51 research outputs found
institutional innovation from the bottom up?
A sustainable economy fulfills societal needs in a fundamentally different
way to the current economic system. Improvements to the efficiency of
existing technologies or practices appear insufficient for achieving
sustainable development within the planetary boundaries. Disruptive,
systemic and transformational changes appear necessary in order to replace
existing technologies and practices to establish a sustainable economy.
Such innovations often start out in niches; however, the scaling up and
the ultimate replacement of current socio-technical systems requires
governance to allow for the coordination of actors, the reorganization of
socio-technical systems and the mobilization and allocation of resources.
As governmental institutions are part of the current (non-sustainable)
systems and thereby fail to provide coherent, integrated and transformative
governance, we explore whether institutional innovation from non-state
actors can step in to provide governance of transformation processes.
Based on explorative qualitative case studies of networks in the food sector,
city planning and reporting tools, we analyze the potential of bottom-up
institutional innovations to coordinate actors in transformation processes
Midgut epithelial endocrine cells are a rich source of the neuropeptides APSGFLGMRamide (Cancer borealis tachykinin-related peptide Ia) and GYRKPPFNGSIFamide (Gly\u3csup\u3e1\u3c/sup\u3e-SIFamide) in the crabs Cancer borealis, Cancer magister and Cancer productus
Over a quarter of a century ago, Mykles described the presence of putative endocrine cells in the midgut epithelium of the crab Cancer magister (Mykles, 1979). In the years that have followed, these cells have been largely ignored and nothing is known about their hormone content or the functions they play in this species. Here, we used a combination of immunohistochemistry and mass spectrometric techniques to investigate these questions. Using immunohistochemistry, we identified both SIFamide-and tachykinin-related peptide (TRP)-like immunopositive cells in the midgut epithelium of C. magister, as well as in that of Cancer borealis and Cancer productus. In each species, the SIFamide-like labeling was restricted to the anterior portion of the midgut, including the paired anterior midgut caeca, whereas the TRP-like immunoreactivity predominated in the posterior midgut and the posterior midgut caecum. Regardless of location, label or species, the morphology of the immunopositive cells matched that of the putative endocrine cells characterized ultrastructurally by Mykles (Mykles, 1979). Matrix-assisted laser desorption/ ionization-Fourier transform mass spectrometry identified the peptides responsible for the immunoreactivities as GYRKPPFNGSIFamide (Gly 1-SIFamide) and APSGFLGMRamide [Cancer boreatis tachykinin-related peptide Ia (CabTRP Ia)], respectively, both of which are known neuropeptides of Cancer species. Although the function of these midgut-derived peptides remains unknown, we found that both Gly1-SIFamide and CabTRP Ia were released when the midgut was exposed to high-potassium saline. In addition, CabTRP Ia was detectable in the hemolymph of crabs that had been held without food for several days, but not in that of fed animals, paralleling results that were attributed to TRP release from midgut endocrine cells in insects. Thus, one function that midgut-derived CabTRP Ia may play in Cancer species is paracrine/hormonal control of feeding-related behavior, as has been postulated for TRPs released from homologous cells in insects
Genetic mapping in mice identifies DMBT1 as a candidate modifier of mammary tumors and breast cancer risk
Low-penetrance breast cancer susceptibility alleles seem to play a significant role in breast cancer risk but are difficult to identify in human cohorts. A genetic screen of 176 N2 backcross progeny of two Trp53+/- strains, BALB/c and C57BL/6, which differ in their susceptibility to mammary tumors, identified a modifier of mammary tumor susceptibility in an ∼25-Mb interval on mouse chromosome 7 (designated SuprMam1). Relative to heterozygotes, homozygosity for BALB/c alleles of SuprMam1 significantly decreased mammary tumor latency from 70.7 to 61.1 weeks and increased risk twofold (P = 0.002). Dmbt1 (deleted in malignant brain tumors 1) was identified as a candidate modifier gene within the SuprMam1 interval because it was differentially expressed in mammary tissues from BALB/c-Trp53+/- and C57BL/6-Trp53+/- mice. Dmbt1 mRNA and protein was reduced in mammary glands of the susceptible BALB/c mice. Immunohistochemical staining demonstrated that DMBT1 protein expression was also significandy reduced in normal breast tissue from women with breast cancer (staining score, 1.8; n = 46) compared with cancer-free controls (staining score, 3.9; n = 53; P < 0.0001). These experiments demonstrate the use of Trp53+/- mice as a sensitized background to screen for low-penetrance modifiers of cancer. The results identify a novel mammary tumor susceptibility locus in mice and support a role for DMBT1 in suppression of mammary tumors in both mice and women
Simulation vs. Reality: A Comparison of In Silico Distance Predictions with DEER and FRET Measurements
