Longer growing seasons do not increase net carbon uptake in Northeastern Siberian tundra

With global warming, snowmelt is occurring earlier and growing seasons are becoming longer around the Arctic. It has been suggested that this would lead to more uptake of carbon due to a lengthening of the period in which plants photosynthesize. To investigate this suggestion, 8 consecutive years of eddy covariance measurements at a northeastern Siberian graminoid tundra site were investigated for patterns in net ecosystem exchange, gross primary production (GPP) and ecosystem respiration (Reco). While GPP showed no clear increase with longer growing seasons, it was significantly increased in warmer summers. Due to these warmer temperatures however, the increase in uptake was mostly offset by an increase in Reco. Therefore, overall variability in net carbon uptake was low, and no relationship with growing season length was found. Furthermore, the highest net uptake of carbon occurred with the shortest and the coldest growing season. Low uptake of carbon mostly occurred with longer or warmer growing seasons. We thus conclude that the net carbon uptake of this ecosystem is more likely to decrease rather than to increase under a warmer climate. These results contradict previous research that has showed more net carbon uptake with longer growing seasons. We hypothesize that this difference is due to site-specific differences, such as climate type and soil, and that changes in the carbon cycle with longer growing seasons will not be uniform around the Arcti

The seasonal cycle of the greenhouse gas balance of a continental tundra site in the Indigirka lowlands, NE Siberia

International audienceCarbon dioxide and methane fluxes were measured at a tundra site near Chokurdakh, in the lowlands of the Indigirka river in north-east Siberia. This site is one of the few stations on Russian tundra and it is different from most other tundra flux stations in its continentality. A suite of methods was applied to determine the fluxes of NEE, GPP, Reco and methane, including eddy covariance, chambers and leaf cuvettes. Net carbon dioxide fluxes were unusually high, compared with other tundra sites, with NEE=?92 g C m?2 yr?1, which is composed of an Reco=+141 g C m?2 yr?1 and GPP=?232 g C m?2 yr?1. This large carbon dioxide sink may be explained by the continental climate, that is reflected in low winter soil temperatures (?14°C), reducing the respiration rates, and short, relatively warm summers, stimulating high photosynthesis rates. Interannual variability in GPP was dominated by the frequency of light limitation (Rg ?2), whereas Reco depends most directly on soil temperature and time in the growing season, which serves as a proxy of the combined effects of active layer depth, leaf area index, soil moisture and substrate availability. The methane flux, in units of global warming potential, was +28 g C-CO2e m?2 yr?1, so that the greenhouse gas balance was ?64 g C-CO2e m?2 yr?1. Methane fluxes depended only slightly on soil temperature and were highly sensitive to hydrological conditions and vegetation composition

