Introduction to the Northwest Ontario Lake Size Series (NOLSS)

1992 ◽  
Vol 49 (12) ◽  
pp. 2434-2444 ◽  
Author(s):  
E. J. Fee ◽  
R. E. Hecky
Keyword(s):  
Turbulent Energy ◽  
Morphological Similarity ◽  
Experimental Lakes Area ◽  
Mixing Depth ◽  
Biological Communities ◽  
Renewal Time ◽  
Northwest Ontario ◽  
Per Se ◽  
Lake Size ◽  
Size Series

The rationale, design, and limitations of the Northwest Ontario Lake Size Series (NOLSS) research program are described. The primary purpose of NOLSS is to discover how lake size per se influences limnological and fisheries phenomena, so that conclusions drawn from studies of particular lakes can be rigorously scaled and applied to lakes of other sizes. NOLSS consists of six lakes located in a remote wilderness region of Northwest Ontario. These lakes were chosen for their geological, hydrological, and morphological similarity (Canadian Shield geology; water renewal time> 5 yr; fully stratified in summer), but they form an exponential gradient in surface area (from 89 to 34 700 ha.) Associated with this gradient of lake size are gradients of physical properties (turbulent energy, mixing depth, thermal behaviour) to which biological communities must adapt. NOLSS fills the conspicuous gap in size that separates two well-studied groups of lakes in Northwest Ontario: the Experimental Lakes Area (ELA), where whole-lake manipulation experiments are performed, and the Laurentian Great Lakes (Nipigon, Superior), where these experiments find some of their most important applications.

scholarly journals Increased relative abundance of colonial scaled chrysophytes since pre-industrial times in minimally disturbed lakes from the Experimental Lakes Area, Ontario

2018 ◽  
Vol 75 (9) ◽  
pp. 1465-1476 ◽  
Author(s):  
Graham R. Mushet ◽  
Karlee Flear ◽  
Brendan Wiltse ◽  
Andrew M. Paterson ◽  
Brian F. Cumming
Keyword(s):  
Relative Abundance ◽  
Sediment Cores ◽  
Experimental Lakes Area ◽  
Scaled Chrysophytes ◽  
Modern Distribution ◽  
Multiple Processes ◽  
High Nutrient ◽  
Northwest Ontario ◽  
Physicochemical Data ◽  
Warm Lakes

A top–bottom paleolimnological analysis of 30 undisturbed lakes in the Experimental Lakes Area (ELA) in northwest Ontario showed marked increases in the relative abundance of colonial scaled chrysophyte taxa in most lakes since pre-industrial times. The increase in abundance of colonial taxa was primarily driven by Synura sphagnicola in small, high-nutrient, and warm lakes. The colonial taxa Synura petersenii and Synura echinulata also increased in the deeper study lakes. Detailed analysis of sediment cores from six lakes revealed that these changes occurred in the early to mid-1900s. Based on the modern distribution of scaled chrysophytes relative to lake physicochemical data, we propose multiple processes that may be contributing to these changes, such as changes in lake thermal properties and historical changes in the flux of important particles and solutes to lakes. Additional mechanisms that may contribute to the observed changes are discussed, including trophic interactions and changes in limnetic pCO2. Because the ELA is relatively undisturbed, our findings provide important information on the drivers responsible for increases in colonial chrysophyte abundance, which have been documented in studies of lakes in central Ontario and northeast United States.

Maintenance of Iron Meromixis by Iron Redeposition in a Rapidly Flushed Monimolimnion

1980 ◽  
Vol 37 (8) ◽  
pp. 1303-1313 ◽  
Author(s):  
P. Campbell ◽  
T. Torgersen
Keyword(s):  
Organic Matter ◽  
Residence Time ◽  
Deep Water ◽  
Lake Water ◽  
Redox Reactions ◽  
Water Mass ◽  
Experimental Lakes Area ◽  
Water Renewal ◽  
Renewal Time ◽  
High Concentrations

