scholarly journals Short-term responses to sheep grazing in a Patagonian steppe

2020 ◽  
Vol 42 (1) ◽  
pp. 1
Author(s):  
Magalí D. Valenta ◽  
Rodolfo A. Golluscio ◽  
Ana L. Frey ◽  
Lucas A. Garibaldi ◽  
Pablo A. Cipriotti
Keyword(s):  
Growing Season ◽  
Rangeland Management ◽  
Ovis Aries ◽  
Direct Effects ◽  
Sheep Grazing ◽  
Short Term ◽  
Soil C ◽  
Patagonian Steppe ◽  
Long Term Studies

Grazing modifies ecosystem function through direct effects on plants, but also through indirect effects mediated by floristic changes induced by grazing. Although both types of effects occur in the long term, only the direct effects are evident in the short term. We evaluated the short-term direct effects of sheep (Ovis aries) grazing on a Patagonian steppe during one growing season. We measured plant aerial cover in permanent transects located at increasing distances from a watering point in three paddocks with different stocking rates through the growing season. We also measured frequency of defoliation for vegetative and reproductive phases of different plant species located along these transects. Sheep grazing directly (a) reduced aerial cover and/or increased frequency of defoliation of certain preferred grasses and perennial forbs, (b) did not increase the aerial cover of any life form, but only the proportion of bare soil, (c) did not change the litter aerial cover, and (d) defoliated the flowers of even the least preferred shrub. Result a) was coincident with previous plant aerial cover long-term studies; but results (b) and (c) were contrary to long-term studies, probably because they resulted from indirect rather than direct grazing effects. Result (d) was not detected by long-term studies, probably because flower defoliation through grazing is undetectable when measuring shrub plant aerial cover. Our study showed that grazing has short-term direct effects mainly on the most preferred species. This could be useful for rangeland management and conservation of Patagonian steppes because short-term effects may be more easily reversible than long-term ones, and may provide early warning of rangeland condition deterioration.

scholarly journals Possible Traffic Safety Effects of the Implementation of Section Control in Hungary

2020 ◽  
Vol 13 (4) ◽  
pp. 309-323
Author(s):  
Zsolt Sándor
Keyword(s):  
Traffic Safety ◽  
Indirect Effects ◽  
Social Cost ◽  
Cost Savings ◽  
International Studies ◽  
Direct Effects ◽  
Implementation Cost ◽  
Short Term ◽  
Environmental Loads

This article presents the anticipated safety effects of the implantation of section control in Hungary. The proposed results were originated from international studies and the local circumstances. Effects are depending on the control coverage and the magnitude of the sanctions. Direct (short term benefits) and indirect effects (long term benefits) can be identified. Direct effects are the decreasing of accident numbers, while indirect effects are the decrease of other externalities of transport like environmental loads. Based on the results the implementation cost of the enforcement system is measureable with the proposed social cost savings come from the decreasing number of accidents.

scholarly journals Creatine Use in Sports

2017 ◽  
Vol 10 (1) ◽  
pp. 31-34 ◽  
Author(s):  
Jessica Butts ◽  
Bret Jacobs ◽  
Matthew Silvis
Keyword(s):  
Dietary Supplement ◽  
National Collegiate Athletic Association ◽  
Creatine Supplementation ◽  
Sports Performance ◽  
Short Term ◽  
Level Of Evidence ◽  
Improved Performance ◽  
Google Search ◽  
Long Term Studies

Context: The use of creatine as a dietary supplement has become increasingly popular over the past several decades. Despite the popularity of creatine, questions remain with regard to dosing, effects on sports performance, and safety. Evidence Acquisition: PubMed was searched for articles published between 1980 and January 2017 using the terms creatine, creatine supplementation, sports performance, and dietary supplements. An additional Google search was performed to capture National Collegiate Athletic Association–specific creatine usage data and US dietary supplement and creatine sales. Study Design: Clinical review. Level of Evidence: Level 4. Results: Short-term use of creatine is considered safe and without significant adverse effects, although caution should be advised as the number of long-term studies is limited. Suggested dosing is variable, with many different regimens showing benefits. The safety of creatine supplementation has not been studied in children and adolescents. Currently, the scientific literature best supports creatine supplementation for increased performance in short-duration, maximal-intensity resistance training. Conclusion: While creatine appears to be safe and effective for particular settings, whether creatine supplementation leads to improved performance on the field of play remains unknown.

