bluuebunny/crossref_metadata_2025 huggingface dataset:
Basis of Differential Tolerance of Two Corn Hybrids (Zea mays) to Metolachlor
Authors: Cottingham Charles K. , Hatzios Kriton K.
Published: May 2019

Greenhouse and laboratory studies were conducted to determine the basis of differential response of two corn hybrids to the chloroacetanilide herbicide metolachlor. In greenhouse experiments, metolachlor at 6.7 kg ha−1reduced the height of the susceptible ‘Northrup-King 9283’ corn by 53% relative to untreated controls and caused extensive visible injury 14 d after treatment Under the same conditions, the height of metolachlor-treated ‘Cargill 7567’ corn seedlings was reduced by only 18% without any visible herbicide injury. The14C-metolachlor was more rapidly absorbed by the emerging shoot of the metolachlor-susceptible hybrid, Northrup-King 9283. Thus, differential metolachlor tolerance may be due in part to processes at the level of herbicide uptake. Metabolism experiments revealed that both hybrids were able to conjugate14C-metolachlor with glutathione at similar rates. However, glutathioneS-transferase activity increased earlier during seedling development and reached higher activities in the metolachlor-tolerant hybrid, Cargill 7567.
Atrazine Phytotoxicity to Common Bean and Redroot Pigweed under Different Temperatures
Authors: Al-Khatib Kassim , Boydston Rick , Parker Robert , Fuerst E. Patrick
Published: May 2019

The basis for increased phytotoxicity of foliar-applied atrazine at high temperature in common bean and redroot pigweed was investigated. Plants were grown under low (15/10 C), medium (25/20 C), or high (35/30 C) temperature regimes. Atrazine absorption by plants grown under different temperatures increased with increasing temperatures in both species. Greater than 90% of absorbed atrazine remained in treated leaves and translocation was not altered by temperature in both species. Metabolism of atrazine by both hydroxylation and glutathione-conjugation was greater in plants grown at 35/30 than 15/10 C in both species. Foliar-applied atrazine reduced extractable photosystem II (PS II) activity as temperature increased in both species. Studies were also conducted on thylakoid membranes from plants not treated with atrazine. The I50for atrazine inhibition of PS II decreased and affinity of atrazine binding to thylakoid membranes increased as temperature increased in both species. We concluded that the increased phytotoxicity of atrazine at high temperatures is caused by enhanced foliar absorption and greater affinity of atrazine for the binding site.
The Critical Period of Weed Control in Grain Corn (Zea mays)
Authors: Hall Michael R. , Swanton Clarence J. , Anderson Glenn W.
Published: May 2019

Field studies were conducted in southern Ontario to determine the critical period of weed control in grain corn and the influence of weed interference on corn leaf area. The Gompertz and logistic equations were fitted to data representing increasing durations of weed control and weed interference, respectively. The beginning of the critical period varied from the 3- to 14-leaf stages of corn development However, the end of the critical period was less variable and ended on average at the 14-leaf stage. Weed interference reduced corn leaf area by reducing the expanded leaf area of each individual leaf and accelerating senescence of lower leaves. In addition, weed interference up to the 14-leaf stage of corn development impeded leaf expansion and emergence in 1989.
Response of Cotton (Gossypium hirsutum) to Coastal Bermudagrass (Cynodon dactylon) Density in a No-tillage System
Authors: Vencill William K. , Giraudo Luis J. , Langdale George W.
Published: May 2019

Field experiments were established in 1989 and 1990 at the Southern Piedmont Conservation Research Center near Watkinsville, GA, to determine effects of coastal bermudagrass density on cotton in a conservation tillage system. Cotton height, canopy width, leaf area indices, and seed cotton yields were determined at coastal bermudagrass densities of 0 to 3600 kg ha−1as achieved by herbicide inputs. Soil water measurements were recorded in cotton plots with a range of coastal bermudagrass densities using time domain reflectometry. Cotton growth and yields were reduced by coastal bermudagrass competition both years of the study. At the highest coastal bermudagrass density of 3600 kg ha−1, cotton height was reduced compared to cotton alone as early as 5 wk after planting. Seed cotton yields were reduced 25% at the highest coastal bermudagrass densities both years of the study. At the 15-cm soil depth, coastal bermudagrass significantly reduced soil water in cotton. Soil water in cotton at 30, 45, and 60 cm was not affected by coastal bermudagrass.
Paraquat Phytotoxicity, Absorption, and Translocation in Peanut and Selected Weeds as Influenced by Chloramben
Authors: Wehtje Glenn , Wilcut John W. , Mcguire John A.
Published: May 2019

The interaction of chloramben and paraquat on weed control and crop safety in peanuts was examined in a series of experiments. Greenhouse experiments revealed that chloramben was antagonistic toward paraquat on sicklepod and peanut, which are species tolerant to chloramben and sensitive to paraquat Control of Florida beggarweed, a species sensitive to both herbicides, was generally improved with tank mixtures. Similar results were obtained in field studies. Antagonism obtained with tank-mixing chloramben plus paraquat was also obtained by applying chloramben prior to paraquat Studies with14C-labeled herbicides on Florida beggarweed revealed that chloramben inhibited foliar penetration of paraquat, but paraquat had no effect on foliar penetration of chloramben.
Comparative Growth and Development of Red Rice (Oryza sativa) and Rice (O. sativa)
Authors: Kwon Sam L. , Smith Roy J. , Talbert Ronald E.
Published: May 2019

