A brief guide to producing a national population projection

Background There are surprisingly few resources available which offer an introductory guide to preparing a national population projection using a cohort-component model. Many demography textbooks cover projections quite briefly, and many academic papers on projections focus on advanced technical issues. Aims The aim of this paper is to provide a short and accessible guide to producing a national-scale population projection using the cohort-component model. Data and methods The paper describes the cohort-component model from a population accounting perspective, presents all the necessary projection calculations, and covers the key steps which form part of the projections preparation process – from gathering input data to validating outputs. An accompanying Excel workbook implements the model and contains example projections for Australia. Conclusions Calculating a national population projection using a cohort-component model involves fairly simple algebra, but the broader projections preparation process is more complex, and requires careful consideration and judgement.

Host-Plant Variations Affect the Biotic Potential, Survival, and Population Projection of Myzus persicae (Hemiptera: Aphididae)

The green peach aphid, Myzus persicae Sulzer (Hemiptera: Aphididae), a polyphagous insect pest is a major threat to a wide range of crops worldwide. Aiming to evaluate the life history traits of M. persicae, feeding on different host plants, we used five vegetables: cabbage, Brassica oleracea (Brassicaceae); chinese cabbage, B. rapa (Brassicaceae); chili pepper, Capsicum annum (Solanaceae); crown daisy, Chrysanthemum coronarium (Asteraceae); and eggplant, Solanum melongena (Solanaceae). TWOSEX-MSchart software was used for the statistical analysis about the age-stage, two-sex life table theory. The highest fecundity (69.65 individuals) rate of M. persicae, intrinsic rate of increase (r = 0.425 d−1), finite rate of increase (λ = 1.531 d−1), net reproductive rate (R0 = 69.65 offspring), and shortest mean generation time (T = 9.964 d) were recorded on the chili pepper plant. Whereas, lower fitness occurred on cabbage. The findings attained from population growth parameters indicate that chili pepper is the most susceptible plant, while cabbage is resistant to aphids. Population projection results also supported this statement, as the final total population size on cabbage was significantly lower than other plants. The reported information would be useful for devising integrated pest management programs, particularly those involving M. persicae. This information also suggests the adaptability of M. persicae causing economic damage to these vegetable cultivars.

Perencanaan Tempat Pengolahan Sampah Reduce, Reuse, Recycle Menggunakan Black Soldier Fly di Desa Karyamulya Kabupaten Ciamis

Solid waste known as garbage still becomes one of the most concerning issues in Indonesia. It increases every year; however, the landfill was not expanded. The accumulation of garbage could give a negative impact on the environment and health. Due to this reason, there is an alternative suggested to reduce the garbage and its sources. The initiative called ‘Bank sampah’, itis a garbage treatment system which is managed by the community. In addition, the Reduce, Reuse, Recycle (3R) laystall was built to carry out some ‘Bank Sampah’. This study conducted a preliminary design of 3R laystall at Desa Karyamulya Kecamatan Cisaga Kabupaten Ciamis. The design of the 3R laystall using black soldier fly method to decompose organic materials is employed in this research. The quantity and the density of the garbage were required to determine the design of the lay stall. Stratified random sampling was conducted for 8 days. Desa Karyamulya generates 2.361 liters/person/day or 0.236 kg/person/day. According to a population projection for the next 10 years, the estimation of garbage composition consists of food waste (52.15%); plastic (23.58%); paper (9.23%); fabric (0.45%); wood/leaf (6.38%); diapers (2.85%); metal (0.94%); rubber/leather (2.19%); glass (0.17%); and styrofoam (2.04%). From the quantity and composition of the garbage, it requires approximately 94 m2 of the area and an estimated funds needed as Rp. 483.908.600

A Balaton régió népességdinamikája 2017-2062 között

The present study examines the population projection of the settlements of the Balaton Region (BKÜ) by 2062, taking into account 180 settlements. The results are presented for the main age groups of the region, at five-year intervals, and broken down as follows: 18 cities, coastal villages (group of 39 settlements), and non-coastal villages (group of 123 settlements). The most recent research report on which this study is based was produced in 2017. For the two years since then, we can also identify deviations from previously forecasted processes. Using another method, we interrogate the reliability of the previous prediction. The population projection shows that the population of the resort area will fall to 184,000 by 2062, and the proportion of the population over the age of 65 will reach or even exceed 35%. In addition to the aging of the villages, the depopulation of dwarf villages further away from the coast poses a serious problem.