Antioxidant activity and chemical composition of the non polar fraction of Gracilaria domingensis (Kützing) Sonder ex Dickie and Gracilaria birdiae (Plastino & Oliveira)

Gracilaria domingensis (Kützing) Sonder ex Dickie and Gracilaria birdiae (Plastino & Oliveira) (Gracilariales, Rhodophyta) are seaweeds that occur on the Brazilian coast. Based on their economic and pharmaceutical importance, we investigated the antioxidant activity of the methanolic, ethyl acetate and hexane extracts of both species. The hexane extracts display a high antioxidant activity and comparative analyses indicated G. birdiae as the most active species. Chemical investigation of these fractions showed several carotenoids and fatty acids, as well as cholesterol and sitosterol derivatives. HPLC-DAD analysis of G. birdiae showed violaxanthin (0.04 μg.mg-1 of dry material), antheraxanthin (5.31 μg.mg-1), aloxanthin (0.09 μg.mg-1), zeaxanthin (0.45 μg.mg-1) and β-carotene (0.37 μg.mg-1) as the major carotenoids. G. domingensis showed a similar carotenoid profile, however, with much lower concentration than G. birdiae. Gas chromatography coupled to mass spectrometry was used to determine other nonpolar compounds of these seaweeds. The main compounds detected in both studied species were the fatty acids 16:0; 18:1 Δ9; 20:3 Δ6,9,12, 20:4 Δ5,8,11,14. We found no specificity of compounds in either species. However, G. birdiae, presented higher contents of carotenoids and arachidonic acid than G. domingensis.

Biosynthesis of vitamins and cofactors in bacterium-harbouring trypanosomatids depends on the symbiotic association as revealed by genomic analyses

Some non-pathogenic trypanosomatids maintain a mutualistic relationship with a betaproteobacterium of the Alcaligenaceae family. Intensive nutritional exchanges have been reported between the two partners, indicating that these protozoa are excellent biological models to study metabolic co-evolution. We previously sequenced and herein investigate the entire genomes of five trypanosomatids which harbor a symbiotic bacterium (SHTs for Symbiont-Haboring Trypanosomatids) and the respective bacteria (TPEs for Trypanosomatid Proteobacterial Endosymbiont), as well as two trypanosomatids without symbionts (RTs for Regular Trypanosomatids), for the presence of genes of the classical pathways for vitamin biosynthesis. Our data show that genes for the biosynthetic pathways of thiamine, biotin, and nicotinic acid are absent from all trypanosomatid genomes. This is in agreement with the absolute growth requirement for these vitamins in all protozoa of the family. Also absent from the genomes of RTs are the genes for the synthesis of pantothenic acid, folic acid, riboflavin, and vitamin B6. This is also in agreement with the available data showing that RTs are auxotrophic for these essential vitamins. On the other hand, SHTs are autotrophic for such vitamins. Indeed, all the genes of the corresponding biosynthetic pathways were identified, most of them in the symbiont genomes, while a few genes, mostly of eukaryotic origin, were found in the host genomes. The only exceptions to the latter are: the gene coding for the enzyme ketopantoate reductase (EC:1.1.1.169) which is related instead to the Firmicutes bacteria; and two other genes, one involved in the salvage pathway of pantothenic acid and the other in the synthesis of ubiquinone, that are related to Gammaproteobacteria. Their presence in trypanosomatids may result from lateral gene transfer. Taken together, our results reinforce the idea that the low nutritional requirement of SHTs is associated with the presence of the symbiotic bacterium, which contains most genes for vitamin production.

A system for classification of time-series data from industrial non-destructive device

This work proposes a system for classification of industrial steel pieces by means of magnetic nondestructive device. The proposed classification system presents two main stages, online system stage and off-line system stage. In online stage, the system classifies inputs and saves misclassification information in order to perform posterior analyses. In the off-line optimization stage, the topology of a Probabilistic Neural Network is optimized by a Feature Selection algorithm combined with the Probabilistic Neural Network to increase the classification rate. The proposed Feature Selection algorithm searches for the signal spectrogram by combining three basic elements: a Sequential Forward Selection algorithm, a Feature Cluster Grow algorithm with classification rate gradient analysis and a Sequential Backward Selection. Also, a trash-data recycling algorithm is proposed to obtain the optimal feedback samples selected from the misclassified ones.

