345 research outputs found
Emission Spectrum of a Dipole in a Semi-infinite Periodic Dielectric Structure: Effect of the Boundary
The emission spectrum of a dipole embedded in a semi-infinite photonic
crystal is calculated. For simplicity we study the case in which the dielectric
function is sinusoidally modulated only along the direction perpendicular to
the boundary surface plane. In addition to oscillations of the emission rate
with the distance of the dipole from the interface we also observed that the
shape of the emission spectrum srongly depends on the \em initial \em phase
of the dielectric modulation. When the direction of light propagation inside
the periodic structure is not normal to the boundary surface plane we observed
aditional singularities in the emission spectrum, which arise due to different
angle-dependence of the Bragg stop-band for and polarizations.Comment: 14 pages, 6 figures, to appear in Phys Rev
Resonant dipole-dipole interaction in the presence of dispersing and absorbing surroundings
Within the framework of quantization of the macroscopic electromagnetic
field, equations of motion and an effective Hamiltonian for treating both the
resonant dipole-dipole interaction between two-level atoms and the resonant
atom-field interaction are derived, which can suitably be used for studying the
influence of arbitrary dispersing and absorbing material surroundings on these
interactions. The theory is applied to the study of the transient behavior of
two atoms that initially share a single excitation, with special emphasis on
the role of the two competing processes of virtual and real photon exchange in
the energy transfer between the atoms. In particular, it is shown that for weak
atom-field interaction there is a time window, where the energy transfer
follows a rate regime of the type obtained by ordinary second-order
perturbation theory. Finally, the resonant dipole-dipole interaction is shown
to give rise to a doublet spectrum of the emitted light for weak atom-field
interaction and a triplet spectrum for strong atom-field interaction.Comment: 15 pages, 1 figure, RevTE
PP2A inhibition overcomes acquired resistance to HER2 targeted therapy
Background: HER2 targeted therapies including trastuzumab and more recently lapatinib have significantly
improved the prognosis for HER2 positive breast cancer patients. However, resistance to these agents is a
significant clinical problem. Although several mechanisms have been proposed for resistance to trastuzumab, the
mechanisms of lapatinib resistance remain largely unknown. In this study we generated new models of acquired
resistance to HER2 targeted therapy and investigated mechanisms of resistance using phospho-proteomic profiling.
Results: Long-term continuous exposure of SKBR3 cells to low dose lapatinib established a cell line, SKBR3-L,
which is resistant to both lapatinib and trastuzumab. Phospho-proteomic profiling and immunoblotting revealed
significant alterations in phospho-proteins involved in key signaling pathways and molecular events. In particular,
phosphorylation of eukaryotic elongation factor 2 (eEF2), which inactivates eEF2, was significantly decreased in
SKBR3-L cells compared to the parental SKBR3 cells. SKBR3-L cells exhibited significantly increased activity of protein
phosphatase 2A (PP2A), a phosphatase that dephosphorylates eEF2. SKBR3-L cells showed increased sensitivity to
PP2A inhibition, with okadaic acid, compared to SKBR3 cells. PP2A inhibition significantly enhanced response to
lapatinib in both the SKBR3 and SKBR3-L cells. Furthermore, treatment of SKBR3 parental cells with the PP2A
activator, FTY720, decreased sensitivity to lapatinib. The alteration in eEF2 phosphorylation, PP2A activity and
sensitivity to okadaic acid were also observed in a second HER2 positive cell line model of acquired lapatinib
resistance, HCC1954-L.
