bluuebunny/crossref_metadata_2025 huggingface dataset:
Metal-ion-controlled growth and nanoindentation response of 3D, bicontinuous Cu–Fe thin films
Authors: Derby Benjamin K. , Chatterjee Arya , Misra Amit
Published: July 2020

Bicontinuous, nanocomposite thin film morphologies depend largely on the deposition conditions applied during physical vapor deposition. With the introduction of high-power impulse magnetron sputtering (HiPIMS), the range of potential morphologies achieved during deposition has been increased. In this work, we compare the deposition outcomes between traditional direct-current magnetron sputtering (DCMS) and HiPIMS for a thin film co-deposit of Cu and Fe. Modular control of the columnarity, porosity, and roughness was achieved by varying the Cu and Fe metal ion currents during deposition. The directionality of the nanostructured phase-separated morphology was also controlled as the ion current increased. At zero ion current for both Cu and Fe sputtered species during DCMS, the film exhibited lateral concentration modulations of Cu and Fe. The directionality of the Cu- and Fe-rich phases shifted to vertical concentration modulations at low ion currents of IFe=1A and ICu=0.1A and to lateral concentration modulations at relatively moderate ion currents of IFe=5A and ICu=2A. At high ion currents of IFe=18A and ICu=2A, a more randomized phase domain structure was observed on the nanoscale. This structural shift is rationalized using an interdiffusion model. The role of different kinds of phase-separated morphologies, achieved during DCMS deposition, on the mechanical properties has also been studied. Results indicated an increase in hardness, indentation modulus, and flow strength values with the increase in indentation strain rates. Bicontinuous Cu–Fe nanocomposites are found to be stronger than multilayer Cu–Fe samples.
In-operando observation of Li depth distribution and Li transport in thin film Li ion batteries
Authors: Mathayan Vairavel , Moro Marcos V. , Morita Kenji , Tsuchiya Bun , Ye Rongbin , Baba Mamoru , Primetzhofer Daniel
Published: July 2020

A quantitative assessment of Li transport is decisive for Li ion battery research. Here, we demonstrate in situ and in-operando depth profiling of the Li-inventory in lithium thin film batteries. We employ non-destructive coincidence elastic recoil detection analysis using different projectile ions in the MeV range to simultaneously quantify the lithium depth distribution in the whole stack with resolution better than 50 nm by simulations of experimental data. Experiments were performed while charging and discharging the stack. 5 MeV 7Li primary ions were employed to extract the Li depth distribution in an ∼3.6 μm thick Ti/LMO/LIPON/NbO/Ti thin film battery. To show the versatility of the approach, a coincidence experiment was also performed using 4 MeV He ions for an ∼3.4 μm thick Ti/LMO/LIPON/NbO/Ti battery. Our results illustrate, for example, lithium accumulation in the 90 nm thick NbO layer upon charging with +3 V. We could also show the transport of large amounts of Li from the LMO/LIPON interface to the LIPON/NbO interface upon overcharging with +5 V. Altogether, these experiments demonstrate the potential of the employed technique, enabling in-operando high resolution composition depth profiling of Li and other light elements (e.g., H, He, C, N, and O) in ultrathin all-solid state batteries.
Scattering mechanisms and mobility enhancement in epitaxial BaSnO3 thin films probed via electrolyte gating
Authors: Wang Helin , Prakash Abhinav , Reich Konstantin , Ganguly Koustav , Jalan Bharat , Leighton Chris
Published: July 2020

The wide-gap semiconducting perovskite BaSnO3 has attracted attention since the discovery of outstanding mobility at high electron densities, spurred on by potential applications in oxide, transparent, and power electronics. Despite progress, much remains to be understood in terms of mobility-limiting scattering in BaSnO3 thin films and thus mobility optimization. Here, we apply solid-state ion-gel-based electrolyte gating to electrostatically control electron density over a wide range (1018 cm−3 to >1020 cm−3) in BaSnO3 films. Temperature- and gate-voltage-dependent transport data then probe scattering mechanisms and mobility vs electron density alone, independently of sample-to-sample defect density variations. This is done on molecular-beam-epitaxy- and sputter-deposited films as a function of thickness, initial chemical doping, and initial mobility. Remarkably universal behavior occurs, the mobility first increasing with electron density to ∼1020 cm−3 before decreasing slightly. This trend is quantitatively analyzed at cryogenic and room temperatures using analytical models for phonon, ionized impurity, charged dislocation, surface/interface roughness, and electrolyte-induced scattering. The mobility maximum is thus understood to arise from competition between charged impurity/dislocation scattering and electrolyte scattering. The gate-voltage-induced mobility enhancement is found as large as 2000%, realizing 300 K mobility up to 140 cm2 V−1 s−1. This work thus significantly advances the understanding of mobility-limiting scattering processes in BaSnO3, resulting in outstanding room temperature mobilities.
Numerical modeling of nonohmic percolation conduction and Poole–Frenkel laws
Authors: Patmiou Maria , Karpov V. G. , Serpen G. , Weborg B. R.
Published: July 2020

