bluuebunny/crossref_metadata_2025 huggingface dataset:
Cultural Forests in Cross Section: Clear-Cuts Reveal 1,100 Years of Bark Harvesting on Vancouver Island, British Columbia
Authors: Earnshaw Jacob K.
Published: May 2019

Culturally modified trees (CMTs) provide tangible evidence of long-term forest use by Indigenous peoples. In Northwest Coast cedar forests, this record rarely spans beyond the last three centuries because older bark-harvest scars have been obscured through taphonomic processes such as natural healing and decay. Thus, archaeological visibility and identification are hindered. Here, I recover chronologies of ancient forest harvesting using a post-impact assessment methodology of targeting old-growth clear-cuts in southern Nuu-chah-nulth territories on the west coast of Vancouver Island, British Columbia, Canada. Bark-peeling scars are identified and dated in cross section by growth-ring patterns of recently logged trees. Approximately half of all bark-peeling scars are “embedded” inside healing lobes, suggesting at least half of all such CMTs are effectively invisible in standing forests. Features in these post-impact surveys predated those discovered in conventional archaeological impact assessments by a mean of almost a century. Additionally, one of the oldest continually used cultural forests ever recorded, dating to AD 908, is found in the Toquaht Nation traditional territory. These findings uncover measurable frequencies of cedar-bark harvesting generations prior to the contact period and reveal the inadequacy of heritage protections for old-growth cedar stands.
Consociational Democracy and Political Engineering in Postwar Kosovo
Authors: Beha Adem
Published: May 2019

This article examines the consociational democracy installed in Kosovo after the war. Starting from the premise that the electoral system is considered one of the key instruments for the engineering of post-conflict societies with deep ethnic divisions, the article analyzes the preferences of local and international actors for the type of electoral system. In particular, the United Nations Interim Administration Mission’s reluctance to organize elections without a prior creation of an institutional base, as well as grand governing coalitions. The mechanisms of consociational democracy aim at addressing elite cooperation between different ethnic communities for building peace and stability in post-conflict societies. But focusing on the intra- and inter-community dynamics of cooperation and confrontation between elites, I conclude that the main obstacle to building a democratic multi-ethnic society in Kosovo and implementing the power-sharing arrangements was the uncertainty over the status of Kosovo.
Le programme de Davidson et les langues naturelles
Authors: Laurier Daniel
Published: May 2019

Une théorie davidsonienne de la signification pour une langue L prend la forme d'une theorie tarskienne (réecursive et vraie) de la véeritée-dans-L. Une telle théeorie sera absolument radicale s'il est possible d'éetablir qu'elle est tarskienne, c'est-à-dire conforme à la convention T de Tarski (1931), en n'utilisant que des donnéees empiriques dont la description ne fait intervenir aucun concept linguistique (tels que ceux de synonymie, d'analyticitée, de signification, etc.), tandis qu'elle sera relativement radicale s'il est possible d'éetablir qu'elle est tarskienne en n'utilisant que des donnéees empiriques dont la description ne fait intervenir aucun concept linguistique propre à L (tels que ceux de synonymie-dans-L, d'analyticitée-dans-L, etc.).
Absolute norms on vector lattices
Authors: Borwein J. M. , Yost D. T.
Published: May 2019

Recall that a norm and monotone if and monotone if If the norm is both absolute and monotone, itis called a Riesz norm. It is easy to show that a norm is Riesz if and only if whenever A Banach lattice is a vector lattice equipped with a complete Riesznorm.
Self-Determination Today: The Metamorphosis of an Ideal
Authors: Pomerance Michla
Published: May 2019

“Self-determination”, the famous catchword of World War I, has become one of the most potent political slogans of our time. In its name battles continue to be waged, and no continent—and scarcely any country—is immune from its grip. The use of force within the most recent period alone in such diverse places as Grenada, Lebanon, the Falkland Islands, Afghanistan, Chad, Angola, Namibia, Punjab, and Kampuchea was related in some way or other to the issue of self-determination. Within the UN, self-determination is viewed by the majority as a kind of “supernorm”, a principle which has been lifted from the realm of politics and morality to the very pinnacle of legal rules. According to this perspective, even the linchpin of the UN Charter, the principle prohibiting the threat or use of force in international relations (Art. 2, para. 4), may be overridden in the name of the more sacred “right of self-determination”.
Surveying the Lands of RepublicanIndígenas: Contentious Nineteenth-Century Efforts to Abolish IndigenousResguardosnear Bogotá, Colombia
Authors: del Castillo Lina
Published: May 2019

Nineteenth-century republicans across the political spectrum agreed: the Spanish monarchy produced ‘miserable Indians’. Abolishing tribute and privatising communal lands, known asresguardosin New Granada (roughly today's Panama and Colombia), would transform that wretched class into equal citizens. Drawing on late eighteenth-century privatisation efforts by the Spanish Crown, early republican leaders in Gran Colombia inaugurated an era seeking equal access to wealth from communal land for all indigenous community members. After Gran Colombia (the first Colombian Republic, 1819–30) dissolved into New Granada, Ecuador and Venezuela in 1830, New Granada's experiments with indigenousresguardopolicies went further. By then, legislative efforts considered the needs of allresguardomembers, including unmarried mothers and their illegitimate children. Complex laws, diverse ecological terrain and nuanced social realities required well-trained surveyors to ensure each eligible indigenous family received a fair share of land. Whereas indigenous communities in Pasto, Santa Marta and the Cauca river valley resorted to armed insurrection against liberal policies through the War of the Supremes (1839–42), those in the highlands near Bogotá did not. Instead, these republicanindígenas– with their greater access to the levers of power housed in the national capital – chose to engage in the reforms of a decentralising state. This article reveals how contentious experiments seeking republican equality within indigenousresguardosas a path towards abolishing the institution were consistently stymied by efforts to ensure that indigenous community governance and communal landholding remained intact.
La gran dama: Science Patronage, the Rockefeller Foundation and the Mexican Social Sciences in the 1940s
Authors: Morcillo Laiz Álvaro
Published: May 2019

