THE BIOLOGY OF CANADIAN WEEDS. 83. Hypericum perforatum L.

1988 ◽  
Vol 68 (1) ◽  
pp. 149-162 ◽  
Author(s):  
C. W. CROMPTON ◽  
I. V. HALL ◽  
K. I. N. JENSEN ◽  
P. D. HILDEBRAND
Keyword(s):  
Hypericum Perforatum ◽  
Control Measures ◽  
Effective Control ◽  
Eastern Canada ◽  
Weed Biology ◽  
Lowbush Blueberry ◽  
Specific Strain ◽  
Hypericum Perforatum L ◽  
Low Levels ◽  
And Control

Hypericum perforatum L., St. John’s-wort is an introduced weed growing in waste places, roadsides, rangelands, pastures and similar habitats of Eastern Canada and British Columbia. It is poisonous to livestock causing a photosensitization in grazing animals with light-colored hair. In Canada, two introduced leaf-feeding beetles Chrysolina quadrigemina and C. hyperici have provided effective control. In Nova Scotia an endemic host-specific "strain" of Colletotrichum gloeosporioides generally maintained this weed at low levels, particularly in lowbush blueberry fields. It spreads both by seeds and vegetatively by rhizomes. Details related to its morphology, reproductive biology, responses to human manipulation, parasites and control measures are summarized.Key words: Hypericum perforatum, weed biology, review

Survey and control of small mammal populations on two hardwood plantations in southern Ontario

1974 ◽  
Vol 50 (5) ◽  
pp. 181-185 ◽  
Author(s):  
Andrew Radvanyi
Keyword(s):  
Small Mammal ◽  
Late Summer ◽  
Control Measures ◽  
Effective Control ◽  
Southern Ontario ◽  
Live Trapping ◽  
Surrounding Areas ◽  
And Control ◽  
Rodent Populations ◽  
Ingredient Cost

Live trapping and tagging methods were employed to assess small mammal populations within two hardwood plantations in southern Ontario. Excessive girdling damage in past years to young planted trees necessitated an evaluation of rodent populations and development of effective control measures. The application of an anticoagulant rodenticide to oat groats bait broadcast over the study area at an ingredient cost of approximately three dollars per acre virtually wiped out the small mammals. Reinvasion from surrounding areas was, however, fairly rapid, particularly during late summer. Further research on longer term control measures using poisoned bait feeder stations is recommended.

scholarly journals Effective control measures limited measles outbreak after extensive nosocomial exposures in January-February 2008 in Gothenburg, Sweden

2008 ◽  
Vol 13 (30) ◽  
Author(s):  
P Follin ◽  
L Dotevall ◽  
M Jertborn ◽  
Y Khalid ◽  
J Å Liljeqvist ◽  
...  
Keyword(s):  
Vaccination Coverage ◽  
Control Measures ◽  
Effective Control ◽  
Imported Case ◽  
Measles Outbreak ◽  
Measles Outbreaks ◽  
Rubella Vaccination ◽  
And Control

In January-February 2008, one imported case of measles initiated a series of exposures with around 380 nosocomial secondary contacts. Susceptible individuals were traced early and control measures were initiated that managed to limit the consequences considerably. Only four secondary cases were identified by the end of March. This minor outbreak illustrates the importance and efficiency of early control measures as well as the fact that the risk of measles outbreaks still exists in a country that has high measles, mumps, rubella vaccination coverage among children.

Yellow Nutsedge (Cyperus esculentus) Competition and Control in Corn (Zea mays)

Weed Science ◽  
1979 ◽  
Vol 27 (1) ◽  
pp. 32-37 ◽  
Author(s):  
E. W. Stoller ◽  
L. M. Wax ◽  
F. W. Slife
Keyword(s):  
Zea Mays ◽  
Control Measures ◽  
Effective Control ◽  
Yield Reduction ◽  
Cyperus Esculentus ◽  
Yellow Nutsedge ◽  
Effective Combination ◽  
Percentage Yield ◽  
Hand Weeding ◽  
And Control

Competition of yellow nutsedge (Cyperus esculentusL.) with corn (Zea maysL.) was evaluated in the field at various yellow nutsedge densities over a 3-yr period. A relationship between yellow nutsedge density (shoots/m2) and percentage yield reduction revealed an 8% yield reduction for every 100 shoots/m2. Two 3-yr studies were conducted to determine the most effective combination of preplant-incorporated, postemergence, or postemergence-directed treatments for yellow nutsedge control in corn. The preplant incorporated treatments were alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], EPTC (S-ethyl dipropylthiocarbamate), or nothing; postemergence treatments were bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4) 3H-one 2,2-dioxide], two cultivations, or nothing; and the postemergence-directed treatments were ametryn [2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine] or nothing. One preplant-incorporated treatment of EPTC or alachlor prevented yield reductions from yellow nutsedge competition. When no control was practiced, yields were reduced 17% in a moderate yellow nutsedge infestation (initially infested with 300 tubers/m2) and 41% in a heavy infestation (initially infested with 1200 tubers/m2). Yields were reduced 7 to 8% in the moderate infestation when no preplant-incorporated treatments were used regardless of whether postemergence or postemergence-directed treatments were also used. After 1 yr, all control measures resulted in less tuber density than no control measures, but all control treatments had essentially similar tuber densities. After the second year, several herbicide treatments were as effective as hand weeding in reducing tuber density. At least 2 yr of effective control treatments were required to reduce tubers to 20% of the original density, and 3 yr of treatment to reduce the density to 15% of the original density. No combination of treatments, including hand weeding, eliminated tubers after 3 yr.

