323 research outputs found

    Four-way, full-throttling valve concept

    Get PDF
    Valve regulates the flow of a fluid over the limits from full flow in one direction to full flow in the opposite direction. At the midpoint valve position both flow paths are closed. Gradually increasing port size on both flow paths results in good throttling characteristics

    Mining the bitter melon (momordica charantia l.) seed transcriptome by 454 analysis of non-normalized and normalized cDNA populations for conjugated fatty acid metabolism-related genes

    Get PDF
    Abstract Background Seeds of Momordica charantia (bitter melon) produce high levels of eleostearic acid, an unusual conjugated fatty acid with industrial value. Deep sequencing of non-normalized and normalized cDNAs from developing bitter melon seeds was conducted to uncover key genes required for biotechnological transfer of conjugated fatty acid production to existing oilseed crops. It is expected that these studies will also provide basic information regarding the metabolism of other high-value novel fatty acids. Results Deep sequencing using 454 technology with non-normalized and normalized cDNA libraries prepared from bitter melon seeds at 18 DAP resulted in the identification of transcripts for the vast majority of known genes involved in fatty acid and triacylglycerol biosynthesis. The non-normalized library provided a transcriptome profile of the early stage in seed development that highlighted the abundance of transcripts for genes encoding seed storage proteins as well as for a number of genes for lipid metabolism-associated polypeptides, including Δ12 oleic acid desaturases and fatty acid conjugases, class 3 lipases, acyl-carrier protein, and acyl-CoA binding protein. Normalization of cDNA by use of a duplex-specific nuclease method not only increased the overall discovery of genes from developing bitter melon seeds, but also resulted in the identification of 345 contigs with homology to 189 known lipid genes in Arabidopsis. These included candidate genes for eleostearic acid metabolism such as diacylglycerol acyltransferase 1 and 2, and a phospholipid:diacylglycerol acyltransferase 1-related enzyme. Transcripts were also identified for a novel FAD2 gene encoding a functional Δ12 oleic acid desaturase with potential implications for eleostearic acid biosynthesis. Conclusions 454 deep sequencing, particularly with normalized cDNA populations, was an effective method for mining of genes associated with eleostearic acid metabolism in developing bitter melon seeds. The transcriptomic data presented provide a resource for the study of novel fatty acid metabolism and for the biotechnological production of conjugated fatty acids and possibly other novel fatty acids in established oilseed crops.</p

    Arkansas Cooperative Beef Bull Performance Test 1991

    Get PDF
    Performance testing of beef bulls was initiated to improve productivity of Arkansas beef cattle through breeding. This cooperative testing program provides cattlemen with reliable information for identifying animals with superior breeding value for the traits of production measured in the test. By using the information as a basis for herd sire selection, a breeder can greatly increase the chances of obtaining a bull that will sire rapid-gaining, more efficient, highquality calves. Such calves can increase profits for both the breeder and the feeder. This testing program provides information that is useful to financial institutes in arranging their lending programs and to companies in developing their educational, promotional and marketing programs

    Hypothermic retrograde venous perfusion with adenosine cools the spinal cord and reduces the risk of paraplegia after thoracic aortic clamping

