This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Columbia Engineering’s computer science Ph.D. candidate Ang Cui designed this device to plug into a Cisco phone and download malware, showing the vulnerabilities of the phone. Credit: Columbia Engineering Citation: Security researchers find vulnerability in Cisco VoIP phones (2012, December 19) retrieved 18 August 2019 from https://phys.org/news/2012-12-vulnerability-cisco-voip.html (Phys.org)—Ang Cui a fifth year PhD student at Columbia University, has given a demonstration at this year’s Amphion Forum in San Francisco, showing a security vulnerability he and colleagues have discovered in Cisco VoIP phones. The vulnerability, he said, allows an intruder to place an electronic device into an on-premise VoIP phone that can be controlled by a nearby smartphone – allowing the “Off Hook Switch” to be manipulated in such as way as to effectively turn the phone into a two-way walkie-talkie. He noted also that once a single phone had been breached all others on the same network could be breached as well though the single device. Cui’s demonstration was part of an overall theme – that embedded devices are vulnerable to attack by people bent on espionage or who wish to cause harm. He noted that devices such as network printers are quite often installed without adequate protection, leaving them open to attack by those outside of the system who wish to get in. VoIP phones, he says, use roughly the same type of technology and thus are equally vulnerable.VoIP phones are normal looking phones that make and receive telephone calls using the Internet instead of the traditional phone network. Many large corporations have installed them because of their increased utility. Governments use them as well, Cui demonstrated, by presenting pictures of them sitting in several different governmental offices, including that of the Director of the CIA. In his demonstration, he affixed a simple circuit board (he calls it the Thingp3wn3r) to a VoIP phone that he said could just as easily have been in someone’s real office – in just minutes. Next, he demonstrated the effectiveness of the Thingp3wn3r by accessing it via a smartphone app. Words he spoke in the vicinity of the phone, despite the receiver being down – the traditional mode of putting a phone offline – were picked up by the circuit board and transmitted to the smarthone app and played for all to hear. The end result is an ability to place a bug in an office using a simple circuit board and available hardware.Cui and his professor, Salvatore Stolfo notified Cisco of the vulnerability prior to the demonstration and Cisco has responded by creating a patch that prevents the vulnerability from occurring. Those who are concerned about the vulnerability of their own systems are urged to contact Cisco for support. More information: ids.cs.columbia.edu/sites/defa … iles/paper-acsac.pdfPress release © 2012 Phys.org Explore further Study Shows Thousands of Consumer Internet Connectivity Devices Are Vulnerable to Attack
(Phys.org) —A team of researchers from Denmark and Italy has created a mathematical model that suggests that if older members of a school of fish are removed, the school may no longer be able to find its way to migration targets. In their paper published in Journal of the Royal Society: Interface, the researchers describe how they created a model based on stochastic networks and how it revealed that older members in a school of fish may hold the information necessary for the school to find its way to migration areas. Robot fish found able to lead real fish (w/ video) A school of sardines in Italy. Credit: Wikimedia / Alessandro Duci © 2014 Phys.org Explore further More information: Fishing out collective memory of migratory schools, J. R. Soc. Interface 6 June 2014 vol. 11 no. 95 20140043. rsif.royalsocietypublishing.or … ntent/11/95/20140043AbstractAnimals form groups for many reasons, but there are costs and benefits associated with group formation. One of the benefits is collective memory. In groups on the move, social interactions play a crucial role in the cohesion and the ability to make consensus decisions. When migrating from spawning to feeding areas, fish schools need to retain a collective memory of the destination site over thousands of kilometres, and changes in group formation or individual preference can produce sudden changes in migration pathways. We propose a modelling framework, based on stochastic adaptive networks, that can reproduce this collective behaviour. We assume that three factors control group formation and school migration behaviour: the intensity of social interaction, the relative number of informed individuals and the strength of preference that informed individuals have for a particular migration area. We treat these factors independently and relate the individuals’ preferences to the experience and memory for certain migration sites. We demonstrate that removal of knowledgeable individuals or alteration of individual preference can produce rapid changes in group formation and collective behaviour. For example, intensive fishing targeting the migratory species and also their preferred prey can reduce both terms to a point at which migration to the destination sites is suddenly stopped. The conceptual approaches represented by our modelling framework may therefore be able to explain large-scale changes in fish migration and spatial distribution. