Cytogenetic analysis of a new subcomplex of Simulium exiguum (Diptera: Simuliidae) in amazonian Ecuador

1998 ◽  
Vol 88 (3) ◽  
pp. 247-255 ◽  
Author(s):  
M. Charalambous ◽  
M. Arzube ◽  
S. Lowell

AbstractTwo new cytotypes of the onchocerciasis vector blackfly Simulium exiguum Roubaud are described from amazonian Ecuador. As transmission of the disease does not occur in the region, the two cytotypes are not currently vectors, The Napo form (N = 113) differs cytologically from the chromosomal standard of the species, the Cayapa form, through possession of the fixed paracentric inversions IL-E and IIIL-L; the Huatarac form (N = 22) differs by the fixed inversions IL-L and IIIL-D + L. Both forms form a subcomplex, termed the ‘amazonian’ subcomplex, through sharing the fixed inversion IIIL-L. They also share a number of polymorphic inversions, but neither form possesses sex-linked inversions. The fixed and sex-linked inversions of the previously described Aguarico form were found to be polymorphic and autosomal in the Napo and Huatarac forms, suggesting a close genetic relationship among these forms. The Napo form is distributed throughout the Napo river system (except in the Rio Huatarac) and found in the Rio Aguarico, whereas the Huatarac form is unique to the Rio Huatarac. As their distributions in this study were allopatric, the species status of the two cytotypes could not be tested. The Aguarico form was not found in the Rio Aguarico, nor in any of the other rivers sampled. Whether the Napo form has replaced the Aguarico form in the Rio Aguarico, or whether its absence is due to seasonal variation requires further investigation.

1990 ◽  
Vol 53 (1) ◽  
pp. 100-114 ◽  
Author(s):  
Mark Durie

The aims of this paper are: (i) to report new dialect data for a vowel contrast in Acehnese which was not recorded in earlier descriptive work, (ii) to show that this contrast is cognate with a contrast reconstructed for Proto–Chamic, and (iii) to reconstruct this part of the vowel system of Proto–Aceh–Chamic.A close genetic relationship between Acehnese and Chamic was first suggested by Nieman (1891). Although a contrary view was expressed by Blagden (1929), the issue has been conclusively put to rest by the work of Cowan (1933, 1948, 1974, 1981, 1983, 1988), Shorto (1975, 1977) and Collins (1975) who all agree on the existence of a distinct Aceh–Chamic sub–group within Austronesian.Unfortunately, comparative work on Aceh-Chamic (Cowan: Chamo- Achehic, Shorto: Achino-Cham) has been hampered by problems of access to the data. In Lee's (1966) and Burnham's (1976) reconstructions of Proto-Chamic no mention is made of Acehnese. On the other hand, Cowan and Shorto, the two scholars who have furthered Aceh-Chamic studies the most, have not had access to Lee (1966), nor, in more recent works, to Burnham (1976). Another problem has been that Acehnese source materials have been restricted to just one dialect, as reflected by Djajadiningrat's (1934) and Kreemer's (1931) Acehnese-Dutch dictionaries.This paper represents one step towards addressing some of these problems, by comparing new Acehnese dialect data with the comparative Chamic wordlist compiled by Lee and augmented by Burnham. I focus here upon a specific


1934 ◽  
Vol 5 (2) ◽  
pp. 101-107 ◽  
Author(s):  
A. C. T. Hewitt

1. The incidence of twins has been one twin birth in every forty-eight Red Poll births, and one twin birth in every thirty-three Friesian births.2. So far as is known no identical twins have been dropped.3. Thirteen of the fourteen freemartins reared have been barren.4. The birth weight of twin calves has been only slightly lower than that of single calves. Bull calves have been approximately 6 lb. heavier than heifer calves.5. The mortality amongst twins is approximately equal to that amongst single calves.6. Twinning appears to be inheritable and to run in strains.7. The gestation period of a cow bearing twins has been from 8 to 10 days shorter than that of a cow bearing a single calf.8. The percentage of twins dropped increased as the age of the dam at calving increases.9. Twinning is not influenced by the season of the year.10. The twins and dams of twins have been consistently heavier producers of milk and butterfat than the other herd members.11. There is some evidence to suggest a close genetic relationship between the following three characters: (i) multiple births, (ii) high milk and butterfat production, (iii) long life and fertility.


