906 resultados para Historical pedagogics


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Apart from a couple of early papers in the 1600s, the development of freshwater biology as a science in Mexico began in the last century. Taxonomic studies were made especially on algae, aquatic insects, crustaceans, annelid worms and aquatic plants. The great impetus acquired by limnology in Europe and America in the first half of the 20th Century stimulated foreign researchers to come and work in Mexico. During this period the Instituto de Biologia, belonging to the Universidad Nacional Autonoma de Mexico, was created in 1930. The Institute had a section of Hydrobiology that contributed to the limnological characterization of Mexican lakes and ponds. In 1962, the Instituto Nacional de Investigaciones Biologico-Pesqueras was created to bring together the work of several institutes working on the native ichthyofauna, the restocking of reservoirs, and aquaculture.

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This short review includes major books, articles and episodes concerned with studies on inland waters that have affected the development of limnology in Argentina. It is divided into three periods; (1) an early period of protolimnologists; (2) a period previous to the present times, subdivided into a first stage from 1900 to 1938 and a second stage from 1938 to 1962; and (3) a period of integrated research.

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This paper is an attempt to set the background, provide a brief history, review some of the Windermere perch and pike project's scientific achievements, note current developments and hopes for the future, and comment on some aspects of such long-term projects. The project was originally started in 1939 in order to provide fish in freshwater lakes which might be harvested to enhance the supplies of food in a country subject to blockade. Pike traps and gill-netting were trialed as fishing methods. Catch statistics are available from 1939 which can be used to study population dynamics or for modelling purposes. The author provides an overview of changes in the population dynamics of perch and pike but covers briefly other species like arctic charr and brown trout. Also covered are several aspects of the basic biology and ecology of the principal species involved.

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During 1993, a comprehensive data set of scale readings, length and weight measurements was established for migratory salmonids on the River Lune. This information was collected using three methods of fish capture: 1. The Lune estuary commercial nets. 2. River Lune Forge weir fish trap. 3. River Lune rod catch scale returns. Additional information was contributed by the Kent, Leven and Duddon rod and commercial fisheries. The data shows that the salmon stock in 1993 was dominated by two year old smolts. This varies from year to year. The sea trout population displays a normal population curve in terms of numbers of fish in each age and weight class. The growth rate of salmon and sea trout is very similar even though salmon have the benefit of high sea feeding.

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The Ribble catchment is the largest and most diverse river system within National Rivers Authority (NRA), North West's Central Area. The river is approximately 100km in length and rises in a limestone area west of the Pennines. This report examines changes in the size and composition of the salmon and sea trout catches from the Ribble migratory salmonid fisheries during the years 1937 to 1991. Comparisons are made between the rod and net fisheries for both salmon and sea trout of the Ribble and Hodder. Patterns of catches shown by the Ribble fisheries are compared with those of other individual rivers and with patterns for the North West Region as a whole. An attempt is made to identify if any relationship exists between catch and stock abundance. Catch patterns shown by the Ribble and Hodder salmon fisheries are compared with electronic resistivity counter data from the two rivers. Annual salmon catch patterns and redd count data are compared both locally and regionally. Recommendations for future studies are made in the light of the report's findings.

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To achieve the apparently simple Periodic Table of the Elements has implied tremendous efforts over thousands of years. In this paper we present a brief history of the discovery of the chemical elements from prehistory to the present day, revealing the controversies that arose on the way and claiming the important work performed by alchemists in the advancement of knowledge. This is especially important if we consider that alchemy had a period of existence of many thousands of years, while the "Chemistry", officially established as a science in the eighteenth century, has operated as such for only a few hundred years. Even so, if we consider the progress of discovery and isolation of chemical elements throughout history, it can be observed that the number of elements identified is achieved mainly in the nineteenth and twentieth centuries, reflecting the development of instrumental techniques, that facilitated this task.

