Dibujantes del Museo de la Plata: Carlos Andrés Tremouilles

En esta colección de la Serie Documentos presentamos a los dibujantes y artistas que pasaron por nuestra institución, lo que representa una tarea nada fácil. Sin embargo, con las imperfecciones del caso, iniciamos este trabajo esperando que, en un futuro próximo, esta iniciativa sea continuada dentro de las diferentes Divisiones que conforman la estructura de nuestro Museo. En este segundo artículo mostramos algunas de las imágenes que pudimos rescatar de Carlos Andrés Tremouilles, formado en la Escuela Superior de Bellas Artes y perteneciente a una dinastía de dibujantes del Museo de La Plata. Su padre Carlos Hipólito y su hijo Carlos también fueron dibujantes de esa institución. Colaboró con Emiliano Mac Donagh y con Raúl A. Ringuelet para ilustrar trabajos sobre nuestra ictiofauna. En 1959 fue reconocido por las autoridades del Primer Congreso Sudamericano de Zoología desarrollado en el Museo de La Plata. Realizó restauraciones de obras pictóricas, guardas y vitrales. Su versatilidad, le permitió realizar también tareas en vitrinas de exhibición, montaje del laboratorio de C14 y reparación de instrumental en base a sus conocimientos de electrónica. Aquí presentamos una pequeña parte de su numerosa obra obtenida de acuarelas y dibujos de peces de los archivos de la División Zoología Vertebrados y los incorporados a las obras Peces marinos de la República Argentina de R. A. Ringuelet y R. H. Arámburu (1960) y Los peces argentinos de agua dulce de R. A. Ringuelet, R. H. Arámburu y A. A. de Arámburu (1967)

Changes over time in the spatial distribution of walleye pollock (Theragra chalcogramma) in the Gulf of Alaska, 1984-1996

Triennial bottom trawl survey data from 1984 to 1996 were used to evaluate changes in the summer distribution of walleye pollock in the western and central Gulf of Alaska. Differences between several age groups of pollock were evaluated. Distribution was examined in relation to several physical characteristics, including bottom depth and distance from land. Interspecies associations were also analyzed with the Bray-Curtis clustering technique to better understand community structure. Our results indicated that although the population numbers decreased, high concentrations of pollock remained in the same areas during 1984–96. However, there was an increase in the number of stations where low-density pollock concentrations of all ages were observed, which resulted in a decrease in mean population density of pollock within the GOA region. Patterns emerging from our data suggested an alternative to Mac-Call’s “basin hypothesis” which states that as population numbers decrease, there should be a contraction of the population range to optimal habitats. During 1984–96 there was a concurrent precipitous decline in Steller sea lions in the Gulf of Alaska. The results of our study suggest that decreases in the mean density of adult pollock, the main food in the Steller sea lion diet, combined with slight changes in the distribution of pollock (age-1 pollock in particular) in the mid-1980s, may have contributed to decreased foraging efficiency in Steller sea lions. Our results support the prevailing conceptual model for pollock ontogeny, although there is evidence that substantial spawning may also occur outside of Shelikof Strait.

Catálogo de ejemplares tipo de la colección ictiológica del Museo de La Plata

La colección actualmente contiene alrededor de 11000 lotes catalogados, que representan más de 400 especies marinas y de agua dulce, de los cuales 3500 se encuentran digitalizados en el sistema de colecciones del Museo. Es importante destacar que las colecciones del Museo forman parte del Sistema Nacional de Datos Biológicos que tiene como misión conformar una base de ProBiota, Serie Técnica y Didáctica Nº 23 – 2014 VI datos unificada de información biológica, a partir de datos taxonómicos, ecológicos, cartográficos, bibliográficos, etnobiológicos, de uso y de catálogos sobre recursos naturales y otros temas afines. Por otra parte, y a modo de resguardo, los registros se continúan asentando en un libro foliado. Su reciente recatalogación ha permitido recuperar algunos materiales de sumo interés y ordenar especimenes tipo existentes, como así también verificar la ausencia de otros, ejemplo, Micropogon barretoi Mac Donagh (1934) cuyo holotipo está asentado en el libro de registros pero nunca pudo ser encontrado. Actualmente la colección cuenta con 28 holotipos y 407 paratipos pertenecientes a 6 órdenes, 13 familias y 49 especies y 4 subespecies los que fueron ordenados sistemáticamente siguiendo el criterio de Nelson (2006). El listado de las especies fue ordenado alfabéticamente. Se incluye el nombre de la especie, los autores, el año de publicación, la página de la diagnosis, figuras y tablas. Cada lote lleva la siguiente información: acrónimo, número de catálogo, número de ejemplares, longitud estándar, localidad, colectores, fecha de captura y observaciones.

