27 research outputs found
The forward testing effect on self-regulated study time allocation and metamemory monitoring.
Spaced Retrieval Practice: Can Restudying Trump Retrieval?
We investigated spaced retrieval and restudying in 3 preregistered, online experiments. In all experiments, participants studied 40 SwahiliâEnglish word pair translations during an initial study phase, restudied intact pairs or attempted to retrieve the English words to Swahili cues twice in three spaced practice sessions, and then completed a final cued-recall test. All 5 sessions were separated by 2 days. In Experiment 1, we manipulated the response format during retrieval (covert vs. overt) and the test list structure (blocked vs. intermixed covert/overt retrieval trials). A memory rating was required on all trials (retrieval: âWas your answer correct?â; restudy: âWould you have remembered the correct translation?â). Response format had no effect on recall, but surprisingly, final test performance for restudied items exceeded both the overt and covert retrieval conditions. In Experiment 2, we manipulated the requirement to make a memory rating. If a memory rating was required, final test restudy performance exceeded retrieval performance, replicating Experiment 1. However, the pattern was descriptively reversed if no rating was required. In Experiment 3, the memory rating was removed altogether, and we examined recall performance for items restudied versus retrieved once, twice, or thrice. Performance improved with practice, and retrieval performance exceeded restudy performance in all conditions. The reversal of the typical retrieval practice effect observed in Experiments 1 and 2 is discussed in terms of theories of reactivity of memory judgments
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Insect pollination as an agronomic input: strategies for oilseed rape production
1.Ecological intensification involves the incorporation of biodiversity based ecosystem service management into farming systems in order to make crop production more sustainable and reduce reliance on anthropogenic inputs, including fertiliser and insecticides.
2.The benefits of effectively managing ecosystem services such as pollination and pest regulation for improved yields have been demonstrated in a number of studies, however recent evidence indicates that these benefits interact with conventional agronomic inputs such as fertiliser and irrigation. Despite the important contribution of biodiversityâbased ecosystem services to crop production their management is rarely considered in combination with more conventional agronomic inputs.
3.This study combines a number of complementary approaches to evaluate the impact of insect pollination on yield parameters of Brassica napus and how this interacts with a key agronomic input, fertiliser. We incorporate data from a flight cage trial and multiple field studies to quantify the relationships between yield parameters to determine whether insufficient insect pollination may limit crop yield.
4.We demonstrate that, by producing larger seeds and more pods, B. napus has the capacity to modulate investment across yield parameters and buffer subâoptimal inputs of fertiliser or pollination. However, only when fertiliser is not limiting can the crop benefit from insect pollination, with yield increases due to insect pollination only seen under high fertiliser application.
5.A nonâlinear relationship between seed set per pod and yield per plant was found, with increases in seed set between 15 and 25 seeds per pod resulting in a consistent increase in crop yield. The capacity for the crop to compensate for lower seed set due to subâoptimal pollination is therefore limited.
6.Synthesis and applications. Oilseed rape has the capacity to compensate for subâoptimal agronomic or ecosystem service inputs although this has limitations. Insect pollination can increase seed set and so there are production benefits to be gained through effective management of wild pollinators or by utilising managed species. Our study demonstrates however that increased insect pollination cannot simply replace other inputs, and if resources such as fertiliser are limiting, then yield potential cannot be reached. We highlight the need to consider insect pollination as an agronomic input to be effectively managed in agricultural systems
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Rapid assessment of insect pollination services to inform decision-making.
