A morphological study of variation in Tyrophagus (Acarina), with particular reference to populations infesting cheese

1961 ◽  
Vol 52 (3) ◽  
pp. 501-529 ◽  
Author(s):  
Phyllis L. Robertson
Keyword(s):  
Close Association ◽  
Distinct Species ◽  
Linear Measurement ◽  
Wide Distribution ◽  
Ecological Data ◽  
Plant Materials ◽  
Frequency Distributions ◽  
Ecological Zones ◽  
Distribution And Ecology ◽  
The Many

The difficulty of deciding the systematic status of variations within and between populations of Tyrophagus is considered in relation to the wide distribution of the genus and the many materials it infests.Variation within populations of what was thought to be one species infesting cheese is explained by the isolation of three closely similar forms which it is difficult, if not impossible, to separate by measurement alone. Frequency distributions overlap slightly for four linear measurement ratios on which separation is attempted, but differences between them are emphasised by differences in minute structural characters and they are therefore accepted as distinct species, identified as longior (Gervais, 1844), palmarum Oudemans, 1924, and putrescentiae (Schrank, 1781).Variation between populations attacking plant materials and other stored products in addition to cheese is accounted for to some extent by the recognition of three further Tyrophagus species, oudemansi Robertson, 1959, brevicrinatus Robertson, 1959, and tropicus Robertson, 1959.Within the species recognised, significant differences are recorded in dorsal hair characters and body proportions between populations on cheese produced in different geographical areas, and also between cheese populations and those infesting other materials, and these differences are thought to be at a racial level.T. longior, T. palmarum and T. putrescentiae are found to be distributed around the world, but as cheese pests they occupy somewhat different, although overlapping, geographical zones, since longior is a temperate-to-cool form, palmarum a temperate form and putrescentiae a subtropical or tropical form. The three are also found to occupy different, but overlapping ecological zones, making possible their association in mixed populations.Confusion in ecological data previously published on Tyrophagus is thought to be attributable in part to similarities in the morphology, geographical distribution and ecology of its species, and to their close association.

scholarly journals Multi-Probe Measurement System Based on Single-Cut Transformation for Fast Testing of Linear Arrays

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1744
Author(s):  
Fernando Rodríguez Varela ◽  
Manuel José López Morales ◽  
Rubén Tena Sánchez ◽  
Alfonso Tomás Muriel Barrado ◽  
Elena de la Fuente González ◽  
...  
Keyword(s):  
Measurement System ◽  
Near Field ◽  
Linear Measurement ◽  
Complete Characterization ◽  
Linear Arrays ◽  
Full Characterization ◽  
X Band ◽  
Measurement Results ◽  
The Many ◽  
3D Information

This paper introduces a near-field measurement system concept for the fast testing of linear arrays suited for mass production scenarios where a high number of nominally identical antennas needs to be measured. The proposed system can compute the radiation pattern, directivity and gain on the array plane, as well as the array complex feeding coefficients in a matter of seconds. The concept is based on a multi-probe antenna array arranged in a line which measures the near field of the antenna under test in its array plane. This linear measurement is postprocessed with state-of-the-art single-cut transformation techniques. To compensate the lack of full 3D information, a previous complete characterization of a “Gold Antenna” is performed. This antenna is nominally identical to the many ones that will be measured with the proposed system. Therefore, the data extracted from this full characterization can be used to complement the postprocessing steps of the single-cut measurements. An X-band 16-probe demonstrator of the proposed system is implemented and introduced in this paper, explaining all the details of its architecture and operation steps. Finally, some measurement results are given to compare the developed demonstrator with traditional anechoic measurements, and show the potential capabilities of the proposed concept to perform fast and reliable measurements.

