531 research outputs found
Development of Supercooling as a storage technique for pork
Supercooling is a food processing technique which has the potential to significantly increase the shelf life of foods and to reduce wastage of food products from the production and retail sectors. The process uses storage temperatures below the initial freezing point of the food without the product freezing, which maintains the quality attributes associated with fresh foods. This paper reports trials carried out to determine best methods to supercool pork meat and methods to maintain the supercooled state. Trials were carried out to compare storage life of pork meat that had been supercooled with samples that had been superchilled and conventionally chilled. Colour, texture, weight loss, drip loss and microbiology of samples was measured and compared. The supercooled and superchilled samples were quite similar in all respects apart from the superchilled samples had greater drip loss
Relating to reading : a psychosocial exploration of the experiences of young people who find reading difficult
Although research studies are plentiful regarding the cognitive aspects of children’s and young people’s reading difficulties, surprisingly few consider the emotional or relational impact of those difficulties. Those which do rarely invite young people to share their experiences of struggling to master this fundamental life skill.
This exploratory, qualitative study used a psychosocial methodology to explore the reading experiences of young people who find reading difficult. A psychosocial ontology and epistemology gave equal consideration to the meaning constructed through participants’ social interactions and the unconscious psychological processes at work for participant and researcher, and facilitated an understanding of the emotional experience of each participant.
Semi-structured interviews were conducted with two 12-year-old boys (UK school year 8) with persistent reading difficulties, using Free Association Narrative Interview (FANI) techniques. Each boy was interviewed twice, creating his own narrative in response to initial questions or prompts. The boys were also observed twice in a typical English lesson, using principles of infant observation. A reflective research diary was used to record the researcher’s personal responses to all aspects of the research.
Interview data were analysed using thematic analysis. Reflective process notes from each observation provided an additional perspective on each boy’s experiences. Psychosocial research supervision enabled a reflexive stance to be maintained, holding in mind the ‘whole’ person, acknowledging the researcher as psychologically defended, and considering the relevance and appropriateness of themes as they emerged.
Semantic and latent themes specific to each participant were identified. Although the aim was not to generalise between the boys’ experiences, similarities were found within the following areas: ‘(un)helpful helping’, ‘believed and understood?’, ‘lazy, dumb and stupid’, and ‘smarter sisters’.
The findings provide a rich account of participants’ experiences as ‘struggling readers’. Strengths and limitations of the study are discussed, together with implications for teaching and Educational Psychology practice
Conformational Changes in the Connector Protein Complex of the Bacteriophage φ29 DNA Packaging Motor
DNA packaging in the bacteriophage φ29 involves a molecular motor. It is proposed that dsDNA is packaged through a channel in a connector located at the 5-fold vertex of a preformed prolate icosahedral capsid. The packaging motor also consists of virally-encoded RNA molecules (pRNA) coupled to ATPases. Data obtained from studies using surface plasmon resonance, fluorescence quenching and circular dichroism are presented to demonstrate the importance of the N-termini of the connector protein subunits in pRNA interaction and in conformational change. Based on our findings, we propose a model of DNA packaging based on connector conformational change
Generation of antibodies against foot-and-mouth-disease virus capsid protein VP4 using hepatitis B core VLPs as a Scaffold