We present a numerical model that simulates the current–voltage (I–V) characteristics of materials exhibiting percolation conduction. The model consists of a two dimensional grid of exponentially different resistors in the presence of an external electric field. We obtained exponentially nonohmic I–V characteristics validating earlier analytical predictions and consistent with multiple experimental observations of the Poole–Frenkel laws in noncrystalline materials. The exponents are linear in voltage for samples smaller than the correlation length of percolation cluster L and square root in voltage for samples larger than L.
High plant diversity and slow assembly of old-growth grasslands
Authors: Nerlekar Ashish N. , Veldman Joseph W.
Published: July 2020

Significance

The idea that grasslands can be ancient, particularly in climates that also support forests, is not widely recognized. Consequently, scientists and conservation planners often misinterpret old-growth grasslands to be low-diversity, successional vegetation, from which little is lost through conversion to tillage agriculture or tree plantations. We used a global analysis of herbaceous plant communities to show that after old-growth grasslands are destroyed, the recovery of plant diversity requires hundreds to thousands of years. Such slow rates of recovery underscore the need to replace outdated models of forest succession with models that emphasize the importance of fire, herbivory, and long periods of time to grassland biodiversity. This study offers evidence that old-growth grasslands, like old-growth forests, should be prioritized for conservation.
Behavioral traits that define social dominance are the same that reduce social influence in a consensus task
Authors: Rodriguez-Santiago Mariana , Nührenberg Paul , Derry James , Deussen Oliver , Francisco Fritz A. , Garrison Linda K. , Garza Sylvia F. , Hofmann Hans A. , Jordan Alex
Published: July 2020

Significance

The attributes allowing individuals to attain positions of social power and dominance are common across many vertebrate social systems: aggression, intimidation, and coercion. These traits may be associated with influence, but may also be socially aversive, and thereby decrease social influence of dominant individuals. Using a social cichlid fish, we show that dominant males are aggressive, socially central, and influence group movement. Yet, dominant males are poor effectors of consensus in a more sophisticated association task compared with passive, socially peripheral subordinate males. These influential, subordinate males possess behavioral traits opposite of those generally associated with dominance, suggesting that the link between social dominance and social influence is context dependent, and behavioral traits of dominant males impede group consensus formation.
HEDGES error-correcting code for DNA storage corrects indels and allows sequence constraints
Authors: Press William H. , Hawkins John A. , Jones Stephen K. , Schaub Jeffrey M. , Finkelstein Ilya J.
Published: July 2020

Significance

This paper constructs an error-correcting code for the

{

A
,
C
,
G
,
T

}

alphabet of DNA. By contrast with previous work, the code corrects insertions and deletions directly, in a single strand of DNA, without the need for multiple alignment of strands. This code, when coupled to a standard outer code, can achieve error-free storage of petabyte-scale data even when

∼

10% of all nucleotides are erroneous.
Investigation on formability of three-layer joined Al/Cu/Al sheets annealed at different temperature
Authors: Roostaei Milad , Darabi Roya
Published: July 2020

Today, the use of multi-layer sheets has expanded widely in various industries. The determination of the forming limit curve for sheets is essential. In this project, three-layer aluminium1100-copper10100-aluminium1100 sheet was produced using an explosive welding method and cold rolling up to 85% strain. Then to eliminate the rolling microstructure and create the isotropic properties and to investigate the effect of annealing temperature on formability, three-layer sheets were annealed at 350°C, 400°C, and 450°C for one hour. Afterward, the numerical and experimental forming limits for these sheets are obtained at room temperature. ABAQUS finite element software and Freudenthal, Cockcroft, and Brozzo ductile fracture criteria were used in numerical method, and punch stretching test was used in the experimental method.
Speaking for a State: Standardized Kichwa Greetings and Conundrums of Commensuration in Intercultural Ecuador
Authors: Limerick Nicholas
Published: July 2020

Can Indigenous language use transform state politics? In Ecuador, speakers of Kichwa (Ecuadorian Quechua) head a national, intercultural bilingual school system that promotes and teaches Indigenous languages. In their professional roles, they give speeches during which they speak as national state agents. Most commonly, they begin such events by using standardized Kichwa to greet and welcome attendees and then switch to Spanish. Although brief, such greetings serve to mark the state as intercultural. However, they also make Kichwa commensurate with Spanish. Speakers encounter a conundrum in how more extensive or illegible Kichwa speech may not demonstrate a modernist, commensurate form of Kichwa for non-Indigenous-identifying addressees and may even trigger anxiety or censure from Ministry of Education higher-ups. Yet, Kichwa state agents simultaneously risk angering Kichwa-speaking addressees with intralinguistic shift and restricting a movement to reclaim a language to curtailed speech acts within extensive non-Kichwa (Spanish) speech, further prioritizing that language and addressees who speak it. Their dilemmas indicate the challenges of language standardization in recognition politics and illustrate how semiotic processes of entextualization and enregisterment are integral to commensuration.
Scaling Femininity: Production of Semiotic Economy in the South Korean Cosmetics Industry
Authors: Koh Kyung-Nan
Published: July 2020

