bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute effect of fructose on postprandial lipaemia in diabetic and non-diabetic subjects
Authors: Abraha Arefaine , Humphreys Sandy M. , Clark Mo L. , Matthews David R. , Frayn Keith N.
Published: May 2019

We investigated whether the potentiation of postprandial lipaemia by fructose occurs in both non-diabetic subjects and those with non-insulin-dependent diabetes mellitus. Six non-diabetic and six diabetic subjects were studied on two occasions. They were given a meal containing 1 g fat/kg body weight with, on one occasion, 0.75 g fructose/kg body weight, on the other occasion 0.75 g starch/kg body weight. In both groups, plasma glucose and insulin concentrations rose more after starch than after fructose. At 1–2 h after the meal, plasma non-esterified fatty acid concentrations were suppressed more after fructose than after starch, but later they rose more after fructose than after starch. Plasma triacylglycerol concentrations rose more slowly after fructose, but were considerably higher than those after starch from 4–6 h after the meal. There were no differences in post-heparin plasma lipoprotein lipase (EC3.1.1.34) activity at the end of the test. The potentiation of postprandial lipaemia by fructose was positively related to the fasting plasma insulin concentration, suggesting that insulin-resistant subjects are more prone to this effect. We conclude that the potentiation of postprandial lipaemia by fructose is seen in both diabetic and non-diabetic subjects. Our results suggest that alterations in the dynamics of plasma non-esterified fatty acids might underlie the effects of fructose on triacylglycerol metabolism.
Maimonides Revised: The Case of theSefer Miṣwot Gadol
Authors: Woolf Jeffrey R.
Published: May 2019

TheSefer Miṣwot Gadol(The Great Book of the Commandments) of R. Moses b. Jacob of Coucy (mid-thirteenth century), is one of the central works of halakhic codification stemming from Franco-German (Ashkenazic) Jewry in the High Middle Ages. It has long had a reputation for being one of the classic compilations of the tosafist age, a period of efflorescence of talmudic scholarship which spanned the twelfth and thirteenth centuries. Its influence both as a legal source and schoolbook was wide-ranging, as the large number of extant manuscripts of the work, as well as the intensive work of annotation and commentary that it inspired, bear witness.
Hungary-Romania: Treaty on Understanding, Cooperation and Good Neighborliness
Authors: Nagy Boldizsár
Published: May 2019

The Hungarian-Romanian Treaty of Understanding, Cooperation and Good Neighborliness is the latest in a series of 13 framework treaties concluded by Hungary after 1989, regulating fundamental elements of interstate contact and settling certain specific disputes. That is why both parties refer to it as the Hungarian-Romanian “Basic Treaty”, as is the case with the two most frequently discussed forerunners to it, the Hungarian-Ukrainian Basic Treaty (done at Kiev on December 6, 1991 and entered into force on June 16, 1993), and the Hungarian-Slovak Basic Treaty (done at Paris on March 19, 1995 and entered into force on May 15, 1996).
Preface: International Organization at Its Golden Anniversary
Authors: Katzenstein Peter J. , Keohane Robert O. , Krasner Stephen D.
Published: May 2019

This special issue of International Organization looks back on the first fifty years, and especially the last thirty, of this journal. As former editors, we were asked by the editorial board in 1996 to create a special fiftieth anniversary issue. In good academic style, the thought came late and the issue is tardy: you will notice that this is volume 52 of International Organization (founded in 1947). Like many a graduate student over these decades, we hope that the quality of our product will compensate for our long-standing “incomplete.”
Humanitarian action and peace-keeping operations
Authors: Sommaruga Cornelio
Published: May 2019

It is an honour and a privilege for me to address this Conference devoted to a topic of great importance to the International Committee of the Red Cross (ICRC). As a humanitarian organization, whose mandate it is to provide protection and assistance for victims of armed conflicts and which is operational worldwide, the ICRC has been directly concerned with many peace-keeping missions undertaken by the United Nations.
Echinoderm Faunas of the Hongguleleng Formation, Late Devonian (Famennian), Xinjiang-Uygur Autonomous Region, People's Republic of China
Authors: Lane N. Gary , Waters Johnny A. , Maples Christopher G.
Published: May 2019

