Population Growth Patterns Research Articles

Current Evaluation on Generation, Storage, And Disposal of Solid Waste from Tourist Lodging Places in Mokokchung Town : A Case Study of Metsuben, Whispering Wind and Marvel Guest House

Rapid urbanization, population growth and changing consumption patterns in Mokokchung Town contribute significantly to the growing volumes of solid waste. The rate of tourist inflow in Mokokchung Town increases especially during the festive season owing to its culture, religion, history and aesthetic character of the town. Growth in the tourism industry along with ineffective solid waste management practises in the accommodation places and the town has resulted in increasing rates of solid waste production. The present study aims to analyse the inflow rate of tourists and to evaluate the current rate of generation, storage, and disposal of solid waste through empirical study. The study finds out that Mokokchung Town generates 14600 metric tons per year out of this, solid waste generated from tourist accommodation in town accounted for 4088 kg per year i.e., 4.08 Metric tons per year. The study suggests alternative storage and disposal options for tourist accommodation places.

Spatial and Temporal Variation in Stored-Product Insect Pest Distributions and Implications for Pest Management in Processing and Storage Facilities

Abstract Insect infestations can result in a damaged or destroyed product, costing producers and retailers millions of dollars annually. Postharvest insects move through space searching for mates, food, and shelter. Movement of product, sanitation activities, and insecticide applications also drive their spatial distribution patterns. Determining spatial distributions and population density of insects provides important information to develop targeted and cost-effective management programs. Monitoring data collected using traps to capture insect pests have provided information under a range of conditions: in bins of grain, grain elevator silos and their immediate environment, milling and processing facilities, commercial warehouses, and retail stores. In evaluating available data, we identified key influences that may be leveraged to increase the impacts of future monitoring schemes. Species-specific locations of infestation were common among stored product insect pests and seasonal variation was highly influential in population growth patterns. Competition among different species also drives spatial and temporal distributions and overlap among species is rare. Vertical distribution of insects was common in bins, elevators, and silos. More insects were often found in the receiving and storage areas of mills and processing facilities and insects often migrated into facilities from surrounding natural reservoirs. Previously stored grain and spillage can also harbor insect populations, which also reinforces the need for sanitation in and around stored grain products. Continued monitoring research will provide information to develop predictive tools which will use behavioral patterns to further our understanding of these insect pests within these unique facilities and circumstances.

The effects of two sized polystyrene nanoplastics on the growth, physiological functions, and toxin production of Alexandrium tamarense

Micro- and nano-plastics (MNPs) are increasingly prevalent pollutants in marine ecosystems and result in various deleterious effects on marine organisms. There have been studies evaluated the toxic effects of MNPs on marine microalgae, but few of them focused on the effects of MNPs on dinoflagellate species and their toxins production, which could have significant implications on human health and ecological safety in coastal areas. In this study, the common harmful algal blooms-causing dinoflagellate Alexandrium tamarense was exposed to 0.1 and 1 μm sized polystyrene nanoplastics (NPs) to investigate the responding patterns of population growth, multiple physiological functions, as well as the intracellular paralytic shellfish toxins (PSTs) productions. The results indicated the population growth, photosynthetic parameters, nutrients (nitrate and phosphate) uptake rates and extracellular carbonic anhydrase activities (CAext) were all inhibited by the two sized NPs, accompanied by the prolonged and more aggregated microalgal cells under the observation of scanning electron microscope (SEM), and the inhibition effects were more severe under 1 μm sized NPs than 0.1 μm sized NPs. Finally, we found the intracellular PSTs contents increased 73.59% exposed to 0.1 μm sized NPs while decreased 85.50% exposed to 1 μm sized NPs comparing the controls at 96 h, without significant changes of relative compositions. These results provided evidence that MNPs were toxic to A. tamarense and affected their intracellular PSTs productions within 96 h, which is critical to consider when evaluating the potential risks of MNPs in marine ecosystems.

