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1.
Phys Rev Lett ; 132(10): 101006, 2024 Mar 08.
Article in English | MEDLINE | ID: mdl-38518351

ABSTRACT

Dark matter (DM) particles with sufficiently large cross sections may scatter as they travel through Earth's bulk. The corresponding changes in the DM flux give rise to a characteristic daily modulation signal in detectors sensitive to DM-electron interactions. Here, we report results obtained from the first underground operation of the DAMIC-M prototype detector searching for such a signal from DM with MeV-scale mass. A model-independent analysis finds no modulation in the rate of 1 e^{-} events with sidereal period, where a DM signal would appear. We then use these data to place exclusion limits on DM in the mass range [0.53,2.7] MeV/c^{2} interacting with electrons via a dark photon mediator. Taking advantage of the time-dependent signal we improve by ∼2 orders of magnitude on our previous limit obtained from the total rate of 1 e^{-} events, using the same dataset. This daily modulation search represents the current strongest limit on DM-electron scattering via ultralight mediators for DM masses around 1 MeV/c^{2}.

2.
Heliyon ; 9(6): e17018, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37484312

ABSTRACT

Harmful algae blooms (HABs) are a conspicuous phenomenon that affect the coastal zone worldwide. Aquaculture industry zones are not excluded from being affected by HAB that cause organism mortality and jeopardize their innocuity due to the contamination by phytotoxins with the concomitant economic losses. Direct ingestion of metabolites from HAB species or organisms contaminated with phycotoxins together with dermal absorption of dissolved metabolites (DM), including toxins, are the two main routes of poisoning. From these poisoning routes, the effect of DM, particularly paralytic shellfish toxins (PST), has been relatively understudied. This intoxication route can be conspicuous and could be involved in many significant mortalities of cultivated marine organisms. In this study, white shrimp juveniles (2.1 g wet weight) of Litopenaeus vannamei were exposed to extracts of 104, 105 and 106 cells/L of the dinoflagellate Gymnodinium catenatum, a PST producer. The experiment ended after 17 h of exposure when shrimps exposed to 106 cells/L extract started to die and the rest of the shrimps, from this and other treatments, did not respond to gentle physical stimulus and their swimming activity was low and erratic. Toxin concentrations were determined using high performance liquid chromatography while qualitative and quantitative histological damages were assessed on the tissues. In general, most toxins were accumulated in the hepatopancreas where more than 90% were found. Other tissues such as intestine, muscle, and gills contained less than 10% of toxins. Compared to the control, the main significative tissue damages were, loss of up to 80% of the nerve cord, 40% of the muscle coverage area, and reduction of the gill lamella width. Also, atrophy in hepatopancreas was observed, manifested by a decrease in the height of B cells, lumen degeneration and thinning of tubules. Some damages were more evident when shrimps were exposed to higher concentrated extracts of G. catenatum, however, not all damages were progressive and proportional to the extract concentration. These data confirm that PST dissolved enter the shrimp, possibly via the gills, and suggest that dissolved metabolites, including PST, may cause tissue damage. Other dissolved metabolites produced by G. catenatum, alone or in synergy, may also be involved. These results also pointed out the importance of dissolved molecules produced for this dinoflagellate and the potential effect on cultured shrimp.

3.
Phys Rev Lett ; 130(17): 171003, 2023 Apr 28.
Article in English | MEDLINE | ID: mdl-37172255

ABSTRACT

We report constraints on sub-GeV dark matter particles interacting with electrons from the first underground operation of DAMIC-M detectors. The search is performed with an integrated exposure of 85.23 g days, and exploits the subelectron charge resolution and low level of dark current of DAMIC-M charge-coupled devices (CCDs). Dark-matter-induced ionization signals above the detector dark current are searched for in CCD pixels with charge up to 7e^{-}. With this dataset we place limits on dark matter particles of mass between 0.53 and 1000 MeV/c^{2}, excluding unexplored regions of parameter space in the mass ranges [1.6,1000] MeV/c^{2} and [1.5,15.1] MeV/c^{2} for ultralight and heavy mediator interactions, respectively.