If Latin America's public universities are considered part of the state, then it seems plausible to characterise them as similar to the state, i.e. as clientelistic. However, this plausible hypothesis has never been examined by the literature on twentieth-century Mexican social sciences. Just like clientelism, science patrons such as US philanthropic foundations have similarly been neglected. In this article I argue that, as an alternative to what the Rockefeller Foundation perceived as clientelism and amateurism at Latin American universities, it claimed to patronise liberal scholarship, practised according to formal rational criteria. While foundations have been frequently considered part of a US imperialistic drive towards cultural hegemony in Latin America, they were not unitary actors and frequently failed to predict the actual impact of their grants. In Mexico in the 1940s, the Rockefeller Foundation boosted the humanities, but missed the opportunity to support a local take on social science teaching and research.
Interactions betweenMoniliformis(Acanthocephala) andNippostrongylus(Nematoda) in the small intestine of laboratory rats
Authors: Holland Celia
Published: May 2019

Rats harbouring a 35-day-old primary infection ofMoniliformis dubiuswere inoculated with constant doses ofNippostrongylus brasiliensisand 10 days later, afterpost mortemexamination, rats with concurrent infections harboured significantly fewerNippostrongylusthan rats with single infections. Similar infections ofMoniliformiswere carried out, but withpost mortemtaking place on days 8,9, 12 and 14 of theNippostrongylusinfections. On days 8 and 9 of infection, rats with concurrent infections did not harbour significantly fewerNippostrongyluscompared with single infections. Both single and concurrent infections of 12-and 14-day-oldNippostrongyluswere found to harbour lower numbers of worms. In the single infection this corresponds to the timing of the typical immune expulsion of a primary single infection which takes place on approximately day 12 of infection. TheMoniliformispopulation was not significantly affected, in terms of numbers, dry weight and length, although each parasite population did show a slight shift in site in the presence of the other. A significant reduction in egg production byNippostrongyluswas detected throughout concurrent infection. The possible role of non-reciprocal cross-immunity is discussed as an explanation for the apparent early expulsion of theNippostrongyluspopulation in the presence ofMoniliformis.
Loss of behavioural dominance in male mice infected with Trichinella spiralis
Authors: Rau M. E.
Published: May 2019

Trichinella spiralis infections may lead to the loss of behavioural dominance among male mice. Reversals of dominance order first appear at the time when newborn larvae are released into the circulation of the host. The duration of dominance reversals bears no relationship to the number of muscle larvae harboured.
Propanil Selectivity for Green Foxtail (Setaria viridis) in Wheat (Triticum aestivum)
Authors: Eberlein Charlotte V. , Behrens Richard
Published: May 2019

Retention, absorption, translocation, and metabolism of propanil (3′,4′-dichloropropionanilide) in tolerant wheat (Triticum aestivumL. ‘Era’) and susceptible green foxtail [Setaria viridis(L.) Beauv. ♯3SETVI] were studied to determine the basis of selectivity. Green foxtail retained 7.7 times more spray on a mg/g fresh weight basis than did wheat. Absorption of14C-propanil by green foxtail was greater than by wheat during most of the 48-h uptake period, but differences in absorption were not large enough for absorption to be a major selectivity factor. Translocation of foliar-applied14C-propanil was limited in both species; after 48 h, 96.7% of absorbed14C remained in the treated wheat leaf and 99.7% remained in the treated green foxtail leaf. Limited metabolism of14C-propanil occurred in green foxtail, with only 6.4% of extractable14C-propanil metabolized to dichlorolactanilide and unknown14C-compounds during a 72-h period. Wheat metabolized 65.8% of the extractable14C-propanil to dichloroaniline and unknown14C compounds by 72 h after treatment. The results of this research indicate that spray retention and propanil metabolism are the major factors involved in wheat tolerance and green foxtail susceptibility to propanil.
Germination Responses of Opuntia spp. to Temperature, Scarification, and Other Seed Treatments
Authors: Potter Robert L. , Petersen Joseph L. , Ueckert Darrell N.
Published: May 2019

Scarification in sulfuric acid consistently increased germination of Opuntia edwardsii sp. nov, O. discata Griffiths, and O. lindheimeri Engelm. ♯ OPULI seeds over that of untreated seeds. Optimum constant temperatures for germination were generally 25 to 35 C and germination was not enhanced by alternating temperatures. There was a trend for increased germination following leaching in water for 12 h which suggested the presence of chemical germination inhibitors. Seeds passed through the digestive tracts of cattle exhibited average germination percentages that were 1.5 times greater than seeds removed from ripe fruits.
Solar Heating of the Soil: Involvement of Environmental Factors in the Weed Control Process
Authors: Rubin Baruch , Benjamin Abraham
Published: May 2019

