Hybrid Race Research Articles

Genomic introgression in laboratory evolved hybrid races, Cytorace 1 and Fissioncytorace-1 of Nasuta-albomicans complex (NAC) of Drosophila (Insecta, Diptera) as revealed by RAPD and ISSR markers

Nasuta-albomicans complex (NAC) of Drosophila is an artificial hybrid zone comprising of Drosophila nasuta nasuta, Drosophila nasuta albomicans and 16 Cytoraces, which are the evolutionary products of a long range hybridization experiment conducted in the laboratory environment. Occurrence of centric fission in the X3 chromosome of Cytorace 1 led to the derivation of Fissioncytorace-1. Molecular techniques have emerged as powerful and valuable tools for detection and exploitation of genetic polymorphism. In the present study, Cytorace 1 and Fissioncytorace-1 were subjected to Random Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeats (ISSR) analyses to determine the introgression of D. n. nasuta and D. n. albomicans genomes. It was found that Cytorace 1 and Fissioncytorace-1 exhibit similarities in RAPD and ISSR profiles although different combinations of genomic regions could have favoured Fissioncytorace-1, for better morphophenotypes and fitness, when compared to Cytorace 1, which has existed for over 15 years from the time of its evolution in the laboratory environment.

Porsche GT3 R Hybrid Prototype and Race Lab

Porsche GT3 R Hybrid Prototype and Race Lab

Porsche GT3 R Hybrid Prototype and Race Lab

Porsche GT3 R Hybrid Prototype and Race Lab

Association between calpain-10 gene polymorphism and risk of type 2 diabetes mellitus: a meta analysis

The purpose of this study was to approach the relation of SNP43, SNP44 locus, main haplotypes and haplotype combinations with type 2 diabetes mellitus (T2DM). According to the theory and principles of systematic review, data from case-control studies regarding the association between calpain-10 (CAPN10) gene and T2DM were derived through electronic search of PubMed and Chinese journals databases. To gain a more precise estimation of the relationship, a stratified Meta-analysis with four subgroups was performed according to the races. Publication bias was also assessed. The association with T2DM in different races was evaluated. In Mongoloid race, SNP43-G allele, G/G genotype and 111/221 haplotype combination showed notable association with T2DM with ORs (95%CI) as 1.368 (1.155 - 1.620), 1.437 (1.186 - 1.741) and 2.762 (1.287 - 5.927) respectively. In Caucasoid race, SNP44-C allele, 111/111 hapotype combination showed strong relationship with T2DM with ORs (95%CI) as 1.144 (1.023 - 1.278), 1.291(1.050 - 1.586) respectively. In Hybrid race, only one positive finding was obtained which was SNP44-C allele with OR (95%CI) as 1.653 (1.025 - 2.665). SNP43-G allele, G/G genotype, 111/221 were risk factors to Mongoloid race. And SNP-C allele, 111/111 haplotype combination were risk factors to Caucasoid race, and SNP44-C allele to Hybrid race.

Hybrid Racing Car with a Lithium-Ion Battery

Ex-Formula 1 driver Heinz-Harald Frentzen surprised many experts by lining up at the start of the Nürburgring 24-hour race in a racing car powered by a hybrid drive system. The combination of a petrol engine and an electric motor provided a total power output of 482 kW at the classic long-distance race at the Nürburgring North Circuit in May. Whereas the Formula 1 rules will not be prescribing the use of hybrid systems until 2009, the team financed by Frentzen is already facing the challenge. Recovery and intermediate storage of the braking energy that is otherwise lost as heat is used to drive an electric motor that supports the petrol engine.

Development a long-term storage method for diapause eggs in some hybrid races of Bombyx mori

Development a long-term storage method for diapause eggs in some hybrid races of Bombyx mori

Gender, Work and Fears of a ‘Hybrid Race’ in 1920s New Zealand

The 1929 New Zealand Committee of Inquiry into the Employment of Maori on Market Gardens affords insight into the ways in which masculine fears of racial degradation through miscegenation – of a ‘hybrid’ Chinese/Maori race – operated within a hierarchy of race, gender and Iwi (tribal) interests. The participation of Maori men in national politics contributed to a new articulation of ‘National Manhood’, in which Maori men and white men combined to express fears about women's work and sexuality and young women's potential to undermine a fragile and contested hierarchy of racial purity. Maori women, silenced in the cacophony of voices lamenting their plight, were at the centre of debates between Maori men, Pakeha (white New Zealander) employers, Chinese market gardeners, Anglican and Methodist interests and Pakeha women's groups. I argue that the Inquiry was about commerce, both in a business and a sexual sense. As a historical episode, it also serves to complicate the picture of New Zealand as a historically bicultural society, made up only of Maori and Pakeha, by signalling the importance of the Chinese in debates about national belonging.

