Studies on the age and growth of Labeo calbasu (Hamilton) with an exploitation pattern from the Ganga River system, Uttar Pradesh (India)

Samples were collected to study the age and growth of Labeo calbasu (Hamilton) from the river Ghaghra (Guptarghat centre, Faizabad). The scales of L. calbasu have been used for age and growth studies in present paper. Study of the marginal rings on the scales of L. calbasu indicates their annual nature. The fish attained growth in 1st 18.7 cm, 2nd 27.8 cm, 3rd 35.7 cm, 4th 41.8 cm, 5th 46.9 cm, 6th 54.9 cm and 7th 57.4 cm years of the life. The growth rate was observed 18.7, 9.1, 7.9, 6.7, 5.1, 8.0 and 2.5 cm for 1st to 7th age classes respectively. The age groups 1+ to 4+ constituted 91.17% of the total exploited population and 8.83% of remaining age groups (5+ to 7+). The maximum exploited population was observed in 2+ age group with 33.68%. Overall exploitation pattern was systematic and a good indicator for heavy recruitment.

Effects of multi-scattering on the performance of a single-beam acoustic manipulation device.

The effects of multiple scattering on acoustic manipulation of spherical particles using helicoidal Bessel-beams are discussed. A closed-form analytical solution is developed to calculate the acoustic radiation force resulting from a Bessel-beam on an acoustically reflective sphere, in the presence of an adjacent spherical particle, immersed in an unbounded fluid medium. The solution is based on the standard Fourier decomposition method and the effect of multi-scattering is taken into account using the addition theorem for spherical coordinates. Of particular interest here is the investigation of the effects of multiple scattering on the emergence of negative axial forces. To investigate the effects, the radiation force applied on the target particle resulting from a helicoidal Bessel-beam of different azimuthal indexes (m = 1 to 4), at different conical angles, is computed. Results are presented for soft and rigid spheres of various sizes, separated by a finite distance. Results have shown that the emergence of negative force regions is very sensitive to the level of cross-scattering between the particles. It has also been shown that in multiple scattering media, the negative axial force may occur at much smaller conical angles than previously reported for single particles, and that acoustic manipulation of soft spheres in such media may also become possible.

The reproductive traits of brown trout (Salmo trutta fario L.) from the Yadong River, Tibet

Some key aspects of the reproductive strategy of the brown trout (Salmo trutta fario L.) in the Yadong River, Tibet, including spawning season, age at sexual maturity, fecundity and egg size, have been studied. The majority of the samples were less than 215 mm and age ranged from 1 to 4 in both sexes, indicating that the majority of the fish were younger and the pressure by overfishing was high. The spawning periodicity was determined to be between the end of October and January, mainly in November and December. The ratio of male to female brown trout population (1.29:1 with P > 0.05) suggested no sex significant differences, although males were significantly more abundant than females in October (P < 0.0001) on monthly basis. Age and size of males and females at maturity was different and males matured earlier than females. Fecundity was markedly correlated with their body weight (P < 0.001, r = 0.9255), standard length (P < 0.01, r = 0.8879), and gonad weight (P < 0.001, r = 0.9366). The mean size of mature eggs in the spawning season was: 4.0 +/- 0.45 mm and tended to increase along with the female spawners size (P < 0.001, r = 0.9641). Further researches about the brown trout population in the Yadong River should be conducted on issues such as artificial reproduction, culture, conservation, management, and restocking.