Solar heating (SH) of wet soil by mulching it with transparent polyethylene (PE) during the hot season increased soil temperature in a typical daily course which varied with soil depth. Annual weed species responded to soil heating in the laboratory with the same pattern as under SH conditions in the field. Rhizomes of bermudagrass (Cynodon dactylonL. Pers. ♯3CYNDA) and johnsongrass (Sorghum halepenseL. Pers. ♯ SORHA) were very sensitive to heat treatment, but purple nutsedge (Cyperus rotundusL. ♯ CYPRO) tubers were able to survive temperatures as high as 80 C for 30 min. Species having big and heavy seeds or vegetative propagules were able to emerge from deep layers of soil, thus practically escaping the lethal temperature prevailing in the upper layer. Transparent and black PE mulching effectively prevented water loss from soil, as compared with perforated PE and nonmulched control. CO2concentration in the soil atmosphere under transparent PE mulching increased rapidly during the first week and reached a maximal level which was 20-fold higher than that formed in nonmulched soil. Ethylene at 0.2 ppm was detected only in a mulched soil environment. No differences in levels of CH4or CO were detected.
Hard Red Spring Wheat (Triticum aestivum) Response to Propanil
Authors: Miller Stephen D. , Nalewaja John D. , Edwards Ian B.
Published: May 2019

The phytotoxicity of postemergence propanil (3′,4′-dichloropropionanilide) to hard red spring (HRS) wheat (Triticum aestivumL.) was determined in the field and controlled environmental chamber. HRS wheat tolerance to propanil was influenced by cultivar, crop growth stage at time of application, and posttreatment temperature. Injury to wheat from propanil was greater at the five- than two-leaf stage of application and at 30- than at 10- or 20-C posttreatment temperatures. ‘Butte’ wheat was the most susceptible HRS wheat cultivar to propanil, with yield reductions ranging from 15 to 40% depending upon year and crop growth stage at application.
Accelerated Degradation of Thiocarbamate Herbicides in Soil with Prior Thiocarbamate Herbicide Exposure
Authors: Wilson Robert G.
Published: May 2019

Laboratory studies were conducted to evaluate the degradation of butylate (S-ethyl diisobutylthiocarbamate), EPTC (S-ethyl dipropylthiocarbamate), cycloate (S-ethylN-ethylthiocyclohexanecarbamate), and vernolate (S-propyldipropylthiocarbamate) in soil with prior thiocarbamate herbicide exposure. EPTC degradation was accelerated in soil which had previously been treated with butylate, vernolate, or EPTC in 1979, 1980, and 1981. The evolution rate of14CO2from14C-labeled vernolate was increased in soil which had previously been treated with vernolate or EPTC in 1979, 1980, and 1981. Cycloate degradation was not enhanced in soil with prior exposure to butylate, EPTC, or vernolate. Butylate breakdown was enhanced to the greatest extent in soil with previous exposure to butylate.
Stem Flow on Western Juniper (Juniperus occidentalis) Trees
Authors: Young James A. , Evans Raymond A. , Easi Debra A.
Published: May 2019

Stem flow is the water from precipitation that is intercepted by plant canopies and conveyed down the outside of stems to wet the soil at the base of the plant. For western juniper (Juniperus occidentalis Hook.) trees, stem flow was only a small fraction of the precipitation intercepted by the canopy. However, this moisture may be important in the nutrient flux of the trees. The first stem flow in the fall after the summer drought was enriched in nitrate-nitrogen although the quantity of nitrogen per unit area was small. The combination of favorable moisture and temperature conditions at the base of the tree leads to litter decay and nitrification. The root system of the trees had many fine roots in the area that received stem flow. Canopy interception and stem flow should be taken into consideration in application of soil active herbicides for control of western juniper.
Soil Seed Bank Changes after Forest Clearing and Agricultural Use in Alaska
Authors: Conn Jeffery S. , Cochrane Catherine L. , Delapp John A.
Published: May 2019

Soil samples representing a time series from forest before clearing to land in cultivation for 20 yr were taken near Delta Junction, AK, to determine the changes that occur in the soil seed bank following clearing and agricultural use. The total number of seed was initially low in the forested sites but increased after 3 to 5 yr in cultivation due to seed production by native colonizers and by introduced weeds such as common lambsquarters (Chenopodium albumL. ♯3CHEAL). Viability of seed of several mature forest species was low. There was a shift from a seed bank dominated by native species in the forest and newly cleared sites to a seed bank dominated by introduced colonizers in the older fields. Although seed of introduced species increased in importance over time, native species, especially native colonizers, continued to be an important component of the seed bank throughout the 20-yr period represented.
Herbicidal Activity of Starch Encapsulated Trifluralin
Authors: White Michael D. , Schreiber Marvin M.
Published: May 2019

The formulation of trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) encapsulated within a starch granule can reduce the loss in activity associated with the delayed incorporation of the emulsifiable concentrate formulation of trifluralin. Good weed control and high soybean [Glycine max(L.) Merr. ‘Wells II’] yields were obtained when a starch formulation of trifluralin was applied in the fall and incorporated at planting time the following spring. The cultural practices of shallow incorporation, delayed incorporation, and/or midseason cultivation intensified the weed control provided by a starch formulation of trifluralin. The adsorption of additional trifluralin onto the granule surface, cross-linking starch xanthate with a weak oxidant, and mixing granules with different release rates also increased initial control. Granules produced by the starch-calcium and starch-borate processes exhibited many of the same characteristics of granules produced by the older starch xanthate process, but are much less expensive to produce and do not require the use of the toxic carbon disulfide in the encapsulation process. The combination of an appropriate starch formulation of trifluralin with proper cultural practices provided good weed control from fall and spring applications of trifluralin.
The Relative Response of Two Foxtail (Setaria) Species to Diclofop
Authors: Morrison Ian N. , Maurice Denise C.
Published: May 2019

