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PubMed1988

Suxamethonium-induced facilitation of spontaneous frontal EMG activity.

The behaviour of spontaneous frontal electromyographic activity (FEMG) was studied during the recovery from suxamethonium and vecuronium block. In order to obtain comparable conditions in the study groups, the duration of the suxamethonium block was prolonged with a suxamethonium infusion. The FEMG was continuously recorded and the evoked electromyographic (EEMG) and twitch tension (ETT) responses were measured every 10 s from the thenar muscles. The median FEMG remained at the base level in 8 of the 12 vecuronium patients, despite a 50% recovery of EEMG. In the suxamethonium group there was an increase in FEMG in all six patients when EEMG had recovered to 10%, and significantly higher FEMG readings were obtained during further recovery from the block. Thus, early recovery of neuromuscular transmission is detected by FEMG more easily when suxamethonium is used instead of vecuronium. The different behaviour of FEMG may reflect a difference in the recovery ratio of ETT/EEMG or in the anaesthetic depth caused by the two types of neuromuscular blockers.

Adult↗

PubMed2001

Patient satisfaction after implantation of diffractive designed multifocal intraocular lenses in dependence on objective parameters.

BACKGROUND: For optimal patient satisfaction and greatest independence from spectacles after implantation of a diffractive designed multifocal intraocular lens (IOL), emmetropia with a low postoperative astigmatism must be achieved. The aim of this study was to prospectively determine patient satisfaction after implantation of diffractive designed multifocal IOLs in relation to objective parameters. PATIENTS AND METHODS: A total of 69 eyes of 50 patients without additional ocular pathology (mean age 64.8 years) received a diffractive designed multifocal IOL and were examined 12 months postoperatively. Overall patient satisfaction, visual phenomena (halos, glare), and frequency of use of reading spectacles and distance correction were assessed as subjective parameters. As objective parameters, uncorrected and best-corrected distance visual acuity (UCVA, BCVA, respectively), uncorrected, distance corrected and best-corrected near visual acuity, contrast sensitivity (Pelli-Robson charts), pre- and postoperative astigmatism, postoperative spherical equivalent and depth of focus (defocusing curve from +5.0 to -5.0 D) were measured. RESULTS: The mean overall satisfaction on a scale from 5 (excellent) to 1 (poor) was 4.49. Mean postoperative UCVA was 0.85 and BCVA was 1.03. Mean uncorrected near visual acuity was J1.04, distance corrected near visual acuity J1.0 and best corrected near visual acuity J1.0. Postoperative mean spherical equivalent was -0.17 +/- 0.43 D and absolute mean astigmatism was 0.64 D. The use of spectacles was highly correlated with postoperative spherical equivalent and absolute postoperative astigmatism. On a subjective scale from 0 (none) to 4 (very disturbing), a mean halo score of 0.45 and a mean glare score of 0.44 was recorded. Overall satisfaction was significantly correlated with UCVA, age, use of spectacles for distance purposes, contrast sensitivity, postoperative astigmatism, and postoperative spherical equivalent (P<0.05). Linear stepwise regression analysis identified UCVA as the most influential factor for overall patient satisfaction. CONCLUSIONS: For diffractive designed multifocal IOLs, emmetropia and a low astigmatism postoperatively are the most important factors for high patient satisfaction.

Adult↗

PubMed2001

Monte Carlo simulation of fast neutron spectra: mean lineal energy estimation with an effectiveness function and correlation to RBE.

PURPOSE: Intercomparisons of radiotherapy trials conducted at different fast neutron facilities are complicated by the dependence of the relative biologic effectiveness (RBE) of the different beams on the fast neutrons spectra. To obtain a better understanding of the influence of neutron energy on radiation quality, Monte Carlo simulations were performed to calculate fast neutron (FN) spectra at different irradiation positions. To allow for comparisons with experimental data, the positions were chosen to be the same as that used by other investigators to obtain microdosimetry readings and radiobiological data. METHODS AND MATERIALS: The primary neutron yield for beryllium targets bombarded with protons at the National Accelerator Center, Louvain, Nice, and Orleans facilities were calculated using the FLUKA code. Neutron transport simulations were performed with MCNP-4A, giving FN spectra for various phantom depths, hardening filter thickness, and field sizes. Using an effectiveness function, FN energy groups were correlated with mean lineal energies (y*-values) obtained experimentally by other workers. RESULTS: Calculations confirm earlier measurements that a decrease in beam quality by a hardening filter is the result of a reduction in the low-energy neutron component, i.e., neutrons below 3 MeV. Variations in RBE due to changes in field size and different phantom depths could also be explained by variations of neutrons with energies between 3-15 MeV. The effectiveness function allows one to calculate changes in y* observed for the NAC beam with great accuracy (R(2) = 0.99, p < 0.0001). Also, when this function is applied to beams with different neutron energies, y* calculated values show a very significant correlation with measured RBE values (R(2) = 0.98, p < 0.0001). CONCLUSION: The effectiveness function appears to be suitable to predict changes in y*-values and variations in RBE, using FN spectra simulated for various neutron therapy facilities.

