Studies of the Biting-habits of African Mosquitos. An Appraisal of Methods employed, with special Reference to the twenty-four-hour Catch

1954 ◽  
Vol 45 (1) ◽  
pp. 199-242 ◽  
Author(s):  
A. J. Haddow
Keyword(s):  
Vertical Distribution ◽  
Special Reference ◽  
Geometric Mean ◽  
Seasonal Abundance ◽  
Central Tendency ◽  
Valuable Method ◽  
Different Seasons ◽  
Working Out ◽  
Different Levels ◽  
Biting Behaviour

It is felt that the 24-hour catch presents a valuable method of studying the biting-behaviour of mosquitos in the field, and further that conclusions concerning seasonal abundance, vertical distribution and times of biting-activity must be based on catches of this type if serious errors of interpretation are to be avoided.The time-divisions of the catch should not exceed one hour, and even shorter intervals may be desirable. Timing should be related to the actual times of sunrise and sunset. Where possible, a series of consecutive catches should be carried out, and a shift system must be carefully considered in relation to the particular series projected.Usually the results from different levels above ground should be treated separately in working out biting-cycles, and this may also apply to results from different seasons or different localities. Further, while in some instances the summation of long series of catches seems permissible, in others it is not, and in these detailed analysis of the figures may be necessary before consistent behaviour-patterns become apparent.In cases where a measure of the central tendency is to be employed, the geometric mean as modified by C. B. Williams appears to be the most suitable.

scholarly journals Orchard Mapping with Deep Learning Semantic Segmentation

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3813
Author(s):  
Athanasios Anagnostis ◽  
Aristotelis C. Tagarakis ◽  
Dimitrios Kateris ◽  
Vasileios Moysiadis ◽  
Claus Grøn Sørensen ◽  
...  
Keyword(s):  
Neural Network ◽  
Deep Learning ◽  
Semantic Segmentation ◽  
Automated Detection ◽  
Aerial Images ◽  
Training Dataset ◽  
Field Boundary ◽  
Different Seasons ◽  
Detection And Localization ◽  
Different Levels

This study aimed to propose an approach for orchard trees segmentation using aerial images based on a deep learning convolutional neural network variant, namely the U-net network. The purpose was the automated detection and localization of the canopy of orchard trees under various conditions (i.e., different seasons, different tree ages, different levels of weed coverage). The implemented dataset was composed of images from three different walnut orchards. The achieved variability of the dataset resulted in obtaining images that fell under seven different use cases. The best-trained model achieved 91%, 90%, and 87% accuracy for training, validation, and testing, respectively. The trained model was also tested on never-before-seen orthomosaic images or orchards based on two methods (oversampling and undersampling) in order to tackle issues with out-of-the-field boundary transparent pixels from the image. Even though the training dataset did not contain orthomosaic images, it achieved performance levels that reached up to 99%, demonstrating the robustness of the proposed approach.

Improving the hydrobiological analysis of activated sludge at the Minsk wastewater treatment facilities

2021 ◽  
pp. 26-36
Author(s):  
О.С. Дубовик ◽  
Р.М. Маркевич ◽  
Е.В. Гаврилович ◽  
И.А. Гребенчикова ◽  
В.В. Иванович
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Point System ◽  
Treatment Conditions ◽  
Filamentous Microorganisms ◽  
Different Seasons ◽  
Treatment Facilities ◽  
Favorable Conditions ◽  
Quantitative Account ◽  
Different Levels

На основании накопленного опыта эксплуатации сооружений Минской очистной станции и обзора источников информации определена схема гидробиологического анализа активного ила, приведена форма регистрации результатов проведенного анализа. Для количественного учета нитчатых микроорганизмов разработана собственная пятибалльная система. Для нитчатых микроорганизмов, выявленных в активном иле, на основании анализа литературных данных определены условия, благоприятствующие их массовому развитию. В течение длительного периода времени, включающего разные сезоны года, проведена апробация усовершенствованной методики для мониторинга состояния иловой суспензии очистных сооружений двух площадок станции: классических четырехкоридорных аэротенков-вытеснителей первой площадки и биореакторов с каскадной денитрификацией второй площадки. Определены представители нитчатых микроорганизмов, постоянно обитающие в очистных сооружениях, выявлены доминирующие виды. Проведено сопоставление результатов анализа нитчатых форм и седиментационных характеристик активного ила. Сделаны заключения об особенностях биоценоза аэротенков первой площадки и биореакторов второй площадки, идентичности по видовому составу сообществ нитчатых бактерий, влиянии состава сточных вод и условий их очистки (нагрузка на ил, наличие зон с разным уровнем аэрации) на свойства иловой суспензии. Based on the accumulated experience in operating the Minsk Wastewater Treatment Facilities and a review of information sources, a scheme for the hydrobiological analysis of activated sludge was determined, and a form for recording the results of the analysis was provided. For the quantitative account of filamentous microorganisms, an original five-point system was developed. Based on the literature data analysis, favorable conditions for the mass growth of filamentous microorganisms found in activated sludge were determined. Over a long period of time, including different seasons of the year, the improved methodology was tested for monitoring the state of the sludge suspension at two sites of the treatment facilities: traditional four-line continuous-flow aeration tanks at the first site and bioreactors with cascade denitrification at the second site. The species of filamentous microorganisms, permanently living in wastewater treatment structures, have been identified, and the dominant species have been determined. The results of the analysis of filamentous forms and sedimentation characteristics of activated sludge are compared. Conclusions were made about the features of the biocenosis in the aeration tanks at the first site and in the bioreactors at the second site; about the identity of the species composition of the filamentous bacteria communities, the effect of the wastewater composition and treatment conditions (sludge load, occurrence of zones with different levels of aeration) on the properties of the sludge suspension.

