改进的以SMT为基础的实时系统限界模型检测

基于SAT的限界模型检测在处理实时系统时具有很高的复杂度.SMT求解器在计算可满足性的同时,还能处理算术和其他可判定性理论.在对实时系统进行检测时,用SMT求解器代替SAT求解器,系统里的时钟就可以用整型或实型变量表示,时钟约束则可以直接表示成线性算术表达式,从而使整个检测过程更加高效.带时间参数的计算树逻辑(timed computation tree logic,简称TCTL)被用来描述实时系统里的性质.同时,还对检测方法作了相应的改进.

基于Yices对时间自动机的有界模型检测

为了避免在有界模型检测过程中对变量进行布尔编码以及对时间自动机模型中的时钟进行预处理,给出一个利用SMT(satisfiability modulo theories)工具进行的对时间自动机进行有界模型检测的方法。该方法将时间自动机模型直接转换成SMT工具可识别的逻辑公式,利用SMT工具可求解包含有整数型和实数型变量逻辑公式的能力来进行模型检测。实验结果表明,对于某些可达性性质的验证,该方法的效率有一定的优势。

Development of rRNA and rDNA-targeted probes for fluorescence in situ hybridization to detect Heterosigma akashiwo (Raphidophyceae)

Heterosigma akashiwo (Hada) is a fragile, fish-killing alga. Efforts to understand and prevent blooms due to this harmful species to mitigate the impact on aquaculture require the development of methods for rapid and precise identification and quantification, so that adequate warning of a harmful algal bloom may be given. Here, we report the development and application of rRNA and rDNA-targeted oligonucleotide probes for fluorescence in situ hybridization (FISH) to aid in the detection and enumeration of H. akashiwo. The designed probes were species specific, showing no cross-reactivity with four common HAB causative species: Prorocentrum micans Ehrenberg, P. minimum (Pavillard) Schiller, Alexandrium tarmarense (Lebour) Balech, and Skeletonema costatum (Greville) Cleve, or with four other microalgae, including Gymnodinium sp. Stein, Platy-monas cordiformis (Karter) Korsch, Skeletonema sp.1 Greville and Skeletonema sp.2. The rRNA-targeted probe hybridized to cytoplasmic rRNA, showing strong green fluorescence throughout the whole cell, while cells labeled by rDNA-targeted probe exhibited exclusively fluorescent nucleus. The detection protocols were optimized and could be completed within an hour. For rRNA and rDNA probes, about a corresponding 80% and 70% of targeted cells could be identified and quantified during the whole growth circle, despite the inapparent variability in the average probe reactivity. The established FISH was proved promising for specific, rapid, precise, and quantitative detection of H. akashiwo. (C) 2008 Elsevier B.V. All rights reserved.

胶州湾典型增养殖海域有害赤潮生消过程及关键因子研究

有害赤潮（Harmful algal blooms, HAB）已成为全球性的海洋灾害，对我国近海养殖业危害尤为巨大，研究赤潮发生、发展的主要环境影响因子，对于控制赤潮的发生以及加强赤潮的防治具有十分重要的意义。本文根据国家自然科学基金“九五”重大项目“中国沿海典型增养殖区有害赤潮发生动力学防治对策研究”项目组近年来对胶州湾东北部养殖海域的监测资料，分析了该海区营养状况，结合该区自然环境特点，探讨了发生于1998年7月和1999年6月两次硅藻赤潮的主要影响因子；并应用胶州现场海水进行了室内模拟培养实验，对影响有害赤潮生消过程的关键环境因子进行了分析探讨。对1998和1999年赤潮多发季节胶州湾东北部增养殖水域海水的营养状况进行了分析，并参照潜在性富营养化的概念，应用NQI指数对该海域的富营养化水平进行了评价。结果表明：（1）胶州湾东北部增养殖海域赤潮多发季节TIN、DIP和活性硅酸盐的含量均较高，远高于同期胶州湾大面观测站各营养盐的平均含量；该海域有机污染物含量相对营养盐含量不高。（2）该海域春季氮、磷营养盐含量充足，水域属富营养化平；夏季该海域具有较高的生物具，磷酸盐水平相对较低，海域多数时间属于磷限制潜在性富营养化水平；但这种限制极易为外界补充所改变，如陆源输入、养殖废水的排放等。（3）该海域为典型增养殖区，养殖废水对海域营养盐的补充有重要意义，因此应当加强对该海域养殖业的综合管理。对分别于1998年7月和1999年6月在胶州湾东北部增养殖海域发生的中肋骨条藻（Skeletonema costatum）赤潮和浮动弯角藻（Eucampia zoodiacus）赤潮生消过程中环境因子的变化进行了探讨。发生赤潮生物量的升高常伴随海水pH值、溶解氧（DO）含量的升高以及各营养盐（氮、磷、硅）含量的降低；认为在该海域较高营养盐含量和较高生物量的情况下，赤潮发生前大规模的降雨过程及随后的气候条件为赤潮生物的快速生长繁殖创造了有利条件；无机磷和活性硅酸盐含量相对于无机氮显得较低，对该海域硅藻赤潮的生消过程起着控制作用。采集胶州湾现场海水进行了实验室模拟培养实验，对影响赤潮生消过程的主要环境因素进行了研究和探讨。结果表明，现场海水进行模拟培养时，排除了潮流、风以及水团间交流混合等因素对水体中浮游生物的影响，培养水体中的浮游植物生物量都存在增高的现象；在氮、磷、硅等营养盐含量充足的条件下，浮游植物可快速进入指数增长期，并较快发展形成赤潮，高浓度的营养盐常导致培养水体中浮游植物的较高的生长速率，浮游植物对氮磷营养盐的吸收受到环境中营养盐含量的影响；初始环境下营养盐的限制可抑制浮游植物的进一步增殖，发生赤潮水体中某种营养盐的含量降低最终导致了赤潮的消亡。