Growth and development of red rice (strawhull) and ‘Lemont’ and ‘Newbonnet’ rice were compared in 1987 and 1988 under noncompetitive field conditions at Stuttgart, AR. Growth and developmental differences were greater between red rice and rice than between rice cultivars. Compared to rice, red rice was taller, produced more culms m−2and aboveground dry weight, had higher leaf area indices, and had a greater flag leaf area. Also, it had lower leaf to stem ratios late in the season, had greater crop growth rate early in the season but less late in the season, and produced a lower grain weight than rice. Compared to Newbonnet, Lemont plants were shorter at 60 d after emergence or later, produced more culms m−2, had a greater leaf area index, and produced higher grain weight than Newbonnet. Also, Lemont and Newbonnet produced comparable leaf to stem ratios, crop growth rates, and flag leaf areas.
Influence of Bentazon on the Phytotoxicity of Paraquat to Peanuts (Arachis hypogaea) and Associated Weeds
Authors: Wehtje Glenn , Wilcut John W. , McGuire John A.
Published: May 2019

Bentazon reduced paraquat phytotoxicity to Texas panicum, sicklepod, Florida beggarweed, and peanut. Bentazon applied alone had minimal effect on these species. Smallflower morningglory was more sensitive to bentazon than to paraquat; the interaction of paraquat and bentazon varied from antagonistic to synergistic depending upon the specific combination of rates. Antagonism with tank-mixed combinations was also obtained by applying bentazon prior to paraquat, but not with the reverse. Studies with14C-labeled herbicides revealed that each herbicide inhibited foliar penetration of the other. In field studies, adding bentazon to paraquat reduced crop injury. However, except for smallflower morningglory, weed control was also reduced.
Chemical Control of Annual Weeds in Field Beans (Vicia faba) in Central Spain
Authors: Garcia De Arevalo Rafael C. , Lusarreta Carmen A. , Neyra Carmen B. , Sanchez Mercedes A. , Algarra Pedro J. H.
Published: May 2019

Field studies were conducted over 3 yr to investigate the effect of chemicals on field beans density and weed control. Predominant weed species were common lambsquarters, fumitory, henbit, corn poppy, prostrate knotweed, and wild mustard. All herbicide treatments except linuron injured field beans. Mean field beans survival at harvest was 78% in alachlor and 84% in alachlor containing treatments. Only 5% survived atrazine at 1.9 kg ai ha−1. Ethalfluralin, pendimethalin, simazine, terbutylazine plus terbutryn, and trifluralin treatments produced plant survival values of 56, 82, 86, 74, and 71%, respectively. Chemical control of the main weed species overshadowed the detrimental effect on field beans density, and thus most herbicide treatments except alachlor resulted in increased dry beans yield. The best overall results occurred with linuron, simazine, terbuthylazine plus terbutryn, and pendimethalin which increased dry beans yields 76, 63, 56, and 40%, respectively, over the control plots. Common lambsquarters was the dominant weed, and prostrate knotweed and corn poppy were the most difficult and the easiest species to control, respectively.
Influence of Application Time on Bioactivity of Imazethapyr in No-tillage Soybean (Glycine max)
Authors: Buhler Douglas D. , Proost Richard T.
Published: May 2019

Field research was conducted at Arlington, WI, in 1988 and 1989 to determine the influence of application time on weed control and residue carryover with imazethapyr in no-tillage soybean production. Imazethapyr at ≥ 55 g ai ha−1applied early preplant controlled > 90% of the common lambsquarters, velvetleaf, and giant foxtail before no-tillage planting of soybean. Early preplant and sequential treatments with an early preplant component controlled ≥ 88% of all weeds for the entire growing season. Delaying the initial imazethapyr application until immediately after soybean planting reduced weed control compared to the early preplant treatments. Low level of weed control with planting time treatments appeared to be due to a lack of control of common lambsquarters emerged at the time of imazethapyr application and dry weather following imazethapyr application. No soybean injury from imazethapyr was observed and differences in soybean yield appeared to be due to differences in weed control. No significant carryover of imazethapyr was detected through a corn bioassay in the field.
Effect of Four Triazine Herbicides on Growth of Nontarget Green Algae
Authors: Hiranpradit Hiran , Foy Chester L.
Published: May 2019

Colorimetry, nephelometry, and chlorophyll assays of cultures ofChlamydomonas reinhardtiiDangeard,Chlorella pyrenoidosaChick., andScenedesmus quadricauda(Turp.) Bréb. were used as criteria for measuring algae growth. Among the fours-triazines studied, cyprazine appeared to be the most inhibitory to algae growth, followed by atrazine > simazine > cyanazine. Stimulatory effects of cyanazine, simazine, and cyprazine on chlorophyll content ofC. reinhardtiiandC. pyrenoidosawere also observed. Cyanazine was most stimulatory on both species but simazine also showed stimulation. Cyprazine was stimulatory only toC. reinhardtiiat 0.22 μM concentration but apparently was inhibitory toC. pyrenoidosaat the same concentration. In one experiment, atrazine caused a slight stimulation inC. reinhardtii. Averaged over two consecutive experiments, however, atrazine was inhibitory. Chlorophyll content of the algae was found to be the best criterion for determining effect of the chemicals on algae growth. Continuous exposure ofC. reinhardtiiculture to the highest concentration of each of the four herbicides resulted in selection of algal lines having increased triazine tolerance.
Sorption of Metribuzin and Metolachlor in Alaskan Subarctic Agricultural Soils
Authors: Graham Jeff S. , Conn Jeffery S.
Published: May 2019

