scholarly journals Analysis of phenotypes altered by temperature stress and hipermutability in Drosophila willistoni

2008 ◽  
Vol 98 (3) ◽  
pp. 345-354 ◽  
Author(s):  
Marícia F. D'Ávila ◽  
Rosane N. Garcia ◽  
Elgion L. S. Loreto ◽  
Vera Lúcia da S. Valente

Drosophila willistoni (Sturtevant, 1916) is a species of the willistoni group of Drosophila having wide distribution from the South of USA (Florida) and Mexico to the North of Argentina. It has been subject of many evolutionary studies within the group, due to its considerable ability to successfully occupy a wide range of environments and also because of its great genetic variability expressed by different markers. The D. willistoni 17A2 strain was collected in 1991 in the state of Rio Grande do Sul, Brazil (30°05'S, 51°39'W), and has been maintained since then at the Drosophila laboratory of UFRGS. Different to the other D. willistoni strains maintained in the laboratory, the 17A2 strain spontaneously produced mutant males white-like (white eyes) and sepia-like (brown eyes) in stocks held at 17°C. In order to discover if this strain is potentially hypermutable, we submitted it to temperature stress tests. Eighteen isofemale strains were used in our tests and, after the first generation, all the individuals produced in each strain were maintained at 29°C. Different phenotype alterations were observed in subsequent generations, similar to mutations already well characterized in D. melanogaster (white, sepia, blistered and curly). In addition, an uncommon phenotype alteration with an apparent fusion of the antennae was observed, but only in the isofemale line nº 31. This last alteration has not been previously described as a mutation in the D. melanogaster species. Our results indicate that the D. willistoni 17A2 strain is a candidate for hypermutability, which presents considerable cryptic genetic variability. Different factors may be operating for the formation of this effect, such as the mobilization of transposable elements, effect of inbreeding and alteration of the heat-shock proteins functions.

Author(s):  
Anna-Maria Hartmann

Mythographies were books that collected, explained, and interpreted myth-related material. Extremely popular during the Renaissance, these works appealed to a wide range of readers. While the European mythographies of the sixteenth century have been utilized by scholars, the short, early English mythographies, written from 1577 to 1647, have puzzled critics. The first generation of English mythographers did not, as has been suggested, try to compete with their Italian predecessors. Instead, they made mythographies into rhetorical instruments designed to intervene in topical debates outside the world of classical learning. Because English mythographers brought mythology to bear on a variety of contemporary issues, they unfold a lively and historically well-defined picture of the roles myth was made to play in early modern England. Exploring these mythographies can contribute to previous insights into myth in the Renaissance offered by studies of iconography, literary history, allegory, and myth theory.


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1027
Author(s):  
Vincenzo De Leo ◽  
Francesco Milano ◽  
Angela Agostiano ◽  
Lucia Catucci

Liposomes are consolidated and attractive biomimetic nanocarriers widely used in the field of drug delivery. The structural versatility of liposomes has been exploited for the development of various carriers for the topical or systemic delivery of drugs and bioactive molecules, with the possibility of increasing their bioavailability and stability, and modulating and directing their release, while limiting the side effects at the same time. Nevertheless, first-generation vesicles suffer from some limitations including physical instability, short in vivo circulation lifetime, reduced payload, uncontrolled release properties, and low targeting abilities. Therefore, liposome preparation technology soon took advantage of the possibility of improving vesicle performance using both natural and synthetic polymers. Polymers can easily be synthesized in a controlled manner over a wide range of molecular weights and in a low dispersity range. Their properties are widely tunable and therefore allow the low chemical versatility typical of lipids to be overcome. Moreover, depending on their structure, polymers can be used to create a simple covering on the liposome surface or to intercalate in the phospholipid bilayer to give rise to real hybrid structures. This review illustrates the main strategies implemented in the field of polymer/liposome assembly for drug delivery, with a look at the most recent publications without neglecting basic concepts for a simple and complete understanding by the reader.