Water mass ages determined by the 3H–3He method gave a water renewal time of 2.5 ± 1 yr for the monimolimnion of softwater iron meromictic Lake 120. The water renewal time of the monimolimnion is less than, or equal to, the renewal time of the whole lake. The monimolimnion of Lake 120 was, therefore, not found to be a stratum of "perennially stagnant deep water." The rates of supply to, and degradation of, organic matter in the monimolimnion are responsible, in the first place, for the low redox potential necessary to establish the high concentrations of soluble Fe2+ observed (up to 4.2 mmol∙L−1). However, it was found that the major key to maintenance of high monimolimnetic concentrations of Fe, i.e. maintenance of iron meromixis, is recycling of Fe at the chemocline by an [Formula: see text] "Ferrous Wheel." Up to 90% recycling of iron between chemocline and monimolimnion results in an iron residence time of [Formula: see text] for the whole lake (greater than 4 times the whole lake water renewal time).Key words: meromixis, iron recycling, 3H–3He water ages, water renewal times, chemical budgets, sediment funneling, redox reactions, Experimental Lakes Area (ELA).

Signals of climate trends and extreme events in the thermal stratification pattern of multibasin Lake Opeongo, Ontario

1999 ◽  
Vol 56 (5) ◽  
pp. 847-852 ◽  
Author(s):  
Jacquelynne R King ◽  
Brian J Shuter ◽  
Ann P Zimmerman
Keyword(s):  
Water Clarity ◽  
Warming Trend ◽  
Climatic Conditions ◽  
Climate Trends ◽  
Mixing Depth ◽  
Air Temperatures ◽  
Wide Range ◽  
Influence Of Water ◽  
Lake Temperature ◽  
Lake Size

Previous empirical observations on thermocline response to warmer conditions have been contradictory. Given that a deepening thermocline was observed for a small lake (0.5 km2) and a shallowing thermocline was observed for a larger system (73.6 km2), these contradictions may be attributable to differences in lake size and the diminishing influence of water clarity on mixing depth. The four basin systems of Lake Opeongo, Ontario, Canada, range in size from 4.4 to 22.1 km2 and build an empirical suite of stratification responses to climate variation for a wide range of lake sizes. From 1958 to 1996, lake temperature profiles were taken in the four major basins of Lake Opeongo. Canonical correlation analyses linked earlier iceout dates, warm July-August air temperatures, and relatively high amounts of bright sunshine in July and August with warmer midsummer epilimnia and shallower midsummer thermoclines for all four basins. The occurrence of stratification patterns associated with warmer climatic conditions increased (r = 0.44, p < 0.01) in parallel with the recent (post-1965) global warming trend. Such patterns also tended to occur in El Niño years. Stratification conditions with cooler midsummer epilimnia and deeper thermoclines tended to occur in La Niña years and provided a pronounced signal in 1992, the year that experienced a global cooling effect due to the eruption of Mount Pinatubo.

Origin of Hepatic Nuclear Inclusion Bodies

1973 ◽  
Vol 31 ◽  
pp. 426-427
Author(s):  
F. G. Zaki ◽  
J. A. Greenlee ◽  
C. H. Keysser
Keyword(s):  
Inclusion Bodies ◽  
Storage Disease ◽  
Glycogen Storage ◽  
Nutritional Deficiencies ◽  
Nuclear Inclusion ◽  
Electron Microscopic ◽  
Human Liver Cells ◽  
Microscopic Studies ◽  
Per Se ◽  
Experimental Liver

Nuclear inclusion bodies seen in human liver cells may appear in light microscopy as deposits of fat or glycogen resulting from various diseases such as diabetes, hepatitis, cholestasis or glycogen storage disease. These deposits have been also encountered in experimental liver injury and in our animals subjected to nutritional deficiencies, drug intoxication and hepatocarcinogens. Sometimes these deposits fail to demonstrate the presence of fat or glycogen and show PAS negative reaction. Such deposits are considered as viral products.Electron microscopic studies of these nuclei revealed that such inclusion bodies were not products of the nucleus per se but were mere segments of endoplasmic reticulum trapped inside invaginating nuclei (Fig. 1-3).

