Autonomous model protocell division driven by molecular replication

The coupling of compartmentalisation with molecular replication is thought to be crucial for the emergence of the first evolvable chemical systems. Minimal artificial replicators have been designed based on molecular recognition, inspired by the template copying of DNA, but none yet have been coupled to compartmentalisation. Here, we present an oil-in-water droplet system comprising an amphiphilic imine dissolved in chloroform that catalyses its own formation by bringing together a hydrophilic and a hydrophobic precursor, which leads to repeated droplet division. We demonstrate that the presence of the amphiphilic replicator, by lowering the interfacial tension between droplets of the reaction mixture and the aqueous phase, causes them to divide. Periodic sampling by a droplet-robot demonstrates that the extent of fission is increased as the reaction progresses, producing more compartments with increased self-replication. This bridges a divide, showing how replication at the molecular level can be used to drive macroscale droplet fission

Beneficiary reactions to the fodder bank trials

Examines ILCA's fodder bank programme w. regard to costs, benefits and beneficiaries, perception of them, relating this to acceptability of this innovation by Fulani pastoralists

Triple collisions (e+p+Be7) in solar plasma

Several nuclear reactions involving the Be7 nucleus, not included into the standard model of the pp-chain, are discussed. A qualitative analysis of their possible influence on the fate of the Be7 in solar plasma and of their role in the interpretation of the solar neutrino experiments is given. As an example, the reaction rate of the nonradiative production of B8 in the triple collision p + e^- + Be7 ---> B8 + e^- is estimated in the framework of the adiabatic approximation. For the solar interior conditions the triple collision reaction rate is approximately 10^{-4} of that for the binary process p + Be7 ---> B8 + gamma .Comment: RevTeX, 15 pages, submitted to Nucl.Phys.

Implementing community based seagrass monitoring in the Wellesley Island Group

A survey was commissioned in 2007 by the Carpentaria Land Council Aboriginal Corporation (CLCAC) and the North Australia Indigenous Land and Sea Management Alliance (NAILSMA) on behalf of the Traditional Owners of the Wellesley Island region who had raised concerns over unhealthy dugong and turtle reported from hunters. Traditional Owners felt that one possible cause of sick animals may have been as a result of seagrass dieback causing a shortage of food to the animals. To answer the concerns of the Traditional Owners, the Department of Primary Industries and Fisheries Marine Ecology Group was commissioned to survey the seagrass communities of the Wellesley Islands and to train Wellesley Islands Rangers on seagrass mapping techniques. This was the first time that seagrasses have been formally surveyed and mapped for 23 years in the Wellesley Islands. Seagrass communities were the dominant benthic habitat in intertidal and shallow subtidal areas with a high diversity (8 specie s) of coastal seagrass compared with other Gulf of Carpentaria locations. Evidence of heavy dugong feeding activity was observed on most intertidal seagrass meadows surveyed. The highest density of dugong feeding trails was observed in seagrass meadows dominated by Halodule uninervis (narrow leaf form) and/or Halophila ovalis. In addition, dugongs were regularly observed feeding in subtidal meadows from the helicopter during surveys. This survey was used to help fill gaps in knowledge and provide a baseline from which future monitoring could be conducted to identify research required to answer the uncertainties raised by the Traditional Owners, and to help with developing zoning plans for the management of their Sea Country

Dynamics of a tropical deepwater seagrass community during a major dredging campaign

A research and monitoring program was established to examine the potential impacts of a large scale capital dredging program on a tropical deepwater seagrass community between December 2005 and June 2008. The aims of the monitoring program were to fill gaps in our understanding of the dynamics of tropical deepwater seagrass habitats, their roles in fisheries productivity and their resilience and capacity for recovery from disturbance associated with dredging. While the dynamics of shallow coastal seagrasses in the region have been the subject of many studies little was previously known about the low density deepwater seagrass habitat that typified the study area. Results of the study revealed that these deepwater meadows had a high natural seasonal and inter-annual variability. Seasonality was substantially different to neighbouring shallow seagrass communities with a winter peak in abundance declining in spring before losing all above-ground biomass during summer months. Turbidity associated with dredging inhibited seagrass recruitment but there was evidence of seagrass recovery 12 months after the completion of dredging activity. Implications of the study for managing impacts to deepwater seagrass communities and differences in response to shallow coastal seagrasses are discussed