在辉光放电中八氟环丁烷聚合的研究

I 理论部分：对未知结构聚合物的ESCA谱进行表征，一是利用已知结构小分子化合物的ESCA谱中结合能值进行标定，二是运用电荷电位模型经量子化学计算对谱峰进行归属。由于所处化学环境不同，用小分子化合物的ESCA谱峰位对象合物标定不够准确，量子化学计算又太复杂。本工作提出了电负性经验公式，可计算ESCA谱中C_(1S)结合能位移值，与实测值作对照即可判断聚合物结构，方法简便，准确可靠。电负性经验公式表达如下：聚合物分子链上某碳原子1S电子结合能位移ΔEc可看作该碳原子与相邻基团间电负性差值和的函数，即ΔEc = K_c ∑ from i=1 to 4 1/(n_i) (X_i - 2.5) + b。聚合物分子链上各碳原子的实际电负性为X_c = (∑ form j=1 to 4 1/(n_j) X_j/∑ form j=1 to 4 1/(n_j) + 2.5)/2运用电负性经验公式计算了九个模型化合物中C_(1S)的ΔEc，推导出F作为α、β、γ位碳上的取代基的对α位碳上1s电子结合能位移影响产生的效应值，即，对于ΔEc = aα + bβ + cγ，有α = 3.018 (±0.007)，β = 0.2513 (±0.0007) γ = 0.0176 (±0.003)。此结果与ESCA谱实测值相符。本工作设计了十六种化合物模型，模型中具有含氟等离子体聚合物中可能存在的大部分基团，通过电负性经验公式计算求得化学环境不同的C_(1S)结合能位移值，把ESCA谱的实测值和计算值进行对照，可对象合物的求知结构作出大致判断。II 在辉光放电中八氟环丁烷的聚合与刻蚀反应：在碳氧化合物的辉光放电中同时存在聚合与刻蚀两种相反的过程，聚合与刻蚀竞争的结果对聚合速率，产物结构都有很大影响。本工作通过测定聚合速率、IR谱、ESCA谱研究了反应条件对八氟环丁烷等离子体聚合与刻蚀的影响，得到了一致的和半定量的结果。实验证实，随着功率的增大或压力的减小，刻蚀有增强的趋势，不同的等离子气体对聚合与刻蚀的竞争过程有不同的影响，刻蚀强弱的顺序为Ar>N_2>H_2>He，增加等离子气体对单体的比率，引起刻蚀增加。聚合速率不随功率的改变而变化的状态是由聚合与刻蚀间的平衡引起的。随着功率增大或压力减少，聚合产物支化程度增加，线性程度减小，F/C比相应减小。同样随等离子气体种类不同，聚合物支化程度大小的顺序是Ar>N_2>H_2>He，F/C比相应变化。总之，聚合产物支化程度的变化和聚合与刻蚀的竞争结果相一致。对等离子体聚合与刻蚀竞争过程的定量描述未见文献报导。III 八氟环丁烷等离子体聚合物的结构和表征：用IR和ESR谱测得OFCB等离子体聚合物中存在五种元素：C、F、O、N、Si，并对可能存在于结构中的基因作了分析。通过NaHSO_3的亲核双键加成反应，用IR和ESR谱证实了等离子体聚合物中存在的双键及其类型。类似工作未见文献报导。