The picornavirus foot-and-mouth disease virus (FMDV) is the causative agent of the eco-nomically important disease of livestock, foot-and-mouth disease (FMD). VP4 is a highly conserved capsid protein, which is important during virus entry. Previous published work has shown that antibodies targeting the N-terminus of VP4 of the picornavirus human rhinovirus are broadly neu-tralising. In addition, previous studies showed that immunisation with the N-terminal 20 amino acids of enterovirus A71 VP4 displayed on the hepatitis B core (HBc) virus-like particles (VLP) can induce cross-genotype neutralisation. To investigate if a similar neutralising response against FMDV VP4 could be generated, HBc VLPs displaying the N-terminus of FMDV VP4 were designed. The N-terminal 15 amino acids of FMDV VP4 was inserted into the major immunodominant region. HBc VLPs were also decorated with peptides of the N-terminus of FMDV VP4 attached using a HBc-spike binding tag. Both types of VLPs were used to immunise mice and the resulting serum was investigated for VP4-specific antibodies. The VLP with VP4 inserted into the spike, induced VP4-specific antibodies, however the VLPs with peptides attached to the spikes did not. The VP4-specific antibodies could recognise native FMDV, but virus neutralisation was not demonstrated. This work shows that the HBc VLP presents a useful tool for the presentation of FMDV capsid epitopes.</p
A Complex Extracellular Sphingomyelinase of Pseudomonas aeruginosa Inhibits Angiogenesis by Selective Cytotoxicity to Endothelial Cells
The hemolytic phospholipase C (PlcHR) expressed by Pseudomonas aeruginosa is the original member of a Phosphoesterase Superfamily, which includes phosphorylcholine-specific phospholipases C (PC-PLC) produced by frank and opportunistic pathogens. PlcHR, but not all its family members, is also a potent sphingomyelinase (SMase). Data presented herein indicate that picomolar (pM) concentrations of PlcHR are selectively lethal to endothelial cells (EC). An RGD motif of PlcHR contributes to this selectivity. Peptides containing an RGD motif (i.e., GRGDS), but not control peptides (i.e., GDGRS), block the effects of PlcHR on calcium signaling and cytotoxicity to EC. Moreover, RGD variants of PlcHR (e.g., RGE, KGD) are significantly reduced in their binding and toxicity, but retain the enzymatic activity of the wild type PlcHR. PlcHR also inhibits several EC-dependent in vitro assays (i.e., EC migration, EC invasion, and EC tubule formation), which represent key processes involved in angiogenesis (i.e., formation of new blood vessels from existing vasculature). Finally, the impact of PlcHR in an in vivo model of angiogenesis in transgenic zebrafish, and ones treated with an antisense morpholino to knock down a key blood cell regulator, were evaluated because in vitro assays cannot fully represent the complex processes of angiogenesis. As little as 2 ng/embryo of PlcHR was lethal to ∼50% of EGFP-labeled EC at 6 h after injection of embryos at 48 hpf (hours post-fertilization). An active site mutant of PlcHR (Thr178Ala) exhibited 120-fold reduced inhibitory activity in the EC invasion assay, and 20 ng/embryo elicited no detectable inhibitory activity in the zebrafish model. Taken together, these observations are pertinent to the distinctive vasculitis and poor wound healing associated with P. aeruginosa sepsis and suggest that the potent antiangiogenic properties of PlcHR are worthy of further investigation for the treatment of diseases where angiogenesis contributes pathological conditions (e.g., vascularization of tumors, diabetic retinopathy)
FMDV replicons encoding green fluorescent protein are replication competent
The study of replication of viruses that require high bio-secure facilities can be accomplished with less stringent containment using non-infectious 'replicon' systems. The FMDV replicon system (pT7rep) reported by Mclnerney et al. (2000) was modified by the replacement of sequences encoding chloramphenicol acetyl-transferase (CAT) with those encoding a functional L proteinase (Lpro) linked to a bi-functional fluorescent/antibiotic resistance fusion protein (green fluorescent protein/puromycin resistance, [GFP-PAC]). Cells were transfected with replicon-derived transcript RNA and GFP fluorescence quantified. Replication of transcript RNAs was readily detected by fluorescence, whilst the signal from replication-incompetent forms of the genome was >2-fold lower. Surprisingly, a form of the replicon lacking the Lpro showed a significantly stronger fluorescence signal, but appeared with slightly delayed kinetics. Replication can, therefore, be quantified simply by live-cell imaging and image analyses, providing a rapid and facile alternative to RT-qPCR or CAT assays
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