Ray Hilborn, Trevor A. Branch, Billy Ernst, Árni Magnússon, Carolina V. Minte‐Vera, Mark D. Scheuerell, Juan L. Valero,
The total world catch from marine and freshwater wild stocks has peaked and may be slightly declining. There appear to be few significant resources to be developed, and the majority of the world's fish stocks are intensively exploited. Many marine ecosystems have been profoundly changed by fishing and other human activities. Although most of the world's major fisheries continue to produce substantial sustainable yield, a number have been severely overfished, and many more stocks appear to be heading ...
Tópico(s): Coral and Marine Ecosystems Studies
2003 - Annual Reviews | Annual Review of Environment and Resources
OKSANA P. ANDRUSHCHYSHYN, Árni Magnússon, D. Dudley Williams,
SUMMARY 1. The ciliate populations of two temporary ponds in southern Ontario were studied throughout their aquatic phases in 2001. Pond I (∼1 ha) held water for 98 days, whereas Pond II (∼0.25 ha) held water for 34 days. Populations were assessed both within the ponds themselves and within a series of enclosures in which invertebrate predator pressure was manipulated. 2. In the natural pond water, total ciliate abundance in Pond II rose rapidly from day 1 increasing two orders of magnitude by day 7. ...
Tópico(s): Coastal wetland ecosystem dynamics
2003 - Wiley | Freshwater Biology
Matz Larsson, H.‐M. Loit, Mari Meren, Jaak Põlluste, Árni Magnússon, Kjell Larsson, Bo Lundbäck,
The aim of the present study was to examine the relationship between reported environmental tobacco smoke (ETS) exposure and respiratory symptoms. In 1996, a postal questionnaire was randomly distributed in three areas of Estonia to a population-based sample, of which 4,995 females and 1,822 males had never smoked. The main outcome measures were current respiratory symptoms and the amount of reported ETS exposure outside the home. ETS exposure at home was more common in females (31% versus 19%), while ...
Tópico(s): Chronic Obstructive Pulmonary Disease (COPD) Research
2003 - European Respiratory Society | European Respiratory Journal
Tópico(s): Marine Bivalve and Aquaculture Studies
2003 - Springer Nature | Estuaries
To review and systematize all epidemiological studies of seasonal affective disorder (SAD).The relevant papers were identified by searches in Medline, Excerpta Medica, PsychLIT and other databases. The primary reports were reviewed for additional citations. The studies were classified into retrospective and prospective population surveys, surveys of patient populations and studies of seasonal variations in psychiatric illnesses other than mood disorders.The prevalence estimates of SAD across 20 retrospective ...
Tópico(s): Neuroendocrine regulation and behavior
2000 - Wiley | Acta Psychiatrica Scandinavica
Michael C. Melnychuk, Hiroyuki Kurota, Pamela M. Mace, Maite Pons, Cóilín Minto, Giacomo Chato Osio, Olaf P. Jensen, Carryn L De Moor, Ana M. Parma, L. Richard Little, Daniel Hively, Charmane E. Ashbrook, Nicole Baker, Ricardo O. Amoroso, Trevor A. Branch, Christopher M. Anderson, Cody Szuwalski, Julia K. Baum, Tim R. McClanahan, Yimin Ye, Alessandro Ligas, Jilali Bensbai, Grant G. Thompson, John DeVore, Árni Magnússon, Bjarte Bogstad, Edward J. G. Wort, Jake Rice, Ray Hilborn,
Tópico(s): Marine Bivalve and Aquaculture Studies
2021 - Nature Portfolio | Nature Sustainability
Rishi Sharma, Polina Levontin, Toshihide Kitakado, Laurence T. Kell, Iago Mosqueira, Ai Kimoto, Rob Scott, Carolina V. Minte‐Vera, Paul De Bruyn, Yimin Ye, Jana Kleineberg, Jo Walton, Shana Miller, Árni Magnússon,
Abstract The five Regional Fishery Management Organizations dedicated to tunas (tRFMOs) are all either developing or implementing Management Strategy Evaluations (MSEs) to provide advice for the stocks under their competencies. Providing a comparative overview will help tRFMOs to learn from one another and to collaborate on common solutions and may also help to more clearly define the challenges of building decision support tools in contexts of large scientific uncertainty and where management requires ...
