Circadian methane oxidation in the root zone of rice plants

In the root zone of rice plants aerobic methanotrophic bacteria catalyze the oxidation of CH4 to CO2, thereby reducing CH4 emissions from paddy soils to the atmosphere. However, methods for in situ quantification of microbial processes in paddy soils are scarce. Here we adapted the push-pull tracer-test (PPT) method to quantify CH4 oxidation in the root zone of potted rice plants. During a PPT, a test solution containing CH4±O2 as reactant(s), Cl− and Ar as nonreactive tracers, and BES as an inhibitor of CH4 production was injected into the root zone at different times throughout the circadian cycle (daytime, early nighttime, late nighttime). After a 2-h incubation phase, the test solution/pore-water mixture was extracted from the same location and rates of CH4 oxidation were calculated from the ratio of measured reactant and nonreactive tracer concentrations. In separate rice pots, O2 concentrations in the vicinity of rice roots were measured throughout the circadian cycle using a fiber-optic sensor. Results indicated highly variable CH4 oxidation rates following a circadian pattern. Mean rates at daytime and early nighttime varied from 62 up to 451μmoll−1h−1, whereas at late nighttime CH4 oxidation rates were low, ranging from 13 to 37μmol l−1h−1. Similarly, daytime O2 concentration in the vicinity of rice roots increased to up to 250% air saturation, while nighttime O2 concentration dropped to below detection (<0.15% air saturation). Our results suggest a functional link between root-zone CH4 oxidation and photosynthetic O2 suppl

Assessing nutrient flux control in agroforestry.

Studies on the strategies for the assessment of relevant factors for the determination of the nutrient output in order to control unporductive nutrient losses and off-site effects of land use by agroforestry, in the Central Amazonia, Brasil

Fertilization effects on soil P, K, Ca and Mg contents in a mixed tree cropping system in Central Amazonia.

The main objective was to study the fertilizer effects on P, K, Ca e Mg contents in mixed tree cropping system with Brazil nut (Bertholletia excelsa), cupuaçu (Theobroma grandiflorum), peach palm (Bactris gasipaes), annatto (Bixa orellana) and pueraria (Pueraria phaseoloides)

Spontane durale arteriovenöse Fistel am Sinus cavernosus: Demaskierung nach endoskopischer Nasennebenhöhlen-Operation

Zusammenfassung: Spontane arteriovenöse Fisteln können sich über längere Zeit symptomlos entwickeln, bevor sie mit Strömungsgeräuschen, Visusminderung, Exophthalmos und konjunktivaler Injektion symptomatisch werden. Wir stellen den seltenen Fall einer okkulten parainfektiösen duralen arteriovenösen Fistel vor. Diese demaskierte sich postoperativ durch akute Verschlechterung der venösen Drainage, möglicherweise aufgrund der intraoperativen Lagerung, positiver Beatmungsdrucke und Stauung durch die Nasentamponad

Pest and disease incidence in agroforestry systems of the Brazilian Central Amazon.

In Central Amazonia there are no examples of pests or diseases whose incidence is reduced in agroforestry systems

Thrombolyse der Arteria cerebri media

Zusammenfassung: In den ersten 3h nach Eintritt eines akuten ischämischen Hirninfarkts ist die intravenöse Thrombolyse (IVT) die evidenzbasierte Therapie (IVT 3-4,5h: "off-label use" mit Einverständnis des Patienten). Die intraarterielle Thrombolyse (IAT) führt in der A.cerebri media (ACM) allerdings häufiger zur Rekanalisation als die IVT. Daher ist die IAT in dafür ausgerüsteten Kliniken ergänzend oder alternativ zur IVT bis zu 6h nach Symptombeginn zu erwäge

Efficacy of PD-1 checkpoint inhibitor therapy in melanoma and beyond: are peripheral T cell phenotypes the key?

Immunotherapy treatment strategies have proven effective in a limited portion of patients, where identifying responders from non-responders to treatment remains a challenge. While some indications can be drawn from invasive biopsies, we need more accessible methods for predicting response and better correlates of response prior to starting therapy. Recent work has identified differences in immune composition at baseline in peripheral blood from melanoma patients responding to PD-1 blockade treatment. Through flow cytometric analysis of T cell receptors, phenotypical features of CD8+ and CD4+ T cells and Tregs could allow for the stratification of treatment response. Analysing T cells within peripheral blood could potentially allow for the stratification of PD-1 treatment response prior to therapy in different cancer settings