用CuSO_4·5H_2作标样，测出PPOFCB中的自由基浓度为10~(19)自旋数/克。在80、100、120、140 ℃考察PPOFCB中俘获自由基的衰减过程，证实此过程涉及两类不同的反应，一是自由基的复合反应，二是自由基的氧气的终止反应。对上述两类反应进行动力学处理，求出了自由基复合反应在不同温度时的速度常数，并得到反应治化能为374焦耳/摩尔或8.869千卡/摩尔。氧和自由基的终止反应中，氧气的扩散过程是决定反应速度的步骤，反应速度常数就是扩散速度常数，K = 5.3 * 10~(-23)自旋数~(-1)、克分~(-1)。根据VPO测出的PPOFCB的分子量和自由基浓度，算出每4.5个分子中有一个自由基。类似工作未见文献报导。PPOFCB的分子量随反应条件不同而变化，用VPO测出，在80W和40W功率，在Ar存在下制备的OFCB等离子体聚合物的分子量分别为2736和2003。用~(19)F-NMR谱对PPOFCB中的基团进行定量计算，得出在一个90W，He气中制备的聚合物分子中，CF_3-CF_2为6.1，CF_2为13.5，CF_3-CF为7.9，CF为17.5，CF_3-C为6.1，C为13.5。在用上述方法进行结构表征的基础上，提出了OFCB等离子体聚合物的结构模型。IV 八氟环丁烷等离子体聚合的反应历程：以Ar、N_2、H_2、He为等离子气体，分别对OFCB等离子体聚合的气体冷凝物进行GC-Mg、~(19)F-NMR和ESR测试，观察到在气相中，OFCB经历了等离子态反应。单体被打断的程度，和高能电子浓度有关。体系中电子浓度依赖于气体的第一电离势和气相内的化学反应类型。初级粒子二氟卡宾：CF_2和中间体六氟丙烯是气相中的主要产物。~(19)F-NMR证实气相中存在支化产物，表明聚合物在气相中发生了重排。ESR谱测得，在气相产物中存在高浓度的由二种以上组分混合而成的自由基，自由基间的复合反应是生成聚合物的主要增长过程，气相产物的分子量随放电功率的升高而增大。根据聚合物中存在的高含量CF_3基团，分析了CF_3基团对聚合过程的影响。CF_3基团产生了屏蔽效应，它既保护了聚合物不致被降解，也限制了生成高分子量产物。实验证实，CF_3基团的生长来自F的重排，同时未自支化气相产物的非均相增长。OFCB等离子体聚合物中俘获自由基主要是由高能电子轰击聚合物表面产生的，同时来自被固相吸附的带有自由基的气相产物。在碳氟化合物的等离子体聚合中，吸附是和聚合同样重要的过程，气相产物被吸附后，可继续再引发、增长、刻蚀等反应过程、直到成为固相内层分子为止。ESR谱证实，高能粒子的轰击在辉光放电中起主导作用，紫外辐射对含氟聚合物引发和脱氟作用微弱。在气相和表面反应历程讨论的基础上，提出了OFCB等离子体聚合的反应历程模型，解释了碳氢和碳氟两个等离子体象合体系遵循不同反应历程的原因。本部分工作的实验和反应历程解释基本未见文献报导。

