Heating of galactic gas by dark matter annihilation in ultracompact minihalos

The existence of substructure in halos of annihilating dark matter would be expected to substantially boost the rate at which annihilation occurs. Ultracompact minihalos of dark matter (UCMHs) are one of the more extreme examples of this. The boosted annihilation can inject significant amounts of energy into the gas of a galaxy over its lifetime. Here we determine the impact of the boost factor from UCMH substructure on the heating of galactic gas in a Milky Way-type galaxy, by means of N-body simulation. If $1\%$ of the dark matter exists as UCMHs, the corresponding boost factor can be of order $10^5$. For reasonable values of the relevant parameters (annihilation cross section $3\times10^{-26} ~\textrm{cm}^3~ \textrm{s}^{-1}$, dark matter mass 100 GeV, 10% heating efficiency), we show that the presence of UCMHs at the 0.1% level would inject enough energy to eject significant amounts of gas from the halo, potentially preventing star formation within $\sim$1 kpc of the halo centre.Comment: 14 pages, 3 figure

TCP throughput guarantee in the DiffServ Assured Forwarding service: what about the results?

Since the proposition of Quality of Service architectures by the IETF, the interaction between TCP and the QoS services has been intensively studied. This paper proposes to look forward to the results obtained in terms of TCP throughput guarantee in the DiffServ Assured Forwarding (DiffServ/AF) service and to present an overview of the different proposals to solve the problem. It has been demonstrated that the standardized IETF DiffServ conditioners such as the token bucket color marker and the time sliding window color maker were not good TCP traffic descriptors. Starting with this point, several propositions have been made and most of them presents new marking schemes in order to replace or improve the traditional token bucket color marker. The main problem is that TCP congestion control is not designed to work with the AF service. Indeed, both mechanisms are antagonists. TCP has the property to share in a fair manner the bottleneck bandwidth between flows while DiffServ network provides a level of service controllable and predictable. In this paper, we build a classification of all the propositions made during these last years and compare them. As a result, we will see that these conditioning schemes can be separated in three sets of action level and that the conditioning at the network edge level is the most accepted one. We conclude that the problem is still unsolved and that TCP, conditioned or not conditioned, remains inappropriate to the DiffServ/AF service

Nietzsche and Amor Fati

This paper identifies two central paradoxes threatening the notion of amor fati [love of fate]: it requires us to love a potentially repellent object (as fate entails significant negativity for us) and this, in the knowledge that our love will not modify our fate. Thus such love may seem impossible or pointless. I analyse the distinction between two different sorts of love (eros and agape) and the type of valuation they involve (in the first case, the object is loved because we value it; in the second, we value the object because we love it). I use this as a lens to interpret Nietzsche?s cryptic pronouncements on amor fati and show that while an erotic reading is, up to a point, plausible, an agapic interpretation is preferable both for its own sake and because it allows for a resolution of the paradoxes initially identified. In doing so, I clarify the relation of amor fati to the eternal return on the one hand, and to Nietzsche?s autobiographical remarks about suffering on the other. Finally, I examine a set of objections pertaining both to the sustainability and limits of amor fati, and to its status as an ideal

A summary of the 2012 JHU CLSP Workshop on Zero Resource Speech Technologies and Models of Early Language Acquisition

We summarize the accomplishments of a multi-disciplinary workshop exploring the computational and scientific issues surrounding zero resource (unsupervised) speech technologies and related models of early language acquisition. Centered around the tasks of phonetic and lexical discovery, we consider unified evaluation metrics, present two new approaches for improving speaker independence in the absence of supervision, and evaluate the application of Bayesian word segmentation algorithms to automatic subword unit tokenizations. Finally, we present two strategies for integrating zero resource techniques into supervised settings, demonstrating the potential of unsupervised methods to improve mainstream technologies.5 page(s

PlasmoView: a web-based resource to visualise global Plasmodium falciparum genomic variation.