AN ANALYSIS OF POPULATION COMPOSITION AND TRENDS IN SELANGOR FROM 1970 TO 2000

Selangor's demography changed between 1970 and 2000 as a result of population growth. This study used data from cencuses and reports to assess Selangor's demographic structure, population growth, and challenges caused by population expansion during this timeframe. The purpose of this study was to assess the demographic composition and population change pattern in Selangor from 1970 to 2000, as well as to analyse the reasons that caused population growth patterns and difficulties induced by population expansion. By using ArcGIS, the demographic maps were generated to provide an overview of the population change over this study period. The outcomes of this study indicated changes in demographic characteristics throughout time, such as total population, age structure of the population, gender ratio, ethnic groups of the population, population distribution, urban population distribution, population growth pattern by district and total net migrant for Selangor. As a result, changes in population structure caused long-term consequences, such as a lack of land resources, a scarcity of natural resources, increased pollution, an increase in the elderly population, a population ratio imbalance, and an increase in crime rates. Between 1970 and 2000, the population of Selangor changed in terms of composition and growth patterns. These changes happened as a consequence of natural factors and migration as a result of rapid socioeconomic expansion during this time period. This situation contributes to the state's population growth. These issues made state planning more challenging.

Persistence of the Exotic Mirid Nesidiocoris tenuis (Hemiptera: Miridae) in South Texas.

Simple SummaryThe Rio Grande Valley is one of the most productive agricultural areas in the U.S, located in the southernmost part of Texas. In October 2013, we detected an exotic species of plant bug occurring in this region. It was identified as Nesidiocoris tenuis, which had a phytophagous behavior on tomato plants in the absence of its preferred prey. We confirmed the species with morphological and genetic tests. We monitored populations of N. tenuis in its introduction phase in commercial fields and corroborated its establishment in research fields for three consecutive years. The presence of N. tenuis could establish a new relationship of trophic insects to produce vegetables in the Rio Grande Valley. However, it is unknown whether the presence of N. tenuis in the Rio Grande Valley can help control pests of economic importance, such as whiteflies in cotton, or become a pest on sesame, which is an emerging crop in this region.The Rio Grande Valley is one of the most productive agricultural areas in the U.S and is located in the southernmost part of Texas. In October 2013, we detected an exotic plant bug, Nesidiocoris tenuis Reuter (Hemiptera: Miridae: Bryocorinae) occurring in the region. Nesidiocoris tenuis has zoophytophagous habits; however, in the absence of insect prey, it feeds on its plant hosts. After its morphological and genetic identification, this study monitored the population of N. tenuis in its introduction phase in commercial fields and corroborated its establishment in research fields for three years. Populations of N. tenuis were high during the fall and low during winter. This study found that N. tenuis populations were higher in tomato fields as compared to adjacent pepper, okra, and squash fields, indicating its host preferences during the introduction phase. Recurrent population growth patterns suggest that N. tenuis was established in Rio Grande Valley with permanent populations in tomato fields. In addition, N. tenuis populations were affected by tomato cultivar selection and by plastic mulch color. The presence of N. tenuis could establish a new trophic insect relationship for vegetable production. However, it is unknown if the presence of N. tenuis may help to control pests of economic importance, such as whiteflies in cotton, or become a pest on sesame, an emerging crop.

Growth, maturity, condition, size at sexual maturity and mortality of the Banded gourami Trichogaster fasciata from the Ganges River, Northwestern Bangladesh

The present study depicts the first comprehensive description on population structure, growth pattern (length-weight relationships, LWRs and length-length relationships, LLRs), condition factor (allometric, KA; Fultonʹs, KF; relative, KR and relative weight, WR), maturity (size at first sexual maturity; Lm), form factor (a3.0) and natural mortality (Mw) of Trichogaster fasciata (Bloch and Schneider, 1801)in the Ganges River, Northwestern Bangladesh. In addition, asymptotic weight (Wα), a3.0, Lm and Mw of this fish species from worldwide different water bodies were calculated based on the maximum total length. Samples of T. fasciata were collected from the fisher’s catch from August 2015 to July 2016 using cast net (mesh size ranges: 1.5 - 2.0 cm). For each individual, total length (TL) and body weight (BW) were measured using digital slide calipers and electronic balance with 0.01 cm and 0.01 g accuracy, respectively. A total of 278 individuals were analyzed, where the minimum and maximum TL were 3.3 cm and 9.9 cm, respectively and BW was 1.1 g and 22.04 g, correspondingly. The highest number (32.4%) of its population stands at 6.0 cm to 7.0 cm TL size group. The b value of LWR indicated negative allometric growth. Fulton′s condition factor (KF) is the best condition and WR showed significant dissimilarity from 100, signifying the balanced habitat for T. fasciata in the Ganges River. The a3.0 was 0.0214, the Lm was 5.91 cm TL and Mw was 1.35 year-1 of T. fasciata in the Ganges River. These findings will be very effective for its sustainable management in the Ganges River and connecting ecosystems.

