A novel compensation scheme based on a virtual air gap variable reactor for AC voltage control

Voltage control based on reactive power compensation is a fundamental aspect of the operation of ac electric power systems. This paper presents a novel shunt compensation scheme based on a virtual air gap variable reactor. The scheme is fully developed, from the adaptation of the virtual air gap principle to high-voltage applications and the determination of its expected performance, to the proposal of a digital cascade control using internal model and proportional-integral controllers. The suitability and flexibility of the device, and the voltage control and reactive power compensation scheme are verified by means of laboratory tests performed in a small-scale prototype. Measured results show that the proposed device and its control provide a robust load compensation scheme for ac systems

GRB 221009A: A light dark matter burst or an extremely bright Inverse Compton component?

Gamma-ray bursts (GRBs) have been considered as potential very high-energy photon emitters due to the large amount of energy released as well as the strong magnetic fields involved in their jets. However, the detection of TeV photons is not expected from bursts beyond a redshift of $z\gtrsim 0.1$ due to their attenuation with the extragalactic background light (EBL). For these reasons, the recent observation of photons with energies of 18 and 251 TeV from GRB 221009A (z=0.151) last October 9th, 2022 has challenged what we know about the TeV-emission mechanisms and the extragalactic background. In order to explain the TeV observations, recent works exploring candidates of dark matter have started to appear. In this paper, we discuss the required conditions and limitations within the most plausible scenario, synchrotron-self Compton (SSC) radiation in the GRB afterglow, to interpret the one 18-TeV photon observation besides the EBL. To avoid the Klein-Nishina effect, we find an improbable value of the microphysical magnetic parameter below $10^{-6}$ for a circumburst medium value $> 1{\rm cm^{-3}}$ (expected in the collapsar scenario). Therefore, we explore possible scenarios in terms of ALPs and dark photon mechanisms to interpret this highly-energetic photon and we discuss the implications in the GRB energetics. We find that the ALPs and dark photon scenarios can explain the 18 TeV photon but not the 251 TeV photon.Comment: 15 pages, 5 figures, 4 table

Coalescent-based species delimitation in the sand lizards of the Liolaemus wiegmannii complex (Squamata: Liolaemidae)

Coalescent-based algorithms coupled with the access to genome-wide data have become powerful tools forassessing questions on recent or rapid diversification, as well as delineating species boundaries in the absence of reciprocal monophyly. In southern South America, the diversification of Liolaemus lizards during the Pleistocene is well documented and has been attributed to the climatic changes that characterized this recent period of time. Past climatic changes had harsh effects at extreme latitudes, including Patagonia, but habitat changes at intermediate latitudes of South America have also been recorded, including expansion of sand fields over northern Patagonia and Pampas). In this work, we apply a coalescent-based approach to study the diversification of the Liolaemus wiegmannii species complex, a morphologically conservative clade that inhabits sandy soils across northwest and south-central Argentina, and the south shores of Uruguay. Using four standard sequence markers (mitochondrial DNA and three nuclear loci) along with ddRADseq data we inferred species limits and a time calibrated species tree for the L. wiegmannii complex in order to evaluate the influence of Quaternary sand expansion/retraction cycles on diversification. We also evaluated the evolutionary independence of the recently described L. gardeli and inferred its phylogenetic position relative to L. wiegmannii. We find strong evidence for six allopatric candidate species within L. wiegmannii, which diversified during the Pleistocene. The Great Patagonian Glaciation (∼1 million years before present) likely split the species complex into two main groups: one composed of lineages associated with sub-Andean sedimentary formations, and the other mostly related to sand fields in the Pampas and northern Patagonia. We hypothesize that early speciation within L. wiegmannii was influenced by the expansion of sand dunes throughout central Argentina and Pampas. Finally, L. gardeli is supported as a distinct lineage nested within the L. wiegmannii complex.Fil: Villamil, Joaquín. Universidad de la República. Facultad de Ciencias; UruguayFil: Avila, Luciano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Morando, Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico para el Estudio de los Ecosistemas Continentales; ArgentinaFil: Sites, Jack W.. University Brigham Young; Estados UnidosFil: Leaché, Adam D.. University of Washington; Estados UnidosFil: Maneyro, Raúl. Universidad de la República. Facultad de Ciencias; UruguayFil: Camargo Bentaberry, Arley. Universidad de la República; Urugua

Interventions for the control of Aedes aegypti in Latin America and the Caribbean: systematic review and meta-analysis

