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1.
Phys Rev Lett ; 132(12): 126502, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38579201

RESUMEN

LiCu_{3}O_{3} is an antiferromagnetic mixed valence cuprate where trilayers of edge-sharing Cu(II)O (3d^{9}) are sandwiched in between planes of Cu(I) (3d^{10}) ions, with Li stochastically substituting Cu(II). Angle-resolved photoemission spectroscopy (ARPES) and density functional theory reveal two insulating electronic subsystems that are segregated in spite of sharing common oxygen atoms: a Cu d_{z^{2}}/O p_{z} derived valence band (VB) dispersing on the Cu(I) plane, and a Cu 3d_{x^{2}-y^{2}}/O 2p_{x,y} derived Zhang-Rice singlet (ZRS) band dispersing on the Cu(II)O planes. First-principle analysis shows the Li substitution to stabilize the insulating ground state, but only if antiferromagnetic correlations are present. Li further induces substitutional disorder and a 2D electron glass behavior in charge transport, reflected in a large 530 meV Coulomb gap and a linear suppression of VB spectral weight at E_{F} that is observed by ARPES. Surprisingly, the disorder leaves the Cu(II)-derived ZRS largely unaffected. This indicates a local segregation of Li and Cu atoms onto the two separate corner-sharing Cu(II)O_{2} sub-lattices of the edge-sharing Cu(II)O planes, and highlights the ubiquitous resilience of the entangled two hole ZRS entity against impurity scattering.

2.
Phys Rev Lett ; 129(24): 246404, 2022 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-36563241

RESUMEN

The electronic structure of Weyl semimetals features Berry flux monopoles in the bulk and Fermi arcs at the surface. While angle-resolved photoelectron spectroscopy (ARPES) is successfully used to map the bulk and surface bands, it remains a challenge to explicitly resolve and pinpoint these topological features. Here we combine state-of-the-art photoemission theory and experiments over a wide range of excitation energies for the Weyl semimetals TaAs and TaP. Our results show that simple surface-band-counting schemes, proposed previously to identify nonzero Chern numbers, are ambiguous due to pronounced momentum-dependent spectral weight variations and the pronounced surface-bulk hybridization. Instead, our findings indicate that dichroic ARPES provides an improved approach to identify Fermi arcs but requires an accurate description of the photoelectron final state.

3.
J Theor Biol ; 545: 111145, 2022 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-35490763

RESUMEN

The many respiratory viruses that cause influenza-like illness (ILI) are reported and tracked as one entity, defined by the CDC as a group of symptoms that include a fever of 100 degrees Fahrenheit, a cough, and/or a sore throat. In the United States alone, ILI impacts 9-49 million people every year. While tracking ILI as a single clinical syndrome is informative in many respects, the underlying viruses differ in parameters and outbreak properties. Most existing models treat either a single respiratory virus or ILI as a whole. However, there is a need for models capable of comparing several individual viruses that cause respiratory illness, including ILI. To address this need, here we present a flexible model and simulations of epidemics for influenza, RSV, rhinovirus, seasonal coronavirus, adenovirus, and SARS/MERS, parameterized by a systematic literature review and accompanied by a global sensitivity analysis. We find that for these biological causes of ILI, their parameter values, timing, prevalence, and proportional contributions differ substantially. These results demonstrate that distinguishing the viruses that cause ILI will be an important aspect of future work on diagnostics, mitigation, modeling, and preparation for future pandemics.


Asunto(s)
Epidemias , Gripe Humana , Virosis , Virus , Humanos , Gripe Humana/diagnóstico , Gripe Humana/epidemiología , Rhinovirus , Virosis/epidemiología
4.
Phys Rev Lett ; 125(7): 076401, 2020 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-32857568

RESUMEN

In nodal-line semimetals, linearly dispersing states form Dirac loops in the reciprocal space with a high degree of electron-hole symmetry and a reduced density of states near the Fermi level. The result is reduced electronic screening and enhanced correlations between Dirac quasiparticles. Here we investigate the electronic structure of ZrSiSe, by combining time- and angle-resolved photoelectron spectroscopy with ab initio density functional theory (DFT) complemented by an extended Hubbard model (DFT+U+V) and by time-dependent DFT+U+V. We show that electronic correlations are reduced on an ultrashort timescale by optical excitation of high-energy electrons-hole pairs, which transiently screen the Coulomb interaction. Our findings demonstrate an all-optical method for engineering the band structure of a quantum material.

