Sustained below replacement fertility leads to declining population size. Several countries in Asia have experienced below replacement fertility for many years. The paper applies a novel approach to examining the viability of using immigration to achieve zero population growth in six Asian countries: China, Japan, Republic of Korea, Thailand, Singapore and Australia. The novel approach is to estimate the level of immigration that would be required to maintain a constant annual number of births in the long term. Maintaining the number of births at the current level is the fastest way to achieve eventual zero population growth. A population with a constant annual number of births, labeled as a quasi-stationary population, also has a near-to constant age structure that is not excessively old. The study concludes that, for all countries except Australia, no reasonable level of immigration could produce a quasi-stationary population if fertility remains at the country's 2020 level. The constraining factors are the current population size and level of fertility and the extent to which there is acceptance of permanent immigrants in the country. If fertility were to increase over 15–20 years to 1.7 births per woman and the country was accepting of relatively large numbers of permanent immigrants, the quasi-stable outcome becomes potentially viable for all countries except China.

European countries are experiencing population decline and the tacit assumption in most analyses is that the decline may have detrimental welfare effects. In this paper we use a survey among the population in the Netherlands to discover whether population decline is always met with fear. A number of results stand out: population size preferences differ by geographic proximity: at a global level the majority of respondents favors a (global) population decline, but closer to home one supports a stationary population. Population decline is clearly not always met with fear: 31 percent would like the population to decline at the national level and they generally perceive decline to be accompanied by immaterial welfare gains (improvement environment) as well as material welfare losses (tax increases, economic stagnation). In addition to these driving forces it appears that the attitude towards immigrants is a very strong determinant at all geographical levels: immigrants seem to be a stronger fear factor than population decline. The data was collected from a Dutch household panel.

Evolution is often conceived as changes in the properties of a population over generations. Does this notion exhaust the possible dynamics of evolution? Life is hierarchically organized, and evolution can operate at multiple levels with conflicting tendencies. Using a minimal model of such conflicting multilevel evolution, we demonstrate the possibility of a novel mode of evolution that challenges the above notion: individuals ceaselessly modify their genetically-inherited phenotype and fitness along their lines of descent, without involving apparent changes in the properties of the population. The model assumes a population of primitive cells (protocells, for short), each containing a population of replicating catalytic molecules. Protocells are selected towards maximizing the catalytic activity of internal molecules, whereas molecules tend to evolve towards minimizing it in order to maximize their relative fitness within a protocell. These conflicting evolutionary tendencies at differ...

Yearly citation counts for the publication titled "Introduction of parasitoids has maintained a stable population of arrowhead scales at extremely low levels".

• Number of males sampled** Collected over number of sampling days*** Collected over number of sampling yearsPopulation level stable isotope metrics derived from δ13C and δ15N of fur samples of M. lucifugus and M. septentrionalis at summering areas and swarming sites in Nova Scotia.

analyze the current population survey (cps) annual social and economic supplement (asec) with r the annual march cps-asec has been supplying the statistics for the census bureau's report on income, poverty, and health insurance coverage since 1948. wow. the us census bureau and the bureau of labor statistics ( bls) tag-team on this one. until the american community survey (acs) hit the scene in the early aughts (2000s), the current population survey had the largest sample size of all the annual general demographic data sets outside of the decennial census - about two hundred thousand respondents. this provides enough sample to conduct state- and a few large metro area-level analyses. your sample size will vanish if you start investigating subgroups b y state - consider pooling multiple years. county-level is a no-no. despite the american community survey's larger size, the cps-asec contains many more variables related to employment, sources of income, and insurance - and can be trended back to harry truman's presidency. aside from questions specifically asked about an annual experience (like income), many of the questions in this march data set should be t reated as point-in-time statistics. cps-asec generalizes to the united states non-institutional, non-active duty military population. the national bureau of economic research (nber) provides sas, spss, and stata importation scripts to create a rectangular file (rectangular data means only person-level records; household- and family-level information gets attached to each person). to import these files into r, the parse.SAScii function uses nber's sas code to determine how to import the fixed-width file, then RSQLite to put everything into a schnazzy database. you can try reading through the nber march 2012 sas importation code yourself, but it's a bit of a proc freak show. this new github repository contains three scripts: 2005-2012 asec - download all microdata.R down load the fixed-width file containing household, family, and person records import by separating this file into three tables, then merge 'em together at the person-level download the fixed-width file containing the person-level replicate weights merge the rectangular person-level file with the replicate weights, then store it in a sql database create a new variable - one - in the data table 2012 asec - analysis examples.R connect to the sql database created by the 'download all microdata' progr am create the complex sample survey object, using the replicate weights perform a boatload of analysis examples replicate census estimates - 2011.R connect to the sql database created by the 'download all microdata' program create the complex sample survey object, using the replicate weights match the sas output shown in the png file below 2011 asec replicate weight sas output.png statistic and standard error generated from the replicate-weighted example sas script contained in this census-provided person replicate weights usage instructions document. click here to view these three scripts for more detail about the current population survey - annual social and economic supplement (cps-asec), visit: the census bureau's current population survey page the bureau of labor statistics' current population survey page the current population survey's wikipedia article notes: interviews are conducted in march about experiences during the previous year. the file labeled 2012 includes information (income, work experience, health insurance) pertaining to 2011. when you use the current populat ion survey to talk about america, subract a year from the data file name. as of the 2010 file (the interview focusing on america during 2009), the cps-asec contains exciting new medical out-of-pocket spending variables most useful for supplemental (medical spending-adjusted) poverty research. confidential to sas, spss, stata, sudaan users: why are you still rubbing two sticks together after we've invented the butane lighter? time to transition to r. :D

