Dynamics of Postfire Aboveground Carbon in a Chronosequence of Chinese Boreal Larch Forests

Boreal forests store a large proportion of the global terrestrial carbon (C), while wildfire plays a crucial role in determining their C storage and dynamics. The aboveground C (AC) pool is an important component of forest C stocks. To quantify the turning point (transforming from C source to C sink) and recovery time of postfire AC, and assess how stand density affects the AC, 175 plots from eight stand age classes were surveyed as a chronosequence in the Great Xing\u27an Mountains of Northeast China. Linear and nonlinear regression analyses were conducted to describe postfire AC recovery patterns. The results showed that (1) postfire AC exhibited a skewed U‐shaped pattern with the turning point at approximately year 30, when the change rate of AC shifted from negative to positive, (2) it took more than 120 years for this forest ecosystem to recover 80% of AC in unburned old‐growth (200 years) stands, and (3) there was an overall positive relationship between AC and stand density over the entire range of stand age classes; and such relationship was stronger during the early‐ and late‐successional stages, but weaker (p \u3e 0.05) during the midsuccessional stage. Although boreal larch forests have been C sinks under historical fire free intervals, predicted increases in fire frequency could potentially shift it to a C source. Understanding postfire AC dynamics in boreal larch forests is central to predicting C cycling response to wildfire and provides a framework for assessing ecosystem resilience to disturbance in this region

Demixed principal component analysis of neural population data

Neurons in higher cortical areas, such as the prefrontal cortex, are often tuned to a variety of sensory and motor variables, and are therefore said to display mixed selectivity. This complexity of single neuron responses can obscure what information these areas represent and how it is represented. Here we demonstrate the advantages of a new dimensionality reduction technique, demixed principal component analysis (dPCA), that decomposes population activity into a few components. In addition to systematically capturing the majority of the variance of the data, dPCA also exposes the dependence of the neural representation on task parameters such as stimuli, decisions, or rewards. To illustrate our method we reanalyze population data from four datasets comprising different species, different cortical areas and different experimental tasks. In each case, dPCA provides a concise way of visualizing the data that summarizes the task-dependent features of the population response in a single figure

Сравнение эффективности режимов самостоятельного дыхания с поддержкой давлением и принудительной вентиляции с управлением по объему во время общей комбинированной анестезии без использования миорелаксантов