2010 ◽  
Vol 27 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Martin Šlachta ◽  
Jan Frelich ◽  
Tomáš Tonka

Function of coprophagous beetles (Coleoptera: Scarabaeidae, Geotrupidae, Hydrophilidae) in cattle pastures inferred from pitfall trapping dataAn analysis of data on the dry weight biomass of coprophagous beetles in standardized dung (4.5 l) was conducted in order to characterize the spatial and the seasonal distribution of the beetles' biomass in cattle pastures and to elucidate their function in dung decomposition. Nested Anova with factors of farm, site (nested in farm), seasonal period and year was used to evaluate the effect of these factors on the biomass of four functional species groups: the dung dwellers ofScarabaeidae(subfamilyAphodiinae), the dung dwellers ofHydrophilidae, the small tunnellers ofScarabaeidae(subfamilyCoprinae) and the large tunnellers ofGeotrupidae. The spatial variation of biomass (between the sites and the farms) was insignificant (P>0.05) in the two dung-dweller groups and in the large-tunnellers group. On the other hand, a significant (P<0.05) seasonal variation of biomass was found in all but the large tunneller group. In dung dwellers, the spring biomass was formed mainly by two species,Aphodius prodromusandA. sphacelatus. In summer, most of the biomass was accounted for bySphaeridium lunatum, S. scarabaeoidesandA. rufipes. In the two tunneller groups,Onthophagus fracticornis, Geotrupes stercorariusandG. spinigerformed a majority of the biomass in dung.


1931 ◽  
Vol 53 (4) ◽  
pp. 535-552 ◽  
Author(s):  
Leslie T. Webster ◽  
Thomas P. Hughes

1. Pneumococci were obtained at one time or another from the nasal passages or throats of 80 per cent of 105 adults and children studied. In adults, they were obtained more frequently from the throat; in children, as often from the nasal passages as from the throat. 2. Of 500 pneumococcus strains studied, 97 per cent proved to be serologically specific. They formed smooth colonies and were for the most part avirulent for mice. Types I and II were obtained from one and two individuals respectively on one occasion only. Type III was obtained from nine individuals; Type XIII from nine individuals; Type XVI and Type XVIII from three individuals, for varying periods in each case. Atypical pneumococci were secured from 13 persons on single and scattered occasions. They varied in colony morphology, did not kill mice, or agglutinate in saline, but flocculated in all types of antipneumococcus sera employed and over a wide pH range in acid buffers. Their occurrence was apparently not associated with any type-transformation or virulence-enhancement process in vivo. 3. Strains of pneumococcus obtained on successive cultures from a given carrier were, with rare exceptions, of the same serological type and were similar in colony morphology, virulence for mice, and other tested biological characteristics. 4. Pneumococci of Types I and II were obtained under conditions suggestive that they lacked a capacity to spread readily; pneumococci of Types III and XIII, on the other hand, were obtained under conditions suggestive that they were spreading from person to person. 5. The persons studied differed consistently with respect to the occurrence of pneumococci. Some were pneumococcus-free, some were transient carriers, some periodic, and some chronic carriers. Data are given which suggest that the differences were due to variations in host resistance. 6. The incidence of pneumococci in all individuals studied underwent a seasonal variation paralleling that of coryza and sore throats in the same persons.


2021 ◽  
Vol 17 (4) ◽  
Author(s):  
Joukje Buiteveld ◽  
Herma JJ Koehorst-van Putten ◽  
Linda Kodde ◽  
Ivo Laros ◽  
Giorgio Tumino ◽  
...  

AbstractThe Netherlands’ field genebank collection of European wild apple (Malus sylvestris), consisting of 115 accessions, was studied in order to determine whether duplicates and mistakes had been introduced, and to develop a strategy to optimize the planting design of the collection as a seed orchard. We used the apple 20K Infinium single nucleotide polymorphism (SNP) array, developed in M. domestica, for the first time for genotyping in M. sylvestris. We could readily detect the clonal copies and unexpected duplicates. Thirty-two M. sylvestris accessions (29%) showed a close genetic relationship (parent-child, full-sib, or half-sib) to another accession, which reflects the small effective population size of the in situ populations. Traces of introgression from M. domestica were only found in 7 individuals. This indicates that pollination preferentially took place among the M. sylvestris trees. We conclude that the collection can be considered as mainly pure M. sylvestris accessions. The results imply that it should be managed as one unit when used for seed production. A bias in allele frequencies in the seeds may be prevented by not harvesting all accessions with a close genetic relationship to the others in the seed orchard. We discuss the value of using the SNP array to elaborate the M. sylvestris genetic resources more in depth, including for phasing the markers in a subset of the accessions, as a first step towards genetic resources management at the level of haplotypes.


