hidenori S.
Published: December 2017

We discuss the Top-Mode pseudo-Nambu–Goldstone Boson Higgs (TMpNGBH) model which has recently been proposed as a variant of the top quark condensate model in light of the 125 GeV Higgs boson discovered at the LHC. In this talk, we focus on the vacuum alignment and the phenomenologies of characteristic particles of the TMpNGBH model.
Holographic estimate of isospin splitting in hadron mass
Authors: Hong Deog Ki
Published: December 2017

We present the calculations of isospin splitting mass of pions and nucleons in the Sakai–Sugimoto model of holographic QCD. We find that [Formula: see text] and the electromagnetic mass difference of nucleons, [Formula: see text], taking the Kaluza–Klein scale, [Formula: see text].
Application of video microscopy in experimental soft matter physics
Authors: Feng Hao , Wang Huaguang , Zhang Zexin
Published: December 2017

Combining precise microscopic measurement with quantitative image analysis, video microscopy has become one of the most important, real-space experiment techniques to study the microscopic properties of soft matter systems. On the one hand, it provides a basic tool to observe and record the microscopic world. On the other hand, it offers a powerful experiment method to study the underlying physics of the microscopic world. In this paper, we review the development of the video microscopy, introduce the corresponding hardware and video processing software, and summarize the typical applications and recent progresses of video microscopy in colloidal suspensions. The future of the video microscopy in the soft condensed matter physics and interdisciplinary research is discussed.
On-chip photonic transistor based on the spike synchronization in circuit QED
Authors: Gül Yusuf
Published: December 2017

We consider the single photon transistor in coupled cavity system of resonators interacting with multilevel superconducting artificial atom simultaneously. Effective single mode transformation is used for the diagonalization of the Hamiltonian and impedance matching in terms of the normal modes. Storage and transmission of the incident field are described by the interactions between the cavities controlling the atomic transitions of lowest lying states. Rabi splitting of vacuum-induced multiphoton transitions is considered in input/output relations by the quadrature operators in the absence of the input field. Second-order coherence functions are employed to investigate the photon blockade and delocalization–localization transitions of cavity fields. Spontaneous virtual photon conversion into real photons is investigated in localized and oscillating regimes. Reflection and transmission of cavity output fields are investigated in the presence of the multilevel transitions. Accumulation and firing of the reflected and transmitted fields are used to investigate the synchronization of the bunching spike train of transmitted field and population imbalance of cavity fields. In the presence of single photon gate field, gain enhancement is explained for transmitted regime.
Considerable improvement of entanglement swapping by considering multiphoton transitions via cavity quantum electrodynamics method
Authors: Pakniat R. , Soltani M. , Tavassoly M. K.
Published: December 2017

Recently we studied the effect of photon addition in the initial coherent field on the entanglement swapping which causes some improvements in the process [Soltani et al., Int. J. Mod. Phys. B 31, 1750198 (2017)]. In this paper, we investigate the influence of multiphoton transitions in the atom–field interaction based on the cavity quantum electrodynamics on the entanglement swapping and show its considerable constructive effect on this process. The presented model consists of two two-level atoms namely A1and A2and two distinct cavity fields F1and F2. Initially, the atoms are prepared in a maximally entangled state and the fields in the cavities are prepared in hybrid entangled state of number and coherent states, separately. Making the atom A2to interact with the field F1(via the generalized Jaynes–Cummings model which allows m-photon transitions between atomic levels in the emission and absorption processes) followed by their detection allows us to arrive at the entanglement swapping from the two atoms A1, A2and the two fields F1, F2to the atom–field A1–F2system. Then, we pay our attention to the time evolution of success probability of detecting processes and fidelity. Also, to determine the amount of entanglement of the generated entangled state in the swapping process, the linear entropy is evaluated and the effect of parameter [Formula: see text] concerning the multiphoton transitions on these quantities is investigated, numerically. It is observed that, by increasing the number of photons in the transition process, one may obtain considerable improvement in the relevant quantities of the entanglement swapping. In detail, the satisfactorily acceptable values 1 and 0.5 corresponding to success probability and fidelity are obtained for most of the times during observing of the above-mentioned procedure. We concluded that the presented formalism in this paper is much more advantageous than our presentation model in our earlier work mentioned above.
Reliability Assessment of Safety Systems with Asymmetrical Redundancy Architecture
Authors: Rogova Elena , Lodewijks Gabriel , Calixto Eduardo
Published: December 2017

