Complex training: The effect of exercise selection and training status on postactivation potentiation in rugby league players

This study compared the postactivation potentiation (PAP) response of the hex bar deadlift (HBD) and back squat (BS) exercises. The PAP response between different levels of athletes was also compared. Ten professional and 10 amateur rugby league players performed 2 experimental sessions. Participants performed a countermovement jump (CMJ) before and 2, 4, 6, 8, 10, 12, 14, and 16 minutes after a conditioning activity (CA) that contained 1 set of 3 repetitions at 93% 1 repetition maximum of either HBD or BS. A force platform determined peak power output (PPO), force at PPO, velocity at PPO, and jump height of each CMJ. Surface electromyography (EMG) of the vastus lasteralis, rectus femoris, tibialis anterior, and gastrocnemius medialis of each participant's dominant leg was recorded during each CMJ. A further 10 participants performed a control trial without a CA. The HBD expressed PAP between 2 and 6 minutes post-CA, whereas the BS did not. The HBD exhibited a significantly (p ≤ 0.05) greater PAP response than the BS for PPO. There were no significant (p > 0.05) differences between stronger and weaker players. There were no significant (p > 0.05) changes in the EMG variables. These results suggest that HBD is a suitable CA for eliciting PAP in stronger and weaker athletes. Strength and conditioning coaches should consider the CA and time frame between the CA and the plyometric exercise for optimal PAP responses

Personally addressed hand-signed letters increase questionnaire response: a meta-analysis of randomised controlled trials

BACKGROUND: Postal questionnaires are commonly used to collect data for health studies, but non-response reduces study sample sizes and can introduce bias. Finding ways to increase the proportion of questionnaires returned would improve research quality. We sought to quantify the effect on response when researchers address participants personally by name on letters that accompany questionnaires. METHODS: All randomised controlled trials in a published systematic review that evaluated the effect on response of including participants' names on letters that accompany questionnaires were included. Odds ratios for response were pooled in a random effects meta-analysis and evidence for changes in effects over time was assessed using random effects meta-regression. RESULTS: Fourteen randomised controlled trials were included covering a wide range of topics. Most topics were unrelated to health or social care. The odds of response when including participants' names on letters were increased by one-fifth (pooled OR 1.18, 95% CI 1.03 to 1.34; p = 0.015). When participants' names and hand-written signatures were used in combination, the effect was a more substantial increase in response (OR 1.45, 95% CI 1.27 to 1.66; p < 0.001), corresponding to an absolute increase in the proportion of questionnaires returned of between 4% and 10%, depending on the baseline response rate. There was no evidence that the magnitude of these effects had declined over time. CONCLUSION: This meta-analysis of the best available evidence indicates that researchers using postal questionnaires can increase response by addressing participants by name on cover letters. The effect appears to be enhanced by including hand-written signatures

Alley farming : new vision for Western Australian farmland

Alley farming is a system where crops and pastures are grown in the alleys between rows of trees and shrubs. The concept is new to Western Australia but one that is likely to become more familiar over the next few years. The objective is to use trees and shrubs to decrease the environmental side effects of agriculture, such as erosion and salinity while increasing farm profit through the direct and indirect value of the trees. This article describes some examples of alley farming in Western Australia and discusses the challenge of getting the right tree species and layout to maximise the benefits, while minimising competition with crops and pastures for water, nutrients and light

Planting trees to control salinity

Dense tree plantings covering at least 30 per cent of cleared land can lower groundwater levels by two metres or more in 10 years from the time of planting. This sizeable drop can be expected at sites receiving 700 to 800 mm of rain a year. Research by the Water Authority of Western Australia shows the most promising strategy when using trees is to put dense plantings on the discharge zone and on lower to midslopes. This strategy is successful where groundwaters contain less than 30,000 milligrams per litre total soluble salts (TSS). This article discusses research in the 450 to 800 mm rainfall zone by the Water Authority, the Department of Agriculture, the Department of Conservation and Land Management (CALM) and CSIRO

Does Campaigning on Social Media Make a Difference? Evidence from candidate use of Twitter during the 2015 and 2017 UK Elections

Social media are now a routine part of political campaigns all over the world. However, studies of the impact of campaigning on social platform have thus far been limited to cross-sectional datasets from one election period which are vulnerable to unobserved variable bias. Hence empirical evidence on the effectiveness of political social media activity is thin. We address this deficit by analysing a novel panel dataset of political Twitter activity in the 2015 and 2017 elections in the United Kingdom. We find that Twitter based campaigning does seem to help win votes, a finding which is consistent across a variety of different model specifications including a first difference regression. The impact of Twitter use is small in absolute terms, though comparable with that of campaign spending. Our data also support the idea that effects are mediated through other communication channels, hence challenging the relevance of engaging in an interactive fashion