2008 ◽  
Vol 65 (2) ◽  
pp. 267-275 ◽  
Author(s):  
Tom L. Catchpole ◽  
Andrew S. Revill ◽  
James Innes ◽  
Sean Pascoe

Abstract Catchpole, T. L., Revill, A. S., Innes, J., and Pascoe, S. 2008. Evaluating the efficacy of technical measures: a case study of selection device legislation in the UK Crangon crangon (brown shrimp) fishery. – ICES Journal of Marine Science, 65: 267–275. Bycatch reduction devices are being introduced into a wide range of fisheries, with shrimp and prawn fisheries particularly targeted owing to the heavy discarding common in these fisheries. Although studies are often undertaken to estimate the impact of a technical measure on the fishery before implementation, rarely have the impacts been assessed ex post. Here, the efficacy of the UK legislation pertaining to the use of sievenets in the North Sea Crangon crangon fishery is assessed. Three impacts were evaluated: on fisher behaviour (social), on the level of bycatch (biological), and on vessel profitability (economic). An apparent high level of compliance by skippers was identified despite a low level of enforcement. The estimated reduction in fleet productivity following the introduction of the legislation was 14%, equalling the mean loss of Crangon landings when using sievenets calculated from catch comparison trawls. Sievenets did reduce the unnecessary capture of unwanted marine organisms, but were least effective at reducing 0-group plaice, which make up the largest component of the bycatch. Clearly the legislation has had an effect in the desired direction, but it does not address sufficiently the bycatch issue in the Crangon fishery.


2021 ◽  
Author(s):  
Jost Hellwig ◽  
Michael Stoelzle ◽  
Kerstin Stahl

<p>Groundwater is the main source of freshwater and maintains streamflow during drought. Potential future groundwater and baseflow drought hazards depend on the systems' sensitivity to altered recharge conditions. We performed groundwater model experiments using three different generic stress tests to estimate the groundwater- and baseflow drought sensitivity to changes in recharge. The stress tests stem from a stakeholder co-design process that specifically followed the idea of altering known drought events from the past, i.e. asking whether altered recharge could have made a particular event worse. Here we show that groundwater responses to the stress tests are highly heterogeneous across Germany with groundwater heads in the North more sensitive to long-term recharge and in the Central German Uplands to short-term recharge variations. Baseflow droughts are generally more sensitive to intra-annual dynamics and baseflow responses to the stress tests are smaller compared to the groundwater heads. The groundwater drought recovery time is mainly driven by the hydrogeological conditions with slow (fast) recovery in the porous (fractured rock) aquifers. In general, a seasonal shift of recharge (i.e., less summer recharge and more winter recharge) will therefore have low effects on groundwater and baseflow drought severity. A lengthening of dry spells might cause much stronger responses, especially in regions with slow groundwater response to precipitation. Water management may need to consider the spatially different sensitivities of the groundwater system and the potential for more severe groundwater droughts in the large porous aquifers following prolonged meteorological droughts, particularly in the context of climate change projections indicating stronger seasonality and more severe drought events.</p>


2021 ◽  
Vol 23 (1) ◽  
pp. 1-4
Author(s):  
Eva Cendon ◽  
John Butcher

This general edition of the journal provides insights and results of research employing a wide range of approaches and perspectives on widening participation and lifelong learning. Studies from across the UK and international sector utilise different methodological approaches, and as such are particularly interesting, with diverse methods and ways of analysis, including phenomenographic, narrative, and thematic analysis. Overall, the articles range from exploratory case studies and small-scale research to wider range and broad scale studies, highlighting different facets and perspectives. Furthermore, the articles in this volume cover a broad spectrum of institutions and places involved in widening participation, with an emphasis on the (higher) education sector in the UK balanced by international perspectives. The first seven empirical articles are based on research activities in a secondary school, a youth centre, in further education colleges (usually focusing on post-compulsory secondary or pre-university education), in so-called post-92 universities (new(er) universities, formerly Polytechnics and teacher training colleges), and last but not least in a research intensive Russell Group university. They reported challenges from the specific local contexts of different regions in England, from the South (Chichester) to London to the North (Carlisle), and can usefully be framed in the context of international discussions appearing later in the journal.


