On the relative efficiency of different shaped otter boards

Rectangular, horizontal curved and oval otter boards were tested under identical fishing conditions and their relative efficiency ascertained on the basis of towing tension and the horizontal opening of the boards. While the tension in the warps with the different otter boards was not significant, the horizontal curved board gave increased lateral spread to the net.

A re-description of the little known rabbit fish Siganus lineatus (Cuvier and Valenciennes) (Pisces:Siganide) with notes on siganid fishes of the Vembanad Lake

Siganus lineatus (Cuv. and Val) is reported from the coast of peninsular India for the first time and a detailed description of it is given based on morphology and meristic characters. It differs from the other allied species of the genus Siganus Forskal in having an oval body without spots and having fifteen parallel longitudinal golden yellow bands, relatively larger last dorsal spine, maxillary position far below the level of the orbit and cheek with distinct rows of scales. S. javus (Linnaeus) and S. canaliculatus (Park) were also obtained from the Vembanad Lake. Short notes on the habitat, occurrence, abundance, seasonal and geographic distribution in relation to fluctuating hydrological conditions of the Vembanad Lake are incorporated together with a key for their identification.

Height-length relation of shells in the Indian backwater oyster Crassostrea madrasensis (Preston) of the Cochin harbour

Height-length relationship in Crassostrea madrasensis (Preston) showed an exponential trend and relation in the form, H=ALᴮ. Deviations of actual values from the mean values consequent to the increase in size were noticed. Height and length approximated in oysters of less than 3.5cm in height resulting in orbicular shape. In oyster of shell height 3.5cm to 8cm, increase in height is faster leading to an oval shape. Above 8cm in height, the oysters become further elongated. Height-length relation is non-linear with an index (B value) of 1.1156. A linear relationship also holds good as the B value is not very much different from unity (H=-2.5424+2.0036L).

Histology and hormonal effect of Ghrelin on ovary of Benni (Barbus sharpeyi) in order to study sexual maturity, zygote and larval generation

Benni (Barbus sharpeyi) is valuable fish that Khuzastan fisheries office propagated it artificially in Susangerd Fish Propagation Center every year. Pituitary gland is used for this aim but female fish lost their fertilization power after 2-3 years, so in present research, new hormone, that is called Ghrelin. The aims of this research are histology, hormonal, zygote and larval generation studies and comparing the results with each other. Ghrelin is a multifunctional peptidyl hormone which increases GTH-II in fish, amphibian, and birds and mammalian so its effect on Benni sexual maturation was studied. Human Ghrelin (hGRL) was obtained from ANASPEC, Canada, with 28 amino acids. In the present study, three levels of ghrelin including 0 (sham treatments), 0.10 (treatment 1) and 0.15 μg/g (treatment 2) body wt and one level of pituitary gland 4000 μg/g (pituitary treatment) with two replications were used. 56 specimens were injected intraperitonealy and their ghrelin level was evaluated immediately after injection and after 24 h. Control fish(n=16) were just injected by physiological saline. For hormonal studies sham and experimental fish(n=40) were anesthetized with MS-222 at a concentration of 250 mg l-1, and blood samples were collected and kept at 4ْC, then spun to collect serum. Serum samples were stores at -20ْC until the RIA for CTH-II. For histology studies immediately after injection a piece of ovary was collected from control fish (Sham zero) after being anesthetized. The sampled ovaries were fixed in Buin solution and embedded in paraffin, and stained to Sections of 5–6 μm using haematoxylin and eosin. The ovarian samples were performed with a compound microscope. Histology and micrometry studies had done. The mature oocytes had given from mature fish, then weighted and the working fecundity were counted. The mature oocytes fertilized, the eggs were incubated and the percentage of fertilization was calculated. After 72h the eggs hatched and the percentage of hatch was counted. The percentage of hindrance was calculated after 6 days. Hormonal results indicate that ghrelin and pituitary increase significantly the GTH-II level in comparison to sham. Macroscopic observations (before taking ovary) showed that ovaries with green colored have couple oval structure located in the abdominal cavity. Microscopic studies of dissected ovaries indicated simultaneous growth of 127 oocytes with 6 stages. The type of the ovary is asynchronous. The results indicated that both of the ghrelin treatment increased the percentage of mature follicles followed by decrease of immature follicles. There were significant differences (P<0.05) between the number of mature and immature follicles. Average diameter of follicle in both of the ghrelin treatment was significantly (P<0.05) declined in the stages of the vitellogenesis when the result compared to the other treatment. Just treatment 1 and pituitary treatment can give mature oocytes. The fecundity of pituitary treatment significantly increase in comparision to ghrelin treatment (P<0.05). In food-restricted fish where endogenous ghrelin levels are known to be increased, a chronic administration of ghrelin induces overt negative effect in releasing mature oocytes. The percentage of fertilization was significantly increase (P<0.05) in ghrelin t. in comparison to pituitary t. and the percentage of hatch was significantly increase (P<0.05) in pituitary t. in comparison to ghrelin t. There was no significant difference (P>0.05) in terms of percentage of hindrance between treatments. In conclusion, the present study demonstrated that ghrelin has positive effect on the level of GTH-II, oocyte maturation, ovarian vitellogenesis and the number of mature follicles of Barbus sharpeyi ovary. Increasing of the mature follicles number reduces their average diameter, indicating stimulating effect of ghrelin in sexual maturation of Barbus sharpeyi.The ghrelin and pituitary treatment have equal chance in the post-stage of spawning.

