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Background Postural tachycardia syndrome (PTS) is a novel identified sequela of COVID-19 infection. This observational study describes clinical presentation, testing, and treatment response in seven patients diagnosed with PTS following COVID-19 infection. Case summary A total of seven active patients (three collegiate athletes, one recreational athlete, two registered nurses, one hospitality employee), age 24 ± 6 years, and six females were followed for a mean of 152 ± 105 days after contracting COVID-19. Tilt table was performed to establish the diagnosis. The most common presenting symptoms were palpitations (7/7), dyspnoea (6/7), and gastrointestinal complaints (5/7). One patient required hospitalization for symptom management. The mean latency of PTS onset following COVID-19 was 21 ± 15 days. Electrocardiograms (ECGs) demonstrated sinus rhythm in all patients, one with resting sinus tachycardia. Echocardiogram demonstrated normal systolic and diastolic left ventricular function in all patients. On tilt table testing, baseline heart rate (HR) was 72 ± 12 with maximum HR reaching 136 ± 13. Six of seven patients failed to respond to supportive therapy alone, and two patients failed medical management with ivabradine, midodrine, and/or metoprolol. Of three severely symptomatic patients, two demonstrated some degree of clinical recovery with intravenous immunoglobulin (IVIG). Discussion This novel case series describes the development of PTS in the context of COVID-19 infection. Severity of symptoms and response to treatment was heterogeneous. Interestingly, patients were poorly responsive to traditional PTS treatments, but IVIG showed potential as a possible therapeutic strategy for refractory PTS in two patients, particularly following COVID-19 infection. [ABSTRACT FROM AUTHOR]

Vitamin C, or ascorbic acid, both tightens the endothelial permeability barrier in basal cells and also prevents barrier leak induced by inflammatory agents. Barrier tightening by ascorbate in basal endothelial cells requires nitric oxide derived from activation of nitric oxide synthase. Although ascorbate did not affect cyclic AMP levels in our previous study, there remains a question of whether it might activate downstream cyclic AMP-dependent pathways. In this work, we found in both primary and immortalized cultured endothelial cells that ascorbate tightened the endothelial permeability barrier by ∼30%. In human umbilical vein endothelial cells, this occurred at what are likely physiologic intracellular ascorbate concentrations. In so doing, ascorbate decreased measures of oxidative stress and also flattened the cells to increase cell-to-cell contact. Inhibition of downstream cyclic AMP-dependent proteins via protein kinase A did not prevent ascorbate from tightening the endothelial permeability barrier, whereas inhibition of Epac1 did block the ascorbate effect. Although Epac1 was required, its mediator Rap1 was not activated. Furthermore, ascorbate acutely stabilized microtubules during depolymerization induced by colchicine and nocodazole. Over several days in culture, ascorbate also increased the amount of stable acetylated α-tubulin. Microtubule stabilization was further suggested by the finding that ascorbate increased the amount of Epac1 bound to α-tubulin. These results suggest that physiologic ascorbate concentrations tighten the endothelial permeability barrier in unstimulated cells by stabilizing microtubules in a manner downstream of cyclic AMP that might be due both to increasing nitric oxide availability and to scavenging of reactive oxygen or nitrogen species. [ABSTRACT FROM AUTHOR]

The article discusses the key points in the morcellation of presumed uterine leiomyoma as recommended by the American College of Obstetricians and Gynecologists (ACOG). Topics include the analysis on women published by the Agency for Healthcare Research and Quality (AHRQ) which provides the risk of a leiomyosarcoma (LMS), the types of morcellation techniques, and the importance of shared decision-making in understanding the risks and benefits of treatment options.

