3,879 research outputs found
On the Forward-Backward Asymmetry of Leptonic Decays of at the Fermilab Tevatron
We report on a study of the measurement techniques used to determine the
leptonic forward-backward asymmetry of top anti-top quark pairs in Tevatron
experiments with a proton anti-proton initial state. Recently it was shown that
a fit of the differential asymmetry as a function of (where
is the charge of the lepton from the cascade decay of the top quarks
and is the final pseudorapidity of the lepton in the detector frame)
to a hyperbolic tangent function can be used to extrapolate to the full
leptonic asymmetry. We find this empirical method to well reproduce the results
from current experiments, and present arguments as to why this is the case. We
also introduce two more models, based on Gaussian functions, that better model
the distribution. With our better understanding, we find that
the asymmetry is mainly determined by the shift of the mean of the
distribution, the main contribution to the inclusive asymmetry
comes from the region around , and the extrapolation from
the detector-covered region to the inclusive asymmetry is stable via a
multiplicative scale factor, giving us confidence in the previously reported
experimental results.Comment: 26 pages, 12 figure
Uncovering the structural diversity of Y(III) naphthalene-2,6-dicarboxylate MOFs through coordination modulation
Metal-organic frameworks (MOFs) – network structures built from metal ions and clusters and connecting organic ligands – are typically synthesized by solvothermal self-assembly. For transition metal based MOFs, structural predictability is facilitated by control over coordination geometries and linker connectivity under the principles of isoreticular synthesis. For rare earth MOFs, coordination behaviour is dominated by steric and electronic factors, leading to unpredictable structures and poor control over self-assembly. Herein we show that coordination modulation – the addition of competing ligands into MOF syntheses – offers programmable access to six different Y(III) MOFs all connected by the same naphthalene-2,6-dicarboxylate ligand, despite controlled synthesis of multiple phases from the same metal-ligand combination often being challenging for rare earth MOFs. Four of the materials are isolable in bulk phase purity, three are amenable to rapid microwave synthesis, and the fluorescence sensing ability of one example towards metal cations is reported. The results show that a huge variety of structurally versatile MOFs can potentially be prepared from simple systems, and that coordination modulation is a powerful tool for systematic control of phase behaviour in rare earth MOFs
Children’s experiences with Child Protection Services: A synthesis of qualitative evidence
Background - Research shows that young adults, previously in contact with Child Protection Services (CPS) often have lower overall wellbeing when compared to their peers in the general population. To redress this balance and fulfil children’s right to receive good quality and child-centred services, the child ´s lived experience of the CPS processes and interventions must be better understood. There is research with children about specific aspects of CPS, such as experiences of investigation, out-of-home care, end of intervention and participation. Yet, there is no available synthesis of the literature that would provide a general overview of children’s lived experiences of these services. Objective - The aim of this review was to comprehensively identify, synthesise and analyse the current empirical research that explored children’s overall experiences of Child Protection Services. Method - This is a systematic review and qualitative evidence synthesis of primary studies. A systematic search was conducted using five databases related to social sciences and social work for relevant qualitative publications in English. Using PRISMA, 39 studies were included in this review. A qualitative evidence synthesis was carried out, which entailed extracting, synthesising and thematic analysis of text from the findings section of the included studies. Results -Most of the literature focused on the perceptions of children in out-of-home care. Four main themes emerged that captured these subjective experiences: children described the processes of coming in contact with CPS, their experiences of the CPS intervention or services, their perceptions of the outcomes of the intervention and lastly their perceptions of self, social identity and stigmatisation. Discussion and Conclusion - This review concludes that, from the perspective of the child, clear, understandable and comprehensive information about the CPS process is required so that they can assert their right to participation and protection. Being in CPS is an emotional experience for them, thus emotional as much as physical safety, is needed. A sense of belongingness and self-actualization are as important as food and shelter. This knowledge should be considered in practice to improve both short and long-term outcomes for children in contact with the CPS
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Transcriptional landscape of epithelial and immune cell populations revealed through FACS-seq of healthy human skin.
