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Growth Dynamics (growth + dynamics)
Selected AbstractsEffect of Timing and Nitrogen Fertilizer Application on Winter Oilseed Rape (Brassica napus L.). I. Growth Dynamics and Seed YieldJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 5 2004P. Bar Abstract The field experiments conducted on the grey-brown podzolic soil in the four growing seasons (1998,2001) at Krzeslice Farm, central-western Poland comprised seven fertilization variants: 80NF + 80CAN; 80CAN + 80CAN; 80AN + 80AN; 80NF + 50CAN + 30CN; 80CAN + 50CAN +30CN; 80AN + 50AN + 30CN (where NF , nitrofos NPK; CAN , calcium-ammonium nitrate; AN , ammonium nitrate; CN , calcium nitrate) and control (without N) applied in split rates at the beginning of spring regrowth (80 kg N ha,1), stem elongation (80 or 50) and flower buds visible stages (30). The yielding effect of tested fertilization variants was significant in comparison with the control (2.24 t ha,1). The highest mean seed yield (3.64 t ha,1) was collected from 80AN + 80AN and 80CAN + 80CAN variants. Mean values of 4 years indicate that the second N rate division (80 + 50 + 30) decreased yield, although not significantly in comparison with these two N treatments. Plants grown on these treatments have developed different patterns of growth to yield the seeds. These patterns were characterized by very high crop growth rate during flowering (above 21 g m,2 day,1) and negative at maturation (down to ,2.5 g m,2 day,1). Plants fertilized with ammonium nitrate (80AN + 80AN) reached maximum growth rate earlier (65 days), which lasted longer (20 days) than plants fertilized with calcium-ammonium nitrate (71 days lasting 17.5 days). Plants grown on the control treatment reached the highest crop growth rate within 79 days (14.8 g m,2 day,1), which lasted 15 days. [source] Effect of Two Thermal Regimes on the Muscle Growth Dynamics of Sea Bass Larvae, Dicentrarchus labrax L.ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2003Mª. D. Ayala Summary Muscle growth was studied in larvae of sea bass, Dicentrarchus labrax L., reared at two temperatures: real ambient temperature (,15°C during vitelline phase and increased gradually) and 19°C from fertilization until the end of larval development. Muscle cellularity, body length and body weight were measured. Early temperature influenced larval development and so, pre-larval phase finished earlier at 19°C than at ambient temperature (4 and 6 days, respectively). Temperature also affected muscle growth such that at hatching and at mouth opening hypertrophy of muscle fibres was greater at 19°C (P < 0.05), whereas hyperplasia was similar in both groups. After 25 days, the cross-sectional area of the white muscle was greater at 19°C (P < 0.05), which was mainly associated with a higher proliferation of new white muscle fibres. At this stage the body length was also higher at 19°C. Metamorphosis finished earlier in fish reared at 19°C (52 days) than at natural temperature (82 days). At this developmental stage body length and cross-sectional area of the myotome were similar in both groups. However, muscle cellularity differed between groups. Thus, hypertrophy of muscle fibres was higher in fish reared at ambient temperature (P < 0.05), whereas proliferation of new muscle fibres was higher at 19°C (P > 0.05). [source] Growth dynamics of dairy processing firms in the European UnionAGRICULTURAL ECONOMICS, Issue 3-4 2010Cornelis Gardebroek EU dairy processing industry; Dynamic panel data; Firm growth Abstract The structure of the dairy processing industry in the European Union has changed enormously in recent decades. In many countries, the industry is characterized by a few large companies with a big market share accompanied by many small processors that often produce for niche markets. This article investigates which factors relate to growth of dairy processing firms. Using a unique 10-year panel data set and recently developed dynamic panel data estimators, the growth process of dairy processors is investigated for six rather diverse European countries. The data structure and the estimation method allow for dealing with endogeneity issues in an appropriate way. Firm size growth measured in total assets is found to be affected by firm size, firm age, and financial variables. Growth in number of employees is only affected by firm age and lagged labor productivity. Implications for these results are given in the final section of the article. [source] Use of monoclonal antibodies to quantify the dynamics of ,-galactosidase and endo-1,4-,-glucanase production by Trichoderma hamatum during saprotrophic growth and sporulation in peatENVIRONMENTAL MICROBIOLOGY, Issue 5 2005Christopher R. Thornton Summary Trichoderma species are ubiquitous soil and peat-borne saprotrophs that have received enormous scientific interest as biocontrol agents of plant diseases caused by destructive root pathogens. Mechanisms of biocontrol such as antibiosis and hyperparasitism are well documented and the biochemistry and molecular genetics of these processes defined. An aspect of biocontrol that has received little attention is the ability of Trichoderma species to compete for nutrients in their natural environments. Trichoderma species are efficient producers of polysaccharide-degrading