Search results for "HORIZON"

Energy use in the A and B horizons of the soil under a pine and a cedar stand

2002

Publisher Summary This chapter discusses a study that compares organic carbon content, availability of substrates, and microbial metabolism in two afforested sites in Sicily (Italy) developed under the same climatic and physical conditions but underlying different tree species. Given the key role of the soil microbiota in promoting energy exchanges and transformations in the soil profile, an analysis of the microbial activity and of organic carbon pools was performed on twenty profiles. The parameters considered in this study were based on microbial activity, organic carbon fractions, and kinetics of organic C mineralization. In the two systems studied, the competition for available energy …

Phylogenomics of Enterococcus faecalis from wild birds: new insights into host‐associated differences in core and accessory genomes of the species

2019

Wild birds have been suggested to be reservoirs of antimicrobial resistant and/or pathogenic Enterococcus faecalis (Efs) strains, but the scarcity of studies and available sequences limit our understanding of the population structure of the species in these hosts. Here, we analysed the clonal and plasmid diversity of 97 Efs isolates from wild migratory birds. We found a high diversity, with most sequence types (STs) being firstly described here, while others were found in other hosts including some predominant in poultry. We found that pheromone‐responsive plasmids predominate in wild bird Efs while 35% of the isolates entirely lack plasmids. Then, to better understand the ecology of the sp…

Design of a sun tracker for the automatic measurement of spectral irradiance and construction of an irradiance database in the 330-1100 nm range

2007

Abstract An automatic global and direct solar spectral irradiance system has been designed based on two LICOR spectroradiometers equipped with fibre optics and remote cosine sensors. To measure direct irradiance a sun tracker based on step motors has been developed. The whole system is autonomous and works continuously. From the measurements provided by this system a spectral irradiance database in the 330–1100 nm range has been created. This database contains normal direct and global horizontal irradiances as well as diffuse irradiance on a horizontal plane, together with total atmospheric optical thickness and aerosol optical depth.

Hawking Radiation by Kerr Black Holes and Conformal Symmetry

2010

The exponential blueshift associated with the event horizon of a black hole makes conformal symmetry play a fundamental role in accounting for its thermal properties. Using a derivation based on two-point functions, we show that the full spectrum of thermal radiation of scalar particles by Kerr black holes can be explicitly derived on the basis of a conformal symmetry arising in the wave equation near the horizon. The simplicity of our approach emphasizes the depth of the connection between conformal symmetry and black hole radiance.

Counteracting the horizontal spread of bacterial antibiotic resistance with conjugative plasmid-dependent bacteriophages

2016

Uzņēmuma SIA “Tālbergs” finansiālā stāvokļa analīze un attīstības perspektīvas

2020

Darba autore pētījuma ietvaros sniedz SIA “Tālbergs” darbības procesu raksturojumu, veicot uzņēmuma finanšu analīzi, lai novērtētu pašreizējo uzņēmuma situāciju, kā arī iespējamos pilnveidojumus uzņēmuma darbībā. Darba mērķis – pamatojoties uz finanšu analīzes teorētisko aspektu raksturojumu, novērtēt SIA “Tālbergs” finansiālo stāvokli un izstrādāt priekšlikumus uzņēmuma tālākai attīstībai. Pētījuma rezultāti parādīja, ka uzņēmuma darbības galvenās problēmas ir saistītas ar izmaksu, ilgstošo debitoru un īstermiņa saistību pieaugumu, kam ir negatīva ietekme uz uzņēmuma darbības rādītājiem, un ir izstrādāti priekšlikumi, kā samazināt šo posteņu vērtības pieaugumu.

Domain organization and evolution of multifunctional autoprocessing repeats-in-toxin (MARTX) toxin in Vibrio vulnificus.

2011

ABSTRACT The objective of this study was to analyze multifunctional autoprocessing repeats-in-toxin (MARTX) toxin domain organization within the aquatic species Vibrio vulnificus as well as to study the evolution of the rtxA1 gene. The species is subdivided into three biotypes that differ in host range and geographical distribution. We have found three different types (I, II, and III) of V. vulnificus MARTX (MARTX Vv ) toxins with common domains (an autocatalytic cysteine protease domain [CPD], an α / β-hydrolase domain, and a domain resembling that of the LifA protein of Escherichia coli O127:H6 E2348/69 [Efa/LifA]) and specific domains (a Rho-GTPase inactivation domain [RID], a domain of …

Why are the genomes of endosymbiotic bacteria so stable?

2003

The comparative analysis of three strains of the endosymbiotic bacterium Buchnera aphidicola has revealed high genome stability associated with an almost complete absence of chromosomal rearrangements and horizontal gene transfer events during the past 150 million years. The loss of genes involved in DNA uptake and recombination in the initial stages of endosymbiosis probably underlies this stability. Gene loss, which was extensive during the initial steps of Buchnera evolution, has continued in the different Buchnera lineages since their divergence.

Changes in the African monsoon region at medium-term time horizon using 12 AR4 coupled models under the A1b emissions scenario.

2011

This study documents simulated precipitation and circulation changes through the 20C3M and A1b scenarios. It portrays a robust pattern, associating rainfall deficits in subtropical regions with rainfall excesses over West Africa, except in Northern Senegal and Mauritania, with a significant enhancement of both the April–June rainy season in 10/12 models and of the July–September rainy season in 8/12 models. Eastward to 5°W a northward shift in the latitude of the moisture flux convergence at 850 hPa is evident in 10/11 models (+0.58° in mean) and a southward shift in 6/11 models in the western region (−0.24°) is observed. Copyright © 2011 Royal Meteorological Society

Depth matters : Effects of precipitation regime on soil microbial activity upon rewetting of a plant-soil system

2018

International audience; Climate change is predicted to affect not only the amount but also the temporal distribution of rain. Changes in frequency and amplitude of rain events, i.e. precipitation patterns, result in different water conditions with soil depth, and likely affect plant growth and shape plant and soil microbial activity. Here, we used 18O stable isotope probing (SIP) to investigate bacterial and fungal communities that actively grew or not upon rewetting, at three different depths in plant-soil mesocosms previously subjected to frequent or infrequent watering for 12 weeks (equal total water input). Phylogenetic marker genes for bacteria and fungi were sequenced after rewetting,…