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1.
Length‐weight and length‐length relationships were investigated for 13 freshwater fish species from the lower Jinsha River, southwest China (from 101°32′49.63″E; 26°35′38.27″N to 104°37′48.14″E; 28°45′59.55″N). Fish were sampled from five sites during 2014 and 2016, using trap‐nets, gillnets (major mesh size: 2–6 cm), longline and electrofishing. Length‐weight relationships for six and length‐length relationships for 12 species are the first report to FishBase, respectively. Moreover, new maximum length for 11 species are also presented to FishBase in this study. All regressions were highly significant (< .001), with the coefficient of determination r> .950. These information will be helpful for management and conservation in local fishes and fisheries.  相似文献   

2.
Length–weight relationships (LWRs) of three fish species: Scomberomorus commerson, Alepes vari, and A. kleinii were estimated from Kerala waters, south‐west coast of India. Fish were captured between June 2016 and June 2017 by various gears such as ring seine (8–26 mm mesh size), trawl (30–40 mm cod end mesh size), hook and line (hook number VI–XII), smaller mesh sized drift gill net (26–90 mm) and larger one (120–170 mm) for bigger size fishes. Fish were collected on weekly basis from Cochin Fisheries Harbour (Lat. 09°56′327″N, Long. 76°15′764″E), Munambam Fisheries Harbour (Lat. 10°10′965″N, Long. 76°10′258″E), Kalamukku (Lat. 09°59′924″N, Long. 76°14′564″E) and Chellanam (Lat. 09°47′950″N, Long. 76°16′551″E). All LWRs were significant with r2 values ranged from 0.944 to 0.996 and b values ranged from 2.722 to 3.021 (< .001). In addition, this study provides the information on LWRs and new maximum size for Alepes vari and A. kleinii.  相似文献   

3.
Abstract

ID NOE 1H NMR spectroscopy at 500 MHz was employed to examine the structure of poly(dA)·poly(dT) in solution. NOE experiments were conducted as a function of presaturation pulse length (50, 30, 20 and 10 msec) and.power (19 and 20 db) to distinguish the primary NOEs from spin diffusion. The 10 msec NOE experiments took 49 hrs and over 55,000 scans for each case and the difference spectra were almost free from diffusion.

The spin diffused NOE difference spectra as well as difference NOE spectra in 90% H2O + 10% D2O in which TNH3 was presaturated enabled to make a complete assignment of the base and sugar protons. It is shown that poly(dA) ·poly(dT) melts in a fashion in which single stranded bubbles are formed with increasing temperature.

Extremely strong primary NOEs were observed at H2′/H2″ when AH8 and TH6 were presaturated. The observed NOEs at AH2′ and that AH2″ were very similar as were the NOEs at TH2′ and TH2″. The observed NOEs at AH2′ and AH2″when AH8 was presaturated were very similar to those observed at TH2′ and TH2″ when TH6 was presaturated. In addition, presaturation of H1′ of A and T residues resulted in similar NOEs at AH2′/H2″ and TH2′/H2″ region and these NOEs at H2′ and H2″ were distinctly asymmetric as expected in a C2′-endo sugar pucker. There was not a trace of NOE at AH8 and TH6 when AH3′ and TH3′ were presaturated indicating that C3′-endo, × = 30–40° conformation is not valid for this DNA. From these NOE data, chemical shift shielding calculations and stereochemistry based computer modellings, we conclude that poly(dA)·poly(dT) in solution adopts a right- handed B-DNA duplex in which both dA and dT strands are conformationally equivalent with C2′-endo sugar pucker and a glycosyl torsion, ×, of ?73°, the remaining backbone torsion angles being φ′ = 221°, ω′ = 212°, ω = 310°, φ = 149°, ψ = 42°, ψ′ = 139°. The experimental data are in total disagreement with the heteronomous DNA model of Arnott et. al. proposed for the fibrous state. (Arnott, S., Chandrasekaran, R., Hall, I.H., and Puigjaner, L.C., Nucl. Acid Res. 11, 4141, 1983).  相似文献   