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[EN] The goal of this contribution is twofold: on the one hand, to review two relatively recent contributions in the field of Eskimo-Aleut historical linguistics in which it is proposed that Eskimo-Aleut languages are related genealogically to Wakashan (Holst 2004) and?/or Nostratic (Krougly-Enke 2008). These contributions can be characterized by saying that their authors have taken little care to be diligent and responsible in the application of the comparative method, and that their familiarity with the languages involved is insufficient. Eskimo-Aleut languages belong to a very exclusive group of language families that have been (and still are) used, sometimes compulsively, in the business of so-called “long-range comparisons”. Those carrying out such studies are very often unaware of the most basic facts regarding the philological and linguistic traditions of those languages, as a result of what mountains of very low quality works with almost no-relevancy for the specialist grow every year to the desperation of the scientific community, whose attitude toward them ranges from the most profound indifference to the toughest (and most explicit) critical tone. Since Basque also belongs to this group of “compare-with-everything-you-come- across” languages, it is my intention to provide the Basque readership with a sort of “pedagogical case” to show that little known languages, far from underrepresented in the field, already have a very long tradition in historical and comparative linguistics, i.e. nobody can approach them without previous acquaintance with the materials. Studies dealing with the methodological inappropriateness of the Moscow School’s Nostratic hypothesis or the incorrectness of many of the proposed new taxonomic Amerindian subfamilies (several of them involving the aforementioned Wakashan languages), that is to say, the frameworks on which Krougly-Enke and Holst work, respectively, are plenty (i.a. Campbell 1997: 260-329, Campbell & Poser 2008: 234-96), therefore there is no reason to insist once more on the very same point. This is the reason why I will not discuss per se Eskimo-Aleut–Wakashan or Eskimo-Aleut–Nostratic. On the contrary, I will focus attention upon very concrete aspects of Krougly-Enke and Holst´s proposals, i.e. when they work on “less ambitious” problems, for example, dealing with the minutiae of internal facts or analyzing certain words from the sole perspective of Eskimo-Aleut materials (in other words, those cases in which even they do not invoke the ad hoc help of Nostratic stuff). I will try to explain why some of their proposals are wrong, demonstrate where the problem lies, and fix it if possible. In doing so, I will propose new etymologies in an attempt at showing how we may proceed. The main difference between this and handbook examples lies in the reality of what we are doing: this is a pure etymological exercise from beginning to end. I will try to throw a bit of light on a couple of problematic questions regarding Aleut historical phonology, demonstrating how much work should be done at the lowest level of the Eskimo-Aleut pyramid; it is technically impossible to reach the peak of the pyramid without having completed the base. As far as Aleut is regarded, I will mainly profit not only from the use of the traditional philological analysis of Aleut (and, eventually, of Eskimo) materials, but also of diachronic typology, bringing into discussion what in my opinion seems useful, and in some cases I think decisive, parallels. It is worth noting that this paper makes up yet another part of a series of exploratory works dealing with etymological aspects of the reconstruction of Proto-Eskimo-Aleut, with special emphasis on Aleut (vid. i.a. Alonso de la Fuente 2006/2007, 2008a, 2008b, 2010a), whose main goal is to become the solid basis for an etymological dictionary of the Aleut language, currently in progress.

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A generalized Bayesian population dynamics model was developed for analysis of historical mark-recapture studies. The Bayesian approach builds upon existing maximum likelihood methods and is useful when substantial uncertainties exist in the data or little information is available about auxiliary parameters such as tag loss and reporting rates. Movement rates are obtained through Markov-chain Monte-Carlo (MCMC) simulation, which are suitable for use as input in subsequent stock assessment analysis. The mark-recapture model was applied to English sole (Parophrys vetulus) off the west coast of the United States and Canada and migration rates were estimated to be 2% per month to the north and 4% per month to the south. These posterior parameter distributions and the Bayesian framework for comparing hypotheses can guide fishery scientists in structuring the spatial and temporal complexity of future analyses of this kind. This approach could be easily generalized for application to other species and more data-rich fishery analyses.

