Level 1A Research Articles

SP2.10 Meta-analysis of adjuvant chemotherapy versus no adjuvant chemotherapy for resected stage I pancreatic cancer

Abstract Aims To evaluate comparative outcomes of pancreatic cancer resection with or without adjuvant chemotherapy in patients with stage I pancreatic cancer. Methods A systematic search of MEDLINE, CENTRAL and Web of Science and bibliographic reference lists were conducted. All comparative studies reporting outcomes of pancreatic cancer resection for stage I cancer with or without adjuvant chemotherapy were included and their risk of bias were assessed using ROBINS-I tool. Survival outcomes were analysed using hazard ratio (HR) and odds ratio (OR) for the time-to-event and dichotomous outcomes, respectively. Results We included 5 comparative studies reporting a total of 4,037 patients with resected stage 1 pancreatic cancer of whom 2,374 patients had no adjuvant chemotherapy and the remaining 1663 patients received adjuvant chemotherapy. The use of adjuvant chemotherapy was associated with significantly higher overall survival rate (HR 0.73, 95% CI 0.63-0.84, p<0.00001) compared to no use of adjuvant chemotherapy. However, there was no statistically significant difference in 1-year (81.9% versus 87.4%, OR 0.51, 95% CI 0.14-1.81, p=0.30), 2-year (60.9% versus 67.5%, OR 0.88, 95% CI 0.75-1.03, p=0.10), 3-year (51.8% versus 54.3%, OR 0.99, 95% CI 0.79-1.24, p=0.93), or 5-year survival (27.4% versus 27.5%, OR 1.11, 95% CI 0.95-1.30, p=0.19) between two groups. Conclusions Meta-analysis of best available evidence (level 2a) demonstrates that adjuvant chemotherapy following resected stage I pancreatic cancer seems to improve overall survival compared to no use of adjuvant chemotherapy. Randomised controlled trials are required to escalate the level of evidence and confirm these findings.

Evaluation of Parametric Roll Mode Applying the IMO Second Generation Intact Stability Criteria for 13K Chemical Tanker

In this paper, the evaluation procedure for Level 1, Level 2A, and Level 2B for the parametric roll among the five modes of the IMO second generation stability criteria was explained in detail. Parametric roll mode evaluation was performed using the design data of a medium-sized 13K chemical tanker instead of a well-known container ship. As a result of the Level 1 evaluation, δGM1/GM was smaller than the standard value, thus satisfying the first criterion, but the second criterion value was smaller than 1, so it was found that the Level 1 criterion was not satisfied. Subsequently, in the Level 2A evaluation, the weighted sum value was larger than the standard value under the ship speed and given wave conditions, so it was also not satisfied. In particular, the process of numerical analysis in the time domain was described through the equation of motion when estimating the maximum roll angle of a ship in the Level 2B evaluation, which was not detailed in previous studies. The calculation result was larger than the standard value, so it was not satisfied, and consequently, the 13K chemical tanker did not satisfy Level 1, Level 2A, and 2B.

Estimation of Attenuation Coefficient Values Using Remote Sensing and Its Relationship With Shallow Water Depth

In ocean remote sensing, the intensity of light entering the water column decreases exponentially with increasing depth due to scattering and particle absorption in the water column. This process of decreasing light intensity is called attenuation. Attenuation is a limiting factor in detecting objects in the water column and seafloor using remote sensing, which relies on light intensity. The attenuation coefficient (Kd) is an important optical property of seawater as it provides information about water clarity and the level of light attenuation. This study aims to analyze the estimation of the attenuation coefficient values and their variability using in-situ measurements and Sentinel-2 level 2A data in Karang Lebar, Pulau Panggang, and Pulau Air, in the Seribu Islands Regency, North Jakarta. We tested several algorithms to estimate the attenuation coefficient values. The research results show that the in-situ Kd and the estimated model values have a good correlation (r = 0.75-0.86). The distribution of attenuation coefficient values in the shallow waters of the study area ranges from 0.06 to 0.18m-1. The accuracy of estimating shallow water depth at the study sites was best represented by R2 and RMSE values in the range of 0-5m with an attenuation coefficient of 0.06-0.11m-1.
 
