Factors affecting the type of population density effect upon average rate of oviposition

1953 ◽  
Vol 2 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Hiroshi Fujita
Keyword(s):  
Population Density ◽  
Average Rate ◽  
Density Effect ◽  
Factors Affecting

scholarly journals Size-at-maturity shift in a male-only fishery: factors affecting molt-type outcomes in Newfoundland and Labrador snow crab (Chionoecetes opilio)

2020 ◽  
Author(s):  
Darrell R J Mullowney ◽  
Krista D Baker
Keyword(s):  
Population Density ◽  
Newfoundland And Labrador ◽  
Cold Water ◽  
Large Male ◽  
Snow Crab ◽  
Size At Maturity ◽  
Chionoecetes Opilio ◽  
Factors Affecting ◽  
Male Density ◽  
Process Factors

Abstract A sex-asymmetric downward shift in size-at-terminal-molt has recently occurred in males in some portions of the Newfoundland and Labrador (NL) snow crab stock range, a first known occurrence for such processes in snow crab (Chionoecetes opilio) stocks. This study examines plausible factors promoting the shift in size-at-terminal-molt [synonymous with size-at-maturity (SaM)] including individual size, temperature, population density, and sex ratio. Analyses highlight expanse of cold water and large male density as being significant predictors of molt-type outcomes. A confluence of cold conditions and low density of large males promoted the SaM shift. In turn, the low male density was associated with recently elevated fishery exploitation rates under quota-controlled management. It remains unknown the extent to which the reduction in terminal size reflects a phenotypic vs. genotypic process. Factors affecting skip-molting in male snow crab are investigated, and we find that skip-molting occurs most frequently under extreme cold and high population density conditions. Potential complications arising from altered growth dynamics are discussed. Overall, the results advance knowledge on intraspecific competition processes within snow crab populations and inform fisheries management systems that male-only harvest strategies do not provide full protection from biological harm to aquatic resources through fishing.

Pemanfaatan Peta Tematik dalam Perencanaan Pembangunan Sarana dan Prasarana Pendukung Pariwisata Daerah di Kabupaten Pangandaran

Tunas Agraria ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 1-19
Author(s):  
Rizka Fakhrizatullah ◽  
Rochmat Martanto ◽  
Yendi Sufyandi
Keyword(s):  
Land Use ◽  
Data Collection ◽  
Population Density ◽  
Literature Review ◽  
Qualitative Method ◽  
Thematic Maps ◽  
Coastal Tourism ◽  
Factors Affecting ◽  
Regional Autonomy

Abstract: Pangandaran is a district with a coastline of 91 Km, so this district has the potential for coastal tourism that needs to be developed. As a new regency of regional autonomy, demands to carry out construction of facilities and infrastructure to support tourism need to be increased. This study aims to determine the distribution of facilities and infrastructure that need to be developed and to know the factors that influence the determination of the construction of facilities and infrastructure. This research uses qualitative method, data collection is done through literature review and interviews. The results of the study indicate that the factors affecting the distribution of infrastructure include land use, population density, tourism objects, land slope and disaster vulnerability. The analysis shows that the distribution of villages suitable for the development of infrastructure includes the villages of Wonoharjo, Babadan, Pananjang and Pangandaran Village.Keyword: tourism, facilities and infrastructure, thematic maps. Intisari: Pangandaran merupakan kabupaten dengan garis pantai sepanjang 91 Km, sehingga kabupaten ini memiliki potensi pariwisata pantai yang perlu dikembangkan. Sebagai Kabupaten yang baru melakukan otonomi daerah, tuntutan untuk melaksanakan pembangunan sarana dan prasarana guna mendukung pariwisata perlu ditingkatkan. Kajian ini bertujuan untuk untuk mengetahui sebaran sarana dan prasarana yang perlu dikembangkan serta mengetahui faktor-faktor yang mempengaruhi penentuan pembangunan sarana dan prasarana. Penelitian ini menggunakan metode kualitatif, pengumpulan data dilakukan melalui kajian pustaka dan wawancara. Hasil kajian menunjukkan bahwa faktor-faktor yang mempengaruhi sebaran sarana prasarana meliputi penggunaan lahan, kepadatan penduduk, obyek wisata, kemiringan lahan dan kerawanan bencana. Dari hasil analisis menunjukkan bahwa sebaran desa yang sesuai untuk pengembangan sarana prasarana meliputi Desa Wonoharjo, Babadan, Pananjang dan Desa Pangandaran.Kata kunci: pariwisata, sarana dan prasarana, peta tematik.