ED50values (the dosage required to reduce the posttreatment gain in dry weight by 50%) for diclofop applied to green and yellow foxtail [Setaria viridis(L.) Beauv. ♯3SETVI andS. lutescens(Weigel.) Hubb. ♯ SETLU] at the two- and four-leaf stages were calculated from linear regression equations derived by plotting the logarithm of the applied dosage against the relative growth reduction expressed as a probit value. At the two-leaf stage, green foxtail was more susceptible to the chemical than yellow foxtail but at the four-leaf stage there was no significant difference in response of the two species. At least part of the difference in sensitivity of the two species at the two-leaf stage could be accounted for by differences in spray retention, with green foxtail retaining 1.8 times (expressed as μL/cm2) or 3.5 times (expressed as μL/g dry weight) as much spray as yellow foxtail, despite the fact that yellow foxtail had a greater projected leaf area. At the four-leaf stage, the amount of spray retained by both species calculated on a per gram dry-weight basis was significantly less than at the two-leaf stage, accounting in part for the higher ED50values obtained at the later growth stage. However, there appeared to be no direct relationship between the amount of spray retained and the comparative growth response of the two weeds at the later stage of application.
Effects of Soil Water Content on Oxadiazon Dissipation
Authors: Barrett Michael R. , Lavy Terry L.
Published: May 2019

In a Crowley silt loam, between 30 kPa, continuous flood, and alternate flood laboratory treatments at 25 C, dissipation of incorporated oxadiazon [2-tert-butyl-4(2,4-dichloro-5-isopropoxyphenyl)-Δ2-1,3,4-oxadiazolin-5-one] varied little, with an average of 59% remaining after 20 weeks. In the greenhouse, subsurface application of oxadiazon reduced its phytotoxicity but increased its persistence up to four times more than with surface-applied oxadiazon. In the field, 50% of the surface-applied oxadiazon dissipated from the soil within 6 to 11 days when the soil was flush irrigated and then flooded, compared to 15 to 17 days when the soil was irrigated but not flooded in two rice (Oryza sativaL.) management systems. Oxadiazon dissipation in the field was greater during the first 2 or 3 weeks after application than in the laboratory study. This is explained at least partially by the lack of herbicide incorporation in the field.
Effects of Insecticide, Weed-Free Period, and Row Spacing on Soybean (Glycine max) and Sicklepod (Cassia obtusifolia) Growth
Authors: Walker Robert H. , Patterson Michael G. , Hauser Ellis , Isenhour David J. , Todd James W. , Buchanan Gale A.
Published: May 2019

Results from identical experiments conducted at Headland, AL, and Plains, GA, from 1980 through 1982 show insecticide treatment had little effect on soybean [Glycine max(L.) Merr. ‘Coker 237′] growth and morphology. Maximum insecticide applications increased soybean seed weight in two of five trials. Soybeans maintained free of sicklepod (Cassia obtusifoliaL. ♯3CASOB) for 4 weeks after emergence produced yields equal to those receiving season-long control in all trials, and 2-week control was equal to season-long maintenance in three trials. Length of weed interference-free maintenance did not affect soybean height. The number of pods per plant and seed weight were decreased when there was no control. Sicklepod shoot fresh weight and numbers decreased as the weed-free period increased from 0 weeks through the season. Row spacing had no effect on soybean height or seed size; however, the number of pods per plant was higher in 80- than in 40-cm rows. Row spacing influenced yield in only one trial where 20-cm rows outyielded 40-cm rows. A significant interaction occurred between the weed-free period and row spacing in two trials. Soybeans in 20-cm rows outyielded those in 40- and 80-cm rows when sicklepod was not controlled (i.e., 0 weeks interference-free maintenance).
Reversal of Fluridone-Reduced Chlorophyll Accumulation in Cucumber (Cucumus sativus) Cotyledons by Stimulatory Compounds
Authors: Fletcher Ronald A. , Meru Sarma V. , Bhardwaj Satindra N.
Published: May 2019

Pretreatment of etiolated cucumber cotyledons with potassium (K), benzyladenine (BA), or δ-aminolevulinic acid (ALA) for 20 h in the dark, followed by exposure to light for 24 h, increased chlorophyll and carotenoid content. A similar treatment with fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone} decreased the levels of these photosynthetic pigments. However, when the etiolated cotyledons were pretreated with either BA or ALA for 20 h in the dark, followed by fluridone during a 24-h light period, the inhibitory effects of fluridone on chlorophyll content were reversed and the values were higher than the controls. In these treatments, ALA did not counteract the inhibitory effects of fluridone on carotenoids, but BA reduced the effects. In the cucumber cotyledon greening system, K was found to be most effective in stimulating both chlorophyll and carotenoid accumulation. When K was administered to the cotyledons either together with, prior to, or after the fluridone treatment, the inhibitory effect of fluridone on chlorophyll accumulation was totally eliminated and the stimulatory effects due to K were still maintained. Although K increased carotenoid content, it did not reverse the inhibitory effect of fluridone on carotenoids. From these findings it is concluded that the inhibition of chlorophyll and carotenoid accumulation by fluridone may be mediated via unrelated mechanisms at fluridone concentrations that do not totally eliminate or drastically reduce carotenoid content.
Effect of Leaf Girdling and Rhizome Girdling on Glyphosate Transport in Quackgrass (Agropyron repens)
Authors: Klevorn Thomas B. , Wyse Donald L.
Published: May 2019

