scholarly journals Farming the waters: Bringing aquatic plant and animal species to agriculture

2000 ◽  
Vol 80 (2) ◽  
pp. 235-243
Author(s):  
John Castell

Aquaculture has a long history, with carp culture in Asia starting before 2000 BC and oyster culture in the Roman Empire before the time of Julius Caesar. However, it is clearly the past 40 yr that have seen the most dramatic expansion of aquaculture. The world's population now exceeds 6 billion people and is still growing at an alarming rate. The world's wild fish harvest has clearly peaked at or above the maximum sustainable yield of about 90 million t. Many fish stocks are suffering from over-fishing and there is little hope of any increase in the capture fisheries production. Though modern agricultural practices have been very efficient at increasing the per acre yields, the world is experiencing an alarmingly steady decrease in the amount of agricultural land devoted to food production. In the past 20–30 yr production of fish, molluscs, crustaceans and aquatic plants (aquaculture) has become an increasingly important means of producing food, and in some countries aquaculture production accounts for more than half of the total fishery harvest and is even as high as 90% in a few countries. I have reviewed the historical growth of aquaculture, compared the product value in various countries and reviewed aquaculture practices for a number of plant, molluscan, crustacean and fish species around the world. These culture technologies were compared and contrasted with agricultural practices. Finally, some predictions for the future of aquaculture development in Canada and the world have been made. Key words: Canadian aquaculture, history, salmon, fish farming, production statistics, fish culture technology

Geologija ◽  
2021 ◽  
Vol 64 (2) ◽  
pp. 267-288
Author(s):  
Nina MALI ◽  
Anja KOROŠA ◽  
Janko URBANC

Groundwater pollution with pesticides is a problem that occurs all over the world as well as in Slovenia. Considering the past high loads of groundwater with pesticides, the purpose of the presented research was to determine the presence of pesticides in the groundwater of Krško-Brežiško polje in the period 2018-2019 and to check the applicability of the passive sampling method. A total of 21 groundwater samples were taken at 11 locations and 2 samples each in the Sava and Krka rivers. We identified 15 pesticides and their degradation products. Atrazine and its degradation product desethylatrazine were most frequently determined in groundwater samples. They are followed by desethylterbutylazine, terbutylazine, metolachlor and simazine. Atrazine, desethylatrazine, chlortoluron, metolachlor and terbuthylazine were detected in surface water. A total of 24 samples were taken in groundwater and surface water using the qualitative passive sampling method. We singled out 8 pesticides that appear in two campaigns. The frequency and occurrence of individual pesticides by both methods are comparable. Passive sampling has proven to be an appropriate method of identifying the presence of pesticides. The highest loads in the Krško-Brežiško field arise from the agricultural land areas. Groundwater is more contaminated with pesticides in the central part of the field in the direction of groundwater flow from west to east. In the groundwater of the Krško-Brežice field, atrazine and desethylatrazine are still the most frequently detected pesticides with higher concentrations, despite a 20 years long ban on the use of atrazine-based plant protection products.


Author(s):  
Brian Fagan

“Time we may comprehend,” wrote the English physician Sir Thomas Browne in 1643. “’Tis but five days older than ourselves.” Browne’s view of the past encompassed the Greeks and Romans and a humankind created by God in the Old Testament. Also in the seventeenth century, Archbishop James Ussher of Armagh in Ireland used the long genealogies in the Scriptures to calculate that the world had been created on the evening of October 22, 4004 B.C. Thus, according to Christian dogma, the entire span of human existence was a mere six thousand years. After the collapse of the Roman Empire, the study of the past fell into oblivion. Babylon reverted to desert; Petra slumbered in its secluded canyon. Ancient ruins of any kind were a curiosity, often thought to be the work of giants. With the Renaissance came a renewed interest in classical learning and in the remains of ancient civilizations. Thomas Browne and his English contemporaries were steeped in knowledge of ancient Greece and Rome. The Renaissance was an age of collectors and scholars, of acquisitive cardinals and nobles who flocked to Mediterranean lands and returned laden with antiquities for their private collections and for what were then known as “cabinets of curiosities.” Soon, a stream of young travelers followed in their footsteps to Italy, taking what became known as the “grand tour” as part of their education (see Chapter 3). Such often frivolous travelers became the first archaeological tourists, but not necessarily the most perceptive. By 1550, it was fashionable to be an antiquary, a collector or student of ancient things. But only the wealthiest traveler could afford a grand tour and could pay for classical treasures. The less affluent indulged their passion for the past at home, collecting Roman coins and inscriptions and, above all, traveling the countryside in pursuit of what the English schoolmaster William Camden (1551–1623) called “the backward-looking curiosity.” This open-ended inquisitiveness took Camden and his contemporaries to eroded burial mounds on windy uplands, to ancient fortifications in Denmark, and to the mysterious stone circles known as Stonehenge.


2020 ◽  
Vol 57 ◽  
pp. 63-88
Author(s):  
Felix Marcu ◽  
◽  
Máté Szabó ◽  

The conflict archaeology topic is a challenge all over the world, developing in the past ten years simultaneously with the new techniques in understanding the past and use of high‑resolution recordings of cultural heritage. Besides, in close relation with the topic of conflict archaeology is continuously improved the methodology of another sub‑domain, the landscape archaeology, with great results in the last couple of years, important here are the discovery of many new temporary camps in Germany and north west of the Iberian Peninsula. Especially the last ones are similar in shape and positioning with the Roman camps in Șureanu Mountains, though each has its own uniqueness. These reveal in a very special way the Roman army strategy in one of the most important conflicts of the Roman Empire in an alpine area.