scholarly journals Pemodelan Kasus DBD di Provinsi Jawa Timur dengan Metode Data Panel

2019 ◽  
Vol 8 (2) ◽  
pp. 101
Author(s):  
Annisa Dwinda Shafira
Keyword(s):  
Panel Data ◽  
Population Density ◽  
Time Series Data ◽  
Secondary Data ◽  
Series Data ◽  
Panel Regression ◽  
Affecting Factors ◽  
Factors Affecting ◽  
Panel Data Regression ◽  
Data Regression

The combination of panel data regression consist of time series data, it was collected based on a characteristic at a certain time (cross section). This research aimed to analyze the affecting factors and dominant factors of Dengue Hemoragic Fever (DHF) cases in East Java using panel data regression. This research uses secondary data published by the East Java Provincial Health Office, namely the Health Profile and the East Java Provincial Statistics Agency such as documents of each Districts/City in Numbers of East Java on 2014––2017 using total research population that were collected in all districts/cities in East Java Province. The data of new cases of DHF and factors affecting the incidence of DHF including clean and healthy living behavior in the household, poverty, population density, rainfall in East Java on 2014––2017. Panel regression analysis is used to determine the best model of the CEM, FEM and REM using Chow test, Hausman test and Langrange Multiplier test. Based on the results, the best model of panel regression is FEM with affecting variables such as poverty, population density, and rainfall.

scholarly journals Faktor-Faktor yang Mempengaruhi Alih Fungsi Lahan Sawah di Kabupaten Aceh Besar

2018 ◽  
Vol 3 (4) ◽  
pp. 525-533
Author(s):  
Raudhatul Husna ◽  
Azhar Azhar ◽  
Edy Marsudi
Keyword(s):  
Time Series ◽  
Population Density ◽  
Rice Field ◽  
Time Series Data ◽  
Statistical Tests ◽  
Secondary Data ◽  
Series Data ◽  
Factors Affecting ◽  
Rice Productivity ◽  
Negative Impacts

