Decline In Population Growth Rate Research Articles

Contribution and Development Trend of the Robotics Industry in the Context of Declining Population Growth Rate

In modern society, with a higher level of education for women, the growth rate of the population is dropping. Together with the improvements in AI systems, robots might play a more crucial role in future development than before. However, some may argue that the application of AI may result in a high unemployment rate which is a phenomenon that the government does not want to see. This paper discussed the problems that arise from aging, the obstacles that have been met in the robotic industry and how to solve them. Although robotics is more sophisticated compared to the past and has already had a significant state in the automated production industry, there are still obvious shortcomings in personalized service since it is too difficult for language models to understand human reactions. In the future, this issue might be solved by instilling more expertise in AI, as well as writing new programming code might solve the existing problems.

Demographic and population response of the threatened coral Acropora cervicornis (Scleractinia, Acroporidae) to fireworm corallivory

Introduction: The fireworm Hermodice carunculata is a widespread polychaete that can prey upon many coral species. However, few studies have examined the effect of fireworm predation on coral demographics during non-outbreak periods. 
 Objective: To determine whether predation by H. carunculata compromised the growth, survival, and population performance of the threatened coral Acropora cervicornis. 
 Methods: Nursery-reared coral fragments (n = 99) were fixed to the bottom of Punta Melones reef in the Island Municipality of Culebra, Puerto Rico. Predation activity and its demographic consequences on coral outplants were assessed from December 2020 to August 2022. Susceptibility to predation was compared between colonies collected directly from the reef and those originating from outside sources (e.g., coral nurseries). With the demographic data, simple size-based population matrix models were developed to 1) examine whether fireworm predation led to a significant decline in population growth rate (λ), 2) determine the demographic transition(s) that contribute the most to λ, and 3) determining the demographic transition(s) that accounted for differences in λ when comparing scenarios that considered either only predated colonies or both predated and non-predated outplants. 
 Results: Predation increased over time, being more frequently observed in the area with the highest topographic relief and on colonies foreign to the study site. Outplants that were partially consumed grew significantly slower than non-predated colonies; however, predation did not threaten their survival. The likelihood of being attacked by the fireworm increased with branching complexity. The estimated λ for a scenario considering only those predated colonies was 0.99, whereas, for a scenario where both predated and non-predated colonies were considered, λ was 0.91. Population growth, under both scenarios, was mainly influenced by the probability of a large colony surviving and remaining at the largest size. 
 Conclusions: Although predation can negatively impact coral growth, the relatively high survival rate of predated colonies compensates for the adverse effects. Since survival is the demographic transition that contributes most to population growth, it could be concluded that under a non-outbreak scenario, fireworm predation may not be the primary cause of A. cervicornis population decline.

Analisis Pengaruh Kependudukan dan Pendidikan Terhadap Pengangguran di Kabupaten Blitar Data Sakernas BPS 2022

Unemployment is a problem that occurs in East Java, especially Blitar Regency. Several factors make the unemployment rate in Blitar Regency fluctuate, including population and education. According to some experts, every resident who enters the labor force but is unable to be absorbed or enters the workforce, this can lead to an increase in the unemployment rate. According to the educational factor, the higher a person's education, the higher the ability and opportunity to work. So that the government's efforts are needed to overcome this unemployment. The purpose of this research is to see the impact of education and population on unemployment in Blitar Regency. The method used is literature review (literature review). Based on the results of the study, it was concluded that the unemployment rate was contributed by residents with the highest educational level who graduated from elementary school, and the unemployment rate decreased by 0.16% from the previous year, from 3.82% to 3.66% of the total workforce of 657,544 residents. This is also influenced by the declining population growth rate and increasing awareness of education.

Temperature variability interacts with mean temperature to influence the predictability of microbial phenotypes.

