Larval survivorship and settlement of crown-of-thorns starfish (Acanthaster cf. solaris) at varying algal cell densities

The dispersal potential of crown-of-thorns starfish (CoTS) larvae is important in understanding both the initiation and spread of population outbreaks, and is fundamentally dependent upon how long larvae can persist while still retaining the capacity to settle. This study quantified variation in larval survivorship and settlement rates for CoTS maintained at three different densities of a single-celled flagellate phytoplankton, Proteomonas sulcata (1 x 10^3, 1 x 10^4, and 1 x 10^5 cells/mL). Based on the larval starvation hypothesis, we expected that low to moderate levels of phytoplankton prey would significantly constrain both survival and settlement. CoTS larvae were successfully maintained for up to 50 days post-fertilization, but larval survival differed significantly between treatments. Survival was greatest at intermediate food levels (1 x 10^4 cells/mL), and lowest at high (1 x 10^5 cells/mL) food levels. Rates of settlement were also highest at intermediate food levels and peaked at 22 days post-fertilization. Peak settlement was delayed at low food levels, probably reflective of delayed development, but there was no evidence of accelerated development at high chlorophyll concentrations. CoTS larvae were recorded to settle 17–43 days post-fertilization, but under optimum conditions with intermediate algal cell densities, peak settlement occurred at 22 days post-fertilization. Natural fluctuations in nutrient concentrations and food availability may affect the number of CoTS that effectively settle, but seem unlikely to influence dispersal dynamics

Bacterial flagellar motors and osmoelectric molecular rotation by an axially transmembrane well and turnstile mechanism

AbstractBacterial ion-driven flagellar motors are the smallest known rotatory mechanical devices, natural or artificial, their overall diameter being only about 25 nm or one millionth of an inch. They are unique in the fields of biology and engineering. This paper develops a possible osmoelectric or local electrokinetic mechanism of molecular rotatory motion in bilayer membranes, which may help to explain how bacterial flagellar motors work, and may incidentally encourage new developments in the bioenergetics and biomechanics of enzyme, osmoenzyme and porter action

Developing Miscanthus seed plug establishment protocols with mulch film for commercial upscaling

High-yielding crops with C4 photosynthesis arising in tropical climates are being bred for, and increasingly grown in, temperate climates. Miscanthus, a C4 from Eastern Asia is a leading perennial biomass crop, but commercial deployment is limited by low temperatures in Northern Europe, low clonal multiplication rates and slow establishment rates requiring up to 4 years to reach mature yields. While new seeded hybrids have multiplication rates >2000, direct field sown seed has proven impractical. Protocols for safe establishment of seeded hybrids require that seedlings are raised in the glasshouse in compost filled modules (also known as ‘plugs’) which are transplanted into the field in springtime. To protect seedlings from damage from late frosts, drought and grazing and to increase temperature stimulating growth rates, plug plants were covered with oxo-degradable plastic mulch film designed for maize. At two sites in the UK, this mulch film significantly reduced plant losses at transplanting and overwintering, increased stem heights and shoot counts, and reduced the time to mature yield from 4 to 3 years (p < 0.01). However, the breakdown products of oxo-degradable mulch films contribute to microplastics in the soil. Therefore, further mulch film experiments were conducted with bio-derived plastics which are bio-degradable in soil at extruded thicknesses of 10, 18 and 30 microns. The 10 micron film combined sufficient strength for machine laying and worked as well as oxo-degradable film on de-risking establishment. Halving the mulch film widths covering 1 row rather than 2 reduced the amount of plastic by 25%. Commercial plug-to-field protocols are built on results from the plot experiments and field-scale plantings over multiple years and locations and are ready for future upscaling of biomass production from seed-based Miscanthus hybrids

The role of the RACK1 ortholog Cpc2p in modulating pheromone-induced cell cycle arrest in fission yeast