4.
Length‐weight relationships (LWRs) for three fish species from the River Ganga (India) is presented. Sampling was conducted from the lower stretch of the River Ganga (Patna: 25°36′51.66″N & 85°12′7.02″E to Freserganj: 21°35′40.58″N & 88°15′28.92″E) during April, June and September and December of 2017. Specimens were caught using gill nets (18 nos.; mesh 18–32 mm), and bag nets (3 nos.; mesh 14–22 mm). The values a and b from LWRs ‐were found to be 0.007 and 2.977 for Eutropiichthys murius; 0.003 and 3.001 for Coilia reynaldi; 0.009 and 3.010 for Johnius gangeticus.  相似文献   

5.
Arsenite‐tolerant bacteria were isolated from an organic farm of Navsari Agricultural University (NAU), Gujarat, India (Latitude: 20°55′39.04″N; Longitude: 72°54′6.34″E). One of the isolates, NAU‐1 (aerobic, Gram‐positive, non‐motile, coccobacilli), was hyper‐tolerant to arsenite (AsIII, 23 mM) and arsenate (AsV, 180 mM). 16S rRNA gene of NAU‐1 was 99% similar to the 16S rRNA genes of Rhodococcus (Accession No. HQ659188). Assays confirmed the presence of membrane bound arsenite oxidase and cytoplasmic arsenate reductase in NAU‐1. Genes for arsenite transporters (arsB and ACR3(1)) and arsenite oxidase gene (aoxB) were confirmed by PCR. Arsenite oxidation and arsenite efflux genes help the bacteria to tolerate arsenite. Specific activities of antioxidant enzymes (catalase, ascorbate peroxidase, superoxide dismutase and glutathione S‐transferase) increased in dose‐dependent manner with arsenite, whereas glutathione reductase activity decreased with increase in AsIII concentration. Metabolic studies revealed that Rhodococcus NAU‐1 produces excess of gluconic and succinic acids, and also activities of glucose dehydrogenase, phosphoenol pyruvate carboxylase and isocitrate lyase were increased, to cope with the inhibited activities of glucose‐6‐phosphate dehydrogenase, pyruvate dehydrogenase and α‐ketoglutarate dehydrogenase enzymes respectively, in the presence of AsIII. Enzyme assays revealed the increase in direct oxidative and glyoxylate pathway in Rhodococcus NAU‐1 in the presence of AsIII.  相似文献   

6.
Aims: To isolate a novel laccase gene from white‐rot fungus Polyporus grammocephalus TR16 and heterologous expression in Pichia pastoris. The characteristics of the heterologously expressed laccase are also studied. Methods and Results: Anchored PCR and 3′ RACE protocol were applied to obtain the full length of the laccase gene, which comprised 12 introns and an opening frame of 1769 bp. The deduced amino acid sequence of the laccase gene had an identity of 45–66% with the laccases reported previously. The cDNA was expressed in Pi. pastoris GS115 with native and α‐factor secretion signal peptides. The laccase activity obtained with the native signal peptide is threefold higher than that obtained with the α‐factor secretion signal peptide. The highest activity of the heterologously expressed laccase reached 893·3 U ml?1, with its molecular mass estimated to be 65·4 kDa by SDS‐PAGE. The purified heterologously expressed laccase was stable at a pH range of 7·0–10·0. The optimum pH and temperature were 4·5 and 50°C, respectively; the Km value for ABTS (3‐ethylbenzthiazoline‐6‐sulphonate) was 0·66 mmol l?1. Conclusion: The novel laccase gene is cloned successfully and heterologously expressed in Pi. pastoris. Significance and Impact of the Study: A novel laccase gene isolated from a tropical fungus serves as a good source for pulp bleaching and wood processing.  相似文献   