Adsorption and desorption of metribuzin and metolachlor were studied for 0- to 15- and 30- to 45-cm soil depths and at 5 and 28 C temperatures for two subarctic Alaskan agricultural soils. Surface soils had five to eight times the organic carbon content of deeper soils and had lower Freundlich isotherm slopes (1/n) for both herbicides. Surface soil Freundlich coefficients (Kf) were affected by both soil type and equilibration temperature, with soil type accounting for greater than 80% of the variation in Kf. Surface soil mean Kfvalues ranged from 1.5 to 2.4 for metribuzin and 4.4 to 9.2 for metolachlor. For soils from the 30- to 45-cm depth, neither soil type nor temperature affected Kf. Isotherm slopes for desorption were less than adsorption, indicating hysteresis. Regressions between desorption Kfand maximum herbicide adsorbed prior to desorption were highly significant with coefficients of determination (r2) between 0.50 and 0.99.
Absorption, Translocation, and Metabolism of Imazaquin in Pitted (Ipomoea lacunosa) and Entireleaf (Ipomoea hederaceavar.integriuscula) Morningglory
Authors: Risley Mark A. , Oliver Lawrence R.
Published: May 2019

Pitted morningglory and entireleaf morningglory treated with14C-imazaquin translocated14C to areas above and below the treated leaf. Pitted morningglory absorbed and translocated more14C from14C-imazaquin than entireleaf morningglory. Translocation of14C from root-supplied14C-imazaquin was similar in both species 1 d after treatment, with14C moving rapidly to the shoots. Entireleaf morningglory metabolized slightly more imazaquin than pitted morningglory in treated leaves. Greater tolerance of entireleaf morningglory than pitted morningglory to postemergence applications of imazaquin is attributed to reduced absorption and translocation and increased metabolism of the herbicide in the entireleaf morningglory.
Absorption, Translocation, and Foliar Activity of Clopyralid and Tribenuron in Perennial Sowthistle (Sonchus arvensis)
Authors: Zollinger Richard K. , Penner Donald , Kells James J.
Published: May 2019

Experiments were conducted to study absorption, translocation, and activity of clopyralid and tribenuron in perennial sowthistle. Absorption and translocation were compared in perennial sowthistle at the rosette and bud stage over a period of 9 d. Both14C-clopyralid and tribenuron were absorbed slowly by perennial sowthistle leaves with 60 and 30% absorption, respectively, 216 h after application. Limited movement of the absorbed14C was observed for both herbicides with less than 28% of either herbicide exported from the treated leaf. Primary movement of14C-herbicide within the plant was acropetal; however, no more than 18% of either herbicide was recovered in the upper shoot or buds. After 216 h, 4.4% of the applied14C-clopyralid and 2.5% of the applied14C-tribenuron were recovered in the roots and secondary shoots of plants at the rosette stage. Application of either herbicide to perennial sowthistle resulted in a decrease in net carbon assimilation and leaf conductance. Transpiration was reduced in rosette stage plants by both herbicides; however, transpiration in plants at the bud stage was not reduced until 216 h after treatment. Plants treated with tribenuron had lower net carbon assimilation, leaf conductance, and transpiration rates than plants treated with clopyralid. Application of clopyralid at 150 and 300 g ha-1resulted in visual injury ratings of 65 and 95%, respectively. Tribenuron applied at 10 and 20 g ha-1gave similar results. Dry weight accumulation was reduced at all application rates compared to untreated plants. Limited absorption and translocation along with high herbicidal activity suggests that small amounts of either herbicide are sufficient to inhibit perennial sowthistle growth.
Modeling Weed Distribution for Improved Postemergence Control Decisions
Authors: Wiles Lori J. , Wilkerson Gail G. , Gold Harvey J. , Coble Harold D.
Published: May 2019

Broadleaf weeds apparently have patchy distributions within a field while POST control decisions are made assuming a regular spatial distribution. As a result, yield loss from weed competition may be overestimated, possibly leading to mistakes in choosing the optimal control treatment. Data on distribution of broadleaf weeds in 14 soybean fields were used in simulation experiments to investigate the potential for improving decision making with information about weed patchiness. The feasibility of modeling weed distribution in individual fields was also examined. Overall, the cost of assuming a regular distribution when making POST decisions was found to be low. Errors that occurred most often involved recommending more intensive control than was actually required, although in a few cases less intensive control was recommended. Error in the yield loss estimated for the uncontrolled population did not indicate the potential for a mistake in decision making for a field. Accurately modeling distribution of weeds within fields may be difficult as a result of correlations between distributions of individual species within a field and variation in distributions between fields.
Foliar Absorption and Phytotoxicity of Quizalofop with Lipid Compounds
Authors: Manthey Frank A. , Szelezniak Edward F. , Anyszka Zbigniew M. , Nalewaja John D.
Published: May 2019

