2,370 research outputs found
Bright spots in the darkness of cancer: A review of starfishes-derived compounds and their anti-tumor action
The fight against cancer represents a great challenge for researchers and, for this reason, the search for new promising drugs to improve cancer treatments has become inevitable. Oceans, due to their wide diversity of marine species and environmental conditions have proven to be precious sources of potential natural drugs with active properties. As an example, in this context several studies performed on sponges, tunicates, mollusks, and soft corals have brought evidence of the interesting biological activities of the molecules derived from these species. Also, echinoderms constitute an important phylum, whose members produce a huge number of compounds with diverse biological activities. In particular, this review is the first attempt to summarize the knowledge about starfishes and their secondary metabolites that exhibited a significant anticancer effect against different human tumor cell lines. For each species of starfish, the extracted molecules, their effects, and mechanisms of action are described
Sablefish, Anoplopoma fimbria, Populations on Gulf of Alaska Seamounts
Sablefish, Anoplopoma fimbria, were tagged and released on Gulf of Alaska seamounts during 1999–2002 to determine the extent, if any, of emigration from the seamounts back to the continental slope and of movement between seamounts.
Seventeen sablefish from Gulf of Alaska seamounts have been recovered on the continental slope since tagging began,
verifying that seamount to slope migration occurs. Forty-two sablefish were recovered on the same seamounts where they were tagged, and none have been recaptured on
seamounts other than the ones where they were released.
Sablefish populations on Gulf of Alaska seamounts are made up of individuals mostly older than 5 years and are maledominant, with sex ratios varying from 4:1 up to 10:1 males to females. Males are smaller than females, but the average age of males is greater than that of females, and males have a greater range of age (4–64 yr) than females (4–48 yr). Otoliths of seamount fish frequently have an area
of highly compressed annuli, known as the transition zone, where growth has suddenly and greatly slowed or even stopped. Because transition zones can be present in both younger and older seamount fish and are rare in slope fish, formation of otolith transition zones may be related to travel to the seamounts.
The route sablefish use to reach the seamounts is so far unknown. One possibility is that fish enter the eastward-flowing North Pacific Current off the Aleutian Islands or
western Gulf of Alaska and travel more or less passively on the current until encountering a seamount. The route from seamount back to slope would likely be the northwardflowing
Alaska Current. These routes are discussed in light of tag recovery locations of slope- and seamount-tagged fish
WHY NUCLEAR DISARMAMENT IS A UTOPIA
Although nuclear disarmament is a worldwide aspiration from many nations around the world, this dream has not come true. In fact, the number of countries developing nuclear weapons is gradually increasing. Despite the legal framework in place, no single nuclear-weapon state has totally complied with nuclear disarmament. However, each state’s decision to acquire its own nuclear weapon is based on the fact that the international system is anarchical. Likewise, history has highlighted that nations cannot totally trust one another. Additionally, ever-increasing technology, low social capital among states, partial compliance with the legal framework, and miscalculated state narratives contribute to increasing rivalry among countries. Finally, despite criticism, nuclear weapons have the ability to protect what states consider important. As a result, nuclear disarmament is a utopia
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Geology and palaeontology of the Telychian (Silurian), reservoir formation of the North Esk inlier, near Edinburgh, Scotland
The North Esk inlier is one of several outcrops of Silurian sediments in the Midland Valley of Scotland. The lowermost sediments exposed are the Reservoir Formation, and these have been studied in detail. These sediments are interbedded shales and siltstones, deposited as the deepest part of a regressive sequence. The sediments are suggested to have been deposited predominantly by storm processes in an outer shelf or marginal basin environment, and not by turbidity currents into a deep ocean basin as previously suggested. Decreasing water depths can be traced by changes in sedimentary structures and in the animals and their bioturbation traces fossilised therein. A correspondence between the graptolites preserved in the North Esk group and models for distribution of graptolites in depth related zones is observed and is compared with other taxa thought to be indicative of water depth. Cycles of sedimentation