Phototropism in Dunaliella and its application in a harvesting device.

Summary The influence of wavelength, light intensity and algal concentration on the phototropism of Dunaliella sp. is described. A practical device for harvesting the alga, based in this effect is shown.     

“Templatic backcopying” in Guarijio abbreviated reduplication

Although a wide array of phonological properties seem to backcopy in reduplication, it is an open question whether reduplicative templates can backcopy as well. It has been argued that natural languages do not have reduplicative constructions where the base truncates to match the truncated reduplicant (McCarthy & Prince, 1994; McCarthy & Prince, 1999; Spaelti, 1997; inter alia). In Guarijio Abbreviated Reduplication (Miller, 1996), however, both copies of the reduplicative construction truncate, instantiating the pattern that has been claimed not to exist. This paper argues that the Guarijio case fills this typological gap. Although the data can be given a templatic backcopying analysis, this paper defends a Morphological Doubling Theory (MDT) analysis using cophonologies (Inkelas & Zoll, 2005). In MDT, Guarijio Abbreviated Reduplication results from the parallel imposition of a truncating cophonology in each copy of the reduplicative construction. Guarijio Abbreviated Reduplication is predicted to exist by MDT together with other documented cases of parallel phonological modification in reduplication. I am grateful to many people for helpful comments and suggestions, including Isabel Barreras Aguilar, Laura Downing, Nicholas Fleisher, Andrew Garrett, Jason Haugen, Larry Hyman, Yuni Kim, Teresa McFarland, David Mortensen, Mary Paster, Eric Raimy, and Timothy Thornes as well as the audience of the LSA 2005 Annual Meeting in Oakland. I would like to extend a special thanks to Alan Yu for his detailed comments and suggestions to latter versions of this paper. I am particularly indebted to Sharon Inkelas, for her generous advice, feedback, and numerous discussions throughout the development of this paper. I am also grateful to two anonymous reviewers for their comments and criticisms, and especially to Ingo Plag for his patience and detailed suggestions as editor. All remaining errors and omissions are mine. This study was made possible by fellowships by CONACYT (Consejo Nacional de Ciencia y Tecnología, México), the University of California Institute for Mexico and the United States (UCMEXUS) and Fulbright.     

Climatic patterns in the establishment of wintering areas by North American migratory birds

Long‐distance migration in birds is relatively well studied in nature; however, one aspect of this phenomenon that remains poorly understood is the pattern of distribution presented by species during arrival to and establishment of wintering areas. Some studies suggest that the selection of areas in winter is somehow determined by climate, given its influence on both the distribution of bird species and their resources. We analyzed whether different migrant passerine species of North America present climatic preferences during arrival to and departure from their wintering areas. We used ecological niche modeling to generate monthly potential climatic distributions for 13 migratory bird species during the winter season by combining the locations recorded per month with four environmental layers. We calculated monthly coefficients of climate variation and then compared two GLM (generalized linear models), evaluated with the AIC (Akaike information criterion), to describe how these coefficients varied over the course of the season, as a measure of the patterns of establishment in the wintering areas. For 11 species, the sites show nonlinear patterns of variation in climatic preferences, with low coefficients of variation at the beginning and end of the season and higher values found in the intermediate months. The remaining two species analyzed showed a different climatic pattern of selective establishment of wintering areas, probably due to taxonomic discrepancy, which would affect their modeled winter distribution. Patterns of establishment of wintering areas in the species showed a climatic preference at the macroscale, suggesting that individuals of several species actively select wintering areas that meet specific climatic conditions. This probably gives them an advantage over the winter and during the return to breeding areas. As these areas become full of migrants, alternative suboptimal sites are occupied. Nonrandom winter area selection may also have consequences for the conservation of migratory bird species, particularly under a scenario of climate change.     

Computerized method for analyzing maximum and partial expiratory flow-volume curves.

