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1.
Behav Res Methods ; 56(3): 1863-1899, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37382812

RESUMEN

Interest in the psychology of misinformation has exploded in recent years. Despite ample research, to date there is no validated framework to measure misinformation susceptibility. Therefore, we introduce Verification done, a nuanced interpretation schema and assessment tool that simultaneously considers Veracity discernment, and its distinct, measurable abilities (real/fake news detection), and biases (distrust/naïvité-negative/positive judgment bias). We then conduct three studies with seven independent samples (Ntotal = 8504) to show how to develop, validate, and apply the Misinformation Susceptibility Test (MIST). In Study 1 (N = 409) we use a neural network language model to generate items, and use three psychometric methods-factor analysis, item response theory, and exploratory graph analysis-to create the MIST-20 (20 items; completion time < 2 minutes), the MIST-16 (16 items; < 2 minutes), and the MIST-8 (8 items; < 1 minute). In Study 2 (N = 7674) we confirm the internal and predictive validity of the MIST in five national quota samples (US, UK), across 2 years, from three different sampling platforms-Respondi, CloudResearch, and Prolific. We also explore the MIST's nomological net and generate age-, region-, and country-specific norm tables. In Study 3 (N = 421) we demonstrate how the MIST-in conjunction with Verification done-can provide novel insights on existing psychological interventions, thereby advancing theory development. Finally, we outline the versatile implementations of the MIST as a screening tool, covariate, and intervention evaluation framework. As all methods are transparently reported and detailed, this work will allow other researchers to create similar scales or adapt them for any population of interest.


Asunto(s)
Comunicación , Juicio , Humanos , Psicometría/métodos , Lenguaje , Análisis Factorial
3.
An Acad Bras Cienc ; 95(1): e20201503, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37222358

RESUMEN

Quantitative data obtained from native forests is costly and time-consuming. Thus, alternative measurement methods need to be developed to provide reliable information, especially in Atlantic Rain Forests. In this study we evaluated the hypothesis that the combination of an Airborne Laser Scanner (ALS) and an Unmanned Aerial Vehicle (UAV) can provide accurate quantitative information on tree height, volume, and aboveground biomass of the Araucaria angustifolia species. The study was carried out in Atlantic Rain forest fragments in southern Brazil. We tested and evaluated 3 digital canopy height model (CHM) scenarios: 1) CHM derived from ALS models; 2) CHM derived from UAV models; and 3) CHM from a combined ALS digital terrain model and UAV digital surface model. The height value at each tree coordinate was extracted from the pixel in the three evaluated scenarios and compared with the field measured values. ALS and UAV+ALS obtained RMSE% of 6.38 and 12.82 for height estimates, while UAV was 49.91%. Volume and aboveground biomass predictions are more accurate by ALS and UAV+ALS, while the UAV produced biased estimates. Since the ALS is currently used, periodic monitoring can be carried out by a combination of active (ALS) and passive (UAV) sensors.


Asunto(s)
Araucaria , Seguimiento de Parámetros Ecológicos , Biomasa , Rayos Láser , Árboles , Dispositivos Aéreos No Tripulados , Seguimiento de Parámetros Ecológicos/instrumentación , Seguimiento de Parámetros Ecológicos/métodos
4.
Am J Health Syst Pharm ; 80(Suppl 1): S33-S41, 2023 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-35868628