Site specific incorporation of molecular probes such as fluorescent- and nitroxide spin-labels into biomolecules, and subsequent analysis by Förster resonance energy transfer (FRET) and double electron-electron resonance (DEER) can elucidate the distance and distance-changes between the probes. However, the probes have an intrinsic conformational flexibility due to the linker by which they are conjugated to the biomolecule. This property minimizes the influence of the label side chain on the structure of the target molecule, but complicates the direct correlation of the experimental inter-label distances with the macromolecular structure or changes thereof. Simulation methods that account for the conformational flexibility and orientation of the probe(s) can be helpful in overcoming this problem. We performed distance measurements using FRET and DEER and explored different simulation techniques to predict inter-label distances using the Rpo4/7 stalk module of the M. jannaschii RNA polymerase. This is a suitable model system because it is rigid and a high-resolution X-ray structure is available. The conformations of the fluorescent labels and nitroxide spin labels on Rpo4/7 were modeled using in vacuo molecular dynamics simulations (MD) and a stochastic Monte Carlo sampling approach. For the nitroxide probes we also performed MD simulations with explicit water and carried out a rotamer library analysis. Our results show that the Monte Carlo simulations are in better agreement with experiments than the MD simulations and the rotamer library approach results in plausible distance predictions. Because the latter is the least computationally demanding of the methods we have explored, and is readily available to many researchers, it prevails as the method of choice for the interpretation of DEER distance distributions
Anti-Staphylococcus aureus activity of methanol extracts of 12 plants used in Cameroonian folk medicine
Exploration of Shared Genetic Architecture Between Subcortical Brain Volumes and Anorexia Nervosa
The calculation of mass fraction burn of ethanol-gasoline blended fuels using single and two-zone models
One-dimensional single-zone and two-zone analyses have been exercised to calculate the mass fraction burned in an engine operating on ethanol/gasoline-blended fuels using the cylinder pressure and volume data. The analyses include heat transfer and crevice volume effects on the calculated mass fraction burned. A comparison between the two methods is performed starting from the derivation of conservation of energy and the method to solve the mass fraction burned rates through the results including detailed explanation of the observed differences and trends. The apparent heat release method is used as a point of reference in the comparison process. Both models are solved using the LU matrix factorization and first-order Euler integration. Experiments were conducted with a Cooperative Fuels Research (CFR) engine holding Net Indicated Mean Effective Pressure (Net IMEP) constant at 330 kPa and fueling at the respective stoichiometric condition for the air flow and ethanol fuel blend being tested. This study included four ethanol-gasoline fuel blends: E20, E40, E60, E84, and gasoline (E0) as a baseline. The results show that all three models consistently produce similar mass fraction burned profiles for the five different fuels tested. Furthermore, utilizing the gasoline case with gamma as a function of temperature shows that the two-zone model indicated 3% higher combustion efficiency compared to the single-zone model and 17% higher than the apparent heat release method. However, the location of the 10%, 50%, and 90% mass fraction burn points calculated between the methods are within 1° of each other when combustion phasing is near maximum brake torque (MBT). For both the single and two-zone models, the effect of crevice and heat transfer effects appears near the end of the combustion process. Without the crevice model, the computed combustion efficiency of the single-zone model decreases by 8%. Without both crevice and heat transfer models the combustion efficiency decreases by 15% compared to the result of the single-zone full model. The combustion efficiency as calculated with the two-zone model decrease by 5% without crevice effects and 11% without both crevice and heat transfer effects
Combustion characterization in an internal combustion engine with ethanol - Gasoline blended fuels varying compression ratios and ignition timing
Although ethanol possesses only two-thirds the energy density of gasoline, it has other properties that are beneficial to combustion in an internal combustion (IC) engine. These include a higher laminar flame speed and higher octane number relative to gasoline. The higher octane number of ethanol improves knock tolerance, and the faster flame speed provides potential benefits to the combustion process. Understanding these attributes will enable flexible fuel engines to benefit from some of the unique properties of ethanol. While data concerning the efficiency of ethanol fuels at varying compression ratios exist in the literature, there is a lack of fundamental combustion data to validate these results. As such, this work makes use of mass fraction burn (MFB) analysis to examine the differences between various blends of ethanol and gasoline, including the effect of the compression ratio relative to optimal combustion phasing, early and bulk burn rates, and combustion variability. Tests were carried out on a port-fuel-injected, electronically-controlled, modified single-cylinder cooperative fuels research engine operating at steady-state conditions and a stoichiometric air/fuel ratio. Combustion experiments were conducted at a constant engine load of 330 kPa net indicated mean effective pressure (NDV1EP). To characterize the combustion process, in-cylinder pressure data were used to calculate MFB profiles. Combustion was examined as a function of the ethanol concentration, spark timing, and compression ratio. The experimental results indicated that higher ethanol blends increased the knock-limited compression ratio (KLCR). KLCR for the speed and load tested is 8 for gasoline with an octane rating of 91 research octane number (RON) as compared to 16 for an ethanol blend of 84% ethanol (E84). With an increased ethanol concentration in the fuel, the 0-10% MFB duration decreased. Of all of the fuel blends tested, pure gasoline had the longest burn duration in both 0-10% and 10-90% MFB intervals. © 2009 American Chemical Society
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