Seasonal changes in populations of phlebotomine sandflies (Dipt., Psychodidae) in Kenya

1964 ◽  
Vol 55 (3) ◽  
pp. 421-435 ◽  
Author(s):  
D. M. Minter
Keyword(s):  
Seasonal Changes ◽  
Rainy Season ◽  
Wide Distribution ◽  
Annual Rainfall ◽  
Limiting Factor ◽  
Rainfall Distribution ◽  
Phlebotomine Sandflies ◽  
Local Abundance ◽  
Dry Seasons ◽  
Termite Hills

An account is given of seasonal changes in the incidence and relative abundance of a number of Phlebotomine sandflies which rest in termite hills in two widely separated areas of Kenya.The annual pattern of rainfall distribution is shown to be of greater importance than the total precipitation in influencing the gross distribution and local abundance of many sandflies.Kenya sandflies fall readily into ‘ perennial ’ and ‘ rainy-season ’ groups: the former have a wide distribution and appear to breed throughout the year. The distribution of the ‘ rainy-season ’ sandflies is relatively restricted, since these species are found almost exclusively in areas with a bimodal pattern of annual rainfall; it is suggested that they may survive the intervening dry periods in larval diapause. The length rather than the severity of the dry seasons is thought to be the limiting factor in the distribution of ‘ rainy-season ’ species.Examples are given of the seasonal changes in structure of populations made up of several species sharing, in the adult form, the same termite-hill habitat.

Behavioral responses to seasonality by two Sceloporine lizard species from a tropical dry forest

2010 ◽  
Vol 60 (1) ◽  
pp. 97-113 ◽  
Author(s):  
Marciano Valtierra-Azotla ◽  
Bradford Lister ◽  
Andrés García
Keyword(s):  
Seasonal Changes ◽  
Rainy Season ◽  
Tropical Dry Forest ◽  
Behavioral Responses ◽  
Dry Forest ◽  
Behavioral Strategies ◽  
Lizard Species ◽  
Western Mexico ◽  
Dry Seasons ◽  
Resource Levels

AbstractWe investigated behavioral responses of two lizards, Sceloporus melanorhinus and S. utiformis, to environmental seasonality in a tropical dry forest of western Mexico. We conducted focal observations of individuals in the field during both the rainy and dry seasons and compared perch use, foraging and social behaviors and displacement activity within and between species. Our results indicate that seasonal changes occur in the behavior and activity of both male and female S. melanorhinus and S. utiformis. Feeding frequency, social displays, and distances travelled increased significantly in both species during the rainy season. These seasonal changes tended to be more pronounced in the arboreal species; S. melanorhinus. Surprisingly, female S. melanorhinus perched higher than males during the rainy season. Most of the observed changes are similar to the responses to seasonality observed in other lizards, both for species that exist within our study area, and for species that inhabit other seasonal environments in tropical and temperate ecosystems. Thus, the seasonal patterns in behavior documented in this study may represent a general set of behavioral strategies that allow lizards to better adapt to seasonal fluctuations in their environment, such as changes in predation pressure, variation in resource levels, and differences in insolation, temperature, and moisture levels.

scholarly journals Statistical Assessment of Rainfall Characteristics in Upper Blue Nile Basin over the Period from 1953 to 2014

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 468 ◽  
Author(s):  
Abeer Samy ◽  
Mona G. Ibrahim ◽  
Wael Elham Mahmod ◽  
Manabu Fujii ◽  
Amr Eltawil ◽  
...  
Keyword(s):  
Trend Analysis ◽  
Rainy Season ◽  
Prediction Models ◽  
Annual Rainfall ◽  
Nile Basin ◽  
Rainfall Distribution ◽  
Blue Nile ◽  
Blue Nile Basin ◽  
Increasing Trend ◽  
Upper Blue Nile Basin

