Grass Phylogeny and Classification: Conflict of Morphology and Molecules

The grass family (Poaceae) has been recognized as a unique lineage for more than 200 years, based initially on characters of inflorescence and spikelet morphology and corroborated by anatomical and other features in the latter half of the twentieth century. There have been a number of attempts to derive a phylogeny of sections of the family from structural (morphological and anatomical) characters. However, more recently the Grass Phylogeny Working Group (2001) applied cladistic principles to the whole family using molecular and structural characters. This study produced a single most-parsimonious tree from six molecular sequence data sets, chloroplast restriction site data, and structural data from a representative set of 62 grasses and four outgroup taxa. However, the cladogram reveals a weak correlation with structural characters. Only three out of 12 subfamilies have unequivocal anatomical synapomorphies and there is no unequivocal morphological synapomorphy in any subfamily. Homoplasious character states outnumber synapomorphic states to a large degree. Cladistic analyses of grass genera in recent studies, based on both micromorphological, anatomical, and molecular data, have often produced clades that are difficult or impossible to define by readily observable features. Examples are shown in this paper for some genera of Danthonioideae, the panicoid tribe Andropogoneae, and the chloridoid tribe Triodieae. A recommendation is made that formal taxonomic and nomenclatural changes should only be applied, particularly at the species level, when the lineages within a phylogeny correlate with marker morphological characters

Application of Reflected Global Navigation Satellite System (GNSS-R) Signals in the Estimation of Sea Roughness Effects in Microwave Radiometry

In February-March 2009 NASA JPL conducted an airborne field campaign using the Passive Active L-band System (PALS) and the Ku-band Polarimetric Scatterometer (PolSCAT) collecting measurements of brightness temperature and near surface wind speeds. Flights were conducted over a region of expected high-speed winds in the Atlantic Ocean, for the purposes of algorithm development for salinity retrievals. Wind speeds encountered were in the range of 5 to 25 m/s during the two weeks deployment. The NASA-Langley GPS delay-mapping receiver (DMR) was also flown to collect GPS signals reflected from the ocean surface and generate post-correlation power vs. delay measurements. This data was used to estimate ocean surface roughness and a strong correlation with brightness temperature was found. Initial results suggest that reflected GPS signals, using small low-power instruments, will provide an additional source of data for correcting brightness temperature measurements for the purpose of sea surface salinity retrievals

EphA2 as a Diagnostic Imaging Target in Glioblastoma: A Positron Emission Tomography/Magnetic Resonance Imaging Study

Noninvasive imaging is a critical technology for diagnosis, classification, and subsequent treatment planning for patients with glioblastoma. It has been shown that the EphA2 receptor tyrosine kinase (RTK) is overexpressed in a number of tumors, including glioblastoma. Expression levels of Eph RTKs have been linked to tumor progression, metastatic spread, and poor patient prognosis. As EphA2 is expressed at low levels in normal neural tissues, this protein represents an attractive imaging target for delineation of tumor infiltration, providing an improved platform for image-guided therapy. In this study, EphA2-4B3, a monoclonal antibody specific to human EphA2, was labeled with Cu-64 through conjugation to the chelator 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA). The resulting complex was used as a positron emission tomography (PET) tracer for the acquisition of high-resolution longitudinal PET/magnetic resonance images. EphA2-4B3-NOTA-Cu-64 images were qualitatively and quantitatively compared to the current clinical standards of [F-18] FDOPA and gadolinium (Gd) contrast-enhanced MRI. We show that EphA2-4B3-NOTA-Cu-64 effectively delineates tumor boundaries in three different mouse models of glioblastoma. Tumor to brain contrast is significantly higher in EphA2-4B3-NOTA-Cu-64 images than in [F-18] FDOPA images and Gd contrast-enhanced MRI. Furthermore, we show that nonspecific uptake in the liver and spleen can be effectively blocked by a dose of nonspecific (isotype control) IgG

Attention on Weak Ties in Social and Communication Networks

Granovetter's weak tie theory of social networks is built around two central hypotheses. The first states that strong social ties carry the large majority of interaction events; the second maintains that weak social ties, although less active, are often relevant for the exchange of especially important information (e.g., about potential new jobs in Granovetter's work). While several empirical studies have provided support for the first hypothesis, the second has been the object of far less scrutiny. A possible reason is that it involves notions relative to the nature and importance of the information that are hard to quantify and measure, especially in large scale studies. Here, we search for empirical validation of both Granovetter's hypotheses. We find clear empirical support for the first. We also provide empirical evidence and a quantitative interpretation for the second. We show that attention, measured as the fraction of interactions devoted to a particular social connection, is high on weak ties --- possibly reflecting the postulated informational purposes of such ties --- but also on very strong ties. Data from online social media and mobile communication reveal network-dependent mixtures of these two effects on the basis of a platform's typical usage. Our results establish a clear relationships between attention, importance, and strength of social links, and could lead to improved algorithms to prioritize social media content

