Maturing oocytes have diverse developmental potential and good quality oocytes exhibit a better ability to attain physiological milestones in a time-dependent manner. This situation necessitates the confirmation of oocyte developmental status more precisely under an in vitro embryo production (IVEP) regime. The aim of this study was to explain timely events in germinal vesicle breakdown (GVBD), an important milestone of oocyte nuclear maturation, to delineate the developmental capacity of Bubalus bubalis oocytes. In addition, the expression profile of genes responsible for GVBD was assessed in order to understand the molecular context responsible for GVBD. The chronology of GVBD events at different time intervals during in vitro maturation (IVM) suggests that the rate at which oocytes undergo GVBD was strikingly different in the brilliant cresyl blue (BCB)+ and BCB− groups. The expression of AKT and CDC25B genes for BCB+ oocytes was maximum at 8 h of IVM, and CCNB (cyclin B) peaked at around 10 h, which suggested that GVBD was finished after 10 h in BCB+ oocytes, whereas the expression of AKT and CDC25B was found to peak at around 12–14 h of IVM. This difference consequently delays the GVBD event by 2–4 h in BCB− oocytes. Poor abundance of gene transcripts was mainly implicated in delay and lower rate of GVBD in BCB− oocytes which in turn strongly affected the translational ability of oocytes to blastocysts. The findings of this study support the idea that there is a propensity in sub-optimal grade oocytes for delayed GVBD that compromises the developmental ability of low grade buffalo oocytes. The study highlights the very small, but importantly vital and separate, time window of the GVBD event during which the competence levels of buffalo oocytes are altered along with their translational ability to develop into the prospective embryos.

Redshifted HI 21-cm signal from the cosmic dawn and epoch of reionization evolve considerably along the LoS. We study the impact of this evolution (so called the light cone effect) on the HI 21-cm power spectrum. It is found that the LC effect has a significant impact on the 3D power spectrum and the change could be up to a factor of few. The LC effect is particularly strong during the cosmic dawn near the ‘peaks’ and ‘dips’ in the power spectrum when plotted with redshift. We also show that the 3D power spectrum, which could fully describe ergodic and periodic signal, losses out some information regarding the second order statistics of the signal as the EoR/CD 21-cm signal is non-ergodic and non-periodic along the line of sight. We show that the multi-frequency angular power spectrum (MAPS) ${\mathcal {C}}_{\ell }(\nu _1, \nu _2)$ captures all the information regarding the second order statistics of the signal even in the presence of the LC effect.

The matched filtering technique is an efficient method to detect H ii bubbles and absorption regions in radio interferometric observations of the redshifted 21-cm signal from the epoch of reionization and the Cosmic Dawn. Here, we present an implementation of this technique to the upcoming observations such as the SKA1-low for a blind search of absorption regions at the Cosmic Dawn. The pipeline explores four dimensional parameter space on the simulated mock visibilities using a MCMC algorithm. The framework is able to efficiently determine the positions and sizes of the absorption/H ii regions in the field of view.

Insulin-like growth factor binding protein-5 (IGFBP-5) is a key molecule inmammary gland development, which facilitates the removal of mammary epithelialcells (MECs) by apoptosis that takes place during remodeling of the mammarygland during involution. IGFBP-5 binds with IGFs for their bioavailability.IGFBP-5 has been reported to perform pleiotropic roles such as cellularapoptosis, proliferation and differentiation. To understand the role of IGFBP-5during lactation and clinical mastitis, expression profiling of IGFBP-5 at theprotein level was performed in both indigenous cows (Bosindicus) and buffaloes (Bubalus bubalis) belonging totwo different breeds – Sahiwal cows and Murrah buffaloes.Reverse-transcriptase PCR (RT-PCR) of IGFBP-5 mRNA confirmed its expression inmilk somatic cells and MECs of Sahiwal cows. ELISA was performed forquantitative measurement of IGFBP-5 concentrations in milk during different days(0, 50, 100, 150, 200, 250 and 300) of lactation, during the involution periodand in animals exhibiting short lactation and clinical mastitis. The highestconcentration of IGFBP-5 in milk was observed during the involution periodfollowed by colostrum, late and early lactation, respectively, in both cattleand buffaloes. No significant difference in the concentration of IGFBP-5 wasobserved during the first 150 days of lactation between cows and buffaloes.However, higher concentration of IGFBP-5 was observed in cows during latelactation (200 to 300 days) in comparison with buffaloes. To validate the ELISAdata, quantitative real-time PCR was performed in MECs of Sahiwal cows. Therelative mRNA abundance of IGFBP-5 was found to be significantly(P<0.05) higher on day 15 than between 50 and 150days of lactation in case of Sahiwal cows. Highest mRNA expression of IGFBP-5was observed around 300 days of lactation followed by 200 and 250 days(P<0.05), respectively. Murrah buffaloes showedlow levels of IGFBP-5 protein in milk as compared with Sahiwal cows duringlactation in ELISA. Animals having history of short lactation length (shortlactating animals) showed higher levels of IGFBP-5 expression (at protein level)in comparison with normal lactating animals. We propose that higher levelIGFBP-5 expression may have functional significance in lactation persistency. Asa pro-apoptotic molecule, higher expression of IGFBP-5 was observed to beinversely related to lactation length and milk production.

