bluuebunny/crossref_metadata_2025 huggingface dataset:
Ovine vital neutrophil extracellular traps bind and impair Haemonchus contortus L3 in a breed‐dependent manner
Authors: Garza Javier J. , Greiner Scott P. , Bowdridge Scott A.
Published: July 2018

This study aimed to characterize neutrophil response to Haemonchus contortus (Hc) in vitro using cells from parasite‐resistant St. Croix (STC) and parasite‐susceptible Suffolk (SUF) sheep. Neutrophils from Hc‐primed and naive STC and SUF sheep were incubated with Hc larval antigen (HcLA), Hc worm antigen (HcWA) or complete media (CM). After HcLA exposure, neutrophils from STC and SUF formed extracellular traps composed of DNA. Stimulation with HcLA induced a 35‐fold increase in extracellular DNA compared to CM controls. However, extracellular DNA was not found when neutrophils were cultured with HcWA. The formation of neutrophil extracellular traps (NET) in response to HcLA yields a low percentage of necrotic cells indicating a form of vital NETosis. Neutrophils from primed and naïve STC bound Hc L3 greater (93% and 68%) than SUF (78% and 45%; P < 0.001). Furthermore, STC neutrophils significantly reduced larval ATP levels compared to SUF neutrophils (0.05 μmol/L vs 0.1 μmol/L ATP, P < 0.001). These data indicate that ovine neutrophils bind, form vital NET and reduce ATP to Hc L3 in a breed and infection status–dependent manner.
Lateral and vertical juxtaposition of matrix‐rich and matrix‐poor lithologies caused by particle settling in mixed mud–sand deep‐marine sediment suspensions
Authors: Angus Katrina , Arnott Robert William Charles , Terlaky Viktor
Published: July 2018

Sandy sedimentary rocks rich in detrital matrix (>10% silt/clay) have long been recognized in the ancient sedimentary record, and nowhere more commonly than in deep‐marine turbidite systems. Despite this, their depositional mechanisms remain poorly understood, in part because these rocks, which are enriched in fine‐grained sediment, are often poorly exposed in outcrop or are confined to observation in core. Matrix‐rich strata in the Neoproterozoic Windermere Supergroup, in contrast, are very well‐exposed and show systematic changes in lithofacies over distances of several tens to a few hundreds of metres along‐strike. Notably, these strata are observed in both basin floor and continental slope deposits, suggesting that their occurrence and systematic lithological arrangement is related to mechanistic, rather than palaeogeographic, controls. Specifically, the facies transect consists of structureless, clayey sandstone that transforms along‐strike to a two‐layer deposit with the development of an upper, planar‐based, markedly more matrix‐rich layer. Further along‐strike, the basal clayey sandstone thins and eventually pinches out, leaving only the (upper) sandy claystone layer, which in turn thins along‐strike and then pinches out. These systematic changes in lithology, but more specifically the distribution of clay, is interpreted to form a depositional continuum related to particle settling in a horizontally advecting, high concentration particle suspension formed along the margins of an avulsion‐related high‐energy turbulent suspension.
Immigrant rights and social movements
Authors: Mora Maria De Jesus , Rodriguez Rodolfo , Zermeño Alejandro , Almeida Paul
Published: July 2018

The disciplinary fields of immigration and social movements have largely developed as two distinct subareas of sociology. Scholars contend that immigrant rights, compared to other movements, have been given less attention in social movement research. Studies of immigrant‐based movements in recent decades have reached a stage whereby we can now assess how immigrant movement scholarship informs the general social movement literature in several areas. In this article, we show the contributions of empirical studies of immigrant movements in four primary arenas of social movement scholarship: (a) emergence; (b) participation; (c) framing; and (d) outcomes. Contemporary immigrant struggles offer social movement scholarship opportunities to incorporate these campaigns and enhance current theories and concepts as earlier protest waves advanced studies of collective action.
Identification of the novel HLA‐A*32:01:01:08 allele in a Saudi individual
Authors: Aloufi F. , Gattan M. , Alanazi H. , Alqasem A. , Hajeer A. H.
Published: July 2018

HLA‐A*32:01:01:08 differs from HLA‐A*32:01:01:01 by a single nucleotide substitution (G → A) at position 2200.
Effect of anaerobic soil disinfestation amendment type and C:N ratio on Cyperus esculentus tuber sprouting, growth and reproduction
Authors: Shrestha U , Rosskopf E N , Butler D M
Published: July 2018