7.
Length–weight relationship (LWR) was estimated for 12 elasmobranch species; five shark species, four species of rays and three species of guitar fishes from north‐eastern Arabian Sea, India. Five major landing centres of Maharashtra were selected; Satpati (Lat. 19°43′15″N, Long. 72°42′00″E), Naigaon (Lat. 19°19′32″N, Long. 72°48′54″E), Versova (Lat. 19°08′33″N, Long. 72°48′11″E), New ferry Wharf (Lat. 18°57′29″N Long. 72°51′01″E) and Sassoon dock (Lat. 18°54′42″N, Long. 72°49′33″E). Samples were collected fortnightly during August 2016 to October 2017 from various gears; drift gill nets (Hung length 114–143 m and #100–270 mm) off Satpati coast at 35–50 m depth, dol nets (length 50–65 m and cod end # 30–69 mm) in Naigaon at 38–50 m depth and trawl (length 33–72 m and cod end # 17–32 mm) in Versova, New ferry Wharf and Sassoon dock operated at 20–50 m depth. Multiday fishing was carried out with 2–3 fishing trips in a month, each trip with duration of 7–13 days. Soaking time of gill net and dol net varied from 4 to 8 hr while each trawl haul lasted for 3–4 hr. Length–weight/Disc‐width‐weight relationship showed good fit with r2 values varying from 0.818 to 0.999. In addition to information on LWR, new maximum size for three species of elasmobranchs is reported in this paper.  相似文献   

8.
Escherichia coli is one of the most common pathogens in nosocomial and community-acquired infections in humans. Fosfomycin is a broad-spectrum antibiotic which inhibits peptidoglycan synthesis responsible for bacterial cell wall formation. Although low, the exact E. coli susceptibility to fosfomycin as well as the mechanisms of resistance in the population from Mainland China are mostly unknown. 1109 non-duplicate clinical E. coli strains isolated from urine, sputum, blood and pus samples in 20 widely dispersed tertiary hospitals from Mainland China were collected from July 2009 to June 2010, followed by determination of minimum inhibitory concentrations of fosfomycin. Detection of the murA, glpT, uhpT, fosA, fosA 3 and fosC genes was performed in fosfomycin non-susceptible E. coli strains and conjugation experiments were employed to determine the mobility of fosA 3 gene. In this study, 7.8% (86/1109) E. coli strains were fosfomycin non-susceptible. Amino acid substitutions in GlpT and MurA were found in six and four E.coli strains, respectively, while the uhpT gene was absent in eighteen E.coli strains. Twenty-nine isolates carried the transferable plasmid with the fosA 3 gene at high frequencies of around 10−6 to 10−7 per donor cell in broth mating. The majority of isolates were susceptible to fosfomycin, showing that the drug is still viable in clinical applications. Also, the main mechanism of E. coli resistance in Mainland China was found to be due to the presence of the fosA 3 gene.  相似文献   

9.
Molecular methods are a necessary tool for sexing monomorphic birds. These molecular approaches are usually reliable, but sexing protocols should be evaluated carefully because biochemical interactions may lead to errors. We optimized laboratory protocols for genetic sexing of a monomorphic shorebird, the upland sandpiper (Bartramia longicauda), using two independent sets of primers, P2/P8 and 2550F/2718R, to amplify regions of the sex‐linked CHD‐Z and CHD‐W genes. We discovered polymorphisms in the region of the CHD‐Z intron amplified by the primers P2/P8 which caused four males to be misidentified as females (n = 90 mated pairs). We cloned and sequenced one CHD‐W allele (370 bp) and three CHD‐Z alleles in our population: Z° (335 bp), Z (331 bp) and Z″ (330 bp). Normal (Z°Z°) males showed one band in agarose gel analysis and were easily differentiated from females (Z°W), which showed two bands. However, males heterozygous for CHD‐Z alleles (Z′Z″) unexpectedly showed two bands in a pattern similar to females. While the Z′ and Z″ fragments contained only short deletions, they annealed together during the polymerase chain reaction (PCR) process and formed heteroduplex molecules that were similar in size to the W fragment. Errors previously reported for molecular sex‐assignment have usually been due to allelic dropout, causing females to be misidentified as males. Here, we report evidence that events in PCRs can lead to the opposite error, with males misidentified as females. We recommend use of multiple primer sets and large samples of known‐sex birds for validation when designing protocols for molecular sex analysis.  相似文献   