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Journal information: Journal of the Royal Society Interface Citation: Math model suggests fishing out older members may destroy collective fish school memory (2014, March 19) retrieved 18 August 2019 from https://phys.org/news/2014-03-math-fishing-older-members-fish.html Stochastic adaptive networks are networks that behave according to the whims of its individual members. In this new effort, the researchers applied lessons learned in the past regarding such networks to schools of fish. They did so by programming in three major factors of fish swimming in schools: the relative strength of linking interactions between individual fish, the percentage of older fish relative to those that were younger, and how strong a preference the older fish had for particular migratory destinations. By adjusting the constraints, the researchers were able to see which factors were most critical in allowing or preventing a particular school from functioning as a viable unit, and most specifically, whether they were able to migrate to where they needed to go to survive.In analyzing what they’d observed, the researchers noted that two of the factors—cohesion of the group, and the presence of older fish—were more important to school survival than any particular migration destination. They noted also that removal of the older fish tended to damage the collective memory of the group and prevented the school from migrating at all. In the real world, that would mean that if fishermen catch the older fish that hold the memories of where to go when it’s time to migrate, the rest of the school won’t know what to do, and likely as a result, will die without even trying.The model might explain, the researchers note, why it is that when a population of fish is decimated (such as bluefin tuna in the 60s) and then efforts are made to help them repopulate, such efforts are oftentimes unsuccessful because there is no way to reintroduce the lost collective memory.The researchers next plan to improve their model by adding data obtained from real life studies of fish populations, including those that have been overfished. The hope is that a model can be constructed that will help prevent collapse of other fish species due to current fishing techniques.
The researchers suggest that in the future, the technique might be used to print intricate electronics, or more importantly, living tissue, though there is still a long way to go before that can happen—one of the hurdles may be cleanly separating the printed object from the gel. (Phys.org)—A team of researchers at the University of Florida has taken the technique of printing objects inside of a gel a step further by using a highly shear-rate sensitive gel. In their paper published in the journal Science Advances, the team describes the technique and the wide variety of objects they were able to print. Synthetic DNA gel points the way to printing artificial organs Cross-linked structures can be removed from the granular gel. Model jellyfish structures are photopolymerized and then washed in water. Floating in a water bath, the jellyfish exhibit life-like motions in gentle convective currents. Credit: T. Bhattacharjee, K. Schulze, W.G. Sawyer, and T.E. Angelini, University of Florida 3D printing has come a long way in a short time, objects are now being created around the world in ways unimaginable just a few decades ago. But despite the gains that have been made there is still one problem area: printing objects that tend to collapse during the printing process. Imagine trying to print a jellyfish for example, the material that makes up its body would sag after the first few injections preventing the rest of the creature from being printed. To get around this problem, researchers have been experimenting with scaffolding, and gels. Hard scaffolding only works in very limited applications—gels on the other hand, can be used in nearly limitless ways. They work by holding the object in place while it is being printed. In this new effort, the researchers have refined the process to the degree that they were able to print extremely thin walled closed shells and delicate branched networks.To improve the process, the team used a commercially available gel made of particles that are just 7µm-wide—that allowed for more precision when printing. To print an object, a gel (the researches describe it as very similar to hand washing gel), is poured into a container, then the printer goes to work—the print-head is shaped like a needle and is dipped down into the gel where “ink” (made of polymers or other materials) is ejected. The ink comes out as a liquid but solidifies as soon as it is ejected into the gel. The printer moves the head around depositing the ink until the object has been completely printed. Once complete the object is pulled from the gel and cleaned. Explore further © 2015 Phys.org Journal information: Science Advances The example of Russian dolls illustrates the unique capabilities of the technique. Writing in the granular gel medium allows the exquisitely controlled creation of detailed surfaces with both smooth curves and sharp corners. The stability and precision provided by the granular gel allow large delicate structures to be assembled in seemingly impossible configurations. Credit: T. Bhattacharjee and T.E. Angelini, University of Florida Citation: Researchers print inside gels to create unique shapes (2015, September 30) retrieved 18 August 2019 from https://phys.org/news/2015-09-gels-unique.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