Beryllium↗

PubMed2002

Acromegaly Quality of Life Questionnaire (ACROQOL) a new health-related quality of life questionnaire for patients with acromegaly: development and psychometric properties.

OBJECTIVE: To develop a disease-specific questionnaire suitable to measure health-related quality of life (HRQOL) in acromegaly (ACROQOL). DESIGN, PATIENTS AND MEASUREMENTS: For the development of the ACROQOL questionnaire different sources of information were used: First, a literature search was performed to identify relevant papers describing the impact of acromegaly in HRQOL. Second, 10 endocrinologists identified the main domains of impact on HRQOL in patients with acromegaly. Third, 10 in-depth, semistructured interviews were conducted in acromegalic patients to identify domains and items related to the self-perceived impact of acromegaly in patients' life. Qualitative analyses of the information were performed identifying domains and items to be included in the questionnaire. Those items considered ambiguous, complicated to read, double-barrelled, with jargon terms, too long, or negatively worded were excluded. Each remaining item was subsequently rated by the same panel of endocrinologists and experts in HRQOL evaluation, and assessed according to clarity of wording, frequency of occurrence and importance among patients with acromegaly. Analysis of internal consistency of the questionnaire was evaluated with a Cronbach's Alpha. A preliminary questionnaire was administered to 72 patients with acromegaly. Rasch analysis (dichotomous logistic response model) of the answers given by these patients allowed parameter estimates and model data fit indices to be computed and misfitting items deleted. Frequency of occurrence and degree of agreement with the statements were selected as response choices in a 5-point Likert type scale. RESULTS: The following domains related to HRQOL in acromegaly were identified: physical and psychological functions, social, daily activities, symptoms, cognition, general health perception, sleep, sexual function, pain, energy and body image. An initial set of 204 expressions were identified from the initial transcripts of the patient interviews. After elimination of ambiguous or unclear expressions, 142 items remained drafted in question form. From the quantitative analysis of the item rank position within each of the three areas of clarity, frequency and importance, the 38-item questionnaire was produced, with satisfactory internal consistency (Cronbach's Alpha 0.94). Rasch analysis produced a further reduction to the final 22-item questionnaire (Cronbach's Alpha 0.91) containing two scales that evaluate physical (eight questions) and psychological aspects related to appearance and personal relations (seven items each). The evaluation of the item parameters confirmed the construct validity of the new instrument. The substantial reliability of the questionnaire suggested the sample was well targeted by the questionnaire. The initial Spanish version was translated into English and presented to five English-speaking Australian patients with acromegaly to assess and correct for comprehension, clarity, cultural relevance and suitable wording. CONCLUSIONS: We present the ACROQOL questionnaire, developed and preliminarily validated to specifically assess HRQOL in patients with acromegaly.

Acromegaly↗

PubMed1994

The experience of spinal cord injury: the individual's perspective--implications for rehabilitation practice.

BACKGROUND AND PURPOSE: Research in rehabilitation has been focused primarily on provision of care issues and treatment intervention outcome measures. The input of the clients involved has not been solicited in a systematic way. As a physical therapist practicing in rehabilitation, the researcher became increasingly aware of a discrepancy between the perception of spinal cord injury and its consequences held by health professionals and those people who experience the injury over many years. It was recognition of this discrepancy that formed the background from which this study evolved. The purpose of this qualitative research study was to explore individual conceptions of the experience of spinal cord injury from the perspective of adult learning. SUBJECTS AND METHODS: Semistructured, in-depth interviews were conducted with 10 individuals who had sustained a traumatic spinal cord injury 3 to 5 years prior to the interview. Questions asked were nondirective and designed to trigger accounts of meaningful aspects of the subjects' disability experience since their injury. Data analysis entailed several thorough readings of the interview transcripts from which three categories of meaning developed and for which criteria were established. RESULTS: The categories of meaning--rediscovery of self, redefining disability, and establishing a new identity--represented commonalities of conceptions of the spinal cord injury and the resulting disability experience. The continuity of "self" was of primary importance to the ongoing experience of disability, and the learning involved was diverse and intensely personal. Strategies used by the subjects in achieving these categories are discussed. CONCLUSION AND DISCUSSION: Although the contribution of the rehabilitation instruction, and particularly that of individual health care professionals, was acknowledged by the subjects, the adequacy of the preparation of clinicians for their role as adult educators in the rehabilitation process is questioned. A theory of transformative learning is introduced as a possible explanatory model for the study findings, application of which may facilitate a more client-centered approach to rehabilitation practice.

