Interannual variation in commercial oyster (Crassostrea gigas) farming in the sea (Florianopolis, Brazil, 27 degrees 44 ' S; 48 degrees 33 ' W) in relation to temperature, chlorophyll a and associated oceanographic conditions

Aquaculture of filter-feeding bivalve mollusks involves the fruitful conversion of marine particulate organic matter into premium protein of high nutritive value. Culture performance of bivalves is largely dependent on hydrological conditions and directly affected by e. g. temperature and chlorophyll levels. Accordingly, these parameters may be related with seasonality but also with oceanographic features combined with climate events. Yields of Pacific cupped oyster (Crassostrea gigas) reared at commercial procedures in suspended structures (long-lines) in a sheltered bay in Southern Brazil (Santa Catarina State, 27S 43'; 48 W 30') were evaluated in relation to local environmental conditions: sea surface temperature, chlorophyll a concentration, and associate effects of cold fronts events and El Nino and La Nina periods. Outputs from four consecutive commercial crop years were analyzed (2005/06, 2006/07, 2007/08, 2008/09) in terms of oyster survival and development time during the following grow-out phases of the culture cycle: seed to juvenile, juvenile to adult, adult to marketable. Since culture management and genetics were standardized significant differences verified among crop performance could be mostly related to environmental effects. Time series of temperature and chlorophyll a (remote sensing data) from crop periods displayed significant seasonal and interannual variation. As expected, performance during initial grow-out stages (seed to juvenile) was critical for final crop yield. Temperature was the main factor affecting survival in these initial stages with a trend of negative correlation, though not statistically significant. On the other hand, oyster development rate was significantly and positively affected by chlorophyll a concentration. Chlorophyll a values could be increased by upwelled cold nutrient-rich South Atlantic Central Water (SACW, related to predominant Northern winds) though further dependent on occurrence of Southern winds (cold fronts) to assist seawater penetration into the sheltered farming area. Lower salinity nutrient-rich northward drifted waters from La Plata River discharge may also result in chlorophyll a rise in the farming area. The El Nino period (July 2006 to February 2007) coincided with lower chlorophyll a levels in the farming site that may be related to both decreased number of cold fronts as well as predominance of Northern winds that retain northward spreading of La Plata River discharge waters. In contrast, the La Nina period (August 2007 to June 2008) corresponded to higher chlorophyll a values in the farming area by both upwelling of SACW and penetration of La Plata River discharge water assisted by increased occurrence of Southern winds and cold fronts. The recognition of the potentially changing climate and effects upon the environment will be an important step in planning future development of bivalve aquaculture.

El concurso del 33 de Amsterdam : una clave de lectura de la residencia de masas europea del XX : la construcción de un mapa

Programa de Doctorado en la gestión urbanística del litoral con fines turísticos y de ocio

La Facultad de Ciencias del Mar : 33 aniversario

[ES]Mesa redonda de orientación profesional con la participación de egresados de la Facultad de Ciencias del Mar

In vivo- und In vitro-DNA-Verpackung in virusähnliche Partikel des Humanen Papillomvirus Typ 33

Die Rolle der DNA-Bindungsdomäne der Kapsidproteine L1 und L2 humaner Papillomviren (HPV) wird bezüglich der in vitro DNA-Verpackung kontrovers diskutiert und ist für die in vivo DNA-Verpackung noch ungeklärt. Ich konnte zeigen, dass die L1 Proteine der HPV Typen 16, 18 und 33 DNA binden, nicht aber das HPV33 L2 Protein. Die DNA-Bindungsdomäne habe ich auf die letzten sieben Aminosäuren des Carboxyterminus eingegrenzt. In Funktionsanalysen zeigte ich, dass die DNA-Bindungsdomäne des L1 Proteins für den Einschluss von Markerplasmid DNA in Kapside in einem in vivo Ansatz essentiell ist, nicht aber für eine in vitro DNA-Verpackung. Das L2 Protein, das in Kapside eingebaut wurde, denen die L1 DNA-Bindungsdomäne fehlte, konnte die DNA-Verpackung nicht aufrechterhalten.Zusätzlich habe ich die Infektiösität in vitro und in vivo hergestellter DNA-haltiger Kapside (Pseudovirionen) verglichen. Dabei konnte ich zeigen, dass in vivo gewonnene Pseudovirionen, die DNA in Form von Chromatin enthalten, bis zu fünffach infektiöser sind als Pseudovirionen, die in vitro hergestellt wurden und histonfreie DNA enthalten. Biochemische und strukturelle Unterschiede konnten zwischen den zwei Arten von Pseudovirionen nicht festgestellt werden. Chromatin scheint demzufolge die Infektiösität der Pseudovirionen zu verstärken.

