Compondo urupemas: observa��ão e reflexão no processo de reconstrução das mem��rias de Infância, de Graciliano Ramos

A proposta deste trabalho é investigar a ficcionaliza��ão do discurso do eu na construção do passado, em Graciliano Ramos, que, utilizando a observa��ão, a experiência, a sensibilidade e imagina��ão, reflete a respeito da intera��ão entre homem e sociedade, negando o aspecto narcísico associado ao gênero autobiográfico e atingindo o universal pelo particular. Para este objetivo, sublinhamos a rela��ão entre autobiografia e individualidade e buscamos destacar aquilo que nos permite realizar uma leitura de viés autobiográfico em Infância, não esquecendo que se trata também de uma composição literária, cujos recursos e técnicas o autor manejava com capricho. Prosseguimos tra��ando um breve panorama da década de 30 e sucintos comentários sobre o conjunto da obra do romancista alagoano. Alcançamos, então, o capítulo principal, no qual baseamos a nossa proposta na obra que é o foco desta pesquisa, elaborada por um escritor já maduro e seguro de sua concepção de literatura; nele se busca demonstrar a relevância da mem��ria na construção da história social, ressaltando a condição fragmentária própria da constituição do sujeito e destacando a função da escrita como instrumento de organiza��ão e construção, para si e para outros, de uma ideia de identidade. Na conclusão, retomamos alguns pontos elencados ao longo deste trabalho, procurando comprovar a articula��ão entre eles, pertinente a nossa proposta

Increased toxicity of Karenia brevis during phosphate limited growth: ecological and evolutionary implications

Karenia brevis is the dominant toxic red tide algal species in the Gulf of Mexico. It produces potent neurotoxins (brevetoxins [PbTxs]), which negatively impact human and animal health, local economies, and ecosystem function. Field measurements have shown that cellular brevetoxin contents vary from 1–68 pg/cell but the source of this variability is uncertain. Increases in cellular toxicity caused by nutrient-limitation and inter-strain differences have been observed in many algal species. This study examined the effect of P-limitation of growth rate on cellular toxin concentrations in five Karenia brevis strains from different geographic locations. Phosphorous was selected because of evidence for regional P-limitation of algal growth in the Gulf of Mexico. Depending on the isolate, P-limited cells had 2.3- to 7.3-fold higher PbTx per cell than P-replete cells. The percent of cellular carbon associated with brevetoxins (%C-PbTx) was ~ 0.7 to 2.1% in P-replete cells, but increased to 1.6–5% under P-limitation. Because PbTxs are potent anti-grazing compounds, this increased investment in PbTxs should enhance cellular survival during periods of nutrient-limited growth. The %C-PbTx was inversely related to the specific growth rate in both the nutrient-replete and P-limited cultures of all strains. This inverse relationship is consistent with an evolutionary tradeoff between carbon investment in PbTxs and other grazing defenses, and C investment in growth and reproduction. In aquatic environments where nutrient supply and grazing pressure often vary on different temporal and spatial scales, this tradeoff would be selectively advantageous as it would result in increased net population growth rates. The variation in PbTx/cell values observed in this study can account for the range of values observed in the field, including the highest values, which are not observed under N-limitation. These results suggest P-limitation is an important factor regulating cellular toxicity and adverse impacts during at least some K. brevis blooms.

Osmotic stress does not trigger brevetoxin production in the dinoflagellate Karenia brevis

With the global proliferation of toxic Harmful Algal Bloom (HAB) species, there is a need to identify the environmental and biological factors that regulate toxin production. One such species, Karenia brevis, forms nearly annual blooms that threaten coastal regions throughout the Gulf of Mexico. This dinoflagellate produces brevetoxins, potent neurotoxins that cause neurotoxic shellfish poisoning and respiratory illness in humans, as well as massive fish kills. A recent publication reported that a rapid decrease in salinity increased cellular toxin quotas in K. brevis and hypothesized that brevetoxins serve a role in osmoregulation. This finding implied that salinity shifts could significantly alter the toxic impacts of blooms. We repeated the original experiments separately in three different laboratories and found no evidence for increased brevetoxin production in response to low-salinity stress in any of the eight K. brevis strains we tested, including three used in the original study. Thus, we find no support for an osmoregulatory function of brevetoxins. The original publication also stated that there was no known cellular function for brevetoxins. However, there is increasing evidence that brevetoxins promote survival of the dinoflagellates by deterring grazing by zooplankton. Whether they have other as yet unidentified cellular functions is currently unknown.

