Instabilities and waves in thin films of living fluids

We formulate the thin-film hydrodynamics of a suspension of polar self-driven particles and show that it is prone to several instabilities through the interplay of activity, polarity and the existence of a free surface. Our approach extends, to self-propelling systems, the work of Ben Amar and Cummings [Phys Fluids 13 (2001) 1160] on thin-film nematics. Based on our estimates the instabilities should be seen in bacterial suspensions and the lamellipodium, and are potentially relevant to the morphology of biofilms. We suggest several experimental tests of our theory.Comment: 4 pages, pdflatex, accepted for publication in Phys Rev Let

Creativity- The Mantra to Success

Creativity is the ability to respond to all that goes on around us, to choose from the hundreds of possibilities of thought, feeling, action, and reaction that arise within us, and to put these together in a unique response, expression, or message that carries moment, passion, and meaning. In general terms, creativity is a way of looking at things with a new and different perspective or it is the tendency to generate or recognize ideas, alternatives or possibilities thus to find new solutions to problems. In other words, it is the thinking out of box

Rescue of stranded Hawksbill turtle in Kollam, Kerala

On 27th  March, 2019, fisher folks of Kakkathoppu, a coastal area of Kollam district in Kerala, India, found a Hawksbill turtle (Eretmochelys imbricata), stranded in the rocky seashore (Fig1). The turtle was live female that weighed approximately 50 kg having a carapace length of 48 cm. According to the local fishermen, the turtle was unable to swim back to sea due to ruptured carapace and fatigued condition. On primary evaluation, barnacles were observed to be covering a part of its body and the carapace as well as head region were found exposed to sunburn

Plan@Earth- NGO for turning waste as a resource

Plan@Earth is a Voluntary organisation registered as a charitable trust under the Travancore-Cochin Literary, Scientific and Charitable Societies Act (Reg No ER-313/09). It works in the area of environment conservation by offering solutions for waste management. Plan@Earth believes that “waste is not a trash but a resource” and proper waste management is the vital part for sustainable development of society. The activities of Plan@Earth are directed towards the 6 Rs namely, Reduce, Reuse, Refuse, Restructure, Remove and Recycle. The first 3 Rs are achieved through awareness classes, campaigns, street-plays. The other 3 Rs are achieved by training the community to segregate waste at source followed by door to door collection of waste from over 20000 households using push carts and directing clean and dry waste collected for recycling. The dry waste that cannot be recycled are washed and made into bags, file-folders, items of home décor using the method of up-cycling. With the help of the mechanical engineering dept of SNGCE College, Kolenchery, Plan@Earth has also developed a machine to make “Eco-Bricks” using discarded plastic packaging and sand. Every year Plan@Earth carries out nearly 200 awareness classes and uses mimes, skits, street plays and dramas performed by student volunteers to get the message across to the public. Each project in this NGO can support 20-25 women from poorer backgrounds as means for poverty alleviation

Training Manual ICAR Short course on Application of advanced molecular methods in marine fishery resource management, conservation and sustainable mariculture

Molecular Biology and Biotechnology has undergone incredible progress in this decade mainly due to the rapid advancements in DNA sequencing technologies. Marine biology and fishery science also reaped the fruits of these modern inventions improving our understanding regarding complex adaptations in aquatic organisms. Fish Genetics have evolved into genomics incorporating knowledge about neutral and non-neutral markers. A project called Genome 10k was started by the international community of scientists for sequencing the genome of 10000 vertebrates. Whole genomes of many marine organisms are now available which provided insights into the evolution of many important traits. Transcriptome sequencing provides insights into expressed genes and metagenome sequencing provides information regarding the microbes present in environment. All these technologies are rapid and cost effective. Over years, these technologies provided exciting opportunities for understanding ecology and evolution. Genomic information can also be sustainably utilized to enhance productivity of mariculture activities by selective breeding, genetic improvement and manipulation of economically important traits. ICAR-Central Marine Fisheries Research Institute has contributed significantly to marine biotechnology research in the country and played a pivotal role in development of marine fisheries sector. The short course on “Application of advanced molecular methods in marine fisheries resource management, conservation and sustainable mariculture” conducted in ICAR-CMFRI from 24th October, 2018 to 2nd November, 2018 is specially designed to provide exposure to various applications of molecular tools in fisheries resource management, conservation of biodiversity and mariculture. I hope this compendium of lectures and protocols will be extremely useful for the participants to effectively utilize the knowledge in their own area of research. Simultaneously, on behalf of ICAR-CMFRI, I warmly welcome all the participants from various institutions and wish them all success in their future endeavors. I am sure that this training will result in new knowledge, collaborations and friendships

