Impacts of farming practice within organic farming systems on below-ground ecology and ecosystem function

Maintaining ecosystem function is a key issue for sustainable farming systems which contribute broadly to global ecosystem health. A focus simply on the diversity of belowground organisms is not sufficient and there is a need to consider the contribution of below-ground biological processes to the maintenance and enhancement of soil function and ecosystem services. A critical literature review on the impacts of land management practices on below-ground ecology and function shows that farm management practices can have a major impact. A particular challenge for organic farming systems is to explore to what extent reduced tillage can be adopted to the benefit of below-ground ecology without critically upsetting the whole farm management balance

Evidence for the Strong Dominance of Proton-Neutron Correlations in Nuclei

We analyze recent data from high-momentum-transfer $(p,pp)$ and $(p,ppn)$ reactions on Carbon. For this analysis, the two-nucleon short-range correlation (NN-SRC) model for backward nucleon emission is extended to include the motion of the NN-pair in the mean field. The model is found to describe major characteristics of the data. Our analysis demonstrates that the removal of a proton from the nucleus with initial momentum 275-550 MeV/c is $92^{+8}_{-18}$ of the time accompanied by the emission of a correlated neutron that carries momentum roughly equal and opposite to the initial proton momentum. Within the NN-SRC dominance assumption the data indicate that the probabilities of $pp$ or $nn$ SRCs in the nucleus are at least a factor of six smaller than that of $pn$ SRCs. Our result is the first estimate of the isospin structure of NN-SRCs in nuclei, and may have important implication for modeling the equation of state of asymmetric nuclear matter.Comment: 4 pages and 3 figures, Revised version to be published in Phys. Rev. Let

A crucial sequence for transglutaminase type 2 extracellular trafficking in renal tubular epithelial cells lies in its N-terminal {beta}-sandwich domain

Transglutaminase type 2 (TG2) catalyzes the formation of an -( -glutamyl)-lysine isopeptide bond between adjacent peptides or proteins including those of the extracellular matrix (ECM). Elevated extracellular TG2 leads to accelerated ECM deposition and reduced clearance that underlie tissue scarring and fibrosis. The extracellular trafficking of TG2 is crucial to its role in ECM homeostasis; however, the mechanism by which TG2 escapes the cell is unknown as it has no signal leader peptide and therefore cannot be transported classically. Understanding TG2 transport may highlight novel mechanisms to interfere with the extracellular function of TG2 as isoform-specific TG2 inhibitors remain elusive. Mammalian expression vectors were constructed containing domain deletions of TG2. These were transfected into three kidney tubular epithelial cell lines, and TG2 export was assessed to identify critical domains. Point mutation was then used to highlight specific sequences within the domain required for TG2 export. The removal of -sandwich domain prevented all TG2 export. Mutations of Asp94 and Asp97 within the N-terminal -sandwich domain were identified as crucial for TG2 externalization. These form part of a previously identified fibronectin binding domain (88WTATVVDQQDCTLSLQLTT106). However, siRNA knockdown of fibronectin failed to affect TG2 export. The sequence 88WTATVVDQQDCTLSLQLTT106 within the -sandwich domain of TG2 is critical to its export in tubular epithelial cell lines. The extracellular trafficking of TG2 is independent of fibronectin

Improving supply and phosphorous use efficiency in organic farming systems

Phosphorus (P) is an essential plant nutrient that needs to be managed carefully in organic systems so that crop yield and quality remain sustainable without contributing to environmental damage, particularly that associated with eutrophication. Under organic regulations, minimally processed rock phosphate (PR) can be used to amend low P fertility soils, although the solubility is extremely low at optimum soil pH for most crop growth (pH 6.5). This paper describes a project (PLINK) which aims to develop methods of improving P efficiency on organic farms, although the same approaches may also be applicable on conventional and low-input farms. The methodologies that the project is developing include the fermentation and composting of crop waste material with PR in order to solubilise P and make it more available to the crop. Some initial results are described here. In addition, the project will investigate the alteration of the rotation to include crops or varieties with high P uptake efficiency, or roots that possess acidifying properties which improve P availability for following crops

