scholarly journals Age and growth of Palaeoloxodon huaihoensis from Penghu Channel, Taiwan: significance of their age distribution based on fossils

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11236
Author(s):  
Jia-Cih Kang ◽  
Chien-Hsiang Lin ◽  
Chun-Hsiang Chang
Keyword(s):  
Age Distribution ◽  
Age Groups ◽  
Age Determination ◽  
Dental Material ◽  
Age And Growth ◽  
Ice Age ◽  
Older Individuals ◽  
African Forest Elephant ◽  
Tooth Width ◽  
Size And Morphology

Dental material attributed to Palaeoloxodon huaihoensis from the Middle to Late Pleistocene were recovered over decades from the Penghu Channel during commercial fisheries activities. The National Museum of Nature Science (NMNS) has a collection of such dental material, which differs in size and morphology and likely represents ontogenetic variation and growth trajectory of various age groups of P. huaihoensis. However, little is known regarding age determination. By using length of dental material, enamel thickness (ET), and plate counts, we established the method to distinguish the age of the species, which is directly derived from the extant African forest elephant Loxodonta africana. When measuring signs of allometric growth, we found that in both the upper and lower jaws, tooth width was correlated negatively with lamellar frequency but positively with ET. In the same age group, the number of lamellae was higher in P. huaihoensis than in L. africana. The reconstructed age distribution indicated no difference in the upper or lower jaw. Notably, within our sample, P. huaihoensis is skewed towards adult and older individuals with median age between 33–34.5 years and differed significantly from that of Mammuthus primigenius in the European Kraków Spadzista site. This age distribution pattern is speculated to be related to the harsh environmental conditions and intense intraspecific competition among P. huaihoensis during the last ice age.

Age and growth pattern of the thin-lipped mullet Liza Ramada in the Eastern coast of Libya.

2016 ◽  
Vol 5 (06) ◽  
pp. 4620
Author(s):  
Manal M. Khalifa ◽  
Ramadan A. S. Ali ◽  
Abdalla N. Elawad* ◽  
Mohammad El. ElMor
Keyword(s):  
Frequency Distribution ◽  
Age Groups ◽  
Age Determination ◽  
Age And Growth ◽  
Eastern Coast ◽  
Growth Equation ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
Scale Reading ◽  
Von Bertalanffy Growth Equation

Age and growth characteristics of the thin-lipped Grey Mullet (Liza ramada) were investigated in Eastern coast of Libya. Aging was done by two methods: counting annuli on scales and by length frequency distribution, a total of 218 scales were studied for age determination, in addition of 334 fishes specimen for length frequency distribution reading. Four age groups were determined from scale reading, and five age groups from length frequency distribution methods, the parameters of the Von Bertalanffy growth equation for both sex of all individuals were estimated at 35.4 cm, 0.187 per year, -1.14 years and 2.4, for male were estimated at 35.7 cm, 0.17 per year, -1.367 and 2.3, for female were 38.6 cm, 0.156 per year, -1.383 and 2.4, for L∞, k and t0, and φ′, respectively.

scholarly journals Age determination and growth of leaping mullet, (Liza saliens R.1810) from the Messolonghi Etoliko lagoon (western Greece)

2002 ◽  
Vol 3 (2) ◽  
pp. 147 ◽  
Author(s):  
G. KATSELIS ◽  
C. KOUTSIKOPOULOS ◽  
P. KASPIRIS
Keyword(s):  
Age Groups ◽  
Age Determination ◽  
Age And Growth ◽  
Central Mediterranean ◽  
Lagoon System ◽  
Liza Saliens ◽  
Large Spread ◽  
Annulus Formation ◽  
Marginal Increment ◽  
Detailed Work

