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101.
A. W. Stoner 《Journal of fish biology》2003,62(5):1176-1193
Laboratory experiments with Pacific halibut Hippoglossus stenolepis revealed that hunger level had a significant effect on the first detection of bait, the number of baits located and attacked, the time required to locate and attack baits and handling times. In all cases, feeding motivation and efficiency increased with hunger. Light level influenced general locomotory activity and location and attacks on baits, but not detection or handling times. The effect of light was interactive with fish hunger level. Hungry fish could locate and consume baits in all light levels, ranging from daylight conditions to near darkness (10−8 µmoles photons m−2 s−1 ), but location, attack and handling times were all significantly elevated in low light conditions, and attack rates were significantly reduced. In the dark, only 50% of the baits were located and only 17% were attacked. Performance metrics were relatively similar among three higher light treatments (10−5 , 10−3 and 10−1 µmoles photons m−2 s−1 ) where bait location and attack were more efficient. Active space and effective area associated with baited fishing gear will vary because hunger and light levels affect variation in bait detection, locomotion and feeding behaviour. Consequently, fishing activity and stock assessments that depend upon bait may be compromised by spatial and temporal variation in prey abundance, time of day, season, depth and other environmental variables that influence feeding motivation and efficiency. 相似文献
102.
Michel A. Paul James C. Miller Ryan J. Love Harris Lieberman Sofi Blazeski Josephine Arendt 《Chronobiology international》2013,30(5):867-890
Jet lag degrades performance and operational readiness of recently deployed military personnel and other travelers. The objective of the studies reported here was to determine, using a narrow bandwidth light tower (500 nm), the optimum timing of light treatment to hasten adaptive circadian phase advance and delay. Three counterbalanced treatment order, repeated measures studies were conducted to compare melatonin suppression and phase shift across multiple light treatment timings. In Experiment 1, 14 normal healthy volunteers (8 men/6 women) aged 34.9±8.2 yrs (mean±SD) underwent light treatment at the following times: A) 06:00 to 07:00 h, B) 05:30 to 07:30 h, and C) 09:00 to 10:00 h (active control). In Experiment 2, 13 normal healthy subjects (7 men/6 women) aged 35.6±6.9 yrs, underwent light treatment at each of the following times: A) 06:00 to 07:00 h, B) 07:00 to 08:00 h, C) 08:00 to 09:00 h, and a no-light control session (D) from 07:00 to 08:00 h. In Experiment 3, 10 normal healthy subjects (6 men/4 women) aged 37.0±7.7 yrs underwent light treatment at the following times: A) 02:00 to 03:00 h, B) 02:30 to 03:30 h, and C) 03:00 to 04:00 h, with a no-light control (D) from 02:30 to 03:30 h. Dim light melatonin onset (DLMO) was established by two methods: when salivary melatonin levels exceeded a 1.0 pg/ml threshold, and when salivary melatonin levels exceeded three times the 0.9 pg/ml sensitivity of the radioimmunoasssy. Using the 1.0 pg/ml DLMO, significant phase advances were found in Experiment 1 for conditions A (p?<?.028) and B (p?<?0.004). Experiment 2 showed significant phase advances in conditions A (p?<?0.018) and B (p?<?0.003) but not C (p?<?0.23), relative to condition D. In Experiment 3, only condition B (p?<?0.035) provided a significant phase delay relative to condition D. Similar but generally smaller phase shifts were found with the 2.7 pg/ml DLMO method. This threshold was used to analyze phase shifts against circadian time of the start of light treatment for all three experiments. The best fit curve applied to these data (R2?=?0.94) provided a partial phase-response curve with maximum advance at approximately 9–11 h and maximum delay at approximately 5–6 h following DLMO. These data suggest largest phase advances will result when light treatment is started between 06:00 and 08:00 h, and greatest phase delays will result from light treatment started between 02:00 to 03:00 h in entrained subjects with a regular sleep wake cycle (23:00 to 07:00 h). 相似文献
103.
人心肌肌球蛋白轻链1的克隆,表达纯化和单抗制备 总被引:2,自引:2,他引:2
报道了中国人心肌肌球蛋白轻链1cDNA的核苷酸序列,并由此推算的氨基酸序列。与国外发表的人心肌肌球蛋白轻链的氨基酸序列比较,发现有两处差异,即在24位,由谷氨酸变为丙氨酸,则从98位起至101位有4个氨基酸序列的连续差异,即由天冬酰胺-精氨酸-丝氨酸-赖氨酸变为赖氨酸-脯氨酸-精氨酸-谷氨酰妥,推测可能是由于人种差异而引起的。利用该cDNA在大肠杆菌内的表达产物,已获得一株高效的抗中国人心肌肌球蛋 相似文献
104.
