二阶混合型周期系统的周期解

本文应用Fourier分析的方法,改进了文〔1〕的主要结果。即把文〔l〕中定理1到定理4的条件|b_2|＋|c_2|＜2~(1/2)改讲为|b_2|＋|c_2|≠1．并指出用本文的方法可以类似研究高阶混合型周期系统的周期解。     

复合氨基酸注射液中氨基酸对山梨醇测定的影响与解决方法

复合氨基酸注射液如１１Ｓ、１４Ｓ中的氨基酸可使山梨醇的测定结果偏高６％,解决方法是将注射液通过磺酸型阳离子交换树脂柱,氨基酸成分在柱上被交换,山梨醇用水洗脱后测定。本方法对制订复合氨基酸类注射液的质量标准与确保产品质量均具有实际应用价值。     

Brave New World: the epistatic foundations of natives adapting to invaders

Classical examples indicated rapid evolution to be both rare and largely anthropogenic. As the pace and scale of human disturbance increase, such evolution is becoming more the norm. Genetically based adaptation may underlie successful biological invasions, and may likewise characterize responses in natives to invasives. Recent published studies confirm that natives are adapting morphologically, behaviorally, physiologically and life historically to selection from invasive species. Some of the processes involved are evident in our studies of recent host shifts to invasive plants by native soapberry bugs in North America and Australia. On both continents populations have differentiated extensively in fitness traits. Genetic architecture of these adaptations involves a surprising degree of non-additive variation (epistasis, dominance), a result that in theory may reflect a history of colonization by a small number of individuals followed by population growth. Such “founder-flush” events may unleash extraordinary evolutionary potential, and their importance will be clarified as more studies take advantage of the accidental perturbation experiments that biotic invasions represent. From a conservation standpoint, rapid evolution in natives will present challenges for ecologically appropriate and sustainable management, but at the same time may enhance the capacity of the native community to act in the biological control of invasive species.     

Role of infection on the stability of a predator-prey system with several response functions--a comparative study

In this paper, we have proposed and analyzed a mathematical model of an infected predator-prey system with different predators' functional response. The existence and uniqueness of solutions are established and solutions are shown to be uniformly bounded for all nonnegative initial values. Our overall mathematical and biological studies reveal that if the prey population is infected by a lethal disease, coexistence of all three species (i.e. host, parasite and predator) for any of three functional responses is never possible but different interesting dynamical behaviors are possible by varying two key parameters viz. the rate of infection and the attack rate on susceptible prey. Interplay between these two factors yields a diverse array of biologically relevant behavior, including switching of stability, extinction and oscillations.     

Culture and inattentional blindness: a global workspace perspective

A recent 'necessary conditions' mathematical treatment of Baars' global workspace consciousness model, analogous to Dretske's communication theory analysis of high level mental function, is used to explore the effects of embedding cultural heritage on inattentional blindness. Culture should express itself quite distinctly in this basic psychophysical phenomenon across a great variety of sensory modalities because the limited syntactic and grammatical bandpass of the rate distortion manifold characterizing conscious attention must conform to topological constraints generated by cultural context.     

Minimizing Leg-Hold Trapping Trauma for Otters With Mobile Phone Technology

ABSTRACT We present and evaluate a protocol for the capture of otters (Lutra lutra) using padded leg-hold traps coupled with Global System for Mobile communication (GSM) trap alarms. The trapping method was highly efficient, capturing 46 otters at 6.9 trap-nights each. Functioning alarms allowed us to remove 36 otters from their traps within 22 (SD = 14) minutes of capture. We caught 10 otters in trap sets with malfunctioning trap alarms and retrieved them the following morning, after ≤24 hours. Functioning alarms reduced the injuries suffered from an average cumulative score of 77.7 to just 5.5 on the International Organization for Standardization 10990-5 trauma scale (Z=-5.074, P ≤ 0.001). As a result, we strongly encourage the use of GSM trap alarms under the principle of refinement in animal experiments.     

