The variability of eddy kinetic energy in the South China Sea deduced from satellite altimeter data

We used fifteen years (1993-2007) of altimetric data, combined from different missions (ERS-1/2, TOPEX/Poseidon, Jason-1, and Envisat), to analyze the variability of the eddy kinetic energy (EKE) in the South China Sea (SCS). We found that the EKE ranged from 64 cm(2)/s(2) to 1 390 cm(2)/s(2) with a mean value of 314 cm(2)/s(2). The highest EKE center was observed to the east of Vietnam (with a mean value of 509 cm(2)/s(2)) and the second highest EKE region was located to the southwest of Taiwan Island (with a mean value of 319 cm(2)/s(2)). We also found that the EKE structure is the consequence of the superposition of different variability components. First, interannual variability is important in the SCS. Spectral analysis of the EKE interannual signal (IA-EKE) shows that the main periodicities of the IA-EKE to the east of Vietnam, to the southwest of Taiwan Island, and in the SCS are 3.75, 1.87, and 3.75 years, respectively. It is to the south of Taiwan Island that the IA-EKE signal has the most obvious impact on EKE variability. In addition, the IA-EKE exhibit different trends in different regions. An obvious positive trend is observed along the east coast of Vietnam, while a negative trend is found to the southwest of Taiwan Island and in the east basin of Vietnam. Correlation analysis shows that the IA-EKE has an obvious negative correlation with the SSTA in Nio3 (5A degrees S-5A degrees N, 90A degrees W-150A degrees W). El Nio-Southern Oscillation (ENSO) affects the IA-EKE variability in the SCS through an atmospheric bridge-wind stress curl over the SCS. Second, the seasonal cycle is the most obvious timescale affecting EKE variability. The locations of the most remarkable EKE seasonal variabilities in the SCS are to the east of Vietnam, to the southwest of Taiwan, and to the west of Philippines. To the east of Vietnam, the seasonal cycle is the dominant mechanism controlling EKE variability, which is attributed primarily to the annual cycle there of wind stress curl. In this area, the maximum EKE is observed in autumn. To the southwest of Taiwan Island, the EKE is enlarged by the stronger SCS circulation, which is caused by the intrusion branch from the Kuroshio in winter. Finally, intra-annual and mesoscale variability, although less important than the former, cannot be neglected. The most obvious intra-annual and mesoscale variability, which may be the result of baroclinic instability of the background flow, are observed to the southwest of Taiwan Island. Sporadic events can have an important effect on EKE variability.