enzymes that enable them to colonize organic matter thereby preventing the saprotrophic spread of plant pathogens. This study details the use of monoclonal antibodies (mAbs) to quantify the production of two enzymes implicated in the saprotrophic growth of Trichoderma species in peat. Using mAbs specific to the hemicellulase enzyme ,-galactosidase (AGL) and the cellulase enzyme endo-1,4-,-glucanase (EG), the relationship between the saprotrophic growth dynamics of a biocontrol strain of Trichoderma hamatum and the concomitant production of these enzymes in peat-based microcosms was studied. Enzyme activity assays and enzyme protein concentrations derived by enzyme-linked immunosorbent assay (ELISA) established the precision and sensitivity of mAb-based assays in quantifying enzyme production during active growth of the fungus. Trends in enzyme activities and protein concentrations were similar for both enzymes, during a 21-day sampling period in which active growth and sporulation of the fungus in peat was quantified using an independent mAb-based assay. There was a sharp increase in active biomass of T. hamatum 3 days after inoculation of microcosms with phialoconidia. After 3 days there was a rapid decline in active biomass which coincided with sporulation of the fungus. A similar trend was witnessed with EG activities and concentrations. This showed that EG production related directly to active growth of the fungus. The trend was not found, however, with AGL. There was a rapid increase in enzyme activities and protein concentrations on day 3, after which they remained static. The reason for the maintenance of elevated AGL probably resulted from secretion of the enzyme from conidia and chlamydospores. ELISA, immunofluoresence and immunogold electron microscopy studies of these cells showed that the enzyme is localized within the cytoplasm and is secreted extracellularly into the surrounding environment. It is postulated that release of oligosaccharides from polymeric hemicellulose by the constitutive spore-bound enzyme leads to AGL induction and could act as an environmental cue for spore germination. [source] Phosphorus-limited growth dynamics in two Baltic Sea cyanobacteria, Nodularia sp. and Aphanizomenon sp.FEMS MICROBIOLOGY ECOLOGY, Issue 3 2006Jenny Degerholm Abstract Rates of carbon (C) specific growth and nitrogen (N2) fixation were monitored in cultures of Baltic Sea Nodularia and Aphanizomenon exposed to gradual limitation by inorganic phosphorus (P). Both cyanobacteria responded by decreased cellular P content followed by lowered rates of growth and N2 fixation. C-specific growth and cellular N content changed faster in Aphanizomenon both when inorganic P was lowered as well as during reintroduction of P. Aphanizomenon also showed a more rapid increase in N-specific N2 fixation associated with increased C-specific growth. When ambient concentrations of inorganic P declined, both cyanobacteria displayed higher rates of alkaline phosphatase (APase) activity. Lower substrate half-saturation constants (KM) and higher Vmax : KM ratio of the APase enzyme associated with Nodularia suggest a higher affinity for dissolved organic P (DOP) substrate than Aphanizomenon. Aphanizomenon, which appears more sensitive to changes in ambient dissolved inorganic P, may be adapted to environments with elevated concentrations of P or repeated intrusions of nutrient-rich water. Nodularia on the other hand, with its higher tolerance to increased P starvation may have an ecological advantage in stratified surface waters of the Baltic Sea during periods of low P availability. [source] Role of reserve carbohydrates in the growth dynamics of Saccharomyces cerevisiae,FEMS YEAST RESEARCH, Issue 8 2004Vincent Guillou Abstract The purpose of this study was to explore the role of glycogen and trehalose in the ability of Saccharomyces cerevisiae to respond to a sudden rise of the carbon flux. To this end, aerobic glucose-limited continuous cultures were challenged with a sudden increase of the dilution rate from 0.05 to 0.15 h,1. Under this condition, a rapid mobilization of glycogen and trehalose was observed which coincided with a transient burst of budding and a decrease of cell biomass. Experiments carried out with mutants defective in storage carbohydrates indicated a predominant role of glycogen in the adaptation to this perturbation. However, the real importance of trehalose in this response was veiled by the unexpected phenotypes harboured by the tps1 mutant, chosen for its inability to synthesize trehalose. First, the biomass yield of this mutant was 25% lower than that of the isogenic wild-type strain at dilution rate of 0.05 h,1, and this difference was annulled when cultures were run at a higher dilution rate of 0.15 h,1. Second, the tps1 mutant was more effective to sustain the dilution rate shift-up, apparently because it had a faster glycolytic rate and an apparent higher capacity to consume glucose with oxidative phosphorylation than the wild type. Consequently, a tps1gsy1gsy2 mutant was able to adapt to the dilution rate shift-up after a long delay, likely because the detrimental effects from the absence of glycogen was compensated for by the tps1 mutation. Third, a glg1,glg2, strain, defective in glycogen synthesis because of the lack of