bluuebunny/crossref_metadata_2025 huggingface dataset:
Status and phenology of breeding seabirds and a review of Important Bird and Biodiversity Areas in the British Indian Ocean Territory
Authors: CARR PETER , VOTIER STEPHEN , KOLDEWEY HEATHER , GODLEY BRENDAN , WOOD HANNAH , NICOLL MALCOLM A. C.
Published: July 2020

Seabirds are one of the most threatened avian taxa and are hence a high conservation priority. Managing seabirds is challenging, requiring conservation actions at sea (e.g. Marine Protected Areas - MPAs) and on land (e.g. protection of breeding sites). Important Bird and Biodiversity Areas (IBAs) have been successfully used to identify sites of global importance for the conservation of bird populations, including breeding seabirds. The challenge of identifying suitable IBAs for tropical seabirds is exacerbated by high levels of dispersal, aseasonal and asynchronous breeding. The western Indian Ocean supports ~19 million breeding seabirds of 30 species, making it one of the most significant tropical seabird assemblages in the world. Within this is the British Indian Ocean Territory (BIOT), encompassing 55 islands of the Chagos Archipelago, which supports 18 species of breeding seabird and one of the world’s largest no-take MPAs. Between January and March in 1975 and 1996, eight and 45 islands respectively were surveyed for seabirds and the data used to designate 10 islands as IBAs. A further two were proposed following an expedition to 26 islands in February/March 2006. Due to the historic and restricted temporal and spatial nature of these surveys, the current IBA recommendations may not accurately represent the archipelago’s present seabird status and distribution. To update estimates of the BIOT breeding seabird assemblage and reassess the current IBA recommendations, we used seabird census data collected in every month except September from every island, gathered during 2008–2018. The maximum number of breeding seabirds for a nominal year was 281,596 pairs of 18 species, with three species making up 96%: Sooty Tern Onychoprion fuscatus - 70%, Lesser Noddy Anous tenuirostris - 18% and Red-footed Booby Sula sula - 8%. Phenology was a complex species-specific mix of synchronous and asynchronous breeding, as well as seasonal and aseasonal breeding. Nine of the 10 designated IBAs and the two proposed IBAs qualified for IBA status based on breeding seabirds. However, not every IBA qualified each year because Sooty Terns periodically abandoned breeding islands and Tropical Shearwater Puffinus bailloni breeding numbers dropped below IBA qualifying criteria in some years. Further, one survey per year does not always capture the periodic breeding of some tropical seabirds. We propose therefore, that IBAs in BIOT are better designated at the island cluster level rather than by specific island and require two surveys six months apart per year. This work highlights the merits of long-term, systematic, versus incidental surveys for breeding tropical seabirds and the subsequent associated designation of IBAs.
Dormancy break and germination requirements in acorns of two bottomlandQuercusspecies (Sect.Lobatae) of the eastern United States with references to ecology and phylogeny
Authors: Hawkins Tracy S.
Published: July 2020

Quercusspecies are ecologically and economically important components of deciduous forests of the eastern United States. However, knowledge pertinent to a thorough understanding of acorn germination dynamics for these species is lacking. The objectives of this research were to determine dormancy break and germination requirements for acorns of two eastern United States bottomland species,Quercus nigraandQuercus phellos(SectionLobatae), and to present results within ecological and phylogenetic contexts. Three replicates of 50 acorns of each species received 0 (control), 6, 12 or 18 weeks of cold stratification, followed by incubation in alternating temperature regimes of 15/6, 20/10, 25/15 and 30/20°C. Eighteen weeks of cold stratification were not sufficient for dormancy break inQ. nigraacorns. Cumulative germination percentages at 4 weeks of incubation were ≥77%, but only in incubation temperatures of 25/15 and 30/20°C. Dormancy break inQ. phellosacorns was achieved with 18 weeks of cold stratification, and cumulative germination percentages were ≥87% at 4 weeks of incubation in all test temperature regimes. Gibberellic acid solutions were not an effective substitute for cold stratification in either species. Phylogenetically,Q. nigraandQ. phellosare closely related species and, ecologically, both grow in the same habitat. Acorns of both species possess deep physiological dormancy (PD), but dormancy break and germination requirements differ in acorns of these twoQuercusspecies.
Relationship between non-cardiac chest pain and internalizing problems in pre-school aged children
Authors: Yoldaş Tamer , Yoldaş Tuba Çelen , Beyazal Meryem , Sayıcı Ufuk İ. , Örün Utku A.
Published: July 2020

Objective:

Non-cardiac chest pain is a common and persistent problem for children; yet, typically, there is no clear medical cause. To date, no behavioural and/or psychological factors have been studied to explain chest pain in a pre-school paediatric sample. We hypothesized that pre-school children with medically unexplained chest pain would have higher rates of behavioural problems compared to healthy controls.

Methods:

We assessed 41 pre-school children with non-cardiac chest pain and 68 age matched children with benign heart murmurs as the control group using the Child Behaviour Check List-1 1/2–5 to evaluate emotional and behavioural problems.

Results:

Internalizing problem scores comprising emotionally reactive, anxiety/depression, and somatic complaints were higher in children with non-cardiac chest pain than in the control group. Among the possible factors, the factor that is related to behaviour problem scores, in univariate analysis, was a significant and inverse correlation between maternal education and behaviour problem scores. Also, maternal employment status was associated with behavioural problems. Children with a housewife mother were more susceptible to having such behavioural problems. Based on multiple regression analyses, being in the non-cardiac chest pain group was found to be significantly related to internalizing problems in our total sample.

