Examining the impact of a change in maternity leave policy in Canada on maternal mental health care visits to the physician.

PURPOSE: Maternity leave is a critical employee benefit that allows mothers to recover from the stress of pregnancy and childbirth and bond with their new baby. We aimed to examine the association between the extension of a maternity leave policy and maternal use of mental health services and prescription drugs in a universal public healthcare system. METHODS: This study uses administrative medical records from 18,000 randomly selected women who gave birth three months before and after an extension of the maternity leave policy. More specifically, mothers who gave birth after January 1st 2001, were entitled to 50 weeks of paid maternity leave, while mothers who gave birth before that date were entitled to only 26 weeks of paid maternity leave. Medical records were analyzed over a seven-year period (i.e., from October 1998 to March 2006). We examined the number and costs of mothers' medical visits for mental health care in the five years following delivery, as well as maternal use of prescribed medication for mental health problems. RESULTS: We found that mothers with extended maternity leave had - 0.12 (95%CI=-0.21; -0.02) fewer medical visits than mothers without a more generous maternity leave and that the cost of mental health services was Can$5 less expensive per women. These differences were found specifically during the extended maternity leave period. CONCLUSIONS: The extra time away from work may help mothers to balance new family dynamics which may result in less demand on the healthcare system.

[Reactive hypoglycaemia, a frequently mentioned functional disorder, yet overestimated in clinical practice]. / L'hypoglycémie réactionnelle : un trouble fonctionnel fréquemment évoqué, mais surestimé en pratique clinique.

Malaises are often attributed to hypoglycaemia in nondiabetic people who don't have any other serious medical problem. Reactive hypoglycaemia, the most frequent one, may be considered as a functional disorder. However, its diagnosis is often overused, because not really demonstrated in most instances. The diagnosis of hypoglycaemia should be structured, based upon the Whipple triad. First, the medical interrogatory must search for adrenergic and neuroglucopenic symptoms that suggest hypoglycaemia. Second, if the malaise is due to a hypoglycaemia, it should resume rapidly after the administration of sugar. Third, hypoglycaemia must be confirmed by a measurement of a low glucose level at the time of a malaise. The latter approach is facilitated by the use of home blood monitoring, a strategy that is now preferred to the use of an oral glucose tolerance test, a non-physiological test far from real-life conditions. When the diagnosis is made based upon this triad, the medical interview should precise the severity of the symptoms and focus on the chronology of the malaises, typically 2-3 hours after a sugar-enriched meal in case of a reactive hypoglycaemia. Therapeutic approach of this functional disorder mostly relies on dietary advices.

La survenue de malaises est souvent attribuée à une hypoglycémie chez des personnes non diabétiques et, a priori, sans autre problème de santé. L'hypoglycémie réactionnelle, la plus fréquente, peut être considérée comme un trouble fonctionnel. Son diagnostic est, cependant, souvent galvaudé, car l'hypoglycémie n'est habituellement pas authentifiée. Le diagnostic d'hypoglycémie doit se faire de façon structurée en se basant sur la «triade de Whipple¼. Tout d'abord, l'anamnèse doit rechercher les symptômes évocateurs d'hypoglycémie, adrénergiques et neuroglucopéniques. Ensuite, s'il s'agit bien d'une hypoglycémie, le malaise doit disparaître rapidement après resucrage. Enfin, l'hypoglycémie doit être authentifiée par une mesure d'une valeur basse au moment d'un malaise. Cette confirmation a été facilitée par l'utilisation des lecteurs de glycémie, une stratégie qui est dorénavant préférée à la réalisation d'une hyperglycémie provoquée par voie orale, test non physiologique fort éloigné des conditions de vraie vie. Une fois le diagnostic posé sur cette triade, l'anamnèse doit faire préciser, outre la sévérité des malaises, leur chronologie, typiquement 2-3 heures après un repas riche en glucides dans le cas d'une hypoglycémie réactive. Le traitement de ce trouble fonctionnel repose principalement sur des mesures diététiques.

Glucagon, from past to present: a century of intensive research and controversies.