伯胺N_(1923)萃取不同金属离子的机理的研究

伯胺N_(1923)(RNH_2)是一种对许多金属具有优良萃取性能的萃取剂，因RNH_2为较强的Lewis碱，能以多种途径与金属离子结合，文献报道的一般为加合反应及阴离子交换机理，至于配位反应未见报道，故详细地研究RNH_2萃取不同金属离子的机理，发现新的萃取，分离体系，具有理论和实际意义。本文分别研究了RNH_2及其相应盐从不同介质中萃取Ag~+，Zn~(2+)，Cd~(2+)，Sc~(3+)的机理。提出了RNH_2能以配位反应萃取金属离子，并且发现对一些体系(如ZnCl_2, Zn(SCN)_2, CdCl_2等)RNH_2及其盐均具有较好的萃取行为。对有关体系详细研究了其萃取机理：1）RNH_2萃取AgNO_3的机理。在接近中性介质中，RNH_2是AgNO_3的优良萃取剂，其反应机理为：2RNH_(2(0)) + Ag~+ + NO_3~- <-> (RNH_2)_2AgNO_(3(0))考察了溶剂，温度等反应平衡的影响，其分配比基本随溶剂介电常数的增大而增大，并且该反应为放热反应，温度升高不利于萃取。我们还解析了该萃合物的IR及NMR。2，RNH_3NO_3萃取硫代硫酸银的机理。与上述AgNO_3体系不同，RNH_2不能萃取硫代硫酸银，但RNH_3NO_3能以阴离子交换反应萃取该体系中的Ag(I)。通过研究不同因素对分配比的影响，指出在该体系中Ag(I)同时以AgS_2O_3~-和Ag(S_2O_3)_2~(3-)两种形式萃入有机相。并且有机相中AgS_2O_3~-/Ag(S_2O_3)_2~(3-)比值随着NO_3~-浓度的增大，RNH_3NO_3、S_2O_3~(2-)浓度的减小而增大。萃合物的IR分析证明存在两种不同配位形式的S_2O_3~(2-)。3，RNH_2萃取ZnCl_2的机理及平衡规律。研究了RNH_2在不同酸度条件下萃取ZnCl_2的机理，在pH值较高时，RNH_2能以配位反应萃取ZnCl_2，其反应为：2RNH_(2(0)) + ZnCl_2 <-> (RNH_2)_2ZnCl_(2(0))并详细地研究了其平衡规律，得出数学模型：1/D = 2/(C_(RMH_(2(o)))) X + (1 + Σ from i = 1 to 4 of β_i C_(cl~-)~i)/(K C_(cl~-)~2 C_(RNH_(2(0))) (X为平衡水相Zn~(2+)总浓度) 在高酸度([HCl] = 2.8 M)条件下，RNH_2萃取ZnCl_2呈加成反应：(RNH_3Cl)_(3(0)) + ZnCl_2 <-> (RNH_3Cl)_2ZnCl_(2(0))求得了萃取过程的各热力学函数。4）RNH_2萃取ZnBr_2, ZnI_2的机理。研究RNH_2萃取ZnBr_2，ZnI_2的性能表明，在pH值较高时, RNH_2能以萃取ZnCl_2相同的机理萃取ZnBr_2, ZnI_2，其反应为：2RNH_(2(0)) + ZnX_2 <-> (RNH_2)_2ZnX_(2(0)) (x~- = Br~-, I~-) 计算了不同RNH_2浓度条件下反应的平衡常数，表明不是RNH_2浓度的函数，该平衡常数随温度升高而降低。同时我们在相同条件下，比较RNH_2萃取ZnX_2的能力为：ZnI_2 > ZnBr_2 > ZnCl_2 5，RNH_2及其硝酸盐萃取Zn(SCN)_2的机理 在Zn(SCN)_2体系中，RNH_2及RNH_3NO_3的均能较有效地萃取Zn(II)，但其反应机理并不相同，RNH_2以配位反应萃取Zn(SCN)_2，相应的反应为：2RNH_(2(0)) + Zn(SCN)_2 <-> (RNH_2)_2Zn(SCN)_(2(0)) RNH_3NO_3则以阴离子交换反应萃取Zn(SCN)_4~(2-)，其反应如下：(RNH_3NO_3)_(2(0)) + Zn(SCN)_4~(2-) <-> (RNH_3)_2Zn(SCN)_(4(0)) + 2NO_3~- 测定并计算了各反应的浓度平衡常数及热力学函数，两反应均为放热反应。同时，在相同条件下，RNH_2比RNH_3NO_3有更强萃取Zn(II)的能力。6，RNH_2萃取CdCl_2及其它Cd(II)盐的机理 RNH_2及RNH_3Cl能分别以配位反应及加合反应萃取CdCl_2，通过萃合物组成的测定，得出反应方程式为：3RNH_(2(o)) + CdCl_2 <-> (RNH_2)_3CdCl_(2(0)) (RNH_3Cl)_(3(o)) + CdCl_2 <-> (RNH_3Cl)_3CdCl_(2(0))计算了各反应的平衡常数及热力学函数。同时观察了RNH_2萃取CdBr_2, CdI_2, Cd(SCN)_2的性能，相应萃合物组成为(RNH_2)_2CdX_2 (X~- = Br~-, I~-, SCN~-)。在相同条件下，CdX_2的萃取率次序为：Cd(NO_2)_2 < CdCl_2 < CdBr_2 < Cd(SCN)_2 < CdI_2。并讨论了CdX_2的生成能，第二级累积稳定常数，X~-的半径等因素与Cd(II)分配比的关系。7，RNH_2硫酸盐萃取Sc_2(SO_4)_3的机理 研究了不同因素对其萃取性能的影响，指出在硫酸介质中，RNH_2是Sc~(3+)的优良萃取剂。通过萃合物组成的测定得到该萃取反应式为：1.25[(RNH_3)_2SO_4]_(2(0)) + Sc(SO_4)_3~(3-) <-> (RNH_3)_3Sc(SO_4)_3·(RNH_3)_2SO_(4(0)) + 1.5SO_4~(2-)测定并计算了该反应的平衡常数及热力学函数。通过详细解释萃合物的IR，证明在该萃合物中SO_4~(2-)是以双配位形式与Sc~(3+)相结合。在上述萃取机理研究了基础上初步探讨了用RNH_2回收银及进行Zn(II)-Cd(II)分离的可能性。

