Increased groundwater usage, rainfall decline and activities such as mining have resulted in the acidification of certain wetlands in the south-west of Western Australia. This study investigated the influence of pH, the factor most commonly associated with acidification, on the invertebrate and diatom community structure of 20 wetlands in the south-west region of Western Australia. Few studies in Western Australia have investigated both biotic groups, particularly in relation to pH. Consequently, this study examined the comparative sensitivity of the two biotic groups to pH in order to identify the most effective biotic tool for assessing the ecological impacts of pH decrease. The wetlands included in this study displayed a wide range of pH from acidic (pH < 6.5) to alkaline (pH > 7.5). Other environmental parameters were also variable. Separation of the wetlands into three pH groups; Group 1 – acidic, Group 2 – circumneutral and Group 3 – alkaline, demonstrated that the acidic Group 1 wetlands generally had higher electrical conductivity than the remaining groups. This was probably due to the association of many Group 1 sites with mining and acid sulphate soils. Seasonal trends in environmental variables across the three pH groups were mostly unclear although some trends were evident within the individual pH groups. The study showed that invertebrate community structure differed in response to pH. However, the results also demonstrated that invertebrate distribution patterns were influenced by other factors. / Potential indicator species identified from the study included Macrothrix indistincta and Tanytarsus fuscithorax/semibarbitarsus which were abundant in acidic waters and Alona quadrangularis which was common in circumneutral sites. Taxa such as Calamoecia tasmanica subattenuata were common over a wider range of pH (acidic to circumneutral) but may still have potential to act as indicators of pH decline. Diatom community structure was also shown to be influenced by pH, with the variable identified as a major determinant of diatom distribution patterns. Nitzschia paleaeformis and Navicula aff. cari were generally recorded from acidic wetlands and are potentially useful as indicators of low pH conditions. Brachysira brebissonii and Frustulia magaliesmontana were also identified as species with the potential to indicate pH decline. In contrast, taxa including Gomphonema parvulum, Staurosira construens var. venter and Nitzschia palea were generally associated with moderate to high pH levels. A comparative study of the two biotic groups using multivariate analyses revealed that diatoms were more sensitive to pH than invertebrates. Further investigation with a larger number of environmental variables would be necessary to ascertain the other factors primarily influencing invertebrate community structure. Nonetheless, the findings imply that diatoms and invertebrates differ in their responsiveness to various environmental factors and may provide complementary information on the integrity of a system. Multivariate analyses on an expanded data-set of 40 sites found that pH accounted for the greatest amount of variation in the data and was conducive to the development of a diatom-based pH inference model. / The strongest model was produced using weighted averaging (WA) with classical deshrinking. While the model displayed a high correlation coefficient, the prediction error was also relatively high, probably as a result of the comparatively small and heterogeneous data-set. Incorporation of the data into a larger training set would be likely to improve the predictive ability. Applications for the model include pH reconstructions or use in monitoring programs. The current study has shown that pH is an important variable influencing both invertebrate and diatom community structure in wetlands in the south-west of Western Australia. However, the greater sensitivity of diatoms to pH suggests that they would be the most effective tool for the biological monitoring of pH in wetlands threatened or impacted by acidification. An integrated monitoring program including both diatoms and invertebrates may provide additional information on the impacts of pH decline and the overall integrity of the systems and should be investigated further.

Impacts of long-term acid deposition on soil and water chemistry are of particular concern in the Great Smoky Mountains National Park (GRSM), receiving some of the highest acid deposition rates in the eastern United States and limited by inadequate acid buffering capacity. In the GRSM, the Noland Divide watershed (NDW) has been monitored since 1991 for water chemistries of precipitation, throughfall, soil, and stream. The impacts of long-term acidic deposition on stream water quality in the NDW were investigated through: 1) development of an ion input-output budget; 2) analysis of trends and seasonal patterns for major ions; 3) comparison of net export rates between baseflow and stormflow periods; and 4) characterization of soil chemistry and transport properties for various potential acid deposition scenarios. Between 1991 and 2006, throughfall deposition remained unchanged and consisted of 1,735 eq ha-1 yr-1 of SO42-, 863 eq ha-1 yr-1 of NO3-, and 284 eq ha-1 yr-1 of NH4+. Net retention of sulfate was estimated at 61% being controlled by soil adsorption, and inorganic nitrogen was retained at 32% presumably due to plant uptake. Nitrogen retention increased by 44.30 eq ha-1 yr-1 over the study period. Besides deposition, soil acidity was increased by nitrification and precipitation-driven desorption of previously accumulated sulfate. To neutralize soil acidity, Ca2+, Mg2+ and Na+ were depleted from NDW by 77, 46 and 66 eq ha-1 yr-1, respectively. Due to the continuous addition of acidity, base saturation in soil was reduced to 4% at present. Mobilization of aluminum and other metals (Mn and Zn) may be enhanced by these geochemical processes, potentially causing toxic conditions to fish and other biota in the GRSM streams. Impacts of acidic deposition on streams were confirmed by measured stream pH below 6 and acid neutralizing capacity below 0.01 meq L-1. During stormflows pH and ANC depressions occurred primarily due to increases in sulfate transport, leading to episodic acidification events. This study provides new information on hydrological and biogeochemical processes that regulate stream acidification events in the southern Appalachian region, supporting improved management strategies for GRSM streams.

