Showing papers by "National University of La Plata published in 2005"

The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI - Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections

Abstract: We present the final data release of observations of ?21-cm emission from Galactic neutral hydrogen over the entire sky, merging the Leiden/Dwingeloo Survey (LDS: Hartmann & Burton 1997, Atlas of Galactic Neutral Hydrogen) of the sky north of ? = ?30? with the Instituto Argentino de Radioastronomia Survey (IAR: Arnal et al. 2000, AA and Bajaja et al. 2005, A&A, 440, 767) of the sky south of ? = ?25?. The angular resolution of the combined material is HPBW ? 0. ?6. The LSR velocity coverage spans the interval ?450 km s?1 to +400 km s?1, at a resolution of 1.3 kms?1. The data were corrected for stray radiation at the Institute for Radioastronomy of the University of Bonn, refining the original correction applied to the LDS. The rms brightness-temperature noise of the merged database is 0.07?0.09 K. Residual errors in the profile wings due to defects in the correction for stray radiation are for most of the data below a level of 20?40 mK. It would be necessary to construct a telescope with a main beam efficiency of ?MB >? 99% to achieve the same accuracy. The merged and refined material entering the LAB Survey of Galactic HI is intended to be a general resource useful to a wide range of studies of the physical and structural characteristices of the Galactic interstellar environment. The LAB Survey is the most sensitive Milky Way HI survey to date, with the most extensive coverage both spatially and kinematically.

Electron Spectroscopy of Aqueous Solution Interfaces Reveals Surface Enhancement of Halides

Abstract: It has been suggested that enhanced anion concentrations at the liquid/vapor interface of airborne saline droplets are important to aerosol reactions in the atmosphere. We report ionic concentrations in the surface of such solutions. Using x-ray photoelectron spectroscopy operating at near ambient pressure, we have measured the composition of the liquid/vapor interface for deliquesced samples of potassium bromide and potassium iodide. In both cases, the surface composition of the saturated solution is enhanced in the halide anion compared with the bulk of the solution. The enhancement of anion concentration is more dramatic for the larger, more polarizable iodide anion. By varying photoelectron kinetic energies, we have obtained depth profiles of the liquid/vapor interface. Our results are in good qualitative agreement with classical molecular dynamics simulations. Quantitative comparison between the experiments and the simulations indicates that the experimental results exhibit more interface enhancement than predicted theoretically.

Atmospheric NLTE-models for the spectroscopic analysis of blue stars with winds. II. Line-blanketed models

Abstract: We present new or improved methods for calculating NLTE, line-blanketed model atmospheres for hot stars with winds (spectral types A to O), with particular emphasis on fast performance These methods have been implemented into a previous, more simple version of the model atmosphere code F (Santolaya-Rey et al 1997) and allow us to spec- troscopically analyze large samples of massive stars in a reasonable time-scale, using state-of-the-art physics Although this updated version of the code has already been used in a number of recent investigations, the corresponding methods have not been explained in detail so far, and no rigorous comparison with results from alternative codes has been performed This paper intends to address both topics In particular, we describe our (partly approximate) approach to solve the equations of statistical equilibrium for those elements that are primarily responsible for line-blocking and blanketing, as well as an approximate treatment of the line-blocking itself, which is based on a simple statistical approach using suitable means of line opacities and emissivities Both methods are validated by specific tests Furthermore, we comment on our implementation of a consistent temperature structure In the second part, we concentrate on a detailed comparison with results from two codes used in alternative spectroscopical investigations, namely  (Hillier & Miller 1998) and -Basic (Pauldrach et al 2001) All three codes predict almost identical temperature structures and fluxes for λ> 400 A, whereas at lower wavelengths a number of discrepancies are found Particularly in the He continua, where fluxes and corresponding numbers of ionizing photons react extremely sensitively to subtle differences in the models, we consider any uncritical use of these quantities (eg, in the context of nebula diagnostics) as unreliable Optical H/He lines as synthesized by  are compared with results from , obtaining a remarkable coincidence, except for the He singlets in the temperature range between 36 000 to 41 000 K for dwarfs and between 31 000 to 35 000 K for supergiants, where  predicts much weaker lines Consequences of these discrepancies are discussed Finally, suggestions are presented as to adequately parameterize model-grids for hot stars with winds, with only one additional parameter compared to standard grids from plane-parallel, hydrostatic models

