Efficient recycling of nutrients in modern and past hypersaline environments.

The biogeochemistry of hypersaline environments is strongly influenced by changes in biological processes and physicochemical parameters. Although massive evaporation events have occurred repeatedly throughout Earth history, their biogeochemical cycles and global impact remain poorly understood. Here, we provide the first nitrogen isotopic data for nutrients and chloropigments from modern shallow hypersaline environments (solar salterns, Trapani, Italy) and apply the obtained insights to δ15N signatures of the Messinian salinity crisis (MSC) in the late Miocene. Concentrations and δ15N of chlorophyll a, bacteriochlorophyll a, nitrate, and ammonium in benthic microbial mats indicate that inhibition of nitrification suppresses denitrification and anammox, resulting in efficient ammonium recycling within the mats and high primary productivity. We also suggest that the release of 15N-depleted NH3(gas) with increasing salinity enriches ammonium 15N in surface brine (≈34.0‰). Such elevated δ15N is also recorded in geoporphyrins isolated from sediments of the MSC peak (≈20‰), reflecting ammonium supply sufficient for sustaining phototrophic primary production. We propose that efficient nutrient supply combined with frequent bottom-water anoxia and capping of organic-rich sediments by evaporites of the Mediterranean MSC could have contributed to atmospheric CO2 reduction during the late Miocene.

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Physiological profile of water polo players in different competitive levels.

AIM: The purpose of this study was to determine if there are different physiological characteristics in water polo players of three different competitive levels (national team, NT, junior national team, NJ, and amateur club, AC). METHODS: To better define the training levels of water polo players competing at different levels, we administered a shuttle swim test (SST, a specific test used by Italian coaches) and a classic speed-lactate test. The shuttle swim test is based on actions at maximum intensity followed by incomplete recoveries. To compare the athletes, we used their morphological characteristics, the speed during an incremental test associated with fixed blood lactate concentrations of 2 mmol*1-1 (Aerobic Threshold, AT) and 4 mmol*1-1 (Anaerobic Threshold, AnT), and the SST data (speed, heart rate and lactate concentration). RESULTS: The heart rate at the end of the SST was 164+/-12 beats*min-1 for NT, 166+/-10 beats*min-1 for NJ (no significant difference, P>0.05) and 179+/-9 beats*min-1 for AC (significantly different from NT and NJ, P<0.05). The AT and AnT speeds were significantly higher in NT than in AC and NJ (P<0.05). No significant differences were found in AT and AnT speeds between AC and NJ (P>0.05). The mean speed during the shuttle swim test was significantly higher in NT and NJ than in AC (P<0.05). Lactate values were similar in the NT, AC and NJ groups (P>0.05). The SST mean speed was significantly correlated with the AT (P<0.01) and AnT speeds (P<0.05) in three groups . In all groups no significant correlation was found between SST blood lactate and AT or AnT speeds (P>0.05). CONCLUSION: Some differences were found among the senior and junior professional and amateur water polo players in both SST performance and Aerobic and Anaerobic Thre-shold speeds. The shuttle swim test for water polo provides conditioning coaches and sport scientists with data on the sport-specific movement speed and the competition-specific fatigue resistance in each athlete.

Ribosomal RNA gene fragments from fossilized cyanobacteria identified in primary gypsum from the late Miocene, Italy.

Earth scientists have searched for signs of microscopic life in ancient samples of permafrost, ice, deep-sea sediments, amber, salt and chert. Until now, evidence of cyanobacteria has not been reported in any studies of ancient DNA older than a few thousand years. Here, we investigate morphologically, biochemically and genetically primary evaporites deposited in situ during the late Miocene (Messinian) Salinity Crisis from the north-eastern Apennines of Italy. The evaporites contain fossilized bacterial structures having identical morphological forms as modern microbes. We successfully extracted and amplified genetic material belonging to ancient cyanobacteria from gypsum crystals dating back to 5.910-5.816 Ma, when the Mediterranean became a giant hypersaline brine pool. This finding represents the oldest ancient cyanobacterial DNA to date. Our clone library and its phylogenetic comparison with present cyanobacterial populations point to a marine origin for the depositional basin. This investigation opens the possibility of including fossil cyanobacterial DNA into the palaeo-reconstruction of various environments and could also be used to quantify the ecological importance of cyanobacteria through geological time. These genetic markers serve as biosignatures providing important clues about ancient life and begin a new discussion concerning the debate on the origin of late Miocene evaporites in the Mediterranean.