the glycogen initiation protein, recovered glycogen accumulation upon further deletion of TPS1. This recovery, however, required glycogen synthase. Finally, we demonstrated that the rapid breakdown of reserve carbohydrates triggered by the shift-up is merely due to changes in the concentrations of hexose-6-phosphate and UDPglucose, which are the main metabolic effectors of the rate-limiting enzymes of glycogen and trehalose pathways. [source] Thermographic assessment of tumor growth in mouse xenograftsINTERNATIONAL JOURNAL OF CANCER, Issue 5 2007Chengli Song Abstract In human breast tumors, a 1,2°C increase in skin surface temperature is usually observed at the periphery; it has been proposed that this change is due to the hypervascularity and increased blood flow resulting from tumor-associated angiogenesis. Here we tested the hypothesis that thermal imaging might represent a useful adjunctive technique in monitoring the growth dynamics of human tumor xenografts. Xenografts were established in immunocomprised nude mice using MDA-MB-231 or MCF7 breast cancer cells. We exploited the inherent noncontact and noninvasive advantages of infrared thermography to detect skin surface temperature changes. Continuous thermographic investigation was performed to detect and monitor tumor growth in vivo and high resolution digital images were analyzed to measure the tumor temperature dynamics. In contrast to the skin temperature increases associated with human breast cancer, a consistent temperature decrease was found in the xenograft mice. In one case, a smaller secondary tumor, otherwise undetectable, was clearly evident by thermal imaging. The tumors were cooler than the surrounding tissue with a maximum temperature reduction of 1.5°C for MDA-MB-231 tumor and 3°C for MCF7 tumors observed on day 14. In addition, the temperature of the xenograft tumors decreased progressively as they grew throughout the observation period. It was demonstrated that thermographic imaging could detect temperature changes as small as 0.1°C on the skin surface at an early stage of tumor development. The findings of the study indicate that thermographic imaging might have considerable potential in monitoring human tumor xenografts and their response to anticancer drugs. © 2007 Wiley-Liss, Inc. [source] Relevance of Osteoinductive Biomaterials in Critical-Sized Orthotopic DefectJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2006Pamela Habibovic Abstract Several publications have shown the phenomenon of osteoinduction by biomaterials to be real. However, whether the ability of a biomaterial to initiate bone formation in ectopic implantation sites improves the performance of such osteoinductive biomaterial in clinically relevant orthotopic sites remains unclear. No studies have been published in which osteoinductive potential of a biomaterial is directly related to its performance orthotopically. In this study, we compared osteoinductive and nonosteoinductive biphasic calcium,phosphate (BCP) ceramics ectopically and in a clinically relevant critical-sized orthotopic defect in goats. The two materials, BCP1150 and BCP1300, had similar chemical compositions, crystallinities, and macrostructures, but their microstructures differed significantly. BCP1150, sintered at a lower temperature, had a large amount of micropores, small average crystal size, and hence a high specific surface area. In contrast, BCP1300, with few micropores, had a significantly lower specific surface area as compared to BCP1150. Twelve-week intramuscular implantation in goats (n,=,10) showed that bone was induced in all BCP1150 implants, while no signs of bone formation were found in any of the BCP1300 implants. After 12 weeks of implantation in a bilateral critical-sized iliac wing defect in the same goats, BCP1150 showed significantly more bone than BCP1300. In addition, the analysis of fluorochrome markers, which were administered to the animals 4, 6, and 8 weeks after implantation to follow the bone growth dynamics, showed an earlier start of bone formation in BCP1150 as compared to BCP1300. Significantly better performance of an osteoinductive ceramic in a critical-sized orthotopic defect in a large animal model in comparison to a nonosteoinductive ceramic suggests osteoinduction to be clinically relevant. Further improvement of material osteoinductive properties is thus a significant step forward in the search for alternatives for autologous bone graft. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source] Hyalgan® has a dose-dependent differential effect on macrophage proliferation and cell deathJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2003Kyle M. Sheehan Abstract The intra-articular injection of high molecular weight hyaluronic acid (HA) has been reported to be an effective treatment for pain of osteoarthritis of the knee. However, the mechanism by which HA exerts its effect is unknown. To explore HA's influence on the growth of U937 human macrophages, cells were incubated for 168 h with three concentrations, 1, 0.1 and 0.01 mg/mL, of Hyalgan®, a high molecular weight HA preparation. At 24-h increments, the cells were examined for proliferation, cell cycle distribution as well as the number of apoptotic and dead cells. Exposing macrophages to 1 mg/mL Hyalgan® significantly reduced the