bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature effects on imazaquin soil bioavailability, uptake, and metabolism in corn (Zea mays)
Authors: Polge Nicholas D. , Barrett Michael
Published: May 2019

Growth chamber experiments were conducted to determine the effects of soil temperature on the response of corn to imazaquin soil residues. In a silt loam soil, 24/30 C (night/day) or 18/24 C soil temperatures caused greater inhibition of shoot growth than 12/18 C soil temperature. However, in a sandy loam soil, inhibition of corn shoot growth was maximal at 18/24 C, and there was no difference in shoot-growth inhibition between the lowest and highest temperatures. Higher soil temperatures caused greater root-growth inhibition in the sandy loam soil but not in silt loam soil. Soil temperature did not affect14C-imazaquin uptake from either soil. Higher soil temperatures increased the translocation of imazaquin from root to shoot tissue in both soils. In the sandy loam soil, imazaquin metabolism in root tissue decreased as soil temperature increased, with twice as much parent herbicide recovered from roots of plants grown under the highest compared with the lowest temperature treatments. Soil temperature had no effect on imazaquin metabolism in shoot tissue. Longer-term experiments (22 d) were conducted with the sandy loam soil to determine the effect of changes in air temperature on corn response to imazaquin soil residues. Plants exposed to 24/30 C for 7 or 14 d of the final 14-d growing period showed greater inhibition of shoot growth compared with plants maintained at 12/18 C. Uptake and translocation of14C-imazaquin to shoots was greater in plants maintained at 24/30 C throughout the final 14-d period than in plants maintained at 12/18 C. Plants grown for 7 d at 24/30 C during the final 14-d period either preceding or following 7 d growth at 12/18 C showed increased translocation of imazaquin to shoots but no difference in imazaquin uptake compared with plants maintained at 12/18 C. Neither air nor soil temperature treatments had any effect on imazaquin concentration in soil water.
Competitive interactions of tomato (Lycopersicon esculentum) and nutsedges (Cyperusspp.)
Authors: Santos Bielinski M. , Bewick Thomas A. , Stall William M. , Shilling Donn G.
Published: May 2019

Replacement series experiments were conducted under greenhouse conditions to evaluate effects of population densities and proportions on the intraspecific and interspecific interference of either purple nutsedge or yellow nutsedge with tomato cv. Sunny, under nonlimiting conditions of water and nutrients. When grown with either nutsedge species for 40 d, tomato dry weight per plant increased and dry weight per plant of nutsedge decreased as their relative proportions decreased in mixture. Relative yield analysis indicated tomato is a stronger competitor than either nutsedge species. Both nutsedges appeared to be weak interspecific competitors but strong intraspecific competitors. Attenuated light on a purple nutsedge canopy showed that tomato additions can reduce light received by the weed compared to pure nutsedge stands.
Giant foxtail (Setaria faberi) interference in nonirrigated corn (Zea mays)
Authors: Fausey Jason C. , Kells James J. , Swinton Scott M. , Renner Karen A.
Published: May 2019

Studies were conducted at East Lansing, MI, in 1994 and 1995 to examine corn yield response to giant foxtail interference and to examine the effect of giant foxtail density on giant foxtail biomass, seed production, and seed germination. Treatments consisted of 0, 10, 30, 60, 84, and 98 giant foxtail plants m−1of row in 1994 and 0, 10, 27, 30, 60, and 69 plants m−1of row in 1995. The influence of giant foxtail density on corn yield fit a hyperbolic equation. Corn yields were reduced 13% in 1994 and 14% in 1995 from 10 giant foxtail plants m−1of row. Corn dry matter at maturity was decreased 24 and 23% from 10 giant foxtail plants m−1of row in 1994 and 1995, respectively. Giant foxtail seed production increased linearly as inflorescence length increased. The length of a single giant foxtail inflorescence increased as plant density increased and the number of inflorescence produced per plant decreased. Giant foxtail seed production ranged from 518 to 2,544 seeds per plant. Ten giant foxtail plants m−1of row produced 15,700 seeds m−2. Giant foxtail seed germination was not affected by plant density.
Modelling the demography of crenate broomrape (Orobanche crenata) as affected by broad bean (Vicia faba) cropping frequency and planting date
Authors: López-Granados Francisca , García-Torres Luis
Published: May 2019

A mathematical model of crenate broomrape populations in broad bean as affected by cropping frequency and planting dates in the absence of crenate broomrape control practices was constructed using previously reported data. In consecutive broad bean cropping, broomrape populations reached a maximum infection severity (D) of 62, 47, and 30 emerged broomrape m−2for early (mid-October), intermediate (mid-November), and late (mid-December) planting dates, respectively. The maximumDvalues were reached earlier as planting dates were brought forward, taking from 4 to 6 yr, starting from very low initial infections (D ≤0.2 emerged broomrape m−2). If broad bean was cropped every 3 yr, 15, 21, and 27 yr were needed, respectively, according to the model, to reach the maximumDfor the three planting dates considered. A sensitivity analysis was conducted to determine the effect of changing the values of the main demographic parameters in broomrape life cycle (germination, attachment, and seed loss) on the output of the model under different management strategies (planting dates and cropping frequency). Generally, an increase in seed attachment and a decrease in seed loss affected broomrape population dynamics. Between the two processes evaluated, the time taken to reach the maximum infection severity (D) was less sensitive than the maximum broomrape population values. Model predictions were validated using results from long-term field studies at the late planting date sown every year. Simulated values generated good predictions (R2= 0.82).
The nature and consequence of weed spread in cropping systems
Authors: Thill Donald C. , Mallory-Smith Carol A.
Published: May 2019