Application of an M-out-of-N redundancy architecture is a well-known measure for improving the reliability of safety systems. Most scientific papers addressing the reliability assessment of such systems consider a conventional homogeneous M-out-of-N redundancy architecture that is performed for identical channels. However, often in practice, an M-out-of-N redundancy architecture does not have identical channels. Reliability assessment of such heterogeneous systems (electrical/electronic and mechanical) with nonidentical channels and a combination of constant and nonconstant failure rates is considered in this paper. Such type of M-out-of-N redundancy architecture is introduced in this research as “asymmetrical redundancy”. It can be used for enhancing the reliability of old mechanical systems or for reducing mutual influence of channels and increase of diagnostic coverage. This paper also presents a new “window-based Markov method” for PFD[Formula: see text] (average probability of failure on demand) and PFH (average frequency of dangerous failures) calculation for systems with an asymmetrical redundancy architecture and compares the results with those obtained by using the steady-state semi-Markov method and Monte-Carlo simulation. The applicability of the developed method is demonstrated in a simple case study.
Effects of Sn doping on capacitive performance of σ-MnO2 on the high operating temperatures
Authors: Lin Hua , Miao Jie , Mao Zhou , He Shijie , Zhang Meng , Li Qing
Published: December 2017

The Sn-doped [Formula: see text]-MnO2 (Sn–MnO2) hollow structures was successfully prepared via a chemical process at room temperature (25[Formula: see text]C). Compared to pure MnO2, Sn–MnO2 shows an obviously enhanced capacitance and outstanding cycling performance at high operating temperature of 85[Formula: see text]C. For Sn–MnO2, the specific capacitance ([Formula: see text]) of 169.9[Formula: see text]Fg[Formula: see text] at current density of 1[Formula: see text]Ag[Formula: see text] was measured at 85[Formula: see text]C and retains over 90% of its initial capacitance after 1000 cycles. Meanwhile, the electrochemical properties of Sn–MnO2 were investigated on different temperatures (25[Formula: see text]C, 45[Formula: see text]C, 65[Formula: see text]C and 85[Formula: see text]C), and an improved capacitive performance was obtained with the temperature increasing.
Gender and the art of community relations
Authors: Mitchell Lesley
Published: December 2017

Aspects of one's personal identity can change the way you experience being part of a community, especially if you are in a minority group. The author reports on her experiences of conducting research with women who participate in the Debian Linux project.
Reflecting on robots, love, and poetry
Authors: Rhee Margaret
Published: December 2017

Finding the poetry in programming and the algorithms in poems
Caenorhabditis elegans: A Convenient In Vivo Model for Assessing the Impact of Food Bioactive Compounds on Obesity, Aging, and Alzheimer's Disease
Authors: Shen Peiyi , Yue Yiren , Zheng Jolene , Park Yeonhwa
Published: December 2017

Caenorhabditis elegans is a small free-living nematode that lives in temperate soil environments. It has been widely employed as an animal model in research involving obesity, aging, and neurodegenerative diseases, including Alzheimer's disease, because of its various advantages, such as small size, large number of progeny, completely sequenced genome, and short life span, over traditional animal models of vertebrates. These benefits contribute to an ideal research model organism. In this review, we provide an introduction to C. elegans and its applications in obesity, aging, and Alzheimer's disease studies, with the aim of stimulating scientists to use C. elegans as an experimental model in various fields of research.
Ultrasound-based lectures on cardiovascular physiology and reflexes for medical students
Authors: Paganini M. , Rubini A.
Published: December 2017

