scholarly journals What is the best fitness measure in wild populations? A case study on the power of short-term fitness proxies to predict reproductive value

2021 ◽  
Author(s):  
Vita Ziva Alif ◽  
Jamie Dunning ◽  
Heung Ying Janet Chik ◽  
Terry Burke ◽  
Julia Schroeder
Keyword(s):  
Passerine Bird ◽  
Individual Growth ◽  
Reproductive Value ◽  
Wild Populations ◽  
Pedigree Data ◽  
Short Term ◽  
Lifetime Fitness ◽  
One Year ◽  
First Year Of Life

Fitness is at the core of evolutionary theory, but it is difficult to measure accurately. One way to measure long-term fitness is by calculating the individual’s reproductive value, which represents the expected number of allele copies an individual passes on to distant future generations. However, this metric of fitness is scarcely used because the estimation of individual’s reproductive value requires long-term pedigree data, which is rarely available in wild populations where following individuals from birth to death is often impossible. Wild study systems therefore use short-term fitness metrics as proxies, such as the number of offspring produced. This study obtained three frequently used short-term proxies for fitness obtained at different offspring life stages (eggs, hatchlings, fledglings and recruits), and compared their ability to predict reproductive values derived from the genetic pedigree of a wild passerine bird population. We used twenty years of precise field observations and a near-complete genetic pedigree to calculate reproductive success, individual growth rate and de-lifed fitness as lifetime fitness measures, and as annual de-lifed fitness. We compared the power of these metrics to predict reproductive values and lineage survival to the end of the study period. The three short-term fitness proxies predict the reproductive values and lineage survival only when measured at the recruit stage. There were no significant differences between the different fitness proxies at the same offspring stages in predicting the reproductive values and lineage survival. Annual fitness at one year old predicted reproductive values equally well as lifetime de-lifed fitness. However, none of the short-term fitness proxies was strongly associated with the reproductive values. In summary, the commonly short-term fitness proxies capture long-term fitness with intermediate accuracy at best, if measured at recruitment stage. As lifetime fitness measured at recruit stage and annual fitness in the first year of life were the best proxies of long-term fitness, we encourage their future use.

scholarly journals Contrarian and Momentum Strategies in the Indian Capital Market

2002 ◽  
Vol 27 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Sanjay Sehgal ◽  
I Balakrishnan
Keyword(s):  
Stock Returns ◽  
Indian Market ◽  
Momentum Effect ◽  
Short Term ◽  
Momentum Strategy ◽  
Momentum Strategies ◽  
Holding Period ◽  
The Us ◽  
One Year

The study attempts to evaluate if there are any systematic patterns in stock returns for the Indian market. The empirical findings reveal that there is a reversal in long-term returns, once the short-term momentum effect has been controlled by maintaining a one year gap between portfolio formation period and the portfolio holding period. A contrarian strategy based on long-term past returns provides moderately positive returns. Further, there is a continuation in short-term returns and a momentum strategy based on it provides significantly positive payoffs. The results in general are in conformity with those for developed capital markets such as the US.

scholarly journals Effect of short-term heart rate variability biofeedback on long-term abstinence in alcohol dependent patients – a one-year follow-up

2017 ◽  
Vol 17 (1) ◽  
Author(s):  
Ana Isabel Penzlin ◽  
Kristian Barlinn ◽  
Ben Min-Woo Illigens ◽  
Kerstin Weidner ◽  
Martin Siepmann ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Short Term ◽  
Heart Rate Variability Biofeedback ◽  
One Year ◽  
Alcohol Dependent

scholarly journals Mitochondrial and Oxidative Impacts of Short and Long-term Administration of HAART on HIV Patients

2020 ◽  
Vol 15 (2) ◽  
pp. 110-124
Author(s):  
Joy E. Ikekpeazu ◽  
Oliver C. Orji ◽  
Ikenna K. Uchendu ◽  
Lawrence U.S. Ezeanyika
Keyword(s):  
Treatment Group ◽  
Term Treatment ◽  
Short Term ◽  
Short Term Treatment ◽  
Hiv Patients ◽  
Long Term Treatment ◽  
Term Administration ◽  
Short And Long Term ◽  
One Year

