Determination Of Growth Rate Research Articles

Defective phenotype of mesenchymal stem cells in patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) has been considered as stem cell disorder. The objective of this study was to examine the phenotype, growth and immunomodulatory effect of mesenchymal stem cells (MSCs) from SLE patients compared with those from age- and sex-matched healthy donors. MSCs were expanded from bone marrow aspirate and were examined for morphological appearance, quantified in different passages to determine growth rate and evaluated for ability of adipogenesis and osteogenesis. Telomerase activity was measured by telomerase repeat amplification protocol. The immunomodulatory effect of MSCs was evaluated by mixed lymphocyte reaction. MSCs from SLE patients were found to be bigger and flattened in appearance after passage 3 and demonstrated slower growth rate compared with fibroblast-like MSCs from normal controls. These cells were not able to reach confluence after passage 4. Telomerase activity was upregulated in five SLE patients mostly with active disease compared with two with negative expression with lesser activity. MSCs from SLE patients were, otherwise, comparable to normal controls in terms of their surface marker (CD73, CD90 and CD105) expression and extent of suppression on proliferation of allogeneic T lymphocytes. In conclusion, MSCs from SLE demonstrated early signs of senescence which may be a corollary of active lupus or a contributory factor to disease pathogenesis.

Rate and extent of decline in Corallium (pink and red coral) populations: existing data meet the requirements for a CITES Appendix II listing

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 397:319-332 (2009) - DOI: https://doi.org/10.3354/meps08110 Rate and extent of decline in Corallium (pink and red coral) populations: existing data meet the requirements for a CITES Appendix II listing Andrew W. Bruckner1,2,* 1NOAA Fisheries, Office of Habitat Conservation, NOAA Coral Reef Conservation Program, 1315 East West Highway, Silver Spring, Maryland 20910, USA 2Khaled bin Sultan Living Oceans Foundation, 8181 Professional Place, Suite 215, Landover, Maryland 20785, USA *Email: andy.bruckner@noaa.gov ABSTRACT: In June 2007, the US government proposed Corallium (pink and red corals) for listing on Appendix II of the Convention on International Trade in Endangered Species (CITES). The proposal was adopted and later overturned due to perceived difficulties in implementing and enforcing a CITES listing and uncertainties on population status. An expert review (Food and Agriculture Organization) questioned whether populations had declined to 20–30% of the historic baseline, the level required for a CITES Appendix II listing. This review used colony abundance and density as surrogates of decline, which may be high (200 to 1300 colonies m–2) in the Mediterranean. Yet assessments of decline for colonial organisms should also consider changes in size, since reproductive output and survival increase exponentially with size. Colonies of C. rubrum historically achieved heights of 50 cm with complex first, second and third order branching patterns. Today, >90% of colonies in fished areas are 3 to 5 cm tall, <50% are sexually mature and most have only rudimentary branches. Few population data are available for Pacific Corallium spp.; however, landings over the last 15 yr have declined from 100–400 to <5 t yr–1. Recovery of populations to their natural state may require decades, as colonies in protected areas are less than half their historic size after 20 to 30 yr of protection. Minimum allowable size for harvest should be increased because traditionally determined growth rates appear to underestimate colony age, and corals are being removed long before achieving maximum sustainable yield. ‘Boom and bust' cycles of Corallium fisheries and dramatic, long-lasting shifts in population demography highlight the need for improved management and trade regulations. KEY WORDS: Precious coral · Pink and red corals · Corallium · Harvest · Trade · Coral jewelry Full text in pdf format See Comment and Reply Comment on this article PreviousNextCite this article as: Bruckner AW (2009) Rate and extent of decline in Corallium (pink and red coral) populations: existing data meet the requirements for a CITES Appendix II listing. Mar Ecol Prog Ser 397:319-332. https://doi.org/10.3354/meps08110 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 397. Online publication date: December 17, 2009 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2009 Inter-Research.