Development and characterization of non-oxide ceramic composites for mechanical and tribological applications

The main reasons for the attention focused on ceramics as possible structural materials are their wear resistance and the ability to operate with limited oxidation and ablation at temperatures above 2000°C. Hence, this work is devoted to the study of two classes of materials which can satisfy these requirements: silicon carbide -based ceramics (SiC) for wear applications and borides and carbides of transition metals for ultra-high temperatures applications (UHTCs). SiC-based materials: Silicon carbide is a hard ceramic, which finds applications in many industrial sectors, from heat production, to automotive engineering and metals processing. In view of new fields of uses, SiC-based ceramics were produced with addition of 10-30 vol% of MoSi2, in order to obtain electro conductive ceramics. MoSi2, indeed, is an intermetallic compound which possesses high temperature oxidation resistance, high electrical conductivity (21·10-6 Ω·cm), relatively low density (6.31 g/cm3), high melting point (2030°C) and high stiffness (440 GPa). The SiC-based ceramics were hot pressed at 1900°C with addition of Al2O3-Y2O3 or Y2O3-AlN as sintering additives. The microstructure of the composites and of the reference materials, SiC and MoSi2, were studied by means of conventional analytical techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (SEM-EDS). The composites showed a homogeneous microstructure, with good dispersion of the secondary phases and low residual porosity. The following thermo-mechanical properties of the SiC-based materials were measured: Vickers hardness (HV), Young’s modulus (E), fracture toughness (KIc) and room to high temperature flexural strength (σ). The mechanical properties of the composites were compared to those of two monolithic SiC and MoSi2 materials and resulted in a higher stiffness, fracture toughness and slightly higher flexural resistance. Tribological tests were also performed in two configurations disco-on-pin and slideron cylinder, aiming at studying the wear behaviour of SiC-MoSi2 composites with Al2O3 as counterfacing materials. The tests pointed out that the addition of MoSi2 was detrimental owing to a lower hardness in comparison with the pure SiC matrix. On the contrary, electrical measurements revealed that the addition of 30 vol% of MoSi2, rendered the composite electroconductive, lowering the electrical resistance of three orders of magnitude. Ultra High Temperature Ceramics: Carbides, borides and nitrides of transition metals (Ti, Zr, Hf, Ta, Nb, Mo) possess very high melting points and interesting engineering properties, such as high hardness (20-25 GPa), high stiffness (400-500 GPa), flexural strengths which remain unaltered from room temperature to 1500°C and excellent corrosion resistance in aggressive environment. All these properties place the UHTCs as potential candidates for the development of manoeuvrable hypersonic flight vehicles with sharp leading edges. To this scope Zr- and Hf- carbide and boride materials were produced with addition of 5-20 vol% of MoSi2. This secondary phase enabled the achievement of full dense composites at temperature lower than 2000°C and without the application of pressure. Besides the conventional microstructure analyses XRD and SEM-EDS, transmission electron microscopy (TEM) was employed to explore the microstructure on a small length scale to disclose the effective densification mechanisms. A thorough literature analysis revealed that neither detailed TEM work nor reports on densification mechanisms are available for this class of materials, which however are essential to optimize the sintering aids utilized and the processing parameters applied. Microstructural analyses, along with thermodynamics and crystallographic considerations, led to disclose of the effective role of MoSi2 during sintering of Zrand Hf- carbides and borides. Among the investigated mechanical properties (HV, E, KIc, σ from room temperature to 1500°C), the high temperature flexural strength was improved due to the protective and sealing effect of a silica-based glassy phase, especially for the borides. Nanoindentation tests were also performed on HfC-MoSi2 composites in order to extract hardness and elastic modulus of the single phases. Finally, arc jet tests on HfC- and HfB2-based composites confirmed the excellent oxidation behaviour of these materials under temperature exceeding 2000°C; no cracking or spallation occurred and the modified layer was only 80-90 μm thick.