To compare efficacy of spontaneous breathing with pressure support and volume-controlled mandatory ventilation during combined general anesthesia using desflurane and without muscle relaxants.Subjects and Methods. 100 patients were included in the study. All underwent low-traumatic operations on the lower limbs under general combined anesthesia using supraglottic air devices without muscle relaxants. Immediately prior to the induction of anesthesia, patients were randomly divided into two groups: Group 1 (VCV) where a mandatory volume control mode was used (n = 50) and Group 2 (PSV) where a pressure support mode was used (n = 50). The following parameters were assessed: hemodynamics, gas exchange, depth of anesthesia before induction, during and after the end of general anesthesia; arterial blood gas composition one hour after induction of anesthesia; indicators of pressure in the respiratory tract during mechanical ventilation, as well as time parameters of awakening.Results. In patients of Group 2 (PSV), according to the analysis of arterial blood gases, a higher level of PaO2 (p = 0.006), Horowitz index (p = 0.005), and carbon dioxide level (p < 0.0001) were noted. In Group 1 (VCV), higher mean and peak airway pressures were found one hour after induction and 10 minutes before the end of surgery (p < 0.05). Also in the groups, there were statistically significant differences in the time parameters of awakening (233 ± 58 sec and 352 ± 83 sec in the PSV and VCV groups, respectively), supraglottic airway device removal time (268 ± 62 sec and 398 ± 84 sec in the PSV and VCV groups, respectively) and transfer to the ward (395 ± 60 sec and 571 ± 66 sec in the PSV and VCV groups, respectively) (p < 0.0001). There were no significant differences in the main parameters of hemodynamics and depth of anesthesia, the consumption of anesthetics used during induction and maintenance of general anesthesia.Conclusion: The use of spontaneous breathing with pressure support during general combined anesthesia without muscle relaxants has a number of advantages versus mandatory ventilation mode. These include better oxygenation rates, lower airway pressure, faster awakening, supraglottic airway device removal time, and transfer of the patient to the ward. At the same time, acceptable ventilation, stable hemodynamic parameters and depth of anesthesia are maintained.Цель: сравнить эффективность режимов самостоятельного дыхания с поддержкой давлением и принудительной вентиляции с управлением по объему во время общей комбинированной анестезии с использованием десфлурана без применения миорелаксантов.Материалы и методы. В исследование включено 100 пациентов. Всем выполнялись малотравматичные операции на нижних конечностях в условиях общей комбинированной анестезии с использованием надгортанных воздуховодов без применения миорелаксантов. Непосредственно перед индукцией анестезии пациенты были случайно разделены на две группы: 1-я группа (VCV), в которой использовали принудительный режим с управлением по объему (n = 50), и 2-я группа (PSV), в которой применяли режим самостоятельного дыхания с поддержкой давлением (n = 50). Оценивали параметры гемодинамики, газообмена, глубины анестезии до индукции, во время и после окончания общей анестезии; газовый состав артериальной крови через 1 ч после индукции анестезии; показатели давления в дыхательных путях во время проведения искусственной вентиляции легких, а также временные параметры пробуждения.Результаты. У пациентов 2-й группы (PSV) по данным анализа газового состава артериальной крови отмечали более высокий уровень РаО2 (p = 0,006), индекса Горовица (p = 0,005), а также уровня углексислого газа (p < 0,0001). В 1-й группе (VCV) были выявлены более высокие уровни среднего и пикового давлений в дыхательных путях через 1 ч после индукции и за 10 мин до окончания операции (p < 0,05). Также между группами наблюдали статистически значимые различия временных показателей пробуждения (233 ± 58 и 352 ± 83 с в группах PSV и VCV соответственно), удаления надгортанного воздуховода (268 ± 62 и 398 ± 84 с в группах PSV и VCV соответственно) и перевода в отделение (395 ± 60 и 571 ± 66 с в группах PSV и VCV соответственно) (p < 0,0001). Не выявлено значимых различий по основным показателям гемодинамики и глубины анестезии, расходу анестетиков, использованных во время индукции и поддержания общей анестезии.Вывод. Применение режима самостоятельного дыхания с поддержкой давлением во время общей комбинированной анестезии без использования миорелаксантов имеет ряд преимуществ по сравнению с принудительным режимом вентиляции. К ним относятся лучшие показатели оксигенации, меньшее давление в дыхательных путях, более короткое время до пробуждения, удаления надгортанного воздуховода и перевода пациента в отделение. При этом сохраняются приемлемая вентиляция, стабильные параметры гемодинамики и глубина анестезии

Direct measurement of hyperfine shifts and radio frequency manipulation of the nuclear spins in individual CdTe/ZnTe quantum dots

We achieve direct detection of electron hyperfine shifts in individual CdTe / ZnTe quantum dots. For the previously inaccessible regime of strong magnetic fields Bz≳0.1T, we demonstrate robust polarization of a few-hundred-particle nuclear spin bath, with an optical initialization time of ∼1 ms and polarization lifetime exceeding ∼1s. Nuclear magnetic resonance spectroscopy of individual dots reveals strong electron-nuclear interactions characterized by Knight fields |Be|≳50 mT, an order of magnitude stronger than in III–V semiconductor quantum dots. Our studies confirm II–VI semiconductor quantum dots as a promising platform for hybrid electron-nuclear spin qubit registers, combining the excellent optical properties comparable to III–V dots and the dilute nuclear spin environment similar to group-IV semiconductors

Automated telephone follow-up after breast cancer: an acceptability and feasibility pilot study

Traditional clinical follow-up after breast cancer is inefficient at detecting relapse and is poorly suited to detecting and ameliorating psychological problems. There is interest in developing more effective and efficient methods of follow-up. We report a prospective cohort study of the acceptability and feasibility of remote, automated telephone follow-up after breast cancer. Women with a history of breast cancer were approached at their annual follow-up visit. For participants, the follow-up questionnaire was administered on paper at baseline. In place of a clinic visit following year, the women completed the same questionnaire using an automated telephone system. All patients were given mammograms. A semi-structured interview was then conducted to assess the acceptability. The potential impact on clinic usage was assessed. In all, 110 of 121 women (91%) agreed to participate. Seventy-five patients (71%) completed follow-up using the new automated system 1 year later. Seventy-one of the 75 patients found the system easy to use. Forty-nine of the 75 (65.33%) liked the system and were happy to use it as their sole method of follow-up. A further 12% were happy to use it as part of their follow-up. In only 10.66% of participants were concerns raised which led to clinic attendance. Automated questionnaire-based telephone follow-up is acceptable to women and has the potential to reduce attendance at clinic. Further studies to validate this method further are planned