ECONOMIC PAPERS: A JOURNAL OF APPLIED ECONOMICS AND POLICY, Issue 1 2007
ANNE M. GARNETT
Regional Australia has experienced significant changes in population and employment since the early 1990s. Evidence regarding these changes has often been anecdotal, with references in political and media spheres to a ,Sea Change' or ,Tree Change'. There has also been considerable public discussion about the effect that the structural changes and misfortunes within the agricultural sector have had on localities in rural regions. The purpose of this paper is to provide and analyse data on regional population and employment changes since the early 1990s. It will also examine the role that the agricultural sector may have had in these changes. This will provide a basis for informed debate and analysis of population changes in regional Australia and the causes and implications of these changes. [source]

CONTROLLING GAMBLING: A POPULATION-BASED PERSPECTIVE TO MEASUREMENT AND MONITORING AS RESOURCE FOR EFFECTIVE INTERVENTIONS

ADDICTION, Issue 7 2009
NORMAN GIESBRECHT
No abstract is available for this article. [source]

EVOLUTION OF DOMINANCE UNDER FREQUENCY-DEPENDENT INTRASPECIFIC COMPETITION IN AN ASSORTATIVELY MATING POPULATION

EVOLUTION, Issue 2 2010
Stephan Peischl
We study the evolution of higher levels of dominance as a response to negative frequency-dependent selection. In contrast to previous studies, we focus on the effect of assortative mating on the evolution of dominance under frequency-dependent intraspecific competition. We analyze a two-locus two-allele model, in which the primary locus has a major effect on a quantitative trait that is under a mixture of frequency-independent stabilizing selection, density-dependent selection, and frequency-dependent selection caused by intraspecific competition for a continuum of resources. The second (modifier) locus determines the degree of dominance at the trait level. Additionally, the population mates assortatively with respect to similarities in the ecological trait. Our analysis shows that the parameter region in which dominance can be established decreases if small levels of assortment are introduced. In addition, the degree of dominance that can be established also decreases. In contrast, if assortment is intermediate, sexual selection for extreme types can be established, which leads to evolution of higher levels of dominance than under random mating. For modifiers with large effects, intermediate levels of assortative mating are most favorable for the evolution of dominance. For large modifiers, the speed of fixation can even be higher for intermediate levels of assortative mating than for random mating. [source]

EVOLUTIONARY POTENTIAL OF A LARGE MARINE VERTEBRATE: QUANTITATIVE GENETIC PARAMETERS IN A WILD POPULATION

EVOLUTION, Issue 4 2009
Joseph D. DiBattista
Estimating quantitative genetic parameters ideally takes place in natural populations, but relatively few studies have overcome the inherent logistical difficulties. For this reason, no estimates currently exist for the genetic basis of life-history traits in natural populations of large marine vertebrates. And yet such estimates are likely to be important given the exposure of this taxon to changing selection pressures, and the relevance of life-history traits to population productivity. We report such estimates from a long-term (1995,2007) study of lemon sharks (Negaprion brevirostris) conducted at Bimini, Bahamas. We obtained these estimates by genetically reconstructing a population pedigree (117 dams, 487 sires, and 1351 offspring) and then using an "animal model" approach to estimate quantitative genetic parameters. We find significant additive genetic (co)variance, and hence moderate heritability, for juvenile length and mass. We also find substantial maternal effects for these traits at age-0, but not age-1, confirming that genotype,phenotype interactions between mother and offspring are strongest at birth; although these effects could not be parsed into their genetic and nongenetic components. Our results suggest that human-imposed selection pressures (e.g., size-selective harvesting) might impose noteworthy evolutionary change even in large marine vertebrates. We therefore use our findings to explain how maternal effects may sometimes promote maladaptive juvenile traits, and how lemon sharks at different nursery sites may show "constrained local adaptation." We also show how single-generation pedigrees, and even simple marker-based regression methods, can provide accurate estimates of quantitative genetic parameters in at least some natural systems. [source]

