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1.
Phys Rev Lett ; 132(18): 182502, 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38759198

RESUMEN

The observation of neutrinoless double-beta (0νßß) decay would offer proof of lepton number violation, demonstrating that neutrinos are Majorana particles, while also helping us understand why there is more matter than antimatter in the Universe. If the decay is driven by the exchange of the three known light neutrinos, a discovery would, in addition, link the observed decay rate to the neutrino mass scale through a theoretical quantity known as the nuclear matrix element (NME). Accurate values of the NMEs for all nuclei considered for use in 0νßß experiments are therefore crucial for designing and interpreting those experiments. Here, we report the first comprehensive ab initio uncertainty quantification of the 0νßß-decay NME, in the key nucleus ^{76}Ge. Our method employs nuclear strong and weak interactions derived within chiral effective field theory and recently developed many-body emulators. Our result, with a conservative treatment of uncertainty, is an NME of 2.60_{-1.36}^{+1.28}, which, together with the best-existing half-life sensitivity and phase-space factor, sets an upper limit for effective neutrino mass of 187_{-62}^{+205} meV. The result is important for designing next-generation germanium detectors aiming to cover the entire inverted hierarchy region of neutrino masses.

2.
Actas Dermosifiliogr ; 115(1): 1-9, 2024 Jan.
Artículo en Inglés, Español | MEDLINE | ID: mdl-37429433

RESUMEN

BACKGROUND AND OBJECTIVE: The treatment of psoriasis should not only focus on skin affectations but also weigh the parameters for health-related quality of life (HRQoL), thereby tackling the concept of cumulative life course impairment (CLCI) and treating the patient from a holistic perspective. The CRYSTAL study aimed to characterize psoriasis with real-word data from Spanish clinical practice in patients with moderate to severe disease who received continuous systemic treatment for at least 24 weeks by using the absolute Psoriasis Area and Severity Index (PASI) score and its correlation to HRQoL. MATERIAL AND METHODS: This was a non-interventional, cross-sectional study conducted in 30 centers in Spain, with 301 patients between the ages of 18 and 75 years. The study collected data regarding current treatment and absolute PASI and their relationship to HRQoL using the Dermatology Life Quality Index (DLQI), to activity impairment using the Work Productivity and Activity Impairment (WPAI) questionnaire, and to treatment satisfaction. RESULTS: The mean (SD) age was 50.5 (12.5) years, with a duration of disease of 14 (14.1) years. The mean (SD) absolute PASI reported was 2.3 (3.5), with 28.7% of patients presenting with PASI from >1 to ≤3 and 22.6% with PASI>3. Higher PASI scores were associated with higher DLQI (p<0.001) and WPAI scores and lower levels of treatment satisfaction (p<0.001). CONCLUSIONS: These data indicate that achieving lower absolute PASI values may correlate not only with better HRQoL but also with better work productivity and treatment satisfaction.


Asunto(s)
Psoriasis , Calidad de Vida , Humanos , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , España/epidemiología , Estudios Transversales , Psoriasis/complicaciones , Psoriasis/tratamiento farmacológico , Piel , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
3.
Actas Dermosifiliogr ; 115(1): T1-T9, 2024 Jan.
Artículo en Inglés, Español | MEDLINE | ID: mdl-37923068

