5,851 research outputs found

    Energy conservation in the one-phase supercooled Stefan problem

    Get PDF
    © . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/A one-phase reduction of the one-dimensional two-phase supercooled Stefan problem is developed. The standard reduction, employed by countless authors, does not conserve energy and a recent energy conserving form is valid in the limit of small ratio of solid to liquid conductivity. The present model assumes this ratio to be large and conserves energy for physically realistic parameter values. Results for three one-phase formulations are compared to the two-phase model for parameter values appropriate to supercooled salol (similar values apply to copper and gold) and water. The present model shows excellent agreement with the full two-phase model.Peer ReviewedPostprint (author's final draft

    Corticospinal and reticulospinal contacts on cervical commissural and long descending propriospinal neurons in the adult rat spinal cord; evidence for powerful reticulospinal connections

    Get PDF
    Descending systems have a crucial role in the selection of motor output patterns by influencing the activity of interneuronal networks in the spinal cord. Commissural interneurons that project to the contralateral grey matter are key components of such networks as they coordinate left-right motor activity of fore and hind-limbs. The aim of this study was to determine if corticospinal (CST) and reticulospinal (RST) neurons make significant numbers of axonal contacts with cervical commissural interneurons. Two classes of commissural neurons were analysed: 1) local commissural interneurons (LCINs) in segments C4-5; 2) long descending propriospinal neurons (LDPNs) projecting from C4 to the rostral lumbar cord. Commissural interneurons were labelled with Fluorogold and CST and RST axons were labelled by injecting the b subunit of cholera toxin in the forelimb area of the primary somatosensory cortex or the medial longitudinal fasciculus respectively. The results show that LCINs and LDPNs receive few contacts from CST terminals but large numbers of contacts are formed by RST terminals. Use of vesicular glutamate and vesicular GABA transporters revealed that both types of cell received about 80% excitatory and 20% inhibitory RST contacts. Therefore the CST appears to have a minimal influence on LCINs and LDPNs but the RST has a powerful influence. This suggests that left-right activity in the rat spinal cord is not influenced directly via CST systems but is strongly controlled by the RST pathway. Many RST neurons have monosynaptic input from corticobulbar pathways therefore this pathway may provide an indirect route from the cortex to commissural systems. The cortico-reticulospinal-commissural system may also contribute to functional recovery following damage to the CST as it has the capacity to deliver information from the cortex to the spinal cord in the absence of direct CST input

    Influences of SALVINORIN A and SEX DIFFERENCES on DEPRESSIVE- AND ANXIETY-LIKE behaviors in a CHRONIC MILD STRESS paradigm

    Get PDF
    Kappa opioid receptors are colocalized with dopamine receptors and are frequently associated with depression, anxiety, stress, and drug use and abuse. KOR antagonism has widely been considered anti-depressive and anxiolytic in animal models while agonism is pro-depressive and anxiogenic. However, recent findings suggest that SalvA, a natural kappa agonist derived from a plant in the mint family, can reduce depressive- and anxiety-like behavior in rats. The current study investigated the effects of chronic mild stress on behavior, attenuation by SalvA, and sex differences. 52 Long-Evans rats, 26 males and 26 females, were exposed to six weeks of CMS. Animals received daily injections of either SalvA or vehicle for the last three weeks of the experiment. Behavioral tests were administered at baseline, three weeks, and six weeks. We predicted that CMS would induce the depressive-like behaviors anhedonia and learned helplessness, as measured by reduced sucrose preference and increased immobility in the forced swim test, respectively. We also predicted that CMS would induce anxiety-like behavior by reducing exploratory behavior and increasing immobility in the open field test. It was predicted that SalvA exposure would attenuate the effects of CMS. Further, we predicted that female rats would be more sensitive to the effects of stress but also show greater response to SalvA. Results showed that CMS did not reliably induce depressive- or anxiety-like behaviors. Because there were no reliable behavioral changes due to stress, the potential antidepressant or anxiolytic effects of SalvA were not apparent. In the male drug group, SalvA appeared to increase anxious behavior in the open field test and depressive-like behavior in the forced swim test, aligning with previous findings that KOR agonists can be anxiogenic and pro-depressive. Additionally, results showed that behavior in the forced swim and open field tests were sex dependent, with males showing more depression- and anxiety-like behaviors than females. More research is necessary to better understand the effects of CMS and SalvA on behavior. Closer examination of the behavioral paradigms measuring depression and anxiety in animals is needed and future research should carefully consider sex differences when employing these behavioral paradigms

