Academic literature on the topic 'Lamb survival'
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Journal articles on the topic "Lamb survival"
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Brien, F. D., M. L. Hebart, D. H. Smith, J. E. Hocking Edwards, J. C. Greeff, K. W. Hart, G. Refshauge, et al. "Opportunities for genetic improvement of lamb survival." Animal Production Science 50, no. 12 (2010): 1017. http://dx.doi.org/10.1071/an10121.
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Data on lamb survival and associated traits involving records from 15 192 lambs, 6308 dams and 284 sires from the Sheep CRC’s Information Nucleus were studied. Lamb survival to 3 days of age and to weaning was 85 and 80%, respectively, and heritability (±s.e.) was 0.014 ± 0.010 and 0.010 ± 0.010, respectively. Of the 14 traits recorded at birth, time taken for the lamb to bleat, rectal temperature and crown–rump length had the highest genetic correlations with lamb survival to weaning (–0.43 ± 0.32, 0.56 ± 0.33 and –0.38 ± 0.36, respectively). Under selection for a multi-trait objective including net reproduction rate (but not lamb survival), survival was predicted to decline genetically by 0.25 lambs weaned per 100 lambs born.year, although this was reversed to a gain of 0.20 lambs weaned per 100 lambs born.year by including the trait in the breeding objective and using 50 half-sib and 50 progeny records per selection candidate. Accuracy of selection for lamb survival was improved to 0.735 with a selection index of lamb survival to weaning, lamb ease, birth coat score, time taken to bleat, rectal temperature and crown–rump length, with the addition of 50 half-sibs and 50 progeny records per candidate. Our results suggest that unless actively incorporated into breeding objectives, lamb survival may genetically decline; however, gains are possible with direct selection using half-sib and progeny records. The addition of indirect selection criteria for lamb survival can further improve accuracy, up to 93.4%, but requires further investigation.
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Morel, P. C. H., S. T. Morris, and P. R. Kenyon. "Effect of birthweight on survival in triplet-born lambs." Australian Journal of Experimental Agriculture 48, no. 7 (2008): 984. http://dx.doi.org/10.1071/ea07401.
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Lambing percentage is the main contributor to higher profit on New Zealand sheep farms and has increased from 98% in 1960 to 124% in 2006. As ewe litter size increases so does the proportion of triplet-born lambs and consequently preweaning mortality rate. The purpose of this study was to investigate the effect of birthweight (BWT) on survival in triplet-born lambs within and among litters. Data from a total of 594 triplet crossbreed lambs born to mixed-age ewes was analysed. For the statistical analysis, the lambs were allocated according to their BWT, and within the litter were then allocated to three BWT groups (light, medium and heavy). The following parameters were calculated: total litter BWT (TBWT), percentage of TBWT for each lamb (PBWT = BWT/TBWT), coefficient of variation for BWT within litter and lamb average daily gain from birth to weaning. The mortality rate for the light, medium and heavy lambs was 56, 40 and 28%, respectively, and consequently the lightest lamb in a litter was 3.2 times more likely to die than the heaviest lamb. In the light lamb group, as BWT increased mortality decreased (P = 0.006), for medium lambs BWT did not influence mortality (P = 0.88) and in the heavy group there was a trend of increased BWT associated with increased mortality (P = 0.10). The negative relationship between lamb mortality and PBWT was identical in the three BWT groups (P < 0.0001). The effect of BWT on lamb mortality became non-significant when PBWT was fitted in the same model. This means that, in triplet-born lambs, mortality is not influenced by the BWT of the lamb itself, but by the BWT of its littermates. It can be calculated that a 4-kg lamb has a 24% chance of surviving in a litter of 16 kg, a 60% chance in a litter of 12 kg and an 87% chance of surviving in a litter of 8 kg. It is concluded that reducing the variation in BWT within a litter, or specifically managing the lightest lamb at birth, will increase the competitive ability for survival of each lamb and, therefore, decrease overall mortality and further improve farm profitability.
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Parkes, K. "Improving lamb survival." Animal Welfare 14, no. 2 (May 2005): 166. http://dx.doi.org/10.1017/s0962728600029250.
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Lockwood, A., J. Trompf, L. Kubeil, A. Thompson, G. Refshauge, G. Kearney, and S. Hancock. "Decreasing the mob size but not stocking rate of ewes at lambing increases the survival of twin lambs born on farms across southern Australia." Animal Production Science 60, no. 16 (2020): 1949. http://dx.doi.org/10.1071/an19632.
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Context Data collected from producers in south-eastern Australia found that the survival of twin-born lambs decreased by 3.5% for each extra 100 ewes in the mob at lambing. Increasing stocking rate by 1 ewe/ha decreased lamb survival by a further 0.7%. These survey findings suggest that lamb survival could be improved by optimising the allocation of ewes to mobs and paddocks at lambing. Aim The present paper reports two experiments. Experiment 1 tested the hypotheses that (1) the survival of twin-born lambs would be greater when ewes lamb in smaller mobs and at lower stocking rates, and (2) the effects of mob size and stocking rate would be greater in Merinos than in non-Merino breeds. Experiment 2 tested the hypothesis that the survival of twin-born Merino lambs would be greater at lower mob sizes when ewes lambed at stocking rates <4 ewes/ha. Methods Experiment 1 investigated a 2 × 2 factorial combination of mob size (high or low) and stocking rate (high or low) on the survival of twin-born Merino and non-Merino lambs at 70 on-farm research sites across southern Australia. Experiment 2 investigated the effect of high or low mob size on the survival of twin-born Merino lambs when ewes lambed at stocking rates of <4 twin ewes/ha at 15 on-farm research sites. In both experiments, adult twin-bearing ewes were randomly allocated into a treatment and lambing paddock on Day 140 from the start of joining at each farm. Lamb survival in each mob was calculated based on lamb losses between pregnancy scanning and lamb marking. Key results In both experiments, the effect of mob size on lamb survival was found to be linear, with survival of twin-born lambs decreasing by between 1.9% and 2.5% per additional 100 ewes in the mob at lambing, regardless of breed (P < 0.001). In Experiment 1, there was no effect of stocking rate or mob size by stocking rate on lamb survival. Conclusions The present research demonstrated that reducing mob size but not stocking rate will improve the survival of twin-born lambs to marking for extensive enterprises in Australia where ewes lamb at stocking rates of up to 12 ewes/ha. Implications These findings will contribute to guidelines for optimising ewe nutrition and resource allocation to improve lamb survival.
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Johns, C., J. Johns, and D. R. Stevens. "Increasing lamb survival and lamb weaning weight through feeding high fecundity crossbred sheep." NZGA: Research and Practice Series 16 (January 1, 2016): 323–28. http://dx.doi.org/10.33584/rps.16.2016.3244.
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The monitoring of a high fecundity ewe flock in the Te Anau basin demonstrates the process of improved feeding to improve lamb survival and growth to weaning. Feed budgeting was changed from traditional to tailored feed requirements based on measured ewe liveweight with wastage of 15% factored in. Feed allocation was changed from monthly to weekly increases during late pregnancy, and set stocking was delayed until the planned start of lambing. This increased late pregnancy feed allocation from 99 kg DM/ewe to 128 and 144 kg DM/ewe for twin and triplet bearing ewes, respectively. Ewe body condition score was maintained at between 3 and 3.5, with condition score loss between scanning and lambing being reduced to zero. Lamb survival and lamb liveweight gain to weaning increased in both twin and triplet bearing ewes. Pregnancy scanning increased from 200 to 222 lambs per 100 ewes, between 2007 and 2012, while lambing percentage (lambs weaned/ ewe mated) rose from 132% to 165%, with more ewes rearing lambs and rearing multiples. Lamb wastage declined from 37% in 2007 and 2008, to 25% in 2011 and 2012, though scanning percentage rose by 20%. Lamb weights increased from 27.5 to 36 kg/lamb at 100 days of age. The increase in the liveweight of lambs and ewes at weaning reduced the calculated feed requirements over summer and autumn, potentially releasing 70 to 110 kg DM/ewe to provide feed to meet the extra winter feed requirements. Keywords: ewe body condition score, feed allocation, lamb survival, lamb weaning weight
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Fogarty, NM, and DG Hall. "Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 3. Reproduction, liveweight and wool production of adult ewes." Australian Journal of Experimental Agriculture 35, no. 8 (1995): 1083. http://dx.doi.org/10.1071/ea9951083.
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Reproduction, liveweight and wool production are reported for 4 cohorts of 377 Trangie Fertility x Dorset (TD) and 261 Booroola x Dorset (BD) ewes over 6 years. The BD ewes were 3-4 kg lighter (P<0.001) and had a higher ovulation rate prior to joining in February-March (2.37 � 0.03 v. 1.65 � 0.03) than TD ewes. This resulted in a higher litter size (2.07 � 0.03 v. 1.66 � 0.04) and number of lambs born per ewe joined (1.92 � 0.04 v. 1.56 � 0.04) for the BD ewes. Lamb survival was lower from BD than TD ewes (0.71 � 0.02 v. 0.85 � 0.02), so that the 2 ewe strains weaned the same number of lambs. The growth rate of lambs was lower from the BD ewes and overall they weaned 3.8 kg less (P<0.001) weight of lamb than TD ewes. Chill (index of environmental conditions at lambing), litter size and average birth weight of lambs in the litter (linear and quadratic) affected (P<0.001) lamb survival. At moderate levels of chill there was little difference in survival of single and twin lambs from BD and TD dams when birth weight was 4-5 kg, but survival declined more rapidly for progeny of BD ewes at lower birth weight. Under severe lambing conditions survival was depressed more for lambs born from BD ewes than TD ewes. Almost all ewes expressed oestrus over the 3, 6-week periods, December-January, January-February and March (joining). There was significant variation (P<0.001) in incidence of oestrus due to year and age (linear and non-linear), but not liveweight at joining, and there was little difference between ewe strains. Similarly, for post-lambing oestrus (to fit 8-monthly joining) and post-lambing anoestrous interval, there was little difference between strains, but year and age were highly significant (P<0.001). BD ewes had a lower (P<0.001) greasy fleece weight (3.76 v. 3.86 kg), than TD ewes. BD ewes were classified as either carriers (F+) or non-carriers (++) of the FecB gene, which was significant (P<0.001) for ovulation rate (+1.14 ovulations), litter size (+0.8 lambs), lamb survival (-18%), lambs born per ewe joined (+0.64 lambs) and total weight of lamb born per ewe joined (0.5 kg, P<0.01). The effect of the FecB gene was non-significant for lamb survival when litter size and lamb birth weight (P<0.001) were included in the model. Repeatability estimates based on over 3 records per ewe were about 0.2 for lambs born, weight of lamb born, lambs weaned and weight of lamb weaned per ewe joined. Component traits ranged from 0.27 for litter size to 0.10 for lamb survival, with fertility intermediate (0.15). Greasy fleece weight (0.72) and ovulation rate (0.41) had high repeatabilities with post-lambing anoestrous interval being low (0.11). Repeatability for ovulation rate was reduced to 0.34 when F+ ewes were excluded.