5.
Phys Rev Lett ; 125(21): 216402, 2020 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-33274982

RESUMEN

Trigonal tellurium, a small-gap semiconductor with pronounced magneto-electric and magneto-optical responses, is among the simplest realizations of a chiral crystal. We have studied by spin- and angle-resolved photoelectron spectroscopy its unconventional electronic structure and unique spin texture. We identify Kramers-Weyl, composite, and accordionlike Weyl fermions, so far only predicted by theory, and show that the spin polarization is parallel to the wave vector along the lines in k space connecting high-symmetry points. Our results clarify the symmetries that enforce such spin texture in a chiral crystal, thus bringing new insight in the formation of a spin vectorial field more complex than the previously proposed hedgehog configuration. Our findings thus pave the way to a classification scheme for these exotic spin textures and their search in chiral crystals.

6.
J Viral Hepat ; 25(7): 870-873, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29316001

RESUMEN

An important subgroup of people who inject drugs (PWID) receiving opioid agonist therapy (OAT) cannot be treated in the setting of a hepatology centre and would not regularly ingest their medication when handed to them for self-administration. Our hypothesis was that chronic hepatitis C in these patients could be ideally managed if modern, interferon-free regimens were administered together with OAT under direct observation of a physician or nurse at a low-threshold facility. In this open-label, noninterventional, proof-of-concept study (ClinicalTrials.gov number, NCT02638233), 40 PWID at risk of nonadherence to direct-acting antivirals (DAA) and previously untreated chronic hepatitis C virus genotype 1 infection without cirrhosis were treated with ledipasvir/sofosbuvir for 8 weeks. Patients received antiviral treatment together with OAT under direct observation of a physician or nurse at a low-threshold facility. By following the concept of directly observed therapy, excellent adherence to antiviral therapy was achieved as follows: only 0.16% (95% CI: 0.03-0.47) of scheduled dates for ingestion of the antiviral therapy in combination with OAT were missed by the 40 patients. The rate of sustained virological response 12 weeks after end of therapy was 100% (95% CI: 91.2-100.0). Between week 12 and week 24 of follow-up reinfections were recorded in 2 of 40 patients (5%). Directly observed therapy of chronic hepatitis C is highly effective in PWID at risk of nonadherence to DAA. By this new concept, a group of difficult-to-treat patients can be cured, who could not have been treated in settings of studies published so far.


Asunto(s)
Antivirales/administración & dosificación , Bencimidazoles/administración & dosificación , Terapia por Observación Directa , Fluorenos/administración & dosificación , Hepatitis C Crónica/tratamiento farmacológico , Sofosbuvir/administración & dosificación , Abuso de Sustancias por Vía Intravenosa/complicaciones , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Genotipo , Hepacivirus/clasificación , Hepacivirus/genética , Hepacivirus/aislamiento & purificación , Humanos , Masculino , Cumplimiento de la Medicación , Persona de Mediana Edad , Respuesta Virológica Sostenida , Resultado del Tratamiento , Adulto Joven
7.
J Appl Microbiol ; 125(2): 513-527, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29624801

RESUMEN

AIMS: Straw wine is a highly valuable oenological production, affected by relevant economical losses due to proliferation of spoilage micro-organisms during drying grapes, after being harvested. In this work, ozone was evaluated as a tool to preserve grapes during drying, in terms of both qualitative and quantitative changes induced in the epiphytic microflora. In addition, the alteration exerted by ozone on grapes' chemical composition was analysed. METHODS AND RESULTS: Grapes from four vine varieties were treated with ozone produced by a cold plasma generator during the entire drying period (6 weeks). The microflora was quantified weekly by plate counts and characterized by 454-pyrosequencing, and was compared with identical, untreated grape samples. At the end of drying, an extensive chemical characterization of the whole mass of grapes by FT-IR and GC-MS was performed. Ozone counteracted the growth of microflora by reducing the microbial population up to 3 log units. From the qualitative point of view, ozone reduced the incidence of spoilage micro-organisms, such as Acetobacter and Botrytis cinerea, among the microbiota of grapes. CONCLUSIONS: The statistical analysis discriminates grape samples based on the residual epiphytic microflora at the end of drying and not on their chemical composition. These evidences confirmed that ozone did control spoilage micro-organisms without altering the volatile profile of grapes. Chemical analysis revealed that untreated grapes are less suitable for winemaking owing to the deprivation of some valuable compounds during the microbial proliferation. SIGNIFICANCE AND IMPACT OF THE STUDY: Ozone is an emerging tool in winemaking, recently applied for controlling spoilage micro-organisms in winery. The present study describes a new application of ozone as an effective and safe alternative to chemical preservatives which are actually involved in the control of microbial alterations of grapes.