RESUMEN

BACKGROUND AND OBJECTIVE: The treatment of psoriasis should not only focus on skin affectations but also weigh the parameters for health-related quality of life (HRQoL), thereby tackling the concept of cumulative life course impairment (CLCI) and treating the patient from a holistic perspective. The CRYSTAL study aimed to characterize psoriasis with real-word data from Spanish clinical practice in patients with moderate to severe disease who received continuous systemic treatment for at least 24 weeks by using the absolute Psoriasis Area and Severity Index (PASI) score and its correlation to HRQoL. MATERIAL AND METHODS: This was a non-interventional, cross-sectional study conducted in 30 centers in Spain, with 301 patients between the ages of 18 and 75 years. The study collected data regarding current treatment and absolute PASI and their relationship to HRQoL using the Dermatology Life Quality Index (DLQI), to activity impairment using the Work Productivity and Activity Impairment (WPAI) questionnaire, and to treatment satisfaction. RESULTS: The mean (SD) age was 50.5 (12.5) years, with a duration of disease of 14 (14.1) years. The mean (SD) absolute PASI reported was 2.3 (3.5), with 28.7% of patients presenting with PASI from >1 to ≤3 and 22.6% with PASI>3. Higher PASI scores were associated with higher DLQI (p<0.001) and WPAI scores and lower levels of treatment satisfaction (p<0.001). CONCLUSIONS: These data indicate that achieving lower absolute PASI values may correlate not only with better HRQoL but also with better work productivity and treatment satisfaction.


Asunto(s)
Psoriasis , Calidad de Vida , Humanos , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , España/epidemiología , Estudios Transversales , Psoriasis/complicaciones , Psoriasis/tratamiento farmacológico , Piel , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
4.
Fish Shellfish Immunol ; 138: 108806, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37169107

RESUMEN

Haemocytes of Mytilus galloprovincialis represent the main component of the internal self-defence system. Although haemocytes from haemolymph are usually studied to analyse these animals' immune response, the presence of haemocytes in the intervalvar liquid, which is essentially sea water, led us to characterize them. Several functional (ROS production, phagocytosis, gene expression, travel velocity and distance) and morphological (area, size and granularity) assays were performed by applying different stimuli to the mussels (waterborne infection, shell injury and their combination). Our results revealed that intervalvar liquid haemocytes share common characteristics with haemolymph haemocytes (for instance, the cell morphology and the cell population structure divided in three main groups) but also show significant differences in size (usually smaller in the intervalvar liquid), mobility (commonly faster in the intervalvar liquid), ROS production (higher in non-stimulated intervalvar liquid cells) and gene expression (IL17, Myd88 and CathL are over expressed in liquid intervalvar cells compared to haemolymph cells). Moreover, differences were observed when mussels were subjected to the mentioned treatments. These free intervalvar haemocytes could constitute the first line of defence as external sentinels extending the immunological alert system outside of the mussel body.


Asunto(s)
Mytilus , Animales , Mytilus/fisiología , Especies Reactivas de Oxígeno/metabolismo , Alimentos Marinos , Hemocitos/fisiología
5.
Med Vet Entomol ; 37(4): 745-753, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37427707

RESUMEN

The cattle tick Rhipicephalus microplus (Acari: Ixodidae) has demonstrated its ability to increase its distribution raising spatially its importance as a vector for zoonotic hemotropic pathogens. In this study, a global ecological niche model of R. microplus was built in different scenarios using Representative Concentration Pathway (RCP), Socio-Economic Pathway (SSP), and a climatic dataset to determine where the species could establish itself and thus affect the variability in the presentation of the hemotropic diseases they transmit. America, Africa and Oceania showed a higher probability for the presence of R. microplus in contrast to some countries in Europe and Asia in the ecological niche for the current period (1970-2000), but with the climate change, there was an increase in the ratio between the geographic range preserved between the RCP and SSP scenarios obtaining the greatest gain in the interplay of RCP4.5-SSP245. Our results allow to determine future changes in the distribution of the cattle tick according to the increase in environmental temperature and socio-economic development influenced by human development activities and trends; this work explores the possibility of designing integral maps between the vector and specific diseases.


