Population Production Research Articles

A novel method for evaluating population accommodation level of adjustable products based on interval estimation

In designing adjustable products, their proper adjustable ranges need to be determined based on an accurate accommodation level evaluation method. Previous accommodation level evaluation methods have employed point estimation for representing an adjustable product's population accommodation level. However, a point estimate of population accommodation level is limited in that it lacks 1) information regarding the precision of an estimated accommodation level, and 2) the capability to conduct statistical comparisons of the differences between accommodation levels of multiple designs/products. Therefore, as a remedy for such limitations, this study developed a novel population accommodation level evaluation method that incorporates both point and interval estimation. The method evaluates an adjustable product's accommodation level on the basis of the adjustable range provided by the product and a set of fitting product configurations of multiple individuals. The method consists of three parts: 1) an accommodation level is evaluated for each individual for a given adjustable range, 2) a population accommodation level is determined based on the obtained individual accommodation levels, and 3) a confidence interval of the population accommodation level is generated. The descriptions of the developed method are provided, presented along with its advantages. Then, a case study is conducted to demonstrate how the method can be applied to practical design problems. Lastly, the practical implications of the developed method are discussed along with some possible future research directions.

A Systematic Literature Review on the Importance of Anthropometric Data Toward the Malaysian Population Productivity and Quality of Life

Anthropometric data is widely used in various applications such as manufacturing, healthcare, forensics, and medical treatments. In addition, the data can be applied to design ergonomic tools, equipment, clothing, and footwear to ensure that the products, facilities, and services fit the users. This paper aims to analyze the existing literature on the importance of anthropometric data on the Malaysian population's productivity and quality of life and look into any further research that needs improvement. Guided by the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses), through Scopus and Web of Science databases, 15 related studies were identified. The review managed to extract six applications of anthropometric data and its seven perceived benefits. Data applications were classified into furniture, clothing and footwear, car seat, fitting and fixture, forensic investigation, and safety products. The benefits were grouped into easy to use, fit, well-being, welfare, safety, work efficiency, and identity verification by using thematic analysis. The review also highlighted the methodological issues related to the number of samples, locations coverage for a survey and the financial support in conducting research. Finally, several recommendations were drawn, including the importance of anthropometric database development at the end of this paper for reference by future scholars.

Reproduction, condition and abundance of the Mediterranean bluefish (Pomatomus saltatrix) in the context of sea warming

AbstractThis study evaluates the link between sea warming and three important aspects of the population dynamics of bluefish, Pomatomus saltatrix, in the north‐western (NW) Mediterranean: condition (health measures), reproduction and abundance (as reflected in catch per unit effort, CPUE). We compared the bluefish populations from two areas with different thermal regimes: the Gulf of Roses and the Ebre Delta. First, in order to compare the condition and reproduction parameters of the two populations, specimens were collected from the commercial catch landed in two ports located in these areas. Several indicators of fish condition and reproduction such as hepatosomatic index, gonadosomatic index, maturation timing, length‐at‐first maturity, fecundity, egg quality and atresia (ovarian follicle resorption) were analysed and compared between study areas. Second, time series analyses of sea surface temperatures (SST) and monthly bluefish CPUEs in the two study areas were assessed using Box–Jenkins transfer function models. Our results indicate that bluefish benefit from sea warming in the NW Mediterranean, particularly in the northernmost zone, as evidenced by increasing fish condition in these waters. Sea warming may favour the changes in spawning phenology and the northward expansion of this species. This study provides evidence that a marine fish species that is able to expand or is forced to shift its distribution as a result of sea warming may take advantage of other environmental conditions of new habitats, contributing to the enhancement of the population's productivity in these areas.