Despite their relatively high thermal optima (T opt), tropical taxa may be particularly vulnerable to a rising baseline and increased temperature variation because they live in relatively stable temperatures closer to their T opt. We examined how microbial eukaryotes with differing thermal histories responded to temperature fluctuations of different amplitudes (0 control, ±2, ±4°C) around mean temperatures below or above their T opt. Cosmopolitan dinoflagellates were selected based on their distinct thermal traits and included two species of the same genus (tropical and temperate Coolia spp.), and two strains of the same species maintained at different temperatures for >500 generations (tropical Amphidinium massartii control temperature and high temperature, CT and HT, respectively). There was a universal decline in population growth rate under temperature fluctuations, but strains with narrower thermal niche breadth (temperate Coolia and HT) showed ~10% greater reduction in growth. At suboptimal mean temperatures, cells in the cool phase of the fluctuation stopped dividing, fixed less carbon (C) and had enlarged cell volumes that scaled positively with elemental C, N, and P and C:Chlorophyll‐a. However, at a supra‐optimal mean temperature, fixed C was directed away from cell division and novel trait combinations developed, leading to greater phenotypic diversity. At the molecular level, heat‐shock proteins, and chaperones, in addition to transcripts involving genome rearrangements, were upregulated in CT and HT during the warm phase of the supra‐optimal fluctuation (30 ± 4°C), a stress response indicating protection. In contrast, the tropical Coolia species upregulated major energy pathways in the warm phase of its supra‐optimal fluctuation (25 ± 4°C), indicating a broadscale shift in metabolism. Our results demonstrate divergent effects between taxa and that temporal variability in environmental conditions interacts with changes in the thermal mean to mediate microbial responses to global change, with implications for biogeochemical cycling.

Modeling of Children Ever Born in Indonesia Using Fourier Series Nonparametric Regression

Nonparametric regression aims to determine the relationship between response and predictor when the data does not follow a specific pattern. Fourier series is a nonparametric regression approach which has the flexibility to follow the characteristics of data. The purpose of this study is to obtain the estimator of the nonparametric regression using Fourier series and apply the model to the fertility data. The fertility rate represented by children ever born is one of the demographic factors that determine the decline in population growth rate. The data were obtained from the Indonesia Demographic and Health Survey 2017 with children ever born as a response. The predictors are the proportion of women graduating from junior high school, the proportion of women having sex before the age of 18, the proportion of women using a modern contraceptive method, and the infant mortality rate. The relationship between response and predictors tends to have a repetitive pattern with a certain trend. The best nonparametric regression model of children ever born in Indonesia is obtained by using 3 oscillation parameters for each predictor variable with GCV = 0.0534 and R-square = 80.04%.

Climate‐induced variation in the demography of 14 tree species is not sufficient to explain their distribution in eastern North America

AbstractAimDynamic range models are proposed to investigate species distributions and to project range shifts under climate change. They are based upon the Hutchinsonian niche theory, specifying that the occurrence of a species in an environmental space should be limited to positions where the intrinsic growth rate is positive. Evaluating population growth rate is, however, difficult for physiologically structured populations, such as forest stands, owing to size‐induced individual variation in performance. Therefore, we still have a limited understanding of which aspect of tree demography contributes the most to their geographical range limit. We develop an index of demographic performance for size‐structured populations and study its variation across a climatic gradient. We then investigate the relationship between the demographic performance index and species distribution.LocationNorth America (57–124° W, 26–52° N).Time period1963–2010.Major taxa studiedFourteen tree species.MethodsWe represent forest dynamics with a size‐structured population model and neighbourhood competition with the perfect plasticity approximation. We then derive the lifetime reproduction per individual, , in the absence of density dependence. Using forest inventory data, we assess how tree demography for each species varies with climate. We test the model by comparing and the probability of occurrence within species ranges.ResultsWe find that both growth and mortality rates vary across species distributions, but climate explains little of the observed variation. Individual size and neighbourhood competition are the primary explanatory variables of tree demography. Finally, we find that relates weakly to the probability of occurrence, with no systematic decline in population growth rates towards the range limits.Main conclusionsSpatial and size‐induced variation in tree growth and mortality do not explain range limits and are insufficient to enable an understanding of tree dynamics. We propose that phenomena perceived mostly at the metapopulation scale should also be considered.