THE INHIBITORY EFFECT OF HONEY BEE VENOM AGAINST SOME DIFFERENT MICROOGANISMS

Venom collected from honey bee (Apis meilifera L.) workers of Egyptian, Carniolian and Carnionlian hybrid races were microbiologically examined for their inhibitory effect against different microorganisms by using disc diffusion technique. There was a clear inhibitory effect (IE) for all bee venom types and this (1E) was strongly dependent on venom type and the type of test microorganism. Bee venom from the Egyptian race showed the strongest inhibitory effect (133-23.? mm) against microorganisms while, the venom obtained from Carniolian race gave the lowest effect (10.3-15.3 mm). Bee venom from Camiolian hybrid race revealed a moderate inhibitory action (11.7490 mm). Gram—positive bacten'a as well as yeast and moulds demonstrated the most susceptible cells for venom type while, in contrary Gram- negative bacteria manifested quite tolerance for the antimicrobial action of bee venom. Antimicrobial activity of bee venom proved to be concentration—dependent and it had a bacteriostatic effect at low concentrations while. at higher concentrations it considered as bactericidal. The incorporation of bee venom in growth medium negatively affected the progress in growth behavior of microorganisms and this effect increased with increasing venom concentration. Viability of Listeria monocytogenes and E.coii cells in their growth media had been lost and completely died-off after 24 and 48 hrs of incubation in the presence of high venom concentration (1000 pgfml) respectively. The presence of a moderate venom concentration (400 pgiml) in the medium delayed the bacterial growth and finally cells disappeared after five days of exposure. Providing growth media with low venom concentrations considerably suppressed the growth of the two bacterial strains. This phenomenon can be used in medical purposes and drug preparations or by some modifications in food preservation.

Immigrant Positioning in Twentieth-Century Mexico: Middle Easterners, Foreign Citizens, and Multiculturalism

Immigrant Positioning in Twentieth-Century Mexico: Middle Easterners, Foreign Citizens, and Multiculturalism

Morphometrical Characteristics of the Common Shrews (Sorex Araneus L.) from Interracial Hybrid Zones

Common shrews are subdivided into numerous chromosome races which make contact and form hybrid zones. To date, no strong differences in morphology have been found between hybrid and pure race individuals from the vicinity of such hybrid zones. To investigate this further, we carried out studies in Poland on three hybrid zones between races belonging to the West and East European Karyotypic Groups using material collected from 1989 to 1994. Shrews were measured (head and body, tail and hindfoot length) and weighed. Statistically significant differences in morphology were only observed in the Stobnica/Legucki Mlyn hybrid zone. The results indicated that both adult and immature animals belonging to the Stobnica race were smaller than those belonging to the Legucki Miyn race. The hybrids were longer than individuals of pure race karyotype but the mean body mass of the hybrids was the lowest. At the population level, the size of the shrews varied with value of a hybrid index. The absence of similar results for the Druznol/Łȩgucki Mtyn and Drnholec/Bialowieza hybrid zones may reflect their narrowness compared with the Stobnica/Łȩgucki Mlyn zone.

Picturing Tropical Nature

Whether as sublime landscape, malignant wilderness or site for environmental conflicts and eco-tourism, tropical is to a great extent an American and European imaginative construct, conveyed in literature, travel writing, drawings, paintings, photographs and diagrams. These images are central to Nancy Leys Stepan's view that a critical examination of the tropicalization of nature can remedy some of the most persistent misrepresentations of the tropics and its peoples. This book reflects on the work of several 19th- and 20th-century scientists and artists, including Alexander von Humboldt, Alfred Russel Wallace, Louis Agassiz, Sir Patrick Manson and Margaret Mee. Their careers illuminate several aspects of tropicalization: science and art in the making of tropical pictures; the commercial and cultural boom in things tropical in the modern period; photographic attempts to represent tropical hybrid races; anti-tropicalism and its role in an emerging environmentalist sensibility; and visual depictions of disease in the new tropical medicine. Essential to Stepan's analysis are the responses to European projections of artists, scientists and intellectuals living in tropical regions.

