179 research outputs found

    The Effects of Artificial Photoperiod on Age at Puberty in Fall-born Ewe Lambs

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    A study, conducted in two replicates, examined the effects of an artificial photoperiod on puberty in fall-born ewe lambs. Replicate I was initiated in December 2011 with prepubertal Dorset ewe lambs (n = 44). Replicate II was initiated beginning in December 2012 and included prepubertal Dorset, Suffolk x Dorset and Texel x Dorset ewe lambs (n = 52). All lambs were weighed at the initiation of each replicate and randomized to one of two treatments, control or treated, based on age, weight, breed and type of birth and rearing. Control ewe lambs were housed in a barn with exposure to natural photoperiod from December 16, 2011 until March 24, 2012 in replicate I and from December 17, 2012 until March 17, 2013 in replicate II. Treated ewe lambs were housed in a section of the same barn, but exposed to natural and supplemental light (~100 lux at lamb eye level) to produce an artificial photoperiod of 16 hours light and 8 hours dark for 14 weeks, from December 16, 2011 until March 24, 2012 in replicate I and from December 17, 2012 until March 25, 2013 in replicate II. Following completion of light treatment, each treated female received a silastic implant containing 20 mg of melatonin (Melovine), subcutaneously in the ear. Light intensity during the artificial lighting period for the treated group was measured, at random intervals, throughout the experiment and had an average value of ~100 lux, at ewe lamb eye level as measured by a Digital Light Meter (LX1010B). Growth of the lambs was monitored, as both weight and age are integral components of puberty. All ewe lambs were weighed at four time points during the study, including onset for each replicate, weaning, light termination and CIDR insertion. Ewe lambs were synchronized for estrus with the use of CIDR-G inserts, administered on May 18 of each year. On May 23 of each year CIDR implants were removed and intact fertile rams introduced. Rams were removed on June 19, 2012 or June 25, 2013 after allowing a breeding period of two opportunities for behavioral estrus. Pregnancy was determined by transrectal ultrasonography 25 days after removal of the rams. Progesterone was assayed, on all animals at four time points, using a radioimmunoassay. Plasma melatonin was assayed, in a subset of both treated and control females in replicate I prior to light termination, using an ELISA method. At light termination; treated females, in replicate I, weighed an average of 52.9 +/- 1.6 kg compared to 48.1 +/- 1.6 kg for control females (P \u3c 0.05). Extended light photoperiod increased weight gain in Replicate I, but not in Replicate II. Overall, fall-born Dorset ewe lambs (56 to 57%) conceived their first spring with no effect of the artificial photoperiod/melatonin treatment. Suffolk- and Texel-sired lambs from Dorset ewes did not have the out-of-season breeding ability seen in the purebred Dorset ewe lambs, even with the artificial photoperiod/melatonin treatment; only 2 0f 14 (14%) of Suffolk-sired ewe lambs conceived

    Polymer bioadhesives for drug delivery

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    This study is a natural follow on from previous work by M. T. Anderson and I. Fiebrig. The goal of those latter and of the present study is to find a mucoadhesive system for improving the oral bioavailability of a number of drugs, for example bioactive peptides and proteins. This current work evaluates the adhesive properties of a cationic polymer and a cationic protein to mucus glycoproteins as a step towards the future development of a mucoadhesive drug delivery system. Four different mucin populations were analysed in solution (a freshly purified sample PGM-MD, and three purified from different regions of the porcine stomach cardiac, antrum and fundus). Their interaction with two groups of chitosans differing in degree of deacetylation (FA = 0.11 and 0.25) and a protein purified from the foot of the blue mussel Mytilus edulis foot protein-1 (Mefp-1) were studied. Interaction was determined using analytical ultracentrifugation and with the chitosan/mucin interaction specifically atomic force microscopy. The influence of ionic strength on the interaction was studied in detail studied as was the effect of the oligosaccharide composition of the mucin population on the interaction. It was found that both groups of chitosans (FA = 0.11 and 0.25) formed a large complex with a freshly purified mucin population (PGM-MD). Ionic strengths above 0.2 M were found to inhibit the interaction. The three mucin species differed in terms of their net charge, with cardiac being the most negatively charged and antrum the least negative. It was found that the cardiac species interacted the most and antrum the least, as would be expected for an ionic interaction. Increasing ionic strength was found to inhibit the interaction. There was also evidence for a hydrophobic interaction at high ionic strengths. The atomic force microscopy results allowed the complex to be visualised under atmospheric conditions and to get away from the harsh sample preparation techniques employed by electron microscopy. Large spherical complexes were seen as entanglements of mucin and chitosan strands