Conclusions: Our data suggests that decreased eEF2 phosphorylation, mediated by increased PP2A activity,
contributes to resistance to HER2 inhibition and may provide novel targets for therapeutic intervention in HER2
positive breast cancer which is resistant to HER2 targeted therapies
Sheep Updates 2005 - Part 5
This session covers eleven papers from different authors; MARKET INFORMATION 1. Crystal Spring - Crystal clear and consistant, Geoff Duddy, Livestock Officer (Sheep & Wool) Yanco, NSW, Brent McLoud, (Product Development Officer) Cowra, NSW, John Sullivan, J.J Dresser and Co (Agent), Woodstock, NSW 2. An overview of Recent Developments in Dark and Medullated Fibre Testing, T.J. Mahar, A. Balasingam, AWTA Ltd 3. Opportunities and Implications for Wool Producers of the TEAM3 Prediction Equations, J.H. Stanton12 K.M.S. Curtis1 , 1Department of Agriculture Western Australia, 2 Curtin University, WA 4. Premiums and Discounts for Fibre Properties in Superfine Wool, Now and in the Future?, K.M.S. Curtis1, P.R. Lamb2, 1 Department of Agriculture Western Australia, 2Lambshift Consulting, Geelong VIC FEEDLOTTING 5. Manure in sheep feedlots: problem or opportunity?, Eliza Dowling, Ned Crossley Department of Agriculture , Western Australia, Surrender Mann, Chemistry Centre (WA), East Perth WA, 6. The State of Lamb Confinement Feeding in WA, Ned Crossley, Department of Agriculture, Western Australia 7. Finishing lambs in a feed lot - Is it profitable?, Lucy Anderton, Department of Agriculture, Western Australia 8. Repeated live weights can mardinally improve prediction of compliance to markey specifications, Mattew Kelly, Andrew Swan, CSIRO livestock industries, Ian McFarland, Department of Agriculture Western Australia. WELFARE 9. Mulesing accreditation - to be or not to be? Di Evans, Department of Agriculture, Western Australia. 10. The Economic and Research Implications of managing Merino Sheep with out Mulesing, K. Bell, Sheep Management and Production Consultants, North Fremantle WA, D. Sackett, Homes Sackett and Associates, Wagga Wagga NSW 11. How do lambs fare during curfew, Dr Robin Jacob, Department of Agriculture, Western Australi
Multicenter Consensus Approach to Evaluation of Neonatal Hypotonia in the Genomic Era: A Review
IMPORTANCE: Infants with hypotonia can present with a variety of potentially severe clinical signs and symptoms and often require invasive testing and multiple procedures. The wide range of clinical presentations and potential etiologies leaves diagnosis and prognosis uncertain, underscoring the need for rapid elucidation of the underlying genetic cause of disease. OBSERVATIONS: The clinical application of exome sequencing or genome sequencing has dramatically improved the timely yield of diagnostic testing for neonatal hypotonia, with diagnostic rates of greater than 50% in academic neonatal intensive care units (NICUs) across Australia, Canada, the UK, and the US, which compose the International Precision Child Health Partnership (IPCHiP). A total of 74% (17 of 23) of patients had a change in clinical care in response to genetic diagnosis, including 2 patients who received targeted therapy. This narrative review discusses the common causes of neonatal hypotonia, the relative benefits and limitations of available testing modalities used in NICUs, and hypotonia management recommendations. CONCLUSIONS AND RELEVANCE: This narrative review summarizes the causes of neonatal hypotonia and the benefits of prompt genetic diagnosis, including improved prognostication and identification of targeted treatments which can improve the short-term and long-term outcomes. Institutional resources can vary among different NICUs; as a result, consideration should be given to rule out a small number of relatively unique conditions for which rapid targeted genetic testing is available. Nevertheless, the consensus recommendation is to use rapid genome or exome sequencing as a first-line testing option for NICU patients with unexplained hypotonia. As part of the IPCHiP, this diagnostic experience will be collected in a central database with the goal of advancing knowledge of neonatal hypotonia and improving evidence-based practice
Corporate identity at the stakeholder group level
