scholarly journals Demographic window to aging in the wild: constructing life tables and estimating survival functions from marked individuals of unknown age

Aging Cell ◽  
2004 ◽  
Vol 3 (3) ◽  
pp. 125-131 ◽  
Author(s):  
Hans-Georg Muller ◽  
Jane-Ling Wang ◽  
James R. Carey ◽  
Edward P. Caswell-Chen ◽  
Carl Chen ◽  
...  
Keyword(s):  
Life Tables ◽  
Survival Functions ◽  
In The Wild

Bias in q and m rate estimates

1987 ◽  
Vol 114 (3) ◽  
pp. 591-599
Author(s):  
L. A. Roberts
Keyword(s):  
United Kingdom ◽  
Survival Function ◽  
Life Tables ◽  
Survival Functions ◽  
Rate Estimate ◽  
Exponential Curve ◽  
The United Kingdom ◽  
True Value ◽  
Straight Line ◽  
General Survival

Bias in estimates of the initial decremental rate q and the central decremental rate m is considered for several survival functions. It is first shown that the central rate estimate is unbiased when the survival function is an exponential curve; is similarly unbiased when the survival function assumes the Balducci shape. The evidence presented here also indicates that the proportional bias (the bias divided by the true value) is approximately twice as great for as for when the survival function is a straight line.Life tables in common use in the United Kingdom are, however, concave at ages arising most frequently in actuarial calculations, while none of the above curves is concave. In order to investigate the bias properties of general survival functions a quadratic is chosen, with a parameter indicating the extent of curvature. For this particular class of survival functions, one can show that bias is approximately minimized when exposure to risk is symmetric about the middle of the rate year.

scholarly journals Fishing in your backyard: otters that prey on urban resources

2021 ◽  
Author(s):  
Jesus Duarte ◽  
Diego Rodríguez ◽  
Miguel Ángel Farfán ◽  
Julia E. Fa
Keyword(s):  
Control Strategies ◽  
Damage Control ◽  
Food Resources ◽  
Survival Functions ◽  
Viable Option ◽  
Urban Location ◽  
The Third ◽  
Wildlife Species ◽  
In The Wild ◽  
Fish Survival

Abstract We monitored the incidence of predation behavior in Eurasian otters (Lutra lutra) from urban ponds in southern Spain, following reports of the mustelids’ presence in various urban locations. In one of the case studies, 30 small common carp and 35 Koi fish were released in May 2017 and April 2018, respectively, into two different ponds. Otters extensively predated on these fish over a period of 75–80 days. Only two small carp (6.6%) survived in one of the ponds and 10 Koi fish (28.5%) in the other. The surviving Koi were relocated. We determined that fish survival functions and mortality rates between these two years were not significantly different. At the second urban location, otters extensively predated on Iberian frogs over a period of 5–6 days in May 2018, left the area, and repeated this pattern in May 2019. Finally, at the third urban location, otters consumed 20 goldfish in 16 days in August 2018. Our results indicate that available food resources in urban settings can become a viable option for certain bold individuals of wildlife species and that otters appear to explore urban habitats when it suits them. Appropriate management and damage control strategies are therefore needed to ensure the survival of this protected species in case food resources in the wild become limited and urban raids become habitual.

Freeze-substituted fungal cells of Nectria haematococca: A comparison of the macroconidial walls of the adhesion-competent wild type with an adhesion-reduced mutant

1990 ◽  
Vol 48 (3) ◽  
pp. 688-689
Author(s):  
Thecan Caesar-Ton That ◽  
Lynn Epstein
Keyword(s):  
Freeze Substitution ◽  
Uranyl Acetate ◽  
Wild Type ◽  
Nectria Haematococca ◽  
Fruit Extract ◽  
Dialysis Tubing ◽  
Tube Emergence ◽  
Contrast Microscopy ◽  
In The Wild ◽  
Freeze Damage

