Organic agriculture: opportunities and challenges

The organic movement may have gained a place in the spotlight of the mainstream media now, but it has not been like that for long. Since the 1950s, organic farmers operating at a grass roots level have devised, tested and shared production methods. They have codified a set of ideals into a pioneering best practice agricultural management system that addresses multiple community values. Niche markets have gradually been created, commonly based on trust and goodwill (formal certification did not begin until the 1960s and 1970s), and often using novel direct marketing strategies such as box schemes and community supported agriculture. After many years of consumers having to hunt around for their organic produce from several suppliers, perhaps directly from the farmer, the task is now a lot easier with specialist food shops and organic shelf space in supermarkets, in the industrialised world at least. Global links have been forged in all continents as organic agriculture has been seen to be an effective rural development option

Australian Organic Market Report 2008

Being four years since the publication of a similar research document, the Australian Organic Market Report (AOMR) 2008 is a landmark report for the organic industry. The report will be invaluable for monitoring and planning the industry development during a period of high growth. Delivering consistent data for benchmarking growth across the various sectors of the industry, it will be a key tool for decision making by organic producers and marketers, along with interested parties such as government and media, in assisting in understanding the nature, size and development of the organic industry in Australia. Supply chain development has been hindered over many years by a lack of basic information about volumes, seasonality, continuity and quality, not only making it difficult for potentially new members of industry to feel confident about investing in organic, however also likely to cause overseas buyers to look for other countries with more comprehensive industry information. The report is an important base research document required by any growing industry. It has been commissioned by Biological Farmers of Australia (BFA), and has been carried out independently by the University of New England’s Organic Research Group. The report has the financial support of major sponsor Westpac Bank, all State Governments in Australia as well as many dedicated industry businesses

Programmed cell death during neuronal development: the sympathetic neuron model.

Developing sympathetic neurons of the superior cervical ganglion are one of the best studied models of neuronal apoptosis. These cells require nerve growth factor (NGF) for survival at the time that they innervate their final target tissues during late embryonic and early postnatal development. In the absence of NGF, developing sympathetic neurons die by apoptosis in a transcription-dependent manner. Molecular studies of sympathetic neuron apoptosis began in the 1980s. We now know that NGF withdrawal activates the mitochondrial (intrinsic) pathway of apoptosis in sympathetic neurons cultured in vitro, and the roles of caspases, Bcl-2 (B-cell CLL/lymphoma 2) family proteins and XIAP (X-linked inhibitor of apoptosis protein) have been extensively studied. Importantly, a considerable amount has also been learned about the intracellular signalling pathways and transcription factors that regulate programmed cell death in sympathetic neurons. In this article, we review the key papers published in the past few years, covering all aspects of apoptosis regulation in sympathetic neurons and focusing, in particular, on how signalling pathways and transcription factors regulate the cell death programme. We make some comparisons with other models of neuronal apoptosis and describe possible future directions for the field.Cell Death and Differentiation advance online publication, 25 April 2014; doi:10.1038/cdd.2014.47

Reactor sterile neutrinos, dark energy and the age of the universe

There are indications that the neutrino oscillation data from reactor experiments and the LSND and MiniBooNE experiments show a preference for two sterile neutrino species, both with masses in the eV region. We show that this result has a significant impact on some important cosmological parameters. Specifically, we use a combination of CMB, LSS and SN1A data and show that the existence of two light, sterile neutrinos would rule out the cosmological constant as dark energy at 95% confidence level, and lower the expansion age of the universe to 12.58 \pm 0.26 Gyr.Comment: Accepted for publication in Astronomy & Astrophysics. References added and typos corrected. Added numerical values for w ranges and Delta chi^2. Minor extension of discussio

