Population Dynamics Among the Totos of West Bengal: A Positive Response to Culture Contact

1983 ◽  
Vol 15 (2) ◽  
pp. 237-245 ◽  
Author(s):  
Debasish Sinha ◽  
Bikas Chandra Pal

SummaryThe population structure of the Toto tribe at Totopara, a small village in West Bengal, District Jalpaiguri, was studied, for since 1951 the Totos have been coming more and more in contact with the outside world and undergoing a process of cultural and developmental change. Demographic data presented include the age-sex structure, marital status, fertility, birth rate, death rate and population growth trends in the pre-contact and contact era. At present the population shows a trend towards increase.

Author(s):  
Xueyan Yang ◽  
Wanxin Li ◽  
Wen Jing ◽  
Chezhuo Gao ◽  
Rui Li ◽  
...  

AbstractThis article analyzes the population dynamics in northwestern China from roughly 2010 to 2020. The area’s dynamics showed a slow, stable increase in population size, a stable increase in the population of non-Han ethnic groups, which increased at a more rapidly than the Han population, and population rejuvenation coupled with a population structure that aged. The biological sex structure fluctuated within a balanced range in northwestern China. Urbanization advanced in northwestern China, throughout this period, but the area’s level of urbanization is still significantly lower than the average level of urbanization nationally.


2004 ◽  
Vol 47 (5) ◽  
pp. 713-723 ◽  
Author(s):  
Andrea Marazzo ◽  
Jean Louis Valentin

Populations of Pseudevadne tergestina were studied in Guanabara Bay, southeastern Brazil, to assess temporal variations in density and population dynamics. Data on temperature, salinity and zooplankton samples were taken from the superficial water of a fixed station, every 3 - 4 days, from February 2 through August 1, 2000. The highest abundance of this species was observed in March, when densities varied widely, from 20 to 600 ind. m-3. Population parameters were calculated, such as birth rate (from 0.25 to 0.90 ind.-1.day-1), growth rate (from -1.30 to 2.09 day-1 ) and death rate ( from -1.6 to 1.9 day-1 ) Start of population could be attributed to the increase of temperature and to the hatching of resting eggs. The population collapsed in fall-winter, as result from the combined effects of different factors: decrease of water temperature (from 27ºC to 21ºC) influencing egg development time (from 2.27 to 3.28 days); predation pressure by chaetognaths (Max. 100 ind. m-3 ) and switch of population from parthenogenic to sexual reproduction. Horizontal transport of water by tidal currents contributed partially to the reduction of population density.


2021 ◽  
Vol 46 (1) ◽  
pp. 1-11
Author(s):  
R. Widyaningrum ◽  
I. G. S. Budisatria ◽  
D. Maharani

This study aimed to estimate natural increase (NI), net replacement rate (NRR), output, and population dynamics of Aceh cattle at Livestock Breeding and Forage Center in Indrapuri, Aceh province. Data of population structure, mortality, birth rate, the number of animals entering the herd, and the number of animals released from the herd during 2019were used for determining NIandNRR, and it isusedfor estimation of output. Population structure data (2015-2019) were used to estimate the population dynamics. The results showed that NI was 19.08% (medium category). The availability of replacement stock exceeded the need for replacement (140.08% for male and 73.33% for female); the NRR was 240.08% (male) and 173.33% (female). The output of Aceh cattle was 3.92% (culled male), 5.58% (culled female); the remaining replacement stocks were 5.49% (male) and 4.09% (female) of the total population. The population of Aceh cattle from 2020 to 2024 was expected to increase by 6.02% (65 heads) on average. In conclusion, that BPTU-HPT Indrapuri can be categorized as a beef cattle producing region, but still need efforts to increase natural increase by increasing birth rate minimum 32.77% and reducing mortality maximum 3.0%, in combination with better management systems. 


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ana I. García-Cervigón ◽  
Pedro F. Quintana-Ascencio ◽  
Adrián Escudero ◽  
Merari E. Ferrer-Cervantes ◽  
Ana M. Sánchez ◽  
...  

AbstractPopulation persistence is strongly determined by climatic variability. Changes in the patterns of climatic events linked to global warming may alter population dynamics, but their effects may be strongly modulated by biotic interactions. Plant populations interact with each other in such a way that responses to climate of a single population may impact the dynamics of the whole community. In this study, we assess how climate variability affects persistence and coexistence of two dominant plant species in a semiarid shrub community on gypsum soils. We use 9 years of demographic data to parameterize demographic models and to simulate population dynamics under different climatic and ecological scenarios. We observe that populations of both coexisting species may respond to common climatic fluctuations both similarly and in idiosyncratic ways, depending on the yearly combination of climatic factors. Biotic interactions (both within and among species) modulate some of their vital rates, but their effects on population dynamics highly depend on climatic fluctuations. Our results indicate that increased levels of climatic variability may alter interspecific relationships. These alterations might potentially affect species coexistence, disrupting competitive hierarchies and ultimately leading to abrupt changes in community composition.


