Spatial Use and Survivorship of Translocated Wild-Caught Texas Horned Lizards

The Texas horned lizard (Phrynosoma cornutum), a state threatened species in Texas, USA, appears to be declining throughout much of its distribution. Because of popular interest in restoring lizard populations, we conducted a 3-year radio-telemetric study to evaluate the feasibility of reintroducing Texas horned lizards into previously occupied areas with suitable habitat characteristics. We translocated lizards from natural populations in western Texas to the McGillivray and Leona McKie Muse Wildlife Management Area (MWMA) in the Cross Timbers and Prairies of north-central Texas, an ecoregion that has experienced apparent local extirpations of horned lizards. We translocated lizards after partly restoring a 32.5-ha portion of the MWMA from ashe juniper (Juniperus ashei)-honey mesquite (Prosopis glandulosa) woodland to mid-grass prairie. After a 10-day acclimation period and soft release, we tracked 57 horned lizards from March 2014 to October 2016 to evaluate daily movements, spatial use, sources of mortality, reproduction, and changes in body condition. Daily movement averages (1.16–174.18 m) and area used by individuals (<0.01–6.81 ha) were similar to those recorded for natural populations, with peaks in movement occurring in May and June. Annual survivorship for individuals (1.1–47.2%) was also similar to that reported from natural populations; however, survivorship declined across the 3 active seasons. Although mortality of translocated lizards was high, body condition remained relatively stable across active seasons, and reproduction occurred each year, indicating that translocation could be a viable option for restoring horned lizard populations to previously occupied parts of their range. © 2019 The Wildlife Society.     

Active Silicon Uptake by Wheat

The absorption of Si by wheat, Triticum aestivum L. ‘Yecora Rojo,’ followed Michaelis–Menten kinetics over a concentration range of 0.004–1.0 mM. K_m and V_max were determined using linear transformations and the calculated curve fitted the data closely. The absorption resulted in accumulation ratios of 200/1 or more. In keeping with that finding, this study also demonstrated that Si uptake by wheat is under metabolic control, being severely restricted by dinitrophenol (DNP) and potassium cyanide (KCN). Silicon uptake by wheat was not significantly affected by phosphate ions, but the chemical analog Ge exerted a direct competitive effect on Si uptake, and vice versa.     

Targeting of Beta Adrenergic Receptors Results in Therapeutic Efficacy against Models of Hemangioendothelioma and Angiosarcoma

Therapeutic targeting of the beta-adrenergic receptors has recently shown remarkable efficacy in the treatment of benign vascular tumors such as infantile hemangiomas. As infantile hemangiomas are reported to express high levels of beta adrenergic receptors, we examined the expression of these receptors on more aggressive vascular tumors such as hemangioendotheliomas and angiosarcomas, revealing beta 1, 2, and 3 receptors were indeed present and therefore aggressive vascular tumors may similarly show increased susceptibility to the inhibitory effects of beta blockade. Using a panel of hemangioendothelioma and angiosarcoma cell lines, we demonstrate that beta adrenergic inhibition blocks cell proliferation and induces apoptosis in a dose dependent manner. Beta blockade is selective for vascular tumor cells over normal endothelial cells and synergistically effective when combined with standard chemotherapeutic or cytotoxic agents. We demonstrate that inhibition of beta adrenergic signaling induces large scale changes in the global gene expression patterns of vascular tumors, including alterations in the expression of established cell cycle and apoptotic regulators. Using in vivo tumor models we demonstrate that beta blockade shows remarkable efficacy as a single agent in reducing the growth of angiosarcoma tumors. In summary, these experiments demonstrate the selective cytotoxicity and tumor suppressive ability of beta adrenergic inhibition on malignant vascular tumors and have laid the groundwork for a promising treatment of angiosarcomas in humans.     

Use of 5'-γ-ferrocenyl adenosine triphosphate (Fc-ATP) bioconjugates having poly(ethylene glycol) spacers in kinase-catalyzed phosphorylations

The 5'-γ-ferrocenyl adenosine triphosphate (Fc-ATP) bioconjugates (3 and 4), containing the poly(ethylene glycol) spacers, were synthesized and compared to a hydrophobic analogue as co-substrates for the following protein kinases: sarcoma related kinase (Src), cyclin-dependent kinase (CDK), casein kinase II (CK2α), and protein kinase A (PKA). Electrochemical kinase assays indicate that the hydrophobic Fc-ATP analogue was an optimal co-substrate for which K(M) values were determined to be in the 30-200 μM range, depending on the particular protein kinase. The luminescence kinase assay demonstrated the kinase utility for all Fc-ATP conjugates, which is in line with the electrochemical data. Moreover, Fc-ATP bioconjugates exhibit competitive behavior with respect to ATP. Relatively poor performance of the polar Fc-ATP bioconjugates as co-substrates for protein kinases was presumably due to the additional H-bonding and electrostatic interactions of the poly(ethylene glycol) linkers of Fc-ATP with the kinase catalytic site and the target peptides. Phosphorylation of the full-length protein, His-tagged pro-caspase-3, was demonstrated through Fc-phosphoamide transfer to the Ser residues of the surface-bound protein by electrochemical means. These results suggest that electrochemical detection of the peptide and protein Fc-phosphorylation via tailored Fc-ATP co-substrates may be useful for probing protein-protein interactions.     

