Systematic visual analysis of groundwater hydrographs: potential benefits and challenges

Visual analysis of time series in hydrology is frequently seen as a crucial step to becoming acquainted with the nature of the data, as well as detecting unexpected errors, biases, etc. Human eyes, in particular those of a trained expert, are well suited to recognize irregularities and distinct patterns. However, there are limits as to what the eye can resolve and process; moreover, visual analysis is by definition subjective and has low reproducibility. Visual inspection is frequently mentioned in publications, but rarely described in detail, even though it may have significantly affected decisions made in the process of performing the underlying study. This paper presents a visual analysis of groundwater hydrographs that has been performed in relation to attempts to classify groundwater time series as part of developing a new concept for prediction in data-scarce groundwater systems. Within this concept, determining the similarity of groundwater hydrographs is essential. As standard approaches for similarity analysis of groundwater hydrographs do not yet exist, different approaches were developed and tested. This provided the opportunity to carry out a comparison between visual analysis and formal, automated classification approaches. The presented visual classification was carried out on two sets of time series from central Europe and Fennoscandia. It is explained why and where visual classification can be beneficial but also where the limitations and challenges associated with the approach lie. It is concluded that systematic visual analysis of time series in hydrology, despite its subjectivity and low reproducibility, should receive much more attention

Similarity-based approaches in hydrogeology: proposal of a new concept for data-scarce groundwater resource characterization and prediction

A new concept is proposed for describing, analysing and predicting the dynamic behaviour of groundwater resources based on classification and similarity. The concept makes use of the ideas put forward by the “PUB” (predictions in ungauged basins) initiative in surface-water hydrology. One of the approaches developed in PUB uses the principle that similar catchments, exposed to similar weather conditions, will generate a similar discharge response at the catchment outlet. This way, models developed for well-observed catchments can be used to make predictions for ungauged catchments with similar properties (topography, land use, etc.). The concept proposed here applies the same idea to groundwater systems, with the goal to make predictions of the dynamic behaviour of groundwater in poorly observed systems using similarities to well-observed and understood systems. This paper gives an overview of the main ideas, the methodological background, the progress so far, and the challenges that the authors regard as most crucial for further development. One of the main goals of this article is thus to raise interest for this new concept within the groundwater community. There are a multitude of highly interesting aspects to investigate, and a community effort, as with PUB, is required. A second goal is to foster and exchange ideas between the groundwater and surface water research communities who, while often working on similar problems, have often missed the opportunity to learn from each other

Changes in seasonality of groundwater level fluctuations in a temperate-cold climate transition zone

In\ua0cold (i.e. boreal, subarctic, snowy)\ua0climate\ua0zones, dynamic\ua0groundwater\ua0storage is greatly affected by the timing and amount of snowmelt. With global warming, cold climates\ua0in\ua0the northern hemisphere will\ua0transition\ua0to temperate. As temperatures rise, the dominant type of precipitation will\ua0change\ua0from snow to rain\ua0in\ua0winter. Further, the growing season is prolonged. This has\ua0a\ua0direct impact on the aquifer recharge pattern. However, little is known about the effect of changing annual recharge regimes on\ua0groundwater\ua0storage. The present work deduces the impact of shifting\ua0climate\ua0zones on\ua0groundwater\ua0storage by evaluating the effect of\ua0climate\ua0seasonality\ua0on intra-annual hydraulic head\ua0fluctuations. The work compares intra-annual hydraulic head\ua0fluctuations\ua0in\ua0a\ua0temperate-cold\ua0climate\ua0transition\ua0zone\ua0(Fennoscandia) from two different periods (1980–1989, 2001–2010). This is done by associating rising vs. declining hydraulic heads with hydrometeorology. Due to the northwards migration of the temperate\ua0climate\ua0zone, there is\ua0a\ua0shift\ua0in\ua0seasonality\ua0between the two periods. This has\ua0a\ua0negative impact on\ua0groundwater\ua0levels, which are significantly lower\ua0in\ua02001–2010, particularly near the\ua0climate\ua0transition\ua0zone. The results demonstrate that increasing temperatures\ua0in\ua0cold\ua0climate\ua0regions may\ua0change\ua0the\ua0seasonality\ua0of\ua0groundwater\ua0recharge, by altering the main recharge period from being snowmelt-dominated (spring) to rain-dominated (winter). Additionally, this is connected to the duration of the growing season, which impedes\ua0groundwater\ua0recharge. The coupled effect of this on\ua0groundwater\ua0in\ua0the study area has led to\ua0a\ua0significant decrease\ua0in\ua0groundwater\ua0storage

Exploiting nanobodies and Affimers for superresolution imaging in light microscopy