Famennian (Late Devonian) echinoderm faunas are poorly known on a global basis, although reasonably diverse faunas have been reported from England and Germany. We have collected a diverse (>500 specimens representing approximately 30 taxa) Famennian echinoderm fauna dominated by blastoids and inadunate, small-calyx camerate, and flexible crinoids from the Hongguleleng Formation, Junggar Basin, Xinjiang–Uygur Autonomous Region, People's Republic of China. Taxa reported here include five new genera and six new species of blastoids along with one new genus and 19 new species of crinoids. Blastoid taxa includeJunggaroblastus hoxtolgayensisnew genus and species,Orophocrinus devonicusnew species,Xinjiangoblastus ornatusnew genus and species,Uyguroblastus conicusnew genus and species,Sinopetaloblastus jinxingaenew genus and species, andHouiblastus devonicusnew genus and species. Crinoid taxa includeUperocrinus zhaoaenew species, ?Hexacrinitesspecies,Agathocrinus junggarensisnew species,Chinacrinus xinjiangensisnew genus and species, ?C.nodosusnew genus and species,C.species A, C. species B,C.species C,Eutaxocrinus chinaensisnew species,E. boulongourensisnew species,E. basellusnew species,Forbesiocrinus inexpectansnew species,Deltacrinus asiaticusnew species,Bridgerocrinus minutusnew species,B. delicatulusnew species,Cosmetocrinus parvusnew species, ?Pachylocrinus subpentagonalisnew species,“Decadocrinus” constrictusnew species, “D.”elongatusnew species, “D.”rugosusnew species, “D.”usitatusnew species, “D.”xinjiangensisnew species, ?Graphiocrinusspecies,Holcocrinus asiaticusnew species, and four species of inadunate crinoids that could not be assigned to genera. This fauna is more abundant and diverse than all other Famennian echinoderm faunas in the world combined, and it is critical in understanding echinoderm biogeography and evolution in the aftermath of the Late Devonian extinction event(s) prior to the Carboniferous echinoderm diversification. This echinoderm fauna is “Carboniferous” in affinity and indicates that echinoderm diversification and reradiation were well underway before the close of the Famennian.
Effect of chlorsulfuron on assimilate transport: ultrastructural implications
Authors: Kim Songmun , Han Sangsop , Born William H. Vanden
Published: May 2019

To determine if cell damage could account for chlorsulfuron inhibition of assimilate transport, the ultrastructure of companion cells and surrounding mesophyll cells was examined following chlorsulfuron treatment. Six hours after treatment of canola leaves, thylakoids in companion cells were swollen and chloroplast structures in mesophyll cells were disorganized. Three days after treatment, the treated leaves contained more starch granules in companion cells than corresponding control leaves, presumably as a result of reduced assimilate export. We conclude that the inhibition of assimilate export in chlorsulfuron-treated canola leaves is associated, at least in part, with the ultrastructural changes described, particularly those in companion cells.
Field mobility of flumetsulam in three Mississippi soils
Authors: Murphy Glen P. , Shaw David R.
Published: May 2019

Research was conducted in 1994 and 1995 to evaluate the field mobility of flumetsulam in three soils of varied texture and organic matter content but constant pH (pH = 6.0 ± 0.1). Flumetsulam was monitored to a depth of 122 cm at 28, 56, and 84 days after treatment (DAT). Flumetsulam concentrations were determined by cotton bioassay, with separate standard curves for various soil–depth combinations. Following a preemergence application of flumetsulam at 224 g ai ha−1, the herbicide was primarily limited to the upper 8 cm of soil, regardless of soil type, year, or DAT. Exceptions to this typically occurred following substantial rainfall amounts early in the season. Beyond 28 DAT, no significant concentrations of flumetsulam were detected below 15 cm. Results from this research suggest that leaching is not a significant route of flumetsulam dissipation in the field.
Activity, adsorption, mobility, efficacy, and persistence of alachlor as influenced by formulation
Authors: Vasilakoglou Ioannis B. , Eleftherohorinos Ilias G.
Published: May 2019

Activity, adsorption, mobility, and field persistence of one emulsifiable concentrate (EC) and three microencapsulated (ME) formulations of alachlor were studied with petri dish bioassay, based on root response of oats grown in sand or soil. Both bioassays indicated that activity of all formulations was increased with increasing herbicide concentration. EC-alachlor in sand showed the highest activity, while ME-alachlorLand ME-alachlorA, the lowest; the activity of ME-alachlorCwas intermediate. In silty clay loam soil, EC-alachlor had the highest activity, while ME-alachlorLhad the lowest; and ME-alachlorAshowed intermediate activity and was similar to that of ME-alachlorCMore alachlor was adsorbed on the soil or remained encapsulated (not biologically available) after ME-alachlorLand ME-alachorAapplication compared to EC-alachlor. An intermediate amount of alachlor was adsorbed or remained inside the capsules when the ME-alachlorCformulation was applied. Greater amounts of alachlor were leached through a silty clay loam after EC-alachlor application compared to the three ME-alachlor formulations. Biologically available alachlor was not detected below 15 or 10 cm after application of EC- and ME-alachlor formulations, respectively. All alachlor formulations applied alone or in mixture with atrazine showed similar field persistence. Biologically available alachlor was not detected in the 0- to 10-cm soil depth 30 d after their application. All alachlor formulations applied alone gave excellent control of redroot pigweed and black nightshade, but only partial control of jimsonweed. None of the herbicide treatments showed any detrimental effect on corn, and all of them increased corn yield to the level of weed-free control.
Weed species diversity in spring barley varies with crop rotation and tillage, but not with nutrient source
Authors: Stevenson F. Craig , Légère Anne , Simard Régis R. , Angers Denis A. , Pageau Denis , Lafond Jean
Published: May 2019

