scholarly journals Assesssing the role of humans in Greater Antillean land vertebrate extinctions: new insights from Cuba

2020 ◽  
Author(s):  
Johanset Orihuela ◽  
Lázaro W. Viñola ◽  
Osvaldo Jiménez Vázquez ◽  
Alexis M. Mychajliw ◽  
Odlanyer Hernández de Lara ◽  
...  
Keyword(s):  
Potential Role ◽  
Late Quaternary ◽  
Ecological Factors ◽  
High Rate ◽  
Archaeological Record ◽  
Cultural Groups ◽  
Archaeological Data ◽  
The Caribbean ◽  
Land Vertebrate

ABSTRACTThe Caribbean archipelago is a hotspot of biodiversity characterized by a high rate of extinction. Recent studies have examined these losses, but the causes of the Antillean Late Quaternary vertebrate extinctions, and especially the role of humans, are still unclear. Current results provide support for climate-related and human-induced extinctions, but often downplaying other complex bio-ecological factors that are difficult to model or to detect from the fossil and archaeological record. Here, we discuss Caribbean vertebrate extinctions and the potential role of humans derived from new and existing fossil and archaeological data from Cuba. Our results indicate that losses of Cuba’s native fauna occurred in three waves: one during the late Pleistocene and early Holocene, a second during the middle Holocene, and a third one during the last 2 ka, coinciding with the arrival of agroceramists and the early Europeans. The coexistence of now-extinct species with multiple cultural groups in Cuba for over 4 ka implies that Cuban indigenous non-ceramic cultures exerted far fewer extinction pressures to native fauna than the later agroceramists and Europeans that followed. This suggests a determinant value to increased technological sophistication and demographics as the most plausible effective extinction drivers.

scholarly journals Pyrite Biooxidation by Acidophilic Archaea AcidiplasmaSp. MBA-1 Under Varied Conditions

2022 ◽  
Author(s):  
Aleksandr Bulaev
Keyword(s):  
Potential Role ◽  
Sulfide Mineral ◽  
High Rate ◽  
Mineral Nutrient ◽  
Acidophilic Microorganisms ◽  
Moderately Thermophilic ◽  
Operational Temperature ◽  
Low Levels ◽  
Acidophilic Archaea

The goal of this research was to study pyrite (FeS2 ) bioleaching by a strain of the genus Acidiplasma under different conditions (temperature, pH) to evaluate the potential role of Acidiplasma representatives in biooxidation of this sulfide mineral. To compare the role of Acidiplasma archaea in pyrite biooxidation with other acidophilic microorganisms, the experiments were also performed with representatives of othergroups of microorganisms predominant in biohydrometallurgical processes.Pure and mixed cultures of moderately thermophilic acidophilic microorganisms, including strains Acidithiobacillus caldus MBC-1, Sulfobacillusthermosulfidooxidans VKMV 1269T and Acidiplasmasp. MBA-1, were used. The experiments were carried out in flasks with 100 mL of mineral nutrient medium supplemented with 0.02% yeast extract and 1 g of pyrite on a rotary shaker for 20 days. Bioleaching was performed at 45, 55, and 60∘С. The results demonstrated that the representatives of the genus Acidiplasmaprovided a comparatively higher rate of pyrite bioleaching at high temperatures (55 and 60∘C) and low pH of the medium (1.0). Thus, according to the results, strains of thegenus Acidiplasma may provide a high rate of pyrite bioleaching at low levels ofpH. Therefore, the results suggest that archaea of the genus Acidiplasma may be promising microorganisms to improve bioleaching processes with an increase in the operational temperature, which is usually maintained at 40–45∘C in industrial-scale reactors. Keywords: biomining, bioleaching, acidophilic microorganisms, sulfide minerals, pyrite

Communicating User Experience

2015 ◽  
Vol 7 (2) ◽  
pp. 14-26 ◽  
Author(s):  
Hilary A. Sarat St. Peter
Keyword(s):  
Project Management ◽  
User Experience ◽  
Potential Role ◽  
High Rate ◽  
User Centered Design ◽  
Resource Constrained ◽  
Project Failure ◽  
Ux Design ◽  
User Centered

Research in the ICT4D field implicates lack of user-centered design in the high rate of ICTD project failure. The field of user experience (UX) offers potentially fruitful approaches for user-centered design. In the ICTD context, these principles and methods clash with the triple constraints of project management (time, scope and funding). This paper introduces the user persona from UX design as a powerful tool for considering the user's perspective within resource-constrained ICTD projects. Although personas appear simple, they introduce complex communicative affordances, pragmatic benefits, and risks to ICTD projects. A brief conclusion revisits the larger problem of ICTD project failure, and considers the potential role of personas in addressing this problem.