Weeds spread through movement of seeds and vegetative reproductive propagules. Pollen movement can spread weedy traits, such as herbicide resistance, between related weed and crop species. Weed seeds can spread short or long distances by natural plant dehiscence mechanisms, wind, water, animals, and man&s activities. This symposium paper is a practical review of short-distance spread of weed seeds in and between nearby arable fields and noncrop lands, examining some of the causes of spread and subsequent effects on crop production. Pollen movement, as it affects the spread of herbicide resistance, also is considered a component of short-distance weed spread. Specific weed management options can be used to reduce man-caused weed seed spread within and between nearby fields, thus reducing potential crop yield losses. Long-term management will be more difficult for weed seed spread by natural dispersal mechanisms.
The nature and consequence of weed spatial distribution
Authors: Cardina John , Johnson Gregg A. , Sparrow Denise H.
Published: May 2019

Seed dispersal, interacting with environmental disturbance and management across heterogeneous landscapes, results in irregular weed spatial distributions. Describing, predicting, and managing weed populations requires an understanding of how weeds are distributed spatially and the consequences of this distribution for population processes. Semivariograms and kriged maps of weed populations in several fields have helped describe spatial structure, but few generalizations can be drawn except that populations are aggregated at one or more scales. Limited information is available on the effect of weed arrangement, pattern, or field location on weed population processes. Because weeds are neither regular nor uniform in distribution, mean density alone is of limited value in estimating yield loss or describing population dynamics over a whole field. Sampling strategies that account for spatial distribution can increase sampling efficiency. Further research should focus on understanding processes that cause changes in spatial distributions over time to help predict rates of invasion and potential extent of colonization.
Characterization of a norflurazon-resistant mutant of Chlamydomonas reinhardtii
Authors: Vartak Varsha , Bhargava Sujata
Published: May 2019

A norflurazon-resistant mutant has been isolated from Chlamydomonas reinhardtii that showed a three-fold factor of resistance over wild type cultures. In comparison to wild type cultures, the mutant showed better retention of chlorophylls and carotenoids when grown in light in the presence of norflurazon. When grown in the dark, chlorophyll losses were similar, while carotenoid losses were lower than in the wild type cultures. Higher levels of phytoene accumulated in the wild type cultures in the presence of norflurazon than in the resistant cultures. The resistant cultures also showed cross tolerance to EMD-IT 5914, a herbicide with a similar mode of action. Norflurazon resistance in this alga appears to arise from alterations in the target enzyme phytoene desaturase.
Response of purple (Cyperus rotundus) and yellow nutsedges (C. esculentus) to selective placement of sulfentrazone
Authors: Wehtje Glenn R. , Walker Robert H. , Grey Timothy L. , Hancock H. Gary
Published: May 2019

A series of greenhouse studies examined the effectiveness of PRE- and POST-applied sulfentrazone in controlling purple and yellow nutsedge as influenced by selective tissue exposure. In addition,14C-sulfentrazone was utilized to contrast absorption and translocation resulting from these exposures. Consistent control with preemergence applications to germinating tubers was obtained with a combined root and shoot zone exposure. Yellow nutsedge was more susceptible than purple nutsedge. Performance of the separate root and shoot zone exposure was soil pH- and nutsedge-species dependent. POST-foliar applications to established nutsedge were more effective when sulfentrazone was allowed to contact the soil surface.14C-sulfentrazone was readily absorbed by the roots and translocated to the foliage of both species in hydroponic culture.
Covariance of cropping systems and foxtail density as predictors of weed interference
Authors: McGiffen Milton E. , Forcella Frank , Lindstrom Michael J. , Reicosky Donald C.
Published: May 2019

Regression models of the effect of weed density on crop yield can form the basis of weed management programs by helping growers decide whether weed control is economically justified. However, few studies have examined whether one regression model can be used across a wide range of tillage systems and crop rotations. We used a nonlinear analysis of covariance to examine experiments conducted in 1990 and 1991 on the interaction of weed interference with conventional, fall chisel, and no-till systems, and rotations of corn, soybean, and wheat on a clay loam soil. Corn and soybean suffered heavy losses due to interference by green foxtail (a mixed population of robust purple and robust white varieties). Both tillage system and crop rotation altered the relationship between weed density and yield for corn in 1990 and 1991, but tillage was not a factor for soybean in 1991. Companion experiments on a sandy loam soil found no relationship between weed density and dryland corn yield in the drought year 1990, but weed density greatly decreased yield in irrigated corn. In 1991, the same model fit both dryland and irrigated corn grown in sandy loam soil. Foxtail density did not affect average weight per foxtail plant in any of our experiments, which indicates a lack of intraspecific competition. Competitiveness of corn better explained variation in dry weight per foxtail than did weather. Economic thresholds for foxtail interference are not constant but vary with weather, cropping system, and soil type.
Effects of temperature and photoperiod on tropical soda apple (Solanum viarumDunal) and its potential range in the U.S.
Authors: Patterson David T. , McGowan Mike , Mullahey J. Jeff , Westbrooks Randy G.
Published: May 2019