TEMPORAL PATTERN OF AFRICANIZATION IN A FERAL HONEYBEE POPULATION FROM TEXAS INFERRED FROM MITOCHONDRIAL DNA

EVOLUTION, Issue 5 2004
M. Alice Pinto
Abstract The invasion of Africanized honeybees (Apis mellifera L.) in the Americas provides a window of opportunity to study the dynamics of secondary contact of subspecies of bees that evolved in allopatry in ecologically distinctive habitats of the Old World. We report here the results of an 11-year mitochondrial DNA survey of a feral honeybee population from southern United States (Texas). The mitochondrial haplotype (mitotype) frequencies changed radically during the 11-year study period. Prior to immigration of Africanized honeybees, the resident population was essentially of eastern and western European maternal ancestry. Three years after detection of the first Africanized swarm there was a mitotype turnover in the population from predominantly eastern European to predominantly A. m. scutellata (ancestor of Africanized honeybees). This remarkable change in the mitotype composition coincided with arrival of the parasitic mite Varroa destructor, which was likely responsible for severe losses experienced by colonies of European ancestry. From 1997 onward the population stabilized with most colonies of A. m. scutellata maternal origin. [source]

ACCUMULATION OF DOBZHANSKY-MULLER INCOMPATIBILITIES WITHIN A SPATIALLY STRUCTURED POPULATION

EVOLUTION, Issue 1 2003
ALEXEY S. KONDRASHOV
Abstract., A simple, deterministic analysis predicts that accumulation of Dobzhansky-Muller incompatibilities by a spatially structured population strongly depends on the number of negative interactions of an allele. If an allele can be incompatible with alleles at only one locus, incompatibilities accumulate linearly with time. In contrast, if an allele can participate in multiple pairwise incompatibilities with alleles at different loci, the expected number of incompatibilities eventually increases quadratically. [source]

WITHIN-HOST POPULATION DYNAMICS AND THE EVOLUTION OF MICROPARASITES IN A HETEROGENEOUS HOST POPULATION

EVOLUTION, Issue 2 2002
Vitaly V. Ganusov
Abstract Why do parasites harm their hosts? The general understanding is that if the transmission rate and virulence of a parasite are linked, then the parasite must harm its host to maximize its transmission. The exact nature of such trade-offs remains largely unclear, but for vertebrate hosts it probably involves interactions between a microparasite and the host immune system. Previous results have suggested that in a homogeneous host population in the absence of super- or coinfection, within-host dynamics lead to selection of the parasite with an intermediate growth rate that is just being controlled by the immune system before it kills the host (Antia et al. 1994). In this paper, we examine how this result changes when heterogeneity is introduced to the host population. We incorporate the simplest form of heterogeneity,random heterogeneity in the parameters describing the size of the initial parasite inoculum, the immune response of the host, and the lethal density at which the parasite kills the host. We find that the general conclusion of the previous model holds: parasites evolve some intermediate growth rate. However, in contrast with the generally accepted view, we find that virulence (measured by the case mortality or the rate of parasite-induced host mortality) increases with heterogeneity. Finally, we link the within-host and between-host dynamics of parasites. We show how the parameters for epidemiological spread of the disease can be estimated from the within-host dynamics, and in doing so examine the way in which trade-offs between these epidemiological parameters arise as a consequence of the interaction of the parasite and the immune response of the host. [source]

HETEROSIS AND OUTBREEDING DEPRESSION IN DESCENDANTS OF NATURAL IMMIGRANTS TO AN INBRED POPULATION OF SONG SPARROWS (MELOSPIZA MELODIA)