Description of two new myxosporean species parasitic in freshwater fishes from the Yangtze River in China

Two new species of myxosporeans (Myxosporea: Myxidiidae), Myxidium tuanfengensis sp. n. and Zschokkella saurogobionis sp. n., Parasitic in freshwater fishes collected from the Yangtze River of China are described in this paper. M. tuanfengensis was found in the liver parenchyma and intestine lumen of Leptobotia taeniops Sauvage, 1878, while Z. saurogobionis was found in the gall bladder of Saurogobio dumerili Bleeker, 1871. The diagnostic characters of M. tuanfengensis are: round or elliptical polysporous plasmodia averaging 118 mum in size; spore oval in frontal view with smooth surface and nearly spindle-shape in sutural view with slightly sinuous sutural ridge, averaging 19.5 x 9.75 x 8.9 mum in size; two large spherical polar capsules 6.8 mum in diameter, with polar filament wound in 4 to 5 coils. The diagnostic characters of Z. saurogobionis are: spore elliptical in both frontal and sutural view measuring 18.3 x 9.8 x 10.8 mum in size; fine sutural ridge in S-form, spore shell marked with 10 to 12 distinct lines paralleled with the sutural line; two spherical polar capsules, 6.7 mum in diameter, with polar filament in 5 coils.

Notholca dongtingensis (Rotifera : Monogononta : Brachionidae), a new species from Dongting Lake, China

Notholca dongtingensis n.sp. was found in the second largest lake of China, Dongting Lake. It is related to Notholca labis Gosse, 1887 and N. kozhovi Vassilijewa & Kutikova, 1969. Its main distinguishing taxonomic features are a square-oval lorica, very short anterior spines, anterior lateral spines curving outwards and protrusile posterior margin of the ventral plate.

Abatement of waste gases and water during the processes of semiconductor fabrication

The purpose of this article is to examine the methods and equipment for abating waste gases and water produced during the manufacture of semiconductor materials and devices. Three separating methods and equipment are used to control three different groups of electronic wastes. The first group includes arsine and phosphine emitted during the processes of semiconductor materials manufacture. The abatement procedure for this group of pollutants consists of adding iodates, cupric and manganese salts to a multiple shower tower (MST) structure. The second group includes pollutants containing arsenic, phosphorus, HF, HCl, NO2, and SO3 emitted during the manufacture of semiconductor materials and devices. The abatement procedure involves mixing oxidants and bases in an oval column with a separator in the middle. The third group consists of the ions of As, P and heavy metals contained in the waste water. The abatement procedure includes adding CaCO3 and ferric salts in a flocculation-sedimentation compact device equipment. Test results showed that all waste gases and water after the abatement procedures presented in this article passed the discharge standards set by the State Environmental Protection Administration of China.

Effects of growth temperature on highly mismatched InAs grown on GaAs substrates by MBE

InAs layers were grown on GaAs by molecular beam epitaxy (MBE) at substrate temperature 450 and 480 degrees C, and the surface morphology was studied with scanning electron microscopy (SEM). We have observed a high density of hexagonal deep pits for samples grown at 450 degrees C, however, the samples grown at 480 degrees C have smooth surface. The difference of morphology can be explained by different migration of cations which is temperature dependent. Cross-sectional transmission electron microscopy (XTEM) studies showed that the growth temperature also affect the distributions of threading dislocations in InAs layers because the motion of dislocations is kinetically limited at lower temperature. (C) 1998 Elsevier Science B.V. All rights reserved.