 Keywords: Diffuse Attenuation Coefficient, Remote Sensing, Sentinel-2 Imagery, Algorithm.

Models of pre-registration student supervision in allied health: a scoping review

Introduction: The aim of this scoping review was to identify, organise and synthesise existing evidence in relation to the supervision of allied health students on clinical placement.Methods: Five databases were searched for peer reviewed articles published from 2000 onwards. Data were extracted and analysed according to approaches to supervision, and student and/or educator outcomes for different models used. Each outcome was aligned to modified Kirkpatrick levels of evaluation.Results: 39 articles were reviewed. The terms models and approaches were poorly defined and used interchangeably in the clinical placement literature. Studies varied in the methods employed and were typically of low to moderate methodological quality with a dominance of Kirkpatrick level 2a outcomes reported.Conclusions: This review has proposed a definition of supervision models to enable future research comparisons between models and to provide clarity to placement providers’ decision making. Overall evidence for reported outcomes is mixed and not strong enough to draw conclusions in favour of any one model. Approaches to supervision, not student ratio, may well be the catalyst for positive outcomes for all stakeholders and therefore should be the focus of future research.

Equal remission rates and reduced length of hospital stay with twice-daily repetitive transcranial magnetic stimulation (rTMS) for major depression – A large naturalistic retrospective cohort association study

ObjectivesRepetitive transcranial magnetic stimulation (rTMS) is a level 1a evidence-based treatment for major depression, but high cost of care and limited effectiveness in naturalistic cohorts have been lingering criticisms. This naturalistic, retrospective cohort analysis compares the effect of once and twice daily treatment protocols of rTMS using quality assurance data collected at an Australian private psychiatric hospital. MethodsA total of 210 inpatients self-selected into two groups receiving up to 30 sessions of either daily (n = 101) or twice daily (n = 109) 10 Hz rTMS to the left dorsolateral prefrontal cortex (DLPFC). The a priori primary outcome measure was remission rate as measured by pre and post treatment HAMD-17 scores. Length of hospital stay was a secondary post hoc outcome adopted due to the importance to cost of acute psychiatric care. ResultsRemission rates were similar across groups, with 44.9% and 45.4% for twice daily and daily rTMS groups respectively, although these may be confounded by patient expectations, other treatments and medication changes given the naturalistic setting. The length of hospital stay was 10.11 days and 18.44 days for twice daily and daily rTMS respectively – the twice daily rTMS length of hospital stay was 45.1% shorter 95% CI [38.7% - 51.56%]. Dropout rates were high; Twenty-seven (24.77%) twice daily participants dropped out before 20 sessions were completed, and 35 (34.65%) of daily participants. ConclusionsTwice daily 10 Hz left sided rTMS remission outcomes were similar to traditional once daily rTMS but required a shorter length of hospital stay. This finding has substantial cost of care implications. If these findings are independently replicated, twice daily rTMS may become the standard of care for inpatient rTMS.

Identification of adverse drug reactions that may be related to pharmacogenetics in a public hospital in the South of Brazil

ABSTRACT Background Adverse drug reactions (ADRs) are of great concern in clinical practice. Pharmacogenetics can identify individuals and groups at increased risk of developing ADRs, enabling treatment adjustments to improve outcomes. The study aimed to determine the prevalence of ADRs related to drugs with pharmacogenetic evidence level 1A in a public hospital in Southern Brazil. Research design and methods ADR information was collected from the pharmaceutical registries from 2017 to 2019. Drugs that have pharmacogenetic evidence level 1A were selected. Public genomic databases were used to estimate the genotypes/phenotypes frequency. Results During the period, 585 ADRs were spontaneously notified. Most were moderate (76.3%), whereas severe reactions accounted for 33.8%. Additionally, 109 ADRs caused by 41 drugs presented pharmacogenetic evidence level 1A, representing 18.6% of all notified reactions. Depending on the drug-gene pair, up to 35% of individuals from Southern Brazil could be at risk of developing ADRs. Conclusions Relevant amount of ADRs were related to drugs with pharmacogenetic recommendations on drug labels and/or guidelines. Genetic information could guide and improve clinical outcomes, decreasing ADR incidence and reducing treatment costs.