2012 ◽  
Vol 29 (7) ◽  
pp. 933-943 ◽  
Author(s):  
Weinan Pan ◽  
R. P. Boyles ◽  
J. G. White ◽  
J. L. Heitman

Abstract Soil moisture has important implications for meteorology, climatology, hydrology, and agriculture. This has led to growing interest in development of in situ soil moisture monitoring networks. Measurement interpretation is severely limited without soil property data. In North Carolina, soil moisture has been monitored since 1999 as a routine parameter in the statewide Environment and Climate Observing Network (ECONet), but with little soils information available for ECONet sites. The objective of this paper is to provide soils data for ECONet development. The authors studied soil physical properties at 27 ECONet sites and generated a database with 13 soil physical parameters, including sand, silt, and clay contents; bulk density; total porosity; saturated hydraulic conductivity; air-dried water content; and water retention at six pressures. Soil properties were highly variable among individual ECONet sites [coefficients of variation (CVs) ranging from 12% to 80%]. This wide range of properties suggests very different behavior among sites with respect to soil moisture. A principal component analysis indicated parameter groupings associated primarily with soil texture, bulk density, and air-dried water content accounted for 80% of the total variance in the dataset. These results suggested that a few specific soil properties could be measured to provide an understanding of differences in sites with respect to major soil properties. The authors also illustrate how the measured soil properties have been used to develop new soil moisture products and data screening for the North Carolina ECONet. The methods, analysis, and results presented here have applications to North Carolina and for other regions with heterogeneous soils where soil moisture monitoring is valuable.


1965 ◽  
Vol 15 ◽  
pp. 165-167 ◽  
Author(s):  
Ruth Amiran

The problem dealt with in the following note, concisely worded in the title, has been occupying the attention of many scholars for quite some time, but seems now to have anchored at a haven, from which further research is already in progress. It may be considered a generally consented assumption, that the phenomenon of the Kh. Kerak Ware (which comprises all the occurrences of this distinctive ware, from Tabara el Akrad Levels IV–I, Amuq Phase H, Hama Niveau K5 in the north, to all the sites in Palestine, as far south as Jericho Tomb A, Tomb F4, etc.) is part of a much larger phenomenon, which stretches over a much wider area. It is evident that we cannot understand a single element, the Kh. Kerak Ware, unless we see it as belonging to a whole phenomenon. It is the great affinity, indeed almost homogeneity of the pottery, both shapes, surface treatment and decoration, which unifies the whole wide range of separated regions, from Transcaucasia (the Kura-Arax culture of B. Kuftin), Armenia and Azerbaidjan, through Eastern and Central Anatolia, to the whole length of the Levant, into one phenomenon.


1997 ◽  
Vol 92 ◽  
pp. 359-371 ◽  
Author(s):  
E. Photos-Jones ◽  
A. Cottier ◽  
A. J. Hall ◽  
L. G. Mendoni

The island of Kea in the North Cyclades was well known in antiquity for its miltos, a naturally occurring red iron oxide valued for its colour and wide range of applications. By combining geological field work, physico-chemical analytical techniques, simulation (heating) experiments as well as simple laboratory tests, this paper describes the study of Kean iron oxides in an attempt to characterize this material which is still largely elusive in the archaeological record. The present work corroborates previous observations about the superior quality of some Kean iron oxides. Furthermore, it puts forward the hypothesis that miltos may have been considered an industrial mineral, and as such may have been used as an umbrella term for a variety of materials including mineralogically distinct purple as well as red iron oxides.


1976 ◽  
Vol 1 (15) ◽  
pp. 143 ◽  
Author(s):  
John Dorrington Mettam

In March 1972 the author's firm in association with two Portuguese firms of consulting engineers, Consulmar and Lusotecna, were appointed by the Portuguese Government agency Gabinete da Area de Sines to prepare designs for the construction of a new harbour at Sines on the west coast of Portugal. The location is shown in Figure 1. The main breakwater, which is the subject of this paper, is probably the largest breakwater yet built, being 2 km long and in depths of water of up to 50 m. It is exposed to the North Atlantic and has been designed for a significant wave height of 11 m. Dolos units invented by Merrifield (ref. 1) form the main armour. The project programme required that studies be first made of a wide range of alternative layouts for the harbour. After the client had decided on the layout to be adopted, documents were to be prepared to enable tenders for construction to be invited in January 1973. This allowed little time for the design to be developed and only one series of flume tests, using regular waves, was completed during this period. Further tests in the regular flume were completed during the tender period and a thorough programme of testing with irregular waves was commenced later in the year, continuing until August 1974 when the root of the breakwater was complete and the construction of the main cross-section was about to start. The model tests, which were carried out at the Laboratorio Nacional de Engenharia Civil in Lisbon, were reported by Morals in a paper presented to the 14th International Coastal Engineering Conference in 1974. (ref. 2)


Sign in / Sign up

Export Citation Format

Share Document