Asunto(s)
Manipulación de Alimentos/métodos , Microbiota/efectos de los fármacos , Ozono/farmacología , Vitis , Vino , Vitis/química , Vitis/efectos de los fármacos , Vino/análisis , Vino/microbiología
9.
Phys Rev Lett ; 118(17): 176404, 2017 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-28498707

RESUMEN

We measured, by angle-resolved photoemission spectroscopy, the electronic structure of LiCu_{2}O_{2}, a mixed-valence cuprate where planes of Cu(I) (3d^{10}) ions are sandwiched between layers containing one-dimensional edge-sharing Cu(II) (3d^{9}) chains. We find that the Cu(I)- and Cu(II)-derived electronic states form separate electronic subsystems, in spite of being coupled by bridging O ions. The valence band, of the Cu(I) character, disperses within the charge-transfer gap of the strongly correlated Cu(II) states, displaying an unprecedented 250% broadening of the bandwidth with respect to the predictions of density functional theory. Our observation is at odds with the widely accepted tenet of many-body theory that correlation effects generally yield narrower bands and larger electron masses and suggests that present-day electronic structure techniques provide an intrinsically inappropriate description of ligand-to-d hybridizations in late transition metal oxides.

10.
Allergy ; 72(5): 754-763, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27753449

RESUMEN

BACKGROUND: Allergen-specific IgE antibodies are a hallmark of type I allergy. The aim of this cross-sectional study was to analyze the sensitization profiles of an Austrian adolescent population utilizing molecule-based IgE diagnosis. METHODS: Serum samples of 501 nonselected pupils from Salzburg, Austria, were tested in ImmunoCAP ISAC® for IgE reactivity to 112 single allergens. Sensitization profiles were assessed and statistically coordinated with reported allergies. RESULTS: In the population aged 12-21 years, 53.5% showed IgE reactivity to at least one allergen tested. The highest prevalence was found for Phl p 1 from grass pollen (26.5%), group 2 mite allergens (18.2%), Bet v 1 from birch pollen (16.3%) and Fel d 1 from cat (14.4%). The majority of participants showed a complex sensitization profile and reacted on average to 9 allergens. Pollen sensitization was highly prevalent (41.7%) and mainly driven by group I grass and PR-10 allergens of the Betulaceae family, while Pla l 1 represented the most relevant weed. Diagnosed and self-reported allergies were noted in 21.9% and 45.5% of participants, respectively, and correlated well with in vitro results. Among atopic individuals, 71.4% reported to suffer from at least one allergy; concordance was found for grass and cat sensitization, while venom- and weed pollen-positive individuals were frequently asymptomatic. CONCLUSIONS: More than half of the tested adolescent population had already established an atopic status presenting a complex IgE reactivity profile dominated by pollen sensitization. Detailed molecule-based analysis allows determining relevant biomarkers and monitoring of the atopic status in populations.


Asunto(s)
Alérgenos/inmunología , Hipersensibilidad/epidemiología , Hipersensibilidad/inmunología , Inmunoglobulina E/inmunología , Adolescente , Adulto , Austria/epidemiología , Niño , Estudios Transversales , Femenino , Humanos , Hipersensibilidad/diagnóstico , Hipersensibilidad Inmediata/epidemiología , Hipersensibilidad Inmediata/inmunología , Masculino , Prevalencia , Adulto Joven
11.
HNO ; 65(8): 671-679, 2017 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-28271168

RESUMEN

BACKGROUND: Age-related hearing loss is one of the most common chronic sensory impairments in the older population. This chronic condition is associated with bio-psychosocial consequences such as cognitive decline, depression, withdrawal, isolation, and reduced wellbeing. OBJECTIVE: This study aimed to investigate the perception of hearing problems among older women and men (≥55 years) with age-related hearing loss. Furthermore, the association between functional hearing loss and perceived hearing problems was examined. Lastly, this study undertook a detailed investigation of subjective experiences in order to better understand the consequences of age-related hearing loss for daily life. MATERIALS AND METHODS: With the aid of mixed methods, quantitative data were gathered from 65 participants with age-related hearing impairment in Austria using the Hearing Handicap Inventory for the Elderly (HHIE). Moreover, qualitative data regarding experiences with hearing problems were collected by performing semi-structured problem-centered interviews and analyzing the results of a further 14 older adults with hearing loss. RESULTS: On average, participants assessed their hearing handicap as mild and perceived consequences on emotional, social, and communication levels. Moreover, feelings of insecurity were evident. In addition, the findings indicate a relationship but also a discrepancy between hearing loss and hearing handicap, i. e., not all participants perceived a hearing handicap. CONCLUSION: Patient-centered care encompassing (1) objective and self-report measures for assessing hearing problems, (2) involvement of family members and significant others, (3) counseling and exchange of information, and (4) a shared decision-making approach could enhance quality of life and quality of care.