Levelling the learning ground for healthcare professionals across the world through SIMBA: a mixed-methods study

ObjectivesTo compare the acceptance, strengths and limitations of Simulation via Instant Messaging-Birmingham Advance (SIMBA) in low/middle-income countries (LMICs) and high-income countries (HICs), on healthcare professionals’ professional development and learning.DesignCross-sectional study.SettingOnline...

Indications for omega-3 fatty acid supplementation in prevention of cardiovascular disease: From fish to pharmaceuticals.

To explore the evidence for omega-3 fatty acid (O3FA) supplementation in primary and secondary prevention of cardiovascular disease (CVD). PubMed, Cochrane reviews, and Google Scholar were searched for meta-analyses and reviews related to O3FAs and CVD. Salient, recent randomized controlled trials referenced in these reviews were retrieved. Current lipid guidelines were reviewed. Most O3FAs are derived from marine or aquatic microalgae, which are consumed by fish. The essential fatty acids eicosapentaenoic acid and docosahexaenoic acid are mainly sourced from fish, with a small fraction coming from plants. Omega-3 fatty acids modestly lower triglyceride levels, but the major impact on CVD is through a variety of other mechanisms related to cell membrane function, antioxidant properties, and reduction of atherogenic small low-density lipoprotein cholesterol particles. Guidelines continue to recommend eating 2 servings of fish per week. There is little evidence of benefit of O3FAs in primary prevention of CVD. Given that 40% of Canadians have insufficient levels and that these low levels may be associated with other chronic diseases over time, supplementation with O3FAs could be considered, particularly in those with hypertriglyceridemia, in those who eat no fish, or for vegetarians or vegans. Doses up to 1 g daily are considered safe. For secondary prevention after statin optimization, if triglyceride levels are between 1.5 and 5.6 mmol/L, guidelines recommend with level 1A evidence taking 2 g of icosapent ethyl twice a day. This is also recommended in primary prevention for patients with diabetes and hypertriglyceridemia and additional CVD risk factors. As fish stocks dwindle over time, preserving fisheries for developing countries and obtaining O3FA from microalgal or genetically modified plant sources may become important. All guidelines recommend at least 2 servings of oily fish per week, although benefit from O3FAs is mostly seen in secondary prevention. Fish oil and combination preparations of eicosapentaenoic acid and docosahexaenoic acid have failed to show benefit at any dose at any level of prevention in patients who are appropriately prescribed statins. High-dose eicosapentaenoic acid shows substantial benefit in selected patients taking statins who have high triglyceride levels.

Losing weight to achieve joint or hernia surgery: is the intragastric balloon the answer?

