Program clocks in small mammals

Complex patterns of time, direction, and speed of running by small nocturnal mammals in activity wheels sometimes are duplicated almost exactly from night to night. These activity pattern repetitions disclose: (i) previously unknown capabilities of biological clocks to act as sequence programmers for behavior; (ii) that animals can retain a record of the sequence and timing of their activities covering an entire night; and (iii) that the activities of one night can bias an animal toward similar behavior on subsequent nights.     

Merging of modalities in the optic tectum: infrared and visual integration in rattlesnakes

The optic tectum of pit vipers (Crotalinae) contains a layer of infrared-sensitive neurons subjacent to the visual layer; these indirectly receive input from the facial pit organs. They respond transiently to the appearance or motion of warm objects within their 25 degrees to 70 degrees excitatory receptive fields (some have inhibitory regions) and presumably allow the snake to orient or strike toward prey. The infrared and visual spatiotopic tectal maps have similar but not identical axes; the infrared magnification is greater than that for vision. Bimodal neurons have receptive fields for each modality that reflect the disparity of the two maps. This finding suggests that (i) during development the infrared and visual fibers spread out independently to fill available tectal sites and (ii) bimodal neurons form local connections without regard to establishing spatial correspondence between the two modalities.     

Pavlovian conditioning with heat reinforcement produces stimulus-directed pecking in chicks

In a cooled chamber, chicks approached and pecked a small disk whose illumination preceded heat lamp activation, even when pecks prevented heat lamp onset. These behaviors did not occur when the disk and heat stimuli were randomly presented. Approach and contact of conditioned stimuli may develop even though these behaviors are not (i) evoked by the reinforcing stimulus, (ii) necessary for reinforcer reception, or (iii) ever followed by the reinforcer.     

Relationship between reaction time and electroencephalographic alpha phase

Demonstrations of a relationship between human 8 to 13 per second (alpha) electroencephalographic activity and simple visual reaction time can be made at reliable levels of confidence by (i) sampling reaction times to stimuli given at phases of the alpha cycle 10 msec apart, (ii) selecting the phase with the slowest reaction times, and (iii) collecting enough reaction times to stimuli at this and some other control phase for statistical comparison.     

Competition between seed-eating rodents and ants in desert ecosystems

Three kinds of evidence indicate that desert rodents and ants compete for seeds: (i) extensive overlaps in diet, (ii) reciprocal increases when one taxon is experimentally excluded, and (iii) complementay patterns of diversity and biomass in georadients of productivity. The effect on seed resources and annual plan geoseems to be similar whether rodents, ants, or both are foraging.     

FEBRILE CONVULSIONS IN INFANT RATS, AND LATER BEHAVIOR

At 3 days of age, rats were (i) subjected to a febrile convulsion, or (ii) were handled, or (iii) were not handled. Evaluation at 30 days of age revealed that animals in the first group were heaviest and most resistant to audiogenic seizure stimuli. No differerences were found in maze-learning ability or activity level.     

四川盆地稻茬麦垄作栽培技术研究初探

垄作(Raised-Bed planting)已成功应用于水浇地小麦生产,但稻茬麦垄作栽培技术研究还是空白。2003~2005年,在四川省双流县和广汉市先后进行了稻茬麦垄作与平作的比较试验和垄作适宜品种筛选试验。结果表明:①以1 m开厢作垄、垄面宽75cm、垄上种植3行小麦的情况下,垄作因群体起点低、有效穗数不足导致单产显著低于平作栽培;当增加垄上种植行数,提高基本苗之后,垄作与平作小麦的单产没有显著差异。②垄作有利于小麦个体发育,其单株干重、单株绿色叶面积均显著高于平作小麦,但群体干物质积累量和LAI略低于平作。③不同品种类型对垄作的反应不一样。分蘖力强、干物质积累量大、抗倒性好的大穗型品种在垄作条件下更具优势。     