Shuttle swim test for water polo players: validity and reliability.

AIM: The purpose of this study, carried out on elite water polo players, was to examine: 1) the relationship between the shuttle swim test (SST) and the performance during official water polo games, and 2) the SST reliability. METHODS: Sixteen male players of the Italian National Water Polo Team (age: 27.9 + or - 2.1 years, body mass: 88.5 + or - 10.3 kg, height: 186.6 + or - 6.9 cm) performed the SST, consisting of two sets of seven repetitions from 40 to 10 m (total of 120 m for each set) at a maximal intensity with 90 s of rest between sets. During the SST, average swimming speed, blood lactate concentration and heart rate were recorded. Direct validity of the SST was evaluated by comparing the average swimming speed with the total distance covered (TD) and the distance covered at high intensity swimming (above 1.8 m x s(-1), HIS) during three official water polo games. SST reliability was assessed by testing the same athletes one week apart. RESULTS: Average swimming speed during the SST was significantly correlated with TD (r=0.67, P<0.01) and HIS (r=0.74, P<0.004). The mean average speed during SST showed high reliability (TE=0.4%; CI 95%: 0.2% to 1.0% ). The T1 vs. T2 difference in mean average speed was not significant. CONCLUSIONS: Present findings demonstrate the validity and reliability of the SST for evaluation of the swimming fitness of water polo players.

Application of an innovative methodology to improve the starting-up of UASB reactors treating domestic sewage.

This study shows the results obtained during the starting-up evaluation of an UASB reactor treating domestic sewage. It is located in the municipality of Ginebra, Valle del Cauca region in Colombia. Its design flow is 7.5 l/s with a maximum capacity of 10 l/s. The reactor was seeded with a deficient quality inoculum which accounted for 20% of the total reactor volume. The starting-up methodology comprised the sequential washing of the sludge (inoculum) by applying three different upflow velocities. This procedure resembles what other authors term the "selective pressure method". Once the sludge was washed, the reactor was started-up with an initial hydraulic retention time (HRT) of 24.9 hours, which was steadily reduced down to 6.7 hours in the final stage. Along the starting-up phase, there was a positive evolution in terms of quantity, quality and spatial distribution of the sludge. Consequently, there was a positive evolution in organic matter removal mechanisms. For HRT above 14 hours, the removal mechanisms were mainly physical whilst for HRT below 9 hours the removal mechanisms were mostly biological. Based on the above considerations and on the water quality parameters measured, it may be concluded that the start-up of an UASB reactor for domestic sewage treatment seeded with a low quality inoculum can be done with HRT as low as 15 or 12 hours. In this way, it is possible to reduce the starting-up period of these reactors down to 4 to 6 weeks, provided that the starting-up methodology is properly applied.

Effects of reality orientation therapy on elderly patients in the community.

Twenty-three institutionalized subjects, confused and disoriented as to time, space and persons, were divided into two groups: the study group and the control group. The study group then participated in a 3-month period of formal Realithy Orientation Therapy (ROT). At the end of the 3 months of therapy significant differences emerged in the scores of MMSE, OSGP and GDS obtained by the two groups. Moreover, significant positive differences were observed only in the study group, comparing the tests' results before and after therapy. Even the comparison of the results obtained at the end of the sessions and 3 months after the interruption of the therapy revealed a difference in the trends that emerged for the two groups.