We explore Random Scale-Free networks of populations, modelled by chaotic Ricker maps, connected by transport that is triggered when population density in a patch is in excess of a critical threshold level. Our central result is that threshold-activated dispersal leads to stable fixed populations, for a wide range of threshold levels. Further, suppression of chaos is facilitated when the threshold-activated migration is more rapid than the intrinsic population dynamics of a patch. Additionally, networks with large number of nodes open to the environment, readily yield stable steady states. Lastly we demonstrate that in networks with very few open nodes, the degree and betweeness centrality of the node open to the environment has a pronounced influence on control. All qualitative trends are corroborated by quantitative measures, reflecting the efficiency of control, and the width of the steady state window.

Series Name: Proportion of population achieving at least a fixed level of proficiency in functional skills by sex age and type of skill (percent)Series Code: SE_ADT_FUNSRelease Version: 2020.Q2.G.03This dataset is the part of the Global SDG Indicator Database compiled through the UN System in preparation for the Secretary-General's annual report on Progress towards the Sustainable Development Goals.Indicator 4.6.1: Proportion of population in a given age group achieving at least a fixed level of proficiency in functional (a) literacy and (b) numeracy skills, by sexTarget 4.6: By 2030, ensure that all youth and a substantial proportion of adults, both men and women, achieve literacy and numeracyGoal 4: Ensure inclusive and equitable quality education and promote lifelong learning opportunities for allFor more information on the compilation methodology of this dataset, see https://unstats.un.org/sdgs/metadata/

In 2024, approximately 965.65 million people in China were of working age between 15 and 64 years. This was equal to a 68.3 percent share of the total population. Age groups between 30 and 59 years represented the largest age cohorts in the Chinese population pyramid. Age demographics in China The change in China’s age distribution over time displayed in the given statistic illustrates the unfolding of an aging population. As the fertility rate in China declined and life expectancy increased, the only age groups that have been growing over the last three decades were those of old people. In contrast, the number of children decreased gradually between 1995 and 2010 and remained comparatively low thereafter. According to the data provided by the National Bureau of Statistics of China, which has not been revised for years before the 2020 census, the size of the working age population declined in 2014 for the first time and entered a downward trajectory thereafter. This development has extended itself into the total population, which has shrunk in 2022 for the first time in decades. Future age development As the fertility rate in China is expected to remain below the reproductive level, the Chinese society will very likely age rapidly. According to UN data, which is based on figures slightly different from the Chinese official numbers, the share of the population above 60 years of age is projected to reach nearly 40 percent in 2050, while the share of children is expected to remain stable. This will lead to an increased burden of the old-age population on the social security system, illustrated by an old-age dependency ratio peaking at nearly 106 percent in 2090. This means that by then, ten working-age adults would have to support nine elderly people.

Indicator 4.6.1The proportion of the population in a given age group achieving at least a fixed level of proficiency in functional (a) literacy and (b) numeracy skills, by sex.Methodology:Literacy Rate for adults =Population (15+ years)for all groups in educational levels table except for the illiterate/total Population (15+ years) * 100.Literacy Rate for youth =Population (15-24 years)for all groups in educational levels table except for the illiterate/total Population (15-24 years) * 100.Data Source:National Planning Council.

The Azores archipelago has been the stage for multiple introductions of Apis mellifera from varying origins, which have led to widespread admixture and the existence of phenotypically and genotypically heterogeneous populations. This is evident on the São Miguel Island, where the historically introduced black phenotype of A. m. iberiensis (lineage M) co-exists with the contemporaneously introduced yellow phenotype of C-lineage ancestry. Interestingly, the cytonuclear markers used herein revealed that C-lineage ancestry is residual at the nuclear level for both the black (5.82 ± 1.66%) and yellow (5.91 ± 1.85%) phenotypes, although this is more pronounced at the mitochondrial level (27.27% for black and 14.74% for yellow). While the C-lineage contribution has remained stable at the nuclear level for over 20 years, there has been a recent decrease in the proportion of C-derived mitotypes.

