scholarly journals Time and spatial trends in landing per unit of effort as support to fisheries management in a multi-gear coastal fishery

2021 ◽  
Author(s):  
P. Leitão ◽  
L. Sousa ◽  
M. Castro ◽  
A. Campos
Keyword(s):  
Linear Models ◽  
Species Abundance ◽  
Explanatory Variables ◽  
Nao Index ◽  
Regional Management ◽  
Density Maps ◽  
Spatial Trends ◽  
Management Plans ◽  
Definition Of ◽  
North And South

AbstractLandings by the multi-gear coastal fleet operating off the Portuguese continental coast include near 300 species, from which only a few are the object of management plans. In this study, daily landings (kg trip_1) are used, along with an effort indicator, vessel length overall (LoA), to obtain landings per unit of effort (LPUE) as a proxy for the species relative abundance for a total of 48 species. LPUE indices were then used as a response variable in linear models where year (2012-2016), season, region (north and south) and NAO index were included as explanatory variables. Season and region effects were found to significantly affect species abundance for a total of 41 and 40 species respectively, while interannual effects were found to be significant for 19 species, and finally, the NAO index for 3 species. Global LPUE density maps are presented for a number of selected species and a subsample of trips where VMS records were available. For the species analysed, it is proposed that geographic and seasonal changes in LPUE indexes can be used to understand trends in abundance and obtain information that can be used in support of the definition of regional management plans.

scholarly journals The unemployment rate in relation with the number of the economic subjects registered units

2004 ◽  
Vol 52 (6) ◽  
pp. 7-18
Author(s):  
Jaroslav Dufek
Keyword(s):  
Unemployment Rate ◽  
Linear Models ◽  
Point Of View ◽  
The Political ◽  
Legal Form ◽  
Explanatory Variables ◽  
High Elasticity ◽  
State Organizations ◽  
Definition Of ◽  
Multiple Factor

This article deals with one-factor and multiple-factor linear models definition of an unemployment rate. As the explanatory variables are considered numbers of registered units of economic subjects to thousand inhabitants separated according to the political economy branch and according to the legal form. Relative to the greatly different sizes of registered units are coefficients of elasticity for average levels calculated for possibility comparison their force. From the branch point of view show industry, building, education, health service and other services relative high elasticity, from the legal form point of view are there state organizations, businessmen and free professions. Multiple models contains variables, which were taken out on the factor analysis base.

Life Course Socioeconomic Position, Intergenerational Social Mobility, and Hypertension Incidence in ELSA-Brasil

2021 ◽  
Author(s):  
José Aparecido Soares Lopes ◽  
Luana Giatti ◽  
Rosane Harter Griep ◽  
Antonio Alberto da Silva Lopes ◽  
Sheila Maria Alvim Matos ◽  
...  
Keyword(s):  
Life Course ◽  
Social Mobility ◽  
Socioeconomic Position ◽  
Linear Models ◽  
Sociodemographic Factors ◽  
Incidence Rates ◽  
Explanatory Variables ◽  
Rate Ratios

Abstract Background Life course epidemiology is a powerful framework to unravel the role of socioeconomic position (SEP) disparities in hypertension (HTN). This study investigated whether life course SEP is associated with HTN incidence. Specifically, to test whether cumulative low SEP throughout life and unfavorable intergenerational social mobility increased HTN incidence. METHODS Longitudinal analysis of 8,754 ELSA-Brasil participants without HTN or cardiovascular in visit 1 (2008–2010). The response variable was the incidence of HTN between visits 1 and 2 (2012–2014). The explanatory variables were childhood, youth, and adulthood SEP, cumulative low SEP, and intergenerational social mobility. Associations were estimated by incidence rate ratios (IRRs) obtained by generalized linear models, with Poisson distribution and logarithmic link function, after adjustment for sociodemographic, behavioral, and health factors. RESULTS The incidence of HTN was 43.2/1,000 person-years, being higher in males, elderly (70–74 years), self-declared black, and low SEP individuals. After considering sociodemographic factors, low SEP in childhood, youth, and adulthood remained statistically associated with increased HTN incidence. Individuals in the third (IRR: 1.26; 95% confidence interval (CI): 1.11–1.44) and fourth top quartiles (IRR: 1.29; 95% CI: 1.11–1.49) of cumulative low SEP, vs. first, as well as those with low stable intergenerational trajectory (IRR: 1.29; 95% CI: 1.16–1.43), vs. high stable, also had increased HTN incidence rates. Conclusions Socioeconomic disparities at all phases of the life cycle appear to raise HTN incidence rates, being the individuals with greater accumulation of exposure to low SEP and with more unfavorable intergenerational mobility at greatest risk, even in a short follow-up time.