The complex hybrid zone between the Abisko and Sidensjö chromosome races of Sorex araneus in Sweden

Six chromosome races of the common shrew occur in Sweden, each with its characteristic arm combination of metacentric chromosomes. G-banded karyotypes were analysed from 201 common shrews in 14 localities of the northern hybrid zone in Sweden. Analyses from another 64 shrews from seven localities outside the hybrid zone w ere included for comparison. The shrews were classified with respect to karyotype into any of five categories: (1) Abisko race, (2) Sidensjo race, (3) hybrids between the parental races, (4) pseudohybrids (a type of hybrid), and (5) AT with all race-specific chromosomes (h, i, n, o, p, r) present as telocentrics. Hybrids occurred at a frequency close to Hardy-Weinberg expectation in the centre of the hybrid zone. Chromosome polymorphism of Robertsonian type was common and 43 different karyotypes were found among the specimens studied. The polymorphism involved six metacentric pairs in the Abisko and three in the Sidensjo race. The frequency of the Sidensjo race-specific metacentric hi decreased and the frequency of the Abisko race-specific hn increased from south-west to north-east along a transect across the hybrid zone. The number of race-specific telocentrics reached a peak 13 km north-east of the hi-hn cline centre. The estimated standardized cline width for chromosomes hi and hn was 16.0 km. The extension of the Sidensjo race is comparatively narrow [c. 50 km in the region of the investigation), and it is regarded to be a ‘hybrid race’ between the Uppsala race, which colonized Sweden from the south-west, and the Abisko race which arrived from the north-east after the most recent glaciation. The origin of the Sidensjo race is thus less than 10 000 years old, because earlier this area was covered by glacial ice.

The complex hybrid zone between the Abisko and Sidensjö chromosome races of Sorex araneus in Sweden

Six chromosome races of the common shrew occur in Sweden, each with its characteristic arm combination of metacentric chromosomes. G-banded karyotypes were analysed from 201 common shrews in 14 localities of the northern hybrid zone in Sweden. Analyses from another 64 shrews from seven localities outside the hybrid zone were included for comparison. The shrews were classified with respect to karyotype into any of five categories: (1) Abisko race, (2) Sidensjö race, (3) hybrids between the parental races, (4) pseudohybrids (a type of hybrid), and (5) AT with all race-specific chromosomes (h, i, n, o, p, r) present as telocentrics. Hybrids occurred at a frequency close to Hardy–Weinberg expectation in the centre of the hybrid zone. Chromosome polymorphism of Robertsonian type was common and 43 different karyotypes were found among the specimens studied. The polymorphism involved six metacentric pairs in the Abisko and three in the Sidensjö race. The frequency of the Sidensjö race-specific metacentric hi decreased and the frequency of the Abisko race-specific hn increased from south-west to north-east along a transect across the hybrid zone. The number of race-specific telocentrics reached a peak 13 km north-east of the hi-hn cline centre. The estimated standardized cline width for chromosomes hi andhn was 16.0 km. The extension of the Sidensjö race is comparatively narrow (c. 50 km in the region of the investigation), and it is regarded to be a «hybrid race» between the Uppsala race, which colonized Sweden from the south-west, and the Abisko race which arrived from the north-east after the most recent glaciation. The origin of the Sidensjö race is thus less than 10 000 years old, because earlier this area was covered by glacial ice.

Assessing the roles of change discrimination and luminance integration: Evidence for a hybrid race model of perceptual decision making in luminance discrimination.

Assessing the roles of change discrimination and luminance integration: Evidence for a hybrid race model of perceptual decision making in luminance discrimination.

Assessing the roles of change discrimination and luminance integration: Evidence for a hybrid race model of perceptual decision making in luminance discrimination.

Many models of perceptual processing assume that participants integrate stimulus evidence over time, for example, random walk models. This class of models is tested in a luminance discrimination paradigm in which the onsets of the stimuli are either instantaneous (stepped) or slowly ramped. The ramped portion of ramped stimuli occurs prior to the stepped stimuli onsets. Consequently, there is more luminance energy in ramped stimuli. Therefore, if participants integrate luminance energy, they should perform better to ramped stimuli. This did not occur in 4 experiments. Participants performed better to stepped stimuli than ramped stimuli in earlier foreperiods and the reverse in later foreperiods. A new model is proposed in which participants monitor both integrated luminance energy and quick temporal changes in luminance, but they do so in a serial fashion. First, participants monitor temporal changes in luminance; later, they monitor integrated luminance energy.