Malaria is a global public health challenge, with drug resistance a major barrier to disease control and elimination. To meet the urgent need for better treatments and vaccines, a deeper knowledge of Plasmodium biology and malaria epidemiology is required. An improved understanding of the genomic variation of malaria parasites, especially the most virulent Plasmodium falciparum (Pf) species, has the potential to yield new insights in these areas. High-throughput sequencing and genotyping is generating large amounts of genomic data across multiple parasite populations. The resulting ability to identify informative variants, particularly single-nucleotide polymorphisms (SNPs), will lead to the discovery of intra- and inter-population differences and thus enable the development of genetic barcodes for diagnostic assays and clinical studies. Knowledge of genetic variability underlying drug resistance and other differential phenotypes will also facilitate the identification of novel mutations and contribute to surveillance and stratified medicine applications. The PlasmoView interactive web-browsing tool enables the research community to visualise genomic variation and annotation (eg, biological function) in a geographic setting. The first release contains over 600,000 high-quality SNPs in 631 Pf isolates from laboratory strains and four malaria-endemic regions (West Africa, East Africa, Southeast Asia and Oceania)

A Pathway to Solving the Structure of cl-Par-4 Tumor Suppressor Protein: Challenges & Findings

Prostate apoptosis response-4 (Par-4) is a pro-apoptotic tumor suppressor protein. Down-regulation of this protein has been reported in a myriad of cancers. Conversely, up-regulation of Par-4 is found to be associated with several neurodegenerative disorders. Par-4 is unique in the sense it can selectively induce apoptosis in cancer cells. For this, caspase-dependent intracellular cleavage of Par-4 is essential to produce the functionally active fragment, cl-Par-4 (caspase-cleaved Par-4). The cl-Par-4 protein inhibits the NF-κB-mediated cell survival pathway and causes selective apoptosis in various tumor cells. Our laboratory is interested in determining the structure of cl-Par-4 and understanding it’s interaction with various proteins. Currently, we are using biophysical techniques such as circular dichroism (CD) spectroscopy, dynamic light scattering (DLS), and SDS-PAGE to characterize the structure of cl-Par-4 in the presence of various concentrations of monovalent and divalent ions, in order to shed light on the possible ion-specific role of cl-Par-4 in inducing structure and self-association of this protein. Results show that effects on cl-Par-4 conformation are ion-specific, and effects of divalent cations are considerably more pronounced than effects from monovalent cations. We have also found that the cl-Par-4 shows a better stability in presence of Cl- ions than in presence of SO42- ions. Further, with the help of D313K mutant of cl-Par-4, we investigated that charge-charge repulsion between similar charged amino acid residues in leucine zipper is responsible for high salt at neutral pH or low salt at low pH requirement of cl-Par-4. All these findings will be helpful in getting the structured conformation of cl-Par-4 and, therefore, determining the structure of this protein via X-ray crystallography or via nuclear magnetic resonance (NMR).https://digitalcommons.odu.edu/gradposters2022_sciences/1013/thumbnail.jp

A barcode of organellar genome polymorphisms identifies the geographic origin of Plasmodium falciparum strains.

Malaria is a major public health problem that is actively being addressed in a global eradication campaign. Increased population mobility through international air travel has elevated the risk of re-introducing parasites to elimination areas and dispersing drug-resistant parasites to new regions. A simple genetic marker that quickly and accurately identifies the geographic origin of infections would be a valuable public health tool for locating the source of imported outbreaks. Here we analyse the mitochondrion and apicoplast genomes of 711 Plasmodium falciparum isolates from 14 countries, and find evidence that they are non-recombining and co-inherited. The high degree of linkage produces a panel of relatively few single-nucleotide polymorphisms (SNPs) that is geographically informative. We design a 23-SNP barcode that is highly predictive (~92%) and easily adapted to aid case management in the field and survey parasite migration worldwide