Ultrasound has become a widely used diagnostic technique. While its role in patient evaluation is well known, its utility during preclinical courses such as anatomy and physiology is becoming increasingly recognized. The aim of the present study was to assess the feasibility/utility of integrating ultrasound-based sessions into conventional undergraduate medical school programs of physiology of the cardiovascular system and cardiovascular reflexes and to evaluate student perceptions of an ultrasound-based didactic session. Second-year medical students enrolled in the University of Padova attended a didactic session during which basic concepts regarding ultrasound instrumentation, image production, and spatial orientation were presented. Five anatomic sectors (the heart, aorta, neck vessels, inferior vena cava, and femoral veins) were then examined on a volunteer. Student perceptions of the images that were projected, the usefulness of the presentation, and the reproducibility of the experience were assessed at the end of the lecture with an anonymous questionnaire consisting of positive and negative items that were rated using a 5-point Likert scale and with two questions. One hundred eleven students attended the lecture; 99% of them found it very interesting, and none considered it boring or a waste of time. More than 96% thought it helped them to gain a better comprehension of the subject and would recommend it to a colleague. In conclusion, as ultrasound has been found to be a valuable resource for the teaching of physiology of the cardiovascular system and cardiovascular reflexes, efforts should be made to integrate ultrasound sessions into the traditional human physiology curriculum.
Effect of veratridine on membrane potential of sartorius muscle from Rana pipiens
Authors: McKinney L. C.
Published: December 2017

The effect of veratridine on the membrane potential of sartorius muscles from Rana pipiens was studied. Membrane potential (Vm) was measured in Ringer solutions containing 2.5, 10, 30, 75, and 190 mM K+ in the absence and presence of veratridine. The product [K]o[Cl]o was kept at 300 mM2 to maintain Donnan equilibrium. External Na+ was lowered to 10 mM. Ouabain (100 microM) was present in all solutions. Vm vs. log [K]o curves were fit using the Goldman-Hodgkin-Katz equation with a single free parameter, alpha = PNa/PK (permeability ratio of Na to K). Veratridine (100 microM) causes alpha to increase 12.6 +/- 1.2-fold (n = 9), from 0.146 to 1.657. The effect of veratridine on Vm is dose dependent and reversible, with a time constant for washout of 40 min. The depolarization produced by veratridine is prevented by tetrodotoxin and by Mg, is sensitive to external Na concentration, and is insensitive to curare.
Micromethodology for measuring ATPase activity in renal tubules: mineralocorticoid influence
Authors: O'Neil R. G. , Dubinsky W. P.
Published: December 2017

The ATPase activity of rabbit isolated renal tubule segments was measured using a microtechnique in which the hydrolysis of ATP was enzymatically coupled to the appearance of an alkali-converted, highly fluorescent form of nicotinamide adenine dinucleotide. The methods are simple, reproducible, and have a high sensitivity in which picomole quantities of hydrolyzed ATP can readily be measured. Several methods for permeabilizing the cell membranes for measurement of Na+-K+-ATPase activity were evaluated, including osmotic (distilled water or 300 mM imidazole) and temperature (freezing) shock and addition of the nonionic detergent octylglucoside. An octylglucoside concentration of 0.5% was found to cause a maximum activation of the Na+-K+-ATPase and was comparable with that observed when tubules were permeabilized by exposure to distilled water and freezing. Incubation of tubules in 300 mM imidazole was less effective in permeabilizing the cell membranes. In all subsequent studies, the cells were permeabilized by exposure to distilled water and freezing as done by others. The methods were used to assay for the basal levels of Na+-K+-ATPase in the superficial proximal convoluted tubule, the superficial proximal straight tubule, and the cortical collecting tubule and were found to average 44.9 +/- 6.3, 26.4 +/- 2.4, and 11.8 +/- 2.2 pmol ADP X mm-1 X min-1, respectively. Furthermore, elevation of plasma mineralocorticoids by daily injections of deoxycorticosterone acetate (2 mg X kg-1 X day-1) for 4-15 days caused a doubling in the Na+-K+-ATPase activity of the cortical collecting duct, confirming the results of others. The methods presented can easily be adapted for microanalysis of other ATPases.
Localization of cAMP in dog and cat trachea: effects of beta-adrenergic agonists
Authors: Lazarus S. C. , Basbaum C. B. , Gold W. M.
Published: December 2017