This study is the first detailed work on the age and growth of the leaping mullet (Liza saliens, Risso 1810) in the central Mediterranean. During the period 1991-1995 the age and growth of leaping mullet from the Messolonghi -Etoliko lagoon system (western Greek coast) were studied. Age and growth determinations were based upon otolith samples taken from 537 fish. Marginal increment analysis was used to validate age determination. Annulus formation took place around November each year. The back-calculated lengths at age estimated from the otoliths showed no differences between sub-areas of the lagoon system and the recorded limited between-years variability showed no persistent temporal pattern. The maximum age of leaping mullet in the Messolonghi - Etoliko lagoon was 5 years for males and 6 years for females. The von Bertalanffy equation (L‡=32.99±1.25 cm, k=0.258 ±0.017 year-1, t0=-0.47±0.04 year) accurately describes the growth of the total length of leaping grey mullet for all life stages (fry, juveniles and adults). A large spread and length overlap characterized the age groups. The estimated Length-Weight relationships were common for the two sexes (W=0.0079L3.01).

scholarly journals Older age groups and country-specific case fatality rates of COVID-19 in Europe, USA and Canada

Infection ◽  
2020 ◽  
Author(s):  
Christian Hoffmann ◽  
Eva Wolf
Keyword(s):  
National Health ◽  
Demographic Data ◽  
Age Distribution ◽  
Age Groups ◽  
Case Fatality ◽  
Older Age ◽  
European Countries ◽  
Older Individuals ◽  
Health Authorities ◽  
Country Specific

Abstract Purpose To evaluate the association between the percentages of older age groups among confirmed SARS-CoV-2 infections and the country-specific case fatality rate (CFR). Methods This ecological study analyzed data from the 20 most severely affected European countries, USA and Canada, in which national health authorities provided data on age distribution and gender among confirmed SARS-CoV-2 cases and deaths. Results The proportion of individuals older than 70 years among confirmed SARS-CoV-2 cases differed markedly between the countries, ranging from 4.9 to 40.4%. There was a strong linear association between the proportion of individuals older than 75 years and the country-specific CFRs (R2 = 0.803 for all countries, R2 = 0.961 after exclusion of three countries with incongruent data). Each 5% point increase of this older age group among confirmed SARS-CoV-2 cases was associated with an increase in CFR of 2.5% points (95% CI 1.9–3.1). Conclusion Data from 20 European countries and the USA and Canada showed that the variance of crude CFR of COVID-19 is predominantly (80–96%) determined by the proportion of older individuals who are diagnosed with SARS-CoV-2. The age distribution of SARS-CoV-2 infections is still far from being homogeneous. Detailed demographic data have to be taken into account in all the analyses on COVID-19-associated mortality. We urgently call for standardized data collection by national health authorities.

Internal Zonations in Sections of Vertebrae from Atlantic Bluefin Tuna, Thunnus thynnus, and Their Potential Use in Age Determination

1985 ◽  
Vol 42 (5) ◽  
pp. 938-946 ◽  
Author(s):  
Eric D. Prince ◽  
Dennis W. Lee ◽  
Joaquin C. Javech
Keyword(s):  
Age Groups ◽  
Age Determination ◽  
Fork Length ◽  
Bluefin Tuna ◽  
Age And Growth ◽  
Thunnus Thynnus ◽  
Thin Sections ◽  
Section Method ◽  
Atlantic Bluefin Tuna ◽  
Cone Surface

Internal zonations (bands) were observed in thin sections of vertebrae from 98% of the 200 Atlantic bluefin tuna, Thunnus thynnus, we examined between 49.5 and 284.5 cm fork length (FL). These zones occurred in the solid bone area of the sections corresponding to the outer margin of the vertebral cone surface. The remaining area of the section nearest the focus is characterized by spongy bone which obstructs internal zonations associated with early growth history. We present a modified method of determining vertebra age of Atlantic bluefin tuna by adopting a counting procedure which involves enumerating distal internal bands in the sections, as well as proximal external bands on the cone surface to assign ages. Accuracy of this methodology was assessed by evaluating fish where age was known from length frequency and tagging data. The accuracy and precision of estimating age of giant bluefin tuna [Formula: see text] was improved using our vertebral section method of age determination compared with the more traditional whole vertebra method of ageing. However, results of the vertebral section method in ageing medium tuna (146.0–208.9 cm FL) were inconclusive and this method overestimated age of school tuna (49.5–145.9 cm FL) and should not be used for juvenile age groups. The occurrence of internal zonations in vertebrae of teleosts other than bluefin tuna should be examined as a possible source of age and growth information.

scholarly journals Updated Incidence of Thyroid Cancer in the North East Region of Romania after 35 Years of Chernobyl Fallout. Is There a Link between?

