Estado e construção ferroviária: quinze anos decisivos para a economia brasileira, 1852-1867

Esta pesquisa procura ampliar e aprofundar o entendimento sobre a participação do Estado na construção ferroviária no século XIX. Com este objetivo, partimos da análise do processo histórico de formação do Estado brasileiro, de 1822 aos anos 1850, a fim de identificar configurações e traços culturais do sistema político no qual se inserem, como prioridade de governo, as políticas públicas e, em especial, o projeto ferroviário. Consideramos que as linhas básicas da política ferroviária, no Império, foram traçadas no período 1852-1867, durante a construção de seis ferrovias pioneiras. Detectamos, ainda, razoável correlação entre o traçado dos caminhos de ferro e os já conhecidos caminhos das minas, que conduziam a zonas onde se localizavam jazigos de pedras e metais preciosos, ferro, carvão, petróleo e outros recursos minerais. Observamos que a participação do Estado na construção ferroviária, no período, desenvolveu-se em duas frentes: como empresário responsável pela construção e gestão de malhas ferroviárias e como agente de regulação de empresas privadas, nacionais e estrangeiras, privilegiadas com longa lista de subvenções e incentivos, entre os quais se destaca a garantia de juro mínimo para os capitais investidos na construção de estradas de ferro.

银杉的分子谱系地理学研究

银杉（Cathaya argyrophylla）是中国特有的濒危裸子植物，孤立分布于我国亚热带山地。虽然以往等位酶和RAPD标记的研究表明，银杉群体的遗传多样性水平很低而群体间的遗传分化很高，但迄今对该种群体的动态变化以及物种的进化历史仍缺乏了解，包括影响群体遗传结构的因素以及物种可能的避难所等，对如何有效地保护和恢复银杉群体仍缺乏科学依据。本文根据8个核基因片段和2个线粒体片段的序列数据，运用群体遗传学和谱系地理学方法，探讨了银杉在DNA水平上的多样性和群体的动态历史，探讨了影响银杉特殊的群体遗传结构的各种因素，并推测了银杉第四纪冰期的避难所，对银杉花粉活力及其变异进行检测。在此基础上，提出了保护和恢复银杉群体的具体策略和措施。主要研究结果如下： 　　1. 核甘酸多态性和群体遗传结构 　　从101个核基因片段中筛选了8个适用于银杉的片段，对来自四个地区15个群体共86个个体的胚乳总DNA进行了扩增和测序。8个核基因座位的平均核苷酸多态性（θs＝0.0022，πs＝0.0027）显著低于其它松杉植物遗传多态性的多座位估计值。四个地区中，大瑶山（DY）的多态性最高（θs＝0.0026，πs＝0.0027），八面山（BM）最低（θs＝0.0014，πs＝0.0018），大娄山（DL）和越城岭（YC）介于二者之间。大多数座位内的多态位点间紧密连锁，座位间的连锁只在八面山地区检测到。AMOVA分析表明显著性的多态性比例存在于地区间（20.05％）和地区内群体间（9.37％）。FST分析也显示群体间（FST＝0.294）和地区间（FST =0.131-0.319）存在显著的遗传分化。推测伴随着瓶颈效应而出现的遗传漂变及其有限的基因流（Nm=1.2）是导致银杉群体低水平多态性和群体间强烈分化的主要原因。 　　2．谱系地理学分析 　　利用2个线粒体片段（nad1和nad4）序列以及高变异量的核2009片段序列对银杉的谱系地理进行了探讨。2个线粒体片段的多态位点组合成3种单倍型，将银杉分成大娄山（DL）、八面山（BM）以及越城岭（YC）和大瑶山（DY）3个地区，地区间的单倍型完全不同（GST=1.0），结合核基因呈现的群体遗传结构，推测现存银杉群体至少来源于4个冰期避难所，相当于银杉现存的4个相互隔离的地区。2009座位上12个变异位点组合成8种单倍型，位于单倍型谱系内部节点的4种祖先单倍型分布广泛、出现频率最高，其它7个核基因座位具有类似谱系结构。遗传距离和地理距离没有相关性，NST (0.138)与GST (0.134)没有显著性差异，说明现存的银杉群体是相对较近的时间内片断化的产物。2009片段分离位点的失配分布（mismatch distribution）呈双峰和多峰，表明银杉群体没有经历近期的扩张，与古生物学研究证据相吻合。 　　3. 银杉的基因杂合性和花粉生命力 　　利用2009和cad两个核基因片段，采用多胚乳序列法得到总的杂合体比率为64％（2009）和60％（cad），说明银杉群体中存在高比例的杂合体。大娄山地区的杂合体比率是八面山地区的2倍。银杉杂合体比率的高低可能与其遗传多态性有关，也可能是自然选择的结果。采用TTC染色法对银杉的花粉生命力进行了测定，在干燥低温条件下银杉花粉的活力很稳定，保存一年后有活力的花粉数仍高达80％以上。通过对来自两个地区（DY和YC）7个群体共16个银杉个体花粉活力的测定发现，银杉有活力花粉比例高达93.3％，与其它裸子植物相当。花粉活力在地区间和群体间存在显著差异，花坪地区（95.2%）的花粉活力高于大瑶山（91.3%）。花粉活力在群体内个体间差异不显著。 　　4．银杉的进化历史及其保护 　　银杉的低水平的遗传多样性和独特的群体遗传结构对我们推测其冰川期避难所提供了重要依据。本研究在银杉4个孤立分布区发现了彼此不重叠的线粒体单倍型，同时核基因表现出了4个地理群，说明随着第四纪冰期气候的波动和银杉分布范围的片段化，原来广布的群体逐步萎缩，最后被保留在位于西部大娄山（DL），东部八面山(BM)，中南部越城岭(YC)和南部大瑶山(DY) 4个相互隔离的避难所。银杉独特的群体结构和动态历史对进一步制定相应的保护措施具有重要参考价值。由于遗传多态性很低，群体又小，几乎所有现存的银杉群体都面临由于随机事件导致的物种灭绝。更严重的是，当前该物种的适生环境不断恶化和片段化，以及异常低的生殖和存活率导致银杉与其它物种竞争能力很低。因此，除目前采取的原地保护策略外，迁地保护应给予优先考虑。此外，采用传统的控制授粉策略（在遗传上有显著差异的群体间开展人工杂交）是丰富其遗传多态性、恢复衰退群体的可行措施之一。