Adenosine 3',5'-cyclic monophosphate (cAMP) is believed to mediate the transport of ions, water, and mucous glycoproteins in the respiratory tract. Because chemical measurements of total tissue levels of cAMP may not always reflect changes in specific cell types, we adapted standard immunocytochemical methods to examine the cellular localization of cAMP in dog and cat tracheae. The beta-adrenergic agonists terbutaline and isoproterenol increased immunoreactive cAMP in ciliated epithelial cells of dog and cat tracheae and in both serous and mucous gland cells of cat tracheae. Epithelial goblet cells did not respond to beta-adrenergic agonists in either species. This study provides information about the location of beta-receptors on individual cells in the trachea that is not available from chemical assays of either cAMP or beta-receptors in these tissues. Our results support the hypothesis that secretory functions in both serous and mucous submucosal gland cells and ciliated epithelial cells, but not goblet cells, may involve cyclic AMP-dependent mechanisms.
Involvement of transport of H+ equivalents in activation-induced alkaline shift in frog muscle
Authors: Connett R. J. , Hays E. T. , Gilda E. N.
Published: December 2017

Previous studies have shown that "activation" of frog skeletal muscle by low concentrations of caffeine (less than 2.5 mM) and K+ (5-20 mM) causes a steady-state alkaline shift and the appearance of H+ in the medium. Both responses are sensitive to blockers of calcium release from sarcoplasmic reticulum. A variety of conditions that inhibit H+-equivalent transport processes in several different tissues were tested for effects on the activation-induced alkaline shift. Blockers of anion transport (4-acetoamido-4'-isothiocyanostilbene-2,2'-disulfonic acid, furosemide, acetazolamide, and Cl- replacement) had no effect on the alkaline shift. Replacement of Na+ by Mg2+, tris(hydroxymethyl)aminomethane, or choline decreased the alkaline shift. Replacement of Na+ by Li+ had no effect. As little as 5 mM external Na+ gave 50% of the alkaline shift. In 15 mM sodium Ringer solution amiloride inhibited the alkaline shift. Lowering extracellular pH (pHe) inhibited the alkaline shift. At pHe less than 7.0 there was a small constant alkaline shift, whereas at pHe greater than 7.0 the shift was dependent on pHe. This pHe sensitivity was independent of changes of intracellular Ca2+ as determined by twitch potentiation or stimulation of Ca2+ flux. It was concluded that the alkaline shift is probably due to activation of a "H+" transport process requiring Na+ and sensitive to external or internal pH.
Increased ouabain sensitivity of cultured human fibroblasts from muscular dystrophy
Authors: Ledbetter M. L.
Published: December 2017

Muscular dystrophy is a disease characterized by wasting of muscle tissue in vivo and net loss of muscle cell protein in vitro. No comparable changes have been reported in other tissues, although all cells of affected individuals must carry the X-linked recessive mutation. On the hypothesis that predisposition to accelerated protein degradation might be latent in nonmuscle cells I investigated protein metabolism in skin fibroblasts from normal individuals and patients with Duchenne and Becker dystrophy. Under normal culture conditions rates of protein synthesis and protein degradation in the two groups of cultures were indistinguishable. Both types of cells responded to treatments that stimulate protein degradation and the extent of response was similar. Treatment with ouabain to reduce cell K+ content, and hence protein synthesis, had no effect on protein degradation in either group. Synthesis of protein was reproducibly more sensitive to ouabain in dystrophic than in normal strains, however, and the rate of protein synthesis was correlated with the steady-state K+ content. Eight out of nine dystrophic strains showed a greater sensitivity of K+ content to ouabain inhibition of the membrane Na+-K+ pump than four normal strains. This increased sensitivity could be conclusively attributed to increased efflux or decreased influx of K+, or to alterations in ouabain binding to intact cells. Others have observed membrane abnormalities in dystrophic muscle as well as in other cell types. Our findings may represent a physiological consequence of that abnormality.
Glucose uptake in porcine carotid artery: relation to alterations in active Na+-K+ transport
Authors: Lynch R. M. , Paul R. J.
Published: December 2017

