Extrasolar enigmas: from disintegrating exoplanets to exoasteroids

Thousands of transiting exoplanets have been discovered to date, thanks in great part to the {\em Kepler} space mission. As in all populations, and certainly in the case of exoplanets, one finds unique objects with distinct characteristics. Here we will describe the properties and behaviour of a small group of `disintegrating' exoplanets discovered over the last few years (KIC 12557548b, K2-22b, and others). They evaporate, lose mass unraveling their naked cores, produce spectacular dusty comet-like tails, and feature highly variable asymmetric transits. Apart from these exoplanets, there is observational evidence for even smaller `exo-'objects orbiting other stars: exoasteroids and exocomets. Most probably, such objects are also behind the mystery of Boyajian's star. Ongoing and upcoming space missions such as {\em TESS} and PLATO will hopefully discover more objects of this kind, and a new era of the exploration of small extrasolar systems bodies will be upon us.Comment: Accepted for publication in the book "Reviews in Frontiers of Modern Astrophysics: From Space Debris to Cosmology" (eds Kabath, Jones and Skarka; publisher Springer Nature) funded by the European Union Erasmus+ Strategic Partnership grant "Per Aspera Ad Astra Simul" 2017-1-CZ01-KA203-03556

Acrylamide in Environmental Water: A Review on Sources, Exposure, and Public Health Risks

TEPE, Yalcin/0000-0002-8415-3754; TEPE, Banu/0000-0002-3428-8167WOS: 000464878700001Acrylamide and polyacrylamide (PAM) are used in diverse industrial processes, mainly the production of plastics, dyes, and paper, in the treatment of drinking water, wastewater, and sewage. Besides inorganic form, acrylamide is formed naturally in certain starchy foods that were heated to cook a temperature above 120 degrees C for elongated time. Researches in rats have demonstrated that acrylamide exposure poses a risk as a neurotoxin to humans and also classified as a carcinogenic and mutagenic compound. Acrylamide may be released into drinking water supplies from its wide-ranging industrial use. Acrylamide has high risk of contamination into surface and ground water supplies due to its rapid solubility and mobility in water. Bacterial use of acrylamide as nitrogen and carbonsource is the main pathway of its degradation in water. The degradation of acrylamide in water occurs about 8-12days depending on water conditions. International Agency for Research on Cancer has declared acrylamide as 2A Group carcinogen in 1994. The major concern related to acrylamide contamination is arising from organic source that occurs especially by consumption of heated starchy food. On the other hand, as acrylamide or PAM is commonly used in different industrial processes, inorganic acrylamide contamination into environment is a big threat and has potential hazards for public health. The main objective of the present review is to summarize the routes of acrylamide contamination, degradation, release and transfer into environmental water, as well as to present integrated information on acrylamide chemistry, toxicity, and analyses, together with potential safety risks for public health. Recommended actions and further studies in needed areas are suggested