Topical anti-inflammatory activity of yacon leaf extracts

Smallanthus sonchifolius (Poepp.) H. Rob. , Asteraceae, known as yacon, is an herb that is traditionally used for the treatment of diabetes in folk medicine. However, recent studies have demonstrated that this plant has other interesting properties such as anti-microbial and anti-inflammatory actions. Thus, the purpose of this study was to evaluate the topical anti-inflammatory property of different extracts prepared from yacon leaves and analyze the role of different chemical classes in this activity. Three yacon leaf extracts were obtained: aqueous extract, where chlorogenic acid derivatives and sesquiterpene lactones were detected; leaf rinse extract, rich in sesquiterpene lactones; and polar extract, rich in chlorogenic acid derivatives. All the extracts exhibited anti-edematogenic activity in vivo (aqueous extract: 25.9% edema inhibition at 0.50 mg/ear; polar extract: 42.7% inhibition at 0.25 mg/ear; and leaf rinse extract: 44.1% inhibition at 0.25 mg/ear). The leaf rinse extract furnished the best results regarding neutrophil migration inhibition, and NO, TNF-? and PGE2 inhibition. These data indicate that both sesquiterpene lactones and chlorogenic acid derivatives contribute to the anti-inflammatory action, although sesquiterpene lactones seem to have more pronounced effects. In conclusion, yacon leaf extracts, particularly the sesquiterpene lactone-rich extract, has potential use as topical anti-inflammatory agent.

Growth of the crabgrass species Digitaria ciliaris and Digitaria nuda

The aim of this research paper was to compare the growth of D. ciliaris and D. nuda crabgrass species under non-competitive conditions. To this end, two experiments were conducted, one from March - July 2010 and the other from February - June 2011. The experimental design of both trials was completely randomized making a factorial (2 seasons x 2 species crabgrass x 12 evaluation periods) with four replications. Assessments began at 15 days after sowing (DAS), and repeated weekly until 92 DAS. The variables evaluated were total dry matter (roots+leaves+stems), leaf area, leaf number and tiller. The results were submitted to analysis of variance and the absolute growth rate, relative growth rate and leaf area ratio were calculated using the means, which were adjusted regression models. The crabgrass species were significantly different in leaf area, leaf number, tiller number and dry matter per plant. D. ciliaris for all variables was statistically higher than D. nuda. Regarding the speed at which the growth of the species occurred, the absolute growth rate and relative growth rate of D. ciliaris was also greater than D. nuda. In addition, D. ciliaris also had a lower leaf area ratio indicating greater efficiency in converting light energy into carbohydrates. It can be concluded that D. ciliaris has a higher growth rate in conditions where there is no limitation of nutrients and water availability in relation to D. nuda, mainly due to D. ciliaris have greater leaf area, number of leaves and dry matter accumulation per plant.

Interspecific variation of the bacterial community structure in the phyllosphere of the three major plant components of mangrove forests

Mangrove forests encompass a group of trees species that inhabit the intertidal zones, where soil is characterized by the high salinity and low availability of oxygen. The phyllosphere of these trees represent the habitat provided on the aboveground parts of plants, supporting in a global scale, a large and complex microbial community. The structure of phyllosphere communities reflects immigration, survival and growth of microbial colonizers, which is influenced by numerous environmental factors in addition to leaf physical and chemical properties. Here, a combination of culture-base methods with PCR-DGGE was applied to test whether local or plant specific factors shape the bacterial community of the phyllosphere from three plant species (Avicenia shaueriana, Laguncularia racemosa and Rhizophora mangle), found in two mangroves. The number of bacteria in the phyllosphere of these plants varied between 3.62 x 10(4) in A. schaeriana and 6.26 x 10³ in R. mangle. The results obtained by PCR-DGGE and isolation approaches were congruent and demonstrated that each plant species harbor specific bacterial communities in their leaves surfaces. Moreover, the ordination of environmental factors (mangrove and plant species), by redundancy analysis (RDA), also indicated that the selection exerted by plant species is higher than mangrove location on bacterial communities at phyllosphere.