DSP等赤潮藻毒素对哺乳类细胞的毒性效应及机制研究

本文研究了腹泻性贝毒的主要组分大田软海绵酸以及几株重要赤潮藻的提取物对四株哺乳类细胞的毒性效应，并探讨了应用细胞毒性检测方法作为赤潮藻毒素毒性检测常规方法的可能性。 结果发现：OA和利玛原甲藻提取物显著地抑制四株细胞的增殖并诱导四株细胞发生凋亡；四株细胞对毒素的敏感性存在一定的差异，人肝癌细胞和小鼠神经瘤细胞较敏感，其次分别为人肝细胞和小鼠皮肤细胞。 小鼠神经瘤细胞对OA反应敏感，细胞毒性检测指标及检测方法灵敏、快速，应用小鼠神经瘤细胞Neuro-2a进行的DSP毒素细胞毒性测试方法具有发展为该类毒素毒性监测常规方法的潜能。 米氏凯伦藻内存在抑制细胞增殖的毒性物质，且该物质是一种具有一定极性的脂溶性物质；该物质能够导致细胞肿胀、破裂，并诱导细胞发生脂质过氧化，导致脂质过氧化产物丙二醛(MDA)的积累。 相关亚历山大藻的去藻过滤液内存在抑制细胞增殖和诱导细胞凋亡的毒性物质，该毒性物质的分子量＞5K，这与本实验室以往的研究结果一致。 　　总之，通过我们的研究发现：DSP等赤潮藻毒素或毒性物质对哺乳类细胞存在毒性影响，且不同毒素的危害机制存在差异，赤潮藻毒素或赤潮藻产生的一些毒性物质威胁人类的健康，应引起我们的高度关注。

Application of rotifer Brachionus plicatilis in detecting the toxicity of harmful algae

The toxicity of seven major HAB (harmful algal bloom) species/strains, Prorocentrum donghaiense, Phaeocystis globosa, Prorocentrum micans, Alexandrium tamarense (AT-6, non-PSP producer), Alexandrium lusitanicum, Alexandrum tamarense (ATHK) and Heterosigma akashiwo were studied against rotifer Brachionus plicatilis under laboratory conditions. The results show that P. donghaiense, P. globosa, P. micans, A. tamarense (AT-6), or A. lusitanicum could maintain the individual survival and reproduction, as well as the population increase of the rotifer, but the individual reproduction would decrease when exposed to these five algae at higher densities for nine days; H. akashiwo could decrease the individual survival and reproduction, as well as population increase of the rotifer, which is similar to that of the starvation group, indicating that starvation might be its one lethal factor except for the algal toxins; A. tamarense (ATHK) has strong lethal effect on the rotifer with 48h LC50 at 800 cells/mL. The experiment on ingestion ability indicated by gut pigment change shows that P. donghaiense, P. globosa, P. micans, A. tamarense (AT-6) and A. lusitanicum can be taken by the rotifers as food, but A. tamarense (ATHK) or H. akashiwo can be ingested by the rotifers. The results indicate that all the indexes of individual survival and reproduction, population increase, gut pigment change of the rotifers are good and convenient to be used to reflect the toxicities of HAB species. Therefore, rotifer is suggested as one of the toxicity testing organisms in detecting the toxicity of harmful algae.

