Tissue-Specific Distribution of Glutamine Synthetase in Potato Tubers

Cytosolic isoforms of the enzyme glutamine synthetase (GS) locatedin the phloem have been implicated in the mobilization of nitrogenfor intracellular transport in higher plants. The potato tuberrepresents an important reservoir of nitrogen and an approachwas made to the characterization of GS in this organ, particularlyat the stages of sprouting and of new tuber formation. By immunoblottingafter SDS-PAGE, and by immunological tissue printing, it waspossible to conclude that a cytosolic GS is present in tubersand sprouts, and that it is mainly expressed in the internalphloem, in a very precise tissue-specific pattern of distribution.These data provide additional clues to the interpretation ofthe functional role of GS in the mobilization of nitrogen andits utilization in growing parts of the plant. The importanceof morphological data and localization studies in complementingmolecular and biochemical work is emphasized. The proposed functionalimportance of the internal phloem inSolanum tuberosum organsis also reinforced. Solanum tuberosum L. cv. Desirée; potato; tubers; plant glutamine synthetase; tissue-specific distribution; phloem; nitrogen mobilization; in situlocalization; tissue printing     

Isolation and characterization of eight microsatellite loci in the icefish Chaenocephalus aceratus (Perciformes,Notothenioidei, Channichthyidae)

We characterized eight polymorphic microsatellites in the Scotia icefish Chaenocephalus aceratus (Perciformes, Notothenioidei, Channichthyidae) that is endemic of Southern Ocean waters surrounding the tip of the Antarctic Peninsula. Microsatellites were isolated from a partial genomic library enriched for an AC motif. The number of alleles ranged from two to 19 with a mean observed hererozygosity of 0.71. Loci were in Hardy–Weinberg equilibrium and no evidence for linkage disequilibrium was found. These molecular markers will be useful to investigate Scotia icefish genetic structure, possibly providing insights on its effective population size and demographic history.     

Implications of the mastoid anatomy of larger extant felids for the evolution and predatory behaviour of sabretoothed cats (Mammalia, Carnivora, Felidae)

Muscle attachments in the mastoid region of the skull of extant felids are studied through dissection of two adult tigers Panthera tigris (Linnaeus, 1758) Pocock, 1930, a lion Panthera leo (Linnaeus, 1758) Pocock, 1930 and a puma Puma concolor (Linnaeus, 1771) Jardine, 1834, providing for the first time an adequate reference for the study of the evolution of that region in sabretoothed felids. Our study supports the inference by W. Akersten that the main muscles inserting in the mastoid process in sabretooths were those originating in the atlas, rather than those from the posterior neck, sternum and forelimb. Those inferences were based on the anatomy of the giant panda, Ailuropoda melanoleuca (David, 1869) Milne-Edwards, 1870, raising uncertainties about homology, which were founded, as revealed by our results. The mastoid muscle insertions in extant felids differ in important details from those described for Ailuropoda , but agree with those described for domestic cats, hyenas and dogs. The large, antero-ventrally projected mastoid process of pantherines allows a moderate implication of the m. obliquus capitis anterior in head-flexion. This contradicts the widespread notion that the function of this muscle in carnivores is to extend the atlanto-cranial joint and to flex it laterally, but supports previous inferences about the head-flexing function of atlanto-mastoid muscles in machairodontines. Sabretooth mastoid morphology implies larger and longer-fibred atlanto-mastoid muscles than in pantherines, and that most of their fibres ran inferior to the axis of rotation of the atlanto-occipital joint, emphasizing head-flexing action.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 140 , 207–221.     

ESTIMATION OF MICROBIOLOGICAL QUALITY OF CHILLED BEEF USING AUTOMATED TURBIDIMETRY

Total bacterial counts on chilled beef samples were estimated by the standard plate count method and by an automated turbidimetric system. The latter method is based on product-specific calibration curves constructed by correlating growth curve parameters calculated for the turbidimeter to the log CFU values obtained by plate counts. A total of 74 beef samples was used to construct the calibration curves. Correlation analysis between turbidimetric parameters and plate count values showed that detection time was the best predictor to estimate microbial loads on fresh (r=0.91) and aged beef (r=0.94). Microbial loads for a different set of aged beef samples (n = 37) refrigerated for 7, 9, 10, 17 and 45 days were compared by turbidimetric measurements and plate counts. Mean total viable counts were log 5.92 ± 1.17 and log 5.54 ± 1.28 CFU/mL, respectively. Results showed that total bacterial counts on chilled beef could be estimated accurately from turbidimetric parameters. Furthermore, setting a cut-off value of log 6 CFU/mL allowed to accepting/rejecting samples according to their microbial condition in shorter periods of time compared to the traditional plate count method.     

High water roost selection by waders: maximizing feeding opportunities or avoiding predation?

During the highest spring tides the intertidal sediment flats of estuaries are fully inundated at high water, and waders have no choice but to move to supratidal roosts, e.g. on open farmland, saltpans or beaches. However, in many estuaries during the lowest neap or intermediate tides there are sectors of upper intertidal sediment flats that remain exposed even at the peak of high water, and so waders have the choice of roosting either there or in supratidal sites. In the Tagus Estuary, Portugal, as elsewhere, waders use both types of roosts during high water. Our main objective was to understand what makes waders opt for one of these two types of available roosts. We monitored wader use of saltpans and intertidal roosts from spring to neap tides, and measured foraging and alarm behaviour, prey availability and disturbance by predators. Most of the wader species studied chose intertidal (mudflat) roosts whenever these were available, and only roosted in saltpans during the peak of spring tides. We hypothesized that this preference was explained either by an attempt (i) to continue feeding into the high water period, or (ii) to minimize predation risk. Extending feeding time into the high water period did not seem to be very relevant for roost choice because both prey availability and foraging activity were low in both types of roosts. However, predator disturbance was several times higher in the saltpans than in the intertidal roosts, suggesting that this factor may be the determinant in the choice of roost type.     

Eating With Your Favourite Mother: Time And Sociality In A Brazilian Amerindian Community

This article is based on an ethnographic account of parent-child relations in a Caboclo-Indian community of south Bahia, Brazil. Raising a child by providing care and food is valued to such an extent that a child's mother may be the woman the child has chosen to be its mother. Choice is not understood as an act of free will, but as a time-frame in the sense that choosing one's mother is a way of emphasizing the possibility of the unmaking or reversibility of parent-child links. The article suggests a 'sociality of becoming a being-in-the-world' as an alternative not only to the notion of socialization but also to the theoretical link between kinship and society.

The Kid has changed the world and myself. Not in the beginning But bit by bit, As I became attached to him Andrei Tarkovskij, The sacrifice