EVOLUTION, Issue 1 2002
Amy B. Marr
Abstract We studied heterosis and outbreeding depression among immigrants and their descendants in a population of song sparrows on Mandarte Island, Canada. Using data spanning 19 generations, we compared survival, seasonal reproductive success, and lifetime reproductive success of immigrants, natives (birds with resident-hatched parents and grandparents), and their offspring (F1s, birds with an immigrant and a native parent, and F2s, birds with an immigrant grandparent and resident-hatched grandparent in each of their maternal and paternal lines). Lifetime reproductive success of immigrants was no worse than that of natives, but other measures of performance differed in several ways. Immigrant females laid later and showed a tendency to lay fewer clutches, but had relatively high success raising offspring per egg produced. The few immigrant males survived well but were less likely to breed than native males of the same age that were alive in the same year. Female F1s laid earlier than expected based on the average for immigrant and native females, and adult male F1s were more likely to breed than expected based on the average for immigrant and native males. The performance differences between immigrant and native females and between F1s and the average of immigrants and natives are consistent with the hypothesis that immigrants were disadvantaged by a lack of site experience and that immigrant offspring benefited from heterosis. However, we could not exclude the possibility that immigrants had a different strategy for optimizing reproductive success or that they experienced ecological compensation for life-history parameters. For example, the offspring of immigrants may have survived well because immigrants laid later and produced fewer clutches, thereby raising offspring during a period of milder climatic conditions. Although sample sizes were small, we found large performance differences between F1s and F2s, which suggested that either heterosis was associated with epistasis in F1s, that F2s experienced outbreeding depression, or that both phenomena occurred. These findings indicate that the performance of dispersers may be affected more by fine-scale genetic differentiation than previously assumed in this and comparable systems. [source]

ANALYSIS ON THE DYNAMICS OF SPATIAL DISTRIBUTION PATTERN OF MIXED SPIDER POPULATION IN RICE FIELD

INSECT SCIENCE, Issue 4 2004
Zhi Wang
Abstract The results make it clear that there are total 11 families, 29 genera and 43 species of spiders in the rice field of Dong Fang Hong Farm. Among them, there are 8 families, 19 genera and 28 species in the early rice field, and 10 families, 27 genera and 36 species in the late rice field. The spatial distribution pattern of mixed spider populations in rice fields was different during different development stages of rice plant. During the prophase, metaphase and anaphase of early rice plant development, the spatial distribution pattern of mixed spider populations was aggregative, random and aggregative respectively. During the prophase, metaphase and anaphase of late rice plant development, the spatial distribution pattern was uniform, aggregative and uniform respectively. [source]

UNDERDIAGNOSIS OF CHRONIC KIDNEY DISEASE IN THE NURSING HOME POPULATION

JOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 6 2009
Jeffrey T. Cohen MD
No abstract is available for this article. [source]

EFFECT OF PROCESSING ON BACTERIAL POPULATION OF CUTTLE FISH AND CRAB AND DETERMINATION OF BACTERIAL SPOILAGE AND RANCIDITY DEVELOPING ON FROZEN STORAGE

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 1 2007
THAILAMBAL ANANTHA SUBRAMANIAN
ABSTRACT Processing techniques like cooking and freezing exhibited significant (P < 0.001) reduction in the bacterial load of cuttlefish, Sepia pharaonis, and marine crab, Portunus pelagicus. Raw cuttle fish had 2.4 × 107 cfu/g which on cooking reduced to 9.7 × 106 cfu/g. Freezing reduced the bacterial load further as cooked frozen product had only 9.9 × 104 cfu/g. Similarly, raw crab had 2.6 × 107 cfu/g which on cooking reduced to 6.5 × 106 cfu/g. A further reduction in bacterial load was seen after freezing as cooked frozen crab exhibited only 7.3 × 104 cfu/g. Escherichia coli and Staphylococcus aureus were present in the limit of acceptability for fish and fish products. Salmonella typhimurium and Vibrio cholerae were absent even in raw stage. Biochemical analysis performed on stored frozen products of cuttle fish and crab exhibited a significant (P , 0.05) increase in bacterial spoilage and rancidity with increasing days of storage. Total volatile base nitrogen, trimethylamine, thiobarbituric acid and free fatty acid contents in frozen products of cuttle fish and crab increased significantly with 120 days of frozen storage. [source]