Growth rate and age determination of bamboo corals from the northeastern Pacific Ocean using refined 210Pb dating

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 397:173-185 (2009) - DOI: https://doi.org/10.3354/meps08193 Growth rate and age determination of bamboo corals from the northeastern Pacific Ocean using refined 210Pb dating Allen H. Andrews1,*, Robert P. Stone2, Craig C. Lundstrom3, Andrew P. DeVogelaere4 1Age and Longevity Research, Moss Landing Marine Laboratories, California State University, 8272 Moss Landing Road, Moss Landing, California 95039, USA 2Auke Bay Laboratories, Alaska Fisheries Science Center, NOAA Fisheries, 17109 Point Lena Loop Road, Juneau, Alaska 99801, USA 3Department of Geology, University of Illinois Urbana-Champaign, 245 Natural History Building, 1301 West Green Street, Urbana, Illinois 61801, USA 4Monterey Bay National Marine Sanctuary, 299 Foam Street, Monterey, California 93940, USA *Email: andrews@mlml.calstate.edu ABSTRACT: Bamboo corals from Davidson Seamount and from the Gulf of Alaska were aged using a refined 210Pb dating technique. The goal was to determine growth rates and age for several bamboo corals with higher precision. Radiometric results for 2 Davidson Seamount corals (Keratoisis sp.) converged on a radial growth rate of ~0.055 mm yr–1. One colony was aged at 98 ± 9 yr, with an average axial growth rate of ~0.7 cm yr–1. The age of a large colony was >145 yr with an estimated axial growth rate of 0.14 to 0.28 cm yr–1. Inconsistent rates may indicate nonlinear axial growth. A Keratoisis sp. specimen from the Gulf of Alaska was aged at 116 ± 29 yr from a radial growth rate of ~0.056 mm yr–1, which led to an average axial growth rate of ~1.0 cm yr–1. An Isidella tentaculum colony was aged at 53 ± 10 yr and grew most rapidly with a radial growth rate of ~0.10 mm yr–1 and an average axial growth rate of ~1.4 cm yr–1; however, the 210Pb decay pattern may have provided evidence for either a hiatus in radial growth or environmental changes in 210Pb. Our findings of slow growth and long life compared favorably with other bamboo coral studies and provided age estimates with greater precision. The high longevity of bamboo coral is an indication that recovery from disturbance or removal may take decades to a century. These age data provide a basis for a defensible position on the protection of bamboo coral and essential information for describing other life history characteristics. KEY WORDS: Lead-210 · Radiometry · Deep sea · Longevity · Isididae Full text in pdf format PreviousNextCite this article as: Andrews AH, Stone RP, Lundstrom CC, DeVogelaere AP (2009) Growth rate and age determination of bamboo corals from the northeastern Pacific Ocean using refined 210Pb dating. Mar Ecol Prog Ser 397:173-185. https://doi.org/10.3354/meps08193 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 397. Online publication date: December 17, 2009 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2009 Inter-Research.

The mechanics behind plant development

Morphogenesis in living organisms relies on the integration of both biochemical and mechanical signals. During the last decade, attention has been mainly focused on the role of biochemical signals in patterning and morphogenesis, leaving the contribution of mechanics largely unexplored. Fortunately, the development of new tools and approaches has made it possible to re-examine these processes. In plants, shape is defined by two local variables: growth rate and growth direction. At the level of the cell, these variables depend on both the cell wall and turgor pressure. Multidisciplinary approaches have been used to understand how these cellular processes are integrated in the growing tissues. These include quantitative live imaging to measure growth rate and direction in tissues with cellular resolution. In parallel, stress patterns have been artificially modified and their impact on strain and cell behavior been analysed. Importantly, computational models based on analogies with continuum mechanics systems have been useful in interpreting the results. In this review, we will discuss these issues focusing on the shoot apical meristem, a population of stem cells that is responsible for the initiation of the aerial organs of the plant.

In situ fluorochrome calcein marking of deep-sea molluscs using a new growth chamber

A new instrument designed for in situ chemical marking experiments was developed and applied to the deep-sea seep clams Calyptogena soyoae and Calyptogenaokutanii. Fluorochrome calcein was used for vital staining of four living clams kept in a specially designed in situ growth chamber that was placed on the seafloor at a cold-seep site off Hatsushima Island, Sagami Bay, central Japan. The shell margins of both C. soyoae and C. okutanii were clearly stained, forming a thin fluorescent band. This method will be useful for age and growth-rate determinations of many other marine organisms with accretionary growing skeletons.

