Cryptosporidium and Giardia in Livestock in Tigray, Northern Ethiopia and Associated Risk Factors for Infection: A Cross-Sectional Study

The occurrence and species/genotypes of Cryptosporidium and Giardia duodenalis infecting young livestock in selected districts of Tigray, Ethiopia were investigated, along with risks associated with infection. A total of 757 faecal samples were collected from calves, lambs, and goat kids from four rural districts in Tigray, and also from calves in periurban Mekelle, Tigray's main city, and analysed for Cryptosporidium oocysts and Giardia cysts. Farmers answered questionnaires regarding potential risk factors at sample collection. Immunofluorescent antibody staining was used for parasite detection, and PCR at selected genes and sequencing of positive samples was used for molecular characterisation. The occurrence of Cryptosporidium infection was 10, 9, and 4% in calves, lambs, and goat kids, respectively; equivalent figures for Giardia infection were 39, 32, and 21%. Molecular characterisation of Cryptosporidium isolates revealed C. ubiquitum, subtype XIIa in all three host species; C. ryanae in calves and goat kids; C. andersoni and C. bovis were identified only in calves, and C. xiaoi was identified in lambs. For Giardia, Assemblage E predominated in all host species, but among calf isolates we also identified a few potentially zoonotic genotypes (assemblages A (AI) and Assemblage B). Periparturient care was shown to be a particularly relevant risk factor for infection, and infections were less likely to occur under extensive management systems. Our major findings were widespread occurrence of both parasites in livestock, and the apparent lack of the most common zoonotic species. Our results are discussed in relation to other relevant studies. As our study was conducted in Tigray, further investigation in different settings in Ethiopia could provide relevant information on transmission and zoonotic potential. In addition, given the dependency on healthy animals for the livelihoods of the population of Tigray, investigation of the effect of these common parasites on livestock productivity is important.

Antigenic evolution of SARS-CoV-2 in immunocompromised hosts

The apparent lack of antigenic evolution by the Delta variant (B.1.617.2) of SARS-CoV-2 during the COVID-19 pandemic is puzzling. The combination of increasing immune pressure due to the rollout of vaccines and a relatively high number of infections following the relaxation of non-pharmaceutical interventions should have created perfect conditions for immune escape variants to evolve from the Delta lineage. Instead, the Omicron variant (B.1.1.529), which is hypothesised to have evolved in an immunocompromised individual, is the first major variant to exhibit significant immune escape following vaccination programmes and is set to become globally dominant in 2022. Here, we use a simple mathematical model to explore possible reasons why the Delta lineage did not exhibit antigenic evolution and to understand how and when immunocompromised individuals affect the emergence of immune escape variants. We show that when the pathogen does not have to cross a fitness valley for immune escape to occur, immunocompromised individuals have no qualitative effect on antigenic evolution (although they may accelerate immune escape if within-host evolutionary dynamics are faster in immunocompromised individuals). But if a fitness valley exists between immune escape variants at the between-host level, then persistent infections of immunocompromised individuals allow mutations to accumulate, therefore facilitating rather than simply speeding up antigenic evolution. Our results suggest that better global health equality, including improving access to vaccines and treatments for individuals who are immunocompromised (especially in lower- and middle-income countries), may be crucial to preventing the emergence of future immune escape variants of SARS-CoV-2.

How Much Do We Value Future Generations? Climate Change, Debt, and Attitudes towards Policies for Improving Future Lives

Do people care much about future generations? Moral philosophers argue that we should, but it is not clear that laypeople agree. Humanity’s thus-far inadequate efforts to address climate change, for example, could be taken as a sign that people are unconcerned about the well-being of future generations. An alternative explanation is that the lack of action is due to public scepticism about climate policies’ effectiveness, rather than the discounting of future lives per se. Based on surveys and survey experiments with representative samples of respondents in four countries—Sweden, Spain, South Korea, and China—we find that most people say they care about future generations, and would even be willing to reduce their standard of living so that people can enjoy better lives in the future. Many do not, however, support policies for reducing either global warming or the national debt—both of which would impose a net cost on current generations for the benefit of future generations. We show that a significant part of the public’s apparent lack of concern for future generations is actually due to disbelief or distrust in the likely benefits of government actions.

Differential Effects of Acute and Chronic Antagonist And An Irreversible Antagonist Treatment On Cocaine Self-Administration Behavior in Rats

According to pharmacological theory, the magnitude of an agonist-induced response is related to the number of receptors occupied. If there is a receptor reserve, when the number of receptors is altered the fractional occupancy required to maintain this set number of receptors will change. Therefore, any change in dopamine receptor number will result in a change in the concentration of cocaine required to induce the satiety response. Rats that self-administered cocaine were treated with the irreversible monoamine receptor antagonist, EEDQ, or were infused continuously for 14 days with the D1-like antagonist, SCH23390, treatments known to decrease or increase, respectively, the number of dopamine receptors with a concomitant decrease or increase in response to dopaminergic agonists. The rate of maintained cocaine self-administration increased or decreased in rats treated with EEDQ or withdrawn from chronic SCH23390 infusion, respectively. After EEDQ treatment, the effect ratio of a single dose of SCH23390 or eticlopride were unchanged, indicating that the same dopamine receptor populations mediated the accelerated cocaine self-administration. The satiety threshold likely corresponds to a specific number of activated dopamine receptors. Changing the receptor reserve is a key determinant of the rate of cocaine self-administration because the resulting increased or decreased concentration of cocaine results in an accelerated or decelerated rate of cocaine elimination as dictated by first-order kinetics. Changes in dopamine receptor number that may occur after continuous treatment with antagonists may account for the apparent lack of efficacy of these antagonists in clinical trials for cocaine use disorder.