The development of sustainable farming systems depends on our ability to predict and manage the response of weed communities to changes in cropping practices. A study was established at Normandin, Québec, Canada, to investigate the influence of liquid dairy manure and mineral fertilizer, as well as chisel and moldboard plow tillage systems, in a spring barley monoculture and a 3-yr spring barley-forage rotation that included red clover and timothy. Weed species richness (Margalef's DMG), evenness (Shannon's E), and diversity (Shannon's H') were examined in these treatments from 1992 to 1995. Nutrient source had no effect on any of the three diversity indices. Evenness values were extremely low in all years, suggesting dominance of a few weed species in most treatments. Weed species richness and diversity generally were greater in the barley-forage rotation compared with the monoculture. Tillage effects on richness and diversity varied with crop rotation. Margalef's DMGand Shannon's H' were greater in 1993 and 1995, but they were lower in 1994 when chisel was compared with moldboard plowing in the monoculture. In 1994, chickweed density was about five times greater in the chisel-plowed monoculture compared with other treatment combinations of rotation and tillage. In 1995, only one species with a density of six plants m−2occurred in the moldboard-plowed monoculture compared with three to six species and densities of 51 to 832 plants m−2in the other rotation by tillage treatments. Climatic conditions and herbicide use patterns in the different crop rotation treatments may have contributed to the more dynamic nature of weed species diversity in the barley monoculture. Reduced frequency of tillage and herbicide application; management of the forage stands, especially with regard to their termination; and improved soil resource availability likely explained the increased but more stable diversity of the weed communities in the barley-forage rotation.
In vitro and whole-plant magnitude and cross-resistance characterization of two imidazolinone-resistant sugarbeet (Beta vulgaris) somatic cell selections
Authors: Wright Terry R. , Penner Donald
Published: May 2019

Acetolactate synthase (ALS)-inhibiting herbicide carryover in soil can severely affect sugarbeets grown in the year(s) following application. Two newly developed imidazolinone-resistant (IMI-R) sugarbeet somatic cell selections (Sir-13 and 93R30B) were examined for magnitude of resistance and extent of cross-resistance to other classes of ALS inhibitors and compared to a previously developed sulfonylurea-resistant (SU-R) selection, Sur. In vitro shoot culture tests indicated Sir-13 resistance was specific to imidazolinone (IMI) herbicides at approximately a 100-fold resistance compared to the sensitive control sugarbeet. Sur was 10,000-fold resistant to the sulfonylurea (SU) herbicide, chlorsulfuron, and 40-fold resistant to the triazolopyrimidine sulfonanilide (TP) herbicide, flumetsulam, but not cross-resistant to the IMI herbicides. 93R30B was selected for IMI-R from a plant homozygous for the SU-R allele,Sur, and displayed similar in vitro SU-R and TP-R as Sur, but also displayed a very high resistance to various IMI herbicides (400- to 3,600-fold). Compared to the sensitive control, Sir-13 was 300- and > 250-fold more resistant to imazethapyr and imazamox residues in soil, respectively. Response by whole plants to postemergence herbicide applications was similar to that observed in shoot cultures. Sir-13 exhibited > 100-fold resistance to imazethapyr as well as imazamox, and 93R30B showed > 250-fold resistance to both herbicides. 93R30B showed great enough resistance to imazamox to merit consideration of imazamox for use as a herbicide in these sugarbeets. Sir-13 showed a two- to threefold higher level of resistance in the homozygous vs. heterozygous state, indicating that like most ALS-inhibitor resistance traits, it was semidominantly inherited.
Phytochrome-mediatedAmaranthusgermination I: effect of seed burial and germination temperature
Authors: Gallagher Robert S. , Cardina John
Published: May 2019

This research was conducted to evaluate the light requirement for redroot and smooth pigweed germination in soil, and how this requirement is affected by germination temperature and seasonal periodicity in seed dormancy. Seed enclosed in nylon mesh bags was buried in the field in December 1993 and 1994 and was recovered throughout the spring and summer of the following year, respectively. Germination was highest with red light or at 30 C. The requirement for red light was more pronounced at 20 vs. 30 C. The saturating fluence of red light was as low as 3 μmol m−2in buried seed and 1,000 μmol m−2in unburied control seed, depending on germination temperature. The effect of light and germination temperature pigweed germination also changed throughout the growing season. Our results indicate that light may be a requirement for germination in only the most dormant weed seed in the soil seedbank.
Influence of cohorts onChenopodium albumdemography
Authors: Mulugeta Dawit , Stoltenberg David E.
Published: May 2019

Peak germination and emergence of common lambsquarters usually occur in early to mid-spring, but both processes can occur during summer and fall. Seeds produced by different common lambsquarters cohorts (seedlings that emerge at nearly the same time) may vary in dormancy status, response to environmental conditions, and response to management factors. Therefore, experiments were conducted to determine the influence of different cohorts on common lambsquarters demography. Field experiments determined plant density, biomass, and seed production of different common lambsquarters cohorts within a crop-free community of annual weed species that included redroot pigweed, giant foxtail, and velvetleaf. Common lambsquarters plant density and aboveground biomass were greater for a mid-May cohort than for early June, late June, mid-July, or early August cohorts, but seed production of the mid-May and early June cohorts did not differ (about 192,000 seeds m−2) and was greater than that of other cohorts (111,500 seeds m−2or less). In the laboratory, percent germination prior to stratification (exposure of seeds to low temperatures) was less for seeds harvested from early May and late May cohorts (≥ 9%) than those of mid-June or early July cohorts (≤ 75%). After stratification in the field, percent emergence (seedlings per number of planted seeds) and mean emergence time were similar among early May, late May, mid-June, and early July cohort seed sources, and were not influenced by shallow burial in soil. These results suggest that recruitment from seeds produced by different common lambsquarters cohorts is similar, but proportional to the number of seeds produced by each cohort.
Functional and quantitative analysis of seed thermal responses in prostrate knotweed (Polygonum aviculare) and common purslane (Portulaca oleracea)
Authors: Kruk B. C. , Benech-Arnold R. L.
Published: May 2019