Growth of Juvenile Scup, Stenotomus chrysops, Fed Three Commercial Diets

Juvenile scup, Stenotomus chrysops, 0.5–1.5 g weight were fed three different commercial diets for six weeks to determine growth rates. Diets were hand-distributed to triplicate groups of 30 fish, four times a day. Survival for all treatments was 93%. The diets used were INVE Aquaculture NRD marine diet (NRD), Skretting Feed Products Gemma starter feed (Gemma), and Salt Creek Progression fish starter diet (Progression). While all diets supported good growth, after 6 weeks scup fed the NRD diet were of significantly greater length and weight (P < 0.05) than fish fed the other diets. The effects of each diet on fish growth were significantly different from each other (P < 0.05), with final live weight (g), total length (mm), relative growth rate (RGR), and daily weight gain (DWG) measurements higher for fish fed the NRD diet. Scup fed the Gemma diet were of significantly greater length and weight than fish fed the Progression diet. The specific growth rate (SGR) of scup fed either the NRD or Gemma diets were not significantly different; however, both of these diets produced fish with significantly higher SGR than those fed the Progression diet. Feed conversion ratios (FCR) of scup fed either the NRD or the Gemma diets were significantly lower than the FCR of fish fed the Progression diet. SGR values were 6.6%, 6.3% and 5.6%/day, and FCR values were 1.03, 1.11, and 1.31 for fish fed the NRD, Gemma, and Progression diets, respectively. RGR values were 1,439%, 1,212%, and 895%, and DWG values were 0.33 g, 0.27 g, and 0.20 g/day for scup fed the NRD, Gemma, and Progression diets, respectively.

Distinct mesenchymal progenitor cell subsets in the adult human synovium

To analyse the heterogeneity at the single-cell level of human mesenchymal progenitor cells from SM. Cell populations were enzymatically released from the knee joint synovium of adult human individuals. Single cell-derived clonal populations were obtained by limiting dilution and serially passaged to determine growth rates. Phenotypic analysis was carried out by flow cytometry. Replicative senescence was assessed by the senescence-associated beta-galactosidase staining. Telomere lengths were determined semiquantitatively by Southern blotting. Telomerase activity was measured using a real-time quantitative telomerase repeat amplification procedure. Culture-expanded clonal populations were subjected to in vitro differentiation assays to investigate their mesenchymal multipotency. The 50 clones analysed displayed wide variations in the proliferation rates, even within the same donor sample. The time taken to reach 20 population doublings ranged from 44 to 130 days. The phenotype of the clones tested was compatible with that of mesenchymal stem cells. Mean telomere lengths ranged from 5.2 to 10.9 kb with positive linear trend with telomerase activity, but no correlation with proliferative rates or cell senescence. All clones tested were capable of chondrogenic and osteogenic differentiation, though with large variability in potency. In contrast, only 30% of the clones were adipogenic. We report for the first time the co-existence, within the synovium, of progenitor cell subsets with distinct mesenchymal differentiation potency. Our findings further emphasize the need for strategies to purify cell populations with the clinically desired tissue formation potentials.

Temperature dependence of nucleation and growth of nanoparticles in low pressure Ar/CH4 RF discharges

The gas temperature (Tg) dependence of nucleation and growth processes of hydrocarbon nanoparticles in low pressure Ar/CH4 RF discharges has been investigated. Measuring the electron density with the microwave cavity resonance technique allowed us to monitor nucleation processes on small (µs) time scales. On larger time scales, coagulation times and growth rates are determined by means of measuring the phase angle between the RF voltage and current in correlation with laser light scattering. The experimental results show a significant gas temperature dependence of both powder nucleation and growth processes. Within the measured gas temperature range (20–130 °C) the particle growth rate decreases by a factor of ∼3.7, while the coagulation time increases by a factor of ∼6.5 with increasing Tg. Moreover, in this paper we present a simplified model which uses the experimentally determined growth rates and coagulation times to predict the value of the critical density of nanometre sized neutral particles, necessary to initiate coagulation. This model estimates a critical density of 3.5 × 1015 m−3 at room temperature which decreases with increasing temperature.