Experiments were conducted to determine the effect of triglycerides, free fatty acids (FFA), and fatty acid methyl esters (FAME) on the foliar absorption, translocation, and phytotoxicity of quizalofop. Absorption, translocation, and phytotoxicity of quizalofop in oats were greater when quizalofop was applied with FFA or FAME than with their respective triglycerides. Triglycerides and FFA generally enhanced quizalofop absorption and translocation more when they contained unsaturated than saturated fatty acids. Methylation of the fatty acids reduced differences among fatty acids, but methyl stearate and methyl linolenate enhanced absorption of quizalofop less than the other FAME for oats and yellow foxtail. Quizalofop absorption and phytotoxicity to oats were greater when applied with sunflower oil, sunflower oil FFA, and sunflower oil FAME than with the corresponding linseed oil derivatives. Emulsifier generally reduced differences between linseed oil and sunflower oil derivatives in their enhancement of absorption, translocation, and phytotoxicity of quizalofop.
Importance of SeedBanks for Establishment of Newly Introduced Weeds—a Case Study of Proso Millet (Panicum miliaceum)
Authors: Cavers Paul B. , Kane Marguerite , O'Toole James J.
Published: May 2019

Proso millet has become a major weed in North America during the past 20 yr. Experiments were conducted to assess the role of the soil seedbank in proso millet's success as a weed. Proso millet has at least eight distinct biotypes, all weeds, which exhibit a wide range of seedbank behavior. At one extreme, weed biotypes resembling crop varieties form transient seedbanks where all viable seed germinate or die before newly ripened seed enter the seedbank. In contrast, the black- and dark-red-seeded biotypes form persistent seedbanks that last several years in the soil. These latter seedbanks differ from those previously described in that there is always a fraction of the seedbank that is not capable of immediate germination. The black-seeded biotype of proso millet can establish a persistent seedbank quickly and that makes the weed very difficult to eradicate.
LA RICOSTRUZIONE ISTITUZIONALE DELLA GERMANIA ORIENTALE
Authors: Lehmbruch Gerhard
Published: May 2019

Introduzione

Lo sviluppo della Germania orientale comunista è stato contrassegnato da trasformazioni sociali e istituzionali per vari aspetti piò radicali di quelle avvenute in altri paesi dell'Europa orientale. Analogamente, anche l'attuale ricostruzione delle istituzioni democratiche e capitalistiche è contrassegnata da mutamenti radicali. è utile così riassumere alcune di queste caratteristiche se vogliamo mettere a confronto i processi che avvengono in Germania orientale con il resto dei paesi già appartenenti al campo del «socialismo reale».
LA RESISTIBILE ASCESA DELLA RAPPRESENTANZA POLITICA IN URSS
Authors: Cappelli Ottorino
Published: May 2019

Introduzione

La caduta dei regimi comunisti in Europa nel 1989-1990 è stata in alcuni casi innescata, in altri sancita dallo svolgimento di libere elezioni. è stato l'imporsi del tema e della pratica della rappresentanza politica, unitamente all'estrema rapidità del processo, che ha spinto alcuni a parlare della transizione democratica in quest'area geopolitica come di una «rivoluzione». Per quei paesi almeno che fanno parte del bacino centro-orientale – esclusa dunque l'area balcanica – è oggi all'ordine del giorno l'obiettivo di completare l'instaurazione di istituzioni democratiche (quanto alla prospettiva di un loro rapido ed efficace consolidamento, non andrebbero invece trascurate le notevoli difficoltà che già stanno emergendo).
IL GOVERNO DIVISO NEGLI STATI UNITI
Authors: Fiorina Morris P.
Published: May 2019

Introduzione

Negli ultimi venticinque anni ci siamo preoccupati del «ri-allineamento elettorale». Oggi non piò. Il ri-allineamento – almeno come è stato tradizionalmente concepito – appare un concetto inutilizzabile (Ladd 1989; Silbey 1989). Abbiamo atteso il ri-allineamento dal 1964, ed ogni volta il consenso accademico annunciava: «No, non è ancora arrivato». Ma, ri-allineamento o meno, la politica americana dell'ultimo quarto di secolo si è comunque trasformata. In particolare, sembra che si sia consolidato un «modello» persistente di governo diviso. Il candidato repubblicano George Bush ha vinto con facilità nel 1988, affermandosi in quaranta stati con il 54% del voto popolare. Ma nello stesso tempo, i candidati democratici conquistarono 260 dei 435 seggi della Camera dei rappresentanti e 18 dei 33 seggi in palio del Senato, facendo sì che il Congresso rimanesse sotto il controllo dei democratici. Tale risultato elettorale diviso non ha sorpreso nessuno: tre delle otto precedenti elezioni presidenziali (1956, 1968, 1972) hanno prodotto la stessa divisione, ed altre due (1980, 1984) hanno collocato la Presidenza e il Senato su un fronte opposto a quello della Camera dei rappresentanti. Delle ultime nove elezioni presidenziali, solamente tre (1960, 1964, 1976) hanno dato ad un partito il controllo sia della Presidenza che di entrambe le camere del Congresso. Se George Bush venisse riconfermato e il controllo della Camera dei rappresentanti da parte dei democratici continuasse, allora i futuri studenti universitari del 1996 non ricorderebbero nessun periodo di governo unificato: e lo stesso interludio di Carter si perderebbe nelle foschie della loro memoria infantile.
INDIVIDUALISMO METODOLOGICO E AUTORITÀ NELLE ORGANIZZAZIONI
Authors: Martelli Paolo
Published: May 2019

Introduzione

Tra gli scienziati sociali che operano oggi in Italia l'espressione «teorie razionali della politica» può far pensare a Max Weber e alla sua concezione del carattere razionale del potere legale con apparato amministrativo burocratico.
POLITICHE REGOLATIVE. FRA SCAMBI E GIOCHI
Authors: Giuliani Marco
Published: May 2019