A screening method was used to characterize seed thermal responses of prostrate knotweed and common purslane, two important weeds invading wheat in the humid Pampa. Through this method, it was possible to detect thermal conditions that induce or break dormancy in both species. In addition, we were able to quantify changes in dormancy level in seed populations as a function of time of burial after dispersal, through changes in width of the thermal range within which germination can occur. Plotting the overlap of this thermal range and observed soil temperature throughout the year allowed the prediction of the seedling emergence period. This prediction was in agreement with observed seedling emergence in the field for both species, during 2 consecutive yr. From the analysis carried out under laboratory conditions, it was also possible to estimate required thermal time for germination of the nondormant fraction of the population and the base temperature above which thermal time is accumulated. The results obtained from this study are the basis for the formulation of seed germination models that predict not only the occurrence of seedling emergence in the field, but also the dynamics of germination within those periods.
Weed control with reduced rates of imazaquin and imazethapyr in no-till narrow-row soybean (Glycine max)
Authors: Johnson William G. , Dilbeck Jeffrey S. , DeFelice Michael S. , Kendig J. Andrew
Published: May 2019

Field studies were conducted at three locations in 1993 and 1994 to evaluate weed control and crop response to metolachlor plus combinations of 0.5 × and 1 × label rates of imazaquin applied preplant and imazethapyr applied early postemergence or postemergence in no-till narrow-row soybean production. Giant foxtail, common ragweed, common cocklebur, and large crabgrass population reductions were greater with sequential preplant metolachlor plus imazaquin followed by early postemergence or postemergence imazethapyr than with preplant metolachlor plus imazaquin or early postemergence/postemergence imazethapyr alone. Ivyleaf morningglory was not effectively controlled by any herbicide program. Pennsylvania smartweed populations were reduced with all herbicide treatments. Soybean yields with treatments utilizing 0.5 × rates were usually equal to 1 × rates if imazethapyr was applied early postemergence or postemergence. Net income with reduced herbicide rates was equal to full-label rates and provided no greater risk to net income.
Influence of pyrithiobac sodium on purple (Cyperus rotundus) and yellow nutsedge (C. esculentus)
Authors: Wilcut John W.
Published: May 2019

Greenhouse studies were conducted to determine purple and yellow nutsedge response to selective placement of a 5-cm layer of pyrithiobac sodium-treated soil above, below, or above and below nutsedge tubers. Pyrithiobac sodium at 36 or 72 g ae ha−1applied postemergence as foliar, soil, or foliar and soil treatments also was evaluated. Pyrithiobac sodium applied above, below, or above and below nutsedge tubers reduced yellow and purple nutsedge shoot number, shoot regrowth, and root-tuber dry weight at least 90%. Foliar-only treatment of pyrithiobac sodium was less effective at reducing emerged purple and yellow nutsedge numbers than application to soil only or to foliage and soil. Best reduction in yellow and purple nutsedge growth with pyrithiobac sodium was obtained with soil-incorporated treatments.
Toxic alkaloid response to herbicides used to control tall larkspur
Authors: Ralphs Michael H. , Manners Gary D. , Gardner Dale R.
Published: May 2019

Herbicides have been used to control tall larkspur to prevent cattle deaths. There is some evidence that tall larkspur may become more toxic and more palatable during the desiccation process following herbicide treatment. A series of studies were conducted to measure toxic alkaloid concentration in tall larkspur following treatment with metsulfuron, picloram, and glyphosate. Herbicides were applied to larkspur plants grown in a greenhouse (1990), to field plots infested with larkspur (1993), and to individual larkspur plants in the field (1995). Leaves were harvested up to 14 or 28 d following treatment, and toxic alkaloids were measured. Metsulfuron increased toxic alkaloid concentration in the 1990 greenhouse study and in 1993 field plot studies, and increased both concentration and absolute amount of toxic alkaloids in 1995 individual plant treatments. Alkaloids in plants treated with picloram either remained unchanged or declined slightly in all three studies and were similar to control plants. In the 1995 study, glyphosate caused the relative concentration of alkaloids to increase as the plants desiccated, but the absolute amount of alkaloids was similar to control plants. Picloram and glyphosate did not reduce alkaloid concentration; thus, the risk of poisoning remains until plants desiccate. Metsulfuron increased alkaloid concentration, thus increasing the risk of poisoning. Cattle should not be allowed to graze sprayed areas until larkspur desiccates and withers.
Influence of surface and subsurface soil properties on atrazine sorption and degradation
Authors: Jenks Brian M. , Roeth Fred W. , Martin Alex R. , McCallister Dennis L.
Published: May 2019

