Christianity in the West and Africa: A Brief Comparison

A cognitive shift has occurred in recent centuries, a shift from understanding and experiencing reality in terms of spiritual forces to a rationality of functional instrumentality. In the West, this shift has largely peripheralised consciousness of spiritual forces. In Africa, by contrast, this is much less the case. Yet this shift seems an essential element of modernity. If Africa is to take its rightful place in the modern world and play its part in addressing the huge problems of modernity, Africa too will have to embrace this shift

Co-option of an endogenous retrovirus envelope for host defense in hominid ancestors

Endogenous retroviral sequences provide a molecular fossil record of ancient infections whose analysis might illuminate mechanisms of viral extinction. A close relative of gammaretroviruses, HERV-T, circulated in primates for ~25 million years (MY) before apparent extinction within the past ~8 MY. Construction of a near-complete catalog of HERV-T fossils in primate genomes allowed us to estimate a ~32 MY old ancestral sequence and reconstruct a functional envelope protein (ancHTenv) that could support infection of a pseudotyped modern gammaretrovirus. Using ancHTenv, we identify monocarboxylate transporter-1 (MCT-1) as a receptor used by HERV-T for attachment and infection. A single HERV-T provirus in hominid genomes includes an env gene (hsaHTenv) that has been uniquely preserved. This apparently exapted HERV-T env could not support virion infection but could block ancHTenv mediated infection, by causing MCT-1 depletion from cell surfaces. Thus, hsaHTenv may have contributed to HERV-T extinction, and could also potentially regulate cellular metabolism

Coyote (Canis latrans) use of marine resources in coastal California: A new behavior relative to their recent ancestors

Coyotes ( Canis latrans) are known to consume marine foods, but the importance and persistence of marine subsidies to coyotes is unknown. Recent access to a marine subsidy, especially if gained following apex predator loss, may facilitate coyote expansion along coastal routes and amplify the effects of mesopredator release. Our goal was to quantify and contextualize past and present marine resource use by coyotes on the central coast of California via stable isotope analysis. We measured δ13C and δ15N values in coyotes, their competitors, and their food resources at two modern sites, seven archaeological sites spanning in age from ~3000 to 750 BP, and from historical (AD 1893–1992) coyote and grizzly bear hair and bone sourced from coastal counties. We found evidence for marine resource use by modern coastal California coyotes at one site, Año Nuevo, which hosts a mainland northern elephant seal ( Mirounga angustirostris) breeding colony. Seals and sea lions account for ~20% of Año Nuevo coyote diet throughout the year and this marine subsidy likely positively impacts coyote population size. Isotopic data suggest that neither historic nor prehistoric coyotes consumed marine-derived foods, even at sites near ancient mainland seal rookeries. Marine resource use by some contemporary California coyotes is a novel behavior relative to their recent ancestors. We hypothesize that human alteration of the environment through extirpation of the California grizzly bear and the more recent protection of marine mammals likely enabled this behavioral shift

Corneal Thickness Changes in Hyperopic Orthokeratology Measured by Optical Pachometry

PURPOSE. To investigate the time course of corneal thickness changes in overnight hyperopic orthokeratology (OK) lens wear for a 4-day lens-wearing period. METHODS. Fourteen subjects (age range, 20 -37 years) were fitted with hyperopic OK lenses in one eye only. The fellow eye acted as a non-lens wearing control. Lenses were worn overnight only for 4 nights, and changes from baseline in subjective refraction, corneal topography, and corneal thickness (Holden-Payor optical pachometer) at central and paracentral locations were measured on days 1 and 4 after overnight lens wear, at lens removal (AM), and 8 hours after lens removal (PM). RESULTS. There was a significant refractive and corneal topographic effect at all visits. The central total cornea thickened significantly at AM visits only because of significant stromal thickening consistent with the overnight lens wearing edema response, and returned to baseline at PM visits once edema resolved. The para-central epithelium significantly thinned at all AM and PM visits. This counteracted para-central stromal thickening at AM and resulted in significant thinning of the total para-central cornea at PM visits when stromal thickness had returned to baseline. CONCLUSIONS. Para-central corneal epithelial thinning explains corneal anterior surface steepening in hyperopic OK and is sufficient to account for the lens-induced refractive response. Whereas corneal thickening is an additional factor reported in myopic OK, this was not the case in hyperopic OK. Constraint of corneal surface change mechanisms to para-central corneal epithelial thinning alone in hyperopic OK may explain the reduced refractive effect compared with myopic OK. (Invest Ophthalmol Vis Sci. 2011;52:3648 -3653) DOI:10.1167/ iovs.10-6323 O rthokeratology (OK) is a procedure by which rigid contact lenses temporarily alter corneal curvature with the intention to correct ametropia after lens removal. A number of studies have shown that myopic OK lenses flatten corneal curvature during wear and provide reliable refractive correction for up to Ϫ4.50D of myopia on lens removal. 1-4 More recently, it has been shown that hyperopic OK lenses steepen corneal curvature during lens wear. 5-9 However, the refractive effect with hyperopic OK lenses is less consistent beyond ϩ1.50D of targeted refractive change. 7 Previous studies have shown that changes to corneal thickness (assuming no change in curvature of the posterior corneal surface) can account for the refractive change induced by myopic OK lenses. 1,4 Swarbrick et al. 1 suggested that OK-induced corneal curvature change represents an anterior corneal phenomenon rather than an overall bending of the cornea. Hyperopic OK lenses are designed on principles similar to those of myopic OK lenses, so it is reasonable to hypothesize that changes in corneal curvature from hyperopic OK lenses could be equally limited to the anterior corneal surface. In a previous study conducted by our group, 7 we reported that the time course of refractive and corneal topographic change in hyperopic OK is analogous to that of myopic OK, at least in the first 7 nights of lens wear. We also reported no increase in central corneal thickness using ultrasonic pachometry once corneal edema from overnight wear had resolved during the day without lens wear, despite significant retention of refractive effect at the end of the day. This led to the suggestion that, in the absence of central corneal thickening, the para-central cornea might have thinned in hyperopic OK to allow for the corneal steepening. Two previous publications have reported on the profile of corneal thickness change after hyperopic OK; both used optical coherence tomography (OCT) to measure changes to total, stromal, and epithelial thickness induced by the Paragon corneal refractive therapy lens for hyperopia (CRT; Paragon Vision Sciences, Mesa, AZ). Lu et al. 10 measured the short-term response over up to 60 minutes of lens wear and found no significant change from baseline in central epithelial thickness but did find significant para-central epithelial thinning after 30 minutes of lens wear. However, when CRT lens wear was extended to 1 night in the closed eye, Haque et al. The purpose of the present study was to gain understanding of the change in the corneal thickness profile during hyperopic OK lens wear over a longer wearing period of 4 nights. In a previously published study