Anaerobic soil disinfestation (ASD) is a cultural technique primarily targeted for control of soilborne plant pathogens, but can also impact weed propagules. A repeated pot study was conducted to evaluate ASD treatment impact on sprouting and growth of introduced Cyperus esculentus (yellow nutsedge) tubers using dry molasses‐based and wheat bran‐based amendment mixtures at four carbon‐to‐nitrogen (C:N) ratios (from 10:1 to 40:1) and compared with a non‐amended control. The mean percentage of sprouted tubers recovered after ASD treatment was lower for wheat bran‐based (42%) than dry molasses‐based (65%) amendments, and tuber production was 1.6‐fold higher in dry molasses‐based than wheat bran‐based treatments. The highest percentage of sprouted tubers (79%) and the highest mean production of large tubers (threefold higher than wheat bran‐based and 1.7‐fold higher than molasses‐based amendments) were observed for the non‐amended control. Tuber sprouting was significantly lower from all ASD treatments (regardless of amendment C:N ratio) compared with the non‐amended control at a 15 cm burial depth. New tuber production was lowest at C:N ratios of 10:1 and 20:1 and more than twofold higher in the non‐amended control. Wheat bran‐based amendments reduced above‐ground C. esculentus biomass compared with the non‐amended control and ASD treatments with molasses‐based amendments, and reduced below‐ground biomass compared with molasses‐based amendments. Above‐ground biomass was highest at amendment C:N ratio of 10:1, and below‐ground biomass was highest at amendment C:N ratio of 40:1 and the non‐amended control. ASD treatment with wheat bran‐based amendments at lower C:N ratios reduced tuber sprouting and reproduction compared with the non‐amended control, but not at rates high enough to use as a primary weed management tactic.
Effect of alpha-particle irradiation dose on SiNx/AlGaN/GaN metal–insulator semiconductor high electron mobility transistors
Authors: Fares Chaker , Ren Fan , Pearton Stephen J. , Yang Gwangseok , Kim Jihyun , Lo Chien-Fong , Wayne Johnson J.
Published: July 2018

The effects of 18 MeV alpha particle irradiation dose on the electrical properties of SiNx/AlGaN/GaN metal insulator semiconductor high electron mobility transistors (MISHEMTs) using in situ grown silicon nitride as the gate dielectric were investigated. The MISHEMT devices were irradiated with alpha particles at doses of 1 × 1012 or 1 × 1013 cm−2 at a fixed energy of 18 MeV. Device performance degradation was more prominent for the irradiated samples under high frequency operation. At a frequency of 100 kHz and gate voltage pulsed from −6 to 3 V, the saturation drain current reduction was 32% and 41% after alpha irradiation doses of 1 × 1012 and 1 × 1013 cm−2, respectively. The drain current reduction at 100 kHz also depended on the duty cycle. At higher duty cycles, the drain current reduction was less severe. The calculated carrier removal rates were in the range of 2062–2175 cm−1 for the alpha doses studied. The results demonstrate the capability of AlGaN/GaN MISHEMTs in environments where resilience to radiation is required.
Frequency-sum beamforming for passive cavitation imaging
Authors: Abadi Shima H. , Haworth Kevin J. , Mercado-Shekhar Karla P. , Dowling David R.
Published: July 2018

Beamforming includes a variety of spatial filtering techniques that may be used for determining sound source locations from near-field sensor array recordings. For this scenario, beamforming resolution depends on the acoustic frequency, array geometry, and target location. Random scattering in the medium between the source and the array may degrade beamforming resolution with higher frequencies being more susceptible to degradation. The performance of frequency-sum (FS) beamforming for reducing such sensitivity to mild scattering while increasing resolution is reported here. FS beamforming was used with a data-dependent [minimum variance (MV)] or data-independent (delay-and-sum, DAS) weight vector to produce higher frequency information from lower frequency signal components via a quadratic product of complex signal amplitudes. The current findings and comparisons are based on simulations and passive cavitation imaging experiments using 3 MHz and 6 MHz emissions recorded by a 128-element linear array. FS beamforming results are compared to conventional DAS and MV beamforming using four metrics: point spread function (PSF) size, axial and lateral contrast, and computation time. FS beamforming produces a smaller PSF than conventional DAS beamforming with less computation time than MV beamforming in free space and mild scattering environments. However, it may fail when multiple unknown sound sources are present.
Ultrasonic atomization of distilled water
Authors: Gaete-Garretón L. , Briceño-Gutiérrez D. , Vargas-Hernández Y. , Zanelli C. I.
Published: July 2018

Experimental data on ultrasonic atomization of distilled water in a frequency range from 5 to 50 kHz are presented. A good agreement was found with the predictions of Rajan and Pandit [Ultrasonics 39, 235–255 (2001)] for the atomized primary drop size as a function of frequency. The correlation of atomization drop size for different frequencies is useful when producing nanoparticles, spray drying of suspensions, and covering of surfaces using different liquid products. Determining the displacement amplitude threshold for atomization at different frequencies is valuable in designing ultrasonic atomization systems. It is essential to measure the displacement amplitude of the atomizing surface rather that power applied to the transducer because the former is absolute while the latter depends on the efficiency of the transducer and other design parameters. As previous predictions for atomization threshold proved inaccurate, an empirical expression is proposed (based on the authors' measurements) to predict the amplitude atomization threshold for the studied frequency range.
Neurite architecture of the planum temporale predicts neurophysiological processing of auditory speech
Authors: Ocklenburg Sebastian , Friedrich Patrick , Fraenz Christoph , Schlüter Caroline , Beste Christian , Güntürkün Onur , Genç Erhan
Published: July 2018

In vivo quantification of planum temporale microcircuitry predicts neurophysiological processing of auditory speech.
Modeling of patient virus titers suggests that availability of a vaccine could reduce hepatitis C virus transmission among injecting drug users
Authors: Major Marian , Gutfraind Alexander , Shekhtman Louis , Cui Qingwen , Kachko Alla , Cotler Scott J. , Hajarizadeh Behzad , Sacks-Davis Rachel , Page Kimberly , Boodram Basmattee , Dahari Harel
Published: July 2018

