Short- and long-term evolution in our arms race with cancer: Why the war on cancer is winnable.

Human society is engaged in an arms race against cancer, which pits one evolutionary process-human cultural evolution as we develop novel cancer therapies-against another evolutionary process-the ability of oncogenic selection operating among cancer cells to select for lineages that are resistant to our therapies. Cancer cells have a powerful ability to evolve resistance over the short term, leading to patient relapse following an initial period of apparent treatment efficacy. However, we are the beneficiaries of a fundamental asymmetry in our arms race against cancer: Whereas our cultural evolution is a long-term and continuous process, resistance evolution in cancer cells operates only over the short term and is discontinuous - all resistance adaptations are lost each time a cancer patient dies. Thus, our cultural adaptations are permanent, whereas cancer's genetic adaptations are ephemeral. Consequently, over the long term, there is good reason to expect that we will emerge as the winners in our war against cancer

Code wars: steganography, signals intelligence, and terrorism

This paper describes and discusses the process of secret communication known as steganography. The argument advanced here is that terrorists are unlikely to be employing digital steganography to facilitate secret intra-group communication as has been claimed. This is because terrorist use of digital steganography is both technically and operationally implausible. The position adopted in this paper is that terrorists are likely to employ low-tech steganography such as semagrams and null ciphers instead

Sex-biased parental care and sexual size dimorphism in a provisioning arthropod

The diverse selection pressures driving the evolution of sexual size dimorphism (SSD) have long been debated. While the balance between fecundity selection and sexual selection has received much attention, explanations based on sex-specific ecology have proven harder to test. In ectotherms, females are typically larger than males, and this is frequently thought to be because size constrains female fecundity more than it constrains male mating success. However, SSD could additionally reflect maternal care strategies. Under this hypothesis, females are relatively larger where reproduction requires greater maximum maternal effort – for example where mothers transport heavy provisions to nests. To test this hypothesis we focussed on digger wasps (Hymenoptera: Ammophilini), a relatively homogeneous group in which only females provision offspring. In some species, a single large prey item, up to 10 times the mother’s weight, must be carried to each burrow on foot; other species provide many small prey, each flown individually to the nest. We found more pronounced female-biased SSD in species where females carry single, heavy prey. More generally, SSD was negatively correlated with numbers of prey provided per offspring. Females provisioning multiple small items had longer wings and thoraxes, probably because smaller prey are carried in flight. Despite much theorising, few empirical studies have tested how sex-biased parental care can affect SSD. Our study reveals that such costs can be associated with the evolution of dimorphism, and this should be investigated in other clades where parental care costs differ between sexes and species

Parasitoid developmental mortality in the field: patterns, causes and consequences for sex ratio and virginity

1. Sex ratio theory predicts that developmental mortality can affect sex ratio optima under Local Mate Competition and also lead to ‘virgin’ broods containing only females with no sibling-mating opportunities on maturity. 2. Estimates of developmental mortality and its sex ratio effects have been laboratory based, and both models and laboratory studies have treated mortality as a phenomenon without identifying its biological causes. 3. We contribute a large set of field data on Metaphycus luteolus Timberlake (Hymenoptera: Encyrtidae), an endoparasitoid of soft scale insects (Hemiptera: Coccidae), which has sex allocation conditional on host quality and female-biased brood sex ratios. Developmental mortality within broods can be both assessed and attributed to distinct causes, including encapsulation by the host and larval–larval competition. 4. Thirty per cent of M. luteolus offspring die during development with 65% of this mortality because of encapsulation and 28% because of larval competition. The distributions of mortality overall and for each cause of mortality separately were overdispersed. 5. The probability of an individual being encapsulated increased with clutch size, while the probability of being killed by a brood mate declined with increasing clutch size and with increasing per capita availability of resources. 6. The sexual compositions of broods at emergence were influenced by both the degree and the type of mortality operating. At higher levels of mortality, single sex broods were more common and sex ratios were less precise. Overall, virginity was more prevalent than predicted and was more greatly affected by the occurrence of competition than by other sources of mortality, almost certainly because competition tended to eliminate males. 7. The reproductive and developmental biology of M. luteolus appears to be influenced by a complex interplay of maternal clutch size and sex allocation strategies, offspring–offspring developmental interactions, host defence mechanisms and postemergence mating behaviour. Despite the great sophistication of sex ratio theory, it has not yet evolved to the point where it is capable of considering all of these influences simultaneously