Supervisor control for a stand-alone hybrid generation system using wind and photovoltaic energy

Abstract: A comprehensive supervisor control for a hybrid system that comprises wind and photovoltaic generation subsystems, a battery bank, and an ac load is developed in this paper. The objectives of the supervisor control are, primarily, to satisfy the load power demand and, second, to maintain the state of charge of the battery bank to prevent blackout and to extend the life of the batteries. For these purposes, the supervisor controller determines online the operation mode of both generation subsystems, switching from power regulation to maximum power conversion. Decision criteria for the supervisor based on measurable system variables are presented. Finally, the performance of the supervisor controller is extensively assessed through computer simulation using a comprehensive nonlinear model of the plant.

Self-assembled monolayers of alkanethiols on Au(111): surface structures, defects and dynamics

Abstract: The surface structures, defects and dynamics of self-assembled monolayers (SAMs) on Au(111) are reviewed. In the case of the well-known c(4 × 2) and √3 × √3 R30° surface structures, the present discussion is centered on the determination of the adsorption sites. A more complex scenario emerges for the striped phases, where a variety of surface structures that depends on surface coverage are described. Recently reported surface structures at non-saturation coverage show the richness of the self-assembly process. The study of surface dynamics sheds light on the relative stability of some of these surface structures. Typical defects at the alkanethiol monolayer are shown and discussed in relation to SAMs applications.

Senescence-associated vacuoles with intense proteolytic activity develop in leaves of Arabidopsis and soybean.

Abstract: Summary Vacuolar compartments associated with leaf senescence and the subcellular localization of the senescence-specific cysteine-protease SAG12 (senescence-associated gene 12) were studied using specific fluorescent markers, the expression of reporter genes, and the analysis of high-pressure frozen/freeze-substituted samples. Senescence-associated vacuoles (SAVs) with intense proteolytic activity develop in the peripheral cytoplasm of mesophyll and guard cells in Arabidopsis and soybean. The vacuolar identity of these compartments was confirmed by immunolabeling with specific antibody markers. SAVs and the central vacuole differ in their acidity and tonoplast composition: SAVs are more acidic than the central vacuole and, whereas the tonoplast of central vacuoles is highly enriched in γ-TIP (tonoplast intrinsic protein), the tonoplast of SAVs lacks this aquaporin. The expression of a SAG12-GFP fusion protein in transgenic Arabidopsis plants shows that SAG12 localizes to SAVs. The analysis of ProSAG12:GUS transgenic plants indicates that SAG12 expression in senescing leaves is restricted to SAV-containing cells, for example, mesophyll and guard cells. A homozygous sag12 Arabidopsis mutant develops SAVs and does not show any visually detectable phenotypical alteration during senescence, indicating that SAG12 is not required either for SAV formation or for progression of visual symptoms of senescence. The presence of two types of vacuoles in senescing leaves could provide different lytic compartments for the dismantling of specific cellular components. The possible origin and functions of SAVs during leaf senescence are discussed.

The formation and evolution of hydrogen-deficient post-AGB white dwarfs: The emerging chemical profile and the expectations for the PG 1159-DB-DQ evolutionary connection

Abstract: We explore the formation and evolution of hydrogen-deficient post-AGB white dwarfs. To this end, we compute the complete evolution of an initially 2.7 Mstar from the zero-age main sequence through the thermally pulsing and mass-loss phases to the white dwarf stage. Particular attention is given to the chemical abundance changes during the whole evolution. A time-dependent scheme for the simultaneous treatment of abundance changes caused by nuclear reactions, diffusive overshoot- ing, salt fingers and convection is considered. We employed the double-diffusive mixing-length theory of convection for fluids with composition gradients. The study can therefore be considered as a test of its performance in low-mass stars. Also, time- dependent element diffusion for multicomponent gases is taken into account during the white dwarf evolution. The evolutionary stages corresponding to the last helium thermal pulse on the early white-dwarf cooling branch and the following born-again episode are carefully explored. Relevant aspects for PG 1159 stars and DB white dwarf evolution are studied in the framework of these new evolutionary models that take into account the history of the white dwarf progenitor. The scope of the calculations is extended to the domain of the helium-rich, carbon-contaminated DQ white dwarfs with the aim of exploring the plausibility of the evolutionary connection PG 1159-DB-DQ. In this regard, the implications for the double-layered chemical structure in pulsating DB white dwarfs is investigated. We examine the consequences of mass-loss episodes during the PG 1159 stage for the chemical stratification of the outer layer of DB and DQ white dwarfs.