KERNEL MORPHOLOGY VARIATION IN A POPULATION DERIVED FROM A SOFT BY HARD WHEAT CROSS AND ASSOCIATIONS WITH END-USE QUALITY TRAITS,

JOURNAL OF FOOD QUALITY, Issue 4 2000
CHRISTINE J. BERGMAN
ABSTRACT Physical attributes, including kernel morphology, are used to grade wheat, and indicate wheat milling and baking quality (MBQ). Using a recombinant inbred population derived from a soft by hard wheat cross, this study quantified kernel traits' sources of variation, studied their heritability, and relationships between morphological and MBQ traits. Transgressive segregation occurred for all traits. Thousand-kernel weight (TKW) and kernel texture (NIR-T) were primarily [source]

EFFECTS OF ORGANIC ACIDS, NISIN, LYZOZYME AND EDTA ON THE SURVIVAL OF YERSINIA ENTEROCOLITICA POPULATION IN INOCULATED ORANGE BEVERAGES

JOURNAL OF FOOD SAFETY, Issue 1 2010
CECILIA S.M. LUCERO ESTRADA
ABSTRACT Inactivation of a Yersinia enterocolitica strain by 3.4% ascorbic acid (AA), 0.5% citric acid (CA), 0.2% lactic acid, 100 IU/mL nisin, 2,400 IU/mL lysozyme and 20 mM ethylenediaminetetraacetic acid disodium salt (EDTA ), alone and combined, was studied at different temperatures (4 and 25C) in commercial and laboratory-prepared orange beverages. In laboratory-prepared juice, highest reductions (between 3.06 and 4.07 log units) were obtained with acid mixtures at 25C after 20 min of incubation. At 24 h of incubation, EDTA was bactericidal and the mixtures with nisin or lysozyme resulted in count reductions of 6.03 and 5.98 log units, respectively. In commercial orange beverage, AA and CA gave reductions of 5.43 and 4.26 log units, respectively. The three acid mixtures were bactericidal within the first 10 min. EDTA alone or mixed completely inhibited Y. enterocolitica strain at 6 and 24 h of incubation. At 4C, all the results were significantly lower than at 25C. PRACTICAL APPLICATIONS Yersinia enterocolitica is a common cause of gastrointestinal disorders and may lead to sequelae. This pathogen can maintain its virulence in a wide temperature range and under adverse conditions such as pH lower than 4. There are reports describing the isolation of Y. enterocolitica from water and ice in Brazil and Latin America. The sale of unpasteurized drinks is a common practice in our region and their consumption has increased over the past years. In the present work, chemical compounds and biological inhibitors were studied. Some of these compounds showed to be efficient for reducing Y. enterocolitica populations. Furthermore, they did not modify the organoleptic characteristics of the beverages and they are not toxic for human beings. [source]

INFLUENCE OF WASHING TREATMENT ON NATIVE MICROFLORA AND ESCHERICHIA COLI POPULATION OF INOCULATED CANTALOUPES

JOURNAL OF FOOD SAFETY, Issue 1 2001
DIKE O. UKUKU
ABSTRACT The influence of chlorine or hydrogen peroxide treatment on populations of Escherichia coli 25922 on the external surface of inoculated cantaloupe was investigated. Surface treatment with 70% EtOH, followed by immersion in 108 CFU/mL E. coli inoculum deposited an average of 4.4 log10CFU/cm2 cell population on the cantaloupe surface. The efficncy of washing inoculated cantaloupe was dependent on storage interval between inoculation and treatment. Dipping the cantaloupes in solutions containing 1000 mg/L chlorine or 5% peroxide for 5 min, within 24 h of inoculation, caused a 2 log10 CFU/cm2 reduction of the indigenous surface microflora and a 3,4.0 log10 CFU/cm2 reduction in E. coli. The efficacy was less when the interval between inoculation and treatment exceeded 24 h. Chlorine appeared in be a better antimicrobial agent than hydrogen peroxide against F. coli ATCC 25922 inoculated on cantaloupe surfaces while hydrogen peroxide was better in reducing surface microflora of cantaloupe. [source]