Introduzione

In questo articolo ci occuperemo di processi regolativi: del loro significato, delle relazioni esistenti con altri tipi di intervento pubblico, e delle ipotesi avanzate per una loro interpretazione.
MOVIMENTI SOCIALI E SISTEMA POLITICO: UN CONFRONTO FRA ITALIA E GERMANIA
Authors: della Portae Donatella , Rucht Dieter
Published: May 2019

Introduzione

La letteratura sulle forme di protesta si è arricchita, di recente, di numerosi contributi che hanno, tra l'altro, affrontato il tema dei rapporti tra sistema politico e movimenti sociali. Ispirati da Eisinger, che aveva dimostrato una relazione curvilinea tra l'incidenza della protesta nelle città americane e l'accesso dei movimenti collettivi nelle arene politiche locali (Eisinger 1973, 28), modelli sempre piò complessi sono stati elaborati per spiegare un numero crescente di variabili. Molte ricerche hanno utilizzato il concetto distruttura delle opportunità politiche, riferendosi ad un complesso e variegato insieme di variabili (Tarrow 1983; Tarrow 1989a; Brand 1985; Kitschelt 1986; Kriesi 1989 e 1991). L'uso di questo concetto in una comparazionecross nationalpresenta, a nostro avviso, tre problemi. In primo luogo, il limitato numero di casi analizzati non permette generalizzazioni accurate. In secondo luogo, il controllo logico delle relazioni ipotizzate raramente è stato facilitato attraverso l'indicazione di variabili intervenienti tra variabili indipendenti e variabili dipendenti molto «distanti» fra loro. In terzo luogo, le analisi proposte sono state, prevalentemente, analisi statiche: riferendo le caratteristiche di un movimento a condizioni strutturali piò o meno inerti, queste analisi non sono state, cioè, in grado di spiegare i mutamenti congiunturali. In questa introduzione, proporremo alcune soluzioni a questi tre problemi, illustrando il modello esplicativo utilizzato nella nostra ricerca.
The Reasons we can Share: An Attack on the Distinction between Agent-Relative and Agent-Neutral Values
Authors: Korsgaard Christine M.
Published: May 2019

To later generations, much of the moral philosophy of the twentieth century will look like a struggle toescapefrom utilitarianism. We seem to succeed in disproving one utilitarian doctrine, only to find ourselves caught in the grip of another. I believe that this is because a basic feature of the consequentialist outlook still pervades and distorts our thinking: the view that the business of morality is tobring something about. Too often, the rest of us have pitched our protests as if we were merely objecting to the utilitarian account ofwhatthe moral agent ought to bring about orhowhe ought to do it. Deontological considerations have been characterized as “side constraints,” as if they were essentially restrictions on ways to realize ends. More importantly, moral philosophers have persistently assumed that the primal scene of morality is a scene in which someone does somethingtoorforsomeone else. This is the same mistake that children make about another primal scene. The primal scene of morality, I will argue, is not one in which I do something to you or you do something to me, but one in which we do something together. The subject matter of morality is not what we should bring about, but how we should relate to one another. If only Rawls has succeeded in escaping utilitarianism, it is because only Rawls has fully grasped this point. His primal scene, the original position, is one in which a group of people must make a decision together. Their task is to find the reasons they can share.
Cosmopolitan Altruism
Authors: Galston William A.
Published: May 2019

This essay focuses on what I shall call “cosmopolitan altruism”—the motivationally effective desire to assist needy or endangered strangers. Section I describes recent research that confirms the existence of this phenomenon. Section II places it within interlocking sets of moral typologies that distinguish among forms of altruism along dimensions of scope, interests risked, motivational source, and baseline of moral judgment. Section III explores some of the relationships between altruism—a concept rooted in modern moral philosophy and Christianity—and the understanding of virtue and friendship characteristic of Aristotelian ethical analysis. Finally, Section IV argues that cosmopolitan altruism does not represent moral progress simpliciter over other, less inclusive views, and that the widening of moral sympathy to encompass endangered strangers entails significant moral costs.
Altruism and the Argument from Offsetting Transfers
Authors: Cowen Tyler
Published: May 2019

Individuals frequently give gifts or make transfers to others for altruistic reasons. Parents devote time to raising their children, spouses make sacrifices on each other's behalf, and friends do favors for friends. We are also linked to many people indirectly because we care for someone who cares for them.
HOW DO SECOND LANGUAGE LISTENERS PERCEIVE THE COMPREHENSIBILITY OF FOREIGN-ACCENTED SPEECH?
Authors: Saito Kazuya , Tran Mai , Suzukida Yui , Sun Hui , Magne Viktoria , Ilkan Meltem
Published: May 2019

The current study examines how second language (L2) users differentially assess the comprehensibility (i.e., ease of understanding) of foreign-accented speech according to a range of background variables, including first language (L1) profiles, L2 proficiency, age, experience, familiarity, and metacognition. A total of 110 L2 listeners first evaluated the global comprehensibility of 50 spontaneous speech samples produced by low-, mid-, and high-proficiency Japanese speakers of English. The listeners were categorized into two subgroups according to a cluster analysis of their rating scores: lenient and strict. Results showed that while the lenient listeners appeared to rely equally on many linguistic areas of speech during their judgments, the strict listeners were strongly attuned to phonological accuracy. Analysis of the background questionnaire data revealed that more lenient listeners likely had higher levels of awareness of the importance of comprehensibility for communication (metacognition); regularly used L2 English in professional settings (experience); and had L1s more linguistically close to the target speech samples, Japanese-accented English (L1-L2 distance).
Interactions Between MPTP-Induced and Age-Related Neuronal Death in a Murine Model of Parkinson’s Disease
Authors: Tatton William G. , Greenwood Carol E. , Seniuk Nadine A. , Salo Paul T.
Published: May 2019