The Eleventh Circuit Holds that Agreements in which Pharmaceutical Companies Pay Generic Companies Not to Compete May be Valid

2004 ◽  
Vol 32 (1) ◽  
pp. 181-184
Author(s):  
Amy Garrigues
Keyword(s):  
Pharmaceutical Companies ◽  
Court Decisions ◽  
Patent Holder ◽  
Trial Court ◽  
Court Of Appeals ◽  
The Us ◽  
Antitrust Laws ◽  
Per Se ◽  
Appeals Court ◽  
Two Sides

On September 15, 2003, the US. Court of Appeals for the Eleventh Circuit held that agreements between pharmaceutical and generic companies not to compete are not per se unlawful if these agreements do not expand the existing exclusionary right of a patent. The Valley DrugCo.v.Geneva Pharmaceuticals decision emphasizes that the nature of a patent gives the patent holder exclusive rights, and if an agreement merely confirms that exclusivity, then it is not per se unlawful. With this holding, the appeals court reversed the decision of the trial court, which held that agreements under which competitors are paid to stay out of the market are per se violations of the antitrust laws. An examination of the Valley Drugtrial and appeals court decisions sheds light on the two sides of an emerging legal debate concerning the validity of pay-not-to-compete agreements, and more broadly, on the appropriate balance between the seemingly competing interests of patent and antitrust laws.

Fusion and Fission Processes in Exocytosis: Possible Roles for Synexin and Osmotic Lysis in the Two Events

1980 ◽  
Vol 38 ◽  
pp. 594-597
Author(s):  
H.B. Pollard ◽  
C.E. Creutz ◽  
C.J. Pazoles ◽  
J.H. Scott
Keyword(s):  
Small Molecules ◽  
Chromaffin Cells ◽  
Adrenal Glands ◽  
General Concept ◽  
Extracellular Calcium ◽  
Large Protein ◽  
Granule Membrane ◽  
Osmotic Lysis ◽  
Per Se ◽  
Chemical Evidence

Exocytosis is a general concept describing secretion of enzymes, hormones and transmitters that are otherwise sequestered in intracellular granules. Chemical evidence for this concept was first gathered from studies on chromaffin cells in perfused adrenal glands, in which it was found that granule contents, including both large protein and small molecules such as adrenaline and ATP, were released together while the granule membrane was retained in the cell. A number of exhaustive reviews of this early work have been published and are summarized in Reference 1. The critical experiments demonstrating the importance of extracellular calcium for exocytosis per se were also first performed in this system (2,3), further indicating the substantial service given by chromaffin cells to those interested in secretory phenomena over the years.

The importance of physical training for preventive care in the elderly

2002 ◽  
Vol 59 (7) ◽  
pp. 323-327
Author(s):  
Baum
Keyword(s):  
Preventive Care ◽  
Körperliche Aktivität ◽  
Physical Training ◽  
Ältere Menschen ◽  
The Elderly ◽  
Per Se

Der mit zunehmendem Alter beobachtbare Verlust an Kraft, Koordination, Ausdauer und Flexibilität ist nur zum Teil als Alterungsprozess per se zu verstehen. Ein wesentlicher Einflussfaktor ist die körperliche Aktivität, d.h. die impliziten oder expliziten Trainingsreize. Denn alle körperlichen Leistungsmerkmale sind noch bis ins höchste Alter unter der Voraussetzung trainierbar, dass die Trainingsintensität und die Reizdichte hinreichend hoch sind. Bei Trainingsangeboten für ältere Menschen kommen der Kraft und der Koordination eine besondere Bedeutung zu, da sie die Basis für eine selbständige Lebensführung darstellen. Um das Krafttraining aus kardio-vaskulärer Sicht möglichst sicher zu gestalten, wurde von uns eine Trainingsform entwickelt und erprobt, bei der es im Gegensatz zu herkömmlichen Methoden zu signifikant geringeren Blutdruckanstiegen kommt.