Studies to predict pesticide fate often lack measurements of model input parameters. Using independent data sets and understanding how soil properties affect herbicide retention and degradation may result in more accurate prediction of herbicide fate. We conducted laboratory studies to determine the influence of soil properties on atrazine adsorption and degradation. These data will be used in a separate study involving a pesticide fate model. Atrazine adsorption and desorption isotherms were constructed for six soil depths of a Hastings silty clay loam (fine, montmorillonitic, mesic Udic Argiustoll) using batch equilibration. The Freundlich adsorption constants (logKf) ranged from 0.38 (60 to 90 cm) to 2.91 (0 to 30 cm). Adsorption was higher in the low pH, high organic matter-containing surface soil compared to the lower soil depths. Multiple regression of the adsorption constants against selected soil properties indicated that organic matter content was the best single predictor of atrazine adsorption (R2= 0.98) followed by soil pH (R2= 0.82). Combining organic matter and cation exchange capacity in the model produced the lowestCpstatistic (2.33) and highestR2value (0.99). We observed hysteresis in atrazine adsorption–desorption isotherms by higher adsorption slopes (1/n)adscompared to desorption slopes (1/n)des. Soils that adsorbed more atrazine also desorbed less atrazine. Desorption correlated negatively with organic matter content and positively with soil pH. Atrazine degradation after 84 d of incubation generally decreased with increasing depth. The first-order degradation rate was highest 0 to 30 cm deep (0.0187 day−1) and lowest 270 to 300 cm deep (0.0031 day−1). Atrazine degradation was faster in soil treated annually for 12 yr than in soil with no previous atrazine history (p = 0.01).
Adjuvant enhancement of large crabgrass (Digitaria sanguinalis) control with dithiopyr
Authors: Keeley Steven J. , Branham Bruce E. , Penner Donald
Published: May 2019

A greenhouse study was conducted to determine the effectiveness of adjuvants on postemergence large crabgrass control with dithiopyr. Using barriers to isolate foliage or soil, the primary site of dithiopyr uptake was found to be via foliage. Laboratory and greenhouse studies elucidated the factors involved in enhancement of crabgrass control by dithiopyr with nine superior adjuvants. Two adjuvants increased dithiopyr absorption by 3.7 to 4.3% over the herbicide alone. However, none of the adjuvants increased dithiopyr translocation out of the treated leaf. Treatment of a single large crabgrass leaf indicated that enhancement of dithiopyr activity by adjuvants involved an effect on translocation, on spray retention, and on the external movement of the spray solution to the apical meristem, with the relative importance of any 1 factor depending on the particular adjuvant used. Because of the large losses of dithiopyr during absorption/translocation studies, a separate volatilization experiment determined that 70% of the applied dithiopyr volatilized within 24 h at 24 C. Dithiopyr absorption decreased and volatilization increased with each 10 C increase in temperature. Nonrecoverable dithiopyr ranged from 46 to 55% at 5 C to 92 to 95% at 35 C. Volatility losses of this magnitude may mitigate adjuvant enhancement of postemergence grass activity of dithiopyr.
Increased weed emergence and seed bank depletion by soil disturbance in a no-tillage system
Authors: Mulugeta Dawit , Stoltenberg David E.
Published: May 2019

The influence of secondary soil disturbance on the emergence pattern and seed bank depletion of an annual weed community in a long-term, no-tillage corn cropping system was determined in 1992 and 1993. As a component of this research, the seed bank was characterized prior to implementation of soil disturbance treatments. The seed bank was initially composed of common lambsquarters, redroot pigweed, and giant foxtail, with approximately 55, 36, and 8% of the total viable seeds, respectively. The remaining 1% was comprised of five other species in 1992 and eight in 1993. The spatial distribution of viable seeds of each species, except common lambsquarters and redroot pigweed, was described by a negative binomial distribution. Three dispersion indices indicated that seeds of individual and total weed species were aggregated and that the level of aggregation of viable seeds of a species was associated with seed density; at lower seed densities, the level of aggregation was greater. Soil disturbance increased common lambsquarters emergence 6-fold in 1992 relative to nondisturbed soil, but did not influence emergence in 1993. Rainfall was about 50% less in 1993. In contrast, soil disturbance increased giant foxtail and redroot pigweed emergence approximately 6- and 3-fold in 1992 and 1993, respectively. Seedling emergence associated with soil disturbance, relative to nondisturbed soil, increased seed bank depletion of common lambsquarters 16-fold in 1992, and giant foxtail and redroot pigweed and average of 6- and 3-fold in 1992 and 1993, respectively. These results indicated that soil disturbance increased seedling emergence and seed bank depletion of the predominant species in the weed community of a long-term, no-tillage system, but that this response was dependent on rainfall for common lambsquarters.
Modeling weed emergence as influenced by burial depth using the Fermi-Dirac distribution function
Authors: Prostko Eric P. , Wu Hsin-I , Chandler James M. , Senseman Scott A.
Published: May 2019

Research was conducted to determine the suitability of the Fermi-Dirac distribution function for modeling the seedling emergence of downy brome, johnsongrass, and round-leaved mallow, as influenced by burial depth. Six sets of previously published emergence data were used to formulate the model and test its adequacy. Two independent johnsongrass emergence data sets were used to validate the model. Constant temperature growth chamber studies were conducted to evaluate the effects of temperature and moisture on the model parameters. The Fermi-Dirac distribution function was found to adequately describe the seedling emergence of downy brome, johnsongrass, and round-leaved mallow as indicated by a good visual data fit, narrow confidence intervals for the model parameters, and regression analysis of observed vs. modeled data. Although this function is a model used in physical science, its parameters can be related to abiotic factors such as soil texture, temperature, and moisture.
Weed Science Society of America weed biology survey
Authors: Norris Robert F.
Published: May 2019