A codeveloped management tool to determine harvest limits of introduced mud crabs,

Hawaiian fishponds, or loko i‘a, are ancient aquaculture systems and models of sustainable aquatic resource management from traditional Native Hawaiian harvest practices. Of the 488 fishponds documented in ancient Hawai‘i, only 38 are currently actively managed. Building on Indigenous and local knowledge, fishponds are being adapted to current community needs. Functional fishponds perpetuate culture, improve food security, enhance ecosystem services and transform conservation biology through Indigenous perspectives. Here we examine how Indigenous practices effectively maintain sustainable harvest of an introduced, but economically important, crab species, the mud crab, Scylla serrata (Forskål 1775). The State of Hawai‘i has only a size limit, and no bag limits, for this species. With Indigenous management in a Hawaiian fishpond, limits are set and enforced in response to fluctuations in catch. We used a mark–recapture experiment to parameterise a size-structured population model, which we used to investigate the impact of changing harvest rates. Throughout the study period of 2017–20, the mean number of crabs per harvest was 28 individuals (s.d. = 7) and average catch per unit effort was 0.20 crabs per trap-hour (s.d. = 0.054). During winter, catch per unit effort was lower but mean crab size was larger than during summer. Model simulations indicated that current Indigenous practices are less likely to cause a decline in population growth rate than a strict size limit. Using information from Indigenous harvest practices and the mark–recapture study, we codeveloped a versatile crab population model that can be tailored to changing management objectives.

The return of Malthus? Resource constraints in an era of declining population growth

Abstract Will natural resources comprise an important constraint on economic development in the 21st century? We use a macroeconomic model (MAVA) to demonstrate the precise nature of this problem. First, we employ the model to demonstrate that resource constraints do not substantially limit future economic growth under parametric conditions prevailing in the period 1960–2010. Second, we examine the sorts of changed conditions that are unavoidable in the coming century and demonstrate that declining population growth (and the increased dependency rates this implies) is likely to result in increasingly important resource constraints. Ironically, it is the decline in population growth rates—and not the opposite—that may occasion the return of Malthusian constraints. 1

Transient population dynamics impede restoration and may promote ecosystem transformation after disturbance

The apparent failure of ecosystems to recover from increasingly widespread disturbance is a global concern. Despite growing focus on factors inhibiting resilience and restoration, we still know very little about how demographic and population processes influence recovery. Using inverse and forward demographic modelling of 531 post-fire sagebrush populations across the western US, we show that demographic processes during recovery from seeds do not initially lead to population growth but rather to years of population decline, low density, and risk of extirpation after disturbance and restoration, even at sites with potential to support long-term, stable populations. Changes in population structure, and resulting transient population dynamics, lead to a >50% decline in population growth rate after disturbance and significant reductions in population density. Our results indicate that demographic processes influence the recovery of ecosystems from disturbance and that demographic analyses can be used by resource managers to anticipate ecological transformation risk.

Predator-mediated effects of severe drought associated with poor reproductive success of a seabird in a cross-ecosystem cascade.

Despite the profound impacts of drought on terrestrial productivity in coastal arid ecosystems, only a few studies have addressed how drought can influence ecological cascades across ecosystem boundaries. In this study, we examine the consequences of rainfall pulses and drought that subsequently impact the breeding success of a threatened nocturnal seabird, the Scripps's Murrelet (Synthliboramphus scrippsi). On an island off the coast of southern California, the main cause of reduced nest success for one of their largest breeding colonies is egg predation by an endemic deer mouse (Peromyscus maniculatus elusus). Mice on the island have an opportunistic diet of primarily terrestrial sources, but drastic declines in terrestrial productivity from drought might be expected to increase their reliance on marine resources, including murrelet eggs. We compiled data on terrestrial and marine productivity between 1983 and 2013 to determine how conditions in these ecosystems influence murrelet nest success. We found that the severity of drought had the strongest negative impact on murrelet nest success. We calculated that the reduction in fecundity during drought years due to increased egg predation by mice was substantial enough to produce a declining population growth rate. Nest success was much higher under normal or high rainfall conditions, depending on whether oceanic conditions were favorable to murrelets. Therefore, the more frequent and severe drought that is projected for this region could lead to an increased risk of murrelet population decline on this island. Our study highlights the need for understanding how species interactions will change through the effects of increasing drought and altered rainfall regimes under global change.