Contrasting seasonal patterns in dimethylsulfide, dimethylsulfoniopropionate, and chlorophyll a in a shallow North Carolina estuary and the Sargasso Sea

Time series measurements of dimethylsulfide (DMS), particulate dimethylsulfoniopropionate (DMSPp), chlorophyll a (chl a), algal pigments, major nutrients, and the potential activity of DMSP lyase enzymes were made over a 2 yr period (6 March 2003 to 28 March 2005) near the mouth of the shallow, tidally mixed Newport River estuary, North Carolina, USA. DMSPp had a mean of 43 ± 20 nM (range = 10.5 to 141 nM, n = 85) and DMS a mean of 2.7 ± 1.2 nM (range = 0.9 to 7.0 nM). The mean DMS in Gallants Channel was not significantly different from that measured in the Sargasso Sea near Bermuda during a previous 3 yr time series study (2.4 ± 1.5 nM), despite there being a 43-fold higher mean chl a concentration (4.9 ± 2.4 µg l–1) at the coastal site. In winter, DMS was low and chl a was high in the surface waters of the Sargasso Sea, while the opposite was true at the coastal site. Consequently, DMS concentrations per unit algal chl a were on average 170 times higher in the Sargasso Sea than at the coastal site during the summer, but only 7 times higher during the winter. The much higher chl a-specific DMS concentrations at the oceanic site during the summer were linked to higher ratios of intracellular DMSP substrate and DMSP lyase enzyme per unit chl a. These differences in turn appear to be linked to large differences in nutrient concentrations and solar UV stress at the 2 sites and to associated differences in the composition of algal assemblages and physiological acclimation of algal cells.

Fish lost at sea: the effect of soak time on pelagic longline catches

Our analyses of observer records reveal that abundance estimates are strongly influenced by the timing of longline operations in relation to dawn and dusk and soak time— the amount of time that baited hooks are available in the water. Catch data will underestimate the total mortality of several species because hooked animals are “lost at sea.” They fall off, are removed, or escape from the hook before the longline is retrieved. For example, longline segments with soak times of 20 hours were retrieved with fewer skipjack tuna and seabirds than segments with soak times of 5 hours. The mortality of some seabird species is up to 45% higher than previously estimated. The effects of soak time and timing vary considerably between species. Soak time and exposure to dusk periods have strong positive effects on the catch rates of many species. In particular, the catch rates of most shark and billfish species increase with soak time. At the end of longline retrieval, for example, expected catch rates for broadbill swordfish are four times those at the beginning of retrieval. Survival of the animal while it is hooked on the longline appears to be an important factor determining whether it is eventually brought on board the vessel. Catch rates of species that survive being hooked (e.g. blue shark) increase with soak time. In contrast, skipjack tuna and seabirds are usually dead at the time of retrieval. Their catch rates decline with time, perhaps because scavengers can easily remove hooked animals that are dead. The results of our study have important implications for fishery management and assessments that rely on longline catch data. A reduction in soak time since longlining commenced in the 1950s has introduced a systematic bias in estimates of mortality levels and abundance. The abundance of species like seabirds has been over-estimated in recent years. Simple modifications to procedures for data collection, such as recording the number of hooks retrieved without baits, would greatly improve mortality estimates.