Tropical soda apple is an exotic perennial pasture weed currently reported in the U.S. only from Florida, Georgia, Alabama, Mississippi, and South Carolina. In experiments to determine its environmental requirements and potential range, tropical soda apple was grown in growth chambers in 16 day/night temperature regimes ranging from 18/8 to 36/26 C. After 100 d of growth, maximum height, leaf area, and shoot biomass occurred at day/night temperatures ranging from 24/26 to 36/26 C. The plants achieved 50% or more of maximum leaf area, biomass, and height at 18/26, 24/20, 24/26, 30/26, and 36/26 C. Plants survived in 8 C nights with day temperatures of 18 to 36 C, but biomass and leaf area were only 3 to 10% of maximum. Leaf appearance rate was linearly related to mean temperature over the range of 11.3 to 29.3 C, with a slope coefficient of 0.018 leaves/day/degree C. Flowering was delayed by photoperiods shorter than 10 h or temperatures lower than 24/20 C. In favorable temperatures, plants flowered within 60 d after emergence in photoperiods ranging from 8 to 16 h. Artificially pollinated flowers produced fruit with germinable seeds within 6 to 7 wk, at temperatures ranging from 23/17 to 32/26 C. A regression equation relating vegetative growth to day and night temperatures indicated that tropical soda apple could achieve 30% or more of its maximum growth rate during 7 mo of the year in southern Alabama, Louisiana, and Texas and during 4 to 5 mo of the year at sites in Georgia, South Carolina, North Carolina, Virginia, Tennessee, Kentucky, Illinois, Arkansas, Missouri, Kansas, and Oklahoma. Neither temperature nor photoperiod will limit its further spread in the southern U.S. and adjacent regions.
Soybean (Glycine max), common cocklebur (Xanthium strumarium), and sicklepod (Senna obtusifolia) sap flow in interspecific competition
Authors: Jones Ronald E. , Walker Robert H. , Wehtje Glenn
Published: May 2019

Two field experiments were conducted to examine the competitive effect of common cocklebur and sicklepod in soybean. Factors examined included sap flow of both the weed and the crop, as well as the traditional parameters of weed and crop growth and crop yield. The intent was to determine to what extent competitive effects could be attributed to differential water utilization. In the first study, soybean planted at 20 plants m−1row was infested with either sicklepod at 10 plants m−1row or common cocklebur at two plants m−1row. Sicklepod reduced soybean sap flow and yield 53 and 49%, respectively. Common cocklebur reduced soybean sap flow and yield 31 and 38%, respectively. Within a weed species, weed-induced yield and sap flow reductions were comparable, indicating that water deprivation was the primary detriment that these weeds inflicted on soybean. Individual common cocklebur plants were 3.9 times more competitive than sicklepod with respect to reducing soybean yield. However, sap flow of individual common cocklebur plants was only 1.4 times more than that of sicklepod, indicating that water deprivation was not the only causal factor in weed-crop competition. In the second experiment, sicklepod was planted in soybean (fixed density) and clipped to either half the height, same height as soybean, or left unclipped, in an attempt to simulate herbicide-induced stunting. Clipping sicklepod had a positive effect on soybean sap flow and yield. Thus, the benefits of reduced weed competition were achieved without killing sicklepod.
Studies of Horned Curassow Pauxi unicornis in Bolivia
Authors: Cox Guy , Read J. M. , Clarke R. O. S. , Easty V. S.
Published: May 2019

Observations of the Horned Curassow Pauxi unicomis in Amboro National Park, depto. Santa Cruz, Bolivia, allowed us to assess the status of a species whose habits in the wild were virtually unknown. Vocalizations, including call notes and the deep booming song, are described. Density was estimated by counting booming birds in the breeding season using a three-hide triangulation method. The study showed birds to be aggregated in one part of the study area. A nest of was found and the incubating female was observed for nine days: the individual incubated alone, left the nest at night, and returned at first light.

Observaciones de la Pava Copete de Piedra (Pava Crista Azul) Pauxi unicomis en el Parque Nacional Amboró, depto. Santa Cruz, Bolivia, nos permitió evaluar el estado de una especie cuyo comportamiento en el ambiente silvestre es prácticamente desconocido. Se describen vocalizaciones, que incluyen notas de llamada “call notes” y el profundo canto de estampida “deep booming song.” Se estimó la densidad de las aves por conteo de los sonidos de estampida “booming birds” durante la estacion reproductiva, usando un método de triangulación con tres puestos de observatión. Este estudio mostró que las aves se agregaban en una parte del área del estudio. Se encontró un nido de Pauxi unicomis y al hembra fue observada durante nueve dias durante la incubación; la hembra incubaba sóla, dejaba el nido por la noche y regresaba a las primeras horas del amanecer.
Harwood's FrancolinFrancolinus harwoodi: recent observations on its status, distribution, habitat requirements, behaviour and threats
Authors: Robertson P.A. , Dellelegn Yilma , Dejene Sileshi , Shimelis Anteneh , W/mariam Tadesse , Alemayehu Million
Published: May 2019

In May 1996 the authors carried out surveys of Harwood's Francolin Francolinus harwoodi, a threatened and restricted-range species, within the upper reaches of the Abay Basin, North Shoa Administrative Region, Ethiopia. The species is known from a small range in the Abay Basin but has not been reliably recorded away from a single site in the Jema Valley since 1930. Harwood's Francolin was found in the Jema Valley and valleys of adjacent river systems and, according to local reports, its range extends northwards into Southern Wello Administrative Region, a northerly extension of its previously known range. The species was found to be locally abundant, with transect counts giving a maximum density estimate of 92 birds/km2.