Tópico(s): Coral and Marine Ecosystems Studies
2020 - Wiley | Fish and Fisheries
M. Brooks, Kasper Kristensen, Koen J. van Benthem, Árni Magnússon, Casper Willestofte Berg, Anders Nielsen, James S. Hans, Martin Mächler, M. Bolker Benjamin,
Count data can be analyzed using generalized linear mixed models when observations are correlated in ways that require random effects.However, count data are often zero-inflated, containing more zeros than would be expected from the typical error distributions.We present a new package, glmmTMB, and compare it to other R packages that fit zero-inflated mixed models.The glmmTMB package fits many types of GLMMs and extensions, including models with continuously distributed responses, but here we focus ...
Tópico(s): Bayesian Modeling and Causal Inference
2017 - | The R Journal
Ingibjörg G. Jónsdóttir, Árni Magnússon, Unnur Skúladóttir,
Tópico(s): Oceanographic and Atmospheric Processes
2013 - Springer Science+Business Media | Marine Biology
Amid Derayat, Árni Magnússon, Agnar Steinarsson, Björn Thrándur Björnsson,
Tópico(s): Fish Ecology and Management Studies
2013 - Springer Science+Business Media | Fish Physiology and Biochemistry
... the University of Iceland-Háskoli Islands; and the Árni Magnússon Institute. I would also like to thank the ...
Tópico(s): Archaeology and ancient environmental studies
2013 - Routledge | World Archaeology
Benjamin M. Bolker, Beth Gardner, Mark N. Maunder, Casper Willestofte Berg, M. Brooks, Liza S. Comita, Elizabeth E. Crone, Sarah Cubaynes, T. D. Davies, Perry de Valpine, Jessica H. Ford, Olivier Giménez, Marc Kéry, Eun Jung Kim, Cleridy E. Lennert‐Cody, Árni Magnússon, Steve Martell, John C. Nash, Anders Nielsen, Jim Regetz, Hans J. Skaug, Elise F. Zipkin,
Summary Ecologists often use nonlinear fitting techniques to estimate the parameters of complex ecological models, with attendant frustration. This paper compares three open‐source model fitting tools and discusses general strategies for defining and fitting models. R is convenient and (relatively) easy to learn, AD M odel B uilder is fast and robust but comes with a steep learning curve, while BUGS provides the greatest flexibility at the price of speed. Our model‐fitting suggestions range from ...
Tópico(s): Species Distribution and Climate Change
2013 - Wiley | Methods in Ecology and Evolution
T. van der Hammen, Jan Jaap Poos, H.M.J. van Overzee, H.J.L. Heessen, Árni Magnússon, A.D. Rijnsdorp,
Abstract Turbot and brill are widely distributed in the Northeast Atlantic but occur at low abundance. They are ecologically very similar and closely related. The low abundance and the similarities make them particularly interesting to study the population dynamics because it raises the questions how the populations can sustain themselves at low abundances and how turbot and brill avoid strong interspecific competition. Knowledge of both species is hampered by lack of analysed data. The main objective ...
Tópico(s): Marine Bivalve and Aquaculture Studies
2013 - Elsevier BV | Journal of Sea Research
Árni Magnússon, André E. Punt, Ray Hilborn,
Abstract Fisheries management depends on reliable quantification of uncertainty for decision‐making. We evaluate which uncertainty method can be expected to perform best for fisheries stock assessment. The method should generate confidence intervals that are neither too narrow nor too wide, in order to cover the true value of estimated quantities with a probability matching the claimed confidence level. This simulation study compares the performance of the delta method, the bootstrap, and Markov ...
Tópico(s): Statistical Methods and Bayesian Inference
2012 - Wiley | Fish and Fisheries
Klara B. Jakobsdóttir, Heidi Pardoe, Árni Magnússon, Höskuldur Björnsson, Christophe Pampoulie, Daniel E. Ruzzante, Guðrún Marteinsdóttir,
The intense fishing mortality imposed on Atlantic cod in Icelandic waters during recent decades has resulted in marked changes in stock abundance, as well as in age and size composition. Using a molecular marker known to be under selection (Pan I) along with a suite of six neutral microsatellite loci, we analysed an archived data set and revealed evidence of distinct temporal changes in the frequencies of genotypes at the Pan I locus among spawning Icelandic cod, collected between 1948 and 2002, ...