2022 corresponds to the 100th anniversary of the discovery of glucagon. This TimeCapsule aims to recall the main steps leading to the discovery, characterisation, and clinical importance of the so-called second pancreatic hormone. We describe the early historical findings in basic research (ie, discovery, purification, structure, α-cell origin, radioimmunoassay, glucagon gene [GCG], and glucagon receptor [GLR]), in which three future Nobel Prize laureates were actively involved. Considered as an anti-insulin hormone, glucagon was rapidly used to treat insulin-induced hypoglycaemic coma episodes in people with type 1 diabetes. A key step in the story of glucagon was the discovery of its role and the role of α cells in the physiology and pathophysiology (ie, paracrinopathy) of type 2 diabetes. This concept led to the design of different strategies targeting glucagon, among which GLP-1 receptor (GLP1R) agonists were a major breakthrough, and combination of inhibition of glucagon secretion with stimulation of insulin secretion (both in a glucose-dependent manner). Taking advantage of the glucagon-induced increase in energy metabolism, biased coagonists were developed. Besides the GLP-1 receptor, these coagonists also target the glucagon receptor to further promote weight loss. Thus, the 100-year story of glucagon has most probably not come to an end.

Effect of solvent motions on the dynamics of the Diels-Alder reaction.

How solvent motions affect the dynamics of chemical reactions in which the solute undergoes a substantial shape change is a fundamental but elusive issue. This work utilizes reactive simulation and Grote-Hynes theory to explore the effect of solvent motions on the dynamics of the Diels-Alder reaction (in the reverse direction, this reaction involves very substantial solute expansion) in aprotic solvents. The results reveal that the solvent environment is not sufficiently constraining to influence transition state passage dynamics, with the calculated transmission coefficients being close to unity. Even when solvent motions are suppressed or artificially slowed down, the solvent only affects the reaction dynamics in the transition state region to a very small extent. The only notable effect of solvent occurs far from the transition state region and corresponds to caging of the reactants within the reactant well.

Climate-driven fluxes of organic-bound uranium to an alpine lake over the Holocene.

Uranium (U) isotopic signatures and concentration in sediments are widely used as paleo-redox proxies, as the behavior of U is often controlled by bottom water oxygenation. Here, we investigated the processes controlling U accumulation in the sediments of Lake Nègre (Mediterranean Alps, South-East France) over the past 9200 years. Exceptionally high natural U concentrations (350-1250 µg·g-1) allowed the measurement of U along with other elements by high-resolution X-Ray Fluorescence core-scanning. Weathering and erosion proxies (Ti content, Zr/Al and K/Ti ratios) indicate that sedimentary inputs were controlled by Holocene climatic variations. After a period of low erosion during the Holocene Climatic Optimum, a major regime shift was recorded at 4.2 kyr BP when terrigenous fluxes consistently increased until present with high sensitivity to centennial-scale climatic events. Sedimentary organic matter (OM) inputs were dominated by terrigenous OM from the catchment soils until 2.4 kyr BP, as attested by carbon to nitrogen (C/N) and bromine to organic carbon (Br/TOC) ratios. From 2.4 kyr BP to present, lake primary production and soils equally contributed to sedimentary OM. Uranium fluxes to the sediments were well correlated to terrigenous OM fluxes from 7 kyr BP to present, showing that U supply to the lake was controlled by U scavenging in the soils of the watershed followed by transport of U bound to detrital organic particles. Higher U/OM ratios before 7 kyr BP likely reflect the development of the upstream wetland. The fluctuations of U sedimentary inputs appear to be independent of bottom water oxygenation, as estimated from constant Fe/Mn ratios and δ238U isotopic signatures, and rather controlled by the production, erosion and sedimentation of terrigenous OM. This finding confirms that the use of U (and potentially other metals with high affinity to OM) concentrations alone should be used with caution for paleo-redox reconstructions.

Diagenetic formation of uranium-silica polymers in lake sediments over 3,300 years.

