Quantifying seasonality along a latitudinal gradient: from stream temperature to growth of invasive mosquitofish

Most ecosystems undergo substantial variation over the seasons, ranging from changes in abiotic features, such as temperature, light and precipitation, to changes in species abundance and composition. How seasonality varies along latitudinal gradients is not well known in freshwater ecosystems, despite being very important in predicting the effects of climate change and in helping to advance ecological understanding. Stream temperature is often well correlated with air temperature and influences many ecosystem features such as growth and metabolism of most aquatic organisms. We evaluated the degree of seasonality in ten river mouths along a latitudinal gradient for a set of variables, ranging from air and water temperatures, to physical and chemical properties of water and growth of an invasive fish species (eastern mosquitofish, Gambusia holbrooki ). Our results show that although most of the variation in air temperature was explained by latitude and season, this was not the case for water features, including temperature, in lowland Mediterranean streams, which depended less on season and much more on local factors. Similarly, although there was evidence of latitude-dependent seasonality in fish growth, the relationship was nonlinear and weak and the significant latitudinal differences in growth rates observed during winter were compensated later in the year and did not result in overall differences in size and growth. Our results suggest that although latitudinal differences in air temperature cascade through properties of freshwater ecosystems, local factors and complex interactions often override the water temperature variation with latitude and might therefore hinder projections of species distribution models and effects of climate change

Hydrology, light and the use of organic and inorganic materials as structuring factors of biological communities in Mediterranean streams

Hydrological disturbances, light availability and nutrients are the most relevant factors determining the structure of the biological communities in Mediterranean rivers. While some hydrological disturbances are able to induce catastrophic effects, which may cause a complete reset in physical and biological conditions, continued enrichment or changes in light availability are factors leading to the progressive shift in the communities of autotrophs and heterotrophs in the systems. Primary production in Mediterranean streams shows relevant seasonal changes which mainly follows the variations in light availability. In most forested streams, the algal community is shade-adapted. Nutrient enrichment (especially phosphorus) leads to marked increases in primary production, but this increase is not lineal and there is a saturation of algal biomass even in the most enriched systems. The heterotrophs (bacteria, fungi) are related to the pattern of DOC availability (which most depends on the seasonal discharge and leaf fall dynamics) and to the available substrata in the stream. It has been repeatedly observed that shorttime increases of extracellular enzyme activities are related to the accumulation of autochthonous (algal) and/or allochthonous (leaves) organic matter on the streambed during spring and summer, this being more remarkable in dry than in wetter years. Flow reduction favours detritus concentration in pools, and the subsequent increase in the density and biomass of the macroinvertebrate community. In Mediterranean streams collectors are accounting for the highest density and biomass, this being more remarkable in the least permanent systems, in accordance with the effect of floods on the organic matter availability. Nutrients, through the effect on the primary producers, also affect the trophic food web in the streams by favouring the predominance of grazers

The dynamics of biofilm bacterial communities is driven by flow wax and wane in a temporary stream

Biofilm communities are exposed to long periods of desiccation in temporary streams. We investigated how water flow intermittency affected the bacterial community structure colonizing three different streambed compartments in a Mediterranean stream. Massive parallel sequencing revealed different bacterial communities in biofilms from sand sediments and cobbles. Bacterial communities were similar (62% of shared operational taxonomic units) in the epipsammic and hyporheic biofilms, and more diverse than those in the epilithic biofilms. The non-flow phase caused a decrease of bacterial diversity in the biofilms, when communities included only bacterial taxa assumed to be adapted to water stress. The most sensitive bacterial communities to flow intermittency were in the epilithic, where the exposure to physical stress was the highest. In sand sediments a wide group of bacterial taxa was tolerant to desiccation. During non-flow the proliferation of opportunistic taxa in the superficial compartments evidenced the biological link with the terrestrial environment. Bacterial communities better tolerate rewetting than desiccation, since a major number of taxa tolerant to rewetting occurred in all biofilms. Overall, bacterial communities in sandy compartments showed higher resistance to flow intermittency than those in epilithic biofilms

Nontypable Haemophilus influenzae displays a prevalent surface structure molecular pattern in clinical isolates.

