438 research outputs found
U-dual fluxes and Generalized Geometry
We perform a systematic analysis of generic string flux compactifications,
making use of Exceptional Generalized Geometry (EGG) as an organizing
principle. In particular, we establish the precise map between fluxes, gaugings
of maximal 4d supergravity and EGG, identifying the complete set of gaugings
that admit an uplift to 10d heterotic or type IIB supegravity backgrounds. Our
results reveal a rich structure, involving new deformations of 10d supergravity
backgrounds, such as the RR counterparts of the -deformation. These new
deformations are expected to provide the natural extension of the
-deformation to full-fledged F-theory backgrounds. Our analysis also
provides some clues on the 10d origin of some of the particularly less
understood gaugings of 4d supergravity. Finally, we derive the explicit
expression for the effective superpotential in arbitrary N = 1 heterotic or
type IIB orientifold compactifications, for all the allowed fluxes.Comment: 58 pages, 6 table
Molecular and Clinical Findings in Patients With Knobloch Syndrome
IMPORTANCE: Knobloch syndrome is a rare, recessively inherited disorder classically characterized by high myopia, retinal detachment, and occipital encephalocele, but it is now known to have an increasingly variable phenotype. There is a lack of reported electrophysiologic data, and some key clinical features have yet to be described. OBJECTIVE: To expand on current clinical, electrophysiologic, and molecular genetic findings in Knobloch syndrome. DESIGN, SETTING AND PARTICIPANTS: Twelve patients from 7 families underwent full ophthalmic examination and retinal imaging. Further investigations included electroretinography and neuroradiologic imaging. Bidirectional Sanger sequencing of COL18A1 was performed with segregation on available relatives. The study was conducted from July 4, 2013, to October 5, 2015. Data analysis was performed from May 20, 2014, to November 3, 2015. MAIN OUTCOMES AND MEASURES: Results of ophthalmic and neuroradiologic assessment and sequence analysis of COL18A1. RESULTS: Of the 12 patients (6 males; mean age at last review, 16 years [range, 2-38 years]), all had high myopia in at least 1 eye and severely reduced vision. A sibling pair had unilateral high myopia in their right eyes and near emmetropia in their left eyes from infancy. Anterior segment abnormalities included absent iris crypts, iris transillumination, lens subluxation, and cataract. Two patients with iris transillumination had glaucoma. Fundus characteristics included abnormal collapsed vitreous, macular atrophy, and a tesselated fundus. Five patients had previous retinal detachment. Electroretinography revealed a cone-rod pattern of dysfunction in 8 patients, was severely reduced or undetectable in 2 patients, and demonstrated cone-rod dysfunction in 1 eye with undetectable responses in the other eye in 2 patients. Radiologic imaging demonstrated occipital encephalocele or meningocele in 3 patients, occipital skull defects in 4 patients, minor occipital changes in 2 patients, and no abnormalities in 2 patients. Cutaneous scalp changes were present in 5 patients. Systemic associations were identified in 8 patients, including learning difficulties, epilepsy, and congenital renal abnormalities. Biallelic mutations including 2 likely novel mutations in COL18A1, were identified in 6 families that were consistent with autosomal recessive inheritance with a single mutation identified in a family with 2 affected children. CONCLUSIONS AND RELEVANCE: This report describes new features in patients with Knobloch syndrome, including pigment dispersion syndrome and glaucoma as well as cone-rod dysfunction on electroretinography. Two patients had normal neuroradiologic findings, emphasizing that some affected individuals have isolated ocular disease. Awareness of the ocular phenotype may aid early diagnosis, appropriate genetic counseling, and monitoring for potential complications
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A pilot investigation to optimise methods for a future satiety preload study
Preload studies are used to investigate the satiating effects of foods and food ingredients. However, the design of preload studies is complex, with many methodological considerations influencing appetite responses. The aim of this pilot investigation was to determine acceptability, and optimise methods, for a future satiety preload study. Specifically, we investigated the effects of altering (i) energy intake at a standardised breakfast (gender-specific or non-gender specific), and (ii) the duration between mid-morning preload and ad libitum lunch meal, on morning appetite scores and energy intake at lunch. Participants attended a single study visit. Female participants consumed a 214-kcal breakfast (n = 10) or 266-kcal breakfast (n = 10), equivalent to 10% of recommended daily energy intakes for females and males, respectively. Male participants (n = 20) consumed a 266-kcal breakfast. All participants received a 250-ml orange juice preload 2 h after breakfast. The impact of different study timings was evaluated in male participants, with 10 males following one protocol (protocol 1) and 10 males following another (protocol 2). The duration between preload and ad libitum lunch meal was 2 h (protocol 1) or 2.5 h (protocol 2), with the ad libitum lunch meal provided at 12.00 or 13.00, respectively. All female participants followed protocol 2. Visual analogue scale (VAS) questionnaires were used to assess appetite responses and food/drink palatability. Correlation between male and female appetite scores was higher with the provision of a gender-specific breakfast, compared to non-gender-specific breakfast (Pearson correlation of 0.747 and 0.479, respectively). No differences in subjective appetite or ad libitum energy intake were found between protocols 1 and 2. VAS mean ratings of liking, enjoyment, and palatability were all > 66 out of 100 mm for breakfast, preload, and lunch meals. The findings of this pilot study confirm the acceptability of this methodology for future satiety preload studies. Appetite scores increased from preload to ad libitum lunch meal; however, no specific differences were found between protocols. The results highlight the importance of considering energy intake prior to preload provision, with a gender-specific breakfast improving the correlation between male and female appetite score responses to a morning preload