Abstrak. Alih fungsi lahan atau lazimnya disebut sebagai konversi lahan adalah  perubahan fungsi sebagian atau seluruh kawasan lahan dari fungsinya semula (seperti yang direncanakan) menjadi fungsi lain yang membawa dampak negatif terhadap lingkungan dan potensi lahan itu sendiri. Penelitian ini bertujuan untuk mengetahui apakah harga lahan, kepadatan penduduk, produktivitas padi dan jumlah PDRB dapat mempengaruhi alih fungsi lahan sawah di Kabupaten Aceh Besar. Data yang digunakan dalam penelitian ini adalah data sekunder. Data yang dikumpulkan adalah data time series dengan range tahun 2002 sampai 2016. Penelitian ini menggunakan metode analisis  regresi linier berganda. hasil penelitian dan pembahasan serta pengujian SPSS menunjukkan bahwa harga lahan, kepadatan penduduk, dan produktivitas padi berpengaruh nyata terhadap alih fungsi lahan sawah di Kabupaten Aceh Besar. sedangkan jumlah PDRB tidak berpengaruh terhadap alih fungsi lahan sawah. Hal ini ditunjukkan oleh koefisien regresi untuk variabel jumlah PDRB sebesar 0,00015. Hasil pengujian statistik menunjukkan nilai t hitung untuk jumlah PDRB sebesar 1,315 dengan nilai signifikan sebesar 0,218. Sedangkan nilai t tabel sebesar 1,782 yang berarti nilai t hitung t tabel (1,315 1,782).  Factors Affecting The Conversion Of Paddy Fields In Kabupaten Aceh Besar Abstract. Land use change or commonly referred to as land conversion is a change in the function of part or all of the land area from its original function (as planned) into other functions that bring negative impacts to the environment and the potential of the land itself. This study aims to find out whether the price of land, population density, rice productivity and the amount of GRDP can affect the conversion of rice field functions in Aceh Besar District. The data used in this research is secondary data. The data collected is time series data with range of year 2002 until 2016. This research use multiple linier regression analysis method. the results of research and discussion and testing of SPSS showed that land price, population density, and rice productivity significantly affected the conversion of wetland in Aceh Besar district. while the number of GDP does not affect the conversion of wetland. This is indicated by the regression coefficient for the GRDP variable of 0.00015. The results of statistical tests show the value of t arithmetic for the amount of GRDP by 1.315 with a significant value of 0.218. While the value of t table of 1.782 which means the value of t arithmetic t table (1,315 1.782).

Biological factors affecting enflagellation of Naegleria fowleri

1982 ◽  
Vol 152 (2) ◽  
pp. 803-808
Author(s):  
T W Woodworth ◽  
D T John ◽  
S G Bradley
Keyword(s):  
Population Density ◽  
Stationary Phase ◽  
Culture Medium ◽  
Actinomycin D ◽  
Suitable Model ◽  
Naegleria Fowleri ◽  
Biological Factors ◽  
Factors Affecting ◽  
Nægleria Fowleri ◽  
Amoeboid Cells

Naegleria fowleri is a pathogenic amoeboflagellate that can be evoked to transform from amoebae to flagellates by subculture to nonnutrient buffer. More than half of the amoebae of strains KUL, nN68, and Lovell became enflagellated 300 min after subculture to amoeba-saline, whereas no amoebae of strains NF66, NF69, and HB4 did. N. fowleri nN68 enflagellated best when grown at 32 or 37 degrees C and subcultured to amoeba-saline at 37 or 42 degrees C. Amoebae from the stationary phase of growth enflagellated more readily than did actively growing amoebae. Incubation in expended culture medium from stationary-phase cultures enhanced the capability of growing amoebae to enflagellate after subculture to amoebasaline. Enflagellation was more extensive when the population density in amoebasaline did not exceed 2 x 10(5) amoebae per ml. Cycloheximide at 1 microgram/ml and actinomycin D at 25 micrograms/ml inhibited growth of N. fowleri nN68. Cycloheximide at 0.5 microgram/ml and actinomycin D at 25 micrograms/ml completely prevented enflagellation when added at time zero. Cycloheximide at 0.5 microgram/ml, added 120 to 300 min after initiation of enflagellation, prevented further differentiation and caused existing flagellates to revert to amoeboid cells. Similarly, actinomycin D at 25 micrograms/ml, added 90 to 300 min after initiation of enflagellation, retarded differentiation and caused flagellates to revert. Radiolabeled precursors were incorporated into macromolecules during differentiation in nonnutrient buffer. Enflagellation of N. fowleri is a suitable model for studying regulation of a eucaryotic protist.

Studies of gametophytes of Matteuccia struthiopteris (ostrich fern) in nature and in culture

1983 ◽  
Vol 61 (12) ◽  
pp. 3267-3270 ◽  
Author(s):  
P. von Aderkas
Keyword(s):  
Population Density ◽  
Field Data ◽  
Sex Expression ◽  
Density Effect

The sex expression of gametophytes of Matteuccia struthiopteris (L.) Todaro was compared in nature and in culture. Plants raised from multispore cultures (100 spores/cm2) exhibited the most variety in sexual–morphological types. Individually raised plants were slower to develop and showed less variety of sexual types than was found in the multispore cultures. There appeared to be a density effect on development. Field-collected gametophytes showed the least diversity, the populations being largely composed of poorly developed male and neuter plants. The experimental and field data are considered in relation to antheridiogen and population density studies.