In vascular smooth muscle (VSM), aerobic lactate production can account for as much as 30% of the basal rate of ATP production. Generally, glucose transport is thought to be the rate-limiting step for glycolysis in unstimulated VSM. In this work we provide evidence that the intracellular concentration of glucose is negligible in porcine carotid artery, indicating that glucose transport is rate limiting for its utilization. Since aerobic glycolysis appears to be coupled to active Na+-K+ transport in this tissue, we examined the effects of altering ion transport on glucose transport. Glucose uptake and 3-O-methyl-D-glucose transport were accelerated, though intracellular glucose remained negligible in artery rings that were incubated with 80 mM KCl, which is known to stimulate active Na+-K+ transport, as well as aerobic glycolysis and mechanical activity. On the other hand, inhibitors of active Na+-K+ transport (ouabain, Na+-free media), which also elicit mechanical activity, had little effect on sugar transport but significantly inhibited aerobic glycolysis and caused an intracellular accumulation of glucose. Our results indicate the following: 1) that glucose transport is regulated in VSM; 2) that the intracellular concentration of Ca2+ does not appear to regulate sugar transport, since changes in glucose and 3-O-methyl-D-glucose transport are not always seen in association with increased mechanical activity, and 3) that the decrease in aerobic glycolysis associated with the inhibition of active Na+-K+ transport is not due to a decrease in glucose transport but rather to an inhibition of glucose utilization.
Physiological responsiveness of isolated rabbit tracheal epithelial cells
Authors: Liedtke C. M. , Tandler B.
Published: December 2017

Surface tracheal epithelial cells (tracheocytes) from rabbit were isolated by treating intact tissue with chelators and proteolytic enzymes. The cells were viable as assessed by the following criteria: fluorescent viability staining, sequestration of lactate dehydrogenase, and maintenance of constant ATP levels. Radiolabeled Na+ was transported into cells with a rate constant of 0.06/min and an initial velocity of 1.6 nmol X 10(6) cells-1 X min-1 X beta-adrenergic agonists increased adenosine 3',5'-cyclic monophosphate (cAMP) levels in a time- and dose-dependent manner. The beta-adrenergic effects were potentiated by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine and blocked by propranolol. The tracheocytes retained the capacity to respond to beta-adrenergic agonists for at least 90 min after isolation. Two major cAMP binding proteins of apparent molecular weights of 50,000 and 54,000 were identified in tracheocytes with the photoaffinity label 8-N3-[32P]cAMP. Agents that increased cAMP levels in intact cells and unlabelled cAMP added to homogenates of cells that were not exposed to drugs decreased photoaffinity labeling. The two proteins correspond in electrophoretic mobility to the regulatory subunits of cAMP-dependent protein kinases I and II, respectively. The results demonstrate that the beta-adrenergic receptors and cAMP binding proteins identified in rabbit tracheal mucosa submucosa are present on tracheocytes, suggesting a role for these receptors in the regulation of tracheocyte physiological events.
Solid-state optical scanning system for remote measurements in biomechanical systems
Authors: Meiss R. A.
Published: December 2017

A remote optical sensing system, employing a self-scanning photodiode array, is described, and its operation is demonstrated for measurements of rapid dimensional changes in contracting smooth muscle preparations. The single-line sensor array, a commercially available charge-coupled device integrated circuit, with 256 elements at 25-microns intervals, is mounted in the image plane of an optical system focused on a backlit test object. The amplitude profile of each scan is proportional to the illumination reaching the individual sensory elements. Auxilliary circuitry generates a raster of successive scan lines on the face of a storage oscilloscope. Spatial and temporal information about the target and its motions may be derived from the displayed raster scan. Performance is illustrated using an artificial target and a muscle fiber bearing opaque markers. Successive lines may be scanned in as briefly as 5 ms (at 10-ms intervals) or in as long as 50 ms (at 1-s intervals). Each raster may contain up to 256 lines, although not all of the lines need to be displayed. The spatial resolution is determined by the photodiode spacing in the sensory array and by the magnitude of the optical system in use; as described here, the resolution is on the order of 0.2 mm for a 20-mm scan length.
Latency of pancreatic enzyme response to intraduodenal stimulants
Authors: Singer M. V. , Solomon T. E. , Wood J. , Grossman M. I.
Published: December 2017