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 907
Author(s):  
Laura Teodoriu ◽  
Maria Christina Ungureanu ◽  
Letitia Leustean ◽  
Cristina Preda ◽  
Delia Ciobanu ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Age Distribution ◽  
Age Groups ◽  
Chernobyl Fallout ◽  
Statistical Correlations ◽  
North East ◽  
The North ◽  
East Region ◽  
Radioactive Cloud ◽  
The Moment

Thyroid cancer (TC) represents a worldwide problem, the consistent growth of the incidence increment issues about management of risk factors and curative treatment. Updated statistical data are not complete in the North East region of Romania and need to be improved. Therefore, through this study, we aim to renew the existing data on thyroid cancer. We conducted a retrospective study covering a period of 10 years. Data were collected from a hospital information system (InfoWorld) between 2009 and 2019. Patients’ age groups were stratified in relation with the age at the moment of the Chernobyl event. A database was obtained (Microsoft Excel) and statistical correlations were applied. In the studied period, 1159 patients were diagnosed: 968 females and 191 males, distributed by region, with the highest addressability in Iasi (529), followed by neighboring counties. Age distribution displayed that most of the thyroid cancers were in the range 4060 years old (50.94%), followed by 60–80 years old (32.41%). Most patients were diagnosed with papillary carcinoma 63.10%, then follicular 14.7%, medullary 6.74% and undifferentiated 1.02%. Romania was in the vicinity of the radioactive cloud at Chernobyl fallout, so we must deliberate whether the increased incidence of thyroid cancer in the age group 40–60 years is associated with radiogenicity (iodine 131) given the fact that over has 35 years and the half-life of other radioisotopes like Caesium-137 and Strontium -90 is completed.

scholarly journals Parasitic fauna of Eurasian beavers (Castor fiber) in Sweden (1997–1998)

2021 ◽  
Vol 63 (1) ◽  
Author(s):  
Per-Arne Åhlen ◽  
Göran Sjöberg ◽  
Margareta Stéen
Keyword(s):  
Age Groups ◽  
Ecological Factors ◽  
Parasite Fauna ◽  
Castor Fiber ◽  
Older Individuals ◽  
Parasitic Fauna ◽  
Eurasian Beaver ◽  
Norwegian Population ◽  
Stichorchis Subtriquetrus ◽  
One Year

Abstract Background The parasitic fauna of beavers (Castor fiber and C. canadensis) has been well studied in many parts of their respective areas of distribution. In Scandinavia there have, however, been limited investigations conducted on the parasites of beavers in recent times. The present study is the first quantitative survey of parasites on beavers living in Sweden and elsewhere in Scandinavia. We investigated the parasitic fauna of the Eurasian beaver (C. fiber) in a North–South gradient in Sweden. The aim of the study was to investigate parasite distribution and prevalence in particular, related to average yearly air temperature and different age groups of beavers. A total of 30 beavers were sampled at eight localities, spanning a 720 km North–South gradient during the springs of 1997 and 1998. Results Five parasite taxa were identified. Four of these were present in all of the examined beavers, Stichorchis subtriquetrus (trematode), Travassosius rufus (nematode), Platypsyllus castoris (coleopteran), and Schizocarpus spp. (arachnid). A higher number of new infections of S. subtriquetrus, and more adults of T. rufus, were seen in beavers in southern Sweden where temperatures are higher. One-year old beavers had a higher infestation of S. subtriquetrus, but not of T. rufus, than older individuals. Conclusions The parasite fauna of Swedish beavers mirrored the impoverished parasite fauna of the original Norwegian population, and the high prevalence of parasites could be due to low major histocompatibility complex (MHC) polymorphism. Young beavers had a higher load of trematodes, probably depending on behavioural and ecological factors. Warmer temperatures in southern localities likely contributed to increased endoparasite loads.