RESUMEN

PURPOSE: To compare rates of treatment failure for patients with bloodstream infections (BSIs) due to Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis who received oral step-down antibiotic therapy with either a fluoroquinolone (FQ) or trimethoprim/sulfamethoxazole (SXT) to rates for those who received an oral ß-lactam (BL). METHODS: This retrospective, multicenter, cohort study included 397 unique adult hospitalized patients with a BSI due to E. coli, K. pneumoniae, or P. mirabilis at 6 hospitals in central Texas between July 11, 2016, and July 11, 2018. The primary outcome was a composite of treatment failure comprising 30-day readmission due to recurrence, 30-day all-cause mortality, and change in oral antibiotic. Secondary outcomes included 90-day development of Clostridioides difficile infection, 90-day colonization with a multidrug-resistant organism, 90-day all-cause readmission, hospital length of stay, and the individual components of the primary outcome. RESULTS: Of the 397 patients included, 200 received oral step-down therapy with a BL while 197 received an FQ or SXT. Most patients had an infection due to E. coli (82.8%) and a urinary source of infection (85%). Median total duration of therapy was 14 days in both groups. No difference in treatment failure was identified between the groups treated with a BL and FQ/SXT (7% vs 5.8%, P = 0.561). Median hospital length of stay was the only secondary endpoint in which there was an observed difference (6 vs 5 days, P = 0.04). CONCLUSION: We observed no difference in treatment failure rates for patients receiving an oral BL compared to an oral FQ or SXT for step-down therapy of BSIs due to E. coli, K. pneumoniae, and P. mirabilis.


Asunto(s)
Bacteriemia , Fluoroquinolonas , Adulto , Humanos , Fluoroquinolonas/uso terapéutico , beta-Lactamas , Escherichia coli , Klebsiella pneumoniae , Proteus mirabilis , Estudios Retrospectivos , Estudios de Cohortes , Antibacterianos/uso terapéutico , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Bacteriemia/tratamiento farmacológico
5.
Emerg Infect Dis ; 27(11): 2937-2939, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34670654

RESUMEN

We report a case of acute, vectorborne Chagas disease, acquired locally in central Texas, USA, manifesting as Romaña's sign, which was initially mistaken for orbital cellulitis. After the infection failed to respond to antibiotics, DNA-based next generation sequencing on plasma yielded high levels of Trypanasoma cruzi; results were confirmed by PCR.


Asunto(s)
Enfermedad de Chagas , Celulitis Orbitaria , Trypanosoma cruzi , Animales , Enfermedad de Chagas/diagnóstico , Enfermedad de Chagas/tratamiento farmacológico , Humanos , Insectos Vectores , Texas/epidemiología
6.
Nat Commun ; 12(1): 4114, 2021 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-34226564

RESUMEN

A fault-tolerant quantum processor may be configured using stationary qubits interacting only with their nearest neighbours, but at the cost of significant overheads in physical qubits per logical qubit. Such overheads could be reduced by coherently transporting qubits across the chip, allowing connectivity beyond immediate neighbours. Here we demonstrate high-fidelity coherent transport of an electron spin qubit between quantum dots in isotopically-enriched silicon. We observe qubit precession in the inter-site tunnelling regime and assess the impact of qubit transport using Ramsey interferometry and quantum state tomography techniques. We report a polarization transfer fidelity of 99.97% and an average coherent transfer fidelity of 99.4%. Our results provide key elements for high-fidelity, on-chip quantum information distribution, as long envisaged, reinforcing the scaling prospects of silicon-based spin qubits.

7.
Psicol. teor. prát ; 23(1): 1-21, Jan.-Apr. 2021. ilus
Artículo en Inglés, Portugués | LILACS, Index Psicología - Revistas | ID: biblio-1250545

RESUMEN

In the 1930s, a group of scientists argued that the empirical concatenation of observable elements was not possible in the human and social sciences and was, thus, not feasible to obtain objective measurements similar to those found in physics. To address this issue, mathematical theories that do not require concatenation were proposed in the 1960s, including the Additive Conjoint Measurement Theory (ACMT). In the same decade, George Rasch developed the simple logistic model for dichotomous data as a probabilistic operationalization of the ACMT. This study investigates the possibility of developing a fundamental measure for the National Exam of Upper Secondary Education (ENEM) that applies Rasch's model to students' performance on the 2011 ENEM exam. The results indicate an adequate model fit, demonstrating the viability of a fundamental measure using ENEM data. Implications are discussed.