Proposal for studying N* resonances with the (p)over-barp -> (p)over-barn pi(+) reaction

A theoretical study of the (p) over barp -> (p) over barn pi(+) reaction for antiproton beam energy from 1 to 4 GeV is made by including contributions from various known N* and Delta* resonances. It is found that for the beam energy around 1.5 GeV, the contribution of the Roper resonance N-(1440)* produced by the t-channel sigma exchange dominates over all other contributions. Since such a reaction can be studied in the forthcoming PANDA experiment at the GSI Facility of Antiproton and Ion Research (FAIR), the reaction will be realistically the cleanest place for studying the properties of the Roper resonance and the best place for looking for other "missing" N* resonances with large coupling to N sigma.

Anticancer Drug-DNA Interactions Measured Using a Photoinduced Electron-Transfer Mechanism Based on Luminescent Quantum Dots

A sensing system based on the photoinduced electron transfer of quantum dots (QDs) was designed to measure the interaction of anticancer drug and DNA, taking mitoxantrone (MTX) as a model drug. MTX adsorbed on the surface of QDs can quench the photoluminescence (PL) of QDs through the photoinduced electron-transfer process; and then the addition of DNA will bring the restoration of QDs PL intensity, as DNA can bind with MTX and remove it from QDs. Sensitive detection of MTX with the detection limit of 10 nmol L-1 and a linear detection range from 10 nmol L-1 to 4.5 mu mol L-1 was achieved. The dependence of PL intensity on DNA amount was successfully utilized to investigate the interactions between MTX and DNA. Both the binding constants and the sizes of binding site of MTX-DNA interactions were calculated based on the equations deduced for the PL recovery process. The binding constant obtained in our experiment was generally consistent with previous reports. The sensitive and speedy detection of MTX as well as the avoidance of modification or immobilization process made this system suitable and promising in the drug-DNA interaction studies.

Determination of total calcium in plasma by flow injection analysis with tris(2,2 '-bipyridyl)ruthenium(II) electrochemiluminescent detection

We described here a new method for the determination of total calcium in plasma. The method is based on the precipitation of calcium with excess oxalate and the measurement of residual oxalate by flow injection analysis with Ru(bpy)(3)(2+) electrochemiluminescent detection. It has the advantages of extremely stable reagent, user-friendly instrument, high selectivity, good analytical recovery, wide dynamic range, and nice correlation with atomic absorption spectroscopy. The calibration plot for calcium is linear over a concentration range from 0.5 mmol L-1 to 4.8 mmol L-1, which is wider than those obtained by most other methods. The analytical recoveries for plasma calcium are 98.4-101.2% with coefficients of variation (CVs) of 1.96-2.52%. The within-day CVs range from 0.76% to 0.95%, and between-day CVs were from 1.12% to 1.46%. The time for each injection is one minute. Because the proposed method can be readily carried out on increasingly popular instruments for Ru(bpy)(3)(2+) ECL immunoassays and DNA probe assays, Ru(bpy)32+ ECL method is suitable for routine clinical analysis of calcium.

A centromeric satellite sequence in the Pacific oyster (Crassostrea gigas Thunberg) identified by fluorescence in situ hybridization

A highly repetitive satellite sequence was previously identified in the Pacific oyster Crassostrea gigas Thunberg. The sequence has 168 bp per unit, present in tandem repeats, and accounts for 1% to 4% of the genome. We studied the chromosomal location of this satellite sequence by fluorescence in situ hybridization (FISH), A probe was made by polymerase chain reaction and incorporation of digoxigenin-11-dUTP. Hybridization was detected with fluorescein-labeled antidigoxigenin antibodies. FISH signals were located at centromeric regions of 7 pairs of the Pacific oyster chromosomes. No interstitial site was found. Signals were strong and consistent on chromosomes 1, 2, 4, and 7, but weak or variable oil chromosomes 5, 8, and 10. No signal was observed on chromosomes 3, 6, and 9. Our results showed that this sequence is clearly a centromeric satellite, disputing its previous assignment to the telomeric and submetacentric regions of 2 chromosomes. No signal was detected in the American oyster (Crassostrea virginica Gmelin).

