Growth and proximate composition of the Chaetoceros calcitrans f. pumilus under different temperature, salinity and carbon dioxide levels

The marine diatom Chaetoceros calcitrans f. pumilus has been examined for its potential source as live feed in aquaculture. The present study investigated effects of temperature (20, 25 and 30 °C), salinity (25 and 35) and carbon dioxide addition (air+CO₂) on the growth and proximate composition of C. calcitrans under laboratory conditions. The growth and biomass of C. calcitrans were primarily affected by carbon dioxide addition, and to a lesser extent by temperature and salinity. In general, lipid and carbohydrate contents were higher at lower temperatures (20 and 25 °C), while the protein content was unaffected. Carbon dioxide addition increased protein, while lowering carbohydrates, but had no effect on lipid content. Carbohydrates were increased while lipids and protein decreased at the highest salinity (35±0.9). These results should be taken into consideration when evaluating the dietary value of this micro alga for aquaculture.     

Biochemical and Microbiological Assessment of Crucifix Crab (Charybdis feriatus) Stored at 4°C

Charybdis feriatus is a highly prized crab in the local and international markets of East Asian countries. In local markets, crabs are sold live, iced, or refrigerated at 2°C – 4°C. The present study was carried out to determine the shelf life of whole crab stored at 4°C for 192 h using a set of biochemical, microbiological, and sensorial parameters. Biochemical indicators such as the total volatile base nitrogen (TVB-N) and trimethylamine nitrogen (TMA-N) increased significantly during storage and within an acceptable limit up to 144 h. Regarding the biogenic amines, cadaverine and spermidine increased significantly (p < 0.05) during the storage period. Among them, cadaverine could be proposed as a useful spoilage indicator for this crab species. The mesophilic and psychotropic bacterial count exceeded the limit of acceptance after 144 h of storage. Sensory attributes were gradually diminished with the storage time. Sensory scores were found to correlate well with both mesophiles and psychrotrophs. Based on the results of this study, the meat quality of Charybdis feriatus can be maintained up to 144 h when properly stored at a temperature of 4°C ± 1°C.     

Genetic variation among highly endangered <Emphasis Type="Italic">Bacopa monnieri</Emphasis> (L.) Pennell from Southern India as detected using RAPD analysis

Randomly amplified polymorphic DNA (RAPD) fingerprinting approach was applied to assess genetic diversity in different accessions of rejuvenating and intellect-promoting ancient ayurvedic medicinal herb Bacopa monnieri (L.) Pennell collected from four Southern Indian states, along with in vitro micropropagated samples maintained in the laboratory for 5 years. With the 10 analyzed primers, 110 distinct bands, in the size range of 250–870 bp were observed, and among which 14 (12.72%) were polymorphic. Among the random primers used, only OPD 02 generated highest percentage of polymorphism with 30.77. Whereas OPD 08 generated a maximum of 18 amplified bands, but with only 1% polymorphism. Cluster analysis done on the basis of similarity co-efficient generated from RAPD profiles indicated all the accessions were divided into two sub-groups based on genetic distances under one major cluster. Major cluster is only the lone loose group of the Bm.2 collected from Kerala (KER) and in vitro micropropagated plant (IVMP) maintained in the lab. The other sub-group consisted of Bm.1 and Bm.3 collected from Tamil Nadu (TN) and Andhra Pradesh (AP) respectively, which are genetically similar and showed similarity with accessions from Karnataka Bm.4 (KK). These two sub-groups were joined together at 0.66 genetic distance level. Overall, the levels of genetic similarity within the accessions varied from 0.24 to 0.80, the matrix ranged from 0.36 to 0.80, with a mean value of 0.68 indicating genetic similarity at low level.     

Quantification of seasonal sediment and phosphorus transport dynamics in an agricultural watershed using radiometric fingerprinting techniques

Purpose

Phosphorus (P) is a limiting nutrient for most US Midwestern aquatic systems and, therefore, increases of P, through point or non-point sources (NPS) of pollution such as agriculture, causes eutrophication. Identifying specific NPS contributions (e.g., upland vs. stream channels) for sediments and P is difficult due to the distributed nature of the pollution. Therefore, studies which link the spatial and temporal aspects of sediment and P transport in these systems can help better characterize the extent of NPS pollution.

Materials and methods

Our study used fingerprinting techniques to determine sources of sediments in an agricultural watershed (the North Fork of the Pheasant Branch watershed; 12.4 km² area) in Wisconsin, USA, during the spring, summer, and fall seasons of 2009. The primary sources considered were uplands (cultivated fields), stream bank, and streambed. The model used fallout radionuclides, ¹³⁷Cs, and ²¹⁰Pb_xs, along with total P to determine primary sediment sources. A shorter-lived fallout radioisotope, ⁷Be, was used to determine the sediment age and percent new sediments in streambed and suspended sediment samples (via the ⁷Be/²¹⁰Pb_xs ratio).

Results and discussion

Upland areas were the primary source of suspended sediments in the stream channels followed by stream banks. The sediment age and percent new sediment for the streambed and suspended sediments showed that the channel contained and transported newer (or more recently tagged with ⁷Be) sediments in the spring season (9–131 days sediment age), while relatively old sediments (165–318 days) were moving through the channel system during the fall season.

Conclusions

Upland areas are the major contributors to in-stream suspended sediments in this watershed. Sediment resuspension in stream channels could play an important role during the later part of the year. Best management practices should be targeted in the upland areas to reduce the export of sediments and sediment-bound P from agricultural watersheds.     