Obesity is an epidemic, with its accompanying medical conditions putting patients at increased risk of postoperative complications. For patients undergoing elective surgery, preoperative weight loss provides an opportunity to decrease complications. We sought to evaluate the safety and efficacy of an intragastric balloon in achieving a body mass index (BMI) < 35kg/m2 prior to elective joint replacement or hernia repair. Retrospective review of all patients who had intragastric balloon placement at a level 1A VA medical center from 1/2019 to 1/2023. Patients who had a scheduled qualifying procedure (knee/hip replacement or hernia repair) and had a BMI > 35kg/m2 were offered intragastric balloon placement to achieve 30-50lbs (13-28kg) weight loss prior to surgery. Participation in a standardized weight loss program for 12months was required. Balloons were removed 6months after placement, preferentially concomitant with the qualifying procedure. Baseline demographics, duration of balloon therapy, weight loss and progression to qualifying procedure were recorded. Twenty patients completed intragastric balloon therapy and had balloon removal. Mean age 54 (34-71years), majority (95%) male. Mean balloon duration was 200 ± 37days. Mean weight loss was 30.8 ± 17.7lbs (14.0 ± 8.0kg) with an average BMI reduction of 4.4 ± 2.9. Seventeen (85%) patients were successful, 15 (75%) underwent elective surgery and 2 (10%) were no longer symptomatic after weight loss. Three patients (15%) did not lose sufficient weight to qualify or were too ill to undergo surgery. Nausea was the most frequent side effect. One (5%) patient was readmitted within 30days for pneumonia. Intragastric balloon placement resulted in an average 30lbs (14kg) weight loss over 6months allowing more than 75% of patients to undergo joint replacement or hernia repair at an optimal weight. Intragastric balloons should be considered in patients requiring 30-50lbs (13-28kg) weight loss prior to elective surgery. More study is needed to determine the long-term benefit of preoperative weight loss prior to elective surgery.

First evaluation of fire severity retrieval from PRISMA hyperspectral data

The unprecedented availability of spaceborne hyperspectral data has great potential to provide fire severity estimates that align with post-fire management needs, overcoming complex logistics and data acquisition costs of airborne hyperspectral sensors, and the suboptimal sensitivity of broadband data to several post-fire ground components. We analyzed the feasibility of the PRISMA mission -one of the first spaceborne spectrometers operationally active- to assess fire severity by leveraging hyperspectral data dimensionality through the retrieval of sub-pixel components directly related to fire severity in the field. Multispectral data provided by Sentinel-2, commonly used in fire severity quantitative assessments, were used as a benchmark method. Multiple endmember spectral mixture analysis (MESMA) was used to retrieve fractional cover of char, photosynthetic vegetation (PV), as well as non-photosynthetic vegetation and soil (NPVS) from post-fire PRISMA Level 2D and Sentinel-2 Level 2A scenes in one of the largest wildfires ever recorded in the western Mediterranean Basin. Ground-truth data were obtained using the Composite Burn Index (CBI) to procure three field-measured severity metrics: vegetation, soil and site. The relationship between the CBI data on a continuum scale and the cover of char, PV and NPVS image fractions retrieved from PRISMA and Sentinel-2 was assessed through Random Forest regression (RFR). Likewise, Ordinal Forests (OF) algorithm was used to classify categorized CBI data (low, moderate and high fire severity). PRISMA-based RFR fire severity estimates at vegetation, soil and site levels (R2 = 0.64–0.79 and RMSE = 0.33–0.41) outperformed those of Sentinel-2 (R2 = 0.27–0.53 and RMSE = 0.54–0.60), and were in line with previous studies using airborne hyperspectral sensors at higher spatial resolution. Fire severity underestimation for high field CBI values was almost unnoticeable in the PRISMA estimates. Categorical fire severity, not currently estimated using hyperspectral data but with high interest in post-fire management, were accurately predicted by PRISMA-based OF classification, with consistent user's and producer's accuracy for each fire severity category. The high confusion between moderate and low/high fire severity categories, typical when unmixing broadband multispectral data, was overcome by the PRISMA-based classification scheme. Our results suggest that new spaceborne spectrometer missions can support reliable fire severity assessments equivalent to airborne spectrometers, but readily applicable to large-scale assessments of extreme wildfire events.

Does Headgear Prevent Sport-Related Concussion? A Systematic Review and Meta-Analysis of Randomized Controlled Trials Including 6311 Players and 173,383 Exposure Hours.