Conclusions:

These results suggest that pre-school children with non-cardiac chest pain may experience increased levels of certain behavioural comorbidities. Systematic behavioural screening could increase the detection of behavioural problems and improve care for this population. Future studies of non-cardiac chest pain in pre-school children should include larger samples and comprehensive diagnostic assessments as well as long-term follow-up evaluations.
In-vivo dosimetry in Total Skin Electron Therapy: Literature review
Authors: Dhivya Sundaramoorthy , Anuradha Chandrasekaran , Murali Venkatraman , Ramasubramanian Velayudham
Published: July 2020

Aim:

Total Skin Electron Therapy (TSET) is a specialised radiotherapy technique to treat cutaneous T-cell lymphomas. The purpose of this article is to review different in-vivo dosimetry techniques and to identify further research direction in TSET

Materials and methods:

Studies focused on in-vivo dosimetry in TSET were included. Studies based on absolute dosimetry in TSET were excluded and no restriction was applied regarding the type of treatment technique and the type of dosimeter.

Result:

From the review of articles, we have found that obesity index and patient position during treatment plays a major role in underdose or overdose in TSET. Many studies favour individualised boost dose to patients. The analysis showed that thermoluminescent dosimeters are the most widely used dosimeters in TSET, and time-consuming is the only drawback in the use of dosimetry.

Conclusion:

Study showed that the practice of using in-vivo dosimetry would be better way to treat TSET by ensuring accuracy of dose delivery to the patients. Further, only limited studies are available for dosimetry with radiochromic films. With this observation, we have started exploring the use of radiochromic film in our TSET dosimetry, and the results can be analysed to standardise the technique in future.
Searching Online for Methods of Suicide
Authors: Eriksen Christian Ulrich , Konradsen Flemming , Vildekilde Thilde
Published: July 2020

Abstract. Background: Information on methods of suicide is available online, and access to information on methods of suicide appears to contribute to a small but significant proportion of suicides. There is limited documentation of how methods of suicide are being profiled, as well as what content exists in other languages than English. Aim: We aimed to analyze and compare how methods of suicide are profiled on Danish and English-language websites. Method: We applied a categorization and content analysis of websites describing methods of suicide. Sites were retrieved by applying widely used Danish and English-language search terms. Results: A total of 136 English-language websites and 106 Danish-language websites were included for analysis. Websites were more often categorized as prevention or support sites, academic or policy sites, and against suicide sites than dedicated suicide sites (i.e., pro-suicide sites), or information sites. However, information on methods of suicide was available, and 20.1% and 8.9% of the English and Danish-language sites, respectively, suggested that a particular method of suicide was quick, easy, painless, or certain to result in death. Limitations: Only one author coded and analyzed all websites. A further operationalization of the content analysis checklist is warranted to increase reliability. Conclusion: The websites primarily had a prevention or anti-suicide focus, but information on methods of suicide was available, requiring an increased focus on how to diminish the negative effects of harmful online content.
Semidiurnal Tidal Influence on the Occurrence of Postmidnight F Region FAI Radar Echoes
Authors: Sridharan S. , Meenakshi S.
Published: July 2020

The Equatorial Atmosphere Radar observations at Kototabang (0.2°S, 100.3°E) are used to study the possible semidiurnal tidal influence on the occurrence of postmidnight echoes from the field‐aligned irregularities (FAIs) due to spread F. It is found that the postmidnight FAI echoes show high percentage of occurrence (PO) during June–July and low PO in December–January of low solar activity years. As solar activity approaches minimum, the PO increase is extended to May, August, and September. The space‐time Fourier analysis on the temperature information obtained from the Sounding of Atmosphere by Broadband Emission Radiometry instrument onboard Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite reveals that at the low‐latitude upper mesospheric heights, though the migrating diurnal tide propagating westward with zonal wavenumber (k) 1 (DW1) dominates the migrating semidiurnal tide propagating westward with k = 2 (SW2) particularly during the equinox months, the SW2 tidal amplitudes are larger than DW1 during June–July. The postmidnight FAI echoes appear to be more frequent during the sudden stratospheric warming of the Solar Minimum Years 2018–2019 and 2008–2009 but not in the Solar Maximum Year 2013. The dominance of SW2 over DW1 is also noted during these years. This indicates that the SW2 plays a major role in the occurrence of postmidnight spread F. It is suggested that the dominant semidiurnal variation of zonal electric field can become eastward and lift the F layer to higher heights during midnight hours, which can favor the growth of the Rayleigh‐Taylor instability to cause delayed spread F around midnight.
The STONE Curve: A ROC‐Derived Model Performance Assessment Tool
Authors: Liemohn Michael W. , Azari Abigail R. , Ganushkina Natalia Y. , Rastätter Lutz
Published: July 2020