The practice of attaching inventive labels for things with a wide spectrum of selections to choose from is a widespread marketing practice. This article examines how unusual “fancy” color names are used in the South Korean cosmetics industry. Selecting and comparing the semiotic composition of color names of four companies operating within a single cosmetics corporation, this article reveals how fancy color term formations ideologically constructed in order to represent color function so as to lay the ground for social semiosis. Color terms in contemporary mediatized interactional settings work to mark and distinguish shades but, further, to provide basis for the characterization of commodities. What is shown is that commodity color terms for female cosmetics entail a scaling of femininity and that this scaling also relates a rescaling of those who can purchase such verbalizable colors.
Multiple photodetachment of atomic anions via single and double core-hole creation
Authors: Schippers S , Perry-Sassmannshausen A , Buhr T , Martins M , Fritzsche S , Müller A
Published: July 2020

We review the recent experimental and theoretical progress in K-shell detachment studies of atomic anions. On the experimental side, this field has largely benefitted from technical advances at 3rd generation synchrotron radiation sources. For multiple detachment of C−, O−, and F− ions, recent results were obtained at the photon-ion merged-beams setup PIPE which is a permanent end station at beamline P04 of the PETRA III synchrotron light source in Hamburg, Germany. In addition to a much increased photon flux as compared to what was available previously, the PIPE setup has an extraordinary detection sensitivity for heavy charged reaction products that allows one to study detachment processes with extremely low cross sections in the kilobarn range, e.g., for processes involving the simultaneous creation of two core-holes by a single photon as observed in the net triple detachment of F− and the net five-fold detachment of C−. Moreover, hitherto disregarded photodetachment resonances have been discovered, which exhibit a variety of line shapes. For O− the core-hole lifetime could be determined precisely from a high-resolution measurement of a photodetachment resonance. These experimental findings pose new challenges for state-of-the-art atomic theory and require calculations combining photoexcitation (ionization) with decay cascade processes that follow after initial core-hole production.
Fast, wafer-scale growth of a nanometer-thick graphite film on Ni foil and its structural analysis
Authors: Deokar Geetanjali , Genovese Alessandro , Costa Pedro M F J
Published: July 2020

The growth of graphite on polycrystalline Ni by chemical vapor deposition (CVD) and the microstructural relation of the graphitic films and the metallic substrate continues to puzzle the scientific community. Here, we report the wafer-scale growth of a nanometer-thick graphite film (∼100 nm, NGF) on Ni foil via a fast-thermal CVD approach (5 min growth). Moreover, we shed light on how localized thickness variations of the NGF relate to the Ni surface topography and grain characteristics. While on a macro-scale (mm2), the NGF film looks uniform—with a few hundred highly ordered graphene layers (d0002 = 0.335 nm), when studied at the micro- and nano-scales, few-layer graphene sections can be identified. These are present at a density of 0.1%–3% areas in 100
µ
m2, can be as thin as two layers, and follow an epitaxial relation with the {111} fcc-Ni planes. Throughout the 50 cm2 NGF, the sharp graphite/substrate interfaces are either composed of a couple of NiCx layers or a graphene layer. Moreover, the NGF was successfully transferred on SiO2/Si substrate by a wet chemical etching method. The as-produced NGFs could complement or offer an alternative to the mm-thick films produced from natural graphite flakes or polymer sheets.
Dynamically controlling electromagnetic reflection using reconfigurable water-based metasurfaces
Authors: Pang Yongqiang , Mo Manman , Li Yongfeng , Qu Bingyue , Xia Song , Qu Shaobo , Xu Zhuo
Published: July 2020

We proposed and demonstrated a reconfigurable water-based metasurface to achieve continuously dynamic control of electromagnetic (EM) reflection within a wide frequency band. The proposed metasurface is an array of an anisotropic unit cell consisting of two metallic layers separated by a dielectric layer. The flowing channel of the distilled water is designed in the dielectric spacer, so the metasurface is reconfigured by simply changing the injection quantity of water. Calculated, simulated and real-time measured results show that the reflection almost monotonically reduces as the water is injected into the metasurface, and the tunable level of reflection is larger than 10 dB from 8 to 18 GHz during the reconfiguring process. Besides the absorption resulting from the injected water, the EM reflection variation is partly contributed to the scattering mechanism. The results here provide an effective solution to flexibly control EM reflection from an object, and may find potential applications in the design of the adaptive EM surfaces and devices.
Effect of extrusion on damping and mechanical properties of Mg-Zn-Y alloy
Authors: Lu Ruopeng , Yao KeYu , Zhao Yuhong , Jiao Kai , Li Kun , Hou Hua
Published: July 2020

