Life Table Research Articles

Effects of Submerged Macrophytes on Demography and Filtration Rates of Daphnia and Simocephalus (Crustacea: Cladocera).

Macrophytes and cladocerans represent the main antagonistic groups that regulate phytoplankton biomass; however, the mechanism behind this interaction is unclear. In laboratory conditions, we separately evaluated the effects of three submerged macrophytes (Ceratophyllum demersum, Myriophyllum aquaticum, and Stuckenia pectinata), as well as their exudates, and plant-associated microbiota (POM < 25 µm) + exudates on the population growth of Daphnia cf. pulex and Simocephalus cf. mixtus. Living Ceratophyllum, exudates, and POM < 25 µm + exudates exhibited the most robust positive effects on Simocephalus density and the rate of population increase (r). Subsequently, we examined the effects of Ceratophyllum on the filtration and feeding rates of Simocephalus and Daphnia, revealing significant (p < 0.001) promotion of filtration and feeding in Simocephalus but not in Daphnia. To elucidate the specific effects of this macrophyte on Simocephalus demography, we assessed selected life table variables across the same treatments. The treatments involving exudates and living Ceratophyllum resulted in approximately 40% longer survivorship and significantly (p < 0.01) enhanced fecundity. Our findings indicate that exudates from submerged macrophytes positively influence Simocephalus demography by increasing filtration rates, survivorship, and fecundity. This synergy suggests a substantial impact on phytoplankton abundance.

Survival analysis and associated factors of highgrade glioma patients

High-grade gliomas are the most common primary brain tumors in adults, and they usually have a quick fatal course. Average survival is 18 months, mainly, because of tumor resistance to Stupp protocol. To determine high-grade glioma patient survival and the effect of persuasion variables on survival. We conducted a longitudinal descriptive study in which 80 untreated recently diagnosed high-grade glioma patients participated. A survey was conducted regarding their exposure to some risk factors, degree of genetic instability in peripheral blood using micronucleus quantification on binuclear lymphocytes, micronuclei in reticulocytes and sister-chromatid exchanges in lymphocytes. In the statistical analysis, this study constructed life tables, used the Kaplan-Meier, and the log-rank test, and in the multivariate analysis, a Cox proportional hazards model was constructed. Eighty patients' clinical, demographic and lifestyle characteristics were analyzed, as well as their survival rates and the average survival time is 784 days (interquartile range: 928). Factors like age, exposure at work to polycyclic hydrocarbons and the number of sister-chromatid exchanges in lymphocytes in the first sampling was significantly survivalrelated in the multivariate analysis. We determined that only three of the analyzed variables have an important effect on survival time when it comes to high-grade glioma patients.

Survival and disease burden analyses of occupational pneumoconiosis during 1958–2021 in Huangshi city, China: a retrospective cohort study

BackgroundPneumoconiosis, a chronic disease stemming from prolonged inhalation of dust particles, stands as a significant global burden of occupational diseases. This study aims to investigate the survival outcomes of pneumoconiosis patients in Huangshi city, China, while also evaluating the disease burden on afflicted patients.MethodsData for this study were sourced from the Huangshi Center for Disease Control and Prevention. Survival analyses of pneumoconiosis patients were conducted employing life tables and the Kaplan-Meier method. The Cox proportional hazards models were deployed to identify factors influencing pneumoconiosis patients’ survival duration. Competing risks models were employed to confirm the validity of the model outcomes. Additionally, in the disease burden assessment, disability-adjusted life years (DALYs) were computed for various demographic groups and time frames.ResultsA total of 5,641 pneumoconiosis cases, diagnosed in Huangshi City, Hubei Province between 1958 and 2021, were incorporated into the cohort analysis. The probability of mortality and the risk ratio increased with advancing age. Notably, the median survival time of stage III pneumoconiosis patients was significantly shorter compared with those in stages I and II. The Cox proportional hazards model and competing risks analyses underscored several significant factors influencing survival time, including dust exposure duration (HR = 1.197, 95% CI: 1.104–1.298), age at first diagnosis (HR = 3.149, 95% CI: 2.961–3.349), presence of silicosis (HR = 1.378, 95% CI: 1.254–1.515), and stage II-III pneumoconiosis (HR = 1.456, 95% CI: 1.148–1.848). Cumulatively, DALYs amounted to 7,974.35 person-years, with an average of 1.41 person-years. The period between 2000 and 2019 witnessed the highest disease burden.ConclusionOur findings highlight the urgent need for improved prevention, earlier detection, and more effective management strategies for the occupational pneumoconiosis population. This study not only underscores the persistent issue of pneumoconiosis in industrial environments but also serves as a crucial call to action for policymakers and healthcare providers.