10.
Length‐weight relationships (LWRs) for four fish species from the River Ganga (India) is presented. Sampling was conducted in the lower stretch of the river (Buxar: 25°33′43.90″N and 83°56′3.10″E to Freserganj: 21°35′40.58″N and 88°15′28.92″E) on tri‐monthly basis from September 2016 to December 2017. Specimens were caught in gill nets (mesh, 18–68 mm), cast nets (mesh, 12–14 mm), seine nets (mesh, 12–14 mm) and various traditional traps those were put over night and lifted in early morning. Total length and wet body weight of fish were measured to the nearest 0.1 cm and 0.01 g by a digital caliper and electronic balance respectively. From LWRs, the estimated b values were found to be 2.88 (Pisodonophis boro) to 3.17 (Gagata sexualis) whereas a value ranged from 0.001 (Pisodonophis boro) to 0.009 (Botia lohachata). As per FishBase, the species Gagata sexualis and Botia lohachata had new TLmax reported for LWR estimation.  相似文献   

11.
Length–weight (LWR) and length–length (LLR) relationships were estimated for specimens of two gobiid species collected from the Anzali Wetland and its related streams in the southern Caspian Sea basin, in August 2017. These represent the first reports of LWR and LLR data for Rhinogobius cf. similis Gill, 1859 (37°28′13″N, 49°20′33″E; 50 individuals) and Proterorhinus nasalis (De Filippi, 1863) (36°54′10.89″N, 53°48′48.33″E; 30 individuals) from the Wetland. A new maximum length is reported for P. nasalis. The length–weight parameter b for these species ranged a minimum of 2.99 for Rhinogobius cf. similis to a maximum of 3.04 for P. nasalis with regression coefficients (r2) ranging from .95 to .97. All LLRs were highly significant (r2>.96).  相似文献   

12.
Aims: To characterize a robust NAD+‐dependent formate dehydrogenase firstly obtained from a nonmethylotroph, Bacillus sp. F1. Methods and Results: The Bacillus sp. F1 NAD+‐dependent formate dehydrogenase (BacFDH) gene was cloned by TAIL‐PCR and heterologous expressed in Escherichia coli. BacFDH was stable at temperatures below 55°C, and the half‐life at 60°C was determined as 52·9 min. This enzyme also showed a broad pH stability and retained more than 80% of the activities after incubating in buffers with different pH ranging from 4·5 to 10·5 for 1 h. The activity of BacFDH was significantly enhanced by some metal ions. Moreover, BacFDH exhibited high tolerance to 20% dimethyl sulfoxide, 60% acetone, 10% methanol, 20% ethanol, 60% isopropanol and 20% n‐hexane. Like other FDHs, BacFDH displayed strict substrate specificity for formate. Conclusion: We isolated a robust formate dehydrogenase, designated as BacFDH, which showed excellent thermal stability, organic solvent stability and a broad pH stability. Significance and Impact of the Study: The multi‐aspect stability makes BacFDH a competitive candidate for coenzyme regeneration in practical applications of chiral chemicals and pharmaceuticals synthesis with a relatively low cost, especially for the catalysis performed in extreme pH conditions and organic solvents.  相似文献   

13.
Length‐weight relationship parameters were calculated for six fish species from São Marcos Bay, in Northeast Brazil (the segment between 02°35′55″S and 44°20′58″W; 02°34′53″S and 44°21′48″W; 02º42′25″S and 44º26′46″W). The specimens were caught quarterly from April 2010 to February 2013, using monofilament gillnets (2, 4 and 6 cm between knots) from 100 m to 3,000 m long and 4 m to 6 m high. The present study covers a much wider size range for four species and adds new information for the maximum length of Notarius bonillai.  相似文献   