棘蛙族(Tribe Paini)精子形态结构及精巢年周期研究

棘蛙族(Tribe Paini)隶两栖纲(Amphibia)、无尾目(Anura)、蛙科(Ranidae)、叉舌蛙亚科(Dicroglossinae)，由棘蛙属(Paa)、倭蛙属(Nanorana) 和沙巴蛙属(Chaparana)构成（Dubois,1992）。由于特殊的形态特征和染色体核型，棘蛙族受到国内外学者的广泛重视和研究，但是到目前为止，棘蛙族的系统发育关系尚未明晰，族下属种的分类和归属问题还有待进一步研究和新的证据出现。本文通过光学显微镜、电子显微镜和石蜡切片对棘蛙族10 物种的精子和精巢进行研究，旨在了解棘蛙族精子的形态、量度、超微结构特征及不同季节精巢结构的变化规律，同时为棘蛙族的系统研究提供新的依据，也为棘蛙族濒危物种的保护和经济物种的繁殖提供基础资料。研究结果表明：棘蛙族各属物种精子的形态基本相似，精子整体呈线形，由头部、中片和尾部构成。精子头部呈长条状，顶体呈锥状，位于头部顶端并向前伸出，中片较长，尾部波动弯曲。棘蛙族各属物种精子量度差异较大，将各属物种精子头部、中片、尾部、头宽、尾宽的量度数据进行聚类分析，结果表明棘蛙族10 物种可分为三类：第一类包括棘侧蛙、合江棘蛙、小棘蛙、棘腹蛙和棘胸蛙，特点是精子较短，全长在72.6～103.35µm 之间；第二类包括倭蛙、高山倭蛙、腹斑倭蛙，特点是精子较长，全长在107.74～129.75µm 之间；第三类包括隆肛蛙和双团棘胸蛙，特点是精子最长，全长在145.89～165.84µm 之间。棘蛙族各属精子超微结构基本相似：精子头部由顶体、细胞核构成；中片由中心粒、线粒体构成；尾部由单根轴丝构成。精子顶体横切呈圆环状，细胞核电子密度高；线粒体为卵圆形，呈环状围绕轴丝排列，线粒体数目较多，约30层；尾部轴丝为典型的9＋2结构，即由2根中央微管和9对外周微管组成。不同季节的倭蛙精巢结构变化表明倭蛙精巢每年只有一个生精周期，生精周期始于7 月，繁殖季节从5 月到6 月，生精高峰期为9 月；根据倭蛙不同季节精巢结构的变化，可将生精周期分为3 个阶段：第一阶段从7 月到9 月，为精子形成期；第二阶段从10 月到翌年4 月，为精子的贮存阶段，也即倭蛙的冬眠期；第三阶段从5 月到6 月，为精子的排放阶段，即倭蛙的繁殖期。不同季节的隆肛蛙精巢结构变化表明5 月为隆肛蛙的繁殖高峰期。根据棘蛙族各属精子的形态、量度和超微结构特征，结合已有的棘蛙族形态学、生态学、染色体核型及系统学研究成果，本文认为：1．基于精子数据对棘蛙族的划分和基于形态学及分子系统学数据对棘蛙族的划分均有相同之处，精子形态结构可为棘蛙族的系统研究提供新的证据。2． 棘蛙族各属精子的形态、量度及超微结构不仅与蛙科其他属种有明显差异，而且在无尾类中也较为特殊，精子学研究结果支持将棘蛙族从蛙科中分离出来，归隶于叉舌蛙科的叉舌蛙亚科的系统学修正。3. 精子的顶体、细胞核、中片的形态结构及量度可作为蛙科的分类指标。On the base of unique morphological and kyrotype characters, Dubois(1992)recognized three genera Paa, Narnorana, Chaparana as tribe Paini, which is amember of Dicroglossinae, Ranidae. In present study, the sperm shape, size andultrastructure of 10 paini species were investigated through the light and electronmicroscope, and testis structure of N. pleskei and F. quadrana was also studied. Wesuppose this study could offer some spermatological evidence to phylogeny andreproduction study of tribe Paini. The results were as follows:The sperm shape of tribe paini is homologically similar, the spermatozoa arefiliform, composed of elongate head, long mid-piece and waved tail. The acrosome isapically associated with the nucleus and extend anteriorly.The sperm length of tribe paini differ remarkably among genera. Cluster for thelength of sperm head, mid-piece, tail, total length, head-width, tail-width of ten painifrogs indicated the 10 species could be separated into three groups: GroupⅠcontainsP. shini, P. robertingeri, P. spinosa, P. exilispinosa, P. boulengeri, the spermatozoa ischaracterized with short in total length, ranging from 72.6µm to 103.35µm; GroupⅡcontains N. pleskei, N. parkeri, N. ventripunctata, the spermatozoa ischaracterized with relatively long in total length, ranging from 107.74µm to129.75µm; Group Ⅲ contains F. quadrana and P. yunnanensis, the spermatozoa is characterized with longest in total length, ranging from 145.89µm to 165.84µm. thethree groups based on spermatological data is partially match the classification basedon morphological and molecular data.The ultrastructure of spermatozoa in tribe paini is also basic similar, includingacrosome vescile, nuleus of the head proper, centriole, mitochondriol of themid-pieces, axoneme of the tail. The acrosome vescle is circle in TEM transversesection, the density of nucleus is high; The mitochondrions is oval, surrounding theaxial filament with about 30 layers of mitochondria; The axoneme has the typical 9+2pattern of microtubules.The seasonal changes in testis of N. pleskei indicates it has only onespermatogenesis circle, which begin in July, the reproduction season is from May toJune, the spermatogenesis is active in September. On the base of seasonal changes intestis, the spermatogenesis circle can be separated into three stages: In stageⅠfromJuly to September, spermatids are formed; In stage Ⅱ from October to April next year,the spermatozoa are stored in testis,which is the hibernated period; In stage Ⅲ fromMay to June, mature spermatozoa were released from the testis, which is thereproduction season of N. pleskei. As to F. quadrana, reproduction is active in May.With the previous study of morphology, ecology, karyotypes and phylogenyresearch of tribe Paini, the spermatological data in present study suggests:1. The spermatological classification of tribe paini is partially consistant with themorphological and molecular classification respectively.2.The sperm morphology and ultrustructure of tribe paini is unique not only inthe family Ranida but also in Anura, which suggest the tribe paini is monophyletic andmight be transfered from the family Ranida to the family Dicroglossidae based onmolecular evidence.3. The acrosome, nuleus, shape, length and ultrastructure of mid-piece can beused as an alternative taxonomic character in Anura.