Identifying essential genes in Escherichia coli from a metabolic optimization principle

Understanding the organization of reaction fluxes in cellular metabolism from the stoichiometry and the topology of the underlying biochemical network is a central issue in systems biology. In this task, it is important to devise reasonable approximation schemes that rely on the stoichiometric data only, because full-scale kinetic approaches are computationally affordable only for small networks (e.g., red blood cells, ≈50 reactions). Methods commonly used are based on finding the stationary flux configurations that satisfy mass-balance conditions for metabolites, often coupling them to local optimization rules (e.g., maximization of biomass production) to reduce the size of the solution space to a single point. Such methods have been widely applied and have proven able to reproduce experimental findings for relatively simple organisms in specific conditions. Here, we define and study a constraint-based model of cellular metabolism where neither mass balance nor flux stationarity are postulated and where the relevant flux configurations optimize the global growth of the system. In the case of Escherichia coli , steady flux states are recovered as solutions, although mass-balance conditions are violated for some metabolites, implying a nonzero net production of the latter. Such solutions furthermore turn out to provide the correct statistics of fluxes for the bacterium E. coli in different environments and compare well with the available experimental evidence on individual fluxes. Conserved metabolic pools play a key role in determining growth rate and flux variability. Finally, we are able to connect phenomenological gene essentiality with “frozen” fluxes (i.e., fluxes with smaller allowed variability) in E. coli metabolism.

Growth rate and rupture rate of unruptured intracranial aneurysms: a population approach

BackgroundUnderstanding aneurysm growth rate allows us to predict not only the current rupture risk, but also accumulated rupture risk in the future. However, determining growth rate of unruptured intracranial aneurysms often requires follow-up of patients for a long period of time so that significant growth can be observed and measured. We investigate a relationship between growth rate and rupture rate and develop a theoretical model that can predict average behavior of unruptured intracranial aneurysms based on existing clinical data.MethodsA mathematical model is developed that links growth rate and rupture rate. This model assumes a stable aneurysm size distribution so the number of aneurysm ruptures is balanced by the growth of aneurysms. Annual growth rates and growth profiles are calculated from a hypothetical size distribution and data from a previous clinical study.ResultsOur model predicts a growth rate of 0.34–1.63 mm/yr for three different growth models when the rupture rate at 10 mm is 1%. The growth rate is 0.56–0.65 mm/yr if annual rupture rate averaged over all aneurysm sizes is assumed to be 2%. The peak of aneurysm size distribution coincides with a period of slow growth between 5 mm and 8 mm.ConclusionThis mathematical model can be used to predict aneurysm growth rate, and the results are consistent with previous clinical studies. Predictions from both hypothetical and clinical cases agree very well. This model explains why some aneurysms may grow into a stable size and remain so without rupture.

European species of Hypocrea Part I. The green-spored species.

