Building Stone Treasure Troves

Cities large and small have a treasure trove of building stones both local as well as imported from various regions of the country as well as foreign sources. Many of them contain fossils which are easily available for teachers to utilize for class field trips. For some areas guidebooks exist which are listed in the attached appendix. Even for localities where no guidebook exists these published guides can be helpful especially if they are illustrated. Field trips are a useful learning tool and teachers are encouraged to create various lesson plans utilizing this generally unrecognized resource.     

Exceptions to Cajal's neuron theory: communicating synapses

Ultrastructural images of some neurons and their synaptic connections, belonging to the nucleus of the periaqueductal grey substance in the domestic cat mesencephalon, are shown. The finding that some axosomatic synapses showed an open communication between the pre- and postsynaptic portion attracted our attention. In this way a continuity is made between the presynaptic bouton of one neuron (axon) and the postsynaptic portion of the other (neuronal soma). Synapses having these interneuronal communications could be denominated communicating synapses. Accepting Cajal's neuron theory and his law of neuronal independence, it is very difficult to interpret these images. We wonder if this type of communicating synapses could be the exception that proves the rule of the neuron independence.     

A Treasure Chest of Balinese Images

Book reviewed in this article:
Images of Power: Balinese Paintings Made for Gregory Bateson and Margaret Mead . Hildred Geertz.     

Your Resting Brain CAREs about Your Risky Behavior

Background

Research on the neural correlates of risk-related behaviors and personality traits has provided insight into mechanisms underlying both normal and pathological decision-making. Task-based neuroimaging studies implicate a distributed network of brain regions in risky decision-making. What remains to be understood are the interactions between these regions and their relation to individual differences in personality variables associated with real-world risk-taking.

Methodology/Principal Findings

We employed resting state functional magnetic resonance imaging (R-fMRI) and resting state functional connectivity (RSFC) methods to investigate differences in the brain''s intrinsic functional architecture associated with beliefs about the consequences of risky behavior. We obtained an individual measure of expected benefit from engaging in risky behavior, indicating a risk seeking or risk-averse personality, for each of 21 participants from whom we also collected a series of R-fMRI scans. The expected benefit scores were entered in statistical models assessing the RSFC of brain regions consistently implicated in both the evaluation of risk and reward, and cognitive control (i.e., orbitofrontal cortex, nucleus accumbens, lateral prefrontal cortex, dorsal anterior cingulate). We specifically focused on significant brain-behavior relationships that were stable across R-fMRI scans collected one year apart. Two stable expected benefit-RSFC relationships were observed: decreased expected benefit (increased risk-aversion) was associated with 1) stronger positive functional connectivity between right inferior frontal gyrus (IFG) and right insula, and 2) weaker negative functional connectivity between left nucleus accumbens and right parieto-occipital cortex.

Conclusions/Significance

Task-based activation in the IFG and insula has been associated with risk-aversion, while activation in the nucleus accumbens and parietal cortex has been associated with both risk seeking and risk-averse tendencies. Our results suggest that individual differences in attitudes toward risk-taking are reflected in the brain''s functional architecture and may have implications for engaging in real-world risky behaviors.     

荒漠珍品—沙冬青

沙冬青 (ＡｍｍｏｐｉｐｔａｎｔｕｓｍｏｎｇｌｉｃｕｓＭａｘｉｍ .ｅｘＫｏｍ)又名蒙古沙冬青、蒙古黄花木 ,属蝶形花科沙冬青属。常绿灌木 ,高约 2ｍ ,冠幅 3ｍ ,掌状三小叶 ,稀单叶。总状花序 ,有花 8～ 10 ,花黄色。果扁平 ,长圆形 ,长 5～ 8ｃｍ ,宽 1.6～ 2ｃｍ ,种子 2～ 5 ,圆肾形 ,花期 4月 ,果期 5月。1　分布现状沙冬青为古老的常绿残遗植物 ,是干旱荒漠区唯一的常绿沙旱生灌木 ,为阿拉善戈壁荒漠的特有种 ,国家三级保护植物。成片或间断分布于东经 97 ～ 10 7 北纬 37 ～ 4 2 的荒漠 ,半荒漠地带 ,在甘肃河西走廊分布有 2 6 …