2,125 research outputs found
Soil organic matter availability and climate drive latitudinal patterns in bacterial diversity from tropical to cold temperate forests
Bacteria are one of the most abundant and diverse groups of micro-organisms and mediate many critical terrestrial ecosystem processes. Despite the crucial ecological role of bacteria, our understanding of their large-scale biogeography patterns across forests, and the processes that determine these patterns lags significantly behind that of macroorganisms. Here, we evaluated the geographic distributions of bacterial diversity and their driving factors across nine latitudinal forests along a 3,700-km north–south transect in eastern China, using high-throughput 16S rRNA gene sequencing. Four of 32 phyla detected were dominant: Acidobacteria, Actinobacteria, Alphaproteobacteria and Chloroflexi (relative abundance > 5%). Significant increases in bacterial richness and phylogenetic diversity were observed for temperate forests compared with subtropical or tropical forests. The soil organic matter (SOM) mineralisation rate (SOM , an index of SOM availability) explained the largest significant variations in bacterial richness. Variation partition analysis revealed that the bacterial community structure was closely correlated with environmental variables and geographic distance, which together explained 80.5% of community variation. Among all environmental factors, climatic features (MAT and MAP) were the best predictors of the bacterial community structure, whereas soil pH and SOM emerged as the most important edaphic drivers of the bacterial community structure. Plant functional traits (community weighted means of litter N content) and diversity resulted in weak but significant correlations with the bacterial community structure. Our findings provide new evidence of bacterial biogeography patterns from tropical to cold temperate forests. Additionally, the results indicated a close linkage among soil bacterial diversity, climate and SOM decomposition, which is critical for predicting continental-scale responses under future climate change scenarios and promoting sustainable forest ecosystem services. A plain language summary is available for this article. min mi
Combined Spatial Filter and Relay Systems in Rotating Compensator Ellipsometer/Polimeter
Low aberration relay systems modified to perform as spatial filters in rotating compensator ellipsometer, polarimeter and the like systems
ROTATING OR ROTATABLE COMPENSATOR SYSTEMI PROVIDING ABERATION CORRECTED ELECTROMAGNETIC RAADATION TO A SPOT ON A SAMPLE AT MULTIPLE ANGLES OF ANCIDENCE
The present invention relates to ellipsometer systems, and more particularly to ellipsometer systems comprising trans missive rotating or stepwise rotatable compensators for continuously or step-wise varying polarization states and further comprising transmissive multi-element lens focusing of a spectroscopic electromagnetic beam into a small, chromatically relatively undispersed area spot on a sample system. The ellipsometer system optionally is present in an environmental control chamber
Transplant Outcomes for Children with Hypodiploid Acute Lymphoblastic Leukemia: The Cibmtr Experience
Cincinnati Childrens Hosp Med Ctr, Cincinnati, OH 45229 USAMed Coll Wisconsin, CIBMTR, Milwaukee, WI 53226 USAMed Coll Wisconsin, Milwaukee, WI 53226 USAInst Oncol Pediat, Sao Paulo, BrazilUniv Michigan, Ann Arbor, MI 48109 USAUniv S Florida, All Childrens Hosp, St Petersburg, FL 33701 USAWeb of Scienc
On multistability of delayed genetic regulatory networks with multivariable regulation functions
The official published version of the article can be found at the link below.Many genetic regulatory networks (GRNs) have the capacity to reach different stable states. This capacity is defined as multistability which is an important regulation mechanism. Multiple time delays and multivariable regulation functions are usually inevitable in such GRNs. In this paper, multistability of GRNs is analyzed by applying the control theory and mathematical tools. This study is to provide a theoretical tool to facilitate the design of synthetic gene circuit with multistability in the perspective of control theory. By transforming such GRNs into a new and uniform mathematical formulation, we put forward a general sector-like regulation function that is capable of quantifying the regulation effects in a more