Intraspecific assisted migration ( ISAM) through seed transfer during artificial forest regeneration has been suggested as an adaptation strategy to enhance forest resilience and productivity under future climate. In this study, we assessed the risks and benefits of ISAM in white spruce based on long-term and multilocation, rangewide provenance test data. Our results indicate that the adaptive capacity and growth potential of white spruce varied considerably among 245 range-wide provenances sampled across North America; however, the results revealed that local populations could be outperformed by nonlocal ones. Provenances originating from south-central Ontario and southwestern Québec, Canada, close to the southern edge of the species' natural distribution, demonstrated superior growth in more northerly environments compared with local populations and performed much better than populations from western Canada and Alaska, United States. During the 19-28 years between planting and measurement, the southern provenances have not been more susceptible to freezing damage compared with local populations, indicating they have the potential to be used now for the reforestation of more northerly planting sites; based on changing temperature, these seed sources potentially could maintain or increase white spruce productivity at or above historical levels at northern sites. A universal response function ( URF), which uses climatic variables to predict provenance performance across field trials, indicated a relatively weak relationship between provenance performance and the climate at provenance origin. Consequently, the URF from this study did not provide information useful to ISAM. The ecological and economic importance of conserving white spruce genetic resources in south-central Ontario and southwestern Québec for use in ISAM is discussed. [ABSTRACT FROM AUTHOR]

The article examines the risk and benefits of bilateral salpingo-oophorectomy (BSO) concurrent with hysterectomy for patients with varying degrees of ovarian cancer risks, and evidence derived from several observational studies including one by the Society of Gynecologic Oncologists Clinical Practice Committee. Details related to BSO in different scenarios are offered, including ovarian cancer prevention in high risk and average risk patients, and also for those with endometriosis.

In an environment of uncertain climatic change, there is an urgent need to develop robust reserve networks, i.e., networks that conserve species across multiple climatic futures. Using climatic envelopes based on multiple future climatic scenarios, we first estimate the impacts that these scenarios might have on the distributions of 63 native tree species in the Province of Ontario. Next, an optimization model is applied to expand an existing system of reserves in this province by determining the minimum number of optimal locations for additional reserves both with and without the need for migration. The optimization model formulated differs from previous work in that it meets the need for present and future distributions to occur in the same reserve and accommodates multiple differing climate change scenarios rather than a single scenario. The reserve selection approach described here can be applied anywhere that species' distributions and environmental grids are available. Although this approach is designed to produce a robust solution to the uncertainties over future climatic scenarios, it does not eliminate these uncertainties because the proposed solutions inherit the uncertainties of the global climate change models. Dans un contexte d'incertitude face au changement climatique, il est urgent de mettre sur pied des réseaux robustes de réserves, c.-à-d. des réseaux qui préservent les espèces face à un éventail d'avenirs climatiques plausibles. À l'aide d'enveloppes climatiques basées sur un ensemble de scénarios climatiques futurs, nous estimons d'abord l'impact que ces scénarios pourraient avoir sur la répartition géographique de 63 espèces indigènes arborescentes dans la province d'Ontario. Ensuite, un modèle d'optimisation est appliqué pour étendre le système existant de réserves dans cette province en déterminant le nombre minimum de localisations optimales pour des réserves additionnelles avec et sans besoin de migration. Le modèle d'optimisation qui a été développé diffère des modèles précédents en ce qu'il répond à la nécessité que les répartitions actuelle et future se retrouvent dans la même réserve et qu'il tient compte de plusieurs scénarios de changement climatique différents plutôt que d'un seul. L'approche présentée ici pour choisir des réserves peut être appliquée partout où la répartition des espèces et des grilles environnementales sont disponibles. Bien que cette approche soit conçue pour produire une solution robuste aux incertitudes inhérentes aux scénarios climatiques futurs, elle n'élimine pas ces incertitudes parce que les solutions proposées héritent des incertitudes des modèles de changement climatique planétaire. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A letter to the editor is presented in response to the article "An open letter to the FDA" in the January 2016 issue.

