The importance of atmospheric and anthropogenic iron for the macroalgae overgrowing coral reefs in the Caribbean Sea

Kaikki yhteyttävät organismit tarvitsevat rautaa. Se rajoittaa tuotantoa laajoilla alueilla avomerta, jossa muita ravinteita olisi riittävästi. Sen jakautuminen on kuitenkin epätasaista. Rautapitoista pölyä kulkeutuu jaksoittaisesti Afrikan aavikolta tuulien mukana Atlantin yli Karibianmerelle. Siitä merkittävä osa on valoreaktioiden johdosta pelkistynyttä ferrorautaa (Fe2+), joka liukenee veteen ja on siten levien saatavilla. Meriin kulkeutuu rautaa ilmakehässä kolme kertaa niin paljon kuin jokivesissä. Karibianmeren koralliriutat selviävät häiriöistä suhteessa heikommin kuin Indo-Tyynenmeren riutat, ja yhdeksi syyksi tähän on arveltu raudan ylimäärää. Kun rauta ei rajoita levien kasvua, ne ovat valmiita hyödyntämään esimerkiksi ihmistoiminnasta seuraavia ravinnepäästöjä ja voivat tukahduttaa korallit kasvamalla niiden päälle. Tässä tutkimuksessa tarkastellaan ilmakehävälitteisen raudan merkitystä Karibian riuttaekosysteemin ravinnetasapainon kannalta sekä ihmistoiminnan vaikutusta tähän. Rauta-, typpi- ja fosforirikastuskokeet tehtiin neljältä Guadeloupen tilaltaan heikentyneeltä riutalta kerätyille ruskolevälajeille in situ. Lajit olivat alueella yleiset Sargassum polyceratium, Dictyota menstrualis ja Dictyota pinnatifida. Ravinteen rajoittavuutta selvitettiin mittaamalla levien klorofyllifluoresenssia Pulse Amplitude Modulator (PAM) -fluorometrillä. Näytteistä havainnoitiin nutrient-induced fluorescence transient (NIFT) -vasteita, jotka osoittavat leväyksilön aktiivisesti assimiloivan tutkittavaa ravinnetta. Raudan rajoittavuutta havaittiin 10 % näytteistä. Alhainen määrä antaa osin tukea hypoteesille raudan kumuloitumisen heikentävästä vaikutuksesta Karibialla. Ihmistoiminnalla ei ollut vaikutusta levien raudantarpeeseen, mutta sen sijaan fosfaatti rajoitti voimakkaammin ihmistoiminnan läheisyydessä. Typen osalta nitraattivasteessa ei ollut merkittävää eroa, mutta ammoniumin rajoittavuutta osoittavia NIFT:a havaittiin. Typen ja fosforin yhteisrajoittavuutta esiintyi myös. Sedimentin sitoman fosforin ja raudan liukoisuudet riippuvat raudan redox-potentiaalista. Raudan saatavuus hyödyntää myös typpeä sitovia bakteereja, jotka kilpailevat levien kanssa. Ravinnepäästöjen vaikutukset riippuvat sekä kyseessä olevasta yhteisöstä että lajista: eri lajien väliset erot ravinteiden hyödyntämisen strategioissa - ja siten myös NIFT-vasteissa - tulivat esiin. Koralliriuttaekosysteemi on monen tekijän yhteispeli, ja sitä tutkittaessa tulee ottaa kvantitatiivisesti huomioon sekä ympäristötekijät että epäyhtenäinen ajallinen taso. NIFT-kokeiden sovellettavuus parantuisi myös, jos käytössä olisi tietoa ympäristön ravinnepitoisuuksista. Menetelmä vaikuttaisi soveltuvan raudan rajoittavuuden tarkasteluun, mutta lisää tutkimusta sen tueksi tarvitaan.Iron is a trace element but indispensable for all photosynthesizing organisms. It is unevenly distributed in the world’s oceans, limiting production in offshore high nitrogen low chlorophyll (HNLC) seas. The Caribbean Sea periodically receives high amounts of iron-carrying aeolian dust originating in the African desert. This aerosol Fe is estimated to contribute three times as much as riverine input to the total iron in the seawater, a considerable fraction of it being soluble ferrous Fe(II) due to photochemical reactions. It has been hypothesized that the excess iron in the Caribbean Sea is one of the reasons why the Caribbean coral reefs are less resilient to degradation. The algae that are not limited by iron have the potential to efficiently utilize the macronutrients from e.g. anthropogenic sources and overgrow the corals. In this study Fe, N & P enrichment experiments were conducted in situ in Guadeloupe to find out if iron limitation can be detected and to contemplate the role of atmospheric iron and the anthropogenic impact. Sargassum polyceratium and Dictyota spp. (Phaeophyceae) were collected from four locations that had degraded coral reefs with macroalgae growing on them. The samples’ fluorescence was measured using Pulse Amplitude Modulator (PAM) fluoroscope to detect nutrient-induced fluorescence transients (NIFTs), rapid changes in chlorophyll fluorescence caused by nutrient assimilation in the algal specimen. Iron limitation was detected in all of the study locations but it was weak, which gives limited support to the hypothesis about iron deteriorating the Caribbean reefs’ chances against disturbance. Comparison of the locations did not result in differences in iron limitation according to the anthropogenic impact level. The difference was statistically significant in P limitation, the algae from high impact sites expressing greater demand. Ammonium and nitrate enrichments did not result in significant differences, but NH4 limitation did occur, as well as co-limitation of N & P. Iron has an important role in the phosphorus flux in the sediments and high Fe availability benefits N-fixing cyanobacteria. Redox conditions in the sediment control both Fe and P availability in the water column. Nutrient leaching does affect the local nutrient dynamics but the effects of eutrophication depend on both the species and the community. Notable differences in the NIFT responses were detected between the species that may indeed exert differing nutritional strategies. Coral reef ecosystem complexity emphasizes the importance of timing as well as consistence in quantification of the environmental parameters. The applicability of NIFT results would improve if they were combined with nutrient concentrations data. The fluorescence method appears to be useful in studying iron limitation but more research on iron-induced NIFTs is needed