    Our first picnic at May Valley

    Get PDF
    Sketch from the scrapbook of Sarah E.E. Mitchell of Lisdillon on the East Coast of Tasmania 1874. Sketch 74 - Taken May 1873 - by Catherine Mitchell. Our first picnic in May Valley, about four miles out at the back of Lisdillon – Amy M.J.M., S.E.E.M., & Minnie Giblin, Kate P.M. & Florence Dandridge, and Mark S.M., and Caleb dog & one of Mark’s dogs. He had several at Lisdillon, when he went to feed them we used to say, “ he had gone to the dogs.” – In after years, when the insects began to make “galls” or lumps on some acres of wattle trees over at Boags, that was opposite, or north of the homestead, over Lisdillon Rivulet, & destroys the trees. He prayed earnestly to God that it would not spread, & it did not. When riding, or walking he would raise his hat & pray a moment. 29.5.1922 The sketches by Catherine Penwarne (Kate), eldest daughter of John and Catherine Mitchell (of Cornwall, England, who settled at Lisdillon, East Coast Tasmania in 1852) were made between 1860 and 1876, and portray aspects of 19th Century social and domestic life. Catherine’s sketches were compiled by her sister Sarah. E.E.Mitchell. Derived from her own collection, from those of friends and relations, and from John Ball, Kate's husband, they were compiled sometime between 1928 and 1933. The sketches are mounted in an album, together with: locks of Kate's hair on red silk; a pressed fern arrangement; a coloured photograph of John and Catherine Ball; and coloured views of Buckland Churchyard in 1850, showing the grave of Paul Thomas Mitchell, aged 3 days, and in 1879 showing the grave of Catherine Penwarne Ball. The scrapbook was bequeathed to The Royal Society of Tasmania in 1946. RS 32/

    Frying Caleb with a bone

    Get PDF
    Sketch from the scrapbook of Sarah E.E. Mitchell of Lisdillon on the East Coast of Tasmania 1874. Sketch 18 - Taken May 5th 1873 - by Catherine Mitchell. A picnic at Mayfield Scrub by the hop ground at Mayfield, Lisdillon, Henry Meredith who was hop measurer washing his hands & Amy M. J. Mitchell talking to him. Kate & Romer Meadows frying “Caleb” with a bone, S.E.E.M & Florence Dandridge eating on a log. Mark S. M showing Minnie Giblin (after Mrs Hamilton Radcliffe) how “Blackfellow” can write its name by holding its paw & scratching the ground. The sketches by Catherine Penwarne (Kate), eldest daughter of John and Catherine Mitchell (of Cornwall, England, who settled at Lisdillon, East Coast Tasmania in 1852) were made between 1860 and 1876, and portray aspects of 19th Century social and domestic life. Catherine’s sketches were compiled by her sister Sarah. E.E.Mitchell. Derived from her own collection, from those of friends and relations, and from John Ball, Kate's husband, they were compiled sometime between 1928 and 1933. The sketches are mounted in an album, together with: locks of Kate's hair on red silk; a pressed fern arrangement; a coloured photograph of John and Catherine Ball; and coloured views of Buckland Churchyard in 1850, showing the grave of Paul Thomas Mitchell, aged 3 days, and in 1879 showing the grave of Catherine Penwarne Ball. The scrapbook was bequeathed to The Royal Society of Tasmania in 1946. RS 32/

    Going to see Mrs Dodge at Saltworks

    Get PDF
    Sketch from the scrapbook of Sarah E.E. Mitchell of Lisdillon on the East Coast of Tasmania 1874. Sketch 111 - Taken 6th June 1874 - by Catherine Mitchell. Kate P. Mitchell, and S.E.E.M., going to see Mrs Dodge at Saltworks, Lisdillon. Mr J Radcliffe long ago set up boilers to get salt, when a duty was on it, & gave up when it was taken off. It was too close to the mouth of Little Swanport River, & therefore too fresh sea water. He had large stone buildings there. Part of the iron work was broken one day & the men did not go out next morn. Mr Radcliffe rode to Swansea, had it mended & put it back. Called his men to go & see if it was broken. They did & found it mended!! James, & Mrs Sarah Dodge paid a rent for the fields, about 50 acres – three sons James, Fred, Alfred & Arthur& they had three daughters Sarah, Emma, & Mary. Mrs Dodge helped nurse my father, & mother at their last illness & was very kind. The sketches by Catherine Penwarne (Kate), eldest daughter of John and Catherine Mitchell (of Cornwall, England, who settled at Lisdillon, East Coast Tasmania in 1852) were made between 1860 and 1876, and portray aspects of 19th Century social and domestic life. Catherine’s sketches were compiled by her sister Sarah. E.E.Mitchell. Derived from her own collection, from those of friends and relations, and from John Ball, Kate's husband, they were compiled sometime between 1928 and 1933. The sketches are mounted in an album, together with: locks of Kate's hair on red silk; a pressed fern arrangement; a coloured photograph of John and Catherine Ball; and coloured views of Buckland Churchyard in 1850, showing the grave of Paul Thomas Mitchell, aged 3 days, and in 1879 showing the grave of Catherine Penwarne Ball. The scrapbook was bequeathed to The Royal Society of Tasmania in 1946. RS 32/

