Corixidae (Water Boatmen) Abundance and Contribution to Littoral Zone Fish Forage in Lake Poinsett, South Dakota

Corixids were sampled each week in littoral zone areas of Lake Poinsett during the open water seasons, April-October, in 1970, 1971, and 1972. Fish were sampled each week in littoral zone areas in 1970 and food habits studies were conducted to determine if fish predation would influence corixid population dynamics. Seven genera and 15 species of the family Corixidae were collected. Major indigenous species were Palmarcorixa buenoi Abbott, Trichocorixa borealis Sailer, Cenocorixa dakotensis (Hungerford), and Sigara conocephala (Hungerford). Species migrating to Lake Poinsett in the fall to overwinter were Sigara alternata (Say), S. solensis (Hungerford), S. bicoloripennis (Walley), Hesperocorixa vulgaris (Hungerford), and Callicorixa audeni Hungerford. Corixid population density increased from a mean annual standing crop of 4.9/m2 in 1970 to 17.6/m2 in 1971 and 56.9/m2 in 1972. The mean density of P. buenoi (19.8/m2) was approximately five fold greater than that of T. borealis (3.8/m2), the second most abundant species, and in combination with T. borealis represented 95 percent of the three year mean standing crop (24.7/m2) of Corixidae in Lake Poinsett. Both P. buenoi and T. borealis produced two generations each year, but P. buenoi overwintered as primarily fourth instar nymphs and T. borealis overwintered as adults. Food habits analysis of littoral zone fishes, Pimephales promelas Rafinesque, Etheostoma nigrum Rafinesque, Ictiobus cyprinellus (Valenciennes), Percopsis omiscomaycus (Walbaum), Notropis hudsonius (Clinton), N. stramineus (Cope), and N. lutrensis {Baired and Girard), indicated that corixids were not prey species and that littoral zone fish predation had no significant effects on corixid population dynamics. The lack of predation of littoral zone fishes on corixids appeared to be primarily related to the fish species composition and to the high densities of more vulnerable prey

Non-congruence of statistical distributions: how different is different?

Call number: LD2668 .T4 1978 A65Master of Scienc

Factor XIII Cross-Linked Hyaluronan Hydrogels for Cartilage Tissue Engineering

ISSN:2373-987

Allometric Equations to Estimate Aboveground Biomass in Spotted Gum (Corymbia citriodora Subspecies variegata) Plantations in Queensland

Accurate equations are critical for estimating biomass and carbon accumulation for forest carbon projects, bioenergy, and other inventories. Allometric equations can provide a reliable and accurate method for estimating and predicting biomass and carbon sequestration. Cross-validatory assessments are also essential to evaluate the prediction ability of the selected model with satisfactory accuracy. We destructively sampled and weighed 52 sample trees, ranging from 11.8 to 42.0 cm in diameter at breast height from three plantations in Queensland to determine biomass. Weighted nonlinear models were used to explore the influence of different variables using two datasets: the first dataset (52 trees) included diameter at breast height (D), height (H) and wood density (ρ); and the second dataset (40 trees) also included crown diameter (CD) and crown volume (CV). Cross validation of independent data showed that using D alone proved to be the best performing model, with the lowest values of AIC = 434.4, bias = −2.2% and MAPE = 7.2%. Adding H and ρ improved the adjusted. R2 (Δ adj. R2 from 0.099 to 0.135) but did not improve AIC, bias and MAPE. Using the single variable of CV to estimate aboveground biomass (AGB) was better than CD, with smaller AIC and MAPE less than 2.3%. We demonstrated that the allometric equations developed and validated during this study provide reasonable estimates of Corymbia citriodora subspecies variegata (spotted gum) biomass. This equation could be used to estimate AGB and carbon in similar spotted gum plantations. In the context of global forest AGB estimations and monitoring, the CV variable could allow prediction of aboveground biomass using remote sensing datasets

The relative impact of baryons and cluster shape on weak lensing mass estimates of galaxy clusters

Weak gravitational lensing depends on the integrated mass along the line of sight. Baryons contribute to the mass distribution of galaxy clusters and the resulting mass estimates from lensing analysis. We use the cosmo-OWLS suite of hydrodynamic simulations to investigate the impact of baryonic processes on the bias and scatter of weak lensing mass estimates of clusters. These estimates are obtained by fitting NFW profiles to mock data using MCMC techniques. In particular, we examine the difference in estimates between dark matter-only runs and those including various prescriptions for baryonic physics. We find no significant difference in the mass bias when baryonic physics is included, though the overall mass estimates are suppressed when feedback from AGN is included. For lowest-mass systems for which a reliable mass can be obtained ($M_{200} \approx 2 \times 10^{14}$ $M_{\odot}$), we find a bias of $\approx -10$ per cent. The magnitude of the bias tends to decrease for higher mass clusters, consistent with no bias for the most massive clusters which have masses comparable to those found in the CLASH and HFF samples. For the lowest mass clusters, the mass bias is particularly sensitive to the fit radii and the limits placed on the concentration prior, rendering reliable mass estimates difficult. The scatter in mass estimates between the dark matter-only and the various baryonic runs is less than between different projections of individual clusters, highlighting the importance of triaxiality