Updating the knowledge of the flower flies (Diptera: Syrphidae) from Chile: Illustrated catalog, extinction risk and biological notes

Zootaxa ◽  
2021 ◽  
Vol 4959 (1) ◽  
pp. 1-178
Author(s):  
RODRIGO M. BARAHONA-SEGOVIA ◽  
PAMELA RIERA ◽  
LAURA PAÑINAO-MONSÁLVEZ ◽  
VICENTE VALDÉS GUZMÁN ◽  
PATRICIA HENRÍQUEZ-PISKULICH
Keyword(s):  
Extinction Risk ◽  
Critical Role ◽  
Floral Biology ◽  
Iucn Red List ◽  
Decomposition Of Organic Matter ◽  
Management Plans ◽  
Flower Flies ◽  
Iucn Red List Criteria ◽  
Definition Of ◽  
First Time

Syrphidae, more commonly known as flower flies, are considered one of the most important Diptera families worldwide because of their critical role in pollination, biological control and decomposition of organic matter. The study of these flies in Chile has stagnated due to a lack of local experts as well as the absence of an updated catalog of species. This study is an attempt to remedy the latter of these issues by providing an illustrated and updated catalog to the Syrphidae of Chile. Species are presented under currently accepted names, with synonyms and previous combinations listed and original references. Type localities, world and Chilean distribution by geopolitical Chilean regions, taxonomic and biological notes, a complete record of bibliographic references and extinction risk under IUCN Red List criteria are provided. This catalog recognizes 132 species of Syrphidae, belonging to four subfamilies (Eristalinae, Microdontinae, Pipizinae and Syrphinae), 13 tribes and 47 genera. A total of 46 species (34.84 %) is restricted to the geopolitical territory of Chile. Eight species are considered exotic, one is considered incertae sedis and three are based on doubtful records. Seventeen species of 10 different genera (Copestylum Macquart, 1846; Dolichogyna Macquart, 1842; Eosalpingogaster Hull, 1949b; Eupeodes Osten Sacken, 1877; Meromacrus Rondani, 1848; Palpada Macquart, 1834; Paragus Latreille, 1804; Sphiximorpha Rondani, 1850; Sterphus Philippi, 1865 and Toxomerus Macquart, 1855) are reported from Chile for the first time. A total of 44 species (33.33 %) reported from Chile are directly threatened by human activities such as agriculture, forestry, mining and/or urbanization and indirectly by climate change. The gaps found in the geographic distribution of Chilean flower fly species and what it means for its use by disciplines such as ecology, floral biology and agronomy, are discussed. In addition, the use of this illustrated catalog for biological conservation, the potential definition of priority areas and ecosystem management plans based on this group of Diptera are also discussed. 

Car Ownership and the Built Environment: A Spatial Modeling Approach

2021 ◽  
pp. 036119812110494
Author(s):  
Jerome Laviolette ◽  
Catherine Morency ◽  
Owen D. Waygood ◽  
Konstadinos G. Goulias
Keyword(s):  
Built Environment ◽  
Spatial Dependence ◽  
Linear Models ◽  
Census Data ◽  
Model Specification ◽  
Car Ownership ◽  
Grocery Stores ◽  
Modeling Framework ◽  
Explanatory Variables ◽  
Environment Variables