Abiotrophy is hypothesized to explain the onset and time course of deficits in Parkinson’s disease (PD) Abiotrophy includes: 1) exposure to agent(s) causing the death of dopaminergic nigrostriatal neurons (DNSns), 2) gradual death of DNSns with age, 3) summation of 1) and 2) until DNSn numbers fall below a threshold for detectable neurological deficits. Murine DNSn death following methyl-phenyl-tetrahydropyridine (MPTP) exposure occurs according to an exponential relationship while age-related death of DNSns occurs according to a second exponential relationship. Summing the two exponential losses overestimates experimental DNSn death showing a simple abiotrophic model is not sufficient. Aged murine DNSns greatly increase their dopamine synthesis and the density of their striatal axon terminals which may explain the above threshold. Murine DNSns die gradually after MPTP exposure and L-deprenyl treatment rescues MPTP-damaged DNSns by a previously undiscovered action, altering the abiotrophic interactions and possibly explaining the slowed progression of PD found with deprenyl treatment.
Levodopa-Induced Dyskinesia: Facts and Fancy. What Does the MPTP Monkey Model Tell Us?
Authors: Bédard Paul J. , Mancilla Baltazar Gomez , Blanchette Pierre , Gagnon Céline , Di Paolo Thérèse
Published: May 2019

Levodopa-induced dyskinesia, one of the most frequent long-term side effects of antiparkinsonian therapy, is often attributed to denervation supersensitivity of dopamine receptors and perhaps more specifically the D-1 receptor. The available evidence based not only on clinico-pathological studies in patients but also on results of experiments performed on methyl-phenyl-tetrahydropyridine (MPTP)-treated monkeys suggests that the mechanisms may be more complex than heretofore believed. Thus it appears that no single receptor is the sole culprit, that some form of denervation supersensitivity is probably involved but not in the form of increased density of dopamine receptors. Moreover, other neurotransmitter systems must be considered such as GABA, excitatory aminoacids and peptides. The MPTP monkey model remains very useful for predicting the potential of new drugs for inducing dyskinesia. Such trials however must be performed in drug-naive animals.
Positron Emission Tomography in Parkinson’s Disease
Authors: Snow Barry J.
Published: May 2019

Positron emission tomography (PET) allows the study of physiological and neurochemical processes which would otherwise be inaccessible, using radioactive labels on biological compounds to follow their fate in the body. By analysing changes of concentration with time we can measure blood flow, neuronal metabolism and receptor ligand interactions. In Parkinson’s disease (PD), PET has been used to examine the dopaminergic deficit and its relationship to motor performance. It has also been shown to detect asymptomatic dopaminergic lesions that have implications for the etiology of PD. In untreated PD there is increased density of D2 binding sites, while in chronically treated PD with motor fluctuations, D2 receptor density is reduced. [18F]-fluorodeoxyglucose studies of demented PD patients show a pattern of cortical metabolism similar to Alzheimer’s disease. Activation studies, which measure changes in blood flow during the performance of motor tasks, show reduced activation of medial frontal areas in PD.
Synergistic Interactions of D1- and D2-Selective Dopamine Agonists in Animal Models for Parkinson’s Disease: Sites of Action and Implications for the Pathogenesis of Dyskinesias
Authors: Robertson H.A.
Published: May 2019

The addition of a D2 agonist such as bromocriptine to L-Dopa therapy can often improve the response of patients with Parkinson’s disease dramatically. Simultaneous activation of D1 and D2 dopamine receptors can produce a synergistic effect on locomotion in rats and primates. However, despite the importance of this addition of a D2 agonist to the D1/D2 agonist L-Dopa, little is known of the sites of action of these agents. Recent work suggests that, in addition to D1 and D2 dopamine receptor sites in the striatum (caudate-putamen), L-Dopa and D1 agonists have important effects at D1 dopamine receptors in the substantia nigra. Animal experiments suggest that D1 and D2 dopamine receptor agonists probably also affect different outflow pathways from the striatum. An understanding of these pathways and how dopamine agonists affect them gives insight into some of the clinical problems experienced in treating Parkinson’s disease (the “on-off phenomenon, for example). D1/D2 dopamine receptors also differentially affect gene expression and regulation in the striatum. An understanding of the anatomical and biochemical location of the actions of dopamine receptor agonists will be important in maximizing the beneficial effects and minimizing the side-effects of both presently-used drugs and new treatments.
Neurological Findings in HIV-infected Children: A Review of 49 Cases
Authors: Roy S. , Geoffroy G. , Lapointe N. , Michaud J.
Published: May 2019

Many HIV-infected children have neurological involvement. We present our observations in 49 cases, 58% of which had some form of clinical neurological impairment. Most of the patients affected (71%) presented with progressive encephalopathy, characterized by developmental delay with loss of acquisitions and cognitive decline, an impaired growth curve, microcephaly and corticospinal dysfunction. CT-scan imaging shows cerebral atrophy in all cases and basal ganglia calcifications in 29%. Non-specific abnormalities are found on the EEG in two-thirds of cases and in the CSF in slightly less than half the cases. Pathological studies sometime revealed HIV encephalitis or lateral corticospinal tracts degeneration. Neurological impairment secondary to vascular events, neoplasms or opportunistic infections were rare, especially when compared with the adult HIV population.
Gliomas in Families
Authors: Ikizler Y. , van Meyel D.J. , Ramsay D.A. , Abdallah G.L. , Allaster R.M. , Macdonald D.R. , Cavenee W.K. , Cairncross J.G.
Published: May 2019