Global burden of mesothelioma attributable to occupational asbestos exposure in 204 countries and territories: 1990–2019

Malignant mesothelioma, a rare and aggressive cancer primarily caused by occupational asbestos exposure, has a poor prognosis. This study leverages the Global Burden of Disease (GBD) 2019 dataset to analyze the burden of mesothelioma linked to occupational asbestos exposure from 1990 to 2019. The analysis includes the number of mesothelioma deaths and disability-adjusted life years (DALYs) attributable to occupational asbestos exposure, focusing on trends in age-standardized mortality rate (ASMR) and age-standardized disability-adjusted life-year rate (ASDR) by year, age, sex, country, region, and Socio-demographic Index (SDI). In 2019, 91.7% of mesothelioma deaths and 85.2% of DALYs were attributable to occupational asbestos exposure, resulting in 26,820 (95% UI 24,312–28,622) deaths and 569,429 (95% UI 509,956–617,484) DALYs. Despite a decline in ASMR and ASDR from 1990 to 2019, the absolute number of deaths and DALYs almost doubled. The United States reported the highest number of mesothelioma deaths, while China had the highest number of DALYs. Age-specific mortality rates and DALYs decreased in the 25–74 age group but increased in the 75+ age group. In conclusion, occupational asbestos exposure remains the primary cause of mesothelioma worldwide, with an increasing number of deaths and DALYs. The highest incidence rates are observed in high-income areas, and rates are rising in low-income areas. It is crucial to raise awareness about the hazards of asbestos to reduce the global burden of mesothelioma linked to occupational exposure.

Assessing trends and burden of occupational exposure to asbestos in the United States: a comprehensive analysis from 1990 to 2019.

This study aimed to analyze the trends and burden of occupational exposure to asbestos in the United States (U.S.) from 1990 to 2019, focusing on mortality rates, geographic distribution, age and sex patterns, and causes of death. Data on the number of deaths attributable to occupational exposure to asbestos were collected from 1990 to 2019 in the U.S. Joinpoint analysis was conducted to assess trends over time, and regression models were applied to calculate annual percentage changes (APC) and annual average percentage changes (AAPC). Geographic distribution was examined using mapping techniques. Age and sex patterns were analyzed, and causes of death were identified based on available data. From 1990 to 2019, the overall number of deaths due to occupational exposure to asbestos in the U.S. increased by 20.2%. However, age-standardized mortality rates (ASMR) and age-standardized disability-adjusted life years (DALYs) rates (ASDR) exhibited a decline over the same period. Geographic analysis revealed differences in the number of deaths across states in 2019, with California reporting the highest number of fatalities. Age-specific mortality and DALYs showed an increase with age, peaking in older age groups. Tracheal, bronchus, and lung cancer were the leading causes of death attributed to asbestos exposure, with increasing trends observed over the past five years. The study highlights significant trends and burden in occupational exposure to asbestos in the U.S., including overall increases in mortality rates, declining ASMR and ASDR, geographic disparities, age and sex patterns, and shifts in causes of death. These findings underscore the importance of continued monitoring and preventive measures to mitigate the burden of asbestos-related diseases.

Estimation and probabilistic projection of age- and sex-specific mortality rates across Brazilian municipalities between 2010 and 2030.

Mortality rate estimation in small areas can be difficult due the low number of events/exposure (i.e. stochastic error). If the death records are not completed, it adds a systematic uncertainty on the mortality estimates. Previous studies in Brazil have combined demographic and statistical methods to partially overcome these issues. We estimated age- and sex-specific mortality rates for all 5,565 Brazilian municipalities in 2010 and forecasted probabilistic mortality rates and life expectancy between 2010 and 2030. We used a combination of the Tool for Projecting Age-Specific Rates Using Linear Splines (TOPALS), Bayesian Model, Spatial Smoothing Model and an ad-hoc procedure to estimate age- and sex-specific mortality rates for all Brazilian municipalities for 2010. Then we adapted the Lee-Carter model to forecast mortality rates by age and sex in all municipalities between 2010 and 2030. The adjusted sex- and age-specific mortality rates for all Brazilian municipalities in 2010 reveal a distinct regional pattern, showcasing a decrease in life expectancy in less socioeconomically developed municipalities when compared to estimates without adjustments. The forecasted mortality rates indicate varying regional improvements, leading to a convergence in life expectancy at birth among small areas in Brazil. Consequently, a reduction in the variability of age at death across Brazil's municipalities was observed, with a persistent sex differential. Mortality rates at a small-area level were successfully estimated and forecasted, with associated uncertainty estimates also generated for future life tables. Our approach could be applied across countries with data quality issues to improve public policy planning.