A future vaccine could reduce hepatitis C virus transmission among those sharing syringes, even in the presence of postexposure viral replication in vaccinees.
Bacterial Y RNAs: Gates, Tethers, and tRNA Mimics
Authors: Sim Soyeong , Wolin Sandra L.
Published: July 2018

Y RNAs are noncoding RNAs (ncRNAs) that are present in most animal cells and also in many bacteria. These RNAs were discovered because they are bound by the Ro60 protein, a major target of autoantibodies in patients with some systemic autoimmune rheumatic diseases. Studies of Ro60 and Y RNAs inDeinococcus radiodurans, the first sequenced bacterium with a Ro60 ortholog, revealed that they function with 3′-to-5′ exoribonucleases to alter the composition of RNA populations during some forms of environmental stress. In the best-characterized example, Y RNA tethers the Ro60 protein to the exoribonuclease polynucleotide phosphorylase, allowing this exoribonuclease to degrade structured RNAs more effectively. Y RNAs can also function as gates to regulate access of other RNAs to the Ro60 central cavity. Recent studies in the enteric bacteriumSalmonella entericaserovar Typhimurium resulted in the discovery that Y RNAs are widely present in bacteria. Remarkably, the most-conserved subclass of bacterial Y RNAs contains a domain that mimics tRNA. In this review, we discuss the structure, conservation, and known functions of bacterial Y RNAs as well as the certainty that more bacterial Y RNAs and additional roles for these ncRNAs remain to be uncovered.
Intimate partner violence during pregnancy in relation to non-psychotic mental health disorders in Rwanda: a cross-sectional population-based study
Authors: Rurangirwa Akashi Andrew , Mogren Ingrid , Ntaganira Joseph , Govender Kaymarlin , Krantz Gunilla
Published: July 2018

Objectives

To investigate the prevalence of non-psychotic mental health disorders (MHDs) and the association between exposure to all forms of intimate partner violence (IPV) during pregnancy and MHDs.

Design

Cross-sectional population-based study conducted in the Northern Province of Rwanda and Kigali city.

Participants and settings

Totally, 921 women who gave birth ≤13 months before being interviewed were included. Simple random sampling was done to select villages, households and participants. Community health workers helped to identify eligible participants and clinical psychologists, nurses or midwives conducted face-to-face interviews. The collected data were analysed using descriptive statistics and bivariable and multivariable logistic regression modelling

Results

The prevalence rates of generalised anxiety disorder, suicide ideation and post-traumatic stress disorder (PTSD) were 19.7%, 10.8% and 8.0%, respectively. Exposure to the four forms of IPV during pregnancy was highly associated with the likelihood of meeting diagnostic criteria for each of the non-psychotic MHDs investigated. Physical, psychological and sexual violence, showed the strongest association with PTSD, with adjusted ORs (aORs) of 4.5, 6.2 and 6.3, respectively. Controlling behaviour had the strongest association with major depressive episode in earlier periods with an aOR of 9.2.

Conclusion

IPV and MHDs should be integrated into guidelines for perinatal care. Moreover, community-based services aimed at increasing awareness and early identification of violence and MHDs should be instituted in all villages and health centres in Rwanda. Finally, healthcare providers need to be educated and trained in a consistent manner to manage the most challenging cases quickly, discreetly and efficiently.
Validation of the Saint George’s Respiratory Questionnaire in Uganda
Authors: Morgan Brooks W , Grigsby Matthew R , Siddharthan Trishul , Kalyesubula Robert , Wise Robert A , Hurst John R , Kirenga Bruce , Checkley William
Published: July 2018

Introduction

Chronic obstructive pulmonary disease (COPD) will soon be the third leading global cause of death and is increasing rapidly in low/middle-income countries. There is a need for local validation of the Saint George’s Respiratory Questionnaire (SGRQ), which can be used to identify those experiencing lifestyle impairment due to their breathing.

Methods

The SGRQ was professionally translated into Luganda and reviewed by our field staff and a local pulmonologist. Participants included a COPD-confirmed clinic sample and COPD-positive and negative members of the community who were enrolled in the Lung Function in Nakaseke and Kampala (LiNK) Study. SGRQs were assembled from all participants, while demographic and spirometry data were additionally collected from LiNK participants.

Results

In total, 103 questionnaires were included in analysis: 49 with COPD from clinic, 34 community COPD-negative and 20 community COPD-positive. SGRQ score varied by group: 53.5 for clinic, 34.4 for community COPD-positive and 4.1 for community COPD-negative (p<0.001). The cross-validatedcstatistic for SGRQ total score predicting COPD was 0.87 (95% CI 0.75 to 1.00). SGRQ total score was associated with COPD severity (forced expiratory volume in 1 s per cent of predicted), with anrcoefficient of −0.60 (−0.75, −0.39). SGRQ score was associated with dyspnoea (OR 1.05/point; 1.01, 1.09) and cough (1.07; 1.03, 1.11).