More information: HATS-50b through HATS-53b: four transiting hot Jupiters orbiting G-type stars discovered by the HATSouth survey, arXiv:1712.04324 [astro-ph.EP] arxiv.org/abs/1712.04324AbstractWe report the discovery of four close-in transiting exoplanets, HATS-50 through HATS-53, discovered using the HATSouth three-continent network of homogeneous and automated telescopes. These new exoplanets belong to the class of hot Jupiters and orbit G-type dwarf stars, with brightness in the range V=12.5-14.0 mag. While HATS-53 has many physical characteristics similar to the Sun, the other three stars appear to be metal rich, larger and more massive. Three of the new exoplanets, namely HATS-50, HATS-51 and HATS-53, have low density and similar orbital period. Instead, HATS-52 is more dense and has a shorter orbital period. It also receives an intensive radiation from its parent star and, consequently, presents a high equilibrium temperature. HATS-50 shows a marginal additional transit feature consistent with an ultra-short period hot super Neptune, which will be able to be confirmed with TESS photometry. Explore further Citation: HATSouth discovers four ‘hot Jupiter’ exoplanets (2017, December 27) retrieved 18 August 2019 from https://phys.org/news/2017-12-hatsouth-hot-jupiter-exoplanets.html The Hungarian-made Automated Telescope Network-South (HATSouth) Exoplanet Survey is a network of 24 robotic wide-field telescopes. The telescopes are distributed over three locations in the southern hemisphere (Las Campanas Observatory in Chile, the H.E.S.S. site in Namibia, and Siding Spring Observatory in Australia). The primary goal of the HATSouth survey is to discover and characterize a large number of transiting extrasolar planets, reaching out to long periods and down to small planetary radii.To date, HATSouth has identified nearly 2,000 candidate transiting alien worlds of which more than 40 were confirmed as planets. Now, a group of researchers led by Thomas Henning of the Max Planck Institute for Astronomy in Heidelberg, Germany, reports the discovery of four new exoplanets, expanding the list of exoworlds found by HATSouth.Using telescopes of the HATSouth network, Henning’s team observed four G-type dwarf stars known as HATS-50, HATS-51, HATS-52 and HATS-53 between March 2010 and February 2016. They also detected transit signals in the light curves of these stars. The planetary nature of the newly found signals was confirmed through photometric follow-up observations and extensive radial velocity measurements.”We report the discovery of four close-in transiting exoplanets (HATS-50b through HATS-53b), discovered using the HATSouth three-continent network of homogeneous and automated telescopes,” the researchers wrote in the paper.HATS-50b is the smallest and least massive alien world of all of the newly discovered exoplanets. It has a radius of about 1.13 Jupiter radii and a mass of approximately 0.39 Jupiter radii. The planet orbits its parent star every 3.83 days at a distance of about 0.05 AU from the host and has an equilibrium temperature of 1,348 K. The system is located some 2,300 light years away from the Earth.With a radius of approximately 1.41 Jupiter radii, HATS-51b is the largest exoworld among the four newly found extrasolar worlds. It is about 23 percent less massive than our solar system’s biggest planet, and has an equilibrium temperature of 1,553 K. HATS-51b has an orbital period of 3.35 days, a semimajor axis of nearly 0.05 AU and is located about 1,560 light years away.In contrast to other exoplanets described in the paper, HATS-52b is a relatively very dense planet as with a radius of 1.38 Jupiter radii it is 2.24 times more massive than Jupiter. It has also a very short orbital period, given that it circles its star every 1.37 days at a distance of about 0.025 AU. The planet has an equilibrium temperature of 1,834 K and is located some 2,060 light years from the Earth.HATS-53b has the longest orbital period when compared to other planets detected by Henning’s team – it takes it 3.85 days to fully circle its host, which is nearly 0.05 AU away. The exoplanet has a radius of 1.34 Jupiter radii, but it is about 40 percent less massive than Jupiter. HATS-53b has an equilibrium temperature of 1,312 K. The planetary system is located approximately 2,000 light years away from the Earth.The derived planetary parameters of the four alien worlds indicate that they all belong to the class of exoplanets known as ‘hot Jupiters.’ Objects of this type are similar in characteristics to Jupiter, with orbital periods of less than 10 days. They have high surface temperatures, as they orbit their parent stars very closely. Phase-folded unbinned HATSouth light curves for HATS-50 (upper left), HATS-51 (upper right), HATS-52 (lower left) and HATS-53 (lower right). In each case we show two panels. The top panel shows the full light curve, while the bottom panel shows the light curve zoomed-in on the transit. The solid lines show the model fits to the light curves. The dark filled circles in the bottom panels show the light curves binned in phase with a bin size of 0.002. Credit: Henning et al. 2017. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. © 2017 Phys.org Four new short-period giant planets discovered An international team of astronomers reports the discovery of four new ‘hot Jupiter’ extrasolar worlds by the HATSouth survey. The newly found exoplanets received designations HATS-50b through HATS-53b. The finding is presented in a paper published December 12 on arXiv.org.
