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101.
Christopher J. Pillidge Lucy M. Sheehy Amal Shihata Zhao-Yan Pu Marian Dobos Ian B. Powell 《International Dairy Journal》2009,19(4):222-227
Partial 16S rRNA gene sequencing of Lactococcus lactis subsp. cremoris strains from our collection identified strains containing sequences diagnostic of both subspecies L. lactis subsp. lactis and L. lactis subsp. cremoris together in the same strain. The presence of a plasmid-encoded 16S rRNA pseudogene partly explained this result. Twenty-four out of 46 L. lactis subsp. cremoris strains tested by PCR contained this pseudogene. However, further analysis showed that five of these 24 strains also contained chromosomal 16S rRNA genes with sequences typical of L. lactis subsp. lactis. Genetic and phenotypic tests indicated these strains were otherwise normal L. lactis subsp. cremoris strains. Past recombination events between the 16S rRNA pseudogene and chromosomal 16S rRNA genes may explain this phenomenon. Genomic heterogeneity for both 16S rRNA and other gene sequences was observed for L. lactis subsp. cremoris SK11 from different laboratories, indicating caution is needed when integrating data from diverse sources for nominally the same strain. 相似文献
102.
M.C. Lucy G.A. Verkerk K.A. Macdonald R.T. Cursons C.W. Holmes 《Journal of dairy science》2009,92(2):526-539
The somatotropic axis [including growth hormone (GH), GH receptor, and insulin-like growth factor (IGF)-I] is uncoupled in high-producing cows in early lactation so that the liver fails to respond to GH and produces less IGF-I. This uncoupling was implicated in the process of nutrient partitioning, enabling high milk production. Different genetic selection goals may affect functional components of the somatotropic axis. Thus, the somatotropic axis was examined in diverse genetic strains of dairy cows [North American Holstein 1990 (NA90), New Zealand Holstein-Friesian 1990 (NZ90), and New Zealand Holstein-Friesian 1970 (NZ70)] that were managed similarly within a pasture-based system but were offered feed allowances commensurate with their genetic ability to produce milk. The NA90 cows produced more milk (26.2 ± 0.3, 24.1 ± 0.3, and 20.1 ± 0.4 kg/d, for NA90, NZ90, and NZ70, respectively), but had lower milk fat percentages (4.28 ± 0.03, 4.69 ± 0.03, and 4.58 ± 0.04 kg/d for NA90, NZ90, and NZ70, respectively) compared with both NZ strains. Milk protein percentages (3.38 ± 0.02, 3.52 ± 0.02, and 3.29 ± 0.03 kg/d for NA90, NZ90, and NZ70, respectively) were greater for NZ90 cows. During early lactation (wk 2 to 6), the total net energy produced in milk was greater in NA90 compared with NZ90 or NZ70 cows, but total net energy in milk after wk 6 was equivalent for NA90 and NZ90 cows. The greater milk production in early lactation in NA90 cows was associated with lower body condition scores (BCS; 1 to 10 scale; 4.0 ± 0.1) elevated blood GH concentrations (1.6 ± 0.1 ng/mL), and low blood IGF-I concentrations (14.8 ± 1.1 ng/mL), indicating an uncoupled somatotropic axis. In comparison, the NZ70 cows retained a coupled somatotropic axis during early lactation, maintaining greater BCS (4.6 ± 0.1), lower blood GH (0.7 ± 0.1 ng/mL), and greater blood IGF-I (21.9 ± 1.2 ng/mL). The degree of uncoupling in NZ90 cows was intermediate between the other 2 strains. Additional feed allowance failed to change blood IGF-I concentrations in NA90 cows but increased IGF-I concentrations in NZ90 cows (20.9 ± 1.4 and 13.2 ± 1.4 ng/mL for the high and low feed allowance, respectively). Furthermore, additional feed allowance in NZ90 cows lessened BCS loss in early lactation, but did not affect BCS loss in NA90 cows. Functional components of the somatotropic axis differed for the respective strains and were consistent with strain differences in milk production, BCS, and feed allowance. 相似文献
103.