scholarly journals Mathematical modeling and comparative analysis of the Ebola epidemic reveal effective control measures

2019 ◽  
Author(s):  
Junlong Li ◽  
Caiping Song ◽  
Jingya Yang ◽  
Jingmin Zheng ◽  
Lina Zhou ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Comparative Analysis ◽  
Sierra Leone ◽  
Development Process ◽  
Ebola Virus ◽  
Virus Disease ◽  
Control Measures ◽  
Effective Control ◽  
Epidemic Outbreak ◽  
And Control

Abstract The Ebola virus disease (EVD) is a highly contagious disease which is caused by the Ebola virus . Various measures were used to prevent and control the spread of EVD. The aim of this study was to find out the most critical measures to prevent and control the spread of EVD. Both mathematical modeling and comparative analysis were used to explore the development process of EVD outbreak in Guinea, Liberia and Sierra Leone. The results of comparative analysis showed quarantined individuals before infection (R 2 = 0.848, ε = 1.012), safe burial teams (R 2 = 0.772, ε = 0.385), and the Ebola treatment units (ETU) bed (R 2 = 0.690, ε = 0.432) could significantly influence the incidence of EVD which were consistent with the results of mathematical modeling. These findings indicted that a timely and effective quarantine played a significant role in preventing and controlling the spread of EVD, and the findings would help us prevent and control the epidemic outbreak of new infectious disease in the future.

scholarly journals A REVIEW OF DAMPING-OFF OF DOUGLAS FIR SEEDLINGS IN BRITISH COLUMBIA

1954 ◽  
Vol 30 (4) ◽  
pp. 407-410 ◽  
Author(s):  
P. J. Salisbury
Keyword(s):  
British Columbia ◽  
Control Measures ◽  
Effective Control ◽  
Damping Off ◽  
Natural Control ◽  
Cover Soil ◽  
Low Degree ◽  
Nursery Practices ◽  
Forest Nurseries ◽  
And Control

Except in new nurseries, damping-off in British Columbia forest nurseries has remained below serious levels. Modification of nursery practices has served to reduce losses. The use of a suitable, sandy cover soil has been effective. Lowered fertility of the soil, though a problem in itself, appears to decrease incidence of damping-off. The acidity of the soil in coast nurseries may have afforded some natural control of the disease. From investigations on the control of damping-off, there appears to be promise in the use of peat as a planting medium for stratified seed, and, based on experiments with unstratified seed, in the application of fungicides to cover soil. In view of the present low degree of the disease, there would appear to be an opportunity for research directed to the biology and control of fungi known to be capable of causing sudden outbreaks, without the urgent need of finding immediately effective control measures.

Postscripts

1979 ◽  
Vol 287 (1022) ◽  
pp. 479-488 ◽  
Keyword(s):  
Young Adults ◽  
Individual Characteristics ◽  
Control Measures ◽  
Western Region ◽  
Eastern Region ◽  
Desert Locust ◽  
Red Sea Coast ◽  
Low Levels ◽  
And Control ◽  
Sea Coast

The period since the Discussion Meeting in June 1977 has witnessed the development of another major Desert Locust upsurge. What in retrospect may have been a key stage had occurred less than 3 weeks before the Meeting. The 1977-8 upsurge showed some striking similarities to earlier upsurges but also some individual characteristics. In the latter part of 1976 the main Desert Locust populations were: in the western region, gregarious hoppers and young adults in northeast Mali, northwest Niger and southern Algeria and, arising from these, a few swarms in southwest Libya and adjacent Algeria, in the central region, groups of hoppers and adults on the Red Sea coast of Sudan; in the eastern region, gregarious populations in India and Pakistan had been reduced to low levels by insecticides. Details of the main populations (using the same criteria as Rainey & Betts in this symposium) and control measures are given in appendix 1 and their probable or possible interconnections are shown in figure 1.

scholarly journals Epidemiological investigation of the Central Scotland outbreak of Escherichia coli O157 infection, November to December 1996

2001 ◽  
Vol 126 (3) ◽  
pp. 335-341 ◽  
Author(s):  
J. M. COWDEN ◽  
S. AHMED ◽  
M. DONAGHY ◽  
A. RILEY
Keyword(s):  
Escherichia Coli ◽  
Bloody Diarrhoea ◽  
Control Measures ◽  
Effective Control ◽  
Escherichia Coli O157 ◽  
Epidemiological Investigation ◽  
Outbreak Strain ◽  
Source Of Infection ◽  
And Control