Espressione e ruolo funzionale di interleuchina-33 e del suo recettore, ST2, nelle malattie infiammatorie croniche intestinali

IL-33 is a novel member of the IL-1 family and ligand for the IL-1 receptor-related protein, ST2. Recent evidence suggests that the IL-33/ST2 axis plays a critical role in several autoimmune and inflammatory disorders; however, its role in inflammatory bowel disease (IBD) has not been clearly defined. We characterized IL-33 and ST2 expression and modulation following conventional anti-TNF therapy in Crohn’s disease and ulcerative colitis (UC) patients, and investigated the role of IL-33 in SAMP1/YitFc (SAMP) mice, a mixed Th1/Th2 model of IBD. Our results showed a specific increase of mucosal IL-33 in active UC, localized primarily to intestinal epithelial cells (IEC) and colonic inflammatory infiltrates. Importantly, increased expression of full-length IL-33, representing the most bioactive form, was detected in UC epithelium, while elevated levels of cleaved IL-33 were present in IBD serum. ST2 isoforms were differentially modulated in UC epithelium and sST2, a soluble decoy receptor with anti-inflammatory properties, was also elevated in IBD serum. Infliximab (anti-TNF) treatment of UC decreased circulating IL-33 and increased sST2, while stimulation of HT-29 IEC confirmed IL-33 and sST2 regulation by TNF. Similarly, IL-33 significantly increased and correlated with disease severity, and potently induced IL-5, IL-6 and IL-17 from mucosal immune cells in SAMP mice. Taken together, the IL-33/ST2 system plays an important role in IBD and experimental colitis, is modulated by anti-TNF therapy, and may represent a specific biomarker for active UC.

Ruolo di interleuchina-33 sull'espressione di geni profibrotici e sull'ipertrofia dei miofibroblasti nella fibrosi intestinale

Background: Intestinal fibrosis is a serious complication of IBD, with more than a third of Crohn’s disease (CD) patients developing a fibrostenosing phenotype with formation of strictures that will require surgical intervention. Remarkably, SAMP1/YitFc (SAMP) mice, a spontaneous model of CD, develop gut fibrosis; similar to IBD patients, the pathophysiology of SAMP fibrosis is unknown. IL-33 is a member of the IL-1 cytokine family and increased expression is associated with IBD. Emerging evidence suggests its potential role in liver and cutaneous fibrosis, as well as myofibroblast-associated colonic ulcerations . Aim: The aim of this study was to evaluate the role of IL-33 as a potential mediator of profibrotic events leading to intestinal fibrosis and possible stricture formation. Methods: A detailed histologic time course study, with collagen-specific Masson trichrome staining and IHC for ST2 (IL-33 receptor), was performed on SAMP and control AKR (parental strain) mice. qRT-PCR was done on full-thickness ilea for the profibrogenic genes, collagen (coll)-1, coll-3, connective tissue growth factor (CTGF) and insulin-like growth factor 1 (IGF-1). Exogenous IL-33 (33 μg/kg, i.p.) or vehicle was administered daily for 7d to SAMP and AKR mice (N=6/exp group), and ileal tissues evaluated as above. Finally, microarray analysis was performed on full-thickness ilea from SAMP and AKR mice, and IL-33 stimulated subepithelial myofibroblasts (SEMFs). Results: SAMP mice displayed ileal skip lesions with randomly distributed strictures, preceded by typical pre-stricture dilations of the ileum. Ileal wall was visibly thickened with hypertrophy of the serosa, muscularis mucosa, muscularis propria, within which intense collagen deposition was observed, and inflammatory infiltrates in segments showing strictures. Interestingly, intense ST2 staining was present within the inflamed lamina propria of SAMP, notably localized to SEMFs. Fibrosis was first observed at 20 wks, and reached its peak by 50 wks of age. mRNA expression of coll-1 (4.74±0.69-fold; P=0.001), coll-3 (4.92±1.05-fold; P=0.01), IGF1 (12.9±3.45; P=0.006), and CTGF (3.29±0.69; P=0.004) was dramatically elevated in SAMP vs. AKR ilea. IL-33 treatment of AKR mice induced a marked increase in muscle fiber/myofibroblast cellularity and hypertrophy of the muscularis propria (4.13±0.74-fold; P<0.0001), and mRNA expression of coll-1 (5.16±0.89-fold; P=0.0009), coll-3 (1.97±0.14-fold; P=0.01), IGF-1 (9.32±2.27-fold; P=0.004), and CTGF (1.43±0.31-fold; P=0.006) vs. vehicle controls. Microarray data from SAMP ilea and IL-33-treated SEMFs confirmed these trends, displaying a global increase in profibrogenic gene expression. Conclusion: These data suggest an important role for IL-33 in intestinal fibrosis, and may represent a potential target for the treatment of IBD-associated fibrosis and stricture formation.