At present 75 species of Hypocrea have been identified in temperate Europe. Nineteen green-spored species and their Trichoderma asexual states are here described in detail. Extensive searches for Hypocrea teleomorphs in 14 European countries, with emphasis on Central Europe, yielded more than 620 specimens within five years. The morphology of fresh and dry stromata was studied. In addition, available types of species described from Europe were examined. Cultures were prepared from ascospores and used to study the morphology of cultures and anamorphs, to determine growth rates, and to extract DNA that was used for amplification and sequencing of three genetic markers. ITS was used for identification, while RNA polymerase II subunit b (rpb2) and translation elongation factor 1 alpha (tef1) were analyzed for phylogenetic reconstruction of the genus.Several unexpected findings resulted from this project: 1) The previous view that only a small number of Trichoderma species form a teleomorph is erroneous. 2) All expectations concerning the number of species in Europe are by far exceeded. Seventy-five species of Hypocrea, two species of Protocrea, and Arachnocrea stipata, are herein identified in temperate Europe, based on the ITS identification routine using fresh material, on species described earlier without molecular data and on species recently described but not collected during this project. 3) Current data suggest that the biodiversity of Hypocrea / Trichoderma above soil exceeds the number of species isolated from soil. 4) The number of Trichoderma species forming hyaline conidia has been considered a small fraction. In Europe, 26 species of those forming teleomorphs produce hyaline conidia, while 42 green-conidial species are known. Three of the detected Hypocrea species do not form an anamorph in culture, while the anamorph is unknown in four species, because they have never been cultured.This work is a preliminary account of Hypocrea and their Trichoderma anamorphs in Europe. Of the hyaline-spored species, H. minutispora is by far the most common species in Europe, while of the green-spored species this is H. strictipilosa.General ecology of Hypocrea is discussed. Specific associations, either with host fungi or trees have been found, but the majority of species seems to be necrotrophic on diverse fungi on wood and bark.The taxonomy of the genus will be treated in two parts. In this first part 19 species of Hypocrea with green ascospores, including six new teleomorph and five new anamorph species, are described in detail. All green-spored species belong to previously recognised clades, except H. spinulosa, which forms the new Spinulosa Clade with two additional new species, and H. fomiticola, which belongs to the Semiorbis Clade and forms effuse to large subpulvinate stromata on Fomes fomentarius, a trait new for species with green ascospores. Anamorph names are established prospectively in order to provide a basis for possible policy alterations towards their use for holomorphs.

Redwood of the reef: growth and age of the giant barrel sponge Xestospongia muta in the Florida Keys

The growth of animals in most taxa has long been well described, but the phylum Porifera has remained a notable exception. The giant barrel sponge Xestospongia muta dominates Caribbean coral reef communities, where it is an important spatial competitor, increases habitat complexity, and filters seawater. It has been called the 'redwood of the reef' because of its size (often(1 m height and diameter) and presumed long life, but very little is known about its demography. Since 1997, we have estab- lished and monitored 12 permanent 16 m diameter circular transects on the reef slope off Key Largo, Florida, to study this important species. Over a 4.5-year interval, we mea- sured the volume of 104 tagged sponges using digital images to determine growth rates of X. muta. Five models were fit to the cubed root of initial and final volume esti- mates to determine which best described growth. Additional measurements of 33 sponges were taken over 6-month intervals to examine the relationship between the spongocoel, or inner-osculum space, and sponge size, and to examine short-term growth dynamics. Sponge volumes ranged from 24.05 to 80,281.67 cm 3 . Growth was variable, and specific growth rates decreased with increasing sponge size. The mean specific growth rate was 0.52 ± 0.65 year -1 , but sponges grew as fast or slow as 404 or 2% year -1 . Negative growth rates occurred over short temporal scales and growth varied seasonally, significantly faster during the summer. No differences in specific growth rate were found between transects at three different depths (15, 20, 30 m) or at two different reef sites. Spongocoel volume was positively allometric with increasing sponge size and scaling between the vertical and horizontal dimensions of the sponge indicated that morphology changes from a frustum of a cone to cylindrical as volume increases. Growth of X. muta was best described by the general von Bertalanffy and Tanaka growth curves. The largest sponge within our transects (1.23 9 0.98 m height 9 diameter) was estimated to be 127 years old. Although age extra- polations for very large sponges are subject to more error, the largest sponges on Caribbean reefs may be in excess of 2,300 years, placing X. muta among the longest-lived animals on earth.

Aspects of the Ecology of the Earth Snakes (Virginia valeriae and V. striatula) in the Upper Coastal Plain

Relatively little is known about the ecology and population biology of Virginia striatula (Rough Earth Snake) and Virginia valeriae (Smooth Earth Snake), especially in the southeastern portion of their geographic ranges. We studied populations of the two species on the Savannah River Site (SRS) in Aiken, SC from 1971 to 2007. We found sexual size dimorphism in both species, in which females were longer and heavier than males, but had relatively shorter tails. Overall, Rough Earth Snakes were longer and heavier than Smooth Earth Snakes, but maximum sizes of both species were smaller on the SRS than at other localities from which data are reported. Additionally, all gravid female Smooth Earth Snakes that we captured on the SRS were smaller than their reported size at sexual maturity from other parts of their range. Seasonal activity of Smooth Earth Snakes peaked in May and October, but both Smooth Earth Snakes and Rough Earth Snakes were frequently captured during all warm months. Distinct age classes in the two species were not readily apparent other than several neonates that we captured. We strongly encourage future studies to determine growth rates, longevity, and minimum size at sexual maturity of earth snakes in the Southeast.

