The haemoglobins of Labeo umbratus (Smith) and Labeo capensis (Smith)

The haemoglobins of both L. umbratus and L. capensis separated into four components on polyacrylamide electrophoresis. The isoelectric points of these fractions were found to be 9.35, 6.89, 6.63 and 6.40. Organic nucleotide triphosphate concentration in the blood of L. capensis was found to be 56.72 ± 18.01 mg% and 58.72 ± 17.9 mg% in the case of L. umbratus . It is not possible to distinguish between L. umbratus and L. capensis purely on the basis of the haemoglobin electropherogram.     

The effects of toxicants on the haematology of Labeo umbratus (Teleostei: Cyprinidae)

The haematology of Labeo umbratus (Smith) was investigated after exposure to four toxicants under controlled static conditions. Statistically significant changes exist between the values of parameters of experimental and control fish. The concentration of haemoglobin fractions changes with different toxicants. Electrophoretograms of plasma proteins showed changing patterns as well as a decrease in fraction numbers.     

Blood respiratory properties of the mudsucker fish Labeo capensis (Smith)

For Labeo capensis (Smith) the increase in blood organic phosphates (ATP, GTP) in winter fish exceeds the increase in summer fish. Blood chlorides, blood osmotic pressure, hematocrit and hemoglobin concentration decrease significantly in winter fish when compared to summer fish. Four effectors, viz. temperature, organic phosphates, H+ and Cl-, could lower the oxygen affinity of whole blood, especially in summer fish.     

The haematology of Rohu, Labeo rohita

Haematocrit values, haemoglobin concentration, erythrocyte counts, leucocyte counts, erythrocyte sedimentation rate and clotting time of Labeo rohita were determined. The variations in haematological parameters in relation to the size and weight of the fish were also examined. Males had higher haematological values than the females. Seasonal and variations due to maturation of gonads were also apparent.     

Hematological and plasma chemistry of Indian major carp,Labeo rohita (Hamilton, 1822)

Hematological and plasma chemistry indices are simple and essential diagnostic tools for monitoring the physiological and health status of fish. Aim of the present study was to obtain reference values for the hematological and plasma chemistry of wild populations of Labeo rohita captured in a freshwater pond between July 2008 and June 2010. These reference values and the mean were evaluated according to sex and season. In summer, the red blood cells (1.84 × 106 38 per cubic mm), haemoglobin (8.52 gm dl^?1) and haematocrit (31.49%) were highest in males, whereas the maximum values for white blood cells (5.635 × 103 40 per cubic mm) were found in females, however, no significant variation of mean corpuscular volume (MCV) or mean corpuscular haemoglobin (MCH) was observed between sexes. Various blood parameter levels between the sexes in summer were notably different from those measured in other seasons except for MCH and MCHC values (p < 0.05). Compared to most teleosts, the L. rohita has similar mean values for PCV and Hb. Throughout summer the glucose (76.0 mg dl^?1), lipid (3.41 gm dl^?1) and cholesterol (145.0 mg dl^?1) levels were highest. In spring the plasma protein levels were higher in males, but higher in winter for females. Consequently, the seasons are key factors when using blood parameters as biomarkers for environmental alterations.     

Polarity-Dependent Misperception of Subjective Visual Vertical during and after Transcranial Direct Current Stimulation (tDCS)

Pathologic tilt of subjective visual vertical (SVV) frequently has adverse functional consequences for patients with stroke and vestibular disorders. Repetitive transcranial magnetic stimulation (rTMS) of the supramarginal gyrus can produce a transitory tilt on SVV in healthy subjects. However, the effect of transcranial direct current stimulation (tDCS) on SVV has never been systematically studied. We investigated whether bilateral tDCS over the temporal-parietal region could result in both online and offline SVV misperception in healthy subjects. In a randomized, sham-controlled, single-blind crossover pilot study, thirteen healthy subjects performed tests of SVV before, during and after the tDCS applied over the temporal-parietal region in three conditions used on different days: right anode/left cathode; right cathode/left anode; and sham. Subjects were blind to the tDCS conditions. Montage-specific current flow patterns were investigated using computational models. SVV was significantly displaced towards the anode during both active stimulation conditions when compared to sham condition. Immediately after both active conditions, there were rebound effects. Longer lasting after-effects towards the anode occurred only in the right cathode/left anode condition. Current flow models predicted the stimulation of temporal-parietal regions under the electrodes and deep clusters in the posterior limb of the internal capsule. The present findings indicate that tDCS over the temporal-parietal region can significantly alter human SVV perception. This tDCS approach may be a potential clinical tool for the treatment of SVV misperception in neurological patients.     