Die vorliegende Dissertation beschäftigt sich mit den Faktoren, die das Wachstum und die Vertikalverteilung von Planktonalgen in extrem sauren Tagebaurestseen (TBS; pH 2-3) beeinflussen. Im exemplarisch untersuchten TBS 111 (pH 2.7; Lausitzer Revier) dominiert die Goldalge Ochromonas sp. in oberen und die Grünalge Chlamydomonas sp. in tieferen Wasserschichten, wobei letztere ein ausgeprägtes Tiefenchlorophyll-Maximum (DCM) ausbildet. Es wurde ein deutlicher Einfluss von Limitation durch anorganischen Kohlenstoff (IC) auf das phototrophe Wachstum von Chlamydomonas sp. in oberen Wasserschichten nachgewiesen, die mit zunehmender Tiefe von Lichtlimitation abgelöst wird. Im Vergleich mit Arbeiten aus neutralen Seen zeigte Chlamydomonas sp. erniedrigte maximale Wachstumsraten, einen gesteigerten Kompensationspunkt und erhöhte Dunkelrespirationsraten, was auf gesteigerte metabolische Kosten unter den extremen physikalisch-chemischen Bedingungen hinweist. Die Photosyntheseleistungen von Chlamydomonas sp. waren in Starklicht-adaptierten Zellen durch IC-Limitation deutlich verringert. Außerdem ergaben die ermittelten minimalen Zellquoten für Phosphor (P) einen erhöhten P-Bedarf unter IC-Limitation. Anschließend konnte gezeigt werden, dass Chlamydomonas sp. ein mixotropher Organismus ist, der seine Wachstumsraten über die osmotrophe Aufnahme gelösten organischen Kohlenstoffs (DOC) erhöhen kann. Dadurch ist dieser Organismus fähig, in tieferen, Licht-limitierten Wasserschichten zu überleben, die einen höheren DOC-Gehalt aufweisen. Da die Vertikalverteilung der Algen im TBS 111 jedoch weder durch IC-Limitation, P-Verfügbarkeit noch die in situ DOC-Konzentrationen abschließend erklärt werden konnte (bottom-up Kontrolle), wurde eine neue Theorie zur Entstehung der Vertikalverteilung geprüft. Grazing der phagotrophen und phototrophen Alge Ochromonas sp. auf der phototrophen Alge Chlamydomonas sp. erwies sich als herausragender Faktor, der über top-down Kontrolle die Abundanz der Beute in höheren Wasserschichten beeinflussen kann. Gemeinsam mit der Tatsache, dass Chlamydomonas sp. DOC zur Wachstumssteigerung verwendet, führt dies zu einer Akkumulation von Chlamydomonas sp. in der Tiefe, ausgeprägt als DCM. Daher erscheint grazing als der Hauptfaktor, der die beobachtete Vertikalschichtung der Algen im TBS 111 hervorruft. Die erzielten Ergebnisse liefern grundlegende Informationen, um die Auswirkungen von Strategien zur Neutralisierung der TBS auf das Nahrungsnetz abschätzen zu können. / In this thesis, I investigated the factors influencing the growth and vertical distribution of planktonic algae in extremely acidic mining lakes (pH 2-3). In the focal study site, Lake 111 (pH 2.7; Lusatia, Germany), the chrysophyte, Ochromonas sp., dominates in the upper water strata and the chlorophyte, Chlamydomonas sp., in the deeper strata, forming a pronounced deep chlorophyll maximum (DCM). Inorganic carbon (IC) limitation influenced the phototrophic growth of Chlamydomonas sp. in the upper water strata. Conversely, in deeper strata, light limited its phototrophic growth. When compared with published data for algae from neutral lakes, Chlamydomonas sp. from Lake 111 exhibited a lower maximum growth rate, an enhanced compensation point and higher dark respiration rates, suggesting higher metabolic costs due to the extreme physico-chemical conditions. The photosynthetic performance of Chlamydomonas sp. decreased in high-light-adapted cells when IC limited. In addition, the minimal phosphorus (P) cell quota was suggestive of a higher P requirement under IC limitation. Subsequently, it was shown that Chlamydomonas sp. was a mixotroph, able to enhance its growth rate by taking up dissolved organic carbon (DOC) via osmotrophy. Therefore, it could survive in deeper water strata where DOC concentrations were higher and light limited. However, neither IC limitation, P availability nor in situ DOC concentrations (bottom-up control) could fully explain the vertical distribution of Chlamydomonas sp. in Lake 111. Conversely, when