Disputatio historica de P. Thrasea Paeto ...

Proefschrift--Groningen.

Plasmas meet plasmonics

The term ‘plasmon’ was first coined in 1956 to describe collective electronic oscillations in solids which were very similar to electronic oscillations/surface waves in a plasma discharge (effectively the same formulae can be used to describe the frequencies of these physical phenomena). Surface waves originating in a plasma were initially considered to be just a tool for basic research, until they were successfully used for the generation of large-area plasmas for nanoscale materials synthesis and processing. To demonstrate the synergies between ‘plasmons’ and ‘plasmas’, these large-area plasmas can be used to make plasmonic nanostructures which functionally enhance a range of emerging devices. The incorporation of plasma-fabricated metal-based nanostructures into plasmonic devices is the missing link needed to bridge not only surface waves from traditional plasma physics and surface plasmons from optics, but also, more topically, macroscopic gaseous and nanoscale metal plasmas. This article first presents a brief review of surface waves and surface plasmons, then describe how these areas of research may be linked through Plasma Nanoscience showing, by closely looking at the essential physics as well as current and future applications, how everything old, is new, once again.

Analysis of multiple crystal forms of Bacillus subtilis BacB suggests a role for a metal ion as a nucleant for crystallization

Bacillus subtilis BacB is an oxidase that is involved in the production of the antibiotic bacilysin. This protein contains two double-stranded beta-helix (cupin) domains fused in a compact arrangement. BacB crystallizes in three crystal forms under similar crystallization conditions. An interesting observation was that a slight perturbation of the crystallization droplet resulted in the nucleation of a different crystal form. An X-ray absorption scan of BacB suggested the presence of cobalt and iron in the crystal. Here, a comparative analysis of the different crystal forms of BacB is presented in an effort to identify the basis for the different lattices. It is noted that metal ions mediating interactions across the asymmetric unit dominate the different packing arrangements. Furthermore, a normalized B-factor analysis of all the crystal structures suggests that the solvent-exposed metal ions decrease the flexibility of a loop segment, perhaps influencing the choice of crystal form. The residues coordinating the surface metal ion are similar in the triclinic and monoclinic crystal forms. The coordinating ligands for the corresponding metal ion in the tetragonal crystal form are different, leading to a tighter packing arrangement. Although BacB is a monomer in solution, a dimer of BacB serves as a template on which higher order symmetrical arrangements are formed. The different crystal forms of BacB thus provide experimental evidence for metal-ion-mediated lattice formation and crystal packing.

Structures of apo and GTP-bound molybdenum cofactor biosynthesis protein MoaC from Thermus thermophilus HB8

The first step in the molybdenum cofactor (Moco) biosynthesis pathway involves the conversion of guanosine triphosphate (GTP) to precursor Z by two proteins (MoaA and MoaC). MoaA belongs to the S-adenosylmethioninedependent radical enzyme superfamily and is believed to generate protein and/or substrate radicals by reductive cleavage of S-adenosylmethionine using an Fe-S cluster. MoaC has been suggested to catalyze the release of pyrophosphate and the formation of the cyclic phosphate of precursor Z. However, structural evidence showing the binding of a substrate-like molecule to MoaC is not available. Here, apo and GTP-bound crystal structures of MoaC from Thermus thermophilus HB8 are reported. Furthermore, isothermal titration calorimetry experiments have been carried out in order to obtain thermodynamic parameters for the protein-ligand interactions. In addition, molecular-dynamics (MD) simulations have been carried out on the protein-ligand complex of known structure and on models of relevant complexes for which X-ray structures are not available. The biophysical, structural and MD results reveal the residues that are involved in substrate binding and help in speculating upon a possible mechanism.

