12,545 research outputs found

    Asymptotic Behavior of Colored Jones polynomial and Turaev-Viro Invariant of figure eight knot

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    In this paper we investigate the asymptotic behavior of the colored Jones polynomials and the Turaev-Viro invariants for the figure eight knot. More precisely, we consider the MM-th colored Jones polynomials evaluated at (N+1/2)(N+1/2)-th root of unity with a fixed limiting ratio, ss, of MM and (N+1/2)(N+1/2). We find out the asymptotic expansion formula (AEF) of the colored Jones polynomials of the figure eight knot with ss close to 11. Nonetheless, we show that the exponential growth rate of the colored Jones polynomials of the figure eight knot with ss close to 1/21/2 is strictly less than those with ss close to 11. It is known that the Turaev Viro invariant of the figure eight knot can be expressed in terms of a sum of its colored Jones polynomials. Our results show that this sum is asymptotically equal to the sum of the terms with ss close to 1. As an application of the asymptotic behavior of the colored Jones polynomials, we obtain the asymptotic expansion formula for the Turaev-Viro invariants of the figure eight knot. Finally, we suggest a possible generalization of our approach so as to relate the AEF for the colored Jones polynomials and the AEF for the Turaev-Viro invariants for general hyperbolic knots.Comment: 40 pages, 0 figure

    Assessment of food safety practices among cassava processors in selected rural communities of Oyo State, Nigeria

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    Food safety assessment is an effective means of discovering knowledge and data gaps that limit effective risk analysis and at the same time providing information to develop public policies on food safety management. The study assessed the cassava food safety practices among cassava processors in selected rural communities of Oyo State. Both qualitative and quantitative research designs were used to examine the following parameters: knowledge, attitude, sources of information and constraints to food safety practices. Focus Group Discussion, In-depth Interview, direct observation and interview schedule were the sources of primary data used. Multi-stage sampling technique was used to select one hundred and fifty-four (154) men and women involved in cassava processing from four Local Government Areas where there is concentration of cassava production and processing activities in the state, namely: Saki-West, Saki-East, Atisbo and Afijio. Data were analyzed using percentage, mean, Analysis of Variance and Chi square. The findings revealed that the mean income was N20,695, majority of the processors have low knowledge (71.4%) and unfavourable attitude (51.3%) towards cassava safety practices. Public sanitary officers (x̅ = 2.61) and fellow processors (x̅ = 2.11) were ranked as the most used sources of information about cassava safety practices. Constraints to food safety practices include: processing is time consuming, the cumbersome nature of the safety practices and inadequate access to clean water. Inferential analysis of results shows that income contributed significantly to the cassava food safety practices (p = 0.04) and safety practices do significantly differ among cassava processors across the selected cassava processors (p = 0.10). However, no significant relationship between sex (p = 0.42), age (p = 0.48), marital status (p = 0.67), educational level (p =0.53), processing experience (p = 0.92) and safety practices of the respondents. Training and effective monitoring by relevant stakeholders will further boost processors’ knowledge and attitudinal change towards food safety and ultimately safe food for the consumers.Keywords: Assessment, Food, Safety, Practices, Processors, Cassava, Rural, Communit

    An Anti-C1s Monoclonal, TNT003, Inhibits Complement Activation Induced by Antibodies Against HLA.

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    Antibody-mediated rejection (AMR) of solid organ transplants (SOT) is characterized by damage triggered by donor-specific antibodies (DSA) binding donor Class I and II HLA (HLA-I and HLA-II) expressed on endothelial cells. While F(ab')2 portions of DSA cause cellular activation and proliferation, Fc regions activate the classical complement cascade, resulting in complement deposition and leukocyte recruitment, both hallmark features of AMR. We characterized the ability of an anti-C1s monoclonal antibody, TNT003, to inhibit HLA antibody (HLA-Ab)-induced complement activation. Complement deposition induced by HLA-Ab was evaluated using novel cell- and bead-based assays. Human aortic endothelial cells (HAEC) were cultured with HLA-Ab and human complement; production of activated complement proteins was measured by flow cytometry. Additionally, C3d deposition was measured on single antigen beads (SAB) mixed with HLA-Ab and human complement. TNT003 inhibited HLA-Ab mediated complement deposition on HAEC in a concentration-dependent manner; C3a, C4a and C5a anaphylatoxin production was also diminished by TNT003. Finally, TNT003 blocked C3d deposition induced by Class I (HLAI-Ab)- and Class II (HLAII-Ab)-specific antibodies on SAB. These data suggest TNT003 may be useful for modulating the effects of DSA, as TNT003 inhibits complement deposition and split product formation generated by HLA-I/II-Ab in vitro