The long-term fate of uranium-contaminated sediments, especially downstream former mining areas, is a widespread environmental challenge. Essential for their management is the proper understanding of uranium (U) immobilization mechanisms in reducing environments. In particular, the long-term behavior of noncrystalline U(IV) species and their possible evolution to more stable phases in subsurface conditions is poorly documented, which limits our ability to predict U long-term geochemical reactivity. Here, we report direct evidence for the evolution of U speciation over 3,300 y in naturally highly U-enriched sediments (350-760 µg ⋅ g-1 U) from Lake Nègre (Mercantour Massif, Mediterranean Alps, France) by combining U isotopic data (δ238U and (234U/238U)) with U L3 -edge X-ray absorption fine structure spectroscopy. Constant isotopic ratios over the entire sediment core indicate stable U sources and accumulation modes, allowing for determination of the impact of aging on U speciation. We demonstrate that, after sediment deposition, mononuclear U(IV) species associated with organic matter transformed into authigenic polymeric U(IV)-silica species that might have partially converted to a nanocrystalline coffinite (UIVSiO4·nH2O)-like phase. This diagenetic transformation occurred in less than 700 y and is consistent with the high silica availability of sediments in which diatoms are abundant. It also yields consistency with laboratory studies that proposed the formation of colloidal polynuclear U(IV)-silica species, as precursors for coffinite formation. However, the incomplete transformation observed here only slightly reduces the potential lability of U, which could have important implications to evaluate the long-term management of U-contaminated sediments and, by extension, of U-bearing wastes in silica-rich subsurface environments.

Acute kidney injury after aneurysmal subarachnoid hemorrhage: is chloride really responsible?

Sadan et al. find an association between acute kidney injury and high chloride containing a hypertonic solution. Recent large prospective non-randomized studies bring conflicting results on the relationship between chloride and acute kidney injury. We discuss Sadan et al.'s results according to the recent literature.

New Insights into Pb Isotope Fingerprinting of U-Mine Material Dissemination in the Environment: Pb Isotopes as a Memory Dissemination Tracer.

Stable Pb isotope ratios were measured and compared to U distributions in three soil cores located in a wetland highly impacted by water discharge of a former U-mine. Pb isotope ratios showed notable alignments in binary mixing plots, demonstrating the dissemination of radioactive-enriched material from the U-mine. Thanks to these alignments and to the measurement of the 204Pb isotope, a precise characterization of the Pb isotope composition of the U-ore was performed without the use of U-ore samples. The well-defined end-members with the help of a reevaluated isotope mixing model allowed the accurate determination of the radiogenic Pb percentages in the cores that were overall found to be >50%. Noncorrelated distributions of radiogenic 206Pb and U are observed in several of the wetland soil samples. They reveal postdepositional U redistribution explained by major U speciation changes due to redox cycling in the wetland. On the contrary, the radiogenic 206Pb showed no or little postdepositional mobility and thus can be considered to be a memory tracer of the dissemination of U-rich radioactive material: even after an important U loss, the radiogenic 206Pb is able to reveal past contamination by U-rich materials.

Experimental redox transformations of uranium phosphate minerals and mononuclear species in a contaminated wetland.

Reducing conditions and high organic carbon content make wetlands favorable to uranium (U) sequestration. However, such environments are subjected to water-table fluctuations that could impact the redox behavior of U and its mobility. Our previous study on U speciation in a contaminated wetland has suggested a major role of water-table redox fluctuations in the redistribution of U from U(IV)-phosphate minerals to organic U(VI) and U(IV) mononuclear species. Here, we investigate the mechanisms of these putative processes by mimicking drying or flooding periods via laboratory incubations of wetland samples. LCF-XANES and EXAFS analyses show the total oxidation/reduction of U(IV)/U(VI)-mononuclear species after 20 days of oxic/anoxic incubation, whereas U-phosphate minerals are partly oxidized/reduced. SEM-EDXS combined with µ-XRF and µ-XANES analyses suggest that autunite Ca(UO2)2(PO4)2⋅11H2O is reduced into lermontovite U(PO4)(OH)⋅H2O, whereas oxidized ningyoite CaU(PO4)2⋅2H2O is locally dissolved. The release of U from this latter process is observed to be limited by U(VI) adsorption to the soil matrix and further re-reduction into mononuclear U(IV) upon anoxic cycling. Analysis of incubation waters show, however, that dissolved organic carbon enhances U solubilization even under anoxic conditions. This study brings important information that help to assess the long-term stability of U in seasonally saturated organic-rich contaminated environments.

