Oceanic SACZ produces an abnormally wet 2021/2022 rainy season in South America.

The oceanic South Atlantic Convergence Zone (SACZ) has played a major role during South America's 2021/2022 summer extreme rainy season, being responsible for more than 90% of the precipitation in some regions of Southeast Brazil and in some regions of the Southwestern Atlantic Ocean (SWA). The summer of 2021/2022 was unique and rare and considered an abnormally humid season as verified by official Brazilian Institutes. First, the unusual number of cases of SACZ episodes (seven), was the highest recorded in the last decade. Second, all the cases that occurred were oceanic SACZ that assumed characteristics of an Atmospheric River and produced an excessively anomalous amount of precipitation during this period. Excess precipitation along with the regions located in mountainous and very uneven relief, which by orographic effects favors high precipitation volumes, were responsible for amplifying the observed impacts, such as landslides and floods that caused several losses to society. We also showed the main effects of coupling and interaction between the waters of the surface layer of the SWA and the atmosphere. Our learning from this study ends with the unprecedented results of how the marine atmospheric boundary layer (MABL) is locally modulated by the sea surface temperature (SST) that lies just below it. Until the present moment, we emphasize that this important mechanism has not been widely highlighted in the literature, showing that even though the ocean is colder than before oceanic SACZ is established, it is still warmer than the overlying air, thus, the ocean continues to be an active source of heat and moisture for the atmosphere and enhances the MABL instability process.

Cell wall and enzyme changes during the graviresponse of the leaf-sheath pulvinus of oat (Avena sativa).

The graviresponse of the leaf-sheath pulvinus of oat (Avena sativa) involves an asymmetric growth response accompanied by several asymmetric processes, including degradation of starch and cell wall synthesis. To understand further the cellular and biochemical events associated with the graviresponse, changes in cell walls and their constituents and the activities of related enzymes were investigated in excised pulvini. Asymmetric increases in dry weight with relatively symmetric increases in wall weight accompanied the graviresponse. Starch degradation could not account for increases in wall weight. However, a strong asymmetry in invertase activity indicated that hydrolysis of exogenous sucrose could contribute significantly to the increases in wall and dry weights. Most cell wall components increased proportionately during the graviresponse. However, beta-D-glucan did not increase symmetrically, but rather increased in proportion in lower halves of gravistimulated pulvini. This change resulted from an increase in glucan synthase activity in lower halves. The asymmetry of beta-D-glucan content arose too slowly to account for initiation of the graviresponse. A similar pattern in change in wall extensibility was also observed. Since beta-D-glucan was the only wall component to change, it is hypothesized that this change is the basis for the change in wall extensibility. Since wall extensibility changed too slowly to account for growth initiation, it is postulated that asymmetric changes in osmotic solutes act as the driving factor for growth promotion in the graviresponse, while wall extensibility acts as a limiting factor during growth.

Purification and characterization of soluble (cytosolic) and bound (cell wall) isoforms of invertases in barley (Hordeum vulgare) elongating stem tissue.

Three different isoforms of invertases have been detected in the developing internodes of barley (Hordeum vulgare). Based on substrate specificities, the isoforms have been identified to be invertases (beta-fructosidases EC 3.2.1.26). The soluble (cytosolic) invertase isoform can be purified to apparent homogeneity by diethylaminoethyl cellulose, Concanavalin-A Sepharose, organo-mercurial Sepharose, and Sephacryl S-300 chromatography. A bound (cell wall) invertase isoform can be released by 1 molar salt and purified further by the same procedures as above except omitting the organo-mercurial Sepharose affinity chromatography step. A third isoform of invertase, which is apparently tightly associated with the cell wall, cannot be isolated yet. The soluble and bound invertase isoforms were purified by factors of 60- and 7-fold, respectively. The native enzymes have an apparent molecular weight of 120 kilodaltons as estimated by gel filtration. They have been identified to be dimers under denaturing and nondenaturing conditions. The soluble enzyme has a pH optimum of 5.5, Km of 12 millimolar, and a Vmax of 80 micromole per minute per milligram of protein compared with cell wall isozyme which has a pH optimum of 4.5, Km of millimolar, and a Vmax of 9 micromole per minute per milligram of protein.

