Bioassay Analysis Using R

We describe an add-on package for the language and environment R which allows simultaneous fitting of several non-linear regression models. The focus is on analysis of dose response curves, but the functionality is applicable to arbitrary non-linear regression models. Features of the package is illustrated in examples.

(Re)Examining the African Diaspora and Christianity

Only recently has Africana studies broken through the ceiling of the academic basement and garnered the attention deserved. “(Re)Examining the African Diaspora and Christianity”, rejects Occidental understandings and interpretations of African Traditional Religions (ATRs). For example, the “fact” ATR’s are polytheistic. The paper begins by setting the general context and events of the African Diaspora and Euro-Christian colonization efforts. Next, I focus in on the West African Yoruba tradition to demonstrate how and why ATRs have been able to remain vibrant even after 500 years of displacement. Then, I put to task the common academic notions of syncretism in order to determine if any such relationship exists between ATRs and Christianity. Following the discussion, I explore the Catholic colonies and Protestant colonies for permissive or restrictive environments and the impact on ATRs. I close the paper by briefly addressing the modern impacts and discussion of reparations

Planogram Compliance Checking Based on Detection of Recurring Patterns

In this paper, a novel method for automatic planogram compliance checking in retail chains is proposed without requiring product template images for training. Product layout is extracted from an input image by means of unsupervised recurring pattern detection and matched via graph matching with the expected product layout specified by a planogram to measure the level of compliance. A divide and conquer strategy is employed to improve the speed. Specifically, the input image is divided into several regions based on the planogram. Recurring patterns are detected in each region respectively and then merged together to estimate the product layout. Experimental results on real data have verified the efficacy of the proposed method. Compared with a template-based method, higher accuracies are achieved by the proposed method over a wide range of products.Comment: Accepted by MM (IEEE Multimedia Magazine) 201

Northern peripheries

Guest editors' introductio

Assessing consumer acceptance and willingness to pay for novel value-added products made from breadfruit in the Hawaiian Islands

Breadfruit is a high yielding tree crop with a long history in the Pacific Islands, with the potential to improve food security under climate change. Traditionally, it has been grown and used extensively as a food source in Hawaii, but in the past decades, it has been neglected, underutilized, and supplanted by imported staple foods. Revitalization of breadfruit is central for reducing dependency on food imports and increasing food resiliency and self-sufficiency in Hawaii. Such a process could potentially be strengthened by the development of novel value-added products. This empirical study investigates consumer acceptance and willingness to pay in two scenarios: with and without detailed product information about breadfruit and its cultural significance, nutritional benefits and potential contribution to increase local food security. A total of 440 consumers participated in the study. Participants receiving descriptive information had a higher level of acceptance and were willing to pay a higher price compared with participants who were not informed that the product was made from breadfruit: 1.33 ± 0.15 acceptance on the hedonic scale and 1.26 ± 0.23 USD (both p < 0.0001). In conclusion, repeated exposure and building a positive narrative around breadfruit products may increase consumer acceptability

Search for gamma-ray emission from pp-wave dark matter annihilation in the Galactic Center

Indirect searches for dark matter through Standard Model products of its annihilation generally assume a cross-section which is dominated by a term independent of velocity ($s$-wave annihilation). However, in many DM models an $s$-wave annihilation cross-section is absent or helicity suppressed. To reproduce the correct DM relic density in these models, the leading term in the cross section is proportional to the DM velocity squared ($p$-wave annihilation). Indirect detection of such $p$-wave DM is difficult because the average velocities of DM in galaxies today are orders of magnitude slower than the DM velocity at the time of decoupling from the primordial thermal plasma, suppressing the annihilation cross-section today by some five orders of magnitude relative to its value at freeze out. Thus $p$-wave DM is out of reach of traditional searches for DM annihilations in the Galactic halo. Near the region of influence of a central supermassive black hole, such as Sgr A$^*$, however, DM can form a localized over-density known as a `spike'. In such spikes the DM is predicted to be both concentrated in space and accelerated to higher velocities, allowing the $\gamma$-ray signature from its annihilation to potentially be detectable above the background. We use the $Fermi$ Large Area Telescope to search for the $\gamma$-ray signature of $p$-wave annihilating DM from a spike around Sgr A$^*$ in the energy range 10 GeV-600 GeV. Such a signal would appear as a point source and would have a sharp line or box-like spectral features difficult to mimic with standard astrophysical processes, indicating a DM origin. We find no significant excess of $\gamma$ rays in this range, and we place upper limits on the flux in $\gamma$-ray boxes originating from the Galactic Center. This result, the first of its kind, is interpreted in the context of different models of the DM density near Sgr A$^*$.Comment: 16 pages, 7 figure

Individual participant data (IPD)-level meta-analysis of randomised controlled trials among dark-skinned populations to estimate the dietary requirement for vitamin D

Estimation of the dietary requirements for vitamin D is crucial from a public health perspective in providing a framework for the prevention of vitamin D deficiency. It has been shown that pooling individual participant-level data (IPD) from selected randomised controlled trials (RCTs) of white children and adults facilitated the generation of more accurate estimates of the vitamin D requirement. Recent RCT data suggest the vitamin D requirement of dark-skinned, particularly black, individuals, an at-risk group of vitamin D deficiency, is greater than those of white counterparts. Thus, we wished to develop a study protocol for the conduct of an IPD-level meta-analysis of vitamin D requirements using data from appropriate vitamin D RCTs in dark-skinned population subgroups

Simultaneous comparisons of treatments at multiple time points: combined marginal models versus joint modeling

We discuss several aspects of multiple inference in longitudinal settings, focusing on many-to-one and all-pairwise comparisons of (a) treatment groups simultaneously at several points in time, or (b) time points simultaneously for several treatments. We assume a continuous endpoint that is measured repeatedly over time and contrast two basic modeling strategies: fitting a joint model across all occasions (with random effects and/or some residual covariance structure to account for heteroscedasticity and serial dependence), and a novel approach combining a set of simple marginal, i.e. occasion-specific models. Upon parameter and covariance estimation with either modeling approach, we employ a variant of multiple contrast tests that acknowledges correlation between time points and test statistics. This method provides simultaneous confidence intervals and adjusted p-values for elementary hypotheses as well as a global test decision. We compare via simulation the powers of multiple contrast tests based on a joint model and multiple marginal models, respectively, and quantify the benefit of incorporating longitudinal correlation, i.e. the advantage over Bonferroni. Practical application is illustrated with data from a clinical trial on bradykinin receptor antagonism

Time delay estimation of reverberant meeting speech: on the use of multichannel linear prediction

Effective and efficient access to multiparty meeting recordings requires techniques for meeting analysis and indexing. Since meeting participants are generally stationary, speaker location information may be used to identify meeting events e.g., detect speaker changes. Time-delay estimation (TDE) utilizing cross-correlation of multichannel speech recordings is a common approach for deriving speech source location information. Research improved TDE by calculating TDE from linear prediction (LP) residual signals obtained from LP analysis on each individual speech channel. This paper investigates the use of LP residuals for speech TDE, where the residuals are obtained from jointly modeling the multiple speech channels. Experiments conducted with a simulated reverberant room and real room recordings show that jointly modeled LP better predicts the LP coefficients, compared to LP applied to individual channels. Both the individually and jointly modeled LP exhibit similar TDE performance, and outperform TDE on the speech alone, especially with the real recordings