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Jordan, DJ, and DG Mayer. "Effects of udder damage and nutritional plane on milk yield, lamb survival and lamb growth of Merinos." Australian Journal of Experimental Agriculture 29, no. 3 (1989): 315. http://dx.doi.org/10.1071/ea9890315.
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A pen study investigated the effects of udder damage and 3 levels of nutrition (110, 90 and 70% of maintenance requirements) during the pre- and post-natal period on the performance of Merino ewes and lambs. Udder damage (only 1 functional teat) significantly reduced (P< 0.05) estimated daily milk yield of ewes (1 139 v. 963 mL/day), growth rate (180.5 v. 143.7 g/ day) and liveweight of lambs (10.1 v. 8.8 kg) at 4-6 weeks of age. Lamb survival was significantly reduced only in the 70% of maintenance treatment (82.2 v. 64.8%). Nutrition level significantly (P< 0.05) affected ewe and lamb performance. Estimated daily ewe milk yield (1146, 1070 and 938 mL/day), ewe liveweight (40.4, 39.2 and 37.1 kg) at lamb marking, and lamb growth rate (178.1, 169.5 and 138.8 g/day) and liveweight (10.2, 9.6 and 8.6 kg) at 4-6 weeks were significantly higher for ewes fed on 110 and 90% of their requirements than for ewes fed at 70% of their requirements respectively. Lamb survival (89.9%) from ewes fed at 110% of requirements was significantly higher than lamb survival (75.3 and 73.5%) from ewes fed at 90 and 70% of requirements respectively. There was no significant interaction between the level of nutrition and udder damage in any parameter of ewe or lamb performance. Birth weight (3.0 v. 3.8 kg) and survival (49.3 v. 84.2%) were significantly (P<0.01) lower in twins than in single birth lambs. Growth rate of single lambs and single survivors of twins reared as single lambs were similar (167 and 160 g/day respectively); both of these groups grew more rapidly (P< 0.01) than lambs reared as twins (91 g/day). Lamb growth rate was positively correlated with ewe milk yield (r=0.75; P<0.01), ewe weight (r = 0.37; P< 0.01) and lamb birth weight (r = 0.24; P< 0.05). Lamb birth weight and ewe milk yield were also significantly and positively correlated with ewe weight. Male lambs were significantly heavier at birth and grew significantly faster than female lambs.
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O'Connor, C. E., and A. B. Lawrence. "Relationship between lamb vigour and ewe behaviour at parturition." Animal Science 54, no. 3 (June 1992): 361–66. http://dx.doi.org/10.1017/s000335610002081x.
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AbstractMaternal behaviour and lamb vigour are both considered major variables affecting lamb survival, but there are few data to describe their relative importance. To investigate the relationship between lamb vigour and maternal behaviour this study compared the behaviour of pure Scottish Blackface lambs with Mule (Bluefaced Leicester ♀. × Scottish Blackface ♂) lambs, all born indoors. Anecdotal accounts suggested a significant reduction in lamb vigour in Mule lambs, a matter also of significant practical importance given the current incease in Mule numbers. Observations on the grooming behaviour of 32 single or twin-bearing ewes, and on the general activity and udder-seeking behaviour of their lambs were made at parturition. In this study, neither ewe grooming behaviour nor general lamb activity were directly related to lamb sucking success. It was shown that, although Mule lambs had high birth weights and stood as quickly as Blackface lambs, they showed significantly fewer sucking attempts (P < 0·01) and took longer to suck successfully (28 min for Blackface v. 55 min for Mules). The inability of Mule lambs to suck successfully was due to their failure to show proper udder-directed behaviour. These results indicate the importance of considering the behaviour of both ewes and lambs as it would seem that it is not ‘poor’ maternal behaviour but inappropriate lamb behaviour that is a limiting factor in lamb survival in the Mule breed.
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GOWANE, G. R., C. P. SWARNKAR, H. K. NARULA, and A. CHOPRA. "Better odds of lamb survival in sheep at dry arid tropical region of India." Indian Journal of Animal Sciences 90, no. 4 (September 1, 2020): 628–35. http://dx.doi.org/10.56093/ijans.v90i4.104222.
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Lamb survival till first 28 days of life is critical as it increases the chances of economic gain in flock. Objective of the current study was to assess the incidence of neonatal mortality in lambs born in arid region of India and genetic and non-genetic factors affecting it. The present study was conducted using the data on 4,137 Magra and 4,595 Marwari sheep over 17 years (1999 to 2016). Incidence of neonatal mortality was very low in Magra (1.04%) and Marwari (2.48%) sheep, respectively in semi-intensive management system. Year and seasonal variation was observed for neonatal losses. Males had lower odds of survival as compared to females. Odds of survival were low if the lambs were born to dams of low body weight and in their first parity. It was observed that the lamb survival can be improved if due care of the lambs born with low birth weight (<2 kg) is taken. The heritability estimate was moderate in Magra sheep (0.17), indicating further scope for genetic improvement for lamb survival through selection. However, for Marwari sheep, the total heritability was 0.02, thus limiting the scope for selection. Arid region favoured the lamb survival. Hardiness of the Magra and Marwari sheep, their high lamb survival along with standard production potential is indicative of the good genetics of these sheep along with better management practices adopted at arid regional campus, thus reflecting better sheep welfare practices.
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Hall, DG, NM Fogarty, and AR Gilmour. "Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 1. Lamb birth weight, survival and growth." Australian Journal of Experimental Agriculture 35, no. 8 (1995): 1069. http://dx.doi.org/10.1071/ea9951069.
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Merino rams of the Trangie Fertility and Booroola strains were joined to Poll Dorset ewes in single sire mating groups over 3 years. Forty sires produced a total of 1250 lambs in 885 litters from 451 ewes. Lamb birth weight averaged 4.1 kg, 80.8% of lambs survived to 3 days of age and growth rates to weaning (mean 93 days) averaged 289 g/day. Lambs with Trangie Fertility sires grew 15 g/day faster and were 1.3 kg heavier at weaning than those lambs with Booroola sires (P<0.001). There were no effects of sire strain on birth weight or lamb survival. Birth weight increased with dam liveweight in mid-pregnancy (P<0.001), and weaning weight and growth rate increased with dam liveweight at joining (P<0.001). Survival of lambs was predominantly a function of birth weight. Lambs weighing 4 kg at birth from primiparous dams had survival rates of 76% compared with 88% for lambs from multiparous dams (P<0.01). No lamb under 2.0 or over 6.3 kg survived, and 48% of deaths occurred within 1 day of birth. Dystocia, particularly of heavy, single-born lambs, caused 53% of observed lamb deaths. For the traits birth weight, lamb survival, weaning weight and growth rate, the direct heritabilities were 0.24 � 0.10, 0.05 � 0.05, 0.19 � 0.10 and 0.12 � 0.08 respectively; the corresponding maternal heritabilities were 0.08 � 0.05, 0.05 � 0.04, 0.05 � 0.05 and 0.07 � 0.05 respectively; and the common environmental effects among litter mates (c2) were 0.57 � 0.08, 0.47 � 0.08, 0.15 � 0.08 and 0.13 � 0.08 respectively.
Dissertations / Theses on the topic "Lamb survival"
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Annett, R. W. "Studies on the effects of the nutrition of ewes during pregnancy on neonatal lamb survival and lamb output at weaning." Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411764.
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Kleemann, D. O. "A study of factors affecting embryonic, fetal and lamb survival in high fecundity merino ewes." Title page, table of contents and abstract only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09phk638.pdf.
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Bibliography : leaves 120-133. Defines the sources of reproductive wastage in FecB FecÊ Booroola Merino x South Australian Merino ewes and examines factors associated with the survival of embryos, fetuses and lambs with the aim of improving net reproduction efficiency. Experiments were conducted to define the problem; to examine factors affecting embryonic and fetal loss; and, to investigate factors influencing wastage at lambing.
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Pattinson, Sandra Elizabeth. "Factors affecting the quantity and quality of colostrum produced by ewes and the subsequent effect on lamb survival and growth." Thesis, University of Liverpool, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.481708.
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Awgichew, Kassahun. "Comparative performance evaluation of Horro and Menz sheep of Ethiopia under grazing and intensive feeding conditions." Doctoral thesis, [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=961806729.
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Lockwood, Amy. "Survival of twin-born lambs on commercial farms can be improved by reducing mob size at lambing." Thesis, Lockwood, Amy (2018) Survival of twin-born lambs on commercial farms can be improved by reducing mob size at lambing. PhD thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/41603/.
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At least 20% of lambs born will die in the first 3 days of life under extensive grazing conditions in southern Australia. Limited research has suggested that increasing the mob size or stocking rate of ewes at lambing may increase the risk of ewe-lamb separations and lamb mortality. Higher lambing densities are likely to exacerbate the attraction of foreign periparturient ewes to amniotic fluids and newborn lambs which may result in greater interference at lambing. This thesis aimed to quantify the impacts of mob size and stocking rate on the survival of lambs born on commercial farms. Furthermore, it aimed to determine whether poorer survival of lambs born at higher mob sizes was associated with greater interaction with foreign ewes and lambs at lambing. Survey data collected from 66 farms in south-eastern Australia indicated the survival of single- and twin-born lambs decreased by 1.4% and 3.5% per additional 100 ewes in the mob at lambing. Furthermore, it suggested that increasing stocking rate by 1 ewe/ha would reduce lamb survival by 0.7%, regardless of breed and birth type. Similar survey data collected from producers in New Zealand found the survival of Merino lambs decreased by 1.3% per additional 100 ewes in the mob at lambing, however there was no effect of stocking rate on lamb survival. Data collected from 60 on-farm research sites across southern Australia confirmed that higher mob sizes result in poorer lamb survival. In this study, the survival of twin-born lambs decreased by 2% per additional 100 ewes in the mob at lambing. However, stocking rate was not found to influence lamb survival suggesting that the number of ewes in the mob regardless of paddock size has a greater influence on lambing density. Detailed experimentation also suggests that the relationship between mob size and lamb survival may be influenced by feed-on-offer (FOO) at lambing. In one experiment, a higher mob size decreased the survival of twin-born lambs when FOO was below 400 kg DM/ha at lambing and ewes were being supplementary fed. However, another experiment found the survival of single- and twin-born lambs was not influenced by mob size when FOO exceeded 2700 kg DM/ha at lambing. Mob size was not observed to influence interaction with foreign ewes or lambs at the time of lambing. However, less than 20% of ewes were observed at lambing and these observations were restricted to within approximately one hour of birth. Therefore, the reasons for poorer lamb survival at higher mob sizes remain unclear. Nevertheless, this research demonstrates that reducing mob size at lambing by 100 ewes will increase the survival of twin-born lambs of Merino and non-Merino breed by at least 2%. Integrating guidelines for producers related to mob size at lambing with existing ewe condition score targets will therefore aid in improving lamb survival on commercial farms.
