1,720 research outputs found
Filtering Irreducible Clifford Supermodules
A Clifford algebra is an associative algebra that generalizes the sequence R, C, H, etc. Filtrations are increasing chains of subspaces that respect the structure of the object they are filtering. In this paper, we filter ideals in Clifford algebras. These filtrations must also satisfy a āClifford conditionā, making them compatible with the algebra structure. We define a notion of equivalence between these filtered ideals and proceed to analyze the space of equivalence classes. We focus our attention on a specific class of filtrations, which we call principal filtrations. Principal filtrations are described by a single element in complex projective space and their equivalence classes are orbits of a group action inside complex projective space. In this paper, we identify when the space of equivalence classes of principal filtrations has a discrete topology or not. We find one example where the space of equivalence classes is not discrete, and is instead homeomorphic to S^2
A Quantum Random Walk Search Algorithm
Quantum random walks on graphs have been shown to display many interesting
properties, including exponentially fast hitting times when compared with their
classical counterparts. However, it is still unclear how to use these novel
properties to gain an algorithmic speed-up over classical algorithms. In this
paper, we present a quantum search algorithm based on the quantum random walk
architecture that provides such a speed-up. It will be shown that this
algorithm performs an oracle search on a database of items with
calls to the oracle, yielding a speed-up similar to other quantum
search algorithms. It appears that the quantum random walk formulation has
considerable flexibility, presenting interesting opportunities for development
of other, possibly novel quantum algorithms.Comment: 13 pages, 3 figure
Changes in invasive pneumococcal disease caused by streptococcus pneumoniae serotype 1 following introduction of pcv10 and pcv13 : Findings from the pserenade project
Funding Information: Funding: The PSERENADE project is funded by the Bill and Melinda Gates Foundation as part of the World Health Organization Pneumococcal Vaccines Technical Coordination Project, grant numā ber INVā010429/OPP1189065. Funding Information: Conflicts of Interest: KH conducted the study and analyses while working at the Johns Hopkins School of Public Health but is an employee at Pfizer, Inc. as of 26 October 2020. MDK reports grants from Merck, personal fees from Merck, and grants from Pfizer, outside the submitted work. JCB reports funding from Pfizer in the past year, unrelated to the submitted work. JAS reports grants from the Bill & Melinda Gates Foundation, the Wellcome Trust, the UK MRC, National Institute of Health Research, outside the submitted work. MCB reports lectures fee from MSD outside from submitted work. AS reports grants and personal fees from Pfizer and personal fees from MSD and Sanofi Pasteur, outside the submitted work. ML has been a member of advisory boards and has received speakers honoraria from Pfizer and Merck. German pneumococcal surveillance has been supported by Pfizer and Merck. SD reports grant from Pfizer, outside the submitted work. KA reā ports a grant from Merck, outside the submitted work. AvG as received researching funding from Pfizer (last year 2017, Pfizer InvestigatorāInitiated Research [IIR] Program IIR WI 194379); attended advisory board meetings for Pfizer and Merck. CMA reports grants and personal fees from Pfizer, Qiagen and BioMerieux and grants from Genomica SAU, outside the submitted work. AMāresearch support to my institution from Pfizer and Merck; honoraria for advisory board membership from GlaxoSmithKline, Merck and Pfizer. SNL performs contract research for GSK, Pfizer, Sanofi Pasteur on behalf of St. Georgeās University of London, but receives no personal remuneration. IY stated she was a member of mRNAā1273 study group and has received funding to her institution to conduct clinical research from BioFire, MedImmune, Regeneron, PaxVax, Pfizer, GSK, Merck, Novavax, SanofiāPasteur, and Micron. RD has received grants/research support from Pfizer, Merck Sharp & Dohme and Medimmune; has been a scientific consultant for Pfizer, MeMed, Merck Sharp & Dohme, and Biondvax; had served on advisory boards of Pfizer, Merck Sharp & Dohme and Biondvax and has been a speaker for Pfizer. LLH reports research grants to her institution from GSK, Pfizer and Merck. JDK has received an unrestricted grantāināaid from Pfizer Canada that supā ports, in part, the CASPER invasive pneumococcal disease surveillance project. MH received an educational grant from Pfizer AG for partial support of this project. However, Pfizer AG had no role in the data analysis and content of the manuscript. MC has previously received a professional fee from Pfizer (Ireland), an unrestricted research grant from Pfizer Ireland (2007ā2016) and an Inā vestigator Initiated Reward from Pfizer Ireland in 2018 (W1243730). CLB, MD has intellectual propā erty in BioFire Diagnostics and receives royalties through the University of Utah. CLB is an advisor to IDbyDNA. AK reports personal fees from Pfizer, outside the submitted work. MT reports grants from