Band Gap Transition Studies of U:ThO\u3csub\u3e2\u3c/sub\u3e Using Cathodoluminescence

The Department of Defense has expressed interest in thorium dioxide (ThO2) and uranium dioxide (UO2) as possible candidates for use as special nuclear material in designing neutron detectors. Both materials have large neutron interaction cross sections. Uranium dioxide is particularly attractive due to its semiconducting properties and a relatively small band gap of 2 eV. Both materials fluoresce under ionizing radiation making them candidates for scintillating detectors. Three Ux:Th1-xO2 (x= 0.00, 0.01, 0.22) hydrothermally grown single crystals were examined using cathodoluminescence to interrogate the changing electronic properties of ThO2 as it became an alloy. Both depth-resolved and temperature- dependent cathodoluminescence studies were performed to examine the crystal structure and the defects present. An ultra-high vacuum system operating at 10 to the minus 8th power Torr was used with electron beam energies ranging from 2 to 14 keV. Spectra were taken on all three samples before and after a proprietary chemical cleaning process involving a crown ether/picric acid solution was applied to the crystals to remove surface contaminants. Spectral deconvolution of the spectra showed evidence of both direct and indirect gap photon transitions from the O 2p to Th 6d at 4.2 eV and 4.8 eV respectively. Uranium-doped spectra showed evidence of the midgap O 2p to U 5f quadrupole transition and O 2p to U 6d transition at 5 eV

Harry Potter\u27s heroics: crossing the thresholds of home, away, and the spaces in-between

This thesis seeks to identify and explore two mechanisms that combine to create a potential source of the widespread popularity and appeal of J.K. Rowling’s Harry Potter stories. The following pages will suggest that the application of literary space theory and heroic archetypal constructs to the series serves to illuminate the methods by which readers are initiated into the imaginary spaces of the Wizarding and Muggle worlds. By drawing connections between elements characteristic of mythographer Joseph Campbell’s hero cycle and literary theorist Gaston Bachelard’s concept of topophilia, this work ultimately concludes that Rowling’s progressive and complex use of liminal space within the series allows both Harry and his readers to become heroes and masters of both worlds

Social subordination alters estradiol-induced changes in cortico-limbic brain volumes in adult female rhesus monkeys

Women have a higher risk of developing stress-related disorders compared to men and the experience of a stressful life event is a potent risk-factor. The rodent literature suggests that chronic exposure to stressors as well as 17β-estradiol (E2) can result in alterations in neuronal structure in corticolimbic brain regions, however the translation of these data to humans is limited by the nature of the stressor experienced and issues of brain homology. To address these limitations, we used a well-validated rhesus monkey model of social subordination to examine effects of E2 treatment on subordinate (high stress) and dominant (low stress) female brain structure, including regional gray matter and white matter volumes using structural magnetic resonance imaging. Our results show that one month of E2 treatment in ovariectomized females, compared to control (no) treatment, decreased frontal cortex gray matter volume regardless of social status. In contrast, in the cingulate cortex, an area associated with stress-induced emotional processing, E2 decreased grey matter volume in subordinates but increased it in dominant females. Together these data suggest that physiologically relevant levels of E2 alter cortical gray matter volumes in females after only one month of treatment and interact with chronic social stress to modulate these effects on brain structure

Pan-European grading scales: lessons from national systems and the ECTS

This article assesses the impact of the Bologna Process on the grading schemes of EU member countries. In light of some problems regarding the implementation of the European Credit Transfer system (ECTS), the author proposes further reforms and offers some elements of a unified grading system for European higher education. The author explores the variation among Europe’s grading systems and the resulting lessons learned are shared here. Lastly, this article also argues that principles of justice and fairness, deemed central to academic freedom, are best upheld by the use of a unified grading system at national and European levels