X-ray and molecular-dynamics studies on Mycobacterium leprae single-stranded DNA-binding protein and comparison with other eubacterial SSB structures

The crystal structures of two forms of Mycobacterium leprae single-stranded DNA-binding protein (SSB) have been determined at 2.05 and 2.8 A resolution. Comparison of these structures with the structures of other eubacterial SSBs indicates considerable variation in their quaternary association, although the DNA-binding domains in all of them exhibit the same OB-fold. This variation has no linear correlation with sequence variation, but could be related to variation in protein stability. Molecular-dynamics simulations have been carried out on tetrameric molecules derived from the two forms and the prototype Escherichia coli SSB and the individual subunits of both proteins. Together, the X-ray studies and molecular-dynamics simulations yield information on the relatively rigid and flexible regions of the molecule and on the effect of oligomerization on flexibility. The simulations provide insight into the changes in subunit structure on oligomerization. They also provide insight into the stability and time evolution of the hydrogen bonds/water bridges that connect the two pairs of monomers in the tetramer.

Resultados de los ensayos de sorgo del programa Cooperativo Centroamericano de Cultivos y Animales (PCCMCA) durante los años 2000 y 2001

Los ensayos de sorgo del PCCMCA suministran informa· clón del comportamiento de los sorgos híbridos comerciales y precomerciales de las empresas proveedoras de semillas y de los programas nacionales de la región. Esta información es la base para recomendar los materiales de siembra que más convengan en las zonas sorgueras en el istmo Centroamericano y el caribe. En el año 2000, se establecieron ensayos de campo en siete localidades, los cuales incluyeron 12 materiales de siembra, entre híbridos y variedades de polinización libre. En el año 2001 los ensayos se establecieron en siete localidades y se incluyeron 16 materiales de siembra, diferentes de los establecidos en el año 2000. En ambos años la siembra se realizó durante la época de postrera. La parcela experimental fue de 14 m2 y la parcela útil de 7. El diseño experimental fue bloques al azar con cuatro repeticiones. Para cada localidad se utilizó el manejo agronó mico que normalmente realizan los agricultores de la zona, el cual coincide en gran medida entre las localidades. En el año 2000, los hlbridos CB-XH 2006 y CB-XH 8976, fueron superiores estadisticamente, con rendimientos de 6340 y 6290 kg ha·1• El coefi ciente de variación fue de 12.19%. Para el año 2001, los hibridos CBX-8016-2 (6822 kg ha·') y CBX-8016-1 (6811 kg ha·'), fueron estadisticamente superiores e iguales a HIMECA-1 01, (6499 kg ha· '), MTC-7439 (6421 kg ha·'), MTC-1197 (6385 kg ha·'), MTC-11n (6241 kg ha·'), D-66 (6176 kg ha·'), MTC-7379 (6159 kglha), MTC- 7389 (6115 kg ha·'), CB-2006 (8090 kg ha·'), HIMECA 404 (5762 kg ha·') y ESHG-2001 (5495 kg ha·'). El coeficiente de variación para el año 2001 fue de 15.04%.