precise way. By resorting to up-to-date techniques, a novel Lyapunov–Krasovskii functional (LKF) is introduced for achieving delay dependence to ensure less conservatism. New conditions are then proposed to ensure the multistability of a GRN in the form of linear matrix inequalities (LMIs) that are dependent on the delays. Our multistability conditions are applicable to several frequently used regulation functions especially the multivariable ones. Two examples are employed to illustrate the applicability and usefulness of the developed theoretical results.This work was supported in part by the Biotechnology and Biological Sciences Research Council (BBSRC) of the UK under Grants BB/C506264/1 and 100/EGM17735, the Royal Society of the UK, the National Natural Science Foundation of China under Grant 61028008, and the International Science and Technology Cooperation Project of China under Grant 2009DFA32050
SAMPLE INVESTIGATING SYSTEM AND METHOD OF USE
A spectroscopic system for adjusting spacing between an adjacent source/detector as a unit, and a sample, and a reflecting means for directing an incident beam which reflects from said sample back onto said sample and then into the detector along a locus which is in a plane of incidence that is offset from that of the incident beam, or directly from the reflecting means into the detector, including means for reducing reflections of a beam of electromagnetic from the back of a sample, including methodology of use
Stable solar-driven oxidation of water by semiconducting photoanodes protected by transparent catalytic nickel oxide films
Reactively sputtered nickel oxide (NiO_x) films provide transparent, antireflective, electrically conductive, chemically stable coatings that also are highly active electrocatalysts for the oxidation of water to O_2(g). These NiO_x coatings provide protective layers on a variety of technologically important semiconducting photoanodes, including textured crystalline Si passivated by amorphous silicon, crystalline n-type cadmium telluride, and hydrogenated amorphous silicon. Under anodic operation in 1.0 M aqueous potassium hydroxide (pH 14) in the presence of simulated sunlight, the NiO_x films stabilized all of these self-passivating, high-efficiency semiconducting photoelectrodes for >100 h of sustained, quantitative solar-driven oxidation of water to O_2(g)
Circumstellar molecular composition of the oxygen-rich AGB star IK~Tau: II. In-depth non-LTE chemical abundance analysis
Aims: Little information exists on the circumstellar molecular abundance
stratifications of many molecules. The aim is to study the circumstellar
chemical abundance pattern of 11 molecules and isotopologs (CO,
CO, SiS, SiO, SiO, SiO, HCN, CN, CS, SO, SO) in
the oxygen-rich evolved star IK~Tau. Methods: We have performed an in-depth
analysis of a large number of molecular emission lines excited in the
circumstellar envelope around IK~Tau. The analysis is done based on a non-local
thermodynamic equilibrium (non-LTE) radiative transfer analysis, which
calculates the temperature and velocity structure in a self-consistent way. The
chemical abundance pattern is coupled to theoretical outer wind model
predictions including photodestruction and cosmic ray ionization. Not only the
integrated line intensities, but also the line shapes, are used as diagnostic
tool to study the envelope structure. Results: The deduced wind acceleration is
much slower than predicted from classical theories. SiO and SiS are depleted in
the envelope, possibly due to the adsorption onto dust grains. For HCN and CS a
clear difference with respect to inner wind non-equilibrium predictions is
found, either indicating uncertainties in the inner wind theoretical modeling
or the possibility that HCN and CS (or the radical CN) participate in the dust
formation. The low signal-to-noise profiles of SO and CN prohibit an accurate
abundance determination; the modeling of high-excitation SO lines is
cumbersome, possibly related to line misidentifications or problems with the
collisional rates. The SiO isotopic ratios (SiO/SiO and
SiO/SiO) point toward an enhancement in SiO compared to
results of classical stellar evolution codes. Predictions for HO lines in
the spectral range of the Herschel/HIFI mission are performed. [abbreviated]Comment: 24 pagees, accepted for publication in Astronomy & Astrophysic
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