Non-typable Haemophilus influenzae (NTHi) is a Gram negative pathogen that causes acute respiratory infections and is associated with the progression of chronic respiratory diseases. Previous studies have established the existence of a remarkable genetic variability among NTHi strains. In this study we show that, in spite of a high level of genetic heterogeneity, NTHi clinical isolates display a prevalent molecular feature, which could confer fitness during infectious processes. A total of 111 non-isogenic NTHi strains from an identical number of patients, isolated in two distinct geographical locations in the same period of time, were used to analyse nine genes encoding bacterial surface molecules, and revealed the existence of one highly prevalent molecular pattern (lgtF+, lic2A+, lic1D+, lic3A+, lic3B+, siaA−, lic2C+, ompP5+, oapA+) displayed by 94.6% of isolates. Such a genetic profile was associated with a higher bacterial resistance to serum mediated killing and enhanced adherence to human respiratory epithelial cells.

Bowing the violin : a case study for auditory-motor pattern modelling in the context of music performance

This project addresses methodological and technological challenges in the development of multi-modal data acquisition and analysis methods for the representation of instrumental playing technique in music performance through auditory-motor patterning models. The case study is violin playing: a multi-modal database of violin performances has been constructed by recording different musicians while playing short exercises on different violins. The exercise set and recording protocol have been designed to sample the space defined by dynamics (from piano to forte) and tone (from sul tasto to sul ponticello), for each bow stroke type being played on each of the four strings (three different pitches per string) at two different tempi. The data, containing audio, video, and motion capture streams, has been processed and segmented to facilitate upcoming analyses. From the acquired motion data, the positions of the instrument string ends and the bow hair ribbon ends are tracked and processed to obtain a number of bowing descriptors suited for a detailed description and analysis of the bow motion patterns taking place during performance. Likewise, a number of sound perceptual attributes are computed from the audio streams. Besides the methodology and the implementation of a number of data acquisition tools, this project introduces preliminary results from analyzing bowing technique on a multi-modal violin performance database that is unique in its class. A further contribution of this project is the data itself, which will be made available to the scientific community through the repovizz platform.

New strategies for treatment and reuse of spent sulfidic caustic stream from petroleum industry

This work examines traditional and new routes for removal of H2S and other sulfur compounds from spent sufidic caustic (SSC). SH- (hydrogenosulfide) and S2- (sulfide) ions were quantitatively oxidized at 25 ºC using H2O2, NaOCl or a spent sulfochromic mixture. SH-/S2- ions were also removed via reaction with freshly prepared iron or manganese hydroxides, or after passing the SSC through strong basic anion exchange resins (OH- form). The treated caustic solution, as well as iron/manganese hydroxides, removed H2S from diesel samples at 25 ºC. SSC treatment via strong basic anion-exchange resins produced the treated caustic solution with the highest free alkalinity.

Virulence pattern of Pyricularia grisea isolates from farmers' fields on newly released upland rice cultivars

The virulence pattern of the isolates of Pyricularia grisea from commercial fields of the upland rice (Oryza sativa) cultivars 'Primavera' and 'BRS Bonança' was analyzed. A hundred and seventy monoconidial isolates of the pathogen virulent to 'Primavera' and 139 to 'BRS Bonança' collected from eight fields, during two years (2001-2003) were tested, under greenhouse conditions, on six newly released rice cultivars. Differences in virulence pattern were observed in pathogenic populations of 'Primavera' and 'BRS Bonança'. Isolates with virulence to improved cultivars were common in samples from farmers' fields in the absence of aloinfection. The virulence frequency of P. grisea isolates collected from 'Primavera'' to cultivars 'BRS Vencedora', 'BRS Colosso', 'BRS Liderança', 'BRS Soberana', 'BRS Curinga' and 'BRS Talento', was high in descending order. On the other hand, in the fungus population of 'BRS BRS Bonança' virulence frequency was high in 'BRS Talento', followed by 'BRS Curinga', 'BRS Vencedora', 'BRS Liderança', 'BRS Colosso' and 'BRS Soberana'. While virulence to 'BRS Talento' was rare among isolates from 'Primavera', it was most frequent in isolates of 'BRS Bonança'. The six improved rice cultivars permitted to differentiating agriculturally important virulences in the pathogen population which can be utilized in selecting breeding lines for specific resistance, in rice blast improvement program.