Conclusion

Our Luganda language SGRQ accurately distinguishes between COPD-positive and negative community members in rural Uganda. Scores were correlated with COPD severity and were associated with odds of dyspnoea and cough. We find that it can be successfully used as a respiratory questionnaire for obstructed adults in Uganda.
Differences of in-hospital outcomes within patients undergoing percutaneous coronary intervention at institutions with high versus low procedural volume: a report from the Japanese multicentre percutaneous coronary intervention registry
Authors: Kodaira Masaki , Kuno Toshiki , Numasawa Yohei , Ohki Takahiro , Nakamura Iwao , Ueda Ikuko , Fukuda Keiichi , Kohsaka Shun
Published: July 2018

Objective

We aimed to determine the relationship between the prevalence of in-hospital complications and annual institutional patient volume in a population of patients undergoing percutaneous coronary intervention (PCI).

Methods

Clinical data of patients receiving PCI between January 2010 and June 2015 were collected from 14 academic institutions in the Tokyo area and subsequently used for analysis. We employed multivariate hierarchical logistic regression models to determine the effect of institutional volume on several in-hospital outcomes, including in-hospital mortality and procedure-related complications.

Results

A total of 14 437 PCI cases were included and categorised as receiving intervention from either lower-volume (<200 procedures/year, n=6 hospitals) or higher-volume (≥200 procedures/year, n=8 hospitals) institutions. Clinical characteristics differed significantly between the two patient groups. Specifically, patients treated in higher-volume hospitals presented with increased comorbidities and complex coronary lesions. Unadjusted mortality and complication rate in lower-volume and higher-volume hospitals were 1.3% and 1.2% (p=0.0614) and 6.2% and 8.1% (p=0.001), respectively. However, multivariate hierarchical logistic regression models adjusting for differences in the patient characteristics demonstrated that institutional volume was not associated with adverse clinical outcomes.

Conclusions

In conclusion, we observed no significant association between annual institutional volume and in-hospital outcomes within the contemporary PCI multicentre registry.

Trial registration number

UMIN R000005598.
Effect of exercise therapy on established and emerging circulating biomarkers in patients with heart failure: a systematic review and meta-analysis
Authors: Pearson Melissa J , King Nicola , Smart Neil A
Published: July 2018

Background

Biomarkers are important in the diagnosis, risk stratification and management of patients with heart failure (HF). The established biomarkers of myocardial stretch, brain natriuretic peptide (BNP) and amino (N) portion of BNP (NT-proBNP) have been extensively studied, and early analyses have demonstrated response to exercise training. Several other biomarkers have been identified over the last decade and may provide valuable and complementary information which may guide treatment strategies, including exercise therapy.

Methods

A systematic search of PubMed, EMBASE and Cochrane Trials Register to 31 October 2017 was conducted for exercise-based rehabilitation trials in HF. Randomised and controlled trials that reported biomarkers, BNP, NT-proBNP, soluble ST2, galectin-3, mid-regional atrial natriuretic peptide, mid-regional adrenomedullin and copeptin, were included.

Results

Forty-three studies were included in the systematic review, with 27 studies suitable for meta-analyses. Data pooling was only possible for NT-proBNP and BNP. Meta-analyses of conventional training studies demonstrated a statistically significant improvement in NT-proBNP (pmol/L); mean difference (MD) −32.80 (95% CI −56.19 to −9.42), p=0.006 and in BNP (pmol/L); MD −17.17 (95% CI −29.56 to −4.78), p=0.007. Pooled data of non-conventional training failed to demonstrate any statistically significant improvements.

Conclusion

Pooled data indicated a favourable effect of conventional exercise therapy on the established biomarkers, NT-proBNP and BNP; however, this was in contrast to a number of studies that could not be pooled. Limited evidence exists as to the effect of exercise training on emerging biomarkers.
Impact of early treatment with intravenous vasodilators and blood pressure reduction in acute heart failure
Authors: Kitai Takeshi , Tang W H Wilson , Xanthopoulos Andrew , Murai Ryosuke , Yamane Takafumi , Kim Kitae , Oishi Shogo , Akiyama Eiichi , Suzuki Satoshi , Yamamoto Masayoshi , Kida Keisuke , Okumura Takahiro , Kaji Shuichiro , Furukawa Yutaka , Matsue Yuya
Published: July 2018

Objective

Although vasodilators are used in acute heart failure (AHF) management, there have been no clear supportive evidence regarding their routine use. Recent European guidelines recommend systolic blood pressure (SBP) reduction in the range of 25% during the first few hours after diagnosis. This study aimed to examine clinical and prognostic significance of early treatment with intravenous vasodilators in relation to their subsequent SBP reduction in hospitalised AHF.

Methods

We performed post hoc analysis of 1670 consecutive patients enrolled in the Registry Focused on Very Early Presentation and Treatment in Emergency Department of Acute Heart Failure. Intravenous vasodilator use within 6 hours of hospital arrival and subsequent SBP changes were analysed. Outcomes were gauged by 1-year mortality and diuretic response (DR), defined as total urine output 6 hours posthospital arrival per 40 mg furosemide-equivalent diuretic use.

Results

Over half of the patients (56.0%) were treated with intravenous vasodilators within the first 6 hours. In this vasodilator-treated cohort, 554 (59.3%) experienced SBP reduction ≤25%, while 381 (40.7%) experienced SBP reduction >25%. In patients experiencing ≤25% drop in SBP, use of vasodilator was associated with greater DR compared with no vasodilators (p<0.001). Moreover, vasodilator treatment with ≤25% drop in SBP was independently associated with lower all-cause mortality compared with those treated without vasodilators (adjusted HR 0.74, 95% CI 0.57 to 0.96, p=0.028).