Asunto(s)
Enfermedades de los Bovinos , Ixodidae , Rhipicephalus , Infestaciones por Garrapatas , Humanos , Bovinos , Animales , Cambio Climático , Infestaciones por Garrapatas/veterinaria
6.
J Environ Manage ; 341: 118100, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37209591

RESUMEN

New cement-based materials such as alkali-activated binders (AABs) or geopolymers allow the incorporation of waste or industrial by-products in their formulation, resulting an interesting valorization technique. Therefore, it is essential to inquire about the potential environmental and health impacts throughout their life cycle. In the European context, a minimum aquatic toxicity tests battery has been recommended for construction products, but their potential biological effects on marine ecosystems have not been considered. In this study, three industrial by-products, PAVAL® (PV) aluminum oxide, weathered bottom ash (WBA) resulting from incinerator bottom ash and glass cullet recycling waste (CSP), were evaluated as precursors in the AAB formulation from an environmental point of view. To determine the potential effects on marine environment caused by the leaching of contaminants from these materials into seawater, the leaching test EN-12457-2 and an ecotoxicity test using the model organism sea urchin Paracentrotus lividus were conducted. The percentage of abnormal larval development was selected as endpoint of the toxicity test. Based on the results obtained from the toxicity tests, AABs have less damaging impact (EC50 values: 49.2%-51.9%) on the marine environment in general than raw materials. The results highlight the need to stablish a specific battery of toxicity tests for the environmental assessment of construction products on marine ecosystem.


Asunto(s)
Ceniza del Carbón , Ecosistema , Animales , Álcalis , Bioensayo , Desarrollo Embrionario , Erizos de Mar
7.
Helminthologia ; 60(1): 106-111, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37305665

RESUMEN

This paper aims to describe the natural infection with Dirofilaria immitis in Nasua narica (white-nosed coati) from Yucatán, Mexico. Two carcasses of N. narica were collected on a highway that crosses through a dense forest with patches used for agriculture and livestock activities. We performed necropsies, and two female adult nematode parasites from the heart of one specimen were collected and preserved for their molecular identification using a conventional PCR directed at a fragment of the small subunit (18S) ribosomal RNA (18S-rRNA) gene. Bioinformatic analysis showed a similarity of 99 % with three sequences from D. immitis (two from Japan). Additionally, we performed a phylogenetic tree with the recovered sequence. All these analyses showed that D. immitis is present in N. narica from Mexico. The transmission of D. immitis toward populations of Nasua sp. may be due to indirect and accidental contact with domestic dogs or wild canids that share the same environment.

8.
Clin Exp Dermatol ; 47(1): 57-62, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34240451

RESUMEN

BACKGROUND: Vascular malformations are a complex pathology with few treatment options. In previously published studies, oral sirolimus (rapamycin) has shown promising results in the treatment of low-flow vascular malformations, but its usefulness in high-flow vascular malformations is controversial. AIM: To evaluate the efficacy and safety of sirolimus for the treatment of high-flow vascular malformations in real-life practice. METHODS: In a unit specializing in vascular anomalies, patients treated with oral sirolimus for high-flow vascular malformations were located by consulting the drug dispensations. Reviewing the electronic medical records, data on patient demographics, vascular malformation characteristics, treatments, toxicity and clinical course were collected and statistically analysed. RESULTS: Nine patients with vascular malformations were included: eight had arteriovenous malformation and one had arteriovenous fistula. Six of these malformations were isolated while three were part of a syndrome. Sirolimus was initiated at a dosage of 1-4 mg/day to be taken as a single dose. Partial response was observed in eight of the nine patients (88.9%) with high-flow vascular malformation, while worsening was observed in the remaining patient. The treatment was well tolerated and at the most recent follow-up, five patients remained on treatment with oral sirolimus. CONCLUSION: Our results show that oral sirolimus is a well-tolerated therapeutic option, with an excellent safety profile, which can be useful in the long-term stabilization of patients with high-flow vascular malformations. Single-daily dosage may improve long-term adherence to treatment without worsening its effectiveness.