Single versus subdivided population strategies in breeding against an adverse genetic correlation

In advanced conifer breeding programmes, the simultaneous genetic improvement of adversely correlated traits constitutes a major challenge. Population subdivision strategies have been proposed to deal with breeding objective uncertainty, to reduce inbreeding depression in production populations and to reduce genetic correlation adversity. We used Monte Carlo simulations based on a finite locus model to study the effect of a two-breeding-population strategy applying selection for each trait in each breeding population on the genetic correlation and on genetic gains in breeding populations (BP) and the production population (PP) within a time frame of ten generations. A single-BP and a two-subline strategy both applying multitrait index selection with equal trait weights were used as references. Two BP strategy simulations indicated that simultaneous genetic gain for the two traits could be achieved in the PP despite adverse pleiotropy. The adversity of the genetic correlations decreased in BPs of the two-BP strategy, in contrast to single-BP and subline strategies, but the adversity reduction came at the cost of a lower rate of aggregated (summed) genetic gain in the PP for the two-BP strategy compared to the single-BP or subline strategies. The subline strategy exhibited increased genetic gain in the PP at equal levels of inbreeding as intended. Two BP strategies could be useful to develop breeds specialised on different traits and to simultaneously reduce adverse genetic correlations. However, if the aggregated genetic gain should be maximised, the single-BP strategy appears a better choice.

The essential parameters of a resource-based carrying capacity assessment model: An Australian case study

Carrying capacity assessments model a population's potential self-sufficiency. A crucial first step in the development of such modelling is to examine the basic resource-based parameters defining the population's production and consumption habits. These parameters include basic human needs such as food, water, shelter and energy together with climatic, environmental and behavioural characteristics. Each of these parameters imparts land-usage requirements in different ways and varied degrees so their incorporation into carrying capacity modelling also differs. Given that the availability and values of production parameters may differ between locations, no two carrying capacity models are likely to be exactly alike. However, the essential parameters themselves can remain consistent so one example, the Carrying Capacity Dashboard, is offered as a case study to highlight one way in which these parameters are utilised. While examples exist of findings made from carrying capacity assessment modelling, to date, guidelines for replication of such studies in other regions and scales have largely been overlooked. This paper addresses such shortcomings by describing a process for the inclusion and calibration of the most important resource-based parameters in a way that could be repeated elsewhere.

Changes in the ecosystem service values of typical river basins in arid regions of Northwest China

ABSTRACTThis study compared the 1994 and 2005 ecosystem service values of the Tarim, Manas, Shiyang and Heihe River Basins, which are four typical examples of river basins in the arid region of Northwest China. The ecosystem areas and service values were obtained from their consumer price indices, and constant prices were calculated on the basis of data from the Land Use Classification Map of 1994, TM images, CBERS images of 2005 and research results from ‘the equivalent factor table of China's ecosystem service value’. The results indicated that between 1994 and 2005 in these four river basins, the land areas supporting the environment and society (i.e. forest, grassland and wetland ecosystem) generally declined, whereas areas of farmland significantly increased. The changes in these areas in smaller basins were larger and occurred more rapidly. The ecosystem service value of the Tarim River Basin was the largest and local residents would rather pay more money for its ecosystem services, which means that the ecosystem service value there had a higher scarcity. The increase in the ecosystem service value of the Heihe River Basin was the largest. The ecosystem service value of the Heihe River Basin had more important and direct influences on the population's productivity and lives than did the Tarim River Basin. In addition, the farmland area in the Tarim River Basin increased more than the other river basins; however, the people's willingness to pay for farmland ecosystem services in this basin was the lowest. Willingness to pay was not linked to resource richness, and the concepts of economic development, water utilization and soil protection need to be strengthened. Copyright © 2013 John Wiley & Sons, Ltd.

Estimating the future decline of wild coho salmon populations resulting from early spawner die-offs in urbanizing watersheds of the Pacific Northwest, USA