GlaxoSmithKline and grants from Pfizer Inc. to the Finnish Institute for Health and Welfare for research projects outside the submitted work, in which she has been a coāinvestigator. JCS reā ports had received assistance from Pfizer for attending to scientific meetings outside the submitted work. SCGA received travel grant from Pfizer. BL had two research grants from Pfizer on Streptoā coccus pneumoniae. EV reports grants from French public health agency, during the conduct of the study; grants from Pfizer, grants from Merck, outside the submitted work. NBZ has received invesā tigatorāinitiated research grants from GlaxoSmithKline, Takeda Pharmaceuticals, Merck and the Seā rum Institute of India, all unrelated to this research. CGS reports grant funding from Pfizer, Merck, and AstraZeneca in the past 3 years. NMvS reports grants and fee for service from Pfizer, fee for service from MSD and GSK, outside the submitted work; In addition, NMvS has a patent WO 2013/020090 A3 with royalties paid to University of California San Diego (inventors: Nina van Sorge/Victor Nizet). All other authors did not declare any conflicts of interest. The funders had no Publisher Copyright: Ā© 2021 by the authors. Licensee MDPI, Basel, Switzerland.Streptococcus pneumoniae serotype 1 (ST1) was an important cause of invasive pneumococ-cal disease (IPD) globally before the introduction of pneumococcal conjugate vaccines (PCVs) con-taining ST1 antigen. The Pneumococcal Serotype Replacement and Distribution Estimation (PSEREā NADE) project gathered ST1 IPD surveillance data from sites globally and aimed to estimate PCV10/13 impact on ST1 IPD incidence. We estimated ST1 IPD incidence rate ratios (IRRs) compar-ing the preāPCV10/13 period to each postāPCV10/13 year by site using a Bayesian multiālevel, mixed-effects Poisson regression and allāsite IRRs using a linear mixedāeffects regression (N = 45 sites). Following PCV10/13 introduction, the incidence rate (IR) of ST1 IPD declined among all ages. After six years of PCV10/13 use, the allāsite IRR was 0.05 (95% credibility interval 0.04ā0.06) for all ages, 0.05 (0.04ā0.05) for <5 years of age, 0.08 (0.06ā0.09) for 5ā17 years, 0.06 (0.05ā0.08) for 18ā49 years, 0.06 (0.05ā0.07) for 50ā64 years, and 0.05 (0.04ā0.06) for ā„65 years. PCV10/13 use in infant immunization programs was followed by a 95% reduction in ST1 IPD in all ages after approximately 6 years. Limited data availability from the highest ST1 disease burden countries using a 3+0 schedule constrains generalizability and data from these settings are needed.publishersversionPeer reviewe
Inadequate reporting of research ethics review and informed consent in cluster randomized trials : review of random sample of published trials
Peer reviewedPublisher PD
The hustle and bustle of city life : monitoring the effects of urbanisation in the African lesser bushbaby
Urbanisation has become a severe threat to pristine natural areas, causing habitat loss and affecting indigenous animals. Species occurring within an urban fragmented landscape must cope with changes in vegetation type as well as high degrees of anthropogenic disturbance, both of which are possible key mechanisms contributing to behavioural changes and perceived stressors. We attempted to elucidate the effects of urbanisation on the African lesser bushbaby, Galago moholi, by (1) recording activity budgets and body condition (body mass index, BMI) of individuals of urban and rural populations and (2) further determining adrenocortical activity in both populations as a measure of stress via faecal glucocorticoid metabolite (fGCM) levels, following successful validation of an appropriate enzyme immunoassay test system (adrenocorticotropic hormone (ACTH) challenge test). We found that both sexes of the urban population had significantly higher BMIs than their rural counterparts, while urban females had significantly higher fGCM concentrations than rural females. While individuals in the urban population fed mainly on provisioned anthropogenic food sources and spent comparatively more time resting and engaging in aggressive interactions, rural individuals fed almost exclusively on tree exudates and spent more time moving between food sources. Although interactions with humans are likely to be lower in nocturnal than in diurnal species, our findings show that the impact of urbanisation on nocturnal species is still considerable, affecting a range of ecological and physiological aspects.Deutsche Forschungsgemeinschaft (DFG; DA 1031/3-1/2) and the DST-NRF SarchI Chair of Mammal Behavioural Ecology and Physiology.http://link.springer.com/journal/1142016-10-31hb201
Spicing up the menu : evidence of fruit feeding in Galago moholi
The African lesser bushbaby, Galago moholi, is currently described as a food specialist, feeding
exclusively on small arthropods and gum primarily from Acacia karroo trees. We studied a
population of G. moholi in a highly-fragmented habitat in the southernmost part of its natural
distributional range in South Africa. In this habitat we opportunistically observed bushbabies
feeding on fruits of the winter fruiting tree, Pappea capensis. Plot counts of tree composition
revealed that although the dominant tree species in the area belonged to the genus Acacia, A.