a novel approach was adopted, the grazing influence of the phagotrophic phototroph, Ochromonas sp., was found to exert top-down control on its prey (Chlamydomonas sp.) reducing prey abundance in the upper water strata. This, coupled with the fact that Chlamydomonas sp. uses DOC for growth, leads to a pronounced accumulation of Chlamydomonas sp. cells at depth; an apparent DCM. Therefore, grazing appears to be the main factor influencing the vertical distribution of algae observed in Lake 111. The knowledge gained from this thesis provides information essential for predicting the effect of strategies to neutralize the acidic mining lakes on the food-web.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Estreptococos do grupo B (EGB) comumente colonizam adultos saudáveis, sem sintomas, mas sob certas circunstâncias possui a capacidade de invadir tecidos do hospedeiro, evadir da detecção imunológica e causar doenças invasivas graves. Por conseguinte, os EGB continuam sendo uma das principais causas de mortalidade neonatal, pneumonia, sepse e meningite. Contudo, a patogênese desta infecção ainda está pouco elucidada. O sorotipo V é freqüentemente associado à doença invasiva em mulheres adultas não gestantes e o segundo mais prevalente em mulheres grávidas. O principal objetivo deste trabalho foi estudar a aderência, invasão e persistência intracelular de amostras pertencentes ao sorotipo V (88641-vagina/portador e 90186-sangue/paciente) usando as células epiteliais respiratórias A549. As amostras de EGB demonstraram capacidade de aderir e invadir as células epiteliais A549, mas somente a amostra 90186-sangue apresentou maior invasão quando comparada com a de vagina (P <0.001). Ambas as amostras demonstraram persistência intracelular sem replicação no interior das células A549. Apenas o isolado 90186-sangue sobreviveu dentro das células epiteliais até 24h de incubação (P <0,05). A fusão dos lisossomas das células epiteliais com vacúolos contendo bactérias foi observada em células A549 tratadas com Lyso Tracker Grenn DND-26 para todas as amostras testadas. Nossos dados indicam pela primeira vez que as amostras viáveis do sorotipo V permanecem dentro de vacúolos ácidos epiteliais. Curiosamente, a amostra 90186- sangue induziu vacuolização celular e a amostra 88641-vagina promoveu a morte celular após 7h de incubação. Finalmente, nossos resultados aumentam o nosso conhecimento sobre eventos celulares da fagocitose e da patogênese das doenças invasivas promovidas pelos EGB. / Group B Streptococcus (GBS) commonly colonizes healthy asymptomatic adults, yetunder certain circumstances displays the ability to invade host tissues, evade the immune system and cause serious invasive disease. Consequently, GBS remains the major cause of neonatal pneumonia, sepsis and meningitis. However, the pathogenesis of this infection is poorly understood. The serotype V is frequently associated with invasive diseases in non-pregnant adults and the second most prevalent in pregnant women. The aim of this work was to study the adherence; invasion and persistence intracellular of the GBS serotype V (88641-vagina/carriers and 90186-blood/patient) in epithelial cells A549. All GBS strains showed ability to adhere and invade the epithelial A549 cells, but GBS 90186-blood was more invasive than the vagina isolate (P<0,001). Both strains persisted intracellular, but without replicating into the A549 cells. Only 90186-blood strain survived within epithelial cells even after a 24h incubation (P<0,05). Fusion of epithelial lysosomes with bacteria containing phagocytic vacuoles was observed in A549 cells treated with Lysotracker Grenn DND-26 for all strains tested. Our data indicate for the first time that viable strains of serotype V remain within acidic epithelial vacuoles. Interestingly, the 90186-blood strain induced cellular vacuolization and 88641-vagina strain caused cell death after 7h incubation. Lastly, our results increase our knowledge about cellular events of phagocytosis and pathogeneses of GBS diseases.

