In a Stationary Population, the Average Lifespan of the Living Is a Length-Biased Life Expectancy

What is the average lifespan in a stationary population viewed at a single moment in time? Even though periods and cohorts are identical in a stationary population, we show that the answer to this question is not life expectancy but a length-biased version of life expectancy. That is, the distribution of lifespans of the people alive at a single moment is a self-weighted distribution of cohort lifespans, such that longer lifespans have proportionally greater representation. One implication is that if death rates are unchanging, the average lifespan of the current population always exceeds period life expectancy. This result connects stationary population lifespan measures to a well-developed body of statistical results; provides new intuition for established demographic results; generates new insights into the relationship between periods, cohorts, and prevalent cohorts; and offers a framework for thinking about mortality selection more broadly than the concept of demographic frailty.

Seasonal Predictability of Wintertime mid-latitude Cyclonic Activity over the North Atlantic and Europe

<p>We analyse the connections between the wintertime North Atlantic Oscillation (NAO), the eddy-driven jet stream with the mid-latitude cyclonic activity over the North Atlantic and Europe. We investigate, through the comparison against ECMWF ERA5 and hindcast simulations from the Max Planck Institute Earth System Model (MPI-ESM), the potential for enhancement of the seasonal prediction skill of the Eddy Kinetic Energy (EKE) by accounting for the connections between large-scale climate and the regional cyclonic activity. Our analysis focuses on the wintertime months (December-March) in the 1979-2019 period, with seasonal predictions initialized every November 1st. We calculate EKE from wind speeds at 250 hPa, which we use as a proxy for cyclonic activity. The zonal and meridional wind speeds are bandpass filtered with a cut-off at 3-10 days to fit with the average lifespan of mid-latitude cyclones. </p><p>Preliminary results suggest that in ERA5, major positive anomalies in EKE, both in quantity and duration, are correlated with a northern position of the jet stream and a positive phase of the NAO. Apparently, a deepened Icelandic low-pressure system offers favourable conditions for mid-latitude cyclones in terms of growth and average lifespan. In contrast, negative anomalies in EKE over the North Atlantic and Central Europe are associated with a more equatorward jet stream, these are also linked to a negative phase of the NAO.  Thus, in ERA5, the eddy-driven jet stream and the NAO play a significant role in the spatial and temporal distribution of wintertime mid-latitude cyclonic activity over the North Atlantic and Europe. We extend this connection to the MPI-ESM hindcast simulations and present an analysis of their predictive skill of EKE for wintertime months.</p>

Comparative mycorrhizal fungal production and respiration of a neotropical rainforest versus a California mixed forest

<p>Mycorrhizae are a symbiosis between fungi and plants. We have learned about the complexity of mechanisms of interaction and interactions between the mycorrhizae and the local environment from over a century of laboratory observations experiments. Point observations and laboratory studies identify processes, but cannot delineate activity. Our goal is to use an in situ system to study mycorrhizal roots and fungi during hot moments, daily shifts, and seasonal change.</p><p>We integrated continuous in situ observation-sensor measurements using our Soil Ecosystem Observatories. As turnover rate estimates are related to sample frequency, individual scans using manual minirhizotrons (Bartz and Rhizosystems) and Rhizosystems Automated Minirhizotrons (32,000-3.01mm x 2.26mm 307,200 pixel images). Automated scans were collected up to 4x daily. Manual scans across multiple tubes in campaigns provided spatial variation. Images were organized into mosaics using RootView software, and roots and hyphae identified and length, width and biovolume determined using RootDetector <http://www.rhizosystems.com/>. Individual roots and hyphae were tracked using RootFly <https://cecas.clemson.edu/~stb/rootfly/>. Lifespans were determined using Mark-Recapture modeling and turnover calculated. With each minirhizotron tube, sensors were placed at 3 or 4 depths for temperature, moisture, CO<sub>2</sub> and O<sub>2</sub> at 5minute intervals.</p><p>Mycorrhizal fungi (MF) explore soil for nutrients and requiring C. Most C to the hyphae is respired (with a <sup>14</sup>C signal of autotrophic respiration), with the remaining divided into decomposing (heterotrophic respiration) and sequestered C pools.</p><p>Our first site is a mature neotropical rainforest, the La Selva Biological Station, Costa Rica. Trees predominantly form arbuscular mycorrhizae (AM). AMF fungi comprise 50% of total fungal mass (PLFA). Aboveground NPP-C was 750g/m<sup>2</sup>. Root standing crop C was 120g/m<sup>2</sup>, average lifespan 60days, =6 generations/y, = root NPP of 720g/m<sup>2</sup>/y. The AMF hyphal standing crop C was 12.5g/m<sup>2</sup>, average lifespan of 25 days, =14.7 generations/y, = AMF NPP of 183g/m<sup>2</sup>/y. With an NPP of 1,650g/m<sup>2</sup>/y, then AMF comprises 11% of NPP.</p><p>Soil respiration provides CO<sub>2</sub>, converting in water to HCO<sub>3</sub><sup>-</sup>, altering soil pH (Henry's Law). AMF respiration thereby increases P availability. If 10% of the AM fungal hyphae are live, then the hyphal respiration is 438g/m<sup>2</sup>/y of C, =38% of total soil respiration and 16% of site respiration.</p><p>Our second site is a mature California mixed forest, USA. Ectomycorrhizal (EM) trees predominate. Annual NPP-C was 200g/m<sup>2</sup>, and root NPP was 200g/m<sup>2</sup>. EMF NPP was 162.6g/m<sup>2</sup>, or 27% of the NPP. N, water, and temperature limit NPP. The seasonal signal was very high in this ecosystem. Peak standing crop of extramatrical EM hyphae was 19gC/m<sup>2</sup> in April. Total soil respiration in April was 0.26g/h, and extramatrical hyphae 0.029g/h, or 11% of the total soil respiration. Since P is less limiting, but N and water are, hyphae likely play a greater role in enzymatic activity and exploratory surface area.</p><p>In summary, different mycorrhizal fungi play different roles depending on ecosystem limiting factors. With global change, our challenge is to determine how an ecosystem will change and the extent and rapidity of mycorrhizal fungal change.</p>

