Generalized Casimir forces in non-equilibrium systems

In the present work we propose a method to determine fluctuation induced forces in non equilibrium systems. These forces are the analogue of the well known Casimir forces, which were originally introduced in Quantum Field theory and later extended to the area of Critical Phenomena. The procedure starts from the observation that many non equilibrium systems exhibit long-range correlations and the associated structure factors diverge in the long wavelength limit. The introduction of external bodies into such systems in general modifies the spectrum of these fluctuations and leads to the appearance of a net force between these bodies. The mechanism is illustrated by means of a simple example: a reaction diffusion equation with random noises.Comment: Submitted to Europhysics Letters. 7 pages, 2 figure

Dynamical approach to the Casimir effect

Casimir forces can appear between intrusions placed in different media driven by several fluctuation mechanisms, either in equilibrium or out of it. Herein, we develop a general formalism to obtain such forces from the dynamical equations of the fluctuating medium, the statistical properties of the driving noise, and the boundary conditions of the intrusions (which simulate the interaction between the intrusions and the medium). As a result, an explicit formula for the Casimir force over the intrusions is derived. This formalism contains the thermal Casimir effect as a particular limit and generalizes the study of the Casimir effect to such systems through their dynamical equations, with no appeal to their Hamiltonian, if any exists. In particular, we study the Casimir force between two infinite parallel plates with Dirichlet or Neumann boundary conditions, immersed in several media with finite correlation lengths (reaction--diffusion system, liquid crystals, and two coupled fields with non-Hermitian evolution equations). The driving Gaussian noises have vanishing or finite spatial or temporal correlation lengths; in the first case, equilibrium is reobtained and finite correlations produce nonequilibrium dynamics. The results obtained show that, generally, nonequilibrium dynamics leads to Casimir forces, whereas Casimir forces are obtained in equilibrium dynamics if the stress tensor is anisotropic.Comment: 12 pages, 1 figur

Geodetic Research on Deception Island and its Environment (South Shetland Islands, Bransfield Sea and Antarctic Peninsula) During Spanish Antarctic Campaigns (1987-2007)

Since 1987, Spain has been continuously developing several scientific projects, mainly based on Earth Sciences, in Geodesy, Geochemistry, Geology or Volcanology. The need of a geodetic reference frame when doing hydrographic and topographic mapping meant the organization of the earlier campaigns with the main goals of updating the existing cartography and of making new maps of the area. During this period of time, new techniques arose in Space Geodesy improving the classical methodology and making possible its applications to other different fields such as tectonic or volcanism. Spanish Antarctic Geodetic activities from the 1987/1988 to 2006/2007 campaigns are described as well as a geodetic and a levelling network are presented. The first network, RGAE, was designed and established to define a reference frame in the region formed by the South Shetlands Islands, the Bransfield Sea and the Antarctic Peninsula whereas the second one, REGID, was planned to control the volcanic activity in Deception Island. Finally, the horizontal and vertical deformation models are described too, as well as the strategy which has been followed when computing an experimental geoid

Immediate effects of dasatinib on the migration and redistribution of naïve and memory lymphocytes associated with lymphocytosis in chronic myeloid leukemia patients

Introduction: Dasatinib is a dual SRC/ABL tyrosine kinase inhibitor used to treat chronic myeloid leukemia (CML) that is known to have unique immunomodulatory effects. In particular, dasatinib intake typically causes lymphocytosis, which has been linked to better clinical response. Since the underlying mechanisms are unknown and SRC family kinases are involved in many cell motility processes, we hypothesized that the movement and migration of lymphocytes is modulated by dasatinib. Patients, Materials and Methods: Peripheral blood samples from CML patients treated with second-line dasatinib were collected before and 2 h after the first dasatinib intake, and follow-up samples from the same patients 3 and 6 months after the start of therapy. The migratory capacity and phenotype of lymphocytes and differential blood counts before and after drug intake were compared for all study time-points. Results: We report here for the first time that dasatinib intake is associated with inhibition of peripheral blood T-cell migration toward the homeostatic chemokines CCL19 and CCL21, which control the trafficking toward secondary lymphoid organs, mainly the lymph nodes. Accordingly, the proportion of lymphocytes in blood expressing CCR7, the chemokine receptor for both CCL19 and CCL21, decreased after the intake including both naïve CD45RA+ and central memory CD45RO+ T-cells. Similarly, naïve B-cells diminished with dasatinib. Finally, such changes in the migratory patterns did not occur in those patients whose lymphocyte counts remained unchanged after taking the drug. Discussion: We, therefore, conclude that lymphocytosis induced by dasatinib reflects a pronounced redistribution of naïve and memory populations of all lymphocyte subsets including CD4+ and CD8+ T-cells and B-cells