4.
Phys Rev Lett ; 125(24): 241803, 2020 Dec 11.
Article in English | MEDLINE | ID: mdl-33412014

ABSTRACT

We present constraints on the existence of weakly interacting massive particles (WIMPs) from an 11 kg d target exposure of the DAMIC experiment at the SNOLAB underground laboratory. The observed energy spectrum and spatial distribution of ionization events with electron-equivalent energies >200 eV_{ee} in the DAMIC CCDs are consistent with backgrounds from natural radioactivity. An excess of ionization events is observed above the analysis threshold of 50 eV_{ee}. While the origin of this low-energy excess requires further investigation, our data exclude spin-independent WIMP-nucleon scattering cross sections σ_{χ-n} as low as 3×10^{-41} cm^{2} for WIMPs with masses m_{χ} from 7 to 10 GeV c^{-2}. These results are the strongest constraints from a silicon target on the existence of WIMPs with m_{χ}<9 GeV c^{-2} and are directly relevant to any dark matter interpretation of the excess of nuclear-recoil events observed by the CDMS silicon experiment in 2013.

5.
Phys Rev Lett ; 123(18): 181802, 2019 Nov 01.
Article in English | MEDLINE | ID: mdl-31763884

ABSTRACT

We report direct-detection constraints on light dark matter particles interacting with electrons. The results are based on a method that exploits the extremely low levels of leakage current of the DAMIC detector at SNOLAB of 2-6×10^{-22} A cm^{-2}. We evaluate the charge distribution of pixels that collect <10e^{-} for contributions beyond the leakage current that may be attributed to dark matter interactions. Constraints are placed on so-far unexplored parameter space for dark matter masses between 0.6 and 100 MeV c^{-2}. We also present new constraints on hidden-photon dark matter with masses in the range 1.2-30 eV c^{-2}.

6.
Cytokine ; 108: 239-246, 2018 08.
Article in English | MEDLINE | ID: mdl-29402723

ABSTRACT

BACKGROUND: Vitamin D is a molecule that modulates the immune response and shows anti-inflammatory effects that are beneficial for the control of chronic diseases such as asthma. The trial aim was to explore the effect of vitamin D supplementation on the colonization of pathogenic bacteria in the upper respiratory tract of allergic asthmatic patients. METHODS: This study was conducted in 86 patients between 18 and 50 years of age who were randomly divided into two groups. Both groups received the treatment recommended by the Global Initiative for Asthma (GINA). One group also received calcitriol (1,25-(OH)2D3), and the other group received a placebo. At baseline and 6 months, skin prick tests were conducted, pharyngeal bacterial cultures were performed, and cathelicidin LL-37 was measured in sputum. Serum levels of IgE, eosinophils, IL-5, IL-9, IL-10, IL-13, and IFNγ were quantified at the beginning and the end of the study. RESULTS: Serum levels of IL-10 and IFNγ increased significantly in the group of patients with vitamin D supplementation, while IL-5, IL-9, and IL-13 decreased significantly. At the end of the trial, IgE and eosinophil levels significantly decreased but allergen sensitivity did not show any changes from baseline. Respiratory infections were drastically reduced, and this decrease was related to the number of patients who had high serum levels of IL-10 and IFNγ and expressed LL-37 in their sputum. CONCLUSION: Treatment of asthma patients with vitamin D reduced respiratory infections, and this effect was related to the increase of cathelicidin LL-37.


Subject(s)
Antimicrobial Cationic Peptides/blood , Asthma/complications , Interferon-gamma/blood , Interleukin-10/blood , Respiratory Tract Infections/prevention & control , Vitamin D/administration & dosage , Adult , Antimicrobial Cationic Peptides/immunology , Asthma/drug therapy , Bacterial Infections/immunology , Bacterial Infections/prevention & control , Calcitriol/administration & dosage , Dietary Supplements , Female , Humans , Immunoglobulin E/blood , Interleukin-10/immunology , Male , Middle Aged , Respiratory Tract Infections/immunology , Sputum/chemistry , Sputum/immunology , Cathelicidins
7.
Phys Rev Lett ; 118(14): 141803, 2017 Apr 07.
Article in English | MEDLINE | ID: mdl-28430473