Pandemic School Closures May Increase Inequality in Test Scores.

Schools have been closed across the country and will remain closed until September in most provinces. The decision to reopen should take into account current inequalities in cognitive skills across the country and the impact of school interruptions on knowledge accumulation. In this article, we use information from a companion article to estimate the socioeconomic achievement gaps of 15-year-olds across Canada and assess the impact of the pandemic on inequalities in education. Using estimates from the literature on the impact of school closures, we find that the socioeconomic skills gap measured using Programme for International Student Assessment data could increase by more than 30 percent.

Les écoles ont été fermées partout au pays et le demeureront jusqu'en septembre dans la plupart des provinces. Dans la décision de rouvrir les écoles, il faudra tenir compte des inégalités actuelles au chapitre des habiletés cognitives des élèves dans l'ensemble du Canada et de l'incidence de l'interruption du fonctionnement des écoles sur le cumul des connaissances. Les auteurs utilisent l'information provenant d'un document complémentaire pour estimer l'écart socioéconomique dans la réussite des jeunes de 15 ans sur l'ensemble du territoire canadien et évaluent les répercussions de la pandémie sur les inégalités dans l'éducation. À l'aide d'estimations tirées de la documentation sur les conséquences de la fermeture des écoles, les auteurs prévoient que les écarts socioéconomiques de compétences mesurés selon les données du PISA pourraient croître de plus de 30 pour cent.

Nickel and iron partitioning between clay minerals, Fe-oxides and Fe-sulfides in lagoon sediments from New Caledonia.

In the tropics, continental weathering and erosion are major sources of trace metals towards estuaries and lagoons, where early diagenesis of sediments may influence their mobility and bioavailability. Determining trace metals speciation in tropical sedimentary settings is thus needed to assess their long-term fate and potential threat to fragile coastal ecosystems. In this study, we determined Fe, Ni and S speciation across a shore-to-reef gradient in sediments from the New Caledonia lagoon that receive mixed contribution from lateritic (iron-oxyhydroxides and clay minerals), volcano-sedimentary (silicates) and marine (carbonate) sources. Sulfur K-edge XANES data indicated a major contribution of pyrite (FeS2) to S speciation close to the shore. However, this contribution was found to dramatically decrease across the shore-to-reef gradient, S mainly occurring as sulfate close to the coral reef. In contrast, Fe and Ni K-edge XANES and EXAFS data indicated a minor contribution of pyrite to Fe and Ni speciation, and this contribution could be evidenced only close to the shore. The major fractions of Fe and Ni across the shore-to-reef gradient were found to occur as Ni- and Fe-bearing clay minerals consisting of smectite (~nontronite), glauconite and two types of serpentines (chrysotile and greenalite/berthierine). Among these clay minerals, greenalite/berthierine, glauconite and possibly smectite, were considered as authigenic. The low contribution of pyrite to trace metals speciation compared to clay minerals is interpreted as a result of (1) a reduced formation rate due to the low amounts of organic carbon compared to the Fe pool and (2) repeated re-oxidation events upon re-suspension of the sediments top layers due to the specific context of shallow lagoon waters. This study thus suggests that green clay authigenesis could represent a key process in the biogeochemical cycling of trace metals that are delivered to lagoon ecosystems upon continental erosion and weathering.

Trapping Dipolar Exciton Fluids in GaN/(AlGa)N Nanostructures.

Dipolar excitons offer a rich playground for both design of novel optoelectronic devices and fundamental many-body physics. Wide GaN/(AlGa)N quantum wells host a new and promising realization of dipolar excitons. We demonstrate the in-plane confinement and cooling of these excitons, when trapped in the electrostatic potential created by semitransparent electrodes of various shapes deposited on the sample surface. This result is a prerequisite for the electrical control of the exciton densities and fluxes, as well for studies of the complex phase diagram of these dipolar bosons at low temperature.

Isotopic Fingerprint of Uranium Accumulation and Redox Cycling in Floodplains of the Upper Colorado River Basin.