rate of cellular proliferation and altered the cell cycle distribution to yield decreased proportions of G0/G1 cells but increased S and G2/M cells. Concomitantly, a 10-fold increase in apoptotic cells and a 12-fold increase in dead cells were observed. The population doubling time (PDT) for cells treated with 1.0 mg/mL Hyalgan® increased from 23.6 to 52.9 h. By contrast, the two lower Hyalgan® concentrations significantly promoted macrophage proliferation in a dose-dependent manner. They also increased the proportion of G2/M cells, but had no effect on the number of apoptotic or dead cells. The PDTs of 21.5 and 22.2 h were less than the control time of 23.6 h. These results demonstrate that Hyalgan® concentrations have a differential effect on macrophage growth dynamics and suggest an anti-inflammatory effect at high HA concentrations. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Scaling phenomena in the growth dynamics of scientific outputJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 9 2005Kaushik Matia We analyze a set of three databases at different levels of aggregation: (a) a database of approximately 106 publications from 247 countries published from 1980,2001, (b) a database of 508 academic institutions from the European Union (EU) and 408 institutes from the United States for the 11-year period of 1991,2001, and (c) a database of 2,330 Flemish authors published in the period from 1980,2000. At all levels of aggregation we find that the mean annual growth rates of publications is independent of the number of publications of the various units involved. We also find that the standard deviation of the distribution of annual growth rates decays with the number of publications as a power law with exponent , 0.3. These findings are consistent with those of recent studies of systems such as the size of research and development funding budgets of countries, the research publication volumes of U.S. universities, and the size of business firms. [source] Firm-like behavior of journals?JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 1 2005Scaling properties of their output, impact growth dynamics In the study of growth dynamics of artificial and natural systems, the scaling properties of fluctuations can exhibit information on the underlying processes responsible for the observed macroscopic behavior according to H.E. Stanley and colleagues (Lee, Amaral, Canning, Meyer, & Stanley, 1998; Plerou, Amaral, Gopikrishnan, Meyer, & Stanley, 1999; Stanley et al., 1996). With such an approach, they examined the growth dynamics of firms, of national economies, and of university research fundings and paper output. We investigated the scaling properties of journal output and impact according to the Journal Citation Reports (JCR; ISI, Philadelphia, PA) and find distributions of paper output and of citations near to lognormality. Growth rate distributions are near to Laplace "tents," however with a better fit to Subbotin distributions. The width of fluctuations decays with size according to a power law. The form of growth rate distributions seems not to depend on journal size, and conditional probability densities of the growth rates can thus be scaled onto one graph. To some extent even quantitatively, all our results are in agreement with the observations of Stanley and others. Further on, a Matthew effect of journal citations is confirmed. If journals "behave" like business firms, a better understanding of Bradford's Law as a result of competition among publishing houses, journals, and topics suggests itself. [source] Water-Yield Reduction After Afforestation and Related Processes in the Semiarid Liupan Mountains, Northwest China,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 5 2008Yanhui Wang Abstract:, The increase of coverage of forest/vegetation is imperative to improve the environment in dry-land areas of China, especially for protecting soil against serious erosion and sandstorms. However, inherent severe water shortages, drought stresses, and increasing water use competition greatly restrict the reforestation. Notably, the water-yield reduction after afforestation generates intense debate about the correct approach to afforestation and forest management in dry-land areas. However, most studies on water-yield reduction of forests have been at catchment scales, and there are few studies of the response of total evapotranspiration (ET) and its partitioning to vegetation structure change. This motivates us to learn the linkage between hydrological processes and vegetation structure in slope ecosystems. Therefore, an ecohydrological study was carried out by measuring the individual items of water balance on sloping plots covered by different vegetation types in the semiarid Liupan Mountains of northwest China. The ratio of precipitation consumed as ET was about 60% for grassland, 93% for shrubs, and >95% for forestland. Thus, the water yield was very low, site-specific, and sensitive to vegetation change. Conversion of grassland to forest decreased the annual water yield from slope by 50-100 mm. In certain periods, the plantations at lower slopes even consumed the runon from upper slopes. Reducing the density of forests and shrubs by thinning was not an efficient approach to minimize water use. Leaf area index was a better