Car ownership is linked to higher car use, which leads to important environmental, social and health consequences. As car ownership keeps increasing in most countries, it remains relevant to examine what factors and policies can help contain this growth. This paper uses an advanced spatial econometric modeling framework to investigate spatial dependences in household car ownership rates measured at fine geographical scales using administrative data of registered vehicles and census data of household counts for the Island of Montreal, Canada. The use of a finer level of spatial resolution allows for the use of more explanatory variables than previous aggregate models of car ownership. Theoretical considerations and formal testing suggested the choice of the Spatial Durbin Error Model (SDEM) as an appropriate modeling option. The final model specification includes sociodemographic and built environment variables supported by theory and achieves a Nagelkerke pseudo-R2 of 0.93. Despite the inclusion of those variables the spatial linear models with and without lagged explanatory variables still exhibit residual spatial dependence. This indicates the presence of unobserved autocorrelated factors influencing car ownership rates. Model results indicate that sociodemographic variables explain much of the variance, but that built environment characteristics, including transit level of service and local commercial accessibility (e.g., to grocery stores) are strongly and negatively associated with neighborhood car ownership rates. Comparison of estimates between the SDEM and a non-spatial model indicates that failing to control for spatial dependence leads to an overestimation of the strength of the direct influence of built environment variables.

scholarly journals Generalized linear models with random effects for the description of data with excess zeros

2011 ◽  
Vol 54 (6) ◽  
pp. 661-675
Author(s):  
N. Mielenz ◽  
K. Thamm ◽  
M. Bulang ◽  
J. Spilke
Keyword(s):  
Random Effects ◽  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Linear Models ◽  
Negative Binomial ◽  
Detailed Comparison ◽  
Response Scale ◽  
Explanatory Variables ◽  
Excess Zeros ◽  
Explanatory Factors

Abstract. In this paper count data with excess zeros and repeated observations per subject are evaluated. If the number of values observed for the zero event in the trial substantially exceeds the expected number (derived from the Poisson or from the negative binomial distribution), then there is an excess of zeros. Hurdle and zero-inflated models with random effects are available in order to evaluate this type of data. In this paper both model approaches are presented and are used for the evaluation of the number of visits to the feeder per cow per hour. Finally, for the analysis of the target trait a hurdle model with random effects based on a negative binomial distribution was used. This analysis was derived from a detailed comparison of models and was needed because of a simpler computer implementation. For improved interpretation of the results, the levels of the explanatory factors (for example, the classes of lactation) were not averaged in the link scale, but rather in the response scale. The deciding explanatory variables for the pattern of visiting activities in the 24-hour cycle are the milking and cleaning times at hours 4, 7, 12 and 20. The highly significant differences in the visiting frequencies of cows of the first lactation and those of higher lactations were explained by competition for access to the feeder and thus to the feed.

scholarly journals Anthropocene and “Development”: Intertwined Trajectories Since the Beginning of The Great Acceleration

2020 ◽  
Vol 24 (5) ◽  
pp. 400-413
Author(s):  
Marina Dantas de Figueiredo ◽  
Fábio Freitas Schilling Marquesan ◽  
José Miguel Imas
Keyword(s):  
Developmental Model ◽  
Environmental Crisis ◽  
Environmental Consequences ◽  
The North ◽  
Development Policies ◽  
Global North ◽  
Definition Of ◽  
Great Acceleration ◽  
North And South

ABSTRACT Objectives: We aim to propose the thesis that the trajectories of the Anthropocene and the current mainstream understandings of development are intertwined from the beginning. It means that the Anthropocene and the “development” are coetaneous: the implementation of development policies for the so-considered underdeveloped regions started to happen at the same time of what is known as The Great Acceleration of production, consumption and environmental degradation in a global level. Method: In this conceptual paper, we adopt a decolonial critique as an analytical lens and argue that different geopolitical positions may be necessary for approaching the issue of the Anthropocene from epistemological reflections that can include the cultural and political context of the production and reproduction of local knowledge. Results: Our theoretical argumentation sheds light on the role of Global North and South relations in shaping the environmental crisis. Latin America (LA) exemplifies the modus operandi of the intertwinement of the practical effects of development policies and the environmental consequences underlying the Anthropocene, in which natural resources are over-explored to satisfy export-oriented trade, from the South toward the North. LA is not only a propitious context to show the validity of our thesis, but also the source of alternatives to such developmental model. Conclusion: The emphasis on development as a cause of the Anthropocene supports The Great Acceleration thesis. The proposition of the name Developmentocene comes from the thesis that development and Anthropocene are coetaneous, the intertwinement of both resulting in the very definition of the new epoch.