The damping and mechanical properties of extruded Mg-ZnX-Y1.33X (X = 1, 2, 3 at%) alloys were investigated in this experiment. The results shown that the alloy was mainly composed by long-period stacking ordered (LPSO) phase and magnesium(Mg) matrix. With the increase of Zinc(Zn) and Yttrium(Y) content, the grains had a certain refinement, the LPSO content was significantly increased, accompanied by a small amount of rare Y-enriched particles. After extrusion, the second phase of the alloys were broken into small pieces. The tensile strength(UTS) and yield strength(YS) of the alloy increased significantly, but the elongation decreased with the increase of LPSO phase. Mg-4.9Zn-8.9Y shown the best mechanical properties, with the tensile strength of 415 MPa, yield strength of 325MPpa, and elongation of 6.5%. Research on alloy damping performance shown that as the content of LPSO increases, the damping performance of as-cast alloys increased, and there is no obvious change after extrusion. It was due to a large number of dislocations entangled with work hardening, which greatly reduced the dislocation damping in magnesium alloys.
Invited Commentary: Reckoning With the Relationship Between Stressors and Suicide Attempts in a Time of COVID-19
Authors: Ettman Catherine K , Gradus Jaimie L , Galea Sandro
Published: July 2020

The coronavirus disease 2019 (COVID-19) pandemic presents a unique set of risk exposures for populations, which might lead to an increase in suicide. While large-scale traumatic events are known to increase psychological disorders, thus far the science has not shown a clear link between these events and suicide. In this issue of the Journal, Elbogen et al. (Am J Epidemiol. 2020;189(11):1266–1274) used representative data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) to show that 4 dimensions of financial strain—financial debt/crisis, unemployment, past homelessness, and lower income—are associated with subsequent suicide attempts. There are 3 main lessons we can take from Elbogen et al.: First, with populations facing record-breaking unemployment, economic recession, and reduced wages, we can anticipate an increase in suicide in the wake of the COVID-19 pandemic. Second, these data show the centrality of financial stressors, marking the current moment as distinct from other disasters or large-scale trauma. Third, the data teach us that financial stressors are linked and cumulative. In this way, Elbogen et al. provide a sobering harbinger of the potential effects on suicide of the collective stressors borne by the COVID-19 pandemic and other mass traumatic events that are accompanied by substantial financial stressors.
Molecular Phylogenetics of The Tody-Tyrant and Flatbill Assemblage of Tyrant Flycatchers (Tyrannidae)
Authors: Tello Jose G. , Bates John M.
Published: July 2020

The tody-tyrant and flatbill assemblage, sensuLanyon (1988a), includes 12 genera of tyrant flycatchers known variously as “tody-tyrants” and “flatbills.” Lanyon supported the monophyly of the group based on similar skull morphology and nest form, and built intergeneric relationships based on syringeal characters. However, these comparisons were made without a phylogenetic framework. A more recent study assessing relationships in the tyrant flycatchers using published morphological and behavioral data failed to recover monophyly of this assemblage (Birdsley 2002). Using DNA sequence data, we test for the monophyly of the tody-tyrant and flatbill assemblage and compare and contrast phylogenetic signals from mitochondrial and nuclear DNA character systems. We discuss our results in light of results from previous studies. We include representatives of the other major tyrant flycatcher assemblages for a total of 42 individuals (representing 27 tyrannid genera and 36 species). We sequenced 3,022 base pairs (bp) of three mitochondrial genes (ND2, ND3, and cytochrome b) and one nuclear intron (FIB5). Our results resolve many of the basal relationships of the tody-tyrant and flatbill phylogeny, but separate and combined analyses of data partitions are necessary to understand the nature of conflict among data sets. The tody-tyrants constitute a monophyletic clade, but the genera Hemitriccus and Lophotriccus are not monophyletic, and the limits of Oncostoma-Lophotriccus need to be revised with more complete sampling at the species level. The flatbills as defined by Lanyon are not monophyletic (Onychorhynchus and Platyrinchus are not true flatbills). Pseudotriccus and Corythopis are sister taxa and, together with Leptopogon and Mionectes, are allied to the tody-tyrant and flatbill clade.

Filogenia Molecular del Grupo de los Picochatos y Mosquiteros de la Familia Tyrannidae
Feeding and Digestive Organ Size in Breeding Lesser Snow Geese
Authors: Ankney C. D.
Published: July 2020

The Lesser Snow Geese that nest at the McConnell River, Northwest Territories, feed heavily before arriving on the breeding grounds. During laying and early incubation, feeding declines to low levels but increases slightly during late incubation. After their eggs hatch the geese greatly increase their food intake. These changes in feeding activity are correlated with changes in the average sizes of four digestive organs (pancreas, liver, gizzard, and intestine). The large digestive organs characteristic of arriving and post-hatch geese are due to hyperphagia. Previously reported situations that produced decreased size of avian digestive organs did not account for that condition in incubating geese. The decrease in size of digestive organs during incubation is claimed to be innate; its evolution is discussed.
Composition of Eggs of Several Bird Species
Authors: Ricklefs Robert E.
Published: July 2020

This paper presents the lipid, nonlipid dry matter, and water contents of the eggs of the Starling, Coturnix Quail, Mourning Dove, Laughing Gull, and Mallard and compares the data with published accounts of the eggs of other species. The lipid level of the yolk and the percentage of yolk in the egg increase in direct relation to the precocity of the young at hatching. The high lipid content of the eggs of precocial species is related primarily to their long incubation periods, resulting in a larger total metabolic requirement than for the embryos of altricial species. The high water levels of the eggs of altricial species are a direct consequence of the high water levels of the chicks at hatching.
Avian Play
Authors: Ficken Millicent S.
Published: July 2020