Glyphosate transport was studied using the14C-labeled herbicide. Because glyphosate appears to undergo little metabolism in plants, detected14C was assumed to indicate the presence of glyphosate. Leaf-girdling experiments demonstrated that14C-glyphosate [N-(phosphonomethyl)glycine] transport in treated quackgrass [Agropyron repens(L.) Beauv. ♯3AGRRE] leaves occurred in both leaf symplast and apoplast. Symplastic transport was toward the leaf tip and the leaf base. Apoplastic transport was toward the leaf tip only. Rhizome-girdling experiments showed that translocation of glyphosate from a treated shoot to another shoot on the same rhizome occurs primarily in the rhizome symplast. Girdling the base of quackgrass culms showed that acropetal transport of glyphosate from the rhizome into quackgrass shoots is in the apoplast and the symplast of the culms of quackgrass shoots. Excision of rhizome buds and rhizome apices indicated that the rhizome is a sink for glyphosate independent of rhizome buds or rhizome apices. The concentration of14C-glyphosate in rhizome buds was less in plants with rhizome apices removed than in those with apices intact. The concentration of C-glyphosate in rhizome apices did not differ between plants with buds removed and those with buds intact.14C-glyphosate applied to a girdled rhizome apex remained primarily in the apex. Some transport of glyphosate past the girdle occurred, indicating apoplastic transport of glyphosate in the rhizome. Apoplastic transport of14C-glyphosate in the rhizome was greatest in water-stressed plants.
Growth Responses of Green and Yellow Foxtail (Setaria viridisand S.lutescens) to Shade
Authors: Bubar Carol J. , Morrison Ian N.
Published: May 2019

The growth of green foxtail (Setaria viridisL. Beauv. ♯3SETVI) and yellow foxtail [S. lutescens(Weigel.) Hubb. ♯ SETLU] in full sunlight, under 55 and 73% shade and within a wheat (Triticum aestivumL. ‘Neepawa’) stand, was compared in field experiments conducted over 3 yr. Shade resulted in a proportionately greater reduction in tiller number of yellow foxtail than of green foxtail. Plants growing in full sunlight produced up to five times more tillers than those growing in the crop. Averaged over the 3 yr, the two shade treatments reduced dry-matter accumulation of both species by 40% or more. The dry weight of plants within the crop was only about one-eighth of that of plants grown in full sunlight. Under both shade treatments and in the crop, yellow foxtail was consistently taller than green foxtail. Nevertheless, no differences in dry weight occurred between species under either shade treatment or in the crop. The results indicate that neither of the two species is distinctly more shade tolerant than the other, nor better adapted to compete with wheat.
The in Vitro Culture of Excised Ovules from Velvetleaf (Abutilon theophrasti)
Authors: Thompson Laura K. , Leather Gerald R. , Hale Maynard G.
Published: May 2019

A culture medium and environmental conditions were selected for ovule culture of velvetleaf (Abutilon theophrastiMedic. ♯4ABUTH), which allowed development parallel to that occurring in vivo. Of the six nutrient media evaluated, the most suitable one contained an organic nitrogen source and was of high osmotic potential. A liquid medium with a pH of 5 to 7, and culture for 14 days at 25 C under green light (1.3 μmole·m-2·-1) encouraged good embryo and ovule development. No difference was recorded between polyethylene glycol 20000 and mannitol in the medium used for dehydration and subsequent imbibition of cultured mature ovules. To investigate the effects of maternal tissues, surgical alterations were performed on the testa and funiculus of immature velvetleaf ovules. The intact testa appears to be a barrier to nutrient absorption and reduces the fresh and dry weights and embryo length. Ovule and embryo development was significantly better if either the testa was nicked or the funiculus removed.
The History and Distribution of Downy Brome (Bromus tectorum) in North America
Authors: Morrow Larry A. , Stahlman Phillip W.
Published: May 2019

Downy brome (Bromus tectorumL. # BROTE) has developed into a severe weed in several agricultural production systems throughout North America, particularly on rangeland and in winter wheat (Triticum aestivumL.). Several million hectares of winter wheat, pastureland, alfalfa (Medicago sativaL.), grass seed fields, and overgrazed rangeland, as well as other crops, have been invaded by this annual grass since its introduction into this hemisphere. Downy brome is most abundant in the Great Basin and Columbia Basin areas of the western United States, but is found throughout the continental United States and parts of Canada and Mexico. In some cases, the vegetation on overgrazed rangeland consists totally of downy brome, while winter wheat growers in the western United States proclaim it as their worst weed problem. Changes in tillage practices that are currently being implemented for the control of soil erosion coupled with the lack of selective herbicides for the control of downy brome have aided its increase and spread.
The Biology of Downy Brome (Bromus tectorum)
Authors: Thill Donald C. , Beck K. George , Callihan Robert H.
Published: May 2019

Downy brome (Bromus tectorumL. # BROTE), also known as cheatgrass, downy chess, broncograss, Mormon oats, and junegrass, was introduced into the United States from Europe, apparently during the middle of the nineteenth century (11, 21). According to Mack (23), downy brome entered British Columbia, Washington, and Utah around 1890; and by 1928 it had reached its present range, occupying much of the perennial grassland in Washington, Idaho, Oregon, Nevada, Utah, and British Columbia. Today, downy brome is a widespread weed throughout most of Canada, Mexico, and the United States, except for the southeastern United States (5, 17). Some consider downy brome to be an important forage because it provides most of the early spring grazing for livestock in western United States rangeland (21). However, it is also considered a troublesome weed in rangeland (31), winter wheat (Triticum aestivumL.) (27), several other crops (29), and noncropland (32).
Chemical and Biological Control of Downy Brome (Bromus tectorum) in Wheat and Alfalfa in North America
Authors: Peeper Thomas F.
Published: May 2019