Interactions among competing nematode species affect population growth rates.

Investigations of the interplay of organisms in an ecological community are a prerequisite to understanding the processes that shape the structures of those communities. Among several types of interactions, interest in the positive interactions of species that compete for the same resource has grown, as they may provide a mechanism enabling coexistence. In the laboratory experiment described herein, the effects of interspecific interaction on the population growth of two bacterial-feeding nematode species, Panagrolaimus cf. thienemanni and Poikilolaimus cf. regenfussi, were investigated. Specifically, we asked: (1) whether there is an interspecific interaction between organisms competing for a mutual resource and (2) whether these interactions are altered by the competitors' initial densities and (3) their variable growth rates (induced by different food supplies). Each treatment initially contained 48 nematode individuals, but at different species ratios (48:0; 32:16; 24:24; 16:32; 0:48). The populations were provided with three different bacterial densities (108, 109, and 1010cellsml-1) as food. The data were analyzed using a generalized linear mixed model. The best-fitting model revealed a significant decline in population growth rates with an increasing species ratio, but depending on the food density and species. These results provide strong evidence for positive interspecific interactions that vary with both species density and food-supply level. They also suggest important roles for positive interspecific interactions in habitat colonization and in maintaining the coexistence of species in the same trophic group.

(2010-1954)النمو السكاني في إقليم بنغازي خلال الفترة من

Through the study of population growth census for the territory of Benghazi that in the period 1954-1964, the rate of population growth was (4.4%) and then declined to (3.7%) during the period 1984-1995. Then it rose slightly to record (2.2%) during the period 2006-2010. Said that the rise in the rate of population growth did not reach the level it was in the 1980s of the last century, this study seeks to answer the following question: what is reason behind the decline in population growth rates in the territory of the Benghazi?The study aimed to clarify the difference in the rate of increase in the size of the population of the territory. As well as highlighting the role played by natural increase and other natural resources. Also, it exhibits the importance of the study of population growth in the affected by economic, social and political factors, which lead to high rates of growth or decline, and this is reflected on the composition and distribution of the population.The descriptive approach of analytical work, based on data collection, compilation and interpretation. As well as the evolutionary historical approach, and the reliance on the comparative approach. The researcher adopted general censuses of population and vital statistics data conversion to tables and forms. The researcher in this study has depended on a set of standards such as the Exponential equation, and the equation of the expected number of years to double the population, the rate of birth and crude. Finally, the study showed that the size of the population of the territory has doubled twice throughout the period of study. It also shows that the crude birth had risen evenly reached their peak in 1984 recorded (52.9 per thousand), and then fell to record in 2009 (27.7 per 1,000)

Population Structure of the Common Hippopotamus (Hippopotamus amphibius) in the Luangwa River, Zambia

Population structure of the common hippopotamus (Hippopotamus amphibius Linnaeus 1758) in the Luangwa Valley, eastern Zambia was assessed during the period 2005-2008. Field observations and laboratory examinations were used to classify hippos in age groups. Chi-square Test of age group composition showed a significant difference in the percent proportion of age groups in the population (i£ 2 = 57.98, DF = 6, i‚µ = 0.05, P< 0.001). Calves one year old and less were not represented. Younger groups ‘iii’ and ‘v’ comprised only 15 percent of the population. The remaining 75 percent were older age groups vii - xix mainly comprising mature and senescent individuals. The age structure was biased towards older age groups. Skewed age distribution in favour of older age groups was an indication of a declining population growth rate. More research is required to investigate factors responsible for the decline in population growth rates.