Made available in DSpace on 2014-08-20T13:59:11Z (GMT). No. of bitstreams: 1 dissertacao_mirian_farias_ribeiro.pdf: 619687 bytes, checksum: cf80f947861c533664196359ce7fe274 (MD5) Previous issue date: 2010-03-04 / The objective of this work was to evaluate the effect of aluminum (Al) on in vitro multiplication and rooting of pear and quince. The explants were nodal segments of pear and quince in vitro cultivated. The culture medium to pear was QL modificated by Leblay and to quince was MS, both added of Al to 0 (pH 5,7, control), 0, 15, 30, 45 e 60 mg L-1 (pH 4,0) put in jars with 1 g of cotton for multiplication and 3 g of vermiculite for rooting and 30 mL of medium. The trial had four replicates and five explants each. At 60 days the percentage of shoots, length and number of shoots, fresh and dry mass and catalase (CAT) and ascorbate peroxidase (APX) activity in pear were assessed. At 45 days the percentage of rooting, length and number of root, fresh and dry mass of shoots and roots, CAT, APX and superoxide dismutase (SOD) activity in pear and nutrients content were assessed. In the multiplication, the quince had 100% of shoot, but decreased the number of shoots. The length of shoots, fresh and dry mass decreased in MC but increased in BA 29 . The pear had high percentage of shoots. The number of shoot was higher for Conference . The length of shoots, fresh and dry mass was increased at Al. CAT activity in Conference was increased at 30 mg L-1 of Al and in Abate Fetel was increased at 30 and 45 mg L-1 of Al. APX activity in Conference was increased at 30 and 60 mg L-1 of Al and in Abate Fetel was increased at 30 mg L-1 of Al. In the rooting, the percentage of rooting, lenght and number of roots was higher for quince. The fresh mass of shoot was higher for Conference and for 30 mg L-1 of Al. The fresh mass of root was higher for BA 29 at 15 mg L-1 of Al. The dry mass of shoot was higher for Conference and for 15 and 30 mg L-1 of Al. The dry mass of root was higher for BA 29 and for 15 mg L-1 of Al. The nutrient content increased at aluminum. In the Abate Fetel the CAT and APX activity was increased and the SOD activity was decreased at aluminum. On the other hand, in the Conference the CAT activity was decreased at aluminum, the APX was decreased only at 45 mg L-1 of Al and the SOD activity was increased. As conclusion, the cultivars answered of different form at Al and, in some parameters, the presence of this metal was beneficial. / O objetivo do presente trabalho foi avaliar o efeito do alumínio (Al) na multiplicação e enraizamento in vitro de pereira e marmeleiro. Os explantes constituíram-se de segmentos nodais de pereira e marmeleiro cultivados in vitro. O meio de cultura para pereira foi o QL modificado por Leblay e para marmeleiro foi o MS, ambos adicionados de Al a 0 (pH 5,7 controle), 0, 15, 30, 45 e 60 mg L-1 (pH 4,0), colocado em frascos contendo 1 g de algodão hidrófilo para multiplicação e 3 g de vermiculita para enraizamento e 30 mL de meio. O experimento constou de quatro repetições com cinco explantes cada. A multiplicação foi avaliada aos 60 dias quanto a percentagem de explantes brotados, número e comprimento das brotações, massa fresca e massa seca total e a atividade das enzimas catalase (CAT) e ascorbato peroxidase (APX) em pereira. O enraizamento foi avaliado aos 45 dias quanto a percentagem de explantes enraizados, número e comprimento das raízes, massa fresca e seca da parte aérea e radicular, a atividade das enzimas CAT, APX e superóxido dismutase (SOD) em pereira e teor de nutrientes. Na multiplicação, o marmeleiro teve 100% de explantes brotados, mas houve diminuição no número de brotos. O MC apresentou diminuição no comprimento dos brotos, na massa fresca e seca, já o BA 29 apresentou aumento desses parâmetros. A pereira teve alta percentagem de explantes brotados. A Conference apresentou maior número de brotos. Com relação ao comprimento dos brotos, massa fresca e seca houve aumento na presença de Al. A atividade da CAT na Conference foi aumentada em 30 mg L-1 de Al e na Abate Fetel foi aumentada em 30 e 45 mg L-1 de Al. A atividade da APX na Conference foi aumentada em 30 e 60 mg L-1 de Al e na Abate Fetel foi aumentada em 30 mg L-1 de Al. No enraizamento, o