Trends in Melanoma Mortality in Serbia: A 22-Year Population-Based Study.

We aimed to investigating the sex-specific and age-specific melanoma mortality trends observed on the territory of Serbia between 2000 and 2021. This population-based study used data from the Statistical Office of the Republic of Serbia database during the period 2000-2021. The calculation of the gender and age-standardized rates (ASR) was performed. We used a regression analysis complete with linear trend model. The mean ASR was 1.77 per 100,000 people, meaning that male mortality rates (2.24 per 100,000) was higher than female mortality rates (1.34 per 100,000). During the observation period, a rising trend in mortality from melanoma skin cancer was reported. Observed by gender, the change of melanoma mortality trend was significant in men (P=0.021), but not in women (P=0.747). The annual growth rate of ASRs values was 1.43%. A increase in the melanoma mortality rate was observed since 2000 by 2.44% annually in males and by 2.79% annually in females. Mortality rates were increasing in both sexes as they aged, and the greatest number of deaths was recorded in the group of those aged 80 yr or above (16.25 per 100,000 for men; 10.45 per 100,000 for women). Our study findings underline the importance of launching more effective public health awareness campaigns to educate people about the dangers of melanoma and its symptoms' detection along with establishing a diagnosis at an early stage of the disease, especially among male patients and those at an advanced age.

Forecasting Inequalities in Survival to Retirement Age by Socioeconomic Status in Denmark and Sweden

In Denmark and Sweden, statutory retirement age is indexed to life expectancy to account for mortality improvements in their populations. However, mortality improvements have not been uniform across different sub-populations. Notably, in both countries, individuals of lower socioeconomic status (SES) have experienced slower mortality improvements. As a result, a uniform rise in the statutory retirement age could disproportionally affect these low-SES groups and may unintentionally lead to a reverse redistribution effect, shifting benefits from short-lived low-SES individuals to long-lived high-SES individuals. The aim of this study is twofold: to quantify and contextualise mortality inequalities by SES in Denmark and Sweden, and to assess how indexing retirement age will affect future survival to retirement age by SES in these countries. We used Danish and Swedish registry data (1988–2019), to aggregate individuals aged 50 + based on their demographic characteristics and SES. We computed period life tables by year, sex, and SES to estimate the difference in survival across different SES groups. We then forecast mortality across SES groups to assess how indexing retirement age will affect survival inequalities to retirement age, using two forecasting models—the Mode model and the Li-Lee model. Mortality inequalities are comparable in Denmark and Sweden, even though the latter generally has higher survival. We also find that indexing retirement age to life expectancy will have two main consequences: it will reduce the probability of reaching retirement for all SES groups, particularly those of low SES, and time spent in retirement will be reduced, particularly for those of high SES.

Age-Stage, Two-Sex Life Table of an Alarming Quarantine Pest Trogoderma granarium on Stored Products

Trogoderma granarium (Coleoptera: Dermestidae) is a polyphagous pest of stored products and an alarming threat to food security around the globe. The current study is designed to construct the life table of T. granarium on four stored products, i.e., wheat, barley, rice, and maize at controlled conditions (33±1°C, 65% RH, and a photoperiod of 14 : 10 (L:D) h). The incubation period of T. granarium was longer (5.13 d) on maize and shorter (4.30 d) on wheat. The developmental period of 1st, 2nd, 3rd, and 4th larval instars of T. granarium was longer on maize than the other three hosts were significant. Statistical difference between the longevity of females and males was recorded, while no statistically significant difference was found in the preoviposition period. The mean fecundity values observed on wheat, barley, rice, and maize were 31.33±1.62, 26.21±1.49, 28.00±1.35, and 25.58±1.13, respectively. The highest fertility was observed in wheat and the lowest in maize. The net reproductive rate (R0) of T. granarium ranged from 8.66±2.86, 13.16±2.65, 12.53±2.27, and 10.23±2.32 offsprings on wheat, barley, rice, and maize, respectively. The highest gross reproductive value (GRR) was for T. granarium reared on barley (18.31±4.10/d), and the lowest was for maize (15.35±2.95/d). To complete the development, T. granarium took 48.97±0.68 d on maize, significantly higher than on other treatments (p&lt;0.05). The mean generation time (T) of T. granarium was considerably affected by tested products. Based on the results of the present study, maize is a less favorable diet for the development and reproduction of T. granarium and may be considered for the management of this detrimental pest.