Peptidase inhibitor from Mucuna pruriens seeds inhibits the growth and development of Zeugodacus cucurbitae larvae

Phytoparasitica - Zeugodacus cucurbitae (Coquillett) is an economically significant destructive pest of many vegetable and fruit crops. Peptidase inhibitors are a class of plant proteins that cause...     

Persistence of serum antibodies to Sarcocystis neurona in horses moved from North America to India

BACKGROUND: The study reported here was undertaken to assess the presence of antibodies to Sarcocystis neurona in the serum of horses of North American origin that had been relocated for 1 year or more to India (ie, outside of the known endemic areas for S. neurona). HYPOTHESIS: The presence or absence of such antibodies should provide information concerning the persistence of such antibodies, or support the presence of chronic infection, or both. ANIMALS: A total of 228 Thoroughbred horses were sampled in India, of which 86 were of North American origin that had been in India between 1 and 13 years, 124 were Indian-born horses that had never been out of India, 8 were of Irish origin, 8 were of English origin, and 2 were originally from France. METHODS: Sera were tested using established western blot analysis. RESULTS: Of the Indian-born horses, 0.8% were test positive, and of the North American horses, 42% were test positive. All of the English and Irish horses were test negative, and the 2 French horses were test positive. CONCLUSIONS AND CLINICAL IMPORTANCE: These data indicate that antibodies against S. neurona can be detected for many years after horses have been removed from an endemic area and that this may be attributable to long half-life of the antibodies or to chronic infection and ongoing antibody production, or both.     

EPR studies on gamma-irradiated barley seeds: identification of trapped electrons.

Electron paramagnetic resonance (EPR) studies were conducted on barley seeds exposed to normal (H(2)O) and deuterated (D(2)O) moisture, irradiated with 750 Gy at 77 K. Reported here, for the first time, are the trapped electrons formed on gamma-irradiation of seeds at 77 K. Electrons are stabilized/solvated with an increase in the moisture content (H(2)O/D(2)O) of seeds. The recombination of the trapped electron with radical cation gave intense thermoluminescence emission at 110 K. With the increase in temperature and the destruction of singlet, unmasking of an underlying heterogeneous population of free radicals was observed. These free radicals emanate mainly from the endosperm (approximately 95% by wt of the seed), whereas irradiated embryos show a broad multiplet of comparatively low amplitude. Radiolysis of carbohydrate, proteins (approximately 95% of endosperm), and lipids could possibly be responsible for the heterogeneous population of free radicals. Peroxyl radicals were also observed on annealing.     

Anti-viral activity of methyl 1-chloro-7-methyl-2-propyl-1h-benzo[d] imidazole-5-carboxylate against white spot syndrome virus in freshwater crab (Paratelphusa hydrodromous)

Shrimp farming industries are subjected to severe economic loss due to a disease called white spot syndrome, a viral disease caused by white spot syndrome virus (WSSV) in penaeid shrimp. Numerous active compounds in the market possess anti-viral activity against the white spot syndrome virus, yet the issue remains unsolved. The present study was carried out to determine the anti-viral activity of methyl 1-chloro-7-methyl-2-propyl-1h-benzo[d] imidazole-5-carboxylate (C₁₃H₁₅N₂O₂Cl) against WSSV. The anti-viral activity of the synthetic compound was determined in freshwater crabs. Crabs were divided into three different experimental groups: healthy control groups (N.C.) received NTE buffer, positive control group (P.C.) crabs received WSSV, and treatment group crabs received WSSV along with synthetic weight compound. Experimental groups were observed for 30 days post-infection. Three different organs (gills, muscles, and head soft tissue (HST)) were dissected from all three groups and analyzed using molecular-based techniques, including polymerase chain reaction (PCR), Western blot, and histopathology. Clinical signs of WSSV were observed in the positive and N.C. groups; however, the treatment group showed a 100% survival rate. Confirmation was done using PCR, Western blot, and histopathology. These results demonstrated that the given synthetic compound has significant anti-viral activity against WSSV.

     

Design and synthesis of peptide-cellulose conjugate molecules —Aspects from energy/steric profiles—

A multipurpose chemical modification of cellulose to yield soluble cellulose derivatives was investigated on the basis of (i) O-acylation of the parent cellulose using N-Boc-protected Gly, αAla, and βAla, and subsequent Boc-removal, (ii) N-acylation of amino acid-modified cellulose in homogenous solution reaction system using Boc-oligopeptides with multiple types of the side-chain functionalities, and (iii) N-acylation of βAla-Cellulose using 10 kinds of simple Boc-oligopeptides. As for the (i), Thermochemical computation to estimate ΔG transition was well coincided with the observed yields in Oacylations. In the case of (ii), beside the similar ΔG-schemes, a strain energy profile, which is coupled with the preferred conformer transition of the amino acid-modified cellulose, was involved to rule out the N-acylation. The symmetric anhydrate in the N-acylating agents in the (iii) are tend to be in torsions due to the β-strand-like steric stabilizations in the peptides, resulting in the highest N-acylation yields as much as 98 %.     

Differential necrotic lesion formation in soybean cultivars in response to soybean mosaic virus

In this study, we examined the necrosis phenotype on leaves of two cultivars of soybean (ZheA8901 and Nannong1138-2) that show varying level of resistance to soybean mosaic virus (SMV). The necrotic symptoms seen on inoculated and systemic leaves of soybean cultivar ZheA8901 were reminiscent of programmed cell death (PCD). The cell death phenotypes were evaluated using the TUNEL method, quantification of hydrogen peroxide (H₂O₂) and salicylic acid, callose production, as well as by monitoring expression of defence genes GmPR-1 and GmNPR1. Our results show that SMV inoculation induced PCD on ZheA8901 is associated with rapid increase in H₂O₂, increased SA and callose accumulation and higher defence gene expression.