Play is more difficult to distinguish from other activities in birds than in mammals. Some cases of play reported in the literature appear to be due to threshold lowering, a type of activity that is usually differentiated from play. The various types of avian play are reviewed. Like mammals, birds exhibit object manipulation and some types of locomotory play. Subsong shows some remarkable similarities with characteristics of nonvocal play as noted in mammals, and birds may engage in other types of acoustic activities with playlike features. The corvids, particularly the Common Raven, exhibit the most complex play known for birds, and these activities, which are part of the learning process in the young, are probably important in the species' adaptation to a wide variety of habitats. Of all animals, only birds and mammals play, and play evolved independently in the two groups probably because of similar selection pressures acting on the developmental process to produce flexibility of behavior and the perfection of certain motor skills.
Breeding Biology of the Savannah Sparrow on Kent Island
Authors: Dixon Clara L.
Published: July 2020

I studied the breeding biology of the Savannah Sparrow (Passerculus sandwichensis) on Kent Island, New Brunswick, Canada from 1964 through 1968. I estimated the breeding population to be 125-135 pairs $(412-445\ \text{individuals}/{\rm km}^{2})$. The mean number of nests produced per female, including those destroyed by predators, was 2.97. Clutch size ranged from 2 to 5. The mean clutch size based on 1,142 eggs in 284 nests of known clutch size was 4.02. Not only was the four-egg clutch most numerous but a greater percentage of eggs in the four-egg clutches hatched and the mean number of young fledged per nest was also highest. The mean incubation period was 12.2 days, the mean duration of nestling life was 9 days, and the approximate length of the breeding season as 52 days. The daily mortality rate of eggs was 11.9% and of nestlings 2.1%. Predation was the major factor affecting reproductive success; 50.5% of all nests located were destroyed by predators. The main nest predators were Common Crows and Herring Gulls. Of the nests destroyed by predators, 87.8% contained eggs rather than nestlings. The intense predation necessitated high nest replacement. The mean interval between the termination of one nest and the appearance of the first egg in the succeeding nest was 6.3 days. If successive nests are destroyed on the day incubation begins, it is hypothetically possible for a pair to produce four nests during a single breeding season; many birds in the population produce at least three. Although enough time was available for birds to fledge two broods in a season, few of them fledged more than one. Thus, the nesting success was low (success from egg to hatching 18.1%). High nest replacement compensated for high egg mortality, and an average of 2.16 young per pair were fledged per season.
Ontogeny of Vocalization in the Greater Rhea
Authors: Beaver Paul W.
Published: July 2020

The call-notes of the Greater Rhea chick were classified according to their acoustical structure and behavioral context. Both rate of vocalization and tonal quality of call-notes were found to deteriorate as a function function of maturation. Call-note production was completely eliminated by 7 weeks of age. Greater Rhea adults are silent except for such relatively infrequent vocalizations as "hissing" that sometimes accompanies agonistic behavior and a disyllabic "grunt" that only the male produces as part of a courtship display. Tracheal growth and a marked reduction in the intrusion of the internal tympanic membranes into the bronchial passages could contribute to the deterioration of vocalization. The use of vocalization as the primary channel of communication is replaced by visual display in the adults. These modalities are best suited to the ecological contingencies facing the chick and adult, respectively.
Hybridization between Gulls (Larus glaucescens and L. occidentalis) in the Pacific Northwest
Authors: Hoffman Wayne , Wiens John A. , Scott J. Michael
Published: July 2020

Interbreeding between Glaucous-winged Gulls (Larus glaucescens) and Western Gulls (L. occidentalis) occurs extensively within a 180-km zone along the Washington coast, producing a high frequency of intermediate morphs in breeding populations. We conducted intensive studies on Destruction Island, Washington, in the midst of the zone of hybridization. There over half of the breeding birds were phenotypically intergrades between pure Glaucous-winged and Western gulls in characters of iris and eye-ring coloration, mantle shade, and wing tip pattern. Mating patterns of Destruction Island gulls were assortative, individuals pairing with mates similar to themselves. Pairs composed of pure Glaucous-winged or Western gulls hatched significantly fewer eggs than pairs containing at least one hybrid individual. The greater apparent reproductive success of the intergrades would seem to be countered by the assortative mating patterns, possibly providing conditions sufficient to maintain an equilibrium system containing both pure types as well as intergrades. These conditions are explored in a simulation model that considered immigration, density-dependent fecundity, pairing and reproduction, and mortality. A stable colony of mixed composition may be maintained by a regular but small influx of pure types into the colony.
Juvenile Dispersal and Development of Site-Fidelity in the Black-Capped Chickadee
Authors: Weise Charles M. , Meyer John R.
Published: July 2020