Nectria haematococca mating population I (anamorph, Fusarium solani) macroconidia attach to its host (squash) and non-host surfaces prior to germ tube emergence. The macroconidia become adhesive after a brief period of protein synthesis. Recently, Hickman et al. (1989) isolated N. haematococca adhesion-reduced mutants. Using freeze substitution, we compared the development of the macroconidial wall in the wild type in comparison to one of the mutants, LEI.Macroconidia were harvested at 1C, washed by centrifugation, resuspended in a dilute zucchini fruit extract and incubated from 0 - 5 h. During the incubation period, wild type macroconidia attached to uncoated dialysis tubing. Mutant macroconidia did not attach and were collected on poly-L-lysine coated dialysis tubing just prior to freezing. Conidia on the tubing were frozen in liquid propane at 191 - 193C, substituted in acetone with 2% OsO4 and 0.05% uranyl acetate, washed with acetone, and flat-embedded in Epon-Araldite. Using phase contrast microscopy at 1000X, cells without freeze damage were selected, remounted, sectioned and post-stained sequentially with 1% Ba(MnO4)2 2% uranyl acetate and Reynold’s lead citrate. At least 30 cells/treatment were examined.

Planning the Size of Clinical Trials with Allowance for Patient Noncompliance

1990 ◽  
Vol 29 (03) ◽  
pp. 243-246 ◽  
Author(s):  
M. A. A. Moussa
Keyword(s):  
Clinical Trial ◽  
Clinical Trials ◽  
Sample Size ◽  
Event Rate ◽  
Survival Functions ◽  
Time Intervals ◽  
Patient Noncompliance ◽  
Event Rates ◽  
Larger Sample

AbstractVarious approaches are considered for adjustment of clinical trial size for patient noncompliance. Such approaches either model the effect of noncompliance through comparison of two survival distributions or two simple proportions. Models that allow for variation of noncompliance and event rates between time intervals are also considered. The approach that models the noncompliance adjustment on the basis of survival functions is conservative and hence requires larger sample size. The model to be selected for noncompliance adjustment depends upon available estimates of noncompliance and event rate patterns.

Prey tell: what quillback rockfish early life history traits reveal about their survival in encounters with juvenile coho salmon

2020 ◽  
Vol 650 ◽  
pp. 7-18 ◽  
Author(s):  
HW Fennie ◽  
S Sponaugle ◽  
EA Daly ◽  
RD Brodeur
Keyword(s):  
Life History ◽  
Early Life ◽  
Life History Traits ◽  
Direct Evidence ◽  
Coho Salmon ◽  
Larval Fish ◽  
Early Life History ◽  
In The Wild ◽  
Otolith Microstructure Analysis ◽  
Pelagic Juvenile

Predation is a major source of mortality in the early life stages of fishes and a driving force in shaping fish populations. Theoretical, modeling, and laboratory studies have generated hypotheses that larval fish size, age, growth rate, and development rate affect their susceptibility to predation. Empirical data on predator selection in the wild are challenging to obtain, and most selective mortality studies must repeatedly sample populations of survivors to indirectly examine survivorship. While valuable on a population scale, these approaches can obscure selection by particular predators. In May 2018, along the coast of Washington, USA, we simultaneously collected juvenile quillback rockfish Sebastes maliger from both the environment and the stomachs of juvenile coho salmon Oncorhynchus kisutch. We used otolith microstructure analysis to examine whether juvenile coho salmon were age-, size-, and/or growth-selective predators of juvenile quillback rockfish. Our results indicate that juvenile rockfish consumed by salmon were significantly smaller, slower growing at capture, and younger than surviving (unconsumed) juvenile rockfish, providing direct evidence that juvenile coho salmon are selective predators on juvenile quillback rockfish. These differences in early life history traits between consumed and surviving rockfish are related to timing of parturition and the environmental conditions larval rockfish experienced, suggesting that maternal effects may substantially influence survival at this stage. Our results demonstrate that variability in timing of parturition and sea surface temperature leads to tradeoffs in early life history traits between growth in the larval stage and survival when encountering predators in the pelagic juvenile stage.