Fruit anatomy,seed germination and seedling development in the Japanese seagrass phyllospadix

Phyllospadix iwatensis Makino and phyllospadix japonicus Makino have similar frunt morphology and anatomy.The rhomboid fruit of Japanese phyllospadix is dark brown in colour and is characterized by two arms bearing stiff inflected bristles which can act as an anchoring system. The fruit covering consists of a thin cuticular seed coat and pericarp remains mainly fibrous endocarp. In the groove region of the fruit.the cuticular seed coat and endocarp are replaced by nucellus cells with wall in growths and crushed pigment strands with lignified walls.these tissues appera to control the transfer of nutrients to developing seed.the seed is oval with a small embryo and a large hypocotyl. the embryo is straight and simple,with the plumule containing three leaf primordia and a pair of root primordia surrounded by a cotyledon.the hypocotyl has large vontral lobe containing central provascular tissue and two small dorsal lobes.the hypocotyl contains starch.lipid and protein.and acts as a nutrient store.the seed of P.iwatensis has a dormancy period of 2-6 weeks and germination eventually reaches-65%.but is not synchronized.during germination the leaves emerge first.and then after at least three young leaves have formed and abseised.the roots emerge,usually?6 months after the commencement of germination.Utilizaton of the nutrient reserves is initially from the perihpery of the hypocotyl and then progressively towards its centre.

Uniform AMoO(4):Ln (A = Sr2+, Ba2+; Ln = Eu3+, Tb3+) submicron particles: Solvothermal synthesis and luminescent properties

Rare-earth ions (Eu3+, Tb3+) doped AMoO(4) (A = Sr, Ba) particles with uniform morphologies were successfully prepared through a facile solvothermal process using ethylene glycol (EG) as protecting agent. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) spectra and the kinetic decays were performed to characterize these samples. The XRD results reveal that all the doped samples are of high purity and crystallinity and assigned to the tetragonal scheelite-type structure of the AMoO(4) phase. It has been shown that the as-synthesized SrMoO4:Ln and BaMoO4:Ln samples show respective uniform pea nut-like and oval morphologies with narrowsize distribution. The possible growth process of the AMoO(4):Ln has been investigated in detail. The EG/H2O volume ratio, reaction temperature and time have obvious effect on themorphologies and sizes of the as-synthesized products.