As an agrestal weed, downy brome (Bromus tectorumL. # BROTE) is most troublesome in winter wheat (Triticum aestivumL. # TRIAE) and alfalfa (Medicago sativaL. # MEDSA) because of the ability of downy brome to reproduce prior to crop harvesting (70, 76). Geographically, downy brome is most common in the western half of the United States where annual rainfall totals 15 to 55 cm and autumn rainfall ranges from 5 to 12 cm (10, 11, 86, 98). In contrast, cheat (Bromus secalinusL. # BROSE) is more common in the eastern portion of the hard red winter wheat producing regions and in the more humid soft red winter wheat region. Behrendt and Hanf (12) state that cheat has been more common on acid sandy or loamy soils while downy brome commonly occurs on dry, mostly alkaline, sandy to loamy soils. Since soils are frequently alkaline in the relatively dry climate of the western regions (61), it is not clear exactly what role pH plays in affecting geographical distribution of the variousBromusspp. Recent serious problems with downy brome in the New England nursery industry (69) and orchards (57) indicate that downy brome could thrive under a relatively wide range of edaphic and climatic conditions. However, as a weed problem in wheat, the common prevalent conditions of low annual precipitation and alkaline soils should not go unnoticed in the development of chemical weed control practices.
Characterization of ans-Triazine-Resistant Biotype ofBrachypodium distachyon
Authors: Gressel Jonathan , Regev Yael , Malkin Shmuel , Kleifeld Yeshaiahu
Published: May 2019

A triazine-resistant (R) biotype of a Graminaceous weed,Brachypodium distachyon(= Trachynia distachya), was found in the lower Galilee area of Israel after repeated treatments of roadsides with simazine [2-chloro-4,6-bis (ethylamino)-s-triazine] and atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine]. It was not affected at levels up to 3.0 kg/ha of soil-incorporated atrazine or simazine. The (R) biotype was unaffected by atrazine, as ascertained by measuring whole-leaf and plastid fluorescences and the Hill reaction. The triazine-sensitive (S) biotype was inhibited in all these reactions. The data suggest that the (R) biotype has a plastid mode of resistance common to many weed species. The (R) biotype metabolized14C-(ring)-atrazine more rapidly to both water-soluble and to chloroform-soluble compounds than the (S) biotype did, but that could not explain the immediate resistance at the plastid level. Probably there was evolution towards increased tolerance by detoxification as well as plastid level resistance.
Effect of Canada Thistle (Cirsium arvense) and Musk Thistle (Carduus nutans) Control on Grass Herbage
Authors: Reece Patrick E. , Wilson Robert G.
Published: May 2019

All herbicide treatments controlled the initial stand of Canada thistle [Cirsium arvense(L.) Scop.] and musk thistle (Carduus nutansL.) on a subirrigated range site. Annual retreatment controlled seedlings and the few plants that emerged from surviving root remnants after the first application. Average perennial grass production on unfertilized, herbicide-treated plots increased 110, 314, and 212%/yr over unfertilized check plots during the 3-yr period of treatment, i.e., 960, 3450, and 4300 kg/ha, respectively. Grasses did not fully reoccupy the site at the end of 3 consecutive yr of excellent thistle and forb control. The increase in grass production varied considerably among several herbicide treatments that controlled thistles equally. Grass production in the third year was greater under the 3,6-dichloropicolinic acid and 2,4-D [(2,4-dichlorophenoxy)acetic acid] treatment series than all other treatments. Ammonium nitrate enhanced the recovery of grass damaged by certain herbicides, but favored the competitive ability of the thistle more than that of the grasses.
Weed Species Shifts with Increasing Field Age in Alaska
Authors: Conn Jeffery S. , Delapp John A.
Published: May 2019

Vegetative cover of weeds was determined in 84 agricultural fields representing a number of crops in Alaska. Multivariate statistical techniques were used with weed, soil, and management data to determine if weed vegetation was related to particular environmental and management variables. Field age was the variable that best explained the variation in vegetation composition. In fields recently cleared, native species were most important, being replaced by introduced weed species with increasing field age. Field horsetail (Equisetum arvenseL.) was an exceptional native species that persisted under cultivation. Total weed cover was low in the first few years of cultivation, but increased as introduced species such as common lambsquarters (Chenopodium albumL.), common chickweed [Stellaria media(L.) Cyrillo], quackgrass [Agropyron repens(L.) Beauv.], and foxtail barley (Hordeum jubatumL.) became more prevalent. A number of introduced species such as hempnettle (Galeopsis tetrahitL.) and Pennsylvania smartweed (Polygonum pensylvanicumL.) were restricted to just a few fields, emphasizing the importance of using weed-free seed and other management practices to minimize the spread of introduced weeds.
Biological Significance and Fate of Atrazine under Aquifer Conditions
Authors: Wehtje Glenn R. , Spalding Roy F. , Burnside Orvin C. , Lowry Stephen R. , Leavitt J. Robert C.
Published: May 2019

Concentrations of atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine] in contaminated groundwater recovered from 41 monitoring wells in Hall and Buffalo counties, Nebraska range from 0.01 to 8.29 μg/L. Over a 1-year period concentrations fluctuated sufficiently in a seasonal pattern to indicate that atrazine dissipation occurs. This reduction in concentration can be attributed to adsorption, dispersion, and degradation. A limited amount of atrazine degraded chemically to hydroxyatrazine [2-hydroxy-4-(ethylamino)-6-(isopropylamino)-s-triazine] under simulated aquifer conditions; microbial degradation could not be detected. A geometrical progression model for predicting long term residue accumulation indicates that current contamination levels probably reflect a steady-state situation between the amount that yearly enters into, and the partial degradation that occurs within, the aquifer. Oat (Avena sativaL. ‘Neal’) bioassays indicate that present levels of groundwater contamination remain well below the threshold necessary for phytotoxicity.
Control of Johnsongrass (Sorghum halepense) in Soybeans (Glycine max) with Foliar-Applied Herbicides
Authors: Banks Philip A. , Tripp Timothy N.
Published: May 2019