Populasi Kepiting Bakau (Scylla serrata) di Perairan Muara Sungai Barumun Kabupaten Labuhanbatu Ditinjau dari Pola Pertumbuhan dan Faktor Kondisi

Mangrove crab (Scylla serrata) is one of the prima donna sources of protein caught by fishermen around mangrove forest waters in the waters of the Barumun River Estuary, Labuhanbatu Regency. This study aims to inform about condition factors, growth patterns of crab populations, and reproductive aspects in the form of abundance of Gonad Maturity Level (TKG). Determination of 3 sampling points is done by using purposive random sampling method. Scylla serrata sampling was carried out using Bubu. Data analysis presents information on the abundance of gonadal maturity level, growth pattern, and Fulton condition factor (K), which is presented quantitatively. The results showed that male and female Scylla serrata growth patterns were categorized as negative allometric b < 3, with carapace width growth being faster than weight gain. Fulton condition factor (K) values obtained ranged from 50.14-132.75 for male Scylla serrata, and female ranged from 80.34-123.94. The gonadal maturity level of Scylla serrata was dominated by TKG II crabs, and the lowest abundance of gonad maturity was in TKG IV crabs. This indicates that, in December-February, the condition of the Scylla serrata population around the mangrove forest waters of the Barumun river estuary, is predicted to be in the stage of adult dominance that is ready to reproduce and prepare to spawn.

Elephant population responses to increased density in Kruger National Park

The elephant population in the Kruger National Park (KNP) has been increasing since the cessation of culling in the mid-1990s. This contrasts with recent trends in elephant populations in many parts of Africa where poaching continues to decrease numbers. Logistic growth theory predicts that increased competition for vital resources when densities increase should serve to constrain population growth, implying a negative density-growth correlation. We tested this prediction using 28 years of elephant census data to investigate how the growth of the KNP’s elephant population responds to increasing elephant density from the period 1985 to 2012. We expected a spatially variable population growth pattern in response to the distribution of elephant densities in the park and thus classified the park into zones with low, medium or high long-term (28 years) average, dry-season elephant density. Zones were named ‘peripheral’, ‘semi-peripheral’ and ‘core’ zones, respectively, and represent proxies of resource availability to elephant herds. Using a Stochastic Ricker growth model, we tested for the presence of negative density-dependence in population growth in the core versus peripheral zones. In response, we only detected density-dependent growth in the core zone. Overall the population grew at 4.1% per year, coupled with local recruitment rates that increased over time, particularly in the peripheral zones. These density-dependent trends support previous observations of homogenisation of elephant distribution and density across the KNP landscapes.Conservation implications: Density-dependent changes to elephant growth rates are scale-dependent (local vs. park level). Only core areas with long-term high density show signs of density-dependent growth. Overall, the distributions of elephants are homogenising in the KNP. Conservation authorities should monitor the impact of such homogenisation to landscape heterogeneity. The spatial variation of the negative density-growth correlation, especially between the core and peripheral zones, can be considered when developing effective strategies to manage the KNP elephant population.

Ecological genetics of Juglans nigra: Differences in early growth patterns of natural populations.