A new model validation and performance assessment tool is introduced, the sliding threshold of observation for numeric evaluation (STONE) curve. It is based on the relative operating characteristic (ROC) curve technique, but instead of sorting all observations in a categorical classification, the STONE tool uses the continuous nature of the observations. Rather than defining events in the observations and then sliding the threshold only in the classifier/model data set, the threshold is changed simultaneously for both the observational and model values, with the same threshold value for both data and model. This is only possible if the observations are continuous and the model output is in the same units and scale as the observations, that is, the model is trying to exactly reproduce the data. The STONE curve has several similarities with the ROC curve—plotting probability of detection against probability of false detection, ranging from the (1,1) corner for low thresholds to the (0,0) corner for high thresholds, and values above the zero‐intercept unity‐slope line indicating better than random predictive ability. The main difference is that the STONE curve can be nonmonotonic, doubling back in both the x and y directions. These ripples reveal asymmetries in the data‐model value pairs. This new technique is applied to modeling output of a common geomagnetic activity index as well as energetic electron fluxes in the Earth's inner magnetosphere. It is not limited to space physics applications but can be used for any scientific or engineering field where numerical models are used to reproduce observations.
Substorm Current Wedge: Energy Conversion and Current Diversion
Authors: Birn J. , Borovsky J. E. , Hesse M. , Kepko L.
Published: July 2020

Using a magnetohydrodynamic simulation of magnetotail reconnection, flow bursts, and dipolarization, we further investigate the current diversion and energy flow and conversion associated with the substorm current wedge (SCW) or smaller‐scale wedgelets. Current diversion into both Region 1 (R1) and Region 2 (R2) sense systems is found to happen inside (that is, closer to the center of the flow burst) and equatorward of the R1 and R2 type field‐aligned currents. In contrast to earlier investigations the current diversion takes place in dipolarized fields extending all the way toward the equatorial plane. An additional FAC system with the signature of Region 0 (R0) (same sense as R2) is found at higher latitudes in taillike fields. The diversion into this system takes place in layers equatorward of the R0 currents but outside the equatorial plane. Whereas the diversion into R1 and R2 systems is pressure gradient dominated, the diversion into the R0 system is inertia dominated and may persist only during flow burst activity. While azimuthally diverging flows near the dipole contribute to the buildup of R1 and R2 systems, converging flows at larger distance contribute to the buildup of R0 and R1 systems. In contrast to the current diversion regions inside the current wedge, generator regions are found on the outside of the wedge, similar to earlier results. Within the tail domain covered, these regions are overpowered by load regions, such that additional generator regions must be expected closer to Earth, not covered by the present simulation.
Long‐Lasting Ground‐Satellite High Coherence of Compressional Dayside Pc3–Pc4 Pulsations
Authors: Kim Gi‐Jeong , Kim Khan‐Hyuk , Kwon Hyuck‐Jin , Shiokawa Kazuo , Takahashi Kazue , Hwang Junga
Published: July 2020

We present observations of broadband (∼10–50 mHz) Pc3–Pc4 waves on 4 January 2014. The waves were detected on the dayside simultaneously in a compressional component (δBz) at the Radiation Belt Storm Probes A (RBSP‐A) in the inner magnetosphere and in the north‐south component (δH) on the ground at a low‐latitude Bohyun (BOH) station (L = 1.3) during an interval of small interplanetary magnetic field cone angle, suggesting that upstream ultralow frequency (ULF) waves were the source of the magnetospheric Pc3–Pc4 waves. We observed the ground‐satellite high coherence between RBSP‐A δBz and BOH δH for a prolonged time interval lasting 6.5 hr, which has not been reported previously, during which RBSP‐A was on the inbound and outbound legs moving from L = ∼3.3 to ∼6.3. In order to understand the spatial mode structure of the compressional waves, we examined the ground‐satellite cross phase for the high‐coherence interval and found that the waves observed in and out of the plasmasphere propagated earthward at the average fast‐mode speed of ∼700–1,000 km/s. We also observed cross‐phase values smoothly changing with the radial distance of the spacecraft across the plasmapause. This indicates that the presence of the plasmapause has little effect on our fast‐mode waves propagating into the inner magnetosphere and to the ground low‐latitude station.
A Model of the Subpacket Structure of Rising Tone Chorus Emissions
Authors: Hanzelka Miroslav , Santolík Ondřej , Omura Yoshiharu , Kolmašová Ivana , Kletzing Craig A.
Published: July 2020

The nonlinear growth theory of chorus emissions is used to develop a simple model of the subpacket formation. The model assumes that the resonant current, which is released from the source to the upstream region, radiates a new whistler mode wave with a slightly increased frequency, which triggers a new subpacket. Saturation of the growth in amplitude is controlled by the optimum amplitude. Numerical solution of advection equations for each subpacket, with the chorus equations acting as the boundary conditions, produces a chorus element with a subpacket structure. This element features an upstream shift of the source region with time and an irregular growth of frequency, showing small decreases between adjacent subpackets. The influence of input parameters on the number of subpackets, the shift of the source, the frequency sweep rate, and the maximum amplitude is analyzed. The model well captures basic features of instantaneous frequency measurements provided by the Van Allen Probes spacecraft. The modeled wave field can be used in future particle acceleration studies.
Thank You to Our 2019 Reviewers
Authors: Brewer Peter , Chambers Don , Friedrichs Marjorie A. M. , Hetland Robert D. , Karnauskas Kristopher B. , Lowe Ryan , Moran S. Bradley , Oey Lie‐Yauw , Padman Laurence , Pinardi Nadia , Zhou Lei
Published: July 2020