Gendered Parenthood-Employment Gaps from Midlife: A Demographic Perspective Across Three Different Welfare Systems

Women’s labor force participation has increased in Western countries, but gender gaps remain, especially among parents. Using a novel comparative perspective, we assess women’s and men’s employment trajectories from midlife onward by parity and education. We provide insights into the gendered parenthood-employment gaps examining the long-term implications of parenthood beyond the core childbearing ages by decomposing years lived between ages 40–74, in years of employment, joblessness, and retirement. Using multistate incidence-based life tables, we compare different cultural and institutional contexts: Finland, Italy, and the USA. Our results document large cross-national variation, with education playing a key role. In Finland, the number of years of employment increases with parity for women and men, and the gender gap is small; in the USA, the relationship between parity and years of employment is relatively flat, although a gender gap emerges among those with two or more children; in Italy, the number of years of employment decreases sharply for women as parity increases, while it increases for men. Notably, education has a similar positive impact on years of employment across all groups in Finland. In contrast, in the USA and Italy, the gender gap is only half as large among highly educated mothers as it is among low educated mothers. The employment trajectories of childless women and men differ greatly across countries.

#1778 Effects of comorbidities, social deprivation and sex on the excess mortality of French ESKD patients on dialysis

Abstract Background and Aims Inequalities in access to care may affect End-stage Kidney Disease (ESKD) patient's overall mortality, i.e. mortality directly or indirectly related to ESRD (excess mortality) as well as mortality related to other causes of death. Previous studies in France have identified sex and comorbidities, especially diabetes and cardiovascular diseases, as factors influencing the overall mortality of ESKD patients, whereas social deprivation was not associated with overall mortality. However, no study has yet examined the impact of these factors on excess mortality in dialysis patients. This study thus aims to quantify the effects of social deprivation, sex and comorbidities on the excess mortality of ESKD patients on dialysis in France. Method This retrospective observational study included adults aged 18-85 years who started dialysis in France between 2017 and 2019, and were followed up until 31 December 2022. Dialysis patients receiving a transplant were censored. Analyses were based on the excess hazard approach: the overall mortality rate was decomposed into the sum of a mortality rate associated with ESKD (the excess rate) and a mortality rate associated with other causes of death (the expected rate). The latter is usually drawn from mortality tables for the general population stratified by demographic covariates. A model is then fitted in order to estimate the excess mortality hazard: the impact of covariates on this hazard is quantified in terms of excess hazard ratios. In France, mortality tables are provided by the “Institut National de la Statistique et des Études Économiques” and stratified by age, calendar year, sex, and “départements” of residence. However, stratification by level of social deprivation or levels of the Charlson Comorbidity Index is not available, which may bias the excess mortality hazard estimates. To assess the impact of using inadequately stratified life tables on estimating excess hazard, we compared the following models using Akaike's Information Criterion: (i) an excess hazard model using the standard life tables and accounting for the hierarchical structure of the data by including a random intercept for the “département” (M0), (ii) an excess hazard model with a model-based life table correction and with (M1) or without (M2) the random intercept at the “département” level, and (iv) an excess hazard model in which the life table correction is achieved by using an individual frailty term (M3). Results 29148 dialysis patients were included in the study, 65% of whom were men. Compared to the other regression models, the excess hazard model (M2) was the best model (AIC: M0 = 58936.69; M1 = 58966.94, M2 = 58870.41, M3 = 58908.59). There were no differences in excess mortality by deprivation status {EHR (Q5 versus others) 1.054 [0.992; 1.120]; p value = 0.088}. Excess mortality was higher for women than for men {HER (women versus men) = 1.083 [1.017; 1.154]; P-value = .012}. Excess mortality was higher in patients with comorbidities than in those without, and in those who started dialysis in emergency compared with those who started on a planned basis. Elderly patients on dialysis had a higher excess hazard than younger patients. The ratio between the other cause mortality of French dialysis patients and general population was equal to 2.18[1.95; 2.45]. This means that the other cause mortality of French dialysis patients is 2.18 higher than that of the general population with the same characteristics (Table 1, Fig. 1). Conclusion Using a methodology allowing to account for the insufficient stratification of population mortality tables, we identified several factors other than sex that might be targeted by public health interventions. For example, improved referral to nephrologists could reduce the impact of emergency dialysis. The extent of these inequalities will be better understood by comparison of these results with those of ESKD patients on dialysis in European countries.