Conclusions

Intravenous vasodilator therapy was associated with greater DR and lower mortality, provided SBP reduction was less than 25%. Our results highlight the importance in early administration of intravenous vasodilators without causing excess SBP reduction in AHF management.

Clinical trial registration

URL:http://www.umin.ac.jp/ctr/Unique identifier: UMIN000014105.
Permeability of mine tailings measured in triaxial cell
Authors: Patiño Hernán , Martínez Eliana , González Jesús , Soriano Antonio
Published: July 2018

The execution of permeability tests using a triaxial cell makes it possible to eliminate the uncertainties that characterize tests performed using conventional equipment. This paper contains the results of 48 tests carried out on three materials recovered from tailings of Riotinto mines (Spain). The equipment involved a modified triaxial system to facilitate the execution of permeability tests under constant head. The tests were performed on samples consolidated to 50, 100, 200, and 300 kPa for four different hydraulic gradients established by applying a backpressure difference (ΔBp). The magnitude of the backpressure difference was applied as a percentage of the initial effective consolidation pressure, expressed as ΔBp/[Formula: see text]; namely, values of 10%, 15%, 20%, and 25%, which resulted in hydraulic gradients between 5 and 80. The backpressure (Bp) was constant (400 kPa) in all cases, allowing a degree of saturation close to 100% to be achieved. This was verified by calculating Skempton’s B parameter, which was very close to unity in all cases. The results indicate that it is feasible to define an empirical function including the coefficient of permeability (k) and the effective consolidation pressure ([Formula: see text]), the mean effective confining pressure ([Formula: see text]), and the backpressure differential (ΔBp).
Phylogenetic relationships among the Rangeomorpha: the importance of outgroup selection and implications for their diversification
Authors: Dececchi T. Alexander , Narbonne Guy M. , Greentree Carolyn , Laflamme Marc
Published: July 2018

The Rangeomorpha are the oldest, most diverse, and most disparate clade of Ediacaran macrofossils. Easily identifiable by their self-similar branching pattern, they occupied epibenthic niche space ranging from the lowest-tiered and recumbent taxa up to metre-long upright fronds. A phylogenetic analysis using the largest and most complete character set known for this group scored for 14 separate taxa was undertaken to resolve their internal relationships and test previous hypotheses of their evolutionary and ecological history. Owing to the lack of consensus on the relationship amongst Ediacaran clades, several permutations with different potential outgroup taxa were performed. Across these analyses, there is a strong signal for an upright frondose ancestral state for this clade, likely displaying primary branches that were double-sided, nonrotated, with the lower-tiered and recumbent forms being derived members of a single subclade. This has implications on the life history reconstruction as well as taxonomic implications for this clade and the origins of large multicellular life in the late Ediacaran.
Phantom fluid supporting traversable wormholes in alternative gravity with extra material terms
Authors: Sahoo P. K. , Moraes P. H. R. S. , Sahoo Parbati , Ribeiro G.
Published: July 2018

Wormholes are tunnels connecting different regions in spacetime. They were obtained originally as a solution for Einstein’s General Relativity theory and according to this theory, they need to be filled by an exotic kind of anisotropic matter. In the present sense, by “exotic matter”, we mean matter that does not satisfy the energy conditions. In this paper, we propose the modeling of wormholes within an alternative gravity theory that proposes an extra material (rather than geometrical) term in its gravitational action. Our solutions are obtained from well-known particular cases of the wormhole metric potentials, named redshift and shape functions, and yield the wormholes to be filled by a phantom fluid, that is, a fluid with equation of state parameter [Formula: see text]. In possession of the solutions for the wormhole material content, we also apply the energy conditions to them. The features of those are carefully discussed.
Some remarks on semirings and their ideals
Authors: Nasehpour Peyman
Published: July 2018

In this paper, we give semiring version of some classical results in commutative algebra related to Euclidean rings, PIDs, UFDs, G-domains, and GCD and integrally closed domains.
Positron emission particle tracking: A powerful technique for flow studies
Authors: Buffler A. , Cole K. , Leadbeater T.W. , van Heerden M.R.
Published: July 2018

Positron emission particle tracking (PEPT) has developed into a flexible applied nuclear technique for measuring the trajectory of a single tracer particle moving in a system of granular or liquid flow or attached to a moving rigid body. The tracer particle is labelled with a radionuclide (such as [Formula: see text]F or [Formula: see text]Ga) that decays via positron emission. The nearly collinear 511 keV annihilation gamma rays are detected in coincidence by a modified positron emission tomography (PET) camera, which defines their line of response (LOR). The chronologically measured LORs may then be used to triangulate the position of the moving tracer particle. We present an introduction to PEPT and illustrate the quality of measurements possible with a high-resolution PET scanner. Data are presented and discussed with reference to a few fundamental measurement scenarios and a framework for the metrology of PEPT is introduced.
Neutron imager with micro channel plates (MCP) in electrostatic mirror configuration: Experimental test with radiation source
Authors: Variale V. , Skarbo B.
Published: July 2018