AMPFlSTR® IdentifilerÔ STR Allele Frequencies in Tanzania, Africa

JOURNAL OF FORENSIC SCIENCES, Issue 1 2008
Bryan W. Forward M.S.
POPULATION:, Identifiler,Employees and students of Muhimibili University College of Health Sciences in Dar es Salaam representing 19 widely distributed administrative districts and 42 tribes within the country. [source]

Haplotype Frequencies of Eight Y-Chromosome Short Tandem Repeats Loci in Four Amerindian Populations (State of Hidalgo, Mexico)

JOURNAL OF FORENSIC SCIENCES, Issue 2 2007
Carme Barrot Ph.D.
POPULATION: Amerindian populations: Huastecos (n=97), Otomies de la Sierra (n=41), Otomies del Valle (n=40), and Tepehuas (n=13). [source]

Allele Frequencies of 20 Y-Chromosomal Short Tandem Repeat Loci in a Tribal Population of Deccan Plateau, India

JOURNAL OF FORENSIC SCIENCES, Issue 2 2007
G. Hima Bindu M.Sc.
POPULATION: Eighty male individuals from a nomadic tribal population belonging to Dravidian and Indo-Caucasian ethnicities from Deccan Plateau, Andhra Pradesh, India (1), were analyzed in the present study. [source]

Polymorphism Analysis of Y-Chromosomal Haplotypes in the Chinese Han Population Living in the Shaanxi Province of China

JOURNAL OF FORENSIC SCIENCES, Issue 2 2007
Junping Xing Ph.D., M.D.
POPULATION: Chinese Han population living in the Shaanxi Province of China. [source]

Allele Frequencies for Two Short Tandem Repeat Loci in the Chinese Han Population from Chengdu, China, and a Thai Population from Thailand

JOURNAL OF FORENSIC SCIENCES, Issue 1 2007
Yanyun Wang M.D.
POPULATION: Chinese Han and Thai. [source]

Southwest China Han Population Data for Nine Y-STR Loci by Multiplex Polymerase Chain Reaction

JOURNAL OF FORENSIC SCIENCES, Issue 1 2007
Meisen Shi Ph.D.
POPULATION: One hundred and twenty unrelated Han ethnic individuals from Chengdu, southwest China. [source]

Haplotype Diversity at 20 Y-Chromosome Microsatellites in an Indo-Caucasian Population of Bengal, India

JOURNAL OF FORENSIC SCIENCES, Issue 6 2006
Anamika Singh M.Sc.
POPULATION: Sixty-one Indo-Caucasian individuals from eastern India. [source]

A New Allele of the Short Tandem Repeat Locus D21S11 in a Venezuelan Population,

JOURNAL OF FORENSIC SCIENCES, Issue 3 2006
Noelia Lander B.S.
POPULATION: Venezuelan, Caracas City, 255 individuals. [source]

Allele Frequency Data for 19 Short Tandem Repeats (PowerPlex® 16 and FFFl) in a Belgian Population Sample

JOURNAL OF FORENSIC SCIENCES, Issue 2 2006
Ronny Decorte Ph.D
POPULATION: Belgian Caucasians (Dutch speaking; n=198). [source]

Genetic Variation for Penta D and Penta E in a Northeast Colombian Population (Department of Santander)

JOURNAL OF FORENSIC SCIENCES, Issue 2 2006
Clara Inés Vargas M.D., M.Sc.
POPULATION: Department of Santander, Colombia (n=104). [source]