Average Lifespan Shortened due to Stroke in Canada

Background and Purpose: There are challenges in comparability when using existing life lost measures to examine long-term trends in premature mortality. To address this important issue, we have developed a novel measure termed average lifespan shortened (ALSS). In the present study, we used the ALSS measure to describe temporal changes in premature mortality due to stroke in the Canadian population from 1990 to 2015. Methods: Mortality data for stroke were obtained from the World Health Organization mortality database. Years of life lost was calculated using Canadian life tables. ALSS was calculated as the ratio of years of life lost in relation to the expected lifespan. Results: Over a 25-year timeframe, the age-standardized rates adjusted to the World Standard Population for deaths from all strokes and stroke types substantially decreased in both sexes. The ALSS measure indicated that men who died of stroke lost 12.1% of their lifespan in 1990 and 11.4% in 2015, whereas these values among women were 11.1% and 10.0%, respectively. Patients with subarachnoid hemorrhagic stroke lost the largest portion whereby both sexes lost about one-third of their lifespan in 1990 and one-fourth in 2015. Men with intracerebral hemorrhagic stroke lost around 18% of their lifespan in 1990 and 14% in 2015 as compared to women who lost about 16% and 12% over the same timeframe. The loss of lifespan for patients with ischemic stroke and other stroke types combined was relatively stable at about 10% throughout the study period. Conclusions: Our study demonstrated a modest improvement in lifespan among patients with stroke in Canada between 1990 and 2015. Our novel ALSS measure provides intuitive interpretation of temporal changes in lifespan among patients with stroke and helps to enhance our understanding of the burden of strokes in the Canadian population.

Analysis of the experience of renovating industrial enterprises into hotels in China

The adaptive reuse of abandoned industrial buildings is a very hot topic in the post-industrial modern society. The re-equipment of these buildings and territories can be carried out in different directions for different functions: exhibition complexes, public centers, museums, trade enterprises. This study focuses on the renovation of such industrial buildings into hotels in China. The experience of reconstruction and related literature has been studied. The study found that since most of the post-industrial buildings in China are small in size, they are suitable for repurposing as boutique hotels. Large industrial buildings and complexes in mega cities in China can be converted into luxury hotels. Renovation of old industrial buildings into hotels makes it possible to double the average lifespan of buildings approximately up to 60-65 years.

