scholarly journals COVID-19 Outbreaks and Age Mortality Patterns

2020 ◽  
Author(s):  
Vladimir Shapiro
Keyword(s):  
Elderly Population ◽  
Regression Line ◽  
Logarithmic Scale ◽  
Age At Death ◽  
Large Magnitude ◽  
Mortality Pattern ◽  
Death Risk ◽  
Lower Point

Abstract As of the Fall of 2020, many countries are still fighting the COVID-19 pandemic. After the painful first massive wave in the Spring, more and more of them are facing the new outbreaks of varying impact. Understanding the mortality pattern associated with such subsequent outbreaks would help governments better prepare and save lives. These secondary outbreaks are still quite new to the scientists as the data have not been sufficient to identify robust trends. By now, US is dealing with the second outbreak of large magnitude and statistically significant analyses are finally possible. We have analyzed the weekly mortality death counts for various ages in US for the entire COVID-19 pandemic duration. Three somewhat related features involving age at death have been extracted: a) COVID-19 average age at death, b) fraction of deaths at ages 65+, and c) slope of age gradient regression line on the logarithmic scale. It turns out that during the outbreak the mortality age gradient is undergoing the following changes: a) average age at death at the peak is 4-5 years higher than at the lower point; b) fraction of deaths of 65+ is by approximately 10% higher, and c) the higher slope of the age gradient translates into an extra death risk of 5.8% every year. In other words, risks, to which an elderly population is exposed during all phases of the pandemic, rise sharply during and right after the outbreak peaks.

scholarly journals COVID-19 Outbreaks and Age Mortality Patterns

2020 ◽  
Author(s):  
Vladimir Shapiro
Keyword(s):  
Elderly Population ◽  
Regression Line ◽  
Logarithmic Scale ◽  
Age At Death ◽  
Large Magnitude ◽  
Mortality Pattern ◽  
Death Risk ◽  
Lower Point

Abstract As of the Fall of 2020, many countries are still fighting the COVID-19 pandemic. After the painful first massive wave in the Spring, more and more of them are facing the new outbreaks of varying impact. Understanding the mortality pattern associated with such subsequent outbreaks would help governments better prepare and save lives. These secondary outbreaks are still quite new to the scientists as the data have not been sufficient to identify robust trends. By now, US is dealing with the second outbreak of large magnitude and statistically significant analyses are finally possible. We have analyzed the weekly mortality death counts for various ages in US for the entire COVID-19 pandemic duration. Three somewhat related features involving age at death have been extracted: a) COVID-19 average age at death, b) fraction of deaths at ages 65+, and c) slope of age gradient regression line on the logarithmic scale. It turns out that during the outbreak the mortality age gradient is undergoing the following changes: a) average age at death at the peak is 4-5 years higher than at the lower point; b) fraction of deaths of 65+ is by approximately 10% higher, and c) the higher slope of the age gradient translates into an extra death risk of 5.8% every year. In other words, risks, to which an elderly population is exposed during all phases of the pandemic, rise sharply during and right after the outbreak peaks.

scholarly journals A Three-Component Approach to Model and Forecast Age-at-Death Distributions

2020 ◽  
pp. 105-129
Author(s):  
Ugofilippo Basellini ◽  
Carlo Giovanni Camarda
Keyword(s):  
Life Table ◽  
Early Adulthood ◽  
Forecast Accuracy ◽  
Relational Model ◽  
Age At Death ◽  
Mortality Pattern ◽  
Mortality Forecasting ◽  
Component Approach ◽  
Using Data ◽  
Mortality Projections

Abstract Mortality forecasting has recently received growing interest, as accurate projections of future lifespans are needed to ensure the solvency of insurance and pension providers. Several innovative stochastic methodologies have been proposed in most recent decades, the majority of them being based on age-specific mortality rates or on summary measures of the life table. The age-at-death distribution is an informative life-table function that provides readily available information on the mortality pattern of a population, yet it has been mostly overlooked for mortality projections. In this chapter, we propose to analyse and forecast mortality developments over age and time by introducing a novel methodology based on age-at-death distributions. Our approach starts from a nonparametric decomposition of the mortality pattern into three independent components corresponding to Childhood, Early-Adulthood and Senescence, respectively. We then model the evolution of each component-specific death density with a relational model that associates a time-invariant standard to a series of observed distributions by means of a transformation of the age axis. Our approach allows us to capture mortality developments over age and time, and forecasts can be derived from parameters’ extrapolation using standard time series models. We illustrate our methods by estimating and forecasting the mortality pattern of females and males in two high-longevity countries using data of the Human Mortality Database. We compare the forecast accuracy of our model and its projections until 2050 with three other forecasting methodologies.

