6,472 research outputs found
Supersymmetric coupling of a self-dual string to a (2,0) tensor multiplet background
We construct an interaction between a (2,0) tensor multiplet in six
dimensions and a self-dual string. The interaction is a sum of a Nambu-Goto
term, with the tension of the string given by the modulus of the scalar fields
of the tensor multiplet, and a non-local Wess-Zumino term, that encodes the
electromagnetic coupling of the string to the two-form gauge field of the
tensor multiplet. The interaction is invariant under global (2,0)
supersymmetry, modulo the equations of motion of a free tensor multiplet. It is
also invariant under a local fermionic kappa-symmetry, as required by the
BPS-property of the string.Comment: 12 pages, LaTe
Functional graphs of families of quadratic polynomials
We study functional graphs generated by several quadratic polynomials, acting
simultaneously on a finite field. We obtain several results about the number of
leaves in such graphs. In particular, in the case of graphs generated by three
polynomials, we relate the distribution of leaves to the Sato-Tate distribution
of Frobenius traces of elliptic curves. We also present extensive numerical
results which we hope may shed some light on the distribution of leaves for
larger families of polynomials.Comment: 29 page
Sustained, multifaceted improvements in mental well-being following psychedelic experiences in a prospective opportunity sample
In the last 15 years, psychedelic substances, such as LSD and psilocybin, have regained legitimacy in clinical research. In the general population as well as across various psychiatric populations, mental well-being has been found to significantly improve after a psychedelic experience. Mental well-being has large socioeconomic relevance, but it is a complex, multifaceted construct. In this naturalistic observational study, a comprehensive approach was taken to assessing well-being before and after a taking a psychedelic compound to induce a “psychedelic experience.” Fourteen measures of well-being related constructs were included in order to examine the breadth and specificity of change in well-being. This change was then analysed to examine clusters of measures changing together. Survey data was collected from volunteers that intended to take a psychedelic. Four key time points were analysed: 1 week before and 2 weeks, 4 weeks, and 2 years after the experience (N = 654, N = 315, N = 212, and N = 64, respectively). Change on the included measures was found to cluster into three factors which we labelled: 1) “Being well”, 2) “Staying well,” and 3) “Spirituality.” Repeated Measures Multivariate Analysis of Variance revealed all but the spirituality factor to be improved in the weeks following the psychedelic experience. Additional Mixed model analyses revealed selective increases in Being Well and Staying Well (but not Spirituality) that remained statistically significant up to 2 years post-experience, albeit with high attrition rates. Post-hoc examination suggested that attrition was not due to differential acute experiences or mental-health changes in those who dropped out vs. those who did not. These findings suggest that psychedelics can have a broad, robust and sustained positive impact on mental well-being in those that have a prior intention to use a psychedelic compound. Public policy implications are discussed
Searching for a light Fermiophobic Higgs Boson at the Tevatron
We propose new production mechanisms for light fermiophobic Higgs bosons
() with suppressed couplings to vector bosons () at the Fermilab
Tevatron. These mechanisms (e.g. ) are complementary to the
conventional process , which suffers from a strong suppression of
in realistic models with a . The new mechanisms extend the
coverage at the Tevatron Run II to the larger region, and offer the
possibility of observing new event topologies with up to 4 photons.Comment: 15 pages, including 5 eps-figure
Comparative salivary gland transcriptomics of sandfly vectors of visceral leishmaniasis
BACKGROUND: Immune responses to sandfly saliva have been shown to protect animals against Leishmania infection. Yet very little is known about the molecular characteristics of salivary proteins from different sandflies, particularly from vectors transmitting visceral leishmaniasis, the fatal form of the disease. Further knowledge of the repertoire of these salivary proteins will give us insights into the molecular evolution of these proteins and will help us select relevant antigens for the development of a vector based anti-Leishmania vaccine. RESULTS: Two salivary gland cDNA libraries from female sandflies Phlebotomus argentipes and P. perniciosus were constructed, sequenced and proteomic analysis of the salivary proteins was performed. The majority of the sequenced transcripts from the two cDNA libraries coded for secreted proteins. In this analysis we identified transcripts coding for protein families not previously described in sandflies. A comparative sandfly salivary transcriptome analysis was performed by using these two cDNA libraries and two other sandfly salivary gland cDNA libraries from P. ariasi and Lutzomyia longipalpis, also vectors of visceral leishmaniasis. Full-length secreted proteins from each sandfly library were compared using a stand-alone version of BLAST, creating formatted protein databases of each sandfly library. Related groups of proteins from each sandfly species were combined into defined families of proteins. With this comparison, we identified families of salivary proteins common among all of the sandflies studied, proteins to be genus specific and proteins that appear to be species specific. The common proteins included apyrase, yellow-related protein, antigen-5, PpSP15 and PpSP32-related protein, a 33-kDa protein, D7-related protein, a 39- and a 16.1- kDa protein and an endonuclease-like protein. Some of these families contained multiple members, including PPSP15-like, yellow proteins and D7-related proteins suggesting gene expansion in these proteins. CONCLUSION: This comprehensive analysis allows us the identification of genus- specific proteins, species-specific proteins and, more importantly, proteins common among these different sandflies. These results give us insights into the repertoire of salivary proteins that are potential candidates for a vector-based vaccine
Norovirus epidemiology in Africa : a review
Norovirus (NoV) is recognised as a leading cause of gastroenteritis worldwide across all
age groups. The prevalence and diversity of NoVs in many African countries is still
unknown, although early sero-prevalence studies indicated widespread early infection.