Many boreal and temperate forest tree species distributed across large geographic ranges are composed of populations adapted to the climate they inhabit. Forestry provenance studies and common gardens provide evidence of local adaptation to climate when associations between fitness traits and the populations' home climates are observed. Most studies that evaluate tree height as a fitness trait do so at a specific point in time. In this study, we elucidate differences in early growth patterns in black walnut (Juglans nigra L.) populations by modeling height growth from seed up to age 11. The data comprise tree height measurements between ages 2 and 11 for 52 natural populations of black walnut collected through its geographic range and planted in one or more of 3 common gardens. We use the Chapman–Richards growth model in a mixed effects framework and test whether populations differ in growth patterns by incorporating populations' home climate into the model. In addition, we evaluate differences in populations' absolute growth and relative growth based on the fitted model. Models indicated that populations from warmer climates had the highest cumulative growth through time, with differences in average tree height between populations from home climates with a mean annual temperature (MAT) of 13°C and of 7°C estimated to be as high as 80% at age 3. Populations from warmer climates were also estimated to have higher and earlier maximum absolute growth rate than populations from colder climates. In addition, populations from warm climates were predicted to have higher relative growth rates at any given tree size. Results indicate that natural selection may shape early growth patterns of populations within a tree species, suggesting that fast early growth rates are likely selected for in relatively mild environments where competition rather than tolerance to environmental stressors becomes the dominant selection pressure.

Indicators of Land, Water, Energy and Food (LWEF) Nexus Resource Drivers: A Perspective on Environmental Degradation in the Gidabo Watershed, Southern Ethiopia.

In Ethiopia, land, water, energy and food (LWEF) nexus resources are under pressure due to population growth, urbanization and unplanned consumption. The effect of this pressure has been a widely discussed topic in nexus resource literature. The evidence shows the predominantly negative impact of this; however, the impact of these factors is less explored from a local scale. As a result, securing nexus resources is becoming a serious challenge for the country. This necessitates the identification of the driving factors for the sustainable utilization of scarce LWEF nexus resources. Our study provides a systemic look at the driving factor indicators that induce nexus resource degradation. We use the Analytical Hierarchical Process (AHP) to develop the indicators’ weights, and use a Path Analysis Model (PAM) to quantitatively estimate the effect of the driving factor indicators on the LWEF nexus resources. The results indicate that social (48%), economic (19%), and policy and institutional changes (14%) are the major nexus resource driving factor indicators. The path analysis results indicate that among the social driving factor indicators, population growth and consumption patterns have a significant direct effect on the LWEF nexus, with path coefficients of 0.15 and 0.089, respectively. Similarly, the potential of LWEF nexus resources is also influenced by the institutional and policy change drivers, such as outdated legislation and poor institutional structure, with path coefficients of 0.46 and 0.39, respectively. This implies that population growth and consumption patterns are the leading social drivers, while outdated legislation and poor institutional structures are the institutional and policies change drivers which have a potential impact on LWEF nexus resource degradation. Similarly, other driving factors such as environmental, economic and technological factors also affect nexus resources to varying degrees. The findings of our study show the benefits of managing the identified driving factors for the protection of LWEF nexus resources, which have close links with human health and the environment. In order to alleviate the adverse effects of driving factors, all stakeholders need to show permanent individual and collective commitment. Furthermore, we underline the necessity of applying LWEF nexus approaches to the management of these drivers, and to optimize the environmental and social outcomes.

Modelling interaction patterns in a predator-prey system of two freshwater organisms in discrete time: an identified structural VAR approach

In ecology, the concept of predation describes interdependent patterns of having one species (called the predator) killing and consuming another (the prey). Specifying the so-called functional response of prey populations to predation is an important matter of debate which is typically addressed by means of continuous time models. Empirical regression or autoregression models applied to discrete predator-prey population data promise feasible steady state approximations of often complicated dynamic patterns of population growth and interaction. Ewing et al. (Ecol Econ 60:605–612, 2007) argue in favour of the informational content of so-called vector autoregressive models for the dynamic analysis of predator-prey systems. In this work we reconsider their analysis of dynamic interaction of two freshwater organisms, and design a structural model that allows to approximate the functional response in causal form. Results from an unrestricted structural model are in line with core axiomatic assumptions of predator-prey models. Conditional on population growth lagged up to three periods (i.e., 36 h), the semi-daily population growth of the prey Paramecium aurelia diminishes, on average, by 1.2 percentage points in response to an increase of the population growth of the predator Didinium nasutum by one percentage point.