Dispersal of young was studied in a non-migratory population of the Black-capped Chickadee (Parus atricapillus) in southeastern Wisconsin. Eighty-eight chickadees were color-banded as nestlings. After fledging, the birds remained with their parents on or near the parental territory for about 3 weeks. In late June or early July family breakup occurred suddenly, with the young moving rapidly away. Most of the birds disappeared completely from the area; 6 were later discovered in the breeding population at distances of 0.4 to ca. 11 km, with a median dispersal distance of 1.1 km. This movement appeared to be an innate dispersal mechanism. In contrast, among 103 chickadees first trapped in July and early August as independent juveniles and later found on their breeding territories, the median distance from point where banded to territory was 204 m (maximum = 1,160 m). As distances up to 2.4 km could have been detected in our study area, we conclude that by late July and August chickadees have virtually finished dispersing and are developing site tenacity in the places where they will subsequently breed. Whether dispersal also occurs in spring was investigated using the monthly patterns of arrivals and disappearances from winter feeders. Adults and summer-banded juveniles inhabiting the parts of the study area nearest the feeders arrived for the first time at the feeders in November and December, but birds from more remote areas continued to arrive through the winter and spring. In previously unbanded juveniles there was an increase in arrivals in March and April. On the basis of an analysis of loss rates by sex and age, we conclude that only about 5% of yearling males and 9% of yearling females undertake some dispersal or spacing movements in spring. Thus, in the Black-capped Chickadee the main dispersal mechanism is an innate, rapid, fairly long-distance movement of the juvenile, taking place in summer just after family breakup. A small fraction of the yearling population undertakes some dispersal movement in the winter or spring.
Relative Heart Size in Alaskan Tetraonidae
Authors: Weeden Robert B.
Published: July 2020

Heart:body size ratios were measured in over 1,900 specimens of seven species of Alaskan Tetraonidae. Blue Grouse (Dendragapus obscurus) and Ruffed Grouse (Bonasa umbellus) have hearts averaging only 0.4 to 0.5% of body weight. At the other extreme, Rock Ptarmigan (Lagopus mutus) have hearts averaging 2.0% of body weight. Between these extremes are White-tailed Ptarmigan (L. leucurus), 1.1%; Spruce Grouse (Canachites canadensis), 1.2%; Sharp-tailed Grouse (Pedioecetes phasianellus), 1.4%; and Willow Ptarmigan (L. lagopus), 1.4%. Intraspecific variations related to sex, age, body size, season, and locality were found in some but not all species. The members of this family seem to have evolved diverse strategies for meeting cardiovascular requirements, and heart size alone does not reveal the nature of these systems.
Male Characteristics and Pairing Success in Red-Winged Blackbirds
Authors: Searcy William A.
Published: July 2020

As female Red-winged Blackbirds (Agelaius phoeniceus) in Washington populations choose mates mainly on the basis of territory quality, sexual selection should favor those characteristics that enhance a male redwing's ability to obtain and defend a good territory. In this study, correlations were sought between harem size and characteristics of male redwings that might be expected to contribute to the ability to compete for territory. Weak evidence is presented that large size, experience, good physiological condition, and the ability to devote a large proportion of daily activity to territory defense contribute to pairing success in some years. Even the significant correlations between success and male characteristics are weak, but strong correlations cannot be expected because (1) many different male characteristics probably contribute to competitive ability, none of which are of overwhelming importance; (2) males will not always make the optimal choice of territory, especially as their choice is constrained by extreme site fidelity; and (3) females will also fail to make optimal choices of territories and mates.
Rainfall on the Galápagos and the Demography of Darwin’s Finches
Authors: Grant Peter R. , Boag Peter T.
Published: July 2020

Monthly rainfall has been registered at eight sites on four of the Galápagos Islands for a variable number of years. The most extensive, continuous records are from a coastal site on San Cristóbal for the period 1950-67. Analysis of all these data establish the following characteristics: (1) Although rainfall is seasonal, it is very variable, particularly in the wet-season months of January to May. (2) Annual variation is very large. The amount of rainfall tends to alternate in successive years, and a 4-yr periodicity in rainfall is indicated. (3) There is also variation on a longer time scale; the 1950's were 50% wetter than the 1960's. (4) There is more precipitation per year at high elevations than at low elevations, it is distributed more evenly throughout the year, and it varies less among years. Finch demography, particularly reproductive aspects, is suggested to be influenced by rainfall through the effect of rainfall upon food supply. Several qualitative predictions about reproduction, mortality, and dispersal are made on the basis of the established patterns of variation in rainfall. The meagre data on finch population dynamics are consistent with these predictions, but future research is required to test them adequately.
Characterization of cardiac troponin subunit release into serum after acute myocardial infarction and comparison of assays for troponin T and I
Authors: Wu Alan H B , Feng Yue-Jin , Moore Robert , Apple Fred S , McPherson Paul H , Buechler Kenneth F , Bodor Geza , for for the American Association , Standardization Clinical Chemistry Subcommittee on cTnI
Published: July 2020

