A preliminary assessment of the feasibility of deriving liquid and gaseous fuels from grown and waste organics

The anticipated depletion of our resources of natural gas and petroleum in a few decades has caused a search for renewable sources of fuel. Among the possibilities is the chemical conversion of waste and grown organic matter into gaseous or liquid fuels. The overall feasibility of such a system is considered from the technical, economic, and social viewpoints. Although there are a number of difficult problems to overcome, this preliminary study indicates that this option could provide between 4 and 10 percent of the U.S. energy needs. Estimated costs of fuels derived from grown organic material are appreciably higher than today's market price for fossil fuel. The cost of fuel derived from waste organics is competitive with fossil fuel prices. Economic and social reasons will prohibit the allocation of good food producing land to fuel crop production

Preliminary assessment of systems for deriving liquid and gaseous fuels from waste or grown organics

The overall feasibility of the chemical conversion of waste or grown organic matter to fuel is examined from the technical, economic, and social viewpoints. The energy contribution from a system that uses waste and grown organic feedstocks is estimated as 4 to 12 percent of our current energy consumption. Estimates of today's market prices for these fuels are included. Economic and social issues are as important as technology in determining the feasibility of such a proposal. An orderly program of development and demonstration is recommended to provide reliable data for an assessment of the viability of the proposal

Robust identification of local adaptation from allele frequencies

Comparing allele frequencies among populations that differ in environment has long been a tool for detecting loci involved in local adaptation. However, such analyses are complicated by an imperfect knowledge of population allele frequencies and neutral correlations of allele frequencies among populations due to shared population history and gene flow. Here we develop a set of methods to robustly test for unusual allele frequency patterns, and correlations between environmental variables and allele frequencies while accounting for these complications based on a Bayesian model previously implemented in the software Bayenv. Using this model, we calculate a set of `standardized allele frequencies' that allows investigators to apply tests of their choice to multiple populations, while accounting for sampling and covariance due to population history. We illustrate this first by showing that these standardized frequencies can be used to calculate powerful tests to detect non-parametric correlations with environmental variables, which are also less prone to spurious results due to outlier populations. We then demonstrate how these standardized allele frequencies can be used to construct a test to detect SNPs that deviate strongly from neutral population structure. This test is conceptually related to FST but should be more powerful as we account for population history. We also extend the model to next-generation sequencing of population pools, which is a cost-efficient way to estimate population allele frequencies, but it implies an additional level of sampling noise. The utility of these methods is demonstrated in simulations and by re-analyzing human SNP data from the HGDP populations. An implementation of our method will be available from http://gcbias.org.Comment: 27 pages, 7 figure

Correlation of Black Hole and Bulge Masses: Driven by Energy but Correlated with Momentum

We use a recent sample of 49 galaxies to show that there is a proportionality relation between the black hole mass M_BH and the quantity \mu =M_G*\sigma /c, where M_G is mass of the spheroidal stellar component and \sigma is the stellar velocity dispersion. \mu is called the momentum parameter and the ratio is M_BH/\mu ~3.3. This result is applied to the penetrating-jet feedback model which argues that the correlation that holds is with a momentum-like parameter, although this feedback mechanism is based on energy balance.Comment: Accepted to MNRA

Structure and functional motifs of GCR1, the only plant protein with a GPCR fold?

Whether GPCRs exist in plants is a fundamental biological question. Interest in deorphanizing new G protein coupled receptors (GPCRs), arises because of their importance in signaling. Within plants, this is controversial as genome analysis has identified 56 putative GPCRs, including GCR1 which is reportedly a remote homologue to class A, B and E GPCRs. Of these, GCR2, is not a GPCR; more recently it has been proposed that none are, not even GCR1. We have addressed this disparity between genome analysis and biological evidence through a structural bioinformatics study, involving fold recognition methods, from which only GCR1 emerges as a strong candidate. To further probe GCR1, we have developed a novel helix alignment method, which has been benchmarked against the the class A – class B - class F GPCR alignments. In addition, we have presented a mutually consistent set of alignments of GCR1 homologues to class A, class B and class F GPCRs, and shown that GCR1 is closer to class A and /or class B GPCRs than class A, class B or class F GPCRs are to each other. To further probe GCR1, we have aligned transmembrane helix 3 of GCR1 to each of the 6 GPCR classes. Variability comparisons provide additional evidence that GCR1 homologues have the GPCR fold. From the alignments and a GCR1 comparative model we have identified motifs that are common to GCR1, class A, B and E GPCRs. We discuss the possibilities that emerge from this controversial evidence that GCR1 has a GPCR fol

Undernutrition and stage of gestation influence fetal adipose tissue gene expression

