scholarly journals Estudio del polen de Phaseolus chiapasanus Piper (Leguminosae: Phaseolinae)

2017 ◽  
pp. 25
Author(s):  
Alfonso Delgado-Salinas ◽  
Enrique Martínez-Hernández ◽  
Pilar Fernández-Ortuño
Keyword(s):  
Pollen Grains ◽  
Size Class ◽  
Important Research ◽  
Large Size ◽  
Large Size Class ◽  
The Creation ◽  
Taxonomical Revision ◽  
Document Relationships ◽  
Genus Vigna

In the course of a taxonomical revision of the genus Phaseolus and considering the recently important research realized in the Phaseolus-Vigna complex, where the palynological attributes for the genus were precised, the present paper describes the pollen of Phaseolus chiapasanus Piper. The large-size class pollen grains of Ph. chiapasanus are tricolporate, brevicolpate, pseudo-operculate; semitectate, and widely reticulate. The structure of the infratectum could be considered of the granular-collumelar type. Some of the attributes found in the polen of Ph. Chiapasanus were not known for the genus, though such attributes are commonly found in the subgenus Sigmoidotropis of the genus Vigna. Ph. chiapasanus shows a series of morphological and palynological differences that open the possibility for the creation of a new section within the genus. More detailed studies will definitely by needed to better document relationships to other species of the genus.

Diet, feeding behaviour and habitat utilisation of the blue stingray Dasyatis chrysonota (Smith, 1828) in South African waters

2003 ◽  
Vol 54 (8) ◽  
pp. 957 ◽  
Author(s):  
David A. Ebert ◽  
Paul D. Cowley
Keyword(s):  
Surf Zone ◽  
Stomach Contents ◽  
Size Class ◽  
Behaviour Pattern ◽  
Medium Size ◽  
Secondary Importance ◽  
Size Classes ◽  
Important Prey ◽  
Large Size ◽  
Large Size Class

Analysis of stomach contents for Dasyatis chrysonota revealed that diet varied with size and habitat. The diet of all size classes in the surf zone was comprised primarily of Callianassa spp., Donax spp. and unidentified polychaete species. The medium and large size classes fed primarily on Donax spp., whereas the very large size class fed mainly on Callianassa spp. Polychaetes were of secondary importance as prey for the medium size class. The diet of D. chrysonota in the nearshore zone consisted mainly of Balanoglossus capensis and Callianassa spp. Balanoglossus capensis decreased from an index of relative importance (IRI) of 75.3% for the medium size class to 59.9% for the very large size class, whereas Callianassa spp. increased from 22.8% to 39.4% between the medium and the very large size classes. The offshore zone was the only area in which small size class D. chrysonota were caught. The diet of these small D. chrysonota was primarily polychaetes and amphipods. Polychaetes increased in importance in the medium size class, but declined in each successively larger size class. Conversely, Pterygosquilla armata capensis became the single most important prey item for the very large size class, comprising an IRI of 50.9%. The behaviour pattern used by D. chrysonota to locate and extract prey is described.

Season and Body Size Influence Movement of Hydropsychid Caddisfly Larvae (Trichoptera: Hydropsychidae)

1992 ◽  
Vol 49 (2) ◽  
pp. 259-265 ◽  
Author(s):  
B. L. Kerans
Keyword(s):  
Body Size ◽  
Relative Size ◽  
Relative Weight ◽  
Central Area ◽  
Size Class ◽  
Directional Bias ◽  
Large Size ◽  
Small Size Class ◽  
First Choice ◽  
Large Size Class

Movement patterns of fifth-instar Hydropsyche slossonae larvae were investigated in artificial streams. In the first choice experiment, larvae were released into a central area and their upstream or downstream crawling or drifting was monitored. A second experiment used the same design; however, fifth instars collected during spring and fall were divided into two, nonoverlapping, relative size-classes (large and small) to determine how these factors influenced movement parameters. In both experiments, larvae always drifted more frequently than they crawled, but in experiment 2, drifting tendency declined with increasing weight in spring. In both experiments, there was no statistically detectable directional bias to crawling nor change in relative crawling direction with season or size-class. In experiment 2, drifting larvae were lighter than nondrifting larvae in the large size-class, but equal in weight in the small size-class. This result was unrelated to absolute weight, as large size-class larvae in fall were similar in weight to small size-class larvae in spring. It is possible that the relative weight differential of drifting and nondrifting larvae in one size-class but not the other may be related to sexual rather than body size differences.