A sport-related concussion (SRC) is a traumatic brain injury that is caused by biomechanical stresses and results in a complex pathophysiological process in the brain. Some in the sporting community believe that headgear (HG) can prevent SRC, and several professional Australian sports organizations, including rugby, football, and soccer clubs, recommend its use. The purpose of this study is to determine whether HG is effective in lowering the prevalence of SRC in sports. A systematic search for related studies published between 1985 and 2023 was conducted using the following databases: Cochrane Library, AMED, PubMed, Web of Science, and Physiotherapy Evidence Database (PEDro). Only randomized controlled trials (RCTs) that investigated the effectiveness of HG in reducing SRC rate were included. Systematic review and meta-analysis of RCTs. Level 1a. Two researchers independently completed the title and abstract search and performed full-text reviews. A third reviewer was consulted to reach a consensus if any discrepancies were noted. The PEDro scale was used to evaluate the quality of the included RCTs. Data recorded from each study included authors, year of publication, type and number of players, study design, duration of the study, injury rate, compliance (%), sports/level, and exposure hours. The pooled results of 6311 players and 173,383 exposure hours showed 0% SRC reduction per 1000 hours of exposure in the experimental group compared with the control group, with an injury risk ratio of 1.03 (95% CI, 0.82-1.30; P = 0.79). This systematic review and meta-analysis demonstrates that HG does not prevent SRC among soccer and rugby players, and therefore the findings from this meta-analysis do not currently support the use of HG to prevent SRC in soccer or rugby.

A systematic review of intellectual and developmental disability curriculum in international pre-graduate health professional education

BackgroundDespite the increasing global population of individuals with intellectual and developmental disabilities (IDD), this population remains especially vulnerable to health disparities through several factors such as a lack of access to sufficient medical care and poor determinants of health. To add, numerous studies have shown that healthcare professionals are still insufficiently prepared to support this population of patients. This review synthesizes the literature on current pre-graduate IDD training programs across healthcare professions with the goal of informing the creation of evidence-based curricula.MethodsFour major databases were searched for current pre-graduate IDD training interventions for healthcare professionals. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis flow diagram and the Best Evidence Medical Educations systematic review guide were used to frame our collection and analysis.ResultsOf the 8601 studies screened, 32 studies were identified, with most studies involving medical students (50%). Of note, 35% of studies were interprofessional. Most interventions utilized multiple pedagogical methods with a majority including clinical experiences (63%) followed by theoretical teaching (59%). Kirkpatrick levels showed 9% were level 0, 6% were level 1, 31% were level 2A, 31% were level 2B, 19% were level 3, 3% were level 4A, and none were level 4B.ConclusionsThere is a paucity of formally evaluated studies in pre-graduate health professional IDD education. As well, there are a lack of longitudinal learning opportunities and integration into formal curriculum. Strengths identified were the use of multimodal approaches to teaching, including interprofessional approaches to optimize team competencies.

Characterization of pharmacogenomic variants in a Brazilian admixed cohort of elderly individuals based on whole-genome sequencing data.

Introduction: Research in the field of pharmacogenomics (PGx) aims to identify genetic variants that modulate response to drugs, through alterations in their pharmacokinetics (PK) or pharmacodynamics (PD). The distribution of PGx variants differs considerably among populations, and whole-genome sequencing (WGS) plays a major role as a comprehensive approach to detect both common and rare variants. This study evaluated the frequency of PGx markers in the context of the Brazilian population, using data from a population-based admixed cohort from Sao Paulo, Brazil, which includes variants from WGS of 1,171 unrelated, elderly individuals. Methods: The Stargazer tool was used to call star alleles and structural variants (SVs) from 38 pharmacogenes. Clinically relevant variants were investigated, and the predicted drug response phenotype was analyzed in combination with the medication record to assess individuals potentially at high-risk of gene-drug interaction. Results: In total, 352 unique star alleles or haplotypes were observed, of which 255 and 199 had a frequency < 0.05 and < 0.01, respectively. For star alleles with frequency > 5% (n = 97), decreased, loss-of-function and unknown function accounted for 13.4%, 8.2% and 27.8% of alleles or haplotypes, respectively. Structural variants (SVs) were identified in 35 genes for at least one individual, and occurred with frequencies >5% for CYP2D6, CYP2A6, GSTM1, and UGT2B17. Overall 98.0% of the individuals carried at least one high risk genotype-predicted phenotype in pharmacogenes with PharmGKB level of evidence 1A for drug interaction. The Electronic Health Record (EHR) Priority Result Notation and the cohort medication registry were combined to assess high-risk gene-drug interactions. In general, 42.0% of the cohort used at least one PharmGKB evidence level 1A drug, and 18.9% of individuals who used PharmGKB evidence level 1A drugs had a genotype-predicted phenotype of high-risk gene-drug interaction. Conclusion: This study described the applicability of next-generation sequencing (NGS) techniques for translating PGx variants into clinically relevant phenotypes on a large scale in the Brazilian population and explores the feasibility of systematic adoption of PGx testing in Brazil.