Demographic consequences of heavy metals and persistent organic pollutants in a vulnerable long-lived bird, the wandering albatross.

Seabirds are top predators of the marine environment that accumulate contaminants over a long life-span. Chronic exposure to pollutants is thought to compromise survival rate and long-term reproductive outputs in these long-lived organisms, thus inducing population decline. However, the demographic consequences of contaminant exposure are largely theoretical because of the dearth of long-term datasets. This study aims to test whether adult survival rate, return to the colony and long-term breeding performance were related to blood mercury (Hg), cadmium (Cd) and persistent organic pollutants (POPs), by using a capture-mark-recapture dataset on the vulnerable wandering albatross Diomedea exulans. We did not find evidence for any effect of contaminants on adult survival probability. However, blood Hg and POPs negatively impacted long-term breeding probability, hatching and fledging probabilities. The proximate mechanisms underlying these deleterious effects are likely multifaceted, through physiological perturbations and interactions with reproductive costs. Using matrix population models, we projected a demographic decline in response to an increase in Hg or POPs concentrations. This decline in population growth rate could be exacerbated by other anthropogenic perturbations, such as climate change, disease and fishery bycatch. This study gives a new dimension to the overall picture of environmental threats to wildlife populations.

Brief Review of World Demographic Trends - Trends in Age Distributions

This report focuses on one demographic trend: Age Distributions. The basic findings of this report are: 1) in all regions, the largest group is the adults (15-59 years old), 2) in Asia, Africa, and Latin America and the Caribbean, there are more children than there are seniors, while, recently, in Europe there are more seniors than children, and in Northern America there will soon be more seniors than children, 3) in almost all regions, the proportion of the population who are children is declining while the proportion who are seniors is increasing. Sub-Saharan Africa is an exception. There are almost as many children as there are seniors, and the proportions of the population who are seniors and children have not yet changed.Changes in age distributions have many implications for society. For example, a larger proportion of younger people means more people who have yet to attain adulthood and who can be expected to have more children, which means continued population growth. So, Sub-Saharan Africa, which has the highest proportion of children, also has the highest population growth rates (as seen in previous reports), and can be expected to continue to have the highest population growth rates. Similarly, Europe and North America, which have the lowest proportion of children, also have the lowest population growth rates, which can be expected to continue to be low. Also, since most regions have declining proportions of children, most regions have declining population growth rates and will likely continue to have declining population growth rates.

Identifying the demographic processes relevant for species conservation in human-impacted areas: does the model matter?

The identification of the demographic processes responsible for the decline in population growth rate (λ) in disturbed areas would allow conservation efforts to be efficiently directed. Integral projection models (IPMs) are used for this purpose, but it is unclear whether the conclusions drawn from their analysis are sensitive to how functional structures (the functions that describe how survival, growth and fecundity vary with individual size) are selected. We constructed 12 IPMs that differed in their functional structure by combining two reproduction models and three functional expressions (generalized linear, cubic and additive models), each with and without simplification. Models were parameterized with data from two populations of two endangered cacti subject to different disturbance intensities. For each model, we identified the demographic processes that most affected λ in the presence of disturbance. Simulations were performed on artificial data and analyzed as above to assess the generality of the results. In both empirical and simulated data, the same processes were identified as making the largest contribution to changes in λ regardless of the functional structure. The major differences in the results were due to misspecification of the fecundity functions, whilst functional expression and model simplification had lesser effects. Therefore, as long as the demographic attributes of the species are well known and incorporated into the model, IPMs will robustly identify the processes that most affect the growth of populations subject to disturbance, making them a reliable tool for developing conservation strategies.

Demographic Change and R&amp;D-Based Economic Growth: Reconciling Theory and Evidence

In recent decades, most industrialized countries experienced declining population growth rates caused by declining fertility and associated with rising life expectancy. We analyze the effect of continuing demographic change on medium- and long-run economic growth by setting forth an R&D-based growth model including an analytically tractable demographic structure. Our results show that, in response to demographic change, technological progress and economic growth accelerate in the medium run but slow down in the long run. Numerical investigation reveals that the time period during which technological progress and economic growth are faster than without demographic change can be very long. Since the theoretical predictions for the medium run are consistent with the negative association between population growth and economic growth found in the empirical literature, the present framework can reconcile R&D-based growth theory with the available empirical evidence.