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Lo, Presti Caroline. "Reprogrammation métabolique dans les leucémies aigues myéloblastiques (LAM) : Impact clinique et mécanismes oncogéniques De novo adult acute myeloid leukemia patients display at diagnosis functional deregulation of redox balance correlated with molecular subtypes and overall survival." Thesis, Université Grenoble Alpes, 2020. http://www.theses.fr/2020GRALV017.
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Le métabolisme des cellules cancéreuses est fortement perturbé et dérégulé dans les cancers. Plusieurs exemples illustrent ce phénomène, notamment la reprogrammation métabolique décrite dans l’effet Warburg, les dérégulations fonctionnelles de certaines voies métaboliques telles que l’augmentation de la production de ROS dans les cellules cancéreuses, ou la mise en évidence d’oncométabolites liés à des mutations acquises telles que les mutations IDH1/2 qui entraînent la production d’un métabolite directement associé au processus leucémique dans les LAM. Afin de caractériser les reprogrammations métaboliques associées au processus leucémique, nous avons analysé par une approche HRMAS les métabolites produits par différentes lignées cellulaires leucémiques représentant différents sous types de LAM (génotype et phénotype différents). Dans ce modèle, nous avons montré que chaque type de lignée présentait un métabolisme particulier à l’état basal, témoin d’une signature métabolique différente selon la nature de la lignée. En situation de stress métabolique (culture en milieu sans sérum), toutes ces lignées développent des mécanismes d’adaptation de leur métabolisme à la carence en nutriments. En particulier, il existe une signature commune caractérisée par la surexpression de métabolites de la voie des phospholipides et de régulation du stress oxydant au bout de 24h de culture en milieu sans sérum. Grâce à ces mécanismes d’adaptation les cellules leucémiques retrouvent au bout de 48h, une viabilité supérieure à 95% et un profil métabolique quasi-identique aux conditions normales. Ces résultats montrent que les cellules leucémiques développent des mécanismes communs de survie, impliquant notamment des dérégulations du métabolisme des lipides, qui leur permettent de continuer à proliférer en situation de stress métabolique. D’autres conditions expérimentales ont été testées, notamment en condition de carence en glucose afin d’explorer la piste de la dérégulation de certains acides aminés comme l’alanine dans ces lignées. De plus, l’étude quantitative et qualitative des acides gras dans les LAM via une approche lipidomique révèle une adaptation similaire des profils lipidomiques des lignées dans les mêmes conditions de privation en sérum précédemment testées. En parallèle, dans une étude sur 54 patients au diagnostic de LAM, nous avons confirmé par l’approche HRMAS qu’il existait chez les patients LAM des différences de profil métabolique en fonction du sous-type de LAM. Nous avons également montré que ces signatures métaboliques étaient significativement corrélées aux sous-groupes pronostiques cytogénétiques, à la réponse au traitement par chimiothérapie et à la survie des patients. Nous montrons notamment que les métabolites surexprimés chez les patients de mauvais pronostic sont retrouvés surexprimés également chez les patients réfractaires au traitement. L’analyse de ces métabolites montrent le rôle particulier de plusieurs voies métaboliques dans le pronostic des LAM : i) la dérégulation de la synthèse de 2-hydroxyglutarate associée aux mutations de l’enzyme IDH1/2, ii) la dérégulation du métabolisme des phospholipides, retrouvant une surexpression de phospholipides dans les plasmas de patients de pronostic défavorable, et iii) la surexpression de la synthèse de certains acides aminés chez les patients chimiorésistants, suggérant une implication de la voie de signalisation LKB1/AMPKCells metabolism is strongly disturbed and deregulated in cancers. Several examples reflect this phenomenon, including metabolic reprogramming described in the Warburg effect, functional deregulations of particular metabolic pathways such as the increase of the ROS production in cancer cells, or the identification of oncometabolites linked to acquired mutations such as IDH1/2 mutations, which lead to the production of a metabolite directly linked to the leukemic process in AML. In order to characterize the metabolic reprogramming associated with the leukemic process, we analyzed by an HRMAS approach the metabolites produced by different leukemic cell lines representing different subtypes of AML (different genotype and phenotype). In this model, we have shown that each type of cell line exhibited a particular metabolism in the basal state, witnessing a different metabolic signature depending on the nature of the cell line. In condition of metabolic stress (culture in a serum-free environment), all these cell lines develop mechanisms to adapt their metabolism to nutrient deficiency. Particularly, there is a common signature characterized by the overexpression of metabolites of the phospholipid pathway and of regulation of oxidative stress after 24 hours of culture in a medium without serum. Thanks to these adaptation mechanisms, the leukemic cells find after 48 hours a viability higher than 95% and a metabolic profile almost identical to normal conditions. These results show that leukemic cells develop common survival mechanisms, notably involving deregulations of lipid metabolism, which allow them to continue to proliferate in condition of metabolic stress. Other experimental conditions have been tested, in particular in glucose deficiency conditions in order to explore the path of deregulation of some amino acids such as alanine in these cell lines. Moreover, the quantitative and qualitative study of fatty acids in AMLs through a lipidomic approach reveals a similar adaptation of the lipidomic profiles of the cell lines in the same serum-free conditions previously tested. In parallel, in a study on 54 patients diagnosed with AML, we confirmed by the HRMAS approach that there were differences in metabolic profile in AML patients according to the AML subtype. We also showed that these metabolic signatures were significantly correlated with cytogenetic prognostic subgroups, response to chemotherapy treatment and patient survival. We show in particular that the metabolites overexpressed in patients with poor prognosis are found overexpressed also in patients refractory to treatment. The analysis of these metabolites shows the particular role of several metabolic pathways in the prognosis of AML: i) deregulation of the synthesis of 2-hydroxyglutarate associated with mutations in the IDH1/2 enzyme, ii) deregulation of the metabolism of phospholipids, showing an overexpression of phospholipids in adverse prognosis patients plasmas, and iii) overexpression of the synthesis of some amino acids in chemoresistant patients, suggesting an involvement of the LKB1/AMPK signaling pathway
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Plush, Kate Joanna. "Metabolic maturity and vigour in neonatal lambs, and subsequent impacts on thermoregulation and survival." Thesis, 2014. http://hdl.handle.net/2440/96730.
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Lamb mortality in Australia averages approximately 20%, representing a major constraint to the profitability of sheep enterprises and compromised animal welfare. Most postpartum lamb loss occurs within the first three days of life and is largely caused by starvation, exposure to cold conditions and mismothering from the ewe. In this thesis we developed an over-arching hypothesis that differences in metabolic or physiological maturity exist between lambs, and that these differences relate to early postnatal vigour and survival, particularly during exposure to cold conditions. To test this hypothesis, behaviour associated with initial vigour was quantified in breeds of sheep which differ widely in neonatal survival and more specifically, risk of hypothermia. Pre-suckling blood samples were collected from these animals in order to identify potential markers of maturity chosen to represent the hypothalamic- pituitary- adrenal (HPA) axis, renal function and energy metabolism. A number of metabolite and endocrine shifts were identified in those that were quicker to reach the udder of the ewe and begin sucking. Namely, creatine, non-esterified fatty acids, leptin and ghrelin concentrations were elevated, implying these individuals may be better able to regulate energy mobilisation soon after birth. Lamb vigour was also strongly associated with rectal temperature at birth, indicating an association between maturity, post-natal behaviour and thermogenesis. A controlled water bath testing system was then used to experimentally induce mild hypothermia in the lambs, and metrics of thermoregulation included time taken for core body temperature to reach 35°C (cold resistance), and time to restore core temperature to 39°C (cold recovery). Lambs that were slow to stand and reach the udder had impaired cold resistance. None of the physiological measures (circulating metabolite and hormone concentrations at birth) were related to performance in the water bath. Somewhat surprisingly, those lambs identified as being more mature, as assessed by speed to perform peri-natal behaviours and physiological blood measures, experienced a delay in cold recovery when compared to those with lower vigour and maturity. We proposed that this may be due to a reduced ability to perform non-shivering thermogenesis in more mature individuals (as is observed to occur with age), but this need further exploration. Given these strong relationships between maturity, peri-natal vigour and thermogenesis, an attempt to alter the metabolic maturity of newborn lambs was made. Peri-conception nutrition was shown previously to influence fetal HPA axis activation (responsible for the maturation of a suite of fetal systems) hence differing nutritional treatments (0.7, 1.0 and 1.5 maintenance energy requirement) were applied to the ewes at this time. No effect of peri-conception nutritional manipulation on lamb survival was observed, but lambs from ewes fed a restricted diet around conception exhibited a decreased crown-rump length when compared to those from the high energy treatment. Whilst this had no effect on survival, under more inclement conditions this finding may increase risk of hypothermia through effects on surface area dependent heat loss. In summary, the findings presented in this thesis provide strong evidence that the metabolic maturity of lambs at birth is related to initial vigour and thermoregulatory ability, two traits that are closely linked with survivability. The attempt to reduce lamb mortality through altering HPA axis activation by nutritional means had limited effects on lamb phenotype. Consequently, peri-conception nutrition failed to influence lamb survival. Future investigations should target other means by which metabolic maturity at birth can be enhanced in order to improve lamb survival.Thesis (Ph.D.) -- University of Adelaide, School of Animal and Veterinary Sciences, 2014
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Kleemann, David Oswald. "A study of factors affecting embryonic, fetal and lamb survival in high fecundity merino ewes." Thesis, 1994. http://hdl.handle.net/2440/80346.
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Defines the sources of reproductive wastage in FecB Fec⁺ Booroola Merino x South Australian Merino ewes and examines factors associated with the survival of embryos, fetuses and lambs with the aim of improving net reproduction efficiency. Experiments were conducted to define the problem; to examine factors affecting embryonic and fetal loss; and, to investigate factors influencing wastage at lambing.Thesis (Ph.D.) -- Dept. of Obstetrics and Gynaecology; Dept. of Animal Sciences, 1994
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Kerslake, Joanne Isabel. "Improving triplet lamb survival in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Palmerston North, New Zealand." 2010. http://hdl.handle.net/10179/1530.