Steel fiber reinforced concrete pipes: part 1: technological analysis of the mechanical behavior

This paper is the first part of an extensive work focusing the technological development of steel fiber reinforced concrete pipes (FRCP). Here is presented and discussed the experimental campaign focusing the test procedure and the mechanical behavior obtained for each of the dosages of fiber used. In the second part ("Steel fiber reinforced concrete pipes. Part 2: Numerical model to simulate the crushing test"), the aspects of FRCP numerical modeling are presented and analyzed using the same experimental results in order to be validated. This study was carried out trying to reduce some uncertainties related to FRCP performance and provide a better condition to the use of these components. In this respect, an experimental study was carried out using sewage concrete pipes in full scale as specimens. The diameter of the specimens was 600 mm, and they had a length of 2500 mm. The pipes were reinforced with traditional bars and different contents of steel fibers in order to compare their performance through the crushing test. Two test procedures were used in that sense. In the 1st Series, the diameter displacement was monitored by the use of two LVDTs positioned at both extremities of the pipes. In the 2nd Series, just one LVDT is positioned at the spigot. The results shown a more rigidity response of the pipe during tests when the displacements were measured at the enlarged section of the socket. The fiber reinforcement was very effective, especially when low level of displacement was imposed to the FRCP. At this condition, the steel fibers showed an equivalent performance to superior class pipes made with traditional reinforced. The fiber content of 40 kg/m3 provided a hardening behavior for the FRCP, and could be considered as equivalent to the critical volume in this condition.

Drastic decadal decline of the seagrass Cymodocea nodosa at Gran Canaria (eastern Atlantic): interactions with the green algae Caulerpa prolifera

[EN] The shoot density, leaf length and biomass of the seagrass Cymodocea nodosa (Ucria) Ascherson were found to severely decline in the last 17 years in the oceanic island of Gran Canaria (central Eastern Atlantic). Five seagrass meadows were sampled in summer and winter of 1994-1995 and in winter and summer 2011. The decrease in C. nodosa correlated with a 3-fold increase in the biomass of the green rhizophytic algae Caulerpa prolifera (Forsskål) J.V. Lamoroux over the same time period, although this increase varied notably among meadows. We also documented a negative correlation between the biomass of C. nodosa and C. prolifera at the island-scale, sampling 16 meadows in 2011. Experimental evidence demonstrated that C. prolifera can cause significant negative impacts on C. nodosa: plots with total (100%) removals of C. prolifera had ca. 2.5 more shoots and 3.5 times more biomass of C. nodosa, after 8 months, compared to plots with 50% removals and untouched control plots. Interference by C. prolifera appears to partially explain the decay in the abundance of C. nodosa populations in Gran Canaria. This study, however, did not identify potential underlying processes and/or environmental alterations that may have facilitated the disappearance of C. nodosa.

Temporal patterns of the seagrass "Cymodocea nodosa" and depth-related patterns of the green algae "Caulerpa prolifera" in the Canarian Archipelago

Máster Oficial en Gestión Costera

Ontogenetic studies on the determination of the apical meristem in racemose inflorescences