This is a descriptive study of 19 families with glial tumors. Twelve were identified prospectively from 178 consecutive, unrelated adults and children with newly diagnosed gliomas seen at a regional cancer center between 01 Jan 89 and 31 Mar 91 (6.7%). There were 45 affected members (42 confirmed); 30 males, 15 females, ages 4 months-78 years (median, 44.5 years; mean, 38.9 years). Two families had four affected members, three families had three, and the others two. All confirmed tumors were supratentorial and all, save one, contained an astrocytic element. Three additional members of two families had other brain or neuroectodermal tumors. These families were not unusually cancer prone and did not appear to have neurofibromatosis, tuberous sclerosis, or colonic polyposis. There was no consistent pattern of inheritance.
The Role of Magnetic Resonance Imaging in Acute Transverse Myelitis
Authors: Austin Sara G. , Zee Chi-Shing , Waters Cheryl
Published: May 2019

Eighteen adult patients presenting with acute transverse myelitis (ATM) were evaluated using magnetic resonance imaging. Only 7 had abnormal scans showing an area of increased signal intensity within the cord solely on T2 weighted images; Tl weighted images were normal. The MRI abnormality did not correlate with the cause of the transverse myelitis, the extent of maximum neurological deficit, or the prognosis. A scan performed more than 5 days after the onset of disease was most likely to be positive. Even though the prognostic value of MRI in ATM may be limited, it remains a valuable technique for ruling out other causes of noncompressive spinal cord lesions, such as hemmorhage, vascular malformation, or tumor.
Diagnosis and Management of Spinal Epidural Abscess
Authors: Redekop Gary J. , Del Maestro Rolando F.
Published: May 2019

Twenty-five patients with spinal epidural abscess were treated at the University of Western Ontario hospitals between July 1980 and July 1990. There were eighteen males (72%) and seven females (28%), with a median age of 60 years. Concurrent illness resulting in immunocompromise was present in 60%. Eleven presented with complete myelopathy, thirteen had limb weakness, and one had no neurological deficit. In twenty cases the abscess consisted of frankly purulent material, while in five the epidural collection consisted of chronic granulation tissue.Staphylococcus aureuswas isolated in 64% of the abscesses. Twenty-seven surgical procedures were performed on 21 patients. Ten cases occurred in the cervical spine (40%), seven in the thoracic spine (28%), three in both the cervical and thoracic spine (12%) and five in the lumbosacral spine (20%). Fourteen patients (56%) retained or recovered ambulation and there were five deaths (20%). The progression from back and radicular pain to weakness and eventual paralysis continues to be characteristic of spinal epidural infection. Morbidity and mortality remain unacceptably high because of delay in diagnosis and treatment. Magnetic resonance imaging is the radiological investigation of choice for the diagnosis of spinal epidural abscess. Prompt intervention, before the development of severe neurological deficits, can improve outcome. Immediate surgical drainage combined with antibiotics remains the treatment of choice.
Cerebral Aneurysms and Polycystic Kidney Disease: A Critical Review
Authors: Lozano Andres M. , Leblanc Richard
Published: May 2019

The pathogenic basis of the association between adult polycystic kidney disease (APKD) and cerebral aneurysms is unknown. We have compared cerebral aneurysms in 79 patients with APKD gleaned from the literature to the sporadic aneurysm cases reported by the Cooperative Study to determine if there are significant biological differences between these two groups. Sixty-eight patients had a single aneurysm and 11 (14%) had multiple aneurysms. In APKD patients with subarachnoid hemorrhage from a single aneurysm there was a significant over-representation of males (72%, p < 0.01); and the APKD group had more aneurysms of the middle cerebral artery (37%, p < 0.05). The peak decennial incidence and mean age of rupture of APKD-associated aneurysms was younger (mean age 39.7 years, p < 0.01) and over 77% of APKD-associated aneurysms had ruptured by age 50 versus 42% for sporadic aneurysms (p < 0.001). Cerebral aneurysms co-existed with APKD in the absence of hypertension in 25% of 45 cases where the presence or absence of hypertension was recorded. These biological differences and the occurrence of aneurysms in normotensive APKD patients suggests an etiology which may be independent of hypertension and that APKD-associated aneurysms may be genetically determined. It is hypothesized that cases of inherited, familial cerebral aneurysms could be linked to a genetic defect resembling that which occurs on chromosome 16 in APKD.
Tegmental Pontine Hemorrhages: Clinical Features and Prognostic Factors
Authors: Lancman Marcelo , Norscini Jorge , Mesropian Hripsime , Bardeci Carlos , Bauso Toselli , Granillo Rubens
Published: May 2019

We report six patients with partial, predominantly paramedian, tegmental pontine hemorrhages. Constant clinical manifestations consisted of: ipsilateral miosis, horizontal gaze paresis, lower motor neuron facial paresis, contralateral hemisensory loss and mild and transitory hemiparesis, dysarthria and mild or no compromise of consciousness. Five out of six were hypertensive. All patients survived with mild sequelae, oculomotor disturbances being the most persistent deficit. We found in our patients that a transverse diameter of less than 17 mm, unilaterality of the injury and absence of coma were the major indicators of a favorable outcome.
The Experience of Family Physicians and Home Health Staff Involved in an Intervention to Increase Patient-Related Collaboration
Authors: Berg Shannon , Sheps Sam , Barer Morris , Wong Sabrina T. , McGregor Margaret , MacNab Ying C
Published: May 2019