Asunto(s)
Audífonos , Pérdida Auditiva , Anciano , Austria , Femenino , Pruebas Auditivas , Humanos , Masculino , Calidad de Vida , Encuestas y Cuestionarios
12.
Epidemiol Infect ; 144(8): 1748-55, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27125574

RESUMEN

Vancomycin-resistant enterococci (VRE) infections are a public health threat associated with increased patient mortality and healthcare costs. Antibiotic usage, particularly cephalosporins, has been associated with VRE colonization and VRE bloodstream infections (VRE BSI). We examined the relationship between antimicrobial usage and incident VRE colonization at the individual patient level. Prospective, weekly surveillance was undertaken for incident VRE colonization defined by negative admission but positive surveillance swab in a medical intensive care unit over a 17-month period. Antimicrobial exposure was quantified as days of therapy (DOT)/1000 patient-days. Multiple logistic regression was used to analyse incident VRE colonization and antibiotic DOT, controlling for demographic and clinical covariates. Ninety-six percent (1398/1454) of admissions were swabbed within 24 h of intensive care unit (ICU) arrival and of the 380 patients in the ICU long enough for weekly surveillance, 83 (22%) developed incident VRE colonization. Incident colonization was associated in bivariate analysis with male gender, more previous hospital admissions, longer previous hospital stay, and use of cefepime/ceftazidime, fluconazole, azithromycin, and metronidazole (P < 0·05). After controlling for demographic and clinical covariates, metronidazole was the only antibiotic independently associated with incident VRE colonization (odds ratio 2·0, 95% confidence interval 1·2-3·3, P < 0·009). Our findings suggest that risk of incident VRE colonization differs between individual antibiotic agents and support the possibility that antimicrobial stewardship may impact VRE colonization and infection.


Asunto(s)
Antibacterianos/uso terapéutico , Portador Sano/epidemiología , Portador Sano/microbiología , Utilización de Medicamentos , Infecciones por Bacterias Grampositivas/epidemiología , Infecciones por Bacterias Grampositivas/microbiología , Enterococos Resistentes a la Vancomicina/aislamiento & purificación , Adulto , Anciano , Monitoreo Epidemiológico , Femenino , Humanos , Incidencia , Unidades de Cuidados Intensivos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo
13.
Br J Anaesth ; 116(3): 405-12, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26865133

RESUMEN

BACKGROUND: Ultrasound guidance allows for the use of much lower volumes of local anaesthetics for nerve blocks, which may be associated with less aberrant spread and fewer complications. This randomized, controlled study used contrast magnetic resonance imaging to view the differential-volume local anaesthetic distribution, and compared analgesic efficacy and respiratory impairment. METHODS: Thirty patients undergoing shoulder surgery were randomized to receive ultrasound-guided interscalene block by a single, blinded operator with injection of ropivacaine 0.75% (either 20 or 5 ml) plus the contrast dye gadopentetate dimeglumine, followed by magnetic resonance imaging. The primary outcome was epidural spread. Secondary outcomes were central non-epidural spread, contralateral epidural spread, spread to the phrenic nerve, spirometry, ultrasound investigation of the diaphragm, block duration, pain scores during the first 24 h, time to first analgesic consumption, and total analgesic consumption. RESULTS: All blocks provided fast onset and adequate intra- and postoperative analgesia, with no significant differences in pain scores at any time point. Epidural spread occurred in two subjects of each group (13.3%); however, spread to the intervertebral foramen and phrenic nerve and extensive i.m. local anaesthetic deposition were significantly more frequent in the 20 ml group. Diaphragmatic paralysis occurred twice as frequently (n=8 vs 4), and changes from baseline peak respiratory flow rate were larger [Δ=-2.66 (1.99 sd) vs -1.69 (2.0 sd) l min(-1)] in the 20 ml group. CONCLUSIONS: This study demonstrates that interscalene block is associated with epidural spread irrespective of injection volume; however, less central (foraminal) and aberrant spread after low-volume injection may be associated with a more favourable risk profile. CLINICAL TRIAL REGISTRATION: This study was registered with the European Medicines Agency (Eudra-CT number 2013-004219-36) and with the US National Institutes' of Health registry and results base, clinicaltrials.gov (identifier NCT02175069).