Prospects for Determining the Mass Distributions of Galaxy Clusters on Large Scales Using Weak Gravitational Lensing

For more than two decades, the Navarro, Frenk, and White (NFW) model has stood the test of time; it has been used to describe the distribution of mass in galaxy clusters out to their outskirts. Stacked weak lensing measurements of clusters are now revealing the distribution of mass out to and beyond their virial radii, where the NFW model is no longer applicable. In this study we assess how well the parameterised Diemer & Kravstov (DK) density profile describes the characteristic mass distribution of galaxy clusters extracted from cosmological simulations. This is determined from stacked synthetic lensing measurements of the 50 most massive clusters extracted from the Cosmo-OWLS simulations, using the Dark Matter Only run and also the run that most closely matches observations. The characteristics of the data reflect the Weighing the Giants survey and data from the future Large Synoptic Survey Telescope (LSST). In comparison with the NFW model, the DK model favored by the stacked data, in particular for the future LSST data, where the number density of background galaxies is higher. The DK profile depends on the accretion history of clusters which is specified in the current study. Eventually however subsamples of galaxy clusters with qualities indicative of disparate accretion histories could be studied

Human muscular fetal cells: a potential cell source for muscular therapies

Myoblast transfer therapy has been extensively studied for a wide range of clinical applications, such as tissue engineering for muscular loss, cardiac surgery or Duchenne Muscular Dystrophy treatment. However, this approach has been hindered by numerous limitations, including early myoblast death after injection and specific immune response after transplantation with allogenic cells. Different cell sources have been analyzed to overcome some of these limitations. The object of our study was to investigate the growth potential, characterization and integration in vivo of human primary fetal skeletal muscle cells. These data together show the potential for the creation of a cell bank to be used as a cell source for muscle cell therapy and tissue engineering. For this purpose, we developed primary muscular cell cultures from biopsies of human male thigh muscle from a 16-week-old fetus and from donors of 13 and 30years old. We show that fetal myogenic cells can be successfully isolated and expanded in vitro from human fetal muscle biopsies, and that fetal cells have higher growth capacities when compared to young and adult cells. We confirm lineage specificity by comparing fetal muscle cells to fetal skin and bone cells in vitro by immunohistochemistry with desmin and 5.1H11 antibodies. For the feasibility of the cell bank, we ensured that fetal muscle cells retained intrinsic characteristics after 5years cryopreservation. Finally, human fetal muscle cells marked with PKH26 were injected in normal C57BL/6 mice and were found to be present up to 4days. In conclusion we estimate that a human fetal skeletal muscle cell bank can be created for potential muscle cell therapy and tissue engineerin

Visual Quality after Wavefront-Guided LASIK for Myopia

This study evaluated the visual quality after wavefront-guided laser in situ keratomileusis (LASIK) for treating myopia. Thirty-two eyes with moderate myopia (-5.78~-2.17D) and 25 eyes with high myopia (-7.78~-6.17D) were prospectively reviewed. The contrast sensitivity (CS), glare and the total higher order aberrations (HOA) were measured before and 1 week, 1 month and 2 months after LASIK. The pupil diameter was measured at day- and night-time illumination. The CS and glare at all spatial frequencies were not reduced after wavefront-guided LASIK (p<0.05) and the difference between the moderate and high myopia group was not significant. No significant correlation was found between the amounts of myopia and the postoperative CS (p>0.05). The area under the log contrast sensitivity function (AULCSF) showed no correlation with the total HOA (r2=-0.071, p=0.612, between the daytime AULCSF and the total HOA with a 4 mm entrance pupil, r2=-0.176, p=0.260, between the nighttime AULCSF and the total HOA with a 6 mm entrance pupil). There was no decrease in CS and glare after wavefront-guided LASIK for myopia. In conclusion, wavefront-guided LASIK based on the individual ablation patterns is a good option for refractive surgery to improve the visual quality in both moderate and high myopia cases

Species-Specific Allometric Equations for Predicting Belowground Root Biomass in Plantations: Case Study of Spotted Gums (Corymbia citriodora subspecies variegata) in Queensland

Spotted gum (Corymbia citriodora spp. variegata; CCV) has been widely planted, has a wide natural distribution, and is the most important commercially harvested hardwood species in Queensland, Australia. It has a great capacity to sequester carbon, thus reducing the impact of CO2 emissions on climate. Belowground root biomass (BGB) plays an important role as a carbon sink in terrestrial ecosystems. To explore the potential of biomass and carbon accumulation belowground, we developed and validated models for CCV plantations in Queensland. The roots of twenty-three individual trees (size range 11.8–42.0 cm diameter at breast height) from three sites were excavated to a 1-m depth and were weighed to obtain BGB. Weighted nonlinear regression models were most reliable for estimating BGB. To evaluate the candidate models, the data set was cross-validated with 70% of the data used for training and 30% of the data used for testing. The cross-validation process was repeated 23 times and the validation of the models were averaged over 23 iterations. The best model for predicting spotted gum BGB was based on a single parameter, with the diameter at breast height (D) as an independent variable. The best equation BGB = 0.02933 × D2.5805 had an adjusted R2 of 0.854 and a mean absolute percentage error of 0.090%. This equation was tested against published BGB equations; the findings from this are discussed. Our equation is recommended to allow improved estimates of BGB for this species