Search results for "general [Binaries]"
showing 10 items of 15079 documents
Biological adaptation in light of the Lewontin–Williams (a)symmetry
2022
Neo-Darwinism characterises biological adaptation as a one-sided process, in which organisms adapt to their environment but not vice versa. This asymmetric relationship – here called Williams’ asymmetry – is called into question by Niche Construction Theory, which emphasises that organisms and their environments often mutually affect each other. Here we clarify that Williams’ asymmetry is specifically concerned with (quasi-) directed modifications towards phenotypes that increase individual fitness. This directedness – which drives the adaptive fit between organism and environment – entails far more than the mere presence of cause-effect relationships. We argue that difficulties with invoki…
Removal of ammonium ions from aqueous solutions using alkali-activated analcime as sorbent
2023
Five alkali-activated analcime (ANA) sorbents (ANA-MK 1, ANA 2, ANA 3, ANA-MK 4, and ANA-MK 5) were developed for ammonium (NH4+) ion removal. Acid treatment and calcination were used as pre-treatments for analcime, and metakaolin (MK) was used as a blending agent in three sorbents. Sorption experiments were performed to evaluate the effects of sorbent dosage (1–20 g L−1), initial NH4+ ion concentration (5–1000 g L−1), and contact time (1 min–24 h). ANA-MK 1, ANA 2, and ANA-MK 4 were the most efficient sorbents for NH4+ ion removal, with a maximum experimental sorption uptake of 29.79, 26.00, and 22.24 mg g−1, respectively. ANA 3 and ANA-MK 5 demonstrated…
Stakeholder salience for small businesses : a social proximity perspective
2017
This paper advances stakeholder salience theory from the viewpoint of small businesses. It is argued that the stakeholder salience process for small businesses is influenced by their local embeddedness, captured by the idea of social proximity, and characterised by multiple relationships that the owner-manager and stakeholders share beyond the business context. It is further stated that the ethics of care is a valuable ethical lens through which to understand social proximity in small businesses. The contribution of the study conceptualises how the perceived social proximity between local stakeholders and small business owner-managers influences managerial considerations of the legitimacy, …
Effect of Cycloplegia on Blur Perception Thresholds as Measured by Source Method
2017
Abstract One of the advantages of a source method over observer method in blur perception measurements is better control of a stimulus blur level, which is achieved with computerised image processing unlike the observer method that requires optical defocusing of the observer. The aim of this study was to determine if paralysation of accommodation has effect on blur perception thresholds, thereby evaluating its necessity in such experiments. Blur perception thresholds (just noticeable blur, clear image, recognition, and non-resolvable blur thresholds) were evaluated with (using cycloplegia) and without paralysed accommodation to determine effect on blur perception. A computerised low-pass sp…
The Export Strategy and SMEs Employment Resilience During Slump Periods
2021
Abstract The Spanish economy was the most hit by the Great Recession. It suffered a greater decrease in the gross domestic product (GDP) (affecting especially internal demand). However, it suffered a greater increase in exports (the so-called Spanish “miracle”). Particularly, Spanish SMEs incorporation into exports has been spectacular since 2008. Further, this has coincided with a huge increase in unemployment. Therefore, our main objective is to investigate the moderating role of exports in job destruction associated with recessive contexts of domestic demand using Spanish manufacturing SMEs as a case study. We obtain for SMEs that export participation helps compensate for the decrease in…
SparseHC: A Memory-efficient Online Hierarchical Clustering Algorithm
2014
Computing a hierarchical clustering of objects from a pairwise distance matrix is an important algorithmic kernel in computational science. Since the storage of this matrix requires quadratic space with respect to the number of objects, the design of memory-efficient approaches is of high importance to this research area. In this paper, we address this problem by presenting a memory-efficient online hierarchical clustering algorithm called SparseHC. SparseHC scans a sorted and possibly sparse distance matrix chunk-by-chunk. Meanwhile, a dendrogram is built by merging cluster pairs as and when the distance between them is determined to be the smallest among all remaining cluster pairs. The k…
Mapping soil water content under sparse vegetation and changeable sky conditions: comparison of two thermal inertia approaches
2013
A critical analysis of a thermal inertia approach to map surface soil water content on bare and sparsely vegetated soils by means of remotely sensed data is reported. The study area is an experimental field located in Barrax, Spain. In situ data were acquired within the Barrax 2011 research project. An advanced hyperspectral scanner airborne imager provides images in the visible/near-infrared and thermal infrared bands. Images were acquired both in day and night times by the Instituto Nacional de Técnica Aeroespacial between 12th and 13th of June 2011. The scene covers a corn irrigation pivot surrounded by bare soil, where a set of in situ data have been collected both previously and simult…
Hétérogénéité spatiale : principes et méthodes
2004
Spatial Heterogeneity : Principles and Methods This article has a dual purpose . First , it describes the main econometric specifications which can be used to represent spatial heterogeneity , reflected in an instability of parameters in space and / or a heteroscedasticity of error terms . Only the specifications valid in cross-section are examined . Second , it explains the links between spatial heterogeneity and autocorrelation , the other major feature of localised data , defined by the absence of independence between geographical observations . In particular , we look at the extent to which traditional tests of heteroscedasticity or instability need to be amended to take account of spat…
Joint second-order parameter estimation for spatio-temporal log-Gaussian Cox processes
2018
We propose a new fitting method to estimate the set of second-order parameters for the class of homogeneous spatio-temporal log-Gaussian Cox point processes. With simulations, we show that the proposed minimum contrast procedure, based on the spatio-temporal pair correlation function, provides reliable estimates and we compare the results with the current available methods. Moreover, the proposed method can be used in the case of both separable and non-separable parametric specifications of the correlation function of the underlying Gaussian Random Field. We describe earthquake sequences comparing several Cox model specifications.
The effect of blue-light-blocking lenses on retinal straylight
2021
Sometimes yellow-tinted lenses are recommended to help improve visual quality. As yellow lenses filter blue light, it is believed that their use could decrease the intensity of scattered light in the eye (retinal straylight). However, the results of some studies have contradicted this assumption (Van Os et al. 2017). Currently various nontinted blue-light-blocking lenses are used to protect the eyes from short-wavelength light. The objective of this study was to determine whether blue-light-blocking lenses affect the levels of retinal straylight in the eye. A straylight meter (C-Quant, Oculus) was used for retinal straylight measurements. The measurements were performed under four different…