Key Points

The editors thank the 2019 peer reviewers
Generating Proxy SWOT Water Surface Elevations Using WRF‐Hydro and the CNES SWOT Hydrology Simulator
Authors: Elmer Nicholas J. , Hain Christopher , Hossain Faisal , Desroches Damien , Pottier Claire
Published: July 2020

The Surface Water Ocean Topography (SWOT) mission will launch in early 2022 to provide the first global inventory of terrestrial surface water. Although SWOT is primarily a research mission with key science objectives in both the oceanography and hydrology domains, SWOT data are expected to have application potential to address many societal needs. To identify SWOT applications, prepare for the use of SWOT data, and quantify SWOT impacts prior to launch, realistic proxy SWOT observations with representative measurement errors are required. This paper provides a step‐by‐step description of two methods for deriving proxy SWOT water surface elevations (WSEs) from an Observing System Simulation Experiment (OSSE) using the Weather Research and Forecasting hydrological extension package (WRF‐Hydro). The first, a basic method, provides a simple and efficient way to sample WRF‐Hydro output according to the SWOT orbit and add random white noise to simulate measurement error, similar to many previous approaches. An alternate method using the Centre National d'Etudes Spatiales (CNES) Large‐Scale SWOT Hydrology Simulator accounts for additional sources of measurement error and produces output in formats comparable to that expected from official SWOT products. The basic method is ideal for river hydrology applications in which a full representation of SWOT measurement errors and spatial resolution is unnecessary, whereas the CNES simulator approach is better‐suited for more rigorous scientific studies that require a comprehensive error budget.
Cross-sectional associations between central and general adiposity with albuminuria: observations from 400,000 people in UK Biobank
Authors: Zhu Pengfei , Lewington Sarah , Haynes Richard , Emberson Jonathan , Landray Martin J. , Cherney David , Woodward Mark , Baigent Colin , Herrington William G. , Staplin Natalie
Published: July 2020

Background

Whether measures of central adiposity are more or less strongly associated with risk of albuminuria than body mass index (BMI), and by how much diabetes/levels of glycosylated haemoglobin (HbA1c) explain or modify these associations, is uncertain.

Methods

Ordinal logistic regression was used to estimate associations between values of central adiposity (waist-to-hip ratio) and, separately, general adiposity (BMI) with categories of urinary albumin-to-creatinine ratio (uACR) in 408,527 UK Biobank participants. Separate central and general adiposity-based models were initially adjusted for potential confounders and measurement error, then sequentially, models were mutually adjusted (e.g. waist-to-hip ratio adjusted for BMI, and vice versa), and finally they were adjusted for potential mediators.

Results

Levels of albuminuria were generally low: 20,425 (5%) had a uACR ≥3 mg/mmol. After adjustment for confounders and measurement error, each 0.06 higher waist-to-hip ratio was associated with a 55% (95%CI 53–57%) increase in the odds of being in a higher uACR category. After adjustment for baseline BMI, this association was reduced to 32% (30–34%). Each 5 kg/m2 higher BMI was associated with a 47% (46–49%) increase in the odds of being in a higher uACR category. Adjustment for baseline waist-to-hip ratio reduced this association to 35% (33–37%). Those with higher HbA1c were at progressively higher odds of albuminuria, but positive associations between both waist-to-hip ratio and BMI were apparent irrespective of HbA1c. Altogether, about 40% of central adiposity associations appeared to be mediated by diabetes, vascular disease and blood pressure.

Conclusions

Conventional epidemiological approaches suggest that higher waist-to-hip ratio and BMI are independently positively associated with albuminuria. Adiposity–albuminuria associations appear strong among people with normal HbA1c, as well as people with pre-diabetes or diabetes.
In situ formation of graphene/metal oxide composites for high-energy microsupercapacitors
Authors: Jung Jaemin , Jeong Jae Ryeol , Lee Jungjun , Lee Sang Hwa , Kim Soo Young , Kim Myung Jun , Nah Junghyo , Lee Min Hyung
Published: July 2020

The current design trends in the field of electronic devices involve efforts to make these devices smaller, thinner, lighter, and more flexible. The development of such systems is expected to further accelerate, resulting in the production of wearable and Internet-of-Things devices. In this respect, microenergy storage systems with high capacity and fast charge/discharge rates have become important power sources for such devices. In particular, interdigitated microsupercapacitors (MSCs) have exhibited remarkable potential as micropower sources owing to their fast charge/discharge processes, long cycle life, and high power density compared with microbatteries. Nevertheless, facile fabrication of MSCs using interdigitated electrodes remains challenging, as it requires selective decoration of electrodes with pseudocapacitive materials, such as transition metal oxides, to increase their capacitance. In the present study, we developed a simple method for fabricating MSCs involving in situ formation of interdigitated graphene electrodes and ZnO nanorods by photothermal conversion of graphene oxide (GO) and Zn precursors using infrared (IR) laser scribing. The fabricated MSCs exhibit a high stack capacitance of 3.90 F cm−3 and an energy density of 0.43 mWh cm−3. Notably, the capacity of the developed material is three times higher than those of previously reported MSCs made from the same type of graphene. In addition, the capacitance retention rate of the fabricated MSC is approximately 70% when measured over 10,000 charging–discharging cycles at a constant current, which evidently indicates a stable device performance.
In situ observation of oscillatory redox dynamics of copper
Authors: Cao Jing , Rinaldi Ali , Plodinec Milivoj , Huang Xing , Willinger Elena , Hammud Adnan , Hieke Stefan , Beeg Sebastian , Gregoratti Luca , Colbea Claudiu , Schlögl Robert , Antonietti Markus , Greiner Mark , Willinger Marc
Published: July 2020