Asunto(s)
Anestésicos Locales/farmacocinética , Medios de Contraste , Imagen por Resonancia Magnética , Bloqueo Nervioso , Nervio Frénico/efectos de los fármacos , Ultrasonografía Intervencional , Adolescente , Adulto , Anciano , Amidas/farmacocinética , Plexo Braquial/diagnóstico por imagen , Plexo Braquial/efectos de los fármacos , Espacio Epidural , Femenino , Gadolinio DTPA , Humanos , Aumento de la Imagen , Masculino , Persona de Mediana Edad , Ropivacaína , Hombro/cirugía , Distribución Tisular , Adulto Joven
14.
Phys Rev Lett ; 115(9): 096404, 2015 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-26371668

RESUMEN

We investigate the polaronic ground state of anatase TiO2 by bulk-sensitive resonant inelastic x-ray spectroscopy (RIXS) at the Ti L3 edge. We find that the formation of the polaron cloud involves a single 95 meV phonon along the c axis, in addition to the 108 meV ab-plane mode previously identified by photoemission. The coupling strength to both modes is the same within error bars, and it is unaffected by the carrier density. These data establish RIXS as a directional bulk-sensitive probe of electron-phonon coupling in solids.

15.
J Econ Entomol ; 108(6): 2761-9, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26318006

RESUMEN

In 2012 and 2013, field trials were conducted near Rosemount, MN, to assess the movement and development of Helicoverpa zea (Boddie) larvae on non-Bt refuge corn plants within a seed mixture of non-Bt and Bt corn. The Bt corn hybrid expressed three Bt toxins-Cry1Ab, Cry1F, and Vip3A. As the use of seed mixtures for insect resistance management (IRM) continues to be implemented, it is necessary to further characterize how this IRM approach impacts resistance development in ear-feeding Lepidopteran pests. The potential for Bt pollen movement and cross pollination of the non-Bt ears in a seed mixture may lead to Bt toxin exposure to larvae developing on those refuge ears. Larval movement and development by H. zea, feeding on non-Bt refuge plants adjacent to either transgenic Bt or non-Bt plants, were measured to investigate the potential for unintended Bt exposure. Non-Bt plants were infested with H. zea eggs and subplots were destructively sampled twice per week within each treatment to assess larval development, location, and kernel injury. Results indicate that H. zea larval movement between plants is relatively low, ranging from 2-16% of larvae, and occurs mainly after reaching the second instar. Refuge plants in seed mixtures did not produce equivalent numbers of H. zea larvae, kernel injury, and larval development differed as compared with a pure stand of non-Bt plants. This suggests that there may be costs to larvae developing on refuge plants within seed mixtures and additional studies are warranted to define potential impacts.


Asunto(s)
Mariposas Nocturnas/crecimiento & desarrollo , Zea mays , Animales , Toxinas de Bacillus thuringiensis , Proteínas Bacterianas , Endotoxinas , Proteínas Hemolisinas , Resistencia a los Insecticidas , Larva/crecimiento & desarrollo , Plantas Modificadas Genéticamente , Dinámica Poblacional
16.
Am J Transplant ; 14(1): 133-43, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24354873

RESUMEN

In this study, we analyze the outcomes of transplant renal artery stenosis (TRAS), determine the different anatomical positions of TRAS, and establish cardiovascular and immunological risk factors associated with its development. One hundred thirty-seven of 999 (13.7%) patients had TRAS diagnosed by angiography; 119/137 (86.9%) were treated with angioplasty, of which 113/137 (82.5%) were stented. Allograft survival in the TRAS+ intervention, TRAS+ nonintervention and TRAS- groups was 80.4%, 71.3% and 83.1%, respectively. There was no difference in allograft survival between the TRAS+ intervention and TRAS- groups, p = 0.12; there was a difference in allograft survival between the TRAS- and TRAS+ nonintervention groups, p < 0.001, and between the TRAS+ intervention and TRAS+ nonintervention groups, p = 0.037. TRAS developed at the anastomosis, within a bend/kink or distally. Anastomotic TRAS developed in living donor recipients; postanastomotic TRAS (TRAS-P) developed in diabetic and older patients who received grafts from deceased, older donors. Compared with the TRAS- group, patients with TRAS-P were more likely to have had rejection with arteritis, odds ratio (OR): 4.83 (1.47-15.87), p = 0.0095, and capillaritis, OR: 3.03 (1.10-8.36), p = 0.033. Patients with TRAS-P were more likely to have developed de novo class II DSA compared with TRAS- patients hazard ratio: 4.41 (2.0-9.73), p < 0.001. TRAS is a heterogeneous condition with TRAS-P having both alloimmune and traditional cardiovascular risk factors.