On Friday, 22 November 1996, the microbiologist at a hospital in Lanarkshire, Scotland, identified presumptive Escherichia coli O157 in faecal specimens submitted by three patients with bloody diarrhoea, and confirmed its presence in one. Over the next 6 h, 12 more potential cases were identified. Investigations first indicated then confirmed a single food premises as the source of infection. Effective control measures were applied promptly. The outbreak was declared over on 20 January 1997, by which time 512 cases had been identified, and infection with the outbreak strain confirmed in 279. Twenty deaths occurred in cases during the outbreak and there were two more in cases during 1997. Seventeen of these deaths resulted from the outbreak. This paper describes the outbreak's epidemiological investigation, referring to other investigations, and control measures, where appropriate.

scholarly journals Effects of medical resource capacities and intensities of public mitigation measures on outcomes of COVID-19 outbreaks

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Xia Wang ◽  
Qian Li ◽  
Xiaodan Sun ◽  
Sha He ◽  
Fan Xia ◽  
...  
Keyword(s):  
Prevention And Control ◽  
Control Strategies ◽  
Control Measures ◽  
Mitigation Measures ◽  
Effective Control ◽  
Medical Resource ◽  
Key Factors ◽  
Medical Resources ◽  
Detection Rates ◽  
And Control

Abstract Background The COVID-19 pandemic is complex and is developing in different ways according to the country involved. Methods To identify the key parameters or processes that have the greatest effects on the pandemic and reveal the different progressions of epidemics in different countries, we quantified enhanced control measures and the dynamics of the production and provision of medical resources. We then nested these within a COVID-19 epidemic transmission model, which is parameterized by multi-source data. We obtained rate functions related to the intensity of mitigation measures, the effective reproduction numbers and the timings and durations of runs on medical resources, given differing control measures implemented in various countries. Results Increased detection rates may induce runs on medical resources and prolong their durations, depending on resource availability. Nevertheless, improving the detection rate can effectively and rapidly reduce the mortality rate, even after runs on medical resources. Combinations of multiple prevention and control strategies and timely improvement of abilities to supplement medical resources are key to effective control of the COVID-19 epidemic. A 50% reduction in comprehensive control measures would have led to the cumulative numbers of confirmed cases and deaths exceeding 590,000 and 60,000, respectively, by 27 March 2020 in mainland China. Conclusions Multiple data sources and cross validation of a COVID-19 epidemic model, coupled with a medical resource logistic model, revealed the key factors that affect epidemic progressions and their outbreak patterns in different countries. These key factors are the type of emergency medical response to avoid runs on medical resources, especially improved detection rates, the ability to promote public health measures, and the synergistic effects of combinations of multiple prevention and control strategies. The proposed model can assist health authorities to predict when they will be most in need of hospital beds and equipment such as ventilators, personal protection equipment, drugs, and staff.

Rabies epidemiology and control in Turkey: past and present

2009 ◽  
Vol 138 (3) ◽  
pp. 305-312 ◽  
Author(s):  
N. JOHNSON ◽  
H. UN ◽  
A. R. FOOKS ◽  
C. FREULING ◽  
T. MÜLLER ◽  
...  
Keyword(s):  
Urban Areas ◽  
Current Control ◽  
Control Measures ◽  
Wildlife Reservoirs ◽  
Current State ◽  
Low Levels ◽  
And Control

SUMMARYTurkey is the only country in Europe where urban dog-mediated rabies persists. Control measures in recent decades have reduced the burden of rabies to relatively low levels but foci of disease still persist, particularly in urban areas. Occasional human cases result from this persistence although the source of these appears to be both dog and wildlife reservoirs. This review considers the current state of rabies in Turkey including current control measures, the varying epidemiology of the disease throughout this country and the prospects for rabies elimination.

scholarly journals Comparison between two types of control strategies for the coronavirus disease 2019 pandemic

2020 ◽  
Vol 14 (07) ◽  
pp. 696-698
Author(s):  
Xiaoyan Zhang ◽  
Yuxuan Wang
Keyword(s):  
Comparative Analysis ◽  
Severe Acute Respiratory Syndrome ◽  
Control Strategy ◽  
Prevention And Control ◽  
Control Strategies ◽  
Influenza Pandemic ◽  
Control Measures ◽  
Effective Control ◽  
Epidemic Control ◽  
And Control

Different countries have employed various strategies for controlling the coronavirus disease (COVID-19) pandemic because there is no consensus regarding effective control measures in the literature. Epidemic control strategies can be classified into two types based on their characteristics. The first type is the “severe acute respiratory syndrome (SARS)-like epidemic control strategy,” i.e., containment. The second type is the “influenza pandemic-like epidemic control strategy” (flu pandemic-like strategy), i.e., mitigation. This paper presents a comparative analysis on the prevention and control strategies for COVID-19 in different countries to provide a reference to control the further spread of the pandemic.

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