Hurtado Sylvia; Griffin Kimberly A.; Arellano Lucy; Cuellar Marcela 《Canadian Metallurgical Quarterly》2008,1(4):204
The authors synthesize existing climate research and climate instruments, as well as introduce several frameworks to help educators understand how institutions and researchers have assessed diversity in the college environment. Over 90 instruments were reviewed and examined for their attention to multiple dimensions of the campus climate, diversity initiatives, and outcomes measures that capture students' values, skills, and knowledge for participation in a diverse society. Frameworks presented include a broad definition of the campus climate, a typology of campus initiatives based on an inventory of campus practice, and a typology of representative outcomes that capture cognitive, socio-cognitive, values/attitudes, and preparation for a multicultural society. Campuses that strive to become functional multicultural learning environments can now rely on a body of empirical information to guide practice and critical self-assessment to deepen their commitment to diversity. The authors recommend that campuses integrate their assessment of the climate with the evaluation of student outcomes and campus practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
104.
Joanna Burger Caleb Gordon J. Lawrence James Newman Greg Forcey Lucy Vlietstra 《Renewable Energy》2011,36(1):338-351
With a worldwide increase in attention toward developing a reliance on renewable energy, there is a need to evaluate the effects of these facilities (solar, wind, hydropower) on ecosystems. We conduct a hazard and risk evaluation for three species of birds that are listed, or candidates for listing, as federally threatened or endangered in the US, and that might occur offshore on the Atlantic Outer Continental Shelf (AOCS) where wind power facilities could be developed. Our objectives were to: 1) provide conceptual models for exposure for each species, and 2) examine potential exposure and hazards of roseate tern (Sterna dougallii) and piping plover (Charadrius melodus, both federally endangered in the US) and red knot (Calidris canutus rufa, candidate species) in the AOCS. We used a weight-of-evidence approach to evaluate information from a review of technical literature. We developed conceptual models to examine the relative vulnerability of each species as a function of life stage and cycle (breeding, staging, migratory, wintering). These methods are useful for conducting environmental assessments when empirical data are insufficient for a full risk assessment. We determined that 1) Roseate terns are likely to be exposed to risk during the migratory and breeding season when they occur in the AOCS, as well as while staging. 2) Piping plovers are not likely to be at risk during the breeding season, but may be at risk during spring or fall migrations. Risk to this species is likely to be low from turbines located far from land as this species migrates mainly along the coast. 3) Red knots are potentially exposed to some risk during migration, especially long-distance migrants whose migratory routes take them over the AOCS. More information is required on exact spatio-temporal migration routes, flight altitudes (especially during ascent and descent), and behavioral avoidance of turbines by birds to ascertain their risk. 相似文献
105.
Docosahexaenoic acid modulates oxidative stress‐induced apoptosis via PI3K/Akt m‐TOR/p70S6K pathways in human RPE cells
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106.
Junli LvHaiqiu Huang Lu YuMonica Whent Yuge Niu Haiming ShiThomas T.Y. Wang Devanand Luthria Denys CharlesLiangli Lucy Yu 《Food chemistry》2012,132(3):1442-1450
Conventional and organic cinnamon and peppermint were investigated for their phenolic profile, anti-proliferative, anti-inflammatory, and antioxidant properties. Accelerated solvent extraction with 75% acetone was used to extract samples. Caffeic acid was the most abundant phenolic acid in peppermint. Catechin, (−)-epigallocatechin gallate, syringic acid, gallic acid, vanillic acid, and p-coumaric acid were also detected in both spices. There was no significant difference between conventional and organic spices in the composition of most individual phenolics. All conventional and organic peppermint and cinnamon extracts exhibited strong anti-proliferative and anti-inflammatory properties. Cinnamon was more efficient in inhibiting IL-1β and COX-2 expression, while peppermint showed better inhibitory effect on IL-6 and MCP-1. This study indicates that cinnamon and peppermint may potentially be used as dietary sources of bioactive phytochemicals for improving health. 相似文献
107.