We examined the release of cardiac troponin T (cTnT) and I (cTnI) into the blood of patients after acute myocardial infarction (AMI). Three postAMI serum samples were applied in separate analytical runs onto a calibrated gel filtration column (Sephacryl S-200), and the proteins were separated by molecular weight. Using commercial cTnT and cTnI assays measured on collected fractions, we found that troponin was released into blood as a ternary complex of cTnT-I-C, a binary complex of cTnI-C, and free cTnT, with no free cTnI within the limits of the analytical methodologies. The serum samples were also examined after incubation with EDTA and heparin. EDTA broke up troponin complexes into individual subunits, whereas heparin had no effect on the assays tested. We added free cTnC subunits to 24 AMI serum samples and found no marked increase in the total cTnI concentrations, using an immunoassay that gave higher values for the cTnI-C complex than free cTnI. To characterize the cross-reactivity of cTnT and cTnI assays, purified troponin standards in nine different forms were prepared, added to serum and plasma pools, and tested in nine quantitative commercial and pre-market assays for cTnI and one approved assay for cTnT. All nine cTnI assays recognized each of the troponin I forms (complexed and free). In five of these assays, the relative responses for cTnI were nearly equimolar. For the remainder, the response was substantially greater for complexed cTnI than for free cTnI. Moreover, there was a substantial difference in the absolute concentration of results between cTnI assays. The commercial cTnT assay recognized binary and ternary complexes of troponin on a near equimolar basis. We conclude that all assays are useful for detection of cardiac injury. However, there are differences in absolute cTnI results due to a lack of mass standardization and heterogeneity in the cross-reactivities of antibodies to various troponin I forms.
Biochemical hallmarks of tyrosine hydroxylase deficiency
Authors: Bräutigam Christa , Wevers Ron A , Jansen Riet J T , Smeitink Jan A M , Andel Johanneke F de Rijk-van , Gabreëls Fons J M , Hoffmann Georg F
Published: July 2020

We report the biochemical hallmarks of tyrosine hydroxylase deficiency with emphasis on reliable diagnostic strategies of four new cases of an inborn error of tyrosine hydroxylase (TH). Three of our patients from different parts of the Netherlands were found homozygous for a mutation in exon 6 (G698A) of the TH gene, and one patient was found compound heterozygous for the same mutation and an additional mutation in exon 3. The first clinical symptoms of hypokinesia, rigidity of arms and legs and axial hypotonia, developed between 3 and 7 months of age. Cerebrospinal fluid investigations revealed a characteristic metabolite constellation in every case: low homovanillic acid (HVA) and 3-methoxy-4-hydroxy-phenylethyleneglycol concentrations in the presence of normal reference range 5-hydroxyindolacetic acid concentrations. Strict adherence to a standardized lumbar puncture protocol and adequate age-related reference values are essential for diagnosis of this “new” treatable neurometabolic disorder. Urinary measurements of HVA, vanillylmandelic acid, and catecholamines can lead to false-negative conclusions. All patients showed a remarkable clinical improvement on a low dose of l-dihydroxyphenylalanine/(S)-2-(3,4-dihydroxybenzyl)-2-hydrazinpropionic acid. During treatment, cerebrospinal fluid HVA, and 3-methoxy-4-hydroxy-phenylethyleneglycol increased substantially.
Miniaturization of analytical systems
Authors: Kricka Larry J
Published: July 2020

Miniaturization has been a long-term trend in clinical diagnostics instrumentation. Now a range of new technologies, including micromachining and molecular self-assembly, are providing the means for further size reduction of analyzers to devices with micro- to nanometer dimensions and submicroliter volumes. Many analytical techniques (e.g., mass spectrometry and electrophoresis) have been successfully implemented on microchips made from silicon, glass, or plastic. The new impetus for miniaturization stems from the perceived benefits of faster, easier, less costly, and more convenient analyses and by the needs of the pharmaceutical industry for microscale, massively parallel drug discovery assays. Perfecting a user-friendly interface between a human and a microchip and determining the realistic lower limit for sample volume are key issues in the future implementation of these devices. Resolution of these issues will be important for the long-term success of microminiature analyzers; in the meantime, the scope, diversity, and rate of progress in the development of these devices promises products in the near future.
Escalation firebreaks in the cyber, conventional, and nuclear domains: moving beyond effects-based logics
Authors: Kreps Sarah , Schneider Jacquelyn
Published: July 2020

Despite the growing literature on cyber security, most studies have sidestepped important questions of how conflict escalates in the cyber domain. To better understand this dynamic, we advance two main theoretical pathways of escalation, one in which actors respond with increasing intensity based on the effect of an attack, irrespective of how it is conducted (through cyber, conventional, or nuclear) and another in which the means of attack determines the actor’s willingness to escalate. We then test those effects- and means-based pathways with an original experiment that probes support for escalation, focusing on the American public, a key actor in debates about nuclear escalation and deterrence. Our study suggests that cyberattacks create a threshold that restrains the escalation of conflict. Americans are less likely to support retaliation with force when the scenario involves a cyberattack even when they perceive the magnitude of attacks across domains to be comparable. Our findings provide support for cyber strategies based on assumptions of cyber thresholds, while also casting doubt on the credibility of cyber deterrence by punishment. More broadly, our research suggests effects-based theories of escalation may not help understand the impact of emerging technologies on strategic stability.
Ventricular fibrillation associated with vasospastic angina pectoris in Fabry disease: a case report
Authors: Kodama Kenji , Ozawa Tomoya , Dochi Kenichi , Ueno Yoshiki
Published: July 2020

Background

Fabry disease (FD) is an X-linked lysosomal storage disorder resulting from a deficiency in alpha-galactosidase A. The major causes of death due to cardiac complications include life-threatening arrhythmias. In addition, life-threatening arrhythmias may be related to myocardial fibrosis assessed by late gadolinium enhancement (LGE).