Since the late 1990 s, monitoring efforts evaluating the effectiveness of urban stream restoration projects in the greater metropolitan area of Seattle, Washington, USA, have detected high rates of premature mortality among adult coho salmon (Oncorhynchus kisutch) in restored spawning habitats. Affected animals display a consistent suite of symptoms (e.g., disorientation, lethargy, loss of equilibrium, gaping, fin splaying) that ultimately progresses to death on a timescale of a few hours. Annual rates of prespawn mortality observed over multiple years, across several drainages, have ranged from approximately 20% to 90% of the total fall run within a given watershed. Current weight-of-evidence suggests that coho prespawn mortality is caused by toxic urban stormwater runoff. To evaluate the potential consequences of current and future urbanization on wild coho salmon, we constructed life-history models to estimate the impacts of prespawn mortality on coho populations and metapopulations. At the low (20%) and high (90%) ends of the range of observed mortality, model results indicated the mean time to extinction of localized coho populations in 115 and 8 y, respectively. The presence of productive source populations (i.e., unaffected by prespawn mortality) within a metapopulation reduced local extinction risk. However, as more populations within a metapopulation become affected by spawner die-offs prior to spawning, the source population's productivity declined. These simple models demonstrate the potential for rapid losses from coho populations in urbanizing watersheds. Because the models do not account for possible impacts of toxic runoff to other coho life stages, they likely underestimate the cumulative impacts of nonpoint source pollution on wild populations.

Efficiencies of Clonally Replicated and Seedling Testing for Spruce Breeding and Deployment Strategies

Abstract Genetic gains based on a genetic test using clonal replicates were compared to those based on a test using seedlings at the same gene diversity and testing effort levels using POPSIM™ Simulator. Three testing and deployment strategies targeting for white spruce (P. glauca [Moench] Voss) and black spruce (P. mariana (Mill.) B.S.P.) in New Brunswick were compared: seedling test with clonal seed orchard deployed as seedlings (CSO_ST), clonally replicated test with clonal seed orchard deployed as seedlings (CSO_CRT), and clonally replicated test deployed as a clone mix (MVF). The breeding populations (BP) were formed by balanced within-family selection and the production populations (PP) were selected by strong restriction on relatedness, i.e., no parent in common. Compared to the seedling test, the clonally replicated test resulted in faster accumulation of additive effects but quicker loss of additive variance in the BP, and this is particular true in the case of lower narrow-sense heritability or less non-additive genetic variance. The quicker loss in BP additive variance was overcompensated for by its faster accumulation in BP additive effect, resulting in higher gain in the clonally replicated test based PPs. Compared to the CSO_ST, the gain superiority of the CSO_CRT increased with generations, decreasing narrow-sense heritability or reducing the amount of non-additive variance. Implementing MVF was the most effective in terms of gain in most simulated cases and its superiority over the CSO_ST increased with generations, decreasing narrowsense heritability, or increasing non-additive genetic variance. Overall results demonstrated significant advantages of using clonally replicated test both for BP advancement and PP selection in most of the scenarios, suggesting that clonally replicated test should be incorporated into current spruce breeding strategies.

Southwestern Willow Flycatcher Population and Habitat Response to Reservoir Inundation

ABSTRACT One of the largest known populations of the federally endangered southwestern willow flycatcher (Empidonax traillii extimus) occurs at Roosevelt Lake, Arizona, USA. Modifications to Roosevelt Dam, completed in 1996, raised the height of the dam and resulted in a high probability of willow flycatcher habitat inundation within the reservoir's conservation pool. We collected habitat measurements and monitored 922 willow flycatcher nests from 1996 to 2006 to investigate effects of inundation on willow flycatcher habitat and subsequent changes in nest success, productivity, and distribution. Inundation of willow flycatcher habitat at Roosevelt Lake occurred in 2005, changing the location and amount of suitable breeding habitat and significantly altering habitat structure (e.g., thinner vegetation, more canopy gaps) of formally occupied nest sites. The willow flycatcher population at Roosevelt Lake decreased 47% from 209 territories in 2004 to 111 territories in 2006 in response to habitat changes. Willow flycatchers made fewer nesting attempts and nest success rates were significantly lower during inundation (2005 and 2006: 45%) than preinundation (1996–2004: 57%). Combined, these factors negatively affected the population's productivity during inundation. Although inundation caused extensive vegetation die‐off, we did observe regeneration of vegetation in some areas at Roosevelt Lake in 2006. The Roosevelt Lake population remains one of the largest willow flycatcher populations in the state and territory numbers remain high enough that the population may not suffer long‐term effects if sufficient suitable habitat continues to exist during the cycle of inundation and regeneration. Reservoir managers may be able to develop dam management guidelines that reduce damage to habitat, encourage habitat growth, and mimic the dynamic nature of unaltered riparian habitat. These guidelines can be implemented, as appropriate, at reservoirs throughout the willow flycatcher's range.