Computerized instrumentation and software have been developed to obtain maximum expiratory flow-volume (MEFV) and partial expiratory flow-volume (PEFV) curves. The computerized system calculates and prints out the flow at 25% and 40% of control vital capacity (VC), the expiratory volume, peak expiratory flow rate and expiratory volume at one second (FEV1) divided by VC, the latter expressed as a percent. The flow-volume curves can be displayed on an oscilloscope or plotter and stored on magnetic tape. A pilot study was completed to demonstrate the reliability and validity of the data obtained.     

GMP Production of Liposomes—A New Industrial Approach

A new scalable liposome production system is presented, which is based on the ethanol injection technique. The system permits liposome manufacture regardless of production scale, as scale is determined only by free disposable vessel volumes. Once the parameters are defined, an easy scale up can be performed by just changing the process vessels. These vessels are fully sterilizeable and all raw materials are transferred into the sanitized and sterilized system via 0.2 μm filters to guarantee an aseptic production.

Liposome size can be controlled by the local lipid concentration at the injection point depending on process parameters like injection pressure, lipid concentration and injection rate. These defined process parameters are furthermore responsible for highly reproducible results with respect to vesicle diameters and encapsulation rates Compared to other technologies like the film method which is normally followed by size reduction through high pressure homogenization, ultrasonication or extrusion, no mechanical forces are needed to generate homogeneous and narrow distributed liposomes.

Another important advantage of this method is the suitability for the entrapment of many different drug substances such as large hydrophilic proteins by passive encapsulation, small amphiphilic drugs by a one step remote loading technique or membrane association of antigens for vaccination approaches     

Nitrogen-source-induced activation of neutral trehalase in Schizosaccharomyces pombe and Pachysolen tannophilus: role of cAMP as second messenger

Abstract Resting cells of the fission yeast Schizosaccharomyces pombe , suspended in buffer with glucose, responded to the addition of asparagine by increasing trehalase activity. This response was preceded by a peak in cAMP concentration. The addition of the nitrogen source to resting cells, devoid of the catalytic subunit of cAMP-dependent protein kinase, produced the transient increase in cAMP but did not promote any change in trehalase activity. In the budding yeast Pachysolen iannophilus , the activation of trehalase by nitrogen source was also accompanied by a sharp peak in cAMP. These results suggest that in the two yeasts cAMP acts as a second messenger in the transduction of the nitrogen-source-induced signal causing the activation of trehalase.     

Separate Intramolecular Targets for Protein Kinase A Control N-Methyl-d-aspartate Receptor Gating and Ca2+ Permeability

Protein kinase A (PKA) enhances synaptic plasticity in the central nervous system by increasing NMDA receptor current amplitude and Ca²⁺ flux in an isoform-dependent yet poorly understood manner. PKA phosphorylates multiple residues on GluN1, GluN2A, and GluN2B subunits in vivo, but the functional significance of this multiplicity is unknown. We examined gating and permeation properties of recombinant NMDA receptor isoforms and of receptors with altered C-terminal domain (CTDs) prior to and after pharmacological inhibition of PKA. We found that PKA inhibition decreased GluN1/GluN2B but not GluN1/GluN2A gating; this effect was due to slower rates for receptor activation and resensitization and was mediated exclusively by the GluN2B CTD. In contrast, PKA inhibition reduced NMDA receptor-relative Ca²⁺ permeability (P_Ca/P_Na) regardless of the GluN2 isoform and required the GluN1 CTD; this effect was due primarily to decreased unitary Ca²⁺ conductance, because neither Na⁺ conductance nor Ca²⁺-dependent block was altered substantially. Finally, we show that both the gating and permeation effects can be reproduced by changing the phosphorylation state of a single residue: GluN2B Ser-1166 and GluN1 Ser-897, respectively. We conclude that PKA effects on NMDA receptor gating and Ca²⁺ permeability rely on distinct phosphorylation sites located on the CTD of GluN2B and GluN1 subunits. This separate control of NMDA receptor properties by PKA may account for the specific effects of PKA on plasticity during synaptic development and may lead to drugs targeted to alter NMDA receptor gating or Ca²⁺ permeability.