Quilting Suture Technique After Mastectomy: A Meta-Analysis.

There is no level 1a evidence testing quilting suture (QS) technique after mastectomy on wound outcomes. The aim of this systematic review and meta-analysis evaluates QS and association with surgical site occurrences as compared to conventional closure (CC) for mastectomy. MEDLINE, PubMed, and Cochrane Library were systematically searched to include adult women with breast cancer undergoing mastectomy. The primary endpoint was postoperative seroma rate. Secondary endpoints included rates of hematoma, surgical site infection (SSI), and flap necrosis. The Mantel-Haenszel method with random-effects model was used for meta-analysis. Number needed to treat was calculated to assess clinical relevance of statistical findings. Thirteen studies totaling 1748 patients (870 QS and 878 CC) were included. Seroma rates were statistically significantly lower in patients with QS (OR [95%CI] = .32 [.18, .57]; P < .0001) than CC. Hematoma rates (OR [95%CI] = 1.07 [.52, 2.20]; P = .85), SSI rates (OR [95%CI] = .93 [.61, 1.41]; P = .73), and flap necrosis rates (OR [95%CI] = .61 [.30, 1.23]; P = .17) did not significantly vary between QS and CC. This meta-analysis found that QS was associated with significantly decreased seroma rates when compared to CC in patients undergoing mastectomy for cancer. However, improvement in seroma rates did not translate into a difference in hematoma, SSI, or flap necrosis rates.

Effectiveness of Injury Prevention Programs With Core Muscle Strengthening Exercises to Reduce the Incidence of Hamstring Injury Among Soccer Players: A Systematic Review and Meta-Analysis.

Muscles in the hamstring group are frequently injured in sporting activities. Injury prevention programs (IPPs), including eccentric training of the hamstrings, have proven to be of great value in decreasing the injury rate of hamstring muscles. To examine the effectiveness of IPPs that include core muscle strengthening exercises (CMSEs) in reducing hamstring injury rates. This systematic review with meta-analysis was based upon the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was conducted for relevant studies published from 1985 to 2021 using the following databases: Cochrane Library, MEDLINE, AMED, PubMed, Web of Science, and Physiotherapy Evidence Database (PEDro). The initial electronic search found 2694 randomized controlled trials (RCTs). After removing duplicate entries, 1374 articles were screened by their titles and abstracts, and 53 full-text records were assessed, of which 43 were excluded. The remaining 10 articles were reviewed in detail, from which 5 studies met our inclusion criteria and were included in the current meta-analysis. Systematic review and meta-analysis of RCTs. Level 1a. Two researchers independently completed the abstract review and performed full-text reviews. A third reviewer was consulted to reach a consensus if any discrepancies were noted. Details were recorded about the participants, methodological aspects, eligibility criteria, intervention data, and outcome measures, including age; number of subjects in the intervention/control group; number of injuries in each group; and the duration, frequency, and intensity of the training conducted in the intervention. The pooled results of 4728 players and 379,102 exposure hours showed 47% hamstring injury reduction per 1000 h of exposure in the intervention group compared with the control group with an injury risk ratio of 0.53 (95% CI [0.28, 0.98], P = 0.04). The results indicate that CMSEs incorporated with IPPs reduce susceptibility and risk of hamstring injuries in soccer players.