How a catalyst behaves microscopically under reaction conditions, and what kinds of active sites transiently exist on its surface, is still very much a mystery to the scientific community. Here we present an in situ study on the red-ox behaviour of copper in the model reaction of hydrogen oxidation. Direct imaging combined with on-line mass spectroscopy shows that activity emerges near a phase boundary, where complex spatio-temporal dynamics are induced by the competing action of simultaneously present oxidizing and reducing agents. Using a combination of in situ imaging with in situ X-ray absorption spectroscopy and scanning photoemission microscopy, we reveal the relation between chemical and morphological dynamics and demonstrate that a static picture of active sites is insufficient to describe catalytic function of redox-active metal catalysts. The observed oscillatory redox dynamics provide a unique insight on phase-cooperation and a convenient and general mechanism for constant re-generation of transient active sites.
A high-resolution transcriptome map identifies small RNA regulation of metabolism in the gut microbe Bacteroides thetaiotaomicron
Authors: Ryan Daniel , Jenniches Laura , Reichardt Sarah , Barquist Lars , Westermann Alexander J.
Published: July 2020

Bacteria of the genus Bacteroides are common members of the human intestinal microbiota and important degraders of polysaccharides in the gut. Among them, the species Bacteroides thetaiotaomicron has emerged as the model organism for functional microbiota research. Here, we use differential RNA sequencing (dRNA-seq) to generate a single-nucleotide resolution transcriptome map of B. thetaiotaomicron grown under defined laboratory conditions. An online browser, called ‘Theta-Base’ (www.helmholtz-hiri.de/en/datasets/bacteroides), is launched to interrogate the obtained gene expression data and annotations of ~4500 transcription start sites, untranslated regions, operon structures, and 269 noncoding RNA elements. Among the latter is GibS, a conserved, 145 nt-long small RNA that is highly expressed in the presence of N-acetyl-D-glucosamine as sole carbon source. We use computational predictions and experimental data to determine the secondary structure of GibS and identify its target genes. Our results indicate that sensing of N-acetyl-D-glucosamine induces GibS expression, which in turn modifies the transcript levels of metabolic enzymes.
Direct observation of a Feshbach resonance by coincidence detection of ions and electrons in Penning ionization collisions
Authors: Margulis Baruch , Narevicius Julia , Narevicius Edvardas
Published: July 2020

Observation of molecular dynamics with quantum state resolution is one of the major challenges in chemical physics. Complete characterization of collision dynamics leads to the microscopic understanding and unraveling of different quantum phenomena such as scattering resonances. Here we present an experimental approach for observing molecular dynamics involving neutral particles and ions that is capable of providing state-to-state mapping of the dynamics. We use Penning ionization reaction between argon and metastable helium to generate argon ion and ground state helium atom pairs at separation of several angstroms. The energy of an ejected electron carries the information about the initial electronic state of an ion. The coincidence detection of ionic products provides a state resolved description of the post-ionization ion-neutral dynamics. We demonstrate that correlation between the electron and ion energy spectra enables us to directly observe the spin-orbit excited Feshbach resonance state of HeAr+. We measure the lifetime of the quasi-bound HeAr+A2 state and discuss possible applications of our method.
Unexpected complexity of everyday manual behaviors
Authors: Yan Yuke , Goodman James M. , Moore Dalton D. , Solla Sara A. , Bensmaia Sliman J.
Published: July 2020

How does the brain control an effector as complex and versatile as the hand? One possibility is that neural control is simplified by limiting the space of hand movements. Indeed, hand kinematics can be largely described within 8 to 10 dimensions. This oft replicated finding has been construed as evidence that hand postures are confined to this subspace. A prediction from this hypothesis is that dimensions outside of this subspace reflect noise. To address this question, we track the hand of human participants as they perform two tasks—grasping and signing in American Sign Language. We apply multiple dimension reduction techniques and replicate the finding that most postural variance falls within a reduced subspace. However, we show that dimensions outside of this subspace are highly structured and task dependent, suggesting they too are under volitional control. We propose that hand control occupies a higher dimensional space than previously considered.
Finding flows of a Navier–Stokes fluid through quantum computing
Authors: Gaitan Frank
Published: July 2020

There is great interest in using quantum computers to efficiently simulate a quantum system’s dynamics as existing classical computers cannot do this. Little attention, however, has been given to quantum simulation of a classical nonlinear continuum system such as a viscous fluid even though this too is hard for classical computers. Such fluids obey the Navier–Stokes nonlinear partial differential equations, whose solution is essential to the aerospace industry, weather forecasting, plasma magneto-hydrodynamics, and astrophysics. Here we present a quantum algorithm for solving the Navier–Stokes equations. We test the algorithm by using it to find the steady-state inviscid, compressible flow through a convergent-divergent nozzle when a shockwave is (is not) present. We find excellent agreement between numerical simulation results and the exact solution, including shockwave capture when present. Finally, we compare the algorithm’s computational cost to deterministic and random classical algorithms and show that a significant speed-up is possible. Our work points to a large new application area for quantum computing with substantial economic impact, including the trillion-dollar aerospace industry, weather-forecasting, and engineered-plasma technologies.
Facile synthesis of Pd@graphene nanocomposites with enhanced catalytic activity towards Suzuki coupling reaction
Authors: Khan Mujeeb , Shaik Mohammed Rafi , Adil Syed Farooq , Kuniyil Mufsir , Ashraf Muhammad , Frerichs Hajo , Sarif Massih Ahmad , Siddiqui Mohammed Rafiq H. , Al–Warthan Abdulrahman , Labis Joselito P. , Islam Mohammad Shahidul , Tremel Wolfgang , Tahir Muhammad Nawaz
Published: July 2020