1960 ◽  
Vol 3 ◽  
pp. 59-73 ◽  
Author(s):  
Leo A. Orleans

Whereas throughout most of the world the results of the 1953 censusregistration of Communist China, reporting a population of 582·6 million, evoked anxiety and even alarm, the Communists expressed only pride and overwhelming confidence. As a people “liberated from the oppressive chains of capitalism,” Communist leaders felt that their horizons were unlimited and that feeding and caring for a population of this size presented no problems under a system in which people are “the most precious of all categories of capital.” The simultaneous release of vital rates which indicated a birth rate of 37 per thousand population and a death rate of 17 per thousand, further stressed the “great vitality of the people of new China.” The 2 per cent, natural increase (excess of births over deaths), resulting in an annual population growth of some 12 million, was declared, in line with Marxist doctrine, to be an asset in a country with vast new lands and unexploited natural resources, where additional people create additional wealth.


2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Yenni Arista ◽  
ZAIRION ◽  
YUSLI WARDIATNO

Abstract. Ekalaturrahmah YAC, Zairon, Wardiatno Y. 2020. Population dynamics of mantis shrimp Harpiosquilla harpax and Oratosquillina sp. in the waters south of Madura Island, Indonesia. Biodiversitas 21: 1458-1466. Mantis shrimps are a potential fishery resource in Indonesia, but information about their population dynamics in the southern waters of Madura is limited. This study aimed to determine the population structure, growth, life span, and rate of exploitation for two taxa of mantis shrimp (Harpiosquilla harpax and Oratosquillina sp.). The research was conducted from September 2018 to February 2019 in the southern waters of Madura. The results showed that for H. harpax the majority of males caught ranged in length between 132.50 and 139.37 mm while the majority of females were between 153.45 and 160.22 mm. For Oratosquillina sp., the majority of males caught ranged from 84.70 and 89.60 mm while the majority of females were between 89.85 and 95.30 mm. The Growth Coefficient (K) for H. harpax was estimated to be 0.65 per year for males and 0.60 per year for females; while for Oratosquillina sp. the estimates were 0.81 and 0.78 per year, respectively. The L∞ value for H. harpax males was 183.00 mm and for females 250.55 mm, while the L∞ values for Oratosquillina sp. were 112.64 mm for males and 137.02 for females. The life span of H. harpax was estimated at 5 years, while for Oratosquillina sp. it was 4 years. The exploitation rate (E) for H. harpax males and females was 0.65 and 0.67 respectively, while for Oratosquillina sp. it was 0.54 and 0.58. These estimations indicated overexploitation of the resource, particularly in the case of H. harpax.


2017 ◽  
Author(s):  
Antoine Frénoy ◽  
Sebastian Bonhoeffer

AbstractThe stress-induced mutagenesis paradigm postulates that in response to stress, bacteria increase their genome-wide mutation rate, in turn increasing the chances that a descendant is able to withstand the stress. This has implications for antibiotic treatment: exposure to sub-inhibitory doses of antibiotics has been reported to increase bacterial mutation rates, and thus probably the rate at which resistance mutations appear and lead to treatment failure.Measuring mutation rates under stress, however, is problematic, because existing methods assume there is no death. Yet sub-inhibitory stress levels may induce a substantial death rate. Death events need to be compensated by extra replication to reach a given population size, thus giving more opportunities to acquire mutations. We show that ignoring death leads to a systematic overestimation of mutation rates under stress.We developed a system using plasmid segregation to measure death and growth rates simultaneously in bacterial populations. We use it to replicate classical experiments reporting antibiotic-induced mutagenesis. We found that a substantial death rate occurs at the tested sub-inhibitory concentrations, and taking this death into account lowers and sometimes removes the signal for stress-induced mutagenesis. Moreover even when antibiotics increase mutation rate, sub-inhibitory treatments do not increase genetic diversity and evolvability, again because of effects of the antibiotics on population dynamics.Beside showing that population dynamic is a crucial but neglected parameter affecting evolvability, we provide better experimental and computational tools to study evolvability under stress, leading to a re-assessment of the magnitude and significance of the stress-induced mutagenesis paradigm.


2016 ◽  
Vol 50 ◽  
pp. 97-126
Author(s):  
Alfred Wong

Latvia has been suffering a substantial decrease in population since the early 1990s. There appears to have been little or no detailed analysis of the genesis of this decline in population. The major political event occurring at the beginning of the population decline was the rapid transitioning from socialism to capitalism. This study has revealed the causes of severe population decline to be a combination of steadily-declining birth rate, sharply rising high death rate, and mass emigration of people to wealthier European states. The cross-over of birth rate and death rate could be attributed to the tumultuous societal upheavals in the changeover from the socialistic protective-welfare system to a free-market capitalistic economic system. In particular, this traumatic event had probably affected the physical and mental health of many people to result in premature deaths from, among other things, consequential morbidity, accidents, homicides and suicides. Practicable remedies to arrest the continuing trend of precipitous decline in the population might include a) repairing the failures of the current modality of national health care, b) creating higher paying jobs in Latvia to entice prospective young emigrants to stay in Latvia, and c) repatriating of recent Latvian émigrés.


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