Technological innovations in sensors for assessment of postharvest mechanical handling systems

Produce damage is a major cause of large postharvest losses internationally. The current level of technology that can enable researchers and industry to understand the mechanical reasons for these levels of damage is discussed. The use of pseudo-fruit to measure the forces acting in the postharvest system can enable repeatable force profiles to be established. Both compression and impact damage events are considered. By using damage studies carried out in a controlled manner and covering the expected range of forces provide the data to allow prediction of expected damage. A probabilistic description for damage likelihood is introduced that describes the damage in terms of the proportion of a product's population that will sustain some commercially significant bruise size. These two relationships can then be combined to provide an estimate of the level of damage that can be expected from any handling event.

Open-nucleus breeding strategies compared with population-wide positive assortative mating: II. Unequal distribution of testing effort.

This study compares population-wide positive assortative mating (PAM) with open-nucleus breeding with an elite and main population when more effort is allocated to parents of the elite. A companion study showed that PAM is advantageous when testing effort is independent of parental value. In the present study,unbalanced testing was imposed by varying the number of crosses or the number of genotypes per cross. These unbalanced alternatives are compared with PAM, where the testing effort was varied so that better parents were mated more frequently. More effort allocated to parents of higher rank increased the additive effect and the additive variance and only slightly altered the group coancestry and inbreeding in the breeding population (BP) compared with completely balanced scenarios. Of particular interest to the breeder, large enhancement of the additive variance in the BP contributed to higher gains in the production population (PP). These simulations demonstrate that population-wide PAM leads to higher genetic gains compared with open-nucleus alternatives at any desired target level of diversity in the PP. This is true for both balanced (part I)and unbalanced distribution of testing effort (part II).

Fertility Control in Wild Populations of Animals

Fertility Control in Wild Populations of Animals

Reactions of poly(ethylene glycol) cations with iodide and perfluorocarbon anions

Multiply charged poly(ethylene glycol) ions of the form (M+ nNa) n+ derived from electrospray ionization have been subjected to reactions with negative ions in the quadrupole ion trap. Mixtures of multiply charged positive ions ranging in average mass from about 2000 to about 14,000 Da were observed to react with perfluorocarbon anions by either proton transfer or fluoride transfer. Iodide anions reacted with the same positive ions by attachment. In no case was fragmentation of the polymer ion observed. In all cases, the multiply charged positive ion charge states could be readily reduced to +1, thereby eliminating the charge state overlap observed in the normal electrospray mass spectrum. With all three reaction mechanisms, however, the +1 product ions were comprised of mixtures of products with varying numbers of sodium ions, and in the case of iodide attachment and fluoride transfer, varying numbers of halogen anions. These reactions shift the mass distributions to higher masses and broaden the distributions. The extents to which these effects occur are functions of the magnitudes of the initial charges and the width of the initial charge state distributions. Care must be taken in deriving information about the polymer molecular weight distribution from the singly charged product ions arising from these ion/ion reactions. The cluster ions containing iodide were shown to be intermediates in sodium ion transfer. Dissociation of the adduct ions can therefore lead to a +1 product ion population that is comprised predominantly of M+Na + ions. However, a strategy based on the dissociation of the iodide cluster ions is limited by difficulties in dissociating high mass-to-charge ions in the quadrupole ion trap.