272 COMPARISON OF VIABILITY BETWEEN SEXED VERSUS CONVENTIONAL BEEF SEMEN AT 37°C and 5% CO2

2013 ◽  
Vol 25 (1) ◽  
pp. 284
Author(s):  
D. Haarmann ◽  
M. Warshaw ◽  
S. P. Lorton ◽  
D. J. Kesler ◽  
C. E. Ferguson
Keyword(s):  
Linear Models ◽  
Regression Line ◽  
Final Analysis ◽  
Mortality Pattern ◽  
Evaluation Time ◽  
Sexed Semen ◽  
Chi Squared ◽  
Red Angus ◽  
Live Sperm

This study was designed to compare the quality of sexed-sorted (X-bearing chromosome) semen and conventional semen over a 24-h period in a controlled in vitro system (37.5°C and 5% CO2). Both conventional and sexed semen (95% accurate for sexed) were collected from one Angus, Red Angus, and Hereford bull owned by CRI (Genex Cooperative, Inc., Shawano, WI, USA). The straws of sexed semen used had sperm cells sorted for X-bearing sperm (2 million sperm per straw) before cryopreservation. Semen samples were thawed in a warm water bath (37°C) and extended with BO-AB fertilization stock media. Samples were placed in the incubator for 15 min before evaluation for microscopic progressive motility, acrosomal integrity, and viability (Eosin B-Fast Green stain) at 0 (15 min after pre-incubation) 3, 6, 9, 15, and 24 h. Slides were evaluated on a heated microscope stage at 37.5°C at 400× magnification. Five replicates were performed over a 5-week period. One straw of conventional semen and one straw of sexed semen from each bull were used for each replicate. The percentage of motility, live/dead, slope of the regression line for percentage of motility, percentage of live with intact acrosome, and percentage of live for both sexed and conventional semen were analysed in SAS using the general linear models procedure (SAS Institute Inc., Cary, NC, USA) and a Tukey chi-squared post hoc test. There were no differences between bulls in each semen type; therefore, all bulls and all replicates were pooled for the final analysis. The number of live spermatozoa with an intact acrosome was higher (P < 0.05) for conventional semen compared with sexed semen at each evaluation time (Table 1). In addition, the motility remained higher (P < 0.05) for conventional semen than for sex-sorted semen throughout the experiment (Table 1). There was a difference (P < 0.05) between conventional and sexed semen in the proportion capable of fertilization (percentage of motile sperm × percentage of live sperm with an intact acrosome) from 0 h through 9 h post-thaw. The slope of the regression line for the decrease in motility plotted versus time was greater (P < 0.05) for conventional (–0.1140) than for sexed semen (–0.096); however, the slope of the regression lines for the decrease in the number of live or live with intact acrosomes was not different (P = 1.0) between conventional (–0.11; –0.11) and sexed (–0.11; –0.11) semen, respectively. These results indicate that sexed semen follows the same mortality pattern as conventional semen; however, at thawing it begins at a lower motility and viability. Table 1.Comparison of sexed versus conventional semen in percentage of live with intact acrosomes and motility at different time points

scholarly journals Regional disparities in Canadian adult and old-age mortality: A comparative study based on smoothed mortality ratio surfaces and age at death distributions

2013 ◽  
Vol 39 (3-4) ◽  
pp. 79 ◽  
Author(s):  
Nadine Ouellette ◽  
Robert Bourbeau ◽  
Carlo G. Camarda
Keyword(s):  
Old Age ◽  
Elderly Population ◽  
The Elderly ◽  
Adult Mortality ◽  
Two Dimensions ◽  
Age At Death ◽  
Mortality Ratio ◽  
Mortality Compression ◽  
Mortality Improvements ◽  
Great Mortality

This paper examines adult and old-age mortality differentials in Canada between 1930 and 2007 at the provincial level, using theCanadian Human Mortality Database and the flexible smoothing P-spline method in two-dimensions well-suited to the study of smallpopulations. Our analysis reveals that provincial disparities in adult mortality in general, and among the elderly population in particular,are substantial in Canada. Moreover, based on the modal age at death and the standard deviation of ages at death above the mode,provincial disparities at older ages have barely reduced over time, despite the great mortality improvements in all provinces since the early 20th century. In the last few years studied, evidence of the shifting mortality regime was found among females in most Western and Central provinces, while all males were still undergoing an old-age mortality compression regime.