Journal information: Science Advances More information: Richard C. Greenwood et al. Oxygen isotopic evidence for accretion of Earth’s water before a high-energy Moon-forming giant impact, Science Advances (2018). DOI: 10.1126/sciadv.aao5928AbstractThe Earth-Moon system likely formed as a result of a collision between two large planetary objects. Debate about their relative masses, the impact energy involved, and the extent of isotopic homogenization continues. We present the results of a high-precision oxygen isotope study of an extensive suite of lunar and terrestrial samples. We demonstrate that lunar rocks and terrestrial basalts show a 3 to 4 ppm (parts per million), statistically resolvable, difference in Δ17O. Taking aubrite meteorites as a candidate impactor material, we show that the giant impact scenario involved nearly complete mixing between the target and impactor. Alternatively, the degree of similarity between the Δ17O values of the impactor and the proto-Earth must have been significantly closer than that between Earth and aubrites. If the Earth-Moon system evolved from an initially highly vaporized and isotopically homogenized state, as indicated by recent dynamical models, then the terrestrial basalt-lunar oxygen isotope difference detected by our study may be a reflection of post–giant impact additions to Earth. On the basis of this assumption, our data indicate that post–giant impact additions to Earth could have contributed between 5 and 30% of Earth’s water, depending on global water estimates. Consequently, our data indicate that the bulk of Earth’s water was accreted before the giant impact and not later, as often proposed. Citation: Study suggests Earth’s water was present before impact that caused creation of the moon (2018, March 29) retrieved 18 August 2019 from https://phys.org/news/2018-03-earth-impact-creation-moon.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. This image shows the far side of the Moon, illuminated by the Sun. Credit: NASA
Kolkata: Although two days have passed since the elusive Royal Bengal Tiger was found dead inside Bagghora forest near Lalgarh with multiple injuries, the district police are yet to make any arrests in this regard.A senior police officer of Jhargram claimed they have interrogated 12 people from the nearby village in this connection so far. The district police super clarified that no FIR was lodged against any particular person. A section of media had reported saying that an FIR was lodged against two hunters who received injuries after being attacked by the tiger. Also Read – Heavy rain hits traffic, flightsThe district police super Alok Rajoria on Sunday said the FIR was lodged by the range officer against unknown persons in connection with the death of the big cat. A case has been started under various sections of Wild Life Protection Act.”There was confusion that an FIR was lodged against two persons. However, it was not lodged against any particular person. We have already interrogated 12 villagers in this connection so far. The two victims – Bablu Hansda and Badal Hasda Also Read – Speeding Jaguar crashes into Merc, 2 B’deshi bystanders killedwho received injuries are also being interrogated. We are talking to the forest department officials in this regard,” Rajoria said during a press conference on Sunday.It was learnt that the two injured persons during investigation have told the police that they did not know about the presence of tiger in the forest. They also narrated the whole incident of getting attacked by the tiger attack.It can also be mentioned here that the postmortem report hinted that the skull of the tiger was crushed by heavy substances. Injury marks also suggested that the tribes who took part in the hunting festival attacked the animal with various weapons. A spear like weapon remained stuck in its throat when it’s body was recovered by the forest department.According to preliminary investigation, police suspect that nearly some one taking part in the hunting festival had attacked the tiger. Police are yet to identify the accused who hit the tiger with the weapons. The CCTV footages are also being examined in this connection so far.