Population Growth and Fertility Patterns in an Old Order Amish Settlement: A 21-Year Follow-Up Study

This report describes population growth and fertility patterns in the Amish settlement centered in Geauga County, Ohio, and in particular, evaluates whether its fertility behavior is that of a natural fertility population. The dates of birth and death, location of household inside or outside the Geauga Settlement, and church status of all household members for the period up to January 1, 2014, were used to estimate population size, population structure, and various measures of fertility behavior. The results based on the 2014 directory were compared with similar data from the 1993 directory (Greksa, 2002) in order to estimate population growth rates and to determine if there has been change over time in population structure and fertility patterns.The settlement consisted of 15,579 individuals distributed in 3,016 households in 107 districts as of January 1, 2014. The average annual growth rate between 1993 and 2014 was 3.0%, with a doubling time of 23.0 years. Mean completed marital fertility was 6.9 live births, ranging from 0 to 17 births. There is a consistent pattern of decreasing total fertility rates (TFR) between 1924 and 2014. In particular, bivariate linear regression indicated that TFR decreased by about 1.7 births during this period. Despite the decrease in fertility over time, which is consistent with the use of birth control measures, the decrease in fertility appears to be independent of parity, suggesting that the Amish in the Geauga Settlement are still a natural fertility population.

Localized control of opportunistic, overabundant species in protected areas: a retrospective modelling approach encompassing future scenarios

AbstractThe yellow‐legged gull (Larus michahellis) is an opportunistic seabird species, whose worldwide demographic increase in the second half of the 20th century was associated to anthropogenic activities, such as the proliferation of open‐air dumps in urban coastal areas. In the small Berlengas archipelago (Peniche, Portugal), the species breeding population reached about 44,000 individuals in 1994, representing a severe ecological pressure in this Biosphere Reserve. In an attempt to control this overpopulation, management actions were implemented in the area, namely, the culling of breeding adults and later egg destruction campaigns. Although the population has been decreasing in recent years, it is unknown how much of this reduction is due to management actions since the closure of open‐air dumps in Portugal might also have influenced the yellow‐legged gull population trends. We developed a dynamic model to test pertinent explanatory hypotheses for this problem, taking into account retrospective population trends under alternative contexts of food availability and management actions. The model was also used to predict population growth patterns under future management scenarios. Our results show that, despite contributing to reduce birds local abundance, egg destruction alone would not be able to trigger the population decrease observed in the last two decades. Instead, the permanent closure of open‐air dumps in 2001 was likely the major driver for the species local decline. In the current context of restricted anthropogenic food sources, our study also suggests that the tendency of the population is to naturally decline. Thus, continuing fertility control campaigns can compromise the future viability of the yellow‐legged gull population on the Berlengas Natural Reserve. Our study highlights the interplay between model‐based research and ecological monitoring to test the effectiveness of ongoing management programmes and to anticipate the ecological consequences of future control of native species.

The legacy of large dams in the United States

The sustainability of large dams has been questioned on several grounds. One aspect that has been less explored is that the development of dams and reservoirs often enables agricultural expansion and urban growth, which in turn increase water consumption. As such, dam development influences, while being influenced by, the spatial and temporal distribution of both supply and demand of water resources. In this paper, we explore the interplay between large dams, patterns of population growth and agricultural expansion in the United States over the past two centuries. Based on a large-scale analysis of spatial and temporal trends, we identify three distinct phases, in which different processes dominated the interplay. Then, we focus on agricultural water use in the Southwest region (Arizona, California and Nevada) and explore chicken-and-egg dynamics where water supply partly meets and partly fuels water demand. Lastly, we show that the legacy of dams in the United States consists of a lock-in condition characterized by high levels of water consumption, especially in the Southwest, which leads to severe water crises and groundwater overexploitation when droughts occur.

Climate and habitat configuration limit range expansion and patterns of dispersal in a non-native lizard.