scholarly journals Statistical research and modeling network traffic

2021 ◽  
Vol 244 ◽  
pp. 07002
Author(s):  
Tatiana Tatarnikova ◽  
Igor Sikarev ◽  
Vladimir Karetnikov ◽  
Artem Butsanets
Keyword(s):  
Network Traffic ◽  
Least Squares Method ◽  
Regression Line ◽  
The Self ◽  
Logarithmic Scale ◽  
Self Similarity ◽  
Statistical Research ◽  
Similarity Parameter ◽  
Real Network ◽  
Self Similar

The self-similarity properties of the considered traffic were checked on different time scales obtained on the available daily traffic data. An estimate of the tail severity of the distribution self-similar traffic was obtained by constructing a regression line for the additional distribution function on a logarithmic scale. The self-similarity parameter value, determined by the severity of the distribution “tail”, made it possible to confirm the assumption of traffic self-similarity. A review of models simulating real network traffic with a self-similar structure was made. Implemented tools for generating artificial traffic in accordance with the considered models. Made comparison of artificial network traffic generators according to the least squares method criterion for approximating the artificial traffic point values by the approximation function of traffic. Qualitative assessments traffic generators in the form of the software implementation complexity were taken into account, which, however, can be a subjective assessment. Comparative characteristics allow you to choose some generators that most faithfully simulate real network traffic. The proposed sequence of methods to study the network traffic properties is necessary to understand its nature and to develop appropriate models that simulate real network traffic.

scholarly journals Association of blood pressure after peritoneal dialysis initiation with the decline rate of residual kidney function in newly-initiated peritoneal dialysis patients

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254169
Author(s):  
Yusuke Kuroki ◽  
Kei Hori ◽  
Kazuhiko Tsuruya ◽  
Dai Matsuo ◽  
Koji Mitsuiki ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Peritoneal Dialysis ◽  
Kidney Function ◽  
European Society ◽  
Regression Line ◽  
Logarithmic Scale ◽  
Residual Kidney Function ◽  
Decline Rate ◽  
European Society Of Cardiology ◽  
Annual Decline

Background Lower blood pressure (BP) levels are linked to a slower decline of kidney function in patients with chronic kidney disease (CKD) without kidney replacement therapy. However, there are limited data on this relation in peritoneal dialysis (PD) patients. Here we evaluated the association of BP levels with the decline of residual kidney function (RKF) in a retrospective cohort study. Methods We enrolled 228 patients whose PD was initiated between 1998 and 2014. RKF was measured as the average of creatinine and urea clearance in 24-hr urine collections. We calculated the annual decline rate of RKF by determining the regression line for individual patients. RKF is thought to decline exponentially, and thus we also calculated the annual decline rate of logarithmic scale of RKF (log RKF). We categorized the patients’ BP levels at 3 months after PD initiation (BP3M) into four groups (Optimal, Normal & High normal, Grade 1 hypertension, Grade 2 & 3 hypertension) according to the 2018 European Society of Cardiology and European Society of Hypertension Guidelines for the management of arterial hypertension. Results The unadjusted, age- and sex-adjusted, and multivariable-adjusted decline rate of RKF and log RKF decreased significantly with higher BP3M levels (P for trend <0.01). Compared to those of the Optimal group, the multivariable-adjusted odds ratios (95% confidence interval) for the faster side of the median decline rate of RKF and log RKF were 4.04 (1.24–13.2) and 5.50 (1.58–19.2) in the Grade 2 and 3 hypertension group, respectively (p<0.05). Conclusions Higher BP levels after PD initiation are associated with a faster decline in RKF among PD patients.

The Longitudinal Effect of a Single Peritonitis Episode on Peritoneal Membrane Transport in CAPD Patients

2000 ◽  
Vol 20 (2) ◽  
pp. 220-226 ◽  
Author(s):  
Kenan Ates ◽  
Rafet Koç ◽  
Gökhan Nergizoglu ◽  
Sehsuvar Ertürk ◽  
Kenan Keven ◽  
...  
Keyword(s):  
Solute Transport ◽  
Membrane Transport ◽  
Regression Line ◽  
University Hospital ◽  
Logarithmic Scale ◽  
Peritoneal Membrane ◽  
Prospective Longitudinal Study ◽  
Glucose Ratio ◽  
Prospective Longitudinal