Biogeochemistry in acid sulphate soil landscapes and small urban centres in Western Finland

The overall purpose of this thesis was to increase the knowledge on the biogeochemistry of rural acid sulphate (AS) soil environments and urban forest ecosystems near small towns in Western Finland. In addition, the potential causal relationship between the distribution of AS soils and geographical occurence of multiple sclerosis (MS) disease was assessed based on a review of existing literature and data. Acid sulphate soils, which occupy an area of approximately 17–24 million hectare worldwide, are regarded as the nastiest soils in the world. Independent of the geographical locality of these soils, they pose a great threat to their surrounding environment if disturbed. The abundant metal-rich acid drainage from Finnish AS soils, which is a result of sulphide oxidation due to artificial farmland drainage, has significant but spatially and temporally variable ecotoxicological impacts on biodiversity and community structure of fish, benthic invertebrates and macrophytes. This has resulted in mass fish kills and even eradication of sensitive fish species in affected waters. Moreover, previous investigations demonstrated significantly enriched concentrations of Co, Ni, Mn and Al, metals which are abundantly mobilised in AS soils, in agricultural crops (timothy grass and oats) and approximately 50 times higher concentrations of Al in cow milk originating from AS soils in Western Finland. Nevertheless, the results presented here demonstrate, in general, relatively moderate metal concentrations in oats and cabbage grown on AS soils in Western Finland, although some of the studied fields showed anomalous values of metals (e.g. Co and Ni) in both the soil and target plants (especially oats), similar to that of the previous investigations. The results indicated that the concentrations of Co, Ni, Mn and Zn in oats and Co and Zn in cabbage were governed by soil geochemistry as these metals were correlated with corresponding concentrations extracted from the soil by NH4Ac-EDTA and NH4Ac, respectively. The concentrations of Cu and Fe in oats and cabbage were uncorrelated to that of the easily soluble concentrations in the soils, suggesting that biological processes (e.g. plant-root processes) overshadow geochemical variation. The concentrations of K and Mg in cabbage, which showed a low spread and were strongly correlated to the NH4Ac extractable contents in the soil, were governed by both the bioavailable fractions in the topsoil and plant-uptake mechanisms. The plant´s ability to regulate its uptake of Ca and P (e.g. through root exudates) seemed to be more important than the influence of soil geochemistry. The distribution of P, K, Ca, Mg, Mn and S within humus, moss and needles in and around small towns was to a high degree controlled by biological cycling, which was indicated by the low correlation coefficients for P, K, Ca, Mg and S between humus and moss, and the low spread of these nutrients in moss and needles. The concentration variations of elements in till are mainly due to natural processes (e.g. intrusions, weathering, mineralogical variations in the bedrock). There was a strong spatial pattern for B in humus, moss and needles, which was suggested to be associated with anthropogenic emissions from nearby town centres. Geogenic dust affected the spatial distribution of Fe and Cr in moss, while natural processes governed the Fe anomaly found in the needles. The spatial accumulation patterns of Zn, Cd, Cu, Ni and Pb in humus and moss were strong and diverse, and related to current industry, the former steel industry, coal combustion, and natural geochemical processes. An intriguing Cu anomaly was found in moss. Since it was located close to a main railway line and because the railway line´s electric cables are made of Cu, it was suggested that the reason for the Cu anomaly is corrosion of these cables. In Western Finland, where AS soils are particularly abundant and enrich the metal concentrations of stream waters, cow milk and to some extent crops, an environmental risk assessment would be motivated to elucidate if the metal dispersion affect human health. Within this context, a topic of concern is the distribution of multiple sclerosis as high MS prevalence rates are found in the main area of AS soils. Regionally, the AS soil type in the Seinäjoki area has been demonstrated to be very severe in terms of metal leaching, this area also shows one of the highest MS rates reported worldwide. On a local scale, these severe AS soil types coincide well with the corresponding MS clustering along the Kyrönjoki River in Seinäjoki. There are reasons to suspect that these spatial correlations are causal, as multiple sclerosis has been suggested to result from a combination of genetic and environmental factors.