РЕЗУЛЬТАТЫ ЭТАПНОГО ХИРУРГИЧЕСКОГО ЛЕЧЕНИЯ ИНФАНТИЛЬНЫХ И ЮВЕНИЛЬНЫХ СКОЛИОЗОВ С ИСПОЛЬЗОВАНИЕМ РАЗЛИЧНЫХ МЕТОДИК

Introduction. The analysis Results of surgical treatment of growing children with infantile and juvenile scoliosis (IS) can the optimal method of treatment select. In young children with significant growth potential spinal fusion may not be the best option as it limits further longitudinal growth of the spine and may to the thoracic insufficiency syndrome result. To address this problem recently several techniques focused, their have advantages and drawbacks.Material and methods. Since 2008 year 127 patients (64 girls, 63 boys) aged (4.5 ± 2.1) years were operated on. In group I 65 patients were operated on using VEPTR (Vertical Expandable Prosthetic Titanium Rib) instrumentation, in group II 42 patients using various spinal instrumentation. 20 patients with congenital kyphosis were excluded. The average follow-up time was (5.6 ± 1.1) years.Results. In group I average value of the primary scoliotic curve before surgery was (74.7 ± 22.9), secondary curve (42.8 ± 16.0), thoracic kyphosis (46.3 ± 27.4), lumbar lordosis (54.6 ± 14). Average value of the primary scoliotic curve after surgery was reduced to (51 ± 20) (correction 31.7%), at followup to (56.5 ± 18.5), secondary curve (31.8 ± 12.8) (25.7%), at follow-up to (32.4 ± 18.4), thoracic kyphosis (36.8 ± 20.8) (20,5%), at follow-up to (41.8 ± 21.0), lumbar lordosis (45.4 ± 12.7) (16,9%), at follow-up to (48.2 ± 11.7) (p < 0.05). Space available for lung before surgery was (84.5 ± 8.7) %, after surgery was (94.8 ± 6.7)%, at follow-up increased to (98.6 ± 5.4) % (p < 0.05). Complications included 11 implant dislocations and 1 infection. In group II average value of the primary scoliotic curve before surgery was (87.6 ± 6.6), secondary curve (47.8 ± 4.6), thoracic kyphosis (61.4 ± 10.4), lumbar lordosis (61.8 ± 4.9). Average value of the primary scoliotic curve after surgery was reduced to 50.6 ± 5.3 (correction 42.3%), at follow-up to (66.1 ± 6.3), secondary curve (24.1 ± 2.9) (49.6%), at follow-up to (37 ± 5.4), thoracic kyphosis (38.8 ± 7.7) (36.8%), at follow-up to (59.4 ± 11.2), lumbar lordosis (47.5 ± 4.1) (23.2%), at follow-up to (64.5 ± 4.5) (p < 0.05). Complications included 23 implant dislocations and 1 infection. No neurological complications.Conclusion. Stage correction fusions using various instrumentation is a method of choice for controlled correction of growing children with IS.Введение. Анализ результатов хирургического лечения сколиотических деформаций позвоночника у активно растущих детей позволяет выбрать оптимальный метод лечения. Стабилизация позвоночника является быть оптимальным вариантом, так как может привести к ограничению его дальнейшего роста и развитию синдрома торакальной недостаточности. На решение этой задачи в последнее время ориентировано несколько методик, имеющих свои достоинства и недостатки.Цель исследования – проанализировать результаты хирургического лечения инфантильных и ювенильных сколиозов с использованием различного инструментария.Материал и методы. В период с 1998 по2014 г. оперировано 127 детей (64 девочки и 63 мальчика) с инфантильными и ювенильными деформациями позвоночника различной этиологии. Операции проводились по двум методикам: первая группа (65 больных) – по методике VEPTR (Vertical Expandable Prosthetic Titanium Rib, США), вторая (42 больных) – с использованием дорсального сегментарного инструментария. Средний возраст начала лечения составил (4,5 ± 2,1) года (I группа), (7,6 ± 2,4) года (II группа). Сроки послеоперационного наблюдения составили (5,6 ± 1,1) года (от 6 мес до 12 лет).Результаты. В группе I средняя величина основной сколиотической дуги перед началом лечения составляла (74,7 ± 22,9)°, противоискривления – (42,8 ± 16)°, грудного кифоза – (46,3±27,4)°, поясничного лордоза – (54,6 ± 14)°. Величина основной сколиотической дуги после операции составляла (51,0 ± 20,0)° (коррекция 31,7%), противоискривления – (31,8 ± 12,8)° (коррекция 25,7%), кифоза – (36,8 ± 20,8)° (коррекция 20,5%), лордоза – (45,4 ± 12,7)° (коррекция 16,9%) (p < 0,05). В конце срока наблюдения величина основной сколиотической дуги составила (56,5 ± 18,5)°, противоискривления – (32,4 ± 18,4)°, кифоза – (41,8 ± 21,0)°, лордоза – (48,2 ± 11,7)° (p < 0,05). При использовании инструментария VEPTR отмечено увеличение отношения пространств доступных для легких в сравнении с исходным – (84,5 ± 8,7), послеоперационным – (94,8 ± 6,7) и значением в конце срока наблюдения – (98,6 ± 5,4) (p < 0,05). У 11 пациентов отмечена нестабильность захватов инструментария, 1 случай нагноения. Во II группе средняя величина основной сколиотической дуги перед началом лечения составляла (87,6 ± 6,6)°, противоискривления – (47,8 ± 4,6)°, грудного кифоза – (61,4 ± 10,4)°, поясничного лордоза – (61,8 ± 4,9)°. Величина основной сколиотической дуги после операции составляла (50,6 ± 5,3)° (коррекция 42,3%), противоискривления – (24,1 ± 2,9)° (коррекция 49,6%), кифоза – (38,8 ± 7,7)° (коррекция 36,8%), лордоза – (47,5 ± 4,1)° (коррекция 23,2%) (p < 0,05). В конце срока наблюдения величина основной сколиотической дуги составила (66,1 ± 6,3)°, противоискривления – (37,0 ± 5,4)°, кифоза – (59,4 ± 11,2)°, лордоза – (64,5 ± 4,5)° (p < 0,05). У 23 пациентов отмечена нестабильность захватов инструментария, 1 случай нагноения. Неврологических осложнений не отмечено.Вывод. При хирургическом лечении инфантильных и ювенильных сколиозов методом выбора являются этапные коррекции с использованием различного инструментария

Clinical case of invasive breast carcinoma with progressive pregnancy

The purpose of the study is to present and analyze the clinical case and therapy approach of invasive breast carcinoma in a pregnant patient.Цель исследования - представить и проанализировать клинический случай и подход к терапии инвазивной карциномы молочной железы у беременной пациентки