Forecasting carrot yield with optimal timing of Sentinel 2 image acquisition

Accurate, non-destructive forecasting of carrot yield is difcult due to its subterranean growing habit. Furthermore, the timing of forecasting usually occurs when the crop is mature, limiting the opportunity to implement alternative management decisions to improve yield (during the growing season). This study aims to improve the accuracy of carrot yield forecasting by exploring time series and multivariate approaches. Using Sentinel-2 satellite imagery in three Australian vegetable regions, we established a time series of carrot phenological stages (PhS) from 'days after sowing' (DAS) to enhance prediction timing. Numerous vegetation indices (VIs) were analyzed to derive temporal growth patterns. Correlations with yield at diferent PhS were established. Although the average root yield (t ha−1) did not signifcantly difer across the regions, the temporal VI signatures, indicating diferent regional crop growth trends, did vary as well as the PhS at when the maximum correlation with yield occurred (PhSR2max) with two of the regions producing a delayed PhSR2max (i.e. 90–130 DAS). The best multivariate model was identifed at 70 DAS, extending the forecasting window before harvest between 20 to 60 days. The performance of this model was validated with new crops producing an average error of 16.9 t ha−1 (27% of total yield). These results demonstrate the potential of the model at such early stage under varying growing conditions ofering growers and stakeholders the chance to optimize farming practices, make informed decisions on selling, harvesting, and labor planning, and adopt precision agriculture methods

Changes in Biology Self-Efficacy during a First-Year University Course

Academic self-efficacy encompasses judgments regarding one’s ability to perform academic tasks and is correlated with achievement and persistence. This study describes changes in biology self-efficacy during a first-year course. Students (n = 614) were given the Biology Self-Efficacy Scale at the beginning and end of the semester. The instrument consisted of 21 questions ranking confidence in performing biology-related tasks on a scale from 1 (not at all confident) to 5 (totally confident). The results demonstrated that students increased in self-efficacy during the semester. High school biology and chemistry contributed to self-efficacy at the beginning of the semester; however, this relationship was lost by the end of the semester, when experience within the course became a significant contributing factor. A proportion of high- and low- achieving (24 and 40%, respectively) students had inaccurate self-efficacy judgments of their ability to perform well in the course. In addition, female students were significantly less confident than males overall, and high-achieving female students were more likely than males to underestimate their academic ability. These results suggest that the Biology Self-Efficacy Scale may be a valuable resource for tracking changes in self-efficacy in first-year students and for identifying students with poorly calibrated self-efficacy perceptions

5-HT2A receptor signalling through phospholipase D1 associated with its C-terminal tail

The 5-HT2AR (5-hydroxytryptamine-2A receptor) is a GPCR (G-protein-coupled receptor) that is implicated in the actions of hallucinogens and represents a major target of atypical antipsychotic agents. In addition to its classical signalling though PLC (phospholipase C), the receptor can activate several other pathways, including ARF (ADP-ribosylation factor)-dependent activation of PLD (phospholipase D), which appears to be achieved through a mechanism independent of heterotrimeric G-proteins. In the present study we show that wild-type and inactive constructs of PLD1 (but not PLD2) respectively facilitate and inhibit ARF-dependent PLD signalling by the 5-HT2AR. Furthermore we demonstrate that PLD1 specifically co-immunoprecipitates with the receptor and binds to a distal site in GST (glutathione transferase) fusion protein constructs of its C-terminal tail which is distinct from the ARF-interaction site, thereby suggesting the existence of a functional ARF-PLD signalling complex directly associated with this receptor. This reveals the spatial co-ordination of an important GPCR, transducer and effector into a physical complex that is likely to reinforce the impact of receptor activation on a heterotrimeric G-protein-independent signalling pathway. Signalling of this receptor through such non-canonical pathways may be important to its role in particular disorders

Stream and slope weathering effects on organic-rich mudstone geochemistry and implications for hydrocarbon source rock assessment: a Bowland Shale case study