Case summary

A 43-year-old man with sinus bradycardia and left ventricular hypertrophy was referred to our cardiology department. Family history includes unexplained hypertrophy and sick sinus syndrome in mother. Additionally, his plasma alpha-galactosidase A activity was low. He was subsequently diagnosed with FD. Enzyme replacement therapy using 1.0 mg/kg agalsidase-β was initiated. During the fifth administration, he developed ventricular fibrillation (VF). Electrocardiography conducted immediately before VF revealed ST elevation in the inferior leads with reciprocated ST depression. Cardiac magnetic resonance imaging showed no LGE in the myocardium. Coronary angiography showed no organic stenosis; moreover, coronary spasms were induced by an intracoronary acetylcholine injection. Ventricular fibrillation was not observed as the patient received calcium antagonists.

Discussion

This report suggests that vasospastic angina pectoris is associated with life-threatening arrhythmias in patient with FD without LGE.
Incidence, characteristics, determinants, and prognostic impact of recurrent syncope
Authors: Zimmermann Tobias , du Fay de Lavallaz Jeanne , Nestelberger Thomas , Gualandro Danielle M , Strebel Ivo , Badertscher Patrick , Lopez-Ayala Pedro , Widmer Velina , Freese Michael , Miró Òscar , Christ Michael , Cullen Louise , Than Martin , Martin-Sanchez F Javier , Di Somma Salvatore , Peacock W Frank , Keller Dagmar I , Boeddinghaus Jasper , Twerenbold Raphael , Wussler Desiree , Koechlin Luca , Walter Joan E , Bürgler Franz , Geigy Nicolas , Kühne Michael , Reichlin Tobias , Lohrmann Jens , Mueller Christian
Published: July 2020

Aims 

The aim of this study is to characterize recurrent syncope, including sex-specific aspects, and its impact on death and major adverse cardiovascular events (MACE).

Methods and results

We characterized recurrent syncope in a large international multicentre study, enrolling patients ≥40 years presenting to the emergency department (ED) with a syncopal event within the last 12 h. Syncope aetiology was centrally adjudicated by two independent cardiologists using all information becoming available during syncope work-up and long-term follow-up. Overall, 1790 patients were eligible for this analysis. Incidence of recurrent syncope was 20% [95% confidence interval (CI) 18–22%] within the first 24 months. Patients with an adjudicated final diagnosis of cardiac syncope (hazard ratio (HR) 1.50, 95% CI 1.11–2.01) or syncope with an unknown aetiology even after central adjudication (HR 2.11, 95% CI 1.54–2.89) had an increased risk for syncope recurrence. Least Absolute Shrinkage and Selection Operator regression fit on all patient information available early in the ED identified >3 previous episodes of syncope as the only independent predictor for recurrent syncope (HR 2.13, 95% CI 1.64–2.75). Recurrent syncope carried an increased risk for death (HR 1.87, 95% CI 1.26–2.77) and MACE (HR 2.69, 95% CI 2.02–3.59) over 24 months of follow-up, however, with a time-dependent effect. These findings were confirmed in a sensitivity analysis excluding patients with syncope recurrence or MACE before or during ED evaluation.

Conclusion 

Recurrence rates of syncope are substantial and vary depending on syncope aetiology. Importantly, recurrent syncope carries a time-dependent increased risk for death and MACE.

Trial registration

BAsel Syncope EvaLuation (BASEL IX, ClinicalTrials.gov registry number NCT01548352).
Fine-scale population structure in the UK Biobank: implications for genome-wide association studies
Authors: Cook James P , Mahajan Anubha , Morris Andrew P
Published: July 2020

The UK Biobank is a prospective study of more than 500 000 participants, which has aggregated data from questionnaires, physical measures, biomarkers, imaging and follow-up for a wide range of health-related outcomes, together with genome-wide genotyping supplemented with high-density imputation. Previous studies have highlighted fine-scale population structure in the UK on a North-West to South-East cline, but the impact of unmeasured geographical confounding on genome-wide association studies (GWAS) of complex human traits in the UK Biobank has not been investigated. We considered 368 325 white British individuals from the UK Biobank and performed GWAS of their birth location. We demonstrate that widely used approaches to adjust for population structure, including principal component analysis and mixed modelling with a random effect for a genetic relationship matrix, cannot fully account for the fine-scale geographical confounding in the UK Biobank. We observe significant genetic correlation of birth location with a range of lifestyle-related traits, including body-mass index and fat mass, hypertension and lung function, even after adjustment for population structure. Variants driving associations with birth location are also strongly associated with many of these lifestyle-related traits after correction for population structure, indicating that there could be environmental factors that are confounded with geography that have not been adequately accounted for. Our findings highlight the need for caution in the interpretation of lifestyle-related trait GWAS in UK Biobank, particularly in loci demonstrating strong residual association with birth location.