Effects of KK-42, an imidazole derivative, on rearing and reproductive performance of Bombyx mori L. during the hot, wet season

Experiments on the effects of KK-42, an anti-juvenile hormone imidazole derivative, on the rearing and reproduction of Bombyx mori L. were carried out in a hot, wet summer in West Bengal, India. A single dose of 3 μg KK-42/larva induced precocious metamorphosis in a bivoltine hybrid (KPGB x P5) race of B. mori when applied topically to freshly moulted (less than 1-h old) fourth instars, and increased their rearing performance over control tetramoulters. However, cocoon and shell weights, shell ratio and filament length were reduced by the anti-JH treatment. Final body weight and head capsule width of the treated fourth instars were significantly higher than those of the controls. Bivoltine trimoulter males also showed good capacity for mating with multivoltine Nistari females. The possibility of obtaining three-way multi-bi hybrid eggs during the wet part of summer in a tropical climate is discussed.

Racing Simulacra?

Racing Simulacra?

Natural and experimental hybridization inArmeria (Plumbaginaceae):A. villosa subsp.carratracensis

An experimental crossing program was carried out in order to test the hypothesis thatArmeria villosa subsp.carratracensis, a serpentine endemic from Southern Spain, is of hybrid origin. Fruit-set and mainly pollen stainability data in artificial hybrids demonstrate that internal interspecific barriers are weak. Two generations of backcrossing with the two putative parents —A. colorata andA. villosa subsp.longiaristata— can restore pollen stainability to an average of 83.2 and 68.7, respectively. A morphometric analysis of 148 specimens belonging to parental species, different artificial hybrid generations and wild putative hybrid race shows that (1) morphological characters have a strong genetic basis and thus are good markers in identifying hybrids and introgression inArmeria; (2) artificial backcrossing produces in morphometrical characters a variation which conforms in both trend and magnitude to what is commonly attributed in the wild to introgression; (3) the position of the putative hybrid race is intermediate between the two parental species used in the program. These results are in accordance with the hypothesis of hybrid origin ofA. villosa subsp.carratracensis.

Espetáculo da miscigenação

Um grande laboratório racial: era essa a imagem do Brasil no final do século XIX. Construída pelos inúmeros viajantes que aqui estiveram, essa alusão a um país de raças híbridas encontrava também acolhida entre os cientistas nacionais, que se congregavam nos diversos centros de ensino e pesquisa: os institutos históricos e geográficos, os museus etnográficos, as faculdades de direito e de medicina. Adotando modelos do determinismo racial coube a esses intelectuais, porém, o estranho papel de difundir um extremo pessimismo no que tange ao futuro dessa nação mestiça. O desafio desse artigo, portanto, é compreender a originalidade do pensamento local, como também a convivência inesperada entre dois modelos supostamente antagônicos: liberalismo e racismo.

SPECIAL PAPER: SYSTEMATICS AND EVOLUTION OF SORGHUM SECT. SORGHUM (GRAMINEAE)

The genus Sorghum Moench is subdivided into sections Chaeotosorghum, Heterosorghum, Parasorghum, Stiposorghum and Sorghum. Section Sorghum includes two rhizomatous species, S. halepense (L.) Pers. (2n = 40) and S. propinquum (Kunth) Hitchcock (2n = 20), as well as the annual S. bicolor (L.) Moench (2n = 20). Sorghum bicolor is divided into subspecies bicolor to include all domesticated grain sorghums, subspecies drummondii (Steud.) de Wet comb. nov. to include stabilized derivatives of hybridization among grain sorghums and their closest wild relatives and subspecies arundinaceum (Desv.) de Wet et Harlan to include the wild progenitors of grain sorghums. Four ecotypes of subspecies arundinaceum are recognized: race aethiopicum of the arid African Sahel. race virgatum of northeastern Africa, race arundinaceum of the African tropical forest, and race verticilliflorum of the African Savanna. The numerous, usually recognized grain sorghums are divided among five basic races, bicolor, caudatum, durra, guinea and kafir, and ten hybrid races that each combine characteristics of at least two of these basic races. Races of grain sorghum are morphologically distinct, and they maintain their unity of type through spacial and ethnological isolation.