Using life-history traits to explain bird population responses to changing weather variability

Bird population dynamics are expected to change in response to increased weather variability, an expression of climate change. The extent to which species are sensitive to effects of weather on survival and reproduction depends on their life-history traits. We investigated how breeding bird species can be grouped, based on their life-history traits and according to weather-correlated population dynamics. We developed and applied the linear trait–environment method (LTE), which is a modified version of the fourth-corner method. Despite our focus on single traits, 2 strategies—combinations of several traits—stand out. As expected, breeding populations of waterfowl species are negatively impacted by severe winters directly preceding territory monitoring, probably because of increased adult mortality. Waterfowl species combine several traits: they often breed at ground or water level, feed on plant material, are precocial and are generally short-distance or partial migrants. Furthermore, we found a decline in population growth rates of insectivorous long-distance migrants due to mild winters and warm springs in the year before territory monitoring, which may be caused by reduced reproduction due to trophic mismatches. We identify species that are expected to show the most significant responses to changing weather variability, assuming that our conclusions are based on causal relationships and that the way species, weather variables and habitat interact will not alter. Species expected to respond positively can again be roughly categorized as waterfowl species, while insectivorous long-distance migrants are mostly expected to respond negatively. As species traits play an important role in constructing functional groups that are relevant to the provisioning of ecosystem services, our study enables the incorporation of ecosystem vulnerability to climate change into such functional approaches

Cholesterol esters as growth regulators of lymphocytic leukaemia cells

Alterations in plasma lipid profile and in intracellular cholesterol homoeostasis have been described in various malignancies; however, significance of these alterations, if any, in cancer biology is not clear. The aim of the present study was to investigate a possible correlation between alterations in cholesterol metabolism and expansion of leukaemia cell numbers. Lipid profiles in plasma and in primary leukaemia cells isolated from patients with acute or chronic lymphocytic leukaemia (ALL and CLL) were studied. Decreased levels of HDL-C were observed in plasma of leukaemic patients, levels of total cholesterol, LDL-C, triglycerides and phospholipids were unchanged or only slightly increased. As compared to normal lymphocytes, freshly isolated leukaemic cells showed increased levels of cholesterol esters and reduction in free cholesterol. Growth stimulation of ALL and CLL cells with phytohemagglutinin led to further increase in levels of cholesterol esters. Conversely, treatment with an inhibitor of cell proliferation such as the mTOR inhibitor, RAD, caused decline in population growth rate of leukaemia cells, which was preceded by sharp reduction in rate of cholesterol esterification. On the other hand, exposure of leukaemic cells to two inhibitors of cholesterol esterification, progesterone and SaH 58-035, caused 60% reduction in their proliferation rate. In addition to demonstrating tight correlation between cell number expansion and cholesterol esterification in leukaemic cells, these results suggest that pathways that control cholesterol esterification might represent a promising targets for novel anticancer strategies.

Toward Sustainable Production of Second Generation Bioenergy Feedstocks†

Some analysts point to continuing advances in agricultural technology and declining global population growth rates to predict a substantial surplus of agricultural land by 2050. Such surplus land could be diverted into growing biomass for renewable energy to help overcome the global challenge of climate change. Others suggest that diversion of agricultural land into bioenergy will exacerbate risk of chronic food shortage by 2050. On balance it appears that declining population growth rate, continuing technology advance, and intensifying use of existing global agricultural land could support sufficient food production as well as some bioenergy production. Competitive bioenergy requires development of second-generation (lignocellulosic) feedstocks rather than first-generation (starch, sugar, and oilseed) feedstocks. Second-generation feedstocks from woody crops have the potential to complement intensive agriculture and ameliorate its environmental impacts. Woody biomass crops may therefore have a lower effe...