E Bario Project

2004 ◽  
pp. 115-131
Author(s):  
Poline Bala ◽  
Roger W. Harris ◽  
Peter Songan
Keyword(s):  
Rural Communities ◽  
Urban Areas ◽  
Close Association ◽  
Communication Technologies ◽  
Well Being ◽  
The Internet ◽  
Information Communication ◽  
Remote Communities ◽  
The People ◽  
The Many

This chapter highlights an initiative by a group of researchers2 from Universiti Malaysia Sarawak (UNIMAS) to connect villagers in the remote and isolated village of Bario to Information Communication Technologies (ICTs), which include computers, telephones, the Internet, and VSATs. This project has eased the information flow in and out of Bario, affecting the well-being of the people by providing a means to keep in touch with friends and relatives in urban areas. The response of the Bario community has been positive, but the objective of the e Bario project is more ambitious than to just provide access to the Internet, computers and other related technologies. The main objective is to identify opportunities for remote and rural communities in Sarawak to develop socially, culturally and economically from the deployment of the technologies. The results of the initiative are expected to demonstrate the many ways in which ICTs can be used to improve the lives of marginalized groups, specifically, here, the rural and remote communities in Malaysia. However, to ensure that the objectives will ultimately be met, the team has had to search for an appropriate methodology that will ensure the full benefits of the initiative to the community. This chapter describes and discusses the approaches adopted, emphasizing the benefits of a close association between the researchers and the community as well as the adoption of suitable participatory methods for engaging with the needs and opportunities that were discovered.

The genus Waltheria in southern Africa

Bothalia ◽  
1981 ◽  
Vol 13 (3/4) ◽  
pp. 275-276 ◽  
Author(s):  
I. C. Verdoorn
Keyword(s):  
West Africa ◽  
Southern Africa ◽  
Distinct Species ◽  
Wide Distribution ◽  
Herbarium Specimens ◽  
South West ◽  
The World ◽  
Northern Cape ◽  
South West Africa ◽  
The Tropics

Waltheria indica L., the only species of Waltheria represented in southern Africa, is revised. This species, which occurs throughout the tropics and substropics of the world, is found abundantly in the northern Cape, Swaziland, northern Natal, Transvaal and northwards through South West Africa/Namibia and Botswana. Thoughout its wide distribution the species is uniform. A scrutiny o f herbarium specimens revealed that what appeared as a distinct species or subspecies was without doubt an abnormality, probably caused by insect injury.

scholarly journals Ecological opportunity shapes a large Arctic charr species radiation

2019 ◽  
Vol 286 (1913) ◽  
pp. 20191992 ◽  
Author(s):  
Carmela J. Doenz ◽  
Andrin K. Krähenbühl ◽  
Jonas Walker ◽  
Ole Seehausen ◽  
Jakob Brodersen
Keyword(s):  
Arctic Charr ◽  
Positive Association ◽  
Distinct Species ◽  
Similar Species ◽  
Small Lakes ◽  
Ecological Data ◽  
Ecological Opportunity ◽  
Intermediate Size ◽  
Variable Population ◽  
Lake Size

Ecological opportunity is considered a crucial factor for adaptive radiation. Here, we combine genetic, morphological and ecological data to assess species and ecomorphological diversity of Artic charr in six lakes of a catchment in southernmost Greenland, where only charr and stickleback occur. Because the diversity of habitats and resources increases with lake size, we predict a positive association between lake size and the extent of ecomorphological diversity. The largest lake of the catchment harbours the largest Arctic charr assemblage known today. It consists of six genetically differentiated species belonging to five ecomorphs (anadromous, littoral benthic, profundal dwarf, planktivorous, piscivorous), of which the latter comprises two ecomorphologically extremely similar species. Lakes of intermediate size contain two ecomorphologically and genetically distinct species. Small lakes harbour one genetically homogeneous, yet sometimes ecomorphologically variable population. Supporting our prediction, lake size is positively correlated with the extent of ecomorphological specialization towards profundal, pelagic and piscivorous lifestyle. Furthermore, assemblage-wide morphospace increases sharply when more than one genetic cluster is present. Our data suggest that ecological opportunity and speciation jointly determine phenotypic expansion in this charr radiation.

