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721.
Masayo Soma Mariko Hiraiwa-Hasegawa Kazuo Okanoya 《Behavioral ecology and sociobiology》2009,63(3):363-370
Birdsong differs from other sexual traits in that the acquisition process involves learning. Especially in close-ended learning
species like the Bengalese finch, conditions experienced during the critical song-learning period can have a profound influence
on song quality. Therefore, to understand song evolution from a life-history perspective, we investigated early ontogenetic
effects on song quality. In particular, we focused on maternal effects and sibling competition. In asynchronously hatching
bird species, the age hierarchy among nestlings affects physical development due to competition for food; mothers may influence
this competition by adjusting their investment in each egg according to its sequence in the laying order. To independently
assess these effects, chicks of the Bengalese finch were cross-fostered so that the age hierarchies formed in fostered broods
were independent of the laying order. Our results indicate that song quality partially reflects early ontogenetic conditions,
whereas song duration and note-type repertoire were independent of either laying order or age hierarchy. The syntactical complexity
of note order declined over the laying sequence. This finding suggests that the song learning ability is influenced by within-clutch
variation in maternal investment toward eggs. Considering that song syntactical complexity is subject to female preference
in the Bengalese finch, it is likely that maternal resource allocation strategies play a role in song evolution. 相似文献
722.
Daniel J. van der Post Bas Ursem Paulien Hogeweg 《Behavioral ecology and sociobiology》2009,63(11):1643-1658
We study how learning is shaped by foraging opportunities and self-organizing processes and how this impacts on the effects
of “copying what neighbors eat” on multiple timescales. We use an individual-based model with a rich environment, where group
foragers learn what to eat. We vary foraging opportunities by changing local variation in resources, studying copying in environments
with pure patches, varied patches, and uniform distributed resources. We find that copying can help individuals explore the
environment by sharing information, but this depends on how foraging opportunities shape the learning process. Copying has
the greatest impact in varied patches, where local resource variation makes learning difficult, but local resource abundance
makes copying easy. In contrast, copying is redundant or excessive in pure patches where learning is easy, and mostly ineffective
in uniform environments where learning is difficult. Our results reveal that the mediation of copying behavior by individual
experience is crucial for the impact of copying. Moreover, we find that the dynamics of social learning at short timescales
shapes cultural phenomena. In fact, the integration of learning on short and long timescales generates cumulative cultural
improvement in diet. Our results therefore provide insight into how and when such processes can arise. These insights need
to be taken into account when considering behavioral patterns in nature.
相似文献
Daniel J. van der PostEmail: |
723.
近年来城市臭氧(O3)污染问题日益突出,影响O3污染的关键气象因子尚不明确,因此分析典型城市——苏州的O3污染特征,探究O3污染的高影响气象因子,对该区域大气污染防治具有重要意义.基于苏州环境监测中心2015~2020年4~9月逐小时O3浓度数据及同期气象观测资料,应用相关分析和机器学习方法对其开展相关分析研究.结果表明:(1) 6年间O3污染高发季,O3污染超标率均达20%以上,O3污染日数和以O3为首要污染物的污染日数占比均逐年上升,O3污染问题日益凸显;(2) O3浓度存在单峰日变化特点,谷值出现在07:00前后,峰值出现在15:00~16:00;其与气温和太阳辐射能的日内变化趋势较一致,但其浓度峰值出现时刻又滞后于二者. 2017年和2019年O3有典型的“周末效应”,周末较高的太阳辐照度对O3浓... 相似文献
724.
以斑马鱼胚胎和幼鱼为实验对象,探讨三氯化铝(Al Cl3)在酸性环境中对斑马鱼幼鱼运动能力及学习记忆的影响。将受精后6 h(hours post-fertilization)的斑马鱼胚胎分成2个大组,分别为对照组和三氯化铝组,以观察三氯化铝的毒性作用。每一大组又分为中性(pH7.4)、微酸(pH6.4)和酸性(pH5.4)组,以观察酸性环境分别及与三氯化铝的共同毒性作用。分别采用72 hpf斑马鱼幼鱼机械逃避反射实验、144 hpf斑马鱼幼鱼自发运动、168 hpf单一多次光刺激斑马鱼幼鱼实验等探讨在中性、微酸和酸性环境下暴露铝离子对斑马鱼幼鱼运动能力以及学习记忆的影响。结果显示:与中性环境下的三氯化铝组相比,微酸和酸性环境下的三氯化铝组可以使斑马鱼幼鱼机械逃避次数减少(P0.05),平均速度和移动距离下降(P0.001),斑马鱼幼鱼运动轨迹杂乱无章,自发触壁活动减少;单一多次光刺激实验结果发现,微酸和酸性环境下的三氯化铝组使斑马鱼幼鱼到达平台速度的光照次数显著增加且差异具有统计学意义(P0.001)。以上结果说明,三氯化铝在微酸和酸性环境下,能导致斑马鱼幼鱼运动能力及学习记忆能力下降,并且酸度值越小,对斑马鱼幼鱼运动和学习记忆的影响更显著。酸度值与三氯化铝之间存在协同作用,酸性环境可以使三氯化铝毒性增加。 相似文献
725.