Asunto(s)
Anticuerpos/análisis , Antígenos de Histocompatibilidad Clase II/inmunología , Trasplante de Riñón/efectos adversos , Obstrucción de la Arteria Renal/inmunología , Donantes de Tejidos , Adulto , Anciano , Angiografía de Substracción Digital/efectos adversos , Femenino , Rechazo de Injerto/etiología , Supervivencia de Injerto , Humanos , Masculino , Persona de Mediana Edad , Obstrucción de la Arteria Renal/diagnóstico , Obstrucción de la Arteria Renal/cirugía , Factores de Riesgo , Stents , Resultado del Tratamiento
17.
Phys Rev Lett ; 113(18): 187001, 2014 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-25396389

RESUMEN

We investigate by angle-resolved photoemission the electronic structure of in situ grown tetragonal CuO, a synthetic quasi-two-dimensional edge-sharing cuprate. We show that, in spite of the very different nature of the copper oxide layers, with twice as many Cu in the CuO layers of tetragonal CuO as compared to the CuO(2) layers of the high-T(c) cuprates, the low-energy electronic excitations are surprisingly similar, with a Zhang-Rice singlet dispersing on weakly coupled cupratelike sublattices. This system should thus be considered as a member of the high-T(c) cuprate family, with, however, interesting differences due to the intralayer coupling between the cupratelike sublattices.

18.
Geohealth ; 8(6): e2024GH001024, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38912225

RESUMEN

Many infectious disease forecasting models in the United States (US) are built with data partitioned into geopolitical regions centered on human activity as opposed to regions defined by natural ecosystems; although useful for data collection and intervention, this has the potential to mask biological relationships between the environment and disease. We explored this concept by analyzing the correlations between climate and West Nile virus (WNV) case data aggregated to geopolitical and ecological regions. We compared correlations between minimum, maximum, and mean annual temperature; precipitation; and annual WNV neuroinvasive disease (WNND) case data from 2005 to 2019 when partitioned into (a) climate regions defined by the National Oceanic and Atmospheric Administration (NOAA) and (b) Level I ecoregions defined by the Environmental Protection Agency (EPA). We found that correlations between climate and WNND in NOAA climate regions and EPA ecoregions were often contradictory in both direction and magnitude, with EPA ecoregions more often supporting previously established biological hypotheses and environmental dynamics underlying vector-borne disease transmission. Using ecological regions to examine the relationships between climate and disease cases can enhance the predictive power of forecasts at various scales, motivating a conceptual shift in large-scale analyses from geopolitical frameworks to more ecologically meaningful regions.

19.
Phys Rev Lett ; 110(19): 196403, 2013 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-23705725

RESUMEN

Oxygen vacancies created in anatase TiO(2) by UV photons (80-130 eV) provide an effective electron-doping mechanism and induce a hitherto unobserved dispersive metallic state. Angle resolved photoemission reveals that the quasiparticles are large polarons. These results indicate that anatase can be tuned from an insulator to a polaron gas to a weakly correlated metal as a function of doping and clarify the nature of conductivity in this material.

20.
Phys Rev Lett ; 110(23): 236401, 2013 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-25167517

RESUMEN

We report a comprehensive study of the paradigmatic quasi-1D compound (TaSe(4))(2)I performed by means of angle-resolved photoemission spectroscopy (ARPES) and first-principles electronic structure calculations. We find it to be a zero-gap semiconductor in the nondistorted structure, with non-negligible interchain coupling. Theory and experiment support a Peierls-like scenario for the charge-density wave formation below T(CDW)=263 K, where the incommensurability is a direct consequence of the finite interchain coupling. The formation of small polarons, strongly suggested by the ARPES data, explains the puzzling semiconductor-to-semiconductor transition observed in transport at T(CDW).

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