Nos anos 1930, um grupo de cientistas argumentou que a concatenação empírica de elementos observáveis não seria possível nas Ciências Humanas e Sociais e por isso era inviável obter medidas verdadeiras nesses campos do conhecimento científico. Para lidar com este problema, foram propostas teorias matemáticas nas quais a concatenação empírica não seria necessária, como a Teoria de Medidas Aditivas Conjuntas (TMAC). No mesmo período, George Rasch desenvolveu o modelo logístico simples para dados dicotômicos, uma operacionalização probabilística da TMAC que viabiliza a análise empírica de pressupostos da medida verdadeira. Em nosso estudo, investigamos o desenvolvimento de uma medida verdadeira para o Exame Nacional do Ensino Médio (ENEM), aplicando o modelo logístico simples em dados referentes à performance dos participantes da edição de 2011 do ENEM. Os resultados indicaram um ajuste adequado do modelo, apontando para a viabilidade da construção de uma medida verdadeira para o ENEM. Implicações são discutidas.


En los años 1930, un grupo de científicos argumentó que la concatenación empírica de elementos observables no sería posible en Ciencias Humanas y Sociales y por consiguiente sería inviable obtener medidas verdaderas similares a las de Física. Para abordar este problema, a partir de los años 1960 se proponían teorías en las cuales la concatenación empírica no es necesaria, como la Teoría de Medidas Aditivas Conjuntas (TMAC). Al mismo período, George Rasch desarrolló el modelo logístico simple para datos dicotómicos, una operacionalización probabilista de la TMAC. Este estudio investigó la posibilidad de desarrollar una medida verdadera para el Examen Nacional de la Secundaria Superior (ENEM), aplicando el modelo logístico simple en los datos referentes a la performance de los participantes en la prueba de 2011 del ENEM. Los resultados indicaron adecuado ajuste del modelo, asi como la viabilidad de una medida verdadera para el ENEM. Implicaciones son discutidas.


Asunto(s)
Humanos , Conocimiento , Educación Primaria y Secundaria , Crecimiento y Desarrollo , Evaluación Educacional , Ciencias Sociales , Estudiantes , Pesos y Medidas , Brasil , Modelos Logísticos , Humanidades
8.
Clin Epigenetics ; 13(1): 23, 2021 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-33516250

RESUMEN

BACKGROUND: The neuropeptide oxytocin regulates mammalian social behavior. Disruptions in oxytocin signaling are a feature of many psychopathologies. One commonly studied biomarker for oxytocin involvement in psychiatric diseases is DNA methylation at the oxytocin receptor gene (OXTR). Such studies focus on DNA methylation in two regions of OXTR, exon 3 and a region termed MT2 which overlaps exon 1 and intron 1. However, the relative contribution of exon 3 and MT2 in regulating OXTR gene expression in the brain is currently unknown. RESULTS: Here, we use the prairie vole as a translational animal model to investigate genetic, epigenetic, and environmental factors affecting Oxtr gene expression in a region of the brain that has been shown to drive Oxtr related behavior in the vole, the nucleus accumbens. We show that the genetic structure of Oxtr in prairie voles resembles human OXTR. We then studied the effects of early life experience on DNA methylation in two regions of a CpG island surrounding the Oxtr promoter: MT2 and exon 3. We show that early nurture in the form of parental care results in DNA hypomethylation of Oxtr in both MT2 and exon 3, but only DNA methylation in MT2 is associated with Oxtr gene expression. Network analyses indicate that CpG sites in the 3' portion of MT2 are most highly associated with Oxtr gene expression. We also identify two novel SNPs in exon 3 of Oxtr in prairie voles and a novel alternative transcript originating from the third intron of the gene. Expression of the novel alternative transcript is associated with genotype at SNP KLW2. CONCLUSIONS: These results identify putative regulatory features of Oxtr in prairie voles which inform future studies examining OXTR in human social behaviors and disorders. These studies indicate that in prairie voles, DNA methylation in MT2, particularly in the 3' portion, is more predictive of Oxtr gene expression than DNA methylation in exon 3. Similarly, in human temporal cortex, we find that DNA methylation in the 3' portion of MT2 is associated with OXTR expression. Together, these results suggest that among the CpG sites studied, DNA methylation of MT2 may be the most reliable indicator of OXTR gene expression. We also identify novel features of prairie vole Oxtr, including SNPs and an alternative transcript, which further develop the prairie vole as a translational model for studies of OXTR.