Hiroshi Nakagawa Hironari Kamikubo Mikio Kataoka 《Biochimica et Biophysica Acta - Proteins and Proteomics》2010,1804(1):27-33
In order to examine the properties specific to the folded protein, the effect of the conformational states on protein dynamical transition was studied by incoherent elastic neutron scattering for both wild type and a deletion mutant of staphylococcal nuclease. The deletion mutant of SNase which lacks C-terminal 13 residues takes a compact denatured structure, and can be regarded as a model of intrinsic unstructured protein. Incoherent elastic neutron scattering experiments were carried out at various temperature between 10 K and 300 K on IN10 and IN13 installed at ILL. Temperature dependence of mean-square displacements was obtained by the q-dependence of elastic scattering intensity. The measurements were performed on dried and hydrated powder samples. No significant differences were observed between wild type and the mutant for the hydrated samples, while significant differences were observed for the dried samples. A dynamical transition at ∼ 140 K observed for both dried and hydrated samples. The slopes of the temperature dependence of MSD before transition and after transition are different between wild type and the mutant, indicating the folding induces hardening. The hydration water activates a further transition at ∼ 240 K. The behavior of the temperature dependence of MSD is indistinguishable for wild type and the mutant, indicating that hydration water dynamics dominate the dynamical properties. 相似文献
105.
David C. Bartholomew Paulo R. L. Bittencourt Antonio C. L. da Costa Lindsay F. Banin Patrícia de Britto Costa Sarah I. Coughlin Tomas F. Domingues Leandro V. Ferreira André Giles Maurizio Mencuccini Lina Mercado Raquel C. Miatto Alex Oliveira Rafael Oliveira Patrick Meir Lucy Rowland 《Plant, cell & environment》2020,43(10):2380-2393
The response of small understory trees to long-term drought is vital in determining the future composition, carbon stocks and dynamics of tropical forests. Long-term drought is, however, also likely to expose understory trees to increased light availability driven by drought-induced mortality. Relatively little is known about the potential for understory trees to adjust their physiology to both decreasing water and increasing light availability. We analysed data on maximum photosynthetic capacity (Jmax, Vcmax), leaf respiration (Rleaf), leaf mass per area (LMA), leaf thickness and leaf nitrogen and phosphorus concentrations from 66 small trees across 12 common genera at the world's longest running tropical rainfall exclusion experiment and compared responses to those from 61 surviving canopy trees. Small trees increased Jmax, Vcmax, Rleaf and LMA (71, 29, 32, 15% respectively) in response to the drought treatment, but leaf thickness and leaf nutrient concentrations did not change. Small trees were significantly more responsive than large canopy trees to the drought treatment, suggesting greater phenotypic plasticity and resilience to prolonged drought, although differences among taxa were observed. Our results highlight that small tropical trees have greater capacity to respond to ecosystem level changes and have the potential to regenerate resilient forests following future droughts. 相似文献
106.
107.
西双版纳人工林林窗光照剖线分布特征 总被引:12,自引:0,他引:12
以林窗北缘为中心,研究了西双版纳地区橡胶林林窗及周边N-S样带上光照水平梯度分布。结果表明:林窗的发生导致光照明显增加,从林内到林窗中央,光强呈明显增大趋势,上午雾末消退时,相对光照强度水平梯度变化曲线峰值出现于林窗中央,午后雾消退后,林窗边缘为相对光强梯度变化最甚的地段,峰值由林窗中央向林窗北缘移进。林窗边缘,林窗中央及林内光照强度日变化曲线均为不对称的单峰型,但峰值出现和振幅不同。在太阳高度角 相似文献
108.
Ultra‐sensitive immunoassay biosensors using hybrid plasmonic‐biosilica nanostructured materials 下载免费PDF全文
Jing Yang Le Zhen Fanghui Ren Jeremy Campbell Gregory L. Rorrer Alan X. Wang 《Journal of biophotonics》2015,8(8):659-667
We experimentally demonstrate an ultra‐sensitive immunoassay biosensor using diatom biosilica with self‐assembled plasmonic nanoparticles. As the nature‐created photonic crystal structures, diatoms have been adopted to enhance surface plasmon resonances of metal nanoparticles on the surfaces of diatom frustules and to increase the sensitivity of surface‐enhanced Raman scattering (SERS). In this study, a sandwich SERS immunoassay is developed based on the hybrid plasmonic‐biosilica nanostructured materials that are functionalized with goat anti‐mouse IgG. Our experimental results show that diatom frustules improve the detection limit of mouse IgG to 10 pg/mL, which is ?100× better than conventional colloidal SERS sensors on flat glass.
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110.