Human skin consists of multiple cell types, including epithelial, immune, and stromal cells. Transcriptomic analyses have previously been performed from bulk skin samples or from epithelial and immune cells expanded in cell culture. However, transcriptomic analysis of bulk skin tends to drown out expression signals from relatively rare cells while cell culture methods may significantly alter cellular phenotypes and gene expression profiles. To identify distinct transcriptomic profiles of multiple cell populations without substantially altering cell phenotypes, we employed a fluorescence activated cell sorting method to isolate keratinocytes, dendritic cells, CD4+ T effector cells, and CD8+ T effector cells from healthy skin samples, followed by RNA-seq of each cell population. Principal components analysis revealed distinct clustering of cell types across samples, while differential expression and coexpression network analyses revealed transcriptional profiles of individual cell populations distinct from bulk skin, most strikingly in the least abundant CD8+ T effector population. Our work provides a high resolution view of cutaneous cellular gene expression and suggests that transcriptomic profiling of bulk skin may inadequately capture the contribution of less abundant cell types
Uncovering the Structural Diversity of Y(III) Naphthalene-2,6-Dicarboxylate MOFs Through Coordination Modulation
Metal-organic frameworks (MOFs)—network structures built from metal ions or clusters and connecting organic ligands—are typically synthesized by solvothermal self-assembly. For transition metal based MOFs, structural predictability is facilitated by control over coordination geometries and linker connectivity under the principles of isoreticular synthesis. For rare earth (RE) MOFs, coordination behavior is dominated by steric and electronic factors, leading to unpredictable structures, and poor control over self-assembly. Herein we show that coordination modulation—the addition of competing ligands into MOF syntheses—offers programmable access to six different Y(III) MOFs all connected by the same naphthalene-2,6-dicarboxylate ligand, despite controlled synthesis of multiple phases from the same metal-ligand combination often being challenging for rare earth MOFs. Four of the materials are isolable in bulk phase purity, three are amenable to rapid microwave synthesis, and the fluorescence sensing ability of one example toward metal cations is reported. The results show that a huge variety of structurally versatile MOFs can potentially be prepared from simple systems, and that coordination modulation is a powerful tool for systematic control of phase behavior in rare earth MOFs
Anything for a Cheerio: Brown Capuchins (\u3cem\u3eSapajus [Cebus] apella\u3c/em\u3e) Consistently Coordinate in an Assurance Game for Unequal Payoffs
Unequal outcomes disrupt cooperation in some situations, but this has not been tested in the context of coordination in economic games. To explore this, we tested brown capuchins (Sapajus [Cebus] apella) on a manual version of the Stag Hunt (or Assurance) Game, in which individuals sequentially chose between two options, Stag or Hare, and were rewarded according to their choices and that of their partner. Typically, coordination on Stag results in an equal highest payout, whereas coordinating on Hare results in a guaranteed equal but lower payoff and uncoordinated play results in the lowest payoff when playing Stag. We varied this structure such that one capuchin received double the rewards for the coordinated Stag outcome; thus, it was still both animals\u27 best option, but no longer equally rewarding. Despite the inequality, capuchins coordinated on Stag in 78% of trials, and neither payoff structure nor their partner\u27s choice impacted their decision. Additionally, there was no relationship between self-scratching, a measure of stress in capuchins, and choices. After completing the study, we discovered our reward, cheerios, was sufficiently valuable that in another study, capuchins never refused it, so post hoc we repeated the study using a lower value reward, banana flavored pellets. Capuchins completed only 26% of the pellet trials (compared to 98% with cheerios), constraining our ability to interpret the results, but nonetheless the monkeys showed a decrease in preference for Stag, particularly when they received fewer rewards for the coordinated Stag outcome. These results reinforce capuchins\u27 ability to find coordinated outcomes in the Stag Hunt game, but more work is needed to determine whether the monkeys did not mind the inequality or were unwilling to sacrifice a highly preferred food to rectify it. In either case, researchers should carefully consider the impact of their chosen rewards on subjects\u27 choices
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Intrathecal B-cell activation in LGI1 antibody encephalitis.