are identified and also record fluctuations in the water depth.The NEI sediments were deposited in the remnant lapetus ocean basin at the time of a three plate collision. The sediments are currently sub-vertically oriented. Emplacement at this attitude was probably associated with thrusting at depth, in turn related to strike-slip movement o f separate terranes along the southern margin of Laurentia. Minor small scale bedding-parallel thrusts are evidence of this at the surface. The North Esk inlier sediments were probably part of a tcrranc now of unknown extent. Minor folding, local thrusting and faulting, indicating one major phase of tectonic deformation are described. Compressional kink folding took place, with pressure applied obliquely to foliation (bedding). Areas of chevron folding and kink bands correspond to deformation along Caledonian trends. The northern boundary of the NEI, previously thought to be fault controlled, is reinterpreted as the regional unconformity at the base of the Upper Old Red Sandstone. Metabentonite horizons are identified. The volcanic source of these ash falls is suggested to have been of calc-alkaline character, and an increase in alkalinity of the volcanic source in Scotland during the Telychian is suggested.A study of the fossils preserved has led to a review of late Llandovery graptolite biostratigraphy. A biozonal scheme based on that currently in use in other parts of the world, particularly in Bohemia, is introduced. Three Llandovery graptolite biozoncs arc recognised between the crenulata biozone and the base of the Wenlock. The Reservoir Formation sediments are correlated with the middle of the O. spiralis graptolite biozone, upper Telychian. Comparisons are made with the biozonal schemes for other fossil groups, and the P. celloni. to P. amorphognathoides conodont biozonc boundary is accurately identified within the Gutterford Burn sediments, facilitating accurate correlation between graptolite and conodont biozonal schemes.Revised taxonomic descriptions and notes on a number of species of graptoloid and dendroid are presented. Further work on the dendroid Dictyonema pentlandica has identified normal and abnormal dendroid growth patterns. The response of dendroids to trauma, and disease are described and possible uses of dendroids as palaeoenvironment and palaeocurrent-direction indicators are discussed. A model for the secretion of dendroid holdfasts by mobile zooids distributed across the sediment surface is suggested, and possible dendroid reproductive processes are outlined.A new technique of producing graptolite “Profile Plots” is introduced. These plots are used to identify, characterise and compare different graptoloid species, where a number of species with similar thecal structure are known. The rate of expansion of the stipe at different levels within the colony and the thecal size can be compared, and characteristic profiles plotted for each species. This technique has possible future uses in the computerised identification of graptolites
The Winonan
https://openriver.winona.edu/thewinonan2010s/1146/thumbnail.jp
Oral history of human use and experience of crown of thorns starfish on the Great Barrier Reef
[Extract] This oral history study was commissioned by the Great Barrier Reef Marine Park Authority "to determine what evidence there is for the occurrence of previous aggregations of crown of thorns starfish". This initiative followed a Crown Of Thorns Starfish Advisory Committee recommendation in January 1985 to conduct "a study of oral history of human use and of experience of the Great Barrier Reef", after a pilot study in oral history was executed at James Cook University of North Queensland for the Great Barrier Reef Marine Park Authority (Burns, 1982). The Authority recommended to focus this study on extractive industries on the Great Barrier Reef prior to 1960 by recording operators, divers and others involved in these industries (trochus, beche-de-mer, pearling, trawling). The study is seen as a contribution to the Great Barrier Reef Marine Park Authority's general interest in the relationship between man and the reef, and is located within the framework of a doctoral dissertation on the development and social relations of the pearl-shell, trochus and beche-de-mer industries on the Great Barrier Reef. These materials represent the fieldwork notes towards a dissertation
Reeflections No. 27, June 1992
Newsletter of the Great Barrier Reef Marine Park Authority. Contents include: New Executive Officer for GBRMPA, More From Quicksilver for Great Barrier Reef Aquarium, Report on Reef Waters, Ocean Rescue 2000, Torres Strait Baseline Study, A 25-Year Strategic Plan for the Great Barrier Reef World Heritage Area, Zoning in the Cairns Section, Spearfishing - Two Points of View in the Marine Park, New Crown-of-Thorns Starfish Research Program, Visitor Facilities at Wistari Reef, Reviews
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