Investigating the trends of hydro-meteorological variables and checking its variability are of great importance for water resources management and development in the River Nile basin. The present study aimed to analyze the rainfall variability and trends in the Upper Blue Nile Basin (UBNB) over a period from 1953 to 2014. Variability analysis showed that the basin has been suffering from variable rainfall events causing severe droughts and floods over different years. According to precipitation concentration index calculations, the basin had irregular and strong irregular rainfall distribution over the annual and dry seasons, while the basin had a uniform and moderate rainfall distribution during the rainy season and small rainy season. For the total annual rainfall, Mann–Kendall test indicated that, for the eastern central part of the basin, a significant increasing trend of 12.85 mm/year occurred over the studied period, while, for the southwestern part of the basin, a significant decrease of 17.78 mm/year occurred. For the rainy season, a significant increasing trend over the northeastern and eastern central parts of the basin with the magnitude of 3.330–12.625 mm/year occurred. Trend analysis was applied on the monthly averaged rainfall over the whole basin and revealed that July and August are the most contributors of rainfall to the basin with 23.32% and 22.65%. Changing point assessment revealed that at Lake Tana outlet there is a decreasing of the rainfall of 17.7% after 1977 that matched with the trend analysis results. The data and results contained herein provide updated information about the current situation in the UBNB. The results can be used to predict future precipitation and estimate the uncertainty in future precipitation prediction models.

RAPID IN VITRO PROPAGATION OF WESTERN GHATS CULTIVAR - COLOCASIA ESCULENTA FOR THE HIGH FREQUENCY OF PLANTLETS

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Jyothi R ◽  
Srinivasa Murthy K M ◽  
Hossein . ◽  
Veena .
Keyword(s):  
Tissue Culture ◽  
Wide Distribution ◽  
Colocasia Esculenta ◽  
Limiting Factor ◽  
Promising Alternative ◽  
Rapid Multiplication ◽  
Medical Plant ◽  
Total Fat ◽  
Planting Materials

Colocasia esculenta is commonly known as Taro, it is referred to as cocoyam in Nigeria. They are cherished for their rich taste, nutritional and medicinal properties. Every 100 g of taro corms possess 112 Kcal, 26.46 g carbohydrate, 1.50 g protein, 0.20 g total fat and 4.1g fiber (USDA National Nutrient Data Base). Besides its nutritional value, taro is used as a medical plant and provides bioactive compounds used as an anti-cancer drugs. Traditionally, cocoyams are vegetative propagated from tuber fragments, a practice that encourages pathogen distribution. Colocasia esculenta is a widely distributed food crop in the humid tropics and subtropics. Despite of its wide distribution, Taro plants are commonly infected with DsMV and other pathogens. This virus induces conspicuous mosaic, malformation, dwarfing or feathering on leaves in taro. As the results of infection, it reduces the quality and yield of taro production greatly. This virus is thus considered as a major limiting factor in the production of taro. Here plays the importance of  tissue culture plays a major role in producing the disease resistant plants round the year with high quality. For rapid multiplication and production of quality planting materials, tissue culture technology offers promising alternative compared to the traditional production methods. KEYWORDS: Colocasia esculenta, Virus, Pathogens, Conventional propagation, Micropropagation, Yield, Rapid multiplication, Quality

scholarly journals Structure of pond vegetation of a vereda in the Brazilian Cerrado

Rodriguésia ◽  
2011 ◽  
Vol 62 (4) ◽  
pp. 721-729 ◽  
Author(s):  
Suzana Neves Moreira ◽  
Arnildo Pott ◽  
Vali Joana Pott ◽  
Geraldo Alves Damasceno-Junior
Keyword(s):  
Water Depth ◽  
Rainy Season ◽  
Life Form ◽  
Mato Grosso ◽  
Relative Cover ◽  
Dry Seasons ◽  
The Relationship ◽  
Measured Water ◽  
Mato Grosso Do Sul ◽  
New Occurrences