农合联服务农民专业合作经济组织研究——以河北省保定市为例

以河北省保定市农合联发展为例,介绍了农合联的服务领域,主要是搭建服务平台,提供科技服务;组织经贸洽谈和交流,推进农超对接;提供金融服务,解决筹资难题。分析了保定市农合联发展存在的问题,一是地域发展不均衡,缺乏组织内部联系;二是部分县(市)农合联发展有待完善,带动效果不明显;三是人才短缺,创新力度不足;四是制度缺失,管理缺乏约束。提出了进一步发挥农合联作用,促进农民专业合作组织发展的对策建议:加强宣传,培养农民的合作意识;将农合联纳入正式制度安排,吸纳专业人才;创新农合联组织体制,完善服务方式;完善农合联组织内部运行机制,在新的发展背景下创新农合联工作内容。     

From Sequential Pattern Mining to Structured Pattern Mining： A Pattern-Growth Approach

Sequential pattern mining is an important data mining problem with broad applications. However, it is also a challenging problem since the mining may have to generate or examine a combinatorially explosive number of intermediate subsequences. Recent studies have developed two major classes of sequential pattern mining methods: (1) a candidate generation-and-test approach, represented by (i) GSP, a horizontal format-based sequential pattern mining method, and (ii) SPADE, a vertical format-based method; and (2) a pattern-growth method, represented by PrefixSpan and its further extensions, such as gSpan for mining structured patterns. In this study, we perform a systematic introduction and presentation of the pattern-growth methodology and study its principles and extensions. We first introduce two interesting pattern-growth algorithms, FreeSpan and PrefixSpan, for efficient sequential pattern mining. Then we introduce gSpan for mining structured patterns using the same methodology. Their relative performance in large databases is presented and analyzed. Several extensions of these methods are also discussed in the paper, including mining multi-level, multi-dimensional patterns and mining constraint-based patterns.     

Paleoceanographic model of neogene phosphorite deposition, u.s. Atlantic continental margin

The Neogene stratigraphic section of the southeastern U.S. continental shelf-coastal plain system is characterized by (i) a series of major regional phosphogenic episodes; (ii) a strong spatial relationship between the structural or topographic framework and phosphate deposition; and (iii) distinct cyclical and regional patterns of deposition of the terrigenous, carbonate, and phosphate lithofacies. The complex depositional patterns are explained by a paleoceanographic model based upon the interaction of glacial eustatic sea-level fluctuations, associated changes in climate, and the dynamics of the Gulf Stream in response to the bathymetric configurations of the continental margin during the past 20 million years.     

Global circumnavigations: tracking year-round ranges of nonbreeding albatrosses

Although albatrosses are paradigms of oceanic specialization, their foraging areas and migration routes when not breeding remain essentially unknown. Our continuous remote tracking of 22 adult gray-headed albatrosses for over 30 bird-years reveals three distinct strategies: (i) Stay in breeding home range; (ii) make return migrations to a specific area of the southwest Indian Ocean; and (iii) make one or more global circumnavigations (the fastest in just 46 days). The consistencies in patterns, routes, and timings offer the first hope of identifying areas of critical habitat for nonbreeding albatrosses, wherein appropriate management of longline fisheries might alleviate the plight of the world's most threatened family of birds.     

An identified neuron (CPR) evokes neuronal responses reflecting food arousal in Aplysia

Feeding behavior of Aplysia is associated with an arousal state characterized by a constellation of maintained behaviors and by a potentiation or depression of responses to specific stimuli. A neuron (the cerebral-pedal regulator or CPR) that has widespread actions on various systems connected with feeding has been identified. CPR excites neurons that modulate or drive (i) body posture, (ii) biting, and (iii) cardiovascular behaviors. CPR also inhibits neurons concerned with defensive responses. Food stimuli, which elicit food arousal in the animal, produce prolonged excitation of the CPR. The results suggest that the CPR may evoke a central motive state representing the neuronal correlate of feeding motivation.     

Anolis carolinensis: Effects of Feeding on Reaction to Aposematic Prey

During a 15-day experiment, green anoles, Anolis carolinensis, were: (i) presented with one of two aposematic insects, Oncopeltus fasciatus or Photinus pyralis, during days 4, 6, and 8; (ii) maintained on one of four different food levels during days 9-14; and (iii) presented with the original model on day 15. Lizards on low rations tended to capture more Photinus on day 15 than did anoles on higher rations. No such correlation was observed with Oncopeltus.     

