Comportement meiotique de populations tetraploides du genre Dactylis

1986 ◽  
Vol 28 (6) ◽  
pp. 899-905 ◽  
Author(s):  
Gaëtan Guignard
Keyword(s):  
Distribution Pattern ◽  
Statistical Study ◽  
Meiotic Behaviour ◽  
Meiotic Behavior ◽  
Ring Bivalents ◽  
The Individual

A statistical study of four criteria applied to the genus Dactylis (Poaceae) enabled us to determine the individual meiotic behaviour of eight tetraploid populations. Those criteria were as follows: the percentage of rod and ring bivalents, the average number of tetravalents, the average number of chiasmata, and the distribution pattern of chromosomic formulas.Key words: Dactylis, populations, meiotic behavior, tetraploidy, cocksfoot.

Glacial and glacially conditioned lake types in the Cordillera Blanca, Peru

2014 ◽  
Vol 38 (5) ◽  
pp. 602-636 ◽  
Author(s):  
Lasafam Iturrizaga
Keyword(s):  
Distribution Pattern ◽  
Field Research ◽  
Spatial Arrangement ◽  
High Mountain ◽  
Mountain Range ◽  
Genetic Classification ◽  
Conceptual Approach ◽  
Cordillera Blanca ◽  
The Andes ◽  
The Individual

The article presents a conceptual approach for the spatiotemporal distribution pattern of principal lake types in the context of the glaciation history in the Cordillera Blanca. The tropical mountain range hosts one of the main concentrations of proglacial lakes in high-mountain settings worldwide, which have formed as a result of the dominant trend of modern glacier retreat. In the 20th century, glacial lake outbursts have severely affected large settlement areas in the Rio Santa Basin. Additionally to the striking newly emerged lakes, geomorphological evidence of paleolakes is found throughout the middle and lower valley sections. Based on empirical data from field research in over 20 valleys and the analysis of air and satellite images, the study provides a genetic classification of major lake types and a generalized model for the distribution of the present lakes and paleolakes. The origin of the lakes and their recurrent distribution pattern are associated with the individual stages of the Pleistocene to modern glaciation and their corresponding geomorphological landforms. Apart from the individual lake, the focus is put on the spatial arrangement of the lakes to each other based on a holistic landscape assessment. Implications are drawn for the hazard potential, in particular in terms of outburst cascades involving two or more lakes. On a supraregional scale, a clustering of certain lake types occurs in different mountain ranges of the Andes according to their specific topographical and glaciological settings. Even though the glaciated areas have all been subject to major ice losses, only some mountain regions are prone to form moraine-dammed lakes such as in the Cordillera Blanca. The key controlling factors for their formation are highlighted from a glacial-geomorphological point of view. The distribution of principal types of glacial lakes is outlined in a N–S profile along the Andes.

C-banding in meiosis: an approach to the study of wheat and rye genome interactions in triticale

Genome ◽  
1989 ◽  
Vol 32 (6) ◽  
pp. 1074-1078 ◽  
Author(s):  
C. Galindo ◽  
N. Jouve
Keyword(s):  
Tetraploid Wheat ◽  
Meiotic Behaviour ◽  
Giemsa Banding ◽  
Hexaploid Triticale ◽  
C Banding ◽  
Triticale Line ◽  
The Individual ◽  
Genome Interactions

Meiosis in four primary hexaploid triticale lines, in their component two tetraploid wheat and two rye parents, and in the hybrids obtained by crossing within each ploidic level was studied using Giemsa banding. The individual chromosomes were identified and their meiotic behaviour at first metaphase was analyzed in each line. In each new triticale line, the level of pairing for wheat chromosomes was moderately reduced and for rye chromosomes was very significantly reduced, in comparison with that of the wheat and rye parents used to synthesize it. The pairing intensity observed suggests the presence of a strong negative intergenomic interaction between the rye and wheat genomes in triticale, irrespective of whether the rye is in a homozygous or heterozygous genotypic condition. The homozygosity or heterozygosity in the wheat constituent does not appear to effect the behaviour of the rye chromosomes in triticale.Key words: triticale, meiosis, C-banding, heterosis.

Carbon dioxide fixing pathways of glutamic acid synthesis in the rumen

1970 ◽  
Vol 48 (4) ◽  
pp. 463-468 ◽  
Author(s):  
L. P. Milligan
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Distribution Pattern ◽  
Acid Synthesis ◽  
Tricarboxylic Acid ◽  
Simultaneous Occurrence ◽  
Rumen Microorganisms ◽  
Glutamate Synthesis ◽  
The Individual

Rumen contents were incubated with NaHCO3-14C and the pattern of incorporation of 14C into glutamic acid was determined. Label was found in C-1, C-2, and C-5 of glutamic acid. This distribution pattern suggested the simultaneous occurrence of the forward tricarboxylic acid (TCA), the atypical forward TCA, and the reverse TCA pathways of glutamate synthesis in the mixed rumen population; these pathways were estimated to account for 63%, 9%, and 28%, respectively, of the glutamate synthesized by pathways entailing CO2 fixation. The contributions of the individual pathways were not influenced by the ration of the host. The significance of these alternate pathways of glutamate synthesis in the metabolism of rumen microorganisms is discussed.