Asunto(s)
Arvicolinae/genética , Trastornos Mentales/genética , Metalotioneína/genética , Receptores de Oxitocina/genética , Experiencias Adversas de la Infancia/psicología , Animales , Encéfalo/metabolismo , Islas de CpG/genética , Metilación de ADN , Ambiente , Epigénesis Genética , Exones/genética , Femenino , Expresión Génica , Humanos , Intrones/genética , Masculino , Trastornos Mentales/metabolismo , Modelos Animales , Núcleo Accumbens/metabolismo , Oxitocina/genética , Polimorfismo de Nucleótido Simple/genética , Conducta Social
9.
Nature ; 580(7803): 350-354, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32296190

RESUMEN

Quantum computers are expected to outperform conventional computers in several important applications, from molecular simulation to search algorithms, once they can be scaled up to large numbers-typically millions-of quantum bits (qubits)1-3. For most solid-state qubit technologies-for example, those using superconducting circuits or semiconductor spins-scaling poses a considerable challenge because every additional qubit increases the heat generated, whereas the cooling power of dilution refrigerators is severely limited at their operating temperature (less than 100 millikelvin)4-6. Here we demonstrate the operation of a scalable silicon quantum processor unit cell comprising two qubits confined to quantum dots at about 1.5 kelvin. We achieve this by isolating the quantum dots from the electron reservoir, and then initializing and reading the qubits solely via tunnelling of electrons between the two quantum dots7-9. We coherently control the qubits using electrically driven spin resonance10,11 in isotopically enriched silicon12 28Si, attaining single-qubit gate fidelities of 98.6 per cent and a coherence time of 2 microseconds during 'hot' operation, comparable to those of spin qubits in natural silicon at millikelvin temperatures13-16. Furthermore, we show that the unit cell can be operated at magnetic fields as low as 0.1 tesla, corresponding to a qubit control frequency of 3.5 gigahertz, where the qubit energy is well below the thermal energy. The unit cell constitutes the core building block of a full-scale silicon quantum computer and satisfies layout constraints required by error-correction architectures8,17. Our work indicates that a spin-based quantum computer could be operated at increased temperatures in a simple pumped 4He system (which provides cooling power orders of magnitude higher than that of dilution refrigerators), thus potentially enabling the integration of classical control electronics with the qubit array18,19.

10.
Nat Commun ; 11(1): 797, 2020 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-32047151

RESUMEN

Once the periodic properties of elements were unveiled, chemical behaviour could be understood in terms of the valence of atoms. Ideally, this rationale would extend to quantum dots, and quantum computation could be performed by merely controlling the outer-shell electrons of dot-based qubits. Imperfections in semiconductor materials disrupt this analogy, so real devices seldom display a systematic many-electron arrangement. We demonstrate here an electrostatically confined quantum dot that reveals a well defined shell structure. We observe four shells (31 electrons) with multiplicities given by spin and valley degrees of freedom. Various fillings containing a single valence electron-namely 1, 5, 13 and 25 electrons-are found to be potential qubits. An integrated micromagnet allows us to perform electrically-driven spin resonance (EDSR), leading to faster Rabi rotations and higher fidelity single qubit gates at higher shell states. We investigate the impact of orbital excitations on single qubits as a function of the dot deformation and exploit it for faster qubit control.