Asunto(s)
Sirolimus/administración & dosificación , Malformaciones Vasculares/tratamiento farmacológico , Administración Oral , Adolescente , Adulto , Niño , Femenino , Hemodinámica , Humanos , Masculino , Flujo Sanguíneo Regional , Sirolimus/efectos adversos , Resultado del Tratamiento , Malformaciones Vasculares/fisiopatología , Adulto Joven
9.
J Endocrinol Invest ; 44(12): 2545-2555, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34304388

RESUMEN

OBJECTIVE: To offer a practical guide for the presurgical and anesthetic management of pheochromocytomas and sympathetic paragangliomas (PGLs). METHODS: This protocol was based on a comprehensive review of the literature and on our own multidisciplinary team's experience from managing pheochromocytoma and sympathetic PGLs at a referral center. RESULTS: Patients with pheochromocytomas and sympathetic paragangliomas (PGLs) may develop potentially life-threatening complications, especially during surgical procedures. A complete biochemical, radiological, genetic, and cardiological assessment is recommended in the preoperative stage as it provides an evaluation of the risk of surgical complications and malignancy, allowing individualization of the presurgical treatment. Treatment with α-blockade and proper volume expansion in the preoperative stage significantly reduces the perioperative morbidity. During surgery, the anesthesiologist should look for a deep anesthetic level that inhibits the cardiovascular effects of catecholamines to minimize the risk of intraoperative complications. CONCLUSIONS: An optimal presurgical evaluation of pheochromocytomas/ sympathetic PGL requires a multidisciplinary approach, including a complete hormonal, radiological, cardiac, genetic, and functioning evaluation in most cases. A proper preoperative evaluation in combination with strict blood pressure and heart rate control, and blood volume status optimization, will significantly reduce the risk of intraoperative and perioperative complications. In those patients who unfortunately develop intraoperative complications, the role of the anesthesiologist is essential since the selection of the appropriate management has a direct impact on morbimortality reduction.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/cirugía , Complicaciones Intraoperatorias/prevención & control , Paraganglioma/cirugía , Feocromocitoma/cirugía , Cuidados Preoperatorios/métodos , Neoplasias de las Glándulas Suprarrenales/patología , Humanos , Paraganglioma/patología , Planificación de Atención al Paciente/normas , Feocromocitoma/patología , Guías de Práctica Clínica como Asunto , Ajuste de Riesgo
10.
Anim Genet ; 52(4): 505-508, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34106478

RESUMEN

The objectives of this study were to provide the buffalo research community with an updated SNP map for the Axiom Buffalo Genotyping (ABG) array with genomic positions for SNP currently unmapped and to map all cattle QTL from the CattleQTLdb onto the buffalo reference assembly. To update the ABG array map, all SNP probe sequences from the ABG array were re-aligned against the UOA_WB_1 assembly. With the new map, the number of mapped markers increased by approximately 10% and went from 106 778 to 116 708, which reduced the average marker spacing by approximately 2 kb. A comparison of results between signatures of autozygosity study using the ABG and the new map showed that, when the additional markers were used there was an increase in the autozygosity peaks and additional peaks in BBU5 and BBU11 could be identified. After sequence alignment and quality control, 64 650 (UMD3.1) and 76 530 (ARS_UCD1.2) cattle QTL were mapped onto the buffalo genome. The mapping of the bovine QTL database onto the buffalo genome should be useful for genome-wide association studies in buffalo and, given the high homology between the two species, the positions of cattle QTL on the buffalo genome can serve as a stepping stone towards a water buffalo QTL database.


Asunto(s)
Búfalos/genética , Estudio de Asociación del Genoma Completo/veterinaria , Genotipo , Sitios de Carácter Cuantitativo , Animales , Bovinos/genética
11.
J Eur Acad Dermatol Venereol ; 35(4): 884-891, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33030772