Pollinator declines have prompted efforts to assess how land-use change affects insect pollinators and pollination services in agricultural landscapes. Yet many tools to measure insect pollination services require substantial landscape-scale data and technical expertise. In expert workshops, 3 straightforward methods (desk-based method, field survey, and empirical manipulation with exclusion experiments) for rapid insect pollination assessment at site scale were developed to provide an adaptable framework that is accessible to nonspecialist with limited resources. These methods were designed for TESSA (Toolkit for Ecosystem Service Site-Based Assessment) and allow comparative assessment of pollination services at a site of conservation interest and in its most plausible alternative state (e.g., converted to agricultural land). We applied the methods at a nature reserve in the United Kingdom to estimate the value of insect pollination services provided by the reserve. The economic value of pollination services provided by the reserve ranged from US11,546/year. The conversion of the reserve to arable land would provide no insect pollination services and a net annual benefit from insect-pollinated crop production of approximately 24âha-1 âyear-1 ). The methods had wide applicability and were readily adapted to different insect-pollinated crops: rape (Brassica napus) and beans (Vicia faba) crops. All methods were rapidly employed under a low budget. The relatively less robust methods that required fewer resources yielded higher estimates of annual insect pollination benefit
Developing Global Maps of the Dominant Anopheles Vectors of Human Malaria
Simon Hay and colleagues describe how the Malaria Atlas Project has collated anopheline occurrence data to map the geographic distributions of the dominant mosquito vectors of human malaria
CropPol: a dynamic, open and global database on crop pollination
Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved
Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial
SummaryBackground Azithromycin has been proposed as a treatment for COVID-19 on the basis of its immunomodulatoryactions. We aimed to evaluate the safety and efficacy of azithromycin in patients admitted to hospital with COVID-19.Methods In this randomised, controlled, open-label, adaptive platform trial (Randomised Evaluation of COVID-19Therapy [RECOVERY]), several possible treatments were compared with usual care in patients admitted to hospitalwith COVID-19 in the UK. The trial is underway at 176 hospitals in the UK. Eligible and consenting patients wererandomly allocated to either usual standard of care alone or usual standard of care plus azithromycin 500 mg once perday by mouth or intravenously for 10 days or until discharge (or allocation to one of the other RECOVERY treatmentgroups). Patients were assigned via web-based simple (unstratified) randomisation with allocation concealment andwere twice as likely to be randomly assigned to usual care than to any of the active treatment groups. Participants andlocal study staff were not masked to the allocated treatment, but all others involved in the trial were masked to theoutcome data during the trial. The primary outcome was 28-day all-cause mortality, assessed in the intention-to-treatpopulation. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.Findings Between April 7 and Nov 27, 2020, of 16 442 patients enrolled in the RECOVERY trial, 9433 (57%) wereeligible and 7763 were included in the assessment of azithromycin. The mean age of these study participants was65·3 years (SD 15·7) and approximately a third were women (2944 [38%] of 7763). 2582 patients were randomlyallocated to receive azithromycin and 5181 patients were randomly allocated to usual care alone. Overall,561 (22%) patients allocated to azithromycin and 1162 (22%) patients allocated to usual care died within 28 days(rate ratio 0·97, 95% CI 0·87â1·07; p=0·50). No significant difference was seen in duration of hospital stay (median10 days [IQR 5 to >28] vs 11 days [5 to >28]) or the proportion of patients discharged from hospital alive within 28 days(rate ratio 1·04, 95% CI 0·98â1·10; p=0·19). Among those not on invasive mechanical ventilation at baseline, nosignificant difference was seen in the proportion meeting the composite endpoint of invasive mechanical ventilationor death (risk ratio 0·95, 95% CI 0·87â1·03; p=0·24).Interpretation In patients admitted to hospital with COVID-19, azithromycin did not improve survival or otherprespecified clinical outcomes. Azithromycin use in patients admitted to hospital with COVID-19 should be restrictedto patients in whom there is a clear antimicrobial indication
Enhancing learning and retrieval of new information: a review of the forward testing effect
Abstract In recent years evidence has accumulated showing that interim testing of studied information facilitates learning and retrieval of new informationâthe forward testing effect. In the current article, we review the empirical evidence and putative mechanisms underlying this effect. The possible negative effects of administering interim tests and how these negative effects can be mitigated are discussed. We also propose some important directions for future research to explore. Finally, we summarize the practical implications for optimizing learning and teaching in educational settings
A comparison of covert and overt retrieval practice over multiple spaced sessions
Retrieval practice can be covert or overt, with only the latter requiring spoken or written responses, and both enhance long-term retention in single study-test designs. However, the benefits of covert retrieval over multiple testing cycles, like those seen in successive relearning, have not been investigated. Participant cooperation with covert retrieval requests may lessen on later cycles, particularly if learners are metacognitively unaware of the benefits of repeated retrieval. In this preregistered study, we investigate whether covert retrieval can be encouraged on all testing cycles by inducing uncertainty about the need to produce a response by varying the proportion of overt trials and whether covert retrieval trials were blocked or interleaved during retrieval practice. We also consider participantsâ assessment of the accuracy of their own retrieval attempts and changes over the learning schedule in important individual differences measures of anxiety, mastery, intrinsic motivation, and attentional control. The data shed light on not only the best method of encouraging active retrieval, but also the affective and metacognitive changes that occur over a multi-session spaced retrieval practice schedule