Study of the oxygen vacancy influence on magnetic properties of Fe- and Co-doped SnO2 diluted alloys
Pablo D Borges Luisa M R Scolfaro Horacio W Leite Alves Eronides F da Silva Jr Lucy V C Assali 《Nanoscale research letters》2012,7(1):540
Transition-metal (TM)-doped diluted magnetic oxides (DMOs) have attracted attention from both experimental and theoretical points of view due to their potential use in spintronics towards new nanostructured devices and new technologies. In the present work, we study the magnetic properties of Sn0.96TM0.04O2 and Sn0.96TM0.04O1.98(VO)0.02, where TM = Fe and Co, focusing in particular in the role played by the presence of O vacancies nearby the TM. The calculated total energy as a function of the total magnetic moment per cell shows a magnetic metastability, corresponding to a ground state, respectively, with 2 and 1 μB/cell, for Fe and Co. Two metastable states, with 0 and 4 μB/cell were found for Fe, and a single value, 3 μB/cell, for Co. The spin-crossover energies (ES) were calculated. The values are ES0/2 = 107 meV and ES4/2 = 25 meV for Fe. For Co, ES3/1 = 36 meV. By creating O vacancies close to the TM site, we show that the metastablity and ES change. For iron, a new state appears, and the state with zero magnetic moment disappears. The ground state is 4 μB/cell instead of 2 μB/cell, and the energy ES2/4 is 30 meV. For cobalt, the ground state is then found with 3 μB/cell and the metastable state with 1 μB/cell. The spin-crossover energy ES1/3 is 21 meV. Our results suggest that these materials may be used in devices for spintronic applications that require different magnetization states. 相似文献
108.
Lucy D. A. Chumpitaz Lilian F. Coutinho Antonio J. A. Meirelles 《Journal of the American Oil Chemists' Society》1999,76(3):379-382
Surface tension as a function of temperature was measured for four fatty acids (lauric, myristic, palmitic, and oleic) and
two triglycerides (tricaprylin and tripalmitin). These surface tension measurements were performed using a K12 vers. 3.1 (Krüss
GmbH) tensiometer at temperatures from 20 (or the melting point of each substance) to 90°C. The constants for a van der Waals-type
correlation as well as for a linear equation are presented. Both equations are quite accurate, presenting mean deviations
not exceeding 0.570%. Such correlation constants are valuable in the design or evaluation of processing equipment, especially
that involving gas-liquid contact such as distillation and stripping columns, deodorizers, reactors, and equipment for physical
refining. 相似文献
109.
Catherine J. Dodds Ian F. Henderson Peter Watson Lucy D. Leake 《Journal of chemical ecology》1999,25(9):2127-2145
A systematic examination was made of the plant family Apiaceae (Umbelliferae) in which extracts of 33 species, representing 32 genera, were screened for antifeedant activity against the field slug Deroceras reticulatum by using an electrophysiological recording assay. In this assay, the olfactory sensory epithelium of the posterior tentacle of the slug was exposed to volatile components of the plant extracts presented in an airstream, and any subsequent activity of the olfactory nerve was recorded. Extracts of 22 species elicited a range of nervous activity in the preparation. A feeding bioassay was used to measure any change in consumption when extracts were added to a standard food. Statistical analysis of data obtained from both electrophysiological traces and the feeding bioassays identified extracts of Petroselinum crispum, Conium maculatum, and Coriandrum sativum as being the most neuroactive as well as the most antifeedant. 相似文献
110.
Marvin KA Johnson JA Rodenbusch SE Gong L Vanden Bout DA Stevenson KJ 《Analytical chemistry》2012,84(11):5154-5158
Spectrophotometric titration and a binding isotherm were used to accurately assess the loading capacity of generation four polyamido(amine) (PAMAM) dendrimer templates with terminal alcohol groups (G4-OH). Preparation of bimetallic G4-OH dendrimer-encapsulated metal nanoclusters (DENs) necessitates knowledge of the precise metal-ion binding capacity. The binding of metal ions such as Pt(2+) and Pd(2+) has proven difficult to assess via UV-vis spectroscopy because the absorbance shifts associated with metal-ion binding within the dendrimer template are masked by the absorbance of the PAMAM dendrimer itself. In contrast, the binding of Cu(2+) to G4-OH PAMAM dendrimer results in a strong, distinct absorption band at 300 nm, making UV-vis spectrophotometric titration with copper straightforward. Here we use copper binding as a means to assess the number of binding sites remaining within the PAMAM G4-OH dendrimer after the complexation of a specified molar excess of Pd(2+) or Pt(2+). In addition, we use a binding isotherm to mathematically estimate the loading capacity of the dendrimer in each case. The loading capacities for M(2+) in the G4-OH dendrimer were found to be ~16 for copper alone, ~21 for copper combined with palladium, and ~25 for copper combined with platinum. 相似文献