indicator than plant density to relate ET to vegetation structure and to evaluate the soil water carrying capacity for vegetation (i.e., the maximum amount of vegetation that can be supported by the available soil water for an extended time). Selecting proper vegetation types and plant species, based on site soil water condition, may be more effective than the forest density regulation to minimize water-yield reduction by vegetation coverage increase and notably by reforestation. Finally, the focuses in future research to improve the forest-water relations in dry-land areas are recommended as follows: vegetation growth dynamics driven by environment especially water conditions, coupling of ecological and hydrological processes, further development of distributed ecohydrological models, quantitative relation of eco-water quota of ecosystems with vegetation structures, multi-scaled evaluation of soil water carrying capacity for vegetation, and the development of widely applicable decision support tools. [source] The influence of pre-fermentative practices on the dominance of inoculated yeast starter under industrial conditionsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2002Maurizio Ciani Abstract The influence of pre-fermentative practices on the growth dynamics of a ,natural' starter culture with specific phenotype (H2S,) concurrently with wild yeast populations was evaluated under winery conditions. Different clarification procedures and added SO2 strongly influenced species and cell numbers isolable at the pre-fermentation stage. Independent treatments of must with sulphite addition or vacuum-filtering clarification caused a 30-fold reduction in viable cells. Clarification procedures, enhanced by the selective effect of SO2 addition, induced the appearance of Saccharomyces cerevisiae ,wild' yeasts. Correct application of the inoculum generally guarantees the dominance of fermentation by starter cultures. However, inoculated fermentations using unclarified white and red musts exhibited a consistent presence and persistence of non- Saccharomyces and/or Saccharomyces ,wild' yeasts during fermentation. The extent and composition of the initial wild microflora at the start of fermentation may affect the presence and persistence of wild Saccharomyces and non- Saccharomyces yeasts during guided fermentations under commercial conditions. The above findings confirm the results of previous works carried out at laboratory- or pilot-scale level. Furthermore, they suggest a clear correlation between the modality of pre-fermentative practices and the presence and persistence of ,wild' yeasts during fermentation. © 2002 Society of Chemical Industry [source] Challenges of introducing quantitative elementary reactions in multiscale models of thin film depositionPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 9 2010Alessandro Barbato Abstract The implementation of detailed surface kinetic mechanisms describing the thin film growth dynamics into models of chemical vapor deposition (CVD) reactors has been a challenge for many years. In this article we review the literature concerning the study of the dynamics of the Si(100)2,×,1 surface and introduce a multiscale model that captures the main features of its reactivity. The model combines the results of ab initio calculations with an atomistic description of the Si surface, obtained using a 3D-kinetic Monte Carlo (KMC) model that explicitly accounts for the 2,×,1 surface reconstruction and the formation and diffusion of Si dimers on a hydrogenated surface. At the atomistic scale, we determined pre-exponential factors and activation energies of hydrogen desorption reactions proceeding through the 2H, 3H, and 4H mechanisms. The calculated kinetic constants were embedded in the KMC model and used to simulate literature TPD experimental data. The simulations were used to fit the activation energies of hydrogen desorption reactions, which showed that DFT calculations performed with B3LYP functionals are likely to overestimate hydrogen desorption energies by up to 9,kcal,mol,1, which was confirmed by successive ab initio calculations. Two examples of the solution of the KMC model in conjunction with a reactor scale model are provided, in which the coupling was performed adopting both a hierarchic and a two-way coupling strategy. We found that in the plasma deposition of nanocrystalline silicon performed at low substrate temperatures the growth proceeds through a layer-by-layer mechanism on a surface almost completely covered by hydrogen. The application of the same model to the simulation of the thermal CVD of Si showed that at intermediate growth temperatures, when the hydrogen surface concentration is high, a new hydrogen desorption mechanism, in which Si adatoms play an important role, is active. Length scales encountered in multiscale modeling of thin films deposition. [source] Root growth dynamics of Nicotiana attenuata seedlings are affected by simulated herbivore attackPLANT CELL & ENVIRONMENT, Issue 10 2007GRÉGOIRE M. HUMMEL ABSTRACT Many studies demonstrate resource-based trade-offs between growth and defence on a large timescale. Yet, the short-term dynamics of this growth reaction are still completely unclear, making it difficult to explain growth-defence trade-offs mechanistically. In this