Hausstaubmilbenallergie

2012 ◽  
Vol 69 (4) ◽  
pp. 249-252 ◽  
Author(s):  
Carrard ◽  
E. Pichler
Keyword(s):  
Per Se

Hausstaubmilben sind kleine Spinnentiere, die weltweit vom gemäßigten bis zum tropischen Klima gefunden werden. Proteine, alle mit enzymatischen Eigenschaften, aus dem Gastrointestinaltrakt und folglich im Hausstaubmilbenkot sind Auslöser von allergischen Erkrankungen, die aufgrund einer kontinuierlichen Exposition von geringen Allergenmengen meist chronisch verlaufen. Klinisch äußert sich dies mit einem schleichenden Krankheitsbeginn: eine chronisch verstopfte Nase und - zu Beginn typischerweise - einem Anstrengungsasthma, das sich bei längerer Dauer verstärkt. Bei Vorliegen einer atopischen Dermatitis kann es auch nach Milbenkontakt zu einer Verstärkung der Dermatitis kommen. Die Anzahl an Hausstaubmilben und die Menge an Milbenallergen hängt von der relativen Luftfeuchtigkeit ab, wobei eine Luftfeuchtigkeit von > 50 %, wie es in sehr gut isolierten Häusern oder durch das Klima per se vorkommt, zu einem guten Gedeihen der Hausstaubmilben führt. Nahrungsquelle der Hausstaubmilben sind Hautschuppen, die ubiquitär in Polstermöbeln, Matratzen und Teppichen vorkommen. Die chronischen, recht unspezifischen und oft allergenunabhängigen Beschwerden verzögern oft die Diagnostik, welche durch eine ausgedehnte Allergieabklärung z. B. mittels Hauttestung erfolgt. Die Therapie besteht in erster Linie aus topischen Kortikosteroiden. Trotz widersprüchlicher Daten und Metaanalysen in der Literatur zur Hausstaubsanierung scheint das allgemein eher trockene Klima im Winter in der Schweiz eine Hausstaubsanierung in den Wohnungen zu begünstigen und wird deshalb auch empfohlen. Eine weitere Therapieoption ist die Durchführung einer spezifischen Immuntherapie mit gutem Erfolg bei Kindern und Erwachsenen. Verbesserungen der Diagnostik und Immuntherapie sind durch Einsatz der rekombinanten Allergene zu erwarten.

Harnsäure, Nierenerkrankungen und Nephrolithiasis

2016 ◽  
Vol 73 (3) ◽  
pp. 159-165 ◽  
Author(s):  
Min Jeong Kim ◽  
Helmut Hopfer ◽  
Michael Mayr
Keyword(s):  
Diabetes Mellitus ◽  
Diabetes Mellitus Typ 2 ◽  
Therapeutische Konsequenzen ◽  
Per Se

Zusammenfassung. Verschiedene Nierenerkrankungen können mit erhöhten Harnsäurewerten einhergehen, wobei die pathophysiologischen Vorgänge sich stark unterscheiden. Dies ist nicht nur von akademischer Bedeutung, sondern hat auch wichtige therapeutische Konsequenzen. Während ein massiver und plötzlicher Harnsäure-Anfall im Rahmen eines Tumor-Lyse-Syndroms zum akuten Nierenversagen führen kann, liegen der umstrittenen chronischen Urat-Nephropathie dauerhaft erhöhte Harnsäurewerte zugrunde. Möglicherweise ist hier das entscheidende Agens aber gar nicht die Hyperurikämie per se, sondern Blei, zumindest gibt es diese Assoziation. Bei der Nephrolithiasis mit Harnsäuresteinen ist der entscheidende Faktor nicht wie zu vermuten wäre eine Hyperurikämie oder Hyperurikosurie, sondern eine Azidifikationsstörung auf renaler Ebene mit persistierend tiefem Urin-pH. Es gibt starke Hinweise, dass die beiden metabolischen Erkrankungen Adipositas und der Diabetes mellitus Typ 2 mit Insulinresistenz wichtige pathophysiologische Faktoren in der Entstehung dieser Azidifikationsstörung sind. Patienten mit Harnsäuresteinen sollten deshalb immer auf das Vorliegen dieser metabolischen Faktoren abgeklärt und dementsprechend behandelt werden.

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