Stability, viscous dissipation and local thermal non-equilibrium in fluid saturated porous media

In this thesis, the field of study related to the stability analysis of fluid saturated porous media is investigated. In particular the contribution of the viscous heating to the onset of convective instability in the flow through ducts is analysed. In order to evaluate the contribution of the viscous dissipation, different geometries, different models describing the balance equations and different boundary conditions are used. Moreover, the local thermal non-equilibrium model is used to study the evolution of the temperature differences between the fluid and the solid matrix in a thermal boundary layer problem. On studying the onset of instability, different techniques for eigenvalue problems has been used. Analytical solutions, asymptotic analyses and numerical solutions by means of original and commercial codes are carried out.

Modelli non lineari statici e dinamici su dati microeconomici: analisi delle condizioni finanziarie delle famiglie italiane

The thesis studies the economic and financial conditions of Italian households, by using microeconomic data of the Survey on Household Income and Wealth (SHIW) over the period 1998-2006. It develops along two lines of enquiry. First it studies the determinants of households holdings of assets and liabilities and estimates their correlation degree. After a review of the literature, it estimates two non-linear multivariate models on the interactions between assets and liabilities with repeated cross-sections. Second, it analyses households financial difficulties. It defines a quantitative measure of financial distress and tests, by means of non-linear dynamic probit models, whether the probability of experiencing financial difficulties is persistent over time. Chapter 1 provides a critical review of the theoretical and empirical literature on the estimation of assets and liabilities holdings, on their interactions and on households net wealth. The review stresses the fact that a large part of the literature explain households debt holdings as a function, among others, of net wealth, an assumption that runs into possible endogeneity problems. Chapter 2 defines two non-linear multivariate models to study the interactions between assets and liabilities held by Italian households. Estimation refers to a pooling of cross-sections of SHIW. The first model is a bivariate tobit that estimates factors affecting assets and liabilities and their degree of correlation with results coherent with theoretical expectations. To tackle the presence of non normality and heteroskedasticity in the error term, generating non consistent tobit estimators, semi-parametric estimates are provided that confirm the results of the tobit model. The second model is a quadrivariate probit on three different assets (safe, risky and real) and total liabilities; the results show the expected patterns of interdependence suggested by theoretical considerations. Chapter 3 reviews the methodologies for estimating non-linear dynamic panel data models, drawing attention to the problems to be dealt with to obtain consistent estimators. Specific attention is given to the initial condition problem raised by the inclusion of the lagged dependent variable in the set of explanatory variables. The advantage of using dynamic panel data models lies in the fact that they allow to simultaneously account for true state dependence, via the lagged variable, and unobserved heterogeneity via individual effects specification. Chapter 4 applies the models reviewed in Chapter 3 to analyse financial difficulties of Italian households, by using information on net wealth as provided in the panel component of the SHIW. The aim is to test whether households persistently experience financial difficulties over time. A thorough discussion is provided of the alternative approaches proposed by the literature (subjective/qualitative indicators versus quantitative indexes) to identify households in financial distress. Households in financial difficulties are identified as those holding amounts of net wealth lower than the value corresponding to the first quartile of net wealth distribution. Estimation is conducted via four different methods: the pooled probit model, the random effects probit model with exogenous initial conditions, the Heckman model and the recently developed Wooldridge model. Results obtained from all estimators accept the null hypothesis of true state dependence and show that, according with the literature, less sophisticated models, namely the pooled and exogenous models, over-estimate such persistence.

RNA non-codificanti indotti da danno al DNA regolano il fattore di trascrizione HIF-1α