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Humpback whales (Megaptera novaeangliae) are significant marine consumers. To examine the potential effect of predation by humpback whales, consumption (kg of prey daily) and prey removal (kg of prey annually) were modeled for a current and historic feeding aggregation of humpback whales off northeastern Kodiak Island, Alaska. A current prey biomass removal rate was modeled by using an estimate of the 2002 humpback whale abundance. A historic rate of removal was modeled from a prewhaling abundance estimate (population size prior to 1926). Two provisional humpback whale diets were simulated in order to model consumption rate. One diet was based on the stomach contents of whales that were commercially harvested from Port Hobron whaling station in Kodiak, Alaska, between 1926 and 1937, and the second diet, based on local prey availability as determined by fish surveys conducted within the study area, was used to model consumption rate by the historic population. The latter diet was also used to model consumption by the current population and to project a consumption rate if the current population were to grow to reach the historic population size. Models of these simulated diets showed that the current population likely removes nearly 8.83

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Whaling for humpback whales, Megaptera novaeangliae, in the North At- lantic Ocean has occurred in various forms (e.g. for local subsistence, for oil to be sold commercially, using hand harpoons and deck-mounted cannons, using oar-driven open boats and modern powered catcher boats) from the early 1600’s to the present. Several previous attempts to estimate the total numbers of humpback whales removed were considered close to comprehensive, but some uncertainties remained. Moreover, the statistical uncertainty was not consistently presented with the previous estimates. Therefore, we have pursued several avenues of additional data collection and conducted further analyses to close outstanding data gaps and address remaining issues. Our new estimates of landings and total removals of humpback whales from the North Atlantic are 21,476 (SE=214) and 30,842 (SE=655), respectively. These results include statistical uncertainty, reflect new data and improved analysis methods, and take account of some fisheries for which estimates had not been made previously. The new estimates are not sufficiently different from previous ones to resolve the major inconsistencies and discrepancies encountered in efforts to determine the conservation status of humpback whale populations in the North Atlantic.

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Rangia and marsh clams, Rangia cuneata, R. flexuosa, and Polymesoda caroliniana, occur in brackish waters along México’s eastern coast from the northern State of Tamaulipas to the southern State of Campeche. The clams were important to the prehispanic people in the southern part of the State of Veracruz, where they were used as food and as construction material. In modern times, they are harvested for food. The fishermen wade in shallow water and harvest the clams in soft sediments by hand. Annual landings of whole clams during a recent 5-yr period, 1998–2002, were 1,139–1,695 t. The only area with a substantial ongoing clam fishery is in the Lower Papaloapan River Basin, including Alvarado Lagoon, where as many as 450 fishermen are licensed harvesters. This fishery for the Rangia and marsh clams is the most important clam fishery along México’s Gulf Coast.

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The northern quahog, Mercenaria mercenaria, ranges along the Atlantic Coast of North America from the Canadian Maritimes to Florida, while the southern quahog, M. campechiensis, ranges mostly from Florida to southern Mexico. The northern quahog was fished by native North Americans during prehistoric periods. They used the meats as food and the shells as scrapers and as utensils. The European colonists copied the Indians treading method, and they also used short rakes for harvesting quahogs. The Indians of southern New England made wampum from quahog shells, used it for ornaments and sold it to the colonists, who, in turn, traded it to other Indians for furs. During the late 1600’s, 1700’s, and 1800’s, wampum was made in small factories for eventual trading with Indians farther west for furs. The quahoging industry has provided people in many coastal communities with a means of earning a livelihood and has provided consumers with a tasty, wholesome food whether eaten raw, steamed, cooked in chowders, or as stuffed quahogs. More than a dozen methods and types of gear have been used in the last two centuries for harvesting quahogs. They include treading and using various types of rakes and dredges, both of which have undergone continuous improvements in design. Modern dredges are equipped with hydraulic jets and one type has an escalator to bring the quahogs continuously to the boats. In the early 1900’s, most provinces and states established regulations to conserve and maximize yields of their quahog stocks. They include a minimum size, now almost universally a 38-mm shell width, and can include gear limitations and daily quotas. The United States produces far more quahogs than either Canada or Mexico. The leading producer in Canada is Prince Edward Island. In the United States, New York, New Jersey, and Rhode Island lead in quahog production in the north, while Virginia and North Carolina lead in the south. Connecticut and Florida were large producers in the 1990’s. The State of Campeche leads in Mexican production. In the northeastern United States, the bays with large openings, and thus large exchanges of bay waters with ocean waters, have much larger stocks of quahogs and fisheries than bays with small openings and water exchanges. Quahog stocks in certifi ed beds have been enhanced by transplanting stocks to them from stocks in uncertified waters and by planting seed grown in hatcheries, which grew in number from Massachusetts to Florida in the 1980’s and 1990’s.