Abstract This is the first report on aquatic macrophytes in ponds of veredas (palm swamps) in the Cerrado (Brazilian savanna). We studied a pond in a vereda in Terenos, Mato Grosso do Sul state, central-western Brazil, during drought and flood periods to assess plant community structure and the relationship between species distribution and water depth. Sampling was carried out in five permanent transects, along which we placed sampling units of 1 m2 quadrats every 5 m. We estimated visually the relative cover of each species, bare ground, dead matter, and exposed water. We also measured water depth. We recorded 77 species of 49 genera and 31 families. The number of species varied between seasons, and in the rainy season the amphibious life form was predominant. The richest families were Poaceae (15 species), Cyperaceae (11), Asteraceae (4) and Lentibulariaceae (4). The richest genera were Rhynchospora (4), Utricularia (4), Eleocharis (4), Aeschynomene (3), Bacopa (3), Ludwigia (3) and Panicum (3). We found six new occurrences for the cerrado. Eleocharis acutangula had the highest relative cover (rainy and dry seasons), followed by Bacopa reflexa (rainy season), Paspalum lenticulare (rainy and dry seasons), Leersia hexandra (rainy and dry seasons), and Sagittaria rhombifolia (rainy season). Some species were distributed mainly at shallower depths, others occurred in deeper water, whereas some species varied greatly in terms of depth. Heliotropium filiforme and Ludwigia nervosa were found only in the dry season. In the rainy season, as expected, the exclusive species were mostly true aquatics.

scholarly journals Analyses of flood peak discharge in Cimadur river basin, Banten Province, Indonesia

2021 ◽  
Vol 331 ◽  
pp. 08006
Author(s):  
Arniza Fitri ◽  
Muhammad Shubhi Nurul Hadie ◽  
Adelia Agustina ◽  
Dian Pratiwi ◽  
Susarman ◽  
...  
Keyword(s):  
River Basin ◽  
Return Period ◽  
Daily Rainfall ◽  
Annual Rainfall ◽  
Rainfall Distribution ◽  
Flood Peak ◽  
Type Iii ◽  
Pearson Type ◽  
Catchment Areas ◽  
Peak Discharges

Cimadur river basin is one of the most important catchment areas in Lebak District, Banten Province. For the past few years, the catchment has experienced floods during the rainy season. The big issue of flooding has been recorded recently in December 2019 which has caused damage and negative impacts to the local people and surrounding community. This study aims to analyze the possibility of flood peak discharges in the catchment area of the Cimadur river. The flood discharges are calculated for 2, 5, 10, 25, 50, and 100 years return period based on the daily rainfall data from the year 2011 to 2020. The rainfall and land use data are obtained from PT Saeba Consultant. In this study, the hydrological analyses are including 1) analyses of average annual rainfall using the Thiessen method; 2) analyses of rainfall distribution and estimation of design rainfall by considering three methods involving: Log-Normal, Log Pearson Type III, and Gumbel Type 1; and 3) analyses of flood discharges by adopting Nakayasu Synthetic Hydrograph Unit (SHU). The rainfall distribution analyses show that the Log Pearson Type III provided the best fit. Based on the flood peak discharges analyses, the results show that the flood discharges for the 5, 10, 25, and 50 years return period in the Cimadur river basin are 470.71 m3/s, 560.16 m3/s, 698 m3/s, and 820.4 m3/s, respectively.

scholarly journals PENENTUAN MUSIM TANAM, JENIS VARIETAS, DAN TEKNIK BUDIDAYA TANAMAN PADI TERKAIT MITIGASI EMISI METANA (CH4) (Determination of Early Planting Season, Type Varieties, and Cultivation Techniques of Rice as Mitigation to Methane Emission)

2018 ◽  
Vol 24 (1) ◽  
pp. 1
Author(s):  
Lilik Slamet Supriatin
Keyword(s):  
Rainy Season ◽  
Growing Season ◽  
Dry Season ◽  
Wetland Mitigation ◽  
Annual Rainfall ◽  
Ch4 Emission ◽  
Ch4 Emissions ◽  
Cultivation Techniques ◽  
Planting Season