羊草cDNA文库的构建及果聚糖水解酶的分离与鉴定

羊草(Leymus chinensis(Trin.) Tzvel.)又称碱草，隶属禾本科赖草属，是欧亚大陆草原区东部草甸草原及干旱草原上的重要建群种之一。作为一种兼具重要经济价值和生态价值的优良牧草，羊草受到了广泛的关注。但长期以来，对羊草的研究主要集中在生态学、生殖生物学方面，在分子生物学方面知之甚少。为了保存羊草基因资源，并在基因水平上研究羊草生物代谢的调控机理，本研究采用羊草根、叶片混合后做为材料，构建cDNA文库，并对文库中部分基因序列进行了分析。同时从中克隆获得羊草果聚糖水解酶全长基因并对这些基因进行了深入的生物信息学分析、转化毕赤酵母研究初步确定其功能，为深入了解羊草代谢的分子机制提供理论依据。主要结果如下： 1. 成功地构建了羊草根、叶混合cDNA文库，原始文库滴度达到4×106 pfu/ml，扩增文库滴度接近1011 pfu/ml ，重组率达97% 。PCR检测插入片段，均在0.5 kb到3 kb之间，l kb以上占68%。从文库中检测到了TC、γ-TMT、FEH基因，文库覆盖度达到要求且为PCR筛选文库提供了可能。 2. 随机挑取经检测过的597个单克隆进行测序，去除插入片段小于和污染序列后，获得了584条高质量的序列。所有584条EST序列与NCBI的核酸数据库比对时，有30.99%的EST序列与己知序列有很大的同源性：而与蛋白质数据库进行比对时，有61.27%的EST序列与已知序列有很大的同源性。核酸比对中，有32.87%的序列为未知功能新基因，而蛋白质比对结果只有11.27%的序列为未知功能新基因。其中获得5条全长基因。 3. 文库中测序得到果聚糖水解酶（FEH）片段，依据其核酸、蛋白序列，以羊草根茎为材料，结合果聚糖水解酶基因的保守序列设计引物，通过 RACE 方法，获得羊草果聚糖水解酶基因 Lc 1-FEH 的全长序列（2040bp），包含一个 1803bp 的开放阅读框，采用生物信息学方法对该基因编码蛋白质进行功能分析，该基因编码的氨基酸序列具有明显的果聚糖水解酶类蛋白特征(NDPNG，FRDP 和[WEC (V/P)D] 结构域)，其分子量为 66.8kD，等电点 pI 为 5.49，是一种酸性蛋白质。同源性分析结果表明Lc1-FEH与单子叶植物小麦、大麦和黑麦草细胞壁类酵素酶同源性最高，分别为89％、87％ 和72％。运用实时定量方法对Lc 1-FEH表达量在羊草发育各时期及不同逆境处理下进行测定，结果发现，幼苗中以叶中表达量最低，根茎中表达较高，成苗中花梗中的表达量最高；Lc1-FEH在转录水平明显受碱、ABA、SA及低温胁迫诱导，随着胁迫时间延长，表达量迅速增加，到达到最大值，之后表达水平逐渐降低，在盐、干旱的诱导下的表达量迅速降低。 4. 羊草果聚糖水解酶Lc1-FEH基因在毕赤酵母中的高效表达 将pMD-Lc1-FEH 质粒经双酶切后构建果聚糖酵母表达载体 pPICZα- Lc1-FEH 。将重组表达载体线性化后电击转化毕赤酵母Pichia pastoris X33，经抗生素 Zeocin 和酵母 PCR 筛选获得高效表达酵母工程菌。毕赤酵母表达的果聚糖水解酶蛋白经SDS-PAGE 分析表明Lc1-FEH表观分子量为 67 kD 左右。其最适反应 pH 值为 5.5，在 pH 值为 4.5~6.5 的范围内能保持较高的酶活力；表达Lc1-FEH的最适反应温度为 30 ℃；在温度在 20～30℃度范围内有较高的酶活。 Lc 1-FEH能够水解含有β-2，1糖苷键类型果聚糖：蔗果四糖、菊粉、6-蔗果三糖；而对β-2，6糖苷键类型果聚糖：6-蔗果三糖、新蔗果三糖、细菌类果聚糖及蔗糖基本不具水解活性。