scholarly journals XXVII.—On Bistratification in the Growth of Languages, with Special Reference to Greek

1895 ◽  
Vol 37 (3) ◽  
pp. 615-620
Author(s):  
Blackie
Keyword(s):  
Special Reference ◽  
Intellectual Culture ◽  
Vocal Expression ◽  
The People ◽  
Written Form ◽  
Working Out ◽  
Common Action

In all languages where there exists a certain amount of intellectual culture, manifesting itself in the oral or written form of what is called Literature, there must always coexist with it an inferior stratum or platform of speech; the platform of common colloquial intercourse of the mass of the people, and specially of the peasantry and lower classes. The necessity of this bistratification arises from the diverse class of ideas, and the diverse style of intercourse, pervading the two platforms. Language is a growth that flows from the intercommunion of associated persons working out, within a certain bounded circle, the vocal expression which their ideas, their energies, and their circumstances demand for the purpose of common action.

Seasonal abundance and vertical distribution of crab larvae from northern Patagonia (Argentina): implications for their transport in a biogeographic boundary region

2013 ◽  
Vol 10 (1) ◽  
pp. 37-50 ◽  
Author(s):  
Fernando Gaspar Dellatorre ◽  
Gustavo Lovrich ◽  
Laura Rojas ◽  
Viviana Milano ◽  
Nerina Delourdes Figueroa ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Boundary Region ◽  
Seasonal Abundance ◽  
Northern Patagonia ◽  
Crab Larvae

Observations on growth and morphogenesis in cultured cells of carrot ( Daucus carota L.)

1975 ◽  
Vol 273 (922) ◽  
pp. 33-53 ◽  
Keyword(s):  
Thin Films ◽  
Somatic Embryogenesis ◽  
Special Reference ◽  
Daucus Carota ◽  
Liquid Culture ◽  
Cultured Cells ◽  
Daucus Carota L ◽  
Practical Applications ◽  
Carrot Cells ◽  
Different Levels

This paper deals with problems of somatic embryogenesis (totipotency) of carrot cells in liquid culture and when dispersed in thin films of nutrient agar. The critical events that intervene between somatic cells and embryo plantlets during morphogenesis are delineated. Factors that affect the course of these events are described with special reference to the stimuli which permit the very smallest units to develop into organized structures. Special attention is directed to the importance of a protracted period of darkness and the use of an ‘embryo-conditioned medium’ as interacting stimuli that facilitate the early stages of development. Means of arresting and releasing the development of pro-embryonic units are discussed. Aspects of growth and form of the developing cultures are presented photographically at different levels. The behaviour of free protoplasts from pro-embryonic units is described and contrasted with that of intact totipotent cells. The significance of all these observations is examined in the light of practical applications and in relation to problems of development.

Observations on the Biting-habits of some Tabanidae in Uganda, with special Reference to arboreal and nocturnal Activity

1950 ◽  
Vol 41 (1) ◽  
pp. 209-221 ◽  
Author(s):  
A. J. Haddow ◽  
J. D. Gillett ◽  
A. F. Mahaffy ◽  
R. B. Highton
Keyword(s):  
Special Reference ◽  
Yellow Fever ◽  
Forest Canopy ◽  
Dry Season ◽  
Forest Trees ◽  
Close Correspondence ◽  
Nocturnal Activity ◽  
Wet Season ◽  
Natural Hosts ◽  
Biting Behaviour

In a search for the forest vector of yellow fever, catches of biting Diptera have been made by various methods in forest trees in Bwamba County, Uganda. The work here reported concerns Tabanids taken in catches made during the period 1944–45.Three species of Tabanids have been taken in trees during these catches, and one of these, Chrysops centurionis, has proved to be mainly arboreal.Observations on C. centurionis have shown that its main biting-activity begins just before sunset and reaches a peak during the hour after sunset. Thereafter the numbers taken diminish rapidly, but some activity continues throughout the night.In the wet-season catches, this species was most prevalent in the forest canopy at heights of 50 to 60 feet above ground. In the dry season the most favourable level was lower, at 20 to 30 feet above ground.It is suggested that monkeys are the natural hosts of C. centurionis, and that C. centurionis may be the vector of filarial infections among wild monkeys.It is shown that there is a very close correspondence between the biting-behaviour of C. centurionis and that of the mosquito, A ëdes africanus.Evidence of nocturnal activity has now been obtained in the case of one species of Tdbanus, three species of Haematopota and two species of Chrysops. It is suggested that there may be some connection between the remarkable eye colours of Tabanids and crepuscular or nocturnal activity.Records of other Bwamba Tabanids are given.

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