Sequence-Based Analysis of Thermal Adaptation and Protein Energy Landscapes in an Invasive Blue Mussel (Mytilus galloprovincialis).

Adaptive responses to thermal stress in poikilotherms plays an important role in determining competitive ability and species distributions. Amino acid substitutions that affect protein stability and modify the thermal optima of orthologous proteins may be particularly important in this context. Here, we examine a set of 2,770 protein-coding genes to determine if proteins in a highly invasive heat tolerant blue mussel (Mytilus galloprovincialis) contain signals of adaptive increases in protein stability relative to orthologs in a more cold tolerant M. trossulus. Such thermal adaptations might help to explain, mechanistically, the success with which the invasive marine mussel M. galloprovincialis has displaced native species in contact zones in the eastern (California) and western (Japan) Pacific. We tested for stabilizing amino acid substitutions in warm tolerant M. galloprovincialis relative to cold tolerant M. trossulus with a generalized linear model that compares in silico estimates of recent changes in protein stability among closely related congeners. Fixed substitutions in M. galloprovincialis were 3,180.0 calories per mol per substitution more stabilizing at genes with both elevated dN/dS ratios and transcriptional responses to heat stress, and 705.8 calories per mol per substitution more stabilizing across all 2,770 loci investigated. Amino acid substitutions concentrated in a small number of genes were more stabilizing in M. galloprovincialis compared with cold tolerant M. trossulus. We also tested for, but did not find, enrichment of a priori GO terms in genes with elevated dN/dS ratios in M. galloprovincialis. This might indicate that selection for thermodynamic stability is generic across all lineages, and suggests that the high change in estimated protein stability that we observed in M. galloprovincialis is driven by selection for extra stabilizing substitutions, rather than by higher incidence of selection in a greater number of genes in this lineage. Nonetheless, our finding of more stabilizing amino acid changes in the warm adapted lineage is important because it suggests that adaption for thermal stability has contributed to M. galloprovincialis' superior tolerance to heat stress, and that pairing tests for positive selection and tests for transcriptional response to heat stress can identify candidates of protein stability adaptation