Interactive Effects of Prey and Weather on Golden Eagle Reproduction

1. The reproduction of the golden eagle Aquila chrysaetos was studied in southwestern Idaho for 23 years, and the relationship between eagle reproduction and jackrabbit Lepus californicus abundance, weather factors, and their interactions, was modelled using general linear models. Backward elimination procedures were used to arrive at parsimonious models. 2. The number of golden eagle pairs occupying nesting territories each year showed a significant decline through time that was unrelated to either annual rabbit abundance or winter severity. However, eagle hatching dates were significantly related to both winter severity and jackrabbit abundance. Eagles hatched earlier when jackrabbits were abundant, and they hatched later after severe winters. 3. Jackrabbit abundance influenced the proportion of pairs that laid eggs, the proportion of pairs that were successful, mean brood size at fledging, and the number of young fledged per pair. Weather interacted with prey to influence eagle reproductive rates. 4. Both jackrabbit abundance and winter severity were important in predicting the percentage of eagle pairs that laid eggs. Percentage laying was related positively to jackrabbit abundance and inversely related to winter severity. 5. The variables most useful in predicting percentage of laying pairs successful were rabbit abundance and the number of extremely hot days during brood-rearing. The number of hot days and rabbit abundance were also significant in a model predicting eagle brood size at fledging. Both success and brood size were positively related to jackrabbit abundance and inversely related to the frequency of hot days in spring. 6. Eagle reproduction was limited by rabbit abundance during approximately two-thirds of the years studied. Weather influenced how severely eagle reproduction declined in those years. 7. This study demonstrates that prey and weather can interact to limit a large raptor population's productivity. Smaller raptors could be affected more strongly, especially in colder or wetter climates.

Recruitment in Rocky Mountain Greater Sandhill Cranes and Comparison with Other Crane Populations

The sandhill crane (Grus canadensis) has the lowest known recruitment (% juv in fall and winter of any avian species hunted in North America. Long-term recruitment data provide insight into a population's productivity, ability to support harvest, and responses to management programs. During 1972-92, we annually collected age ratio (n = 191,968) and brood size (n = 12,239) data for greater sandhill cranes (G. c. tabida [greaters]) of the Rocky Mountain Population (RMP) at their migration stopover in the San Luis Valley, Colorado (fall), and at sites in New Mexico (winter) and southeastern Arizona (winter). We collected similar data (1987-92) for lesser sandhill cranes (G. c. canadensis [lessers]) from the Midcontinent Population (MCP) wintering in flocks mixed with RMP cranes, and for greaters of the Lower Colorado River Valley Population (LCRVP) wintering in western Arizona (1973-75 and 1989-92). Annual recruitment in the RMP averaged 8.1% (SE = 0.6) in fall and 8.0% (SE = 0.5) in winter over 21 years; mean brood size was 1.25 (SE = 0.02) in fall and 1.23 (SE = 0.02) in winter. In years with higher percent juveniles, more pairs fledged multiple young (P < 0.01); second and rarely third chicks in broods composed 20% of RMP recruitment. Recruitment and brood size had a downward trend (P < 0.01) over 21 years. During 1986-92, recruitment and brood size were below average (P < 0.01), apparently due to drought in breeding areas. We estimated survival rates of RMP cranes to be 0.95 during 1972-85, 0.94 during 1985-90, and 0.91 during 1990-92. Recruitment, survival estimates, and count data during 1985-92 suggest that the RMP is stable at 20,000-21,500 or declining slightly and cannot sustain increased harvest. Recruitment in MCP lessers averaged 11.2% (SE = 0.34) and mean brood size was 1.14 (SE = 0.02). Mean recruitment in LCRVP greaters was 4.8% (SE = 0.93), and mean brood size was 1.14 (SE = 0.028). Mean recruitment in most other North American crane populations was 5-14%. The whooping crane (G. americana) has the highest long-term (55 yr) recruitment (13.9%) of any North American crane population. Recruitment data alone cannot be used to estimate rate of increase and are difficult to interpret without additional demographic information. However, perennially low recruitment (≤ 5-6%) approximates the lowest documented mortality rates in any North American crane population, and should be a cause for concern, particularly in hunted populations. Management of crane populations can be improved by annually gathering data on recruitment, population size, and hunter harvest, and by obtaining survival estimates from long-term studies