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The general problem addressed by this study is that of designing a decision support system for planned adaptation to climate change that uses the principles of modern portfolio theory to minimise risk and maximise return of adaptive actions in an environment of deep uncertainty over future climate scenarios. Here we show how modern portfolio theory can use the results of a climate change impact model to select an optimal set of seed sources to be used in regenerating forests of white spruce in an environment of multiple, equally plausible future climates. This study shows that components of solutions are not selected to perform equally well across all plausible futures; but rather, that components are selected to specialise in particular climate scenarios. The innovation of this research rests in demonstrating that the powerful and widely used principles of quantifying and planning for risk and return in the uncertain environment of asset markets can be applied successfully to serve the objectives of planned adaptation to climate change. [ABSTRACT FROM AUTHOR]

Height, diameter, and survival data were obtained from 16 rangewide jack pine provenance trials in eastern Canada and the United States. Climate data for each seed source and test location were used to relate height growth to 72 climate variables. Population response functions based on August minimum and January maximum temperatures were developed to predict climate values maximizing height growth for individual seed sources. Site transfer functions based on March precipitation and December minimum temperature were developed to predict climate values maximizing height growth for test locations. Contour lines representing optimal performance were fitted to current (1971–2000) and future (2041–2070) climate grids. Optimal growth is currently achieved between 46°N and 47°N latitude for most seed sources. Future temperature increases are expected to cause a northward shift of the optimal habitat by approximately 2°. Northern sources are growing at temperatures below optimum and would benefit from warmer environments provided other environmental factors do not become limiting. Central sources are growing at close to optimum and will be negatively affected by increased temperatures in the future. Southern sources performed better in cooler environments, and warmer temperatures may cause significant height growth loss and the potential extirpation of these populations. Des données de hauteur, de diamètre et de survie ont été obtenues pour 16 essais de provenances de pin gris couvrant l’ensemble de la distribution naturelle de l’espèce et localisés dans l’est du Canada et aux tats-Unis. Les auteurs ont utilisé les données climatiques associées à chaque source de semences et à chaque endroit où était établi un essai pour déterminer les relations entre la croissance en hauteur et 72 variables climatiques. Des fonctions de réponse des populations basées sur la température minimum du mois d’août et la température maximum du mois de janvier ont été développées afin de prédire les valeurs climatiques associées à une croissance en hauteur maximale pour chaque source de semences. Des fonctions de transfert de site basées sur la précipitation du mois de mars et la température minimum du mois de décembre ont été développées afin de prédire les valeurs climatiques associées à une croissance en hauteur maximale pour les localités où étaient établis les essais. Des lignes de contour représentant la performance optimale ont été ajustées aux réseaux de données climatiques actuelles (1971–2000) et futures (2041–2070). La croissance optimale est présentement atteinte entre 46° et 47° de latitude Nord pour la plupart des sources de semences. Les augmentations futures de température devraient entraîner un déplacement de l’habitat optimal d’approximativement 2° vers le nord. Les sources nordiques croissent à des températures sous-optimales et bénéficieraient d’un environnement plus chaud, dans la mesure où les autres facteurs environnementaux ne deviennent pas limitants. Les sources centrales croissent à un rythme qui est près de l’optimum et seront affectées négativement par les augmentations de température dans le futur. Les sources méridionales avaient une meilleure performance dans les milieux plus frais et des températures plus élevées pourraient entraîner des pertes de croissance en hauteur importantes et potentiellement éliminer ces populations. [ABSTRACT FROM AUTHOR]

This article examines the notions among gynecologists that prophylactic oophorectomy is the best way to decrease the rate of ovarian cancer. According to a research, for women of average risk of ovarian cancer, it is better to spare a woman's ovaries at the time of hysterectomy for benign disease because risk of myocardial infarction doubles for women following oophorectomy.

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Botany is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Traditionally, the Pomeroy ligation via minilaparotomy has been the most common method of postpartum tubal sterilization. However, in the obese patient, achieving adequate exposure using this technique is particularly difficult due to the depth of adipose tissue. We report on a small series of five morbidly obese women with body mass indix (BMI) > 35 who underwent laparoscopic postpartum tubal sterilization under general anesthesia within 48 hours of vaginal delivery. Operating room time was less than that for women of similar weights operated on by minilaparotomy. In our series, there were no intraoperative or postoperative complications and the patients were discharged to home on second day postpartum. We have found that for morbidly obese women, laparoscopic postpartum tubal sterilization appears to be safe and effective in the hands of the experienced laparoscopist. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)