scholarly journals The relative effect of altitude and aspect on saxicolous lichen communities at mountain summits from central-west of Argentina

Rodriguésia ◽  
2021 ◽  
Vol 72 ◽  
Author(s):  
Santiago Martín Costas ◽  
Norma Canton ◽  
Juan Manuel Rodríguez
Keyword(s):  
Linear Models ◽  
Climatic Factors ◽  
Elevation Gradient ◽  
Relative Effect ◽  
Lichen Species ◽  
Substrate Type ◽  
Rock Outcrops ◽  
The North ◽  
Relative Cover ◽  
North And South

Abstract The altitudinal patterns of lichen communities in altitudinal gradients are very variable. The changes that occur along the mountains depend on climatic factors but also on microsite variables such as substrate type and aspect. The effect of altitude and aspect on richness, cover and composition of saxicolous lichens communities along an elevation gradient in extra Andean mountains from the central-west of Argentina was studied. Rock outcrops on the north and south aspect of three mountain summits distributed between 2,500 and 4,500 m.a.s.l. were sampled. Lichen species present in a 20 × 20 cm square were identified and the relative cover was measured using digital photography. Richness, cover and composition were analyzed through linear models and multivariate analysis. Fifty-eight saxicolous lichen species were identified between the three sites. Richness and cover were maximum at middle altitude. Also compositional differences among communities of each mountain summit were found. Finally, the effect of the aspect was significant at lower altitudes for cover and composition.

Challenges for Diadromous Fishes in a Dynamic Global Environment

2009 ◽  
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Generalized Additive Models ◽  
Habitat Characteristics ◽  
Explanatory Variables ◽  
Temperature And Precipitation ◽  
Management Plans ◽  
The Face ◽  
Uncertain Future ◽  
Diadromous Species

<em>Abstract</em>.-Climate change can have an effect on species distributions. The 1900 distribution and potential future distribution of diadromous fish in Europe, North Africa, and the Middle East were explored using generalized additive models (GAMs) and selected habitat characteristics of 196 basins. Robust presence-absence models were built for 20 of the 28 diadromous species in the study area using longitude, annual temperature, drainage surface area, annual precipitation, and source elevation as explanatory variables. Inspection of the relationship between each variable and species presence-absence revealed that the GAMs were generally interpretable and plausible. Given the predicted rise in annual temperature in climate models ranging between 1°C and 7°C by 2100, the fish species were classified according to those losing suitable basins, those gaining suitable basins, and those showing little or no change. It was found that the climate envelopes based on temperature and precipitation for diadromous species would, in general, be shifted farther northeastwards by 2100, and these shifting ranges were comparable with those assessed in other studies. The uncertain future of some species was highlighted, and it was concluded that conservation policy and management plans will need to be revised in the face of climate change.

More generalized linear modelling.

2021 ◽  
pp. 171-186
Author(s):  
Donald Quicke ◽  
Buntika A. Butcher ◽  
Rachel Kruft Welton
Keyword(s):  
Generalized Linear Models ◽  
Count Data ◽  
Binary Data ◽  
Linear Models ◽  
Explanatory Variable ◽  
Response Variable ◽  
Explanatory Variables ◽  
Continuous Response ◽  
Generalized Linear Modelling ◽  
Linear Modelling

Abstract This chapter employs generalized linear modelling using the function glm when we know that variances are not constant with one or more explanatory variables and/or we know that the errors cannot be normally distributed, for example, they may be binary data, or count data where negative values are impossible, or proportions which are constrained between 0 and 1. A glm seeks to determine how much of the variation in the response variable can be explained by each explanatory variable, and whether such relationships are statistically significant. The data for generalized linear models take the form of a continuous response variable and a combination of continuous and discrete explanatory variables.

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