Background and Objective: There may be a possible link between the use of HAART and oxidative stress-related mitochondrial dysfunction in HIV patients. We evaluated the mitochondrial and oxidative impacts of short and long-term administration of HAART on HIV patients attending the Enugu State University Teaching (ESUT) Hospital, Enugu, Nigeria following short and long-term therapy. Methods: 96 patients categorized into four groups of 24 individuals were recruited for the study. Group 1 comprised of age-matched, apparently healthy, sero-negative individuals (the No HIV group); group 2 consisted of HIV sero-positive individuals who had not started any form of treatment (the Treatment naïve group). Individuals in group 3 were known HIV patients on HAART for less than one year (Short-term treatment group), while group 4 comprised of HIV patients on HAART for more than one year (Long-term treatment group). All patients were aged between 18 to 60 years and attended the HIV clinic at the time of the study. Determination of total antioxidant status (TAS in nmol/l), malondialdehyde (MDA in mmol/l), CD4+ count in cells/μl, and genomic studies were all done using standard operative procedures. Results: We found that the long-term treatment group had significantly raised the levels of MDA, as well as significantly diminished TAS compared to the Short-term treatment and No HIV groups (P<0.05). In addition, there was significantly elevated variation in the copy number of mitochondrial genes (mtDNA: D-loop, ATPase 8, TRNALEU uur) in the long-term treatment group. Interpretation and Conclusion: Long-term treatment with HAART increases oxidative stress and causes mitochondrial alterations in HIV patients.

scholarly journals General Assessment of the Operational Utility of National Water Model Reservoir Inflows for the Bureau of Reclamation Facilities

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2897
Author(s):  
Francesca Viterbo ◽  
Laura Read ◽  
Kenneth Nowak ◽  
Andrew W. Wood ◽  
David Gochis ◽  
...  
Keyword(s):  
Water Model ◽  
Short Term ◽  
Bureau Of Reclamation ◽  
Hydrologic Processes ◽  
One Year ◽  
Inflow Performance ◽  
Basin Area ◽  
National Water ◽  
Total Inflow

This work investigates the utility of the National Oceanic and Atmospheric Administration’s National Water Model (NWM) for water management operations by assessing the total inflow into a select number of reservoirs across the Central and Western U.S. Total inflow is generally an unmeasured quantity, though critically important for anticipating both floods and shortages in supply over a short-term (hourly) to sub-seasonal (monthly) time horizon. The NWM offers such information at over 5000 reservoirs across the U.S., however, its skill at representing inflow processes is largely unknown. The goal of this work is to understand the drivers for both well performing and poor performing NWM inflows such that managers can get a sense of the capability of NWM to capture natural hydrologic processes and in some cases, the effects of upstream management. We analyzed the inflows for a subset of Bureau of Reclamation (BoR) reservoirs within the NWM over the long-term simulations (retrospectively, seven years) and for short, medium and long-range operational forecast cycles over a one-year period. We utilize ancillary reservoir characteristics (e.g., physical and operational) to explain variation in inflow performance across the selected reservoirs. In general, we find that NWM inflows in snow-driven basins outperform those in rain-driven, and that assimilated basin area, upstream management, and calibrated basin area all influence the NWM’s ability to reproduce daily reservoir inflows. The final outcome of this work proposes a framework for how the NWM reservoir inflows can be useful for reservoir management, linking reservoir purposes with the forecast cycles and retrospective simulations.

scholarly journals The use of borehole inclinometry in determining basal sliding and internal deformation at Haut Glacier d’Arolla, Switzerland

1997 ◽  
Vol 24 ◽  
pp. 331-337 ◽  
Author(s):  
Luke Copland ◽  
Jon Harbor ◽  
Marie Minner ◽  
Martin Sharp
Keyword(s):  
Hot Water ◽  
Short Term ◽  
Digital Inclinometer ◽  
Basal Sliding ◽  
Internal Deformation ◽  
One Year ◽  
Annual Scale ◽  
Insight Into ◽  
Displacement Measurements