11.
Assessment ; 27(6): 1349-1367, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-29911418

RESUMEN

During the present decade a large body of research has employed confirmatory factor analysis (CFA) to evaluate the factor structure of the Strengths and Difficulties Questionnaire (SDQ) across multiple languages and cultures. However, because CFA can produce strongly biased estimations when the population cross-loadings differ meaningfully from zero, it may not be the most appropriate framework to model the SDQ responses. With this in mind, the current study sought to assess the factorial structure of the SDQ using the more flexible exploratory structural equation modeling approach. Using a large-scale Spanish sample composed of 67,253 youths aged between 10 and 18 years (M = 14.16, SD = 1.07), the results showed that CFA provided a severely biased and overly optimistic assessment of the underlying structure of the SDQ. In contrast, exploratory structural equation modeling revealed a generally weak factorial structure, including questionable indicators with large cross-loadings, multiple error correlations, and significant wording variance. A subsequent Monte Carlo study showed that sample sizes greater than 4,000 would be needed to adequately recover the SDQ loading structure. The findings from this study prevent recommending the SDQ as a screening tool and suggest caution when interpreting previous results in the literature based on CFA modeling.


Asunto(s)
Lenguaje , Tamizaje Masivo , Adolescente , Niño , Análisis Factorial , Humanos , Análisis de Clases Latentes , Encuestas y Cuestionarios
12.
Nat Commun ; 10(1): 5500, 2019 12 03.
Artículo en Inglés | MEDLINE | ID: mdl-31796728

RESUMEN

Single-electron spin qubits employ magnetic fields on the order of 1 Tesla or above to enable quantum state readout via spin-dependent-tunnelling. This requires demanding microwave engineering for coherent spin resonance control, which limits the prospects for large scale multi-qubit systems. Alternatively, singlet-triplet readout enables high-fidelity spin-state measurements in much lower magnetic fields, without the need for reservoirs. Here, we demonstrate low-field operation of metal-oxide-silicon quantum dot qubits by combining coherent single-spin control with high-fidelity, single-shot, Pauli-spin-blockade-based ST readout. We discover that the qubits decohere faster at low magnetic fields with [Formula: see text] µs and [Formula: see text] µs at 150 mT. Their coherence is limited by spin flips of residual 29Si nuclei in the isotopically enriched 28Si host material, which occur more frequently at lower fields. Our finding indicates that new trade-offs will be required to ensure the frequency stabilization of spin qubits, and highlights the importance of isotopic enrichment of device substrates for the realization of a scalable silicon-based quantum processor.

13.
Nature ; 569(7757): 532-536, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31086337

RESUMEN

Universal quantum computation will require qubit technology based on a scalable platform1, together with quantum error correction protocols that place strict limits on the maximum infidelities for one- and two-qubit gate operations2,3. Although various qubit systems have shown high fidelities at the one-qubit level4-10, the only solid-state qubits manufactured using standard lithographic techniques that have demonstrated two-qubit fidelities near the fault-tolerance threshold6 have been in superconductor systems. Silicon-based quantum dot qubits are also amenable to large-scale fabrication and can achieve high single-qubit gate fidelities (exceeding 99.9 per cent) using isotopically enriched silicon11,12. Two-qubit gates have now been demonstrated in a number of systems13-15, but as yet an accurate assessment of their fidelities using Clifford-based randomized benchmarking, which uses sequences of randomly chosen gates to measure the error, has not been achieved. Here, for qubits encoded on the electron spin states of gate-defined quantum dots, we demonstrate Bell state tomography with fidelities ranging from 80 to 89 per cent, and two-qubit randomized benchmarking with an average Clifford gate fidelity of 94.7 per cent and an average controlled-rotation fidelity of 98 per cent. These fidelities are found to be limited by the relatively long gate times used here compared with the decoherence times of the qubits. Silicon qubit designs employing fast gate operations with high Rabi frequencies16,17, together with advanced pulsing techniques18, should therefore enable much higher fidelities in the near future.