Antibodies have long been the main approach used for localizing proteins of interest by light microscopy. In the past 5 yr or so, and with the advent of superresolution microscopy, the diversity of tools for imaging has rapidly expanded. One main area of expansion has been in the area of nanobodies, small single-chain antibodies from camelids or sharks. The other has been the use of artificial scaffold proteins, including Affimers. The small size of nanobodies and Affimers compared with the traditional antibody provides several advantages for superresolution imaging

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

Changes in seasonality of groundwater level fluctuations in a temperate-cold climate transition zone

Abstract In cold (i.e. boreal, subarctic, snowy) climate zones, dynamic groundwater storage is greatly affected by the timing and amount of snowmelt. With global warming, cold climates in the northern hemisphere will transition to temperate. As temperatures rise, the dominant type of precipitation will change from snow to rain in winter. Further, the growing season is prolonged. This has a direct impact on the aquifer recharge pattern. However, little is known about the effect of changing annual recharge regimes on groundwater storage. The present work deduces the impact of shifting climate zones on groundwater storage by evaluating the effect of climate seasonality on intra-annual hydraulic head fluctuations. The work compares intra-annual hydraulic head fluctuations in a temperate-cold climate transition zone (Fennoscandia) from two different periods (1980–1989, 2001–2010). This is done by associating rising vs. declining hydraulic heads with hydrometeorology. Due to the northwards migration of the temperate climate zone, there is a shift in seasonality between the two periods. This has a negative impact on groundwater levels, which are significantly lower in 2001–2010, particularly near the climate transition zone. The results demonstrate that increasing temperatures in cold climate regions may change the seasonality of groundwater recharge, by altering the main recharge period from being snowmelt-dominated (spring) to rain-dominated (winter). Additionally, this is connected to the duration of the growing season, which impedes groundwater recharge. The coupled effect of this on groundwater in the study area has led to a significant decrease in groundwater storage

Airway clearance techniques in neuromuscular disorders: A state of the art review

International audienceThis is a unique state of the art review written by a group of 21 international recognized experts in the field that gathered during a meeting organized by the European Neuromuscular Centre (ENMC) in Naarden, March 2017. It systematically reports the entire evidence base for airway clearance techniques (ACTs) in both adults and children with neuromuscular disorders (NMD). We not only report randomised controlled trials, which in other systematic reviews conclude that there is a lack of evidence base to give an opinion, but also include case series and retrospective reviews of practice. For this review, we have classified ACTs as either proximal (cough augmentation) or peripheral (secretion mobilization). The review presents descriptions; standard definitions; the supporting evidence for and limitations of proximal and peripheral ACTs that are used in patients with NMD; as well as providing recommendations for objective measurements of efficacy, specifically for proximal ACTs. This state of the art review also highlights how ACTs may be adapted or modified for specific contexts (e.g. in peopl

Protocol for a systematic review of prognosis after mild traumatic brain injury : an update of the WHO Collaborating Centre Task Force findings

Background: Mild traumatic brain injury (MTBI) is a major public-health concern and represents 70-90% of all treated traumatic brain injuries. The last best-evidence synthesis, conducted by the WHO Collaborating Centre for Neurotrauma, Prevention, Management and Rehabilitation in 2002, found few quality studies on prognosis. The objective of this review is to update these findings. Specifically, we aim to describe the course, identify modifiable prognostic factors, determine long-term sequelae, and identify effects of interventions for MTBI. Finally, we will identify gaps in the literature, and make recommendations for future research. Methods: The databases MEDLINE, PsychINFO, Embase, CINAHL and SPORTDiscus were systematically searched (2001 to date). The search terms included 'traumatic brain injury', 'craniocerebral trauma', 'prognosis', and 'recovery of function'. Reference lists of eligible papers were also searched. Studies were screened according to pre-defined inclusion and exclusion criteria. Inclusion criteria included original, published peer-reviewed research reports in English, French, Swedish, Norwegian, Danish and Spanish, and human participants of all ages with an accepted definition of MTBI. Exclusion criteria included publication types other than systematic reviews, meta-analyses, randomized controlled trials, cohort studies, and case-control studies; as well as cadaveric, biomechanical, and laboratory studies. All eligible papers were critically appraised using a modification of the Scottish Intercollegiate Guidelines Network (SIGN) criteria. Two reviewers performed independent, in-depth reviews of each eligible study, and a third reviewer was consulted for disagreements. Data from accepted papers were extracted into evidence tables, and the evidence was synthesized according to the modified SIGN criteria. Conclusion: The results of this study form the basis for a better understanding of recovery after MTBI, and will allow development of prediction tools and recommendation of interventions, as well as informing health policy and setting a future research agenda