Shanghai Cooperation Organisation (SCO) on Friday decided to include India as a full member, prompting Prime Minister Narendra Modi to offer to work with the six- member grouping to enhance connectivity, combat terror and create an environment for boosting trade by easing barriers.India, which has an Observer status for the past 10 years, will technically become the member by next year after completion of certain procedures. Beijing-based SCO currently has China, Russia, Kazakhstan, Kyrgyzstan, Uzbekistan and Tajikistan as members. Along with India, the process to include Pakistan as a member was also initiated here on Friday. Also Read – Pro-Govt supporters rally as Hong Kong’s divisions deepen“I convey our deep sense of gratitude to the members of SCO for accepting India as a full member,” Modi said after the announcement was made at the Summit, attended by leaders like Russian President Vladimir Putin, Chinese President Xi Jinping and Pakistan Prime Minister Nawaz Sharif.“Our membership of Shanghai Cooperation Organisation is a natural extension” of the relationships that India has with member countries “and mirrors the region’s place in India’s future”, he said. Also Read – Pak Army ‘fully prepared’ to face any challenge: Army spokesmanNoting that India’s membership “reflects the natural links of history”, he said, “it will also promote peace and prosperity in this vast region that has often been called the pivot of human history.” Modi said the membership also advances the shared vision to reconnect and integrate Eurasia’s different region.India was made an Observer in the SCO in 2005 and it made an application last year for full membership of the grouping whose focus is on connectivity, counter-terrorism cooperation, bolstering cooperation in energy sector, enhancing trade and dealing with drug trafficking. “We will work with SCO to combat terrorism and extremism that is a rising threat to the entire region. A stable and peaceful Afghanistan is a future that the Afghan people richly deserve, but it will also advance peace, stability and prosperity in the region,” the Prime Minister said. “As we look forward, we would lend our support to improving transportation and
Indian bowlers led by Ravichandran Ashwin showed outstanding perseverance to end South Africa’s dogged resistance and register a comprehensive 337 run victory in the final cricket Test, winning the four-match series by a historic 3-0 margin.Needing a mammoth 481 to win, South Africa depended on their ultra-defensive strategy before being bowled out for 143 in 143.1 overs, the last five wickets falling for a mere seven runs in a dramatic collapse.The 3-0 series win also enabled India to climb upto No 2 in the ICC Test rankings. Also Read – A league of his own!Fittingly Ashwin (5/61 in 49.1 overs) got the final wicket with an angular delivery that Morne Morkel left and was bowled, triggering scenes of celebration in the Indian dressing room and among the players on the ground.Skipper Virat Kohli and Man of the Match Ajinkya Rahane picked the souvenir stumps as players engaged in hearty celebrations and also thanked the spectators who gave them a standing ovation.The Proteas, courtesy AB de Villiers’ 43 off 297 balls, looked like pulling off an improbable draw from the jaws of defeat before the Indian bowling came to life in the final session courtesy pacer Umesh Yadav’s fiery spell and Ravichandran Ashwin ending the stodgy De Villiers’ near six- hour battle. Also Read – Domingo named new Bangladesh cricket coachAshwin produced a magical delivery a sharp bouncing off-break that de Villiers played awkwardly and the resultant catch was taken by Jadeja at leg-slip.The emphatic Test series victory more than made up for the losses in the ODIs and Twenty20s played earlier.Credit should also be given to Umesh Yadav (3/9 in 21 overs) for starting the slide in the final session by rattling Dane Vilas and Kyle Abbott’s stumps. Dane Piedt was gone when Wriddhiman Saha took a stunner. The visions of victory were raised in the post-lunch session, Faf Du Plessis’ (10, 97 balls) resistance ended when Ravindra Jadeja bowled an armer which the right-hander intended to play for the turn. It hit plumb in-front much to the delight of Jadeja.India’s most successful bowler in the series, Ravichandran Ashwin got his 30th victim when JP Duminy (0) was caught plumb on the backfoot having played a dozen of deliveries.Having got a couple of wickets, the drooping shoulders of the Indian fielders suddenly had some life in them.The Proteas, who continued with their ‘Blockathon’ added only 21 runs in the first session of the final day consuming another 35 overs while the post lunch session produced 42 runs in 31 overs.With a session left, it looked as if South Africa were inching towards one of their most creditable draws in Test history.However, the Indian bowlers ensured that the hosts wrapped up the series in style.While the pitch made it easier for the South Africans but no credit can be snatched away from currently the world’s best batsman, De Villiers, who showed that