Recenti analisi sull’intero trascrittoma hanno rivelato una estensiva trascrizione di RNA non codificanti (ncRNA), le quali funzioni sono tuttavia in gran parte sconosciute. In questo lavoro è stato dimostrato che alte dosi di camptotecina (CPT), un farmaco antitumorale inibitore della Top1, aumentano la trascrizione di due ncRNA antisenso in 5’ e 3’ (5'aHIF-1α e 3'aHIF-1α rispettivamente) al locus genico di HIF-1α e diminuiscono i livelli dell’mRNA di HIF-1α stesso. Gli effetti del trattamento sono Top1-dipendenti, mentre non dipendono dal danno al DNA alla forca di replicazione o dai checkpoint attivati dal danno al DNA. I ncRNA vengono attivati in risposta a diversi tipi di stress, il 5'aHIF-1α è lungo circa 10 kb e possiede sia il CAP in 5’ sia poliadenilazione in 3’ (in letteratura è noto che il 3'aHIF-1α è un trascritto di 1,7 kb, senza 5’CAP né poliadenilazione). Analisi di localizzazione intracellulare hanno dimostrato che entrambi sono trascritti nucleari. In particolare 5'aHIF-1α co-localizza con proteine del complesso del poro nucleare, suggerendo un suo possibile ruolo come mediatore degli scambi della membrana nucleare. È stata dimostrata inoltre la trascrizione dei due ncRNA in tessuti di tumore umano del rene, evidenziandone possibili ruoli nello sviluppo del cancro. È anche noto in letteratura che basse dosi di CPT in condizioni di ipossia diminuiscono i livelli di proteina di HIF-1α. Dopo aver dimostrato su diverse linee cellulari che i due ncRNA sopracitati non potessero essere implicati in tale effetto, abbiamo studiato le variazioni dell’intero miRnoma alle nuove condizioni sperimentali. In tal modo abbiamo scoperto che il miR-X sembra essere il mediatore molecolare dell’abbattimento di HIF-1α dopo trattamento con basse dosi di CPT in ipossia. Complessivamente, questi risultati suggeriscono che il fattore di trascrizione HIF-1α venga finemente regolato da RNA non-codificanti indotti da danno al DNA.

Development and application of a GC system for NMHC analyses of air samples from the CARIBIC aircraft project

The subject of this thesis is the development of a Gaschromatography (GC) system for non-methane hydrocarbons (NMHCs) and measurement of samples within the project CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container, www.caribic-atmospheric.com). Air samples collected at cruising altitude from the upper troposphere and lowermost stratosphere contain hydrocarbons at low levels (ppt range), which imposes substantial demands on detection limits. Full automation enabled to maintain constant conditions during the sample processing and analyses. Additionally, automation allows overnight operation thus saving time. A gas chromatography using flame ionization detection (FID) together with the dual column approach enables simultaneous detection with almost equal carbon atom response for all hydrocarbons except for ethyne. The first part of this thesis presents the technical descriptions of individual parts of the analytical system. Apart from the sample treatment and calibration procedures, the sample collector is described. The second part deals with analytical performance of the GC system by discussing tests that had been made. Finally, results for measurement flight are assessed in terms of quality of the data and two flights are discussed in detail. Analytical performance is characterized using detection limits for each compound, using uncertainties for each compound, using tests of calibration mixture conditioning and carbon dioxide trap to find out their influence on analyses, and finally by comparing the responses of calibrated substances during period when analyses of the flights were made. Comparison of both systems shows good agreement. However, because of insufficient capacity of the CO2 trap the signal of one column was suppressed due to breakthroughed carbon dioxide so much that its results appeared to be unreliable. Plausibility tests for the internal consistency of the given data sets are based on common patterns exhibited by tropospheric NMHCs. All tests show that samples from the first flights do not comply with the expected pattern. Additionally, detected alkene artefacts suggest potential problems with storing or contamination within all measurement flights. Two last flights # 130-133 and # 166-169 comply with the tests therefore their detailed analysis is made. Samples were analyzed in terms of their origin (troposphere vs. stratosphere, backward trajectories), their aging (NMHCs ratios) and detected plumes were compared to chemical signatures of Asian outflows. In the last chapter a future development of the presented system with focus on separation is drawn. An extensive appendix documents all important aspects of the dissertation from theoretical introduction through illustration of sample treatment to overview diagrams for the measured flights.