Dibujantes del Museo de la Plata: Carlos Andrés Tremouilles.

En esta colección de la Serie Documentos presentamos a los dibujantes y artistas que pasaron por nuestra institución, lo que representa una tarea nada fácil. Sin embargo, con las imperfecciones del caso, iniciamos este trabajo esperando que, en un futuro próximo, esta iniciativa sea continuada dentro de las diferentes Divisiones que conforman la estructura de nuestro Museo. En este segundo artículo mostramos algunas de las imágenes que pudimos rescatar de Carlos Andrés Tremouilles, formado en la Escuela Superior de Bellas Artes y perteneciente a una dinastía de dibujantes del Museo de La Plata. Su padre Carlos Hipólito y su hijo Carlos también fueron dibujantes de esa institución. Colaboró con Emiliano Mac Donagh y con Raúl A. Ringuelet para ilustrar trabajos sobre nuestra ictiofauna. En 1959 fue reconocido por las autoridades del Primer Congreso Sudamericano de Zoología desarrollado en el Museo de La Plata. Realizó restauraciones de obras pictóricas, guardas y vitrales. Su versatilidad, le permitió realizar también tareas en vitrinas de exhibición, montaje del laboratorio de C14 y reparación de instrumental en base a sus conocimientos de electrónica. Aquí presentamos una pequeña parte de su numerosa obra obtenida de acuarelas y dibujos de peces de los archivos de la División Zoología Vertebrados y los incorporados a las obras Peces marinos de la República Argentina de R. A. Ringuelet y R. H. Arámburu (1960) y Los peces argentinos de agua dulce de R. A. Ringuelet, R. H. Arámburu y A. A. de Arámburu (1967).

灵长类脑研究中的计算机应用

1985年作者进行了计算机在灵长类神经生理学中的应用研究的工作, 建立了一套脑电, 脑形态和声波数据的微处理机采集分析和模拟控制系统, 经数年的应用, 其性能表明它能满足灵长类脑研究需要. 本系统共由传感器, 微电极前置放大器, 八道脑电图机, 调频式数据记录仪, Mac32位计算机, APPLE Ⅱ计算机和其它外围设备等所组成, 该系统受50多个软件所支持. 数据采集: 经缓冲放大器出来的讯号被送入A/D板进行模/数转换, 在 Mac 计算机, 模/数转换精度为12bit, 共有16道转换口, 采样频率最高为40MHz, 在 APPLE Ⅱ 计算机, A/D板为 8bit, 八道模/数输入, 最高采样频率40 MHz, 数据的采集和处理可在线进行, 也可离线处理。

Effect of organophosphate, diazinon on some immunophysiological, haematological and histological variable of Rutilus frisii kutum (Kamensky,1901)

The acute toxicity and effects of diazinon on some haematological parameters of kutum (Rutilus frisii kutum, Kamensky, 1901) weighing 613.33 g±157.06 g were studied under static water quality conditions at 15°C ± 2ºC in winter and spring 2009. The effective physical and chemical parameters of water were pH= 7-8.2, dh= 300mg/L (caco3), DO= 7 ppm and T= 15°C±2ºC. The first test was primarily to determine the effects of acute toxicity (LC5096 h) of the agricultural toxicant diazinon (emulsion 60%) on kutum male brood stocks. For this purpose, 4 treatments were used to test toxicity; each treatment was repeated in 3 tanks with 9 fish per treatment and with 180 litres water capacity. After obtaining the final results, the information was analysed statistically with Probit version 1.5 (USEPA, 1985), and we determined the LC10, LC50 and LC90 values at 24 hours, 48 hours, 72 hours and 96 hours; the maximum allowable concentration value (LC5096 h divided by 10) (TRC, 1984); and the degree of toxicity. The second stage of testing consists of four treatments: LC0= 0 as experimental treatment, treatment A with a concentration of LC1= 0.107 mg/L, treatment B with concentration of LC5= 0.157 mg/L, treatment C with concentration of MAC value= 0.04 mg/L. Male brood stocks of kutum were treated with these concentrations for 45 days. Experiments were carried out under static conditions based on the standard TRC, 1984 method over 45 days. Our results show that long-term exposure to diazinon causes a decrease in the erythrocyte count (RBC), haemoglobin (Hb), haematocrit (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), leucocyte count (WBC), lymphocyte, testosterone, iron (Fe), sodium (Na), lactate dehydrogenase (LDH), and cholinesterase (CHeS). In addition, diazinon also causes an increase in prolymphocyte, aspartate aminotransferase (AST), cholesterol, alkaline phosphatase (ALP) and adrenaline (P<0.05). There are no significant effects on monocyte, eosinophil, magnesium (Mg), chloride (Cl), glucose (BS), urea (BUN), uric acid (U.A), triglyceride (TG), calcium (Ca), albumin (Alb), total protein (TP), cortisol, noradrenaline and high density lipoprotein (HDL) levels in kutum male brood stocks (P>0.05). Pathology results showed toxin diazinon no effect on average weight and fish body length, the average weight of heart, brain, spleen, liver, kidney and liver index but caueses decrease of gonad weigth and gonad index and also, cause complications of tissue necrosis, vascular congestion, inflammation in the liver, a sharp reduction in the number of glomeruli, necrosis, vascular congestion and haemorage in the kidney, capsule thickening and fibrosis, atrophy, vascular congestion, macrophages release increased, increasing sediment Hemosiderine and thickening of artery walls in the spleen, atrophy, fibrosis and necrosis in testis , vascular congestion, increased distance between the myocardium and fibrous string in heart and neuronal loss, vascular congestion and edema in the brain of kutum male brood stocks.