A buffalo oocyte-specific subtracted cDNA library was constructed to identify exclusively or preferentially oocyte-expressed genes. The library represented an enriched population of transcripts obtained from oocytes of diverse ovarian follicular origin and at different stages of in vitro maturation. A total of 1173 high-quality sequences of oocyte-specific genes were clustered into 645 unique sequences, out of which 65.76% were represented as singlets and 34.26% as contig expressed sequence tags (ESTs; clusters). Analysis of sequences revealed that 498 of these sequences were identified as a known sequence in mammalian species including buffalo, 103 as uncharacterized ESTs and 44 unknown sequences including 1 novel EST, so far not reported in any species. Gene ontology annotation classified these sequences into functional categories of cellular events and biological processes associated with oocyte competence. Expression status of the isolated unknown ESTs confirmed that many of these are expressed in oocytes exclusively and in others preferentially, some in excess of 80-fold greater in comparison with a variety of somatic tissues. The isolated novel EST was detected to be expressed exclusively in oocytes and testicular cells only. To our knowledge, this is the first report giving a detailed transcriptome account of oocyte-expressed genes in buffalo. This study will provide important information on the physiological control of oocyte development, as well as many questions yet to be addressed on the reproductive process of buffalo.

Nitrogen efficiency from Azolla microphylla or Sesbania rostrata green manure, rice straw, and inorganic fertilizer-N was compared in two long-term experiments with irrigated lowland rice (Oryza sativa L.). Treatments included a control and each nitrogen source alone or in combinations that provided 50% of the total applied nitrogen from an organic and inorganic nitrogen source. All nitrogen sources were applied at equivalent nitrogen rates to 19–22 consecutive rice crops. Residual effects were assessed in two subsequent cropping seasons at one site. Lower grain yield, agronomic efficiency (Δgrain per kg total applied nitrogen), and apparent nitrogen uptake were obtained from green manure and rice straw nitrogen as sole or dual nitrogen sources rather than from a standard split application of prilled urea. Compared to prilled urea, residual effects from green manure or rice straw included a significant increase in soil organic carbon and total nitrogen, and greater extractable soil nitrogen in the vegetative growth period. After panicle initiation there was no residual effect on the rate of crop nitrogen accumulation, and final grain yields were similar regardless of previous nitrogen source. Recycling of rice straw appeared to have greater potential for reducing fertilizer-N requirements than use of green manure because rice straw is often a wasted resource in irrigated rice systems of the humid tropics, the efficiency of rice straw nitrogen in combination with prilled urea is comparable to green manure nitrogen, and the increase in soil nitrogen from rice straw was 50–150% greater than from green manure.

Experiments were conducted during three crop seasons to determine the effects of lindane and carbary1, applied to the irrigation water or incorporated in the soil, on the control of insects, on the nitrogen status of the soil and plant, and on grain yield of lowland rice. In two crop seasons the highest grain yield was obtained from three applications of lindane to the irrigation water and carbaryl sprays at 7- to 10-day intervals, and in the third season from 20 kg/ha. carbaryl incorporated in the soil without any lindane treatment or carbaryl spray. In two seasons, soil-incorporated carbaryl at 20 kg/ha. active ingredient gave a significantly higher yield than the no-insecticide control, and in one season the increase in grain yield was just below the significant level. Most of the grain yield increase with 20 kg/ha. carbaryl incorporated into the soil was caused by better control of stem borer and leafhopper and a significant reduction in virus infection.

An investigation was conducted to determine the distribution, virulence gene profile and phenotypes of Shiga toxin-producing Escherichia coli (STEC) strains within a dairy farm in Kolkata, India by characterizing the STEC strains isolated from healthy dairy cow and calf stool samples, raw milk and farm floor swabs from July 2001 to March 2002. Primary screening by multiplex-PCR detected stx1 and stx2, the common virulence genes of STEC, in 18·9% of cow faeces, 32·4% of calf stool samples, 21·6% of farm floor swabs and 4·5% of raw milk samples and viable STEC were recovered from 4·5, 9·9, 8·1 and 1·8% of the corresponding PCR-positive samples. Strains harbouring stx1 (63·3%) and hlyA (53·3%) were frequently detected compared to eae (13·3%). Most of the strains harboured similar sets of reported virulence genes common among isolates from diarrhoea patients. Most of the strains also exhibited multidrug resistance, sorbitol fermentation and produced enterohaemolysin. The randomly amplified polymorphic DNA–PCR (RAPD–PCR) profile of the STEC strains isolated from the farm milieu revealed diverse banding patterns and clonal analysis demonstrated that the strains from different sources were not identical but showed some genetic relatedness. The study demonstrates the potential of dairy farm for housing virulent STEC.

Antimicrobial susceptibilities of Vibrio cholerae strains isolated from cholera patients admitted to the Infectious Diseases Hospital, Calcutta, India for 6 years were analysed to determine the changing trends; 840 V. cholerae strains isolated in 1992–1997 were included in this study. Among V. cholerae serogoup O1 and O139, ampicillin resistance increased from 1992 (35 and 70%, respectively) to 1997 (both serogroups 100%). Resistance to furazolidone and streptomycin was constantly high among V. cholerae O1 strains with gradual increase in resistance to other drugs such as ciprofloxacin, co-trimoxazole, neomycin and nalidixic acid. V. cholerae O139 strains exhibited susceptibilities to furazolidone and streptomycin comparable with those of O1 strains. However, after initial increase in resistance to chloramphenicol and co-trimoxazole, all the V. cholerae O139 strains became susceptible to these two drugs from 1995 onwards. Both V. cholerae O1 and O139 remained largely susceptible to gentamicin and tetracycline. V. cholerae non-O1, non-O139 strains, in contrast, exhibited high levels of resistance to virtually every class of antimicrobial agents tested in this study especially from 1995. Kruskal–Wallis one-way analysis showed that V. cholerae O1 Ogawa serogroup exhibited significant yearly increase in resistance to nine antibiotics followed by non-O1 non-O139 and O139 strains to six antibiotics and two antibiotics respectively. Interesting observation encountered in this study was the dissipation of some of the resistant patterns commonly found among V. cholerae non-O1 non-O139 or O1 serogroups to the O139 serogroup and vice versa during the succeeding years.