Typhabeds had been considered a crucial element in the species's habitat, but our observations suggest that althoughTyphabeds are sometimes used they are not an essential requirement. The main threat to the species's survival appears to be from clearance of thorn scrub rather than from clearance of Typha beds. Additional threats come from hunting for food and for sale at market, and collection of eggs.

Observations of courtship and mating in May and local reports of eggs in October indicate an earlier start to the breeding season than previously reported (first egg dates in December). The species may have two broods or have an extended, non-synchronous breeding season, timed to coincide with the rainy season and early dry season (May-December). Birds were observed to be highly gregarious and observations of courtship suggest that the species may be polygamous.

Recommendations are given for the conservation of the species, including further survey work and collaboration with local communities to identify and protect key areas of habitat.
An Investigation of School Principals’ Attitudes Toward Inclusion
Authors: Bailey Jeff , du Plessis Diana
Published: May 2019

This paper reports on an investigation of the attitudes of 225 principals employed in Queensland state schools, toward inclusion of students with disabilities. The justification for the study lay in the important role of school principals in implementing social justice strategies, together with the need to focus on attitudes toward inclusion, as opposed to mainstreaming or integration. The approach to inclusion taken in this study was the placement of students with disabilities and special needs in classrooms with children who do not have such disabilities or needs, together with the provision of support for the included student. A 30‐item scale measuring attitudes toward inclusion was developed and administered. In an attempt to identify the influence of factors which might be seen to influence inclusion attitudes, the following demographic variables were used for analysis: principals’ age and gender; type and size of school; previous and present experience with students with disabilities; and special education qualifications. The results showed the large majority of school principals were positive about inclusion. It was found that the demographics age, gender, and school size had no impact on attitudes toward inclusion. Using a two‐factor solution and a clustering of types of disability, significant differences emerged on the basis of type of school (secondary vs primary), type of disability (a combination of sensory, learning, intellectual, speech) vs aggressive behaviour, and previous teaching experience with students with disabilities. In terms of the implementation of inclusion, all respondents were equally cautious, pointing to the need for further training of teachers, aides and principals, and additional resources to ensure effective inclusion.
Teachers’ Perceptions of Possible Best Practices, Reported Implementation and Training Needs for Students with High Support Needs: Comparisons Across Qualification Status and Teacher Location
Authors: Carter Mark , Chalmers Susanne E. , Clayton Mark , Hook Julie
Published: May 2019

This study reports a further analysis of data presented by Chalmers, Carter, Clayton and Hook (in press) that examined teachers’ perceptions of possible best practice, reported implementation and training needs. Teachers of students with severe disabilities in 3 NSW Department of School Education regions were surveyed with 83 useable surveys being returned. Comparisons were made between teachers who worked in Schools for Specific Purposes (SSP) and those who working in support classes in regular schools as well as teachers with formal special education qualifications and those without such qualifications. Teachers in support classes reported a higher level of agreement with a majority of practices and disproportionately high levels of implementation when compared with teachers in SSPs. Teachers with formal special education qualifications reported higher levels of agreement than teachers without formal qualifications on the majority of items, but implementation levels were similar. There also appeared to be systematic differences in reported inservice training needs. Inadequacies in therapy services were reported as a barrier to best practice by over 50% of support class teachers.
Antiphase Domain Boundaries in Thin Films of Magnetite
Authors: Rudee M.L. , Margulies D.T. , Berkowitz A.E.
Published: May 2019

Abstract: Films of Fe3O4 were prepared by sputter deposition onto MgO substrates of both 〈100〉 and 〈110〉 orientations. The films used in this study were mainly 50 nm thick. X-ray diffraction, Mössbauer spectroscopy, and other techniques revealed that the films were stoichiometric single crystals. Electron microscopy showed that the films were essentially dislocation free. Despite this high degree of perfection, the magnetic properties of the films were inconsistent with bulk single crystal properties. For example, the magnetization of the films did not saturate in fields as large as 7 Tesla, while bulk single crystals saturate by 0.1 Tesla.
Phase Transformations during Transient Liquid Phase Bonding of NiAl
Authors: Gale W.F. , Guan Y. , Orel S.V.
Published: May 2019