The design of a new high-transparency device based on a Micro Channel Plate (MCP) detector was recently proposed for monitoring the flux and beam spatial profile of neutron beams. The proposed device consists of a very thin aluminum (Al) foil (with a [Formula: see text]Li deposit) placed in the neutron beam and an MCP detector equipped with a phosphor-screen readout linked to a charge-coupled device (CCD) camera outside the neutron beam. A critical feature of this device is that it uses an electrostatic mirror to minimize the perturbation of the neutron beam (i.e., absorption and scattering). It can be used at existing neutron time-of-flight (n_TOF) facilities (in particular at the n_TOF facility at CERN) for monitoring the flux and spatial profile of neutron beams in the thermal and epithermal region. The experimental tests conducted for this study using a radioactive source to determine the behavior of the electrostatic mirror behavior will be presented and discussed in this paper.
Adsorptive transport of noble gas tracers in porous media
Authors: Paul Matthew J. , Biegalski Steven R. , Haas Derek A. , Lowrey Justin D.
Published: July 2018

The transport of noble gas radionuclides in porous media is relevant to the detection of underground nuclear detonations as well as the sequestration of reprocessing off-gases. However, in field tests releasing radioxenon underground, the quantity of radioxenon observed at the surface has fallen well below expectations.[Formula: see text] This study examined the diffusivity of noble gases (Kr and Xe) and the inert molecular gas sulfur hexafluoride (SF[Formula: see text] in porous media to observe any unexpected behavior. To replicate the transport of radiogenic noble gases in underground media, a two-bulb gaseous diffusion apparatus was constructed. The two bulbs were connected with a column of 10–30 Ottawa sand and ordinary atmosphere filled both the bulbs and pore spaces. The tracer gases were diluted in an isolated bulb to approximately 1000 ppm. Once released, the gases were allowed to diffuse through the column. Aliquots were withdrawn at regular time intervals from both bulbs and concentrations were quantified using a Shimadzu QP2010 SE gas chromatograph-mass spectrometer. The effective diffusivity was then calculated using a maximum likelihood estimate on the quasi-steady state model. The effective diffusivity of Xe in the silica sand was observed to be 135.2% that of SF[Formula: see text] whereas the effective diffusivity of Kr was observed to be 161.4% that of sulfur hexafluoride. These findings are consistent with the binary diffusivities in N[Formula: see text]: 132.6% and 161.7%, respectively. However, the apparent volume of the system was inconsistent amongst the species, with Xe converging at slightly lower gas-phase concentrations than Kr or SF[Formula: see text]. This apparent reduction in gas-phase concentration occurred within the first few measurements and is consistent with transient accumulation of an adsorbed phase. As the effective diffusivities in the silica sand were shown to be consistent with the binary diffusivities in N[Formula: see text], a porosity-tortuosity model appears to be sufficient when considering similar geological materials. However, with the observation of significant gas adsorption, consideration of adsorbed-phase accumulation is necessary when scaling to larger geological systems.
Implementation of Isogeometric Fast Multipole Boundary Element Methods for 2D Half-Space Acoustic Scattering Problems with Absorbing Boundary Condition
Authors: Chen Leilei , Marburg Steffen , Zhao Wenchang , Liu Cheng , Chen Haibo
Published: July 2018

Isogeometric Analysis (IGA), which tries to bridge the gap between Computer Aided Engineering (CAE) and Computer Aided Design (CAD), has been widely proposed in recent research. According to the concept of IGA, this work develops a boundary element method (BEM) using non-Uniform Rational B-Splines (NURBS) as basis functions for the 2D half-space acoustic problems with absorbing boundary condition. Fast multipole method (FMM) is applied to accelerate the solution of an isogeometric BEM (IGA-BEM). Several examples are tested and it is shown that this advancement on isogeometric fast multipole boundary element method improves the accuracy of simulations.
A Multi-Institutional Perspective on H/FOSS Projects in the Computing Curriculum
Authors: Braught Grant , Maccormick John , Bowring James , Burke Quinn , Cutler Barbara , Goldschmidt David , Krishnamoorthy Mukkai , Turner Wesley , Huss-Lederman Steven , Mackellar Bonnie , Tucker Allen
Published: July 2018

Many computer science programs have capstone experiences or project courses that allow students to integrate knowledge from the full breadth of their major. Such capstone projects may be student-designed, instructor-designed, designed in conjunction with outside companies, or integrated with ongoing free and open source (FOSS) projects. The literature shows that the FOSS approach has attracted a great deal of interest, in particular when implemented with projects that have humanitarian goals (HFOSS). In this article, we describe five unique models from five distinct types of institutions for incorporating sustained FOSS or HFOSS (alternatively H/FOSS) project work into capstone experiences or courses. The goal is to provide instructors wishing to integrate open source experiences into their curriculum with additional perspectives and resources to help in adapting this approach to the specific needs and goals of their institution and students. All of the models presented are based on sustained engagement with H/FOSS projects that last at least one semester and often more. Each model is described in terms of its characteristics and how it fits the needs of the institution using the model. Assessment of each model is also presented. We then discuss the themes that are common across the models, such as project selection, team formation, mentoring, and student assessment. We examine the choices made by each model, as well as the challenges faced. We end with a discussion how the models have leveraged institutional initiatives and collaborations with outside organizations to address some of the challenges associated with these projects.
A Scalable Methodology to Guide Student Teams Executing Computing Projects
Authors: Saltz Jeffrey S. , Heckman Robert R.
Published: July 2018

