The science education of biology teachers

A report of a conference discussion at Nottingham on the need for augmenting the scientific knowledge of trainee biology teachers in University Departments of Education. Statistics were gathered from a sample of 64 students as a basis for the discussion. These indicate the extent to which the students lack training in relevant scientific subjects and in particular biological topics.     

Biology and the B.Ed. Degree

The dispersion of animals is one aspect of ecology that lends itself to laboratory simulation. Photographs of the Tenebrionid beetle Catamerus rugosus were taken at different stages in its life cycle. Students were asked to relate these to real life and carry out a statistical analysis to determine the degree of dispersion of the animals. The photographs are shown and the results demonstrate a change in dispersion throughout the life cycle.     

The protective effect of eicosapentaenoic acid-enriched phospholipids from sea cucumber Cucumaria frondosa on oxidative stress in PC12 cells and SAMP8 mice

Alzheimer’s disease (AD) is a common neurodegenerative disorders, in which oxidative stress plays an important role. The present study investigated the effect of eicosapentaenoic acid-enriched phospholipids (EPA-enriched PL) from the sea cucumber Cucumaria frondosa on oxidative injury in PC12 cells induced by hydrogen peroxide (H₂O₂) and tert-butylhydroperoxide (t-BHP). We also studied the effect of EPA-enriched PL on learning and memory functions in senescence-accelerated prone mouse strain 8 (SAMP8) in vivo. Pretreatment with EPA-enriched PL resulted in an enhancement of survival in a dose-dependent manner in H₂O₂ or t-BHP damaged PC12 cells. EPA-enriched PL pretreatment could also reduce the leakage of lactate dehydrogenase (LDH), and increase the intracellular total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity compared with the H₂O₂ or t-BHP group. The down-regulated Bcl-2 mRNA level and up-regulated Bax, Caspase-9, and Caspase-3 mRNA expression induced by H₂O₂ or t-BHP could be restored by EPA-enriched PL pretreatment. These results demonstrated that EPA-enriched PL exhibited its neuroprotective effects by virtue of its antioxidant activity, which might be achieved by inhibiting the mitochondria-dependent apoptotic pathway. The neuroprotective effect of EPA-enriched PL was also verified in vivo test: the EPA-enriched PL administration prevented the development of learning and memory impairments in SAMP8 mice. Our results indicated that EPA-enriched PL could offer an efficient and novel strategy to explore novel drugs or functional food for neuronprotection and cognitive improvement.     

‘Why do parrots talk?’ co-investigation as a model for promoting family learning through conversation in a natural history gallery*

Research into how and what families learn in science museums and other informal science learning settings suggests that parent-child interactions play an important role in shaping children’s learning experiences. Our exploratory case study set out to discover and analyse learning happening within family groups during a visit to a traditional museum natural history gallery. Research methods were influenced by a growing body of literature that looks for learning in family visitor talk. Conversations of 18 families were recorded as they explored a gallery after being introduced to six learning games which fostered a ‘climate of inquiry’ and which were designed to spark family dialogue. Our findings indicate that families adopt a range of interactional approaches for building meaning together in a museum gallery. These approaches fell along a spectrum that varied according to the level of co-investigation and co-operation between group members. We suggest that family learning could be supported in informal learning contexts through simple, low-cost learning strategies that encourage dialogue and co-investigatory behaviours.     

乌鸦学会打开巢箱进行捕食

本文首次报道了大嘴乌鸦（Corvus macrorhynchos）学会打开人工巢箱捕食在里面繁殖的绿背山雀（Parus monticolus）,包括成鸟、雏鸟和卵。这种行为极有可能是通过观察人类行为而习得,但需要进一步研究来验证。     

Effects of penitrem A on rat's performances in passive avoidance and Morris water maze tests

Intraperitoneal administration of the mycotoxin penitrem A 30 min before a training session in passive avoidance task, impaired performance of rats subjected to a test-session 24 h after. This effect was not antagonised by pretraining administration of physostigmine or bicuculline. Administration of penitrem A 20 min before a training session or 30 min before a test-session did not impair performance. In the Morris water maze, doses of penitrem A that induces slight to moderate tremors, but not a lower dose, disrupted place learning. These results suggest that penitrem A disrupts the processes that take place at the time of acquisition, but not those just after acquisition, and does not alter the restitution of information. This effect would not be related to a decrease of cholinergic neurotransmission nor to a stimulation of GABA A receptors. Nevertheless, it could not be totally excluded that the performance impairments induced by penitrem A would be secondary to a motor disruption. This revised version was published online in June 2006 with corrections to the Cover Date.     

Scrounger numbers and the inhibition of social learning in pigeons

Social foraging can inhibit the learning and performance of food-finding behaviours. Confusion, overshadowing and frequency-dependent payoffs may all contribute to the inhibition, but standard experimental procedures make the separation of these effects difficult. In this study, we combine characteristics of cage and aviary experiments and present either a single naive pigeon or groups of three naive pigeons with a pre-trained producer opening an apparatus in an aviary. All naive birds scrounged on the 3456 openings they witnessed. In a post-test given in the absence of other birds, all single scroungers opened the apparatus, but only one of the group-scrounging pigeons did. Scrounger numbers appear to play an important role in the inhibition of food-finding behaviour, suggesting that confusion is a major component of learning in a social context.     

Eye-specific learning of routes and “signposts” by walking honeybees

This study investigates the honeybee's ability to learn routes based on visual stimuli presented to a single eye, and to then navigate these routes using the other (naive) eye. Bees were trained to walk through a narrow tunnel carrying visual stimuli on the two walls. At the end of the tunnel the bees had to choose between two arms, one of which led to a feeder. In a first experiment, bees had to learn to choose the left arm to get a reward when the right wall carried a yellow grating, but the right arm when the left wall carried a blue grating. The bees learned this task well, indicating that stimuli encountered by different eyes could be associated with different routes. In a second experiment, bees had to turn left when the right eye saw a blue grating, but to the right when the same eye saw a yellow grating. They also learned this task well. In subsequent tests, they chose the correct arm even when these gratings were presented to the untrained eye. These results suggest that there is interocular transfer of route-specific learning with respect to visual stimuli that function as navigational “signposts”. Accepted: 18 December 1997     

Memory dynamics in the honeybee

Reward learning in honeybees initiates a sequence of events which leads to long-lasting memory passing through multiple phases of transient memories. The study of memory dynamics is performed at the behavioral (both natural foraging behavior and appetitive conditioning), neural circuit and molecular levels. The results of these combined efforts lead to a model which assumes five kinds of sequential memories, each characterized by a set of behavioral and mechanistic properties. It is argued that these properties, although reflecting general characteristics of step-wise memory formation, are adapted to the species-specific adaptations in natural behavior, here to foraging at scattered and unreliable food sources. Accepted: 12 May 1999