The influence of mixtures of Stylosanthes spp. accessions on the occurrence of anthracnose caused by Colletotrichum gloeosporioides

1994 ◽  
Vol 45 (1) ◽  
pp. 203 ◽  
Author(s):  
RD Davis ◽  
S Chakraborty ◽  
DF Cameron ◽  
JAG Irwin ◽  
RM Boland
Keyword(s):  
Colletotrichum Gloeosporioides ◽  
Resistant Cultivar ◽  
Pure Stand ◽  
Northern Australia ◽  
Short Term ◽  
Mixed Stands ◽  
The Mean ◽  
Moderately Resistant ◽  
Long Term Studies

The effectiveness of using accession mixtures of Stylosanthes spp. to manage anthracnose (Colletotrichum gloeosporioides) in pastures in northern Australia was examined during three consecutive years. Two mixtures containing six accessions were compared with the components grown as pure stands. No significant differences in anthracnose incidence (proportion of infected plants/plot) were indicated between the two mixtures and the mean incidence of their respective components grown in pure swards. Areas under the disease progress curves for the accessions were not significantly different between pure and mixed stands of the cultivars other than Seca and Verano. Resistant cultivar Seca developed more disease in a mixture than in a pure stand, and moderately resistant Verano had less disease in a mixture than in a pure stand. In the short term, no apparent anthracnose control advantage is achieved in highly susceptible accessions of Stylosanthes spp. when they are included in mixtures with less susceptible accessions. Long term studies involving grazing animals are necessary to adequately evaluate control of this disease through the use of mixtures.

Effectiveness of two tagging devices in the sea cucumber Holothuria (Halodeima) grisea

2017 ◽  
Vol 68 (3) ◽  
pp. 563
Author(s):  
Ruber Rodríguez-Barreras ◽  
Julián López-Morell ◽  
Alberto M. Sabat
Keyword(s):  
Sea Cucumber ◽  
Body Wall ◽  
The Body ◽  
Short Term ◽  
Pit Tag ◽  
Sea Cucumbers ◽  
Pit Tags ◽  
Significant Difference ◽  
Long Term Studies

A reliable and harmless mark–recapture method provides valuable information for the management of commercial sea cucumber species. Nevertheless, marking and tracking sea cucumbers is notoriously difficult and represents a serious challenge. In this study, we tested one external and one internal tag in the sea cucumber Holothuria grisea. A passive integrated transponder (PIT) tag was inserted into the coelomic cavity in one treatment, whereas a T-bar (external tag) was attached in the upper surface of the body wall in the other treatment; sea cucumbers were then followed for 17 weeks. The tagging procedure caused no evisceration in the experimental groups, nor was a significant difference in growth rate found between treatments. The retention of the PIT tag was low, with 100% lost by Week 9. Retention of T-bars was higher, with 90% still attached by the end of the Week 8, but retention decreased thereafter as T-bar absorption increased. No relationship was found between initial weight and the number of weeks PIT tags (r=–0.173, P=0.781) or T-bars (r=–0.220, P=0.652) were retained. Neither the T-bar nor the PIT tags fulfilled the requirements of high retention required for long-term studies. However, we do recommend the use of T-bars for short-term studies for H. grisea under laboratory conditions or in a habitat with low substrate complexity.

An analysis of climatic environments for plant-breeding purposes

1976 ◽  
Vol 27 (1) ◽  
pp. 19 ◽  
Author(s):  
WJR Boyd ◽  
NA Goodchild ◽  
WK Waterhouse ◽  
BB Singh
Keyword(s):  
Plant Breeding ◽  
Regional Distribution ◽  
Central Zone ◽  
Growing Season ◽  
Short Term ◽  
Yield Variation ◽  
Selection Strategies ◽  
Marginal Areas ◽  
Highly Correlated

Variations in the regional means of a number of growing-season climatic variables, and combinations of them, are not highly correlated with the long-term regional distribution of mean wheat yields in Western Australia or with their variation between years. The data suggest that the growing season is characterized by a cyclical alternation of favourable and unfavourable conditions for crop growth. This oscillating pattern varies in amplitude and wavelength as a result of unpredictable 'between'- and 'within'-season variation in the regional distribution of rainfall. In the central zone of the study area, wheat production is subject mainly to between-season variation whilst in more marginal areas yield variation is confounded by opposing and reciprocating within-season effects. The consequences for plant breeding are that specific regional environments expected on the basis of climate do not occur predictably in the short term. It is argued that breeding objectives, selection strategies and regional testing should initially avoid complications associated with specific marginal environments by concentrating on general adaptability within the central zone, which monitors between-season variation only. Subsequent evaluation for additional adaptive features specific to marginal areas should be undertaken.