Growth rates of six coccolithophorid strains as a function of temperature

We determined growth rates of six coccolithophorid strains (five species) as a function of temperature. We grew four strains (three species: Emiliania huxleyi, Gephyrocapsa oceanica, and two strains of Calcidiscus leptoporus) at six temperatures between 6°C and 25°C, Coccolithus braarudii at four temperatures, and Syracosphaera pulchra at two temperatures. The growth rates were to a large extent consistent with the biogeographical distributions of these species. C. braarudii grows relatively fast at low temperatures, the two strains of C. leptoporus have temperature optima of 12°C and 20°C, E. huxleyi has an optimum at 20°C, and the growth rate of G. oceanica (and S. pulchra) increases up to the highest tested temperature of 25°C. This shows that maximum growth rate is an important factor in controlling distribution in the ocean, but it is not the only one.

Habitat specific growth rates and condition indices for the sympatric soles Solea solea (Linnaeus, 1758) and Solea senegalensis Kaup 1858, in the Tagus estuary, Portugal, based on otolith daily increments and RNA-DNA ratio

Habitat specific growth rates and condition indices were estimated for Solea solea and Solea senegalensis, in two nursery areas within the Tagus estuary, at the end of the estuarine colonization process, in 2005. While in the uppermost nursery area the two species of sole live in sympatry, in the lower nursery only S. senegalensis is present. Daily increments of left lapillar otoliths were used to estimate age (in days) and determine growth rates (mm per day). Condition indices were assessed through RNA-DNA ratio in muscle samples. Growth rates were higher for S. senegalensis (0.970and 1.180 mm per day in nursery A and B, respectively) than for S. solea (0.767 mm per day in nursery A). Growth rates of S. senegalensis from the uppermost nursery area were lower when compared to those obtained for the other nursery. The RNA/DNA condition index followed the general trend given by the growth rate estimates, i.e. values were higher for S. senegalensis than for S. solea. However, no significant differences were detected in S. senegalensis from the two nurseries. Larger variations in salinity (10‰ amplitude in the uppermost nursery vs 0.2‰ in the lower nursery) and highest pollution loads may be important factors lowering the habitat quality of the uppermost nursery in comparison to the lower nursery. The use of growth rate estimates based on otolith readings and the RNA/DNA index as tools for habitat quality assessment was discussed.

O crescimento econômico dos municípios mineiros tem sido pró-pobre? Uma análise para o período 1991-2000

O principal objetivo deste artigo é analisar a relação entre crescimento econômico e pobreza do ponto de vista qualitativo. Em outras palavras, busca-se analisar em que medida o crescimento econômico dos municípios mineiros mostrou-se um mecanismo relativamente eficaz de combate à pobreza do Estado entre 1991 e 2000. Os resultados revelaram a diversidade do território mineiro. Foram encontradas regiões com uma boa qualidade de crescimento onde existe maior elasticidade "pobreza-crescimento", ou seja, uma relativa maior capacidade de reduzir a proporção de pobres para uma determinada taxa de crescimento. Esse resultado é explicado não apenas pela sua menor intensidade de pobreza, mas também pelo relativo maior impacto do crescimento econômico sobre os mais pobres, isto é, pela "qualidade" do crescimento municipal. Por outro lado existem regiões com menor elasticidade "pobreza-crescimento". Por fim, foram analisadas as características socioeconômicas dos municípios pertencentes a cada um dos quatro padrões de crescimento verificados.