A series of boreholes were drilled with high-pressure hot water across a section of Haut Glacier d’Arolla, Switzerland, in summer 1995. Twenty-three of the boreholes were profiled with a digital inclinometer soon aller drilling, and 14 were re-profiled up to 6 weeks later to determine changes in the longitudinal shape of boreholes with time. In addition to the main surveys, three boreholes were surveyed 14 times each to assess the accuracy and reproducibility of inclinometry measurements. These repeat surveys suggest that caution is needed in the interpretation of short-term borehole displacement measurements, and that the reoccupation of boreholes from one year to the next may be a better way to determine patterns of internal deformation and basal sliding. The annual scale may also have advantages in providing more long-term insight into glaciological processes than short term (single season) measurements.

scholarly journals Prevalence and prognostic implication of iron deficiency and anaemia in patients with severe aortic stenosis

Open Heart ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. e000901
Author(s):  
Anette Borger Kvaslerud ◽  
Amjad Iqbal Hussain ◽  
Andreas Auensen ◽  
Thor Ueland ◽  
Annika E Michelsen ◽  
...  
Keyword(s):  
Iron Deficiency ◽  
Aortic Stenosis ◽  
Severe Aortic Stenosis ◽  
Iron Status ◽  
Transferrin Saturation ◽  
Short Term ◽  
Prognostic Implication ◽  
Wide Range ◽  
One Year

ObjectiveThe aim of this study was to evaluate the prevalence and prognostic implication of iron deficiency (ID) and anaemia in patients with severe aortic stenosis (AS).MethodsIn an observational study of consecutive patients referred for aortic valve replacement (AVR), we assessed a wide range of biomarkers of iron status, including the definition of ID commonly applied in patients with chronic heart failure (ferritin <100 µg/L or ferritin 100–299 µg/L with a transferrin saturation <20%). The endpoints were short-term (one-year) and long-term (median 4.7 years, IQR: 3.8–5.5) mortality and major adverse cardiovascular events (MACE) within the first year after inclusion.Results464 patients were included in this substudy. 91 patients (20%) received conservative treatment and 373 patients (80%) received AVR. ID was detected in 246 patients (53%). 94 patients (20%) had anaemia. Patients with ID had an overall worse clinical profile than patients without ID. During follow-up, 129 patients (28%) died. Neither ID as defined above, soluble transferrin receptor nor hepcidin were associated with short-term or long-term mortality or MACE independent on treatment allocation. Anaemia was associated with one-year mortality in conservatively treated patients.ConclusionsID and anaemia are prevalent in patients with severe AS. In our cohort, ID did not provide independent prognostic information on top of conventional risk factors. More studies are required to determine how to correctly diagnose ID in patients with AS.Trial registration numberNCT01794832.

Simple Techniques for Monitoring Footpath Erosion in Mountain Areas of North-West England

1977 ◽  
Vol 4 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Rosalind A. Coleman
Keyword(s):  
Aerial Photography ◽  
Technical Expertise ◽  
Short Term ◽  
Mountain Areas ◽  
North West ◽  
Different Types ◽  
Different Seasons ◽  
One Year ◽  
Site Types

Very precise measurements of the movement of coarse-textured, unconsolidated materials may be meaningless. Therefore the study of individual processes operating on footpaths may require a different approach. However, for identification of changes of reasonable dimensions, methods such as those described above are inexpensive, quick, and require no technical expertise. It may be argued that, for path management, erosion that is too limited to be measured by these methods is too limited to be a problem. It can certainly be argued that the problem of spatial correlation implies a large number of measurements. What is lost in lack of precision may be more than compensated for by the gain in data from the larger area and wider variation in site-types that it is possible to monitor with such simple techniques.To monitor the effects of recreation in mountain areas, it is desirable to be able to measure any change in path-state and relate this to recreation factors at different seasons and under different sit; -conditions. Three methods of measurement have been considered in this paper, corresponding to three time-scales. Aerial photography has been used to demonstrate trends over the long term, and has proved adequate to differentiate between path sections with differing resistance to erosion.Short-term measurement has been carried out relative to known fixed positions. Two methods are suggested. One is less precise, but simple and widely applicable, and can be used for measurement intervals of six months to one year. The other is more detailed and can be used for measurement intervals of a few days, but is limited in its application by practical considerations.It is suggested that simple techniques used at a large number of different types of site may be more effective than detailed measurements at a few sites.