Up-regulation of the mitochondrial alternative oxidase pathway enhances photosynthetic electron transport under drought conditions

Abstract: The aim of this study was to explore the role of the mitochondrial alternative oxidase (AOX) in the protection of photosynthesis during drought in wheat leaves. The relative water contents of water-replete and drought-exposed wheat plants were 97.2+/-0.3 and 75+/-2, respectively. Drought increased the amount of leaf AOX protein and also enhanced the rate of AOX-dependent O(2) uptake by the respiratory electron transport chain. The amount of the reduced, active form of the AOX protein was specifically increased by drought. The AOX inhibitor salicylhydroxamic acid (1 mM; SHAM) inhibited 70% of AOX activity in vivo in both water-replete and drought-exposed plants. Plants treated with SHAM were then exposed to low (100), high (350), or excess light (800 mumol photons m(-2) s(-1)) for 90 min. SHAM did not modify chlorophyll a fluorescence quenching parameters in water-replete controls after any of these treatments. However, while the maximal quantum yield of photosystem II (PSII) electron transport (F(v)/F(m)) was not affected by SHAM, the immediate quantum yield of PSII electron transport (Phi(PSII)) and photochemical quenching (qP) were gradually reduced by increasing irradiance in SHAM-treated drought-exposed plants, the decrease being most pronounced at the highest irradiance. Non-photochemical quenching (NPQ) reached near maximum levels in plants subjected to drought at high irradiance. However, a combination of drought and low light caused an intermediate increase in NPQ, which attained higher values when AOX was inhibited. Taken together, these results show that up-regulation of the respiratory AOX pathway protects the photosynthetic electron transport chain from the harmful effects of excess light.

Immunomodulatory dendritic cells in intestinal lamina propria

Abstract: The lamina propria (LP) of the small intestine contains many dendritic cells (DC), which are likely to be in close contact with luminal antigens, but their role in intestinal immune responses has been overlooked. Here we show that after feeding mice ovalbumin (OVA), the majority of antigen uptake is associated with DC in the small intestinal LP, and we describe the isolation, purification and initial characterization of theses DC. We obtained >90% CD11c+ DC using magnetic cell sorting, of which the majority were CD11b+CD8–, with smaller numbers of CD11b–CD8+ and CD11b–CD8– DC as well as a distinct population of CD11cintclass II MHClo B220+ DC. Freshly isolated LP DC expressed variable but generally low levels of CD40, CD80 and CD86, which were up-regulated by activation with LPS. LP DC were endocytic in vivo and in vitro and could present antigen to OVA-specific CD4+ T cells in vitro. Antigen-loaded LP DC from OVA-fed mice also primed specific CD4+ T cells in vivo and in vitro, but adoptive transfer of these DC into naive recipients induced hyporesponsiveness to subsequent challenge. LP DC also expressed significant levels of mRNA for IL-10 and type I IFN, but not IL-12, suggesting they may play a central and unique role in immune homeostasis in the gut.

Appearance of room-temperature ferromagnetism in Cu-doped TiO 2-δ films

Abstract: We report here the unexpected observation of significant room-temperature ferromagnetism in a semiconductor doped with nonmagnetic impurities, Cu-doped ${\mathrm{TiO}}_{2}$ thin films grown by pulsed laser deposition. The magnetic moment, calculated from the magnetization curves, resulted surprisingly large, about $1.5\phantom{\rule{0.3em}{0ex}}{\ensuremath{\mu}}_{B}$ per Cu atom. A large magnetic moment was also obtained from ab initio calculations, but only if an oxygen vacancy in the nearest-neighbor shell of Cu was present. This result suggests that the role of oxygen vacancies is crucial for the appearance of ferromagnetism. The calculations also predict that Cu doping favors the formation of oxygen vacancies.

Ear of durum wheat under water stress: water relations and photosynthetic metabolism.