南沙珊瑚礁生态系的营养动力学过程

本论文首次报道了在珊瑚礁向海坡上投放沉积物捕捉器的结果和若干非生源要素如Mo、W、Re、Os、Ni、Ir等在泻湖内外的垂直通量，并在国内首次报道了珊瑚活体培养的结果。将海水、沉降颗粒物、生物和泻湖表层沉积物统一进行系统的研究，重点讨论了珊瑚礁营养动力学过程和维持高生产力的机制等问题。主要的研究内容和结果包括：1. 物理动力过程对营养物质的循环有重要影响物理因素尤其是海水的动力过程更可能是珊瑚礁生长的限制性因素。南沙珊瑚礁的形态及其相关的沉积环境明显受本海区物理过程（海洋和大气）的控制。与此相适应，珊瑚礁生态系统造就了有效保持和快速吸收营养盐的特性。泻湖海水中营养盐分布明显受到泻湖水运动方式的影响，尤其是PO_4-P。2. 营养物质的循环具有快速高效和不均衡的特点 对渚碧礁生源要素的生物地球化学循环研究表明，快速分解、高效再利用是珊瑚礁总生产力很高，净生产力却较低的主要原因。渚碧礁泻湖内两个站的POC分别有93.55%和95.83%在进入沉积物前被消耗，能真正进入沉积物中的却很少。其中99%左右的生物碎屑POC通过生物捕食或腐解作用转变为无机碳重新进入循环。珊瑚礁生态系的高生产力主要是依靠其系统内部快速而高效的再生循环过程维持的。营养盐的原位再生是珊瑚礁营养盐的主要来源，泻湖内PTN和PON释放率分别超过90%和86%；PTP释放率为58.7%～85.2%，多数站位POP的释放率在90%以上。泻湖水中N:P摩尔比平均值仅为8.1，可能存在着氮限制。而在礁坪区，N:P摩尔比的日平均值为26.7，磷的限制作用非常明显。整体来看，氮在泻湖内进入再循环的速度和效率要高于磷2.5～12.8 倍，由于磷缺乏类似于生物固氮作用的持续的供氮机制，磷在珊瑚礁生态系中的限制作用更为明显，至少在礁坪区是如此。珊瑚活体培养的实验表明，珊瑚也存在着短时间里大量消耗营养盐的“奢侈消费”现象。珊瑚对营养盐的吸收速度与营养盐的浓度和珊瑚的种类均有关系。添加营养盐起始浓度高的组营养盐消耗的速度快，与之相适应，其它的各种溶解性营养盐浓度也产生复杂的变化，对迅速稳定水体营养盐浓度产生协同作用，这一过程有助于珊瑚充分吸收突然输入的营养盐。在此实验条件下，珊瑚对含氮盐类的浓度变化要比对磷酸盐更为敏感，可以认为NH_4-N是珊瑚生长的限制性营养盐。在自然界中，这种情况常发生在有大量营养盐输入之后。实验中还发现，对营养盐的吸收速度比营养盐水平更为重要。吸收速度快于某种形态限制性营养盐的输入速度也会导致珊瑚的死亡。反过来讲，珊瑚礁系统可以通过降低对营养盐的消费速度而摆脱营养盐的限制。3. 非生源要素的循环也与生物过种密切相关 非生源要素在海洋颗粒物、生物和沉积物中的分布主要受两种作用的影响，一是颗粒物在生产、沉降和分解过程中的吸附释放作用，另一种是生物的直接利用。颗粒物对IIA族、过渡族的大部分和La系元素都是分布的制约性因素。而IA族、过渡族的一部分和部分非金属元素分布上属于营养盐型，主要受浮游生物直接吸收溶解的盐类（浮游植物）和捕食作用（浮游动物）的影响。轻元素、第四周期的过渡族元素在含量和性质上往往有别于重元素和其它周期的同族过渡元素，更多的参与生物过程。元素分析进一步显示珊瑚礁泻湖内沉降颗粒物主要是自生碎屑，而礁外沉降颗粒物包含了一部分再悬浮的碎屑矿物，但元素在泻湖内外的转移机制是类似的，造成颗粒物来源差别的主要原因是动力学因素。水动力始终是颗粒物中元素垂直转移的主要的、关键性的因素。对于营养盐型的元素，生物的捕食富集是另一个主要控制因素。4. 多种机制的协同作用维持了珊瑚礁生态系的高生产力 考虑到珊瑚礁营养盐的收支并非总是平衡的，珊瑚礁的高生产力的维持可能是通过以珊瑚礁发育位置的选择为基础，“流网”策略、快速吸收营养盐、营养盐的快速循环和高效利用以及“休渔”策略等的协同作用实现的。“休渔”策略是指捕食因素决定的食物链上游生物迁出和初级生产力的恢复过程，当捕食作用高于生产者的生产速度或营养盐供应严重不足时，许多处于食物链上游的游泳动物将迁徙到生产力更高的珊瑚礁中去。大量的生物碎屑和代谢产物中的营养成分重新释放利用。一段时间后又能够重新繁荣起来。由于生物对磷和金属元素等的富集作用，食物链上游生物及其代谢产物作为营养物质输入的一个经常性来源的作用不可忽视。