ObjectiveTo study intrathecal B-cell activity in leucine-rich, glioma-inactivated 1 (LGI1) antibody encephalitis. In patients with LGI1 antibodies, the lack of CSF lymphocytosis or oligoclonal bands and serum-predominant LGI1 antibodies suggests a peripherally initiated immune response. However, it is unknown whether B cells within the CNS contribute to the ongoing pathogenesis of LGI1 antibody encephalitis.MethodsPaired CSF and peripheral blood (PB) mononuclear cells were collected from 6 patients with LGI1 antibody encephalitis and 2 patients with other neurologic diseases. Deep B-cell immune repertoire sequencing was performed on immunoglobulin heavy chain transcripts from CSF B cells and sorted PB B-cell subsets. In addition, LGI1 antibody levels were determined in CSF and PB.ResultsSerum LGI1 antibody titers were on average 127-fold higher than CSF LGI1 antibody titers. Yet, deep B-cell repertoire analysis demonstrated a restricted CSF repertoire with frequent extensive clusters of clonally related B cells connected to mature PB B cells. These clusters showed intensive mutational activity of CSF B cells, providing strong evidence for an independent CNS-based antigen-driven response in patients with LGI1 antibody encephalitis but not in controls.ConclusionsOur results demonstrate that intrathecal immunoglobulin repertoire expansion is a feature of LGI1 antibody encephalitis and suggests a need for CNS-penetrant therapies
Understory 2014
“Art is the struggle to be, in a particular sort
of way, virtuous.” —Iris Murdoch
Indeed, when we embark on any creative adventure
it is with the purpose of conveying a certain truth; an
emotion, an idea that brings us together and reminds us
of the innate consciousness that dwells within.
Understory is emblematic of this; where individuals
intent on honing their craft can join others to become a
part of something greater, their work immortalized to
become a time capsule. Decades from now a volume of
Understory may be discovered on a dusty bookshelf in
some forgotten corner and the lucky explorer who finds it
shall be enlightened by pages of gold.
We, as editors of Understory 2014, have worked
very hard this year to put together a journal that showcases
the very best of the University of Alaska Anchorage
undergraduate student work. We hope you enjoy your
journey through this issue as much as we have enjoyed ours.
Thank you to the English and Art Departments,
for the staff and faculty’s unerring support of our club;
to Provost Baker, for seeing and believing in the vision
of Understory; and to our club’s faculty advisor, Douglass
Bourne, for his guidance and tireless assistance. Finally,
thank you to the wonderful students who submit such
excellent work each year. Without your passion for the
arts, we would not be here.Staff / Letter from the Editors / Glass Blower / Writing / Obsolete Evolution / Permafrost / Phoenix / Untitled / Ratio / Tripping / Abiogenesis / My Heart Beats for You / Meeting of the Fingerprint Lines / You Are No Stranger / Nightmare Fuel / Cane-Sugar / Gossamer Strands / Panthera Gold / Butterfly / A Mantis Too Far / Long and Winding Road / Chasing Shadows / Merisunas / Chequer Grove / Modzilla / Beans / Little Red and Mr. Wolf / In Memoriam, Joel Fletcher Armstrong / Glance / Courage / Uranium Waltz / Danger / Journey to the West / Antumbra / Roaring Like a Lion / Pre-boarding / Untitled / How Do You Say a Word / Fishing for Doom/ Contributor
Identification of a functional interaction of HMGB1 with Receptor for Advanced Glycation End-products in a model of neuropathic pain
Recent studies indicate that the release of high mobility group box 1 (HMGB1) following nerve injury may play a central role in the pathogenesis of neuropathic pain. HMGB1 is known to influence cellular responses within the nervous system via two distinct receptor families; the Receptor for Advanced Glycation End-products (RAGE) and Toll-like receptors (TLRs). The degree to which HMGB1 activates a receptor is thought to be dependent upon the oxidative state of the ligand, resulting in the functional isoforms of all-thiol HMGB1 (at-HMGB1) acting through RAGE, and disufide HMGB1 (ds-HMGB1) interacting with TLR4. Though it is known that dorsal root ganglia (DRG) sensory neurons exposed to HMGB1 and TLR4 agonists can influence excitation, the degree to which at-HMGB1 signaling through neuronal RAGE contributes to neuropathic pain is unknown. Here we demonstrate that at-HMGB1 activation of nociceptive neurons is dependent on RAGE and not TLR4. To distinguish the possible role of RAGE on neuropathic pain, we characterized the changes in RAGE mRNA expression up to one month after tibial nerve injury (TNI). RAGE mRNA expression in lumbar dorsal root ganglion (DRG) is substantially increased by post-injury day (PID) 28 when compared with sham injured rodents. Protein expression at PID28 confirms this injury-induced event in the DRG. Moreover, a single exposure to monoclonal antibody to RAGE (RAGE Ab) failed to abrogate pain behavior at PID 7, 14 and 21. However, RAGE Ab administration produced reversal of mechanical hyperalgesia on PID28. Thus, at-HMGB1 activation through RAGE may be responsible for sensory neuron sensitization and mechanical hyperalgesia associated with chronic neuropathic pain states
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