ABSTRACT

We present direct detection constraints on the absorption of hidden-photon dark matter with particle masses in the range 1.2-30 eV c^{-2} with the DAMIC experiment at SNOLAB. Under the assumption that the local dark matter is entirely constituted of hidden photons, the sensitivity to the kinetic mixing parameter κ is competitive with constraints from solar emission, reaching a minimum value of 2.2×10^{-14} at 17 eV c^{-2}. These results are the most stringent direct detection constraints on hidden-photon dark matter in the galactic halo with masses 3-12 eV c^{-2} and the first demonstration of direct experimental sensitivity to ionization signals <12 eV from dark matter interactions.

8.
Rev. mex. cardiol ; 27(2): 77-86, Apr.-Jun. 2016. tab, graf
Article in English | LILACS | ID: biblio-830577

ABSTRACT

Abstract: The information system on chronic diseases is an electronic system that was recently established in Mexico to monitor new cases and cumulative chronic diseases that are increasing. The aim of this study was to evaluate the qualitative and quantitative consistency of the electronic record of diseases such as diabetes, obesity, hypertension and dyslipidemia, in contrast to what was found in the medical records through a validation system exprofeso data. It followed up on 3,293 diseases recorded and compared with the pathologies registered in the files, these were higher than the records (n = 4,188). It was found that there is an electronic sub-register of diseases recorded in medical units with a differential in the quality standards of care. Our results reveal that to increase the effectiveness of electronic health information it is required a mechanism of annual or biennial review by a systematic validation and based on clinical records. This system also enables validation mechanisms and promotes greater adherence to treatment in the management of chronic diseases, contributing to quality improvement and cost containment in health.


Resumen: El sistema de información en enfermedades crónicas, es un sistema electrónico que se estableció en México recientemente para el monitoreo de los casos nuevos y acumulados de enfermedades crónicas que van en aumento. El objetivo de este estudio fue evaluar la consistencia cualitativa y cuantitativa del registro electrónico de enfermedades como la diabetes, obesidad, hipertensión arterial y dislipidemias, en contraste con lo encontrado en el expediente clínico a través de un sistema de validación de datos exprofeso. Se dio seguimiento a 3,293 patologías registradas y se compararon con las patologías registradas en los expedientes las cuales fueron mayores a los registros en los expedientes (n = 4,188). Se encontró que existe un sub-registro electrónico de las enfermedades registradas en las unidades médicas con un diferencial en los estándares de calidad de la atención. Nuestros resultados dejan ver que para incrementar la efectividad de un sistema de información electrónica en salud se requiere de un mecanismo de revisión anual o bianual a través de una validación sistematizada y basada en los expedientes clínicos. Este sistema de validación también permite y promueve mecanismos de mayor adherencia al tratamiento en el manejo de las enfermedades crónicas contribuyendo a mejoras en la calidad y en la contención de costos en salud.

9.
J Environ Radioact ; 138: 444-6, 2014 Dec.
Article in English | MEDLINE | ID: mdl-24725806

ABSTRACT

The decays of (214)Po into (210)Pb and of (212)Po into (208)Pb tagged by the previous decays from (214)Bi and (212)Bi have been studied inserting quartz vials inside the Counting Test Facility (CTF) at the underground laboratory in Gran Sasso (LNGS). We find that the mean lifetime of (214)Po is (236.00 ± 0.42(stat) ± 0.15(syst)) µs and that of (212)Po is (425.1 ± 0.9(stat) ± 1.2(syst)) ns. Our results are compatible with previous measurements, have a much better signal to background ratio, and reduce the overall uncertainties.