Abstract: Transient liquid phase (TLP) bonding is a joining process in which a liquid-forming interlayer is placed between the substrates to be joined. At the bonding temperature, the interlayer initially liquates. Subsequently, interdiffusion between the liquid interlayer and the adjacent substrates results in a change in the overall composition of the joint, such that isothermal resolidification of the joint takes place. Standard models of the TLP process assume the sequential occurrence of discrete dissolution, isothermal solidification, and homogenization processes. This study uses edge-on transmission electron microscopy investigations to challenge the general applicability of such standard models to the TLP bonding of a variety of systems involving the B2 type intermetallic compound NiAl as a substrate material. This article considers the formation of boride phases apparently at the bonding temperature in NiAl/Ni-Si-B/Ni bonds. The precipitation of repeating sequences of phases in NiAl/Cu/Ni joints and the reliquation of the NiTi substrate in NiAl/Cu/NiTi bonds after the completion of isothermal solidification are examined.
Monte Carlo Simulation of Discrete Space Charge Effects in Photoelectron Emission Microscopy
Authors: Lovegren Jon C. , Massey Gail A.
Published: May 2019

Abstract: Interactions among discrete charges in the emission current of a photoelectron imaging system can limit its spatial resolution, significantly affecting the performance and design of emission microscopes employing high current densities. Under intense laser illumination a sample can emit photocurrent densities exceeding tens of amperes/cm2. This study describes Monte Carlo estimations of electron trajectory aberrations produced by discrete electron space charge interactions in a photoelectron emission microscope. The results also apply to photoelectron sources that might be used in other kinds of devices. A model of the emission process was used to assemble bunches of about 500 randomly positioned electrons whose individual trajectories were computed. Trajectory distortions of one member in each bunch that were due to the coulomb forces exerted by its neighbors were used to evaluate aberrations for a variety of voltages, current densities, and instrument configurations. Aberrations estimated in this way are smaller than those predicted by earlier theory or obtained in pulsed imaging experiments. Here we discuss the reasons for these differences, offer suggestions for improved instruments, and present experimental images.
High Resolution Electron Microscopy In Situ Observation of Dynamic Behavior of Grain Boundaries and Interfaces at Very High Temperatures
Authors: Kamino T. , Sasaki K. , Saka H.
Published: May 2019

High Resolution Electron Microscopy In Situ Observation of Dynamic Behavior of Grain Boundaries and Interfaces at Very High Temperatures
Combination of Annular Aperture and Polarization Gating Methods for Efficient Microscopic Imaging through a Turbid Medium: Theoretical Analysis
Authors: Gan X. , Schilders S. , Gu M.
Published: May 2019

Abstract: In this study, we investigate the principle of the annular aperture and polarization gating methods for microscopic imaging through a turbid medium using images simulated by a modified Monte Carlo program. Significant improvement in image quality is shown when thin annular apertures are used in the illumination and detection paths of a microscopic imaging system. The polarization gating method is proven to be an efficient gating method for selecting ballistic photons that carry the information of an object embedded in a turbid medium. We also demonstrate that the combination of the annular aperture and polarization gating methods is highly efficient in suppressing the scattered light in microscopic imaging through a turbid medium. It is also revealed that a pinhole used in a confocal microscope plays an independent angle-gating role.
Quantitative Electron Probe Microanalysis of Bi-Sr-Ca-Cu-O High Tc Superconductors Using Energy- and Wavelength-Dispersive Spectrometry
Authors: Marinenko Ryna B. , Teplitsky Mark
Published: May 2019

Abstract: Multiple linear least squares (MLLSQ) and sequential simplex spectral processing procedures were used in an electron probe energy-dispersive (EDS) analysis of a 2223 Bi-Sr-Ca-Cu-O (BSCCO) high Tc superconductor specimen. This phase is normally difficult to quantify by EDS at voltages below 25 kV because of the severe overlap of the BiM lines with the M lines from a small amount of Pb that is added to the phase for stability. Quantitative results from the MLLSQ spectral processing and ZAF matrix correction procedures agreed well with wavelength-dispersive analysis (WDS) of the same specimen.
Quantitative X-ray Images Calculated on the Basis of Mass and Volume
Authors: Kirk R. Gary , Gates Michael E. , Provance Aaron J. , Lee Ping
Published: May 2019

Abstract: Quantitative X-ray microanalysis is used to obtain the elemental compositions of tissues and cells. Concentrations are calculated on the basis of volume (mmolL−1 of packed cells) and mass (mmolkg−1 dry weight). Elemental maps are obtained by using a computer to control the position of a beam in an electron microscope and to record the signals from the scanning transmission electron microscope (STEM) and energy dispersive X-ray spectrometer (EDS) X-ray detectors. These X-ray images provide better visualization of elemental distributions than ``spot'' mode analysis by analyzing thousands of spots sequentially. When concentrations are determined on the basis of volume, it is assumed that the section thickness created during cryosectioning, and shrinkage during freeze-drying of a frozen section, are uniform. These assumptions have been examined with a nucleated red blood cell model. Even distributions of cytoplasmic Fe and K, which we observed, can only occur if cryomicrotomy produces sections with smooth surfaces and uniform thickness. In addition, by using bone marrow cryosections we have found that the relative shrinkage between nucleated and non-nucleated cells is similar. Therefore, the assumptions made about volume calculations do appear to be reasonable under the conditions used in this study.
Bis(trimethylsilyl)amide complexes of s-block metals with bidentate ether and amine ligands
Authors: Schüler Philipp , Görls Helmar , Westerhausen Matthias , Krieck Sven
Published: May 2019