自治水下机器人在深海采矿系统湖试中的应用

以大洋采矿前期的湖试为例,介绍了AUV在矿产资源调查和深海采矿中的应用。在深海采矿系统作业前期,利用AUV调查湖底的地形地貌、结核的分布与覆盖率,确定集矿机作业地点的大地坐标。在深海采矿系统作业后期,利用AUV调查集矿机在湖底的行走轨迹和压陷深度,估算回采率。

基于以太网的工业控制网络

应用传统现场总线的工业控制网络无法实现办公室自动化与工业自动化的无缝结合 .由于以太网在确定性、速度和优先法则等方面性能的提高 ,阻碍以太网应用于实时控制环境的难点已被解决 .以太网早已成为商业管理网络的首要选择 ,那么它应用于企业现场设备控制层是控制网络发展的趋势 ,将极大地促进信息从传感器到管理层的集成

Modeling of protein adsorption in membrane affinity chromatography

For the design of affinity membranes, protein adsorption in membrane affinity chromatography (MAC) was studied by frontal analysis. According to fast mass transfer, small thickness of affinity membranes and high affinity between the protein and the ligand, an ideal adsorption (IA) model was proposed for MAC and was used together with equilibrium-dispersive (E-D) model to describe the adsorption of bovine serum albumin (BSA) onto cellulose diacetate/polyethyleneimine (CA/PEI) blend membranes with and without Cu2+ chelating. E-D model was found to better describe the initial region of experimental breakthrough curves. The influence of axial dispersion was revealed and it showed the importance of design of the module to homogenously distribute feed solution. IA model was found to be better for the whole experimental breakthrough curve. According to it, the capacity of affinity membranes and the specificity of the interaction are of equal importance for the design of affinity membranes. An optimum feed concentration was also found in the operation of MAC. The discrepancy between experimental optimum feed concentrations and predicted ones from IA model may be due to the ignorance of some experimental effects such as axial dispersion.

Avaliacao de genotipos de trigo em diferentes regioes triticolas do Parana, em solos sem aluminio, na safra de 1996.

O estado do Parana apresenta uma diversidade de clima, com invernos irregulares em relacao a precipitacoes pluviometricas e ocorrencia de geadas, e tambem, com relacao aos tipos de solos, que influem na adaptacao e no desempenho dos genotipos de trigo. Em vista disto, ha necessidade de um maior numero de cultivares, com caracteristicas diferenciadas para serem utilizadas pelos produtores. O presente trabalho tem por objetivo avaliar, nas zonas A e B, em solos com ate 5% de saturacao de aluminio, os novos genotipos de trigo criados pelas diferentes instituicoes que desenvolvem trabalhos de melhoramento genetico de trigo. Esta avaliacao e realizada pelo Instituto Agronomico do Parana (IAPAR), pelo Centro Nacional de Pesquisa de Soja (Embrapa Soja) e pela Cooperativa Central de Desenvolvimento Tecnologico e Economico (COODETEC), atraves da instalacao de diferentes ensaios de competicao de genotipos. Os resultados aqui relatados sao resultantes de dez experimentos do Ensaio Intermediario Paranaense (IPS), doze experimentos do Ensaio Centro-Sul Brasileiro (CSBS) e onze experimentos do Ensaio de Cultivares em Cultivo (ECS), para solos com ate 5% de saturacao de aluminio, instalados em 1996, em diferentes epocas, nas localidade de Cambara, Londrina, Engenheiro Beltrao, Palotina e Sao Miguel do Iguacu. Devido a longa estiagem ocorrida no periodo de abril a julho, no Norte do estado (zona A1), alguns experimentos foram prejudicados e, outros perdidos. Em Londrina e Palotina, os experimentos receberam irrigacoes na fase inicial para propiciar uma boa germinacao e desenvolvimento das plantas. A incidencia de molestias foi baixa, em ambas as zonas predominando no entanto, uma razoavel infeccao de oidio, nas semeaduras mais tardias, e de ferrugem da folha. Observou-se uma variabilidade dos genotipos quanto ao grau de tolerancia e/ou suscetibilidade a estas molestias, como tambem, uma resposta no rendimento de graos ao controle destas, pelo uso de fungicidas especificos. Os rendimentos obtidos, em geral, foram muitos bons, alcancando, em alguns casos, a 6,7 t/ha. No ensaio IPS, em funcao do rendimento de graos e outras caracteristicas, foram selecionadas as linhagens IA 952, IWT 9430, LD 941, LD 946, OC 962, OC 963, OC 965, ORL 92203 e PR 961. NO CSBS, foram mantidas as linhagens IOR 90226 e PF 91450. No ECS, destacaram-se, em ambas as zonas, as cultivares IAPAR 60, IAPAR 78 e OR 1. Considerando os resultados de rendimentos de graos e outras caracteristicas agronomicas e, principalmente, a qualidade da farinha para panificacao, foram recomendadas como novas cultivares, as linhagens IDS 934-21 e OC 939, denominadas, respectivamente, de Manitoba 97 e COODETEC 101.