marmeleiro apresentou maior percentagem de enraizamento, maior número e comprimento das raízes. A maior massa fresca da parte aérea foi obtida pela Conference e por 30 mg L-1 de Al. A massa fresca da raiz foi maior no BA 29 em 15 mg L-1 de Al. A maior massa seca da parte aérea foi obtida pela Conference e por 15 e 30 mg L-1 de Al. A maior massa seca da raiz foi obtida pelo BA 29 e por 15 mg L-1 de Al. O teor de nutrientes aumentou na presença de Al. A atividade da CAT e APX aumentou e da SOD diminuiu em Abate Fetel na presença de Al, enquanto que na Conference a atividade da CAT diminui, da APX diminuiu somente em 45 mg L-1 de Al e da SOD aumentou. De modo geral, os cultivares responderam de vii forma diferente a presença de Al e, em alguns parâmetros, a presença desse metal foi benéfica.

Une approche expérimentale mettant en œuvre des techniques électrochimiques et mécaniques a été utilisée pour étudier la corrosion sous contrainte (CSC) de l’acier inoxydable 304L dans des électrolytes acides (0,5-5 M H2SO4) avec et sans chlorure. La CSC a été réalisée dans le but d’étudier les aspects cristallographique et cinétique de la rupture. La microscopie électronique à balayage a dévoilé, d’une part, des traces successives au niveau des plans de glissement sur les facettes de la fissure, et d’autre part une vitesse non-linéaire de la fissuration. Une méthode a été proposée pour accéder à la cristallographie de fissuration en utilisant la diffraction d'électrons rétrodiffusés (EBSD). Il a été démontré que les ruptures préférentielles s’effectuent au niveau des plans {111} pour ¾ du temps et des plans {110} le reste du temps. Ces résultats soutiennent les modèles récents de la CSC, tels que la plasticité localisée rehaussée par la corrosion. Les profils d’évolution de la contrainte appliquée/résiduelles ont été déterminés par diffraction des rayons X avant et après CSC. Ces analyses serviront à développer un modèle de rupture micro-mécanique. Lors des essais potentiodynamiques optimisés de corrosion, les taux de dissolution élémentaires et le courant total ont été mesurés en combinant une cellule d'écoulement électrochimique et l'analyse des produits de corrosion par spectroscopie d'émission atomique à plasma à couplage inductif. Ces résultats ont été utilisés, pour séparer la partie de courant consacré à la formation de la couche passive du courant total. Le modèle de conduction ionique sous tension élevée a été mis à jour pour calculer le taux de passivation et l'épaisseur de la couche passive. Les contraintes dans le matériau expliquent une différence mesurable de la cinétique de croissance du film passif et de son épaisseur. / : A multidisciplinary experimental approach of electrochemical and mechanical techniques was employed to study the corrosion of different stress states of 304L stainless steel in acidic electrolytes (0.5-5 M H2SO4) with and without chloride additives. Stress corrosion cracking (SCC) conditions were applied to evidence cracking crystallographical and propagation aspects. Scanning electron microscopy of SCC revealed clear traces of successive slipping planes and consequent dissolutions on the crack facets, and nonlinear crack propagation kinetics. A method was proposed to access cracking crystallography using electron back scattered diffraction. It demonstrated {111} and {110} preferential cracking planes in proportion of about 75% and 25% respectively, which supports recent SCC models such as corrosion enhanced localized plasticity. The profiles of (applied/residual) stress evolution measured by X-ray diffraction before and after SCC were used as an introduction to develop a micro-mechanical cracking model. During optimized potentiodynamic corrosion tests, elemental dissolution rates and total current transients were measured by combining electrochemical flow cell and downstream solution analysis by inductively coupled plasma atomic emission spectroscopy. The results were used to separate the current portion spent on passive film formation from the total current. The high field ion conduction model was upgraded to calculate the constructed passive film thickness and passivation rate. The applied stress caused a measurable difference in passive film growth kinetics and its thickness.