The Wastewater Contamination Index: A methodology to assess the risk of wastewater contamination from satellite-derived water quality indicators

One of the major sources of pollution affecting inland and coastal waters is related to poorly treated or untreated wastewater discharge, particularly in urbanized watersheds. The excess of nutrients, organic matter, and pathogens causes an overall deterioration of water quality and impairs valuable ecosystem services. The detection of wastewater pollution is essential for the sustainable management of inland and coastal waters, and remote sensing has the capability of monitoring wastewater contamination at extended spatial scales and repeated frequencies. This study employed satellite-derived water quality indicators and spatiotemporal analysis to assess the risk of wastewater contamination in Conceição Lagoon, a coastal lagoon in Southern Brazil. Using an analytical model, three water quality indicators were derived from Level 2A Sentinel-2 MSI images: the absorption coefficients of chlorophyll-a and detritus combined with coloured dissolved organic matter, and the backscattering coefficient of suspended solids. The temporal standardized anomalies were calculated for each water quality indicator for the period of 2019–2021, and their anomalies during a known outfall event were used to evaluate spatial variation modes. The spatial mode explaining most of the variability was used to estimate weights for the water quality indicators anomalies in a linear transformation that can indicate the risk of wastewater contamination. Results showed that the wastewater spatial mode for this region was characterized by positive anomalies of backscattering coefficient of particulate matter and absorption coefficient of detritus combined with coloured dissolved organic matter, each with a relative importance of 50%. The application of this spatiotemporal analysis was formulated as the Wastewater Contamination Index. With the aid of photographic records, and additional meteorological and water quality data, the results of the index were verified for wastewater outfall events in the study area. The methodology for constructing the proposed Wastewater Contamination Index applies to other locations and can be a valuable tool for operational monitoring of wastewater contamination.

Crowdsourced Data Highlight Precipitation Phase Partitioning Variability in Rain‐Snow Transition Zone

AbstractTo increase the number of direct observations of rain and snow, we started a citizen science project that crowdsources precipitation phase reports from volunteers using a smartphone app. We focused on the Lake Tahoe region of California and Nevada, USA which forms part of the rain‐snow transition zone, an area where both solid and liquid precipitation occur in winter months. In two study years, we received 2,495 reports, of which 2,248 (90.1%) passed our quality control checks. Snow was the most frequent phase (64.0%), followed by rain (21.0%) and mixed precipitation (15.0%). We compared these values to estimates from 14 common precipitation phase partitioning methods that use near‐surface meteorology as well as to two remote sensing products from the Global Precipitation Measurement mission (GPM). We found the meteorology‐based methods tended to underestimate snowfall on average (60.9%) with a sizable standard deviation of 18%. The Integrated Multi‐satellitE Retrievals for GPM level 3 probabilityLiquidPrecipitation product also underestimated snowfall (57.5%) relative to the crowdsourced data, while the Dual‐frequency Precipitation Radar level 2A phaseNearSurface product had little spatiotemporal overlap with the observations. We also found slight differences in the rain‐snow line elevations measured by a freezing‐level radar versus those estimated from the crowdsourced data, with the former being 165 m lower than the latter on average. These findings underscore the importance of collecting ground‐truth observations of precipitation phase in the rain‐snow transition zone. We hope future studies will consider the use of crowdsourced data for improved insights into and better representation of hydrometeorological processes.