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This thesis sets out to identify physical and physiological differences between lambs of different birth ranks at birth, and to use this information to identify practical on-farm management strategies which could improve triplet-born lamb survival. Triplet-born lambs, especially the lightest-triplet-born lambs, not only had a greater capacity to lose heat but also had a reduced capacity to produce heat when compared to twin-born lambs. Due to their lighter birth weights, triplet-born lambs had lower plasma thyroxine (T4) concentrations within the first 24 hours of life than twin-born lambs, and within twin- and triplet-born litters, the lightest- and medium-triplet-born lambs had greater plasma lactate concentrations than all twin-born lambs and the heaviest-triplet-born lambs. Independent of lamb birth weight, triplet-born lambs had lower plasma tri-iodothyronine (T3) concentrations within five minutes of birth, and within twin- and triplet-born litters, the lightest- and medium-triplet-born lambs had lower plasma T4 and T3 concentrations within five minutes of birth than all twin-born lambs and the heaviest-triplet-born lambs. It was hypothesised that because triplet-born lambs had a lighter birth weight and lower plasma thyroid hormone concentrations, they would have inadequate thermoregulatory capabilities when compared to twin-born lambs. The lower rectal temperatures of triplet-born lambs within the first hour of life and the lower heat production on a per lamb basis at 24 to 36 hours of age, and the lack of difference in maximum heat production on a per kg of birth weight basis at 24 to 36 hours of age support this hypothesis. Two practical on-farm management strategies trialled in this thesis to improve triplet-born lamb thermoregulation were offering concentrate supplement during late pregnancy to improve lamb birth weights, and maternal iodine supplementation to improve lamb plasma thyroid hormone concentrations. While offering concentrate showed positive effects such as increasing lamb birth weights, colostrum uptake and triplet-born lamb heat production on a per kg of birth weight basis, the results were either inconsistent across experiments or between birth ranks suggesting additional work is required to determine the repeatability and cost effectiveness of these findings. Maternal iodine supplementation offered no iv | P a g e benefits in terms of lamb birth weights, plasma thyroid hormone concentrations or lamb heat production. Further investigations identified that lamb birth weights, thyroid hormone concentrations, glucose and NEFA concentrations are positively associated with maximum heat production at 24 to 36 hours of age. Practical on-farm management strategies which could target these physical and physiological factors may improve triplet-born lamb heat production, and therefore the survival rates of triplet-born lambs.
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林燕如. "Effect of sucrose pretreatment on the survival rate of Tai-nung 31, Tai-nung New 31, and Tai-nung 60 sweet potato.(Ipomoea batatas [L.] Lam) after cryopreservation." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/64388593237165138717.
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碩士國立中興大學
生命科學系
92
Abstract This study investigates the effect of preculturing high sucrose concentration on three sweet potato cultivar [Ipomoea batatas(L.) Lam] cv. Tainung NO. 31(TN31), Tainung New NO. 31(TN New31), Tainung No. 60(TN60)]. We analyzed the physiological respones of sweet potato to understand the relations between preculture and cryopreserved survival rate. After 3 days precultured in 0.7M sucrose medium, shoot tips of TN New31 were pretreated with LS for 60 minutes, followed by PVS2 dehydration for 55minutes, and immersed in liquid nitrogen directly. The post-thaw survival rates of shoot tips were up to 85%. After 5 days precultured in 0.5M sucrose medium, shoot tips of TN60 were pretreated with LS for 60 minutes, followed by PVS2 dehydration for 55minutes, and immersed in liquid nitrogen directly. The post-thaw survival rates of shoot tips were up to 50%. After 3 days precultured in 0.3M sucrose medium, shoot tips of TN31 were pretreated with LS for 60 minutes, followed by PVS2 dehydration for 55minutes, and immersed in liquid nitrogen directly. The post-thaw survival rates of shoot tips were up to 23%. This research shows that after cryopreservation and was not increased activation of antioxidat enzymes, the high sucrose concentration preculture, soluble sucrose accumulation of sweet potato shoot tips close relation with decrease in osmotic potential. On the other hand, high sucrose concentration precultue did not elevate antioxidant enzymes of sweet potato. Thus, the activity of these antioxidat enzymes has nothing to do with the enhanced sweet potato freezing tolerance.
Books on the topic "Lamb survival"
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J, Fitzgibbon Robert, and Statland Bernard E, eds. DRG survival manual for the clinical lab. Oradell, N.J: Medical Economics Books, 1985.
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Zubrick, James W. The organic chem lab survival manual: A student's guide to techniques. 3rd ed. New York: Wiley, 1992.
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Zubrick, James W. The organic chem lab survival manual: A student's guide to techniques. 8th ed. Hoboken, NJ: John Wiley, 2011.
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Zubrick, James W. The organic chem lab survival manual: A student's guide to techniques. Hoboken, NJ: John Wiley & Sons, Inc., 2015.
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The organic chem lab survival manual: A student's guide to techniques. 4th ed. New York: J. Wiley, 1997.
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Zubrick, James W. The organic chem lab survival manual: A student's guide to techniques. 8th ed. Hoboken, NJ: John Wiley, 2010.
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The organic chem lab survival manual: A student's guide to techniques. 6th ed. Hoboken, NJ: Wiley, 2003.
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The organic chem lab survival manual: A student's guide to techniques. 5th ed. New York: John Wiley, 2001.
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The organic chem lab survival manual: A student's guide to techniques. 7th ed. Hoboken, N.J: John Wiley, 2007.
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The organic chem lab survival manual: A student's guide to techniques. 8th ed. Hoboken, NJ: John Wiley, 2010.
Find full textBook chapters on the topic "Lamb survival"
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Geiger, Franz, Peter Rutschmann, and Ulli Stoltz. "Measures to Improve Fish Passage Through a Turbine." In Novel Developments for Sustainable Hydropower, 117–24. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-99138-8_10.
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AbstractThis chapter focuses on the topic of measures to improve the fish passage through a turbine. Based on applications at the bulb units of the FIThydro Testcases of Guma, Bannwil and Obernach cost efficient and simple to apply measures are analysed. In the following two methods are presented. Applying a numerical analysis of the downstream fish passage typical physical stressor variables as strike, shear and barotrauma can be identified and correlated to the biological impact on the fish. In the FIThydro project, Voith applied the method to a wide range of operating conditions to derive fish-passage hill-charts. These allow a judgment of the physical impact on fish, dependent on the operating condition of the turbine. The studies at the Obernach lab performed by the team of the Technical University of Munich, show another method to improve fish survival rates by influencing fish pathways through the turbine. These promising results can be used for the Induced Drift Application (IDA), which are described in detail.
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Guarria, Charles I. "Chapter 3 1990–1999: In Like a Lion Out Like a Lamb." In Proposition 13 – America’s Second Great Tax Revolt: A Forty Year Struggle for Library Survival, 59–79. Emerald Publishing Limited, 2018. http://dx.doi.org/10.1108/978-1-78769-017-220181003.
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Cubaynes, Sarah, Simon Galas, Myriam Richaud, Ana Sanz Aguilar, Roger Pradel, Giacomo Tavecchia, Fernando Colchero, Sebastien Roques, Richard Shefferson, and Carlo Giovanni Camarda. "Survival analyses." In Demographic Methods across the Tree of Life, 229–44. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198838609.003.0013.
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Survival analyses are a key tool for demographers, ecologists, and evolutionary biologists. This chapter presents the most common methods and illustrates their use for species across the Tree of Life. It discusses the challenges associated with various types of survival data, how to model species with a complex life cycle, and includes the impact of environmental factors and individual heterogeneity. It covers the analysis of ‘known-fate’ data collected in lab conditions, using the Kaplan–Meier estimator and Cox’s proportional hazard regression analysis. Alternatively, survival data collected on free-ranging populations usually involve individuals missing at certain monitoring occasions and unknown time at death. The chapter provides an overview of capture–mark–recapture (CMR) models, from single-state to multi-state and multi-event models, and their use in animal and plant demography to estimate demographic parameters while correcting for imperfect detection of individuals. It discusses various inference frameworks available to implement CMR models using a frequentist or Bayesian approach. Only humans are an exception among free-ranging populations, with the existence of several consequent databases with perfect knowledge of age and cause of death for all individuals. The chapter presents an overview of the most common models used to describe mortality patterns over age and time using human mortality data. Throughout, focus is placed on eight case studies, which involve lab organisms, free-ranging animal populations, plant populations, and human populations. Each example includes data and codes, together with step-by-step guidance to run the survival analysis.
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Graybill, Rhiannon. "A Grittier Daughter Zion." In Texts after Terror, 113–43. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780190082314.003.0006.
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Daughter Zion (Lam 1–2) is often read as a rape victim. Furthermore, and unlike most biblical victims of sexual violence, she has a voice in the text. As a result, there is a pronounced tendency in the scholarship to treat Daughter Zion as an ideal and praiseworthy victim/survivor. However, this representation is both problematic and contradicted by Daughter Zion’s own speech in Lamentations 1–2. In response, this chapter argues for Daughter Zion as a “gritty” survivor with a fuzzy, messy, and icky survival story. Her story is further illuminated when read together with other survivor texts, including Queering Sexual Violence (edited by Jennifer Patterson), Leah Lakshmi Piepzna-Samarasinha’s Care Work: Dreaming Disability Justice, and Carmen Maria Machado’s In the Dream House. Together, these stories form a “survivor archive,” building on Ann Cvetkovich’s description of queer and affective archives.
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"The Wolf Is Fed and the Lamb Survives." In Russian Cuisine in Exile, 64–66. Academic Studies Press, 2018. http://dx.doi.org/10.2307/j.ctv1zjg7dp.31.
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"26. The Wolf Is Fed and the Lamb Survives." In Russian Cuisine in Exile, 64–66. Academic Studies Press, 2019. http://dx.doi.org/10.1515/9781618117311-029.
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Forshaw, Barry. "Lecter’s Progeny." In The Silence of the Lambs, 89–96. Liverpool University Press, 2013. http://dx.doi.org/10.3828/liverpool/9781906733650.003.0007.