2n gametes in Solanum commersonii and cytological mechanisms of triplandroid formation in triploid hybrids of Solanum commersonii × Solanum gourlayi

Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 864-869 ◽  
Author(s):  
R. W. Masuelli ◽  
E. L. Camadro ◽  
A. O. Mendiburu
Keyword(s):  
2N Gametes ◽  
Pollen Grains ◽  
Solanum Commersonii ◽  
Stainable Pollen ◽  
Large Size ◽  
Common Potato ◽  
Aneuploid Chromosome ◽  
The Common ◽  
Bridge Species ◽  
Solanum Gourlayi

Solanum commersonii Dun. (cmm) is a diploid wild species of potential value for potato breeding. Ploidy level manipulations are necessary to cross this species with the common potato. This could be achieved by the use of "bridge" species and sexual polyploidization in which 2n gametes are involved. Eight introductions of cmm were screened for production of (i) diplandroids, through cytological observations confirmed by controlled 4x Solanum acaule Bitt. (acl) × 2x cmm crosses, and (ii) diplogynoids, by controlled 2x cmm × 2x Solanum gourlayi Haw. (grl) crosses. Eleven plants produced 1–3% large size pollen and one plant produced more than 3% of this type of pollen. Twelve triploid and seven tetraploid hybrids were obtained when these plants were used in crosses with acl. On the other hand, 75 triploid hybrids were obtained from the second type of cross. The average pollen stainability in the diplogynoid triploid cmm × grl hybrids was 18.9%, with a range of 2–34.4%. Forty-four to 54.6% of meiocytes with parallel spindles in metaphase II and anaphase II were observed in microsporogenesis of these hybrids. For each clone, the frequency of triplandroids predicted according to the frequency of meiocytes with parallel, fused and tripolar spindles in anaphase II were 52.3, 36.6, and 45.2%, respectively. These values were highly superior to the frequency of triplandroids predicted according to the number of dyads and triads observed, 8.8, 0.7, and 3.9%, respectively. However, triplandroid frequencies predicted according to the frequencies of fused and tripolar spindles agree with the triplandroid frequencies observed. The frequencies of stainable pollen grains are not completely accounted for by the formation of fused and tripolar spindles. In view of the variability encountered in size, it is assumed that a high proportion of gametophytes with aneuploid chromosome numbers are also stainable. A hypothesis is put forward regarding the possible genetic control of triplandroid formation in the diplogynous triploid hybrids analyzed.Key words: 2n gametes, triploid hybrids, spindle orientation, Solanum commersonii Dun.

scholarly journals FORMATION OF GEOGRAPHY AS A SCIENCE IN UZBEKISTAN IN THE XX CENTURY

2020 ◽  
pp. 202-203
Author(s):  
Tolibov Nurbek
Keyword(s):  
Twentieth Century ◽  
Central Asia ◽  
Important Research ◽  
Great Contribution ◽  
Stage Of Development ◽  
Ancient Times ◽  
The Creation

From ancient times the scientists of Central Asia have made a great contribution to the development of geography. In the twentieth century, Uzbekistan experienced its own stage of development. This article analyzes the most important research conducted in the twentieth century for the development of geography in Uzbekistan, the work on the creation of geographical atlases and maps, as well as geographical dictionaries in the country.

scholarly journals Morphology of Anemone sylvestris L. flower (Ranunculaceae)

2016 ◽  
Vol 75 (1) ◽  
pp. 74-80 ◽  
Author(s):  
Bożena Denisow ◽  
Sebastian Antoń ◽  
Małgorzata Wrzesień
Keyword(s):  
Seed Set ◽  
Pollen Dispersal ◽  
Pollen Grains ◽  
Starch Accumulation ◽  
Pollination Syndrome ◽  
Wind Pollination ◽  
Intermediate Form ◽  
Protected Species ◽  
Large Size ◽  
Opening And Closing

Abstract During the monitoring of populations of Anemone sylvestris L. (Ranunculaceae), a protected species in Poland, we found that the seed set is impaired. The flower is considered an adaptation that has coevolved to achieve effective pollination and successful fertilization. Therefore we have focused on the morphological and anatomical characteristics of the flowers of A. sylvestris L. as a prelude to the study of the species’ pollination biology and plant breeding system. The large size of the flower (50.6 ± 16.4 mm in dimensions) and its bowl shape fulfil both the biotic pollination syndrome and the aerodynamic requirements for pollen dispersal and capture. The opening and closing of the perianth provide a shelter for beetles. The odourless perianth, absence of nectar, scarcity of pollen (approximately 200 000 pollen grains per flower) and its traits - small size (axis P = 18.52 ± 1.0 μm; E = 16.59 ± 0.9 μm), lack of balsam on the exine surface, starch accumulation in more than 95% of pollen grains correspond to the specialization in anemophily. The stigma is papillous, the dense hairs are situated between single carpels indicating adaptation to capturing dry pollen and specialization in the wind pollination syndrome. The flower of A. sylvestris is an example for an intermediate form between entomophily and anemophily, i.e. a secondary and more advanced feature among Ranunculaceae.

