numerical variation
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Flora ◽  
2021 ◽  
Vol 276-277 ◽  
pp. 151785
Author(s):  
Zixuan Huang ◽  
Yi Ren ◽  
Xiaohui Zhang

Zootaxa ◽  
2021 ◽  
Vol 4933 (1) ◽  
pp. 98-112
Author(s):  
CLÁUDIO H. ZAWADZKI ◽  
GABRIELA NARDI ◽  
LUIZ FERNANDO CASERTA TENCATT

The menaced and poorly-known waters of the Bodoquena Plateau revealed a new resident, the stunning Hypostomus froehlichi sp. n., a large-sized armored catfish, which is finally described after more than twenty years since its discovery. The Bodoquena Plateau is drained by the rio Paraguay basin, and is located in the state of Mato Grosso do Sul, Brazil. The new species differs from its congeners on the Bodoquena crystalline waters by having teeth with morphological and numerical variation in adult specimens. There is a continuous range of specimens having about 20 thick and worn teeth to specimens having about 50 thin teeth with intact crowns and lanceolate main cusps. Additional diagnostic characters are: dentaries angled more than 90 degrees, dark blotches, one plate bordering supraoccipital, moderate keel along dorsal series of plates, usually two rows of blotches per interradial membrane on dorsal, pectoral and ventral fins, and by attaining comparatively large size. Hypostomus froehlichi seems to be endemic to the area of the Bodoquena Plateau, in rivers draining to the rio Miranda. The description of the new species reveals a potential conservation flagship species as it is one of the most seen and documented fish by visitors and divers in the clear waters from the touristic, though menaced, Bonito region in Brazil. 


2020 ◽  
Vol 14 (6) ◽  
pp. 1957-1966
Author(s):  
Wenceslas Yana ◽  
Victor Joly Dzokou ◽  
Yves Patrick Mveyo Ndankeu ◽  
Joseph Lebel Tamesse

Diclidophlebia irvingiae is a sap-sucking insect of Irvingia gabonensis inducing important damage to its host plant which has medicinal and nutritional importance in Africa particularly in Cameroon. The aim of the survey was to study numerical variation of the pest during the year and impact of biotic and abiotic factors on numerical variation. The study was carried in Bamenda from March 2018 to March 2019 where larvae and adults of D. irvingiae were collected monthly. The study permitted us to record 3290 individuals 1341 males, 1396 females and 553 larvae. Population fluctuation of the pest during the year showed five periods of individual outbreak corresponding to the generation number of the pest. As most tropical and sub-tropical psyllid species D. irvingiae is a multivoltine species with five annual generations. The outbreak periods depend principally on the phenology of host plant. The statistical test showed that the numerical individual variation of D. irvingiae is not directly related to climatic factors because they do not show significant probability.Keywords: Impact, Biotic, Abiotic, Factors, Insect, Faunistic.


2020 ◽  
Vol 12 (2) ◽  
pp. 221-228
Author(s):  
Dzokou Victor Joly ◽  
Yana Wenceslas ◽  
Soufo Laurentine ◽  
Tamesse Joseph Lebel

Prunus africana is threatened in Cameroon by xylophagous and sap-sucking pest as Cacopsylla sp. This last causes deformations of the young leaves and buds and the plant end up losing all its leaves. Effective control of phytophagous pests requires a thorough understanding of their seasonal population dynamics. The objective of this work carried out on 150 young plants of P. africana in the nursery in Dschang, was to study the population dynamics of Cacopsylla sp. and the impact of climatic factors on the population. From January 2006 to December 2007, monthly collections of larvae, males and females of Cacopsylla sp. were carried out. The results showed, in 2006, three peaks (March, August and December) and two peaks in 2007 (March and August) with larvae. The fluctuation of males' population showed five peaks with two peaks in 2006 (March and December) and three peaks in 2007 (March, June and December) while in females' population, four peaks with two peaks in 2006 (March and December) and two peaks in 2007 (March and November). The annual numerical variation of Cacopsylla sp. individual is statistically correlated with variation of precipitations and the insolation. The precipitations have a negative effect on the numerical variation of males (r=-0.430, p<0.0360) and females (r=-0,434, p<0.0336) of Cacopsylla sp. The insolation has a positive effect on the numerical variation of males (r=0.732, p<0.0000002), females (r=0.653, p<0.000523) and the total individuals (r=0.601, p<0.00197) of Cacopsylla sp. With the larvae, the correlation was negative and non-significant. This work showed that March and December were better indicated to engage the fight against Cacopsylla sp. in Dschang.


2020 ◽  
Author(s):  
Dan Su ◽  
Lei Chen ◽  
Jianying Sun ◽  
Luyue Zhang ◽  
Runfei Gao ◽  
...  