Similarities between stratum corneum basic protein and histidine-rich protein II from newborn rat epidermis.

The stratum corneum basic protein and histidine-rich protein II were each isolated from newborn rat epidermis and compared by biochemical and immunologic methods. The proteins were indistinguishable by immunodiffusion using antiserum elicited to either protein. The migration of the proteins on SDS-polyacrylamide gel electrophoresis was identical giving a molecular weight of 49 000. These proteins, which have similar but unusual amino acid compositions, give very similar tryptic peptide maps. Both proteins aggregate with keratin filaments to form macrofibrils. These results suggest that histidine-rich protein II and stratum corneum basic protein are the same protein. We suggest that this protein be called histidine-rich basic protein.

Molecular markers of differentiation in the epidermis of the newborn rat.

Regulation in epidermal differentiation can best be studied if molecular mechanism can be associated with structural and functional changes. Such recognized associations include the cessation of mitosis through inhibition of DNA replication by a G1-inhibitor present in the suprabasal cells, the biosynthesis of a tonofilament-protein as an early event in keratinization, the biosynthesis of HRP0 (histidine-rich protein) and its polymerization to HRPI during the formation of keratohyalin, the conversion of HRPI to HRPII coincident with the loss of the nucleus from the granular cell, and the aggregation of the stratum corneum basic protein and keratin filaments to form fibers in the cornified cell. To this list can now be added changes in specificity for lectin-binding to the cell surface as the keratinocyte progresses toward the cutaneous surface. This report presents data on a) the conversion of HRPI to HRPII and b) the differential lectin-binding in the epidermis of the newborn rat. HRPI (Mol. Wgt. greater than or equal to 10(6)) and HRPII (Mol. Wgt. 6 X 10(4)) have similar unique amino acid compositions and exhibit extensive-but not complete-homology in primary structures as determined by peptide mapping after exposure to trypsin. When labeled by exposure in vivo to radioactivity histidine, about 75 of the labeled histidine from both HRPI and HRPII appeared in one peptide fraction in the map, HRPI appears to have on histidine-containing fragment which is not present in HRPII. This peptide appears to contain phosphate and to account for the organically-bound phosphate which was found in HRPI but not defected in HRPII. Changes which occur in the lectin-binding specificity of the cell during differentiation may result from either movement or chemical change in carbohydrates at the cell surface. Immunofluorescent studies have shown that an isolectin from Bandieraea simplicifolia with specificity for alpha-D-galactose binds to the surface of basal and lower spinous cells, a lectin from Ulex europaeus with specificity for alpha-L-focus labels spinous cells, and a second lectin from B. simplicifolia with specificity for N-acetyl-D-glucosamine labels cornified cells. The relationship fo these alterations in the carbohydrates of the cell surface in intracellular structural and/or functional changes in unknown.

Characterization and biosynthesis of cytochrome b(5) in rat liver microsomes.

1. Cytochrome b(5) is released from rat liver microsomes by both proteolytic enzymes and by treatments that disrupt phospholipids. Cytochrome P-420 is only released to a marked extent by treatments that disrupt phospholipids. 2. Cytochrome b(5) was isolated in a pure state from both the rough and smooth fractions of rat liver microsomes after treatment with trypsin, and was shown to contain two cytochrome components with identical spectral properties. 3. Amino acid analyses of the two components are presented, together with peptide ;fingerprint' patterns of tryptic digests of the two components. 4. Studies based on the direct isolation of cytochrome b(5) after administration of a single dose of radioactive amino acid to rats demonstrate that the cytochrome is synthesized initially in the rough fraction of microsomes and only subsequently appears in the smooth fraction. 5. Isolated rat liver microsomes are capable of incorporating radioactive amino acids into cytochrome b(5) under standard conditions. 6. Under these conditions the amino acid is incorporated into peptide linkage in the cytochrome.