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AbstractChromian tourmaline, in association with other Cr-bearing minerals (amphibole, mica, epidote, chlorite, titanite, rutile and chromian spinel), occurs in fine calc-schist levels within metacarbonate rocks from the Nevado-Filabride Complex, SE Spain. Electron microprobe analyses of tourmaline and coexisting minerals document both chemical differences dependent on the host-rock type and an irregular distribution of Cr at grain scale. Tourmaline is Na-rich dravite, with average Mg/(Mg+Fe) ratios of 0.83 and 0.63 a.p.f.u. and Cr contents of 0.32 and 0.18 a.p.f.u., in dolomitic and ankeritic marbles, respectively. Tourmaline contains small but significant concentrations of Zn (av. 0.01 a.p.f.u.) and in ankeritic marble it also contains Ni (av. 0.04 a.p.f.u.). Zn-rich chromian spinel appears as small relict inclusions in silicates, with average Cr, Fe, Al and Zn contents of 1.201, 1.241, 0.411 and 0.107 a.p.f.u., respectively. Amphibole, epidote, mica and chlorite show average Cr contents of 0.088, 0.138, 0.115 and 0.267 a.p.f.u., respectively, in dolomitic marbles, and 0.103, 0.078, 0.065 and 0.185 a.p.f.u., respectively, in ankeritic marbles. Cr-silicates formed through metamorphic reactions involving detrital Cr-rich spinel, in addition to clay minerals and carbonates. The B necessary to form tourmaline was probably derived from the leaching of underlying evaporitic rocks.

During the 1st and 2nd centuries AD, more than 500 gold mines were operating in the northwest (NW) of Spain. The region was then a part of the Roman Empire and known as Iberia. Corresponding excavations totaled 600million cubic meters (Mm3), with about 300Mm3coming from alluvial mines. Miocene sediments (mainly alluvial fans) derived from the Cantabrian Mountain and León Mountain uplifts, and Quaternary deposits (principally regolith, fluvial terraces, moraines and fluvio-glacial fans) were exploited by the Roman miners, using hydraulic mining methods.

To verify that variations caused by total parenteral nutrition (TPN) in O2 intake (VO2) and CO2 output (VCO2) can affect respiratory function of non-hypercatabolic patients, we studied 18 patients in two groups; group I (control): eight patients receiving 75–100g glucose/24 h, and group II: ten patients fed intravenously on 13.6 g N2 and approximately 2,800 kcal/24 h given as a) 62% glucose+38% fats (TPN-G+F) and b) 100% glucose (TPN-G). VO2, VCO2, respiratory quotient (RQ) and minute ventilation (VE) were measured in all patients. We found that VCO2 was 27% higher in intravenously fed patients (p<0.01 andp<0.02). similarly, VE was 26% higher in intravenously fed patients (p<0.001 andp<0.02). Comparison of TPN-G+F and TPN-G results showed no differences in VCO2; by contrast, VO2 was 21% less during TPN-G(p<0.01).

The strata-bound fluorite-(barite-)Pb-Zn ore deposits occurring within the more than 3,000 m thick Alpujárride Carbonate Formation of the Betic Cordillera, southern Spain, are linked to two defined stratigraphic positions (within the Anisian and at the Ladinian-Carnian transition) and to definite sedimentary contexts. These are highly restricted lagoons isolated from the open sea by calcarenitic barriers with noticeable development of algal mats in their inner margins. Preevaporitic deposition conditions are usually recognized. The ore-bearing horizons are located either at the transition from evaporitic to normal marine deposition (as in the case of the Anisian ore-bearing horizon) or at the transition from normal marine to evaporite deposition (as in the case of the uppermost Ladinian to lowermost Carnian ore-bearing horizon). These vertical facies changes correspond also to the transitions from predominantly terrigenous (continental and/or coastal) sedimentation to marine carbonate sedimentation (Anisian ore deposits) and vice versa (upper Ladinian-lower Carnian). It is proposed that the ore deposits in the Triassic Alpujárride Formation are controlled by certain facies associations in the lagoonal environment. The depositional environment determines the hydrologic regimes responsible for early diagenetic formation of fluorite and of the related ore minerals in a way similar to that of early-diagenetic dolomite. This hypothesis is consistent with field and petrographic observations and with available geochemical and itotopic data reported in other works. The present investigation intends to underline the role played by surface-linked ore formation processes, i.e., by ore-forming processes essentially linked to the environments in which sedimentation and early diagenesis takes place, in the genesis of numerous strata-bound Zn-Pb-(F-Ba) ore deposits in carbonate rocks.