Abstract Background: In recent years, purple-fleshed sweet potato has been paid more and more attention because of its high nutritional value. However, the current studies on purple-fleshed sweet potato were still focused on the research and production of the related products. The research on its cytogenetics is relatively lagging behind, which cannot satisfy the study of genetic diversity of purple-fleshed sweet potato. Therefore, we carried out cytogenetic analysis on 76 purple-fleshed sweet potato cultivars, aim to analyze the chromosome structure and distribution of 45S rDNA and 5S rDNA in 76 purple-fleshed sweet potato cultivars.Results: We have found that only 62 purple-fleshed sweet potato cultivars with 90 chromosomes, and the others were aneuploid with 88, 89, 91, 92 chromosomes. The number of 45S rDNA in 76 purple-fleshed sweet potato cultivars varies from 16 to 21, with different signal sizes and intendities, and localized at the terminal or satellite of chromosomes. The number of 5S rDNA were relatively stable, 74 of the varieties investigated contained 6 sites, located at the terminal of chromosomes and near centromere. Only the Quanzishu 96 has 7 5S rDNA sites, and Yuzixiang 10 has 5 5S rDNA sites. In addition, rDNA analysis was also performed on two parents of Quanzishu 96. Both the two parents had 18 45S rDNA sites and 6 5S rDNA sites, which were different from the results of Quanzishu 96.Conclusions: For hexaploid sweet potato cultivars, there is genetic instability between purple-fleshed sweet potato cultivars. The 45S rDNA sites showed numerical variation, whereas conserved number of 5S rDNA sites were observed.


2020 ◽  
pp. 1713
Author(s):  
Shirley Viana Peçanha ◽  
Raquel Batista Junger de Carvalho ◽  
Carlos Augusto Santos-Sousa ◽  
Emanoelli Aparecida Rodrigues dos Santos ◽  
Paulo Souza Júnior ◽  
...  

Objective. The aim of this study was explored the duplicity of renal artery in a specimen of Cerdocyon thous, focusing on the possibilities of clinical-surgical implication of this anatomical variation. Materials and Methods. Were dissected 32 specimens of Cerdocyon thous, obtained from the collections of the Laboratório de Ensino e Pesquisa em Morfologia dos Animais Domésticos e Selvagens do Departamento de Anatomia Animal e Humana, da Universidade Federal Rural do Rio de Janeiro e Laboratório de Anatomia Animal da Universidade Federal do Pampa. Results. Were observed a numerical variation in the left renal artery in an adult female cadaver. The left kidney had two renal arteries, one cranial and another caudal. The first renal artery of the left kidney, measuring 2.25 cm in length, originated laterally from the abdominal aorta at the level of the third lumbar vertebra. Moreover, it emanated two pre-hilar branches, one dorsal and one ventral, with the ventral branch supplying also to the adrenal gland. The second renal artery also originated laterally from the abdominal aorta at the level of the third lumbar vertebra and measured 2.36 cm in length. It also emitted two pre-hilar branches, one cranial and another caudal, which emitted the ureteral branch. Conclusions. Numerical variations of the renal arteries should be considered in the execution of surgical, radiological and experimental procedures in order to avoid mistakes made due to lack of knowledge of the possibility these variations both in domestic and wild animals.


2020 ◽  
Vol 49 (3) ◽  
pp. 20190002 ◽  
Author(s):  
Qi Sun ◽  
Min-jun Dong ◽  
Xiao-feng Tao ◽  
Meng-da Jiang ◽  
Chi Yang

Objective: To compare and evaluate the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) values between a 15-channel phased array head coil and 6-channel dS Flex M surface coil in the MRI of temporomandibular joint. Methods: 300 patients were randomly assigned to two groups: 150 patients were examined by using a 15-channel phased array head coil and the other 150 patients were scanned by using a 6-channel dS Flex M surface coil. All of the data were set in the same 6 regions of interest including the temporal lobe, condyle neck, lateral pterygoid muscle, parotid gland, the adipose area and an area of the background noise). SNR and CNR values were measured respectively. Results: The numerical variation law of SNR and CNR values measured in regionsof interest of each group was similar, although different coils were used. There were statistically significant differences of SNR values in all of the oblique sagittal (OSag) proton density-weighted imaging, the part of OSag T 2 weighted image (T 2WI) except for SNR4 and SNR5. and oblique coronal (OCor) T 2WI sequence except for SNR2. On the contrary, SNR4 and SNR5 values in the OCor T 2WI and SNR5 values in OSag T 2WI sequences by using the surface coil were higher than those by using the head coil. There were no statistically significant intergroup differences of CNR values in OSag proton density-weighted imaging sequence except CNR1 and in OSag T 2WI sequence except CNR5. But, statistically significant differences of all the values in the OCor T 2WI sequence except for CNR1 were observed. Conclusion: Both the phased array head coil and dS Flex M surface coil can be used for temporomandibular joint MRI.


2020 ◽  
pp. 302-302
Author(s):  
Aleksandar Milivojevic ◽  
Miroljub Adzic ◽  
Milan Gojak ◽  
Mirjana Stamenic ◽  
Vuk Adzic

The paper presents results of theoretical numerical research dealing with CO and NOX emission performed in the process of optimization of the performance of low-power atmospheric burners. The theoretical part of this paper, whose main goals were better understanding of the complex issues of methodology and establishment of performance prediction and optimization of low-power atmospheric gas burner included numerical variation of independent parameters, such as burner geometry, the coefficients of primary and secondary air and different gaseous fuels including biogas. The findings of theoretically obtained performance prediction and optimization of atmospheric burners were experimentally investigated in purpose built test rigs for a number of variable parameters. The obtained results fully justified the proposed models of performance prediction and burner optimization.


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