Subject(s)
Lead Radioisotopes/analysis , Polonium/analysis , Radioactive Pollutants/analysis , Alpha Particles , Half-Life , Laboratories , Radiation Monitoring
10.
Phys Rev Lett ; 108(5): 051302, 2012 Feb 03.
Article in English | MEDLINE | ID: mdl-22400925

ABSTRACT

We observed, for the first time, solar neutrinos in the 1.0-1.5 MeV energy range. We determined the rate of pep solar neutrino interactions in Borexino to be 3.1±0.6{stat}±0.3{syst} counts/(day·100 ton). Assuming the pep neutrino flux predicted by the standard solar model, we obtained a constraint on the CNO solar neutrino interaction rate of <7.9 counts/(day·100 ton) (95% C.L.). The absence of the solar neutrino signal is disfavored at 99.97% C.L., while the absence of the pep signal is disfavored at 98% C.L. The necessary sensitivity was achieved by adopting data analysis techniques for the rejection of cosmogenic {11}C, the dominant background in the 1-2 MeV region. Assuming the Mikheyev-Smirnov-Wolfenstein large mixing angle solution to solar neutrino oscillations, these values correspond to solar neutrino fluxes of (1.6±0.3)×10{8} cm{-2} s^{-1} and <7.7×10{8} cm{-2} s{-1} (95% C.L.), respectively, in agreement with both the high and low metallicity standard solar models. These results represent the first direct evidence of the pep neutrino signal and the strongest constraint of the CNO solar neutrino flux to date.

11.
Phys Rev Lett ; 107(14): 141302, 2011 Sep 30.
Article in English | MEDLINE | ID: mdl-22107184

ABSTRACT

The rate of neutrino-electron elastic scattering interactions from 862 keV (7)Be solar neutrinos in Borexino is determined to be 46.0±1.5(stat)(-1.6)(+1.5)(syst) counts/(day·100 ton). This corresponds to a ν(e)-equivalent (7)Be solar neutrino flux of (3.10±0.15)×10(9) cm(-2) s(-1) and, under the assumption of ν(e) transition to other active neutrino flavours, yields an electron neutrino survival probability of 0.51±0.07 at 862 keV. The no flavor change hypothesis is ruled out at 5.0 σ. A global solar neutrino analysis with free fluxes determines Φ(pp)=6.06(-0.06)(+0.02)×10(10) cm(-2) s(-1) and Φ(CNO)<1.3×10(9) cm(-2) s(-1) (95% C.L.). These results significantly improve the precision with which the Mikheyev-Smirnov-Wolfenstein large mixing angle neutrino oscillation model is experimentally tested at low energy.

12.
Rev. méd. (La Paz) ; 16(2): 87-90, 2010.
Article in Spanish | LILACS | ID: lil-738172

ABSTRACT

Han transcurrido 50 años en que por iniciativa de un grupo de anestesiólogos se funda la Sociedad Boliviana de Anestesiología (hoy SBARD) en una de las aulas del Edificio del Colegio Médico de La Paz, el 9 de diciembre de 1960, por los Drs. Carlos Conrado Castaños A., René Del Barco, Rolando Lara, Raúl Montaño, Edmundo Pando y Jaime Rollano como Socios Fundadores .


Subject(s)
Anesthesiology
13.
Transfus Med ; 19(3): 125-31, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19566669

ABSTRACT

We evaluated the incidence of anti-Dengue virus (DENV) antibodies and dengue viremia in a region of Mexico with a high prevalence of dengue. DENV is the most important arthropod-borne virus in terms of human morbidity and mortality in America We tested 800 blood donors from a tertiary care teaching hospital that provides care in Northeast Mexico, to identify anti-DENV IgM and IgG antibodies by enzyme-linked immunosorbent assay (ELISA) and DENV genome by reverse transcription polymerase chain reaction (RT-PCR). In addition, routine tests for donors including Brucella, Hepatitis C virus (HCV), Venereal Disease Research Laboratory (VDRL), HIV-1 and HBsAg identification were performed. We found that 59% of donors were reactive for anti-DENV IgG and none of them had reported recent DENV infection; however, 16 (2%) were reactive for anti-DENV IgM antibodies. None of them were viremic at the time of donation. Routine tests showed that the prevalence of anti-Brucella was 0.71%, anti-HCV 0.71%, anti-HIV-1-2 0.14%, HBsAg 0.14% and VDRL test 0.57%. Although DENV transmission by blood transfusion had not been confirmed in Mexico, the finding of a high prevalence of anti-DENV IgM-positive donors with asymptomatic manifestations and the recent viremia reported in blood donors suggests that this route of transmission might be possible.


