Occurrence and bioaccumulation study of PCDD and PCDF from mineral feed additives

Occurrence of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) was evaluated in sepiolite as a widely employed binder and anti-caking agent for animal feed. Also, naturally contaminated kaolinitic clay was used for comparative purposes. Since sepiolite shows remarkable adsorption properties, particular interest was paid to the extraction steps as they become critical for the final determination of these pollutants in such matrixes. Furthermore, classical Soxhlet extraction using different extracting strategies as well as acid treatment were carried out with simultaneous liquid-liquid extraction. Results obtained depended on the extraction procedure applied. Acid treatment or Soxhlet extraction using a mixture of toluene:ethanol as solvent allowed to reach the minimum requirements of recovery rates. However, Soxhlet extraction using a mixture cyclohexane:toluene as extracting solvent did not allow to comply with minimum specifications for recovery. Significant differences were obtained in TEQ units when acid treatment was applied in comparison to Soxhlet extraction. This fact can be explained because the use of drastic acid conditions allows removing strongly adsorbed analytes which can be uniquely extracted after a total destruction of the crystalline structure of sepiolite. On the contrary, Soxhlet extraction was not able to destroy the structure of sepiolite and as a consequence the PCDDs/Fs were strongly adsorbed in the internal structure of the mineral. From biological point of view the availability of these toxicants constitutes a critical aspect playing an important role in the final decision choosing particular analytical procedures. Then, acid conditions in the digestive tract should be taken into account. In this scenario, a bioaccumulation study was conducted to evaluate the transference of PCDDs/PCDFs from the sepiolite into the animal tissues when fed with feed containing sepiolite. To this end, chickens were used as a model to examine the bioavailability of PCDDs/PCDFs. Four groups of chickens were exposed through their diet to a control feed, feed with 3% w/w sepiolite as additive, feed contaminated with PCDDs/PCDFs at concentration around 2.8 pg WHO-TEQ/g and feed with 2% of a contaminated kaolinitic clay (460 pg TEQ/g mineral). Livers of the four studied groups were analyzed throughout the exposure period. Results of this trial showed that the performance of broilers was not affected by the presence of dioxins at levels tested, and chickens did not show any abnormal behaviour. Dioxins intentionally added to the diet were absorbed and accumulated in the liver in a significant manner, whereas the PCDDs/Fs from sepiolite were not available for chickens since livers from broilers fed 3% sepiolite presented similar WHO-TEQ values than those from broilers fed control diet.

Del mineral al frontal romànic: aplicació dels pigments minerals en pintura romànica al Berguedà

Treball de recerca realitzat per una alumna d’ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l’any 2008. L’objectiu principal ha estat fer una reproducció a escala d’un frontal del romànic berguedà emprant pigments minerals. Sobre la base d’una recerca bibliogràfica exhaustiva, s’ha realitzat primer una aproximació teòrica amb l’objectiu de poder estudiar els pigments minerals des de diversos punts de vista: el científic, explicant la física, química i geologia del color; i l’artístic, explicant l’evolució dels pigments al llarg de la història de l’art –especialment en el Romànic català -. Paral•lelament, els estudis experimentals es van estructurar en quatre apartats: localització i recol•lecció de minerals, obtenció del pigment, elaboració de la pintura i reproducció del frontal romànic de Sant Andreu de Sagàs. Per tal de comprendre millor el procediment d’elaboració del frontal se’n va confeccionar un altre que es va dividir en quatre parts, corresponents als diferents passos que s’havien de seguir. El treball realitzat mostra que les dues grans branques del saber, l’art i la ciència, es troben íntimament relacionades. A més ha demostrat que gran part dels pigments que s’utilitzaven per elaborar les pintures romàniques del Berguedà provenien de l’entorn més directe, però en cas necessari s’utilitzaven minerals importats de terres llunyanes, com el cinabri. Les pintures elaborades amb pigments minerals tenen un alt valor afegit, ja que requereixen tot un procés de preparació molt llarg i laboriós.

Hiperparatiroidismo primario en mujeres postmenopáusicas: evolución de la densidad mineral ósea tras tratamiento quirúrgico

Es realitza un estudi prospectiu observacional amb 158 dones postmenopàusiques diagnosticades d’hiperparatiroidisme primari. L’objectiu és descriure i analitzar l’evolució de la densitat mineral òssia d’aquestes dones després de ser sotmeses a tractament quirúrgic. Els resultats mostren que l’os més afectat en aquesta malaltia és l’os cortical, però el que més es recupera i de forma més ràpida després de la paratiroidectomia és l’os trabecular. Així mateix, les malaltes que tenen un hiperparatiroidisme més sever presenten una major recuperació de la densitat mineral òssia després de la cirurgia.

Bottled natural mineral water in catalonia: origin and geographical evolution of its consumption and production

During the second half of the nineteenth century a major mineral water bottling industry appeared in Catalonia which vigorously lasted until the first third of the 20th century. The fact that the industry appeared in Catalonia and in other parts of Europe and the United States almost at the same time and had not existed before can be explained by a series of factors which coincided in time. This situation encouraged producers to pack, transport and sell bottled water from their respective sources. Among these factors there is the rise of hygienism, very influential in Catalonia, the declining water quality due to industrialization, the increase in population density, the improvement in transport, the emergence of thermal tourism or the invention of better containers used to store water. This project aims to explain thoroughly all the mentioned factors, and to give some light to why, when and how the Catalan bottled water industry appeared.

Litterfall and mineral return in two cork-oak forests in northeast spain

Seasonal trends in littertall and potential mineral return were studied in two cork-oak forest sites in the northeastern Iberian peninsula. The estimated average litter production was 3.9.M- gy.e1ahar for one site and 4.6 .M- gy.e1ahar for the other; these figures are similar to those reported for holm-oak (Quercus ilex) forests in the same area. Seasonal litterfall patterns were typical of Mediterranean forest ecosystems. Leaves accounted for 46 to 78% of the total dry matter. Their annual weighted-average mineral composition was low in macronutrients (N 8-9; K 4-5; Mg 0.8-1.3; Ca 9-10 and P 0.4-1 m-)g.1g and relatively high in micronutrients such as Mn (2-2.2 m-)g.1g or Fe (0.3-0.4 m)-g..1g Minimum N and P concentrations were found during the growth period. Estimates of potential mineral return for an annual cycle were N 38-52, P 2.1-5.2, K 20-28, Ca 44-53 and Mg 5.4-5.0 k-,g.1ha depending on the site biomass and fertility