Comparison of maturation of female Clethrionomys glareolus from cyclic and noncyclic populations

1986 ◽  
Vol 64 (10) ◽  
pp. 2099-2102 ◽  
Author(s):  
Søren Bondrup-Nielsen ◽  
Rolf Anker Ims
Keyword(s):  
Population Density ◽  
Clethrionomys Glareolus ◽  
Previous Knowledge ◽  
Factors Affecting ◽  
Laboratory Colonies ◽  
Density Dynamics ◽  
Cyclic Populations

We examined the effect of mothers with and without new litters on maturation and growth of their daughters in laboratory colonies derived from cyclic and noncyclic populations of Clethrionomys glareolus. Mature individuals from cyclic populations are heavier than those from noncyclic populations, however, this difference was lost in our colonies. The presence of a mother had a significant effect in delaying vaginal perforation in cyclic females but not in noncyclic females. If a mother in the cyclic colony had a new litter and was lactating she appeared to be more effective in delaying vaginal perforation of her daughter than if she did not have a litter. The results are discussed in light of previous knowledge of factors affecting maturation in males and theory on population density dynamics.

The Life System of Cardiaspina Albitextura (Psyllidae), 1950-74.

1975 ◽  
Vol 23 (4) ◽  
pp. 523 ◽  
Author(s):  
LR Clark ◽  
MJ Dallwitz
Keyword(s):  
Population Density ◽  
Natural Enemies ◽  
Average Rate ◽  
The Other ◽  
Population Densities ◽  
Insect Abundance ◽  
Complete Development ◽  
Rate Of Increase ◽  
Adverse Weather ◽  
Survival And Reproduction

In 1958-63 and 1964-71 the life systems of four kinds of test-forming psyllid that coexist on Eucalyptus blakelyi were investigated intensively in a comparative study of insect abundance. This paper deals mainly with C. albitextura, which was kept under observation from 1950 to 1974. (The others were two species of Glycaspis, Spondyliaspis sp, and Creiis costatus.) The results indicate that the differences in maximal abundance reached by the four kinds of psyllid are mainly the outcome of differences in their ability tg utilize the leaves of the host plant as a source of food, C. albitextura being much more effective than the other species. For the latter, it appears that the principal environmental determinant of abundance was the number of feeding places where nymphs could survive long enough to complete development. That number varied according to foliage and weather. C. albitextura also differed from the other species by having its population densities held for long periods far below the levels at which the food supply would be limiting, by restrictions imposed upon reproduction by adverse weather and foliage conditions (the latter being due partly to poor synchronization between the emergence of adults in spring and the occurrence of foliage attractive for oviposition), and by high mortalities due to natural enemies. The life system of C. albitextura lacks an element that can stabilize abundance at low population densities, but adverse environmental influences usually limit the rate of increase greatly when abundance is low. The magnitude of the average rate of increase to high levels of population density, and the length of time for which high average densities are maintained, depend upon the frequency with which favourable conditions of weather, foliage and predation combine to promote both survival and reproduction.

Population density effect on radio frequencies interference (RFI) in radio astronomy

2012 ◽  
Author(s):  
Roslan Umar ◽  
Zamri Zainal Abidin ◽  
Zainol Abidin Ibrahim ◽  
Mohd Saiful Rizal Hassan ◽  
Zulfazli Rosli ◽  
...  
Keyword(s):  
Population Density ◽  
Radio Astronomy ◽  
Density Effect ◽  
Radio Frequencies
Sign in / Sign up

Export Citation Format

Share Document