The detection and amplification of extracellular signals requires the involvement of multiple protein components. In mammalian cells the receptor of activated C kinase (RACK1) is an important scaffolding protein for signal transduction networks. Further, it also performs a critical function in regulating the cell cycle by modulating the G1/S transition. Many eukaryotic cells express RACK1 orthologs, with one example being Cpc2p in the fission yeast Schizosaccharomyces pombe. In contrast to RACK1, Cpc2p has been described to positively regulate, at the ribosomal level, cells entry into M phase. In addition, Cpc2p controls the stress response pathways through an interaction with Msa2p, and sexual development by modulating Ran1p/Pat1p. Here we describe investigations into the role, which Cpc2p performs in controlling the G protein-mediated mating response pathway. Despite structural similarity to Gβ-like subunits, Cpc2p appears not to function at the G protein level. However, upon pheromone stimulation, cells overexpressing Cpc2p display substantial cell morphology defects, disorientation of septum formation and a significantly protracted G1 arrest. Cpc2p has the potential to function at multiple positions within the pheromone response pathway. We provide a mechanistic interpretation of this novel data by linking Cpc2p function, during the mating response, with its previous described interactions with Ran1p/Pat1p. We suggest that overexpressing Cpc2p prolongs the stimulated state of pheromone-induced cells by increasing ste11 gene expression. These data indicate that Cpc2p regulates the pheromone-induced cell cycle arrest in fission yeast by delaying cells entry into S phase

Towards quantum 3d imaging devices

We review the advancement of the research toward the design and implementation of quantum plenoptic cameras, radically novel 3D imaging devices that exploit both momentum–position entanglement and photon–number correlations to provide the typical refocusing and ultra-fast, scanning-free, 3D imaging capability of plenoptic devices, along with dramatically enhanced performances, unattainable in standard plenoptic cameras: diffraction-limited resolution, large depth of focus, and ultra-low noise. To further increase the volumetric resolution beyond the Rayleigh diffraction limit, and achieve the quantum limit, we are also developing dedicated protocols based on quantum Fisher information. However, for the quantum advantages of the proposed devices to be effective and appealing to end-users, two main challenges need to be tackled. First, due to the large number of frames required for correlation measurements to provide an acceptable signal-to-noise ratio, quantum plenoptic imaging (QPI) would require, if implemented with commercially available high-resolution cameras, acquisition times ranging from tens of seconds to a few minutes. Second, the elaboration of this large amount of data, in order to retrieve 3D images or refocusing 2D images, requires high-performance and time-consuming computation. To address these challenges, we are developing high-resolution single-photon avalanche photodiode (SPAD) arrays and high-performance low-level programming of ultra-fast electronics, combined with compressive sensing and quantum tomography algorithms, with the aim to reduce both the acquisition and the elaboration time by two orders of magnitude. Routes toward exploitation of the QPI devices will also be discussed

On finding minimal absent words

<p>Abstract</p> <p>Background</p> <p>The problem of finding the shortest absent words in DNA data has been recently addressed, and algorithms for its solution have been described. It has been noted that longer absent words might also be of interest, but the existing algorithms only provide generic absent words by trivially extending the shortest ones.</p> <p>Results</p> <p>We show how absent words relate to the repetitions and structure of the data, and define a new and larger class of absent words, called minimal absent words, that still captures the essential properties of the shortest absent words introduced in recent works. The words of this new class are minimal in the sense that if their leftmost or rightmost character is removed, then the resulting word is no longer an absent word. We describe an algorithm for generating minimal absent words that, in practice, runs in approximately linear time. An implementation of this algorithm is publicly available at <url>ftp://www.ieeta.pt/~ap/maws</url>.</p> <p>Conclusion</p> <p>Because the set of minimal absent words that we propose is much larger than the set of the shortest absent words, it is potentially more useful for applications that require a richer variety of absent words. Nevertheless, the number of minimal absent words is still manageable since it grows at most linearly with the string size, unlike generic absent words that grow exponentially. Both the algorithm and the concepts upon which it depends shed additional light on the structure of absent words and complement the existing studies on the topic.</p

Quality of life following liver transplantation: a comparative study between Familial Amyloid Neuropathy and liver disease patients