Movimento dos Trabalhadores Rurais Sem Terra: Constructing Humanity

Neo-Marxist theory suggests that capitalist structures are dehumanizing and that alternative structures should be constructed to re-humanize the people. Movimento dos Trabalhadores Rurais Sem Terra (MST) constructs settlements of small, self-governing family farms as an alternative to the large agricultural estates that dominate Brazil. The settlements have transformed the way workers see themselves. They have successfully developed a humanizing alternative; MST members see themselves as subjects. It is important for Social Justice movements to understand how MST has achieved such powerful differences from Capitalist societies in order to replicate humanizing social structures. My study sought to understand how MST’s agricultural system cultivates humanity, human dignity, and subjectivity in its community. Assentamento Palmares, a MST settlement in Ceará, generously allowed me to pursue my research in their community. I interviewed 5 members of the settlement. I also participated in and recorded information about a regional MST meeting, a day of farm work, and a meeting of the settlement’s women’s group. In MST’s farming system, workers have direct control over food production, which humanizes the communities in many ways. They can secure their health and human dignity by farming nutritious food without pesticides and they own the products of their labor, so they are not alienated from it. Life at the settlement requires sharing and fighting together for everyone’s right to human dignity, so members to work together and help each other out, a collective consciousness that equalizes and humanizes. MST’s leadership draws from the farming-class/working-class members of the settlements; this alternative to Capitalist divisions of labor encourages its members to voice their political opinions and creative expressions. The community promotes the knowledge that workers have valuable thoughts and feelings; they are human beings. However, my time with the women’s group showed me that they are still fighting sexism in the settlement. Full humanization would require equal respect for women’s work, bodies, and voices

The 13C Suess Effect in Scleractinian Corals Mirror Changes in the Anthropogenic CO2 Inventory of the Surface Oceans

New δ13C data are presented from 10 coral skeletons collected from Florida and elsewhere in the Caribbean (Dominica, Dominican Republic, Puerto Rico, and Belize). These corals range from 96 to 200 years in age and were collected between 1976 and 2002. The change in the δ13C of the skeletons from these corals between 1900 and 1990 has been compared with 27 other published coral records from the Atlantic, Pacific, and Indian Oceans. The new data presented here make possible, for the first time, a global comparison of rates of change in the δ13C value of coral skeletons. Of these records, 64% show a statistically significant (p \u3c 0.05) decrease in δ13C towards the modern day (23 out of 37). This decrease is attributable to the addition of anthropogenically derived CO2 (13C Suess effect) to the atmosphere. Between 1900 and 1990, the average rate of change of the δ13C in all the coral skeletons living under open oceanic conditions is approximately −0.01‰ yr−1. In the Atlantic Ocean the magnitude of the decrease since 1960,−0.019 yr−1 ±0.015‰, is essentially the same as the decrease in the δ13C of atmospheric CO2 and the δ13C of the oceanic dissolved inorganic carbon (−0.023 to −0.029‰ yr−1), while in the Pacific and Indian Oceans the rate is more variable and significantly reduced (−0.007‰ yr−1 ±0.013). These data strongly support the notion that (i) the δ13C of the atmosphere controls ambient δ13C of the dissolved inorganic carbon which in turn is reflected in the coral skeletons, (ii) the rate of decline in the coral skeletons is higher in oceans with a greater anthropogenic CO2inventory in the surface oceans, (iii) the rate of δ13C decline is accelerating. Superimposed on these secular variations are controls on theδ13C in the skeleton governed by growth rate, insolation, and local water masses

Variation in beta-defensin expression in the control of Mycobacterium tuberculosis