Elucidating the neuropathologic mechanisms of SARS-CoV-2 infection

Acknowledgements We want to express our gratitude to the Union Medical University Clinic, Dominican Republic, for their support and collaboration in the development of this research project. We also want to express our gratitude to the Mexican families who have donated the brain of their loved ones affected with Alzheimer's disease and made our research possible. This work is dedicated to the memory of Professor Dr. José Raúl Mena López†.Peer reviewedPublisher PD

Concepts in Animal Parasitology, Part 3: Endoparasitic Platyhelminths

Part III: Endoparasitic Platyhelminths, chapters 15-47, pages 231-532, in Concepts in Animal Parasitology. 2024. Scott L. Gardner and Sue Ann Gardner, editors. Zea Books, Lincoln, Nebraska, United States; part III doi: 10.32873/unl.dc.ciap073 Platyhelminthes Chapter 15: Introduction to Endoparasitic Platyhelminths (Phylum Platyhelminthes) by Larry S. Roberts, John J. Janovy, Jr., Steve Nadler, and Scott L. Gardner, pages 231-240 Cestoda Chapter 16: Introduction to Cestodes (Class Cestoda) by Scott L. Gardner, pages 241-246 Eucestoda Chapter 17: Introduction to Cyclophyllidea Beneden in Braun, 1900 (Order) by Scott L. Gardner, pages 247-250 Chapter 18: Taenia (Genus) by Sumiya Ganzorig and Scott. L. Gardner, pages 251-261 Chapter 19: Echinococcus (Genus) by Akira Ito and Scott. L. Gardner, pages 262-275 Chapter 20: Proteocephalidae La Rue, 1911 (Family) by Tomáš Scholz and Roman Kuchta, pages 276-282 Chapter 21: Bothriocephalidea Kuchta et al., 2008 (Order) by Jorge Falcón-Ordaz and Luis García-Prieto, pages 283-288 Chapter 22: Diphyllobothriidea Kuchta et al., 2008 (Order): The Broad Tapeworms by Tomáš Scholz and Roman Kuchta, pages 289-296 Chapter 23: Trypanorhyncha Diesing, 1863 (Order) by Francisco Zaragoza-Tapia and Scott Monks, pages 297-305 Chapter 24: Cathetocephalidea Schmidt and Beveridge, 1990 (Order) by Luis García-Prieto, Omar Lagunas-Calvo, Brenda Atziri García-García, and Berenice Adán-Torres, pages 306-309 Chapter 25: Diphyllidea van Beneden in Carus, 1863 (Order) by Luis García-Prieto, Brenda Atziri García-García, Omar Lagunas-Calvo, and Berenice Adán-Torres, pages 310-315 Chapter 26: Lecanicephalidea Hyman, 1951 (Order) by Luis García-Prieto, Berenice Adán-Torres, Omar Lagunas-Calvo, and Brenda Atziri García- García, pages 316-320 Chapter 27: Litobothriidea Dailey, 1969 (Order) by Luis García-Prieto, Berenice Adán-Torres, Brenda Atziri García-García, and Omar Lagunas-Calvo, pages 321-325 Chapter 28: Phyllobothriidea Caira et al., 2014 (Order) by Brenda Atziri García-García, Omar Lagunas-Calvo, Berenice Adán-Torres, and Luis García-Prieto, pages 326-331 Chapter 29: Rhinebothriidea Healy et al., 2009 (Order) by Omar Lagunas-Calvo, Brenda Atziri García-García, Berenice Adán-Torres, and Luis García-Prieto, pages 332-339 Chapter 30: Relics of “Tetraphyllidea” van Beneden, 1850 (Order) by Berenice Adán-Torres, Omar Lagunas-Calvo, Brenda Atziri García-García, and Luis García-Prieto, pages 340-346 Amphilinidea Chapter 31: Amphilinidea Poche 1922 (Order) by Klaus Rohde, pages 347-353 Gyrocotylidea Chapter 32: Gyrocotylidea (Order): The Most Primitive Group of Tapeworms by Willi E. R. Xylander and Klaus Rohde, pages 354-360 Trematoda Aspidogastrea Chapter 33: Aspidogastrea (Subclass) by Klaus Rohde, pages 361-377 Digenea: Diplostomida Chapter 34: Introduction to Diplostomida Olson et al., 2003 (Order) by Lucrecia Acosta Soto, Bernard Fried, and Rafael Toledo, pages 378-393 Chapter 35: Aporocotylidae (Family): Fish Blood Flukes by Russell Q.-Y. Yong, pages 394-401 Digenea: Plagiorchiida Chapter 36: Introduction to Plagiorchiida La Rue, 1957 (Order) by Rafael Toledo, Bernard Fried, and Lucrecia Acosta Soto, pages 402-404 Chapter 37: Bivesiculata Olson et al., 2003 (Suborder): Small, Rare, but Important by Thomas H. Cribb and Scott C. Cutmore, pages 405-408 Chapter 38: Echinostomata La Rue, 1926 (Suborder) by Rafael Toledo, Bernard Fried, and Lucrecia Acosta Soto, pages 409-422 Chapter 39: Haplosplanchnata Olson et al., 2003 (Suborder): Two Hosts with Half the Guts by Daniel C. Huston, pages 423-427 Chapter 40: Hemiurata Skrjabin & Guschanskaja, 1954 (Suborder) by Lucrecia Acosta Soto, Bernard Fried, and Rafael Toledo, pages 428-435 Chapter 41: Monorchiata Olson et al., 2003 (Suborder): Two Families Separated by Salinity by Nicholas Q.-X. Wee, pages 436-442 Chapter 42: Opisthorchis (Genus) compiled from material from the United States Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria by Sue Ann Gardner, pages 443-445 Xiphidiata Chapter 43: Allocreadiidae Looss, 1902 (Family) by Gerardo Pérez-Ponce de León, David Iván Hernández-Mena, and Brenda Solórzano-García, pages 446-459 Chapter 44: Haematoloechidae Odening, 1964 (Family) by Virginia León-Règagnon, pages 460-469 Chapter 45: Lecithodendriidae Lühe, 1901 (Family) by Jeffrey M. Lotz, pages 470-479 Chapter 46: Opecoelidae Ozaki, 1925 (Family): The Richest Trematode Family by Storm B. Martin, pages 480-489 Digenea Summary Chapter 47: Summary of the Digenea (Subclass): Insights and Lessons from a Prominent Parasitologist by Robin M. Overstreet, pages 490-53