Natural categories or fundamental dimensions: On carving nature at the joints and the rearticulation of psychopathology

2003 ◽  
Vol 15 (3) ◽  
pp. 529-551 ◽  
Author(s):  
ANDREW PICKLES ◽  
ADRIAN ANGOLD
Keyword(s):  
Clinical Practice ◽  
Distinct Species ◽  
Natural Categories ◽  
Methods Of Analysis ◽  
The Many

The question of whether to view psychopathology as categorical or dimensional continues to provoke debate. We review the many facets of this argument. These include the pragmatics of measurement; the needs of clinical practice; our ability to distinguish categories from dimensions empirically; methods of analysis appropriate to each and how they relate; and the potential theoretical biases associated with each approach. We conclude that much of the debate is misconceived in that we do not observe pathology directly; rather, we observe its properties. The same pathology can have some properties that are most easily understood using a dimensional conceptualization while at the same time having other properties that are best understood categorically. We suggest replacing Meehl's analogy involving qualitatively distinct species with an alternative analogy with the “duality” of light, a phenomenon with both wave- and particle-like properties.

A Parapatric Boundary between Ranidella signifera and R. riparia (Anura: Leptodactylidae) in South Australia

1982 ◽  
Vol 30 (1) ◽  
pp. 49 ◽  
Author(s):  
FJ Odendaal ◽  
CM Bull
Keyword(s):  
Competitive Advantage ◽  
Close Association ◽  
South Australia ◽  
Wide Distribution ◽  
Habitat Types ◽  
South Eastern ◽  
The North ◽  
Flinders Ranges ◽  
Eastern Australia ◽  
Overlap Area

Ranidella signifera has a wide distribution in south-eastern Australia; R. riparia is endemic to the Flin- ders Ranges in South Australia. The ranges of the two species are largely allopatric, but they contact and overlap in a zone about 10 km wide, in the southern Flinders Ranges. The nature of the creeks changes across this zone. Immediately to the south and east, where only R. signifera is found, the creeks are slow-flowing and heavily vegetated, with mud or sand substrates. To the north and west the creeks are swift-flowing, and have rocky substrates and little vegetation; only R. riparia is found in these. In the sympatric overlap zone creeks are heterogeneous, with both habitat types represented. The close association between species and creek habitat is lost in populations not immediately adjacent to the overlap zone. This implies that each species can survive in both creek habitats but that R. riparia has a competitive advantage in swift, rocky creeks and R, signifera has an advantage in slow, vegetated creeks. This prevents either species from expanding its distribution beyond the narrow overlap area.

Nature’s Own Remedies

2019 ◽  
Vol 88 (3) ◽  
pp. 378-409
Author(s):  
Tamara Venit Shelton
Keyword(s):  
United States ◽  
Chinese Medicine ◽  
Environmental History ◽  
Progressive Era ◽  
Chinese Culture ◽  
Close Association ◽  
The United States ◽  
Natural Medicine ◽  
The Many ◽  
Deliberate Strategy

This article examines American perceptions of Chinese herbalism as natural medicine in the Progressive Era. In doing so, it uses the lens of environmental history to consider three meanings of nature for Chinese medicine in the United States: First, as a material, trans-Pacific environment where medicinal ingredients were procured, distributed, and consumed; second, as part of the evolving distinction between modern, scientific “regular” medicine and anti-modern, unscientific “irregular” medicine that reached a moment of crisis at the turn of the twentieth century; and third, as a reflection of the racialization of Chinese health practices co-created by Asian practitioners and their American patients, who were conditioned by Orientalist stereotypes to perceive Chinese culture as close to a pastoral or primitive nature. The close association between herbs and nature enabled Chinese doctors to thrive as “irregular” or “alternative” practitioners in the American medical marketplace. While American patients may have perceived Chinese medicine as closer to nature, the many meanings of nature reveal the extent to which the association was a deliberate strategy for survival and success adopted by Chinese doctors in the United States.

Rejoinder to Dykstra and Kousser

1986 ◽  
Vol 10 (1) ◽  
pp. 87-90 ◽  
Author(s):  
William H. Flanigan ◽  
Nancy H. Zingale
Keyword(s):  
Individual Behavior ◽  
Ecological Data ◽  
Ecological Analysis ◽  
Ecological Patterns ◽  
Way Of Knowing ◽  
The Many ◽  
The Individual ◽  
Inherent Ambiguity

In our article “Alchemist’s Gold”, we tried to make three main points. First, a large number of models of individual behavior can fit observed ecological patterns, and these models entail different assumptions about the nature of the individual relationship within and across the ecological units. This topic has been most impressively developed by Gudmund Iversen (1981). Second, there is nothing in the ecological data or the various types of ecological analysis that informs the researcher about how to choose among the many dissimilar models. All the models are compatible with the ecological data, and we have no way of knowing whether a particular inference about individual behavior is quite accurate or extremely misleading. Because of the inherent ambiguity over the unobserved individual behavior within ecological units, we made a third point of recommending techniques for reducing the amount of uncertainty surrounding estimates.