The synthesis of the bis(trimethylsilyl)amide complexes of alkali and alkaline-earth metals with bidentate ether and amine bases 1,2-bis(dimethylamino)ethane (tmeda), dimethyl-methoxyethylamine (dmmea), and 1,2-dimethoxyethane (dme) succeedsviaaddition of these bases to coligand-free complexes orvialigand exchange of thf adducts.
Amino acid-derived alternating polyampholyte luminogens
Authors: Saha Biswajit , Choudhury Neha , Bhadran Abhi , Bauri Kamal , De Priyadarsi
Published: May 2019

A unique polyampholyte luminogen comprised of alternatively placed oppositely charged moieties onto the poly(styrene-alt-maleimide) skeleton was synthesized, and used for the specific detection of carbon disulfide (CS2) in both solution and vapor phases.
An ultrafast self-healing polydimethylsiloxane elastomer with persistent sealing performance
Authors: Wang Da-Peng , Zhao Zi-Han , Li Cheng-Hui , Zuo Jing-Lin
Published: May 2019

A novel polydimethylsiloxane elastomer obtained by crosslinking a long chain of poly(dimethylsiloxane) with tetra-functional biphenyl via an aldimine polycondensation reaction, exhibits ultrafast self-healing capability and persistent sealing performance (can completely self-heal punctured holes or scratches in seconds and therefore maintain its excellent sealing property).
Electrochemical mercury biosensors based on advanced nanomaterials
Authors: Liu Tao , Chu Zhenyu , Jin Wanqin
Published: May 2019

This review presents an overview of the synthesis strategies and electrochemical performance of recently developed nanomaterials for the Hg2+ assay.
A thorough understanding of the nonlinear optical properties of BODIPY/carborane/diketopyrrolopyrrole hybrid chromophores: module contribution, linear combination, one-/two-dimensional difference and carborane's arrangement
Authors: Wang Hong-Qiang , Ye Jin-Ting , Zhang Yuan , Zhao Yuan-Yuan , Qiu Yong-Qing
Published: May 2019

The high modularity of multicomponent photoactive BODIPY/carborane/diketopyrrolopyrrole hybrid chromophores was explored for linear/nonlinear optical applications.
Image encryption based on Fisher‐Yates shuffling and three dimensional chaotic economic map
Authors: Karawia Abdelrahman
Published: May 2019

Recently, few researchers investigated algorithms of image encryption using different chaotic economic maps (CEMs). However, the authors investigated the effect of these maps on the encryption of the plain image. In the current study, an image encryption algorithm via Fisher–Yates shuffling (FYS) combined with a three‐dimensional (3D) CEM is given. FYS is used to generate the random permutation of a finite sequence. First, it is used to shuffle the rows and the columns of the plain image. Second, the 3DCEM is used in the substitution stage to confuse the pixels of the shuffling image. The proposed algorithm is applied to several types of images. Many measurements are performed to check the security and performance of the proposed algorithm. In addition, numerical simulations and experimental results have been implemented to verify that the proposed algorithm can resist different attack types.
Improved CPT system with less voltage stress and sensitivity using a step‐down transformer on receiving side
Authors: Mostafa Tarek M. , Muharam Aam , Patrick Hu Aiguo , Hattori Reiji
Published: May 2019

This paper proposes a capacitive power transfer (CPT) system with a step‐down transformer on the secondary side to reduce the circuit quality factor (Q), and thereby reduce the sensitivity to parameters variations, as well as the voltage stress across the coupling interface. The system operating principle is analyzed mathematically, and the focus is given to understand the effect of the leakage inductance (Llk) of the non‐ideal transformer on the system performance. The analytical and simulation results show that at a given constant output power, the voltage across the plates is significantly reduced, and the system becomes less sensitive to the coupling variations by increasing the turns ratio of the step‐down transformer. It is found that Llk can be advantageously utilized as a tuning inductor (L) or part of it. The proposed method is verified by building a prototype CPT system that delivered 25 W at an operation frequency of 1 MHz, and an efficiency of more than 70%. Simultaneously, the voltage stress across the single pair of the coupling plates is reduced from 252 V of a conventional CPT system without a step‐down transformer, to 50.4 V using a high‐frequency transformer with a turns ratio of 5.
Device‐level modelling and FPGA‐based real‐time simulation of the power electronic system in fuel cell electric vehicle
Authors: Bai Hao , Liu Chen , Ma Rui , Paire Damien , Gao Fei
Published: May 2019

Power electronic converters are essential components in the fuel cell electric vehicle (FCEV) powertrain, which precisely control the power output of the fuel cell stack, the charging and discharging process of the battery, and the operation of the traction motor. The hardware‐in‐the‐loop (HIL) simulation plays an important role in the rapid validation of power converters in their early development stages. In this study, a device‐level model of the power converters in FCEV powertrain is developed for the FPGA‐based real‐time simulation. By fulfilling the circuit topology partitioning and the switch model partitioning, the FCEV power electronic system can be simulated with sub‐microsecond time‐step while producing the detailed switching waveforms with 5 ns resolution. Therefore, the device electrical stress, and the switching power losses can be evaluated in real time. Furthermore, the electro‐thermal converter model is developed accordingly, which makes it possible to evaluate the IGBT/Diode thermal behaviour in the HIL simulation. In this study, the FPGA hardware is designed with the NI LABVIEW FPGA module and implemented on the NI‐7975R FLEXRIO FPGA board. The accuracy of the FPGA‐based simulation results is evaluated by the results from offline simulation tools. The effectiveness of the proposed model is then validated by the controller HIL experiments.
Optimal home energy management under hybrid photovoltaic‐storage uncertainty: a distributionally robust chance‐constrained approach
Authors: Zhao Pengfei , Wu Han , Gu Chenghong , Hernando‐Gil Ignacio
Published: May 2019