Phylogeny and zoogeography of the cyprinid genus Epalzeorhynchos Bleeker (Cyprinidae : Ostariophysi)

A total of 62 variable osteological and external characters was found among the five currently recognized species of Epalzeorhynchos. When the genera Crossocheilus and Paracrossocheilus are combined as the outgroup, only 30 of these characters can be polarized. This includes six autapomorphies. The remaining 24 polarized characters form a data matrix which yields a single, 26-step tree with a Consistency Index (CI) of 1 and a Retention Index (RI) of 1, The analysis was also performed on a combined dataset in which the 32 unpolarized characters (characters for which the combined outgroup was dimorphic) were added and coded as missing data (i.e., "?"), Analyzing this data matrix with all multistate characters ordered generates the same single most-parsimonious tree with a length of 63 steps, a CI of 0.98 and a RI of 0.97, When either Crossocheilus or Paracrossocheilus is used as the sole outgroup, the same single most-parsimonious tree is produced although the numbers of informative characters and some of the polarities differ. Evidence is presented to support the following hypotheses: (1) E, kalopterus + E, frenatus + E. bicolor + E. munensis form a monophyletic group; (2) E. frenatus + E, bicolor + E, munensis form a monophyletic group with E, kalopterus as its sister group; this speciation event is congruent with the predictions of vicariant speciation mode I; and (3) E. bicolor and E. munensis are sister groups, again congruent with vicariant speciation mode I, Evidence presented here also supports the zoogeographical hypothesis that the faunas of the Indochinese region and the Greater Sundas are more closely related to each other than either of them is to the lower Salween basin fauna and that the lower Mekong, Chao Phraya, and Mac Khlong basin faunas are more closely related to each other than any of them is to the Greater Sundas, In addition, the monophyly of Epalzeorhynchos is also preliminarily discussed by including either Paracrossocheilus or Crossocheilus in the ingroup. It is demonstrated that E. bicornis clusters with Paracrossocheilus when Paracrossocheilus is included in the ingroup. It seems likely that the taxonomic position of E. bicornis will be resolved as more fishes of the Crossocheilus group are included in future studies.

Nearest neighbour decoding with pilot-assisted channel estimation for fading multiple-access channels

This paper studies a noncoherent multiple-input multiple-output (MIMO) fading multiple-access channel (MAC). The rate region that is achievable with nearest neighbour decoding and pilot-assisted channel estimation is analysed and the corresponding pre-log region, defined as the limiting ratio of the rate region to the logarithm of the signal-to-noise ratio (SNR) as the SNR tends to infinity, is determined. © 2011 IEEE.