Objective: To determine the effectiveness and degree of implementation of interventions for the control of Aedes aegypti in Latin America and the Caribbean (LAC) as reported in scientific literature. Methods: We searched MEDLINE, EMBASE, CENTRAL, SOCINDEX, and LILACS, for experimental and observational studies, economic assessments and qualitative experiences carried out in LAC from 2000 to 2016. We assessed incidence and morbimortality of Aedes aegypti-related diseases and entomological indices: Breteau (containers), House, and Pupae per Person. We used GRADE methodology for assessing quality of evidence. Results: Of 1826 records retrieved, 75 were included and 9 cluster randomised clinical trials could be meta-analysed. We did not identify any intervention supported by a high certainty of evidence. In consistency with qualitative evidence, health education and community engagement probably reduces the entomological indices, as do the use of insecticide-treated materials, indoor residual spraying and the management of containers. There is low certainty of evidence supporting the use of ovitraps or larvitraps, and the integrated epidemiological surveillance strategy to improve indices and reduce the incidence of dengue. The reported degree of implementation of these vector control interventions was variable and most did not extend to whole cities and were not sustained beyond 2 years. Conclusions: We found a general lack of evidence on effectiveness of vector control in the region, despite a few interventions that showed moderate to low certainty of evidence. It is important to engage and educate the community, apart from achieving the implementation of integrated actions between the health and other sectors at national and regional level.Fil: Bardach, Ariel Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; ArgentinaFil: García Perdomo, Herney Andrés. Universidad del Valle; ColombiaFil: Alcaraz, Andrea. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Tapia López, Elena. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Ruano Gandara, Ruth Amanda. Instituto de Efectividad Clínica y Sanitaria; ArgentinaFil: Ruvinsky, Silvina. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Ciapponi, Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; Argentin

A preliminary overview of skin and skeletal diseases and traumata in small cetaceans from South American waters

We succinctly review and document new cases of diseases of the skin and the skeletal system and external traumata in cetaceans from Ecuador, Colombia, Peru, Chile, Argentina, Uruguay, Brazil, and Venezuela. The survey revealed 590 cases diagnosed with a significant pathology, injury or malformation on a total of 7635 specimens of 12 odontocete species examined or observed in 1984-2007. Tattoo skin disease (TSD), lobomycosis-like disease (LLD) and cutaneous diseases of unknown aetiology seem to be emerging in several populations. TSD was confirmed in eight species from the SE Pacific and SW Atlantic. LLD affected only inshore Tursiops truncatus but was found in four tropical countries, namely Colombia, Ecuador, Peru and Brazil. Lobomycosis was confirmed by histology in one male from the Tramandaí estuary, southern Brazil. All LLD-affected specimens were encountered in the vicinity of major ports and cities and a possible association with chemical or organic water pollution is suspected. Whitish velvety cutaneous marks associated with scars occurred in inshore T. truncatus, Sotalia guianensis and Pseudorca crassidens. Large, rounded lesions were seen in a Cephalorhynchus eutropia calf and a C. commersonii. Cutaneous wounds and scars as well as body traumata possibly related to net entanglements and boat collisions were observed in 73 delphinids and Phocoena spinipinnis. Traumatic injuries resulted in the partial or complete amputation and other disfiguring scars of appendages in 17 cases. Fractures of the skull, ribs and vertebrae thought to be caused by fisheries-related interactions or boat collisions were seen in single individuals of Delphinus capensis, Lagenorhynchus obscurus, T. truncatus, S. guianensis and Ziphius cavirostris. Prevalence of osteopathology in small cetaceans from Peru, Brazil and Venezuela ranged widely, from 5.4% to 69.1%. In four species from Peru, lytic cranial lesions were the most frequently observed disease (5.4%-42.9%), followed by hyperostosis and ankylosing spondylitis in offshore (31%, n=42) and inshore (15.4%, n=26) T. truncatus. Fractures and other bone traumata were present in 47.2% of 53 axial skeletons of S. guianensis from the northern Rio de Janeiro state (Brazil) in 1987-1998. A high prevalence (48.4%, n=31) of, apparently congenital, malformations of cervical vertebrae, observed in a 2001-2006 sample, may be explained by a hypothetical genetic bottleneck in this population. Malformations with deficient ossification would clearly increase susceptibility for fractures. This study demonstrates the utility of a continent-wide analysis to discern epizootiological trends more readily than any local study could provide. Secondly, it underscores the need for focussed research on the effects of human activities on the spread of diseases in cetaceans, particularly in near-shore populations that utilize highly degraded coastal habitats

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Microwave assisted solvent free synthesis of 1,3-diphenylpropenones