猴和人T淋巴细胞表面TRBC受体和E受体的比较研究

1985年贲昆龙等首次发现人和猴T淋巴细胞能与树鼩(Tupaia belangeri)的红细胞(TRBC)形成亲和力极强的玫瑰花结，它与绵羊红细胞(SRBC)玫瑰花结(E花结)明显不同。例如，TRBC经神经氨酸酶处理之后，结花率明显下降，TRBC与T淋巴细胞所形成的玫瑰花结，经45℃保温，仍不受影响，为了进一步探讨TRBC受体和SRBC受体(CD2)，以及与其它T细胞表面分化搞原(CD)的系。我用某些抗人T细胞CD的单克隆抗体(McAb)对人和猴淋巴细胞进行玫瑰花结抑制试验，抗原调变和共调变(Antigenic modulation or co-modulation)实验，并且研究了TRBC受体在其它免疫细胞和某些人类和长臂猿细胞系的分布。结果表明，TRBC与外周血E~+-PBL形成玫瑰花结的百分率为88.8%。而E~--PBL仅为4.16%。TRBC受体存在于所有被试T细胞系(CEM, H33JHJA1, Jurkat, MLA-144, Molt-3, Molt-4, Molt-4 clone-8 和PEER)，但不存在于外周血粒细胞，B细胞，以及B细胞系的绝大多数细胞表面(Daudi, Raji和Reh)。分布于全T细胞的CD3, TCR, CD5, CD6和CD7的相McAb OKT3, T108(F1), T136(F101-15), T149(M-T604)和T152(7G5)均不能调变和共调变TRBC受体。猴和人外周血淋巴细胞与TRBC玫瑰花结的形成，不被T11.1 McAb OKT11所阻断，相反，OKT11显著地阻断猴和人外周血淋巴细胞E玫瑰花结的形成，最大抑制率分别为49.3%和77.7%。在世界各地10个实验室送交第四次国际人白细胞化化抗原讨论会待鉴定的13个CD2 McAb中，除T089 (39C1.5)因抗体量不够未作实验外，对其他12种McAb都进行试验，T081 (x/3)，T082 (GLB-T11.2/1)，T083 (GLB-T11.1/1)，T085 (RPA-2.10)，T1088 (0-275)和T092 (M-T201)对TRBC玫瑰花结和E玫瑰花结都呈现明显的阻断作用，T084 (F110.08)，T091 (AICD2.1)以及已知参数CD2 McAb-T086 (D-66 clonel)和T087 (GT-2)都不阻TRBC玫瑰花结的形成，亦不调变TRBC受体，而对E玫瑰花结则有不同程度阻断效应，并且调变E变体，使E玫瑰花结形成细胞百分率下降。T090 (6F10.3)和T198 (JOR-T2)即不阻TRBC玫瑰花结的形成，也不抑制E玫瑰花结的形成。由此可见，TRBC受体分布于全T细胞，它不同于已知的全T细胞表面分化抗原CD2 (gp50), CD3/TCR复合物，CD5, CD6和CD7。CD2分子不与TRBC玫瑰花结的形成，也不是介导E玫瑰花结的唯一分子。至少有二个或三个以上的蛋白质与E玫瑰花结和TRBC玫瑰花结的形成有关，其中有的分子为E受体和TRBC受体所共有。TRBC受体很有可能包括新的T淋巴细胞分化抗原。

长白山阔叶红松林CO_2通量季节和年际变化特征及控制机制

老龄林碳代谢的长期测定对于预测其在未来气候条件下的碳收支状态,减小陆地生态系统碳收支的不确定性十分重要．本研究使用连续两个生长季节(2003和2004年)的涡度相关CO2净交换通量测定和常规气象资料分析平均林龄200年的长白山阔叶红松林生态系统(128°28′E, 42°24′N,中国吉林省)FNEE及其主要成分FGPP与Re的季节和年际变化特征及环境和生物因子对其的影响．通量数据进行了平面坐标旋转,储存项和μ*修正．叶面积指数和温度分别控制着该生态系统FGPP和Re的季节动态和年际差别．水汽压亏缺和气温在更小尺度上调节生长季节的生态系统光合生产,根部水分条件显著影响生态系统冬季维持性的碳代谢过程．2003年1月至2004年12月该生态系统累计截获碳-449 g C·m-2,其中2003和2004年分别为-278和-171 g C·m-2．这两年FGPP和Re分别为-1332,-1294 g C·m-2和1054,1124 g C·m-2．这显示老龄森林可以成为强的碳汇．受环境因子调控,长白山阔叶红松林生态系统的碳代谢表现出显著的季节和年际差异．冬季该生态系统存在弱的光合作用,但总体上向大气释放CO2．春秋季节碳代谢非常活跃,但生态系统吸收和释放几乎相同数量的碳,对全年碳截获贡献并不显著．夏季碳代谢对该生态系统全年碳收支意义重大．90 d的夏季分别贡献全年66．9,68．9％的FGPP和60．4,62．1％的Re．