There is a paucity of literature regarding the construction and operation of corporate identity at the stakeholder group level. This article examines corporate identity from the perspective of an individual stakeholder group, namely, front-line employees. A stakeholder group that is central to the development of an organization’s corporate identity as it spans an organization’s boundaries, frequently interacts with both internal and external stakeholders, and influences a firm’s financial performance by building customer loyalty and satisfaction. The article reviews the corporate identity, branding, services and social identity literatures to address how corporate identity manifests within the front-line employee stakeholder group, identifying what components comprise front-line employee corporate identity and assessing what contribution front-line employees make to constructing a strong and enduring corporate identity for an organization. In reviewing the literature the article develops propositions that, in conjunction with a conceptual model, constitute the generation of theory that is recommended for empirical testing
Post-streptococcal glomerulonephritis is a strong risk factor for chronic kidney disease in later life
Although unusual in western countries and in Australia in general, post-streptococcal glomerulonephritis (PSGN) is still common in Australian Aboriginal children living in remote communities. Here, we evaluated whether episodes of acute PSGN increased the risk for chronic kidney disease in later life in 1519 residents of a remote Aboriginal community (85% of those age eligible), with high rates of renal and cardiovascular disease, who participated in a health screen over a 3-year period. Of these, 200 had had at least one episode of PSGN, with 27 having had multiple episodes, usually in childhood. High levels of albuminuria (albumin/creatinine ratio) with increasing age were confirmed. All PSGN episodes were associated with group A streptococcal skin infections, often related to scabies. In both genders, aged 10-39 years at screening, about one in five had such a history. Among them, PSGN (5 years or more earlier) was significantly associated with higher levels of albuminuria than those without. In women, aged 30-39 years, a history of PSGN was associated with a significantly higher frequency of estimated glomerular filtration rates < 60 ml/min. The adjusted odds ratios for an albumin/creatinine ratio over 34 g/mol (overt albuminuria) in males and females with a history of PSGN were 4.6 and 3.1, respectively, compared with those without a history. Thus, PSGN contributes to the very serious burden of chronic kidney disease in this community. Rigorous strategies to prevent scabies and Group A streptococcal infections will reduce this burden
Mutation of FIG4 causes neurodegeneration in the pale tremor mouse and patients with CMT4J
Membrane-bound phosphoinositides are signalling molecules that have a key role in vesicle trafficking in eukaryotic cells(1). Proteins that bind specific phosphoinositides mediate interactions between membrane-bounded compartments whose identity is partially encoded by cytoplasmic phospholipid tags. Little is known about the localization and regulation of mammalian phosphatidylinositol-3,5-bisphosphate ( PtdIns( 3,5)P-2), a phospholipid present in small quantities that regulates membrane trafficking in the endosome - lysosome axis in yeast(2). Here we describe a multi-organ disorder with neuronal degeneration in the central nervous system, peripheral neuronopathy and diluted pigmentation in the 'pale tremor' mouse. Positional cloning identified insertion of ETn2 beta ( early transposon 2 beta)(3) into intron 18 of Fig4 (A530089I17Rik), the homologue of a yeast SAC ( suppressor of actin) domain PtdIns(3,5) P-2 5-phosphatase located in the vacuolar membrane. The abnormal concentration of PtdIns( 3,5) P2 in cultured fibroblasts from pale tremor mice demonstrates the conserved biochemical function of mammalian Fig4. The cytoplasm of fibroblasts from pale tremor mice is filled with large vacuoles that are immunoreactive for LAMP-2 (lysosomal-associated membrane protein 2), consistent with dysfunction of the late endosome - lysosome axis. Neonatal neurodegeneration in sensory and autonomic ganglia is followed by loss of neurons from layers four and five of the cortex, deep cerebellar nuclei and other localized brain regions. The sciatic nerve exhibits reduced numbers of large-diameter myelinated axons, slowed nerve conduction velocity and reduced amplitude of compound muscle action potentials. We identified pathogenic mutations of human FIG4 (KIAA0274) on chromosome 6q21 in four unrelated patients with hereditary motor and sensory neuropathy. This novel form of autosomal recessive Charcot - Marie - Tooth disorder is designated CMT4J.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62835/1/nature05876.pd
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