Screening of surfactants for harmful algal blooms mitigation

Screening experiments were conducted in order to find promising synthetic surfactants for harmful algal blooms (HABs) mitigation. The chemically synthesized surfactant cocamidopropyl betaine (CAPB) showed characteristics of relatively high inhibition efficiency, high biodegradability and low cost. The motility inhibition ratios of 10 mg/L CAPB on Cochlodinium polykrikoides and Alexandrium tamarense were about 60% after 5 min. The biodegradation test indicated that the half-life of CAPB in seawater was shorter than one day and 90% was biodegraded after five days under the initial concentration of 100 mg/L at 25degreesC. Further cell lysis experiments revealed the selective lysis effect of CAPB on different HAB organisms. More than 90% of C. polykrikoides lysed at the concentration of 10 mg/L CAPB after 24 h and at 15 mg/L CAPB after 4 h, whereas the lysis effect of CAPB on A. tamarense was slight, no more than 10% after 2 h interaction with 50 mg/L CAPB. This research provided preliminary data for CAPB as a candidate in harmful algal blooms mitigation and pointed out unresolved problems for its practical application in the meantime. (C) 2003 Elsevier Ltd. All rights reserved.

Environmental and health effects associated with Harmful Algal Bloom and marine algal toxins in China

The frequency and scale of Harmful Algal Bloom (HAB) and marine algal toxin incidents have been increasing and spreading in the past two decades, causing damages to the marine environment and threatening human life through contaminated seafood. To better understand the effect of HAB and marine algal toxins on marine environment and human health in China, this paper overviews HAB occurrence and marine algal toxin incidents, as well as their environmental and health effects in this country. HAB has been increasing rapidly along the Chinese coast since the 1970s, and at least 512 documented HAB events have occurred from 1952 to 2002 in the Chinese mainland. It has been found that PSP and DSP toxins are distributed widely along both the northern and southern Chinese coasts. The HAB and marine algal toxin events during the 1990s in China were summarized, showing that the HAB and algal toxins resulted in great damages to local fisheries, marine culture, quality of marine environment, and human health. Therefore, to protect the coastal environment and human health, attention to HAB and marine algal toxins is urgently needed from the environmental and epidemiological view.

A comparison of future increased CO2 and temperature effects on sympatric Heterosigma akashiwo and Prorocentrum minimum

Very little is known about how global anthropogenic changes will affect major harmful algal bloom groups. Shifts in the growth and physiology of HAB species like the raphidophyte Heterosigma akashiwo and the dinoflagellate Prorocentrum minimum due to rising CO2 and temperature could alter their relative abundance and environmental impacts in estuaries where both form blooms, such as the Delaware Inland Bays (DIB). We grew semi-continuous cultures of sympatric DIB isolates of these two species under four conditions: (1) 20 degrees C and 375 ppm CO2 (ambient control), (2)20 degrees C and 750 ppm CO2 (high CO2),(3) 24 degrees C and 375 ppm CO2 (high temperature), and (4) 24 degrees C and 750 ppm CO2 (combined). Elevated CO2 alone or in concert with temperature stimulated Heterosigma growth, but had no significant effect on Prorocentrum growth. P-Bmax (the maximum biomass-normalized light-saturated carbon fixation rate) in Heterosigma was increased only by simultaneous CO2 and temperature increases, whereas P-Bmax in Prorocentrum responded significantly to CO2 enrichment, with or without increased temperature. CO2 and temperature affected photosynthetic parameters alpha, Phi(max), E-k, and Delta F/F'(m) in both species. Increased temperature decreased and increased the Chl a content of Heterosigma and M Prorocentrum, respectively. CO2 availability and temperature had pronounced effects on cellular quotas of C and N in Heterosigma, but not in Prorocentrum. Ratios of C:P and N:P increased with elevated carbon dioxide in Heterosigma but not in Prorocentrum. These changes in cellular nutrient quotas and ratios imply that Heterosigma could be more vulnerable to N limitation but less vulnerable to P-limitation than Prorocentrum under future environmental conditions. In general, Heterosigma growth and physiology showed a much greater positive response to elevated CO2 and temperature compared to Prorocentrum, consistent with what is known about their respective carbon acquisition mechanisms. Hence, rising temperature and CO2 either alone or in combination with other limiting factors could significantly alter the relative dominance of these two co-existing HAB species over the next century. (c) 2007 Elsevier B.V. All rights reserved.

