苏丹GNPOC原油管道减阻剂工业试验及应用

介绍了在苏丹GNPOC原油长输管道超长管段上采用EP W2 0 3减阻剂进行工业试验及其应用情况。先后在 1号站和 3号站间进行 1号站单点注入减阻试验与增输试验 ,在 1号站和 2号站进行两点注入增输试验。其后开始例行两点注入工业应用。分析了减阻剂工业应用中存在的问题 ,由于原油来源发生变化 ,原油粘度升高 ,同时受到雨季环境条件的影响 ,导致该管道 2号、3号站间原油雷诺数大大降低 ,因此降低了减阻剂的作用效果     

Genetic diversity,population structure and genetic relationships in apricot (Prunus armeniaca L.) germplasm of Jammu and Kashmir,India using ISSR markers

Genetic Resources and Crop Evolution - The collection and characterization of apricot germplasm is an important step for its utilization, conservation, and breeding programs. In the present study,...     

Agronomic evaluation of controlled release of micro urea encapsulated in rosin maleic anhydride adduct

Abstract

Plant derived bio-based materials are environmental-friendly and provide a cheap and an attractive source for synthesis of controlled release urea fertilizers which have positive impact on plants’ health. In this work, application of rosin-maleic anhydride adduct encapsulated controlled release micro urea fertilizer (RA-mCRUF) was investigated for the optimization of its controlled urea release properties and evaluation of growth promoting effect on maize (Zea mays) plant under three different soil texture classes. Through response surface methodology, the independent response variables, were optimized for controlled release response of urea. Study found optimized coating repeats, 5.00 cycles; drying time, 11.71?h; and particle size, 41.82?µm; at urea release response of 331.62?mg L^?1 in distilled water. Optical microscopy images further demonstrated a more compact and homogeneous surface of RA-mCRUF without any coating defects. Besides, RA-mCRUF predicted a better growth performance of maize plant in clay loam soil. Moreover, RA-mCRUF treated maize plant showed 9.0–24.5?mg g^?1 increase in chlorophyll contents and 7.44–12.75?g rise in plant dry biomass. This work successfully produced a new type of RA-mCRUF which has applied role in soil nutrients conservation and addressing effectively food security through crops protection.     

基于高速摄影的冬枣果实振动脱落规律分析

为研究冬枣振动采收过程中果实的运动规律和脱落轨迹,采用改装的电动往复锯连接自制振动采摘头对树枝进行高速振动,用高速相机记录不同振动频率(15、20、25 Hz)下冬枣果实的运动轨迹,对高速视频进行分析,计算在振动过程中的枣果脱落类型、脱落时间和运动轨迹,以及果实脱落时的速度、加速度和惯性力。结果表明:1)冬枣果实的主要脱落类型是旋倾型,15、20和25Hz时,旋倾型脱落的果实个数比例分别为81%、66%和78%,参考已有研究经验,冬枣机械收获宜选用连续式振动设备;2)随着振动频率的增大,果实的平均脱落时间减小,3个频率的果实脱落时间分别为1.71、0.54和0.43s,15Hz时果实脱落时间与20和25Hz时的果实脱落时间存在显著性差异,而20与25Hz时的果实脱落时间无显著性差异;3)果实的速度和加速度随着振动频率的增大而增大,但不同频率的果实平均脱落惯性力不存在显著性差异,3个频率下分别为0.48、0.43和0.49N。本研究结果可为机械收获装备的设计选型与研发提供理论依据。     

A new strain of white spot syndrome virus affecting Litopenaeus vannamei in Indian shrimp farms

White spot syndrome virus (WSSV)‐infected shrimp samples collected from grow‐out ponds located at Nellore, Andhra Pradesh, India, showed WSSV negative and positive by PCR using primer sets specific to ORF119 and VP28 gene of WSSV, respectively. This indicated the deletion of genetic fragments in the genome of WSSV. The WSSV isolate along with lab strain of WSSV was subjected to next‐generation sequencing. The sequence analysis revealed a deletion of 13,170 bp at five positions in the genome of WSSV‐NS (new strain) relative to WSSV‐TH and WSSV‐LS (lab strain). The PCR analysis using the ORF's specific primer sets revealed the complete deletion of 10 ORFs in the genome of WSSV‐NS strain. The primer set was designed based on sequence covering ORF161/162/163 to amplify a product of 2,748 bp for WSSV‐LS and 402 bp for WSSV‐NS. Our surveillance programme carried out since 2002 revealed the replacement of WSSV‐LS by WSSV‐NS in Indian shrimp culture system.     