Effect of fertility control on a population's productivity

The effect of a sterilising agent upon the productivity of vertebrate pests, such as feral horses, feral dogs, wild rabbits or fruit-eating birds, depends upon the population's social structure and mating system. We investigated the theoretical effect on productivity of three forms of dominance, two effects of sterilisation on dominance, and four modes of transmission. Seventeen of the possible 24 combinations are feasible but lead to only four possible outcomes. Three of these result in lowered productivity. The fourth, where the breeding of a dominant female suppresses breeding in the subordinate females of her group, leads to a perverse outcome. Productivity increases with sterilisation unless the proportion of females sterilised exceeds (n–2)/(n–1) where n (&gt;2) is the number of females in the group. A knowledge of social structure and mating system is therefore highly desirable before population control by suppressing female fertility is attempted or even contemplated.

Recovering crater production functions from densely cratered surfaces

Two techniques proposed for the recovery of the crater‐production functions on densely cratered surfaces have been appraised. The first technique classifies craters according to their degree of nm preservation, then interprets the statistics of the freshest craters as closely mimicking the full population's production function. Although commonly practiced, in fact, this method is demonstrably misleading for densely cratered surfaces. The second technique uses a weighting scheme to recover the production function. Each crater diameter measured is weighted by the fraction of the crater that remains unoverlapped by subsequent impacts. While this method is theoretically sound even at saturation crater densities, it too fails at high densities due to practical difficulties. For this technique to work effectively, one would have to be able to recognize and accurately measure the diameters of craters having less than 10% of their nms remaining, a feat beyond reasonable expectation.

Density‐Dependent Natural Selection

Density—dependent selective values illustrate the evolutionary effect of population—regulating processes that diminish an individual's probability of survival with increased crowding. The selective values, assumed to decrease as a linear function of density, lead in a mild environment to the evolution of phenotypes having a high carrying capacity, K, at the expense of a low intrinsic rate of increase, r. A graphical technique shows that selection causes evolution of phenotypes having a high r at the expense of a low K in harsh seasonal environments. A mathematical technique developed for analyzing evolution in coarse—grained seasonal environments reveals genetic mechanisms, including ones with full dominance, with which a moderately harsh seasonal environment causes stable polymorphism between high—r and high—K genes. The energy balance equation demonstrates the role of high—r and high—K phenotypes in the population's energy flow. A high—r phenotype makes a large expected contribution to the population's productivity under conditions of negligible crowding, and a high—K phenotype has, for a given contribution to the population's productivity under uncrowded conditions, a low sensitivity to having that contribution diminished by crowding.

Some Population Mechanics of the American Coot

This paper is concerned with the annual mortality rate, age composition, and migratory distribution of the population of American coot (Fulica americana) contributing to the hunting kill in the northern Mississippi Flyway. It also evaluates three possible aging techniques and one sexing technique. Most studies of the coot (Sooter, 1945; Gullion, 1954; Kiel, 1955; and others) have dealt with the local breeding activity of the species, its large clutch size, and its high nesting success. Kiel and Hawkins (1953) described the status of the coot in the Mississippi Flyway on the basis of relative kill and winter inventory. With the exception of the mallard (Anas platyrhynchos), the coot has in recent years generally exceeded each species of waterfowl in numbers bagged in the Mississippi Flyway (Williams, 1953; Crissey, 1954, 1955, 1956, 1957). This status in the bag indicates a potential need for management of the species and for such basic information as estimates of the population's productivity and over-all mortality. Reeve and Pimlott (1950) have attempted to obtain an age and sex ratio for coots bagged at Lake Puckaway, Wisconsin. They found that some females possessed small bursae and adult-appearing ovaries. As the observed percentage of juveniles (90 per cent) seemed too high for normal production, these authors suggested differential migration by age groups. Working with small samples, Gullion (1952) was unable to demonstrate regression of the bursa with age or season. As an alternative method of aging, he suggested the use of tarsal color, and found a reasonable percentage of young (79 per cent in a sample of 79) in a California population. The further testing of this tarsal-color method and the determination of age structure in the bag were important objectives of the study reported here.