This thesis presents a comparative developmental study of inflorescences and focuses on the production of the terminal flower (TF). Morphometric attributes of inflorescence meristems (IM) were obtained throughout the ontogeny of inflorescence buds with the aim of describing possible spatial constraints that could explain the failure in developing the TF. The study exposes the inflorescence ontogeny of 20 species from five families of the Eudicots (Berberidaceae, Papaveraceae-Fumarioideae, Rosaceae, Campanulaceae and Apiaceae) in which 745 buds of open (i.e. without TF) and closed (i.e. with TF) inflorescences were observed under the scanning electron microscope.rnThe study shows that TFs appear on IMs which are 2,75 (se = 0,38) times larger than the youngest lateral reproductive primordium. The shape of these IMs is characterized by a leaf arc (phyllotactic attribute) of 91,84° (se = 7,32) and a meristematic elevation of 27,93° (se = 5,42). IMs of open inflorescences show a significant lower relative surface, averaging 1,09 (se=0,26) times the youngest primordium size, which suggests their incapacity for producing TFs. The relative lower size of open IMs is either a condition throughout the complete ontogeny (‘open I’) or a result from the drastic reduction of the meristematic surface after flower segregation (‘open II’). rnIt is concluded that a suitable bulge configuration of the IM is a prerequisite for TF formation. Observations in the TF-facultative species Daucus carota support this view, as the absence of the TF in certain umbellets is correlated with a reduction of their IM dimensions. A review of literature regarding histological development of IMs and genetic regulation of inflorescences suggests that in ‘open I’ inflorescences, the histological composition and molecular activity at the tip of the IM could impede the TF differentiation. On the other side, in ‘open II’ inflorescences, the small final IM bulge could represent a spatial constraint that hinders the differentiation of the TF. The existence of two distinct kinds of ontogenies of open inflorescences suggests two ways in which the loss of the TF could have occurred in the course of evolution.rn

In vitro synthesis of the light-harvesting complex into artificial membrane systems

In green plants, the function of collecting solar energy for photosynthesis is fulfilled by a series of light-harvesting complexes (LHC). The light-harvesting chlorophyll a/b protein (LHCP) is synthesized in the cytosol as a precursor (pLHCP), then imported into chloroplasts and assembled into photosynthetic thylakoid membranes. Knowledge about the regulation of the transport processes of LHCP is rather limited. Closely mimicking the in vivo situation, cell-free protein expression system is employed in this dissertation to study the reconstitution of LHCP into artificial membranes. The approach starts merely from the genetic information of the protein, so the difficult and time-consuming procedures of protein expression and purification can be avoided. The LHCP encoding gene from Pisum sativum was cloned into a cell-free compatible vector system and the protein was expressed in wheat germ extracts. Vesicles or pigment-containing vesicles were prepared with either synthetic lipid or purified plant leaf lipid to mimic cell membranes. LHCP was synthesized in wheat germ extract systems with or without supplemented lipids. The addition of either synthetic or purified plant leaf lipid was found to be beneficial to the general productivity of the expression system. The lipid membrane insertion of the LHCP was investigated by radioactive labelling, protease digestion, and centrifugation assays. The LHCP is partially protected against protease digestion; however the protection is independent from the supplemented lipids.

Tailoring molecular weight of the conjugated model polymer MEH-PPV and its structure-property relations