Multiple infections caused by white spot syndrome virus and Enterocytozoon hepatopenaei in pond‐reared Penaeus vannamei in India and multiplex PCR for their simultaneous detection

White leg shrimp, Penaeus vannamei, were collected on a monthly basis from grow‐out ponds located at Tamil Nadu and Andhra Pradesh states along the east coast of India for screening of viral and other pathogens. Totally 240 shrimp samples randomly collected from 92 farms were screened for white spot syndrome virus (WSSV), infectious hypodermal and haematopoietic necrosis virus (IHHNV), infectious myonecrosis virus (IMNV) and Enterocytozoon hepatopenaei (EHP). The number of shrimp collected from shrimp farms ranged from 6 to 20 based on the body weight of the shrimp. All the shrimp collected from one farm were pooled together for screening for pathogens by PCR assay. Among the samples screened, 28 samples were WSSV‐positive, one positive for IHHNV and 30 samples positive for EHP. Among the positive samples, four samples were found to be positive for both WSSV and EHP, which indicated that the shrimp had multiple infections with WSSV and EHP. This is the first report on the occurrence of multiple infections caused by WSSV and EHP. Multiplex PCR (m‐PCR) protocol was standardized to detect both pathogens simultaneously in single reaction instead of carrying out separate PCR for both pathogens. Using m‐PCR assay, naturally infected shrimp samples collected from field showed two prominent bands of 615 and 510 bp for WSSV and EHP, respectively.     

Pox-like lesions in a colony of carp (Cyprinus carpio)

Twelve carp (Cyprinus carpio) out of a total of 100 were affected with skin nodules, mainly located on the dorsal and lateral surface. Post mortem examination of six of the worst affected fish showed the nodules consisting of white gel-like outgrowths. No abnormality was apparent in any other tissue examined. Microscopically, the nodules were formed by proliferating hyperplastic epidermal cells. The other six fish were left for recovery and their nodules regressed spontaneously. The possible aetiological factors are listed.     

Immune responses of whiteleg shrimp,Litopenaeus vannamei (Boone, 1931), to bacterially expressed dsRNA specific to VP28 gene of white spot syndrome virus

In this study, dsRNA specific to VP28 gene of white spot syndrome virus (WSSV) of shrimp was synthesized in Escherichia coli in large scale and studied the immune response of shrimp to dsRNA‐VP28. The haematological parameters such as clotting time and total haemocytes counts, and immunological parameters such as prophenoloxidase (proPO), superoxide dismutase (SOD), superoxide anion (SOA) and malondialdehyde content, as well as the mRNA expression of ten immune‐related genes were examined to estimate the effect of dsRNA‐VP28 on the innate immunity of Litopenaeus vannamei. The activities of proPO, SOA and SOD significantly increased in haemocyte after dsRNA‐VP28 treatment, whereas MDA content did not change significantly. Among the ten immune‐related genes examined, only the mRNA expression of proPO, cMnSOD, haemocyanin, crustin, BGBP, lipopolysaccharides (LPs), lectin and lysozyme in haemocytes, gill and hepatopancreas of L. vannamei, was significantly upregulated at 12 h after dsRNA‐VP28 treatment, while no significant expression changes were observed in Toll receptor and tumour receptor genes. The increase of proPO and SOD activities, and SOA level and mRNA expression level of proPO, cMnSOD, haemocyanin, crustin, BGBP, LPs, lectin and lysozyme after dsRNA‐VP28 stimulation indicate that these immune‐related genes were involved in dsRNA‐VP28‐induced innate immunity in shrimp.     

Tissue distribution of hepatopancreatic parvo‐like virus of shrimp in freshwater rice‐field crab,Paratelphusa hydrodomous (Herbst)

An attempt was made to determine the replication efficiency of hepatopancreatic parvo‐like virus (HPV) of shrimp in different organs of freshwater rice‐field crab Paratelphusa hydrodomous (Herbst) using bioassay, PCR, RT‐PCR, ELISA, Western blot and q‐PCR analyses. Another attempt was made to use this crab as an alternative to penaeid shrimp for the large‐scale production of HPV. This crab was found to be highly susceptible to HPV by intramuscular injection. The systemic HPV infection was confirmed by PCR and Western blot analyses in freshwater crab. The expression of capsid protein gene in different organs of infected crab was revealed by RT‐PCR analysis. Indirect ELISA was used to quantify the capsid protein in different organs of the crab. The copy number of HPV in different organs of the infected crab was quantified by q‐PCR. The results revealed a steady decrease in C_T values in different organs of the infected crab during the course of infection. The viral inoculum that was prepared from different organs of the infected crab caused significant mortality in post‐larvae of tiger prawn, Penaeus monodon (Fabricius). The results revealed that this rice‐field crab could be used as an alternative host for HPV replication and also for large‐scale production of HPV.