Birkhoff normal forms for Fourier integral operators II

Iantchenko, A.; Sj?strand, J., (2001) 'Birkhoff normal forms for Fourier integral operators II', American Journal of Mathematics 124(4) pp.817-850 RAE2008

Adaptive Neural Networks for Control of Movement Trajectories Invariant under Speed and Force Rescaling

This article describes two neural network modules that form part of an emerging theory of how adaptive control of goal-directed sensory-motor skills is achieved by humans and other animals. The Vector-Integration-To-Endpoint (VITE) model suggests how synchronous multi-joint trajectories are generated and performed at variable speeds. The Factorization-of-LEngth-and-TEnsion (FLETE) model suggests how outflow movement commands from a VITE model may be performed at variable force levels without a loss of positional accuracy. The invariance of positional control under speed and force rescaling sheds new light upon a familiar strategy of motor skill development: Skill learning begins with performance at low speed and low limb compliance and proceeds to higher speeds and compliances. The VITE model helps to explain many neural and behavioral data about trajectory formation, including data about neural coding within the posterior parietal cortex, motor cortex, and globus pallidus, and behavioral properties such as Woodworth's Law, Fitts Law, peak acceleration as a function of movement amplitude and duration, isotonic arm movement properties before and after arm-deafferentation, central error correction properties of isometric contractions, motor priming without overt action, velocity amplification during target switching, velocity profile invariance across different movement distances, changes in velocity profile asymmetry across different movement durations, staggered onset times for controlling linear trajectories with synchronous offset times, changes in the ratio of maximum to average velocity during discrete versus serial movements, and shared properties of arm and speech articulator movements. The FLETE model provides new insights into how spina-muscular circuits process variable forces without a loss of positional control. These results explicate the size principle of motor neuron recruitment, descending co-contractive compliance signals, Renshaw cells, Ia interneurons, fast automatic reactive control by ascending feedback from muscle spindles, slow adaptive predictive control via cerebellar learning using muscle spindle error signals to train adaptive movement gains, fractured somatotopy in the opponent organization of cerebellar learning, adaptive compensation for variable moment-arms, and force feedback from Golgi tendon organs. More generally, the models provide a computational rationale for the use of nonspecific control signals in volitional control, or "acts of will", and of efference copies and opponent processing in both reactive and adaptive motor control tasks.

The role of the dopaminergic neurotrophin growth/differentiation factor-5 in the developing rat ventral midbrain