Study of the interactions of Neptunium with humic substances and the clay mineral montmorillonite by direct and non direct speciation methods

For the safety assessment of radioactive waste, the possibility of radionuclide migration has to be considered. Since Np (and also Th due to the long-lived 232-Th) will be responsible for the greatest amount of radioactivity one million years after discharge from the reactor, its (im)-mobilization in the geosphere is of great importance. Furthermore, the chemistry of Np(V) is quite similar (but not identical) to the chemistry of Pu(V). Three species of neptunium may be found in the near field of the waste disposal, but pentavalent neptunium is the most abundant species under a wide range of natural conditions. Within this work, the interaction of Np(V) with the clay mineral montmorillonite and melanodins (as model substances for humic acids) was studied. The sorption of neptunium onto gibbsite, a model clay for montmorillonite, was also investigated. The sorption of neptunium onto γ-alumina and montmorillonite was studied in a parallel doctoral work by S. Dierking. Neptunium is only found in ultra trace amounts in the environment. Therefore, sensitive and specific methods are needed for its determination. The sorption was determined by γ spectroscopy and LSC for the whole concentration range studied. In addition the combination of these techniques with ultrafiltration allowed the study of Np(V) complexation with melanoidins. Regrettably, the available speciation methods (e.g. CE-ICP-MS and EXAFS) are not capable to detect the environmentally relevant neptunium concentrations. Therefore, a combination of batch experiments and speciation analyses was performed. Further, the preparation of hybrid clay-based materials (HCM) montmorillonitemelanoidins for sorption studies was achieved. The formation of hybrid materials begins in the interlayers of the montmorillonite, and then the organic material spreads over the surface of the mineral. The sorption of Np onto HCM was studied at the environmentally relevant concentrations and the results obtained were compared with those predicted by the linear additive model by Samadfam. The sorption of neptunium onto gibbsite was studied in batch experiments and the sorption maximum determined at pH~8.5. The sorption isotherm pointed to the presence of strong and weak sorption sites in gibbsite. The Np speciation was studied by using EXAFS, which showed that the sorbed species was Np(V). The influence of M42 type melanodins on the sorption of Np(V) onto montmorillonite was also investigated at pH 7. The sorption of the melanoidins was affected by the order in which the components were added and by ionic strength. The sorption of Np was affected by ionic strength, pointing to outer sphere sorption, whereas the presence of increasing amounts of melanoidins had little influence on Np sorption.

Development of a field method to assess root parasites of woody plants - ecological analyses of the grapevine-phylloxera interaction

The development and the growth of plants is strongly affected by the interactions between roots, rootrnassociated organisms and rhizosphere communities. Methods to assess such interactions are hardly torndevelop particularly in perennial and woody plants, due to their complex root system structure and theirrntemporal change in physiology patterns. In this respect, grape root systems are not investigated veryrnwell. The aim of the present work was the development of a method to assess and predict interactionsrnat the root system of rootstocks (Vitis berlandieri x Vitis riparia) in field. To achieve this aim, grapernphylloxera (Daktulosphaira vitifoliae Fitch, Hemiptera, Aphidoidea) was used as a graperoot parasitizingrnmodel.rnTo develop the methodical approach, a longt-term trial (2006-2009) was arranged on a commercial usedrnvineyard in Geisenheim/Rheingau. All 2 to 8 weeks the top most 20 cm of soil under the foliage wallrnwere investigated and root material was extracted (n=8-10). To include temporal, spatial and cultivarrnspecific root system dynamics, the extracted root material was analyzed digitally on the morphologicalrnproperties. The grape phylloxera population was quantified and characterized visually on base of theirrnlarvalstages (oviparous, non oviparous and winged preliminary stages). Infection patches (nodosities)rnwere characterized visually as well, partly supported by digital root color analyses. Due to the knownrneffects of fungal endophytes on the vitality of grape phylloxera infested grapevines, fungal endophytesrnwere isolated from nodosity and root tissue and characterized (morphotypes) afterwards. Further abioticrnand biotic soil conditions of the vineyards were assessed. The temporal, spatial and cultivar specificrnsensitivity of single parameters were analyzed by omnibus tests (ANOVAs) and adjacent post-hoc tests.rnThe relations between different parameters were analyzed by multiple regression models.rnQuantitative parameters to assess the degeneration of nodosity, the development nodosity attachedrnroots and to differentiate between nodosities and other root swellings in field were developed. Significantrndifferences were shown between root dynamic including parameters and root dynamic ignoringrnparameters. Regarding the description of grape phylloxera population and root system dynamic, thernmethod showed a high temporal, spatial and cultivar specific sensitivity. Further, specific differencesrncould be shown in the frequency of endophyte morphotypes between root and nodosity tissue as wellrnas between cultivars. Degeneration of nodosities as well as nodosity occupation rates could be relatedrnto the calculated abundances of grape phylloxera population. Further ecological questions consideringrngrape root development (e.g. relation between moisture and root development) and grape phylloxerarnpopulation development (e.g. relation between temperature and population structure) could be answeredrnfor field conditions.rnGenerally, the presented work provides an approach to evaluate vitality of grape root systems. Thisrnapproach can be useful, considering the development of control strategies against soilborne pests inrnviticulture (e.g. grape phylloxera, Sorospheara viticola, Roesleria subterranea (Weinm.) Redhaed) as well as considering the evaluation of integrated management systems in viticulture.