Invasive species are one of the main causes of biodiversity loss worldwide. As introduced, populations increase in abundance and geographical range, so does the potential for negative impacts on native communities. As such, there is a need to better understand the processes driving range expansion as species become established in recipient landscapes. Through an investigation into capacity for population growth and range expansion of introduced populations of a non‐native lizard (Podarcis muralis), we aimed to demonstrate how multi‐scale factors influence spatial spread, population growth, and invasion potential in introduced species. We collated location records of P. muralis presence in England, UK through data collected from field surveys and a citizen science campaign. We used these data as input for presence‐background models to predict areas of climate suitability at a national‐scale (5 km resolution), and fine‐scale habitat suitability at the local scale (2 m resolution). We then integrated local models into an individual‐based modeling platform to simulate population dynamics and forecast range expansion for 10 populations in heterogeneous landscapes. National‐scale models indicated climate suitability has restricted the species to the southern parts of the UK, primarily by a latitudinal cline in overwintering conditions. Patterns of population growth and range expansion were related to differences in local landscape configuration and heterogeneity. Growth curves suggest populations could be in the early stages of exponential growth. However, annual rates of range expansion are predicted to be low (5–16 m). We conclude that extensive nationwide range expansion through secondary introduction is likely to be restricted by currently unsuitable climate beyond southern regions of the UK. However, exponential growth of local populations in habitats providing transport pathways is likely to increase opportunities for regional expansion. The broad habitat niche of P. muralis, coupled with configuration of habitat patches in the landscape, allows populations to increase locally with minimal dispersal.

Economic effects of shifting airport activity in the Los Angeles metro region

We estimate the economic effects of a reallocation of passenger traffic from congested Los Angeles International Airport (LAX) to Ontario International Airport (ONT). We find that the relative market shares of the two airports are a function of time and distance, relative fares, and absolute frequencies. Given increasing congestion and population growth patterns, there appears to be potential for expanded operations at Ontario, with resulting economic and environmental benefits. We define the potential market as those travelers choosing LAX despite being closer in travel time and distance to ONT, based on specific postal codes. Using estimates of the value of time, vehicle and aircraft operating costs, and emissions, we calculate the potential effects of shifting both for the average individual passenger and for 10 percent of the potential market from LAX to ONT. These estimated shifts would require only a relatively small percentage change in flight operations. We estimate the value of time and cost savings for both private and ride-sharing services at between $6 million and $11 million annually for a 10 percent shift, depending on whether parking fee differentials are included. The parking fee differentials represent just over half the estimated savings for private vehicle travelers, and to some degree may reflect locational rents rather than resource costs to the overall economy. We also estimate potential reductions in CO2 emissions of more than 4200 tons annually for a 10 percent shift, as well as meaningful reductions in hydrocarbons, CO, and NOx.

On estimating the parameters of generalized logistic model from census data: Drawback of classical approach and reliable inference using Bayesian framework

In ecology, a nonconstant functional relationship between per capita growth rate and population size is referred as density dependence and mathematical models are utilized to detect its presence in natural populations. The theta-logistic model (parameterized by rm: intrinsic growth rate; θ: shape parameter; and K: carrying capacity) has been extensively discussed through various generalizations in the literature due to its flexibility and sound ecological interpretations which can be generalized for many natural populations. In this article, we show that nonlinear least squares approach is not an appropriate choice for estimating the model using real data. Using simulation, we show that the unknown parameters are better estimated under a Bayesian framework. We utilize the Gibbs algorithm for simulating samples from the posterior density, which is approximated by grid approximation and Bayesian credible intervals are obtained. Reliability of the estimation process is shown by using simulated data sets. Rules for choosing the prior distributions are discussed. We also apply the proposed strategy to estimate parameters using real data sets from the global population dynamics database. The robustness of the method with respect to prior distribution of the parameters is investigated by taking different choice of priors. We also establish its effectiveness in estimating parameters in a predator-prey system. The discussed method is computationally intensive, but its simple implementation will be useful for fitting complex models to study growth patterns of natural populations.