Growth differentiation factor-5 (GDF-5) is a member of the transforming growth factor-β superfamily, a family of proteins that play diverse roles in many aspects of cell growth, proliferation and differentiation. GDF-5 has also been shown to be a trophic factor for embryonic midbrain dopaminergic neurons in vitro (Krieglstein et al. 1995) and after transplantation to adult rats in vivo (Sullivan et al. 1998). GDF-5 has also been shown to have neuroprotective and neurorestorative effects on adult dopaminergic neurons in the substantia nigra in animal models of Parkinson’s disease (Sullivan et al. 1997, 1999; Hurley et al. 2004). This experimental evidence has lead to GDF-5 being proposed as a neurotrophic factor with potential for use in the treatment of Parkinson’s disease. However, it is not know if GDF-5 is expressed in the brain and whether it plays a role in dopaminergic neuron development. The experiments presented here aim to address these questions. To that end this thesis is divided into five separate studies each addressing a particular question associated with GDF-5 and its expression patterns and roles during the development of the rat midbrain. Expression of the GDF-5 in the developing rat ventral mesencephalon (VM) was found to begin at E12 and peak on E14, the day that dopaminergic neurons undergo terminal differentiation. In the adult rat, GDF-5 was found to be restricted to heart and brain, being expressed in many areas of the brain, including striatum and midbrain. This indicated a role for GDF-5 in the development and maintenance of dopaminergic neurons. The appropriate receptors for GDF-5 (BMPR-II and BMPR-Ib) were found to be expressed at high levels in the rat VM at E14 and BMPR-II expression was demonstrated on dopaminergic neurons in the E13 mouse VM. GDF-5 resulted in a three-fold increase in the numbers of dopaminergic neurons in cultures of E14 rat VM, without affecting the numbers of neurones or total cells. GDF-5 was found to increase the proportion of neurons that were dopaminergic. The numbers of Nurr1-positive cells were not affected by GDF-5 treatment, but GDF-5 did increase the numbers of Nurr1- positive cells that expressed tyrosine hydroxylase (TH). Taken together this data indicated that GDF-5 increases the conversion of Nurr1-positive, TH-negative cells to Nurr1-positive, TH-positive cells. In GDF-5 treated cultures, total neurite length, neurite arborisation and somal area of dopaminergic were all significantly increased compared to control cultures. Thus this study showed that GDF-5 increased the numbers and morphological differentiation of VM dopaminergic neurones in vitro. In order to examine if GDF-5 could induce a dopaminergic phenotype in neural progenitor cells, neurosphere cultures prepared from embryonic rat VM were established. The effect of the gestational age of the donor VM on the proportion of cell types generated from neurospheres from E12, E13 and E14 VM was examined. Dopaminergic neurons could only be generated from neurospheres which were prepared from E12 VM. Thus in subsequent studies the effect of GDF-5 on dopaminergic induction was examined in progentior cell cultures prepared from the E12 rat VM. In primary cultures of E12 rat VM, GDF-5 increased the numbers of TH-positive cells without affecting the proliferation or survival of these cells. In cultures of expanded neural progenitor cells from the E12 rat VM, GDF-5 increased the expression of Nurr1 and TH, an action that was dependent on signalling through the BMPR-Ib receptor. Taken together, these experiments provide evidence that GDF-5 is expressed in the developing rat VM, is involved in both the induction of a dopaminergic phenotype in cells of the VM and in the subsequent morphological development of these dopaminergic neurons

Characterisation of the role of canonical BMP-Smad 1/5/8 signalling in the development of ventral midbrain dopaminergic neurons

Ventral midbrain (VM) dopaminergic (DA) neurons, which project to the dorsal striatum via the nigrostriatal pathway, are progressively degenerated in Parkinson’s disease (PD). The identification of the instructive factors that regulate midbrain DA neuron development, and the subsequent elucidation of the molecular bases of their effects, is vital. Such an understanding would facilitate the generation of transplantable DA neurons from stem cells and the identification of developmentally-relevant neurotrophic factors, the two most promising therapeutic approaches for PD. Two related members of the bone morphogenetic protein (BMP) family, BMP2 and growth/differentiation factor (GDF) 5, which signal via a canonical Smad 1/5/8 signalling pathway, have been shown to have neurotrophic effects on midbrain DA neurons both in vitro and in vivo, and may function to regulate VM DA neuronal development. However, the molecular (signalling pathway(s)) and cellular (direct neuronal or indirect via glial cells) mechanisms of their effects remain to be elucidated. The present thesis hypothesised that canonical Smad signalling mediates the direct effects of BMP2 and GDF5 on the development of VM DA neurons. By activating, modulating and/or inhibiting various components of the BMP-Smad signalling pathway, this research demonstrated that GDF5- and BMP2-induced neurite outgrowth from midbrain DA neurons is dependent on BMP type I receptor activation of the Smad signalling pathway. The role of glial cell-line derived neurotrophic factor (GDNF)-signalling, dynamin-dependent endocytosis and Smad interacting protein-1 (Sip1) regulation, in the neurotrophic effects of BMP2 and GDF5 were determined. Finally, the in vitro development of VM neural stem cells (NSCs) was characterised, and the ability of GDF5 and BMP2 to induce these VM NSCs towards DA neuronal differentiation was investigated. Taken together, these experiments identify GDF5 and BMP2 as novel regulators of midbrain DA neuronal induction and differentiation, and demonstrate that their effects on DA neurons are mediated by canonical BMPR-Smad signalling.