Assimilation of data from conventional and non conventional networks through a LETKF scheme in the COSMO model

The present work studies a km-scale data assimilation scheme based on a LETKF developed for the COSMO model. The aim is to evaluate the impact of the assimilation of two different types of data: temperature, humidity, pressure and wind data from conventional networks (SYNOP, TEMP, AIREP reports) and 3d reflectivity from radar volume. A 3-hourly continuous assimilation cycle has been implemented over an Italian domain, based on a 20 member ensemble, with boundary conditions provided from ECMWF ENS. Three different experiments have been run for evaluating the performance of the assimilation on one week in October 2014 during which Genova flood and Parma flood took place: a control run of the data assimilation cycle with assimilation of data from conventional networks only, a second run in which the SPPT scheme is activated into the COSMO model, a third run in which also reflectivity volumes from meteorological radar are assimilated. Objective evaluation of the experiments has been carried out both on case studies and on the entire week: check of the analysis increments, computing the Desroziers statistics for SYNOP, TEMP, AIREP and RADAR, over the Italian domain, verification of the analyses against data not assimilated (temperature at the lowest model level objectively verified against SYNOP data), and objective verification of the deterministic forecasts initialised with the KENDA analyses for each of the three experiments.

Small study effects in meta-analyses of osteoarthritis trials: meta-epidemiological study

Objective To examine the presence and extent of small study effects in clinical osteoarthritis research. Design Meta-epidemiological study. Data sources 13 meta-analyses including 153 randomised trials (41 605 patients) that compared therapeutic interventions with placebo or non-intervention control in patients with osteoarthritis of the hip or knee and used patients’ reported pain as an outcome. Methods We compared estimated benefits of treatment between large trials (at least 100 patients per arm) and small trials, explored funnel plots supplemented with lines of predicted effects and contours of significance, and used three approaches to estimate treatment effects: meta-analyses including all trials irrespective of sample size, meta-analyses restricted to large trials, and treatment effects predicted for large trials. Results On average, treatment effects were more beneficial in small than in large trials (difference in effect sizes −0.21, 95% confidence interval −0.34 to −0.08, P=0.001). Depending on criteria used, six to eight funnel plots indicated small study effects. In six of 13 meta-analyses, the overall pooled estimate suggested a clinically relevant, significant benefit of treatment, whereas analyses restricted to large trials and predicted effects in large trials yielded smaller non-significant estimates. Conclusions Small study effects can often distort results of meta-analyses. The influence of small trials on estimated treatment effects should be routinely assessed.

Relevance of In-vitro Tests of Adhesive and Composite Dental Materials. A Review in 3 Parts. Part 2: Non-standardized tests of composite materials

Summary The first part of this review examined ISO approval requirements and in vitro testing. In the second part, non-standardized test methods for composite materials are presented and discussed. Physical tests are primarily described. Analyses of surface gloss and alterations, as well as aging simulations of dental materials are presented. Again, the importance of laboratory tests in determining clinical outcomes is evaluated. Differences in the measurement protocols of the various testing institutes and how these differences can in?uence the results are also discussed. Because there is no standardization of test protocols, the values determined by different institutes cannot be directly compared. However, the ranking of the tested materials should be the same if a valid protocol is applied by different institutes. The modulus of elasticity, the expansion after water sorption, and the polishability of the material are all clinically relevant, whereas factors measured by other test protocols may have no clinical correlation. The handling properties of the materials are highly dependent on operators' preferences. Therefore, no standard values can be given.