scholarly journals Estimating effective infection fatality rates during the course of the COVID-19 pandemic in Germany

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Christian Staerk ◽  
Tobias Wistuba ◽  
Andreas Mayr
Keyword(s):  
Age Distribution ◽  
Age Groups ◽  
Case Fatality ◽  
Time Dependent ◽  
Temporary Increase ◽  
International Studies ◽  
Age Group ◽  
Fatality Rate ◽  
Substantial Fraction ◽  
Second Wave

Abstract Background The infection fatality rate (IFR) of the Coronavirus Disease 2019 (COVID-19) is one of the most discussed figures in the context of this pandemic. In contrast to the case fatality rate (CFR), the IFR depends on the total number of infected individuals – not just on the number of confirmed cases. In order to estimate the IFR, several seroprevalence studies have been or are currently conducted. Methods Using German COVID-19 surveillance data and age-group specific IFR estimates from multiple international studies, this work investigates time-dependent variations in effective IFR over the course of the pandemic. Three different methods for estimating (effective) IFRs are presented: (a) population-averaged IFRs based on the assumption that the infection risk is independent of age and time, (b) effective IFRs based on the assumption that the age distribution of confirmed cases approximately reflects the age distribution of infected individuals, and (c) effective IFRs accounting for age- and time-dependent dark figures of infections. Results Effective IFRs in Germany are estimated to vary over time, as the age distributions of confirmed cases and estimated infections are changing during the course of the pandemic. In particular during the first and second waves of infections in spring and autumn/winter 2020, there has been a pronounced shift in the age distribution of confirmed cases towards older age groups, resulting in larger effective IFR estimates. The temporary increase in effective IFR during the first wave is estimated to be smaller but still remains when adjusting for age- and time-dependent dark figures. A comparison of effective IFRs with observed CFRs indicates that a substantial fraction of the time-dependent variability in observed mortality can be explained by changes in the age distribution of infections. Furthermore, a vanishing gap between effective IFRs and observed CFRs is apparent after the first infection wave, while an increasing gap can be observed during the second wave. Conclusions The development of estimated effective IFR and observed CFR reflects the changing age distribution of infections over the course of the COVID-19 pandemic in Germany. Further research is warranted to obtain timely age-stratified IFR estimates, particularly in light of new variants of the virus.

Social Well-Being of the Population of Russia During the Pandemic (Based on Sample Survey Data)

2021 ◽  
Vol 28 (4) ◽  
pp. 67-79
Author(s):  
L. A. Davletshina ◽  
N. A. Sadovnikova ◽  
A. V. Bezrukov ◽  
O. G. Lebedinskaya
Keyword(s):  
Health Status ◽  
Population Health ◽  
Age Distribution ◽  
Age Groups ◽  
Rank Correlation ◽  
Well Being ◽  
Russian Population ◽  
Sample Survey ◽  
The Social ◽  
The Relationship