2004 ◽  
Vol 58 (1-2) ◽  
pp. 127-133 ◽  
Author(s):  
Cemal Oguz ◽  
Öztürk Oguz ◽  
Hayati Güre

This study was carried out at the Yenice Irrigation Pond between October 1999 and October 2000. For this study 368 roach (Rutilus rutilus) were examined and 37 parasites and 93 Ligula intestinalis were found in the abdominal cavity of the host (prevalence 10.1%, mean intensity 2.51 specimens/fish). Based on season, the highest number of infected fish occurred during summer (33.3%, 4 parasite/fish), and during the other season the mean intensity of infection was relatively low (prevalence 3.3%, 1 specimens/fish). On the other hand, the parasite species was determined especially on small and medium host fish sizes (2.17-100%). Basic criteria for the assessment of the parasite species of host fish were the general parameters related to parasite populations, which are prevalence, mean intensity, seasonal variation, and relationship between host size and infection.


1963 ◽  
Vol 26 (1) ◽  
pp. 133-144 ◽  
Author(s):  
Denis Sinor

The comparative Altaic phonology recently published by Professor Poppe is the third post-war attempt to give body to the theory of the genetic relationship of Altaic languages. In the recent spectacular renascence of Altaic studies two similar works have been published: one by Kotwicz, the other by Ramstedt. It is interesting to note that these surveys were published at a time when the genetic relationship of the Altaic language had already been tacitly admitted for about a century.


1988 ◽  
Vol 24 (1-4) ◽  
pp. 93-95 ◽  
Author(s):  
T. Nishikawa ◽  
S. Okabe ◽  
M. Aoki

Abstract The atmospheric radon daughters concentration at Fukui in the Japanese coastal region of the Sea of Japan shows a seasonal variation whose high values appear in summer and low values in winter. On the other hand, the radon daughters concentration in precipitation at Fukui and that in the maritime atmosphere over the Sea of Japan are high in winter and low in summer. It is concluded from these phenomena that the greater part of the continental radon and its daughters are transported by seasonal winds from Siberia and China to Japan across the Sea of Japan in winter. However, when the air masses approach the shore, the cumulonimbus grows and the heavy snowfall scavenges out the radon daughters from the air masses in large quantities at the Japanese coastal region of the Sea of Japan.


Author(s):  
Suparat Srithawong ◽  
Kanha Muisuk ◽  
Metawee Srikummool ◽  
Jatupol Kampuansai ◽  
Pittayawat Pittayaporn ◽  
...  

BMC Genomics ◽  
2020 ◽  
Vol 21 (S7) ◽  
Author(s):  
José R. Sandoval ◽  
Daniela R. Lacerda ◽  
Marilza M. S. Jota ◽  
Paulo Robles-Ruiz ◽  
Pierina Danos ◽  
...  

Abstract Background According to history, in the pre-Hispanic period, during the conquest and Inka expansion in Ecuador, many Andean families of the Cañar region would have been displaced to several places of Tawantinsuyu, including Kañaris, a Quechua-speaking community located at the highlands of the Province of Ferreñafe, Lambayeque (Peru). Other families were probably taken from the Central Andes to a place close to Kañaris, named Inkawasi. Evidence of this migration comes from the presence near the Kañaris–Inkawasi communities of a village, a former Inka camp, which persists until the present day. This scenario could explain these toponyms, but it is still controversial. To clarify this historical question, the study presented here focused on the inference of the genetic relationship between ‘Cañaris’ populations, particularly of Cañar and Ferreñafe, compared to other highland populations. We analysed native patrilineal Y chromosome haplotypes composed of 15 short tandem repeats, a set of SNPs, and maternal mitochondrial DNA haplotypes of control region sequences. Results After the genetic comparisons of local populations—three from Ecuador and seven from Peru—, Y chromosome analyses (n = 376) indicated that individuals from the Cañar region do not share Y haplotypes with the Kañaris, or even with those of the Inkawasi. However, some Y haplotypes of Ecuadorian ‘Cañaris’ were associated with haplotypes of the Peruvian populations of Cajamarca, Chivay (Arequipa), Cusco and Lake Titicaca, an observation that is congruent with colonial records. Within the Kañaris and Inkawasi communities there are at least five clans in which several individuals share haplotypes, indicating that they have recent common ancestors. Despite their relative isolation, most individuals of both communities are related to those of the Cajamarca and Chachapoyas in Peru, consistent with the spoken Quechua and their geographic proximity. With respect to mitochondrial DNA haplotypes (n = 379), with the exception of a shared haplotype of the D1 lineage between the Cañar and Kañaris, there are no genetic affinities. Conclusion Although there is no close genetic relationship between the Peruvian Kañaris (including Inkawasi) and Ecuadorian Cañar populations, our results showed some congruence with historical records.


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