Length-Weight Relationship, Condition Factor, and Age Estimation of Commercially Important Trawl Species from Mersing Coastal Waters, Johor, Malaysia

Trawl fishing contributes to majority of the total fishes’ landings, supporting the choice of using age, growth determination, and condition factors (K) as part of the monitoring method for the fishes in Malaysia waters. This research specifically examines the use of age, length-weight relationship (LWR), and K to monitor the status of the commercially important fishes in Malaysia waters. LWR, K, and age of 10 commercially important trawl species (Gerres erythrourus, Drepane punctata, Otolithes ruber, Anodontostoma chacunda, Drepane longimana, Dendrophysa russelii, Sillago parvisquamis, Cynoglossus bilineatus, Sardinella brachysoma,and Alepes kleinii) from Mersing coastal waters, Johor, Malaysia, were studied. LWR (W=aLb) indicated positive allometric growth (b > 3) for G. erythrourus and D. punctata but negative allometric growth (b < 3) for the other species. Results indicated that the species collected were in good conditions (average K, Kn > 1) in Mersing coastal waters, Johor, Malaysia. The daily growth rings of scale counts confirmed that the ages of the 10 species were typically less than 1 year (age range: 50-170 days; mean age: 95 days). The data obtained from this study will be useful for understanding the population growth pattern, age, and well-being of commercially important trawl species, which will facilitate better management techniques of these important fishery resources.

Investigating density-dependent patterns of population growth in Southern Italy, 1861–2019

Density-dependent population growth is a powerful engine of metropolitan expansion. However, spatial heterogeneity in demographic dynamics of advanced economies makes identification of density-dependent mechanisms of population growth a particularly hard task. The intrinsic linkage between long-term population increase, settlement expansion, and economic growth was investigated in Southern Italy, a peripheral European region, with use of Geographically Weighted Regressions verifying (global and local) mechanisms of density-dependent population growth in 2500 municipalities between 1861 and 2019. At the global scale, results demonstrate that population growth rates increased with population density since 1951. At the local scale, this relationship was particularly evident in the largest metropolitan regions (Naples, Bari, Palermo, Cagliari) between 1951 and 1981, becoming more intense in coastal, rural districts between 1991 and 2019. These findings delineate the predominance of density-independent mechanisms of population growth up to World War II, in a context of high fertility and accelerated emigration rates from Southern Italy. A density-dependent population growth was observed since 1951, enlarging socioeconomic disparities and consolidating the urban hierarchy centred on few large cities. Taken together, these results evidence the intrinsic nexus between demographic dynamics and agglomeration/scale factors fuelling urban expansion and state-driven industrialization in Italy.

A review paper on the growth pattern of head

Growth is defined as quantitative increase in size and mass. (Bogin,) It is measurable in numerical forms and hence easily comparable as well. It is a true indicator of health for an individual, population and community. It is also a dynamic phenomenon, so regular screening of growth pattern of child is necessary to make country healthier. Several studies have been conducted and still are being conducted to perceive growth pattern of different population at ethnic, regional and country level (WHO, 2007) as well as to perceive changes occur in a population growth pattern with time. There are many anthropometric measurements to assess human growth pattern such as head length, head breadth, head circumference, bizygometic breadth, mid upper arm circumference, hand length, height, weight etc. Measurements on head are vital from clinical, forensic and medical point of view. The objective of this study is to represent and understand the overall growth pattern or status in human head (0 to 18 years) including head circumference, head length and head breadth on the basis of previous studies in different part of the world. To identify variation that exists in the growth pattern among different population groups. The total 43 papers on the growth of head from different corners of the world were reviewed and try to use a systematic approach for comparing among several studies. Author has categorised all papers into three sections i.e. long term study, short term study and midterm study based on the nature of the method and time period utilized while conducting the study. Each parameter of the head has discussed under all three given categories. It was found that head circumference (HC) growth increment of boys and girls for aged between 0 to 18 years was varies nearly from 21cm to 24 cm. The total growth increment for head length (HL) and head breadth (HB) is ranges between 6 to 8 cm and 5 to 7cm in boys and girls (0–18 yrs) respectively. The dissimilarities in total mean increment of head circumference (HC), head length (HL) and head breadth (HB) of different population is visible for different age group. This leads us to conclude that single growth standard for entire world is not sufficient and it is desired to create separate growth standard for different population.