The percentage of immigrant youth and adults (15 years and above) who have achieved or exceeded a given level of proficiency in numeracy. This indicator is collected via skills' assessment surveys of the adult population (e.g. the Programme for the International Assessment of Adult Competencies (PIAAC), the Skills Towards Employment and Productivity (STEP) Measurement programme, the Literacy Assessment Measurement Programme (LAMP) and national adult literacy and numeracy surveys.

Understanding the population health status of long-lived and slow-reproducing species is critical for their management. However, it can take decades with traditional monitoring techniques to detect population-level changes in demographic parameters. Early detection of the effects of environmental and anthropogenic stressors on vital rates would aid in forecasting changes in population dynamics and therefore inform management efforts. Changes in vital rates strongly correlate with deviations in population growth, highlighting the need for novel approaches that can provide early warning signs of population decline (e.g., changes in age-structure). We tested a novel and frequentist approach, using Unoccupied Aerial System- (UAS) photogrammetry, to assess the population age-structure of small delphinids. First, we measured the precision and accuracy of UAS-photogrammetry in estimating total body length (TL) of trained bottlenose dolphins (Tursiops truncatus). Using a log-transformed linear model, we estimated TL using the blowhole-to-dorsal-fin-distance (BHDF) for surfacing animals. To test the performance of UAS-photogrammetry to age-classify individuals, we then used length measurements from a 35-year dataset from a free-ranging bottlenose dolphin community to simulate UAS-estimates of BHDF and TL. We tested five age-classifiers and determined where young individuals (<10 years) were assigned when misclassified. Finally, we tested whether UAS-simulated BHDF only or the associated TL estimates provided better classifications. TL of surfacing dolphins was overestimated by 3.3% ±3.1% based on UAS-estimated BHDF. Our age-classifiers performed best in predicting age-class when using broader and fewer (two and three) age-class bins with ~80% and ~72% assignment performance, respectively. Overall, 72.5-93% of the individuals were correctly classified within two years of their actual age-class bin. Similar classification performances were obtained using both proxies. UAS-photogrammetry is a non-invasive, inexpensive, and effective method to estimate TL and age-class of free-swimming dolphins. UAS-photogrammetry can facilitate the detection of early signs of population changes, which can provide important insights for timely management decisions. Methods We physically measured TL (i.e., the tip of the rostrum to the tip of the natural notch created by the overlapping fluke lobes, hereafter referred to as the notch) and BHDF for 18 bottlenose dolphins under human care at two facilities in Hawaiʻi, USA. The distance from the center of the blowhole to the anterior insertion of the dorsal fin (BHDF) is an established proxy for TL in bottlenose dolphins (Cheney et al., 2018; van Aswegen et al., 2019). Six adult males ranging from 11.5 to 34.5 years of age (mean = 23.6 ±7.9 years) at Dolphin Quest Oʻahu (DQO); HI, USA, were measured in June 2019. Six females and six males ranging from 4.0 to 49.0 years of age (mean = 17.4 ± 14.8 years) at Dolphin Quest Hawaiʻi (DQH); HI, USA, were measured in August–October 2019. The date of birth (DOB) of the 14 individuals born in facilities is known. The other four individuals (two males and two females) were born in the Gulf of Mexico. The age of these animals was based on the size that they were when collected. Dolphins were measured in a stationary and straight position for all measurements. TL was collected on the ventral side of the dolphin in an inverted position using a tape measure attached to a rigid PVC pipe. The base of the measuring pipe was placed onto a rigid plate aligned with the tip of the rostrum to allow for straight-line measurements. BHDF measurements were made from the center of the blowhole to the insertion of the dorsal fin using a soft measuring tape. One measurement set (consisting of 2–3 replicates per measurement) was collected on the day or within a week of the UAS sampling. To increase sample size, 4–6 additional replicates were collected within the next seven months (total of 7–10 TL and BHDF measurements per animal). DQH measurements per animal were collected on the same day. A DJI Inspire-2 quadcopter was used to collect aerial imagery. The Inspire-2 was equipped with a DJI Zenmuse X5s digital camera (20.8-megapixel, Micro Four Thirds format; calibrated following Dawson et al. (2017)) with an Olympus M.Zuiko 25 mm f/1.8 lens. A LightWare SF11/C laser altimeter (Dawson et al., 2017) was attached, providing an accuracy of 0.1 m and resolution of 1 cm. Despite the precision, some inaccurate altitude readings were recorded. To correct these errors, a custom-made smoother was applied to the original data. The Inspire-2 recorded videos in 4k resolution (3840x2150 pixels). Consecutive flights using both platforms (n=24 flights in total) were conducted at five altitudes (16m, 20m, 30m, 40m and 50m). Dolphins were sampled under two scenarios: stationary and positioned flat and straight in the water and with the slight arching that occurs when surfacing naturally while swimming. Stationary animals were supported by husbandry staff under the caudal region to maintain the body straight and the fluke flat. Photogrammetry of stationary behaviors was collected to compare UAS measurements of TL and BHDF (Fig. 2) with the respective physical measurements. A target of three images was selected per individual, altitude, and behavior (i.e., stationary and surfacing) combination. Images were extracted using VLC Media Player Software (VideoLAN). For surfacing dolphins, video stills and photographs were selected when both the blowhole and dorsal fin insertion were visible and when the individual’s body was as straight and horizontal as possible (i.e., minimal body arch). Available images of sufficient quality varied by platform. In total, 144 video stills (75 stationary and 69 surfacing) of sufficient quality were used. Due to weather or the lack of images of sufficient quality, individual F was removed from the analyses.