The article present results of the authors’ study of the social well-being of the Russian population – an assessment of the population’s health and attitudes towards a healthy lifestyle amid viral pandemic, based on materials of the Rosstat sample surveys of 2019 and 2020 and data from the All-Russian survey conducted by the Russian Public Opinion Research Center (VCIOM) on 27 September 2020. The authors described the transformation of living conditions in the light of the complex epidemiological situation and the increase in coronavirus cases among the population. Changes in the health status of the Russian population were analyzed by individual age groups.The article assesses the strength of the relationship between the social well-being of the population by selected socio-demographic groups and the period of self-isolation, quarantine, or other restrictions imposed during the coronavirus pandemic in 2020. To solve this problem, demographic and socio-economic characteristics of respondents are presented, the distribution of responses according to the survey results is estimated, and the most signifcant factor characteristics are selected. Respondent replies were grouped according to the selected questions, including in the territorial context (by federal districts). To determine the strength of the relationship between the respondents' answers to the question and their gender or age distribution, the coefcients of mutual conjugacy and rank correlation coefcients were calculated and analyzed.Analysis of the changes in the social well-being of population for 2019–2020 and the assessment of the strength of the relationship between the discussed indicators (gender, wealth, territory of residence) revealed the parameters that form the differences. After comparing the health status of the Russian population as a whole and by age groups in 2019 and 2020 based on data of sample survey on population health status, the following points were identifed. With the expected assessment of the population health status in the age distribution (deterioration in the older ages and better health in the younger ones), it also remains unchanged that more than half of the respondents characterize their health status as «very good» and «good». Noteworthy is the fact that the assessment of the health status of the Russian population has improved during the year. It is evidenced from changes in the structure of respondent replies, even though population health status survey of 2020 was conducted in the middle of lockdown amid the continuing negative trends in coronavirus morbidity and mortality.

Rubidium and Strontium age determination of some Pre-Cambrian granitic rocks, S.E. Uganda

1971 ◽  
Vol 108 (5) ◽  
pp. 353-360 ◽  
Author(s):  
R. A. Old ◽  
D. C. Rex
Keyword(s):  
Age Groups ◽  
Age Determination ◽  
Granitic Rocks ◽  
Age Limit ◽  
Age Determinations

SummaryWhole rock rubidium-strontium age determinations on granitic bodies in S.E. Uganda give ages of 2930 m.y. for the Masaba Granite and 2430 m.y. for the Buteba Granite and granitic gneisses. The former age is considered to represent the upper age limit of the post-Nyanzian orogeny, and 2430 m.y. the upper age limit of the post-Kavirondian orogeny. A second isochron age of 2100 m.y. for the Masaba Granite may reflect a second intrusion, or remobilization of part of the original granite associated with the Buganda–Toro orogeny. Tentative correlations are suggested between these age groups and others within the Tanzanian Shield and beyond.

Validity of using translucent zones of otoliths to age the pilchard Sardinops sagax neopilchardus from Albany, Western Australia

1996 ◽  
Vol 47 (4) ◽  
pp. 617 ◽  
Author(s):  
WJ Fletcher ◽  
SJ Blight
Keyword(s):  
Western Australia ◽  
Age Groups ◽  
Growth Curves ◽  
Relative Number ◽  
Older Individuals ◽  
Commercial Catch ◽  
Monthly Basis ◽  
Lower Accuracy ◽  
Sardinops Sagax ◽  
Catch Rates

Otoliths (sagittae) of the pilchard (Sardinops sagax neopilchardus) from the Albany region of Western Australia were examined on a monthly basis during 1989 to 1991. When read consecutively, with the month of capture known, a clear annual cycle of an increase in marginal increments to October followed by a decline was recorded. This pattern was, however, severely distorted when samples were re-examined after having been jumbled and the month of capture concealed. Younger age groups (≤3) showed evidence of multiple rings being formed annually, but not in all years or individuals, and this was not evident in older individuals (≥4). Agreement between readings was low (43-53%), especially between different readers. Resultant growth curves showed that males grow to a smaller size (L∞ =164, K = 0.805, Φ = 1.03) than females (L∞ = 174, K = 0.584, Φ= 0.95). Agreement between counts of annuli and ages estimated by using otolith weight and length was only 54% for all individuals, but increased to 76% for individuals assigned the same age by different readers. Given the poorer predictions of future catch rates from the relative number of 2-year-olds in the commercial catch using annuli (implying lower accuracy) and increased complexity in preparation, otolith weights will be the method adopted for future ageing.

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