Fish waste management: turning fish waste into healthy fertilizer

In recent decades there has been a constant increase in global population which generates the gigantic challenge of providing food and livelihoods to a population well of greater than 9 billion people by the middle of twenty-first century (FAO, 2018). Fisheries sector plays a key role in providing food safety and employment formany people. Global fish production has touched about 171 million tonnesby 2016 (FAO, 2018) and further increase in fish production through growing aquaculture industry is expected in coming decades. On contrast, of the overall worldwide fish production, almost 75% is only used for human consumption (FAO, 2007).The abandons from the world’s fisheries exceed 20 million tons annually(equivalent to 25% of total production) which include “non-target” species, fish processing wastes and by-products. Most of these are simply disposed off in landfills, by incineration, or dumping at sea or lands. Considering the high organic content fish waste is categorized as “certified waste” that is even more costly to dispose. Management of fish waste is coming under increased scrutiny to environmental issues (Jesperson et al., 2000) and is an emerging alarm and cost burden to whole fish industry (Anon, 2002). Considering the present and future intensity of fish production, the ultimate disposal of fish waste will turn out to be a serious problem for environment. Utilization of fish wastes help to eliminate harmful environmental aspects and improve the income for fish farmers, demanding the critical necessity to find ecologically acceptable means for reutilization of these wastes

Abating coastal pollution for protecting environment in ecologically sensitive area of Astaranga, Puri district, Odisha

Pir Jahania, the famous shrine situated in the shore of Bay of Bengal and its scenic beach attract many tourists for their religious sentiment and as a beautiful picnic spot. The green cover of casuarinas, good mangrove vegetation and the mass nesting site of Olive ridley (Lepidochelys olivacea) turtles are the specialty of this place. In spite of constant efforts by the forest department of Puri, continuous human interference deteriorates the environment with plastic pollution and other non-biodegradable materials like stray foam, thermocol, glass bottles turning the protection of the same as a major concern for the environmentalists. Puri Field Centre of ICAR-CMFRI along with forest department of Puri thus decided to make an awareness programme on plastic pollution in this tourist place

Insight into the gut microbiology of wild-caught Mangrove Red Snapper, Lutjanus argentimaculatus (Forsskal, 1775)

Documenting bacteria present in healthy individuals forms the first step in understanding the effects of microbial manipulation in aquaculture systems. Among the commensal microflora, gut microbiota has attracted extensive attention owing to their role in host metabolism and health maintenance. Basic knowledge on normal gut microbes within a particular host species is thus essential to determine how successfully these microbes can be manipulated and engineered for sustainable aquaculture systems. In spite of the good aquaculture potential of Mangrove red snapper, Lutjanus argentimaculatus, the information on microbial communities associated with the gut of this fish, and their contribution towards digestive efficiency and disease resistance is scarce. Therefore, an attempt was made to elucidate the abundance and diversity of cultivable gut microbes of wild caught L. argentimaculatus along with their digestive exoenzyme profiles and prohibitory effect against fish pathogens. Results on abundance showed similar gut bacterial loads as that of other marine fish imposing the less contribution of microflora to the volume of gut materials in fish. Eleven distinct bacterial species including two proposed novel vibrios were identified. An incidental observation of Morganella morganii throughout samples is an alarming signal, emphasizing the need for immediate de-gutting to avoid histamine intoxication. Abundance of digestive enzyme producers and excellent enzymatic potential of some isolates suggested the contribution of digestive enzymes may supplement to the symbiosis between gut flora and host and the information is of interest to aquaculture nutritionists/commercial industries. Interestingly, some isolates demonstrated estimable co-aggregation with aquatic pathogens, indicating their involvement in disease resistance and the results correlated well with gut microbial diversity. These findings highlight the significant role of gut microbes towards nutritional physiology and disease resistance of this aquaculture candidate in natural ecosystem. The culturable microbiota profiles of wild fish generated in the study can be applied for measuring the quality of husbandry routines in aquaculture facility of this marine fish. Overall, the present study fetches insights on the gut microbiome of healthy L. argentimaculatus which forms a platform for follow-up studies. The study may also help in the development of “functional” fish feeds for L. argentimaculatus. The investigation also demonstrated some potential digestive enzyme-producing isolates having probiotic applications in commercial aquaculture

Development of a novel multiplex-PCR technology for simultaneous detection of five major aquaculture pathogens

Early and precise pathogen identification and corresponding disease management are primary concerns in aquaculture. Here, we attempted at diagnostic methods that can simultaneously identify multiple pathogens, where many samples, several pathogens, and concurrent infections are to be handled. Hence, a multiplex PCR assay targeting five major aquaculture pathogens, viz. Vibrio parahaemolyticus, Vibrio anguillarum, Vibrio alginolyticus, Vibrio vulnificus and Vibrio harveyi was developed for the first time. The primers targeting toxR of V. parahaemolyticus, amiB of V. anguillarum, col o

A case of encysted endoparasitic copepods in the Spiny cheek grouper

During the routine biological investigations on Epinephelus diacanthus (Spiny cheek grouper), a fish with a pair of cysts attached to the abdominal musculature was observed. The cysts were oval, thin-walled, dark grey coloured, measured approximately 3 cm in diameter, and located adjacent to each other