Analysis of Y-STR Loci in a Population Sample from Northeast China

JOURNAL OF FORENSIC SCIENCES, Issue 1 2006
Xiuling Wang Ph.D.
POPULATION: A total of 141 unrelated Chinese Han male individuals living in Liaoning in northeast China. [source]

DNA Sequence Characterization of the FGA STR Locus in the Free State Population of South Africa

JOURNAL OF FORENSIC SCIENCES, Issue 1 2006
André de Kock Ph.D.
POPULATION: African (n=52), Mixed Ancestry (n=5), Caucasian (n=4) SAN (n=1). [source]

HELICOBACTER PYLORI INFECTION IN ASYMPTOMATIC POPULATION IN SURABAYA

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 12 2000
Pangestu Adi
[source]

A COMPREHENSIVE STUDY OF THE LIFE CYCLE OF A SOUTH AMERICAN POPULATION OF STIGEOCLONIUM TENUE (CHAETOPHORALES, CHLOROPHYTA),

JOURNAL OF PHYCOLOGY, Issue 5 2010
Karina M. Michetti
The diplobiontic,haplodiplontic life cycle with alternating isomorphic generations in Stigeoclonium tenue (C. Agardh) Kütz. is described for the first time. Sporophytes (2n = 10) arise from tetraflagellate zoospores that are produced by meiosis. Sporic meiosis might be inferred from the cruciform divisions formed during zoosporogenesis and is confirmed through observations of prophase I substages. Zoospores do not germinate directly but produce a haploid cyst that germinates to give rise to a gametophyte (n = 5). Gametophytes produce biflagellate isogametes, which fuse to produce zygotes that germinate by mitosis into the sporophytic stage. Gametophytes and sporophytes reproduce asexually both via mitotic tetraflagellate zoospores and by thallus fragmentation. Results from this study indicate that both the cosmopolitan distribution and dominance of S. tenue in many periphytic communities might be due to its multiple reproductive strategies. [source]

A RESIDENT POPULATION OF INDO-PACIFIC BOTTLENOSE DOLPHINS (TURSIOPS ADUNCUS) IN AMAKUSA, WESTERN KYUSHU, JAPAN

MARINE MAMMAL SCIENCE, Issue 1 2002
Miki Shirakihara
Abstract Residency patterns and population size were examined for Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the coastal waters of Amakusa-Shimoshima Island, western Kyushu, Japan, from summer 1994 to fall 1998. A total of 203 individuals were identified. The number of newly identified individuals barely increased after the first 1.5 yr. The identified individuals in one season were frequently resighted with percentages of mostly over 60% during the subsequent seasons. Most of the dolphins off Amakusa were yearround residents, although the total range of their habitat was unknown. The population size estimated by the mark-recapture technique was 218 individuals with a CV of 5.41% in 1995,1997. The group commonly consisted of more than 100 individuals. The large group size was thought to be a response to feeding on schooling fishes. [source]

HARVESTING AN AGE-STRUCTURED POPULATION AS BIOMASS: DOES IT WORK?

NATURAL RESOURCE MODELING, Issue 4 2008
OLLI TAHVONEN
Abstract The economics of fisheries is based heavily on describing fish populations by the surplus production model. Both economists and ecologists have different opinions on whether this approach provides an adequate biological basis for economic analysis. This study takes an age-structured population model and shows how, under equilibrium conditions, it determines the surplus production model. The surplus production model is then used to solve an optimal feedback policy for a generic optimal harvesting problem. Next, it is assumed that the fishery manager applies this feedback policy even though the fish population actually evolves according to the age-structured model. This framework is applied to the widow rockfish, Atlantic menhaden, and Pacific halibut fisheries. Population age-structure contains information on future harvest possibilities. The surplus production model neglects this information and may lead to major deviations between the expected and actual outcomes especially under multiple steady states and nonlinearities. [source]