Adult↗

PubMed1999

AAPM's TG-51 protocol for clinical reference dosimetry of high-energy photon and electron beams.

A protocol is prescribed for clinical reference dosimetry of external beam radiation therapy using photon beams with nominal energies between 60Co and 50 MV and electron beams with nominal energies between 4 and 50 MeV. The protocol was written by Task Group 51 (TG-51) of the Radiation Therapy Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol uses ion chambers with absorbed-dose-to-water calibration factors, N(60Co)D,w which are traceable to national primary standards, and the equation D(Q)w = MkQN(60Co)D,w where Q is the beam quality of the clinical beam, D(Q)w is the absorbed dose to water at the point of measurement of the ion chamber placed under reference conditions, M is the fully corrected ion chamber reading, and kQ is the quality conversion factor which converts the calibration factor for a 60Co beam to that for a beam of quality Q. Values of kQ are presented as a function of Q for many ion chambers. The value of M is given by M = PionP(TP)PelecPpolMraw, where Mraw is the raw, uncorrected ion chamber reading and Pion corrects for ion recombination, P(TP) for temperature and pressure variations, Pelec for inaccuracy of the electrometer if calibrated separately, and Ppol for chamber polarity effects. Beam quality, Q, is specified (i) for photon beams, by %dd(10)x, the photon component of the percentage depth dose at 10 cm depth for a field size of 10x10 cm2 on the surface of a phantom at an SSD of 100 cm and (ii) for electron beams, by R50, the depth at which the absorbed-dose falls to 50% of the maximum dose in a beam with field size > or =10x10 cm2 on the surface of the phantom (> or =20x20 cm2 for R50>8.5 cm) at an SSD of 100 cm. R50 is determined directly from the measured value of I50, the depth at which the ionization falls to 50% of its maximum value. All clinical reference dosimetry is performed in a water phantom. The reference depth for calibration purposes is 10 cm for photon beams and 0.6R50-0.1 cm for electron beams. For photon beams clinical reference dosimetry is performed in either an SSD or SAD setup with a 10x10 cm2 field size defined on the phantom surface for an SSD setup or at the depth of the detector for an SAD setup. For electron beams clinical reference dosimetry is performed with a field size of > or =10x10 cm2 (> or =20x20 cm2 for R50>8.5 cm) at an SSD between 90 and 110 cm. This protocol represents a major simplification compared to the AAPM's TG-21 protocol in the sense that large tables of stopping-power ratios and mass-energy absorption coefficients are not needed and the user does not need to calculate any theoretical dosimetry factors. Worksheets for various situations are presented along with a list of equipment required.

Biophysical Phenomena↗

PubMed2026

Syndromic cholera diagnosis masks diverse causes of diarrhoeal disease in Burundi revealed by portable metagenomics.

BACKGROUND: Cholera outbreaks remain a major public-health challenge in sub-Saharan Africa, where diagnostic capacity is limited and clinical case definitions are non-specific and re ly heavily on syndromic diagnosis. Rapid identification of Vibrio cholerae is critical, yet cholera-suspected diarrhoea can have multiple infectious causes not captured by targeted diagnostics. METHODS: We evaluated a mobile, culture-independent metagenomic sequencing workflow for on-site detection of gastrointestinal pathogens directly from faecal samples in Burundi. The offline workflow combined long-read Oxford Nanopore Technologies (ONT) sequencing with rapid, laptop-based taxonomic and antimicrobial resistance (AMR) screening and was deployed across a health centre, a district hospital, and a refugee transit camp. The frontline and real-time results were verified using both conventional culturing and in-depth bioinformatic analyses. RESULTS: V. cholerae signals were only detected in a subset of suspected cholera cases, while many samples were dominated by alternative bacterial taxa, most frequently Escherichia coli. V. cholerae abundance correlated strongly with detection of the C holera T oxin P hage CTXφ, supporting differentiation between toxigenic signal and background exposure. AMR genes were detected across samples, providing early situational insight into resistance determinants among gastrointestinal bacteria. CONCLUSIONS: Mobile, offline metagenomic sequencing enables rapid frontline characterization of gastrointestinal disease, especially cholera-suspected, in resource-limited settings and complements existing diagnostics by improving etiological resolution and outbreak response.