karroo trees were widely absent and gum could only be found in small quantities on other Acacia
species. The analysis of P. capensis fruits showed high levels of protein, fat and energy content,
making the fruits a potentially important food source for G. moholi during winter when insect
availability is low. Our observation is the first documented case of fruit-feeding in G. moholi,
suggesting that the species is not a food specialist as previously reported, but can
opportunistically supplement its diet with fruit when available.Deutsche Forschungsgemeinschaft (DFG; DA 1031/3-1), the Department of
Research and Innovation (University of Pretoria) and the DST-NRF SarchI Chair of Mammal Behavioural Ecology and Physiology.http://link.springer.com/journal/10329hb201
Female reproductive activity and its endocrine correlates in the African lesser bushbaby, Galago moholi
Steroid hormones play an important role in
female reproductive physiology and behaviour and are
often used to monitor important female reproductive events.
However, such studies are often attempted on captive populations
alone, delivering limited data. One such example
is the African lesser bushbaby, Galago moholi, for which
contradicting observational data exist between captive and
free-ranging populations, while hormonal analyses have
only been obtained from a single captive population. To
extend and rectify the limited information, we monitored
faecal progestagen and oestrogen metabolite levels across
various important life history stages of both captive and
free-ranging G. moholi. We additionally recorded changes
in vaginal state as well as the occurrence of reproductive
and aggressive behaviour throughout the study. Data from
our captive population revealed an ovarian cycle length of
33.44 Ā± 0.59 days (mean Ā± SD), with follicular and luteal
phases of 14.2 Ā± 1.0 and 19.1 Ā± 1.5 days, respectively,
and an average pregnancy length of 128 Ā± 3.3 days. The initiation of female reproductive activity was closely linked
to an oestrus-related increase in faecal oestrogen metabolite
levels. Four of the seven captive females monitored in
our study conceived during the May mating period, with
one additional female fertilised in September, supporting
the idea that the September mating period functions as a
back-up for female G. moholi. Identified benchmark faecal
progestagen metabolite levels (non-pregnant: >1 Ī¼g/g dry
weight (DW), pregnant: >9 Ī¼g/g DW) should help researchers
to determine pregnancy status of randomly wild-caught
females in even a cross-sectional study setup.Deutsche Forschungsgemeinschaft (DFG; DA 1031/3-1/2) and the DST-NRF SarchI Chair of Mammal Behavioural Ecology and Physiology.http://link.springer.com/journal/3602017-02-28hb201
Comparative gastrointestinal morphology of three small mammalian insectivores : Acomys spinosissimus (Rodentia), Crocidura cyanea (Eulipotyphla), and Amblysomus hottentotus (Afrosoricida)
The gastrointestinal morphology was investigated in three mammalian insectivorous species, namely Acomys spinosissimus, Crocidura cyanea, and Amblysomus hottentotus. The aim of the study was to provide a comprehensive morphological comparison between the different species and to explore whether anatomical gastrointestinal adaptations are associated with the insectivorous diet of these species. The shape, proportional length, and proportional surface areas of the different gastrointestinal regions were recorded and compared in the three insectivores. Hematoxylin and Eosin (H&E) and Alcian Blue/Periodic Acid Schiff (AB/PAS) were used for morphological assessment. In all three species, the stomach was simple and uncompartmentalized. The internal aspect of the stomach in A. spinosissimus was hemi-glandular, containing stratified squamous epithelium in the fundus, with glandular epithelium in the body and pyloric region. However, C. cyanea and A. hottentotus had wholly glandular stomachs. Paneth cells were not observed in the intestinal tracts of C. cyanea and A. hottentotus. Acomys spinosissimus was the only species studied that had a cecum. The proximal colonic region of A. spinosissimus had V-shaped mucosal folds. Histologically, C. cyanea had villi throughout the entire gastrointestinal tract (GIT), whereas for A. hottentotus villi were not present in the most distal gastrointestinal regions. In both C. cyanea and A. hottentotus, longitudinal mucosal folds were present in the distal part of the colon. The GITs of C. cyanea and A. hottentotus showed little morphological differentiation namely, a simple, glandular stomach and the lack of a cecum.http://www.interscience.wiley.com/journal/35280/homehb201
