Black Holes in Modified Gravity (MOG)

The field equations for Scalar-Tensor-Vector-Gravity (STVG) or modified gravity (MOG) have a static, spherically symmetric black hole solution determined by the mass $M$ with two horizons. The strength of the gravitational constant is $G=G_N(1+\alpha)$ where $\alpha$ is a parameter. A regular singularity-free MOG solution is derived using a nonlinear field dynamics for the repulsive gravitational field component and a reasonable physical energy-momentum tensor. The Kruskal-Szekeres completion of the MOG black hole solution is obtained. The Kerr-MOG black hole solution is determined by the mass $M$, the parameter $\alpha$ and the spin angular momentum $J=Ma$. The equations of motion and the stability condition of a test particle orbiting the MOG black hole are derived, and the radius of the black hole photosphere and the shadows cast by the Schwarzschild-MOG and Kerr-MOG black holes are calculated. A traversable wormhole solution is constructed with a throat stabilized by the repulsive component of the gravitational field.Comment: 14 pages, 3 figures. Upgraded version of paper to match published version in European Physics Journal

The Status of Dosage Compensation in the Multiple X Chromosomes of the Platypus

Dosage compensation has been thought to be a ubiquitous property of sex chromosomes that are represented differently in males and females. The expression of most X-borne genes is equalized between XX females and XY males in therian mammals (marsupials and “placentals”) by inactivating one X chromosome in female somatic cells. However, compensation seems not to be strictly required to equalize the expression of most Z-borne genes between ZZ male and ZW female birds. Whether dosage compensation operates in the third mammal lineage, the egg-laying monotremes, is of considerable interest, since the platypus has a complex sex chromosome system in which five X and five Y chromosomes share considerable genetic homology with the chicken ZW sex chromosome pair, but not with therian XY chromosomes. The assignment of genes to four platypus X chromosomes allowed us to examine X dosage compensation in this unique species. Quantitative PCR showed a range of compensation, but SNP analysis of several X-borne genes showed that both alleles are transcribed in a heterozygous female. Transcription of 14 BACs representing 19 X-borne genes was examined by RNA-FISH in female and male fibroblasts. An autosomal control gene was expressed from both alleles in nearly all nuclei, and four pseudoautosomal BACs were usually expressed from both alleles in male as well as female nuclei, showing that their Y loci are active. However, nine X-specific BACs were usually transcribed from only one allele. This suggests that while some genes on the platypus X are not dosage compensated, other genes do show some form of compensation via stochastic transcriptional inhibition, perhaps representing an ancestral system that evolved to be more tightly controlled in placental mammals such as human and mouse

Fucking failures: The future of fat sex

In the context of the obesity ‘epidemic’ fat people’s sex lives are cast as sterile, sexually dysfunctional or just plain non-existent. This article analyzes medical discourses of obesity and sex in order to argue that fat sex is constructed as a type of failure. Using insights from antisocial queer theory, fat sex is further shown to be queer in its failure to adhere to the specifically heteronormative dictates of what Edelman (2004) calls ‘reproductive futurism’. The analysis finally engages with Halberstam’s (2011) notion of queer failure to demonstrate how deconstructing notions of success and failure might offer fat political projects new ways to imagine the future of fat sex

Karyotypic polymorphism of the zebra finch Z chromosome

We describe a karyotypic polymorphism on the zebra finch Z chromosome. This polymorphism was discovered because of a difference in the position of the centromere and because it occurs at varying frequencies in domesticated colonies in the USA and Germany and among two zebra finch subspecies. Using DNA fluorescent in situ hybridization to map specific Z genes and measurements of DNA replication, we show that this polymorphism is the result of a large pericentric inversion involving the majority of the chromosome. We sequenced a likely breakpoint for the inversion and found many repetitive sequences. Around the breakpoint, there are numerous repetitive sequences and several copies of PAK3 (p21-activated kinase 3)-related sequences (PAK3Z) which showed testes-specific expression by RT-PCR. Our findings further suggest that the sequenced genome of the zebra finch may be derived from a male heterozygote for the Z chromosome polymorphism. This finding, in combination with regional differences in the frequency of the polymorphism, has important consequences for future studies using zebra finches

Strict evolutionary conservation followed rapid gene loss on human and rhesus Y chromosomes

The human X and Y chromosomes evolved from an ordinary pair of autosomes during the past 200–300 million years[superscript 1, 2, 3]. The human MSY (male-specific region of Y chromosome) retains only three percent of the ancestral autosomes’ genes owing to genetic decay[superscript 4, 5]. This evolutionary decay was driven by a series of five ‘stratification’ events. Each event suppressed X–Y crossing over within a chromosome segment or ‘stratum’, incorporated that segment into the MSY and subjected its genes to the erosive forces that attend the absence of crossing over[superscript 2, 6]. The last of these events occurred 30 million years ago, 5 million years before the human and Old World monkey lineages diverged. Although speculation abounds regarding ongoing decay and looming extinction of the human Y chromosome[superscript 7, 8, 9, 10], remarkably little is known about how many MSY genes were lost in the human lineage in the 25 million years that have followed its separation from the Old World monkey lineage. To investigate this question, we sequenced the MSY of the rhesus macaque, an Old World monkey, and compared it to the human MSY. We discovered that during the last 25 million years MSY gene loss in the human lineage was limited to the youngest stratum (stratum 5), which comprises three percent of the human MSY. In the older strata, which collectively comprise the bulk of the human MSY, gene loss evidently ceased more than 25 million years ago. Likewise, the rhesus MSY has not lost any older genes (from strata 1–4) during the past 25 million years, despite its major structural differences to the human MSY. The rhesus MSY is simpler, with few amplified gene families or palindromes that might enable intrachromosomal recombination and repair. We present an empirical reconstruction of human MSY evolution in which each stratum transitioned from rapid, exponential loss of ancestral genes to strict conservation through purifying selection