Humans↗

PubMedDate not supplied

Traumatic injuries of the pelvis. SIOT paper 1967.

The paper that Prof. Campanacci read at the Annual Meeting of the Italian Society of Orthopaedics and Traumatology in 1967 was the product of vast research aimed at clarifying and classifying traumatic injuries of the pelvic girdle. The basic idea behind the study was that correct therapeutic conduct cannot neglect an in-depth knowledge of the pathologic anatomy and pathogenesis of the injury. What emerges, in addition to the knowledge of anatomopathology, is the continuing validity of the scientific method with which the problem was dealt with.

Biomedical Research↗

PubMed2002

Influence of optical properties and fiber separation on laser doppler flowmetry.

Microcirculatory blood flow can be measured using a laser Doppler flowmetry (LDF) probe. However, the readings are affected by the tissue's optical properties (absorption and scattering coefficients, mu(a) and mu(s)) and probe geometry. In this study the influence of optical properties [mu(a)in(0.053,0.23) mm-1,mu(s)in(14.7,45.7) mm-1] on LDF perfusion and LDF sampling depth was evaluated for different fiber separations. In vitro measurements were made on a sophisticated tissue phantom with known optical properties that mimicked blood flow at different depths. Monte Carlo simulations were carried out to extend the geometry of the tissue phantom. A good correlation between measured and simulated data was found. The simulations showed that, for fixed flow at a discrete depth, the influence of mu(s) or mu(a) on LDF perfusion increased with an increase in flow depth and decreased with an increase in fiber separation. For a homogeneous flow distribution, however, the perfusion varied 40% due to variations in the optical properties, almost independent of the fiber separation (0.23-1.61 mm). Therefore, the effect in real tissue is likely to vary due to the unknown heterogeneous blood flow distribution. Further, the LDF sampling depth increased with a decrease in mu(s) or mu(a) and an increase in fiber separation. For fiber separation of 0.46 mm, the e-1 sampling depth ranged from 0.21 to 0.39 mm.

Blood Flow Velocity↗

PubMed1997

Gingival microcirculation response to tooth brushing measured by laser Doppler flowmetry.

This study quantified changes in blood flow following tooth brushing, using laser Doppler flowmetry (LDF). Twenty subjects had polysiloxane stents fabricated with openings to permit placement of the LDF probe on the mesial papillae of 6 teeth. Probing depth, plaque index, and gingival index were recorded and subjects instructed in brushing. LDF initially recorded a 30 second baseline blood flow. The stent was removed and subjects brushed the site for either 3 or 10 seconds. The stent was repositioned and recordings again taken, followed by a control reading. The process was repeated 4 weeks later. Correlations between baseline and control readings were 0.585 (P < 0.001) at the first visit, and 0.654 (P < 0.001) at the return visit. The mean control blood flow was 156.4 perfusion units. The 3 and 10 second brushing increased the mean value 22.6 units and 21.2 units respectively (both P < 0.001). Tooth brushing for both 3 and 10 seconds significantly increased gingival blood flow in the papillary gingiva of healthy individuals.

Adult↗

PubMed1998

Factors influencing palliative care. Qualitative study of family physicians' practices.

OBJECTIVE: To examine factors that influence family physicians' decisions to practise palliative care. DESIGN: Qualitative method of in-depth interviews. SETTING: Southwestern Ontario. PARTICIPANTS: Family physicians who practise palliative care on a full-time basis, who practise on a part-time basis, or who have retired from active involvement in palliative care. METHOD: Eleven in-depth interviews were conducted to explore factors that influence family physicians' decisions to practise palliative care and factors that sustain their interest in palliative care. All interviews were audiotaped and transcribed verbatim. The analysis strategy used a phenomenological approach and occurred concurrently rather than sequentially. All interview transcriptions were read independently by the researchers, who then compared and combined their analyses. Final analysis involved examining all interviews collectively, thus permitting relationships between and among central themes to emerge. MAIN OUTCOME FINDINGS: The overriding theme was a common philosophy of palliative care focusing on acceptance of death, whole person care, compassion, communication, and teamwork. Participants' philosophies were shaped by their education and by professional and personal experiences. In addition, participants articulated personal and systemic factors currently affecting their practice of palliative care. CONCLUSIONS: Participants observed that primary care physicians should be responsible for their patients' palliative care within the context of interdisciplinary teams. For medical students to be knowledgeable and sensitive to the needs of dying patients, palliative care should be given higher priority in the curriculum. Finally, participants argued compellingly for transferring the philosophy of palliative care to the overall practice of medicine.

