Cross-language qualitative research occurs when a language barrier is present between researchers and participants. The language barrier is frequently mediated through the use of a translator or ...interpreter. The purpose of this analysis of cross-language qualitative research was threefold: (1) review the methods literature addressing cross-language research; (2) synthesize the methodological recommendations from the literature into a list of criteria that could evaluate how researchers methodologically managed translators and interpreters in their qualitative studies; (3) test these criteria on published cross-language qualitative studies.
A group of 40 purposively selected cross-language qualitative studies found in nursing and health sciences journals.
The synthesis of the cross-language methods literature produced 14 criteria to evaluate how qualitative researchers managed the language barrier between themselves and their study participants. To test the criteria, the researcher conducted a summative content analysis framed by discourse analysis techniques of the 40 cross-language studies.
The evaluation showed that only 6 out of 40 studies met all the criteria recommended by the cross-language methods literature for the production of trustworthy results in cross-language qualitative studies. Multiple inconsistencies, reflecting disadvantageous methodological choices by cross-language researchers, appeared in the remaining 33 studies. To name a few, these included rendering the translator or interpreter as an invisible part of the research process, failure to pilot test interview questions in the participant's language, no description of translator or interpreter credentials, failure to acknowledge translation as a limitation of the study, and inappropriate methodological frameworks for cross-language research.
The finding about researchers making the role of the translator or interpreter invisible during the research process supports studies completed by other authors examining this issue. The analysis demonstrated that the criteria produced by this study may provide useful guidelines for evaluating cross-language research and for novice cross-language researchers designing their first studies. Finally, the study also indicates that researchers attempting cross-language studies need to address the methodological issues surrounding language barriers between researchers and participants more systematically.
The ability to quickly and reliably fabricate nanoscale pore arrays in ultra‐thin membranes such as silicon nitride (SixN) is extremely important for the growing field of nanopore biosensing. ...Laser‐based etching of thin SixN membranes immersed in aqueous solutions has recently been demonstrated as a method to produce stable functional pores. Herein, the principal mechanism governing material etching and pore formation using light is investigated. It is found that the process is extremely sensitive to the relative content of Si over N atoms in the amorphous membrane, produced by chemical vapor deposition. Commonly, SixN membranes are made to be Si‐rich to increase their mechanical stability, which substantially reduces the material's bandgap and increases the density of Si‐dangling bonds. Hence, even minimal batch‐to‐batch variation may lead to remarkably different etch rates. It is shown that higher Si content results in orders of magnitude faster etching rates. This rate is further accelerated in an alkaline environment allowing on‐demand controlled nanopore formation in about 10 s time even at low laser radiation intensities. These results highlight that photoactivation of the SixN by the incident beam is critical to the chemical etching process and can be used to readily produce nanopore arrays at any specific location.
Low‐intensity laser etching and nanopore formation in amorphous silicon‐nitride (SixN) freestanding films is found to be highly dependent on the Si to N ratio. Increasing the relative Si content yields orders of magnitude increases in etch rate, which is further accelerated in alkaline environments, enabling the fabrication of nanopore arrays within tens of seconds at any arbitrary location.
Phycobilisomes are highly organized pigment–protein antenna complexes found in the photosynthetic apparatus of cyanobacteria and rhodophyta that harvest solar energy and transport it to the reaction ...center. A detailed bottom-up model of pigment organization and energy transfer in phycobilisomes is essential to understanding photosynthesis in these organisms and informing rational design of artificial light-harvesting systems. In particular, heterogeneous photophysical behaviors of these proteins, which cannot be predicted de novo, may play an essential role in rapid light adaptation and photoprotection. Furthermore, the delicate architecture of these pigment–protein scaffolds sensitizes them to external perturbations, for example, surface attachment, which can be avoided by study in free solution or in vivo. Here, we present single-molecule characterization of C-phycocyanin (C-PC), a three-pigment biliprotein that self-assembles to form the midantenna rods of cyanobacterial phycobilisomes. Using the Anti-Brownian Electrokinetic (ABEL) trap to counteract Brownian motion of single particles in real time, we directly monitor the changing photophysical states of individual C-PC monomers from Spirulina platensis in free solution by simultaneous readout of their brightness, fluorescence anisotropy, fluorescence lifetime, and emission spectra. These include single-chromophore emission states for each of the three covalently bound phycocyanobilins, providing direct measurements of the spectra and photophysics of these chemically identical molecules in their native protein environment. We further show that a simple Förster resonant energy transfer (FRET) network model accurately predicts the observed photophysical states of C-PC and suggests highly variable quenching behavior of one of the chromophores, which should inform future studies of higher-order complexes.