No description available.

The cytoskeletal protein vinculin plays a key role in the control of cell-cell or cell-matrix adhesions. It is involved in the assembly and disassembly of focal adhesions and affects their mechanical stability. While many facts highlight the importance and significance of vinculin for vital processes, its precise role in the regulation of cell adhesions is still only partially understood. Various EPR methods are used in this work in order to study the vinculin tail (Vt) domain in an aqueous buffer solution and its structural changes induced by F-actin and acidic phospholipids. EPR results in combination with a rotamer library approach (RLA), MD simulation and other computational methods allowed the construction of molecular models of Vt and dimeric Vt in the presence and absence of its binding partners. Furthermore, X-band orientation selective DEER measurements were applied on a Vt double mutant. It could be shown that the determination of the mutual orientation of protein bound spin labels is possible at X-band frequencies, if the orientation correlation of the spin label pair is strong. The method established here can be used to determine valuable information about proteins and nucleic acids, expanding the virtue of DEER spectroscopy as a tool for structure determination.

No description available.

Introduktion/Bakgrund: Dental erosion är en irreversibel kemisk process som innebär förlust avtandsubstans. Läskförsäljning i Sverige ökar varje år och ungdomars konsumtion av läsk är en bidragandeorsak till dental erosion. Ungdomar som konsumerar sur dryck har låg kunskap om dryckens påverkan påtänderna, samtidigt som ungdomar utvecklar hälsovanor som kan påverka hälsan.Syfte: Syftet med denna studie var att undersöka ungdomars kunskap om dental erosion samt deraskonsumtion av sur dryck.Metod: Studien var en tvärsnittsstudie och datainsamlingen genomfördes med hjälp av en enkät. Enkäteninnehöll 18 kryssfrågor och besvarades med en- eller flersvarsalternativ. Studien genomfördes på tvågymnasieskolor, en i Västernorrland och en i Värmland. Totalt deltog 164 elever i studien.Resultat: Resultatet visade att majoriteten (82 %) av ungdomarna hade hört talas om dental erosion, menmindre än hälften (47 %) visste vad det innebar. Tandvården var huvudkällan (81 %) för information omdental erosion. Många ungdomar konsumerade sport/energidryck (29 %) och läsk (54 %) flera gånger iveckan, och den största anledningen till konsumtionen av dessa drycker var att smaken var tilltalande.Slutsats: Studien visade att det finns kunskapsbrist hos ungdomar om dental erosion och tandvården varden huvudsakliga informationskällan om dental erosion. Sur dryck konsumerades flera gånger i veckan ochsmaken var den starkaste drivkraften till konsumtionen av sport/energidryck och läsk. / Introduction/Background: Dental erosion is an irreversible chemical process that involves the loss oftooth substance. Soft drink sales in Sweden are rising every year, and adolescents’ consumption of softdrinks is a contributing cause of dental erosion. Adolescents who consume acidic drinks have littleknowledge of the drink's impact on the teeth, while adolescents develop health habits that can affect theirhealth.Aim: The aim of this study was to investigate adolescents’ knowledge of dental erosion as well as theirconsumption of acidic drinks.Method: The study was a cross-sectional study, and the data collection was carried out using aquestionnaire. The questionnaire contained 18 multiple choice questions and was answered with single ormultiple answer options. The study was conducted at two high schools, one in Västernorrland and one inVärmland. A total of 164 students participated in the study.Results: The results showed that the majority (82%) of the adolescents had heard of dental erosion, butless than half (47%) knew what it meant. Dental care was the main source (81 %) of information aboutdental erosion. Many adolescents consumed sports/energy drinks (29%) and soft drinks (54%) severaltimes a week, and the main reason for the consumption of these drinks was that the taste was appealing.Conclusion: The study showed that there is a lack of knowledge among adolescents about dental erosion,with dental care being their main source of information about dental erosion. Acidic drinks wereconsumed several times a week by over half of the participants, with taste being strongest driving forcefor consumption of sports/energy drinks and soft drinks.