Energy storage and demand response (DR) resources, in combination with intermittent renewable generation, are expected to provide domestic customers with the ability to reducing their electricity consumption. This study highlights the role that an intelligent battery control, in combination with solar generation, could play to increase renewable uptake while reducing customers’ electricity bills without intruding on people's daily life. The optimal performance of a home energy management system (HEMS) is investigated through a range of interventions, leading to different levels of customer weariness and consumption patterns. Thus, the DR is applied with efficient and specific control of domestic appliances through load shifting and curtailment. Regarding the uncertainty associated with the photovoltaic generation, a chance‐constrained (CC) optimal scheduling is considered subject to the operation constraints from each power component in the HEMS. By applying distributionally robust optimisation, the ambiguity set is accurately built for this distributionally robust CC (DRCC) problem without the need for any probability distribution associated with uncertainty. Based on the greatly altered consumption profiles in this study, the proposed DRCC‐HEMS is proven to be optimally effective and computationally efficient while considering uncertainty.
Implementation of a combinatorial‐optimisation‐based threat evaluation and jamming allocation system
Authors: You Shixun , Diao Ming , Gao Lipeng
Published: May 2019

Electromagnetic warfare is the most extensive and most hidden theatre of battle in modern warfare. To enhance the jamming effectiveness of a cooperative jammer platform against the threat of a radar net, a combinatorial‐optimisation‐based threat evaluation and jamming allocation (COTEJA) system is proposed. This COTEJA system fully considers the confrontation analysis in the jammer‐radar process, including the interactions between radars, jammers, and jammer‐radar pairs, and emphasises the realisation of cooperative jamming strategies. The cooperative jamming strategies include the combination of jamming techniques and optimisation algorithms for the objective function. The performance of the COTEJA system is evaluated through a combat mission that considers a platform with four jammers attacking five threats. In addition, the extended permutation‐based differential evolution algorithm is used for the first time to optimise the jamming coding matrix, which effectively reduces the danger value of netted radar under multiple constraints. The numerical results reveal that the COTEJA system can make the optimal jamming decision within 1 s, which improves the survival ability of the platform in a complicated electromagnetic environment.
Comparative investigation of stator‐mounted permanent magnet machines under fault conditions
Authors: Taras Petrica , Li Guang‐Jin , Zhu Zi‐Qiang , Foster Martin P. , Stone David A.
Published: May 2019

Here, machines having permanent magnets (PM) mounted in the stator are compared during fault operations such as armature winding short circuits. The magnet potential irreversible demagnetisation is also investigated due to the fact that the PMs are placed close to the armature coils (heat sources) and hence are prone to temperature‐related demagnetisations. It is found that the doubly salient and flux reversal machines have inherently higher fault tolerant capabilities when compared with the switched‐flux one. To the point of view of demagnetisation withstand capability, the doubly salient topology stands out as the most robust one while the switched flux is the weakest one.
Caulobacter crescentus
Hfq structure reveals a conserved mechanism of RNA annealing regulation
Authors: Santiago-Frangos Andrew , Fröhlich Kathrin S. , Jeliazkov Jeliazko R. , Małecka Ewelina M. , Marino Giada , Gray Jeffrey J. , Luisi Ben F. , Woodson Sarah A. , Hardwick Steven W.
Published: May 2019

We have solved the X-ray crystal structure of the RNA chaperone protein Hfq from the alpha-proteobacterium
Caulobacter crescentus
to 2.15-Å resolution, resolving the conserved core of the protein and the entire C-terminal domain (CTD). The structure reveals that the CTD of neighboring hexamers pack in crystal contacts, and that the acidic residues at the C-terminal tip of the protein interact with positive residues on the rim of Hfq, as has been recently proposed for a mechanism of modulating RNA binding. De novo computational models predict a similar docking of the acidic tip residues against the core of Hfq. We also show that
C. crescentus
Hfq has sRNA binding and RNA annealing activities and is capable of facilitating the annealing of certain
Escherichia coli
sRNA:mRNA pairs in vivo. Finally, we describe how the Hfq CTD and its acidic tip residues provide a mechanism to modulate annealing activity and substrate specificity in various bacteria.
One-Stage Augmentation Mastopexy: A Retrospective Ten-Year Review of 2183 Consecutive Procedures
Authors: Messa Charles A , Messa Charles A
Published: May 2019

Background

Although numerous studies supporting breast augmentation with simultaneous mastopexy have been reported, concerns persist among surgeons regarding the safety of this procedure.

Objectives

The authors sought to evaluate the safety and effectiveness of 1-stage augmentation mastopexy by analyzing long-term complication and reoperation rates.

Methods

The authors conducted a retrospective review of 1131 patients who underwent 2183 consecutive 1-stage augmentation mastopexy procedures from January 2006 to August 2016. Patient demographics, operative technique, and implant specifications were measured and analyzed with surgical outcomes. Long-term complication and reoperation rates were noted.