Two families of antimicrobial peptides with multiple functions from skin of rufous-spotted torrent frog, Amolops loloensis

There are around 27 species of Amolops amphibian distributed in South-east of Asia. Seven antimicrobial peptides (AMPs) belonging to two different families were purified from skin of rufous-spotted torrent frog, Amolops loloensis, and designated brevinins

Vespid chemotactic peptide precursor from the wasp, Vespa magnifica (Smith)

Despite the evolutional distance between wasp and amphibian, vespid chemotactic peptide (VCP), an important component of wasp venom, are found sharing remarkable similarities with the temporin antimicrobial peptides (AMPs) from Ranid frog, Amolops loloens

A bactericidal homodimeric phospholipases A(2) from Bungarus fasciatus venom

Group IIA secretory phospholipases A(2) (sPLA(2)-II) is generally known to display potent grampositive bactericidal activity, while group IA sPLA(2) (sPLA(2)-I) reportedly is not. In this work, a novel sPLA(2)-I named BFPA was identified from Bungarus fas

Toward an understanding of the molecular mechanism for successful blood feeding by coupling proteomics analysis with pharmacological testing of horsefly salivary glands

Horseflies are economically important blood-feeding arthropods and also a nuisance for humans and vectors for filariasis. They rely heavily on the pharmacological properties of their saliva to get a blood meal and suppress immune reactions of hosts. Little information is available on antihemostatic substances in horsefly salivary glands; especially no horsefly immune suppressants have been reported. By proteomics or peptidomics and coupling transcriptome analysis with pharmacological testing, several families of proteins or peptides, which act mainly on the hemostatic system or immune system of the host, were identified and characterized from 30,000 pairs salivary glands of the horsefly Tabanus yao (Diptera, Tabanidae). They are: (i) a novel family of inhibitors of platelet aggregation including two members, which possibly inhibit platelet aggregation by a novel mechanism and act on platelet membrane, (ii) a novel family of immunosuppressant peptides including 12 members, which can inhibit interferon-gamma production and increase interleukin-10 secretion, (iii) a serine protease inhibitor with 56 amino acid residues containing anticoagulant activity, (iv) a serine protease with anticoagulant activity, (v) a protease with fibrinogenolytic activity, (vi) three families of antimicrobial peptides including six members, (vii) a hyaluronidase, (viii) a vasodilator peptide, which is an isoform of vasotab identified from Hybomitra bimaculata, and interestingly (ix) two metallothioneins, which are the first metallothioneins reported from invertebrate salivary glands. The current work will facilitate the understanding of the molecular mechanisms of the ectoparasite-host relationship and help in identifying novel vaccine targets and novel leading pharmacological compounds.