Author(s):  
Zia Ur Rahman Farooqi ◽  
Zahoor Ahmad ◽  
Muhammad Ashar Ayub ◽  
Wajid Umar ◽  
Muhammad Nadeem ◽  
...  

Arable lands are the major source of food production worldwide. Increasing crop cultivation in the response to population pressure and the use of synthetic fertilizers and chemicals are the main reasons for the conversion of arable lands into problematic soils. Increasing food demand requires to increase the per acre yield of agricultural crops resulting in over exploitation of soil resources. This is a major contributor to soil degradation which is the major threat to the food security of the world. Climate change and poor-quality irrigation are the other problems are also affecting crop productivity and the conversion of arable lands into problematic lands. Deforestation and urbanization are the main reasons behind the conversion of agricultural land into infrastructure. Adopting precision agriculture, vertical farming and good agricultural practices are the only ways to conserve arable lands. This chapter provides a keen overview of world arable land issues with the focus on threats to arable land and possible solutions to overcome this issue.


2018 ◽  
Vol 21 (2) ◽  
pp. 30-35 ◽  
Author(s):  
Samuel Adamec ◽  
Alena Andrejiová

Abstract From year to year, the world growing area is being more poluted with heavy metals or excessive salt level and exposed to lack of moisture or avaiable nutrients in the soil. This resulting in a loss of agricultural land where vegetables were grown in the past. The producers must also fight with more resistant and new species or strains of soil pathogens, while chemical protection is not always the most suitable solution for human health and the environment. Our review focuses on the great importance of using arbuscular mycorrhizal fungi to alleviate abiotic and biotic stress, taking into account the use in vegetable production. The review is gradually focusing on individual stressors and defines the mechanisms of mycorrhizal fungi that contribute to the sustainable agriculture even under severe stress conditions.


Author(s):  
Catherine E. Clark

Parisians’ interest in photography’s potential as a historical medium gained increasing purchase after World War II, as exemplified by the celebrations of the Bimillénaire de Paris, a public festival to commemorate Paris’s two thousandth birthday, the two millennia since the arrival of Julius Caesar. Exhibitions, press coverage, and books sold photography to the world as the future of studying the past. Faced with the specter of Paris—and France’s—global decline, writers, magazine editors, and municipal officials nonetheless leaned heavily on old prints, paintings, and their historical styles in order to call forth better times from the city’s venerated past. They contributed to Paris’s visual vocabulary, a set of standard image subjects and styles that knit the past into the present both on the printed page and in the historical imagination.


Author(s):  
John Mansfield

Advances in camera technology and digital instrument control have meant that in modern microscopy, the image that was, in the past, typically recorded on a piece of film is now recorded directly into a computer. The transfer of the analog image seen in the microscope to the digitized picture in the computer does not mean, however, that the problems associated with recording images, analyzing them, and preparing them for publication, have all miraculously been solved. The steps involved in the recording an image to film remain largely intact in the digital world. The image is recorded, prepared for measurement in some way, analyzed, and then prepared for presentation.Digital image acquisition schemes are largely the realm of the microscope manufacturers, however, there are also a multitude of “homemade” acquisition systems in microscope laboratories around the world. It is not the mission of this tutorial to deal with the various acquisition systems, but rather to introduce the novice user to rudimentary image processing and measurement.


This paper critically analyzes the symbolic use of rain in A Farewell to Arms (1929). The researcher has applied the Sapir-Whorf Hypothesis as a research tool for the analysis of the text. This hypothesis argues that the languages spoken by a person determine how one observes this world and that the peculiarities encoded in each language are all different from one another. It affirms that speakers of different languages reflect the world in pretty different ways. Hemingway’s symbolic use of rain in A Farewell to Arms (1929) is denotative, connotative, and ironical. The narrator and protagonist, Frederick Henry symbolically embodies his own perceptions about the world around him. He time and again talks about rain when something embarrassing is about to ensue like disease, injury, arrest, retreat, defeat, escape, and even death. Secondly, Hemingway has connotatively used rain as a cleansing agent for washing the past memories out of his mind. Finally, the author has ironically used rain as a symbol when Henry insists on his love with Catherine Barkley while the latter being afraid of the rain finds herself dead in it.


The Eye ◽  
2019 ◽  
Vol 21 (128) ◽  
pp. 19-22
Author(s):  
Gregory DeNaeyer

The world-wide use of scleral contact lenses has dramatically increased over the past 10 year and has changed the way that we manage patients with corneal irregularity. Successfully fitting them can be challenging especially for eyes that have significant asymmetries of the cornea or sclera. The future of scleral lens fitting is utilizing corneo-scleral topography to accurately measure the anterior ocular surface and then using software to design lenses that identically match the scleral surface and evenly vault the cornea. This process allows the practitioner to efficiently fit a customized scleral lens that successfully provides the patient with comfortable wear and improved vision.


Author(s):  
Seva Gunitsky

Over the past century, democracy spread around the world in turbulent bursts of change, sweeping across national borders in dramatic cascades of revolution and reform. This book offers a new global-oriented explanation for this wavelike spread and retreat—not only of democracy but also of its twentieth-century rivals, fascism, and communism. The book argues that waves of regime change are driven by the aftermath of cataclysmic disruptions to the international system. These hegemonic shocks, marked by the sudden rise and fall of great powers, have been essential and often-neglected drivers of domestic transformations. Though rare and fleeting, they not only repeatedly alter the global hierarchy of powerful states but also create unique and powerful opportunities for sweeping national reforms—by triggering military impositions, swiftly changing the incentives of domestic actors, or transforming the basis of political legitimacy itself. As a result, the evolution of modern regimes cannot be fully understood without examining the consequences of clashes between great powers, which repeatedly—and often unsuccessfully—sought to cajole, inspire, and intimidate other states into joining their camps.


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