Screening on oil-decomposing microorganisms and application in organic waste treatment machine 总被引:5,自引:0,他引:5
As an oil-decomposable mixture of two bacteria strains ( Bacillus sp. and Pseudomonas sp. ), Y3 was isolated after 50 d domestication under the condition that oil was used as the limited carbon source. The decomposing rate by Y3 was higher than that by each separate individual strain, indicating a synergistic effect of the two bacteria. Under the conditions that T = 25-40℃, pH = 6--8, HRT (Hydraulic retention time) = 36 h and the oil concentration at 0.1%,Y3 yielded the highest decomposing rate of 95.7 %. Y3 was also applied in an organic waste treatment machine and a certain rate of activated bacteria was put into the stuffing. A series of tests including humidity, pH, temperature, C/N rate and oil percentage of the stuffing were carried out to check the efficacy of oil-decomposition. Results showed that the oil content of the stuffing with inoculums was only half of that of the control. Furthermore, the bacteria were also beneficial to maintain the stability of the machine operating. Therefore, the bacteria mixture as well as the machines in this study could be very useful for waste treatment. 相似文献
726.
727.
728.
Maud C. O. Ferrari François Messier Douglas P. Chivers 《Behavioral ecology and sociobiology》2008,62(7):1079-1083
A prerequisite for prey to show adaptive behavioural responses to predators is that the prey has the ability to recognise
predators as threats. While predator recognition can be innate in many situations, learning is often essential. For many aquatic
species, one common way to learn about predators is through the pairing of a novel predator odour with alarm cues released
from injured conspecifics. One study with fish demonstrated that this mode of learning not only allows the prey to recognise
the predatory cues as a threat, but also mediates the level of threat associated with the predator cues (i.e. threat-sensitive
learning). When the prey is exposed to the novel predator with a high concentration of alarm cues, they subsequently show
a high intensity of antipredator response to the predator cues alone. When exposed to the predator with a low concentration
of alarm cues, they subsequently show a low-intensity response to the predator cues. Here, we investigated whether larval
mosquitoes Culex restuans have the ability to learn to recognise salamanders as a threat through a single pairing of alarm cues and salamander odour
and also whether they would learn to respond to salamander cues in a threat-sensitive manner. We conditioned individual mosquitoes
with water or a low, medium or high concentration of crushed conspecific cues (alarm cues) paired with salamander odour. Mosquitoes
exposed to salamander odour paired with alarm cues and subsequently exposed to salamander odour alone responded to the salamander
as a threat. Moreover, the intensity of antipredator response displayed during the conditioning phase matched the response
intensity during the testing phase. This is the first demonstration of threat-sensitive learning in an aquatic invertebrate. 相似文献
729.
叙述某烧结厂3套烧结机尾及整粒除尘系统的电除尘器改造为长袋低压脉冲除尘器的设计及工程实例。介绍原电除尘器存在的缺陷、“电改袋”具体措施、主要设备选型以及除尘系统运行数据测试结果等方面的问题。除尘系统可靠运行已2年,各项技术指标始终保持优良状态。 相似文献
730.
Individual bees often restrict their visits to only a few species out of the multitude of available plants. This flower constancy
is likely caused by limitations of memory for motor patterns, sensory stimuli, or reward levels. Here we test the implications
of sensori-motor learning and memory for flower constancy. Artificial “flowers” with two distinct “morphologies” were used,
so that in each flower type, a different motor pattern was needed to reach the nectar. As in natural flowers, these morphological
types were associated with sensory signals (blue and yellow color stimuli). Bees which learned only a single task were more
efficient in several ways than those which had learned two: they made fewer errors, had shorter flower handling times, took
shorter times to correct errors, and transitions between flowers were initially more rapid. For bees which had learned two
tasks, performance depended strongly on the training schedule: if each task was learned with blocked trials, the memory for
the second appeared to interfere with that for the first. Interference affected only the association between flower signal
and motor pattern, not the motor pattern itself. This was not the case if bees were trained for both tasks with alternating
trials. In that case, bees rapidly learned both tasks, albeit with worse saturation levels than bees which had learned only
one. Bees transferred the experience gained on one task to a second task: their initial performance on the second task was
better than their initial performance on the first. On the other hand, performance on the second task in the saturation level (in which bees no longer improve their efficiency) was worse than on the first task (negative transfer). In the saturation
phase, performance did not directly depend on switch frequency, but on whether the bee had one or two options in memory. Thus,
while bees would become proficient at two tasks more quickly if their acquisition phase included switches, such switches had
no measurable effect in the saturation phase. The implications of these findings for foraging are discussed using modern learning
theory.
Received: 4 April 1997 / Accepted after revision: 8 August 1997 相似文献