Subject(s)
Antibodies, Viral/blood , Blood Donors , Dengue/blood , Endemic Diseases , Immunoglobulin G/blood , Immunoglobulin M/blood , Adolescent , Adult , Aged , Antibodies, Bacterial/blood , Antibodies, Viral/immunology , Brucella/immunology , Dengue/epidemiology , Dengue/transmission , Dengue Virus/immunology , Female , HIV-1/immunology , Hepacivirus/immunology , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Male , Mexico/epidemiology , Middle Aged , Sexually Transmitted Diseases/blood , Sexually Transmitted Diseases/epidemiology , Sexually Transmitted Diseases/immunology , Viremia/blood , Viremia/epidemiology , Viremia/immunology
14.
Environ Health Insights ; 3: 37-51, 2009 06 23.
Article in English | MEDLINE | ID: mdl-20508756

ABSTRACT

In response to the human health threats stemming from Hurricanes Katrina and Rita, inter-disciplinary working groups representing P30-funded Centers of the National Institute Environmental Health Sciences were created to assess threats posed by mold, harmful alga blooms, chemical toxicants, and various infectious agents at selected sites throughout the hurricane impact zone. Because of proximity to impacted areas, UTMB NIEHS Center in Environmental Toxicology was charged with coordinating direct community outreach efforts, primarily in south Louisiana. In early October 2005, UTMB/NIEHS Center Community Outreach and Education Core, in collaboration with outreach counterparts at The University of Texas MD Anderson Cancer Center @ Smithville TX/Center for Research in Environmental Disease sent two groups into southern Louisiana. One group used Lafourche Parish as a base to deliver humanitarian aid and assess local needs for additional supplies during local recovery/reclamation. A second group, ranging through New Iberia, New Orleans, Chalmette, rural Terrebonne, Lafourche and Jefferson Parishes and Baton Rouge met with community environmental leaders, emergency personnel and local citizens to 1) sample public risk perceptions, 2) evaluate the scope and reach of ongoing risk communication efforts, and 3) determine how the NIEHS could best collaborate with local groups in environmental health research and local capacity building efforts. This scoping survey identified specific information gaps limiting efficacy of risk communication, produced a community "wish list" of potential collaborative research projects. The project provided useful heuristics for disaster response and management planning and a platform for future collaborative efforts in environmental health assessment and risk communication with local advocacy groups in south Terrebonne-Lafourche parishes.

15.
Phys Rev Lett ; 101(9): 091302, 2008 Aug 29.
Article in English | MEDLINE | ID: mdl-18851600

ABSTRACT

We report the direct measurement of the 7Be solar neutrino signal rate performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The interaction rate of the 0.862 MeV 7Be neutrinos is 49+/-3stat+/-4syst counts/(day.100 ton). The hypothesis of no oscillation for 7Be solar neutrinos is inconsistent with our measurement at the 4sigma C.L. Our result is the first direct measurement of the survival probability for solar nu(e) in the transition region between matter-enhanced and vacuum-driven oscillations. The measurement improves the experimental determination of the flux of 7Be, pp, and CNO solar nu(e), and the limit on the effective neutrino magnetic moment using solar neutrinos.

16.
Parasite Immunol ; 29(12): 621-36, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18042169

ABSTRACT

This article reviews current knowledge on the innate and acquired immune responses in human Taenia solium neurocysticercosis, highlighting the conditions that appear to be favourable for the survival or destruction of the parasite and for the benefit or injury to its host.


Subject(s)
Cysticercosis/immunology , Cysticercosis/pathology , Taenia solium/immunology , Animals , Humans
17.
J Parasitol ; 90(3): 531-46, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15270097

ABSTRACT

A review of current literature on mammalian hosts' sexual dimorphism (SD) in parasitic infections revealed that (1) it is a scarcely and superficially studied biological phenomenon of considerable significance for individual health, behavior, and lifestyles and for the evolution of species; (2) there are many notable exceptions to the rule of a favorable female bias in susceptibility to infection; (3) a complex network of molecular and cellular reactions connecting the host's immuno-neuroendocrine systems with those of the parasite is responsible for the host-parasite relationship rather than just an adaptive immune response and sex hormones; (4) a lack of gender-specific immune profiles in response to different infections; (5) the direct effects of the host hormones on parasite physiology may significantly contribute to SD in parasitism; and (6) the need to enrich the reductionist approach to complex biological issues, like SD, with more penetrating approaches to the study of cause-effect relationships, i.e., network theory. The review concludes by advising against generalization regarding SD and parasitism and by pointing to some of the most promising lines of research.


