699 research outputs found
Spatial Differences of Land Use Change within Oklahoma's Wheat Belt
Farm Service Agency acreage data for the nine Oklahoma Agricultural Statistics Service districts is analyzed to determine the degree of price response in wheat acreage allocation decisions. Some critics have stated that land use after Freedom to Farm would change little, however these findings show acreage shifted greatly after the policy throughout the state.Land Economics/Use,
Stably free modules over virtually free groups
Let be the free group on generators and let be a finite
nilpotent group of non square-free order; we show that for each the
integral group ring has infinitely many stably free
modules of rank 1.Comment: 9 pages. The final publication is available at
http://www.springerlink.com doi:10.1007/s00013-012-0432-
Advantages and challenges of microalgae as a source of oil for biodiesel
Microalgal oil is currently being considered as a promising alternative feedstock for
biodiesel. The present demand for oil for biofuel production greatly exceeds the supply,
hence alternative sources of biomass are required. Microalgae have several advantages over
land-based crops in terms of oil production. Their simple unicellular structure and high
photosynthetic efficiency allow for a potentially higher oil yield per area than that of the
best oilseed crops. Algae can be grown on marginal land using brackish or salt water and
hence do not compete for resources with conventional agriculture. They do not require
herbicides or pesticides and their cultivation could be coupled with the uptake of CO2 from
industrial waste streams, and the removal of excess nutrients from wastewater (Hodaifa et
al., 2008; An et al., 2003). In addition to oil production, potentially valuable co-products such
as pigments, antioxidants, nutraceuticals, fertilizer or feeds could be produced (Mata et al.,
2010; Rodolfi et al., 2009)
`In pursuit of the Nazi mind?' the deployment of psychoanalysis in the allied struggle against Germany
This paper discusses how psychoanalytic ideas were brought to bear in the Allied struggle against the Third Reich and explores some of the claims that were made about this endeavour. It shows how a variety of studies of Fascist psychopathology, centred on the concept of superego, were mobilized in military intelligence, post-war planning and policy recommendations for âdenazificationâ. Freud's ideas were sometimes championed by particular army doctors and government planners; at other times they were combined with, or displaced by, competing, psychiatric and psychological forms of treatment and diverse studies of the Fascist âpersonalityâ. This is illustrated through a discussion of the treatment and interpretation of the deputy leader of the Nazi Party, Rudolf Hess, after his arrival in Britain in 1941
Skeletal dysplasia-causing TRPV4 mutations suppress the hypertrophic differentiation of human iPSC-derived chondrocytes
Mutations in the TRPV4 ion channel can lead to a range of skeletal dysplasias. However, the mechanisms by which TRPV4 mutations lead to distinct disease severity remain unknown. Here, we use CRISPR-Cas9-edited human-induced pluripotent stem cells (hiPSCs) harboring either the mild V620I or lethal T89I mutations to elucidate the differential effects on channel function and chondrogenic differentiation. We found that hiPSC-derived chondrocytes with the V620I mutation exhibited increased basal currents through TRPV4. However, both mutations showed more rapid calcium signaling with a reduced overall magnitude in response to TRPV4 agonist GSK1016790A compared to wildtype (WT). There were no differences in overall cartilaginous matrix production, but the V620I mutation resulted in reduced mechanical properties of cartilage matrix later in chondrogenesis. mRNA sequencing revealed that both mutations up-regulated several anterio
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Ten policies for pollinators
Earlier this year, the first global thematic assessment from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) evaluated the state of knowledge about pollinators and pollination (1, 2). It confirmed evidence of large-scale wild pollinator declines in northwest Europe and North America and identified data shortfalls and an urgent need for monitoring elsewhere in the world. With high-level political commitments to support pollinators in the United States (3), the United Kingdom (4), and France (5); encouragement from the Convention on Biological Diversity's (CBD's) scientific advice body (6); and the issue on the agenda for next month's Conference of the Parties to the CBD, we see a chance for global-scale policy change. We extend beyond the IPBES report, which we helped to write, and suggest 10 policies that governments should seriously consider to protect pollinators and secure pollination services. Our suggestions are not the only available responses but are those we consider most likely to succeed, because of synergy with international policy objectives and strategies or formulation of international policy creating opportunities for change. We make these suggestions as independent scientists and not on behalf of IPBES
The binding affinity of PTPN13âs tandem PDZ2/3 domain is allosterically modulated
Background
Protein tyrosine phosphatase PTPN13, also known as PTP-BL in mice, is a large multi-domain non-transmembrane scaffolding protein with a molecular mass of 270âkDa. It is involved in the regulation of several cellular processes such as cytokinesis and actin-cytoskeletal rearrangement. The modular structure of PTPN13 consists of an N-terminal KIND domain, a FERM domain, and five PDZ domains, followed by a C-terminal protein tyrosine phosphatase domain. PDZ domains are among the most abundant protein modules and they play a crucial role in signal transduction of protein networks.