Towards a new test of time dilation: Laser spectroscopy on lithium ions stored at a velocity of 33.8 % of the speed of light

The subject of the presented thesis is the accurate measurement of time dilation, aiming at a quantitative test of special relativity. By means of laser spectroscopy, the relativistic Doppler shifts of a clock transition in the metastable triplet spectrum of ^7Li^+ are simultaneously measured with and against the direction of motion of the ions. By employing saturation or optical double resonance spectroscopy, the Doppler broadening as caused by the ions' velocity distribution is eliminated. From these shifts both time dilation as well as the ion velocity can be extracted with high accuracy allowing for a test of the predictions of special relativity. A diode laser and a frequency-doubled titanium sapphire laser were set up for antiparallel and parallel excitation of the ions, respectively. To achieve a robust control of the laser frequencies required for the beam times, a redundant system of frequency standards consisting of a rubidium spectrometer, an iodine spectrometer, and a frequency comb was developed. At the experimental section of the ESR, an automated laser beam guiding system for exact control of polarisation, beam profile, and overlap with the ion beam, as well as a fluorescence detection system were built up. During the first experiments, the production, acceleration and lifetime of the metastable ions at the GSI heavy ion facility were investigated for the first time. The characterisation of the ion beam allowed for the first time to measure its velocity directly via the Doppler effect, which resulted in a new improved calibration of the electron cooler. In the following step the first sub-Doppler spectroscopy signals from an ion beam at 33.8 %c could be recorded. The unprecedented accuracy in such experiments allowed to derive a new upper bound for possible higher-order deviations from special relativity. Moreover future measurements with the experimental setup developed in this thesis have the potential to improve the sensitivity to low-order deviations by at least one order of magnitude compared to previous experiments; and will thus lead to a further contribution to the test of the standard model.

Pathogenic role of IL-33-mediated eosinophil infiltration and function in experimental inflammatory bowel disease

IL-33/ST2 axis is known to promote Th2 immune responses and has been linked to several autoimmune and inflammatory disorders, including inflammatory bowel disease (IBD), and recent evidences show that it can regulate eosinophils (EOS) infiltration and function. Based also on the well documented relationship between EOS and IBD, we assessed the role of IL-33-mediated eosinophilia and ileal inflammation in SAMP1/YitFc (SAMP) murine model of Th1/Th2 chronic enteritis, and we found that IL-33 is related to inflammation progression and EOS infiltration as well as IL-5 and eotaxins increase. Administering IL-33 to SAMP and AKR mice augmented eosinophilia, eotaxins mRNA expression and Th2 molecules production, whereas blockade of ST2 and/or typical EOS molecules, such as IL-5 and CCR3, resulted in a marked decrease of inflammation, EOS infiltration, IL-5 and eotaxins mRNA expression and Th2 cytokines production. Human data supported mice’s showing an increased colocalization of IL-33 and EOS in the colon mucosa of UC patients, as well as an augmented IL-5 and eotaxins mRNA expression, when compared to non-UC. Lastly we analyzed SAMP raised in germ free (GF) condition to see the microbiota effect on IL-33 expression and Th2 responses leading to chronic intestinal inflammation. We found a remarkable decrease in ileal IL-33 and Th2 cytokines mRNA expression as well as EOS infiltration in GF versus normal SAMP with comparable inflammatory scores. Moreover, EOS depletion in normal SAMP didn’t affect IL-33 mRNA expression. These data demonstrate a pathogenic role of IL-33-mediated eosinophilia in chronic intestinal inflammation, and that blockade of IL-33 and/or downstream EOS activation may represent a novel therapeutic modality to treat patients with IBD. Also they highlight the gut microbiota role in IL-33 production, and the following EOS infiltration in the intestinal mucosa, confirming that the microbiota is essential in mounting potent Th2 response leading to chronic ileitis in SAMP.