In der vorliegenden Arbeit wurden Struktur-Eigenschaftsbeziehungen des konjugierten Modell-Polymers MEH-PPV untersucht. Dazu wurde Fällungs-fraktionierung eingesetzt, um MEH-PPV mit unterschiedlichem Molekulargewicht (Mw) zu erhalten, insbesondere MEH-PPV mit niedrigem Mw, da dieses für optische Wellenleiterbauelemente optimal geeignet ist Wir konnten feststellen, dass die Präparation einer ausreichenden Menge von MEH-PPV mit niedrigem Mw und geringer Mw-Verteilung wesentlich von der geeigneten Wahl des Lösungsmittels und der Temperatur während der Zugabe des Fällungsmittels abhängt. Alternativ dazu wurden UV-induzierte Kettenspaltungseffekte untersucht. Wir folgern aus dem Vergleich beider Vorgehensweisen, dass die Fällungsfraktionierung verglichen mit der UV-Behandlung besser geeignet ist zur Herstellung von MEH-PPV mit spezifischem Mw, da das UV-Licht Kettendefekte längs des Polymerrückgrats erzeugt. 1H NMR and FTIR Spektroskopie wurden zur Untersuchung dieser Kettendefekte herangezogen. Wir konnten außerdem beobachten, dass die Wellenlängen der Absorptionsmaxima der MEH-PPV Fraktionen mit der Kettenlänge zunehmen bis die Zahl der Wiederholeinheiten n  110 erreicht ist. Dieser Wert ist signifikant größer als früher berichtet. rnOptische Eigenschaften von MEH-PPV Wellenleitern wurden untersucht und es konnte gezeigt werden, dass sich die optischen Konstanten ausgezeichnet reproduzieren lassen. Wir haben die Einflüsse der Lösungsmittel und Temperatur beim Spincoaten auf Schichtdicke, Oberflächenrauigkeit, Brechungsindex, Doppelbrechung und Wellenleiter-Dämpfungsverlust untersucht. Wir fanden, dass mit der Erhöhung der Siedetemperatur der Lösungsmittel die Schichtdicke und die Rauigkeit kleiner werden, während Brechungsindex, Doppelbrechung sowie Wellenleiter-Dämpfungsverluste zunahmen. Wir schließen daraus, dass hohe Siedetemperaturen der Lösungsmittel niedrige Verdampfungsraten erzeugen, was die Aggregatbildung während des Spincoatings begünstigt. Hingegen bewirkt eine erhöhte Temperatur während der Schichtpräparation eine Erhöhung von Schichtdicke und Rauhigkeit. Jedoch nehmen Brechungsindex und der Doppelbrechung dabei ab.rn Für die Schichtpräparation auf Glassubstraten und Quarzglas-Fasern kam das Dip-Coating Verfahren zum Einsatz. Die Schichtdicke der Filme hängt ab von Konzentration der Lösung, Transfergeschwindigkeit und Immersionszeit. Mit Tauchbeschichtung haben wir Schichten von MEH-PPV auf Flaschen-Mikroresonatoren aufgebracht zur Untersuchung von rein-optischen Schaltprozessen. Dieses Verfahren erweist sich insbesondere für MEH-PPV mit niedrigem Mw als vielversprechend für die rein-optische Signalverarbeitung mit großer Bandbreite.rn Zusätzlich wurde auch die Morphologie dünner Schichten aus anderen PPV-Derivaten mit Hilfe von FTIR Spektroskopie untersucht. Wir konnten herausfinden, dass der Alkyl-Substitutionsgrad einen starken Einfluss auf die mittlere Orientierung der Polymerrückgrate in dünnen Filmen hat.rn

Analysis of the relationships between Spartina maritima and nutrient enrichment in North Adriatic salt marshes

Salt marshes are coastal ecosystem in the upper intertidal zone between internal water and sea and are widely spread throughout Italy, from Friuli Venezia Giulia, in the North, to Sicily, in the South. These delicate environments are threatened by eutrophication, habitat conversion (for land reclaiming or agriculture) and climate change impacts such as sea level rise. The objectives of my thesis were to: 1) analyse the distribution and biomass of the perennial native cordgrass Spartina maritima (one of the most relevant foundation species in the low intertidal saltmarsh vegetation in the study region) at 7 sites along the Northern Adriatic coast and relate it to critical environmental parameters and 2) to carry out a nutrient manipulation experiment to detect nutrient enrichment effects on S. maritima biomass and vegetation characteristics. The survey showed significant differences among sites in biological response variables - i.e., live belowground, live aboveground biomass, above:belowground (R:S) biomass ratio, % cover, average height and stem density – which were mainly related to differences in nitrate, nitrite and phosphate contents in surface water. Preliminary results from the experiment (which is still ongoing) showed so far no significant effects of nutrient enrichment on live aboveground and belowground biomass, R:S ratio, leaf %Carbon, average height, stem density and random shoot height; however, a significantly higher (P=0.018) increase in leaf %Nitrogen content in treated plots indicated that nutrient uptake had occurred.

