The protein, peptide and free amino-acid contents of some species of Gracilaria from south-east coast of India

Four species of Gracilaria are investigated for their free amino-acid contents, as well as amino-acid constituents in the proteins and the peptides, using quantitative paper chromatographic technique. Amino-acid constituents of different species of Gracilaria differ only in amount, while free amino-acids and the amino-acids in the peptides vary both in quality and quantity. A number of amino-acids recorded as protein constituents have even escaped detection in the peptides, while in the free state they occur either in all the species or in some only except homocystine. Moreover, some amino-acids occur exclusively in the free state.

Studies on the biochemical composition of some freshwater fishes. Pt. 2. Liver

Although considerable work has been done on the composition of fish liver oils, most of which includes the study of various vitamins and fatty acids, little attention has been paid towards the composition of fish liver as a whole.

Preliminary studies on the effect of irradiation as a means of preservation of fish and shellfish

Preliminary investigations on the effect of irradiation on commercially important fish and shell fish like silver pomfret, Bombay duck and prawns were conducted. Irradiated samples had an extended storage life compared to their respective controls even though yellowish or brownish discoloration occurred earlier in irradiated fish. Irradiation enhanced the rate of drip formation. Brine treatment prior to irradiation retarded this rate. Pre-blanching was found to further extend the storage life of irradiated fish.

Preservation of fish by freezing and glazing. Pt. 3. Effect of freezing, glazing and frozen storage on the B-vitamins and essential minerals present in the fish flesh

The changes occurring in moisture, thiamine, riboflavin niacin, phosphorus, iron and calcium in pomfret, surmai and frozen mackerel, glazed with ascorbic acid, citric acid, sodium chloride, glucose, sodium nitrite and kept under frozen storage were studied up to 6 months and results reported.

Effect of deposition conditions on the chemical bonding in sputtered carbon nitride films

A balanced planar r.f. powered magnetron sputter source has been used to deposit carbon nitride films from a graphite target under various conditions. Sample temperature, bias voltage and nitrogen content in the gas mixture were varied. The effects of oxygen, methane and ammonia on the film growth were also studied. Special attention was paid to the effects of the deposition parameters on the structure of the films, in particular the hybridisation of the carbon and nitrogen bonding. The chemical bonding of the carbon and nitrogen atoms was studied by electron energy loss spectroscopy (EELS). The chemical composition was evaluated by Rutherford back-scattering. The intensity of transitions to π antibonding orbitals, as revealed by EELS, was found to increase with the nitrogen content in the films. Ion bombardment of the films during growth and the addition of oxygen or hydrogen-rich gases further increased the proportion of π bonds of both the carbon and nitrogen atoms. It is suggested that the increase in the transitions to μ antibond orbitals is to be explained by increased sp2 or possibly sp hybridisation of the carbon and nitrogen. Also, the effect of annealing on the bonding of nitrogen rich films after deposition was tested. The changes caused by nitrogen and deposition conditions are consistent with previous reports on the formation of paracyanogen structures.

DEVELOPMENT OF THE WAVE CONTOURING RAFT.

The wave contouring raft system is the outcome of ideas initiated and developed by Sir Christopher Cockerell from 1972 onwards. His objective was to develop a wave energy device which is within the bounds of current technology. It should consist of simple, relatively small units, amenable to quantity production, which would enable a power generating system to be built up and commissioned in stages according to needs and production capability. This thinking led to the investigation of chains of pontoons, hinged together so that the passage of a wave down the chain causes the pontoons to oscillate relative to one another. Energy is extracted from the sea by applying a torque about the hinges to damp the motion. The work has involved extensive model testing in wave tanks and the building and testing of a 3-unit 1/10 scale power generating installation in the Solent, as well as design studies for a full size installation for Atlantic conditions.

濒危植物大花黄牡丹种子休眠与萌发特性研究

本文以中国极危种大花黄牡丹种子为研究材料，对其种子生物学、休眠与萌发特性进行研究，采用变温层积和激素处理解除种子休眠，并通过生物抑制物测试、胚培养、激素含量动态变化的测定，研究种子休眠的原因，从根本上解决了大花黄牡丹迁地保护过程中种子繁殖的技术难题，并初步探讨了大花黄牡丹致濒因素与种子休眠及萌发特性的关系，结果表明： 1.大花黄牡丹种子饱实度高，活力强，种皮较坚硬，但不存在吸水障碍，干燥条件下易因失水而丧失活力。迁地保护冷室中盆播18个月方可出苗，出苗率约4%;变温层积实验表明该种具有典型的下胚轴休眠和上胚轴生长抑制。 2.胚组织培养表明：带胚乳和种皮的胚不能萌发，剥除种皮和胚乳后，胚根可萌发，胚芽不生长，GA3处理上胚轴可促进生长，说明种皮和胚乳是导致大花黄牡丹种子下胚轴休眠的关键因素，而上胚轴生长抑制与胚本身关系更密切。 3.抑制物质提取实验表明：大花黄牡丹种子胚乳、种皮、胚等各部位的浸提液均存在抑制小白菜种子萌发的物质，且抑制作用依次增强，说明胚乳和胚是其下胚轴休眠的主要原因。经过暖层积（15 ℃/90 d）种子（未解除上胚轴生长抑制）的胚根、子叶、胚轴浸提液对小白菜和已解除休眠的大花黄牡丹种子的萌发均有不同程度的抑制作用，并依次减弱，说明种胚本身的抑制物质是导致生理休眠的主要原因。 4.变温层积处理和外源激素实验表明：新鲜种子采收后15 ℃暖层积3个月生根率可达85%，下胚轴休眠解除对温度要求严格，高于或低于15 ℃及变温条件均不利于下胚轴萌发;暖层积90d、根长大于6 cm种子再经过60～80 d/ 5 ℃冷层积，即可有效解除大花黄牡丹种子上胚轴的生长抑制，出芽率达80%，最终出苗率68%。不同浓度GA3及不同处理时间促进上胚轴伸长实验结果显示，GA3　400 mg/L浸种根长大于1.5 cm的种子2 h，出芽率可达100%，可以完全解除上胚轴的生长抑制作用。 5.休眠萌发过程中种子各部位内源激素含量动态变化分析结果说明，初始状态脱落酸含量高是导致大花黄牡丹种子下胚轴休眠、上胚轴生长抑制的主要原因之一，且上胚轴抑制与子叶、下胚轴和根的脱落酸含量密切相关;同时认为种子各部位初始生长素含量水平低是导致其休眠的另一个主要原因;变温层积过程中胚各部位脱落酸含量的急剧下降和生长素的迅速升高是解除休眠的关键;同时发现赤霉素在解除休眠和促进萌发过程中起着重要的促进作用，外源GA3能够有效地打破上胚轴的深度休眠。玉米素核苷在休眠与萌发进程中变化趋势与生长素和赤霉素相似，说明其对种子胚根和上胚轴的萌发和生长具有一定的促进作用。