Abstract: The photosynthetic characteristics of the ear and flag leaf of well-watered (WW) and water-stressed (WS) durum wheat (Triticum turgidum L. var. durum) were studied in plants grown under greenhouse and Mediterranean field conditions. Gas exchange measurements simultaneously with modulated chlorophyll fluorescence were used to study the response of the ear and flag leaf to CO2 and O2 during photosynthesis. C4 metabolism was identified by assessing the sensitivity of photosynthetic rate and electron transport to oxygen. The presence of CAM metabolism was assessed by measuring daily patterns of stomatal conductance and net CO2 assimilation. In addition, the histological distribution of Rubisco protein in the ear parts was studied by immunocytochemical localisation. Relative water content (RWC) and osmotic adjustment (osmotic potential at full turgor) were also measured in these organs. Oxygen sensitivity of the assimilation rate and electron transport, the lack of Rubisco compartmentalisation in the mesophyll tissues and the gas-exchange pattern at night indicated that neither C4 nor CAM metabolism occurs in the ear of WW or WS plants. Nevertheless, photosynthetic activity of the flag leaf was more affected by WS conditions than that of the ear, under both growing conditions. The lower sensitivity under water stress of the ear than of the flag leaf was linked to higher RWC and osmotic adjustment in the ear bracts and awns. We demonstrate that the better performance of the ear under water stress (compared to the flag leaf) is not related to C4 or CAM photosynthesis. Rather, drought tolerance of the ear is explained by its higher RWC in drought. Osmotic adjustment and xeromorphic traits of ear parts may be responsible.

Cypermethrin and chlorpyrifos concentration levels in surface water bodies of the Pampa Ondulada, Argentina.

Abstract: No abstract available.

Classification of Marek's disease viruses according to pathotype: philosophy and methodology.

Abstract: The concept of pathotype in Marek's disease (MD) probably dates from the recognition of a more virulent form of the disease in the late 1950s (Benton & Cover, 1957). Distinctions between MD virus strains were further expanded with the description of the vv pathotype in the early 1980s and of the vv+ pathotype in the 1990s. Pathotype designations reflect important biological properties that correlate with the break-through of vaccinal immunity in the field. However, pathotyping methods applied by various laboratories have not been uniform, preventing critical comparison of results. Better uniformity of pathotyping procedures is desirable.The Avian Disease and Oncology Laboratory (ADOL) method is based on induction of lymphoproliferative lesions in vaccinated chickens. This method has been used to pathotype more than 45 isolates and is the basis for the current pathotype classification of MD virus strains. Its limitations include requirements for a specific type of chickens (15x7 ab+), large numbers of animals, and a statistical method to compare lesion responses to those of JM/102W and Md5 control strains. Because of these limitations, it has not been and is not likely to be used in other laboratories. Comparability in pathotyping can be improved by the comparison of field isolates with standard prototype strains such as JM/102W, Md5 and 648A (American Type Culture Collection) or their equivalents. Data may be generated by different in vivo procedures that measure tumour induction, neurological disease (both neoplastic and non-neoplastic lesions), or solely non-neoplastic criteria (such as lymphoid organ weights or virus replication). Methods based on neoplastic criteria, especially when generated in MD-immunized chickens, will probably correlate most closely with that of the ADOL method and be most relevant to evolution of MD virus in the field. Based on data from several trials, a modification of the ADOL method that utilizes fewer chickens and can be conducted with commercial specific pathogen free strains is proposed. The modified method is based on "best fit" comparisons with prototype strains, and is expected to provide results generally comparable with the original method. A variety of other alternative criteria (see earlier) are also evaluated both for primary pathotyping and as adjuncts to other pathotyping methods. Advantages and disadvantages of alternative methods are presented.

