Identification of senescence and death in Emiliania huxleyi and Thalassiosira pseudonana: Cell staining, chlorophyll alterations, and dimethylsulfoniopropionate (DMSP) metabolism

We measured membrane permeability, hydrolytic enzyme, and caspase-like activities using fluorescent cell stains to document changes caused by nutrient exhaustion in the coccolithophore Emiliania huxleyi and the diatom Thalassiosira pseudonana, during batch-culture nutrient limitation. We related these changes to cell death, pigment alteration, and concentrations of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) to assess the transformation of these compounds as cell physiological condition changes. E. huxleyi persisted for 1 month in stationary phase; in contrast, T. pseudonana cells rapidly declined within 10 d of nutrient depletion. T. pseudonana progressively lost membrane integrity and the ability to metabolize 5-chloromethylfluorescein diacetate (CMFDA; hydrolytic activity), whereas E. huxleyi developed two distinct CMFDA populations and retained membrane integrity (SYTOX Green). Caspase-like activity appeared higher in E. huxleyi than in T. pseudonana during the post-growth phase, despite a lack of apparent mortality and cell lysis. Photosynthetic pigment degradation and transformation occurred in both species after growth; chlorophyll a (Chl a) degradation was characterized by an increase in the ratio of methoxy Chl a : Chl a in T. pseudonana but not in E. huxleyi, and the increase in this ratio preceded loss of membrane integrity. Total DMSP declined in T. pseudonana during cell death and DMS increased. In contrast, and in the absence of cell death, total DMSP and DMS increased in E. huxleyi. Our data show a novel chlorophyll alteration product associated with T. pseudonana death, suggesting a promising approach to discriminate nonviable cells in nature

Total mercury and methylmercury in commercial marine species from the Goa coast: Constraints on risk assessment and environmental issues

1925-1932Mercury (Hg) is a toxic element which accumulates in fish and other aquatic organisms from various sources and poses potential risk to the consumers. Methylmercury (MeHg), the common organic species of mercury, usually forms in aquatic environments and is known for neurotoxicity. In this study, the concentration of total Hg and MeHg in 12 commercial species of fish, shellfish, prawn, and crab from coastal areas of Goa were investigated. The total Hg contents varied between 18.5 -260 µg/kg; while the concentration of MeHg had a range of 7.2 -129 µg/kg. Both the ranges were well below the values recorded at other polluted coastal sites and also meet the permissible limits for human consumption. The interspecies comparison shows species from pelagic and benthic habitats with different food habits have significant difference in body loads of total Hg and MeHg, which increases across the trophic levels. The exposure to higher level of Hg in sediment is likely responsible for enhanced bio-concentration of Hg in benthic species as compared to the values in pelagic fishes

Pharmacological profile of a bifunctional ligand of the formyl peptide receptor1 fused to the myc epitope

In human peripheral blood neutrophils or in myeloid PLB-985 cells differentiated towards a neutrophil-like phenotype, the peptide N-formyl-L-norleucyl-L-leucyl-L-phenylalanyl-L-norleucyl-L-tyrosyl-L-leucyl-fluorescein isothiocyanate (f-Nle-Leu-Phe-Nle-Tyr-Lys-FITC) binds to and activates formyl peptide receptor1 (FPR1) and is submitted to receptor-mediated endocytosis (microscopy, cytofluorometry). This peptide may be considered a C-terminally extended version of f-Met-Leu-Phe which carries a fluorescent cargo into cells. By analogy to other peptide hormones for which we have evaluated epitope-tagged agonists as carriers of antibody cargoes, we have designed and evaluated f-Nle-Leu-Phe-Nle-Tyr-Lys-myc, C-terminally extended with the 10-residue myc tag. This peptide is as potent as f-Met-Leu-Phe to compete for f-Nle-Leu-Phe-Nle-Tyr-Lys-FITC uptake by PLB-985 cells, but did not mediate (10–1000 nM) the internalization of the fluorescent anti-myc monoclonal antibody 4A6 added to the extracellular fluid at ~ 7 nM (microscopy). The nonfluorescent version of the antibody (28 nM) acts as a pre-receptor antagonist of f-Nle-Leu-Phe-Nle-Tyr-Lys-myc, but not of f-Met-Leu-Phe (superoxide release assay in differentiated PLB-985 cells). A further prolonged analog, f-Nle-Leu-Phe-Nle-Tyr-Lys-(Asn-Gly)5-myc, designed to decrease the possible steric hindrance between FPR1 and the bound anti-myc antibody, has little affinity for the receptor, precluding a direct assessment of this issue. Thus, the relatively low-affinity anti-myc antibody used at a high concentration functionally behaves as a selective pre-receptor antagonist of the agonist f-Nle-Leu-Phe-Nle-Tyr-Lys-myc

Relokasi Hiposenter untuk Data Gempa Bumi di Wilayah Sumatera Barat dan Sekitarnya dengan Menggunakan Hypo71 (2009-10-01 – 2010-12-21)

Relokasi hiposenter (kedalaman pusat gempa bumi) dilakukan sebagai upaya untuk mengetahui parameter yang dapat dipakai untuk menggambarkan bagaimana gempa bumi tersebut terjadi sehingga dapat diketahui jenis dari gempa. Dengan menggunakan perangkat lunak hypo71 pada data sebanyak 49 event gempa pada periode 2009-10-01 - 2010-12-21  untuk area di wilayah sumatera barat dan sekitarnya untuk mendapatkan koreksi relokasi hiposenter yang ada sehingga dapat diketahui hiposenternya menggunakan data longitude, latitude, magnitude dan kedalaman sehingga diketahui bahwa relokasi hiposenter dengan menggunakan hypo71 ini lebih akurat daripada perangkat lunak lainnya. Hasil yang didapat diolah dengan menggunakan perangkat lunak winquake terlebih dahulu melalui data hasil picking gelombang p dan gelombang s yang kemudian diolah dengan memakai hypo71 sehingga hasilnya didapat seperti pada tabel 4.1 dan juga berupa gambar 4.1 yang mana menggunakan GMT. Hasil yang didapat dari penelitian ini adalah koreksi dari relokasi hiposenter yang dilakukan pada kesemua data gempa