Cooperative defence and other benefits among exposed spiny lobsters: inferences from group size and behaviour

2001 ◽  
Vol 52 (8) ◽  
pp. 1113 ◽  
Author(s):  
William F. Herrnkind ◽  
Michael J. Childress ◽  
Kari L. Lavalli
Keyword(s):  
Drag Reduction ◽  
Group Size ◽  
Field Data ◽  
Close Association ◽  
Size Distributions ◽  
Frequency Distributions ◽  
Large Numbers ◽  
Spiny Lobsters ◽  
Migratory Period ◽  
Previous Group

Caribbean spiny lobsters show strikingly coordinated queuing behaviour and resting, outward-facing radial formations, especially during mass migrations when large numbers cross shelter-poor substrate in daylight. The close association of individual lobsters during these behaviours could be due to chance or some benefit of association such as dilution (and associated selfish-herd effects), group vigilance, cooperative defence, and/or drag reduction during migration. To infer probable beneficial functions, we examined the frequency distributions of individuals and groups using a seven-year set of field data and additional behavioural observations in large seawater enclosures. Group size distributions were not significantly aggregated in dens during the non-migratory period but became highly aggregated during migration. The group size distributions of lobsters initially leaving dens and those observed moving in the open were statistically different from one another, indicating that group sizes at each of these steps in the migration are not simply the result of previous group sizes. The distribution of group sizes suggests that, during movement in the open, dilution, vigilance, cooperative defence, and/or drag reduction may all favour the formation of queues. During resting in the open, dilution, vigilance, and cooperative defence may continue to favour individuals that remain in formation within the group.

scholarly journals The first ribonucleotide reductase without an activating radical cysteine

2014 ◽  
Vol 70 (a1) ◽  
pp. C1053-C1053
Author(s):  
Oskar Aurelius ◽  
Renzo Johansson ◽  
Viktoria Bågenholm ◽  
Daniel Lundin ◽  
Alexander Balhuizen ◽  
...  
Keyword(s):  
Thermotoga Maritima ◽  
Building Blocks ◽  
Time Frame ◽  
Wide Distribution ◽  
Reduction Reaction ◽  
Cysteine Residue ◽  
Substrate Reduction ◽  
Allosteric Effector ◽  
Metal Cofactor ◽  
The Many

Ribonucleotide reductases (RNRs) catalyze the reduction of ribonucleotides to deoxyribonucleotides, the building blocks for DNA synthesis, and are found in all but a few organisms. RNRs use radical chemistry to catalyze the reduction reaction. Despite RNR having evolved several different mechanisms for generation of different kinds of essential radicals across a large evolutionary time frame, for over 30 years the paradigm has been that this initial radical is always channeled to a strictly conserved cysteine residue directly adjacent to the substrate for initiation of substrate reduction. Such a cysteine residue has been present in the structure of each of the many RNRs determined to date. We present the crystal structure of an anaerobic RNR from the extreme thermophile Thermotoga maritima (tmNrdD), both alone and in complex with allosteric effector dATP and substrate CTP. Remarkably, tmNrdD lacks a cysteine for radical transfer to the substrate, and is the first structurally or biochemically characterized RNR to do so. However in many other respects tmNrdD appears to be a normal anaerobic RNR, including gene structure, expression levels, metal cofactor and binding of allosteric effectors and substrates in the expected conformations. Furthermore, it is possible to generate a glycyl radical as expected. We present evidence that the structure of tmNrdD is representative for the new RNR subclass IIIh, present in all Thermotoga species plus a wider group of bacteria from the distantly related phyla Firmicutes, Bacteroidetes and Proteobacteria, all lacking the canonical cysteine residue. The wide distribution provides further evidence that the subclass IIIh is a functional RNR. Taken together, the results imply that an alternative initiation route for the RNR reduction reaction must exist that do not require channeling through a cysteine side chain.

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