<p>Abstract</p> <p>Background</p> <p>1,3-Diphenylpropenones (chalcones) are well known for their diverse array of bioactivities. Hydroxyl group substituted chalcones are the main precursor in the synthesis of flavonoids. Till date various methods have been developed for the synthesis of these very interesting molecules. Continuing our efforts for the development of simple, eco-friendly and cost-effective methodologies, we report here a solvent free condensation of aryl ketones and aldehydes using iodine impregnated alumina under microwave activation. This new protocol has been applied to a variety of substituted aryl carbonyls with excellent yield of substituted 1,3-diphenylpropenones.</p> <p>Results</p> <p>Differently substituted chalcones were synthesized using iodine impregnated neutral alumina as catalyst in 79-95% yield in less than 2 minutes time under microwave activation without using any solvent. The reaction was studied under different catalytic conditions and it was found that molecular iodine supported over neutral alumina gives the best yield. The otherwise difficult single step condensation of hydroxy substituted aryl carbonyls is an attractive feature of this protocol to obtain polyhydroxychalcones in excellent yields. In order to find out the general applicability of this new endeavor it was successfully applied for the synthesis of 15 different chalcones including highly bioactive prenylated hydroxychalcone xanthohumol.</p> <p>Conclusion</p> <p>A new, simple and solvent free method was developed for the synthesis of substituted chalcones in environmentally benign way. The mild reaction conditions, easy work-up, clean reaction profiles render this approach as an interesting alternative to the existing methods.</p

Performance and Operation of the CMS Electromagnetic Calorimeter

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented

Evaluation of IL-12 and CXCL-10 in patients with hepatitis C, non-alcoholic fatty liver disease and liver damage for alcohol consumption

Introduction and Objectives: To Compare serum levels of IL-12 and CXCL-10 in different etiologies of liver disease. Materials and methods: A cross-sectional and multicenter study was carried out, including subjects with alcoholism according to criteria WHO, without (OH) and with liver injury (cirrhosis, CiOH) and (Alcoholic Hepatitis, HA); non-alcoholic fatty liver (NAFLD) and chronic Hepatitis C (CHC), diagnosed by clinical, biochemical data. They were compared with subjects control (CT). For determination of IL-12 and CXCL-10 with Multiplex®-MERCK©. Statistical analysis by SPSS V.22 using U de Mann Whitney, p<0.05; values expressed as mean ± standard error. Results: Included 20 subjects with NAFLD, 78 CHC, 14 HA, 20 CiOH, 15 OH y 60 CT. IL-12 was found elevated in OH, HA, CHC vs. CT in OH vs. HCc y HGNA (p≤0.05). CXCL-10 was found elevated in CiOH, HA and CHC vs. CT(p≤0.050). Discussion: The IL-12 showed elevated levels in subjects with alcohol consumption and CHC vs. CT that activates other cell types involved in inflammation. CXCL-10 is induced by IFN-γ, was found elevated in CiOH, HA and CHC, exerting their biological effects through CXCR3, including activation of peripheral immune cells and apoptosis. The ratio of IL-12/CXCL-10 in OH increased 4.6 times, ratifying the participation in chronic and continual inflammatory response by alcohol consumption. Conclusions: IL-12 and CXCL-10 have an important role in alcohol-induced liver disease, confirming their contribution to inflammation, being evident CXCL-10 in advanced stages of the disease, by stimulating and favoring the migration of immune cells to the damage sites. Funding: This work was partially financed by CONACyT SALUD-2016-272579 and PAPIIT- UNAM TA200515. Declaration of interest: The authors declare no potential conflicts of interest

Immunosuppression during Acute Infection with Foot-and-Mouth Disease Virus in Swine Is Mediated by IL-10

Foot-and-mouth disease virus (FMDV) is one of the most contagious animal viruses, causing a devastating disease in cloven-hoofed animals with enormous economic consequences. Identification of the different parameters involved in the immune response elicited against FMDV remains unclear, and it is fundamental the understanding of such parameters before effective control measures can be put in place. In the present study, we show that interleukin-10 (IL-10) production by dendritic cells (DCs) is drastically increased during acute infection with FMDV in swine. In vitro blockade of IL-10 with a neutralizing antibody against porcine IL-10 restores T cell activation by DCs. Additionally, we describe that FMDV infects DC precursors and interferes with DC maturation and antigen presentation capacity. Thus, we propose a new mechanism of virus immunity in which a non-persistent virus, FMDV, induces immunosuppression by an increment in the production of IL-10, which in turn, reduces T cell function. This reduction of T cell activity may result in a more potent induction of neutralizing antibody responses, clearing the viral infection