Is inorganic nutrient enrichment a driving force for the formation of red tides? A case study of the dinoflagellate Scrippsiella trochoidea in an embayment

Red tides (high biomass phytoplankton blooms) have frequently occurred in Hong Kong waters, but most red tides occurred in waters which are not very eutrophic. For example, Port Shelter, a semi-enclosed bay in the northeast of Hong Kong, is one of hot spots for red tides. Concentrations of ambient inorganic nutrients (e.g. N, P), are not high enough to form the high biomass of chlorophyll a (chl a) in a red tide when chl a is converted to its particulate organic nutrient (N) (which should equal the inorganic nutrient, N). When a red tide of the dinoflagellate Scrippsiella trochoidea occurred in the bay, we found that the red tide patch along the shore had a high cell density of 15,000 cells ml(-1), and high chl a (56 mu g l(-1)), and pH reached 8.6 at the surface (8.2 at the bottom), indicating active photosynthesis in situ. Ambient inorganic nutrients (NO3, PO4, SiO4, and NH4) were all low in the waters and deep waters surrounding the red tide patch, suggesting that the nutrients were not high enough to support the high chl a >50 mu g l(-1) in the red tide. Nutrient addition experiments showed that the addition of all of the inorganic nutrients to a non-red-tide water sample containing low concentrations of Scrippsiella trochoidea did not produce cell density of Scrippsiella trochoidea as high as in the red tide patch, suggesting that nutrients were not an initializing factor for this red tide. During the incubation of the red tide water sample without any nutrient addition, the phytoplankton biomass decreased gradually over 9 days. However, with a N addition, the phytoplankton biomass increased steadily until day 7, which suggested that nitrogen addition was able to sustain the high biomass of the red tide for a week with and without nutrients. In contrast, the red tide in the bay disappeared on the sampling day when the wind direction changed. These results indicated that initiation, maintenance and disappearance of the dinoflagellate Scrippsiella trochoidea red tide in the bay were not directly driven by changes in nutrients. Therefore, how nutrients are linked to the formation of red tides in coastal waters need to be further examined, particularly in relation to dissolved organic nutrients. (C) 2008 Elsevier B.V. All rights reserved.

地震资料叠前储层预测综合研究--以辽中凹陷东二下段浊积扇气藏为例

Reservoir prediction techniques from prestack seismic are among the most important ones for exploration of lithologic hydrocarbon reservoir. In this paper, we set the turbidite fan sandstone reservoir in Liao-Zhong depress as our researching target, and aims to solve the apllication difficulties on pre-stack inversion in the area, where the drilling data is scarce and the reservoir is lateral varied. Meanwhile, AVO analysis and pre-stack inversion for gas-bearing detection is systematically researched. The seismic reflection characters of gas-bearing sandstone in turbidite fan with different fluid content are defined, after analyzing results from AVO seismic simulation and porous fluid replacement of real log data, and under the guides of the seismic characters from classical gas-bearing sandstone reservoir and numerical simulation for complicate gas-bearing sandstone. It is confirmed that detecting gas-bearing sandstone in turbidite fan via AVO technologies is feasible. In terms of AVO analysis, two AVO characters, fluid detection factor and product of intercept and gradient, can effectively identify top and bottom boundaries and lateral range of tuibidite gas sand by comparing real drilling data. Cross-plotting of near and far angle stack data could avoid the correlation existing in P-G analysis. After comparing the acoustic impedance inversions with routine stacked data and AVO intercept, impedance derived from AVO intercept attribute could reduce the acoustic impedance estimating error which is caused by AVO. On the aspect of elastic impedance inversion, the AVO information in the pre-stack gathers is properly reserved by creating partial angle stack data. By the far angle elastic impedance alone, the gas sand, with abnormally low range of values, can be identified from the background rocks. The boundary of gas sand can also be clearly determined by cross-plotting of near and far angle elastic impedances. The accuracy of far angle elastic impedance is very sensitive to the parameter K, and by taking the statistical average of Vp/Vs on the targeted section in key wells, the accuracy of low frequency trends is gurranteed; the intensive absorsion within the area of the gas sand, which tends to push the spectral of seismic data to the lower end, will cause errors on the inversion result of elastic impedance. The solution is to confine the inversion on the interested area by improving the wavelet. On the aspect of prestack AVA simultaneous inversion, the constraint of local rock-physical trends between velocities of P-wave、S-wave and density successfully removes the instability of inversion, thus improves the precision of the resulting elastic parameters. Plenty of data on rock properties are derived via AVO analysis and prestack seismic data inversion. Based on them, the fluid anomaly is analysized and lithological interpretation are conducted. The distribution of gas sand can be consistently determined via various of ways, such as cross-plotting of P and G attributes, near and far partial angle stack data, near and far angle elastic impedances, λρ and Vp/Vs, etc. The shear modulo and density are also reliable enough to be used for lithological interpretation. We successfully applied the AVO analysis and pre-stack inversion techniques to gas detecting for turbidite fan sand reservoir in Liao-Zhong depression.