Cloning of cDNAs encoding C-type lectins from Elapidae snakes Bungarus fasciatus and Bungarus multicinctus

A number of C-type lectins with various biological activities have been purified and characterized from Viperidae snake venoms. In contrast, only a few reports could be found in literature concerning the C-type lectins in Elapidae snake venoms. Based on t

从线粒体细胞色素b探讨长臀ba���三个种分类与进化的关系

细尾长臀ba���月斑长臀ba���长臀ba���存在遗传分化,分化程度与鲤科其它鱼类相似;而月斑长臀ba���长臀ba���无法分开。结果提示,月斑长臀ba���长臀ba���可能为同一个种。此外,长臀ba���与云南倒刺ba���亲缘关系较近,表明有争议的长臀ba���归入ba���科是合理的。

Co-occurrence flow for pedestrian detection

The last few years have seen considerable progress in pedestrian detection. Recent work has established a combination of oriented gradients and optic flow as effective features although the detection rates are still unsatisfactory for practical use. This paper introduces a new type of motion feature, the co-occurrence flow (CoF). The advance is to capture relative movements of different parts of the entire body, unlike existing motion features which extract internal motion in a local fashion. Through evaluations on the TUD-Brussels pedestrian dataset, we show that our motion feature based on co-occurrence flow contributes to boost the performance of existing methods. © 2011 IEEE.

愿长江女神永留倩影——白鳍豚、江豚保护工作回顾

白鳍豚与长江江豚不仅属于长江,也不仅属于中国,白鳍豚与长江江豚更属于世界,属于大自然。只有全世界人民共同携手,保护长江,保护我们赖以生存的大江大河,保护我们的共同家园———地球,白鳍豚与长江江豚才会永驻江河,与人类一道共同走向未来。

2-Scale topography dry electrode for biopotential measurements.

The design and fabrication of a novel 2-scale topography dry electrode using macro and micro needles is presented. The macro needles enable biopotential measurements on hairy skin, the function of the micro needles is to decrease the electrode impedance even further by penetrating the outer skin layer. Also, a fast and reliable impedance characterization protocol is described. Based on this impedance measurement protocol, a comparison study is made between our dry electrode, 3 other commercial dry electrodes and a standard wet gel electrode. Promising results are already obtained with our electrodes which do not have skin piercing micro needles. For the proposed electrodes, three different conductive coatings (Ag/AgCl/Au) are compared. AgCl is found to be slightly better than Ag as coating material, while our Au coated electrodes have the highest impedance.

红蛭属及其一新种的记述——(蛭纲:石蛭科)

<正> 关于红蛭属Dina Blanchard,1892的系统位置,一个多世纪以来一直是个有争议的问题。最初在Blainville 1818年命名石蛭属Erpobdella���,曾将红蛭属的种类都包括在内,直至1892年Blanchard以完全体节的第5环是否较宽和有无次生环沟将石蛭属分成红蛭属和石蛭属两个属。1930 Moorc用Dina quaternaria���述了从中国得到的一新

Single mode operation of a Fabry-Perot laser locked by a tunable laser

In this article, the single mode operation of a Fabry-Perot laser (FP-LD) subject to the optical injection from a tunable laser is investigated. The maximum side mode suppression ratio (SMSR) is 53 dB, and the locked wavelength range is about 46 nm, which can cover 58 International Telecommunication Union (ITU) wavelengths with 100 GHz spacing or 115 ITU wavelengths with 50 GHz spacing for wavelength division multiplexing (WDM) system. In the wavelength range front 1535 to 1569 nm, the SMSR is over 46 dB, and the frequency response of the injection-locked FP-LD can be improved with the proper wavelength detuning. (c) 2008 Wiley Periodicals, Inc.

域间动态角色转换中的静态互斥角色约束违反

安全互操作是实现跨管理域的资源共享与保护的关键技术．Kapadia���人的IRBAC2000模型提供了一种灵活的通过角色关联和动态角色转换实现安全互操作的方法．廖俊国等人指出该模型可能违反静态互斥角色约束，对问题的原因进行了分析，提出了约束违反检测算法和添加角色关联的先决条件．首先指出廖俊国等人关于约束违反原因的分析是片面的，其检测算法和先决条件也不能保证系统不会违反约束；然后指出在给定角色关联的前提下，外域的用户／角色分配是造成约束违反的根本原因；进而提出动态角色转换违反静态互斥角色约束的充要条件和约束违反检测算法；给出了添加角色关联和用户／角色分配的先决条件，保证了模型状态始终满足静态互斥角色约束．