Physical characteristics of the blood plasma of Labeo ruddi and Labeo rosae (Pisces: Cyprinidae).

1. The physical composition of blood plasma of Labeo ruddi and Labeo rosae males were determined during the breeding and post breeding phases. 2. The mean values for most blood electrolytes, pH and osmolality of the two species showed the same variation as was found for other cyprinids. 3. The ability to handle stress may be reflected in the presence of certain electrolytes in the blood and efforts are made to relate differences in the concentration of these parameters to interspecies differences between L. ruddi and L. rosae.     

Parenteral immunization of fish,Labeo rohita with Poly d,l-lactide-co-glycolic acid (PLGA) encapsulated antigen microparticles promotes innate and adaptive immune responses

Immunogenicity of different antigen preparations of outer membrane proteins (OMP) of Aeromonas hydrophila such as Poly d, l-lactide-co-glycolic acid (PLGA) microparticles, oil emulsion, neat OMP and bacterial whole cells were compared through intra-peritoneal injection in fish, Labeo rohita. Among these preparations, PLGA encapsulated antigen stimulated both innate and adaptive immune parameters and the immunogenicity exhibited by PLGA microparticles was significantly higher (p < 0.05) at both 21 and 42 days post-immunization suggesting that the above delivery system would be a novel antigen carrier for parenteral immunization in fish, Labeo rohita     

The plasma proteins of Labeo umbratus (Smith) and Labeo capensis (Smith)

The plasma proteins of L. umbratus and L. capensis have been investigated by means of cellulose-acetate and polyacrylamide gel electrophoresis. Characteristic patterns were obtained for each specie although variations occur within a certain basic framework. Certain fractions were further isolated and approximate average molecular weights were found to vary between 55 000 and above 120 000 and isoelectric points between 5.78 and 4.2. Certain fractions were found to exist in dimeric form. It is concluded that the application of the human nomenclature to fish plasma protein fractions is of dubious value and that the fish fractions can only be classified after thorough biochemical investigation.     

Annual cyclical changes in the testicular activity of an Indian freshwater major carp, Labeo rohita (Hamilton)

Different male germ cells identified on the basis of histological and cytological characteristics in the testicular lobules of Labeo rohita have been grouped into spermatogonia, primary spermatocytes, secondary spermatocytes, spermatids and spermatozoa. The seasonal changes of the testis in L. rohita have been described according to its morphological peculiarities as well as to its variations in gonadal volumes, GSI values and frequency percentages of the different male germ cells occurring in the testicular lobules. Consequently, the entire testicular cycle in L. rohita may be categorised into 4 distinct phases viz., growth, maturation of pre-spawning, spawning, and resting or post-spawning phases.     

Labeo rosae (Cypriniformes: Cyprinidae) in the Congo basin: a relict distribution or a historical introduction?

Labeo rosae, a species with a native range in Southern Africa, was discovered in the Congo basin by re‐identification of two museum specimens previously identified as Labeo mesops. The occurrence of this species in the upper Congo implies a range extension of the species of more than 1000 km. Although the species' distribution is mirrored by that of some other Cypriniformes, its occurrence in the Congo might be due to introduction by humans.     