This article reports on a sequential mixed-methods research study, which compared different approaches on how to guide students through a semester-long data science project. Four different methodologies, ranging from a traditional “just assign some intermediate milestones” to other more Agile methodologies, were first compared via a controlled experiment. The results of this initial experiment showed that the project methodology used made a significant difference in student outcomes. Surprisingly, the Agile Kanban approach was found to be much more effective than the Agile Scrum methodology. Based on these initial results, in the second semester, we focused on use of the Kanban methodology. The findings in the second, more qualitative phase, confirmed the methodology's usefulness and scalability. A key issue when using the scrum methodology was that the students had a very difficult time estimating what could be completed in each of their two-week sprints. The Kanban board, which visually shows and limits work-in-progress, was found to be an effective way for students to communicate with each other as well as with their instructor. In addition, Agile Kanban also streamlined the work required for instructors to efficiently provide guidance to student teams and to understand each team's status. In summary, a scalable Kanban methodology, which can be applied to a wide variety of student computing projects, was found to an effective methodology to guide and manage student projects, improving student outcomes and minimizing instructor workload.
SHARP
Authors: Vanwinkle Scott , Kodi Avinash Karanth
Published: July 2018

As the relentless quest for higher throughput and lower energy cost continues in heterogenous multicores, there is a strong demand for energy-efficient and high-performance Network-on-Chip (NoC) architectures. Heterogeneous architectures that can simultaneously utilize both the serialized nature of the CPU as well as the thread level parallelism of the GPU are gaining traction in the industry. A critical issue with heterogeneous architectures is finding an optimal way to utilize the shared resources such as the last level cache and NoC without hindering the performance of either the CPU or the GPU core. Photonic interconnects are a disruptive technology solution that has the potential to increase the bandwidth, reduce latency, and improve energy-efficiency over traditional metallic interconnects.

In this article, we propose a CPU-GPU heterogeneous architecture called
Shared Heterogeneous Architecture with Reconfigurable Photonic Network-on-Chip (SHARP)
that clusters CPU and GPU cores around the same router and dynamically allocates bandwidth between the CPU and GPU cores based on application demands. The SHARP architecture is designed as a Single-Writer Multiple-Reader (SWMR) crossbar with reservation-assist to connect CPU/GPU cores that dynamically reallocates bandwidth using buffer utilization information at runtime. As network traffic exhibits temporal and spatial fluctuations due to application behavior, SHARP can dynamically reallocate bandwidth and thereby adapt to application demands. SHARP demonstrates 34% performance (throughput) improvement over a baseline electrical CMESH while consuming 25% less energy per bit. Simulation results have also shown 6.9% to 14.9% performance improvement over other flavors of the proposed SHARP architecture without dynamic bandwidth allocation.
Plant Secondary Metabolite Diversity and Species Interactions
Authors: Kessler André , Kalske Aino
Published: July 2018

Ever since the first plant secondary metabolites (PSMs) were isolated and identified, questions about their ecological functions and diversity have been raised. Recent advances in analytical chemistry and complex data computation, as well as progress in chemical ecology from mechanistic to functional and evolutionary questions, open a new box of hypotheses. Addressing these hypotheses includes the measurement of complex traits, such as chemodiversity, in a context-dependent manner and allows for a deeper understanding of the multifunctionality and functional redundancy of PSMs. Here we review a hypothesis framework that addresses PSM diversity on multiple ecological levels (α, β, and γ chemodiversity), its variation in space and time, and the potential agents of natural selection. We use the concept of chemical information transfer as mediator of antagonistic and mutualistic interaction to interpret functional and microevolutionary studies and create a hypothesis framework for understanding chemodiversity as a factor driving ecological processes.
Activated natural killer T cells in mice induce acute kidney injury with hematuria through possibly common mechanisms shared by human CD56+T cells
Authors: Uchida Takahiro , Nakashima Hiroyuki , Ito Seigo , Ishikiriyama Takuya , Nakashima Masahiro , Seki Shuhji , Kumagai Hiroo , Oshima Naoki
Published: July 2018

Although activation of mouse natural killer T (NKT) cells by α-galactosylceramide (α-GalCer) causes failure of multiple organs, including the kidneys, the precise mechanisms underlying kidney injury remain unclear. Here, we showed that α-GalCer-activated mouse NKT cells injured both kidney vascular endothelial cells and tubular epithelial cells in vitro, causing acute kidney injury (AKI) with hematuria in middle-aged mice. The perforin-mediated pathway was mainly involved in glomerular endothelial cell injury, whereas the TNF-α/Fas ligand pathway played an important role in the injury of tubular epithelial cells. Kidney injury in young mice was mild but could be significantly exacerbated if NKT cells were strongly activated by NK cell depletion alone or in combination with IL-12 pretreatment. When stimulated by a combination of IL-2 and IL-12, human CD56+T cells, a functional counterpart of mouse NKT cells, also damaged both glomerular endothelial cells and tubular epithelial cells, with the former being affected in a perforin-dependent manner. These data suggest that both mouse NKT cells and human CD56+T cells are integral to the processes that mediate AKI. Targeting CD56+T cells may, therefore, be a promising approach to treat AKI.
Vocal learning in songbirds requires cholinergic signaling in a motor cortex-like nucleus
Authors: Puzerey Pavel A. , Maher Kamal , Prasad Nikil , Goldberg Jesse H.
Published: July 2018