Results
Here, we have analysed the binding characteristics of the isolated PDZ domains 2 and 3 from PTPN13 and compared them to the tandem domain PDZ2/3, which interacts with 12 C-terminal residues of the tumour suppressor protein of APC, using heteronuclear multidimensional NMR spectroscopy. Furthermore, we could show for the first time that PRK2 is a weak binding partner of PDZ2 and we demonstrate that the presence of PDZ3 alters the binding affinity of PDZ2 for APC, suggesting an allosteric effect and thereby modulating the binding characteristics of PDZ2. A HADDOCK-based molecular model of the PDZ2/3 tandem domain from PTPN13 supports these results.
Conclusions
Our study of tandem PDZ2/3 in complex with APC suggests that the interaction of PDZ3 with PDZ2 induces an allosteric modulation within PDZ2 emanating from the back of the domain to the ligand binding site. Thus, the modified binding preference of PDZ2 for APC could be explained by an allosteric effect and provides further evidence for the pivotal function of PDZ2 in the PDZ123 domain triplet within PTPN13
Protecting an Ecosystem Service: Approaches to Understanding and Mitigating Threats to Wild Insect Pollinators
Molecular basis of class III ligand recognition by PDZ3 in murine protein tyrosine phosphatase PTPN13
Protein tyrosine phosphatase PTPN13, also known as PTP-BL in mice, represents a large multi-domain non-transmembrane scaffolding protein that contains five consecutive PDZ domains. Here, we report the solution structures of the extended murine PTPN13 PDZ3 domain in its apo form and in complex with its physiological ligand, the carboxy-terminus of protein kinase C-related kinase-2 (PRK2), determined by multidimensional NMR spectroscopy. Both in its ligand-free state and when complexed to PRK2, PDZ3 of PTPN13 adopts the classical compact, globular D/E fold. PDZ3 of PTPN13 binds five carboxy-terminal amino acids of PRK2 via a groove located between the EB-strand and the DB-helix. The PRK2 peptide resides in the canonical PDZ3 binding cleft in an elongated manner and the amino acid side chains in position P0 and P-2, cysteine and aspartate, of the ligand face the groove between EB-strand and DB-helix, whereas the PRK2 side chains of tryptophan and alanine located in position P-1 and P-3 point away from the binding cleft. These structures are rare examples of selective class III ligand recognition by a PDZ domain and now provide a basis for the detailed structural investigation of the promiscuous interaction between the PDZ domains of PTPN13 and their ligands. They will also lead to a better understanding of the proposed scaffolding function of these domains in multi-protein complexes assembled by PTPN13 and could ultimately contribute to low molecular weight antagonists that might even act on the PRK2 signaling pathway to modulate rearrangements of the actin cytoskeleton
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Editorial: summary for policymakers of the thematic assessment on pollinators, pollination and food production
Values of pollinators and pollination
1. Animal pollination plays a vital role as a regulating ecosystem service in nature. Globally, nearly 90 per cent of wild flowering plant species depend, at least in part, on the transfer of pollen by animals. These plants are critical for the continued functioning of ecosystems as they provide food, form habitats, and provide other resources for a wide range of other species.
2. More than three quarters of the leading types of global
food crops rely to some extent on animal pollination for yield and/or quality. Pollinator-dependent crops contribute to 35 per cent of global crop production volume.
3. Given that pollinator-dependent crops rely on animal pollination to varying degrees, it is estimated that 5â8 per cent of current global crop production is directly attributed to animal pollination with an annual market value of 577 billion (in 2015, United States dollars1) worldwide
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