218 research outputs found

    Biological Control of Ground Ivy Using a Rust Fungus

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    Ground-ivy or creeping Charlie (Glechoma hederacea) is a creeping perennial in the Mint Family that forms dense prostrate patches in turfgrass, damp shady meadows, and disturbed sites. The control of ground ivy using chemical and mechanical methods has largely been unsuccessful in turfgrass where it is considered a major weed. Thus, there is a pressing need to develop and evaluate alternative approaches for the control of ground ivy in turfgrass that are effective and environmentally sound

    Planting date effects on the germinability and seedling vigour of Abutilon theophrasti (Malvaceae) seeds

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    Abutilon theophrasti (Malvaceae) is a troublesome annual weed in many maize and soybean cropping systems of Canada and the United States. Seeds of A. theophrasti exhibit physical dormancy. Differences in the growing environment of parent plants may influence the germinability of seeds and vigour of seedlings produced by this species because of variation in resource allocation to seed development. Thus, the germinability of seeds and subsequent seedling vigour were examined for A. theophrasti plants grown in monoculture at a density of 4.2 plants m-2 under varying natural photoperiods in central New York State. Treatments were established by transplanting A. theophrasti seedlings on three dates: 15 May, 4 June, and 30 June 2000, which correspond to peak photoperiods of 15, 14, and 13 hours, respectively. Seeds produced under the shorter photoperiod (13 h) weighed, on average, 1.5 mg less than seeds produced under the longer photoperiod (15 h). Contrary to expectations, seeds of A. theophrasti that matured under shorter photoperiods had lower germinability (80%) than seeds produced under longer photoperiods (98%). Early radicle growth, a measure of seedling vigour, did not differ between the photoperiod treatments. Environmental conditions other than photoperiod (i.e. water availability) prevailing during the 2000-growing season may have influenced seed coat thickness and consequently affected the germinability of seeds.L’Abutilon theophrasti (Malvaceae) est une mauvaise herbe annuelle qui gĂȘne la production du maĂŻs et du soja dans plusieurs systĂšmes de culture du Canada et des États-Unis. Les graines de l’A. theophrasti possĂšdent une dormance physique. Des diffĂ©rences de l’environnement dans lequel croissent les plantes mĂšres peuvent influencer la germination des graines et la vitalitĂ© des plantules de cette espĂšce Ă  cause de variations dans l’affectation des ressources avant que les graines soient pleinement dĂ©veloppĂ©es. Ainsi, la germination des graines et la vitalitĂ© des plantules qui en sont issues ont Ă©tĂ© Ă©tudiĂ©es pour l’A. theophrasti en monoculture Ă  une densitĂ© de 4,2 plantes m-2 sous diverses photopĂ©riodes naturelles du centre de l’État de New York. Les traitements ont dĂ©butĂ© par la plantation de plantules de l’A. theophrasti Ă  trois dates, 15 mai, 6 juin et 30 juin 2000, qui correspondent respectivement Ă  des photopĂ©riodes maximales de 15, 14 et 13 heures. Les graines produites avec la photopĂ©riode la plus courte (13 h) pesaient en moyenne 1,5 mg de moins que les graines produites avec les plus longues photopĂ©riodes (15 h). Contrairement Ă  ce qui Ă©tait prĂ©vu, les graines de l’A. theophrasti qui se sont formĂ©es lors des photopĂ©riodes les plus courtes avaient une germination plus faible (80 %) que les graines formĂ©es lors des photopĂ©riodes les plus longues (98 %). La croissance prĂ©coce de la radicule, une mesure de la vitalitĂ© des plantules, est restĂ©e la mĂȘme pour les diffĂ©rentes photopĂ©riodes. Les conditions environnementales autres que la photopĂ©riode (c.-Ă -d. la disponibilitĂ© en eau) qui rĂ©gnaient au cours de la saison de croissance de 2000 peuvent avoir influencĂ© l’épaisseur du tĂ©gument et avoir ainsi eu un effet sur la germination des graines

    Perceptions of Reading Instruction

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    It follows that there exists an obvious need for elementary reading programs to be closely articulated with the developing and changing reading requirements of pupils as they progress through the elementary grades. There is an even more obvious need for close cooperation between teachers and administrators in order to implement reading programs that meet pupil requirements