Cardiovascular disease (CVD) prevalence is high in Ghana-but awareness, prevention, and treatment is sparse, particularly in rural regions. The nurse-led Community-based Health Planning and Services ...program offers general preventive and primary care in these areas, but overlooks CVD and its risk factors.
We conducted in-depth interviews with 30 community members (CM) in rural Navrongo, Ghana to understand their knowledge and beliefs regarding the causes and treatment of CVD and the potential role of community nurses in rendering CVD care. We transcribed audio records, coded these data for content, and qualitatively analyzed these codes for key themes.
CMs described CVD as an acute, aggressive disease rather than a chronic asymptomatic condition, believing that CVD patients often die suddenly. Yet CMs identified causal risk factors for CVD: not only tobacco smoking and poor diet, but also emotional burdens and stressors, which cause and exacerbate CVD symptoms. Many CMs expressed interest in counseling on these risk factors, particularly diet. However, they felt that nurses could provide comprehensive CVD care only if key barriers (such as medication access and training) are addressed. In the interim, many saw nurses' main CVD care role as referring to the hospital.
CMs would like CVD behavioral education from community nurses at local clinics, but feel the local health system is now too fragile to offer other CVD interventions. CMs believe that a more comprehensive CVD care model would require accessible medication, along with training for nurses to screen for hypertension and other cardiovascular risk factors-in addition to counseling on CVD prevention. Such counseling should build upon existing community beliefs and concerns regarding CVD-including its behavioral and mental health causes-in addition to usual measures to prevent CVD mortality such as diet changes and physical exercise.
Solid-state nanopores show promise as single-molecule sensors for biomedical applications, but to increase their resolution and efficiency, analyte molecules must remain longer in the nanopore ...sensing volume. Here we demonstrate a novel, facile, and customizable nanopore sensor modification that reduces the double-stranded DNA translocation velocity by 2 orders of magnitude or more via interactions outside the nanopore. This is achieved by electrospinning a copolymer nanofiber mesh (NFM) directly onto a solid-state nanopore (NP) chip. The effect of NFMs on dsDNA translocation through an NP is highlighted using a set of NFMs of varying mesh composition that reduce the translocation speed relative to a bare pore from 1- to >100-fold. A representative NFM from this set is effective on DNA as long as 20 kbp, improves the nanopore resolution, and allows discrimination among different DNA lengths.
Single-molecule fluorescence spectroscopy allows direct, real-time observation of dynamic photophysical changes in light harvesting complexes. The Anti-Brownian ELectrokinetic (ABEL) trap is one such ...single-molecule method with useful advantages. This approach is particularly well-suited to make detailed spectroscopic measurements of pigment-protein complexes in a solution phase because it enables extended-duration single-molecule observation by counteracting Brownian motion. This Perspective summarizes recent contributions by the authors and others that have utilized the unique capabilities of the ABEL trap to advance our understanding of phycobiliproteins and the phycobilisome complex, the primary light-harvesting apparatus of cyanobacteria. Monitoring the rich spectroscopic data from these measurements, which include brightness, fluorescence lifetime, polarization, and emission spectra, among other measurable parameters, has provided direct characterization of pigments and energy transfer pathways in the phycobilisome, spanning scales from single pigments and monomeric phycobiliproteins to higher order oligomers and protein-protein interactions of the phycobilisome complex. Importantly, new photophysical states and photodynamics were observed to modulate the flow of energy through the phycobilisome and suggest a previously unknown complexity in phycobilisome light harvesting and energy transport with a possible link to photoadaptive or photoprotective functions in cyanobacteria. Beyond deepening our collective understanding of natural light-harvesting systems, these and future discoveries may serve as inspiration for engineering improved artificial light-harvesting technologies.