RESUMEN

BACKGROUND: Recent studies suggest that cutaneous melanoma mortality rates in Spain are stabilizing and even decreasing in younger cohorts. OBJECTIVES: To analyse mortality rates of melanoma from the last 40 years, focusing on changes related with the development of new therapeutic approaches. METHODS: Death records and mid-year population data were collected from the National Statistics Institute. By using the direct method, age-standardized mortality rates were calculated for overall population and for each sex and age group. Significant changes in mortality trends were identified by Joinpoint regressions. The independent effects of age, period and cohort (APC) and potential years of life lost (PYLL) due to melanoma were also analysed. RESULTS: Age-standardized melanoma mortality rates rose in Spain from 0.78 to 2.13 deaths per 100 000 from the first to the last quinquennium of the study (1979-1983 to 2014-2018) for the overall population. After a marked increase until 1995, mortality rates levelled off. Following this stabilization, from 2015 to 2018 there was a decrease in mortality rates for the overall population (average annual per cent change (AAPC): -4.3, not significant), more accused in males over 64 years old (yo). A period effect was observed from the beginning of 21st century, with mortality rates dropping to date. CONCLUSIONS: There is a decrease in melanoma mortality rates from 2015 in all age groups that confirms previous trends in mortality in younger cohorts. Improvement in diagnosis and development of new therapies for advanced melanoma may have a crucial role in this event. Close monitoring of melanoma mortality rates is necessary to confirm these trends.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Estudios de Cohortes , Humanos , Inmunoterapia , Masculino , Melanoma/terapia , Persona de Mediana Edad , Neoplasias Cutáneas/terapia , España/epidemiología
12.
J Dairy Sci ; 104(2): 1917-1927, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33272579

RESUMEN

Characterization of autozygosity is relevant to monitor genetic diversity and manage inbreeding levels in breeding programs. Identification of autozygosity hotspots can unravel genomic regions targeted by selection for economically important traits and can help identify candidate genes for selection. In this study, we estimated the inbreeding levels of a Brazilian population of Murrah buffalo undergoing selection for milk production traits, particularly milk yield. We also studied the distribution of runs of homozygosity (ROH) islands and identified putative genes and quantitative trait loci (QTL) under selection. We genotyped 422 Murrah buffalo for 51,611 SNP; 350 of these had ROH longer than 10 Mb, indicating the occurrence of inbreeding in the last 5 generations. The mean length of the ROH per animal was 4.28 ± 1.85 Mb. Inbreeding coefficients were calculated from the genomic relationship matrix, the pedigree, and the ROH, with estimates varying between 0.242 and 0.035. Inbreeding estimates from the pedigree had a low correlation with the genomic estimates, and estimates from the genomic relationship matrix were much higher than those from the pedigree or the ROH. Signatures of selection were identified in 6 genomic regions, located on chromosomes 1, 2, 3, 5, 16, and 18, encompassing a total of 190 genes and 174 QTL. Many of the genes (e.g., APRT and ACSF3) and QTL identified are related to milk production traits, such as milk yield, milk fat yield and percentage, and milk protein yield and percentage. Other genes are associated with reproduction and immune response traits as well as morphological aspects of the buffalo species. Inbreeding levels in this population are still low but are increasing due to selection and should be managed to avoid future losses due to inbreeding depression. The proximity of genes linked to milk production traits with genes associated with reproduction and immune system traits suggests the need to include these latter genes in the breeding program to avoid negatively affecting them due to selection for production traits.


Asunto(s)
Búfalos/genética , Genómica , Leche/metabolismo , Reproducción , Animales , Brasil , Búfalos/fisiología , Femenino , Genotipo , Homocigoto , Endogamia , Masculino , Linaje , Fenotipo , Sitios de Carácter Cuantitativo/genética
13.
Exp Appl Acarol ; 85(1): 113-129, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34431045