Implementing community based seagrass monitoring in the Wellesley Island Group

A survey was commissioned in 2007 by the Carpentaria Land Council Aboriginal Corporation (CLCAC) and the North Australia Indigenous Land and Sea Management Alliance (NAILSMA) on behalf of the Traditional Owners of the Wellesley Island region who had raised concerns over unhealthy dugong and turtle reported from hunters. Traditional Owners felt that one possible cause of sick animals may have been as a result of seagrass dieback causing a shortage of food to the animals. To answer the concerns of the Traditional Owners, the Department of Primary Industries and Fisheries Marine Ecology Group was commissioned to survey the seagrass communities of the Wellesley Islands and to train Wellesley Islands Rangers on seagrass mapping techniques. This was the first time that seagrasses have been formally surveyed and mapped for 23 years in the Wellesley Islands. Seagrass communities were the dominant benthic habitat in intertidal and shallow subtidal areas with a high diversity (8 specie s) of coastal seagrass compared with other Gulf of Carpentaria locations. Evidence of heavy dugong feeding activity was observed on most intertidal seagrass meadows surveyed. The highest density of dugong feeding trails was observed in seagrass meadows dominated by Halodule uninervis (narrow leaf form) and/or Halophila ovalis. In addition, dugongs were regularly observed feeding in subtidal meadows from the helicopter during surveys. This survey was used to help fill gaps in knowledge and provide a baseline from which future monitoring could be conducted to identify research required to answer the uncertainties raised by the Traditional Owners, and to help with developing zoning plans for the management of their Sea Country

Dynamics of a tropical deepwater seagrass community during a major dredging campaign

A research and monitoring program was established to examine the potential impacts of a large scale capital dredging program on a tropical deepwater seagrass community between December 2005 and June 2008. The aims of the monitoring program were to fill gaps in our understanding of the dynamics of tropical deepwater seagrass habitats, their roles in fisheries productivity and their resilience and capacity for recovery from disturbance associated with dredging. While the dynamics of shallow coastal seagrasses in the region have been the subject of many studies little was previously known about the low density deepwater seagrass habitat that typified the study area. Results of the study revealed that these deepwater meadows had a high natural seasonal and inter-annual variability. Seasonality was substantially different to neighbouring shallow seagrass communities with a winter peak in abundance declining in spring before losing all above-ground biomass during summer months. Turbidity associated with dredging inhibited seagrass recruitment but there was evidence of seagrass recovery 12 months after the completion of dredging activity. Implications of the study for managing impacts to deepwater seagrass communities and differences in response to shallow coastal seagrasses are discussed

One-loop Yukawas on Intersecting Branes

We calculate Yukawa interactions at one-loop on intersecting D6 branes. We demonstrate the non-renormalization theorem in supersymmetric configurations, and show how Yukawa beta functions may be extracted. In addition to the usual logarithmic running, we find the power-law dependence on the infra-red cut-off associated with Kaluza-Klein modes. Our results may also be used to evaluate coupling renormalization in non-supersymmetric cases.Comment: 48 pages, 9 figures; minor corrections, JHEP styl

Prone to Supine CT Colonography Registration Using a Landmark and Intensity Composite Method

Matching corresponding location between prone and supine acquisitions for CT colonography (CTC) is essential to verify the existence of a polyp, which can be a difficult task due to the considerable deformations that will often occur to the colon during repositioning of the patient. This can induce error and increase interpretation time. We propose a novel method to automatically establish correspondence between the two acquisitions. A first step segments a set of haustral folds in each view and determines correspondence via a labelling process using a Markov Random Field (MRF) model. We show how the landmark correspondences can be used to non-rigidly transform a 2D source image derived from a conformal mapping process on the 3D endoluminal surface mesh to achieve full surface correspondence between prone and supine views. This can be used to initialise an intensity-based non-rigid B-spline registration method which further increases the accuracy. We demonstrate a statistically significant improvement over the intensity based non-rigid B-spline registration by using the composite method