Sometimes you have to take the person and show them how : adapting behavioral activation for peer recovery specialist-delivery to improve methadone treatment retention
BACKGROUND: Despite efficacy of medication for opioid use disorder, low-income, ethno-racial minoritized populations often experience poor opioid use disorder treatment outcomes. Peer recovery specialists, individuals with lived experience of substance use and recovery, are well-positioned to engage hard-to-reach patients in treatment for opioid use disorder. Traditionally, peer recovery specialists have focused on bridging to care rather than delivering interventions. This study builds on research in other low-resource contexts that has explored peer delivery of evidence-based interventions, such as behavioral activation, to expand access to care.
METHODS: We sought feedback on the feasibility and acceptability of a peer recovery specialist-delivered behavioral activation intervention supporting retention in methadone treatment by increasing positive reinforcement. We recruited patients and staff at a community-based methadone treatment center and peer recovery specialist working across Baltimore City, Maryland, USA. Semi-structured interviews and focus groups inquired about the feasibility and acceptability of behavioral activation, recommendations for adaptation, and acceptability of working with a peer alongside methadone treatment.
RESULTS: Participants (N = 32) shared that peer recovery specialist-delivered behavioral activation could be feasible and acceptable with adaptations. They described common challenges associated with unstructured time, for which behavioral activation could be particularly relevant. Participants provided examples of how a peer-delivered intervention could fit well in the context of methadone treatment, emphasizing the importance of flexibility and specific peer qualities.
CONCLUSIONS: Improving medication for opioid use disorder outcomes is a national priority that must be met with cost-effective, sustainable strategies to support individuals in treatment. Findings will guide adaptation of a peer recovery specialist-delivered behavioral activation intervention to improve methadone treatment retention for underserved, ethno-racial minoritized individuals living with opioid use disorder
Variation in the Neisseria lactamica porin, and its relationship to meningococcal PorB
One potential vaccine strategy in the fight against meningococcal disease involves the exploitation of outer-membrane components of Neisseria lactamica, a commensal bacterium closely related to the meningococcus, Neisseria meningitidis. Although N. lactamica shares many surface structures with the meningococcus, little is known about the antigenic diversity of this commensal bacterium or the antigenic relationships between N. lactamica and N. meningitidis. Here, the N. lactamica porin protein (Por) was examined and compared to the related PorB antigens of N. meningitidis, to investigate potential involvement in anti-meningococcal immunity. Relationships among porin sequences were determined using distance-based methods and FST, and maximum-likelihood analyses were used to compare the selection pressures acting on the encoded proteins. These analyses demonstrated that the N. lactamica porin was less diverse than meningococcal PorB and although it was subject to positive selection, this was not as strong as the positive selection pressures acting on the meningococcal porin. In addition, the N. lactamica porin gene sequences and the protein sequences of the loop regions predicted to be exposed to the human immune system were dissimilar to the corresponding sequences in the meningococcus. This suggests that N. lactamica Por, contrary to previous suggestions, may have limited involvement in the development of natural immunity to meningococcal disease and might not be effective as a meningococcal vaccine component
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