发酵鸡粪的高温蛋白分解菌的筛选

采用含有酪素的细菌培养基进行稀释分离,从自然鸡粪堆肥中筛选出16株分解蛋白能力较强的菌株,透明圈直径(d)最大达到66.5mm;通过酶活性的测定,得到9个菌株其中性蛋白酶活力较高,并且在50℃能良好生长;将9个高温菌株分别回接灭菌鸡粪,筛选得到有5个菌株能在鸡粪中定殖,50℃恒温发酵10天,活菌数达到109个g-1以上;接种JS8菌株进行鸡粪发酵,从温度、含水量及pH值指标上,均明显好于鸡粪自然发酵,说明人工添加外源菌群有利于缩短发酵时间、减少发酵过程中养分损失,具有广阔的应用前景。

Parthenogenetic activation of bovine oocytes using single and combined strontium, ionomycin and 6-dimethylaminopurine treatments

In vitro-matured (IVM) bovine oocytes were activated with single and combined treatments of strontium (S), ionomycin (1) and 6-DMAP (D). Using oocytes IVM for 26 h, we observed that activation altered cell cycle kinetics (faster progression, MIII arrest, or direct transition from MII to pronuclear stage) when compared to in vitro fertilization. The effect of oocyte age on early parthenogenesis was assessed in oocytes IVM for 22, 26 and 30 h. Better results in pronuclear development were obtained in treatments ISD (81.7%) at 22 h; D (66.7%), IS (63.3%), ID (73.3%) and ISD (76.7%) at 26 h; and D (86.7%), IS (85.0%) and ID (78.3%) at 30 h. Higher cleavage occurred on ISD (80.0%) at 22 h; ID (83.3%) and ISD (91.7%) at 26 h; and 1 (86.7%), IS (90.0%), ID (85.0%) and ISD (95.0%) at 30 h. More blastocysts were achieved in ID (25.0%) and ISD (18.3%) at 22h; and in ID at 26h (45.0%) and 30h (50.0%). We also observed that IS allowed higher haploid (77.4%) embryonic development, whilst ID was better for diploid (89.1%) development. It was concluded that association of S and D without I was not effective for blastocyst development; treatments using S were less influenced by oocyte age, but when S was associated with D there was a detrimental effect on aged oocytes; treatment ISD promoted higher activation and cleavage rates in young oocytes and ID protocol was the best for producing blastocysts.

Ultrasonographic monitoring of early pregnancy development in Murrah buffalo heifers (Bubalus bubalis)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Classical versus quantum equivalence between sine-Gordon, Liouville and other solitons

In this work we present a mapping between the classical solutions of the sine-Gordon, Liouville, λφ4 and other kinks in 1+1 dimensions. This is done by using an invariant quantity which relates the models. It is easily shown that this procedure is equivalent to that used to get the so called deformed solitons, as proposed recently by Bazeia et al. [Phys. Rev. D. 66 (2002) 101701(R)]. The classical equivalence is explored in order to relate the solutions of the corresponding models and, as a consequence, try to get new information about them. We discuss also the difficulties and consequences which appear when one tries to extend the deformation in order to take into account the quantum version of the models.