Cholinergic inputs to cortex modulate plasticity and sensory processing, yet little is known about their role in motor control. Here, we show that cholinergic signaling in a songbird vocal motor cortical area, the robust nucleus of the arcopallium (RA), is required for song learning. Reverse microdialysis of nicotinic and muscarinic receptor antagonists into RA in juvenile birds did not significantly affect syllable timing or acoustic structure during vocal babbling. However, chronic blockade over weeks reduced singing quantity and impaired learning, resulting in an impoverished song with excess variability, abnormal acoustic features, and reduced similarity to tutor song. The demonstration that cholinergic signaling in a motor cortical area is required for song learning motivates the songbird as a tractable model system to identify roles of the basal forebrain cholinergic system in motor control.

NEW & NOTEWORTHY Cholinergic inputs to cortex are evolutionarily conserved and implicated in sensory processing and synaptic plasticity. However, functions of cholinergic signals in motor areas are understudied and poorly understood. Here, we show that cholinergic signaling in a songbird vocal motor cortical area is not required for normal vocal variability during babbling but is essential for developmental song learning. Cholinergic modulation of motor cortex is thus required for learning but not for the ability to sing.
Late maturation of backward masking in auditory cortex
Authors: Mattingly Michelle M. , Donell Brittany M. , Rosen Merri J.
Published: July 2018

Speech perception relies on the accurate resolution of brief, successive sounds that change rapidly over time. Deficits in the perception of such sounds, indicated by a reduced ability to detect signals during auditory backward masking, strongly relate to language processing difficulties in children. Backward masking during normal development has a longer maturational trajectory than many other auditory percepts, implicating the involvement of central auditory neural mechanisms with protracted developmental time courses. Despite the importance of this percept, its neural correlates are not well described at any developmental stage. We therefore measured auditory cortical responses to masked signals in juvenile and adult Mongolian gerbils and quantified the detection ability of individual neurons and neural populations in a manner comparable with psychoacoustic measurements. Perceptually, auditory backward masking manifests as higher thresholds for detection of a short signal followed by a masker than for the same signal in silence. Cortical masking was driven by a combination of suppressed responses to the signal and a reduced dynamic range available for signal detection in the presence of the masker. Both coding elements contributed to greater masked threshold shifts in juveniles compared with adults, but signal-evoked firing suppression was more pronounced in juveniles. Neural threshold shifts were a better match to human psychophysical threshold shifts when quantified with a longer temporal window that included the response to the delayed masker, suggesting that temporally selective listening may contribute to age-related differences in backward masking.

NEW & NOTEWORTHY In children, auditory detection of backward masked signals is immature well into adolescence, and detection deficits correlate with problems in speech processing. Our auditory cortical recordings reveal immature backward masking in adolescent animals that mirrors the prolonged development seen in children. This is driven by both signal-evoked suppression and dynamic range reduction. An extended window of analysis suggests that differences in temporally focused listening may contribute to late maturing thresholds for backward masked signals.
Pupil-linked arousal modulates behavior in rats performing a whisker deflection direction discrimination task
Authors: Schriver Brian J. , Bagdasarov Svetlana , Wang Qi
Published: July 2018

Non-luminance-mediated changes in pupil size have been widely used to index arousal state. Recent animal studies have demonstrated correlations between behavioral state-related pupil dynamics and sensory processing. However, the relationship between pupil-linked arousal and behavior in animals performing perceptual tasks has not been fully elucidated. In the present study, we trained head-fixed rats to discriminate between directions of whisker movements using a Go/No-Go discrimination paradigm while imaging their pupils. Reaction times in this discrimination task were significantly slower than in previously reported detection tasks with similar setup, suggesting that discrimination required an increased cognitive load. We found the pupils dilated for all trials following stimulus presentation. Interestingly, in correct rejection trials, where pupil dilations solely resulted from cognitive processing, dilations were larger for more difficult stimuli. Baseline pupil size before stimulus presentation strongly correlated with behavior, as perceptual sensitivity peaked at intermediate pupil baselines and reaction time was fastest at large baselines. We further explored these relationships by investigating to what extent pupil baseline was predictive of upcoming behavior and found that a Bayesian decoder had significantly greater-than-chance probability in correctly predicting behavioral outcomes. Moreover, the outcome of the previous trial showed a strong correlation with behavior on present trials. Animals were more liberal and faster in responding following hit trials, whereas perceptual sensitivity was greatest following correct rejection trials. Taken together, these results suggest a tight correlation between pupil dynamics, perceptual performance, and reaction time in behaving rats, all of which are modulated by fluctuating arousal state.

NEW & NOTEWORTHY In this study, we for the first time demonstrated that head-fixed rats were able to discriminate different directions of whisker movement. Interestingly, we found that the pupil dilated more when discriminating more difficult stimuli, a phenomenon reported in human subjects but not in animals. Baseline pupil size before stimulus presentation was found to strongly correlate with behavior, and a Bayesian decoder had significantly greater-than-chance probability in correctly predicting behavioral outcomes based on the baseline pupil size.