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This chapter reflects on the figure of the hyper-intelligent serial killer. The influence of the film of The Silence of the Lambs on the horror (and thriller) genre has been considerable, not just on individual films, but in terms of broadening the parameters audiences have come to expect — both in terms of material that might fundamentally disturb, but also in raising the bar for an intelligent approach to genre material. The sophistication of the Hannibal Lecter character might be said to be a metaphor for the extra levels of nuance which became the norm for the most accomplished entries in the field — no longer were rudimentary characterisations of the heroes and villains of such films the yardstick, or even a straightforwardly Manichean attitude to notions of good and evil. A more ambitious and richly textured approach became the norm. Thomas Harris's character — in screen terms at least — survived in a handful of films that matched impeccable writing and direction with some truly idiosyncratic and offkilter playing, two of them directed by the talented David Fincher. The chapter then studies Fincher's Se7en (1995) and Zodiac (2007).
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Russell, David. "Aesthetic Liberalism." In Tact, 41–58. Princeton University Press, 2019. http://dx.doi.org/10.23943/princeton/9780691196923.003.0003.
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This chapter aims to resituate John Stuart Mill's early essays on aesthetics and poetry within the tradition of the tactful essayists studied in the other chapters of this book. As much as those of Charles Lamb, Mill's early essays are experiments, at once in both aesthetic and social form. Moreover, one can propose that the young Mill's aesthetic liberalism did survive: only not so much in the development of the discipline of political theory as in the nineteenth-century literary essay. The chapter looks closely at the tension between Mill's aesthetic and his argumentative liberalisms. It considers how and why the latter won out over the former during the course of his career.
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Qutab, Saima, Syed Adnan Adil, Lesley A. Gardner, and Farasat Shafi Ullah. "The Role of Libraries, Archives, and Museums for Metaliteracy in Smart Cities." In Advances in Library and Information Science, 355–75. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-8363-0.ch019.
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The concept of smart cities is gaining popularity within academic, practice, and policy circles. Smart cities are intended to be self-sufficient via cutting-edge technologies, purposive innovations, and inventions. However, while technology is growing at an unexpectedly fast pace, one of the essential components of smart cities ‘humans' is lagging behind. The need for and scope of literacies to survive in smart cities pose challenges for their citizens. This study aims to identify the range of literacies required in smart cities and the roles of libraries, archives, and museums (LAM) in supporting citizen literacies for social and digital inclusion. The LAM sector is one of the major stakeholders in the digital transformation sphere. Therefore, the LAM sector must identify the nature of required literacies, the roles and strengths of other stakeholders, and the opportunities to increase its presence in the process. This study systematically identifies and addresses these issues through a conceptual framework process and proposes future research directions for the LAM sector.
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Finkel, Evgeny. "Resistance." In Ordinary Jews. Princeton University Press, 2017. http://dx.doi.org/10.23943/princeton/9780691172576.003.0007.
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This chapter examines resistance as a Jewish survival strategy during the Holocaust. Jewish resistance has historically been of interest to Holocaust scholars, mainly due to the desire to counter accusations that Jews were passive, complacent, and went “like lambs to the slaughter.” Holocaust historians, especially those based in Israel, have explored the Jews' resistance to Nazi persecution. They argue that armed resistance was infrequent, but equating resistance with violence is unnecessarily restrictive, and that the Jews had almost unanimously engaged in amidah (“standing up against” in Hebrew), or unarmed resistance. The chapter looks at Jewish resistance organizations in the ghettos of Minsk, Kraków, and Białystok and suggests that people with a history of pre–World War II political activism were significantly overrepresented in the resistance. It explains why some resistance groups failed early on, while others managed to put up a sustained fight.
Conference papers on the topic "Lamb survival"
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Belloni, F., P. Alifano, A. Lorusso, C. Monaco, V. Nassisi, A. Talà, and M. Tredici. "Effects induced by XeCl laser radiation and germicidal lamp radiation on E. coli strains survival and mutability." In Photonics Europe, edited by Romualda Grzymala and Olivier Haeberle. SPIE, 2006. http://dx.doi.org/10.1117/12.662486.
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Somcio, N. S., Andrew J. Komrowski, Luis Curiel, Charles R. Silvis, and Daniel J. D. Sullivan. "An Evolution in Plastic Decapsulation Process Improvement." In ISTFA 2003. ASM International, 2003. http://dx.doi.org/10.31399/asm.cp.istfa2003p0301.
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Abstract Decapsulating wire-bonded plastic packages using fuming nitric or sulfuric acid is one of the most widely used methods for exposing a die during failure analysis [1]. The need to have physical access to the die in a packaged semiconductor device is often essential in the FA process. Regularly, the entire surface of the die must be exposed to take full advantage of techniques such as Emission Microscopy or Liquid Crystal. However, removing the plastic encapsulant using corrosive acids, such as fuming sulfuric acid, presents a challenge: achieving a fully exposed die surface while maintaining the device’s electrical functionality. Here we describe how our decapsulation process has evolved to address this challenge, resulting in improved survival rates for plastic packages decapsulated in the lab.
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Padmanee, Sharma. "Abstract IA05: From the clinic to the lab: Investigating response and resistance mechanisms to immune checkpoint therapy." In Abstracts: Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; September 30 - October 3, 2018; New York, NY. American Association for Cancer Research, 2019. http://dx.doi.org/10.1158/2326-6074.cricimteatiaacr18-ia05.
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Tubbs, Richard L. "Simple Flip Chip Analysis Strategies." In ISTFA 1998. ASM International, 1998. http://dx.doi.org/10.31399/asm.cp.istfa1998p0307.
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Abstract Recent customer demands and advances in technology are expanding the use of flip chip ICs. The higher coefficients of thermal expansion differences and fragile nature of assemblies have made underfilling mandatory for product survival in the field. This article describes a few techniques employed for failure analysis of these complex devices: epoxy development, substrate pre-encapsulation, universal polishing media, cyanoacrylate use, substrate analysis, plan view sectioning/inspection, die backside polishing for infra-red inspection, and chemical deprocessing. Almost all of the techniques presented will involve traditional cross sectioning tools which can be applied to flip chips. These techniques include improvements to the traditional material analysis cross section as well as aids for die level electrical analysis and visual inspection methods. The article demonstrates that with the use of the described techniques, and literally no investment, any lab which can presently perform semiconductor related cross-sections, will be able to confidently expand into flip chips.
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Ling, Bradley A., Terry Lettenmaier, Matthew Fowler, Matthew Cameron, and Anthony M. Viselli. "Design and Construction of a 1/15th Scale Wave Tank Model of the Azura Commercial Wave Energy Converter." In ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/omae2019-95538.
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Abstract The design of a 1/15th geometrically scaled wave tank model of the Azura™ commercial-scale wave energy device is presented. The objectives of the wave tank tests, conducted at the University of Maine Harlod Alfond Wind/Wave Ocean Engineering Lab (W2), included verification of the Azura’s energy capture in irregular waves, evaluation of performance in survival wave conditions, and testing of two advanced control algorithms. Due to the difficulty in properly Froude Scaling a hydraulic system, the model used a direct-drive rotary motor/generator power takeoff (PTO), with the dynamics of the hydraulic PTO included via a hardware-in-the-loop simulation. This PTO implementation led to additional design requirements being imposed on the model drivetrain. In addition to the model PTO design, the instrumentation design, structural design, and test plans are presented. The resulting model and PTO achieved a high level of controllability, and accurately emulated the dynamics of the hydraulic PTO of the full-scale Azura prototype.
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De Marco, Raffaella, Francesca Galasso, and Chiara Malusardi. "Digital documentation of fortified urban routes in Pavia (Italy): territorial databases and structural models for the preservation of military ruins." In FORTMED2020 - Defensive Architecture of the Mediterranean. Valencia: Universitat Politàcnica de València, 2020. http://dx.doi.org/10.4995/fortmed2020.2020.11518.
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The analysis of the fortified routes in the city of Pavia (Italy) clarifies the adaptation of the medieval capital in the historical politics of the Mediterranean, where the evolution of the defensive system till the Spanish bastioned walls (sixteenth century) identifies the updating of the Lombard tradition to the practices of modern military architecture. Their defensive structures survive in the urban design of the contemporary city, in the configuration of infrastructures and urban aggregates, reflecting the consequences of the great processes of their dismantling (from 1905). The comparison between historical investigations and the current ruins, fragmented into disconnected portions between the historical bastions and the monumental gates, shows a picture of abandonment of the military structures that generates repeated collapses and emerging risk factors towards the surrounding densified urban context. The experimentation of military architectural approaches of documentation at the urban scale, developed by the research laboratory DAda Lab. of University of Pavia, defines an analysis process through the digital representation of the urban remains that is suitable for the preservation of the survived city walls and the enhancement of their fortified identity. The application of different 3D LiDAR systems for morphological acquisition promotes an integrated digitation process of scansets on the fortified system controlled at the urban metric scale: the experimentation applies the use of a mobile real time scanner for the digital tracking of historical routes, on which to implement the georeferencing of detailed static scanworlds, integrated in correspondence of Bastions and Monumental Gates. The optimization of architectural data density and the integration between data contribute to finalize a 3D territorial database predisposed to the architectural modelling of volumes and scenarios of structural instability of the military ruins, defining a virtual framework of widespread knowledge for the historical conservation and urban prevention of the fortified system.
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Bru¨ckner-Foit, A., P. Hu¨lsmeier, E. Diegele, U. Rettig, and C. Hohmann. "Simulating the Failure Behaviour of Ceramic Components Under Gas Turbine Conditions." In ASME Turbo Expo 2002: Power for Land, Sea, and Air. ASMEDC, 2002. http://dx.doi.org/10.1115/gt2002-30502.
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Advanced monolithic ceramics have a good potential to survive under the severe thermal and mechanical loading conditions which are present in stationary gas turbines. Long term volume stability and high creep resistance are hard to achieve from a materials point of view but comparatively easy to verify. Resistance against thermal shock loading, on the other, has to be tested in a test rig, and test results obtained in the lab have to be scaled up to provide a database for a reliable design. This implies that advanced methods of fracture statistics have to be used. In this paper, failure probabilities under thermal shock loading are calculated using a modified version of the Weibull theory which takes the pronounced stress gradients into account. The basic idea is to determine the stress intensity factors of the natural flaws using weight functions. The new approach is used to estimate the failure probability in a thermal shock experiment which is designed to simulate critical gas turbine conditions. The predicted value of the failure probability is lowered by a factor of about 5 if the stress gradients are taken into considerations. The agreement between theory and experiments is very good.
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Koo, Bonjun, Andrew J. Goupee, Kostas Lambrakos, and Richard W. Kimball. "Model Tests for a Floating Windturbine on Three Different Floaters." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83642.