Numerical model of the human cornea based on stromal microstructure: identification of mechanical properties for two age groups

The optical quality of the human eye mainly depends on the refractive performance of the cornea. The shape of the cornea is a mechanical balance between intraocular pressure and tissue intrinsic stiffness. Several surgical procedures in ophthalmology alter the biomechanics of the cornea to provoke local or global curvature changes for vision correction. Legitimated by the large number of surgical interventions performed every day, the demand for a deeper understanding of corneal biomechanics is rising to improve the safety of procedures and medical devices. The aim of our work is to propose a numerical model of corneal biomechanics, based on the stromal microstructure. Our novel anisotropic constitutive material law features a probabilistic weighting approach to model collagen fiber distribution as observed on human cornea by Xray scattering analysis (Aghamohammadzadeh et. al., Structure, February 2004). Furthermore, collagen cross-linking was explicitly included in the strain energy function. Results showed that the proposed model is able to successfully reproduce both inflation and extensiometry experimental data (Elsheikh et. al., Curr Eye Res, 2007; Elsheikh et. al., Exp Eye Res, May 2008). In addition, the mechanical properties calculated for patients of different age groups (Group A: 65-79 years; Group B: 80-95 years) demonstrate an increased collagen cross-linking, and a decrease in collagen fiber elasticity from younger to older specimen. These findings correspond to what is known about maturing fibrous biological tissue. Since the presented model can handle different loading situations and includes the anisotropic distribution of collagen fibers, it has the potential to simulate clinical procedures involving nonsymmetrical tissue interventions. In the future, such mechanical model can be used to improve surgical planning and the design of next generation ophthalmic devices.

Induction of the Neurokinin 1 Receptor by TNFα in Endometriotic Tissue Provides the Potential for Neurogenic Control Over Endometriotic Lesion Growth

Context: Endometriosis is characterized by the growth of ectopic endometrial tissue. Nerve fibers are frequently associated with ectopic lesions, and neurogenic inflammation may play a role in endometriosis. Objective: The purpose of this study was to determine the presence of tachykinin receptors in endometriotic lesions and the role of TNFα on their expression. Design: This study was an assessment of matching eutopic and ectopic endometrial tissue and peritoneal fluid from patients with endometriosis and an in vitro analysis of primary endometrial cells. Setting: The setting was a university hospital. Patients: Participants were premenopausal women undergoing laparoscopy. Interventions: Endometriotic lesions were removed surgically. Main Outcome Measures: Tachykinin mRNA (TACR1/2) and protein (neurokinin 1 receptor [NK1R]) expression in both eutopic and ectopic endometrial tissue from patients with endometriosis and the correlation to peritoneal fluid TNFα were measured. Primary endometrial epithelial and stromal cells were assessed in vitro to determine the induction of TACR1/2 and NK1R expression after TNFα treatment. Cell viability of endometrial stromal cells after substance P exposure was also assessed. Results: Expression of both TACR1 and TACR2 mRNA was significantly higher in the ectopic than in the eutopic tissue. Both TACR1 mRNA and NK1R protein expression was significantly correlated with peritoneal fluid TNFα, and in vitro studies confirmed that TNFα treatment induced both TACR1 mRNA and NK1R protein expression in endometrial stromal cells. In endometrial stromal cells, substance P treatment enhanced cell viability, which was inhibited by a specific NK1R antagonist. Conclusions: NK1R expression is induced in ectopic endometrial tissue by peritoneal TNFα. Induction of NK1R expression may permit endometriotic lesion maintenance via exposure to substance P.

Line-scan diffusion tensor imaging of the posttraumatic brain stem: changes with neuropathologic correlation

Following trauma, imaging of brain stem lesions is often inconclusive. In a man who suffered a lethal accident, postmortem MR diffusion tensor (DT) imaging of the brain and neuropathologic examination were performed. DT imaging showed a disorganization of fibers in the brain stem that was not found in 2 controls and corresponded to changes on neuropathologic correlation. Diffusion tensor imaging provides an insight into the organization of myelinated structures of the CNS, potentially allowing diagnosis of traumatic fiber tract rupture.