    Weed Hosts for Onion Thrips (Thysanoptera: Thripidae) and Their Potential Role in the Epidemiology of Iris Yellow Spot Virus in an Onion Ecosystem

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    Onion thrips, Thrips tabaci Lindeman, is a key foliage-feeding pest of onion worldwide and the principal vector of a serious onion pathogen, Iris yellow spot virus (IYSV). Long-term management of T. tabaci and IYSV will require an understanding of T. tabaci ecology and IYSV epidemiology in onion ecosystems. This study focused on identifying winter-annual, biennial and perennial weed species that host both T. tabaci and IYSV. Unlike summer-annual weeds, weeds with these habits survive overwinter and could serve as a green bridge for IYSV to survive between onion-growing seasons. T. tabaci larvae and adults were sampled every two weeks from 69 weed species in five areas located adjacent to onion fields in western New York in 2008 and 2009. Twenty-five of the 69 weed species were identified as hosts for T. tabaci larvae and populations were highest on the Brassicaceous weeds, Barbarea vulgaris Ait. f., Sinapis arvensis L., and Thalspi arvense L. None of these species are hosts for IYSV. Four of the 25 weed species were hosts for both T. tabaci larval populations and IYSV: common burdock, Arctium minus Bernh., dandelion, Taraxacum officinale G.H. Weber ex Wiggers, curly dock, Rumex crispus L., and chicory, Cichorium intybus L. Of these four weed species, T. officinale and A. minus may play an important role in the epidemiology of IYSV in New York onion fields because they may survive between onion-growing seasons, they are relatively abundant in the landscape, and they support relatively high densities of T. tabac

    Peer Coaching as Professional Development for Remote, Online Faculty

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    To date, much of the coaching literature focuses on work with elementary teachers in the area of literacy (for example, Stover, Kissel, Haag, & Schoniker, 2011). Very little research regarding faculty coaching at the university level has been conducted. Anecdotal evidence suggests that coaching is beneficial to higher education faculty and that those who engage in coaching are more confident in their teaching (McDowell, Bedford & DiTommaso Downs, 2014). . However, no empirical evidence exists to support this, nor is there data to indicate the extent to which pedagogical straggles learned in coaching are transferred to the classroom.https://scholarworks.waldenu.edu/symposium2018/1010/thumbnail.jp

    Exploring Possibilities of Predicting Positive Counselor Qualities in Counseling Students from Personality Domains

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    In this pilot study, the authors investigated the degree that Big Five personality domains may predict the positive counselor qualities among 160 students enrolled in sections of a combined undergraduate/graduate Counseling Skills course. Positive counselor qualities of focus in this study are empathy, mindfulness or self-awareness, and unconditional positive self-regard in students studying counseling skills. The results do not suggest a significant predictive role for the Big Five personality domains for the Counseling Skills students, except that the Big Five domain of neuroticism predicted enough variation in mindfulness and unconditional positive self-regard to be practically significant. Limitations and potential implications of these findings for counselor educators and for future research are discussed

    Advanced Video-Based Processing for Low-Cost Damage Assessment of Buildings under Seismic Loading in Shaking Table Tests

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    This paper explores the potential of a low-cost, advanced video-based technique for the assessment of structural damage to buildings caused by seismic loading. A low-cost, high-speed video camera was utilized for the motion magnification processing of footage of a two-story reinforced-concrete frame building subjected to shaking table tests. The damage after seismic loading was estimated by analyzing the dynamic behavior (i.e., modal parameters) and the structural deformations of the building in magnified videos. The results using the motion magnification procedure were compared for validation of the method of the damage assessment obtained through analyses of conventional accelerometric sensors and high-precision optical markers tracked using a passive 3D motion capture system. In addition, 3D laser scanning to obtain an accurate survey of the building geometry before and after the seismic tests was carried out. In particular, accelerometric recordings were also processed and analyzed using several stationary and nonstationary signal processing techniques with the aim of analyzing the linear behavior of the undamaged structure and the nonlinear structural behavior during damaging shaking table tests. The proposed procedure based on the analysis of magnified videos provided an accurate estimate of the main modal frequency and the damage location through the analysis of the modal shapes, which were confirmed using advanced analyses of the accelerometric data. Consequently, the main novelty of the study was the highlighting of a simple procedure with high potential for the extraction and analysis of modal parameters, with a special focus on the analysis of the modal shape's curvature, which provides accurate information on the location of the damage in a structure, while using a noncontact and low-cost method