Reports on NoVs in Africa vary widely in terms of study duration, population groups and
size, inclusion of asymptomatic controls, as well as genotyping information. This review provides
an estimate of NoV prevalence and distribution of genotypes of NoVs in Africa. Inclusion
criteria for the review were study duration of at least 6 months, population size of >50
and diagnosis by RT-PCR. As regions used for genotyping varied, or genotyping was not
always performed, this was not considered as an inclusion criteria. A literature search containing
the terms norovirus+Africa yielded 74 publications. Of these 19 studies from 14 out
of the 54 countries in Africa met the inclusion criteria. Data from studies not meeting the
inclusion criteria, based on sample size or short duration, were included as discussion
points. The majority of studies published focused on children, under five years of age, hospitalised
with acute gastroenteritis. The mean overall prevalence was 13.5% (range 0.8–
25.5%) in children with gastroenteritis and 9.7% (range 7–31%) in asymptomatic controls,
where tested. NoV GII.4 was the predominant genotype identified in most of the studies that
presented genotyping data. Other prevalent genotypes detected included GII.3 and GII.6.
In conclusion, NoV is a common pathogen in children with diarrhoea in Africa, with considerable
carriage in asymptomatic children. There is however, a paucity of data on NoV infection
in adults.http://www.plosone.orgam2016Medical Microbiolog
Expression of an Arc-Immunoreactive Protein in the Adult Zebrafish Brain Increases in Response to a Novel Environment
Zebrafish are a powerful research tool in the field of neuroscience, offering several logistical and physiological advantages over rodents as a research model. However, the molecular dynamics of this model organism, especially with regards to learning and memory, are scarcely known. The current study explored the zebrafish brain for the presence of a protein bearing a similar function to the activity-regulated, cytoskeleton-associated protein (Arc), a critical player in synaptic plasticity. The adult zebrafish brain was found to express a protein with immunoreactivity against the anti-Arc antibody H-300. Immunoreactivity was detected ubiquitously, especially in areas known as adult progenitor cell zones. The protein, termed Arc-immunoreactive protein (AIP), increased in the telencephalon but not the optic tectum 60 min after exposure to a novel environment. Epileptiform brain activity, however, did not induce AIP expression. Evidence presented herein suggests AIP may be the neuropeptide Y receptor rather than a zebrafish homolog of Arc
Data Transformation and Semantic Log Purging for Process Mining
Existing process mining approaches are able to tolerate a certain degree of noise in the process log. However, processes that contain infrequent paths, multiple (nested) parallel branches, or have been changed in an ad-hoc manner,
still pose major challenges. For such cases, process mining typically returns "spaghetti-models", that are hardly usable even as a starting point for process (re-)design. In this paper, we address these challenges by introducing data transformation and pre-processing steps that improve and ensure the quality of mined models for existing process mining approaches. We propose the concept of semantic log purging, the cleaning of logs based on domain specific
constraints utilizing semantic knowledge which typically complements processes. Furthermore we demonstrate the feasibility and effectiveness of the approach based
on a case study in the higher education domain. We think that semantic log purging will enable process mining to yield better results, thus giving process (re-)designers a valuable tool
- …