Life expectancy for dogs from the City of Buenos Aires

The aim of the present study was to develop the first life tables for the dog population of the Autonomous City of Buenos Aires by constructing life expectancy tables. Data on canines received for final disposal at the Luis Pasteur Zoonosis Institute of the Autonomous City of Buenos Aires from January 2018 to December 2021 were used to prepare the life tables. Of the 11,429 dogs that died in that period, the overall life expectancy at birth was 11.88 years (95% CI = 11.37–12.39). There was no difference in life expectancy at birth by sex or by pure versus cross breeds. According to neuter status, life expectancy at birth in neutered (13.98 years) was significantly higher than in entire (11.46 years) (p-value = 0.00001). Life tables varied according to the breed studied, with the Pekingese having the highest life expectancy at birth 16.42 years (95% CI: 15.87–16.98), and the Pit bull having the lowest life expectancy at birth 10.13 years (95% CI: 9.58–10.68). The current study provides useful information for veterinary professionals and pet owners and is a valuable tool for planning and developing effective health policies.

Effects of miR-306 Perturbation on Life Parameters in the English Grain Aphid, Sitobion avenae (Homoptera: Aphididae).

MicroRNAs (miRNA) play a vital role in insects' growth and development and have significant potential value in pest control. Previously, we identified miR-306 from small RNA libraries within the English grain aphid, Sitobion avenae, a devasting insect pest for wheat. miR-306 not only involves in wing morphogenesis, but also is critically important for aphid survival. Its specific impacts on the life history traits, however, remain unclear. Here, we evaluate the impact of miR-306 perturbation on S. avenae populations using a two-sex life table approach. This comprehensive analysis revealed that miR-306 perturbation significantly prolongs the developmental stages (9.64% and 8.20%) and adult longevity of S. avenae, while decreasing pre-adult survival rate (41.45% and 38.74%) and slightly reducing average fecundity (5.80% and 13.05%). Overall, miR-306 perturbation negatively affects the life table parameters of the aphid population. The population prediction models show a significant decline in the aphid population 60 days post interference, compared to the control groups (98.14% and 97.76%). Our findings highlight the detrimental effects of miR-306 perturbation on S. avenae population growth and suggest potential candidate genes for the development of RNAi-based biopesticides targeted specifically at this pest species.

#620 Remaining life expectancy of Korean hemodialysis patients: how much longer can they live?

Abstract Background and Aims Hemodialysis (HD) patients have a higher mortality rate compared to general population. However, no study has investigated life expectancy in Korean HD patients so far. Therefore, this study aimed to calculate the remaining life expectancy among Korean maintenance HD patients and compare it to those of general population as well as HD patients from other countries. Method Baseline data were retrieved from HD quality assessment data from October to December 2015. Among the total number of patients who were alive at the beginning of 2016 (20,537 men and 14,404 women), a total of 22,439 (12,848 men and 9,591 women) were still alive at the end of 2021 while 12,502 (7,689 men and 4,813 women) were deceased during 6 years of follow-up. We used the life table method to calculate the expected remaining years of life in two-year increments. Results The mean age of the patients was 60.5 ± 12.4 years, and 58.7% were male. The average duration of HD was 5.63 ± 5.11 years. The most common cause of end-stage kidney disease was diabetes mellitus (42.0%), followed by hypertension (27.1%) and glomerulonephritis (10.9%). The remaining life expectancy for 60-year-old patients were 11.64 years for men and 14.64 years for women. The average remaining lifetimes of the HD population were only about a half of the general population (Fig.). Diabetic patients demonstrated shorter life expectancy compared to the patients with hypertension or glomerulonephritis. The remaining life expectancy of Korean HD patients was similar to that of Japanese and was almost double that of HD patients in Western countries such as Europe and United States. Conclusion HD population showed shorter life expectancy compared to the general population. Asian HD population seemed to demonstrate better patient survival compared to other countries. Longitudinal analysis should be warranted to analyze the effect of advanced dialysis technology upon improved survival rate among HD population.