Tópico(s): Fish Ecology and Management Studies
2011 - Wiley | Evolutionary Applications
Dani Boix, Árni Magnússon, Stéphanie Gascón, Jordi Sala, D. Dudley Williams,
Tópico(s): Species Distribution and Climate Change
2011 - Springer Science+Business Media | Wetlands
David Fournier, Hans J. Skaug, Johnoel Ancheta, James N. Ianelli, Árni Magnússon, Mark N. Maunder, Anders Nielsen, John Sibert,
Many criteria for statistical parameter estimation, such as maximum likelihood, are formulated as a nonlinear optimization problem. Automatic Differentiation Model Builder (ADMB) is a programming framework based on automatic differentiation, aimed at highly nonlinear models with a large number of parameters. The benefits of using AD are computational efficiency and high numerical accuracy, both crucial in many practical problems. We describe the basic components and the underlying philosophy of ADMB, ...
Tópico(s): Neural Networks and Applications
2011 - Taylor & Francis | Optimization methods & software
... 6. Ray Hilborn, Trevor A. Branch, Billy Ernst, Arni Magnusson, Carolina V. Minte-Vera, Mark D. Scheuerell, and ...
Tópico(s): Arctic and Russian Policy Studies
2009 - Taylor & Francis | Ocean Development & International Law
Árni Magnússon, D. Dudley Williams,
The role of predation in the regulation of freshwater communities is predicted to decrease along a habitat-duration gradient, from permanent to episodic waters. We tested the role of invertebrate predation in shaping the community structure in a fishless temperate intermittent pond with a three month long hydroperiod by comparing the community structure in two large field enclosures (4.2 m2) with added predators to two enclosures without added predators. The added predators reflected the density ...
Tópico(s): Fish Ecology and Management Studies
2009 - EDP Sciences | Annales de Limnologie - International Journal of Limnology
Abstract Informative data in fisheries stock assessment are those that lead to accurate estimates of abundance and reference points. In practice, the accuracy of estimated abundance is unknown and it is often unclear which features of the data make them informative or uninformative. Neither is it obvious which model assumptions will improve estimation performance, given a particular data set. In this simulation study, 10 hypotheses are addressed using multiple scenarios, estimation models, and reference ...
Tópico(s): Coral and Marine Ecosystems Studies
2007 - Wiley | Fish and Fisheries
D. Dudley Williams, Nynke Heeg, Árni Magnússon,
Tópico(s): Hydrology and Sediment Transport Processes
2007 - Springer Science+Business Media | Hydrobiologia
S. Asghar, Akhtar Hussain, S Ali, A. K. Azad Khan, Árni Magnússon,
Abstract Aims To determine the extent of depressive symptoms in a rural community of Bangladesh and its association with newly recognized diabetes. Methods Depressive symptoms were assessed in 184 newly diagnosed diabetic subjects and 768 randomly selected individuals without diabetes. The Montogomery and Aasberg Depression Rating Scale (MADRS) was used to assess depressive symptoms. A structured interview was performed to obtain socio‐demographic and economic information and anthropometric measures ...
Tópico(s): Cardiac Health and Mental Health
2007 - Wiley | Diabetic Medicine
The importance of top-down and bottom-up mechanisms in lentic systems has largely been explored in stable systems; however, their influence is likely to change along a habitat duration gradient. Using a case study of four intermittent ponds, we test the generality of these paradigms in systems nearing the extreme short end of this gradient. Intermittent ponds fill up with water on a seasonally predictable basis, and are considered more regulated by physicochemical constraints than by biological ...
Tópico(s): Aquatic Ecosystems and Phytoplankton Dynamics
2006 - Schweizerbart science publishers | Archiv für Hydrobiologie
Mónika Varga, Árni Magnússon, K FLEKKOY, Unni Rønneberg, Stein Opjordsmoen,
Level of insight and its relationship to clinical variables and neurocognitive functions was assessed in bipolar I patients. Verbal memory, executive functioning, sustained attention, general intelligence and other neurocognitive functions were compared between 37 chronic in- and outpatients and 31 matched normal controls. Detailed psychiatric interviews were completed to define the level of symptomatology and psychosocial functioning. Insight was assessed by the Scale to Assess Unawareness of Mental ...