Uranium (U) groundwater contamination is a major concern at numerous former mining and milling sites across the Upper Colorado River Basin (UCRB), USA, where U(IV)-bearing solids have accumulated within naturally reduced zones (NRZs). Understanding the processes governing U reduction and oxidation within NRZs is critical for assessing the persistence of U in groundwater. To evaluate the redox cycling of uranium, we measured the U concentrations and isotopic compositions (δ238U) of sediments and pore waters from four study sites across the UCRB that span a gradient in sediment texture and composition. We observe that U accumulation occurs primarily within fine-grained (low-permeability) NRZs that show active redox variations. Low-permeability NRZs display high accumulation and low export of U, with internal redox cycling of U. In contrast, within high-permeability NRZs, U is remobilized under oxidative conditions, possibly without any fractionation, and transported outside the NRZs. The low δ238U of sediments outside of defined NRZs suggests that these reduced zones act as additional U sources. Collectively, our results indicate that fine-grained NRZs have a greater potential to retain uranium, whereas NRZs with higher permeability may constitute a more-persistent but dilute U source.

Redox Fluctuations and Organic Complexation Govern Uranium Redistribution from U(IV)-Phosphate Minerals in a Mining-Polluted Wetland Soil, Brittany, France.

Wetlands have been proposed to naturally attenuate U transfers in the environment via U complexation by organic matter and potential U reduction. However, U mobility may depend on the identity of particulate/dissolved uranium source materials and their redox sensitivity. Here, we examined the fate of uranium in a highly contaminated wetland (up to 4500 mg·kg-1 U) impacted by former mine water discharges. Bulk U LIII-EXAFS and (micro-)XANES combined with SEM-EDXS analyses of undisturbed soil cores show a sharp U redox boundary at the water table, together with a major U redistribution from U(IV)-minerals to U(VI)-organic matter complexes. Above the water table, U is fully oxidized into mono- and bidentate U(VI)-carboxyl and monodentate U(VI)-phosphoryl complexes. Minute amounts of U(VI)-phosphate minerals are also observed. Below the water table, U is fully reduced and is partitioned between U(IV)-phosphate minerals (i.e., ningyoite and a lermontovite-like phase), and bidentate U(IV)-phosphoryl and monodentate U(IV)-carboxyl complexes. Such a U redistribution from U-minerals inherited from mine water discharge deposits could result from redox cycling nearby the water table fluctuation zone. Oxidative dissolution of U(IV)-phosphate minerals could have led to U(VI)-organic matter complexation, followed by subsequent reduction into U(IV)-organic complexes. However, uranium(IV) minerals could have been preserved in permanently waterlogged soil.

Electron-Withdrawing Effects in the Photodissociation of CH2ICl To Form CH2Cl Radical, Simultaneously Viewed Through the Carbon K and Chlorine L2,3 X-ray Edges.

A fundamental chlorine-containing radical, CH2Cl, is generated by the ultrafast photodissociation of CH2ICl at 266 nm and studied at both the carbon K edge (∼284 eV) and chlorine L2,3 edge (∼200 eV) by femtosecond X-ray transient absorption spectroscopy. The electronic structure of CH2Cl radical is characterized by a prominent new carbon 1s X-ray absorption feature at lower energy, resulting from a transition to the half-filled frontier carbon 2p orbital (singly occupied molecular orbital of the radical; SOMO). Shifts of other core-to-valence absorption features upon photodissociation of CH2ICl to yield ·CH2Cl indicate changes in the energies of core-level transitions of carbon and chlorine to the σ*(C-Cl) valence orbital. When the C-I bond breaks, loss of the electron-withdrawing iodine atom donates electron density back to carbon and shields the carbon 1s core level, resulting in a ∼0.8 eV red shift of the carbon 1s to σ*(C-Cl) transition. Meanwhile, the 2p inner shell of the chlorine atom in the radical is less impacted by the iodine atom removal, as demonstrated by the observation of a ∼0.6 eV blue shift of the transitions at the chlorine L2,3 edges, mainly due to the stronger C-Cl bond and the increased energy of the σ*(C-Cl) orbital. The results suggest that the shift in the carbon 1s orbital is greater than the shift in the σ*(C-Cl) orbital upon going from the closed-shell molecule to the radical. Ab initio calculations using the equation of motion coupled-cluster theory establish rigorous assignment and positions of the X-ray spectral features in the parent molecule and the location of the SOMO in the CH2Cl radical.