Funded by the Scottish Government’s Rural and Environment Science and Analytical Services Division (RESAS), including the Strategic Partnership for Animal Science Excellence (SPASE) and the U.S. National Institutes of Health (HD045784). None of the authors had any financial or personal conflicts of interest.Peer reviewedPostprin

Assessing the effect of dynamics on the closed-loop protein-folding hypothesis

The closed-loop (loop-n-lock) hypothesis of protein folding suggests that loops of about 25 residues, closed through interactions between the loop ends (locks), play an important role in protein structure. Coarse-grain elastic network simulations, and examination of loop lengths in a diverse set of proteins, each supports a bias towards loops of close to 25 residues in length between residues of high stability. Previous studies have established a correlation between total contact distance (TCD), a metric of sequence distances between contacting residues (cf. contact order), and the log-folding rate of a protein. In a set of 43 proteins, we identify an improved correlation ( r 2 = 0.76), when the metric is restricted to residues contacting the locks, compared to the equivalent result when all residues are considered ( r 2 = 0.65). This provides qualified support for the hypothesis, albeit with an increased emphasis upon the importance of a much larger set of residues surrounding the locks. Evidence of a similar-sized protein core/extended nucleus (with significant overlap) was obtained from TCD calculations in which residues were successively eliminated according to their hydrophobicity and connectivity, and from molecular dynamics simulations. Our results suggest that while folding is determined by a subset of residues that can be predicted by application of the closed-loop hypothesis, the original hypothesis is too simplistic; efficient protein folding is dependent on a considerably larger subset of residues than those involved in lock formation. </jats:p

Modes of ocean variability in the tropical Pacific as derived from Geosat altimetry

Satellite-derived (Geosat altimetry) sea surface height anomalies for the period November 1986 to September 1989 were investigated in order to extract the dominant modes of climate variability in the tropical Pacific. We applied the technique of principal oscillation patterns and computed associated wind stress patterns for each mode. Four modes were identified. The first mode has a time scale of about 3 months and can be identified with the first baroclinic equatorial Kelvin wave mode, which is excited by intraseasonal wind variations over the western equatorial Pacific. The second mode has a time scale of about 6 months and describes the semiannual cycle in the tropical Pacific sea level. Equatorial wave dynamics appears to be crucial for this mode also. The third mode is the annual cycle which shows evidence of off-equatorial Rossby wave propagation. The fourth mode is associated with the El Niño/Southern Oscillation (ENSO) phenomenon. The ENSO mode is found to be consistent with the “delayed action oscillator” scenario

Centaurus A: multiple outbursts or bursting bubble?

We present new radio observations of the brighter region of the northern lobe (the Northern Middle Lobe, NML) of Centaurus A obtained at 20 cm with the Australia Telescope Compact Array. The angular resolutions are ~50 and ~130 arcsec, therefore much higher than for the previously available radio images of this region. The most interesting feature detected is a large-scale jet that connects the inner radio lobe and the NML and that is imaged for the first time. The NML itself appears as diffuse emission with a relatively bright ridge on the eastern side. The radio morphology of Centaurus A and, in particular, its NML could be the result of a precessing jet that has undergone a strong interaction with the environment at least in the northern side. The very big drop in intensity between the inner jet and the large-scale jet can be explained with a sequence of bursts of activity at different epochs in the life of the source. Alternatively (or additionally) a ``bursting bubble'' model is proposed which could also explain the good collimation of the large-scale jet. In this model, the plasma accumulated in the inner lobe would be able to ``burst'' out only through one nozzle that would be the region where the large-scale jet forms. From the comparison between the radio emission and the regions of ionized gas we find that the inner optical filament falls about 2 arcmin (~2 kpc) away from the large-scale radio jet. Thus, this filament does not seem to have experienced a direct interaction with the radio plasma. The outer filaments appear to be, in projection, closer to the radio emission, arguing for a direct interaction with the radio jet. However, also in this case a more complicated interaction than assumed so far has to be occuring.Comment: To appear in MNRAS; 11 pages, LateX, 7 figures. Fig 1 is available at http://www.ira.bo.cnr.it/~rmorgant/Centaurus

Air transport liberalisation and airport dependency: developing a composite index

Air transport liberalisation in Europe has produced some major changes to the networks operated by airlines and the services available at airports. Within this context the degree of airport dependency in terms of market, spatial and temporal concentration is important to know from an economic geography and risk management perspective. A composite index called the Airport Dependency Index (ADI) is developed to measure airport dependency based on the concept of the relative Gini coefficient. Liberalisation has had varying impacts depending on the size and type of airport and so a comparison is made of the degree of dependency at a large sample of European airports using the ADI. The ADI has the potential to provide insight on the sustainability and worthiness of financing airport projects, and on whether airports should diversify further their activities by investing in the growth and expansion of their network