The size-Ramsey number of powers of paths

Given graphs $G$ and $H$ and a positive integer $q$, say that $G$ \emph{is $q$-Ramsey for} $H$, denoted $G\rightarrow (H)_q$, if every $q$-colouring of the edges of $G$ contains a monochromatic copy of $H$. The \emph{size-Ramsey number} \sr(H) of a graph $H$ is defined to be \sr(H)=\min\{|E(G)|\colon G\rightarrow (H)_2\}. Answering a question of Conlon, we prove that, for every fixed~$k$, we have \sr(P_n^k)=O(n), where~$P_n^k$ is the $k$th power of the $n$-vertex path $P_n$ (i.e., the graph with vertex set $V(P_n)$ and all edges $\{u,v\}$ such that the distance between $u$ and $v$ in $P_n$ is at most $k$). Our proof is probabilistic, but can also be made constructive.Most of the work for this paper was done during my PhD, which was half funded by EPSRC grant reference 1360036, and half by Merton College Oxford. The third author was partially supported by FAPESP (Proc.~2013/03447-6) and by CNPq (Proc.~459335/2014-6, 310974/2013-5). The fifth author was supported by FAPESP (Proc.~2013/11431-2, Proc.~2013/03447-6 and Proc.~2018/04876-1) and partially by CNPq (Proc.~459335/2014-6). This research was supported in part by CAPES (Finance Code 001). The collaboration of part of the authors was supported by a CAPES/DAAD PROBRAL grant (Proc.~430/15)

Partly burnt runaway stellar remnants from peculiar thermonuclear supernovae

We report the discovery of three stars that, along with the prototype LP40-365, form a distinct class of chemically peculiar runaway stars that are the survivors of thermonuclear explosions. Spectroscopy of the four confirmed LP 40-365 stars finds ONe-dominated atmospheres enriched with remarkably similar amounts of nuclear ashes of partial O- and Si-burning. Kinematic evidence is consistent with ejection from a binary supernova progenitor; at least two stars have rest-frame velocities indicating they are unbound to the Galaxy. With masses and radii ranging between 0.20-0.28 Msun and 0.16-0.60 Rsun, respectively, we speculate these inflated white dwarfs are the partly burnt remnants of either peculiar Type Iax or electron-capture supernovae. Adopting supernova rates from the literature, we estimate that ~20 LP40-365 stars brighter than 19 mag should be detectable within 2 kpc from the Sun at the end of the Gaia mission. We suggest that as they cool, these stars will evolve in their spectroscopic appearance, and eventually become peculiar O-rich white dwarfs. Finally, we stress that the discovery of new LP40-365 stars will be useful to further constrain their evolution, supplying key boundary conditions to the modelling of explosion mechanisms, supernova rates, and nucleosynthetic yields of peculiar thermonuclear explosions.Comment: 22 pages, 14 figures, 6 tables. Accepted for publication on MNRA

The pancreas responds to remote damage and systemic stress by secretion of the pancreatic secretory proteins PSP/regI and PAP/regIII.

In patients with infection and sepsis serum levels of Pancreatic Stone protein/regenerating protein I (PSP) are highly elevated. The origin of PSP during these conditions is presumably the pancreas, however, an intestinal origin cannot be excluded. Similarly, pancreatitis-associated protein (PAP) was identified in the pancreas. These proteins were also localized in intestinal organs. Here we aim to elucidate the bio-distribution of PSP and PAP in animal models of sepsis and in healthy humans. PSP and PAP responded to remote lesions in rats although the pancreatic response was much more pronounced than the intestinal. Tissue distribution of PSP demonstrated a 100-fold higher content in the pancreas compared to any other organ while PAP was most abundant in the small intestine. Both proteins responded to CLP or sham operation in the pancreas. PSP also increased in the intestine during CLP. The distribution of PSP and PAP in human tissue mirrored the distribution in the murine models. Distribution of PSP and PAP was visualized by immunohistochemistry. Rats and mice underwent midline laparotomies followed by mobilization of tissue and incision of the pancreatic duct or duodenum. Standard cecum-ligation-puncture (CLP) procedures or sham laparotomies were performed. Human tissue extracts were analyzed for PSP and PAP. The pancreas reacts to remote lesions and septic insults in mice and rats with increased PSP synthesis, while PAP is selectively responsive to septic events. Furthermore, our results suggest that serum PSP in septic patients is predominantly derived through an acute phase response of the pancreas

Electronic structure of hydrothermally synthesized single crystal U0.22Th0.78O2

Single crystals of ThO2, UO2, and their solid solutions, UxTh1–xO2, have been obtained through various hydrothermal growth conditions. This technique offers the better of two other growth processes: (i) single crystal purity as by photochemical growth of nanocrystals; and (ii) large/bulk sizes as obtained by the arc melt method. The band gap of the UxTh1–xO2 single crystal solid solution, along with the luminescence transition, have been characterized. The occupied and unoccupied structures are determined using ultraviolet and inverse photoemission spectroscopy and the electronic band gap was measured to be 3–4 eV. The strain of incorporating U into the ThO2 is analyzed through Vegard’s law. In this crystal there are defect and impurity sites, likely arising from the kinetic growth process, giving rise to a similar yet slightly different optical gap evident with cathodoluminescence spectroscopy. There is a major luminescence feature spanning the range from 3.18 to 4.96 eV (250–390 nm) with a maximum at 4.09 eV (303 nm), corresponding with the measured electronic band gap. In this paper, the electronic properties of a solid solution U0.22Th0.78O2 are measured and interpreted compared to the pure actinide oxides, ThO2 and UO2