The giant panda (Ailurapoda melanoleuca) somatic nucleus can dedifferentiate in rabbit ooplasm and support early development of the reconstructed egg

The giant panda skeletal muscle cells, uterus epithelial cells and mammary gland cells from an adult individual were cultured and used as nucleus donor for the construction of interspecies embryos by transferring them into enucleated rabbit eggs. All the three kinds of somatic cells were able to reprogram in rabbit ooplasm and support early embryo development, of which mammary gland cells were proven to be the Lest, followed by uterus epithelial cells and skeletal muscle cells. The experiments showed that direct injection of mammary gland cell into enucleated rabbit ooplasm, combined with in vivo development in ligated rabbit oviduct, achieved higher blastocyst development than in vitro culture after the somatic cell was injected into the perivitelline space and fused with the enucleated egg by electrical stimulation. The chromosome analysis demonstrated that the genetic materials in reconstructed blastocyst cells were the same as that in panda somatic cells. In addition, giant panda mitochondrial DNA (mtDNA) was shown to exist in the interspecies reconstructed blastocyst. The data suggest that (i) the ability of ooplasm to dedifferentiate somatic cells is not species-specific; (ii) there is compatibility between interspecies somatic nucleus and ooplasm during early development of the reconstructed egg.

Microsatellite DNA analysis proves nucleus of interspecies reconstructed blastocyst coming from that of donor giant panda

A method for DNA isolation from early development of blastocyst and further analysis of nuclear and mitochondrial DNA was developed in present study. Total DNA was prepared from interspecies reconstructed blastocyst and a giant panda specific microsatellite locus g(010) was successfully amplified. DNA sequencing of the PCR product showed that two sequences of reconstructed blastocysts are the same as that of positive control giant panda. Our results prove that the nucleus of interspecies reconstructed blastocyst comes from somatic nucleus of donor giant panda.

Interspecies implantation and mitochondria fate of panda-rabbit cloned embryos

Somatic cell nuclei of giant pandas can dedifferentiate in enucleated rabbit ooplasm, and the reconstructed eggs can develop to blastocysts. In order to observe whether these interspecies cloned embryos can implant in the uterus of an animal other than th

Preliminary chemical and physical evaluation of some formulated feeds for P. monodon

The culture of Penaeus monodon has explicitly defined the need for diet formulations or supplementary feeds that would promote optimum growth and survival of the animal. A total of 28 feed combinations were developed for P. monodon. Fish meal, shrimp head meal, squid head meal, Ascetes spp. rice bran, and soybean cake were used as primary ingredients in these feeds. The commercial vitamin mix No. 22 was added to the dry ingredients. Gelatinized corn starch and wheat flour were used as binders. The pellets were extruded using a portable kitchen grinder with a diameter of 4 mm. The products were either sun-dried for 8 hours or oven-dried overnight at 50 degree C to stabilize moisture at 8-10%. The pellets were then kept in covered glass bottles and stored in the laboratory at room temperature. The cost of the feeds excluding labour were also computed. The pellets were analyzed for protein, fat, carbohydrate, crude fiber, ash, and moisture contents using standard procedures. They were also analyzed for water stability. To test the stability of pellets in water, 2-g samples were placed in plankton nets (mesh #40) and suspended in water for two, and six hours. The undissolved samples were then vacuum-dried and the moisture determined. Cost of the feeds ranged from P1.10 to P2.60 per kg depending on the feed ingredient. Squid and Ascetes spp. were rather expensive for use as basic ingredients. Proximate analysis of dry weight showed percentage protein content ranged from 20-63 g; fat, 8-20 g; carbohydrate (by difference), 11-36 g; ash, 8-28 g; moisture, 6-11 g; and crude fiber, 5 . 13 g. Stability tests showed that after two hours, 35-88% of solids remained intact and after 6 hours, 20-55% of the pellets remained undissolved. When a pellet disintegrates easily, pollution of the water occurs. Chances for the shrimp to feed on the pellet is minimized when the pellet is unstable. Thus, the search for a more compact feed pellet has to be continued.