In clinical settings, rapid and accurate characterization of pathogens is essential for effective treatment of patients; however, subtle genetic changes in pathogens which elude traditional ...phenotypic typing may confer dangerous pathogenic properties such as toxicity, antibiotic resistance, or virulence. Existing options for molecular typing techniques characterize the critical genomic changes that distinguish harmful and benign strains, yet the well-established approaches, in particular those that rely on electrophoretic separation of nucleic acid fragments on a gel, have room for only incremental future improvements in speed, cost, and complexity. Solid-state nanopores are an emerging class of single-molecule sensors that can electrophoretically characterize charged biopolymers, and which offer significant advantages in terms of sample and reagent requirements, readout speed, parallelization, and automation. We present here the first application of nanopores for single-molecule molecular typing using length based "fingerprints" of critical sites in bacterial genomes. This technique is highly adaptable for detection of different types of genetic variation; as we illustrate using prototypical examples including Mycobacterium tuberculosis and methicillin-resistant Streptococcus aureus, the solid-state nanopore diagnostic platform may be used to detect large insertions or deletions, small insertions or deletions, and even single-nucleotide variations in bacterial DNA. We further show that Bayesian classification of test samples can provide highly confident pathogen typing results based on only a few tens of independent single-molecule events, making this method extremely sensitive and statistically robust.
Optical sensing of solid-state nanopores is a relatively new approach that can enable high-throughput, multicolor readout from a collection of nanopores. It is therefore highly attractive for ...applications such as nanopore-based DNA sequencing and genotyping using DNA barcodes. However, to date optical readout has been plagued by the need to achieve sufficiently high signal-to-noise ratio (SNR) for single fluorophore sensing, while still maintaining millisecond resolution. One of the main factors degrading the optical SNR in solid-state nanopores is the high photoluminescence (PL) background emanating from the silicon nitride (SiN x ) membrane in which pores are commonly fabricated. Focusing on the optical properties of SiN x nanopores we show that the local membrane PL intensity is substantially reduced, and its spectrum is shifted toward shorter wavelengths with increasing e-beam dose. This phenomenon, which is correlated with a marked photocurrent enhancement in these nanopores, is utilized to perform for the first time single molecule fluorescence detection using both green and red laser excitations. Specifically, the reduction in PL and the concurrent measurement of the nanopore photocurrent enhancement allow us to maximize the background suppression and to detect a dual color, five-unit DNA barcode with high SNR levels.
The Orange Carotenoid Protein (OCP) is a cytosolic photosensor that is responsible for non-photochemical quenching (NPQ) of the light-harvesting process in most cyanobacteria. Upon photoactivation by ...blue-green light, OCP binds to the phycobilisome antenna complex, providing an excitonic trap to thermally dissipate excess energy. At present, both the binding site and NPQ mechanism of OCP are unknown. Using an Anti-Brownian ELectrokinetic (ABEL) trap, we isolate single phycobilisomes in free solution, both in the presence and absence of activated OCP, to directly determine the photophysics and heterogeneity of OCP-quenched phycobilisomes. Surprisingly, we observe two distinct OCP-quenched states, with lifetimes 0.09 ns (6% of unquenched brightness) and 0.21 ns (11% brightness). Photon-by-photon Monte Carlo simulations of exciton transfer through the phycobilisome suggest that the observed quenched states are kinetically consistent with either two or one bound OCPs, respectively, underscoring an additional mechanism for excitation control in this key photosynthetic unit.
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