Firm Performance, Capital Structure, and the Tax Benefits of Employee Stock Options

2005 ◽  
Vol 40 (1) ◽  
pp. 135-160 ◽  
Author(s):  
Kathleen M. Kahle ◽  
Kuldeep Shastri
Keyword(s):  
Capital Structure ◽  
Stock Options ◽  
Employee Stock Options ◽  
Short Term ◽  
Tax Shield ◽  
Tax Benefits ◽  
One Year ◽  
Increasing Function ◽  
Options Theory

AbstractThis paper analyzes the relation between the capital structure of a firm and the tax benefits realized from the exercise of stock options. Theory suggests that firms with tax benefits from the exercise of stock options should carry less debt since tax benefits are a non-debt tax shield. We find that both long- and short-term debt ratios are negatively related to the size of tax benefits from option exercise. Moreover, one-year changes in long-term leverage are negatively related to changes in the number of options exercised. Such a relation does not exist for changes in short-term leverage. Finally, firms with option-related tax benefits tend to issue equity, with the net amount of equity issued an increasing function of these tax benefits.

scholarly journals Filling in the Gaps for Aquatic Ecosystem Conservation – Biomonitoring forBaseline Information and Capacity Building in Meghalaya, India

2017 ◽  
Vol 29 (1) ◽  
Author(s):  
Sonali Saha ◽  
Lucy Mary Jywra ◽  
Marvellous B. Lynser ◽  
Darina Kharchandi ◽  
Banri Dohling ◽  
...  
Keyword(s):  
College Students ◽  
Quality Parameters ◽  
Aquatic Biota ◽  
Freshwater Ecology ◽  
Initial Training ◽  
Short Term ◽  
Hydrological Parameters ◽  
Spatial Trends ◽  
One Year

This paper describes a stream biomonitoring program that builds capacity in undergraduate college students in the field of freshwater ecology and conservation. The program involves sampling of aquatic macroinvertebrates and hydrological parameters in streams of the state of Meghalaya, India. Several colleges from Shillong initiated short-term, one-year and long-term biomonitoring of streams in East Khasi Hills and Ri-Bhoi districts. Nine stream locations sampled over October-December in 2014 provided a snapshot of physical and biotic conditions, thus enabling the examination of spatial trends in water quality parameters and aquatic biota. A year-long sampling study from 2014-2015 provided a seasonal view of stream parameters at Lwai (clean) and Umkaliar (moderately polluted) streams. Results from both sampling sets suggest that turbidity negatively affected the richness of pollution sensitive taxa. Dissolved Oxygen values were lower in polluted streams and were non-significantly lower in summer than in winter. After an initial training in the field, the sampling was conducted by college students under supervision from their lecturers. Data obtained on macroinvertebrates adds to the sparse information available on stream ecosystems in the biodiversity-rich northeast Indian region. We hope the paper provides a template for monitoring of vital ecosystems in this and similar regions.

scholarly journals Marine Biofouling Communities of Manila South Harbor, Philippines

2020 ◽  
Vol 35 (1-2) ◽  
pp. 115-123
Author(s):  
Hildie M.E. Nacorda ◽  
Nero M. Austero ◽  
Cesar R. Pagdilao ◽  
Koh Siang Tan ◽  
Rhodora V. Azanza
Keyword(s):  
Crude Oil ◽  
Green Algae ◽  
Sea Surface ◽  
Perna Viridis ◽  
Fouling Communities ◽  
Short Term ◽  
Marine Biofouling ◽  
Immersion Experiment ◽  
One Year

An immersion experiment was conducted in the Manila South Harbor to document the development of sessile biofouling communities. Test panels were submerged below the sea surface in April 2012 for short- (one and three months) and long-term (one year) exposures in seawater, then foauling types and occurrences were scored based on digital images of panel surfaces. The short-term immersed panels were found with significant cover of soft fouling (undet.), slime, and the invasive Balanus (=Amphibalanus) amphitrite. These also filled the long-term immersed panels, although some fell off due to mortality from crude oil smothering. Perna viridis, native but also invasive, successfully established and then dominated the fouling cover by the 12th month (April 2013). Oysters, bryozoans (Watersipora sp.), colonial tunicates, polychaetes (Hydroides sp.), and green algae contributed minor to fouling cover. These fouling communities in the Manila South Harbor consisted of organisms that were cosmopolitan in port waters of SE Asia. A similar study must be carried out in other major ports of the country and then compared.

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