<p>Abstract</p> <p>Background</p> <p>It has been demonstrated in many studies that quality of life can be improved after liver transplantation in patients with liver disease. Nevertherless quality of life improvement in specific groups of transplantated patients such as those with Familial Amyloid Polineuropathy hasn't yet been explored. The present study aimed to compare the change in quality of life following liver transplantation between patients with Familial Amyloid Polineuropathy (FAP) and patients with liver disease.</p> <p>Results</p> <p>Patient's mental quality of life showed an improvement in all liver disease patients, and a worsening in FAP patients, resulting in a significant difference between the two groups. Regarding physical quality of life, although a similar improvement was seen in both groups, FAP patients had significantly less improvement than the sub-group of decompensated liver disease (Child-Pugh B and C).</p> <p>Conclusion</p> <p>It is concluded that liver transplantation has a less beneficial impact in FAP patient's physical quality of life, probably because they are not so much disabled by their disease at the moment of liver transplantation. The lesser improvement in mental quality of life of FAP patients may be due to their particular psychological profile and greater expectations towards transplantation.</p

Acute-phase reactants after paediatric cardiac arrest. Procalcitonin as marker of immediate outcome

<p>Abstract</p> <p>Objective</p> <p>Procalcitonin (PCT) and C reactive protein (CRP) have been used as infection parameters. PCT increase correlates with the infection's severity, course, and mortality. Post-cardiocirculatory arrest syndrome may be related to an early systemic inflammatory response, and may possibly be associated with an endotoxin tolerance. Our objective was to report the time profile of PCT and CRP levels after paediatric cardiac arrest and to assess if they could be use as markers of immediate survival.</p> <p>Materials and methods</p> <p>A retrospective observational study set in an eight-bed PICU of a university hospital was performed during a period of two years. Eleven children younger than 14 years were admitted in the PICU after a cardiac arrest. PCT and CRP plasma concentrations were measured within the first 12 and 24 hours of admission.</p> <p>Results</p> <p>In survivors, PCT values increased 12 hours after cardiac arrest without further increase between 12 and 24 hours. In non survivors, PCT values increased 12 hours after cardiac arrest with further increase between 12 and 24 hours. Median PCT values (range) at 24 hours after cardiac arrest were 22.7 ng/mL (0.2 – 41.0) in survivors vs. 205.5 ng/mL (116.6 – 600.0) in non survivors (p < 0.05). CRP levels were elevated in all patients, survivors and non-survivors, at 12 and 24 hours without differences between both groups.</p> <p>Conclusion</p> <p>Measurement of PCT during the first 24 hours after paediatric cardiac arrest could serve as marker of mortality.</p

Complex regional pain syndrome 1 – the Swiss cohort study

BACKGROUND: Little is known about the course of Complex Regional Pain Syndrome 1 and potential factors influencing the course of this disorder over time. The goal of this study is a) to set up a database with patients suffering from suspected CRPS 1 in an initial stadium, b) to perform investigations on epidemiology, diagnosis, prognosis, and socioeconomics within the database and c) to develop a prognostic risk assessment tool for patients with CRPS 1 taking into account symptomatology and specific therapies. METHODS/DESIGN: Prospective cohort study. Patients suffering from a painful swelling of the hand or foot which appeared within 8 weeks after a trauma or a surgery and which cannot be explained by conditions that would otherwise account for the degree of pain and dysfunction will be included. In accordance with the recommendations of International Classification of Functioning, Disability and Health (ICF model), standardised and validated questionnaires will be used. Patients will be monitored over a period of 2 years at 6 scheduled visits (0 and 6 weeks, 3, 6, 12, and 24 months). Each visit involves a physical examination, registration of therapeutic interventions, and completion of the various study questionnaires. Outcomes involve changes in health status, quality of life and costs/utility. DISCUSSION: This paper describes the rationale and design of patients with CRPS 1. Ideally, potential risk factors may be identified at an early stage in order to initiate an early and adequate treatment in patients with increased risk for delayed recovery