Les médecins de famille (MF) et le personnel de soins de santé à domicile (PSD) canadiens rencontrent d’importants obstacles lorsqu’ils doivent collaborer pour la prestation de soins aux patients qu’ils ont en commun. Cette étude à méthodologie mixte visait à évaluer la qualité et la viabilité de l’utilisation de l’audioconférence sécurisée dans une optique d’amélioration de la planification des soins pour ces patients. Les données primaires incluaient les résultats d’un sondage réalisé avant et après l’intervention, ainsi que des entretiens semi-structurés et des groupes de discussion post-intervention. Des méthodes statistiques non paramétriques ont été utilisées pour analyser les résultats du sondage, et les données qualitatives ont fait l’objet d’une analyse thématique de contenu. Les résultats des analyses quantitatives et qualitatives ont ensuite été intégrés afin de faire ressortir les inférences reflétant les approches des MF et du PSD relatives aux obstacles et aux avantages de la planification interdisciplinaire des soins. Les MF et le PSD ont montré que des obstacles structurels limitent leur capacité à collaborer. Le PSD et les MF ont également convenu que les rencontres entre les intervenants des deux services étaient bénéfiques pour les patients et que l’utilisation de l’audioconférence constituait une méthode efficiente de planification collaborative des soins. Les limites comprenaient la petite taille de l’échantillon et la courte période d’intervention, compte tenu de l’ampleur des changements attendus.
The Global Competitiveness of the U.S. Food-Processing Industry
Authors: Reed Michael R. , Marchant Mary A.
Published: May 2019

Before the 1970s, the U.S. economy was so large relative to the rest of the world that few American economists worried about the international sector and its relation to the U.S. economy. That view has changed dramatically in the past two decades. Total U.S. trade has increased from only $83 billion in 1970 to $866 billion in 1990, averaging a 12.4% increase each year. Exports accounted for less than 4% of U.S. gross national product (GNP) in the 1950s and 1960s, but now exports account for about 6% of U.S. GNP. These changes have radical implications for U.S. firms and government policies. The U.S. can no longer disregard economic occurrences in the rest of the world.
Issues in Risk/Benefit Evaluation for Pesticide Registration
Authors: Taylor C. Robert
Published: May 2019

The Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) and its amendments and related legislation currently require that applicants for registration or reregistration of a pesticide demonstrate to the U.S. Environmental Protection Agency (EPA) that there is not “any unreasonable risk to man or the environment, taking into account the economic, social, and environmental costs and benefits of use of the pesticide.” Present benefit evaluation guidelines call for consideration of effects on users, nonusers, consumers, GNP, and employment. Minimum guidelines call for a partial budgeting analysis and, if output effects of eliminating the pesticide appear large, a more sophisticated analysis using neoclassical multimarket economic-surplus concepts.
Pesticide Regulation and the Rule-Making Process
Authors: Cropper Maureen L. , Evans William N. , Berardi Stephen J. , Ducla-Soares Maria M.
Published: May 2019

In previous work (Cropper et al.), we examined the U.S. Environmental Protection Agency's (EPA's) decision to cancel or continue the registration of pesticides that went through its Special Review process between 1975 and 1989. Our focus in that paper was on the final decision (Notice of Final Determination) issued by the EPA at the end of the rule-making process. Specifically, we asked whether this decision could be explained by the reported risks and benefits associated with pesticide use, and by the comments of special-interest groups that were entered in the public docket.
Alternative Approaches to Pesticide Regulation
Authors: Lichtenberg Erik
Published: May 2019

Pesticide regulation has become a topic of increasing interest in recent years, owing to rising public concerns about residues on foods, in drinking-water wells, and damage to wildlife. Public-opinion polls and political responses to incidents like the controversy over Alar suggest that demand for government intervention to protect public health and the environment from pesticides is high. Pesticides are toxic by design; survey evidence indicates that they are perceived as riskier than other, more common pollutants like auto exhaust (see, for example, Horowitz). Pesticide residues are not easily observable (short of laboratory analysis), making averting strategies by individuals extremely difficult and/or excessively costly to implement.
Issues in Pesticide Policy: Discussion
Authors: Abler David G.
Published: May 2019

The paper by Taylor has merit because it is provocative, but like many things, this can be overdone. His self-described diatribe against neoclassical economics is in special need of a response. He appears to dismiss the notion of utility maximization, but in fact there is nothing to dismiss. Although many economists do not realize this fact, the assumption of utility maximization is not testable. Give me any pattern of behavior by an individual (or a society) and I can give you a utility function which, when maximized subject to whatever constraints that person or society may face, yields the observed behavior. An obvious example would be U = 1 for the observed behavior and U = 0 otherwise, although more complicated examples could also be constructed. The power of economics lies not in utility maximization, but in the specification of constraints on choice and in describing how changes in the constraints affect behavior. To illustrate, even a consumer who made decisions randomly would tend to have downward-sloping demand curves because of his or her budget constraint (Becker).
Issues in Pesticide Policy: Discussion
Authors: Harper Carolyn R.
Published: May 2019

Two issues lurk in the background of the papers by Lichtenberg, Taylor, and Cropper et al. The first is a specific question about the goal of regulatory policy. The second is a more global consideration regarding politics, technological change, and the future.