Genesis of petroleum hydrocarbons in marine sediments

Distribution patterns of isopentane and normal pentane in marine sediments show a reversal in slope at a subsurface temperature of about 90 degrees C. The data indicate that three types of reactions are involved in pentane formation: (i) biological origin at the sediment surface, (ii) low-temperature (< 90 degrees C) chemical reactions yielding predominately secondary carbon structures, and (iii) high-temperature (> 90 degrees C) cracking reactions at great depth yielding predominately straight carbon chains.     

基于和谐社区构建的中国城市社区治理多元互动模式研究

纵观中国社区治理模式的历史演变,可以将其概括为三种主要类型:政府主导型治理模式;社区合作型治理模式;居民自治型治理模式。针对目前社区治理模式的主要问题,构建城市社区治理的多元互动模式主要体现为发挥社区居民的自治性权利,实现社区治理主体、居民参与、社区公共事务治理、社区制度建构等层面的分权参与。基于和谐社区构建要求,中国城市社区治理多元互动模式的路径选择主要在于转变地方政府职能、强化多元合作关系、重视公民社会的主体权威维护、构建和谐治理机制等。     

Central neuron initiation of periodic gill movements

In Aplysia periodic spontaneous gill movements are controlled by activity endogenous to the abdominal ganglion. These movements were still observed when only the ctenidio-genital nerve was left intact between the ganglion and the gill. One kind of spontaneous gill movement (one per 5 minutes at 15 degrees C) was correlated with the expression of activity of interneuron II; others were not. With reference to this kind of spontaneous gill movement, four types of central neurons in the ganglion send processes to the gill via the nerve. Two cell types (ii, iii) are inhibited and the other two (i, iv) are excited. Two types (i, ii) elicited gill movement-one type activating large gill areas elicited spontaneous gill movements, and the other activating specific gill regions did not participate in the spontaneous gill movements. The value of this preparation in studying the role of central neurons eliciting specific patterned movements and the temporal organization of their activity is shown.     

Toward a universal law of generalization for psychological science

A psychological space is established for any set of stimuli by determining metric distances between the stimuli such that the probability that a response learned to any stimulus will generalize to any other is an invariant monotonic function of the distance between them. To a good approximation, this probability of generalization (i) decays exponentially with this distance, and (ii) does so in accordance with one of two metrics, depending on the relation between the dimensions along which the stimuli vary. These empirical regularities are mathematically derivable from universal principles of natural kinds and probabilistic geometry that may, through evolutionary internalization, tend to govern the behaviors of all sentient organisms.     

Regional ground-water mixing and the origin of saline fluids: midcontinent, United States

Ground waters in three adjacent regional flow systems in the midcontinent exhibit extreme chemical and isotopic variations that delineate large-scale fluid flow and mixing processes and two distinct mechanisms for the generation of saline fluids. Systematic spatial variations of major ion concentrations, H, O, and Sr isotopic compositions, and ground-water migration pathways indicate that each flow system contains water of markedly different origin. Mixing of the three separate ground waters exerts a fundamental control on ground-water composition. The three ground waters are: (i) dilute meteoric water recharged in southern Missouri; (ii) saline Na-Ca-Cl water in southeastern Kansas of far-traveled meteoric origin that acquired its salinity by halite dissolution; and (iii) Na-Ca-Cl brines in north-central Oklahoma that may have originated as Paleozoic seawater.     

Lactate dehydrogenase isozymes in human cardiac transplantation

Lactate dehydrogenase (LDH) isozyme activities have been followed in 17 human cardiac allografts. A pattern of abnormality associated with cardiac rejection during the first month after operation has been determined: (i) LDH-1 activity is greater than LDH-2 activity; (ii) LDH-1 activity is greater than 35 percent of total LDH activity; and (iii) LDH-1 activity is greater than 100 international units. The LDH-1 abnormality helps to meet the need for an index of cardiac rejection during the early weeks after operation when the electro-cardiogram is least reliable.