scholarly journals Synergy between Allopatry and Ecology in Population Differentiation and Speciation

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Yann Surget-Groba ◽  
Helena Johansson ◽  
Roger S. Thorpe
Keyword(s):  
Population Differentiation ◽  
Ecological Factors ◽  
Ecological Speciation ◽  
Morphological Characters ◽  
Relative Importance ◽  
Sharp Reduction ◽  
Diversity Pattern ◽  
Allopatric Divergence ◽  
The Caribbean

The general diversity pattern of the Caribbean anole radiation has been described in detail; however, the actual mechanisms at the origin of their diversification remain controversial. In particular, the role of ecological speciation, and the relative importance of divergence in allopatry and in parapatry, is debated. We describe the genetic structure of anole populations across lineage contact zones and ecotones to investigate the effect of allopatric divergence, natural selection, and the combination of both factors on population differentiation. Allopatric divergence had no significant impact on differentiation across the lineage boundary, while a clear bimodality in genetic and morphological characters was observed across an ecotone within a single lineage. Critically, the strongest differentiation was observed when allopatry and ecology act together, leading to a sharp reduction in gene flow between two lineages inhabiting different habitats. We suggest that, for Caribbean anoles to reach full speciation, a synergistic combination of several historical and ecological factors may be requisite.

scholarly journals The distributional consequences of social distancing on poverty and labour income inequality in Latin America and the Caribbean

2021 ◽  
Author(s):  
Isaure Delaporte ◽  
Julia Escobar ◽  
Werner Peña
Keyword(s):  
Income Inequality ◽  
Latin American ◽  
Potential Role ◽  
Income Loss ◽  
Social Distancing ◽  
Labour Income ◽  
Distributional Consequences ◽  
The Caribbean ◽  
Latin American And Caribbean

AbstractThis paper estimates the potential distributional consequences of the first phase of the COVID-19 lockdowns on poverty and labour income inequality in 20 Latin American and Caribbean (LAC) countries. We estimate the share of individuals that are potentially able to remain active under the lockdown by taking into account individuals’ teleworking capacity but also whether their occupation is affected by legal workplace closures or mobility restrictions. Furthermore, we compare the shares under the formal (de jure) lockdown policies assuming perfect compliance with the shares under de facto lockdowns where there is some degree of non-compliance. We then estimate individuals’ potential labour income losses and examine changes in poverty and labour income inequality. We find an increase in poverty and labour income inequality in most of the LAC countries due to social distancing; however, the observed changes are lower under de facto lockdowns, revealing the potential role of non-compliance as a coping strategy during the lockdowns. Social distancing measures have led to an increase in inequality both between and within countries. Lastly, we show that most of the dispersion in the labour income loss across countries is explained by the sectoral/occupational employment structure of the economies.

Polyploidy and possible implications for the evolutionary history of some Australian Danthonieae

2010 ◽  
Vol 58 (1) ◽  
pp. 23 ◽  
Author(s):  
C. Waters ◽  
B. G. Murray ◽  
G. Melville ◽  
D. Coates ◽  
A. Young ◽  
...  
Keyword(s):  
Evolutionary History ◽  
Potential Role ◽  
New South ◽  
Ecological Factors ◽  
Distribution Patterns ◽  
Low Frequencies ◽  
Rapid Speciation ◽  
South Wales ◽  
History Of

Polyploidy is a widespread feature of some plants that allows for rapid speciation and occurs widely in Poaceae. However, there have been few studies of Australian native grasses reporting the distribution patterns of cytotypes and examining the potential role of different cytotypes in adaptation. We determined chromosome number for 48, 113, 8, 43 and 33 plants of Austrodanthonia bipartita (Link) H.P.Linder, A. caespitosa (Gaudich.) H.P.Linder, A. eriantha (Lindl.) H.P.Linder, A. fulva (Vickery) H.P.Linder and A. setacea (R.Br.) H.P.Linder, respectively, representing 28 wild populations collected in central western New South Wales. A widespread distribution is reported for tetraploids (2n = 48), whereas diploids (2n = 24) and a limited number of hexaploids (2n = 72) appear to be associated with northern and western populations. In all populations, coexistent cytotypes were found, although tetraploids were the most widespread cytotype for the most commonly occurring species, A. caespitosa. The occurrence of low frequencies of putative intermediate cytotypes, particularly triploids, in all five species provides evidence for inter-specific hybridisation and/or intra-specific crossing between cytotypes. The lack of common ecological factors (climate, edaphic or micro-site) that clearly distinguish diploid from tetraploid A. caespitosa plants provides further evidence for hybridisation between cytological races of this species.