Surface wind convergence as a short-term predictor of cloud-to-ground lightning at Kennedy Space Center: A four-year summary and evaluation

Since 1986, USAF forecasters at NASA-Kennedy have had available a surface wind convergence technique for use during periods of convective development. In Florida during the summer, most of the thunderstorm development is forced by boundary layer processes. The basic premise is that the life cycle of convection is reflected in the surface wind field beneath these storms. Therefore the monitoring of the local surface divergence and/or convergence fields can be used to determine timing, location, longevity, and the lightning hazards which accompany these thunderstorms. This study evaluates four years of monitoring thunderstorm development using surface wind convergence, particularly the average over the area. Cloud-to-ground (CG) lightning is related in time and space with surface convergence for 346 days during the summers of 1987 through 1990 over the expanded wind network at KSC. The relationships are subdivided according to low level wind flow and midlevel moisture patterns. Results show a one in three chance of CG lightning when a convergence event is identified. However, when there is no convergence, the chance of CG lightning is negligible

Near-Infrared, Adaptive Optics Observations of the T Tauri Multiple-Star System

With high-angular-resolution, near-infrared observations of the young stellar object T Tauri at the end of 2002, we show that, contrary to previous reports, none of the three infrared components of T Tau coincide with the compact radio source that has apparently been ejected recently from the system (Loinard, Rodriguez, and Rodriguez 2003). The compact radio source and one of the three infrared objects, T Tau Sb, have distinct paths that depart from orbital or uniform motion between 1997 and 2000, perhaps indicating that their interaction led to the ejection of the radio source. The path that T Tau Sb took between 1997 and 2003 may indicate that this star is still bound to the presumably more massive southern component, T Tau Sa. The radio source is absent from our near-infrared images and must therefore be fainter than K = 10.2 (if located within 100 mas of T Tau Sb, as the radio data would imply), still consistent with an identity as a low-mass star or substellar object.Comment: 11 pages, 3 figures, submitted to ApJ

Two-body non-leptonic decays on the lattice

We show that, under reasonable hypotheses, it is possible to study two-body non-leptonic weak decays in numerical simulations of lattice QCD. By assuming that final-state interactions are dominated by the nearby resonances and that the couplings of the resonances to the final particles are smooth functions of the external momenta, it is possible indeed to overcome the difficulties imposed by the Maiani-Testa no-go theorem and to extract the weak decay amplitudes, including their phases. Under the same assumptions, results can be obtained also for time-like form factors and quasi-elastic processes.Comment: 15 pages, 1 Postscript figur

Information extraction and transmission techniques for spaceborne synthetic aperture radar images

Information extraction and transmission techniques for synthetic aperture radar (SAR) imagery were investigated. Four interrelated problems were addressed. An optimal tonal SAR image classification algorithm was developed and evaluated. A data compression technique was developed for SAR imagery which is simple and provides a 5:1 compression with acceptable image quality. An optimal textural edge detector was developed. Several SAR image enhancement algorithms have been proposed. The effectiveness of each algorithm was compared quantitatively

Teacher change in post-16 mathematics: a multiple case analysis of teachers in the Zone of Enactment.

This research focuses on the use of teaching resources that support an ambitious student-centred approach to learning mathematics. A multiple case study involving three teachers of post-16 mathematics is presented to develop new insights into the process of teacher change. Data sources include classroom observations in addition to teacher and student interviews. Using the concept of Zone of Enactment (ZoE) and teacher self-efficacy as a theoretical framework this research reveals the importance of teachers being aware of, and able to reflect on, the ZoE and their self-efficacy

D/H of water released by stepped heating of Shergotty, Zagami, Chassigny, ALH 84001, and Nakhla

We report the yield and D/H of water released by stepped heating of bulk Shergotty, Zagami, Chassigny, and the newest martian meteorite, ALH 84001. For comparison, we also report data from Nakhla using the same procedure since the heating steps in this study are slightly different than our previously reported nakhlite analyses