Resetting of the 24-nt siRNA landscape in rice zygotes

The zygote, a totipotent stem cell, is crucial to the life cycle of sexually reproducing organisms. It is produced by the fusion of two differentiated cells - the egg and sperm, which in plants have radically different siRNA transcriptomes from each other, and from multicellular embryos. Due to technical challenges, the epigenetic changes that accompany the transition from differentiated gametes to totipotent zygote are poorly understood. Since siRNAs serve as both regulators and outputs of the epigenome, we performed here the successful characterization of small RNA transcriptomes of zygotes from rice. Zygote small RNAs exhibited extensive maternal carryover and an apparent lack of paternal contribution, indicated by absence of sperm signature siRNAs. Zygote formation was accompanied by widespread redistribution of 24-nt siRNAs relative to gametes, such that ~70% of the zygote siRNA loci did not overlap any egg cell siRNA loci. Newly-detected siRNA loci in zygote are gene proximal and not associated with centromeric heterochromatin, similar to canonical siRNAs, in sharp contrast to gametic siRNA loci which are gene-distal and heterochromatic. In addition, zygote but not egg siRNA loci were associated with high DNA methylation in the mature embryo. Thus, the zygote begins transitioning before the first embryonic division to an siRNA profile that is associated with future RdDM in embryogenesis. These findings indicate that in addition to changes in gene expression, the transition to totipotency in the plant zygote is accompanied by resetting of the epigenetic reprogramming that occurred during gamete formation.

Propagation paths and source distributions of resolved gravity waves in ECMWF-IFS analysis fields around the southern polar night jet

In the southern winter polar stratosphere, the distribution of gravity wave momentum flux in many state-of-the-art climate simulations is inconsistent with long-time satellite and superpressure balloon observations around 60∘ S. Recent studies hint that a lateral shift between prominent gravity wave sources in the tropospheric mid-latitudes and the location where gravity wave activity is present in the stratosphere causes at least part of the discrepancy. This lateral shift cannot be represented by the column-based gravity wave drag parameterisations used in most general circulation models. However, recent high-resolution analysis and re-analysis products of the European Centre for Medium-Range Weather Forecasts Integrated Forecast System (ECMWF-IFS) show good agreement with the observations and allow for a detailed investigation of resolved gravity waves, their sources, and propagation paths. In this paper, we identify resolved gravity waves in the ECMWF-IFS analyses for a case of high gravity wave activity in the lower stratosphere using small-volume sinusoidal fits to characterise these gravity waves. The 3D wave vector together with perturbation amplitudes, wave frequency, and a fully described background atmosphere are then used to initialise the Gravity Wave Regional or Global Ray Tracer (GROGRAT) gravity wave ray tracer and follow the gravity waves backwards from the stratosphere. Finally, we check for the indication of source processes on the path of each ray and, thus, quantitatively attribute gravity waves to sources that are represented within the model. We find that stratospheric gravity waves are indeed subject to far (>1000 km) lateral displacement from their sources, which already take place at low altitudes (<20 km). Various source processes can be linked to waves within stratospheric gravity wave (GW) patterns, such as the orography equatorward of 50∘ S and non-orographic sources above the Southern Ocean. These findings may explain why superpressure balloons observe enhanced gravity wave momentum fluxes in the lower stratosphere over the Southern Ocean despite an apparent lack of sources at this latitude. Our results also support the need to improve gravity wave parameterisations to account for meridional propagation.

Cancer risk across mammals

Cancer is a ubiquitous disease of metazoans, predicted to disproportionately affect larger, long-lived organisms owing to their greater number of cell divisions, and thus increased probability of somatic mutations1,2. While elevated cancer risk with larger body size and/or longevity has been documented within species3–5, Peto’s paradox indicates the apparent lack of such an association among taxa6. Yet, unequivocal empirical evidence for Peto’s paradox is lacking, stemming from the difficulty of estimating cancer risk in non-model species. Here we build and analyse a database on cancer-related mortality using data on adult zoo mammals (110,148 individuals, 191 species) and map age-controlled cancer mortality to the mammalian tree of life. We demonstrate the universality and high frequency of oncogenic phenomena in mammals and reveal substantial differences in cancer mortality across major mammalian orders. We show that the phylogenetic distribution of cancer mortality is associated with diet, with carnivorous mammals (especially mammal-consuming ones) facing the highest cancer-related mortality. Moreover, we provide unequivocal evidence for the body size and longevity components of Peto’s paradox by showing that cancer mortality risk is largely independent of both body mass and adult life expectancy across species. These results highlight the key role of life-history evolution in shaping cancer resistance and provide major advancements in the quest for natural anticancer defences.