Theoretical study of magnetism in transition-metal-doped Ti O 2 and Ti O 2 − δ

Abstract: In recent years there has been an intense search for room temperature ferromagnetism in semiconductors doped with dilute magnetic impurities, in particular, oxides. In this work we study the structural, electronic, and magnetic properties of doped rutile $\mathrm{Ti}{\mathrm{O}}_{2}$ for two different impurity concentrations (25% and 6.25%), considering different distributions of the impurities in the host lattice. Calculations were performed with ab initio methods, assuming that the magnetic impurities substitutionally replace the Ti ions. Our results show that a local magnetic moment appears in the cases of Mn, Fe, and Co impurities, but not in the cases of Ni and Cu impurities. They also show that in the system ${\mathrm{Ti}}_{1\ensuremath{-}x}{\mathrm{Co}}_{x}{\mathrm{O}}_{2}$ the magnetic ions align ferromagnetically, while in ${\mathrm{Ti}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}{\mathrm{O}}_{2}$ and ${\mathrm{Ti}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x}{\mathrm{O}}_{2}$ the antiferromagnetic alignment is energetically favorable. We have also studied the effect of oxygen vacancies, which turned out to be very important. Their presence decreases the energy required to introduce the impurities in the host lattice and reciprocally, the presence of impurities is related to a higher vacancy concentration. The pairs impurity-nearest-neighbor oxygen vacancy seem to be the energetically preferred structures and to produce the highest local magnetic moments. Ni and even Cu impurities acquire magnetic moments in this environment.

Direct effect of melatonin on Syrian hamster testes: melatonin subtype 1a receptors, inhibition of androgen production, and interaction with the local corticotropin-releasing hormone system

Abstract: Besides the hypothalamus and pituitary, melatonin action at the testicular level has been recently suggested. Therefore, we investigated in the Syrian hamster, a well-characterized seasonal breeder, melatonin action on Leydig cells, testicular expression of melatonergic receptors, and possible interactions between melatonin receptors and the previously identified testicular serotoninergic and CRH systems. In isolated Leydig cells from active testes of adult hamsters kept in a long-day (14 h light, 10 h dark) photoperiod and from regressed testes of adult animals exposed to a short-day photoperiod during 16 wk (6 h light, 18 h dark), melatonin significantly reduced human chorionic gonadotropin-stimulated production of cAMP and the main androgens: testosterone and androstane-3alpha,17beta-diol, respectively, and decreased the expression of steroidogenic acute regulatory protein, P450 side chain cleavage, 3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase. In Leydig cells exposed to a short-day photoperiod during 16 wk, melatonin stimulated the conversion of testosterone into 5alpha-reduced androgens by inducing 5alpha-reductase isoform 1, and controlled androstane-3alpha,17beta-diol production by inhibiting 3alpha-hydroxysteroid dehydrogenase expression. Melatonin subtype (mel1a) receptors were detected in Leydig cells. Although the local serotonin system did not mediate melatonin action on androgen production, melatonergic effect on steroidogenesis involved the interaction between mel1a receptors and the inhibitory CRH system. Moreover, melatonin significantly increased CRH mRNA levels and production in hamster Leydig cells expressing CRH subtype 1 receptors. Our studies indicate that melatonin may act as a local inhibitor of human chorionic gonadotropin-stimulated cAMP and androgen production through mel1a receptors, down-regulation of steroidogenic acute regulatory protein, and key steroidogenic enzymes expression and its interaction with the local CRH system.

Sizing gold nanoparticles by optical extinction spectroscopy

Abstract: The measurement of optical extinction is used to determine the size of nearly spherical gold nanoparticles suspended in solution, produced by a 'reverse micelles' process. The contrast between the maximum and the minimum in the extinction spectra around 450 and 520 nm shows a linear dependence with the mean radius of the gold particles less than 3 nm; however, the method can be used to size particles up to 7 nm. Experimental results for extinction spectra can be fitted by Mie's theory if the optical constants from bulk material values are modified by introducing the limitation of the mean free path due to collisions of conduction electrons with the boundary of the nanoparticles.

Comparison of UV and visible Raman spectroscopy of bulk metal molybdate and metal vanadate catalysts.