Analysis and optimisation of semiconductor reflective modulators for optical networks

Reflective modulators based on the combination of an electroabsorption modulator (EAM) and semiconductor optical amplifier (SOA) are attractive devices for applications in long reach carrier distributed passive optical networks (PONs) due to the gain provided by the SOA and the high speed and low chirp modulation of the EAM. Integrated R-EAM-SOAs have experimentally shown two unexpected and unintuitive characteristics which are not observed in a single pass transmission SOA: the clamping of the output power of the device around a maximum value and low patterning distortion despite the SOA being in a regime of gain saturation. In this thesis a detailed analysis is carried out using both experimental measurements and modelling in order to understand these phenomena. For the first time it is shown that both the internal loss between SOA and R-EAM and the SOA gain play an integral role in the behaviour of gain saturated R-EAM-SOAs. Internal loss and SOA gain are also optimised for use in a carrier distributed PONs in order to access both the positive effect of output power clamping, and hence upstream dynamic range reduction, combined with low patterning operation of the SOA Reflective concepts are also gaining interest for metro transport networks and short reach, high bit rate, inter-datacentre links. Moving the optical carrier generation away from the transmitter also has potential advantages for these applications as it avoids the need for cooled photonics being placed directly on hot router line-cards. A detailed analysis is carried out in this thesis on a novel colourless reflective duobinary modulator, which would enable wavelength flexibility in a power-efficient reflective metro node.

Burst-mode electronic dispersion compensation in long reach PONs

Long reach passive optical networks (LR-PONs), which integrate fibre-to-the-home with metro networks, have been the subject of intensive research in recent years and are considered one of the most promising candidates for the next generation of optical access networks. Such systems ideally have reaches greater than 100km and bit rates of at least 10Gb/s per wavelength in the downstream and upstream directions. Due to the limited equipment sharing that is possible in access networks, the laser transmitters in the terminal units, which are usually the most expensive components, must be as cheap as possible. However, the requirement for low cost is generally incompatible with the need for a transmitter chirp characteristic that is optimised for such long reaches at 10Gb/s, and hence dispersion compensation is required. In this thesis electronic dispersion compensation (EDC) techniques are employed to increase the chromatic dispersion tolerance and to enhance the system performance at the expense of moderate additional implementation complexity. In order to use such EDC in LR-PON architectures, a number of challenges associated with the burst-mode nature of the upstream link need to be overcome. In particular, the EDC must be made adaptive from one burst to the next (burst-mode EDC, or BM-EDC) in time scales on the order of tens to hundreds of nanoseconds. Burst-mode operation of EDC has received little attention to date. The main objective of this thesis is to demonstrate the feasibility of such a concept and to identify the key BM-EDC design parameters required for applications in a 10Gb/s burst-mode link. This is achieved through a combination of simulations and transmission experiments utilising off-line data processing. The research shows that burst-to-burst adaptation can in principle be implemented efficiently, opening the possibility of low overhead, adaptive EDC-enabled burst-mode systems.