Molecular cloning, promoter analysis and induced expression of the complement component C9 gene in the grass carp Ctenopharyngodon idella

Complement-mediated killing of pathogens through lytic pathway is an important effector mechanism of innate immune response. C9 is the ninth member of complement components, creating the membrane attack complex (MAC). In the present study, a putative cDNA sequence encoding the 650 amino acids of C9 and its genomic organization were identified in grass carp Ctenopharyngodon idella. The deduced amino acid sequence of grass carp C9 (gcC9) showed 48% and 38.5% identity to Japanese flounder and human C9, respectively. Domain search revealed that gcC9 contains a LDL receptor domain, an EGF precursor domain, a MACPF domain and two TSP domain located in the N-terminal and C-terminal, respectively. Phylogenetic analysis demonstrated that gcC9 is clustered in a same clade with Japanese flounder, pufferfish and rainbow trout C9. The gcC9 gene consists of 11 exons with 10 introns, spacing over approximately 7 kb of genomic sequence. Analysis of gcC9 promoter region revealed the presence of a TATA box and some putative transcription factor such as C/EBP, HSF, NF-AT, CHOP-C, HNF-3B, GATA-2, IK-2, EVI- 1, AP-1, CP2 and OCT-1 binding sites. The first intron region contains C/EBPb, HFH-1 and Oct-1 binding sites. RT-PCR and Western blotting analysis demonstrated that the mRNA and protein of gcC9 gene have similar expression patterns, being constitutively expressed in all organs examined of healthy fish, with the highest level in hepatopancreas. By real-time quantitative RT-PCR analysis, gcC9 transcripts were significantly up-regulated in head kidney, spleen, hepatopancreas and down-regulated in intestine from inactivated fish bacterial pathogen Flavobacterium columnare-stimulated fish, demonstrating the role of C9 in immune response. (c) 2007 Elsevier B.V. All rights reserved.

Stocking models of Chinese mitten crab (Eriocheir japonica sinensis) in Yangtze lakes

The fanning of Chinese mitten crab, a quality aquatic product in China and neighbouring Asian countries, has been developing rapidly in China since last decade. It reached a total yield of 3.4 X 10(5) tonnes in 2002. Due to the successive over-stocking year after year, many lakes in the mid-lower Yangtze Basin, the main farming area, are under deterioration, leading to a reduction of crab yield and quality, and, subsequently, a loss of fanning profits. Aiming at a normal development of crab culture and the sustainable use of lakes, an annual investigation dealing with lake environmental factors in relation to stocked crab populations was carried out at 20 farms in 4 lakes. The results show that the submersed macrophyte biomass (B-Mac) is the key factor affecting annual crab yield (CY). Using the ratio of Secchi depth to mean depth (Z(SD)/Z(M)), an easily measured parameter closely correlated to BMac, as driving variable, 10 regression models of maximal crab yields were generated (r(2) ranging 0.49-0.81). Based on the theory of MSY (Maximum Sustainable Yield), in combination with body-weight (BW) and recapture rate (RR) of adult crabs, a general optimal stocking model was eventually formulated. All models are simple and easy to operate. Comments on their applications and prospects are given in brief. (c) 2006 Elsevier B.V. All rights reserved.

A power-saving scheme for IEEE 802.11 Ad hoc networks

In the Wireless Local Area Networks (WLANs), the terminals are often powered by battery, so the power-saving performance of the wireless network card is a very important issue. For IEEE 802.11 Ad hoc networks, a power-saving scheme is presented in Medium Access Control (MAC) layer to reduce the power consumption by allowing the nodes enter into the sleep mode, but the scheme is based on Time-Drive Scheme (TDS) whose power-saving efficiency becomes lower and lower with the network load increasing. This paper presented a novel energy-saving mechanism, called as Hybrid-Drive Scheme (HDS), which introduces into a Message.-Drive Scheme (MDS) and combines MDS with the conventional TDS. The MDS, could obtain high efficiency when the load is heavy; meanwhile the TDS has high efficiency when the network load is small. The analysis shows that the proposed HDS could obtain high energy-efficiency whether the network load is light or heavy and have higher energy-saving efficiency than conventional scheme in the IEEE 802.11 standard.

