Biometric, nutritional and sensory characteristic modifications in farmed Murray cod (Maccullochella peelii peelii) during the purging process

Intensively farmed, market-size Murray cod (~ 600 g), were purged (transferred into a clean water system and starved) and sampled at three day intervals for a total of 18 days (D0, D3, D6, D9, D12, D15 and D18). Purged fish lost from 6% (D3) to 14% (D18) body weight, and the weight loss was highly correlated to the number of days of purging/starvation. Condition factor and Hepatosomatic Index decreased significantly (P < 0.05) only after 18 days of purging compared to the control (D0). Fillet lipid content (%) did not vary during the trial. Eicosapentaenoic acid (EPA: 20:5 n&minus;3) decreased and docosapentaenoic acid (DPA: 22:5 n&minus;3) increased (P < 0.05) during the trial, while docosahexaenoic acid (DHA: 22:6 n&minus;3) did not show any significant variation. Purging contributed positively to the improvement of the volatile flavour compound composition, with a significant (P < 0.05) reduction in total volatile aldehydes and an increase in total volatile hydrocarbons. Since no major differences were found between samples during the last stages of the purging process (D12, D15 and D 18), it is possible to conclude that, under these experimental conditions, 12 days is the minimum duration to obtain an improvement in the volatile compound profile of intensively farmed Murray cod whilst keeping body weight loss to a minimum.

Traceability and discrimination among differently farmed fish : a case study on Australian murray cod

The development of traceability methods to distinguish between farmed and wild-caught fish and seafood is becoming increasingly important. However, very little is known about how to distinguish fish originating from different farms. The present study addresses this issue by attempting to discriminate among intensively farmed freshwater Murray cod originating from different farms (indoor recirculating, outdoor floating cage, and flow through systems) in different geographical areas, using a combination of morphological, chemical, and isotopic analyses. The results show that stable isotopes are the most informative variables. In particular, &delta;13C and/or &delta;15N clearly linked fish to a specific commercial diet, while &delta;18O linked fish to a specific water source. Thus, the combination of these isotopes can distinguish among fish originating from different farms. On the contrary, fatty acid and tissue proximate compositions and morphological parameters, which are useful in distinguishing between farmed and wild fish, are less informative in discriminating among fish originating from different farms.

Changes in organic-matter dynamics and physicochemistry, associated with riparian vegetation loss and river regulation in floodplain wetlands of the Murray River, Australia

Extensive clearing of floodplain forests potentially reduces organic matter available to floodplain wetlands. Furthermore, on rivers regulated to provide irrigation water in summer, floodplain wetlands that were previously inundated in spring, now flood in summer/autumn. In the Murray&ndash;Darling Basin, Australia, this has changed the timing of organic matter entering the aquatic phase, since leaf fall peaks in summer. Field surveys and mesocosm experiments on floodplain wetlands on the River Murray revealed faster processing rates of leaves in summer/autumn than spring, and no difference between cleared and forested wetlands. Temperature and leaf carbon : nitrogen ratio could not explain these differences, and instead, changes to leaf chemistry associated with &lsquo;terrestrial ageing&rsquo; between peak leaf fall in summer and inundation in spring is more likely. The results indicated that the reduction of input of organic matter through riparian tree clearing and changing the timing of inundation interact to alter organic-matter standing stocks and rates of decomposition in floodplain wetlands. Restoring both natural timing of high flows and riparian vegetation might be required for recovery of these wetlands.

Study of high-p(T) charged particle suppression in PbPb compared to pp collisions at root s(NN)=2.76 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for jet extinction in the inclusive jet-p(T) spectrum from proton-proton collisions at root s=8 TeV

The first search at the LHC for the extinction of QCD jet production is presented, using data collected with the CMS detector corresponding to an integrated luminosity of 10.7 fb-1 of proton-proton collisions at a center-of-mass energy of 8 TeV. The extinction model studied in this analysis is motivated by the search for signatures of strong gravity at the TeV scale (terascale gravity) and assumes the existence of string couplings in the strong-coupling limit. In this limit, the string model predicts the suppression of all high-transverse-momentum standard model processes, including jet production, beyond a certain energy scale. To test this prediction, the measured transverse-momentum spectrum is compared to the theoretical prediction of the standard model. No significant deficit of events is found at high transverse momentum. A 95% confidence level lower limit of 3.3 TeV is set on the extinction mass scale.

Evidence for collective multiparticle correlations in p-pb collisions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the W boson helicity in events with a single reconstructed top quark in p p collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)