Tuberculosis is a bacterial infection caused by Mycobacterium tuberculosis (Mtb) and remains a leading cause of death by an infectious agent worldwide. The intracellular survival and replication of Mtb within macrophages is a determinate of Mtb persistence and pathogenesis. Our understanding of the physiological mechanisms behind human macrophage restriction of Mtb remains limited. Beta-defensins are antimicrobial peptides proposed to mediate antimicrobial restriction of Mtb. I investigated their induction and cellular source in the tuberculin skin test (TST) as an in vivo human experimental challenge model. This model revealed striking inter-individual variation in expression of beta-defensins independent of interferon-gamma (IFNγ). To elucidate the causes of expression variation in TST RNA- sequencing data, genome-wide single nucleotide polymorphism array profiling, gene modules analysis, and typing of genetic copy number were used. These data attributed inter-individual variation in expression to both differences in genetic copy number and variation in cytokine signalling upstream of beta-defensins. Beta-defensins are expressed by epithelial and myeloid cells, but it was not known which cell types were producing beta-defensins in vivo during anti- Mtb immune responses. To address this knowledge gap, single cell RNA-sequencing (scRNA-seq) and spatial gene expression with RNAscope fluorescence in situ hybridisation (FISH) were employed, revealing inducible expression exclusively limited to epithelial cells. Publicly available scRNA-seq and assay for transposase-accessible chromatin using sequencing (ATAC-seq) data were interrogated to support conclusions. Whether beta-defensins represent a physiologically important mechanism of antimicrobial defence against Mtb required further study. Using a fluorescent Mtb-infection model, I quantified intracellular and extracellular Mtb growth in human monocyte-derived macrophage (MDM) culture by flow cytometry. I demonstrated variable production of beta-defensins by airway epithelial cells in vitro and found no effect of secreted beta-defensins on macrophage control of Mtb. Taken together these data suggest beta-defensins do not contribute towards antimicrobial restriction of Mtb early during infection in humans

Nothing More Real Than Nothing: The Unnamable as Self-Annihilating Fiction

Nature abhors nothing; it is the mind which cannot bear to live in a state of suspension, in absence, in a vacuum. The very existence of fiction testifies to man\u27s need for intricate models through which he may fashion and explore his life. In the last eighty years, a great deal of research has been devoted to discovering the ways in which fictions are structured; the ways, that is, in which literature replaces chaos not with content, but with form; with elaborate verbal webs that hold in abeyance the hollow of life without language. Russian formalism, mythcriticism like Northrop Frye\u27s, structuralism, poststructuralism and phenomenological analysis have clearly demonstrated the fact that literature is shaped by unconscious conventions on the levels of genre, plot and character, and in the deployment of multiple pairs of binary oppositions which create a kind of symbolic code within the work. Perhaps most significantly, theorists like Roland Barthes and Jonathan Culler have begun to make explicit the interpretive conventions which readers bring to a work and the ways in which these conventions influence their reading. Unlike most fictions, however, The Unnamable radically subverts many of these conventions, consequently invalidating the implicit narrative contracts signed between reader and author. Since its publication in 1953, The Unnamable has provoked hundreds of pages of comment; yet few English-speaking critics have thought closely about the specific ways in which the novel undermines narrative and linguistic conventions. Instead, The Unnamable has traditionally been treated either as Beckett\u27s bleak vision of the human condition, or as a reflection of his philosophic thought

Growth rates, stable oxygen isotopes (δ^18O), and strontium (Sr/Ca) composition in two species of Pacific sclerosponges (Acanthocheatetes wellsi and Astrosclera willeyana) with δ^18O calibration and application to paleoceanography

The isotopic and elemental composition of sclerosponge skeletons is used to reconstruct paleoceanographic records. Yet few studies have systematically examined the natural variability in sclerosponge skeletal δ^(18)O, growth, and Sr/Ca, and how that may influence the interpretation of sclerosponge proxy records. Here, we analyzed short records in seven specimens of Acanthocheatetes wellsi (high-Mg calcite, 21 mol% Mg) from Palau, four A. wellsi (high-Mg calcite, 21 mol% Mg) from Saipan, and three Astrosclera willeyana (aragonite) sclerosponges from Saipan, as well as one long record in an A. wellsi specimen from Palau spanning 1945–2001.5. In Saipan, species-specific and mineralogical effects appear to have a negligible effect on sclerosponge δ^(18)O, facilitating the direct comparison of δ^(18)O records between species at a given location. At both sites, A. wellsi δ^(18)O and growth rates were sensitive to environmental conditions, but Sr/Ca was not sensitive to the same conditions. High-resolution δ^(18)O analyses confirmed this finding as both A. wellsi and A. willeyana deposited their skeleton in accordance with the trends in isotopic equilibrium with seawater, though with a 0.27‰ offset in the case of A. willeyana. In the high-Mg-calcite species A. wellsi, Mg may be interfering with Sr incorporation into the skeleton. On multidecadal timescales, A. wellsi sclerosponge δ^(18)O in Palau tracked the Southern Oscillation Index variability post-1977, but not pre-1977, coincident with the switch in the Pacific Decadal Oscillation (PDO) at ~1976. This suggests that water mass circulation in the region is influenced by El Niño— Southern Oscillation variability during positive PDO phases, but not during negative ones