    Reduction in weed seedling emergence by pathogens following the incorporation of green crop residue

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    Summary Because tillage promotes the germination of many weed species and freshly killed plant material favours the growth of microbial pathogens, we hypothesised that the incorporation of green crop residue should temporarily reduce weed seedling emergence relative to unamended soil. Soil with field-incorporated green crop residue was compared with non-amended soil in glasshouse experiments by sowing several weed species at different times after incorporation. Species included Abutilon theophrasti, Chenopodium album, Amaranthus powellii, Setaria faberi, Echinochloa crus-galli and, in one year, lettuce and red clover. Soils with green crop residue reduced seedling emergence for 0-4 days after incorporation by an average of 30%. Comparison of emergence in nonsterilised soil with that in sterilised soil, with and without fresh crop residue, indicated that a biological agent caused the depressed emergence. In the third year of the study, the fungi Fusarium oxysporum and F. chlamydosporum were isolated from seeds exposed to soil amended with green crop residues, and their pathogenicity to seeds and seedlings was confirmed in bioassays. This study indicated that incorporation of fresh crop residue reduces the first flush of weed seedlings following tillage and that this depression in emergence is probably caused by pathogen attack on seeds and seedlings before emergence

    A cross-sectional study of SARS-CoV-2 seropositivity among healthcare workers and residents of long-term facilities in Italy, January 2021

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    Long‐term care facilities (LTCFs) are high‐risk settings for SARS‐CoV‐2 infection. This study aimed to describe SARS‐CoV‐2 seropositivity among residents of LTCFs and health‐care workers (HCWs). Subjects were recruited in January 2021 among unvaccinated HCWs of LTCFs and hospitals and residents of LTCFs in Northern Italy. Information concerning previous SARS‐CoV‐2 infections and a sample of peripheral blood were collected. Anti‐S SARS‐CoV‐2 IgG antibodies were measured using the EUROIMMUN Anti‐SARS‐CoV‐2 QuantiVac ELISA kit (EUROIMMUN Medizinische Labordiagnostika AG). For subjects with previous COVID‐19 infection, gender, age, type of subject (HCW or resident), and time between last positive swab and blood draw were considered as possible determinants of two outcomes: the probability to obtain a positive serological result and antibody titer. Six hundred and fifty‐eight subjects were enrolled. 56.1% of all subjects and 65% of residents presented positive results (overall median antibody titer: 31.0 RU/ml). Multivariable models identified a statistically significant 4% decrease in the estimated antibody level for each 30‐day increase from the last positive swab. HCWs were associated with significant odds for seroreversion over time (OR: 0.926 for every 30 days, 95% CI: 0.860–0.998), contrary to residents (OR: 1.059, 95% CI: 0.919–1.22). Age and gender were not factors predicting seropositivity over time. Residents could have a higher probability of maintaining a seropositive status over time compared to HCWs

    Has VZV epidemiology changed in Italy? Results of a seroprevalence study

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    The aim of the study was to evaluate if and how varicella prevalence has changed in Italy. In particular a seroprevalence study was performed, comparing it to similar surveys conducted in pre-immunization era. During 2013–2014, sera obtained from blood samples taken for diagnostic purposes or routine investigations were collected in collaboration with at least one laboratory/center for each region, following the approval of the Ethics Committee. Data were stratified by sex and age. All samples were processed in a national reference laboratory by an immunoassay with high sensitivity and specificity. Statutory notifications, national hospital discharge database and mortality data related to VZV infection were analyzed as well. A total of 3707 sera were collected and tested. In the studied period both incidence and hospitalization rates decreased and about 5 deaths per year have been registered. The seroprevalence decreased in the first year of life in subjects passively protected by their mother, followed by an increase in the following age classes. The overall antibody prevalence was 84%. The comparison with surveys conducted with the same methodology in 1996–1997 and 2003–2004 showed significant differences in age groups 1–19 y. The study confirms that in Italy VZV infection typically occurs in children. The impact of varicella on Italian population is changing. The comparison between studies performed in different periods shows a significant increase of seropositivity in age class 1–4 years, expression of vaccine interventions already adopted in some regions
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