study, image-based non-destructive methods were used to quantify root growth reactions happening within hours following simulated herbivore attack. The induction of wound reactions in Nicotiana attenuata in the seedling stage led to transiently decreased root growth rates. Application of the oral secretion of the specialist herbivore Manduca sexta to the leaves led to a transient decrease in root growth that was more pronounced than if a mere mechanical wounding was imposed. Root growth reduction was more pronounced than leaf growth reduction. When fatty acid,amino acid conjugates (FACs) were applied to wounds, root growth reduction occurred in the same intensity as when oral secretion was applied. Timing of the transient growth reduction coincided with endogenous bursts of jasmonate (JA) and ethylene emissions reported in literature. Simulation of a wound response by applying methyl jasmonate (MeJA) led to more prolonged negative effects on root growth. Increased nicotine concentrations, trichome lengths and densities were observed within 72 h in seedlings that were treated with MeJA or that were mechanically wounded. Overall, these reactions indicate that even in a very early developmental stage, the diversion of plant metabolism from primary (growth-sustaining) to secondary (defence-related) metabolism can cause profound alterations of plant growth performance. [source] Brief communication: Identification of bone formation and resorption surfaces by reflected light microscopyAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2010Cayetana Martinez-Maza Abstract Developmental and evolutionary changes in craniofacial morphology are a central issue in paleoanthropology, but the underlying bone growth processes have been scarcely studied. Relevant knowledge on bone growth dynamics can be obtained from the spatial distribution of bone formation and resorption activities. Determining these patterns from the valuable samples typically used in anthropology and palaeoanthropology necessarily implies nondestructive procedures. In this work, we present a methodology based on the analysis of high-resolution replicas by reflected light microscopy, describing how microfeatures related to bone formation and resorption activities are recognized on both recent and fossil bone surfaces. The proposed method yields highly similar images to those obtained with scanning electron microscope and has proven its utility in an analysis of a large sample of extant and extinct hominoids. Am J Phys Anthropol 143:313,320, 2010. © 2010 Wiley-Liss, Inc. [source] Osteological Development of the Garfish (Belone belone) LarvaeANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2009S. Ku Summary Garfish, Belone belone (Linnaeus, 1761) is an elongate, slander fish inhabiting the Eastern Atlantic and Mediterranean Sea. These fish from the Belonidae (Actinopterygii) family have important commercial value for Croatian fisheries. Samples for research were collected from experimental hatching in the Novigrad Sea. Preparation techniques included fixation in buffered formalin, trypsin clearing and staining with alcian blue and alizarin red. As little is known of garfish osteology and bone morphology, the main goal of this study was to describe ossification process in garfish fry. At hatching, no skeletal structure is present. Newly-hatched larvae also had no osteological elements. Ossification started at 7 day post-hatching (DPH) [total length (TL) 18 mm] with head bones and vertebral neural arch. Head skeleton continued to develop mostly over the period from 7 to 10 DPH. At 21 DPH (TL 49 mm), ossification process seemed to be finished, but it was not possible to distinguish borders of all bones. The primary interest of our research was to understand the growth dynamics as well as transformation of supporting body elements from cartilage to bone. At the end, developmental characteristics and functional aspects of this formation in different fish species are discussed. [source] Optimal management of the New Zealand longfin eel (Anguilla dieffenbachii),AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 4 2005Graeme J. Doole Annual recruitment of the New Zealand longfin eel (Anguilla dieffenbachii) has decreased by 75 per cent since significant levels of commercial fishing began in the early 1970s. This motivates application of a multiple-cohort bioeconomic model to a New Zealand longfin eel fishery to investigate its optimal management and ascertain the suitability of existing regulatory policy. The use of historical harvest to calculate total allowable catch is asserted to be unsustainable based on recovery dynamics. In addition, individual transferable quota systems are argued to be fundamentally flawed for the protection of longfin fisheries because of high-grading, low-surplus production and a current lack of effective stock-assessment procedures. Area closure and the spatial definition of harvest rights are attractive alternatives given the territoriality of longfins and high larval spillover. The importance of unfished reserves is reinforced when significant uncertainties regarding population strength, harvest intensity and growth dynamics are considered. Restriction of exploitation to older cohorts in fished areas is demonstrated to maximise economic yield. [source] | |||||||||||||