WSSA members were surveyed in 1993–1994 to determine their perceptions of the contribution of weed biology to weed management. A questionnaire was included in the society newsletter, from which 152 responses were returned by mail or collected at the 1994 annual meeting. Over half the respondents felt that the overall contribution of weed biology to weed management had been moderate to high. Aspects of population dynamics and competition emerged as the areas that respondents felt should have the greatest impact on weed management in the future. The areas of computer modeling, interactions between weeds and other pests, and seedbank dynamics were predicted to show the greatest increases in importance in the future. The relative importance of taxonomy and weed identification was expected to decrease. Allelopathy, morphology and anatomy, and genetics and evolution were considered least likely to be important to weed management.
Dog mustard (Erucastrum gallicum) response to crop competition
Authors: Wall David A.
Published: May 2019

Greenhouse studies suggested that dog mustard was less competitive than wheat, but of similar competitiveness to flax. In field studies, dog mustard growth and development were markedly affected by crop competition. Competition from flax and wheat reduced dog mustard leaf area, shoot dry weight, plant height, and seed production compared with the weed grown on summer-fallow. Dog mustard was a prolific seed producer when grown in the absence of interspecific competition. On summer-fallow, dog mustard produced as many as 79,100 seeds plant−1when moisture was not a limiting factor. However, average seed production was 19,400 and 8000 seeds plant−1in 1994 and 1995, respectively.
Phenology and biomass dynamics of cattail (Typha subulata) in southern Argentina
Authors: Sobrero Maria T. , Sabbatini M. R. , Fernández O. A.
Published: May 2019

The phenology and biomass dynamics ofTypha subulatawere studied for 2 yr under two natural conditions, a marsh and an irrigation channel. Populations demonstrated a spring to summer growth pattern, with peak aboveground biomass in spring. The phenological phases identified for both populations were identical, but plants growing in the marsh averaged 38 and 28% less aboveground biomass and height, respectively, than plants growing in the channel. Noticeable differences were found in the timing of both phenological phases and biomass cycle between growth seasons, suggesting that the susceptibility of cattail to weed control during the seasons could vary between years.
Education of Students With High Support Needs: Teachers’ Perceptions of Possible Best Practices, Reported Implementation and Training Needs
Authors: Chalmers Susanne E. , Carter Mark , Clayton Mark , Hook Julie
Published: May 2019

Teachers of students with severe disabilities in three NSW Department of School Education regions were surveyed to obtain their views on a set of 42 statements reflecting possible “best practices” in the education of students with severe disabilities. Teachers were also surveyed regarding their reported extent of implementation of each practice, their training needs and the perceived barriers to implementation. A total of 99 responses were received, 83 of which were appropriately targeted. Results indicated that teachers agreed for the most part with the statements but reported they were not always able to implement fully every practice for reasons such as inadequate staffing, lack of time, insufficient funds and inadequate access to therapy services. Teachers indicated that their greatest needs for inservicing were in the areas of managing challenging behaviour and teaching communication and social skills.
Twinning and Interfacial Planes in Copper
Authors: Randle Valerie , Caul Mark , Fiedler Jörn
Published: May 2019

Abstract: This work reports the distribution of a large, representative sample population of grain boundary plane crystallography in pure, annealed copper by use of an improved experimental procedure. The new methodology reduces the laboriousness and improves the accuracy of data collection, and so is described in detail. Analysis of the results concentrates on the Σ3 boundaries, and shows that three-quarters of these were tilt boundaries on the 011 zone. Of these tilt boundaries, nearly half were coherent twins, i.e., on 111/111 planes, or near coherent twins on 23,17,17/775 planes. The high population of the second group is thought to be due to oxygen take-up during annealing. The data in general showed a trend for lower energy Σ3s to occur more frequently. The results were interpreted in terms of boundary energies, local equilibration, and comparisons with previous work in copper and other systems.
Reflections on the Use of Microtomy for Materials Science Specimen Preparation
Authors: Plummer H.K.
Published: May 2019

Abstract: Since 1972 the author and colleagues at Ford Motor Company have been publishing results of materials analyses which were obtained using ambient temperature or cryomicrotomy as one of the sample preparation techniques. Generally two types of sectioning, thin and ultrathin, were pursued for light-optical and electron-optical microscopy, respectively. These papers include the study of the following materials, which have been separated into nine classes: polymer composites, polymer blends, reverse osmosis membranes, carbon fibers, elastomers, automotive exhaust catalysts, aluminum surface coatings, aluminum alloy automotive wheels, and rapidly solidified aluminum alloys. This review is not intended to reiterate the conclusions of these prior publications but will provide the reader with an insight into the many ways microtomy can be used for materials studies.
In Situ Transmission Electron Microscopy Observations of Alloying of Nanoscale Pb Inclusions by Implantation with Cd Ions
Authors: Johnson E. , Dahmen U.
Published: May 2019

In Situ Transmission Electron Microscopy Observations of Alloying of Nanoscale Pb Inclusions by Implantation with Cd Ions
Segregation of Bismuth to Triple Junctions in Copper
Authors: Yin K.-M. , King A.H. , Hsieh T.E. , Chen F.-R. , Kai J.J. , Chang L.
Published: May 2019

Segregation of Bismuth to Triple Junctions in Copper
Analysis of Experimental Error in High Resolution Electron Micrographs
Authors: Campbell Geoffrey H. , King Wayne E. , Cohen Dov
Published: May 2019