A Review of Isaac Oluwole Delano’s Pioneering Works on Yoruba Grammar, Orthography, Lexicography and Cultural Education.

Tis is a reproduction and an improved version of our opening chapter on Selected Works of Chief Isaac O. Delano on Yoruba Language. In it, we reintroduce the seminal works of the legendary writer and language educator, I. O. Delano. Many of these works have become obscure to the reading public due to an apparent lack of intentional publication. Delano, known for his prolific writings, wrote a few books relating to Yoruba language and grammar. Tis segment looks at four major non-fiction works of Chief Isaac O. Delano. For the most part, the segment deals with his efforts on Yoruba language, but to some extent, too, it looks at some additional non-language related writings often embedded in his works on language. For example, in Appendix I of his 1965 book, A Modern Yoruba Grammar, the author provides an array of proverbs and sayings in the language with their English equivalents. In Appendix II, Delano infused two old texts into the book, which comprise of a sermon and an essay on schooling. Clearly, Delano seems to have a penchant for dissemination of relevant cultural education in all his works. Indeed, one could say Yoruba Cultural education has always been apparently one of Delano’s passions as well as hidden agenda in writing his books, and he does so relentlessly. In what follows, we 216 Toyin Falola and Michael Oladejo Afolayan examine the four works in no particular order, although the Modern Grammar is given a relatively more detailed review and summarization. The four books are: A Modern Yoruba Grammar; Àgbékà Ọr̀ ọ̀ Yorùbá: Appropriate Words and Expressions in Yoruba; Conversation in Yoruba and English; and Atúmọ̀Èdè Yorùbá.

Disentangling the contributions of orographic waves, boundary-layer coupling, and aerosol to the occurrence of ice in mixed-phase clouds

&lt;p&gt;We will present a study on the impacts of orographic waves, surface coupling, and aerosol load on the frequency of heterogeneous ice formation in stratiform clouds using ground-based remote-sensing observations. Disentangling the convoluted effects of vertical motions and aerosols is critical for the understanding of heterogeneous ice formation and requires comprehensive observations. For the study, multi-year datasets from Punta Arenas (53.1&amp;#176;S 70.9&amp;#176;W, Chile, &gt;2 years) and the northern hemispheric sites of Leipzig (51.4&amp;#176;N 12.4&amp;#176;E, Germany, 2.6 years) and Limassol (34.7&amp;#176;N 33.0&amp;#176;E, Cyprus, 1.5 years) were obtained by the same set of ground-based instruments (35-GHz cloud radar, Raman polarization lidar, 14-channel microwave radiometer, Doppler lidar, and disdrometer). The datasets at Limassol and Punta Arenas resemble the first multi-year ground-based remote-sensing datasets in the Eastern Mediterranean and in the western part of the Southern Ocean, respectively.&lt;/p&gt; &lt;p&gt;The cloud properties were extracted from the synergistic dataset and the following key results on the efficiency of heterogeneous ice formation emerged:&lt;br /&gt;The apparent lack of ice forming clouds at Punta Arenas below -15 &lt;strong&gt;&amp;#176;&lt;/strong&gt;C can be related to orographic gravity waves, which allow persistent liquid saturation. These clouds could be identified by the autocorrelation function of the in-cloud vertical air velocity. Additionally, a correlation between the surface-coupling of a cloud and the likelihood of ice formation was found for Punta Arenas and Leipzig. At T&gt;-10&amp;#176;C clouds coupled to the aerosol-rich boundary layer, were found to contain ice more frequently. Taking both effects into account, free-tropospheric, fully turbulent clouds at Punta Arenas form ice less frequently than their northern-hemispheric counterparts. This difference is linked to the lower abundance of INP in the free troposphere over the Southern Ocean.&lt;/p&gt;

Coloniality, Epistemic Imbalance, and Africa’s Emigration Crisis

The paper has two complementary objectives. First, it sustains an analysis of the concept of ‘coloniality’ that accounts for the epistemic imbalance in the modern world, demonstrating precisely how Africa is adversely affected, having been caught up in the throes of coloniality and its epistemic implications. Second – and complementarily – the paper attempts to bring this very concept of ‘coloniality’ into the discourse on Africa’s emigration crisis, arguing that Africa’s emigration crisis is traceable, inter alia, to the epistemic imbalance in the very structure of modernity. This imbalance results from the stifling of Africa’s epistemic resources under Western epistemic hegemony. Epistemic coloniality, of course interacting with some material factors, creates a sufficient condition for emigration. It is further theorized that the apparent lack of epistemic will on the part of Africans to mobilize some surviving epistemic resources to address some problems on their own is also a function of coloniality.