A facile and chemical specific method to synthesize highly reduced graphene oxide (HRG) and Pd (HRG@Pd) nanocomposite is presented. The HRG surfaces are tailored with amine groups using 1-aminopyrene (1-AP) as functionalizing molecules. The aromatic rings of 1-AP sit on the basal planes of HRG through π–π interactions, leaving amino groups outwards (similar like self-assembled monolayer on 2D substrates). The amino groups provide the chemically specific binding sites to the Pd nucleation which subsequently grow into nanoparticles. HRG@Pd nanocomposite demonstrated both uniform distribution of Pd nanoparticles on HRG surface as well as excellent physical stability and dispersibility. The surface functionalization was confirmed using, ultraviolet–visible (UV–Vis), Fourier transform infra-red and Raman spectroscopy. The size and distribution of Pd nanoparticles on the HRG and crystallinity were confirmed using high-resolution transmission electron microscopy and powder X-ray diffraction and X-ray photoelectron spectroscopy. The catalytic efficiency of highly reduced graphene oxide-pyrene-palladium nanocomposite (HRG-Py-Pd) is tested towards the Suzuki coupling reactions of various aryl halides. The kinetics of the catalytic reaction (Suzuki coupling) using HRG-Py-Pd nanocomposite was monitored using gas chromatography (GC).
Study on the 3D printability of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(lactic acid) blends with chain extender using fused filament fabrication
Authors: Vigil Fuentes Miguel A. , Thakur Suman , Wu Feng , Misra Manjusri , Gregori Stefano , Mohanty Amar K.
Published: July 2020

In this study, the 3D printability of a series of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/poly(lactic acid) (PLA) blends were investigated using fused filament fabrication (FFF). The studied blends suffered from poor 3D printability due to differences in compatibility and low thermal resistance. These shortcomings were addressed by incorporating a functionalized styrene-acrylate copolymer with oxirane moieties as a chain extender (CE). To enhance mechanical properties, the synergistic effect of 3D printing parameters such as printing temperature and speed, layer thickness and bed temperature were explored. Rheological analysis showed improvement in the 3D printability of PHBV:PLA:CE blend by allowing a higher printing temperature (220 °C) and sufficient printing speed (45 mm s−1). The surface morphology of fractured tensile specimens showed good bonding between layers when a bed temperature of 60 °C was used and a layer thickness of 0.25 mm was designed. The optimized printing samples shown higher storage modulus and strength, resulting in stiffer and stronger parts. The crystallinity, morphology and performance of the 3D printed products were correlated to share key methods to improve the 3D printability of PHBV:PLA based blends which may be implemented in other biopolymer blends, and further highlight how process parameters enhance the mechanical performance of 3D printed products.
Species traits predict the aryl hydrocarbon receptor 1 (AHR1) subtypes responsible for dioxin sensitivity in birds
Authors: Bianchini Kristin , Morrissey Christy A.
Published: July 2020

Differences in avian sensitivity to dioxin-like compounds (DLCs) are directly attributable to the identities of amino acids at two sites within the ligand binding domain (LBD) of the aryl hydrocarbon receptor 1 (AHR1). Recent work suggests that by influencing avian exposure to naturally occurring dioxins, differences in diet, habitat, and migration may have influenced the evolution of three AHR1 LBD genotypes in birds: type 1 (high sensitivity), type 2 (moderate sensitivity), and type 3 (low sensitivity). Using a boosted regression tree (BRT) analysis, we built on previous work by examining the relationship between a comprehensive set of 17 species traits, phylogeny, and the AHR1 LBD across 89 avian species. The 17 traits explained a combined 74% of the model deviance, while phylogenetic relatedness explained only 26%. The strongest predictors of AHR1 LBD were incubation period and habitat type. We found that type 3 birds tended to occupy aquatic habitats, and, uniquely, we also found that type 3 birds tended to have slower developmental rates. We speculate that this reflects higher evolutionary exposure to naturally occurring dioxins in waterbirds and species with K-selected life histories. This study highlights the value of trait-based approaches in helping to understand differing avian species sensitivities to environmental contaminants.
Exploiting defective RRAM array as synapses of HTM spatial pooler with boost-factor adjustment scheme for defect-tolerant neuromorphic systems
Authors: Woo Jiyong , Van Nguyen Tien , Kim Jeong Hun , Im Jong-Pil , Im Solyee , Kim Yeriaron , Min Kyeong-Sik , Moon Seung Eon
Published: July 2020