This study contributes to the exploration and quantification of the weathering of organic-rich mudstones under temperate climatic conditions. Bowland Shales, exposed by a stream and slope, were sampled in order to develop a model for the effects of weathering on the mudstone geochemistry, including major and trace element geochemistry, Rock-Eval pyrolysis and δ13Corg. Four weathering grades (I – IV) are defined using a visual classification scheme; visually fresh and unaltered (I), chemically altered (II, III) and ‘paper shale’ that typifies weathered mudstone on slopes (IV). Bedload abrasion in the stream exposes of visually fresh and geochemically unaltered mudstone. Natural fractures are conduits for oxidising meteoric waters that promote leaching at the millimetre scale and/or precipitation of iron oxide coatings along fracture surfaces. On the slope, bedding-parallel fractures formed (and may continue to form) in response to chemical and/or physical weathering processes. These fractures develop along planes of weakness, typically along laminae comprising detrital grains, and exhibit millimetre- and centimetre-scale leached layers and iron oxide coatings. Fracture surfaces are progressively exposed to physical weathering processes towards the outcrop surface, and results in disintegration of the altered material along fracture surfaces. Grade IV, ‘paper shale’ mudstone is chemically unaltered but represents a biased record driven by initial heterogeneity in the sedimentary fabric. Chemically weathered outcrop samples exhibit lower concentrations of both ‘free’ (S1) (up to 0.6 mgHC/g rock) and ‘bound’ (S2) (up to 3.2 mgHC/g rock) hydrocarbon, reduced total organic carbon content (up to 0.34 wt%), reduced hydrogen index (up to 58 mgHC/gTOC), increased oxygen index (up to 19 mgCO + CO2/gTOC) and increased Tmax (up to 11 °C) compared with unaltered samples. If analysis of chemically weathered samples is unavoidable, back-extrapolation of Rock-Eval parameters can assist in the estimation of pre-weathering organic compositions. Combining Cs/Cu with oxygen index is a proxy for identifying the weathering progression from fresh material (I) to ‘paper shale’ (IV). This study demonstrates that outcrop samples in temperate climates can provide information for assessing hydrocarbon potential of organic-rich mudstones

Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.

Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (n = 143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (n = 152), or no hydrocortisone (n = 108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (n = 137), shock-dependent (n = 146), and no (n = 101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Transformed statistical distributions with applications to financial data and modelling of financial systems

The ability to model extreme events is important across many applications, including extreme weather events, length of long hospital stays and large price changes in financial markets. This thesis uses statistical methods to describe the chance of extreme events occurring. Different methods for estimating the chance of extreme events are compared, and some new methodologies for describing the chance of these events are presented

Multi-modifier strategies to improve rumen health, growth and carcass attributes of grain-fed cattle - Dataset

Dataset relating to multi-modifier strategies to improve rumen health, growth and carcass attributes of grain-fed cattle

Changes in biology self-efficacy during a first-year university course

Academic self-efficacy encompasses judgments regarding one's ability to perform academic tasks and is correlated with achievement and persistence. This study describes changes in biology self-efficacy during a first-year course. Students (n = 614) were given the Biology Self-Efficacy Scale at the beginning and end of the semester. The instrument consisted of 21 questions ranking confidence in performing biology-related tasks on a scale from 1 (not at all confident) to 5 (totally confident). The results demonstrated that students increased in self-efficacy during the semester. High school biology and chemistry contributed to self-efficacy at the beginning of the semester; however, this relationship was lost by the end of the semester, when experience within the course became a significant contributing factor. A proportion of high-and low-achieving (24 and 40%, respectively) students had inaccurate self-efficacy judgments of their ability to perform well in the course. In addition, female students were significantly less confident than males overall, and high-achieving female students were more likely than males to underestimate their academic ability. These results suggest that the Biology Self-Efficacy Scale may be a valuable resource for tracking changes in self-efficacy in first-year students and for identifying students with poorly calibrated self-efficacy perceptions