In the United States (US), 99.88 percent of the population of rural regions had access to at least one fixed-broadband provider as of June 2020. While 99.76 percent of the population in rural areas have access to two or more fixed-broadband providers, when considering areas covered by three or more providers, this figure drops to 85.14 percent.

The Adjusted Native Parity Index (NPIA) is calculated by dividing the immigrant value for the indicator by the non-immigrant value for the indicator. If the resulting value exceeds 1, the ratio is inverted and subtracted from 2. The adjusted native parity index is symmetrical around 1 and lies in the range 0-2. An adjusted NPI equal to 1 indicates parity between immigrants and non-immigrants. In general, a value less than 1 indicates disparity in favor of non-immigrants and a value greater than 1 indicates disparity in favor of immigrants.

ODS / Goals and targets (from the 2030 Agenda for Sustainable Development) / Goal 4. Ensure inclusive and equitable quality education and promote lifelong learning opportunities for all) / Target 4.6. By 2030, ensure that all youth and a substantial proportion of adults, both men and women, achieve literacy and numeracy. / Indicator 4.6.1. Youth/adult literacy rate

Network of 44 papers and 69 citation links related to "Introduction of parasitoids has maintained a stable population of arrowhead scales at extremely low levels".

The percentage of immigrant youth and adults (15 years and above) who have achieved or exceeded a given level of proficiency in literacy. Functional literacy is defined by UIS as the capacity of a person to engage in all those activities in which literacy is required for effective function of his or her group and community and also for enabling him or her to continue to use reading, writing and calculation for his or her own and the community’s development. This indicator is collected via skills' assessment surveys of the adult population (e.g. the Programme for the International Assessment of Adult Competencies (PIAAC), the Skills Towards Employment and Productivity (STEP) Measurement programme, the Literacy Assessment Measurement Programme (LAMP) and national adult literacy and numeracy surveys.

In the United States, access to fixed-line broadband providers was lowest in rural and tribal regions as of June 2020. While 99.76 percent of the population in rural areas have access to two or more fixed-broadband providers, when considering areas covered by three or more providers, this figure drops to 85.14 percent.

From now until 2100, India and China will remain the most populous countries in the world, however China's population decline has already started, and it is on course to fall by around 50 percent in the 2090s; while India's population decline is projected to begin in the 2060s. Of the 10 most populous countries in the world in 2100, five will be located in Asia, four in Africa, as well as the United States. Rapid growth in Africa Rapid population growth across Africa will see the continent's population grow from around 1.5 billion people in 2024 to 3.8 billion in 2100. Additionally, unlike China or India, population growth in many of these countries is not expected to go into decline, and instead is expected to continue well into the 2100s. Previous estimates had projected these countries' populations would be much higher by 2100 (the 2019 report estimated Nigeria's population would exceed 650 million), yet the increased threat of the climate crisis and persistent instability is delaying demographic development and extending population growth. The U.S. as an outlier Compared to the nine other largest populations in 2100, the United States stands out as it is more demographically advanced, politically stable, and economically stronger. However, while most other so-called "advanced countries" are projected to see their population decline drastically in the coming decades, the U.S. population is projected to continue growing into the 2100s. This will largely be driven by high rates of immigration into the U.S., which will drive growth despite fertility rates being around 1.6 births per woman (below the replacement level of 2.1 births per woman), and the slowing rate of life expectancy. Current projections estimate the U.S. will have a net migration rate over 1.2 million people per year for the remainder of the century.