Heat shock proteins (HSPs) are a family of genes classically used to measure levels of organism stress. We have previously identified two HSP70 genes (HSP70A and HSP70B) in sub-tidal populations of the Antarctic limpet (Nacella concinna). These genes are up-regulated in response to increased seawater temperatures of 15°C or more during acute heat shock experiments, temperatures that have very little basis when considering the current Antarctic ecology of these animals. Therefore, the question was posed as to whether these animals could express HSP70 genes when subjected to more complex environmental conditions, such as those that occur in the inter-tidal. Inter-tidal limpets were collected on three occasions in different weather conditions at South Cove, Rothera Point, over a complete tidal cycle, and the expression levels of the HSP70 genes were measured. Both genes showed relative up-regulation of gene expression over the period of the tidal cycle. The average foot temperature of these animals was 3.3°C, far below that of the acute heat shock experiments. These experiments demonstrate that the temperature and expression levels of HSP production in wild animals cannot be accurately extrapolated from experimentally induced treatments, especially when considering the complexity of stressors in the natural environment. However, experimental manipulation can provide molecular markers for identifying stress in Antarctic molluscs, provided it is accompanied by environmental validation, as demonstrated here.
We introduce a methodology to visualise rapid vertical and zonal tropical transport pathways. Using prescribed sea-surface temperatures in four monthly model integrations for 2005, we characterise preferred transport routes from the troposphere to the stratosphere in a high resolution climate model. Most efficient transport is modelled over the Maritime Continent (MC) in November and February, i.e., boreal winter. In these months, the ascending branch of the Walker Circulation over the MC is formed in conjunction with strong deep convection, allowing fast transport into the stratosphere. In the model the upper tropospheric zonal winds associated with the Walker Circulation are also greatest in these months in agreement with ERA-Interim reanalysis data. We conclude that the Walker circulation plays an important role in the seasonality of fast tropical transport from the lower and middle troposphere to the upper troposphere and so impacts at the same time the potential supply of surface emissions to the tropical tropopause layer (TTL) and subsequently to the stratosphere.
Written by FacebookTwitterLinkedInEmailEricVega/iStockBy CARMEN COX, ABC News(NEW YORK) — The NFL and the NFL Players Association have reached an agreement on team salary caps. On Wednesday, the league and its players’ union agreed to cap each team’s salary at $182.5 million in 2021 — down 8% from last season, according to a memo obtained by ESPN.In previous years, teams saw increasing salary caps as league revenues continued to rise. But as the COVID-19 pandemic forced city and statewide lockdowns, game attendance fell by 92% and caused a decline in 2020 revenues.Teams must comply with the new salary cap limits by next Wednesday at 4 p.m. ET — the start of the new league year. The decreased limits will likely mean teams will have to make difficult roster decisions and release a significantly high number of players into the free agent market to bring team salaries below the league’s required cap.As COVID restrictions relax and the NFL works to lock in new broadcasting deals, pro football attendance and revenues are expected to rebound in the 2021 season.Copyright © 2021, ABC Audio. All rights reserved. March 10, 2021 /Sports News – National NFL and players’ union agree to reduced team salary limits Beau Lund