Silica scaled Chrysophytes during spring in the Kis-Balaton reservoir, Hungary

As a result of taking water samples in spring 1999, 26 species of silica-scaled chrysophytes were found in the Kis-Balaton Reservoir I, one of the most remarkable aquatic habitats in Hungary. From them, 23 have been identified with certanity, two were questionable and two were identified to genus level. 12 species are new to Hungary and 19 species had not been found in Kis-Balaton before. Most of the species are widely distributed, occuring mainly in eutrophic waters. The most abundant species were Paraphysomonas vestita, Synura petersenii and Mallomonas alpina, all three widely distributed, cosmopolitan species. Beside these, Mallomonas cratis and Mallomonas acaroides were found to be common members of the vernal flora of silica-scaled chrysophytes in Kis-Balaton. Mallomonas pseudocratis has been found only in a few places in the world, while Mallomonas alata and Mallomonas parvula have bipolar distribution

On the regularization of impact without collision: the Painlevé paradox and compliance

We consider the problem of a rigid body, subject to a unilateral constraint, in the presence of Coulomb friction. We regularize the problem by assuming compliance (with both stiffness and damping) at the point of contact, for a general class of normal reaction forces. Using a rigorous mathematical approach, we recover impact without collision (IWC) in both the inconsistent and indeterminate Painlev\'e paradoxes, in the latter case giving an exact formula for conditions that separate IWC and lift-off. We solve the problem for arbitrary values of the compliance damping and give explicit asymptotic expressions in the limiting cases of small and large damping, all for a large class of rigid bodies.Comment: Compared to previous version of the paper, we have: (a) Added a new theorem 2, (b) added a new discussion section with numerical computations, and (c) changed the overall exposition of the manuscrip

The MEK-ERK pathway negatively regulates bim expression through the 3' UTR in sympathetic neurons

Background: Apoptosis plays a critical role during neuronal development and disease. Developing sympathetic neurons depend on nerve growth factor (NGF) for survival during the late embryonic and early postnatal period and die by apoptosis in its absence. The proapoptotic BH3-only protein Bim increases in level after NGF withdrawal and is required for NGF withdrawal-induced death. The regulation of Bim expression in neurons is complex and this study describes a new mechanism by which an NGF-activated signalling pathway regulates bim gene expression in sympathetic neurons.Results: We report that U0126, an inhibitor of the prosurvival MEK-ERK pathway, increases bim mRNA levels in sympathetic neurons in the presence of NGF. We find that this effect is independent of PI3-K-Akt and JNK-c-Jun signalling and is not mediated by the promoter, first exon or first intron of the bim gene. By performing 3' RACE and microinjection experiments with a new bim-LUC+3'UTR reporter construct, we show that U0126 increases bim expression via the bim 3' UTR. We demonstrate that this effect does not involve a change in bim mRNA stability and by using PD184352, a specific MEK1/2-ERK1/2 inhibitor, we show that this mechanism involves the MEK1/2-ERK1/2 pathway. Finally, we demonstrate that inhibition of MEK/ERK signalling independently reduces cell survival in NGF-treated sympathetic neurons.Conclusions: These results suggest that in sympathetic neurons, MEK-ERK signalling negatively regulates bim expression via the 3' UTR and that this regulation is likely to be at the level of transcription. This data provides further insight into the different mechanisms by which survival signalling pathways regulate bim expression in neurons

On the use of blow up to study regularizations of singularities of piecewise smooth dynamical systems in R3\mathbb{R}^3

In this paper we use the blow up method of Dumortier and Roussarie \cite{dumortier_1991,dumortier_1993,dumortier_1996}, in the formulation due to Krupa and Szmolyan \cite{krupa_extending_2001}, to study the regularization of singularities of piecewise smooth dynamical systems \cite{filippov1988differential} in $\mathbb R^3$. Using the regularization method of Sotomayor and Teixeira \cite{Sotomayor96}, first we demonstrate the power of our approach by considering the case of a fold line. We quickly recover a main result of Bonet and Seara \cite{reves_regularization_2014} in a simple manner. Then, for the two-fold singularity, we show that the regularized system only fully retains the features of the singular canards in the piecewise smooth system in the cases when the sliding region does not include a full sector of singular canards. In particular, we show that every locally unique primary singular canard persists the regularizing perturbation. For the case of a sector of primary singular canards, we show that the regularized system contains a canard, provided a certain non-resonance condition holds. Finally, we provide numerical evidence for the existence of secondary canards near resonance.Comment: To appear in SIAM Journal of Applied Dynamical System