Perturbation of DNA repair gene expression due to interspecies hybridization

The effect of interspecies hybridization on gene regulation was examined using real-time polymerase chain reaction (RT-PCR) to measure the expression of five base-excision repair genes in brain, eye, gill, liver, and tailfin tissues from Xiphophorus parental species and F(1) hybrids. Relative mRNA levels of uracil N-glycosylase (Ung), Apurinic/apyrimidinic endonuclease (Ape1), polymerase-beta (Polb), flap endonuclease (Fen1), and DNA ligase (Lig1) were measured in three parental Xiphophorus species (X. maculatus Jp 163 B, X. helleri Sarabia, and X. andersi andC) and in two interspecies F(1) hybrids, the Sp-helleri hybrid (X. maculatus Jp 163 BxX. helleri Sarabia) and the Sp-andersi hybrid (X. maculatus Jp 163 BxX. andersi) to identify genes that undergo changes in expression levels upon interspecies hybridization. Significant differences in gene expression were observed between parental animals and their respective F(1) hybrids in both interspecies crosses. Generally, marked increases in DNA repair gene mRNA levels were observed across all tissues in F(1) hybrid animals from the Sp-helleri cross compared to either X. maculatus or X. helleri parents. In contrast, the Sp-andersi F(1) hybrid animals generally exhibited decreased base-excision repair gene expression, although this trend was more specific to individual tissues than observed for Sp-helleri hybrids.     

Computational modeling and experimental validation of odor detection behaviors of classically conditioned parasitic wasp,Microplitis croceipes

A prototype chemical sensor named Wasp hound® that utilizes five classically conditioned parasitoid wasps, Microplitis croceipes (Cresson) (Hymenoptera: Braconidae), to detect volatile odors was successfully implemented in a previous study. To improve the odor‐detecting ability of Wasp Hound®, searching behaviors of an individual wasp in a confined area are studied and modeled through stochastic differential equations in this paper. The wasps are conditioned to 20 mg of coffee when associated with food and subsequently, tested to 5, 10, 20, and 40 mg of coffee. A stochastic model is developed and validated based on three positive behavioral responses (walking, rotation around odor source, and self‐rotation) from conditioned wasps at four different test dosages. The model is capable to reproducing the behaviors of conditioned wasps, and can be used to improve the ability of Wasp Hound® to assess changes in odor concentration. The model simulation results show the behaviors of conditioned wasps are significantly different when tested at different coffee dosages. We conjecture that the searching behaviors of conditioned wasps are based on the temporal and spatial neuron activity of olfactory receptor neurons and glomeruli, which are strongly correlated to the training dosages. The overall results demonstrate the utility of mathematical models for interpreting experimental observations, gaining novel insights into the dynamic behavior of classically conditioned wasps, as well as broadening the practical uses of Wasp Hound. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 31:596–606, 2015     

Kinetics and Energetics of Light-enhanced Potassium Absorption by Corn Leaf Tissue

The effect of illumination on the absorption of K⁺ by leaf tissue of Zea mays was investigated. The rate of K⁺ absorption was enhanced by exposure of slices of corn leaf tissue to light, even of relatively low intensities. Potassium was transported inward, with virtually no efflux of previously accumulated K⁺. The evidence indicates that the transport mechanism for absorption of K⁺ is the same in the light as in the dark, but that the source of energy for absorption of K⁺ is different in the light from that in the dark. Various anti-metabolites were used to establish that the energy utilized for active ion transport in the light came partly from ATP supplied by cyclic photophosphorylation. Expenditure of ATP was required in the dark too, but this ATP was formed by oxidative phosphorylation. Establishing the ultimate source of energy for active ion uptake by higher plants might be facilitated by demonstration of an ion-transport process that is not linked directly with the transfer of electrons in the mitochondrial cytochrome chain.     

Influence of calcium on sodium and potassium absorption by fresh and aged bean stem slices

The influence of Ca on the aging processes of bean stem (Phaseolus vulgaris) slices and on the absorption of K and Na by fresh and aged slices was investigated. In the presence of Ca, fresh tissue showed a preferential Na uptake. The preference for Na over K resulted from a differential depressive effect of Ca on absorption of these two ions. In aged tissue Na uptake was also depressed, but K absorption was accelerated, with a net result of a much greater absorption of K than Na.     

Simultaneous measurement of nitrogen fixation estimated by acetylene-ethylene assay and nitrate absorption by soybeans

An apparatus was designed for simultaneous measurement of rates of N₂ fixation estimated by C₂H₂-C₂H₄ assay (N₂[C₂H₂] fixation) and NO₃⁻ absorption by roots of intact, nodulated soybeans (Glycine max [L.] Merr.). The principal design features include: (a) a gas-tight mist chamber in which nodulated roots can be exposed simultaneously to C₂H₂ in the gas phase and to a liquid phase containing NO₃⁻ sprayed in a fine mist; and (b) provision for sampling the gas phase for C₂H₄ determination, and the liquid phase for NO₃⁻ determination.