Electrokinetic movement of Escherichia coli in capillaries

The movement of Escherichia coli K-12 has been studied in capillaries with an 8 μm inside diameter under a DC electric field. At low applied voltages (< 0.2 V cm⁻¹), bacterial motility is the predominant mode of motion, with bacteria swimming, tumbling and moving unidirectionally towards the anode and the cathode, although a significant difference between the mean moving speeds towards the two electrodes was observed. When the electric field was removed, the mean swimming speeds were the same for both directions. At higher voltages, all the cells were swept by electro-osmotic flow exclusively towards the cathode.     

Enzymatic biofuel cell based on anode and cathode powered by ethanol

Enzymatic biofuel cell based on enzyme modified anode and cathode electrodes are both powered by ethanol and operate at ambient temperature is described. The anode of the presented biofuel cell was based on immobilized quino-hemoprotein-alcohol dehydrogenase (QH-ADH), while the cathode on co-immobilized alcohol oxidase (AOx) and microperoxidase (MP-8). Two enzymes AOx and MP-8 acted in the consecutive mode and were applied in the design of the biofuel cell cathode. The ability of QH-ADH to transfer electrons directly towards the carbon-based electrode and the ability of MP-8 to accept electrons directly from the same type of electrodes was exploited in this biofuel cell design. Direct electron transfer (DET) to/from enzymes was the basis for generating an electric potential between the anode and cathode. Application of immobilized enzymes and the harvesting of the same type of fuel at both electrodes (cathode and anode) avoided the compartmentization of enzymatic biofuel cell. The maximal open circuit potential of the biofuel cell was 240mV.     

Electrotropism of Maize (Zea mays L.) Roots (Facts and Artifacts)

Intact and decapped primary roots of maize (Zea mays L.) were exposed to DC electric fields of 0.5 to 8.0 V/cm in low-salinity media to resolve conflicting results about the direction of electrotropism. In DC fields of 0.5 V/cm or 1.0 V/cm, intact roots always curved toward the cathode. In a field of 8.0 V/cm, intact roots curved toward the anode and stopped growth. Decapped roots also curved toward the anode both in weak and strong fields. The results indicate that growth toward the cathode is the true response of healthy roots.     

Input-output relationship in galvanotactic response of Dictyostelium cells

Under a direct current electric field, Dictyostelium cells exhibit migration towards the cathode. To determine the input-output relationship of the cell's galvanotactic response, we developed an experimental instrument in which electric signals applied to the cells are highly reproducible and the motile response are analyzed quantitatively. With no electric field, the cells moved randomly in all directions. Upon applying an electric field, cell migration speeds became about 1.3 times faster than those in the absence of an electric field. Such kinetic effects of electric fields on the migration were observed for cells stimulated between 0.25 and 10 V/cm of the field strength. The directions of cell migrations were biased toward the cathode in a positive manner with field strength, showing galvanotactic response in a dose-dependent manner. Quantitative analysis of the relationship between field strengths and directional movements revealed that the biased movements of the cells depend on the square of electric field strength, which can be described by one simple phenomenological equation. The threshold strength for the galvanotaxis was between 0.25 and 1 V/cm. Galvanotactic efficiency reached to half-maximum at 2.6 V/cm, which corresponds to an approximate 8 mV voltage difference between the cathode and anode direction of 10 microm wide, round cells. Based on these results, possible mechanisms of galvanotaxis in Dictyostelium cells were discussed. This development of experimental system, together with its good microscopic accessibility for intracellular signaling molecules, makes Dictyostelium cells attractive as a model organism for elucidating stochastic processes in the signaling systems responsible for cell motility and its regulations.     