Field and greenhouse experiments were conducted to evaluate factors affecting johnsongrass [Sorghum halepense(L.) Pers. # SORHA] control in soybeans [Glycine max(L.) Merr. ‘Essex’] with three foliarly-applied herbicides. In 1980, johnsongrass height at treatment time had little effect on control due to inadequate soil moisture. In 1981, a wet year, best control was achieved on 15- or 40-cm-tall johnsongrass. BAS-9052 {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} at 0.6 kg/ha gave good to excellent control at all growth stages. Two applications of 0.3 kg/ha of BAS-9052 in both years and PP-009 butyl {2-[4-[5-(trifluoromethyl-2-pyridinyloxy)] phenoxy] propanoate} in 1981 increased johnsongrass control compared to only one treatment. Mixing BAS-9052 with other herbicides significantly reduced johnsongrass control. Greenhouse studies to determine the effect of soil water on herbicide response indicated that drier soils decreased johnsongrass regrowth with PP-009 and increased regrowth with BAS-9052.
MSMA-Induced Straighthead in Rice (Oryza sativa) and Effect upon Metabolism and Yield
Authors: Horton Diana K. , Frans Robert E. , Cothren Tom
Published: May 2019

The effects of MSMA on the development of straighthead, yields of rice, and hormonal balance in rice plants were observed in a greenhouse study. MSMA was applied to soil at 0, 6, and 9 kg ai/ha. At 6 kg/ha some straighthead and a 45% yield reduction occurred. At 9 kg/ha straighthead was evident, and yield was reduced by 85%. Analyses were made for ethylene with gas chromatography and for indoleacetic acid (IAA) with high performance liquid chromatography. Concentrations of ethylene and total arsenic detected in the tissue from rice leaves grown in MSMA-treated soil were higher at every growth stage when compared to plants grown in untreated soil. Both treated and untreated plants showed marked increases of these compounds during the reproductive stage and a decrease prior to panicle emergence. Significant changes occurred in IAA levels with the growth stage of treated and untreated samples, but MSMA had no obvious effect on IAA levels at any of the stages examined in this study.
Localization of Atrazine in Corn (Zea mays), Oat (Avena sativa), and Kidney Bean (Phaseolus vulgaris) Leaf Cells
Authors: Norris Robert F. , Fong Ivy E.
Published: May 2019

Corn (Zea maysL. ‘DeKalb 640′), kidney beans (Phaseolus vulgarisL. ‘Light red’) and oats (Avena sativaL. ‘Kanota’) were grown in solution culture and the roots exposed to radioactively labeled atrazine [2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine]. The radioactivity from3H-atrazine, or its metabolites, was located in microautoradiographs of corn leaf sections, almost exclusively at the perimeter of the vascular bundles, and was primarily confined to the cell walls and intercellular spaces, with no activity associated with subcellular organelles. Radioactivity from3H-atrazine in oat leaf section microautoradiographs was primarily associated with the chloroplasts, with no evidence of radioactivity specifically associated with other subcellular organelles. Sucrose density gradient centrifugation of homogenized leaf tissue following exposure of the plants to14C-atrazine showed that most of the radioactivity was associated with the light cell fragments and cytoplasm for the test species. There was no accumulation of14C-activity in any of the heavier subcellular organelles from corn leaf cells. A peak of radioactivity was associated with the chloroplast fraction from oat and kidney bean leaves.
Effect of Irrigation on Quackgrass (Agropyron repens) Interference in Soybeans (Glycine max)
Authors: Young Frank L. , Wyse Donald L. , Jones Robert J.
Published: May 2019

Research was conducted at Rosemount, Minnesota in 1979 and 1980 to evaluate the effect of soil moisture on quackgrass [Agropyron repens(L.) Beauv. # AGRRE] interference in soybeans [Glycine max(L.) Merr.]. Four treatments were studied: 1) nonirrigated soybeans, 2) irrigated soybeans, 3) nonirrigated soybeans, quackgrass-infested, and 4) irrigated soybeans, quackgrass-infested. Percent N, P, and K of soybeans was not affected by quackgrass interference. Irrigation did not increase the yield of quackgrass-free soybeans. The yield of quackgrass-infested soybeans was increased by irrigation when soil moisture was limited, but yields were always less than quackgrass-free soybeans. Quackgrass was nearly the same height or taller than the soybeans at all stages of soybean development and offered substantial competition for light throughout the growing season. This research indicates that an adequate supply of soil moisture can reduce quackgrass interference in soybeans, but cannot eliminate it, since quackgrass apparently continues to compete with soybeans for light.
Distribution and Metabolism of Simazine in Simazine-Tolerant and -Intolerant Poplar (Populussp.) Clones
Authors: Akinyemiju O. A. , Dickmann D. I. , Leavitt R. A.
Published: May 2019