RESUMEN

The southern cattle tick Rhipicephalus microplus is a major problem for the cattle industry in tropical and subtropical areas worldwide. Chemical products are commonly applied to control it; however, their indiscriminate use has resulted in the appearance of resistant lineages. In the last decades, plants have been used as an alternative to conventional acaricidal drugs, as several plant compounds repel activity, decrease the reproductive potential and reduce the survival rate of ticks. For this reason, the in vitro efficacy of hexanic and hydroalcoholic extracts of Randia aculeata, Moringa oleifera and Carica papaya were evaluated against the larvae and engorged females of R. microplus. Larval packet tests and adult immersion tests were performed with seven concentrations of each of the extracts. The extracts obtained with hydroethanolic solution (polar solvent) exhibited a higher acaricidal activity than extracts prepared with n-hexane (non-polar solvent). Hydroethanolic extracts of R. aculeata seed and shell showed the highest larvicidal activity against R. microplus (100 and 91% mortality, respectively) at a concentration of 100 mg/mL. Randia aculeata (seed and shell), M. oleifera and C. papaya treatments at the same concentration (100 mg/mL) also resulted in adult mortality of 85, 75, 66 and 55%, respectively. The adult immersion test showed that hydroethanolic extracts derived from R. aculeata seed significantly reduced the index of egg laying and increased the percentage inhibition of oviposition of female ticks at a concentration of 100 mg/mL. These results indicate that the tested extracts exhibit acaricidal activity and could be considered as potential agents for the development of alternative natural acaricides against R. microplus.


Asunto(s)
Acaricidas , Ixodidae , Plantas Medicinales , Rhipicephalus , Animales , Larva , Extractos Vegetales/farmacología
14.
J Hum Evol ; 142: 102736, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32193025

RESUMEN

Despite the scarcity of fossil specimens of Theropithecus oswaldi in Eurasia, its presence out of Africa attests to the great dispersal of this Papionini genus during the Early Pleistocene. In the present study, we analyze the buccal dental microwear of T. oswaldi (T. o. leakeyi) fossil specimens from Cueva Victoria (Southeastern Spain). This analysis is the first characterization of the feeding ecology of T. oswaldi in Europe. The buccal microwear pattern of the molar and premolar teeth of T. oswaldi from Cueva Victoria shows great similarities to that observed for the extant frugivorous forest-dwelling Mandrillus sphinx and mangabeys (Cercocebus sp.)-both species adapted to durophagous dietary habits-while significantly different from that observed for the gramnivorous Theropithecus gelada. These results suggest that T. oswaldi from Cueva Victoria could have exploited both hard-shelled fruits or seeds and succulent fruits from open and forested Mediterranean ecosystems.


Asunto(s)
Dieta/veterinaria , Fósiles/anatomía & histología , Theropithecus/fisiología , Desgaste de los Dientes/veterinaria , Diente/anatomía & histología , Animales , Conducta Alimentaria , España , Desgaste de los Dientes/patología
15.
Geophys Res Lett ; 47(1): e2019GL085776, 2020 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-32713973

RESUMEN

We investigate the launch of negative upward streamers from sprite glows. This phenomenon is readily observed in high-speed observations of sprites and underlies the classification of sprites into carrot or column types. First, we describe how an attachment instability leads to a sharply defined region in the upper part of the streamer channel. This region has an enhanced electric field, low conductivity and strongly emits in the first positive system of molecular nitrogen. We identify it as the sprite glow. We then show how, in the most common configuration of a carrot sprite, several upward streamers emerge close to the lower boundary of the glow, where negative charge gets trapped and the lateral electric field is high enough. These streamers cut off the current flowing toward the glow and lead to the optical deactivation of the glow above. Finally, we discuss how our results naturally explain angel sprites.

17.
Mol Psychiatry ; 23(5): 1169-1180, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29155802

RESUMEN

Anorexia nervosa (AN) is a complex neuropsychiatric disorder presenting with dangerously low body weight, and a deep and persistent fear of gaining weight. To date, only one genome-wide significant locus associated with AN has been identified. We performed an exome-chip based genome-wide association studies (GWAS) in 2158 cases from nine populations of European origin and 15 485 ancestrally matched controls. Unlike previous studies, this GWAS also probed association in low-frequency and rare variants. Sixteen independent variants were taken forward for in silico and de novo replication (11 common and 5 rare). No findings reached genome-wide significance. Two notable common variants were identified: rs10791286, an intronic variant in OPCML (P=9.89 × 10-6), and rs7700147, an intergenic variant (P=2.93 × 10-5). No low-frequency variant associations were identified at genome-wide significance, although the study was well-powered to detect low-frequency variants with large effect sizes, suggesting that there may be no AN loci in this genomic search space with large effect sizes.