Analysis of Experimental Error in High Resolution Electron Micrographs
Transient Ionospheric Upflow Driven by Poleward Moving Auroral forms Observed During the Rocket Experiment for Neutral Upwelling 2 (RENU2) Campaign
Authors: Burleigh M. , Zettergren M. , Lynch K. , Lessard M. , Moen J. , Clausen L. , Kenward D. , Hysell D. , Liemohn M.
Published: May 2019

This study examines cumulative effects of a series of poleward moving auroral forms on ion upflow and downflow. These effects are investigated using an ionospheric model with inputs derived from the Rocket Experiment for Neutral Upwelling 2 (RENU2) sounding rocket campaign. Auroral precipitation inputs are constrained by all‐sky imager brightness values resulting in significant latitudinal structuring in simulated ionospheric upflows due to transient forcing. For contrast, a case with steady forcing generates almost double the O+ upflow transport through 1,000 km when compared to poleward moving auroral form‐like structures. At high altitudes, model results show a spread in upflow response time dependent on ion mass, with molecular ions responding slower than atomic ions by several minutes. While the modeled auroral precipitation is not strong enough to accelerate ions to escape velocities, source populations available for higher‐altitude energization processes are greatly impacted by variable forcing exhibited by the RENU2 event.
A Comparison of Electron Densities Derived by Tomographic Inversion of the 135.6‐nm Ionospheric Nightglow Emission to Incoherent Scatter Radar Measurements
Authors: Dymond K. F. , Nicholas A. C. , Budzien S. A. , Stephan A. W. , Coker C. , Hei M. A. , Groves K. M.
Published: May 2019

The 135.6‐nm emission of atomic oxygen has become a workhorse for satellite remote sensing of the nighttime ionosphere. Previous work on interpreting the 135.6‐nm emission established the importance of properly modeling the mutual neutralization and radiative recombination contributions to the volume emission rate and emphasized the importance of modeling and interpreting the transfer and transport of the radiation. Recently, we developed and published a new inversion approach called Volume Emission Rate Tomography, which handles the radiation transfer as part of the tomography process. We compare electron density distributions derived using the Volume Emission Rate Tomography technique to interpret the 135.6‐nm measurements made by the Special Sensor Ultraviolet Limb Imager instruments aboard the Defense Meteorological Satellite Program satellites in 2010. These retrievals are validated against electron densities measured during overflights of the Advanced Research Project Agency Long‐range Tracking and Identification Radar incoherent scatter radar. The mean percentage difference between the Special Sensor Ultraviolet Limb Imager‐derived electron densities and those measured by Advanced Research Project Agency Long‐range Tracking and Identification Radar was 14%, when radiative recombination was the only source considered in the inversion process. When the mutual neutralization and radiation transport sources of emission are included in the inversions, the mean percentage decreased to 4%, thereby confirming that these sources are necessary to accurately derive the electron density from the 135.6‐nm emission.
New Global Analysis Reveals Amount of Sediment on the Ocean Floor
Authors: Shultz David
Published: May 2019

Researchers calculate that there are ~3.37 � 108 cubic kilometers of sediment on the world’s ocean floor.
Metal Asteroid Inspires Works of Art
Authors: Cartier Kimberly
Published: May 2019

Student artists explore a mysterious metallic world through acrylic, ceramic, LEDs, and even string.
Amoeba People Find a Niche for Nerdy Science Music
Authors: Showstack Randy
Published: May 2019

The group’s rocking new album, The Fossil Record, includes a genre-bending set of songs that helps make science foot-tapping fun.
Wave Attenuation by Sea Ice Turbulence
Authors: Voermans J. J. , Babanin A. V. , Thomson J. , Smith M. M. , Shen H. H.
Published: May 2019

The dissipation of wave energy in the marginal ice zone is often attributed to wave scattering and the dissipative mechanisms associated with the ice layer. In this study we present observations indicating that turbulence generated by the differential velocity between the sea ice cover and the orbital wave motion may be an important dissipative mechanism of wave energy. Through field measurements of under‐ice turbulence dissipation rates in pancake and frazil ice, it is shown that turbulence‐induced wave attenuation coefficients are in agreement with observed wave attenuation in the marginal ice zone. The results suggest that the turbulence‐induced attenuation rates can be parameterized by the characteristic wave properties and a coefficient. The coefficient is determined by the ice layer properties.
Study of the supercapacitive activity of a Eu-MOF as an electrode material
Authors: Shiralizadeh Dezfuli Amin , Kohan Elmira , Naderi Hamid Reza , Salehi Elaheh
Published: May 2019

High surface area and redox activity are indispensable characteristics for a material to be considered as an electrode material in pseudocapacitors.
Identifying the challenging characteristics of systems thinking encountered by undergraduate students in chemistry problem-solving of gas laws
Authors: Chen Ya-Chun , Wilson Kimberley , Lin Huann-shyang
Published: May 2019