Soil uptake, translocation, and metabolism of simazine (2-chloro-4,6-bis(ethylamino)-s-triazine) by tolerant poplar clonePopulus × euramericanaI-45/51, a section Aigeiros hybrid, and intolerant cloneP. maximowiczii × P. trichocarpaKingston, a section Tacamahaca hybrid were compared. Concentrations of simazine in the two clones were not different 48 h and 1 week after application. However, the presence of 2-chloro-4-amino-6-ethylamino-s-triazine (G-28279), a less toxic simazine metabolite, was detected in tolerant clone I-45/51 after 12 h and it increased steadily through 1 week after simazine application. In contrast, no trace of G-28279 was found in susceptible clone, Kingston.
Effect of Simazine on Photosynthesis and Growth of Filamentous Algae
Authors: O'Neal Steven W. , Lembi Carole A.
Published: May 2019

Simazine [2-chloro-4,6-bis(ethylamino)-s-triazine] inhibited photosynthesis 50% at concentrations of 1.1 μM forSpirogyra jurgensii(Kutz), 3.0 μM forPithophora oedogonia(Mont.) Wittr., and 3.8 μM forCladophora glomerata(L.) Kutz. Photosynthesis ofAnkistrodesmus braunii(Brun.), a nonfilamentous species, was inhibited the same amount by 4.7 μM simazine. The filamentous algal species had significant reductions in growth but no other phytotoxic symptoms when exposed to 5 μM simazine at light intensities of 100 μE·m–2·s–1and below. Algicidal effects did occur at a light intensity of 400 μE·m–2·s–1and were most severe inSpirogyra.The relationship between light intensity and simazine toxicity indicates algicidal effectiveness on these filamentous algae will be limited in habitats where light is reduced by turbidity, depth, or self-shading.
LE CONTRADDIZIONI INTERNE DEL SISTEMA PARLAMENTARE-INTEGRALE
Authors: Miglio Gianfranco
Published: May 2019

Introduzione

La mia tesi è nota: io sostengo che le gravi disfunzioni di cui soffre il sistema politico italiano non potranno essere corrette finché verrà mantenuto l'ordinamento «parlamentare-integrale» (o«puro») adottato dai costituenti del 1946–1947. La così detta «ingovernabilità» è infatti il prodotto necessario di quel modello.
LE «LEGGI» SULLA INFLUENZA DEI SISTEMI ELETTORALI
Authors: Sartori Giovanni
Published: May 2019

Introduzione

Nei testi di filosofia della scienza e di metodologia ci viene quasi sempre detto che senza leggi non si dà scienza. La scienza «spiega» quando arriva a formulare leggi, e cioè generalizzazioni di tipo causale. Un atto o fatto è spiegato (scientificamente) quando viene sussunto nell'ambito di una legge ricomprendente. Se così è, allora le cosiddette scienze sociali non avanzano, o avanzano di poco. Da più di trent'anni i progressi scientífici delle scienze dell'uomo sono progressi in sede di quantificazione e di misurazione, non in sede nomotetica. Come mai? Potremmo rispondere che solo il mondo fisico è governato da leggi, non quello dell'uomo. Ma il grosso dei cultori delle scienze sociali resta fedele al modello di una scienza nomotetica. I più rispondono, dunque, che le leggi che governano gli aggregati umani restano da scoprire perché sono «difficili», più difficili delle leggi che governano la natura. Che siano difficili è ben certo. Ma la verità è, mi sembra, che le «leggi» che non troviamo sono leggi che nemmeno cerchiamo. Tanto poco le cerchiamo che non sappiamo nemmeno come sono da cercare (e ancor meno da formulare). La tesi di questo scritto è dunque che la nostra retorica metodologica fa a pugni con la nostra pratica di ricerca. Fatte le dovute riverenze alla retorica nomotetica, il ricercatore se la cava lasciando intendere che, quantomeno pro tempore, l'impresa è troppo difficile per essere tentata. Ma cavarsela così è troppo facile.
The Pacific War Controversy in Britain: Sir Robert Craigie Versus The Foreign Office
Authors: Agbi S. Olu
Published: May 2019

Unlike the State Department Officials of the United States who were subjected by the Senate to postwar Congressional investigation in the Pearl-Harbor hearing, British Far Eastern policy-makers were saved such parliamentary ordeals. The loss of the whole British position in the Far-East at the hands of the Japanese between December 1941 and May 1942 was humiliating enough. It was, as Winston Churchill later claimed, ‘the worst disaster and the largest capitulation of British history’.
NONPARAMETRIC DENSITY ESTIMATION BY B-SPLINE DUALITY
Authors: Cui Zhenyu , Kirkby Justin Lars , Nguyen Duy
Published: May 2019

In this article, we propose a new nonparametric density estimator derived from the theory of frames and Riesz bases. In particular, we propose the so-called bi-orthogonal density estimator based on the class of B-splines and derive its theoretical properties, including the asymptotically optimal choice of bandwidth. Detailed theoretical analysis and comparisons of our estimator with existing local basis and kernel density estimators are presented. The estimator is particularly well suited for high-frequency data analysis in financial and economic markets.
The Political Foundations of Bureaucratic Autonomy: A Response to Kernell
Authors: Carpenter Daniel
Published: May 2019

Bureaucrats are politicians of a sort, and bureaucracies are organizations of political actors. Bureaucracies gain a measure of autonomy when they are able to successfully practice a politics of legitimacy. When and where they are found, autonomous bureaucrats launch policy innovations that differ materially from the designs of elected authorities. Autonomous bureaucrats build these program innovations slowly, and they try to generate visible efficiency from these innovations. The most successful bureaucrats, however, transcend achievements such as “innovation” and “efficiency.” They get their hands dirty, and they engage in coalition politics. They assemble broadbased alliances behind their new programs, coalitions wrought from the multiple networks in which these unique bureaucrats travel.