Investigational glucagon receptor antagonists in Phase I and II clinical trials for diabetes.

INTRODUCTION: Despite type 2 diabetes (T2D) being recognized as a bihormonal pancreatic disease, current therapies are mainly focusing on insulin, while targeting glucagon has been long dismissed. However, glucagon receptor (GCGr) antagonists are currently investigated in clinical trials. Area covered: Following a brief description of the rationale for antagonizing GCGr in T2D, lessons from GCGr knock-out mice and pharmacological means to antagonize GCGr, a detailed description of the main results obtained with GCGr antagonists in Phase I-II clinical trials is provided. The development of several small molecules has been discontinued, while new ones are currently considered as well as innovative approaches such as monoclonal antibodies or antisense oligonucleotides inhibiting GCGr gene expression. Their potential benefits but also limitations are discussed. Expert opinion: The proof-of-concept that antagonizing GCGr improves glucose control in T2D has been confirmed in humans. Nevertheless, some adverse events led to stopping the development of some of these GCGr antagonists. New approaches seem to have a better benefit/risk balance, although none has progressed to Phase III clinical trials so far. Pharmacotherapy of T2D is becoming a highly competitive field so that GCGr antagonists should provide clear advantages over numerous existing glucose-lowering medications before eventually reaching clinical practice.

Single Dexamethasone Intravitreal Implant in the Treatment of Noninfectious Uveitis.

PURPOSE: To investigate the effect of a single intravitreal dexamethasone implant (IVT-DI; Ozurdex; Allergan, Inc.) on visual acuity, macular thickness, and intraocular pressure (IOP) in active noninfectious uveitis. METHODS: Medical records of patients with noninfectious active uveitis treated by IVT-DIs were retrospectively reviewed. Uveitis etiologies, treatment indications, best corrected visual acuity (BCVA), central retinal thickness measured by ocular coherence tomography, IOP, and systemic, local, and topical treatments were collected. Parameters were analyzed before the injection of the implant, after 1.5 ± 0.8 months and 4.4 ± 0.9 months for the BCVA, after 2 ± 1.3 months and 4.6 ± 1.3 months for the ocular coherence tomography, and after 1.3 ± 0.7 months and 4.4 ± 1 months for the IOP. RESULTS: We included 14 patients (20 eyes, 20 implant injections) with cystoid macular edema (78%), vasculitis (7%), choroiditis (7%), and vasculitis associated with choroiditis (7%). Before the injection, mean visual acuity was 0.4 ± 0.5 logMAR (logarithm of the minimum angle of resolution) that improved to 0.3 ± 0.5 logMAR (P = 0.0002) after 1.5 ± 0.8 months and to 0.3 ± 0.5 logMAR (P = 0.005) after 4.4 ± 0.9 months. A statistically significant decrease of macular thickness was observed both at 2 ± 1.3 months and at 4.6 ± 1.3 months after IVT-DI. Mean IOP was 16 ± 5 mmHg before injections, 18 ± 6 mmHg (P = 0.13) at 1.3 ± 0.7 months, and 15 ± 4 mmHg (P = 0.65) at 4.4 ± 1 months. By Kaplan-Meier analysis, we found that after 3.3 months, 17% of the eyes still present a BCVA amelioration ≥0.3 logMAR. CONCLUSIONS: In our patients with active noninfectious uveitis, injection of a first single dexamethasone implant was found to improve visual acuity and decrease macular thickness without significant increase of IOP, although the effect seems limited in time.

[Measuring the impact of an "age-friendly city" approach on a territory by setting up cross-cutting indicators]. / Mesurer l'impact d'une démarche ville amie des aînés sur un territoire par la mise en place d'indicateurs transversaux.

The "Age-friendly cities" program has been developing in France since 2010. So far the existing protocols had not allowed cities to assess actions taken in favor of elderly people comprehensively. The work done with the Francophone network of age-friendly cities (RFVAA) has led to the definition of an indicator consisting of 12 points; the relative importance of each target was weighted using a decision-making tool. This work has demonstrated the major role of governance in the implementation of cross-cutting policies for the benefit of older people.