Free-air exposure systems to scale up ozone research to mature trees

Because seedlings and mature trees do not necessarily respond similarly to O(3) stress, it is critically important that exposure systems be developed that allow exposure of seedlings through to mature trees. Here we describe three different O(3) Free-Air Exposure Systems that have been used successfully for exposure at all growth stages. These systems of spatially uniform O(3) release have been shown to provide reliable O(3) exposure with minimal, if any, impact on the microclimate. This methodology offers a welcome alternative to chamber studies which had severe space constraints precluding stand or community-level studies and substantial chamber effects on the microclimate and, hence physiological tree performance.     

Generation of mice deficient for Lbx2, a gene expressed in the urogenital system, nervous system, and Pax3 dependent tissues

Lbx2 is a member of the ladybird family of homeobox genes. The first murine ortholog identified, Lbx1, is required for hypaxial musculature and dorsal spinal cord neuron development. The second murine ortholog, Lbx2, is expressed in the developing urogenital and nervous systems. To elucidate the function of Lbx2, we generated a gene-targeted allele of Lbx2 in mice. Lbx2 deficiency did not impair mouse development, and Lbx2 null mice appeared healthy and fertile. Replacement of Lbx2 by the lacZ gene provides a valuable histological marker for Lbx2-expressing cells. Given the important role of Pax3 in neural crest, we intercrossed our Lbx2 deficient mice with Splotch Pax3 mutant mice to determine if Pax3 affects Lbx2 expression. There was reduced Lbx2 expression in dorsal root ganglia and cranial nerve ganglia with Pax3 deficiency, but not in the genital tubercle. This suggested that Pax3 is required for Lbx2 expression in affected neural crest-derived tissues.     

Protein,phycocyanin, and polysaccharide production by Arthrospira platensis grown with LED light in annular photobioreactors

Journal of Applied Phycology - Arthrospira platensis is a cyanobacterium known for its widespread use as nutraceutical and food additive. Besides a high protein content, this microorganism is also...     

Grazing conserves threatened carabid beetles in semi-natural calcareous grasslands better than mowing,especially at low intensities

Biodiversity and Conservation - Semi-natural grasslands are biodiverse ecosystems that support many threatened species, but they require management interventions to maintain their habitat...     

Core pathways operating during methylotrophy of Bacillus methanolicus MGA3 and induction of a bacillithiol‐dependent detoxification pathway upon formaldehyde stress

Bacillus methanolicus MGA3 is a model facultative methylotroph of interest for fundamental research and biotechnological applications. Previous research uncovered a number of pathways potentially involved in one‐carbon substrate utilization. Here, we applied dynamic ¹³C labeling to elucidate which of these pathways operate during growth on methanol and to uncover potentially new ones. B. methanolicus MGA3 uses the assimilatory and dissimilatory ribulose monophosphate (RuMP) cycles for conversion of the central but toxic intermediate formaldehyde. Additionally, the operation of two cofactor‐dependent formaldehyde oxidation pathways with distinct roles was revealed. One is dependent on tri‐ and tetraglutamylated tetrahydrofolate (THF) and is involved in formaldehyde oxidation during growth on methanol. A second pathway was discovered that is dependent on bacillithiol, a thiol cofactor present also in other Bacilli where it is known to function in redox‐homeostasis. We show that bacillithiol‐dependent formaldehyde oxidation is activated upon an upshift in formaldehyde induced by a substrate switch from mannitol to methanol. The genes and the corresponding enzymes involved in the biosynthesis of bacillithiol were identified by heterologous production of bacillithiol in Escherichia coli. The presented results indicate metabolic plasticity of the methylotroph allowing acclimation to fluctuating intracellular formaldehyde concentrations.     

Mating success at high temperature in highland‐ and lowland‐derived populations as well as in heat knock‐down selected Drosophila buzzatii

Thermal‐stress selection can affect multiple fitness components including mating success. Reproductive success is one of the most inclusive measures of overall fitness, and mating success is a major component of reproduction. However, almost no attention has been spent to test how mating success can be affected by thermal‐stress selection. In this study, we examine the mating success in the cactophilic Drosophila buzzatii Patterson & Wheeler (Diptera: Drosophilidae) derived from two natural populations that nearly represent the ends of an altitudinal cline for heat knock‐down resistance. Furthermore, we extended the analysis using laboratory lines artificially selected for high and low heat knock‐down resistance. Mating success at high temperature was found to be higher in the lowland than the highland population after a heat pre‐treatment. Moreover, individuals selected for heat knock‐down resistance showed higher mating success at high temperature than did individuals selected for low knock‐down resistance. These results indicate that adaptation to thermal stress can confer an advantage on fitness‐related traits including mating success and highlight the benefits of earlier heat exposure as an adaptive plastic response affecting mating success under stress of higher temperature.     

Identification of P‐glycoprotein co‐fractionating proteins and specific binding partners in rat brain microvessels

Drug delivery to the brain for the treatment of pathologies with a CNS component is a significant clinical challenge. P‐glycoprotein (PgP), a drug efflux pump in the endothelial cell membrane, is a major factor in preventing therapeutics from crossing the blood‐brain barrier (BBB). Identifying PgP regulatory mechanisms is key to developing agents to modulate PgP activity. Previously, we found that PgP trafficking was altered concomitant with increased PgP activity and disassembly of high molecular weight PgP‐containing complexes during acute peripheral inflammatory pain. These data suggest that PgP activity is post‐translationally regulated at the BBB. The goal of the current study was to identify proteins that co‐localize with PgP in rat brain microvessel endothelial cell membrane microdomains and use the data to suggest potential regulatory mechanisms. Using new density gradients of microvessel homogenates, we identified two unique pools (1,2) of PgP in membrane fractions. Caveolar constituents, caveolin1, cavin1, and cavin2, co‐localized with PgP in these fractions indicating the two pools contained caveolae. A chaperone (Hsc71), protein disulfide isomerase and endosomal/lysosomal sorting proteins (Rab5, Rab11a) also co‐fractionated with PgP in the gradients. These data suggest signaling pathways with a potential role in post‐translational regulation of PgP activity at the BBB.

     

Studies on 6-chloro-5-(1-naphthyloxy)-2-(trifluoromethyl)-1H-benzimidazole/2-hydroxypropyl-β-cyclodextrin association: Characterization, molecular modeling studies, and in vivo anthelminthic activity

The purpose of this work is to study the molecular association that occurs between 2-hydroxypropyl-β-cyclodextrin (HPβCD) and 6-chloro-5-(1-naphthyloxy)-2-(trifluoromethyl)-1H-benzimidazole (RCB20), an antiparasitic compound recently found by our research group, with poor aqueous solubility. The complex stability constant and stoichiometric ratio determined by phase-solubility diagram and Job's plot provided evidence that HPβCD enhanced water solubility of RCB20 through inclusion complex formation. Two-dimensional 1H NMR spectroscopy is used to study the molecular arrangement of inclusion complex in solution. These results are further supported using molecular modeling studies. In the solid state, the complexation is confirmed by differential scanning calorimetry, powder X-ray diffraction, and scanning electron microscopy. Finally, RCB20/HPβCD complex has better activity than RCB20 against the adult and muscle larvae phase of Trichinella spiralis.