Sustainability and Functionality of Railway Network and its Connecting Facilities in Kosovo

The railway network presents a special communication function, which keeps humanity closer. The first developments of the railway network in Kosovo date back to 1874 when the first train entered this area from Thessaloniki through Skopje. This paper aims to provide some data generated during the year 2020 regarding the railway network in Kosovo and its connecting facilities. Construction of railway lines, stations, tunnels, bridges, watersheds, protective walls, canals for surface water drainage has an average lifespan of 92 years. The total length of the railway network is 336.68 km, in which are built 23 tunnels with a total length of 9789.5 m. 26.1% of them are of medium depth, while 73.9% are of shallow depth from the ground surface. 66.07% of the railway lines are active, while 33.42% are non-functional. Doi: 10.28991/HEF-2020-01-03-02 Full Text: PDF

Average Life Expectancy, the Most Common Cause of Death and Illness of Giant Dog Breeds

The aim of this study was to analyze the most common diseases and genetic defects that occur during the lifetime of giant dog breeds, to determine the average lifespan and the cause of death/euthanasia. Data were obtained through a survey and concerned the health of 241 individuals of giant dog breeds held in the Czech Republic. Evaluated items involved an average lifespan, an average lifespan per gender, cause of death, reasons for euthanasia, cause of mortality (especially in selected Mastiff type breeds), life expectancy per breed and incidence of diseases among giant breeds during the lifetime. The average lifespan in giant breed dogs was found to be 7.60 years. A significant difference (P ˂ 0.05) was found between life expectancies in males and females, with female dogs reaching 1.42 year higher age (8.10 years) than males (6.68 years). The most common cause of spontaneous death among giant breeds was gastric dilatation and torsion (28% of dogs) and for euthanasia osteosarcoma (38% of dogs). The cause of mortality especially in selected Mastiff type breeds of dogs was gastric dilatation and torsion (30% of dogs). This is the first broad analytical study concerning this topic published in the Czech Republic.

Congenital Absence of Skin on the Right Leg and Nail Abnormalities-Epidermolysis Bullosa or Bart’s Syndrom ?

Children born with the epidermolysis bullosa (so-called “butterfly children”) can eat only liquid or soft food due to the blisters on their mouth, tongue and esophagus. Due to their inactivity and permanent wounds, their fingers are curved and grown with a fist. Their eyes, anus and genitals are not spared either. The digestion is usually poor, so they often suffer from the constipation, and sometimes the intestine discharge can be performed only surgically. Due to frequent and numerous wounds, infections may develop, which can lead to sepsis. Wounds are caused by any kind of the pressure and re-bandaging of wounds is the most painful. These children can later be susceptible to other diseases, especially the skin cancer. More than 80% of children diagnosed with this disease become disabled in the first years of their lives, and some of them pass away immediately after birth. The average lifespan of the diseased is about 28 years. Here we have presented a rare case of a newborn male infant with a dystrophic epidermolysis bullousa, a congenital skin aplasia on the right leg and a nail dystrophy. Based on a typical clinical presentation, we think that it is Bart’s syndrome.

Estimating network changes from lifespan measurements using a parsimonious gene network model of cellular aging

Background Cellular aging is best studied in the budding yeast Saccharomyces cerevisiae. As an example of a pleiotropic trait, yeast lifespan is influenced by hundreds of interconnected genes. However, no quantitative methods are currently available to infer system-level changes in gene networks during cellular aging. Results We propose a parsimonious mathematical model of cellular aging based on stochastic gene interaction networks. This network model is made of only non-aging components: the strength of gene interactions declines with a constant mortality rate. Death of a cell occurs in the model when an essential node loses all of its interactions with other nodes, and is equivalent to the deletion of an essential gene. Stochasticity of gene interactions is modeled using a binomial distribution. We show that the exponential increase of mortality rate over time can emerge from this gene network model during the early stages of aging.We developed a maximal likelihood approach to estimate three lifespan-influencing network parameters from experimental lifespans: t0, the initial virtual age of the network system; n, the average lifespan-influencing interactions per essential node; and R, the initial mortality rate. We applied this model to yeast mutants with known effects on replicative lifespans. We found that deletion of SIR2, FOB1, and HXK2 considerably altered the initial virtual age but not the average lifespan-influencing interactions per essential node, suggesting that these mutations mainly influence the reliability of gene interactions but not the overall configurations of gene networks.We applied this model to investigate replicative lifespans of yeast natural isolates. We estimated that the average number of lifespan-influencing interactions per essential node is 7.0 (6.1–8) and the average estimated initial virtual age is 45.4 (30.6–74) cell divisions in these isolates. We also found that t0 could potentially mediate the observed Strehler-Mildvan correlation in yeast natural isolates. Conclusions Our theoretical model provides a parsimonious interpretation of experimental lifespan data from the perspective of gene networks. We hope that our work will stimulate more interest in developing network models to study aging as a pleiotropic trait.