Financial Analysis of Performance and Risk : Case: Svenska Handelsbanken AB

The aim of the study was to examine the development of financial performance in the 21st century through a case company, Svenska Handelsbanken AB. The element of risk was added to the study with the objective to identify correlations between performance and risk. Another objective was to identify if the financial crisis of 2007 had had an effect on the development of the financial performance as well as on the correlation between performance and risk. The research was conducted as a case study using the mixed method approach in the data collection. The data was primarily collected from secondary sources. The most relevant source regarding the actual research was the Annual Reports of Svenska Handelsbanken AB. Moreover, the Nasdaq-website played an important role when examining risk ratios. The research was conducted by observing the company’s balance sheets and income statements in order to formulate the calculations for performance and risk ratios. The data was collected and analyzed for the period of 2000-2016. This supported the element of choosing the financial crisis as an important event during the analysis. The research results were explained in detail separately with regard to the performance analysis and risk analysis. The results were summarized in the end by taking the financial crisis into account. The results showed that Handelsbanken had a good financial position and that its strict risk management had worked effectively. Overall, the financial crisis had had no significant effect on the performance and risk development of Handelsbanken. Lastly, recommendations for future research were given.Opinnäytetyön tavoitteena oli tutkia taloudellisen suorituskyvyn kehittymistä 2000-luvulla case-yrityksen Svenska Handelsbanken AB:n kautta. Tutkimukseen otettiin mukaan riski toisena osatekijänä, jotta suorituskyvyn ja riskin yhteys voitaisiin selvittää. Toisena tavoitteena oli selvittää finanssikriisin vaikutus taloudellisen suorituskyvyn kehittymiseen sekä riskin ja suorituskyvyn yhteyteen. Opinnäytetyön tutkimusmenetelmäksi valittiin tapaustutkimus, jossa data kerättiin monimenetelmätutkimuksen avulla. Data kerättiin pääasiassa sekundäärilähteistä, mutta yksi tärkeimmistä lähteistä oli case-yrityksen vuosiraportit. Nasdaqin nettisivuilta kerättiin myös tärkeää dataa tutkimuksen suorittamista varten. Vuosiraporteista kerättiin tietoa pääasiassa taseesta ja tuloslaskelmasta. Data kerättiin ja analysoitiin vuosilta 2000-2016, mikä tukee finanssikriisin valitsemista toisen tavoitteen osatekijäksi, sillä sen ajoittuminen on tärkeä osa finanssialan tapahtumia. Tutkimustulokset analysoitiin ja esitettiin erikseen suorituskykynä ja riskinä, tuoden kuitenkin molempien tulokset lopussa yhteen sekä ottaen finanssikriisin huomioon. Tulokset osoittavat, että Handelsbankenilla on hyvä taloudellinen asema ja sen tiukka riskienhallinta on tuottanut tulosta. Yleisesti ottaen finanssikriisillä ei ole ollut huomattavaa merkitystä Handelsbankenin taloudellisen suorituskyvyn tai riskin kehittymiseen. Lopuksi esitettiin suosituksia jatkotutkimuksia varten

Veebipõhine linnaruum Võru linna näitel

The theme of the present graduation thesis was “Web-based city space on the example of Võru city”, I consider its practical value to lie in the proposed suggestions for the IT and communications specialist of the city government. In this graduation thesis I have studied the importance of the web site of a small town, and the opinion of two target groups concerning the renewed web site. The methods I have applied were observation schedule based analysis, and multiple choice and free- answer questionnaires. The observation schedule based analysis was used to map the current situation. In the theoretical part of the paper I have given an overview of the notion of information society and of the development of information society in Estonia, mainly attempting to incorporate the theoretical part from the point of view of the subject of web-based city space. Creating a possible theoretical framework for defining information society in the context of web-based city space was complicated, as the concept of information society is rather wide and multi-faceted. The multiple choice and free-answer questionnaires that were used as research method answered the posed questions. As the main result of the research it transpired that the web site is an important communication channel for the studied target groups, and the renewed web site is considerably simpler and user-friendlier than the previous one was. To summarize, it may be said that in creating a web-based city space the issues that must constantly be considered are the e- services and the hierarchical pattern of the existing communication practices that will make it possible to create synergies between the city government and the citizens

Nitrogen Loading From Wastewater Treatment Plants To Upper Narragansett Bay

Increasing awareness of low-oxygen conditions in Narragansett Bay, as well as other symptoms of eutrophication such as macroalgae accumulation, eelgrass failure, and fish kills, has led to management actions to reduce nitrogen loads to the upper Ba

Physical Property and Chemical Characteristics of Surface Sediment Grab Samples from Narragansett Bay and the Providence and Seekonk Rivers

This document contains data tables, maps, plots, and documentation on Brown University’s Narragansett Bay Sediment Project compiled by David W. Murray, Brown University, for the New England Interstate Water Pollution Control Commission with support from the U.S. Environmental Protection Agency. The data were compiled and analyzed as part of a New England pilot project exploring the development of a biological condition gradient applicable to estuarine systems

Spatio-temporal distribution of Spiroplasma infections in the tsetse fly (Glossina fuscipes fuscipes) in northern Uganda