On handling urban informality in southern Africa

In this article I reconsider the handling of urban informality by urban planning and management systems in southern Africa. I argue that authorities have a fetish about formality and that this is fuelled by an obsession with urban modernity. I stress that the desired city, largely inspired by Western notions of modernity, has not been and cannot be realized. Using illustrative cases of top–down interventions, I highlight and interrogate three strategies that authorities have deployed to handle informality in an effort to create or defend the modern city. I suggest that the fetish is built upon a desire for an urban modernity based on a concept of formal order that the authorities believe cannot coexist with the “disorder” and spatial “unruliness” of informality. I question the authorities' conviction that informality is an abomination that needs to be “converted”, dislocated or annihilated. I conclude that the very configuration of urban governance and socio-economic systems in the region, like the rest of sub-Saharan Africa, renders informality inevitable and its eradication impossible

Measurement of the Crab Nebula Spectrum Past 100 TeV with HAWC

We present TeV gamma-ray observations of the Crab Nebula, the standard reference source in ground-based gamma-ray astronomy, using data from the High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory. In this analysis we use two independent energy-estimation methods that utilize extensive air shower variables such as the core position, shower angle, and shower lateral energy distribution. In contrast, the previously published HAWC energy spectrum roughly estimated the shower energy with only the number of photomultipliers triggered. This new methodology yields a much improved energy resolution over the previous analysis and extends HAWC's ability to accurately measure gamma-ray energies well beyond 100 TeV. The energy spectrum of the Crab Nebula is well fit to a log parabola shape $\left(\frac{dN}{dE} = \phi_0 \left(E/\textrm{7 TeV}\right)^{-\alpha-\beta\ln\left(E/\textrm{7 TeV}\right)}\right)$ with emission up to at least 100 TeV. For the first estimator, a ground parameter that utilizes fits to the lateral distribution function to measure the charge density 40 meters from the shower axis, the best-fit values are $\phi_o$=(2.35$\pm$0.04$^{+0.20}_{-0.21}$)$\times$10$^{-13}$ (TeV cm$^2$ s)$^{-1}$, $\alpha$=2.79$\pm$0.02$^{+0.01}_{-0.03}$, and $\beta$=0.10$\pm$0.01$^{+0.01}_{-0.03}$. For the second estimator, a neural network which uses the charge distribution in annuli around the core and other variables, these values are $\phi_o$=(2.31$\pm$0.02$^{+0.32}_{-0.17}$)$\times$10$^{-13}$ (TeV cm$^2$ s)$^{-1}$, $\alpha$=2.73$\pm$0.02$^{+0.03}_{-0.02}$, and $\beta$=0.06$\pm$0.01$\pm$0.02. The first set of uncertainties are statistical; the second set are systematic. Both methods yield compatible results. These measurements are the highest-energy observation of a gamma-ray source to date.Comment: published in Ap