14.
Coicis semen (=the hulled seed of Coix lacryma‐jobi L. var. ma‐yuen (Rom.Caill. ) Stapf ; Gramineae), commonly known as adlay and Job's tears, is widely used in traditional medicine and as a nutritious food. Bioassay‐guided fractionation of the AcOEt fraction of unhulled adlays, using measurement of nitric oxide (NO) production on lipopolysaccharide (LPS)‐stimulated RAW 264.7 macrophage cells, led to the isolation and identification of two new stereoisomers, (+)‐(7′S,8′R,7″S,8″R)‐guaiacylglycerol βO‐4′‐dihydrodisinapyl ether ( 1 ) and (+)‐(7′S,8′R,7″R,8″R)‐guaiacylglycerol βO‐4′‐dihydrodisinapyl ether ( 2 ), together with six known compounds, 3 – 8 . Compounds 3 and 4 exhibited inhibitory activities on LPS‐induced NO production with IC50 values of 1.4 and 3.7 μM , respectively, and suppressed inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2) protein expressions in RAW 264.7 macrophage cells. Simple high‐performance liquid chromatography with ultraviolet detection (HPLC/UV) was used to compare the AcOEt fraction of unhulled adlays responsible for the anti‐inflammatory activity in RAW 264.7 cells and the inactive AcOEt fraction of hulled adlays.  相似文献   

15.
Aims: To isolate and characterize a potent molybdenum‐reducing bacterium. Methods and Results: A minimal salt medium supplemented with 10 mmol l?1 molybdate, glucose (1·0%, w/v) as a carbon source and ammonium sulfate (0·3%, w/v) as a nitrogen source was used in the screening process. A molybdenum‐reducing bacterium was isolated and tentatively identified as Pseudomonas sp. strain DRY2 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. Strain DRY2 produced 2·4, 3·2 and 6·2 times more molybdenum blue compared to Serratia marcescens strain DRY6, Enterobacter cloacae strain 48 and Eschericia coli K12, respectively. Molybdate reduction was optimum at 5 mmol l?1 phosphate. The optimum molybdate concentration that supported molybdate reduction at 5 mmol l?1 phosphate was between 15 and 25 mmol l?1. Molybdate reduction was optimum at 40°C and at pH 6·0. Phosphate concentrations higher than 5 mmol l?1 strongly inhibited molybdate reduction. Inhibitors of electron transport system such as antimycin A, rotenone, sodium azide and cyanide did not inhibit the molybdenum‐reducing enzyme activity. Chromium, copper, mercury and lead inhibited the molybdenum‐reducing activity. Conclusions: A novel molybdenum‐reducing bacterium with high molybdenum reduction capacity has been isolated. Significance and Impact of the Study: Molybdenum is an emerging global pollutant that is very toxic to ruminants. The characteristics of this bacterium suggest that it would be useful in the bioremediation of molybdenum pollutant.  相似文献   

16.
Aims: The objective was to study the response of Cronobacter sakazakii ATCC 29544 cells to heat, pulsed electric fields (PEF), ultrasound under pressure (Manosonication, MS) and ultraviolet light (UV‐C) treatments after exposure to different sublethal stresses that may be encountered in food‐processing environments. Methods and Results: Cronobacter sakazakii stationary growth‐phase cells (30°C, 24 h) were exposed to acid (pH 4·5, 1 h), alkaline (pH 9·0, 1 h), osmotic (5% NaCl, 1 h), oxidative (0·5 mmol l?1 H2O2, 1 h), heat (47·5°C, 1 h) and cold (4°C, 4 h) stress conditions and subjected to the subsequent challenges: heat (60°C), PEF (25 kV cm?1, 35°C), MS (117 μm, 200 kPa, 35°C) and UV‐C light (88·55 mW cm?2, 25°C) treatments. The inactivation kinetics of Csakazakii by the different technologies did not change after exposure to any of the stresses. The combinations of sublethal stress and lethal treatment that were protective were: heat shock–heat, heat shock–PEF and acid pH–PEF. Conversely, the alkaline shock sensitized the cells to heat and UV‐C treatments, the osmotic shock to heat treatments and the oxidative shock to UV‐C treatments. The maximum adaptive response was observed when heat‐shocked cells were subjected to a heat treatment, increasing the time to inactivate 99·9% of the population by 1·6 times. Conclusions: Cronobacter sakazakii resistance to thermal and nonthermal preservation technologies can increase or decrease as a consequence of previous exposure to stressing conditions. Significance and Impact of the Study: The results help in understanding the physiology of the resistance of this emerging pathogen to traditional and novel preservation technologies.  相似文献   