An Algorithm to Retrieve Precipitable Water Vapor from Sentinel-2 Data

As one of the most important greenhouse gases, water vapor plays a vital role in various weather and climate processes. In recent years, a near-infrared ratio technique based on satellite images has become a research hotspot in the field of precipitable water vapor (PWV) monitoring. This study proposes a Level 2A PWV data retrieval method based on Sentinel-2 images (S2-L2A), which considers land-cover types and is more suitable for local areas. The radiative transfer model MODTRAN 5 is used to simulate the atmospheric radiative transfer process and obtain lookup tables (LUTs) for PWV retrieval. The spatial distribution of S2-L2A PWV is validated using Global Positioning System (GPS), Terra-MODIS PWV product (MOD05), and Level 2A product provided by ESA (ESA-L2A), while the time series results are evaluated using MOD05. Results show that the PWV retrieved by S2-L2A is both highly correlated and has low bias with the three PWV products, and is closer to the reference data than the MOD05 and ESA-L2A PWV. The relative PWV value in the morning is: bare soil &gt; vegetation-covered area &gt; construction land; as the elevation increases, the PWV value decreases. This study also analyzes the error distribution of the PWV data retrieved by S2-L2A, and finds that inversion error increases with AOT value, but decreases with elevation and normalized difference vegetation index (NDVI). Compared with the three water vapor products, the PWV data retrieved by the proposed method has high accuracy and can provide large-scale and high-spatial-resolution PWV data for many research fields, such as agriculture and meteorology.

Target and suspect screening of pesticide residues in soil samples from peach orchards using liquid chromatography quadrupole time-of-flight mass spectrometry

Agricultural soil contamination by pesticide residues has become a serious issue of increasing concern due to their high persistence and toxicity to non-target species. However, as the world’s largest peach producer, national scale surveys on pesticide residues in peach orchard soils are scarce in China. In this study, a target and suspect screening method covering over 200 pesticides commonly used in peach orchards was developed using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry in MSE. An identification strategy using different data processing parameters was developed to identify the pesticide occurrence in soil. The method was applied to soil samples from typical peach orchards in 12 regions across China. The present work also discusses in detail the frequency of occurrence, concentration of pesticides, spatial distribution of multiresidues, and relationship between pesticide occurrence and soil properties. In the tested soil samples, 21 herbicides (level 1), 31 fungicides (level 2a), 24 insecticides (level 2a), and 3 growth regulators (level 2a) were identified. The total concentrations of quantifiable herbicides in the soil samples ranged from 1.05 to 327 ng/g. Only in 5.4% of the soil samples, no pesticide residues were present. By contrast, more than 86% of the total contained multiple residues. This study represents the first large-scale survey of pesticides in soil from peach orchards and provides comprehensive and accurate information on the pesticide residue status for risk assessment.

Systematic Review and Meta-Analysis of Randomized Controlled Trials for Scalp Block in Craniotomy.

Scalp block is regional anesthetic injection along nerves innervating the cranium. Scalp blocks for craniotomy may decrease postoperative pain and opioid consumption. Benefits may extend beyond the anesthetic period. To analyze evidence for scalp block on postoperative pain and opioid use. This systematic review and meta-analysis, Prospective Register of Systematic Reviews registration (CRD42022308048), included Ovid Medical Literature Analysis and Retrieval System Online, Embase, and Cochrane Central Register of Controlled Trials inception through February 9, 2022. Only randomized controlled trials were included. We excluded studies not reporting either main outcome. Duplicate reviewers performed study selection, risk of bias assessment, data extraction, and evidence certainty Grading of Recommendations Assessment, Development, and Evaluation appraisal. Main outcomes were postoperative pain by visual analog scale within 72 hours and opioid consumption as morphine milligram equivalent (MME) within 48 hours. Screening filtered 955 studies to 23 trials containing 1532 patients. Risk of bias was overall low. Scalp block reduced postoperative pain at 2 through 72 hours, visual analog scale mean differences of 0.79 to 1.40. Opioid requirements were reduced at 24 hours by 16.52 MME and 48 hours by 15.63 MME. Scalp block reduces postoperative pain at 2 through 48 hours and may reduce pain at 72 hours. Scalp block likely reduces opioid consumption within 24 hours and may reduce opioid consumption to 48 hours. The clinical utility of these differences should be interpreted within the context of modest absolute reductions, overall care optimization, and patient populations. This is the first level 1A evidence to evaluate scalp block efficacy in craniotomy.