分组密码的分析与设计

分组密码作为现代密码学的一个重要组成部分，是目前最重要和流行的一种数据加密技术，有着非常广泛的应用。此外，近年来分组密码或其组件还经常作为基础模块用于构造Hash函数，MAC算法等。因此对分组密码安全性的分析以及设计安全高效的分组密码算法，在理论研究及实际应用中都有着非常重要的意义。本文的研究内容主要包括两个方面：对现有常用分组密码的安全性分析，以及分组密码及其组件的设计。这两个方面是密不可分，相互融合的。通常都是利用算法存在的弱点或算法设计特点，提出新的密码分析算法。而在算法设计过程中，正是从密码分析获取经验，掌握设计算法的技巧和避免可能存在的缺陷。 本文首先对分组密码分析方法作了大量的调查和研究，在此基础上分析了一些国内外常用和有影响的分组密码，得到了一系列有价值的分析结果。并在密码分析工作的经验基础上，结合现有密码设计理论，在分组密码及其组件的设计方面做了比较深入的研究。本文的主要成果包括： (1) DES算法的分析。DES算法是迄今最重要的分组密码算法之一，目前在一些金融领域，DES和Triple-DES仍被广泛使用着。本文考察了DES算法针对Boomerang攻击和Rectangle攻击的安全性。通过利用DES算法各轮的最优差分路径及其概率，分别给出了这两种攻击方法对DES的攻击算法。 (2) Rijndael算法的分析。Rijndael算法是高级加密标准AES的原型。本文针对大分组Rijndael算法的各个不同版本，利用算法行移位和列混淆变换的一些密码特性，改进了原有的不可能差分攻击结果，极大的降低了攻击的数据和时间复杂度。同时还分别构造了一些新的更长轮的不可能差分路径，利用这些路径给出了一系列对大分组Rijndael算法的改进的不可能差分攻击，这些结果是目前已知的对该算法的最好攻击结果。 (3) SMS4算法的分析。SMS4算法是中国公布的用于无线局域网产品保护的算法。本文首先构造了SMS4算法的一类5轮循环差分特征，利用该特征分别给出了对16轮SMS4算法的矩阵攻击和对21轮SMS4算法的差分分析。随后考察了SMS4算法抵抗差分故障攻击的能力，基于字节故障模型，结合实验指出需要32次故障诱导来恢复全部密钥。后续的工作又进一步将结果改进为只需要进行一次故障诱导再结合2^{44}次密钥搜索即可恢复全部密钥。 (4) CLEFIA密码算法的分析。CLEFIA算法是索尼公司于2007年提出的用于产品版权保护和认证的分组密码算法。针对CLEFIA算法，本文构造了一条概率为1的5轮截断差分特征，再结合其扩散矩阵的密码特性构造了一条3轮线性逼近。随后利用这两条路径组成的8轮差分-线性区分器，给出了对10轮CLEFIA算法的有效的差分-线性攻击。 (5) 分组密码结构的设计及其应用。本文提出了两种新的分组密码结构，并指出了其与原有结构相比的优势，同时分别评估了这两种结构针对差分分析和线性分析等常用密码分析方法的安全性。基于这两个密码结构，结合部分密码组件的设计和测试工作，本文还完成了两个分组密码算法的概要设计，并简要评估了它们的实现效率及针对现有的几种主要密码分析方法的安全性。

一种可证明安全的消息认证码

消息认证码是保证消息完整性的重要工具,它广泛应用于各种安全系统中.随着可证明安全理论的逐渐成熟,具备可证明安全的消息认证码无疑成为人们的首选.本文基于XOR MAC和PMAC的构造方法,使用分组密码构造了一种确定性、可并行的消息认证码-DXOR MAC(Deterministic XOR MAC).在底层分组密码是伪随机置换的假设下,本文使用Game-Playing技术量化了攻击者成功伪造的概率,从而证明了其安全性.

多安全策略访问控制的关键技术研究

在网络环境中，计算机系统面临的安全威胁是复杂的、多样的和动态变化的，因而，计算机系统的安全需求具有复杂性、多样性和动态变化性等特点。研究表明，多安全策略访问控制是应对复杂、动态安全需求的有效手段。本文对多安全策略访问控制的关键技术进行了研究，并取得了以下研究成果： 第一，对操作系统的强制访问控制框架的正确性验证进行了研究，提出了正确性验证的三个目标，给出了路径敏感的基于静态分析的正确性验证方法，对TrustedBSD MAC框架进行了正确性验证，并成功发现了多处钩子函数放置错误。 第二，对RBAC模型的安全策略的动态调整进行了研究，指出了RBAC模型在安全策略动态调整，特别是角色授权动态调整方面存在的不足，给出了基于状态的安全策略动态调整模型，并给出了基于虚拟域的安全策略动态调整模型的实现方法。 第三，对RBAC模型和Clark-Wilson模型的融合进行了研究，指出了这两个模型在大型应用的完整性保护方面存在的不足，对Clark-Wilson模型的验证规则和实施规则进行了扩展，并给出了RBAC模型和Clark-Wilson模型基于层次方法的融合。 第四，对安全策略描述框架的评价进行了研究，分析了灵活表达安全策略所需的安全策略描述组件，总结了六类典型的安全策略描述框架，提出了基于描述性和实施性评价指标的安全策略描述框架的评价方法，并对六类典型的安全策略描述框架进行了评价。 本文的研究解决了多安全策略访问控制的一些关键问题，为进一步研究多安全策略的实施、多安全策略的动态调整以及多安全策略的融合等问题奠定了理论与实践基础。