3D vanadium oxide inverse opal growth by electrodeposition

Three-dimensional vanadium pentoxide (V2O5) material architectures in the form of inverse opals (IOs) were fabricated using a simple electrodeposition process into artificial opal templates on stainless steel foil using an aqueous solution of VOSO4.χH2O with added ethanol. The direct deposition of V2O5 IOs was compared with V2O5 planar electrodeposition and confirms a similar progressive nucleation and growth mechanism. An in-depth examination of the chemical and morphological nature of the IO material was performed using X-ray crystallography, X-ray photoelectron spectroscopy, Raman scattering and scanning/transmission electron microscopy. Electrodeposition is demonstrated to be a function of the interstitial void fraction of the artificial opal and ionic diffusivity that leads to high quality, phase pure V2O5 inverse opals is not adversely affected by diffusion pathway tortuosity. Methods to alleviate electrodeposited overlayer formation on the artificial opal templates for the fabrication of the porous 3D structures are also demonstrated. Such a 3D material is ideally suited as a cathode for lithium ion batteries, electrochromic devices, sensors and for applications requiring high surface area electrochemically active metal oxides.

Quantitative analysis of the effect of derivatisation of [Ru(BPY) phen] with a quinoline moiety on the interaction with DNA

The bifunctional Ru(II) complex [Ru(BPY)2POQ-Nmet]2+ (1), in which the metallic unit is tethered by an aliphatic chain to an organic DNA binder, was designed in order to increase the affinity toward nucleic acids. The interaction of 1 with DNA was characterised from luminescence and absorption data and compared with the binding of its monofunctional metallic and organic analogues, [Ru(BPY)2(ac)phen]2+ (2) and Nmet-quinoline (3). The bifunctional complex has a binding affinity one order of magnitude higher than that of each of its separated moieties. Absorption changes induced upon addition of DNA at different pH indicate protonation of the organic sub-unit upon interaction with DNA under neutral conditions. The combination of the luminescence data under steady-state and time-resolved conditions shows that the attachment of the organic unit in 1 induces modifications of the association modes of the metallic unit, owing to the presence of the aliphatic chain which probably hinders the metallic moiety binding. The salt dependence of the binding constants was analysed in order to compare the thermodynamic parameters describing the association with DNA for each complex. This study demonstrates the interest of the derivatisation of a Ru(II) complex with an organic moiety (ia the bifunctional ligand POQ-Nmet) for the development of high affinity DNA probes or photoreactive agents.

Factors associated with mortality in transplant patients with invasive aspergillosis.

BACKGROUND: Invasive aspergillosis (IA) is an important cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT) recipients. The purpose of this study was to evaluate factors associated with mortality in transplant patients with IA. METHODS: Transplant patients from 23 US centers were enrolled from March 2001 to October 2005 as part of the Transplant Associated Infection Surveillance Network. IA cases were identified prospectively in this cohort through March 2006, and data were collected. Factors associated with 12-week all-cause mortality were determined by logistic regression analysis and Cox proportional hazards regression. RESULTS: Six-hundred forty-two cases of proven or probable IA were evaluated, of which 317 (49.4%) died by the study endpoint. All-cause mortality was greater in HSCT patients (239 [57.5%] of 415) than in SOT patients (78 [34.4%] of 227; P<.001). Independent poor prognostic factors in HSCT patients were neutropenia, renal insufficiency, hepatic insufficiency, early-onset IA, proven IA, and methylprednisolone use. In contrast, white race was associated with decreased risk of death. Among SOT patients, hepatic insufficiency, malnutrition, and central nervous system disease were poor prognostic indicators, whereas prednisone use was associated with decreased risk of death. Among HSCT or SOT patients who received antifungal therapy, use of an amphotericin B preparation as part of initial therapy was associated with increased risk of death. CONCLUSIONS: There are multiple variables associated with survival in transplant patients with IA. Understanding these prognostic factors may assist in the development of treatment algorithms and clinical trials.