Defining issues

2015 ◽  
Author(s):  
Dennis Harding
Keyword(s):  
Middle Ages ◽  
Significant Shift ◽  
Archaeological Record ◽  
Current Generation ◽  
Archaeological Data ◽  
Secular Society ◽  
The Dead ◽  
The Many ◽  
Archaeological Cultures

The universality of human mortality is the commonest of truisms, but the prospect of mortality evidently has weighed differently on different societies over the course of human history, from the oppressive burden of the later Middle Ages to the more relaxed live-for-the-present-ism of the current generation. The disposal of the dead is at basis a hygienic necessity that is recognized in all but the most socially disrupted circumstances, but the manner of disposal may reveal attitudes of society towards death and the concept of afterlife, or the role of the dead in the continuing life of the community. Even in our contemporary secular society, relatives of the victims of murder or abduction or of death in foreign parts crave the recovery of bodies for due burial, without which they apparently cannot ‘achieve closure’, a condition of grace that might have been considered essential to the dead, but which evidently matters equally to the bereaved. The discipline of archaeology is methodologically disposed to distort the reality of the past in that it seeks to recognize ordered patterns where in reality diversity and apparent irrationality must have been inherent. The keystone of Childe’s approach, the identification of archaeological cultures, was dependent upon recurrence of diagnostic types in association, which would permit the comparison of one cultural assemblage with another in time or space. Even in processual and post-processual approaches the essence is to reduce the ever-burgeoning data-base to some semblance of order, without which it is impossible for interpretation to proceed, other than intuitively, empathically, or experientially, that is, based upon imaginative reconstruction rather than being inferred, however inadequately, from archaeological data. The consequence of this process of classification has been to emphasize certain outstanding classes of data, like long barrows, stone circles, or hillforts, as typical of their period or region, at the expense of a subtler analysis of the many possible variations of settlement or burial sites that are detectable, even from the surviving archaeological record. In recent years there has been a significant shift in archaeological approaches to burial data.

ARTISANS AND TRADERS IN THE EARLY BYZANTINE CITY: EXPLORING THE LIMITS OF ARCHAEOLOGICAL EVIDENCE

2006 ◽  
Vol 3 (1) ◽  
pp. 371-411
Author(s):  
Enrico Zanini
Keyword(s):  
Middle Class ◽  
Social Groups ◽  
Archaeological Record ◽  
Economic Role ◽  
Archaeological Data ◽  
Research Perspectives ◽  
The Social ◽  
Written Sources ◽  
Early Byzantine

The application of research methodologies and strategies derived from western urban archaeology to Early Byzantine contexts renders traditionally obscure social groups, like the productive and commercial “middle class”, visible in the archaeological record. Working from both a re-examination of written sources and an assessment of new archaeological data, it seems possible to trace the evolution of the social and economic role of artisans and shopkeepers in the Early Byzantine city between the 5th and 7th centuries. At the same time, the investigation of such undetermined social groups calls for a reflection about the limits of archaeological knowledge and the need for closer interaction between different disciplines and research perspectives.

scholarly journals Continental variation in relative hippocampal volume in birds: the phylogenetic extent of the effect and the potential role of winter temperatures

2005 ◽  
Vol 1 (3) ◽  
pp. 330-333 ◽  
Author(s):  
László Zsolt Garamszegi ◽  
Jeffrey R Lucas
Keyword(s):  
North American ◽  
Potential Role ◽  
Ecological Factors ◽  
Hippocampal Volume ◽  
North American Species ◽  
Food Hoarding ◽  
Evolutionary Spectrum ◽  
Winter Temperatures ◽  
Using Data

Hippocampal (HC) volume has been hypothesized to increase with an increase in food-hoarding specialization in corvids and parids. Recent studies revealed that (i) the HC/hoarding relationship is significant when a difference in HC volume between Eurasian and North American species is controlled for and (ii) the evolutionary association has been acting on a broader phylogenetic context involving avian families outside the Corvidae and Paridae. However, the phylogenetic extent of the continent effect has not been previously addressed. Using data representing 48 avian species, we performed a phylogenetic analysis to test if continental effects are important in a wider evolutionary spectrum. Our results support the observation that Eurasian species have generally larger HC than North American species if variation in food hoarding, which also varied between continents, was held constant. Surprisingly, the relationship between continental distribution and relative HC volume was significant when we included only non-hoarding families in our analysis, indicating that the extent of the continent effect is much broader than originally described. We investigated the potential role of minimal winter temperatures at the northernmost distribution borders in mediating continent effects. The effect of winter temperatures on HC volume was weak and it did not vary consistently along continents. We suggest that the general continental differences in relative HC size are independent of food hoarding and that its determinants should be sought among other ecological factors and life-history traits.

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

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