Earthworm population dynamics as influenced by cropping and tillage history

No-tillage farming has become an important practice in many areas of the United States. Because of the loessal soils that exist in West Tennessee and their highly erodible nature, no-till farming is becoming the primary cropping technique with which to reduce erosion and conserve topsoil. Many aspects of no-till farming have been researched in past years; the effects of no-tillage on earthworm population have received little attention in Tennessee agriculture. Earthworms significantly influence the structure and fertility of soils and in turn effect root growth, infiltration of soil water, microbial populations, soil aggregation, and other properties. This research project was conducted to determine and compare the population dynamics of earthworms in cultivated production fields versus no-till production fields. Sites located at the University of Tennessee Milan Experiment Station were chosen for sampling. The sampling was done 4/94, 10/94, and 4/95. Samples for determining the effect of no-till were taken from three no-till and two tilled production fields and from an ongoing experiment containing both no-till and tilled plots. Samples were also taken from a long term no-till cover crop experiment to compare the effects of various covers. Six 30cm X 30cm X 15cm deep volumes of soil were taken from each production field and one sample per plot from the ongoing experiments. Soil samples were taken to determine bulk density, volumetric water content, total carbon, and pH. Surface residue samples were also taken at each no-till sample site. Earthworms were extracted by hand sorting and preserved in 10% formalin solution for identification. Three seperate species were identified: two native species; Diplocardia caroliniana and Bimastos longicinctus and one exotic; Apporectodea trapeszoides No-till cropping systems had a significant effect on earthworm populations for the 10/94 and 4/95 sampling periods and over the entire period due to the availability of food and limited soil disturbance. Length of time in no-till also had a significant effect on population for the 4/94 and 10/94 sampling periods and over the entire sampling period. Cover crop showed no significant difference for the 10/94 and 4/95 periods, but did for the 4/94 sample period. The results of the analysis performed had a high rate of variability overall

Global impact of the first coronavirus disease 2019 (COVID-19) pandemic wave on vascular services

This online structured survey has demonstrated the global impact of the COVID-19 pandemic on vascular services. The majority of centres have documented marked reductions in operating and services provided to vascular patients. In the months during recovery from the resource restrictions imposed during the pandemic peaks, there will be a significant vascular disease burden awaiting surgeons. One of the most affected specialtie

Documenting the Recovery of Vascular Services in European Centres Following the Initial COVID-19 Pandemic Peak: Results from a Multicentre Collaborative Study

Objective: To document the recovery of vascular services in Europe following the first COVID-19 pandemic peak. Methods: An online structured vascular service survey with repeated data entry between 23 March and 9 August 2020 was carried out. Unit level data were collected using repeated questionnaires addressing modifications to vascular services during the first peak (March - May 2020, "period 1"), and then again between May and June ("period 2") and June and July 2020 ("period 3"). The duration of each period was similar. From 2 June, as reductions in cases began to be reported, centres were first asked if they were in a region still affected by rising cases, or if they had passed the peak of the first wave. These centres were asked additional questions about adaptations made to their standard pathways to permit elective surgery to resume. Results: The impact of the pandemic continued to be felt well after countries' first peak was thought to have passed in 2020. Aneurysm screening had not returned to normal in 21.7% of centres. Carotid surgery was still offered on a case by case basis in 33.8% of centres, and only 52.9% of centres had returned to their normal aneurysm threshold for surgery. Half of centres (49.4%) believed their management of lower limb ischaemia continued to be negatively affected by the pandemic. Reduced operating theatre capacity continued in 45.5% of centres. Twenty per cent of responding centres documented a backlog of at least 20 aortic repairs. At least one negative swab and 14 days of isolation were the most common strategies used for permitting safe elective surgery to recommence. Conclusion: Centres reported a broad return of services approaching pre-pandemic "normal" by July 2020. Many introduced protocols to manage peri-operative COVID-19 risk. Backlogs in cases were reported for all major vascular surgeries