17.
This study provides the first measurements of the standard respiration rate (RS) and growth dynamics of European sardine Sardina pilchardus larvae reared in the laboratory. At 15° C, the relationship between RS (µl O2 individual?1 h?1) and larval dry mass (MD, µg) was equal to: RS = 0·0057(±0·0007, ± s.e.)·MD0·8835(±0·0268), (8–11% MD day?1). Interindividual differences in RS were not related to interindividual differences in growth rate or somatic (Fulton's condition factor) or biochemical‐based condition (RNA:DNA).  相似文献   

18.
Conjugal transferability of drug resistance was examined, in eleven Pseudomonas aeruginosa strains which were isolated in Frankfurt. Four R factors were demonstrated from three strains using P. aeruginosa as recipients but they were nontransferable to Escherichia coli K12. Two R factors, i.e., Rms146 and Rms147, mediated resistances to tetracycline (TC), streptomycin (SM), sulfanilamide (SA), kanamycin (KM), lividomycin (LV), gentamicin C complex (GM) and 3′,4′-dideoxykanamycin B (DKB). They mediated the formation of aminoglycoside-inactivating enzymes, i.e., SM phosphotransferase, SM adenylyltransferase, KM and LV phosphotransferase 1, and GM and DKB 6′-N-acetyltransferase. TC resistance conferred by these R factors was due to impermeability of the drug. P. aeruginosa Ps 142 carried two kinds of R factor in one cell, Rms148 (SM) and Rms149 (SM·SA·GM·CPC) (CPC, carbenicillin). Rms148 (SM) was transferable at a high frequency of 10–1 and mediated the formation of SM phosphotransferase. Rms149 mediated the formation of drug-inactivating enzymes, i.e., GM 3-N-acetyltransferase and β-lactamase, but did not inactivate SM. SM resistance was probably due to impermeability of the drug.  相似文献   

19.
This investigation prepares the length–weight relationships (LWRs) of two fish species, including Alburnoides nicolausi (Bogutskaya & Coad, 2009) and Alburnus zagrosensis (Coad, 2009) from Houzian River (latitude 33°22′15.20″ to 33°21′31.57″N; longitude 49°44′39.66″ to 49°44′17.67″E), Lorestan province, Iran. Fish specimens were collected monthly using seine net with 5 mm (Stretched) mesh size between April to September 2017. The LWRs for fish species were W = 0.0059L3.405 (male) and W = 0.0053L3.494 (female) for A. nicolausi, W = 0.0035L3.341 (male) and W = 0.003L3.387 (female) for A. zagrosensis, respectively. The highest value of r2 was .931 for male of A. zagrosensis and lowest value was .964 for male of A. nicolausi.  相似文献   

20.
Present study provides length–weight relationships (LWRs) and length–length relationships (LLRs) of eight fish species from river Ganga, India. Specimens were sampled from gill nets (mesh, 22–120 mm), cast nets (mesh, 12–14 mm), and seine nets (mesh, 12 mm) on quarterly basis from September 2016 to September 2017 within the river stretch from Buxar (25°33′43.90″N and 83°56′3.10″E) to Freserganj (21°35′40.58″N and 88°15′28.92″E). The b value ranged from 2.86 (Otolithoides pama) to 3.08 (Polynemus paradiseus), whereas a value ranged from 0.004 (P. paradiseus) to 0.016 (Rita rita). Both relationships (LWRs and LLRs) were found to be highly correlated (p < .001). This study provides first report on LWR for Amblyceps mangois and Osteobrama cotio, whereas new maximum length recorded for Macrognathus pancalus. Furthermore, the estimate of R. rita should be considered as tentative because of the limited size range in the study.  相似文献   

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