In six dogs with pancreatic fistulas, secretin (500 ng . kg-1 . h-1) was given to provide a flow of pancreatic juice of about 1 drop/s. Amylase concentration was measured in each drop before and after rapid intraduodenal injection of L-tryptophan, sodium oleate, and NaCl or after rapid intraportal injection of cholecystokinin (CCK). Latency of response (time between injection and a sustained increase in amylase output greater than the mean + 3 SD of prestimulation output) was 0.30 min to tryptophan and 0.33 min to oleate. These were significantly (P less than 0.01) less than the latency to intraportal CCK (0.53 min). Atropine and truncal vagotomy increased the latency to tryptophan and oleate 10-fold but had no effect on the latency to intraportal CCK. We conclude that, since the latency of amylase response to intraduodenal stimulants was shorter than to intraportal CCK, the initial response is probably not due to release of hormones. The finding that atropine and vagotomy increased latency of response to intraduodenal stimulants indicates that a vagovagal cholinergic reflex mediates the early pancreatic enzyme response to intestinal stimulants.
Effect of genetic diabetes on enzymes of mouse intestinal brush-border membrane
Authors: Ramaswamy K. , Flint P. W.
Published: December 2017

Activities of intestinal enzymes were measured in genetically diabetic mouse of strain C57BL/KsJ-dbm to determine the long-term effects of genetic and uncontrolled diabetes on intestinal digestive function. Specific activities of enzymes were measured in intestinal homogenates, brush-border membrane fractions, and everted sacs from diabetic mice and their littermate controls. Sucrase, maltase, trehalase, alkaline phosphatase, and leucylnaphthylamidase activities were elevated in diabetes; lactase did not show any changes. The increases in disaccharidase activities in diabetes were in homogenates from both proximal and distal intestine but the increases in distal were more pronounced than in the proximal. Measurement of enzyme activities in brush-border membrane fractions showed a pattern similar to that observed in homogenates. Hydrolysis of sucrose and trehalose by everted sacs was markedly higher in the diabetic mice. It is therefore concluded that in genetic diabetes the digestive function of the intestine is stimulated, that the increased enzymes were incorporated into the brush-border membrane, and that the additional enzymes are accessible to the substrates in the intestinal lumen and so of physiological significance.
Receptors for vasoactive intestinal peptide and secretin on small intestinal epithelial cells
Authors: Binder H. J. , Lemp G. F. , Gardner J. D.
Published: December 2017

Binding of 125I-labeled vasoactive intestinal peptide (VIP) to dispersed enterocytes prepared from guinea pig small intestine was saturable, temperature dependent, and reversible, and reflected interaction of the labeled peptide with a single class of binding sites. Each enterocyte possessed approximately 60,000 binding sites and binding of the tracer to these sites could be inhibited by VIP [concentration for half-maximal effect (Kd), 12 nM] and by secretin (Kd greater than 1 micro M), but not by glucagon, gastrin, cholecystokinin, calcitonin, bombesin, litorin, physalaemin, substance P, eledoisin, serotonin, carbamylcholine, or histamine. With VIP and secretin, there was a close correlation between the relative potency for inhibition of binding of 125I-VIP and that for increasing cellular cAMP. For a given peptide, however, a 10-fold higher concentration was required for half-maximal inhibition of binding than for half-maximal stimulation of cellular cAMP. In addition to inhibiting binding of 125I-VIP and increasing cellular cAMP in enterocytes, secretin caused an increase in short-circuit current across guinea pig small intestine in vitro. Prostaglandin E1 increased cellular cAMP, but did not alter binding of 125I-VIP and the increase in cAMP caused by prostaglandin E1 plus VIP or secretin was equal to the sum of the increase caused by each agent alone.
Asymmetry in osmotic response of frog gastric mucosa
Authors: Villegas L.
Published: December 2017

The effects of hyperosmolality of the serosal and mucosal bathing solutions on the transmucosal net water and ion fluxes were studied in frog gastric mucosa. Addition of 100 mosM glucose to the solution at the serosal surface produces a reversed mucosal-to-serosal net water flux of 7.1 +/- 1.4 microliter . cm-2 . h-1. When added to the abolished spontaneous net water flux, this results in an increment in the net water flux of -17.8 +/- 1.4 microliter . cm-2 . h-1. Addition of the same amount of glucose to the solution at the mucosal surface produces an increment in the serosal-to-mucosal net water flux of 3.7 +/- 1.1 microliter . cm-2 . h-1 when the solution at the opposite surface was kept in 220 mosmol/kg H2O. Simultaneous increments of both solutions of 320 to 420 and 420 to 520 mosM changes the osmotic serosal-to-mucosal induced fluxes to 1.9 +/- 0.9 and 3.4 +/- 1.6 microliter . cm-2 . h-1, respectively. The initial spontaneous net water fluxes measured in 220, 320, and 420 mosM solutions were 11.3 +/- 0.9, 6.9 +/- 1.6, and -1.5 +/- 1.5 microliter . cm-2 . h-1. It is proposed that the osmotic water flux is asymmetric, independent of the solutions tonicities, and not significantly affected by the sweep of solutes at the mucosal surface.
Secretagogue stimulation of [14C]aminopyrine accumulation by isolated canine parietal cells
Authors: Soll A. H.
Published: December 2017