Universal time-dependent deformations of Schrodinger geometry
We investigate universal time-dependent exact deformations of Schrodinger
geometry. We present 1) scale invariant but non-conformal deformation, 2)
non-conformal but scale invariant deformation, and 3) both scale and conformal
invariant deformation. All these solutions are universal in the sense that we
could embed them in any supergravity constructions of the Schrodinger invariant
geometry. We give a field theory interpretation of our time-dependent
solutions. In particular, we argue that any time-dependent chemical potential
can be treated exactly in our gravity dual approach.Comment: 24 pages, v2: references adde
Influence of different treatment techniques on radiation dose to the LAD coronary artery
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Multifunctionality of silver closo-boranes
Silver compounds share a rich history in technical applications including photography, catalysis, photocatalysis, cloud seeding and as antimicrobial agents. Here we present a class of silver compounds (Ag2B10H10 and Ag2B12H12) that are semiconductors with a bandgap at 2.3?eV in the green visible light spectrum. The silver boranes have extremely high ion conductivity and dynamic-anion facilitated Ag(+) migration is suggested based on the structural model. The ion conductivity is enhanced more than two orders of magnitude at room temperature (up to 3.2?mS?cm(-1)) by substitution with AgI to form new compounds. Furthermore, the closo-boranes show extremely fast silver nano-filament growth when excited by electrons during transmission electron microscope investigations. Ag nano-filaments can also be reabsorbed back into Ag2B12H12. These interesting properties demonstrate the multifunctionality of silver closo-boranes and open up avenues in a wide range of fields including photocatalysis, solid state ionics and nano-wire production
Hierarchy Theory of Evolution and the Extended Evolutionary Synthesis: Some Epistemic Bridges, Some Conceptual Rifts
Contemporary evolutionary biology comprises a plural landscape of multiple co-existent conceptual frameworks and strenuous voices that disagree on the nature and scope of evolutionary theory. Since the mid-eighties, some of these conceptual frameworks have denounced the ontologies of the Modern Synthesis and of the updated Standard Theory of Evolution as unfinished or even flawed. In this paper, we analyze and compare two of those conceptual frameworks, namely Niles Eldredge’s Hierarchy Theory of Evolution (with its extended ontology of evolutionary entities) and the Extended Evolutionary Synthesis (with its proposal of an extended ontology of evolutionary processes), in an attempt to map some epistemic bridges (e.g. compatible views of causation; niche construction) and some conceptual rifts (e.g. extra-genetic inheritance; different perspectives on macroevolution; contrasting standpoints held in the “externalism–internalism” debate) that exist between them. This paper seeks to encourage theoretical, philosophical and historiographical discussions about pluralism or the possible unification of contemporary evolutionary biology
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Reducing non-attendance rates for assessment at an eating disorders service: a quality improvement initiative
Rates of non-attendance at initial appointments within community eating disorder (ED) services are frequently high, although this has received relatively little research attention and no reports of interventions designed to address this. The current report describes outcomes following a change of procedure introducing a ‘partial booking’ system. Attendance rates at first appointments (N = 1260) were audited following introduction of a system designed to reduce non-attendance in January 2013 within a UK ED service. Rates were compared following implementation of the new system, using a historical control group for comparison, and showed a decline from 20.4 to 15.1%, a medium-sized effect. Use of a system asking patients to book an appointment reduced non-attendance at initial appointments and may be of use to similar services experiencing high non-attendance rates. Opt-in initiatives can reduce burden resulting from long waiting times and can be easily adapted to individual services
Reduction of Dopamine Level Enhances the Attractiveness of Male Drosophila to Other Males
Dopamine is an important neuromodulator in animals and its roles in mammalian sexual behavior are extensively studied. Drosophila as a useful model system is widely used in many fields of biological studies. It has been reported that dopamine reduction can affect female receptivity in Drosophila and leave male-female courtship behavior unaffected. Here, we used genetic and pharmacological approaches to decrease the dopamine level in dopaminergic cells in Drosophila, and investigated the consequence of this manipulation on male homosexual courtship behavior. We find that reduction of dopamine level can induce Drosophila male-male courtship behavior, and that this behavior is mainly due to the increased male attractiveness or decreased aversiveness towards other males, but not to their enhanced propensity to court other males. Chemical signal input probably plays a crucial role in the male-male courtship induced by the courtees with reduction of dopamine. Our finding provides insight into the relationship between the dopamine reduction and male-male courtship behavior, and hints dopamine level is important for controlling Drosophila courtship behavior
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