A crossbar array architecture employing resistive switching memory (RRAM) as a synaptic element accelerates vector–matrix multiplication in a parallel fashion, enabling energy-efficient pattern recognition. To implement the function of the synapse in the RRAM, multilevel resistance states are required. More importantly, a large on/off ratio of the RRAM should be preferentially obtained to ensure a reasonable margin between each state taking into account the inevitable variability caused by the inherent switching mechanism. The on/off ratio is basically adjusted in two ways by modulating measurement conditions such as compliance current or voltage pulses modulation. The latter technique is not only more suitable for practical systems, but also can achieve multiple states in low current range. However, at the expense of applying a high negative voltage aimed at enlarging the on/off ratio, a breakdown of the RRAM occurs unexpectedly. This stuck-at-short fault of the RRAM adversely affects the recognition process based on reading and judging each column current changed by the multiplication of the input voltage and resistance of the RRAM in the array, degrading the accuracy. To address this challenge, we introduce a boost-factor adjustment technique as a fault-tolerant scheme based on simple circuitry that eliminates the additional process to identify specific locations of the failed RRAMs in the array. Spectre circuit simulation is performed to verify the effect of the scheme on Modified National Institute of Standards and Technology dataset using convolutional neural networks in non-ideal crossbar arrays, where experimentally observed imperfective RRAMs are configured. Our results show that the recognition accuracy can be maintained similar to the ideal case because the interruption of the failure is suppressed by the scheme.
A strong preference for the TA/TA dinucleotide step discovered for an acridine-based, potent antitumor dsDNA intercalator, C-1305: NMR-driven structural and sequence-specificity studies
Authors: Laskowski Tomasz , Andrałojć Witold , Grynda Jakub , Gwarda Paulina , Mazerski Jan , Gdaniec Zofia
Published: July 2020

Triazoloacridinone C-1305, a potent antitumor agent recommended for Phase I clinical trials, exhibits high activity towards a wide range of experimental colon carcinomas, in many cases associated with complete tumor regression. C-1305 is a well-established dsDNA intercalator, yet no information on its mode of binding into DNA is available to date. Herein, we present the NMR-driven and MD-refined reconstruction of the 3D structures of the d(CGATATCG)2:C-1305 and d(CCCTAGGG)2:C-1305 non-covalent adducts. In both cases, the ligand intercalates at the TA/TA site, forming well-defined dsDNA:drug 1:1 mol/mol complexes. Orientation of the ligand within the binding site was unambiguously established by the DNA/ligand proton-proton NOE contacts. A subsequent, NMR-driven study of the sequence-specificity of C-1305 using a series of DNA duplexes, allowed us to confirm a strong preference towards TA/TA dinucleotide steps, followed by the TG/CA steps. Interestingly, no interaction at all was observed with duplexes containing exclusively the AT/AT, GG/CC and GA/TC steps.
Sine ventilation in lung injury models: a new perspective for lung protective ventilation
Authors: Spassov Sashko , Wenzel Christin , Lozano-Zahonero Sara , Boycheva Dimona , Streicher Lea , Schmidt Johannes , Schumann Stefan
Published: July 2020

Mechanical ventilation is associated with the risk of ventilator induced lung injury. For reducing lung injury in mechanically ventilated patients, the application of small tidal volumes and positive end-expiratory pressures has become clinical standard. Recently, an approach based on linear airway pressure decline and decelerated expiratory flow during expiration implied lung protective capacities. We assumed that ventilation with a smoothed, i.e. sinusoidal airway pressure profile may further improve ventilation efficiency and lung protection. We compared the effects of mechanical ventilation with sinusoidal airway pressure profile (SINE) regarding gas exchange, respiratory system compliance and histology to conventional volume and pressure controlled ventilation (VCV and PCV) and to VCV with flow-controlled expiration (FLEX) in two rat models of lung injury, tween induced surfactant depletion and high tidal volume mechanical ventilation. In both lung injury models ventilation with SINE showed more efficient CO2 elimination and blood oxygenation, improved respiratory system compliance and resulted in lower alveolar wall thickness, compared to VCV, PCV and FLEX. Optimization of the airway pressure profile may provide a novel means of lung protective mechanical ventilation.
Large-scale microlens arrays on flexible substrate with improved numerical aperture for curved integral imaging 3D display
Authors: Wang Wenwen , Chen Guixiong , Weng Yalian , Weng Xuyang , Zhou Xiongtu , Wu Chaoxing , Guo Tailiang , Yan Qun , Lin Zhixian , Zhang Yongai
Published: July 2020

Curved integral imaging 3D display could provide enhanced 3D sense of immersion and wider viewing angle, and is gaining increasing interest among discerning users. In this work, large scale microlens arrays (MLAs) on flexible PMMA substrate were achieved based on screen printing method. Meanwhile, an inverted reflowing configuration as well as optimization of UV resin’s viscosity and substrate’s surface wettability were implemented to improved the numerical aperture (NA) of microlenses. The results showed that the NA values of MLAs could be increased effectively by adopting inverted reflowing manner with appropriate reflowing time. With decreasing the substrate’s wettability, the NA values could be increased from 0.036 to 0.096, when the UV resin contact angles increased from 60.1° to 88.7°. For demonstration, the fabricated MLAs was combined to a curved 2D monitor to realize a 31-inch curved integral imaging 3D display system, exhibiting wider viewing angle than flat integral imaging 3D display system.
VOC fingerprints: metabolomic signatures of biothreat agents with and without antibiotic resistance
Authors: Dailey Allyson , Saha Jessica , Zaidi Fatima , Abdirahman Hafsa , Haymond Amanda , Alem Farhang , Hakami Ramin , Couch Robin
Published: July 2020