Nitrogen immobilization in decomposing litter contributes to productivity decline in ageing pastures of green panic (Panicum maximum var. trichoglume)

1989 ◽  
Vol 113 (3) ◽  
pp. 401-406 ◽  
Author(s):  
G. B. Robbins ◽  
J. J. Bushell ◽  
G. M. McKeon
Keyword(s):  
C:N Ratio ◽  
Panicum Maximum ◽  
Short Term ◽  
Term Study ◽  
N Concentration ◽  
Short Term Study ◽  
N Release ◽  
Productivity Decline ◽  
Long Term Studies

SUMMARYThe extent and rate of N release from nylon bags containing green panic (Panicum maximumvar.trichoglume)litter was measured for up to 319 days (long-term studies) in 1978/79 and 1979/80 in Gayndah, Australia. Dry matter (DM) decomposition rates were measured in 41 periods of 39 days and related to environmental variables and initial litter N concentrations (short-term study).About half of litter DM decomposed during the long-term studies, while N concentration in the remaining litter increased from an initial average of 0–57 % N, to 0–95 % N. Net release of N from bags began when its concentration in the residue increased to c.0–65% N (or when the C:N ratio decreased to 75:1). Only a net 20–30 % of the initial N was released for potential plant uptake by the end of the study. The short-term study showed that DM decomposition was rapid and independent of pasture age. Decomposition rate increased with soil moisture and average daily temperature but was unaffected by initial litter N concentration. Release of N from decomposing litter was slow, despite rapid DM decomposition. It was concluded that a major cause of declining productivity in sown grass pastures is the immobilization of N in decomposing grass litter.

scholarly journals Air pollution, SARS-CoV-2 transmission, and COVID-19 outcomes: A state-of-the-science review of a rapidly evolving research area

2020 ◽  
Author(s):  
Anushka Bhaskar ◽  
Jay Chandra ◽  
Danielle Braun ◽  
Jacqueline Cellini ◽  
Francesca Dominici
Keyword(s):  
Air Pollution ◽  
Time Series ◽  
Health Outcomes ◽  
Study Design ◽  
Air Pollutant ◽  
Short Term ◽  
Cross Sectional ◽  
Short And Long Term ◽  
Long Term Studies

Background: As the coronavirus pandemic rages on, 692,000 (August 7, 2020) human lives and counting have been lost worldwide to COVID-19. Understanding the relationship between short- and long-term exposure to air pollution and adverse COVID-19 health outcomes is crucial for developing solutions to this global crisis. Objectives: To conduct a scoping review of epidemiologic research on the link between short- and long-term exposure to air pollution and COVID-19 health outcomes. Method: We searched PubMed, Web of Science, Embase, Cochrane, MedRxiv, and BioRxiv for preliminary epidemiological studies of the association between air pollution and COVID-19 health outcomes. 28 papers were finally selected after applying our inclusion/exclusion criteria; we categorized these studies as long-term studies, short-term time-series studies, or short-term cross-sectional studies. One study included both short-term time-series and a cross-sectional study design. Results: 27 studies of the 28 reported evidence of statistically significant positive associations between air pollutant exposure and adverse COVID-19 health outcomes; 11 of 12 long-term studies and all 16 short-term studies reported statistically significant positive associations. The 28 identified studies included various confounders, spatial and temporal resolutions of pollution concentrations, and COVID-19 health outcomes. Discussion: We discuss methodological challenges and highlight additional research areas based on our findings. Challenges include data quality issues, ecological study design limitations, improved adjustment for confounders, exposure errors related to spatial resolution, geographic variability in testing, mitigation measures and pandemic stage, clustering of health outcomes, and a lack of publicly available data and code.

The Use of the Sonicguide in Infancy

1982 ◽  
Vol 76 (3) ◽  
pp. 91-100 ◽  
Author(s):  
Stuart Aitken ◽  
T. G. R. Bower
Keyword(s):  
Age Differences ◽  
Intervention Programs ◽  
Short Term ◽  
Effective Use ◽  
Selection Of ◽  
Long Term Studies

This study investigates the use of an ultrasonic sonar device—the Sonicguide™—by blind infants. Both short-term studies, lasting up to three days, and long-term studies, lasting up to two years, are reported. The importance of the selection of strict criteria for evaluating “use” of the device is emphasized. Using such criteria, age differences in ability to make effective use of the information provided by the device were found. These findings have important implications for any future intervention programs with blind infants.

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