Mice with a targeted disruption of the Fgfrl1 gene die at birth due to alterations in the diaphragm

FGFRL1 is a recently discovered member of the fibroblast growth factor receptor family that is lacking the intracellular tyrosine kinase domain. To elucidate the function of the novel receptor, we created mice with a targeted disruption of the Fgfrl1 gene. These mice develop normally until term, but die within a few minutes after birth due to respiratory failure. The respiratory problems are explained by a significant reduction in the size of the diaphragm muscle, which is not sufficient to inflate the lungs after birth. The remaining portion of the diaphragm muscle appears to be well developed and innervated. It consists of differentiated myofibers with nuclei at the periphery. Fast and slow muscle fibers occur in normal proportions. The myogenic regulatory factors MyoD, Myf5, myogenin and Mrf4 and the myocyte enhancer factors Mef2A, Mef2B, Mef2C and Mef2D are expressed at normal levels. Experiments with a cell culture model involving C2C12 myoblasts show that Fgfrl1 is expressed during the late stages of myotube formation. Other skeletal muscles do not appear to be affected in the Fgfrl1 deficient mice. Thus, Fgfrl1 plays a critical role in the development of the diaphragm.

An investigation of phenolic glycoside and condensed tannin homeostasis in Populus by salicyl alcohol feeding to cell cultures and by transgenic manipulation of the sucrose transporter, PTSUT4, in planta

Secondary metabolites play an important role in plant protection against biotic and abiotic stress. In Populus, phenolic glycosides (PGs) and condensed tannins (CTs) are two such groups of compounds derived from the common phenylpropanoid pathway. The basal levels and the inducibility of PGs and CTs depend on genetic as well as environmental factors, such as soil nitrogen (N) level. Carbohydrate allocation, transport and sink strength also affect PG and CT levels. A negative correlation between the levels of PGs and CTs was observed in several studies. However, the molecular mechanism underlying such relation is not known. We used a cell culture system to understand negative correlation of PGs and CTs. Under normal culture conditions, neither salicin nor higher-order PGs accumulated in cell cultures. Several factors, such as hormones, light, organelles and precursors were discussed in the context of aspen suspension cells’ inability to synthesize PGs. Salicin and its isomer, isosalicin, were detected in cell cultures fed with salicyl alcohol, salicylaldehyde and helicin. At higher levels (5 mM) of salicyl alcohol feeding, accumulation of salicins led to reduced CT production in the cells. Based on metabolic and gene expression data, the CT reduction in salicin-accumulating cells is partly a result of regulatory changes at the transcriptional level affecting carbon partitioning between growth processes, and phenylpropanoid CT biosynthesis. Based on molecular studies, the glycosyltransferases, GT1-2 and GT1-246, may function in glycosylation of simple phenolics, such as salicyl alcohol in cell cultures. The uptake of such glycosides into vacuole may be mediated to some extent by tonoplast localized multidrug-resistance associated protein transporters, PtMRP1 and PtMRP6. In Populus, sucrose is the common transported carbohydrate and its transport is possibly regulated by sucrose transporters (SUTs). SUTs are also capable of transporting simple PGs, such as salicin. Therefore, we characterized the SUT gene family in Populus and investigated, by transgenic analysis, the possible role of the most abundantly expressed member, PtSUT4, in PG-CT homeostasis using plants grown under varying nitrogen regimes. PtSUT4 transgenic plants were phenotypically similar to the wildtype plants except that the leaf area-to-stem volume ratio was higher for transgenic plants. In SUT4 transgenics, levels of non-structural carbohydrates, such as sucrose and starch, were altered in mature leaves. The levels of PGs and CTs were lower in green tissues of transgenic plants under N-replete, but were higher under N-depleted conditions, compared to the levels in wildtype plants. Based on our results, SUT4 partly regulates N-level dependent PG-CT homeostasis by differential carbohydrate allocation.