    A picnic at Little Swanport Bridge

    Get PDF
    Sketch from the scrapbook of Sarah E.E. Mitchell of Lisdillon on the East Coast of Tasmania 1874. Sketch 73 - Taken 22nd January 1874 - by Catherine Mitchell. A picnic at Little Swanport Bridge. We went round by sea & home the same way – Henry Meredith 6ft 4in, who we called the “Hop- pole”, frying; Mark with water-billy, Kate, Self (S.E.E.M) and Miss Harriet Jones, of Riccarton who was at Miss Garrett’s School in Hobart with Amy M.J.M., and so came for her holidays, that summer, with us at Lisdillon – (Her brother called at Tirzah, May 1922 and said she died a few months ago. S.E.E.M) The sketches by Catherine Penwarne (Kate), eldest daughter of John and Catherine Mitchell (of Cornwall, England, who settled at Lisdillon, East Coast Tasmania in 1852) were made between 1860 and 1876, and portray aspects of 19th Century social and domestic life. Catherine’s sketches were compiled by her sister Sarah. E.E.Mitchell. Derived from her own collection, from those of friends and relations, and from John Ball, Kate's husband, they were compiled sometime between 1928 and 1933. The sketches are mounted in an album, together with: locks of Kate's hair on red silk; a pressed fern arrangement; a coloured photograph of John and Catherine Ball; and coloured views of Buckland Churchyard in 1850, showing the grave of Paul Thomas Mitchell, aged 3 days, and in 1879 showing the grave of Catherine Penwarne Ball. The scrapbook was bequeathed to The Royal Society of Tasmania in 1946. RS 32/

    Minnie Giblin was a great attraction

    Get PDF
    Sketch from the scrapbook of Sarah E.E. Mitchell of Lisdillon on the East Coast of Tasmania 1874. Sketch 32 - Taken 22.4.1875 - by Catherine Mitchell. Fishing in our Lisdillon boat near Seaford – Minnie Giblin caught her first shark four feet long, Hamilton Radcliffe and Mark S.M. help land it in the boat. I have the stear oar and Kate fishes. It was only sometimes Mark would come, but Minnie Giblin, was a great attraction. The sketches by Catherine Penwarne (Kate), eldest daughter of John and Catherine Mitchell (of Cornwall, England, who settled at Lisdillon, East Coast Tasmania in 1852) were made between 1860 and 1876, and portray aspects of 19th Century social and domestic life. Catherine’s sketches were compiled by her sister Sarah. E.E.Mitchell. Derived from her own collection, from those of friends and relations, and from John Ball, Kate's husband, they were compiled sometime between 1928 and 1933. The sketches are mounted in an album, together with: locks of Kate's hair on red silk; a pressed fern arrangement; a coloured photograph of John and Catherine Ball; and coloured views of Buckland Churchyard in 1850, showing the grave of Paul Thomas Mitchell, aged 3 days, and in 1879 showing the grave of Catherine Penwarne Ball. The scrapbook was bequeathed to The Royal Society of Tasmania in 1946. RS 32/

    Oliver Latham boasting how well he could ride

    Get PDF
    Sketch from the scrapbook of Sarah E.E. Mitchell of Lisdillon on the East Coast of Tasmania 1874. Sketch 33 - Taken 25.8.1874 - by Catherine Mitchell. Oliver Latham boasting how well he could ride over fences, falling on the horses neck over the first broken fence. Caleb the Newfoundland, dog looking pleased as well as Kate and myself. I had to hide this sketch to keep him from tearing it up. The sketches by Catherine Penwarne (Kate), eldest daughter of John and Catherine Mitchell (of Cornwall, England, who settled at Lisdillon, East Coast Tasmania in 1852) were made between 1860 and 1876, and portray aspects of 19th Century social and domestic life. Catherine’s sketches were compiled by her sister Sarah. E.E.Mitchell. Derived from her own collection, from those of friends and relations, and from John Ball, Kate's husband, they were compiled sometime between 1928 and 1933. The sketches are mounted in an album, together with: locks of Kate's hair on red silk; a pressed fern arrangement; a coloured photograph of John and Catherine Ball; and coloured views of Buckland Churchyard in 1850, showing the grave of Paul Thomas Mitchell, aged 3 days, and in 1879 showing the grave of Catherine Penwarne Ball. The scrapbook was bequeathed to The Royal Society of Tasmania in 1946. RS 32/
    • …
    corecore