a class player can change and adapt his game according to adverse situations.De Villiers was in that zone where he did have only one thing in mind. Defend dourly and destroy the opposition’s confidence.It was not destructive T20 batting for which he is so revered but slow disintegration of a team that has been on top on 10 out of the 12 days of Test cricket that has happened during the series.There were times when the odd boundary was hit and the players carried out the formality of picking the ball from the boundary and throwing it back to the bowler.In the morning session, Jadeja ended Hashim Amla’s dogged vigil with a beautiful delivery but de Villiers frustrated the Indian bowlers no end. Amla faced 244 balls for his ‘epic’ 25 before Jadeja bowled him with one that drifted in and then straightened knock the off-stump.If Amla was not enough, in came Du Plessis, who surpassed his skipper’s South African record, set on Sunday, of playing 46 dot balls before opening his account.Du Plessis played 52 dots before taking a single of the 53rd delivery. He in fact also surpassed Grant Flower (51 balls vs New Zealand in 2000) to become the third slowest player of all time to open his account.Make no mistake, Du Plessis has done this kind of defending earlier in Adelaide (2012) when he batted close to eight hours (7 hours and 46 minutes) to score 110 and denied the Aussies what looked like an inevitable win.And his partner in crime was none other than de Villiers, who had played 220 balls for his 33 in that particular match. Amla’s strike-rate of 10.44 might have put everyone to sleep but his was a perfect example of how to save a Test match from a miraculously hopeless position.Amla’s innings might set future templates on how to save a match as the art of drawing a Test match has become virtually extinct.Obviously the drab Kotla wicket which became literally lifeless on the final morning did help but it is never easy to save a Test match by batting out more than 160 overs but South Africa nearly did the unthinkable.India’s Test captain Virat Kohli was at his jovial best as he took a dig at the media stating that his team always “had answers” when it came to winning matches irrespective of the playing conditions.Kohli has had to answer the maximum questions on spin-friendly tracks provided at Mohali and Nagpur where the Test matches ended inside three days.When asked if he has replied to all those who were seeking an answer on how the team plays in adverse conditions, Kohli gave a tongue-in cheek reply.“We always knew the answer. It is you people, who perhaps did not get the answer but today I guess you got the answer. I was waiting for this question (laughs), 5-6 questions and no questions on the pitch. No questions on whether the ball was turning,” he had that wry smile on his face as everyone presented started laughing.He then explained that what is being written is not in his hands but terming victories on basis of pitches prepared was something that he found unfair.“The articles that are being written and what people read is also a sort of reaction. You watch something and you write an article. So when you ask a question on a specific issue, you will get a specific answer (from me). It’s not that you will ask a question and I will say ‘Next question’. Obviously I will answer that but I have a way of explaining while giving an answer,” the skipper said.“We believe we can win against any opposition at any place in the world. Now how that will be presented (by you) is not in our control. We can only control our performance with the bat and the ball. We can’t control what people hear and read.“Now, I can’t sit and vouch about how good a team we are. You are free to write whatever you want. All we can do is to perform. If we do well, you will write good things, if we falter, our weaknesses will be pointed out which is fair. But if it’s written that pitch is a factor in victory, then it’s unfair,” Kohli in a polite yet firm manner put across his point on the entire debate about the tracks.Kohli also lauded the dogged defending by the Proteas and called it a “difficult skill” as it also tested the ability of his bowlers.
Kolkata: The MeT department on Tuesday predicted heavy rain in South Bengal from Wednesday night owing to formation of a low pressure area over eastcentral Bay of Bengal.The low pressure is likely to become more marked and concentrate into a depression by Wednesday night, the weatherman said. The system is likely to move west-northwestwards towards north Andhra Pradesh and South Odisha coasts during the period, the Met said.Rainfall in South Bengal may commence from Wednesday night and may continue till Saturday. Heavy rainfall is likely from Thursday in the districts of North and South 24-Parganas, East and West Midnapore, Howrah and Hooghly.All the districts of South Bengal are likely to experience heavy rain owing to the depression on Friday, the MeT said. Fishermen were told not to venture along and off Bengal, Odisha coasts and towards Bangladesh coasts from September 19 to 21, the weatherman said.