Analysis of control mechanism in a re-entrant manufacturing system

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1997, and Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1997.Includes bibliographical references (p. 67-68).by Paul Gifford.M.S

The medicine hat block and the early paleoproterozoic assembly of Western Laurentia

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. The accretion of the Wyoming, Hearne, and Superior Provinces to form the Archean core of western Laurentia occurred rapidly in the Paleoproterozoic. Missing from Hoffman’s (1988) original rapid aggregation model was the Medicine Hat block (MHB). The MHB is a structurally distinct, complex block of Precambrian crystalline crust located between the Archean Wyoming Craton and the Archean Hearne Province and overlain by an extensive Phanerozoic cover. It is distinguished on the basis of geophysical evidence and limited geochemical data from crustal xenoliths and drill core. New U‐Pb ages and Lu‐Hf data from zircons reveal protolith crystallization ages from 2.50 to 3.28 Ga, magmatism/metamorphism at 1.76 to 1.81 Ga, and εHfT values from −23.3 to 8.5 in the Archean and Proterozoic rocks of the MHB. These data suggest that the MHB played a pivotal role in the complex assembly of western Laurentia in the Paleoproterozoic as a conjugate or extension to the Montana Metasedimentary Terrane (MMT) of the northwestern Wyoming Province. This MMT–MHB connection likely existed in the Mesoarchean, but it was broken sometime during the earliest Paleoproterozoic with the formation and closure of a small ocean basin. Closure of the ocean led to formation of the Little Belt arc along the southern margin of the MHB beginning at approximately 1.9 Ga. The MHB and MMT re‐joined at this time as they amalgamated into the supercontinent Laurentia during the Great Falls orogeny (1.7–1.9 Ga), which formed the Great Falls tectonic zone (GFTZ). The GFTZ developed in the same timeframe as the better‐known Trans‐Hudson orogen to the east that marks the merger of the Wyoming, Hearne, and Superior Provinces, which along with the MHB, formed the Archean core of western Laurentia

Phylogenetic surveillance of viral genetic diversity and the evolving molecular epidemiology of human immunodeficiency virus type 1

With ongoing generation of viral genetic diversity and increasing levels of migration, the global human immunodeficiency virus type 1 (HIV-1) epidemic is becoming increasingly heterogeneous. In this study, we investigate the epidemiological characteristics of 5,675 HIV-1 pol gene sequences sampled from distinct infections in the United Kingdom. These sequences were phylogenetically analyzed in conjunction with 976 complete-genome and 3,201 pol gene reference sequences sampled globally and representing the broad range of HIV-1 genetic diversity, allowing us to estimate the probable geographic origins of the various strains present in the United Kingdom. A statistical analysis of phylogenetic clustering in this data set identified several independent transmission chains within the United Kingdom involving recently introduced strains and indicated that strains more commonly associated with infections acquired heterosexually in East Africa are spreading among men who have sex with men. Coalescent approaches were also used and indicated that the transmission chains that we identify originated in the late 1980s to early 1990s. Similar changes in the epidemiological structuring of HIV epidemics are likely to be taking in place in other industrialized nations with large immigrant populations. The framework implemented here takes advantage of the vast amount of routinely generated HIV-1 sequence data and can provide epidemiological insights not readily obtainable through standard surveillance methods