A Statistical Study of Criminal Drug Addicts

1965 ◽  
Vol 11 (3) ◽  
pp. 283-292 ◽  
Author(s):  
Emanuel Messinger ◽  
Arthur Zitrin
Keyword(s):  
New York ◽  
Statistical Study ◽  
Mental Deficiency ◽  
Psychiatric Clinic ◽  
Drug Addicts ◽  
Moral Standards ◽  
Individual Citizen ◽  
The Individual ◽  
And Behavior ◽  
Clinic Study

Psychiatric Clinic study covering all drug addicts arraigned for felonious crimes in New York City between 1954 and 1960 showed that the incidence of psychosis and psychoneurosis in this group is insignificant. The incidence of definite mental deficiency is also extremely low, .02 per cent. Probably half of the individuals seen can be best described as various types of psychopathic personalities. The remainder may be considered to show, at least initially in their histories, lesser types of character and behavior disorders; and their personality defects tend to be predominantly in the fields of ethical and moral laxity and social irresponsibility. Therefore, the logical way for society to deal with the problem of criminal addicts is to use primarily the sociological measures that are determined to be most effective in curbing the depredations of the psychopath, and secondarily whatever educational and sociological measures are determined most useful in elevating the ethical and moral standards and responsibility of the individual citizen.

scholarly journals Penyebaran Jenis Puspa (Schima wallichii (DC.) Korth) di Resort Kawah Ratu, Taman Nasional Gunung Halimun Salak, Jawa Barat

2021 ◽  
Vol 12 (2) ◽  
pp. 86-94
Author(s):  
Iwan Hilwan ◽  
Savira Nurul Aulia Rahman
Keyword(s):  
Distribution Pattern ◽  
Plant Species ◽  
National Park ◽  
West Java ◽  
Schima Wallichii ◽  
The Individual ◽  
Individual Trees

Puspa (Schima wallichii (DC.) Korth.) is a type of plant that dominates the area of Gunung Halimun Salak National Park, especially at Kawah Ratu Resort. Puspa type is one of the upland plant species that can grow in critical land. The objective of this study is to identify the distribution pattern and the potential for regeneration of puspa species (Schima wallichii (DC.) Korth.) at Kawah Ratu Resort, Gunung Halimun Salak National Park, West Java. Data were collected by analyzing vegetation with a single plot method covering an area of 1 hectare at each location. The research was conducted in the Pamengpeuk Block and the Leles Block. The species found in the two research locations were 98 species. The results showed that the distribution pattern of puspa was clustered, both in the Pamengpeuk block and in the Leles block. A clustered spread indicates good youth growth. The ability of puspa regeneration in both locations was quite good because the number of puspa regeneration individuals was more than the individual trees. Keywords: distribution, Gunung Halimun Salak National Park, Kawah Ratu Resort,puspa, Schima wallichii

scholarly journals Meiotic Behaviour in Ten Species of Pteridophytes From Bangladesh

2021 ◽  
pp. 135-142
Author(s):  
MA Mannan ◽  
G Kabir
Keyword(s):  
Meiotic Behaviour ◽  
Meiotic Behavior ◽  
Morphological Variations ◽  
Wide Range ◽  
Adiantum Capillus Veneris

Meiotic behavior of ten pteridophyte species from Bangladesh was analyzed in the present investigation. In SMCs of Adiantum capillus-veneris, thirty distinct bivalents were enumerated. In A. caudatum 16 SMCs resulting 64 spores were observed in sporangium which appeared to be diploid sexual. A. lunulatum was found to be triploid apogamous and as diploid sexual forms, thus this species of Adiantum exhibited wide range of morphological variations. Pteris biaurita, P. graffithi and P. vittata were recorded to be n = 29 as diploid. In thelypterids, all the four species were observed to be diploid sexual except C. dentata when it was tetraploid (n = 36, 4x = 144). In C. arida, meiosis was almost regular with 2n = 72 chromosomes. C. cylindrothrix and Ampelopteris prolifera were also found to be diploid sexual, with 2n = 72 chromosomes. J. Bio-Sci. 29(1): 135-142, 2021 (June)

Pit Alignments in the Milfield Basin, and the Excavation of Ewart 1

1981 ◽  
Vol 47 ◽  
pp. 137-146 ◽  
Author(s):  
Roger Miket
Keyword(s):  
Distribution Pattern ◽  
Preceding Paper ◽  
Aerial Survey ◽  
The South ◽  
Cambridge University ◽  
Marked Elevation ◽  
Present Distribution ◽  
The Individual ◽  
Sand And Gravel ◽  
Newcastle Upon Tyne

The pit alignment at Milfield North, discussed in the preceding paper, is one of six alignments revealed in the Milfield Basin within the last decade. All discoveries have so far been confined to the sands and gravels of the former delta surface, and whereas additional examples, as well as their extension onto the heavier loams overlying the sandstone series, remain to be found, so crisp has been the definition by means of intensive aerial survey in this valley, that only a limited enlargement of the present distribution pattern by this means is anticipated. The characteristics of the individual alignments are as follows:1. Ewart 1. NT95343209 to NT96103162An irregular line of closely spaced pits that for most of its observable course follows the crest of a gentle but marked elevation in the sand and gravel-terrace. Two interruptions are visible towards its eastern end before it angles southwards to disappear into a wood. Observed over 1100 m.Source: Cambridge University Collection. BDE35, BDE36, BKC40.Museum of Antiquities, Newcastle upon Tyne. A1656–1662.2. Ewart 2. NT95353165 to NT95803159Lying to the south of Ewart 1 and running broadly parallel to it. The pit sizes and spacing is similar to Ewart 1 although their inter-relationship is obscured at their eastern end by a plantation. Ewart 2 fades away at its western extremity. Observed over 300 m.Source: Cambridge University Collection. BDE35, BDE36.

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