Objective To evaluate the longitudinal effect of a single peritonitis episode on peritoneal membrane transport. Design A prospective longitudinal study. Setting Department of nephrology in a university hospital. Patients Eighteen continuous ambulatory peritoneal dialysis patients with peritonitis. Methods Peritoneal transport for low, middle, and high molecular weight (MW) solutes was evaluated by peritoneal equilibration test (PET). The first PET was performed on the day following the diagnosis of peritonitis. The test was repeated at weeks 1, 2, 4, 12, and 24 and the results were compared to baseline PET data obtained before peritonitis. In addition, dialysate CA125 concentration and leukocyte count were measured. Results During peritonitis there were significant increases in dialysate-to-plasma (D/P) ratios for all low, middle, and high MW solutes except potassium, and decreases in D4/D0 glucose ratio and ultrafiltration (UF) volume. Over the subsequent 2 weeks, solute transport gradually decreased to the baseline values then remained unchanged during follow-up. Although net UF volume demonstrated a similar course during the study, it did not completely return to the baseline value. No decrease in D/P sodium ratio was found at 60 minutes during the PET performed 24 weeks after peritonitis. The percent change in solute transport during peritonitis compared to baseline value was significantly correlated with a solute's MW ( r = 0.776, p = 0.014). The slope of the regression line for D/P ratios versus MW, in double logarithmic scale, before peritonitis (-0.73 ± 0.09) was steeper than the slope during peritonitis (-0.59 ± 0.08). Conclusions These findings indicate that a single peritonitis episode does not permanently affect peritoneal solute transport. However, the loss of net UF that accompanies peritonitis is not completely recovered, probably due to impairment of transcellular water transport. The transport changes associated with peritonitis may be due to the combined effect of increased effective peritoneal surface area and intrinsic permeability. Our findings suggest that the latter mechanism seems to be more important.

scholarly journals COVID-19 and excess mortality: Was it possible to lower the number of deaths in Slovenia?

Stanovnistvo ◽  
2021 ◽  
Vol 59 (1) ◽  
pp. 17-30
Author(s):  
Damir Josipovic
Keyword(s):  
Mortality Rate ◽  
Acute Respiratory Infection ◽  
Elderly Population ◽  
Excess Mortality ◽  
Age Groups ◽  
The Elderly ◽  
Mortality Pattern ◽  
Severe Acute Respiratory Infection ◽  
High Share ◽  
Excess Deaths

This paper presents new data on the age structure of hospitalised SARI (severe acute respiratory infection) patients, with or without COVID-19, broken down by gender, place of infection, and region. The leading hypothesis that COVID-19 deaths are overestimated despite the high share of excess deaths was confirmed, bringing to light the important issue of the demographic breakdown of the population at risk. Thus, the main reason for the decreasing number of COVID-19 deaths is to be sought within the exhausted demographic pool of the elderly population in 2020, when the mortality rate was 19% higher compared to the previous five-year period (2015-2019). Demographic disparities across regions are immense and statistically explain the differences in the ?infected versus deceased? ratio. The excess mortality in 2020 was unusually high, but the projected value for 2020 based on the mortality pattern across age groups from 2015 to 2019 contributed up to one-third of the surplus. So, for one-quarter of alleged COVID-19 deaths (roughly 600 out of some 3,300 in 2020), death was expected to take place in 2020 anyway.

Surface recombination effects on minority carrier diffusion length measurements using electron beam-induced current

1990 ◽  
Vol 48 (4) ◽  
pp. 744-745
Author(s):  
D.P. Malta ◽  
M.L. Timmons
Keyword(s):  
Electron Beam ◽  
Beam Energy ◽  
Minority Carrier ◽  
Diffusion Length ◽  
Effective Diffusion ◽  
Surface Recombination ◽  
Surface Recombination Velocity ◽  
Logarithmic Scale ◽  
Minority Carrier Diffusion Length ◽  
Carrier Diffusion

Measurement of the minority carrier diffusion length (L) can be performed by measurement of the rate of decay of excess minority carriers with the distance (x) of an electron beam excitation source from a p-n junction or Schottky barrier junction perpendicular to the surface in an SEM. In an ideal case, the decay is exponential according to the equation, I = Ioexp(−x/L), where I is the current measured at x and Io is the maximum current measured at x=0. L can be obtained from the slope of the straight line when plotted on a semi-logarithmic scale. In reality, carriers recombine not only in the bulk but at the surface as well. The result is a non-exponential decay or a sublinear semi-logarithmic plot. The effective diffusion length (Leff) measured is shorter than the actual value. Some improvement in accuracy can be obtained by increasing the beam-energy, thereby increasing the penetration depth and reducing the percentage of carriers reaching the surface. For materials known to have a high surface recombination velocity s (cm/sec) such as GaAs and its alloys, increasing the beam energy is insufficient. Furthermore, one may find an upper limit on beam energy as the diameter of the signal generation volume approaches the device dimensions.

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