    First demonstration of effective spatial training for near-transfer to spatial performance and far-transfer to a range of mathematics skills at 8 years

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    There is evidence that spatial thinking is malleable, and that spatial and mathematical skills are associated (Mix et al. [2016] Journal of Experimental Psychology: General, 145, 1206; Mix et al. [2017] Journal of Cognition and Development, 18, 465; Uttal et al. [2013] Psychological Bulletin, 139, 352). However, few studies have investigated transfer of spatial training gains to mathematics outcomes in children, and no known studies have compared different modes of spatial instruction (explicit vs. implicit instruction). Based on a sample of 250 participants, this study compared the effectiveness of explicit and implicit spatial instruction in eliciting near transfer (to the specific spatial skills trained), intermediate transfer (to untrained spatial skills) and far transfer (to mathematics domains) at age 8. Spatial scaling and mental rotation skills were chosen as training targets as previous studies have found, and proposed explanations for, associations between these skills and mathematics in children of this age (Journal of Experimental Psychology: General, 145, 2016 and 1206). In this study, spatial training led to near, intermediate and far transfer of gains. Mental visualization and proportional reasoning were proposed to explain far transfer from mental rotation and spatial scaling skills respectively. For most outcomes, except for geometry, there was no difference in the effectiveness of implicit (practice with feedback) compared to explicit instruction (instructional videos). From a theoretical perspective, the study identified a specific causal effect of spatial skills on mathematics skills in children. Practically, the results also highlight the potential of instructional videos as a method of introducing spatial thinking into the classroom

    Magnetic resonance angiography signal intensity as a marker of hemodynamic impairment in intracranial arterial stenosis.

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    BackgroundIntracranial arterial stenosis (ICAS) is the predominant cause of ischemic stroke and transient ischemic attack in Asia. Change of signal intensities (SI) across an ICAS on magnetic resonance angiography (MRA) may reflect its hemodynamic severity.MethodsIn-patients with a symptomatic single ICAS detected on 3D time-of-flight MRA were recruited from 2 hospitals. Baseline and 1-year follow-up data were collected. Signal intensity ratio (SIR) [ =  (mean post-stenotic SI -mean background SI)/(mean pre-stenotic SI - mean background SI)] was evaluated on baseline MRA to represent change of SIs across an ICAS. Acute infarct volume was measured on baseline diffusion-weighted images (DWI). Relationships between SIR and baseline characteristics as well as 1y outcomes were evaluated.ResultsThirty-six subjects (86.1% males, mean age 55.0) were recruited. Overall, mean SIR was 0.84±0.23. Mean SIRs were not significantly different between the 23 (63.9%) anatomically severe stenoses and the 13 (36.1%) anatomically moderate stenoses (0.80±0.23 versus 0.92±0.21, p = 0.126). SIR was significantly, linearly and negatively correlated to acute infarct volume on DWI (Spearman correlation coefficient -0.471, p = 0.011). Two patients (5.6%) had recurrent ischemic strokes at 1y, not related to SIR values.ConclusionsChange of signal intensities across an ICAS on MRA may reflect its hemodynamic and functional severity. Future studies are warranted to further verify the relationships between this index and prognosis of patients with symptomatic ICAS

    The global warming hiatus: Slowdown or redistribution?

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    Global mean surface temperatures (GMST) exhibited a smaller rate of warming during 1998-2013, compared to the warming in the latter half of the 20th Century. Although, not a "true" hiatus in the strict definition of the word, this has been termed the "global warming hiatus" by IPCC (2013). There have been other periods that have also been defined as the "hiatus" depending on the analysis. There are a number of uncertainties and knowledge gaps regarding the "hiatus." This report reviews these issues and also posits insights from a collective set of diverse information that helps us understand what we do and do not know. One salient insight is that the GMST phenomenon is a surface characteristic that does not represent a slowdown in warming of the climate system but rather is an energy redistribution within the oceans. Improved understanding of the ocean distribution and redistribution of heat will help better monitor Earth's energy budget and its consequences. A review of recent scientific publications on the "hiatus" shows the difficulty and complexities in pinpointing the oceanic sink of the "missing heat" from the atmosphere and the upper layer of the oceans, which defines the "hiatus." Advances in "hiatus" research and outlooks (recommendations) are given in this report
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