14.
Antivir Ther ; 24(4): 291-300, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30977467

RESUMEN

BACKGROUND: HIV viral load (VL) and resistance testing are limited in sub-Saharan Africa, so individuals may have prolonged time on failing first-line antiretroviral therapy (ART). Our objective was to describe the evolution of drug resistance mutations among adults failing first-line ART in Zambia. METHODS: We analysed data from a trial of VL monitoring in Lusaka, Zambia. From 2006 to 2011, 12 randomized sites provided either routine VL monitoring (intervention) or discretionary (control) after ART initiation. Samples were collected prospectively following the same schedule in each arm but analysed retrospectively in the control group. For those with virological failure (VF; >400 copies/ml), HIV genotyping was performed retrospectively on baseline (BL) and on all subsequent specimens until censored due to study completion, withdrawal or death. RESULTS: Of 1,973 enrollees, 165 (8.4%) developed VF. 464 genotype results were available including 132 (80%) at BL, 116 (70%) at VF and 125 (76%) had at least one result between VF and censoring. Major nucleoside reverse transcriptase inhibitor (NRTI) or non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations increased from 26% (BL) to 82% (VF) to 89% at last genotype (LG). M184 mutations increased from 2% to 59% to 71%; K65R from 2% to 11% to 13%; 2 or more thymidine analogue mutations from 1% to 3% to 12%. Among those on a failing tenofovir disoproxil fumarate (TDF)-based regimen, TDF resistance increased from 42% to 58%. CONCLUSIONS: We found substantial resistance to NRTIs and NNRTIs at VF with incremental increases after VF while still on a failing first-line ART; this resistance may compromise attainment of the UNAIDS 90-90-90 goals.


Asunto(s)
Fármacos Anti-VIH/farmacología , Farmacorresistencia Viral , Infecciones por VIH/virología , VIH-1/efectos de los fármacos , Adulto , Fármacos Anti-VIH/uso terapéutico , Terapia Antirretroviral Altamente Activa , Recuento de Linfocito CD4 , Femenino , Genotipo , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , VIH-1/genética , Humanos , Masculino , Persona de Mediana Edad , Mutación , ARN Viral , Insuficiencia del Tratamiento , Carga Viral/efectos de los fármacos , Zambia/epidemiología
16.
Schizophr Res ; 206: 43-51, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30573405

RESUMEN

The present study examined the dimensional structure underlying the Multidimensional Schizotypy Scale (MSS) and its brief version (MSS-B). We used Exploratory Graph Analysis (EGA) to evaluate their dimensional structure in two large, independent samples (n = 6265 and n = 1000). We then used Confirmatory Factor Analysis (CFA) to compare the fit of the theoretical dimensions with the EGA dimensions. For the MSS, EGA identified four dimensions: positive schizotypy, two dimensions of negative schizotypy (affective and social anhedonia), and disorganized schizotypy. For the MSS-B, EGA identified three dimensions, which corresponded to the theorized positive, negative, and disorganized dimensions. Based on the MSS's EGA dimensions, we also estimated a four-factor model for the MSS-B. The CFA comparison found that the four-factor model fit significantly better than the theoretical three-factor model for both the MSS and MSS-B, providing support for the theoretical model and offering a more nuanced interpretation of the negative schizotypy factor. In addition, EGA also revealed that the positive and negative schizotypy dimensions of the MSS and MSS-B might be mediated by the disorganized dimension. Our findings offer new implications for future research on the MSS and MSS-B dimensions that may provide differential associations with interview and questionnaire measures.


Asunto(s)
Trastornos Psicóticos/psicología , Esquizofrenia , Psicología del Esquizofrénico , Trastorno de la Personalidad Esquizotípica/psicología , Adolescente , Adulto , Anhedonia , Análisis Factorial , Femenino , Humanos , Masculino , Escalas de Valoración Psiquiátrica , Psicometría , Adulto Joven
17.
Nat Commun ; 9(1): 4370, 2018 10 30.
Artículo en Inglés | MEDLINE | ID: mdl-30375392

RESUMEN

Silicon quantum dot spin qubits provide a promising platform for large-scale quantum computation because of their compatibility with conventional CMOS manufacturing and the long coherence times accessible using 28Si enriched material. A scalable error-corrected quantum processor, however, will require control of many qubits in parallel, while performing error detection across the constituent qubits. Spin resonance techniques are a convenient path to parallel two-axis control, while Pauli spin blockade can be used to realize local parity measurements for error detection. Despite this, silicon qubit implementations have so far focused on either single-spin resonance control, or control and measurement via voltage-pulse detuning in the two-spin singlet-triplet basis, but not both simultaneously. Here, we demonstrate an integrated device platform incorporating a silicon metal-oxide-semiconductor double quantum dot that is capable of single-spin addressing and control via electron spin resonance, combined with high-fidelity spin readout in the singlet-triplet basis.