Developmental outcomes of early adverse care on amygdala functional connectivity in nonhuman primates

Despite the strong link between childhood maltreatment and psychopathology, the underlying neurodevelopmental mechanisms are poorly understood and difficult to disentangle from heritable and prenatal factors. This study used a translational macaque model of infant maltreatment in which the adverse experience occurs in the first months of life, during intense maturation of amygdala circuits important for stress and emotional regulation. Thus, we examined the developmental impact of maltreatment on amygdala functional connectivity (FC) longitudinally, from infancy through the juvenile period. Using resting state functional magnetic resonance imaging (MRI) we performed amygdala-prefrontal cortex (PFC) region-of-interest and exploratory whole-brain amygdala FC analyses. The latter showed (a) developmental increases in amygdala FC with many regions, likely supporting increased processing of socioemotional-relevant stimuli with age; and (b) maltreatment effects on amygdala coupling with arousal and stress brain regions (locus coeruleus, laterodorsal tegmental area) that emerged with age. Maltreated juveniles showed weaker FC than controls, which was negatively associated with infant hair cortisol concentrations. Findings from the region-of-interest analysis also showed weaker amygdala FC with PFC regions in maltreated animals than controls since infancy, whereas bilateral amygdala FC was stronger in maltreated animals. These effects on amygdala FC development may underlie the poor behavioral outcomes associated with this adverse experience

EFFICACY AND SAFETY OF EPTACOG BETA (RECOMBINANT HUMAN FVIIA) ACCORDING TO AGE IN PERSONS WITH HAEMOPHILIA A/B WITH INHIBITORS UNDERGOING SURGICAL PROCEDURES

Introduction: Eptacog beta (CEVENFACTA®) is a new rFVIIa approved by the EMA for the treatment of bleeding events and prevention of bleeding during surgery in persons with haemophilia A/B with inhibitors (PwHABI) aged ≥12 years (y). Methods: PERSEPT 3 was a Phase 3 (NCT02020369) trial of eptacog beta in PwHABI who required surgical procedures. Eptacog beta was administered at an initial dose of 200μg/kg or 75μg/kg for major or minor procedures respectively. This was followed by 75μg/kg for ≥5 (major procedures) or ≥2 (minor procedures) days. Haemostatic efficacy was assessed using a 4-point scale during the intra and postoperative care period (primary efficacy endpoint was determined by the investigator at the study centre 48±4h after the last dose of eptacog beta, based on the totality of the assessments performed on the patient (pt) at each timepoint). This post-hoc analysis compared the efficacy and safety of eptacog beta by age (pts aged \u3c12 vs ≥12y). Results: Twelve pts were included (\u3c12y: n=5, 1 major and 4 minor procedures; ≥12y: n=7, 5 major and 2 minor procedures). The primary endpoint success proportion was 100% (95% CI: 39.8-100) in pts aged \u3c12y (4 successes, 1 missing) and 71.4% (95% CI: 29.0-96.3) in pts aged ≥12y (5 successes; 2 failures). The intraoperative success proportion was 100% (95% CI: 47.8-100) for pts aged \u3c12y (5 successes) and 100% (95% CI: 59.0-100) for pts aged ≥12y (7 successes). The success proportion 24h post-procedure was 100% (95% CI: 47.8-100) for pts aged \u3c12y (5 successes) and 100% (95% CI: 47.8-100) for pts aged ≥12y (5 successes; 2 missing). Two pts discontinued treatment (1 aged \u3c12y withdrew consent; 1 aged ≥12y due to an adverse event (AE): postprocedural hematoma). One pt experienced 2 serious AEs leading to death, both were considered unrelated to the treatment. No allergic or thrombotic events occurred; no neutralising antibodies were detected. Antifibrinolytics were used concomitantly with eptacog beta in 4 patients without any safety concerns. Discussion/Conclusion: This post-hoc subgroup analysis shows that eptacog beta is effective and well-tolerated in perioperative care irrespective of patient age (\u3c12 vs ≥12y), supporting the use of eptacog beta for bleed management (prevention and treatment) in major and minor surgical procedures in all PwHABI