Abstract: The visible (532 and 442 nm) and UV (325 nm) Raman spectra of bulk mixed metal oxides (metal molybdates and metal vanadates) were compared on the same spectrometer, for the first time, to allow examination of how varying the excitation energy from visible to UV affects the resulting Raman spectra. The quality of the Raman spectra was found to be a strong function of the absorption properties of the bulk mixed oxide. For bulk mixed metal oxides that absorb weakly in the visible and UV regions, both the visible and UV Raman spectra were of high quality and exhibit identical vibrational bands, but with slightly different relative intensities. For bulk mixed metal oxides that absorb strongly in the UV and visible regions and/or strongly in the UV and weakly in the visible regions, the visible Raman spectra are much richer in structural information and of higher resolution than the corresponding UV Raman spectra. This is a consequence of the strong UV absorption that significantly reduces the sampling volume and number of scatterers giving rise to the Raman signal. The shallower escape depth of UV Raman, however, was not sufficient to detect vibrations from the surface metal oxide species that are present on the outermost surface layer of these crystalline mixed metal oxide phases as previously suggested. It was also demonstrated that there is no sample damage by the more energetic UV excitation when very low laser powers and fast detectors are employed, thus avoiding the need of complicated fluidized bed sample arrangements sometimes used for UV Raman investigations. The current comparative Raman investigation carefully documents, for the first time, the advantages and disadvantages of applying different excitation energies in collecting Raman spectra of bulk mixed metal oxide materials.

Enterococcus faecium SF68 Enhances the Immune Response to Giardia intestinalis in Mice

Abstract: We studied the ability of the probiotic organism Enterococcus faecium SF68 to antagonize Giardia intestinalis infection in mice. Oral feeding of E. faecium strain SF68 starting 7 d before inoculation with Giardia trophozoites significantly increased the production of specific anti-Giardia intestinal IgA and blood IgG. This humoral response was mirrored at the cellular level by an increased percentage of CD4(+) T cells in the Peyer's patches and in the spleens of SF68-fed mice. The improvement of specific immune responses in probiotic-fed mice was associated with a diminution in the number of active trophozoites in the small intestine as well as decreased shedding of fecal Giardia antigens (GSA65 protein). The ability of SF68 to stimulate the immune system at both mucosal and systemic levels highlights mechanisms by which this probiotic might antagonize pathogens in vivo. Taken together, the data demonstrate the strong potential of strain SF68 to prevent protozoa from causing intestinal infections.

Dilated cardiomyopathy in Erb-b4-deficient ventricular muscle

Abstract: The neuregulin receptor tyrosine kinase Erb-b4, initially linked to early cardiac development, is shown here to play a critical role in adult cardiac function. In wild-type mice, Erb-b4 protein localized to Z lines and to intercalated disks, suggesting a role in subcellular and intercellular communications of cardiomyocytes. Conditional inactivation of erb-b4 in ventricular muscle cells led to a severe dilated cardiomyopathy, characterized by thinned ventricular walls with eccentric hypertrophy, reduced contractility, and delayed conduction. This cardiac dysfunction may account for premature death in adult erb-b4-knockout mice. This study establishes a critical role for Erb-b4 in the maintenance of normal postnatal cardiac structure and function.

Galectin-1 receptors in different cell types.

Abstract: Galectins are a family of animal lectins defined by two properties: shared amino acid sequences in their carbohydrate-recognizing domain, and β-galactoside affinity. A wide variety of biological phenomena are related to galectins, i.e., development, differentiation, morphogenesis, tumor metastasis, apoptosis, RNA splicing, and immunoregulatory function. In this review, we will focus on galectin-1 receptors, and some of the mechanisms by which this lectin affects different cell types. Several galectin-1 receptors are discussed such as CD45, CD7, CD43, CD2, CD3, CD4, CD107, CEA, actin, extracellular matrix proteins such as laminin and fibronectin, glycosaminoglycans, integrins, a β-lactosamine glycolipid, GM1 ganglioside, polypeptide HBGp82, glycoprotein 90 K/MAC-2BP, CA125 cancer antigen, and pre-B cell receptor.

A high sensitivity HI survey of the sky at δ ≤ -25 ° . Final data release

Abstract: We present the final data release of the high sensitivity λ 21-cm neutral hydrogen survey of the sky south of δ ≤− 25 ◦ . A total of 50 980 positions lying on a galactic coordinate grid with points spaced by (∆l, ∆b) = (0. ◦ 5/cos b, 0. 5) were observed with the 30-m dish of the Instituto Argentino de Radioastronomia (IAR). The angular resolution of the survey is HPBW = 0. ◦ 5 and the velocity coverage spans the interval −450 km s −1 to +400 km s −1 (LSR). The velocity resolution is 1.27 km s −1 and the final rms noise of the entire database is 0.07 K. The data are corrected for stray radiation and converted to brightness temperatures.