Isolated canine gastric mucosal cells accumulate [14C]aminopyrine (AP) when treated with histamine, gastrin, and carbachol. In fractions of varying parietal cell content, this accumulation of AP correlated with the parietal cell content. Cimetidine caused parallel displacement of the dose-response curve to histamine, but failed to alter the response to carbachol or gastrin. Atropine caused parallel displacement of the dose-response curve to carbachol, but failed to inhibit the response to histamine or gastrin. The dissociation constants (Kb) for cimetidine inhibition of histamine and for atropine inhibition of carbachol were found to be 1.0 micro M and 1.3 nM, respectively, values comparable to those reported for other tissues. Thus, the isolated parietal cell appears to have pharmacologically typical H2- and muscarinic receptors, with gastrin acting at a third receptor site. Isobutyl methylxanthine (IMX) and the cAMP analogues dibutyryl cAMP (DBcAMP) and 8-bromo cAMP (but not the same analogues of cGMP) also stimulated AP accumulation. Atropine failed to inhibit the responses to IMX or DBcAMP, whereas cimetidine did inhibit the response to IMX, but not to DBcAMP.
Effect of glucagon on gastrointestinal blood flow of dogs in hypovolemic shock
Authors: Bond J. H. , Levitt M. D.
Published: December 2017

A microsphere technique was used to study the effect of glucagon on blood flow to the different tissue layers of the stomach, small bowel, and colon of the dog in hypovolemic shock. In normal dogs, glucagon caused a twofold rise in flow to all layers of the stomach and colon, and a threefold increase to all layers of the small bowel. After administration of glucagon, a larger fraction of cardiac output was diverted to the gut microcirculation. In acute hypovolemic shock, intestinal perfusion was preserved relative to cardiac output inasmuch as cardiac output and gastric blood flow fell 75% and flow to the small bowel and colon fell by only about 50%. Glucagon markedly increased the fraction of cardiac output passing to the gut circulation in hypovolemic shock and, most importantly, sustained flow to the areas most prone to ischemic necrosis; gastric mucosa, colonic mucosa, and small intestinal villi. In more prolonged shock, however, glucagon precipitated fatal cardiovascular collapse unless part of the lost blood volume first was replaced. Glucagon, therefore, should not be used in patients in hypovolemic shock without prior replacement of at least part of the lost blood volume.
Inhibition of pancreatic alpha-aminoisobutyric acid uptake by cholecystokinin and other secretagogues
Authors: Iwamoto Y. , Williams J. A.
Published: December 2017

The uptake of the non-metabolizable amino acid, alpha-aminoisobutyric acid (AIB), by isolated mouse pancreatic acini was studied. AIB was concentrated in acinar cell water by an Na+-dependent mechanism. The protein hormone secretagogues caerulein, cholecystokinin, and gastrin and the cholinergic agent carbachol inhibited AIB uptake by greater than 50% of control. The effect of secretagogues on AIB uptake was maximal at hormone concentrations that are slightly higher than those that are maximal for amylase release, but comparable to those concentrations that maximally increase glucose transport by acini. This inhibition of AIB uptake was mediated by both inhibition of AIB influx and stimulation of AIB efflux. In the presence of Ca2+, the Ca2+ ionophore A23187 mimicked the effect of caerulein on AIB uptake. In the absence of Ca2+, control AIB uptake was markedly decreased and both caerulein and A23187 had no further effects. It was concluded, therefore, that secretagogues known to induce enzyme release by an effect on cellular Ca2+ also decrease AIB uptake and that this effect on uptake is most likely mediated by Ca2+.