Electrokinetic movement and biodegradation of 2,4-dichlorophenoxyacetic acid in silt soil

The coupling of electrokinetic movement of an organic contaminant, 2,4-dichlorophenoxyacetic acid (2,4-D), through soil and its biodegradation in situ has been demonstrated. In a first experiment, the direction and rate of movement of 2,4-D were determined using homogeneously contaminated soil (864 mg 2,4-D/kg dry weight soil) compacted into six individual compartments, 6 cm long, 3 cm wide, and 4 cm deep. Each compartment was bordered by a carbon felt anode and a stainless steel cathode. The application of a current density of 3.72 A/m(2) led to migration of 2,4-D towards the anode at a rate of approximately 4 cm/day. In a second experiment, electrokinetic movement and biodegradation were combined in situ. Sterilized silt soil contaminated with ring-labeled 14C-2,4-D (811 mg 2,4-D/kg dry weight soil) was compacted into a single soil compartment, 22 cm long, 7 cm wide, and 4 cm deep, in a 4.5 cm region adjacent to the cathode. The remainder of the compartment was filled with sterilized soil (to a total weight of 1,015 g). Burkholderia spp. RASC c2 (1.88 x 10(11) cells), a tetracycline-resistant bacterium with chromosomally encoded degradative genes for 2,4-D, was inoculated into the soil at a position 14-16 cm from the cathode. The reactor was placed within a sealed perspex box, with a constant air flow connected to sodium hydroxide traps. Under an applied current density of 0.89 A/m(2), the pollutant moved towards the bacteria. As it reached the inoculated region, its concentration decreased in the soil and 14CO2 was recovered in the traps. At the end of the experiment, 87.1% of radiolabel had been removed from the soil, 5.8% of which was recovered as 14CO2. A third, control, experiment showed a significant contrast in the absence of an electric current, where a slow rate of diffusion controlled the movement of both 2,4-D and bacteria in the soil and biodegradation occurred at the interface between the diffusing fronts.     

Fish (Labeo rohita) Scales as Potential Low-Cost Biosorbent for Removal of Malachite Green from Aqueous Solutions

The feasibility of using fish (Labeo rohita) scales as low-cost biosorbent for the removal of hazardous Malachite Green (MG) dye from aqueous solutions was investigated. Employing a batch experimental setup, the effect of operational parameters such as biosorbent dose, initial solution pH, contact time, and temperature on the dye removal process was studied. The equilibrium biosorption data followed both Langmuir and Freundlich isotherm models, whereas the experimental kinetic data fitted well to the pseudo-second-order kinetic model. Thermodynamic study indicated spontaneous and endothermic nature of the biosorption process. The results suggest that fish scales could be used as an effective biosorbent for removal of MG dye from aqueous solutions.     

Descriptive morphology of early developmental stages of laboratory-reared black sharkminnow Labeo chrysophekadion (Cypriniformes: Cyprinidae)

Ichthyological Research - In this study, we describe the morphological development of laboratory-reared black sharkminnow Labeo chrysophekadion larvae and juveniles. The body lengths (BL) were...     

The growth of PC-12 neurites is biased towards the anode of an applied electrical field

We have exposed cultures of PC12 cells to uniform DC electric fields following the addition of NGF. The success of these experiments relied upon the design of new chambers enabling fields to be applied to mammalian cell cultures. After 48 h of field application, the distribution of neurite outgrowths was biased towards the anode. More neurites faced the anode than would be expected if growth was uniform. The magnitude of this bias was strongly correlated with field strenght, with a threshold value of about 1 mV/mm. At field strengths above 30 mV/mm, the neurites growing towards the cathode were shorter than those growing towards the anode or perpendicular to the field. This response was not correlated with field strenght. This report confirms that mammalian neurons respond to electrical fields and supports the notion that neurites are influenced by endogenous electrical fields during development. As far as we are aware, this is the only report the documents a response towards the anode. 1994 John Wiley & Sons, Inc.     

Purification of intact chloroplasts from spruce (Picea abies) by free-flow electrophoresis

Highly purified chloroplasts were isolated from spruce ( Picea abies [L.] Karst.) needles by free-flow electrophoresis. The chloroplast crude suspension was separated into two structurally different populations. The two populations could not be distinguished according to their protein/chlorophyll ratios and protein patterns from two-dimensional gel electrophoresis. The O² evolution, however, showed differences: the chloroplast population deflected towards the cathode contained a major part of structurally intact chloroplasts in contrast to the population deflected towards the anode. The two populations were not contaminated by endoplasmatic membranes or mitochondria.