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Wind energy is a promising alternate energy resource. However, the on-land wind farms are limited by space, noise, and visual pollution, and therefore many countries build wind farms near shore. Up to now, most of offshore wind farms have been built in relatively shallow water (less than 30m) with fixed tower type wind turbines. Recently, several countries plan to move wind farms to deep water offshore locations to find stronger and steadier wind fields as compared to near shore locations. For the wind farms in deeper water, floating platforms have been proposed to support the wind turbine. The model tests described in this paper were performed at MARIN (Maritime Research Institute Netherlands) with a model set-up corresponding to a 1:50 Froude scaling. The wind turbine was a scaled model of the National Renewable Energy Lab (NREL) 5MW, horizontal axis reference wind turbine supported by three different generic floating platforms: a spar, a semi-submersible and a tension-leg platform (TLP). The wave environment used in the tests is representative of the offshore in the state of Maine. In order to capture coupling between the floating platform and the wind turbine, the 1st bending mode of the turbine tower was also modeled. The main purpose of the model tests was to generate data on coupled motions and loads between the three floating platforms and the same wind turbine for the operational, design, and survival seas states. The data are to be used for calibration and improvement of existing design analysis and performance numerical codes. An additional objective of the model tests was to establish advantages and disadvantages among the three floating platform concepts on the basis of test data. The paper gives details of the scaled model wind turbine and floating platforms, the set-up configurations, and the instrumentation to measure motions, accelerations and loads as well as wind turbine rpm, torque and thrust for the three floating wind turbines. The data and data analysis results are the subject of another paper in this conference [1].
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Manga, Patrick, Sherif Mohamed, and Devesh Bhaisora. "High Performance Tailored Mechanically Enhanced Cement Slurry Helped in Delivering Dependable Barriers Across HPHT Reservoir: Case Study from UAE Offshore." In Abu Dhabi International Petroleum Exhibition & Conference. SPE, 2021. http://dx.doi.org/10.2118/208079-ms.
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Abstract The concept of zonal isolation has evolved recently addressing new industry challenges to provide dependable barriers throughout the life of the well. This helps ensure long term well integrity for safer and more efficient hydrocarbon production, especially for the fields predicted to have a long lifetime. This leads to tailoring of cement slurry designs for superior mechanical parameters to avoid deteriorating them under post cementing operational loads. Following cementing best practices is a key parameter to achieve a successful cementing job, however adequate mechanical properties will help a cement slurry to withstand all the cyclic loads that the well will experience during its lifetime. Determining these properties and tailoring cement slurry designs to meet these properties will help ensure that the cement slurry will still survive these loads, all the way from placement until it has experienced all the post cementing operational loads including but not limited to multiple pressure testing, unloading the well, perforations, various thermal loads during well production, hydraulic fracturing etc. The tailored cement slurry was able to provide an adequate solution of such challenges faced by an operator in Offshore UAE under a high pressure – high temperature (HPHT) environment. Stress modelling was performed for the life of the well considering post cementing operations. This helped in determining optimum mechanical properties required for the cement slurries considered. Specialized testing was performed in both lab and yard to achieve such properties for field execution. Based on various stress and hydraulic modelling, slurries ranging from 13 to 17.5 ppg were designed and pumped successfully in the wellbore. Post cementing bond logs showed adequate placement of a tailored dependable barrier across a complete wellbore including an HPHT reservoir section. This approach can be used for wells with similar challenges around the world for long term zonal isolation.
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Chen, Hsieh, Sehoon Chang, Gawain Thomas, Wei Wang, Afnan Mashat, and Hussain Shateeb. "Comparison of Water and Gas Tracers Field Breakthrough." In SPE Annual Technical Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/205863-ms.
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Abstract We are developing new classes of barcoded advanced tracers, which, compared to present commercial offerings, can be optically detected in an automated fashion. The eventual goal for the advanced tracers is to deploy cost-effective, ubiquitous, long-term, and full-field tracer tests in supporting large-scale waterflooding optimization for improved oil recovery. In this paper, we compare model predictions to breakthrough data from two field tests of advanced tracers in a pilot during water alternating gas (WAG) cycles, where gas tracer tests have recently been performed as well. Two advanced tracer injections were performed at the test site. For the first injection, only a dipicolinic acid based advanced tracer (DPA) was injected. For the second injection, DPA and a phenanthroline- based advanced tracer, 4,7-bis(sulfonatophenyl)-1,10-phenanthroline-2,9-dicarboxylic acid (BSPPDA), was injected in conjunction with a commercially available fluorobenzoic acid-based tracer (FBA) to benchmark their performance. Produced water samples were collected weekly for tracer analysis. Both newly developed 2D-high performance liquid chromatography/time-resolved fluorescence optical detection method (2D-HPLC/TRF) and liquid chromatography-mass spectrometry (LC-MS) were used to construct the breakthrough curves for the advanced tracers. In parallel, gas chromatography-mass spectrometry (GC-MS) was used to detect FBA tracer. Gas tracer tests have been performed on the same field. Since DPA, BSPPDA and FBA tracers were water tracers as designed, they were expected to appear in between gas tracer breakthroughs, and we observed exactly that for BSPPDA and FBA. Unexpectedly, the DPA predominantly appeared along with gas tracer breakthroughs, suggesting its favorable compatibility with the gas phase. We suspect the presence of some gas components rendered the medium more acidic, which likely protonates DPA molecules, thereby alters its hydrophilicity. A wealth of information could be gathered from the field tests. First, all tracers survived not only the harsh reservoir conditions but also the irregular WAG injections. Their successful detection from the producers suggested robustness of these materials for reservoir applications. Second, the breakthrough curves of the BSPPDA tracers using optical detection method were very similar to those of FBA tracers detected by GC-MS, substantiating the competency of our in-house materials and detection methods to the present commercial offerings. Finally, even though DPA has passed prior lab tests as a good water tracer, its high solubility to gas phase warrants further investigation. This paper summarizes key results from two field trials of the novel barcoded advanced tracers, of which both the tracer materials and detection methods are new to the industry. Importantly, the two co- injected advanced tracers showed opposite correlations to the gas tracers, highlighting the complex physicochemical interactions in reservoir conditions. Nevertheless, the information collected from the field trials is invaluable in enabling further design and utilization of the advanced tracers in fulfilling their wonderful promises.
Reports on the topic "Lamb survival"
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Spencer, Thomas E., Elisha Gootwine, Arieh Gertler, and Fuller W. Bazer. Placental lactogen enhances production efficiency in sheep. United States Department of Agriculture, December 2005. http://dx.doi.org/10.32747/2005.7586543.bard.
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The key objectives of this BARD project were to: (1) study long-term effects of immunization of prepubertal ewes against recombinant ovine placental lactogen (roPL) on subsequent birth weights of their lambs and their milk production; (2) optimize the anti-roPL immunization protocol using adjuvant preparations acceptable to producers and regulatory agencies; and (3) determine the physiological mechanism(s) whereby immunization against oPL increases fetal growth and development and mammogenesis. These objectives were based on key findings from a previous BARD project that: (a) immunization of ewes against roPL increased lamb birth weight and ewe milk production during lactation; (b) roPL and recombinant ovine growth hormone (roGH) increased the proliferation and differentiated function of endometrial glands that, in turn, would enhance uterine secretions necessary for fetal and placental growth; and (c) exogenous roPL and roGH stimulated mammogenesis and milk production during lactation. The BARD projects address central problems in sheep production, including reproductive failure due to embryonic/fetal mortality, low birth weight of lambs especially in prolific breeds, and reduced milk yields which affect neonatal survival. The sheep placenta secretes both lactogenic (oPL) and somatogenic (oGH) hormones. The receptors for those hormones are present in the fetus and placenta as well as maternal uterus, and mammary gland. Our research has focused on determining the biological role of these placental hormones in development and differentiation of the uterus during gestation and the mammary gland during pregnancy and lactation. Studies conducted in the current BARD project indicated that the effects of anti-roPL immunization were variable in ewes and that commercially available and widely acceptable adjuvant preparations were not effective to produce high anti-roPL titers in pre-pubertal ewes. In the non-prolific Rambouillet ewe in Texas and in the Awassi and the Assaf in Israel, anti-roPL immunization increased lamb birth weight; however, the magnitude of this effect and the inherent variability precluded our ability to determine the physiological mechanism of how the immunization increases fetal growth. Collectively, our findings suggest that anti-roPL immunization is not currently feasible as an easy and efficacious tool for the producer to increase flock reproductive and production efficiency. The variability in response of individual ewes to anti-roPL immunization likely includes modifying the recombinant hormone and the type of adjuvant used for the immunization. In particular, the oPL may need to be modified to ensure maximum antigenicity in a broad range of breed types. Nonetheless, the investigators continue to collaborate on identifying fundamental mechanisms that can be improved by genetics or management to enhance the efficiency of uteroplacental function and, in turn, fetal growth and development. High prolificacy is a desirable trait in intensive sheep production systems. One of the main limitations of using prolific breeds of sheep is that increased litter size is associated with low birth weights and increased mortality of lambs. Further, low birth weight is associated with an increased propensity for adult diseases and decreased production efficiency. Indeed, our recent studies find that the birth weights of lambs born in large litters can be improved by both genetics and management. Future cooperative research will continue to focus on reproductive efficiency of sheep that have broader implications for improving production efficiency in all types of ruminant livestock.
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Gootwine, Elisha, David Thomas, Ruth Braw-Tal, Amir Bor, and P. J. Dziuk. Improvement of Prolificacy of Israeli and U.S. Sheep Breeds through Inclusion of the F Gene of the Booroola Merino-Stage II. United States Department of Agriculture, May 1995. http://dx.doi.org/10.32747/1995.7604931.bard.
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The purposes of this project were: 1) to introduce the FecB gene to the Awassi and Assaf breeds in Israel and the Rambouillet breed in the U.S.A. aiming in the long run to establish Awassi, Assaf and Rambouillet nucclei breeding flocks homozygous for the F gene in which the contribution of the Booroola Merino genetic background will be less than 10%; (In the U.S., Booroola crosses with Suffolk and Targhee were also studied. 2) to evaluate the effect of the FecB gene and different proportions of Booroola Merino genetic background on lamb survival, growth, milk production and wool production in Booroola crosses with the native breeds; 3) to reveal the specific effect of the FecB gene on ovarian development, follicle stimulating hormone (FSH) and inhibin secretion in prepubertal ewe lambs and in adult ewes in order to define physiological criteria for distinguishing carriers of the FecB allele from non-carriers and 4) to identify genetic markers linked to the FecB gene to assist in selection of genotypes within the Booroola crosses. Introgression of the Booroola gene reached the stage of the third backcross in the Awassi, Assaf and the Rambouillet crosses. In all cases the Booroola crosses were superior in prolificacy. However, they were inferior in comparison to the local breeds in production due to Booroola Merino genes other than the FecB. It is expected that the beneficial economic contribution of the Booroola gene will increase along with the upgrading to the local breeds. FSH plasma levels and induced ovulation rate of 5 month old FecB carriers among the crossbreeds. The OarAE101 marker can assist in detecting FecB carriers among Booroola-Awassi crosses. However, this marker is informative only in some of the families.