Tópico(s): Psychosomatic Disorders and Their Treatments
2006 - Elsevier BV | Journal of Affective Disorders
O. Lingærde, A. R. Fφreland, Árni Magnússon,
Lingjærde O, Fφreland AR, Magnusson A. Can winter depression be prevented by Ginkgo biloba extract? A placebo‐controlled trial. Acta Psychiatr Scand 1999: 100 : 62–66. © Munksgaard 1999. Objective: The aim was to test the hypothesis that the Ginkgo biloba extract PN246, in tablet form (brand name Bio‐Biloba), may prevent the symptoms of winter depression (WD) in patients with seasonal affective disorder (SAD). Method A total of 27 SAD patients were randomized to receive double‐blind placebo or Bio‐Biloba ...
Tópico(s): Biochemical Acid Research Studies
1999 - Wiley | Acta Psychiatrica Scandinavica
Marie Nordström, Lennart Hardell, Árni Magnússon, Hans Hagberg, Anna Rask‐Andersen,
To investigate the role of occupation as a risk factor for hairy cell leukaemia a case-control study on 121 male, hairy cell leukaemia (HCL) patients, and 484 controls matched for age and sex, was conducted. We found significantly elevated risk for HCL among building painters (OR, 5.7; 95% CI, 1.6–20.8; based on six cases and four controls) and construction workers (OR, 3.3; CI, 1.2–9.2; based on seven cases and eight controls). Farming has been suggested as a risk factor in HCL. In this investigation ...
Tópico(s): CAR-T cell therapy research
1997 - Lippincott Williams & Wilkins | European Journal of Cancer Prevention
Amanda Hilmarsson-Dunn, Ari Páll Kristinsson,
... Institute in 1997, since 2006 part of the Árni Magnússon Institute for Icelandic Studies. This survey was carried ...
Tópico(s): Hungarian Social, Economic and Educational Studies
2009 - Taylor & Francis | Current Issues in Language Planning
Suman Barua, Árni Magnússon, Nasiruddin Md. Humayun,
This study presents the results of analytical assessment of offshore shrimp stock in Bangladesh marine waters. A time series of annual catch per unit effort (CPUE) was derived from commercial logbook data during the period from 1986 to 2016 and used as a turning series for a Schaefer biomass model. The current stock size and annual harvest rate were estimated to be around 20300 t and 20% respectively, with the stock size increasing in the last ten years. The estimated maximum sustainable yield (MSY) ...
Tópico(s): Marine Bivalve and Aquaculture Studies
2018 - Indian Council of Agricultural Research | Indian Journal of Fisheries
Itai Beeri, Magnús Árni Magnússon,
This article examines and compares governance relations of big cities in relatively small nation states in Reykjavík, Iceland, and Tel Aviv, Israel. The international literature has extensively explored governance at the municipal and national levels. We aim to enlarge this discussion by examining the unique role, experience and dynamics of large, dominant cities vis-à-vis other governance entities in the era of local governance. Using a grounded theory approach we suggest the frameworks of 'building ...
Tópico(s): Political Systems and Governance
2019 - | Lex localis - Journal of Local Self-Government
Shaheen Asghar, Árni Magnússon, Akhtar Hussain, Lien My Diep, Bishwajit Bhowmik, Per Medbøe Thorsby,
Aims: To clarify the relationship between depression and glucose metabolism using sensitive measures of insulin resistance, and to assess if remission of depression results in enhanced insulin sensitivity. Methods: An intervention study to quantify changes in insulin sensitivity before and after treatment of depression was carried out. Twenty six Pakistani women with newly diagnosed depression underwent euglycemic insulin clamp to measure insulin sensitivity at inclusion and again after treatment ...
Tópico(s): Diabetes, Cardiovascular Risks, and Lipoproteins
2012 - Scientific Research Publishing | International Journal of Clinical Medicine