Gry fabularne jako technika autonomizująca studenta

Publikacja (…) jest zbiorem tekstów poświęconych zagadnieniu autonomii w dydaktyce języków obcych. Teksty te – w obecnej postaci artykułów – stanowią zapis referatów wygłoszonych na konferencji poświęconej temu właśnie, niezwykle istotnemu dla nowoczesnej dydaktyki zagadnieniu. Konferencje tego typu nigdy dotąd w Polsce się nie odbywały. Jest to więc novum na naszym terenie i wielki tytuł do chwały dla uczelni, która podjęła się organizacji takiego wydarzenia i publikacji artykułów opracowanych na podstawie wygłoszonych tam referatów. Dlatego publikację uważam za niezwykle ważną i potrzebną. (z recenzji wydawniczej Prof. dr hab. Hanny Komorowskiej)

Charakter i cele Polskiego Towarzystwa Badania Gier oraz perspektywy badań nad grami w Polsce

Wartość poznawcza zamieszczonych w tomie artykułów polega na oglądzie gier jako nowego zjawiska w kulturze i na staraniach o zrozumienie ich atrakcyjności oraz na wysiłku poszukiwania ich pozytywnej roli wobec użytkowników. Autorzy artykułów podejmują rozmaite tematy związane w pierwszym rzędzie z grami komputerowymi i fabularnymi. Przedstawiają ich nowe cechy, oświetlają je z różnych punktów widzenia: medialnego, socjologicznego, psychologicznego, etycznego. I co równie interesujące, dostrzegają wiele powiązań z dobrze zakorzenionymi w kulturze dziedzinami, na przykład z literaturą czy filozofią. Czytelnik zyskuje wgląd w dzisiejszy stan badań nad grami. Nie tylko otrzymuje obraz wstępnych refleksji, ale ma szansę zetknąć się z postawą badawczą w stosunku do gier. (z recenzji wydawniczej prof. dr hab. Maryli Hopfinger)

Miasto Poznań w perspektywie badań interdyscyplinarnych

Książka podzielona została na cztery części. W każdej z nich znajdują się teksty ukazujące inną stronę badań miasta wynikających z odmiennych perspektyw badawczych prezentowanych przez nasz interdyscyplinarny zespół badaczy. Książka dofinansowana ze środków: Prof. dr hab. Jacka Witkosia, prorektora Uniwersytetu im. Adama Mickiewicza w Poznaniu ds. nauki i współpracy międzynarodowej Prof. dr hab. Hanny Kóčki-Krenz, dziekan Wydziału Historycznego Prof. dr hab. Michała Buchowskiego, dyrektora Instytutu Etnologii i Antropologii Kulturowej

On Learning Counting Functions With Queries

We investigate the problem of learning disjunctions of counting functions, which are general cases of parity and modulo functions, with equivalence and membership queries. We prove that, for any prime number p, the class of disjunctions of integer-weighted counting functions with modulus p over the domain Znq (or Zn) for any given integer q ≥ 2 is polynomial time learnable using at most n + 1 equivalence queries, where the hypotheses issued by the learner are disjunctions of at most n counting functions with weights from Zp. The result is obtained through learning linear systems over an arbitrary field. In general a counting function may have a composite modulus. We prove that, for any given integer q ≥ 2, over the domain Zn2, the class of read-once disjunctions of Boolean-weighted counting functions with modulus q is polynomial time learnable with only one equivalence query, and the class of disjunctions of log log n Boolean-weighted counting functions with modulus q is polynomial time learnable. Finally, we present an algorithm for learning graph-based counting functions.