Systems thinking has been an educational priority for more than a decade, yet its related assessment and teaching strategies have been understudied in the chemistry education research community. Through the lens of systems thinking, this study explores how undergraduate students connect and translate their conceptual representations when they are involved in contextualised problem-solving. The ‘Contextualised Problem Solving’ (CPS) assessment instrument contains four open-ended questions about gas law. Three different cohorts of students registered in a physical science course (2016 Fall, 2017 Spring, 2017 Fall semesters) participated in the problem-solving component of CPS. The results showed that only 8% of students were capable of higher order systems thinking ability when they engaged in problem solving. Over half of the students failed to retrieve essential concepts in problem situations. Most of the participants demonstrated difficulties in organising related systems’ components, understanding the cyclic nature of relationships among systems, and identifying limitations in a specific problem context. By identifying the difficulties and challenges of systems thinking experienced by undergraduate students in solving complex chemistry problems, these findings have the potential to provide fresh insights into effective teaching strategies to promote students’ higher order thinking skills.
Implantable CMOS image sensor with incident‐angle‐selective pixels
Authors: Sugie K. , Sasagawa K. , Guinto M.C. , Haruta M. , Tokuda T. , Ohta J.
Published: May 2019

Angle‐selective pixels fabricated by using metal layers of the image sensor chip are proposed. Four incident‐angle‐selective pixels share one aperture. The selective pixel has a peak at 40° and full width at half maximum of ∼23°. An image sensor composed of normal and angle‐sensitive pixels was designed and fabricated. The reconstruction of a high‐resolution image from the blurred image using five different views is demonstrated.
Divergence based SLIC
Authors: Gupta A.K. , Seal A. , Khanna P.
Published: May 2019

The success of cluster analysis for revealing natural grouping in a dataset depends heavily on the chosen dissimilarity measure. Recently, several attempts have been made to replace the popular Euclidean distance measure for dissimilarity with divergences that are known to disobey triangular inequality. In this Letter, a representative partitioning based superpixel algorithm called Simple Linear Iterative Clustering (SLIC) is experimented with a divergence measure. In particular, the Jeffery divergence is employed for dissimilarity computation between colour‐image plane space vectors while performing cluster assignment. Despite being a non‐metric, the Jeffery divergence based SLIC has shown better boundary adherence performance on BSDS500 dataset as compared to the conventional SLIC algorithm.
Deep CNN for removal of salt and pepper noise
Authors: Xing Yan , Xu Jian , Tan Jieqing , Li Daolun , Zha Wenshu
Published: May 2019

Image denoising is a common problem during image processing. Salt and pepper noise may contaminate an image by randomly converting some pixel values into 255 or 0. The traditional image denoising algorithm is based on filter design or interpolation algorithm. There exists no work using the convolutional neural network (CNN) to directly remove salt and pepper noise to the authors’ knowledge. In this study, they utilise CNN with the multi‐layer structure for the removal of salt and pepper noise, which contains padding, batch normalisation and rectified linear unit. In training, they divide images into three parts: training set, validation set and test set. Experimental results demonstrate that the architecture can effectively remove salt and pepper noise for the various noisy images. In addition, their model can remove high‐density noise well due to the extensive local receptive fields of the deep neural networks. Finally, extensive experimental results show that their denoiser is effective for those images with a large number of interference pixels which may cause misjudgement. In a word, they generalise the application of CNN to salt and pepper noise removal and obtain competitive results.
Long‐term adaptive tracking via complementary trackers
Authors: Dai Weicong , Jin Longxu , Li Guoning
Published: May 2019

In recent years, kernelised correlation filter‐based trackers have been employed to manage short‐term tracking problems and help long‐term trackers achieve excellent accuracy and robustness under challenging conditions, such as geometry/photometry changes, heavy occlusion, fast motion, motion blur, and out‐of‐camera view. Nonetheless, the inherent boundary effects and risky update strategy of correlation filters constrain the performance of short‐term tracking, which limits the performance of long‐term trackers. Moreover, the complicated redetection module leads to high‐computational cost, which results in the long‐term trackers to run at a low speed, thereby significantly restricting their applications. In the present work, the authors propose to employ complementary trackers in designing an efficient long‐term tracker. Furthermore, a sigmoid penalty coefficient is proposed to update the tracking model with an adaptive learning rate that adjusts the learning rate while the target encounters appearance variation. Finally, they propose a novel redetection method that combines a redetection classifier with a short‐term component to redetect the target while satisfying the explicit condition. The long‐term tracker proposed in this study is proven to perform real‐time speed of more than 65 frames per second and state‐of‐the‐art accuracy by the experimental result on several challenging benchmarks.
Comparison among different analysis methodologies for LLC resonant converter
Authors: Wei Yuqi , Luo Quanming , Chen Si , Sun Pengju , Altin Necmi
Published: May 2019

The LLC resonant converters have been widely used in many applications due to their features such as wide input voltage range, high efficiency, and high power density. Therefore, the analysis methodology for the LLC resonant converter is of great importance. Based on the existing literature, there are mainly four analysis methodologies: (i) fundamental harmonic analysis; (ii) frequency domain with time domain partial correction; (iii) frequency domain with time domain complete correction; (iv) time domain analysis or operation mode‐based analysis. However, there is no systematic view and study on different LLC analysis methodologies. Therefore, the main purpose and contribution of this study are to make a comprehensive study and comparison of these analysis methodologies and to provide guidance on analysing and designing of the LLC resonant converter to the readers. In this study, the principles of these four analysis methodologies are introduced briefly. Then, by introducing gain error and peak gain frequency error as definitions, comprehensive comparison studies on these four different methodologies for different conditions are implemented. Recommended applications for each methodology are summarised; finally, an experimental prototype is built to verify the theoretical analysis, and a conclusion is drawn.