运动与重定向时物-我、物-物空间表征的使用

Eight experiments tested how object array structure and learning location influenced the establishing and utilization of self-to-object and object-to-object spatial representations in locomotion and reorientation. In Experiment 1 to 4, participants learned either at the periphery of or amidst regular or irregular object array, and then pointed to objects while blindfolded in three conditions: before turning (baseline), after rotating 240 degrees (updating), and after disorientation (disorientation). In Experiment 5 to 8, participants received instruction to keep track of self-to-object or object-to-object spatial representations before rotation. In each condition, the configuration error, which means the standard deviation of the means per target object of the signed pointing errors, was calculated as the index of the fidelity of representation used in each condition. Results indicate that participants form both self-to-object and object-to-object spatial representations after learning an object-array. Object-array structure influences the selection of representation during updating. By default, object-to-object spatial representation is updated when people learned the regular object-array structure, and self-to-object spatial representation is updated when people learned the irregular object array. But people could also update the other representation when they are required to do so. The fidelity of representations will confine this kind of “switch”. People could only “switch” from a low fidelity representation to a high fidelity representation or between two representations of similar fidelity. They couldn’t “switch” from a high fidelity representation to a low fidelity representation. Leaning location might influence the fidelity of representations. When people learned at the periphery of object array, they could acquire both self-to-object and object-to-object spatial representations of high fidelity. But when people learned amidst the object array, they could only acquire self-to-object spatial representation of high fidelity, and the fidelity of object-to-object spatial representation was low.

Motion Planning with Six Degrees of Freedom

The motion planning problem is of central importance to the fields of robotics, spatial planning, and automated design. In robotics we are interested in the automatic synthesis of robot motions, given high-level specifications of tasks and geometric models of the robot and obstacles. The Mover's problem is to find a continuous, collision-free path for a moving object through an environment containing obstacles. We present an implemented algorithm for the classical formulation of the three-dimensional Mover's problem: given an arbitrary rigid polyhedral moving object P with three translational and three rotational degrees of freedom, find a continuous, collision-free path taking P from some initial configuration to a desired goal configuration. This thesis describes the first known implementation of a complete algorithm (at a given resolution) for the full six degree of freedom Movers' problem. The algorithm transforms the six degree of freedom planning problem into a point navigation problem in a six-dimensional configuration space (called C-Space). The C-Space obstacles, which characterize the physically unachievable configurations, are directly represented by six-dimensional manifolds whose boundaries are five dimensional C-surfaces. By characterizing these surfaces and their intersections, collision-free paths may be found by the closure of three operators which (i) slide along 5-dimensional intersections of level C-Space obstacles; (ii) slide along 1- to 4-dimensional intersections of level C-surfaces; and (iii) jump between 6 dimensional obstacles. Implementing the point navigation operators requires solving fundamental representational and algorithmic questions: we will derive new structural properties of the C-Space constraints and shoe how to construct and represent C-Surfaces and their intersection manifolds. A definition and new theoretical results are presented for a six-dimensional C-Space extension of the generalized Voronoi diagram, called the C-Voronoi diagram, whose structure we relate to the C-surface intersection manifolds. The representations and algorithms we develop impact many geometric planning problems, and extend to Cartesian manipulators with six degrees of freedom.