Evolution of the black muntjac (Muntiacus crinifrons) karyotype revealed by comparative chromosome painting

The black muntjac (Muntiacus crinifrons) has an unusual karyotype of 2n = 8 in females and 2n = 9 in males. We have studied the evolution of this karyotype by hybridising chromosome-specific paints derived from flow-sorted chromosomes of the Chinese muntjac (M. reevesi, 2n = 46) to chromosomes of the black muntjac. The hybridisation pattern allowed us to infer chromosomal homologies between these two species. Tandem and centromeric fusions, reciprocal translocations, and insertions are involved in the reduction of the diploid number from 2n = 46 to 2n = 8, 9. The painting patterns further show complex chromosomal rearrangements in the male black muntjac which involve more than half the karyotype, including both sex chromosomes. Since early meiosis is reported to be normal without any visible inversion loops of the synaptonemal complex, the observed chromosomal rearrangements would lead to heterosynapsis and, therefore, leave a large fraction of the male black muntjac karyotype balanced between the two sexes.

Superconducting properties of Gd-Ba-Cu-O single grains processed from a new, Ba-rich precursor compound

Gd-Ba-Cu-O (GdBCO) single grains have been previously melt-processed successfully in air using a generic Mg-Nd-Ba-Cu-O (Mg-NdBCO) seed crystal. Previous research has revealed that the addition of a small amount of BaO 2 to the precursor powders prior to melt processing can suppress the formation of Gd/Ba solid solution, and lead to a significant improvement in superconducting properties of the single grains. Research into the effects of a higher Ba content on single grain growth, however, has been limited by the relatively small grain size in the earlier studies. This has been addressed by developing Ba-rich precursor compounds Gd-163 and Gd-143, fabricated specifically to enable the presence of greater concentrations of Ba during the melt process. In this study, we propose a new processing route for the fabrication of high performance GdBCO single grain bulk superconductors in air by enriching the precursor powder with these new Ba rich compounds. The influence of the addition of the new compounds on the microstructures and superconducting properties of GdBCO single grains is reported. © 2008 IOP Publishing Ltd.

African origin of modern humans in East Asia: A tale of 12,000 Y chromosomes

To test the hypotheses of modern human origin in East Asia, we sampled 12,127 male individuals from 163 populations and typed for three Y chromosome biallelic markers (YAP, M89, and M130). All the individuals carried a mutation at one of the three sites.

Cementation liquefaction remediation for existing buildings

Many typical liquefaction remediation techniques are not appropriate for application under existing buildings and more novel techniques are required. This paper describes centrifuge tests investigating the performance of cementation as a liquefaction remediation method. Two soil profiles with the same superstructure were tested under earthquake shaking. The first profile consisted of a deep layer of loose, liquefiable sand. The second comprised a shallow layer of loose sand overlying dense sand. Centrifuge tests were carried out with a cemented zone underneath the structure, through the full depth of the liquefiable layers and also partial depth. The superstructure was modelled as a single-degree-offreedom system. It is found that a cemented zone through the full depth of a liquefiable layer results in considerable reduction of structural settlements. Increased magnitude and higher frequency accelerations are transmitted to the structure but, depending on the building characteristics, it is likely that improved overall seismic performance can be achieved. Improvements in structural settlements can also be obtained with partialdepth remediation, if the depth of the cemented zone is greater than the depth of liquefaction. This type of remediation seems to have little effect on the accelerations transmitted to the structure.

Sustainable binders for soil stabilisation

Portland cement is the most commonly and widely used binder in ground improvement soil stabilisation applications. However, many changes are now affecting the selection and application of stabilisation additives. These include the significant environmental impacts of Portland cement, increased use of industrial by-products and their variability, increased range of application of binders and the development of alternative cements and novel additives with enhanced environmental and technical performance. This paper presents results from a number of research projects on the application of a number of Portland cement-blended binders, which offer sustainability advantages over Portland cement alone, in soil stabilisation. The blend materials included ground granulated blastfurnace slag, pulverised fuel ash, cement kiln dust, zeolite and reactive magnesia and stabilised soils, ranging from sand and gravel to clay, and were assessed based on their mechanical performance and durability. The results are presented in terms of strength and durability enhancements offered by those blended binders.