    Get PDF
    AbstractObjective: We evaluated the utility of retrograde venous perfusion to cool the spinal cord and protect neurologic function during aortic clamping. We hypothesized that hypothermic adenosine would preserve the spinal cord during ischemia. Methods: Six swine (group I) underwent thoracic aortic occlusion for 30 minutes at normothermia. Group II animals underwent spinal cooling by retrograde perfusion of the paravertebral veins with hypothermic (4°C) saline solution during aortic occlusion. The spinal cords of group III animals were cooled with a hypothermic adenosine solution in a similar fashion. Intrathecal temperature was monitored and somatosensory evoked potentials assessed the functional status of spinal pathways. Results: Spinal cooling without systemic hypothermia significantly improved neurologic Tarlov scores in group III (4.8 ± 0.2) and group II (3.8 ± 0.4) when compared with group I scores (1.3 ± 0.6) (P < .001). Furthermore, 5 of the 6 animals in group III displayed completely normal neurologic function, whereas only one animal in group II and no animals in group I did (P = .005). Somatosensory evoked potentials were lost 10.6 ± 1.4 minutes after ischemia in group I. In contrast, spinal cooling caused rapid cessation of neural transmission with loss of somatosensory evoked potentials at 6.9 ± 1.2 minutes in group II and 7.0 ± 0.8 minutes in group III (P = .06). Somatosensory evoked potential amplitudes returned to 85% of baseline in group III and 90% of baseline in group II compared with only 10% of baseline in group I (P = .01). Conclusions: We conclude that retrograde cooling of the spinal cord is possible and protects against ischemic injury and that adenosine enhances this effect. The efficacy of this method may be at least partly attributed to a more rapid reduction in metabolic and electrical activity of the spinal cord during ischemia. (J Thorac Cardiovasc Surg 2000;119:588-95

    Highlights of recent progress in plant lipid research

    Get PDF
    Raw fossil material reserves are not inexhaustible and as prices continue to raise it is necessary to find new sources of alternative and renewable energy. Oils from oleaginous field crops (sunflower and rape) with properties close to those of fossil fuel could constitute an alternative source of energy for the production of raw materials. This is the context in which the 18th International Symposium on Plant lipids (ISPL) was held in Bordeaux from 20th to 25th July 2008 at “La Cité Mondiale”. The 18th ISPL gathered 270 researchers from 33 countries. Sixty nine oral communications and 136 posters were presented during the 12 sessions of the Symposium. The sessions have covered all the different aspects of the Plant Lipid field including: Surface lipids: suberin, cutin and waxes, Fatty acids, Glycerolipids, Plant lipids as renewable sources of energy, Seed oils and bioengineering of metabolic pathways, Lipid catabolism, Models for lipid studies: lower plants, micro-organisms and others, Modifications of proteins by lipids, Sphingolipids, sterols and isoprenoids, Lipid signaling and plant stress responses, Lipid trafficking and membrane dynamics, New methods and technologies: functional lipidomics, fluxome, modelling

    New Pleistocene cave faunas of the Andes of central Peru : radiocarbon ages and the survival of low latitude pleistocene DNA

    Get PDF
    Peruvian citizens have led our team to their discoveries of Pleistocene cave faunas in the central Andes of Per. These caves (Jatun Uchco, Departamento de Huanuco; Cueva Rosello, Departamento de Junin; and Trigo Jirka, Departamento de Huanuco) preserve numerous carnivorans (Puma, a sabercat [Smilodon populator], an unnamed large extinct felid, fox [Lycalopex sp.], hognose skunk [Conepatus sp.]), deer (cf. Pudu and cf. Hippocamelus), vicuna, an extinct horse (dagger Onohippidium devillei), a chinchillid rodent (cf. Lagidium), bats (Anoura, Desmodus, and Platalina), and sloths (dagger Megatherium, dagger Scelidodon, and, dagger Diabolotherium). Bats were found only in the lowest cave (Jatun Uchco, 2,150 m), and ungulates were found only at Cueva Rosello-the only cave studied in a region of flat terrain. Trigo Jirka preserved ancient feces of a large animal and the keratin claw of dagger Diabolotherium. Collagen for radiocarbon dating and DNA for phylogenetic studies have been isolated from bone from Cueva Rosello (3,875 m) and Trigo Jirka (2,700 m). Conventional radiometric ages from Cueva Rosello are 23,340 +/- 120 and 22,220 +/- 130 years before present and that of Trigo Jirka is 29,140 +/- 260. Ancient DNA (aDNA) from dagger Onohippidium of Cueva Rosello (12 degrees South latitude) and dagger Diabolotherium of Trigo Jirka (10 degrees South) is being used in phylogenetic studies. The successful recovery of aDNA suggests that the cool temperatures, low humidity, and the shield from UV radiation of caves at high elevation can permit aDNA studies at low latitudes. Previously, such studies have been limited to latitudes greater than 35 degrees for Pleistocene samples
    corecore