Novel smart modules for imaging, communications, and displays

This dissertation proposes and demonstrates novel smart modules to solve challenging problems in the areas of imaging, communications, and displays. The smartness of the modules is due to their ability to be able to adapt to changes in operating environment and application using programmable devices, specifically, electronically variable focus lenses (ECVFLs) and digital micromirror devices (DMD). The proposed modules include imagers for laser characterization and general purpose imaging which smartly adapt to changes in irradiance, optical wireless communication systems which can adapt to the number of users and to changes in link length, and a smart laser projection display that smartly adjust the pixel size to achieve a high resolution projected image at each screen distance. The first part of the dissertation starts with the proposal of using an ECVFL to create a novel multimode laser beam characterizer for coherent light. This laser beam characterizer uses the ECVFL and a DMD so that no mechanical motion of optical components along the optical axis is required. This reduces the mechanical motion overhead that traditional laser beam characterizers have, making this laser beam characterizer more accurate and reliable. The smart laser beam characterizer is able to account for irradiance fluctuations in the source. Using image processing, the important parameters that describe multimode laser beam propagation have been successfully extracted for a multi-mode laser test source. Specifically, the laser beam analysis parameters measured are the M2 parameter, w0 the minimum beam waist, and zR the Rayleigh range. Next a general purpose incoherent light imager that has a high dynamic range (>100 dB) and automatically adjusts for variations in irradiance in the scene is proposed. Then a data efficient image sensor is demonstrated. The idea of this smart image sensor is to reduce the bandwidth needed for transmitting data from the sensor by only sending the information which is required for the specific application while discarding the unnecessary data. In this case, the imager demonstrated sends only information regarding the boundaries of objects in the image so that after transmission to a remote image viewing location, these boundaries can be used to map out objects in the original image. The second part of the dissertation proposes and demonstrates smart optical communications systems using ECVFLs. This starts with the proposal and demonstration of a zero propagation loss optical wireless link using visible light with experiments covering a 1 to 4 m range. By adjusting the focal length of the ECVFLs for this directed line-of-sight link (LOS) the laser beam propagation parameters are adjusted such that the maximum amount of transmitted optical power is captured by the receiver for each link length. This power budget saving enables a longer achievable link range, a better SNR/BER, or higher power efficiency since more received power means the transmitted power can be reduced. Afterwards, a smart dual mode optical wireless link is proposed and demonstrated using a laser and LED coupled to the ECVFL to provide for the first time features of high bandwidths and wide beam coverage. This optical wireless link combines the capabilities of smart directed LOS link from the previous section with a diffuse optical wireless link, thus achieving high data rates and robustness to blocking. The proposed smart system can switch from LOS mode to Diffuse mode when blocking occurs or operate in both modes simultaneously to accommodate multiple users and operate a high speed link if one of the users requires extra bandwidth. The last part of this section presents the design of fibre optic and free-space optical switches which use ECVFLs to deflect the beams to achieve switching operation. These switching modules can be used in the proposed optical wireless indoor network. The final section of the thesis presents a novel smart laser scanning display. The ECVFL is used to create the smallest beam spot size possible for the system designed at the distance of the screen. The smart laser scanning display increases the spatial resoluti on of the display for any given distance. A basic smart display operation has been tested for red light and a 4X improvement in pixel resolution for the image has been demonstrated.

A cephalometric study of class II malocclusions treated with mandibular surgery

INTRODUCTION:

Class II malocclusion is often associated with retrognathic mandible. Some of these problems require surgical correction. The purposes of this study were to investigate treatment outcomes in patients with Class II malocclusions whose treatment included mandibular advancement surgery and to identify predictors of good outcomes.
METHODS:

Pretreatment and posttreatment cephalometric radiographs of 90 patients treated with mandibular advancement surgery by 57 consultant orthodontists in the United Kingdom before September 1998 were digitized, and cephalometric landmarks were identified. Paired samples t tests were used to compare the pretreatment and posttreatment cephalometric values for each patient. For each cephalometric variable, the proportion of patients falling within the ideal range was identified. Multiple logistic regression analysis was performed to identify predictors of achieving ideal range outcomes for the key skeletal (ANB and SNB angles), dental (overjet and overbite), and soft-tissue (Holdaway angle) measurements.
RESULTS:

An overjet within the ideal range of 1 to 4 mm was achieved in 72% of patients and was more likely with larger initial ANB angles. Horizontal correction of the incisor relationship was achieved by a combination of 75% skeletal movement and 25% dentoalveolar change. An ideal posttreatment ANB angle was achieved in 42% of patients and was more likely in females and those with larger pretreatment ANB angles. Ideal soft-tissue Holdaway angles (7 degrees to 14 degrees ) were achieved in 49% of patients and were more likely in females and those with smaller initial SNA angles. Mandibular incisor decompensation was incomplete in 28% of patients and was more likely in females and patients with greater pretreatment mandibular incisor proclination. Correction of increased overbite was generally successful, although anterior open bites were found in 16% of patients at the end of treatment. These patients were more likely to have had initial open bites.
CONCLUSIONS:

Mandibular surgery had a good success rate in normalizing the main dental and skeletal relationships. Less ideal soft-tissue profile outcomes were associated with larger pretreatment SNA-angle values, larger final mandibular incisor inclinations, and smaller final maxillary incisor inclinations. The use of mandibular surgery to correct anterior open bite was associated with poor outcomes.

Micromorphology of lamellae formed in an alluvial soil, Big Pine Tree Archeological Site, South Carolina

The formation of lamellae in soils is not clearly understood. The objectives of this study are to examine the microscopical characteristics of selected well developed lamellae inorder to identify the major processes involved in their formation at the Big Pine Tree Archaeological site on the Savannah River, South Carolina. Well developed lamellae have formed in a fine sandy alluvial soil that is about 11,000 to 12,000 years old. In the field, these lamellae are observed as 1 to 4.2 cm thick horizontal layers having a smooth upper and a wavy, sometimes irregular, lower boundary with adjacent interlamellae horizons. Soil thin sections reveal denser accumulations of brown fine silt and clay coatings in the upper and lower sections of the lamellae. The center of the lamellae has mainly orange highly oriented discontinuous clay coatings bridging quartz grains and some silt accumulations. Although, horizontal layering of denser areas (accumulations of fine silt and clay coatings) is also observed in the middle of the lamellae. The interlamellae horizons are mainly loose quartz grains. Low total carbon values (

Psychological problems in children with cerebral palsy: A cross-sectional European study

Objectives: To describe psychological symptoms in 8–12-year-old children with cerebral palsy; to investigate predictors of these symptoms and their impact on the child and family.

Design: A cross-sectional multi-centre survey.

Participants: Eight hundred and eighteen children with cerebral palsy, aged 8–12 years, identified from population-based registers of cerebral palsy in eight European regions and from multiple sources in one further region.

Main outcome measures: The Strengths and Difficulties Questionnaire (SDQ)P4-16 and the Total Difficulties Score (TDS) dichotomised into normal/borderline (TDS = 16) versus abnormal (TDS > 16).

Statistical analysis: Multilevel, multivariable logistic regression to relate the presence of psychological symptoms to child and family characteristics.

Results: About a quarter of the children had TDS > 16 indicating significant psychological symptoms, most commonly in the domain Peer Problems. Better gross motor function, poorer intellect, more pain, having a disabled or ill sibling and living in a town were independently associated with TDS > 16. The risk of TDS > 16 was odds ratio (OR) = .2 (95% CI: .1 to .3) comparing children with the most and least severe functional limitations; OR = 3.2 (95%CI: 2.1 to 4.8) comparing children with IQ < 70 and others; OR = 2.7 (95% CI: 1.5 to 4.6) comparing children in severe pain and others; OR = 2.7 (95% CI:1.6 to 4.6) comparing children with another disabled sibling or OR = 1.8 (95%CI: 1.2 to 2.8) no siblings and others; OR = 1.8 (95% CI: 1.1 to 2.8) comparing children resident in a town and others. Among parents who reported their child to have psychological problems, 95% said they had lasted over a year, 37% said they distressed their child and 42% said they burdened the family at least ‘quite a lot’.

Conclusions: A significant proportion of children with cerebral palsy have psychological symptoms or social impairment sufficiently severe to warrant referral to specialist services. Care must be taken in the assessment and management of children with cerebral palsy to ensure psychological problems are not overlooked and potentially preventable risk factors like pain are treated effectively. The validity of the SDQ for children with severe disability warrants further assessment.