    Polymer bioadhesives for drug delivery

    Get PDF
    This study is a natural follow on from previous work by M. T. Anderson and I. Fiebrig. The goal of those latter and of the present study is to find a mucoadhesive system for improving the oral bioavailability of a number of drugs, for example bioactive peptides and proteins. This current work evaluates the adhesive properties of a cationic polymer and a cationic protein to mucus glycoproteins as a step towards the future development of a mucoadhesive drug delivery system. Four different mucin populations were analysed in solution (a freshly purified sample PGM-MD, and three purified from different regions of the porcine stomach cardiac, antrum and fundus). Their interaction with two groups of chitosans differing in degree of deacetylation (FA = 0.11 and 0.25) and a protein purified from the foot of the blue mussel Mytilus edulis foot protein-1 (Mefp-1) were studied. Interaction was determined using analytical ultracentrifugation and with the chitosan/mucin interaction specifically atomic force microscopy. The influence of ionic strength on the interaction was studied in detail studied as was the effect of the oligosaccharide composition of the mucin population on the interaction. It was found that both groups of chitosans (FA = 0.11 and 0.25) formed a large complex with a freshly purified mucin population (PGM-MD). Ionic strengths above 0.2 M were found to inhibit the interaction. The three mucin species differed in terms of their net charge, with cardiac being the most negatively charged and antrum the least negative. It was found that the cardiac species interacted the most and antrum the least, as would be expected for an ionic interaction. Increasing ionic strength was found to inhibit the interaction. There was also evidence for a hydrophobic interaction at high ionic strengths. The atomic force microscopy results allowed the complex to be visualised under atmospheric conditions and to get away from the harsh sample preparation techniques employed by electron microscopy. Large spherical complexes were seen as entanglements of mucin and chitosan strands

    INTERIM REPORT: for distribution and discussion How can the Newcastle Diocese Safeguarding Team better support Incumbents, Parish Safeguarding Officers and Churchwardens in the effective implementation of Church of England safeguarding policy in practice?

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    The purpose of the report is to share initial findings from a mixed methods research study aimed at understanding the experiences of Incumbents, Parish Safeguarding Officers and Churchwardens in implementing safeguarding policy in practice, within the Diocese of Newcastle. A mixed methods self-completion electronic survey was distributed across the Diocese of Newcastle, containing a range of open and closed questions so that both quantitative (statistical) and qualitative (narratives) data could be generated. The survey was completed by Incumbents (n=18), Parish Safeguarding Officers (n=39) and Churchwardens (n=43)

    Development and Validation of the Combined Action Observation and Motor Imagery Ability Questionnaire

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    Combined use of action observation and motor imagery (AOMI) is an increasingly popular motor-simulation intervention, which involves observing movements on video while simultaneously imagining the feeling of movement execution. Measuring and reporting participant imagery-ability characteristics are essential in motor-simulation research, but no measure of AOMI ability currently exists. Accordingly, the AOMI Ability Questionnaire (AOMI-AQ) was developed to address this gap in the literature. In Study 1, two hundred eleven participants completed the AOMI-AQ and the kinesthetic imagery subscales of the Movement Imagery Questionnaire-3 and Vividness of Motor Imagery Questionnaire-2. Following exploratory factor analysis, an 8-item AOMI-AQ was found to correlate positively with existing motor-imagery measures. In Study 2, one hundred seventy-four participants completed the AOMI-AQ for a second time after a period of 7-10 days. Results indicate a good test-retest reliability for the AOMI-AQ. The new AOMI-AQ measure provides a valid and reliable tool for researchers and practitioners wishing to assess AOMI ability

    Nanoscopy through a plasmonic nanolens.

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    Plasmonics now delivers sensors capable of detecting single molecules. The emission enhancements and nanometer-scale optical confinement achieved by these metallic nanostructures vastly increase spectroscopic sensitivity, enabling real-time tracking. However, the interaction of light with such nanostructures typically loses all information about the spatial location of molecules within a plasmonic hot spot. Here, we show that ultrathin plasmonic nanogaps support complete mode sets which strongly influence the far-field emission patterns of embedded emitters and allow the reconstruction of dipole positions with 1-nm precision. Emitters in different locations radiate spots, rings, and askew halo images, arising from interference of 2 radiating antenna modes differently coupling light out of the nanogap, highlighting the imaging potential of these plasmonic "crystal balls." Emitters at the center are now found to live indefinitely, because they radiate so rapidly.We acknowledge EPSRC grants EP/N016920/1, EP/L027151/1, and NanoDTC EP/L015978/1. OSO acknowledges support of Rubicon fellowship from the Netherlands Organisation for Scientific Research, and RC thanks support from Trinity College Cambridge

    A novel role for the immunophilin FKBP52 in motor coordination

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    FKBP52 is a ubiquitously distributed immunophilin that has been associated with wideranging functions in cell signalling as well as hormonal and stress responses. Amongst other pathways, it acts via complex-formation with corticosteroid receptors and has consequently been associated with stress- and age-related neurodegenerative disorders including Alzheimer’s and Parkinson’s diseases. Reduced levels of FKBP52 have been linked to tau dysfunction and amyloid beta toxicity in AD. However, FKBP52’s role in cognition and neurodegenerative disorder-like phenotypes remained to be elucidated. The present study aimed therefore at investigating the cognitive and behavioural effects of reduced FKBP52 levels of genetically modified mice during ageing. Female and male FKBP52+/+, FKBP52+/- and FKBP52-/- mice were compared at two-, ten-, twelve-, fifteenand eighteen-months-of-age in a series of behavioural tests covering specie-specific behaviour, motor activity and coordination, fear-, spatial and recognition memory as well as curiosity and emotionality. Whilst cognitively unimpaired, FKBP52+/- mice performed worse on an accelerating rotating rod than FKBP52+/+ littermates across all age-groups suggesting that FKBP52 is involved in processes controlling motor coordination. This deficit did not exacerbate with age but did worsen with repeated testing; pointing towards a role for FKBP52 in learning of tasks requiring motor coordination abilities. This study contributes to the knowledge base of FKBP52’s implication in neurodegenerative diseases by demonstrating that FKBP52 by itself does not directly affect cognition and may therefore rather play an indirect, modulatory role in the functional pathology of AD, whereas it directly affects motor coordination, an early sign of neurodegenerative damages to the brain
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