CNN-based Rain Reduction in Street View Images

2020 ◽  
Vol 2020 (1) ◽  
pp. 78-81
Author(s):  
Simone Zini ◽  
Simone Bianco ◽  
Raimondo Schettini
Keyword(s):  
Character Recognition ◽  
Optical Character Recognition ◽  
State Of The Art ◽  
Weather Conditions ◽  
Specific Interest ◽  
Optical Character ◽  
Street View ◽  
In The Wild ◽  
Bad Weather ◽  
Detection And Recognition

Rain removal from pictures taken under bad weather conditions is a challenging task that aims to improve the overall quality and visibility of a scene. The enhanced images usually constitute the input for subsequent Computer Vision tasks such as detection and classification. In this paper, we present a Convolutional Neural Network, based on the Pix2Pix model, for rain streaks removal from images, with specific interest in evaluating the results of the processing operation with respect to the Optical Character Recognition (OCR) task. In particular, we present a way to generate a rainy version of the Street View Text Dataset (R-SVTD) for "text detection and recognition" evaluation in bad weather conditions. Experimental results on this dataset show that our model is able to outperform the state of the art in terms of two commonly used image quality metrics, and that it is capable to improve the performances of an OCR model to detect and recognise text in the wild.

On behalf of Pascal: A Reply to Le Poidevin

2020 ◽  
Vol 12 (3) ◽  
pp. 189
Author(s):  
Sebastian Gäb
Keyword(s):  
Christian Spirituality ◽  
Potential Candidate ◽  
Christian Doctrine ◽  
Real Possibility ◽  
Doctrine Of God ◽  
The Future ◽  
In The Wild ◽  
As If

When we were on the subway back from his lecture, I said to Robin: “I’m not sure there actually are any religious fictionalists.” We keep talking about them in papers and lectures, acting as if fictionalism in religion is a real possibility, but to be honest, I haven’t been able to spot one in the wild so far. The only potential candidate who comes to mind is Don Cupitt, who wrote things like: “I still pray and love God, even though I fully acknowledge that no God actually exists.”[1] Perhaps this is as fictionalist as it gets. But then again, Cupitt never explicitly declared himself a fictionalist (at least to my knowledge). Moreover, on other occasions he sounds more like an expressivist than a fictionalist, e.g. when he says: “The Christian doctrine of God just is Christian spirituality in coded form.”[2] So, if there are any actual fictionalists out there, please step forward.[1] Don Cupitt, After God: The Future of Religion (Basic Books, 1997), 85.[2] Don Cupitt, Taking leave of God (SCM Press, 1980), 14.

THE ESSENTIAL CONTRIBUTION OF CAPTIVE SUMATRAN ELEPHANT IN ELEPHANT TRAINING CENTER, WAY KAMBAS NATIONAL PARK FOR WILDLIFE GENETICS CONSERVATION

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Elly Lestari Rustiati ◽  
Priyambodo Priyambodo ◽  
Yanti Yulianti ◽  
Eko Agus Srihanto ◽  
Dian Neli Pratiwi ◽  
...  
Keyword(s):  
National Park ◽  
In Situ Conservation ◽  
Training Center ◽  
Conservation Effort ◽  
In The Wild ◽  
Wildlife Genetics ◽  
Way Kambas National Park ◽  
Human Conflict ◽  
Essential Contribution

Way Kambas National Park (WKNP) is home of five protected big mammals including sumatran elephants.  It shares its border with 22 of 37 villages surrounding the national park.  Understanding their existence in the wild is a priority, and  wildlife genetics is a crucially needed. Besides poaching and habitat fragmentation, wildlife-human conflict is one big issue.  Elephant Training Center (ETC) in WKNP is built for semi in-situ conservation effort on captive sumatran elephants that mainly have conflict histories with local people.  Participative observation and bio-molecular analysis were conducted to learn the importance of captive Sumatran elephant for conservation effort.  Through captive sumatran elephants, database and applicable methods are expected to be developed supporting the conservation of their population in the wild.  Participative observation and molecular identification was carried on captive sumatran elephants in ETC, WKNP under multiple year Terapan grant of Ministry of Research and Technology Higher Education, Indonesia. Gene sequence and cytological analyses showed that the captive sumatran elephants are closely related and tend to be domesticated.  Translocation among ETC to avoid inbreeding, and maintaining the captive sumatran elephant as natural as possible are highly recommended. Developing genetic database can be a reference for both captive and wild sumatran elephants.

Sign in / Sign up

Export Citation Format

Share Document