Prior research suggested that the genes for large (L) and small (S) subunits of ribulose bisphosphate carboxylase/oxygenase (RuBisCO) are amplified in ampicillin-resistant pBR322-transformants of Anacystis nidulans 6301. We now report that chromosomal DNA from either untransformed or transformed A. nidulans cells hybridizes with nick-translated [32P]-pBR322 at moderately high stringency. Moreover, nick-translated [32-P]-pCS75, which is a pUC9 derivative containing a PstI insert with L and S subunit genes (for RuBisCO) from A. nidulans, hybridizes at very high stringency with restriction fragments from chromosomal DNA of untransformed and transformed cells as does the 32P-labeled PstI fragment itself. The hybridization patterns suggest the creation of two EcoRI sites in the transformant chromosome by recombination. In pBR322-transformants the RuBisCO activity is elevated 6- to 12-fold in comparison with that of untransformed cells. In spite of the difference in RuBisCO activity, pBR322-transformants grow in the presence of ampicillin at a similar initial rate to that for wild-type cells. Growth characteristics and RuBisCO content during culture in the presence or absence of ampicillin suggest that pBR322-transformants of A. nidulans 6301 are stable. The data also collectively suggest that a given plasmid in the transformed population replicates via a pathway involving recombination between the plasmid and the chromosome.

The use of extrinsic positive end expiratory pressure (PEEPe) in patients with auto-PEEP (AP) can reduce the respiratory work during weaning from mechanical ventilation. However, the application of PEEPe produce a certain level of hyperinflation, an undesirable effect which can limit the efficacy of the reduction of respiratory work. The objective of the present study has been to determine if the encrease in end expiratory lung volume (EELV) originated by the PEEPe is related to static lung compliance (SLC). We have studied 14 patients on mechanical ventilation in whom an AP of between 4 and 12 cmH2O was detected. On applying PEEPe equal to half the AP, the EELV increased slightly (77±64 ml) and was not related to pulmonary compliance. When PEEPe equal to the AP was applied, the EELV increased by 178±110 ml (range 45–375 ml,p<0.05), and there was a significant correlation with SLC (r=0.659,p<0.05). In conclusion, the application of PEEPe equal to the AP causes a moderate increace in EELV. However, in patients with high pulmonary compliance this increase can be more important and must be taken into account when considering the use of PEEPe during weaning.

Summary Tourmalinites containing quartz, Li- and Cs-micas, and small amounts of arsenopyrite occur near Cáceres, Spain. The tourmalinites are developed within Ordovician pelites near the eastern margin of the Cabeza de Araya batholith and close to several small bodies of tectonized granite. Field and textural relationships document an epigenetic character for the tourmalinites. The tourmaline is fine to very fine-grained and its composition is intermediate within the schorl-dravite solid-solution series. Hydrothermal veins containing quartz, muscovite, amblygonite-montebrasite, apatite, fluorite, and/or cassiterite appear spatially related to the tourmalinites. The mineralized area is located in a shear zone that was active during D3 Hercynian deformation and the emplacement of granitic bodies. Tourmalinites and veins derived from B- and Li-rich magmatic-hydrothermal fluids are believed to have been associated with the intrusion of a hidden granite dome, the tourmalinites being produced by extensive metasomatism of Ordovician metasedimentary rocks.

Summary Chromitites (Cr ores) of the Ojen lherzolite massif (Serranía de Ronda, Betic Cordillera, Southern Spain) were found to contain platinum-group minerals (PGM) as discrete inclusions in the chromite and in the associated silicates. The PGM mineralogy consists of sulfides [laurite, erlichmanite, malanite, unnamed (Ni-Fe-Cu)2 (Ir, Rh) S3, unidentified Pd-S], sulfarsenides (irarsite, hollingworthite, ruarsite, and osarsite), arsenides [sperrylite, unidentified (Pd, Ni)-As], one unidentified Pd-Bi compound, and native platinum group elements (PGE) consisting of Ru and Pt-Fe alloys. Textural considerations suggest that the PGE chalcogenides with S and As were formed in the high-temperature magmatic stages, as part of the chromite precipitation event (primary PGM), in contrast with the native PGE, which originated during the low-temperature serpentinization of the ultramafic host of the chromitites (secondary PGM).