Changes in the functional diversity of modern bird species over the last million years

Despite evidence of declining biosphere integrity, we currently lack understanding of how the functional diversity associated with changes in abundance among ecological communities has varied over time and before widespread human disturbances. We combine morphological, ecological, and life-history trait data for >260 extant bird species with genomic-based estimates of changing effective population size (Ne) to quantify demographic-based shifts in avian functional diversity over the past million years and under pre-anthropogenic climate warming. We show that functional diversity was relatively stable over this period, but underwent significant changes in some key areas of trait space due to changing species abundances. Our results suggest that patterns of population decline over the Pleistocene have been concentrated in particular regions of trait space associated with extreme reproductive strategies and low dispersal ability, consistent with an overall erosion of functional diversity. Further, species most sensitive to climate warming occupied a relatively narrow region of functional space, indicating that the largest potential population increases and decreases under climate change will occur among species with relatively similar trait sets. Overall, our results identify fluctuations in functional space of extant species over evolutionary timescales and represent the demographic-based vulnerability of different regions of functional space among these taxa. The integration of paleodemographic dynamics with functional trait data enhances our ability to quantify losses of biosphere integrity before anthropogenic disturbances and attribute contemporary biodiversity loss to different drivers over time

Exploring Protein-Protein Interactions as Drug Targets for Anti-cancer Therapy with In Silico Workflows

We describe a computational protocol to aid the design of small molecule and peptide drugs that target protein-protein interactions, particularly for anti-cancer therapy. To achieve this goal, we explore multiple strategies, including finding binding hot spots, incorporating chemical similarity and bioactivity data, and sampling similar binding sites from homologous protein complexes. We demonstrate how to combine existing interdisciplinary resources with examples of semi-automated workflows. Finally, we discuss several major problems, including the occurrence of drug-resistant mutations, drug promiscuity, and the design of dual-effect inhibitors.Fil: Goncearenco, Alexander. National Institutes of Health; Estados UnidosFil: Li, Minghui. Soochow University; China. National Institutes of Health; Estados UnidosFil: Simonetti, Franco Lucio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Shoemaker, Benjamin A. National Institutes of Health; Estados UnidosFil: Panchenko, Anna R. National Institutes of Health; Estados Unido

Knowledge of Malaria and Its Association with Malaria-Related Behaviors—Results from the Malaria Indicator Survey, Ethiopia, 2007

Background: In 2005, the Ministry of Health in Ethiopia launched a major effort to distribute over 20 million long-lasting insecticidal nets, provide universal access to artemisinin-based combination therapy (ACTs), and train 30,000 village-based health extension workers.\ud \ud Methods and Findings: A cross-sectional, nationally representative Malaria Indicator Survey was conducted during the malaria transmission season in 2007. Multivariate logistic regression analyses were performed to assess the effect of women's malaria knowledge on household ITN ownership and women's ITN use. In addition, we investigated the effect of mothers' malaria knowledge on their children under 5 years of age's (U5) ITN use and their access to fever treatment on behalf of their child U5. Malaria knowledge was based on a composite index about the causes, symptoms, danger signs and prevention of malaria. Approximately 67% of women (n = 5,949) and mothers of children U5 (n = 3,447) reported some knowledge of malaria. Women's knowledge of malaria was significantly associated with household ITN ownership (adjusted Odds Ratio [aOR] = 2.1; 95% confidence interval [CI] 1.6–2.7) and with increased ITN use for themselves (aOR = 1.8; 95% CI 1.3–2.5). Knowledge of malaria amongst mothers of children U5 was associated with ITN use for their children U5 (aOR = 1.6; 95% CI 1.1–2.4), but not significantly associated with their children U5 seeking care for a fever. School attendance was a significant factor in women's ITN use (aOR = 2.0; 95% CI 1.1–3.9), their children U5′s ITN use (aOR = 4.4; 95% CI 1.6–12.1), and their children U5 having sought treatment for a fever (aOR = 6.5; 95% CI 1.9–22.9).\ud \ud Conclusions: Along with mass free distribution of ITNs and universal access to ACTs, delivery of targeted malaria educational information to women could improve ITN ownership and use. Efforts to control malaria could be influenced by progress towards broader goals of improving access to education, especially for women

Artificial intelligence extension of the OSCAR-IB criteria

Artificial intelligence (AI)-based diagnostic algorithms have achieved ambitious aims through automated image pattern recognition. For neurological disorders, this includes neurodegeneration and inflammation. Scalable imaging technology for big data in neurology is optical coherence tomography (OCT). We highlight that OCT changes observed in the retina, as a window to the brain, are small, requiring rigorous quality control pipelines. There are existing tools for this purpose. Firstly, there are human-led validated consensus quality control criteria (OSCAR-IB) for OCT. Secondly, these criteria are embedded into OCT reporting guidelines (APOSTEL). The use of the described annotation of failed OCT scans advances machine learning. This is illustrated through the present review of the advantages and disadvantages of AI-based applications to OCT data. The neurological conditions reviewed here for the use of big data include Alzheimer disease, stroke, multiple sclerosis (MS), Parkinson disease, and epilepsy. It is noted that while big data is relevant for AI, ownership is complex. For this reason, we also reached out to involve representatives from patient organizations and the public domain in addition to clinical and research centers. The evidence reviewed can be grouped in a five-point expansion of the OSCAR-IB criteria to embrace AI (OSCAR-AI). The review concludes by specific recommendations on how this can be achieved practically and in compliance with existing guidelines