Category A and B biothreat agents are deemed to be of great concern by the US Centers for Disease Control and Prevention (CDC) and include the bacteria Francisella tularensis, Yersinia pestis, Burkholderia mallei, and Brucella species. Underscored by the impact of the 2020 SARS-CoV-2 outbreak, 2016 Zika pandemic, 2014 Ebola outbreak, 2001 anthrax letter attacks, and 1984 Rajneeshee Salmonella attacks, the threat of future epidemics/pandemics and/or terrorist/criminal use of pathogenic organisms warrants continued exploration and development of both classic and alternative methods of detecting biothreat agents. Volatile organic compounds (VOCs) comprise a large and highly diverse group of carbon-based molecules, generally related by their volatility at ambient temperature. Recently, the diagnostic potential of VOCs has been realized, as correlations between the microbial VOC metabolome and specific bacterial pathogens have been identified. Herein, we describe the use of microbial VOC profiles as fingerprints for the identification of biothreat-relevant microbes, and for differentiating between a kanamycin susceptible and resistant strain. Additionally, we demonstrate microbial VOC profiling using a rapid-throughput VOC metabolomics method we refer to as ‘simultaneous multifiber headspace solid-phase microextraction’ (simulti-hSPME). Finally, through VOC analysis, we illustrate a rapid non-invasive approach to the diagnosis of BALB/c mice infected with either F. tularensis SCHU S4 or Y. pestis CO92.
Caspofungin induces the release of Ca2+ ions from internal stores by activating ryanodine receptor-dependent pathways in human tracheal epithelial cells
Authors: Müller Sabrina , Koch Christian , Weiterer Sebastian , Weigand Markus A. , Sander Michael , Henrich Michael
Published: July 2020

The antimycotic drug caspofungin is known to alter the cell function of cardiomyocytes and the cilia-bearing cells of the tracheal epithelium. The objective of this study was to investigate the homeostasis of intracellular Ca2+ concentration ([Ca2+]i) after exposure to caspofungin in isolated human tracheal epithelial cells. The [Ca2+]i was measured using the ratiometric fluoroprobe FURA-2 AM. We recorded two groups of epithelial cells with distinct responses to caspofungin exposure, which demonstrated either a rapid transient rise in [Ca2+]i or a sustained elevation of [Ca2+]i. Both patterns of Ca2+ kinetics were still observed when an influx of transmembraneous Ca2+ ions was pharmacologically inhibited. Furthermore, in extracellular buffer solutions without Ca2+ ions, caspofungin exposure still evoked this characteristic rise in [Ca2+]i. To shed light on the origin of the Ca2+ ions responsible for the elevation in [Ca2+]i we investigated the possible intracellular storage of Ca2+ ions. The depletion of mitochondrial Ca2+ stores using 25 µM 2,4-dinitrophenol (DNP) did not prevent the caspofungin-induced rise in [Ca2+]i, which was rapid and transient. However, the application of caffeine (30 mM) to discharge Ca2+ ions that were presumably stored in the endoplasmic reticulum (ER) prior to caspofungin exposure completely inhibited the caspofungin-induced changes in [Ca2+]i levels. When the ER-bound IP3 receptors were blocked by 2-APB (40 µM), we observed a delayed transient rise in [Ca2+]i as a response to the caspofungin. Inhibition of the ryanodine receptors (RyR) using 40 µM ryanodine completely prevented the caspofungin-induced elevation of [Ca2+]i. In summary, caspofungin has been shown to trigger an increase in [Ca2+]i independent from extracellular Ca2+ ions by liberating the Ca2+ ions stored in the ER, mainly via a RyR pathway.
Histological validation of in vivo assessment of cancer tissue inhomogeneity and automated morphological segmentation enabled by Optical Coherence Elastography
Authors: Plekhanov Anton A. , Sirotkina Marina A. , Sovetsky Alexander A. , Gubarkova Ekaterina V. , Kuznetsov Sergey S. , Matveyev Alexander L. , Matveev Lev A. , Zagaynova Elena V. , Gladkova Natalia D. , Zaitsev Vladimir Y.
Published: July 2020

We present a non-invasive (albeit contact) method based on Optical Coherence Elastography (OCE) enabling the in vivo segmentation of morphological tissue constituents, in particular, monitoring of morphological alterations during both tumor development and its response to therapies. The method uses compressional OCE to reconstruct tissue stiffness map as the first step. Then the OCE-image is divided into regions, for which the Young’s modulus (stiffness) falls in specific ranges corresponding to the morphological constituents to be discriminated. These stiffness ranges (characteristic "stiffness spectra") are initially determined by careful comparison of the "gold-standard" histological data and the OCE-based stiffness map for the corresponding tissue regions. After such pre-calibration, the results of morphological segmentation of OCE-images demonstrate a striking similarity with the histological results in terms of percentage of the segmented zones. To validate the sensitivity of the OCE-method and demonstrate its high correlation with conventional histological segmentation we present results obtained in vivo on a murine model of breast cancer in comparative experimental study of the efficacy of two antitumor chemotherapeutic drugs with different mechanisms of action. The new technique allowed in vivo monitoring and quantitative segmentation of (1) viable, (2) dystrophic, (3) necrotic tumor cells and (4) edema zones very similar to morphological segmentation of histological images. Numerous applications in other experimental/clinical areas requiring rapid, nearly real-time, quantitative assessment of tissue structure can be foreseen.