Copyright: © 2019 Schneider et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Tsetse flies (Glossina spp.) are vectors of parasitic trypanosomes, which cause human (HAT) and animal African trypanosomiasis (AAT) in sub-Saharan Africa. In Uganda, Glossina fuscipes fuscipes (Gff) is the main vector of HAT, where it transmits Gambiense disease in the northwest and Rhodesiense disease in central, southeast and western regions. Endosymbionts can influence transmission efficiency of parasites through their insect vectors via conferring a protective effect against the parasite. It is known that the bacterium Spiroplasma is capable of protecting its Drosophila host from infection with a parasitic nematode. This endosymbiont can also impact its host\u27s population structure via altering host reproductive traits. Here, we used field collections across 26 different Gff sampling sites in northern and western Uganda to investigate the association of Spiroplasma with geographic origin, seasonal conditions, Gff genetic background and sex, and trypanosome infection status. We also investigated the influence of Spiroplasma on Gff vector competence to trypanosome infections under laboratory conditions. Generalized linear models (GLM) showed that Spiroplasma probability was correlated with the geographic origin of Gff host and with the season of collection, with higher prevalence found in flies within the Albert Nile (0.42 vs 0.16) and Achwa River (0.36 vs 0.08) watersheds and with higher prevalence detected in flies collected in the intermediate than wet season. In contrast, there was no significant correlation of Spiroplasma prevalence with Gff host genetic background or sex once geographic origin was accounted for in generalized linear models. Additionally, we found a potential negative correlation of Spiroplasma with trypanosome infection, with only 2% of Spiroplasma infected flies harboring trypanosome co-infections. We also found that in a laboratory line of Gff, parasitic trypanosomes are less likely to colonize the midgut in individuals that harbor Spiroplasma infection. These results indicate that Spiroplasma infections in tsetse may be maintained by not only maternal but also via horizontal transmission routes, and Spiroplasma infections may also have important effects on trypanosome transmission efficiency of the host tsetse. Potential functional effects of Spiroplasma infection in Gff could have impacts on vector control approaches to reduce trypanosome infections

Genetic diversity and connectivity within Mytilus spp. in the subarctic and Arctic

Climate changes in the Arctic are predicted to alter distributions of marine species. However, such changes are difficult to quantify because information on present species distribution and the genetic variation within species is lacking or poorly examined. Blue mussels,Mytilusspp. are ecosystem engineers in the coastal zone globally. In order to improve knowledge of distribution and genetic structure of theMytilus eduliscomplex in the Arctic, we analyzed 81 SNPs in 534Mytilusspp. individuals sampled at 13 sites to provide baseline data for distribution and genetic variation ofMytilusmussels in the European Arctic.Mytilus eduliswas the most abundant species found with a clear genetic split between populations in Greenland and the Eastern Atlantic. Surprisingly, analyses revealed the presence ofM. trossulusin high Arctic NW Greenland (77°N) andM. galloprovincialisor their hybrids in SW Greenland, Svalbard and the Pechora Sea. Furthermore, a high degree of hybridization and introgression between species was observed. Our study highlights the importance of distinguishing between congener species, which can display local adaptation and suggests that information on dispersal routes and barriers are essential for accurate predictions of regional susceptibility to range expansions or invasions of boreal species in the Arctic

Multiple evolutionary origins of Trypanosoma evansi in Kenya

Trypanosoma evansi is the parasite causing surra, a form of trypanosomiasis in camels and other livestock, and a serious economic burden in Kenya and many other parts of the world. Trypanosoma evansi transmission can be sustained mechanically by tabanid and Stomoxys biting flies, whereas the closely related African trypanosomes T. brucei brucei and T. b. rhodesiense require cyclical development in tsetse flies (genus Glossina) for transmission. In this study, we investigated the evolutionary origins of T. evansi. We used 15 polymorphic microsatellites to quantify levels and patterns of genetic diversity among 41 T. evansi isolates and 66 isolates of T. b. brucei (n = 51) and T. b. rhodesiense (n = 15), including many from Kenya, a region where T. evansi may have evolved from T. brucei. We found that T. evansi strains belong to at least two distinct T. brucei genetic units and contain genetic diversity that is similar to that in T. brucei strains. Results indicated that the 41 T. evansi isolates originated from multiple T. brucei strains from different genetic backgrounds, implying independent origins of T. evansi from T. brucei strains. This surprising finding further suggested that the acquisition of the ability of T. evansi to be transmitted mechanically, and thus the ability to escape the obligate link with the African tsetse fly vector, has occurred repeatedly. These findings, if confirmed, have epidemiological implications, as T. brucei strains from different genetic backgrounds can become either causative agents of a dangerous, cosmopolitan livestock disease or of a lethal human disease, like for T. b. rhodesiense