Population Density Estimates and Growth Rates of Eleutherodactylus coqui in Hawaii

The Puerto Rican terrestrial frog (Eleutherodactylus coqui) has received considerable attention in Hawaii because of its rapid spread, loud mating calls, and its potential threat to native species. Thus far, its invasion potential on the Island of Hawaii remains poorly understood. Critical components for determining this potential are robust estimates of abundance and vital rates across habitat types. To address this lack of information, we used mark-recapture methods to estimate E. coqui survival and abundance, determine growth rates of adult male and female frogs, and relate densities to elevation, snout-vent length (SVL), habitat structure, and invertebrate abundance. Mean adult E. coqui density across eight sites was 62 6 12 adults/100 m 2 and ranged from 6-138 adults/100 m 2 . Our three-year mean adult density estimates were three times greater at three of our study sites (100 adults/100 m 2 ) than the highest long-term estimates from Puerto Rico (33 adults/100 m 2 ). Mean individual growth rates were 0.0078 mm/day (6 0.007 SD, N = 87) for males and 0.0097 mm/day (6 0.009 SD, N = 11) for females. Frogs of similar size were found to be growing slower in Hawaii than Puerto Rico. We found no relationship between elevation and E. coqui density or elevation and SVL or between invertebrate abundance and E. coqui density. However, there was a positive relationship between understory structure and E. coqui density. This relationship suggests that removing understory structure could reduce E. coqui densities, although other potential implications of this management treatment should be considered.

Water-Pathway Sealing by Crystallization under Advective Supersaturated Solution Conditions

The objective of this study is to promote understanding of the structural evolution of fractures that affect the transport of contaminants in geological media. Highly soluble potassium alum was used as an analogue material, and was grown in an open fracture from a solvent transported by advection along the fracture, in order to observe decreases in the aperture of the fracture. In addition, the growth rate law of K-alum was experimentally determined based on the relationship between relative supersaturation and linear flow velocity. The sealing result was compared with simulations based on a simplified numerical model using the experimentally determined growth rate law, and it was found that the time necessary for sealing was longer for the simulation than for the experimental sealing. This discrepancy was explained by the additive growth rate of the original seed crystal and secondary crystals nucleated near the fixed seed crystal. Thus, it was shown that primary and/or secondary nucleation is an additional factor for prediction of the structural evolution of fractures in geological media.

Wood density and fiber dimensions of Gmelina arborea in fast growth trees in Costa Rica: relation to the growth rate

The objective of this research was to determine growth rate effects measured in tree diameter on wood density parameters (mean, minimum, maximum and intra-ring variation) and in fiber dimensions (wall thickness, fiber width, lumen diameter and fiber length) of trees from fast growth plantations. Thirty mature trees were sampled from thirty different fast-growth plantations with a wide growth rate in Costa Rica. A disc was cut from each tree at DBH. The wood density parameters and fiber dimensions were determined in each growth ring. Some wood density parameters and fiber dimensions were related with growth rate. The minimum and mean density, cell wall thickness, fiber width and lumen diameter decreased with increase in growth rate. Intra-ring wood density variation increased with growth rate but the weak correlation was established. Maximum wood density was not found correlation with growth rate. A pronounced decrease was presented in minimum and mean density from 0 to 20 mm/year and after to 45 mm/year. A pronounced decrease and increase with increase in growth rate were presented in the fiber length and intra-ring wood density, respectively. Lumen diameter and fiber width presented few variations, until 40 mm/year; however, they showed decrease after this growth rate value.

Antisolvent Precipitation of PDI 747: Kinetics of Particle Formation and Growth

The application of two recently developed protocols for the fast and robust determination of nucleation and growth kinetics to the antisolvent precipitation of PDI 747 is presented in this work. Both characterization methods are based on two in situ process analytical technologies, i.e., attentuated total reflection-Fourier transform infrared spectroscopy and focused beam reflectance measurement, to monitor the liquid and the solid phase during the characterization experiments. The method to determine growth rate kinetics is based on seeded batch desupersaturation experiments. It combines the accurate characterization of seed particle size distributions and the measurement of desupersaturation profiles for different experimental conditions with population balance modeling and an optimization routine to determine the growth mechanism and the kinetic parameters. In a second step, the growth kinetics are combined with induction time experiments to calculate the nucleation rate. Earlier, these protocols were ...