Comparing the immune response to a novel intranasal nanoparticle PLGA vaccine and a commercial BPI3V vaccine in dairy calves

peer-reviewedBackground There is a need to improve vaccination against respiratory pathogens in calves by stimulation of local immunity at the site of pathogen entry at an early stage in life. Ideally such a vaccine preparation would not be inhibited by the maternally derived antibodies. Additionally, localized immune response at the site of infection is also crucial to control infection at the site of entry of virus. The present study investigated the response to an intranasal bovine parainfluenza 3 virus (BPI3V) antigen preparation encapsulated in PLGA (poly dl-lactic-co-glycolide) nanoparticles in the presence of pre-existing anti-BPI3V antibodies in young calves and comparing it to a commercially available BPI3V respiratory vaccine. Results There was a significant (P < 0.05) increase in BPI3V-specific IgA in the nasal mucus of the BPI3V nanoparticle vaccine group alone. Following administration of the nanoparticle vaccine an early immune response was induced that continued to grow until the end of study and was not observed in the other treatment groups. Virus specific serum IgG response to both the nanoparticle vaccine and commercial live attenuated vaccine showed a significant (P < 0.05) rise over the period of study. However, the cell mediated immune response observed didn’t show any significant rise in any of the treatment groups. Conclusion Calves administered the intranasal nanoparticle vaccine induced significantly greater mucosal IgA responses, compared to the other treatment groups. This suggests an enhanced, sustained mucosal-based immunological response to the BPI3V nanoparticle vaccine in the face of pre-existing antibodies to BPI3V, which are encouraging and potentially useful characteristics of a candidate vaccine. However, ability of nanoparticle vaccine in eliciting cell mediated immune response needs further investigation. More sustained local mucosal immunity induced by nanoparticle vaccine has obvious potential if it translates into enhanced protective immunity in the face of virus outbreak

The Substructure Hierarchy in Dark Matter Haloes

We present a new algorithm for identifying the substructure within simulated dark matter haloes. The method is an extension of that proposed by Tormen et al. (2004) and Giocoli et al. (2008a), which identifies a subhalo as a group of self-bound particles that prior to being accreted by the main progenitor of the host halo belonged to one and the same progenitor halo (hereafter satellite). However, this definition does not account for the fact that these satellite haloes themselves may also have substructure, which thus gives rise to sub-subhaloes, etc. Our new algorithm identifies substructures at all levels of this hierarchy, and we use it to determine the mass function of all substructure (counting sub-haloes, sub-subhaloes, etc.). On average, haloes which formed more recently tend to have a larger mass fraction in substructure and to be less concentrated than average haloes of the same mass. We provide quantitative fits to these correlations. Even though our algorithm is very different from that of Gao et al. (2004), we too find that the subhalo mass function per unit mass at redshift z = 0 is universal. This universality extends to any redshift only if one accounts for the fact that host haloes of a given mass are less concentrated at higher redshifts, and concentration and substructure abundance are anti-correlated. This universality allows a simple parametrization of the subhalo mass function integrated over all host halo masses, at any given time. We provide analytic fits to this function which should be useful in halo model analyses which equate galaxies with halo substructure when interpreting clustering in large sky surveys. Finally, we discuss systematic differences in the subhalo mass function that arise from different definitions of (host) halo mass.Comment: 18 pages, 24 figures, accepted for publication on MNRA

Spatial, temporal and molecular dynamics of swine influenza virus-specific CD8 tissue resident memory T cells

For the first time we have defined naïve, central memory, effector memory and differentiated effector porcine CD8 T cells and analyzed their distribution in lymphoid and respiratory tissues after influenza infection or immunization, using peptide-MHC tetramers of three influenza nucleoprotein (NP) epitopes. The hierarchy of response to the three epitopes changes during the response in different tissues. Most NP-specific CD8 T cells in broncho-alveolar lavage (BAL) and lung are tissue resident memory cells (TRM) that express CD69 and downregulate CD45RA and CCR7. NP-specific cells isolated from BAL express genes characteristic of TRM, but gene expression differs at 7, 21 and 63 days post infection. In all tissues the frequency of NP-specific CD8 cells declines over 63 days almost to background levels but is best maintained in BAL. The kinetic of influenza specific memory CD8 T cell in this natural host species differs from that in small animal models

Affordances, constraints and information flows as ‘leverage points’ in design for sustainable behaviour

Copyright @ 2012 Social Science Electronic PublishingTwo of Donella Meadows' 'leverage points' for intervening in systems (1999) seem particularly pertinent to design for sustainable behaviour, in the sense that designers may have the scope to implement them in (re-)designing everyday products and services. The 'rules of the system' -- interpreted here to refer to affordances and constraints -- and the structure of information flows both offer a range of opportunities for design interventions to in fluence behaviour change, and in this paper, some of the implications and possibilities are discussed with reference to parallel concepts from within design, HCI and relevant areas of psychology