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Cattaneo, Alessandro. Engineering Survival Skills: Keeping a Lab Notebook. Office of Scientific and Technical Information (OSTI), November 2016. http://dx.doi.org/10.2172/1331252.
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Weinberg, Zwi G., Richard E. Muck, Nathan Gollop, Gilad Ashbell, Paul J. Weimer, and Limin Kung, Jr. effect of lactic acid bacteria silage inoculants on the ruminal ecosystem, fiber digestibility and animal performance. United States Department of Agriculture, September 2003. http://dx.doi.org/10.32747/2003.7587222.bard.
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The overall objective of the whole research was to elucidate the mechanisms by which LAB silage inoculants enhance ruminant performance. The results generated will permit the development of better silage inoculants that maximize both silage preservation and animal performance. For this one-year BARD feasibility study, the objectives were to: 1. determine whether lactic acid bacteria (LAB) used in inoculants for silage can survive in rumen fluid (RF) 2.select the inoculants that survived best, and 3. test whether LAB silage inoculants produce bacteriocins-like substances. The most promising strains will be used in the next steps of the research. Silage inoculants containing LAB are used in order to improve forage preservation efficiency. In addition, silage inoculants enhance animal performance in many cases. This includes improvements in feed intake, liveweight gain and milk production in 25-40% of studies reviewed. The cause for the improvement in animal performance is not clear but appears to be other than direct effect of LAB inoculants on silage fermentation. Results from various studies suggest a possible probiotic effect. Our hypothesis is that specific LAB strains interact with rumen microorganisms which results in enhanced rumen functionality and animal performance. The first step of the research is to determine whether LAB of silage inoculants survive in RF. Silage inoculants (12 in the U.S. and 10 in Israel) were added to clarified and strained RF. Inoculation rate was 10 ⁶ (clarified RF), 10⁷ (strained RF) (in the U.S.) and 10⁷, 10⁸ CFU ml⁻¹ in Israel (strained RF). The inoculated RF was incubated for 72 and 96 h at 39°C, with and without 5 g 1⁻¹ glucose. Changes in pH, LAB numbers and fermentation products were monitored throughout the incubation period. The results indicated that LAB silage inoculants can survive in RF. The inoculants with the highest counts after 72 h incubation in rumen fluid were Lactobacillus plantarum MTD1 and a L. plantarum/P. cerevisiae mixture (USA) and Enterococcus faecium strains and Lactobacillus buchneri (Israel). Incubation of rumen fluid with silage LAB inoculants resulted in higher pH values in most cases as compared with that of un-inoculated controls. The magnitude of the effect varied among inoculants and typically was enhanced with the inoculants that survived best. This might suggest the mode of action of LAB silage inoculants in the rumen as higher pH enhances fibrolytic microorganisms in the rumen. Volatile fatty acid (VFA) concentrations in the inoculated RF tended to be lower than in the control RF after incubation. However, L. plalltarull1 MTDI resulted in the highest concentrations of VFA in the RF relative to other inoculants. The implication of this result is not as yet clear. In previous research by others, feeding silages which were inoculated with this strain consistently enhanced animal performance. These finding were recently published in Weinberg et.al.. (2003), J. of Applied Microbiology 94:1066-1071 and in Weinberg et al.. (2003), Applied Biochemistry and Biotechnology (accepted). In addition, some strains in our studies have shown bacteriocins like activity. These included Pediococcus pentosaceus, Enterococcus faecium and Lactobacillus plantarum Mill 1. These results will enable us to continue the research with the LAB strains that survived best in the rumen fluid and have the highest potential to affect the rumen environment.
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Weinberg, Zwi G., Adegbola Adesogan, Itzhak Mizrahi, Shlomo Sela, Kwnag Jeong, and Diwakar Vyas. effect of selected lactic acid bacteria on the microbial composition and on the survival of pathogens in the rumen in context with their probiotic effects on ruminants. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7598162.bard.
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This research project was performed in context of the apparent probiotic effect of selected lactic acid bacteria (LAB) silage inoculants on the performance of ruminants (improved feed intake, faster live-weight gain, higher milk yields and improved feed efficiency). The overall objective was to find out how LAB affect ruminant performance. The project included several “chapters” as follows: 1. The effect of LAB silage inoculants on the survival of detrimental bacteria in rumen fluid, in vitro study (Weinberg et al., The Volcani Center). An in vitro model was developed to study the interaction between selected LAB and an E. coli strain tagged with green fluorescence protein (GFP) in buffered RF. Results indicated that both LAB inoculants and E. coli survived in the RF for several days; both LAB inoculants and LAB-treated silages did not affect survival of E. coli in rumen fluid in vitro. The effect of feeding baled wheat silages treated with or without three selected LAB silage inoculants on the performance of high-lactating cows (Weinberg et al., The Volcani Center). Treatments included control (no additive), Lacobacillusbuchneri40788 (LB), Lactobacillus plantarumMTD1 40027 (LP) and Pediococcuspentosaceus30168 (PP), each applied at 10⁶ cfu/g FM. The silages were included in the TMR of 32 high milking Holstein cows in a controlled feeding experiment. All baled silages were of good quality. The LB silage had the numerically highest acetic acid and were the most stable upon aerobic exposure. The cows fed the LB silages had the highest daily milk yields, percent milk fat and protein. The microbiome of baled wheat silages and changes during ensiling of wheat and corn (Sela et al., The Volcani Center). Bacterial community of the baled silages was dominated mainly of two genera in total, dominated by Lactobacillus and Clostridium_sensu_stricto_12 with 300 other genera at very low abundance. Fungal community was composed mainly of two genera in total, dominated by Candida and Monascuswith 20 other genera at very low abundance. In addition, changes in the microbiome during ensiling of wheat and corn with and without addition of L. plantarumMTD1 was studied in mini-silos. Overall 236 bacterial genera were identified in the fresh corn but after 3 months Lactobacillus outnumbered all other species by acquiring 95% of relative abundance. The wheat silage samples are still under analysis. The effect of applying LAB inoculants at ensiling on survival of E. coli O157:H7 in alfalfa and corn silages(Adesogan et al., University of Florida). E. coli (10⁵ cfu/g) was applied to fresh alfalfa and corn at ensiling with or without L. plantarumor L. buchneri. The pathogen was added again after about 3 moths at the beginning of an aerobic exposure period. The inoculants resulted in faster decrease in pH as compared with the control (no additives) or E. coli alone and therefore, the pathogen was eliminated faster from these silages. After aerobic exposure the pathogen was not detected in the LAB treated silages, whereas it was still present in the E. coli alone samples. 5. The effect of feeding corn silage treated with or without L. buchnerion shedding of E. coli O157:H7 by dairy cows (Adesogan et al., UFL). BARD Report - Project 4704 Page 2 of 12 Five hundred cows from the dairy herd of the University of Florida were screened for E. coli shedding, out of which 14 low and 13 high shedders were selected. These cows were fed a total mixed ration (TMR) which was inoculated with E. coli O157:H7 for 21 days. The TMR included corn silage treated with or without L. buchneri. The inoculated silages were more stable upon aerobic exposure than the control silages; the silage inoculant had no significant effect on any milk or cow blood parameters. However, the silage inoculant tended to reduce shedding of E. coli regardless of high or low shedders (p = 0.06). 6. The effect of feeding baled wheat silages treated with or without three selected LAB silage inoculants on the rumen microbiome (Mizrahi et al., BGU). Rumen fluid was sampled throughout the feeding experiment in which inoculated wheat silages were included in the rations. Microbial DNA was subsequently purified from each sample and the 16S rRNA was sequenced, thus obtaining an overview of the microbiome and its dynamic changes for each experimental treatment. We observed an increase in OTU richness in the group which received the baled silage inoculated with Lactobacillus Plantarum(LP). In contrast the group fed Lactobacillus buchneri(LB) inoculated silage resulted in a significant decrease in richness. Lower OTU richness was recently associated in lactating cows with higher performance (Ben Shabatet al., 2016). No significant clustering could be observed between the different inoculation treatments and the control in non metric multi-dimentional scaling, suggesting that the effect of the treatments is not the result of an overall modulation of the microbiome composition but possibly the result of more discrete interactions. Significant phylum level changes in composition also indicates that no broad changes in taxa identity and composition occurred under any treatment A more discrete modulation could be observed in the fold change of several taxonomic groups (genus level analysis), unique to each treatment, before and after the treatment. Of particular interest is the LB treated group, in which several taxa significantly decreased in abundance. BARD Report - Project 4704 Page 3 of 12
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Boisclair, Yves R., and Arieh Gertler. Development and Use of Leptin Receptor Antagonists to Increase Appetite and Adaptive Metabolism in Ruminants. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7697120.bard.
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Objectives The original project had 2 major objectives: (1) To determine the effects of centrally administered leptin antagonist on appetite and adaptive metabolism in the sheep; (2) To develop and prepare second-generation leptin antagonists combining high binding affinity and prolonged in vivo half-life. Background Periods of suboptimal nutrition or exaggerated metabolic activity demands lead to a state of chronic energy insufficiency. Ruminants remain productive for a surprisingly long period of time under these circumstances by evoking adaptations sparing available energy and nutrients. The mechanism driving these adaptations in ruminant remains unknown, but could involve a reduction in plasma leptin, a hormone acting predominantly in the brain. In laboratory animals, reduced leptin signaling promotes survival during nutritional insufficiency by triggering energy sparing adaptations such as reduced thyroid hormone production and insulin resistance. Our overall hypothesis is that similar adaptations are triggered by reduced leptin signaling in the brain of ruminants. Testing of this hypothesis in ruminants has not been possible due to inability to block the actions of endogenous leptin and access to ruminant models where leptin antagonistic therapy is feasible and effective. Major achievements and conclusions The Israeli team had previously mutated 3 residues in ovine leptin, with no effect on receptor binding. This mutant was renamed ovine leptin antagonist (OLA) because it cannot activate signaling and therefore antagonizes the ability of wild type leptin to activate its receptor. To transform OLA into an effective in vivo antagonist, the Israeli made 2 important technical advances. First, it incorporated an additional mutation into OLA, increasing its binding affinity and thus transforming it into a super ovine leptin antagonist (SOLA). Second, the Israeli team developed a method whereby polyethylene glycol is covalently attached to SOLA (PEG-SOLA) with the goal of extending its half-life in vivo. The US team used OLA and PEG-SOLA in 2 separate animal models. First, OLA was chronically administered directly into the brain of mature sheep via a cannula implanted into the 3rdcerebroventricule. Unexpectedly, OLA had no effect of voluntary feed intake or various indicators of peripheral insulin action but reduced the plasma concentration of thyroid hormones. Second, the US team tested the effect of peripheral PEG-SOLA administration in an energy sensitive, rapidly growing lamb model. PEG-SOLA was administered for 14 consecutive days after birth or for 5 consecutive days before sacrifice on day 40 of life. Plasma PEG-SOLA had a half-life of over 16 h and circulated in 225- to 288-fold excess over endogenous leptin. PEG-SOLA administration reduced plasma thyroid hormones and resulted in a higher fat content in the carcass at slaughter, but had no effects on feed intake, body weight, plasma glucose or insulin. These results show that the team succeeded in developing a leptin antagonist with a long in vivo half-life. Moreover, in vivo results show that reduced leptin signaling promotes energy sparing in ruminants by repressing thyroid hormone production. Scientific and agricultural implications The physiological role of leptin in ruminants has been difficult to resolve because peripheral administration of wild type leptin causes little effects. Our work with leptin antagonists show for the first time in ruminants that reduced leptin signaling induces energy sparing mechanisms involving thyroid hormone production with little effect on peripheral insulin action. Additional work is needed to develop even more potent leptin antagonists, to establish optimal administration protocols and to narrow down phases of the ruminant life cycle when their use will improve productivity.