Waste Stream Investigation from Perspective of Changing Waste Legislation at Green Sand Foundries

The update of the Finnish legislation concerning waste was unavoidable, to comply with the European Union (EU) requirements defined in the EU-Directive on Waste. The new waste law updates were enacted into the Finnish legislation on the 11.03.2011 and targeted for applicability by the 11.03.2012. This thesis investigates the implications of the new amendments to the waste legislation from the perspective of green sand foundries. The investigations are conducted by comparing two of Componenta’s green sand foundries and evaluating their waste streams. Additionally, the impacts of legislation amendments are critiqued on their environmental and economic aspects. The study’s comparison of waste fractions at the two foundries reveals that sand is dominant in absolute tonnage and costs. The increments of waste taxes forces foundries to focus on waste management, recycling and disposing. The new legislation’s promotion of material efficiency, also guides foundries towards the prevention of waste. A potential preventive measure is to regenerate waste sand resulting to cost savings on both raw-materials and waste management. However, the lack of absolute targets for waste prevention or recycling rates discourages the interests towards creating or adopting new technologies and methods for the waste handling.

Soil sampling intensity and spatial distribution pattern of soils attributes and corn yield in no-tillage system

Taking into account that the sampling intensity of soil attributes is a determining factor for applying of concepts of precision agriculture, this study aims to determine the spatial distribution pattern of soil attributes and corn yield at four soil sampling intensities and verify how sampling intensity affects cause-effect relationship between soil attributes and corn yield. A 100-referenced point sample grid was imposed on the experimental site. Thus, each sampling cell encompassed an area of 45 m² and was composed of five 10-m long crop rows, where referenced points were considered the center of the cell. Samples were taken from at 0 to 0.1 m and 0.1 to 0.2 m depths. Soil chemical attributes and clay content were evaluated. Sampling intensities were established by initial 100-point sampling, resulting data sets of 100; 75; 50 and 25 points. The data were submitted to descriptive statistical and geostatistics analyses. The best sampling intensity to know the spatial distribution pattern was dependent on the soil attribute being studied. The attributes P and K+ content showed higher spatial variability; while the clay content, Ca2+, Mg2+ and base saturation values (V) showed lesser spatial variability. The spatial distribution pattern of clay content and V at the 100-point sampling were the ones which best explained the spatial distribution pattern of corn yield.

Environmental adaptation of the source of the subbasin of Rico Stream, Monte Alto - SP, Brazil

The aim of this study was to define the photographic patterns that represent the use and occupation of the landcover of the "spring" of the Rico Stream subbasin, located at Monte Alto, state of São Paulo (SP), Brazil, for environmental adaptation regarding the Brazilian Forest Law. The mapping was performed using remote sensing techniques and visual interpretation of the World View image, followed by the digitalization of the net of drainage and vegetation (natural and agricultural) at the AutoCad software with documents and field work. The study area has 2141.53 ha and the results demonstrated that the main crop is sugarcane with 546.34 ha, followed by 251.22 ha of pastures, 191.71 ha of perennial crops, 57.31 ha of Eucalyptus and 49.52 ha of onion, confirming the advance of sugarcane culture in the region. The region has 375.04 ha of areas of permanent preservation (APPs), and of this area it was found that only 72.17 ha (19.24%) has arboreal vegetation or natural forest, and 302.87 ha of these areas need to be enriched and reforested with native vegetation from the region, according to the current legislation. The data of the area enable future proposals of models for environmental adaptation to the microbasin according to the current environmental legislation.