Die Frühspezialisierung von Juniorennationalspielern im Fussball: Ein Vergleich zweier Generationen

Einleitung: Die Nachwuchsarbeit im Schweizer Fussball ist seit 1995 stark professionalisiert worden, was sich in den letzten 15 Jahren in mehrere internationale Erfolge niedergeschlagen hat. Im Hinblick auf den sportlichen Erfolg hat sich dabei gezeigt, dass sich die Karrieren der erfolgreichsten Schweizer Spieler, deren Förderung in die ersten Jahre dieser Professionalisierung fällt, bereits in der Sampling Phase (Coté, 1999) durch eine frühe Spezialisierung beschreiben lässt (Zibung & Conzelmann, 2013). Die Trainingsumfänge beinhalten v.a. Clubtraining und viel freies Spiel ausserhalb des Clubs oder fussballnahe andere sportliche Aktivitäten. In diesem Beitrag wird der Frage nachgegangen, inwiefern sich die in den folgenden Jahren nochmals akzentuierte Professionalisierung auf die sportlichen Karrieren der aktuellen Generation von talentierten Fussballspielern ausgewirkt hat. Methode: N = 32 Juniorennationalspieler mit mind. 1 Aufgebot in die U15 oder U16 Nationalmannschaft (Jg. 99; Stichprobe A) werden mit n = 151 ehemaligen Juniorennationalspielern (Jg. 81-87; Stichprobe B aus Zibung & Conzelmann, 2013) in Bezug auf relevante Indikatoren zur Frühspezialisierung verglichen. Dafür wurden die beiden Stichproben in Anlehnung an Zibung und Conzelmann (2013) mittels t-Tests (p < .05) bezüglich folgender Indikatoren für Frühspezialisierung verglichen: Alter beim Beginn freies Fussballspiel und beim ersten Clubeintritt, Trainingsstunden im Club, freies Fussballspiel sowie sportliche Aktivitäten neben dem Fussball (jeweils bis 12-jährig). Die Variablen wurden in beiden Studien retrospektiv per Fragebogen erfasst. Resultate: Die Spieler der jüngeren Generation haben bis 12 Jahre weniger Stunden frei Fussball gespielt (MA = 2016.6, SDA = 1107.1) als die Spieler der älteren Generation (MB = 2535.5, SDB = 1277.3) (t(50.1) = 2.34, p = .02, d = .66). Gleichzeitig haben sie neben dem Fussball weniger andere sportliche Aktivitäten aufzuweisen (t(68.0) = 2.53, p = .01, d = .61). In den Variablen Trainingsstunden im Club (MA = 923.0, SDA = 166.6; MB = 967.0, SDB = 287.1), Alter beim Beginn des freien Fussballspiels (MA = 4.08, SDA = 1.5; MB = 4.36, SDB = 1.2) und beim ersten Clubeintritt (MA = 5.75, SDA = 1.0; MB = 6.07, SDB = 1.3) unterscheiden sich die beiden Stichproben nicht. Diskussion: Der Vergleich der beiden Stichproben zeigt, dass es in den letzten 15 Jahren zu einer Veränderung der Trainingsumfänge von Juniorennationalspielern gekommen ist. Die aktuelle Generation von Juniorennationalspielern spielt neben dem Clubtraining weniger frei Fussball und betreibt aber auch weniger andere Sportarten als die Juniorennationalspieler vor 10-15 Jahren. Ob vermehrte schulische Anforderungen diesen Rückgang in der generellen sportlichen Aktivität verschulden, müsste in der Folge weiter untersucht werden. Ebenso bleibt offen, ob die Einschätzung der Stichprobe B, aufgrund des relativ langen Zeitraums, der zwischen der Erhebung und dem zu erfassenden Zeitraum liegt, zu einer Antwortverzerrung und damit einer Erhöhung der geschätzten Trainingsstunden geführt hat. Literatur: Côté, J. (1999). The influence of the family in the development of talent in sport. The Sport Psychologist, 13 (4), 395–417. Zibung, M. & Conzelmann, A. (2013). The role of specialisation in the promotion of young football talents: A person-oriented study. European Journal of Sport Science, 13 (5), 452–460.