scholarly journals Spatial and temporal distribution patterns of brown shrimp (Crangon crangon) derived from commercial logbook, landings, and vessel monitoring data

2020 ◽  
Vol 77 (3) ◽  
pp. 1017-1032 ◽  
Author(s):  
K F Schulte ◽  
V Siegel ◽  
M Hufnagl ◽  
T Schulze ◽  
A Temming
Keyword(s):  
Temporal Distribution ◽  
Distribution Patterns ◽  
Early Summer ◽  
Brown Shrimp ◽  
Spatial And Temporal Distribution ◽  
Crangon Crangon ◽  
Large Size ◽  
System Data ◽  
Large Size Class ◽  
Local Recruitment

Abstract In this study, logbook, landings, and vessel monitoring system data of German brown shrimp (Crangon crangon L.) fishers were combined to analyse spatial and temporal distribution patterns. Landings per unit effort (LPUE) were standardized to the efficiency level of a reference vessel. The standardization altered the spatial–temporal patterns of the LPUE as the vessels differed by a factor of up to 4.7. LPUE data were separated into two size classes according to sieve fractions. Small brown shrimps were characterized by LPUE values increasing early in the year in shallow waters, especially in estuaries in July. Subsequently, peak LPUE values are reached at the end of September in all depths, but with variable spatial patterns between years. LPUE data indicate a general outward migration between early summer and winter. In winter, large shrimp shows a clear increase in LPUE with depths mainly in regions adjacent to the Dutch coast and a reversed pattern close to the Danish coast. The large size class in winter—which consists mainly of mature or egg-bearing females—showed high LPUE values along two persistent diagonal bands in the German Bight. These patterns could lead to local recruitment overfishing, if fishermen are aware of such patterns.

Finance-led divergence in the regions of Italy

2005 ◽  
Vol 12 (1) ◽  
pp. 7-41 ◽  
Author(s):  
BRIAN A'HEARN
Keyword(s):  
Entire Range ◽  
Banking System ◽  
Subsequent Development ◽  
Size Class ◽  
Matrix Analysis ◽  
Local Economies ◽  
Lower Growth ◽  
The North ◽  
Large Size ◽  
Regional Divergence

The article evaluates finance-led growth as an explanation for regional divergence in Italy over the years 1890–1910. Regional banking disparities are documented and the hypothesis developed that the financial crisis of the early 1890s struck the fledgling Southern Italian banking system at a vulnerable moment, distorting its subsequent development and handicapping the region's economy. The South is revealed to have been a chronically (over the entire period) and comprehensively (on every indicator) unhealthy environment for banks. Further evidence indicates that regional divergence in bank assets was largely due to the South's failure to develop the entire range of large banks. Size-class transition matrix analysis reveals that the typical Southern bank failed to reach a large size because it was born smaller (and less frequently) than in the North, suffered a higher mortality rate, especially in the smaller classes, and had lower growth probabilities, especially in the larger categories. The salience of deposits on the liability side and government securities on the asset side suggests that they reflected more than directly caused the development of their local economies.

scholarly journals Quantification of Tremolite in Friable Material Coming from Calabrian Ophiolitic Deposits by Infrared Spectroscopy

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Antonella Campopiano ◽  
Angelo Olori ◽  
Annapaola Cannizzaro ◽  
Antonino Iannò ◽  
Pietro Paolo Capone
Keyword(s):  
Infrared Spectroscopy ◽  
Quantitative Analysis ◽  
Absorption Band ◽  
Size Class ◽  
Medium Size ◽  
Friable Material ◽  
Large Size ◽  
Mineral Silicates ◽  
Ir Bands ◽  
Absorbance Band

The aim of this study is to identify the infrared absorption band suitable for quantifying tremolite in three powdered samples (fine, medium, and large size classes) coming from a quarry of ophiolitic friable rocks in the western part of the Calabria region of Italy. Three IR bands were considered: OH stretching band between 3700 and 3650 cm−1, the stretching bands of the Si-O-Si linkage between 1200 and 900 cm−1, and the absorbance band at 756 cm−1attributable to tremolite. The amount of tremolite in the test samples was quantified by using the curve parameters of the three analytical bands. The quantitative analysis of tremolite using the band due to OH stretchings (3700–3650 cm−1) and the bands attributed to the Si-O-Si stretchings (1200–900 cm−1) showed high values for all test samples. Their use overestimated the tremolite amount because both bands were affected at the interfering mineral silicates such as talc, kaolinite, chlorite, and serpentinites. The abundant presence of antigorite in studied samples mainly in medium size class sample had a key role in our findings. The band at 756 cm−1was not affected at the interfering minerals and can be used for quantitative analysis of tremolite in sample coming from ophiolitic deposits.

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