18.
Nat Commun ; 9(1): 3255, 2018 08 14.
Artículo en Inglés | MEDLINE | ID: mdl-30108212

RESUMEN

Valence band holes confined in silicon quantum dots are attracting significant attention for use as spin qubits. However, experimental studies of single-hole spins have been hindered by challenges in fabrication and stability of devices capable of confining a single hole. To fully utilize hole spins as qubits, it is crucial to have a detailed understanding of the spin and orbital states. Here we show a planar silicon metal-oxide-semiconductor-based quantum dot device and demonstrate operation down to the last hole. Magneto-spectroscopy studies show magic number shell filling consistent with the Fock-Darwin states of a circular two-dimensional quantum dot, with the spin filling sequence of the first six holes consistent with Hund's rule. Next, we use pulse-bias spectroscopy to determine that the orbital spectrum is heavily influenced by the strong hole-hole interactions. These results provide a path towards scalable silicon hole-spin qubits.

19.
AIDS Behav ; 22(2): 471-478, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28101789

RESUMEN

Men are key decision makers for their son's circumcision, so understanding their beliefs is important for the uptake of early infant male circumcision in countries in sub-Saharan Africa that have high HIV prevalence. We analyzed men's preferences for circumcising their sons using data from a population-representative survey of 1501 uncircumcised men aged 25-49 years in western Kenya. Most men (59%) reported they would "definitely" want their son circumcised if a son was born to them within the next year. However, only 25% intended to become circumcised themselves. In multivariable Poisson regression models to estimate prevalence ratios, key predictors of the desire to circumcise their sons included knowledge that circumcision reduces HIV acquisition, having a supportive partner, discussing circumcision with the partner, altruism, and intention to be circumcised himself. Focusing on partner dynamics may have the greatest capacity to increase demand since 55% had not talked to their partner about circumcision.


Asunto(s)
Circuncisión Masculina/psicología , Toma de Decisiones , Padre/psicología , Infecciones por VIH/prevención & control , Conocimientos, Actitudes y Práctica en Salud , Intención , Adulto , Estudios Transversales , Humanos , Lactante , Kenia , Masculino , Persona de Mediana Edad , Núcleo Familiar , Prevalencia , Parejas Sexuales , Encuestas y Cuestionarios , Adulto Joven
20.
Open AIDS J ; 11: 45-51, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28839514

RESUMEN

BACKGROUND: Little is known about the use of statin for cardiovascular disease (CVD) risk reduction among HIV-infected patients on protease inhibitors (PI`s) in sub-Saharan Africa (SSA). OBJECTIVE: Cholesterol screening and statin use were retrospectively assessed among HIV-infected participants on PI`s between 2008 and 2012 at a large urban HIV clinic in Botswana. METHODS: Proportion of participants screened per year was calculated and statin indication was assessed using atherosclerosis CVD (ASCVD) and Framingham risk (FRS) scores as of the year 2012 guidelines. RESULTS: Cholesterol screening ranged between 19% and 30% per year (2008-2011) but increased to 80% after study enrollment. The rate of hypercholesterolemia (> 5.0 mmol/L) was 31% in 2012. Fewer than 1% participants were on statin therapy but 14.3% and 9.4% had statins indicated by ASCVD and FRS respectively. CONCLUSION: The high proportion of participants indicated for, but not prescribed statins highlights a substantial gap in the care to reduce CVD risk among these patients.

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