The Spatial Signature of Biotic Interactions of a Clonal and a Non-clonal Palmetto in a Subtropical Plant Community

Spatial analyses of plant-distribution patterns can provide inferences about intra- and interspecific biotic interactions. Yet, such analyses are rare for clonal plants because effective tools (i.e., molecular markers) needed to map naturally occurring clonal individuals have only become available recently. Clonal plants are unique in that a single genotype has a potential to spatially place new individuals (i.e., ramets) in response to intra- and interspecific biotic interactions. Laboratory and greenhouse studies suggest that some clonal plants can avoid intra-genet, inter-genet, and inter-specific competition via rootplacement patterns. An intriguing and yet to be explored question is whether a spatial signature of such multi-level biotic interactions can be detected in natural plant communities. The facultatively clonal Serenoa repens and non-clonal Sabal etonia are ecologically similar and co-dominant palmettos that sympatrically occur in the Florida peninsula. We used amplified fragment length polymorphisms (AFLPs) to identify Serenoa genets and also to assign field-unidentifiable small individuals as Sabal seedlings, Serenoa seedlings, or Serenoa vegetative sprouts. Then, we conducted univariate and bivariate multi-distance spatial analyses to examine the spatial interactions of Serenoa (n=271) and Sabal (n=137) within a 20x20 m grid at three levels, intragenet, intergenet and interspecific. We found that spatial interactions were not random at all three levels of biotic interactions. Serenoa genets appear to spatially avoid self-competition as well as intergenet competition. Furthermore, Serenoa and Sabal were spatially negatively associated with each other. However, this negative association pattern was also evident in a spatial comparison between non-clonal Serenoa and Sabal, suggesting that Serenoa genets’ spatial avoidance of Sabal through placement of new ramets is not the explanation of the interspecific-level negative spatial pattern. Our results emphasize the importance of investigating spatial signatures of biotic as well as abiotic interactions at multiple levels in understanding spatial distribution patterns of clonal plants in natural plant communities.

Life stage differences in mammary gland gene expression profile in non-human primates

Breast cancer (BC) is the most common malignancy of women in the developed world. To better understand its pathogenesis, knowledge of normal breast development is crucial, as BC is the result of disregulation of physiologic processes. The aim of this study was to investigate the impact of reproductive life stages on the transcriptional profile of the mammary gland in a primate model. Comparative transcriptomic analyses were carried out using breast tissues from 28 female cynomolgus macaques (Macaca fascicularis) at the following life stages: prepubertal (n = 5), adolescent (n = 4), adult luteal (n = 5), pregnant (n = 6), lactating (n = 3), and postmenopausal (n = 5). Mammary gland RNA was hybridized to Affymetrix GeneChip(®) Rhesus Macaque Genome Arrays. Differential gene expression was analyzed using ANOVA and cluster analysis. Hierarchical cluster analysis revealed distinct separation of life stage groups. More than 2,225 differentially expressed mRNAs were identified. Gene families or pathways that changed across life stages included those related to estrogen and androgen (ESR1, PGR, TFF1, GREB1, AR, 17HSDB2, 17HSDB7, STS, HSD11B1, AKR1C4), prolactin (PRLR, ELF5, STAT5, CSN1S1), insulin-like growth factor signaling (IGF1, IGFBP1, IGFBP5), extracellular matrix (POSTN, TGFB1, COL5A2, COL12A1, FOXC1, LAMC1, PDGFRA, TGFB2), and differentiation (CD24, CD29, CD44, CD61, ALDH1, BRCA1, FOXA1, POSTN, DICER1, LIG4, KLF4, NOTCH2, RIF1, BMPR1A, TGFB2). Pregnancy and lactation displayed distinct patterns of gene expression. ESR1 and IGF1 were significantly higher in the adolescent compared to the adult animals, whereas differentiation pathways were overrepresented in adult animals and pregnancy-associated life stages. Few individual genes were distinctly different in postmenopausal animals. Our data demonstrate characteristic patterns of gene expression during breast development. Several of the pathways activated during pubertal development have been implicated in cancer development and metastasis, supporting the idea that other developmental markers may have application as biomarkers for BC.