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Bazer, Fuller W., Arieh Gertler, and Elisha Gootwine. Role of Placental Lactogen in Sheep. United States Department of Agriculture, January 2001. http://dx.doi.org/10.32747/2001.7574339.bard.
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Central problems in sheep and dairy cattle production are reproductive failure due to embryonic/fetal mortality and low birth weights, especially in prolific breeds, and reduced milk yields which adversely affect neonatal survival and economy of production. The sheep placenta expresses lactogenic (ovine placental lactogen, oPL) and somatogenic (ovine placental growth hormone, oGH) hormones. Our research has focused on the biological roles of oPL and oGH in function of the uterine endometrium during gestation and the mammary gland during pregnancy and lactation. Major conclusions were that: ( 1 ) immunization of prepubertal ewes against oPL resulted in increased birth weights of their lambs and their milk production during lactation; (2) neither oPL nor oGH had an antiluteolytic effect on uterine endometrium to affect lifespan of the corpus luteum; (3) only sequential exposure of the progesterone stimulated uterus to oIFNt and oPL or oGH increased endometrial gland proliferation and secretory protein gene expression; (4) oPL signals through a homodimer of ovine prolactin receptor (PRL-R) and heterodimer of oPRL-R and growth hormone receptor (GH-R); (5) exogenous recombinant oPL and oGH stimulated mammogenesis and milk yield during lactation; and (6) mutation of oPL and oGH was used to define specific biological effects and a rational basis for design of a specific receptor agonists or antagonists. This project was very productive in elucidating basic biological effects of oPL and oGH on intracellular signal transduction pathways, uterine development and secretory function, as well as mammogenesis and lactogenesis. We determined that immunization of prepubertal ewes against roPL increased birth weights of their lambs, especially those born as twins and triplets, as well as enhanced lactational performance. These studies significantly extended our knowledge of uterine and fetal-placental physiology and provided a foundation for new strategies to enhance reproductive and lactation efficiency. Based on these results, the major achievements were: 1) creation of a practical and cost effective management tool for producers to increase reproductive performance, neonatal survival, and milk yield of ewes in commercial flocks; and 2) define, for the first time, biological effects of oPL on endometrial functions and gene expression by uterine gland epithelium.
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Zevotek, Robin, Keith Stakes, and Joseph Willi. Impact of Fire Attack Utilizing Interior and Exterior Streams on Firefighter Safety and Occupant Survival: Full-Scale Experiments. UL Firefighter Safety Research Institute, January 2018. http://dx.doi.org/10.54206/102376/dnyq2164.
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As research continues into how fire department interventions affect fire dynamics in the modern fire environment, questions continue to arise on the impact and implications of interior versus exterior fire attack on both occupant survivability and firefighter safety. This knowledge gap and lack of previous research into the impact of fire streams has driven the need for further research into fire department interventions at structure fires with a focus on hose streams and suppression tactics. As the third report in the project “Impact of Fire Attack Utilizing Interior and Exterior Streams on Firefighter Safety and Occupant Survival”, this report expands upon the fire research conducted to date by analyzing how firefighting tactics, specifically suppression methods, affect the thermal exposure and survivability of both building occupants and firefighters in residential structures. • Part I: Water Distribution • Part II: Air Entrainment • Part III: Full-Scale Residential Fire Experiments. This report evaluates fire attack in residential structures through twenty-six full-scale structure fire experiments. Two fire attack methods, interior and transitional, were preformed at UL’s large fire lab in Northbrook, IL, in a single-story 1,600 ft2 ranch test structure utilizing three different ventilation configurations. To determine conditions within the test structure it was instrumented for temperature, pressure, gas velocity, heat flux, gas concentration, and moisture content. Ad- ditionally, to provide information on occupant burn injuries, five sets of instrumented pig skin were located in pre-determined locations in the structure. The results were analyzed to determine consistent themes in the data. These themes were evaluated in conjunction with a panel of fire service experts to develop 18 tactical considerations for fire ground operations. As you review the following tactical considerations it is important to utilize both these research results and your per- sonal experience to develop your department’s polices and implement these considerations during structural firefighting.
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Houck, Marilyn, Uri Gerson, and Robert Luck. Two Predator Model Systems for the Biological Control of Diaspidid Scale Insects. United States Department of Agriculture, June 1994. http://dx.doi.org/10.32747/1994.7570554.bard.
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Hemisarcoptes (Acari: Hamisarcoptidae) is a parasite of scale insects (Diaspididae), tenacious pests of vascular plants. Hemisarcoptes also has a stenoxenic phoretic (dispersal) relationship with Chilocorus (Coleoptera: Coccinellidae). Chilocorus feeds on diaspidids, transports mites as they feed, and has been applied to the control of scales, with limited success. U.S.-Israeli cooperation focused on this mite-beetle interaction so that a two-component system could be applied to the control of scale insects effectively. Life history patterns of Hemisarcoptes were investigated in response to host plant type and physical parameters. Field and lab data indicated that mites attack all host stages of scales tested, but preferred adult females. Scale species and host plant species influenced the bionomics of Hemisarcoptes. Beetle diet also influenced survival of phoretic mites. Mites use a ventral sucker plate to extract material from Chilocorus, that is essential for development. Seven alkaloids were found in the hemolymph of Chilocorus and three were characterized. Examination of the subelytral surface of Chilocorus indicated that microsetae play a role in the number and distribution of mites a beetle transports. While Hemisarcoptes can be innoculatd into agroecosystems using various indigenous or imported Chilocorus species, the following are preferred: C. bipustulatus, C. cacti, C. distigma, C. fraternus, C. orbus, and C. tristis.
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Splitter, Gary, and Menachem Banai. Microarray Analysis of Brucella melitensis Pathogenesis. United States Department of Agriculture, 2006. http://dx.doi.org/10.32747/2006.7709884.bard.
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Original Objectives 1. To determine the Brucella genes that lead to chronic macrophage infection. 2. To identify Brucella genes that contribute to infection. 3. To confirm the importance of Brucella genes in macrophages and placental cells by mutational analysis. Background Brucella spp. is a Gram-negative facultative intracellular bacterium that infects ruminants causing abortion or birth of severely debilitated animals. Brucellosis continues in Israel, caused by B. melitensis despite an intensive eradication campaign. Problems with the Rev1 vaccine emphasize the need for a greater understanding of Brucella pathogenesis that could improve vaccine designs. Virulent Brucella has developed a successful strategy for survival in its host and transmission to other hosts. To invade the host, virulent Brucella establishes an intracellular niche within macrophages avoiding macrophage killing, ensuring its long-term survival. Then, to exit the host, Brucella uses placenta where it replicates to high numbers resulting in abortion. Also, Brucella traffics to the mammary gland where it is secreted in milk. Missing from our understanding of brucellosis is the surprisingly lillie basic information detailing the mechanisms that permit bacterial persistence in infected macrophages (chronic infection) and dissemination to other animals from infected placental cells and milk (acute infection). Microarray analysis is a powerful approach to determine global gene expression in bacteria. The close genomic similarities of Brucella species and our recent comparative genomic studies of Brucella species using our B. melitensis microarray, suqqests that the data obtained from studying B. melitensis 16M would enable understanding the pathogenicity of other Brucella organisms, particularly the diverse B. melitensis variants that confound Brucella eradication in Israel. Conclusions Results from our BARD studies have identified previously unknown mechanisms of Brucella melitensis pathogenesis- i.e., response to blue light, quorum sensing, second messenger signaling by cyclic di-GMP, the importance of genomic island 2 for lipopolysaccharide in the outer bacterial membrane, and the role of a TIR domain containing protein that mimics a host intracellular signaling molecule. Each one of these pathogenic mechanisms offers major steps in our understanding of Brucella pathogenesis. Strikingly, our molecular results have correlated well to the pathognomonic profile of the disease. We have shown that infected cattle do not elicit antibodies to the organisms at the onset of infection, in correlation to the stealth pathogenesis shown by a molecular approach. Moreover, our field studies have shown that Brucella exploit this time frame to transmit in nature by synchronizing their life cycle to the gestation cycle of their host succumbing to abortion in the last trimester of pregnancy that spreads massive numbers of organisms in the environment. Knowing the bacterial mechanisms that contribute to the virulence of Brucella in its host has initiated the agricultural opportunities for developing new vaccines and diagnostic assays as well as improving control and eradication campaigns based on herd management and linking diagnosis to the pregnancy status of the animals. Scientific and Agricultural Implications Our BARD funded studies have revealed important Brucella virulence mechanisms of pathogenesis. Our publication in Science has identified a highly novel concept where Brucella utilizes blue light to increase its virulence similar to some plant bacterial pathogens. Further, our studies have revealed bacterial second messengers that regulate virulence, quorum sensing mechanisms permitting bacteria to evaluate their environment, and a genomic island that controls synthesis of its lipopolysaccharide surface. Discussions are ongoing with a vaccine company for application of this genomic island knowledge in a Brucella vaccine by the U.S. lab. Also, our new technology of bioengineering bioluminescent Brucella has resulted in a spin-off application for diagnosis of Brucella infected animals by the Israeli lab by prioritizing bacterial diagnosis over serological diagnosis.