Technology Perspectives and Innovative Scenarios Applied in the Amazon Region

This paper aims to summarize the technology perspectives and innovative scenarios applied in the Amazon region. A call for papers for the Special Issue yielded four accepted articles that serve as the source for the summary. All these articles focus on specific cases in the Legal Amazon region and provide empirical evidence supported by theories and relevant literature. All the articles emphasized the need for investment in the form of networks for development and innovation. A descriptive, qualitative approach using the bibliometric software WordStat 8® identified the words most frequently used in the four papers included this special issue. The most relevant terms identified were: network, innovation, firms, production, research and development. In total, these articles point to varied partners and institutions necessary for building networks to further development and innovation. This Special Issue is a first step to building a knowledge base focused on the Amazon region that is missing in the academic literature. Future contributions must build and expand the discussion of empirical cases and reflect different disciplines that contribute to industries, policies, society and networks. This is necessary to improve innovation and economic development of this important region

Properties of the giant HII regions and bar in the nearby spiral galaxy NGC5430

In order to better understand the impact of the bar on the evolution of spiral galaxies, we measure the properties of giant HII regions and the bar in the SB(s)b galaxy NGC5430. We use two complementary data sets, both obtained at the Observatoire du Mont-M\'egantic: a hyperspectral data cube from the imaging Fourier transform spectrograph SpIOMM, and high-resolution spectra across the bar from a long-slit spectrograph. We flux-calibrate SpIOMM spectra for the first time, and produce H{\alpha} and [NII]{\lambda}6584\r{A} intensity maps from which we identify 51 giant HII regions in the spiral arms and bar. We evaluate the type of activity, the oxygen abundance and the age of the young populations contained in these giant HII regions and in the bar. Thus, we confirm that NGC5430 does not harbour a strong AGN, and that its Wolf-Rayet knot shows a pure HII region nature. We find no variation in abundance or age between the bar and spiral arms, nor as a function of galactocentric radius. These results are consistent with the hypothesis that a chemical mixing mechanism is at work in the galaxy's disc to flatten the oxygen abundance gradient. Using the starburst99 model, we estimate the ages of the young populations, and again find no variations in age between the bar and the arms or as a function of radius. Instead, we find evidence for two galaxy-wide waves of star formation, about 7.1 Myr and 10.5 Myr ago. While the bar in NGC5430 is an obvious candidate to trigger these two episodes, it is not clear how the bar could induce widespread star formation on such a short time-scale.Comment: 14 pages, 9 figures, 3 tables, accepted for publication in MNRA

Endothelin-1 in osteoarthritic chondrocytes triggers nitric oxide production and upregulates collagenase production

The mechanism of endothelin-1 (ET-1)-induced nitric oxide (NO) production, MMP-1 production and MMP-13 production was investigated in human osteoarthritis chondrocytes. The cells were isolated from human articular cartilage obtained at surgery and were cultured in the absence or presence of ET-1 with or without inhibitors of protein kinase or LY83583 (an inhibitor of soluble guanylate cyclase and of cGMP). MMP-1, MMP-13 and NO levels were then measured by ELISA and Griess reaction, respectively. Additionally, inducible nitric oxide synthase (iNOS) and phosphorylated forms of p38 mitogen-activated protein kinase, p44/42, stress-activated protein kinase/Jun-N-terminal kinase and serine-threonine Akt kinase were determined by western blot. Results show that ET-1 greatly increased MMP-1 and MMP-13 production, iNOS expression and NO release. LY83583 decreased the production of both metalloproteases below basal levels, whereas the inhibitor of p38 kinase, SB202190, suppressed ET-1-stimulated production only. Similarly, the ET-1-induced NO production was partially suppressed by the p38 kinase inhibitor and was completely suppressed by the protein kinase A kinase inhibitor KT5720 and by LY83583, suggesting the involvement of these enzymes in relevant ET-1 signalling pathways. In human osteoarthritis chondrocytes, ET-1 controls the production of MMP-1 and MMP-13. ET-1 also induces NO release via iNOS induction. ET-1 and NO should thus become important target molecules for future therapies aimed at stopping cartilage destruction

The C. elegans tailless/Tlx homolog nhr-67 regulates a stage-specific program of linker cell migration in male gonadogenesis

Cell migration is a common event during organogenesis, yet little is known about how migration is temporally coordinated with organ development. We are investigating stage-specific programs of cell migration using the linker cell (LC), a migratory cell crucial for male gonadogenesis of C. elegans. During the L3 and L4 larval stages of wild-type males, the LC undergoes changes in its position along the migratory route, in transcriptional regulation of the unc-5 netrin receptor and zmp-1 zinc matrix metalloprotease, and in cell morphology. We have identified the tailless homolog nhr-67 as a cell-autonomous, stage-specific regulator of timing in LC migration programs. In nhr-67-deficient animals, each of the L3 and L4 stage changes is either severely delayed or never occurs, yet LC development before the early L3 stage or after the mid-L4 stage occurs with normal timing. We propose that there is a basal migration program utilized throughout LC migration that is modified by stage-specific regulators such as nhr-67