Regional differences in the neuroprotective effect of minocycline in a mouse model of global forebrain ischemia

We investigated the effect of minocycline on neuronal damage in the hippocampus and striatum in a mouse model of transient global forebrain ischemia. Male C57BL/6 mice were anesthetized with halothane and subjected to bilateral occlusion of the common carotid artery (BCCAO) for 30 min. Minocycline (90 mg/kg, i.p., qd) or saline was injected immediately after BCCAO and daily for the next two days (45 mg/kg, i.p., bid). In order to reduce the variability in ischemic neuronal damage, we applied selection criteria based on regional cerebral blood flow (rCBF), evaluated using laser Doppler flowmetry, and the plasticity of the posterior communicating artery (PcomA), evaluated using India ink solution. In animals with rCBF that was less than 15% of the baseline value and with a smaller PcomA, of diameter less than one-third that of the basilar artery, we consistently observed neuronal damage in the striatum and hippocampal subfields, including medial CA1, CA2, and CA4. When the effect of minocycline was assessed with cresyl violet staining, neuronal damage in the medial part of the CA1 subfield and the striatum was found to be significantly attenuated, although minocycline did not protect against neuronal damage in the remaining hippocampal subfields. Immunohistochemistry for NeuN, adenosine A1 receptor, and SCIP/Oct-6 confirmed the region-specific effect of minocycline in the hippocampus. In summary, our results suggest that minocycline protects neurons against global forebrain ischemia in a subregion-specific manner.     

A web-based GIS tool for exploring the world's biodiversity: The Global Biodiversity Information Facility Mapping and Analysis Portal Application (GBIF-MAPA)

Legacy biodiversity data from natural history and survey collections are rapidly becoming available in a common format over the Internet. Over 110 million records are already being served from the Global Biodiversity Information Facility (GBIF). However, our ability to use this information effectively for ecological research, management and conservation lags behind. A solution is a web-based Geographic Information System for enabling visualization and analysis of this rapidly expanding data resource. In this paper we detail a case study system, GBIF Mapping and Analysis Portal Application (MAPA), developed for deployment at distributed database portals. Building such a system requires overcoming a series of technical and research challenges. These challenges include: assuring fast speed of access to the vast amounts of data available through these distributed biodiversity databases; developing open standards based access to suitable environmental data layers for analyzing biodiversity distribution; building suitably flexible and intuitive map interfaces for refining the scope and criteria of an analysis; and building appropriate web-services based analysis tools that are of primary importance to the ecological community and make manifest the value of online biodiversity GBIF data. After discussing how we overcome these challenges, we provide case studies showing two examples of the use of GBIF-MAPA analysis tools.     

Ranking bioprocess variables using global sensitivity analysis: a case study in centrifugation

The selection of appropriate operating conditions for bioprocessing is complex due to the large number of interacting stages and variables. Bioprocesses also operate under tight regulation and therefore tools to assist bioprocess design are of significant utility. Conventional approaches for the analysis of variable sensitivities are inadequate. We propose the use of global sensitivity analysis to determine the level of importance of each variable and their interactions. Once key variables have been determined, the designer may focus on the most significant subset. Two case studies are used to demonstrate the applicability of the approach. Each is based on centrifugation and determines the impact of flow-rate, feed viscosity, density difference and particle size, while performance is assessed by supernatant clarification. Significant differences in sensitivities were found between the two studies due to the different feed material properties. Variable sensitivities were found to be system-specific and provide insight for potential operating strategies.     

Towards a collaborative, global infrastructure for biodiversity assessment

Biodiversity data are rapidly becoming available over the Internet in common formats that promote sharing and exchange. Currently, these data are somewhat problematic, primarily with regard to geographic and taxonomic accuracy, for use in ecological research, natural resources management and conservation decision-making. However, web-based georeferencing tools that utilize best practices and gazetteer databases can be employed to improve geographic data. Taxonomic data quality can be improved through web-enabled valid taxon names databases and services, as well as more efficient mechanisms to return systematic research results and taxonomic misidentification rates back to the biodiversity community. Both of these are under construction. A separate but related challenge will be developing web-based visualization and analysis tools for tracking biodiversity change. Our aim was to discuss how such tools, combined with data of enhanced quality, will help transform today's portals to raw biodiversity data into nexuses of collaborative creation and sharing of biodiversity knowledge.