Asunto(s)
Anorexia Nerviosa/genética , Moléculas de Adhesión Celular/genética , Exoma/genética , Familia , Femenino , Proteínas Ligadas a GPI/genética , Predisposición Genética a la Enfermedad/genética , Variación Genética/genética , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Intrones/genética , Masculino , Fenotipo , Polimorfismo de Nucleótido Simple/genética , Población Blanca/genética
18.
Geophys Res Lett ; 46(7): 4029-4038, 2019 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-31244497

RESUMEN

We investigate the emergence of space stems ahead of negative leaders. These are luminous spots that appear ahead of an advancing leader mediating the leader's stepped propagation. We show that space stems start as regions of locally depleted conductivity that form in the streamers of the corona around the leader. An attachment instability enhances the electric field leading to strongly inhomogeneous, bright, and locally warmer regions ahead of the leader that explain the existing observations. Since the attachment instability is only triggered by fields above 10 kV/cm and internal electric fields are lower in positive than in negative streamers, our results explain why, although common in negative leaders, space stems, and stepping are hardly observed if not absent in positive leaders. Further work is required to fully explain the streamer to leader transition, which requires an electric current persisting for timescales longer than the typical attachment time of electrons, around 100 ns.

19.
Phys Chem Chem Phys ; 21(36): 20118-20131, 2019 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-31482890

RESUMEN

A classical interatomic potential for iron/iron-fluoride systems is developed in the framework of the charge optimized many-body (COMB) potential. This interatomic potential takes into consideration the effects of charge transfer and many-body interactions depending on the chemical environment. The potential is fitted to a training set composed of both experimental and ab initio results of the cohesive energies of several Fe and FeF2 crystal phases, the two fluorine molecules F2 and the F2-1 dissociation energy curve, the Fe and FeF2 lattice parameters of the ground state crystalline phase, and the elastic constants of the body centered cubic Fe structure. The potential is tested in an NVT ensemble for different initial structural configurations as the crystal ground state phases, F2 molecules, iron clusters, and iron nanospheres. In particular, we model the FeF2/Fe bilayer and multilayer interfaces, as well as a system of square FeF2 nanowires immersed in an iron solid. It has been shown that there exists a reordering of the atomic positions for F and Fe atoms at the interface zone; this rearrangement leads to an increase in the charge transfer among the atoms that make the interface and put forward a possible mechanism of the exchange bias origin based on asymmetric electric charge transfer in the different spin channels.

20.
Bull Environ Contam Toxicol ; 102(4): 486-491, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30953087

RESUMEN

A single specimen of the anemone Paraphelliactis pabista was recovered from the Southern Trough of Guaymas Basin during the deep-sea expedition Extreme 2008 conducted onboard the R/V Atlantis/DSRV-2 ALVIN. We studied the bioaccumulation capacity of heavy metals in various tissues of the anemone (oral disk-columella-pedal disk), and retention or adhesion of mineral particles in the epidermis, mesoglea, and gastrodermis. The digested tissues were analyzed for As, Ba, Co, Cu, Cr, Fe, Mn, Ni, Pb, Se, Sb, Sr, Ti, V, and Zn by inductively coupled plasma mass spectrometry. This analysis revealed the capacity of P. pabista for accumulating heavy metals. The predominant mineral particles identified in tissue samples was barite followed by Fe, aluminum-silicates, Sr, and with less presence Cr, Ti, and pyrite. Of the three body compartments analyzed of this anemone, the oral and pedal disks show a greater capacity of bioaccumulation of heavy metals than the columella.


Asunto(s)
Monitoreo del Ambiente/métodos , Metales Pesados/análisis , Anémonas de Mar/efectos de los fármacos , Agua de Mar/química , Contaminantes Químicos del Agua/análisis , Animales , Disponibilidad Biológica , California , Sedimentos Geológicos/química , Calor , Anémonas de Mar/metabolismo
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