ABSTRAKEmisi metana (CH4) dari pertanian padi lahan sawah dapat dipengaruhi oleh faktor-faktor seperti cara pemberian air, pengolahan tanah, varietas padi, dan iklim. Pada penelitian ini dikaji tahap penentuan musim tanam, pemilihan varietas padi, dan tahap terakhir adalah teknik budidaya pertanian padi lahan sawah yang terkait mitigasi emisi CH4. Hasil kajian menunjukkan bahwa musim tanam padi pada musim kemarau menghasilkan emisi CH4 lebih kecil daripada di musim hujan dengan pengurangan emisi CH4 sebesar 18,13%. Indonesia yang memiliki tiga tipe pola curah hujan tahunan (monsunal, equatorial, lokal) mengakibatkan periode musim tanam rendah emisi CH4 berbeda antara tipe curah hujan yang satu dengan lainnya. Varietas padi Way apo buru adalah varietas yang menghasilkan emisi CH4 terendah tetapi tetap optimum dalam produksi gabah sehingga dapat dipilih menjadi prioritas pertama untuk ditanam. Teknik budidaya pertanian padi lahan sawah yang menghasilkan rendah emisi CH4 dapat dilakukan dengan membuat genangan air yang dangkal saja, dengan cara pemberian air berselang, dan kombinasi antara pemeliharaan padi, ganggang, tanaman paku air, ikan air tawar, dan bakteri metanotrof dalam satu petak lahan sawah (mina padi plus). Pemberian air dengan cara berselang menurunkan emisi CH4 pada musim kemarau sebesar 59,36% dan pada musim hujan sebesar 51,68% jika dibandingkan dengan pemberian air secara terus-menerus (kontinyu). Teknik budidaya mina padi plus mengurangi emisi CH4 sebesar 21,5 kg/ha/musim tanam dan bakteri metanotrof mengurangi emisi CH4 ke atmosfer sebesar 20-60 Tg. Sawah dapat dijadikan sebagai instalasi terbuka pengolahan udara berlimbah CH4. ABSTRACTMethane (CH4) emissions from rice cultivation can be influenced by several factors i.e. the provision of water, soil cultivation, varieties of rice, and the climate. This study will examine the determination of the growing season, the selection of rice varieties and cultivation techniques of rice agriculture-related wetland mitigation of the CH4 emission. The results showed that the rice planting season in the dry season produces CH4 emissions is smaller than in the rainy season with CH4 emission reduction of 18.13%. Indonesia, which has three types of annual rainfall patterns resulting in periods of low growing season CH4 emissions differ between types of rainfall each other. Way apo buru rice species are varieties that produce low emissions of CH4 but remains optimum in grain production. Cultivation techniques of rice farming rice fields that produce low emissions of CH4 can be done by creating a pool of shallow water only, by way of provision of water intermittent, and the combination of maintenance of rice, algae, plants salviniales, freshwater fish, and bacteria metanotrof in a wetland. The provision of water by intermittent lowering emissions of CH4 in the dry season by 59.36% and in the rainy season amounted to 51.68% when compared to the provision of water continuously (continuous). Mina padi plus cultivation techniques reduce CH4 emissions by 21.5 kg/ha/planting and metanotrof bacteria can reduce CH4 emissions to the atmosphere by 20-60 Tg. 

scholarly journals THE INFLUENCE OF THE BRAZILIAN CERRADO DEFORESTATION IN GRAIN CULTURE AND ITS CONSEQUENCES TO LOSSES THE SOIL IN THE CACHOEIRA DOURADA RESERVOIR REGION – CENTRAL - WESTERN BRAZIL

2013 ◽  
pp. 01
Author(s):  
João Batista Pereira Cabral ◽  
Valter Antonio Becegato ◽  
Francismário Ferreira dos Santos
Keyword(s):  
Annual Cycle ◽  
Annual Rainfall ◽  
Brazilian Cerrado ◽  
Rainfall Distribution ◽  
Rainfall Variation ◽  
Influence Area ◽  
Average Annual Rainfall ◽  
Average Rainfall ◽  
Soil Preparation ◽  
Erosivity Index

The erosivity index (EI30) and its spatialization were determined for the contribution basins of the Cachoeira Dourada hydroelectric system reservoir, located between the states of Goiás and Minas Gerais and limited by coordinates 640000-760000 m W and 7910000-7975000 m N. Average monthly and annual rainfall data corresponding to eight localities and to a 30-year period were treated. It was observed that in this period the average annual rainfall was 1441 mm, the highest and lowest indexes having occurred respectively in January and July (7.5 mm). EI30 varied from 7100 to 8500 MJ mm (ha h)-1. The most representative period was October to March, corresponding to 7880.3 MJ mm (ha h)-1and 94% of the average annual EI30. The average rainfall variation coefficient for all stations was 82.73%. There is an irregular rainfall distribution in the region and consequently a non-uniform spatialization of the erosivity indexes within the influence area of the reservoir. The highest rainfall values coincide with the period of soil preparation and development of annual-cycle plants, mainly soybean and corn.