Results

Over a mean follow-up period of 43 months (range, 4-121 months), the overall complication rate was 15.3% (n = 173) with a reoperation rate of 14.7% (n = 166). Tissue-related complications included hypertrophic scarring in 2.5% (n = 28) and recurrent ptosis in 2.1% (n = 24). The most common implant-related complication was capsular contracture (Baker III or IV) in 2.8% (n = 32). The most common indications for reoperation were recurrent ptosis in 3.5% (n = 40 patients) and desire to change implant size in 3.2% (n = 36 patients). Circumareolar augmentation mastopexy technique was associated with a higher reoperation rate of 25.7% (P < 0.0005). Patients with a history of smoking had a higher incidence of complications (26.1%) and reoperations (22.5%; P < 0.0005). There were no cases of significant skin flap necrosis (>2 cm).

Conclusions

One-stage augmentation mastopexy can be safely performed with a reoperation rate that is significantly lower than when the procedure is staged. The effectiveness of this procedure is defined by a low complication rate and a reduced number of operations for the patient.

Level of Evidence: 4
Perceived threat to paternity reduces likelihood of paternal provisioning in house wrens
Authors: DiSciullo Rachael A , Thompson Charles F , Sakaluk Scott K
Published: May 2019

Biparental care is a critical and, occasionally, unequally shared obligation that ensures that young survive to maturity. Such care may be complicated in systems in which one parent, typically the male, is unsure of his genetic relatedness to the young. Males may reduce paternal provisioning when full paternity is not assured, as occurs in mating systems in which females engage in extrapair copulations. Moreover, other factors independent of extrapair matings, such as male personality traits, likely also affect the level of paternal care. In this study, we determined the effect of a paternity threat event (i.e., a conspecific or a heterospecific territory intrusion) and male personality (i.e., the level of aggressiveness) on provisioning effort by male house wrens (Troglodytes aedon). Males were more likely to attack a conspecific intruder than a heterospecific intruder. Males that were exposed to a conspecific intruder were less likely to provision young at all. Of those males that did feed the young in their nest, male aggressiveness did not relate to feeding effort. These findings suggest that the likelihood of paternal care is reduced by perceived threats to paternity but that the costs of not feeding potentially multisired young are high and feeding efforts are unrelated to male personality.
Alignment-free filtering for cfNA fusion fragments
Authors: Yang Xiao , Saito Yasushi , Rao Arjun , Kim Hyunsung John , Singh Pranav , Scott Eric , Larson Matthew , Pan Wenying , Desai Mohini , Hubbell Earl
Published: May 2019

Motivation

Cell-free nucleic acid (cfNA) sequencing data require improvements to existing fusion detection methods along multiple axes: high depth of sequencing, low allele fractions, short fragment lengths and specialized barcodes, such as unique molecular identifiers.

Results

AF4 was developed to address these challenges. It uses a novel alignment-free kmer-based method to detect candidate fusion fragments with high sensitivity and orders of magnitude faster than existing tools. Candidate fragments are then filtered using a max-cover criterion that significantly reduces spurious matches while retaining authentic fusion fragments. This efficient first stage reduces the data sufficiently that commonly used criteria can process the remaining information, or sophisticated filtering policies that may not scale to the raw reads can be used. AF4 provides both targeted and de novo fusion detection modes. We demonstrate both modes in benchmark simulated and real RNA-seq data as well as clinical and cell-line cfNA data.

Availability and implementation

AF4 is open sourced, licensed under Apache License 2.0, and is available at: https://github.com/grailbio/bio/tree/master/fusion.
Establishment of novel monoclonal antibodies for identification of type A spermatogonia in teleosts†
Authors: Hayashi Makoto , Ichida Kensuke , Sadaie Sakiko , Miwa Misako , Fujihara Ryo , Nagasaka Yasuhiko , Yoshizaki Goro
Published: May 2019

We recently established a germ cell transplantation system in salmonids. Donor germ cells transplanted into the body cavity of recipient embryos migrate toward and are incorporated into the recipient gonad, where they undergo gametogenesis. Among the various types of testicular germ cells, only type A spermatogonia (A-SG) can be incorporated into the recipient gonads. Enriching for A-SG is therefore important for improving the efficiency of germ cell transplantation. To enrich for A-SG, an antibody against a cell surface marker is a convenient and powerful approach used in mammals; however, little is known about cell surface markers for A-SG in fish. To that end, we have produced novel monoclonal antibodies (mAbs) against cell-surface molecules of rainbow trout (Oncorhynchus mykiss) A-SG. We inoculated mice with living A-SG isolated from pvasa-GFP transgenic rainbow trout using GFP-dependent flow cytometry. By fusing lymph node cells of the inoculated mice with myeloma cells, we generated 576 hybridomas. To identify hybridomas that produce mAbs capable of labeling A-SG preferentially and effectively, we screened them using cell ELISA, fluorescence microscopy, and flow cytometry. We thereby identified two mAbs that can label A-SG. By using flow cytometry with these two antibodies, we could enrich for A-SG with transplantability to recipient gonads from amongst total testicular cells. Furthermore, one of these mAbs could also label zebrafish (Danio rerio) spermatogonia. Thus, we expect these monoclonal antibodies to be powerful tools for germ cell biology and biotechnology.