Impact of changes in malignant tumor death spectrum on life expectancy in Tianjin residents from 1999-2019

Objective: To analyze the effects of changes in the spectrum of deaths from malignant tumors on the life expectancies of residents of different ages, sexes, and regions (urban or rural) in Tianjin from 1999 to 2019. Methods: The Abridged Life Table method and the Arriaga's decomposition method were used to calculate the effects of changes in spectrum of deaths from malignant tumors on the life expectancies of Tianjin residents of different ages, sexes, and regions. Results: During 1999-2019, the life expectancies increased by 4.96 years and 5.69 years for males and females, respectively, in Tianjin. The decreases in the mortalities from malignant neoplasms contributed 0.12 year (3.30%) and 0.03 year (0.77%) for males and females, respectively, to the increase during 1999-2007, and 0.05 year (3.13%) and 0.12 year (6.08%) for males and females, respectively, during 2007-2019. The decreases in the mortality rates of malignant tumors contributed the most to the increase among residents in the 60-69 years group, and the decreases in mortality rates of lung, gastric, esophageal, and liver cancers had relatively larger contribution. Lung cancer had a negative effect on the life expectancies of men and rural residents, but a positive effect on those of women and urban residents. The significant increases in the mortality rates of lung, colorectal, and pancreatic cancers in the ≥85 years group had a large negative effect on the overall life expectancy. Breast and ovarian cancers contributed negatively to the life expectancy of female residents. Conclusion: The overall increase in the life expectancy in Tianjin from 1999 to 2019 was mainly attributed to the elderly and the decreases in the mortality rates of gastric, esophageal, and liver cancers, among other malignancies, while the increases in the mortality rates of lung, colorectal, gallbladder, pancreatic, and breast cancers were the most significant factors hindering the increase of the life expectancy in Tianjin.

Measuring population health using health expectancy estimates from morbidity and mortality databases.

The progressive incorporation of quality of life indicators in health planning meets a critical need: The evaluation of the performance of health services, which are under stress by multiple causes, but in particular by an ageing population. In general, national health plans rely on health expectancies obtained using the Sullivan method. The Sullivan health expectancy index combines age-specific mortality rates and age-specific prevalence of healthy life, obtained from health surveys. The objective of this work is to investigate an equivalent estimation, using available information from morbidity and mortality datasets. Mortality and morbidity information, corresponding to years 2016 and 2017, was obtained for the population of the county of Baix Empordà (Catalonia), N = 91,130. Anonymized individual information on diagnoses, procedures and pharmacy consumption contained in the individual clinical record (ICD and ATC codes), were classified into health states. Based on the observed health transitions and mortality, life expectancies by health state were obtained from a multistate microsimulation model. Healthy life expectancies at birth and 65 years for females and males were respectively HLE0female = 39.94, HLE0male = 42.87, HLE65female = 2.43, HLE65male = 2.17. These results differed considerably from the Sullivan equivalents, e.g., 8.25 years less for HLE65female, 9.26 less for HLE65male. Point estimates for global life expectancies at birth and 65 years of age: LE0female = 85.82, LE0male = 80.58, LE65female = 22.31, LE65male = 18.86. Health indicators can be efficiently obtained from multistate models based on mortality and morbidity information, without the use of health surveys. This alternative method could be used for monitoring populations in the context of health planning. Life Expectancy results were consistent with the standard government reports. Due to the different approximation to the concept of health (data-based versus self-perception), healthy life expectancies obtained from multistate micro simulation are consistently lower than those calculated with the standard Sullivan method.

Life Table, Host Selection Behavior and Biochemical Aspects of Fall Armyworm, Spodoptera frugiperda (J. E. Smith) Reared on Various Host Plants on Laboratory

Life Table, Host Selection Behavior and Biochemical Aspects of Fall Armyworm, Spodoptera frugiperda (J. E. Smith) Reared on Various Host Plants on Laboratory

Using Age-Stage Two-Sex Life Tables to Assess the Suitability of Three Solanaceous Host Plants for the Invasive Cotton Mealybug Phenacoccus solenopsis Tinsley.