The Production Technology of the Ceramic Brick Soft Molding Based on Opoka-Like Rocks

2020 ◽  
Vol 1011 ◽  
pp. 79-84
Author(s):  
J. Bozhko ◽  
J. Teryokhina ◽  
Kira Lapunova ◽  
Roman Yashchenko
Keyword(s):  
Production Technology ◽  
Front Surface ◽  
Wide Distribution ◽  
Limiting Factor ◽  
Technological Parameters ◽  
Urgent Task ◽  
Wide Circle ◽  
The Aesthetic ◽  
Ceramics Industry

The results of the scientific research and pilot tests on the production technology of soft molded ceramic bricks based on siliceous opoka-like rocks are presented. A description of soft-molded brick, which is distinguished by a huge variety of appearance and unusual design, which has earned recognition from architects and designers, is given. It is emphasized that the main limiting factor for the wide distribution of this type of brick is its high cost, due to the very small volumes of its production in Russia. It is indicated that the current situation poses a very difficult and urgent task for the wall ceramics industry - to establish the widespread production of soft-molded bricks, which in addition to the aesthetic properties will have the good operational properties. The opoka-like rocks’ characteristics and the results of studying their ceramic properties in relation to the technology of soft molding are given. The classification of the soft molded brick front surface types is presented for discussion. The main technological parameters of production, the relationship and the influence of various technological factors on the properties of the products obtained, as well as the mechanism for forming the structure of the calcined products are determined. A variable technological scheme for the production of soft molded ashlar brick has been developed. It is emphasized that the presented research results will be of interest to a wide circle of the molded ceramic bricks’ manufacturers and will help to establish the wide production of soft-molded bricks in Russia.

scholarly journals Nymphal feeding habits of two Anacroneuria species (Plecoptera, Perlidae) from Sierra Nevada de Santa Marta, Colombia

2018 ◽  
Vol 78 (1) ◽  
Author(s):  
Yesely M. Hurtado ◽  
Cesar E. Tamaris-Turizo ◽  
Manuel J. López Rodriguez ◽  
J. Manuel Tierno de Figueroa
Keyword(s):  
Sierra Nevada ◽  
Rainy Season ◽  
Feeding Habits ◽  
Niche Overlap ◽  
Trophic Niche ◽  
Freshwater Ecosystems ◽  
Use Of Resources ◽  
Trophic Resources ◽  
Tropical Areas ◽  
Dry Seasons

The knowledge of the diet of aquatic insects is important to assess the use of resources and overlap of trophic niche between species, as well as to understand their role in the food web of the freshwater ecosystems they inhabit. This is particularly necessary in tropical areas where information on this topic is scarce. The aim of the present work is to describe the feeding habits of the species Anacroneuria marta Zúñiga and Stark, 2002 and Anacroneuria caraca Stark, 1995 in the middle section of the Gaira River (Sierra Nevada de Santa Marta, Colombia). We performed three samplings during the rainy and dry seasons in the two main different microhabitats of the reach (leaf packs and gravel) in 2014. The diet of a total of 87 and 90 individuals of A. caraca and A. marta, respectively, was studied. With this information, niche breadth for each species and niche overlap between them in terms of trophic resources were calculated. The main trophic resource for both species in the dry and rainy season was the animal matter. In the dry season, FPOM was also important in the diet of A. caraca, and A. marta ingested a great quantity of CPOM in the rainy season. Larvae of Trichoptera, were the most ingested prey in both species, followed by Chironomidae, Coleoptera Hydrophilidae, and Ephemeroptera. No differences in diet between both species were detected, so this could favor the niche overlap in terms of trophic resources and could lead to competition between them. The possible ecological scenarios are discussed.

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