Subject(s)
Endocrine System/physiology , Immune System/physiology , Mammals/parasitology , Parasitic Diseases/immunology , Parasitic Diseases/metabolism , Sex Characteristics , Animals , Cysticercosis/immunology , Cysticercosis/metabolism , Female , Gonadal Steroid Hormones/physiology , Host-Parasite Interactions , Humans , Male , Neurosecretory Systems/physiology
18.
Autoimmun Rev ; 3(4): 251-60, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15246020

ABSTRACT

The aim of this work was to review the inflammatory factors involved in central nervous system (CNS) inflammation and the damage associated to their participation in an inflammatory disease of CNS, multiple sclerosis in humans and experimental allergic encephalomyelitis in the murine model. Inflammation has an important repairing function, nevertheless frequently in the CNS inflammation is the cause of damage and it does not fulfill this repairing function as it happens in other compartments of the body. The inflammatory response in the CNS involves the participation of different cellular types of the immune system (macrophages, mast cells, T and B lymphocytes, dendritic cells) and resident cells of the CNS (microglia, astrocytes, neurons), adhesion molecules, cytokines and chemokines among other proteic components. During neuroinflammation chemotaxis is an important event in the recruitment of cells to the CNS. The lymphocyte recruitment implies the presence of chemokines and chemokine receptors, the expression of adhesion molecules, the interaction between lymphocytes and the bloodbrain barrier (BBB) endothelium, and finally their passage through the BBB to arrive at the site of inflammation. If this process is not controlled, is prolonged, inflammation loses its repairing function and can be the cause of damage. Usually neuroinflammation has the tendency to decline to damage, which would explain most of the CNS pathologies.


Subject(s)
Central Nervous System/immunology , Central Nervous System/pathology , Inflammation , Animals , Antigen-Presenting Cells/immunology , CD4-Positive T-Lymphocytes/immunology , Chemokines/metabolism , Chemotaxis , Cytokines/metabolism , Encephalomyelitis, Autoimmune, Experimental/immunology , Encephalomyelitis, Autoimmune, Experimental/pathology , Humans , Interferon-gamma/immunology , Models, Biological , Multiple Sclerosis/immunology , Multiple Sclerosis/pathology , T-Lymphocytes/immunology , Th1 Cells/immunology , Tumor Necrosis Factor-alpha/immunology
19.
Neuroepidemiology ; 22(2): 139-45, 2003.
Article in English | MEDLINE | ID: mdl-12629280

ABSTRACT

Human neurocysticercosis (NC) is a parasitic disease caused by TAENIA SOLIUM when its larvae lodge in the central nervous system. NC prevalence estimates are obscured by the variable and often asymptomatic clinical picture. While infection depends on exposure, severity is possibly related with various host factors (immunity, genes and gender). This epidemiological study of cranial CT scans in an endemic rural community found that 9.1% of apparently healthy subjects had calcified lesions and were completely asymptomatic. Silent NC cases did not correlate with the exposure factors tested but showed family aggregation and higher rates of positive serology. Thus, NC prevalence may be higher than currently considered and host-related factors appear to be involved in infection and pathogenesis.


Subject(s)
Calcinosis/epidemiology , Calcinosis/etiology , Neurocysticercosis/complications , Neurocysticercosis/epidemiology , Rural Population/statistics & numerical data , Adolescent , Adult , Age Distribution , Aged , Animals , Calcinosis/diagnostic imaging , Child , Female , Humans , Male , Mexico/epidemiology , Middle Aged , Neurocysticercosis/diagnostic imaging , Prevalence , Swine , Taenia solium/isolation & purification , Tomography, X-Ray Computed
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