Phenacoccus solenopsis Tinsley (Hemiptera: Coccomorpha: Pseudococcidae), the cotton mealybug, is an invasive polyphagous species that has been extending its geographic range, posing a conspicuous threat to many Mediterranean crops of economic importance. These include three species of Solanaceae, namely Solanum lycopersicum L. (tomato), Solanum tuberosum L. (potato) and Solanum melongena L. (eggplant) all of which are economically important worldwide. In this study, we used age-stage two-sex life tables to investigate the suitability of these three plant species as hosts for P. solenopsis and to calculate pest fitness, life history parameters and population projection parameters. All tested host plants that were suitable for the pest and eggplant host plant induced a higher fecundity (276.50 ± 10.78 eggs/female), net reproductive rate (R0) (243.32 ± 15.83 offspring/female) and finite rate of increase (λ) (1.18 ± 0.0043 day-1) and more extended adult longevity (males: 6.50 ± 0.34 days and females: 24.15 ± 0.50 days). Population growth predictions over a period of 90 days of infestation, commencing with an initial population of 10 eggs showed that adult population size was 674,551 on tomato, 826,717 on potato and 355,139 on eggplant. Our data on plant host preference of P. solenopsis will aid the development of appropriate management strategies and achieve successful control of this invasive pest in key Mediterranean crop systems.

Population Status of the Endangered Semi-Mangrove Dolichandrone spathacea on Hainan Island, China

In China, Dolichandrone spathacea is a rare and endangered semi-mangrove plant species with an extremely small population, naturally distributed only in Zhanjiang City and the east coast of Hainan Island. Despite conservation concerns, the population status of D. spathacea has received little scientific attention. In this study, we evaluated the current status of D. spathacea on Hainan Island, China, in order to propose sustainable conservation strategies for future ecological restoration of its natural population. D. spathacea on Hainan Island can be divided into four populations. All the D. spathacea populations present a state of overall dispersion, local concentration, and occasionally sporadic existence, and they exist in geographical isolation. The young, middle, and old D. spathacea plants account for 20.42%, 66.20%, and 13.38%, respectively, indicating that the D. spathacea population on Hainan Island is declining. Furthermore, instead of temporal structure, we used diameter at breast height (DBH) to establish a static life table, draw a population survival curve, and quantify the future development trend through population dynamic analysis and time-series prediction. These results suggest that the D. spathacea population in the Bamen Gulf (Wenchang) and Qingmei Harbor (Sanya) on Hainan Island is sensitive to external disturbances and possesses two main increases in mortality rate—namely, in its juvenile and mature stages—due to competition and anthropogenic interferences, which might be the most important reasons for its endangered status. Depending on the current conditions of the D. spathacea population, we should conserve and expand mature trees in situ, preserve their germplasm resources, rehabilitate their habitats to promote provenance restoration, and conduct artificial cultivation and spreading planting in order to realize the sustainable conservation and management of D. spathacea.

ANALISIS PREMI TAHUNAN INDIVIDU DENGAN MANFAAT YANG DIBAYARKAN PADA AKHIR TAHUN KEMATIAN

Life insurance is an insurance product that provides guarantees in the form of benefits to the insured's family if the insured dies in the future. The amount of this benefit is influenced by the amount of the annual premium paid by the insurer to the insured. The researcher will calculate the amount of the individual's annual premium on endowment insurance. The researcher will use a fixed interest rate to calculate the discount factor and the Gompertz distribution approach to calculate the insurer's chance of survival. Previously, the researcher will estimate the Gompertz distribution parameters using the Maximum Likelihood Method (MLE) based on the 2011 Indonesian Mortality Table (female). Furthermore, the researcher will calculate the insurer's chance of survival using the Gompertz distribution to obtain the actuarial present value of the initial term annuity and the actuarial present value of the endowment life insurance. In addition, the researcher will calculate the comparison of the present value of the endowment life insurance to the present value of the life annuity. The last step is that the researcher will multiply the comparison of this present value by the benefits received to calculate the amount of the individual's annual premium. The calculation results show that the comparison of the present value of dual-purpose life insurance to the present value of a living annuity is getting smaller as the policy coverage period increases. As a result, the amount of the individual's annual premium will also be smaller. This shows that the amount of the annual premium is influenced by interest rate factors, the insurer's life chances, and the length of the coverage period.