Solvothermal synthesis and luminescent properties of monodisperse LaPO4:Ln (Ln = Eu3+, Ce3+, Tb3+) particles

Monodisperse rare-earth ion (Eu3+, Ce3+, Tb3+) doped LaPO4 particles with oval morphology were successfully prepared through a facile solvothermal process without further hear treatment. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectra (XPS), Fourier transform infrared spectroscopy (FT-IR), photoluminescence (PL) spectra and the kinetic decays were performed to characterize these samples. The XRD results reveal that all the doped samples are well crystalline at 180 degrees C and assigned to the monoclinic monazite-type structure of the LaPO4 phase. It has been shown that all the as-synthesized samples show perfectly oval morphology with narrow size distribution. The possible growth mechanism of the LapO(4):Ln has been investigated as well.

Molecular characterization of beef liver catalase by scanning tunneling microscopy

Beef liver catalase molecules can stick tenaciously to the highly oriented pyrolytic graphite (HOPG) surface which has been activated by electrochemical anodization. The immobilized sample is stable enough for high resolution scanning tunneling microscope (STM) imaging. When the anodized conditions are controlled properly, the HOPG surface will be covered with a very thin oxide layer which can bind the protein molecules. Individual molecules of native beef liver catalase are directly observed in detail by STM, which shows an oval-shape structure with a waist. The dimensions of one catalase molecule in this study are estimated as 9.0 x 6.0x 2.0 nm(3), which are in good agreement with the known data obtained from X-ray analysis, except the height can not be exactly determined from STM. Electrochemical results confirm that the freshly adsorbed catalase molecules maintain their native structures with biological activities. However, the partly unfolding structure of catalase molecules is observed after the sample is stored for 15 days, this may be caused by the long-term interaction between catalase molecules and the anodized HOPG surface.

In situ electrochemical scanning tunnelling microscopy investigation of structure for horseradish peroxidase and its electrocatalytic property

Immobilization of protein molecules is a fundamental problem for scanning tunnelling microscopy (STM) measurements with high resolution. In this paper, an electrochemical method has been proved to be an effective way to fix native horseradish peroxidase (HRP) as well as inactivated HRP from electrolyte onto a highly oriented pyrolytic graphite (HOPG) surface. This preparation is suitable for both ex situ and in situ electrochemical STM (ECSTM) measurements. In situ STM has been successfully employed to observe totally different structures of HRP in three typical cases: (1) in situ ECSTM reveals an oval-shaped pattern for a single molecule in neutral buffer solution, which is in good agreement with the dimension determined as 6.2 x 4.3 x 1.2. nm(3) by ex situ STM for native HRP; (2) in situ ECSTM shows that the adsorbed HRP molecules on HOPG in a denatured environment exhibit swelling globes at the beginning and then change into a V-shaped pattern after 30 min; (3) in situ ECSTM reveals a black hole in every ellipsoidal sphere for inactivated HRP in strong alkali solution. The cyclic voltammetry results indicate that the adsorbed native HRP can directly catalyse the reduction of hydrogen peroxide, demonstrating that a direct electron transfer reduction occurred between the enzyme and HOPG electrode, whereas the corresponding cyclic voltammograms for denatured HRP and inactivated HRP adsorbed on HOPG electrodes indicate a lack of ability to catalyse H2O2 reduction, which confirms that the HRP molecules lost their biological activity. Obviously, electrochemical results powerfully support in situ STM observations.

STM OF FOLDED AND UNFOLDED HEMOGLOBIN MOLECULES ELECTROCHEMICALLY DEPOSITED ON HIGHLY ORIENTED PYROLYTIC-GRAPHITE

The structural characterization of folded and unfolded haemoglobin has been performed by scanning tunnelling microscopy (STM) for the first time. STM images show an oval-shaped pattern for the folded structure of this protein, and moreover two dimers consisting of one haemoglobin molecule can be clearly discerned. The dimensions of a folded molecule were determined as 6.4 x 5.4 x 0.7 nm(3), which are in good agreement with the known size obtained from X-ray analysis. We have found that unfolding of haemoglobin molecules on the surface of highly oriented pyrolytic graphite (HOPG) can be achieved by electrochemical deposition. The STM analysis indicates clearly that the tertiary structure of the protein was lost by electrochemical deposition, and most of the haemoglobin molecules were almost fully extended and exhibited a twisted rope-like or a rod-like aggregated structure. Our investigation demonstrates the capability of the electrochemical method in denaturing this redox protein and in preparing stable biological samples for use in STM imaging.