Adult↗

PubMed2005

Shotgun sequencing of the negative-sense RNA genome of the rhabdovirus Maize mosaic virus.

The maize-infecting nucleorhabdovirus, Maize mosaic virus (MMV), was sequenced to near completion using the random shotgun approach. Sequences of 102 clones from a cDNA library constructed from randomly-primed viral RNA were compiled into a 12,133 nucleotide (nt) contig containing six open reading frames. The contig consisted of 97 sequences averaging 660 bp in length. The average sequence coverage was six-fold, and 93% of the contig had sequence reads covering both strands. The remaining sequence was derived from single (5%) or multiple (2%) reads on the same strand. Three of the six ORFs showed significant similarities to the deduced protein sequences of the nucleocapsid, glycoprotein and polymerase sequences of other rhabdoviruses. The predicted gene order of the MMV genome was 3'-N-P-3-M-G-L-5'. Shotgun sequencing of the MMV genome took approximately 127 h and cost 0.38 dollars per nt (including labor), whereas the primer walking approach for sequencing the 13,782-nt MFSV genome [Tsai, C.-W., Redinbaugh, M.G., Willie, K.J., Reed, S., Goodin, M., Hogenhout, S. A., 2005. Complete genome sequence and in planta subcellular localization of maize fine streak virus proteins. J. Virol. 79, 5304-5314] took about 217 h and cost 0.50 dollars per nt. Thus, the shotgun approach gave good depth of coverage for the viral genome sequence while being significantly faster and less expensive than the primer walking method. This technique will facilitate the sequencing of multiple rhabdovirus genomes.

DNA-Directed RNA Polymerases↗

PubMed1994

Polarity effect of plane-parallel ionization chambers in electron radiation.

Although plane-parallel ionization chambers have been in use for some time, there is still much to be learned about their performance characteristics. This work is concerned with the polarity effect in electron beams about which there is little published data. The investigations involved several popular ionization chambers; the PTW Markus chamber, the NACP chamber and its Calcam version, the Vinten-631 chamber, and the NE 2571 (Farmer-type) thimble chamber. The chambers were irradiated in electron beams of nominal energies between 4 MeV and 18 MeV. It was found in this study that the NACP, Markus and Vinten chambers require a correction of the order of 0.2% in the energy range between 4.5 MeV and 18 MeV. The overall behaviour of the Calcam chamber was similar with the exception of energies below 4 MeV. The depth dependence of the polarity effect seemed closely related to the mean beam energy at the depth of measurement. There is some evidence that the effect is also dependent on the angular spread of the electron beam and its spectrum. The authors considered how best to quantify the polarity effect practically, and propose that it should be expressed as a correction factor to be applied to readings with one particular chamber bias.

Calibration↗

PubMed2002

Focal motor seizures with secondary generalization arising in the cerebellum. Case report and review of the literature.

The issue of whether seizures can arise in the cerebellum remains controversial. The authors present the first known case of focal subcortical epilepsy with secondary generalization thought to arise from a dysplastic lesion within the cerebellum. A newborn infant presented with daily episodes of left eye blinking, stereotyped extremity movements, postural arching, and intermittent altered consciousness lasting less than 1 minute. These episodes began on his 1st day of life and progressively increased in frequency to more than 100 events per day. Antiepileptic medications had no effect, and interictal and ictal scalp electroencephalography (EEG) recordings demonstrated bilateral electrical abnormalities. Magnetic resonance imaging revealed a mass in the left cerebellar hemisphere, and ictal and interictal single-photon emission computerized tomography revealed a focal perfusion abnormality in the region of the cerebellar mass. The patient subsequently underwent intraoperative EEG monitoring with cortical scalp electrodes and cerebellar depth electrodes. Intraoperative EEG recordings revealed focal seizure discharges that arose in the region of the cerebellar mass and influenced electrographic activity in both cerebral hemispheres. Resection of this mass and the left cerebellar hemisphere led to complete resolution of the patient's seizures and normalization of the scalp EEG readings. Neuropathological findings in this mass were consistent with ganglioglioma. A review of the literature on the cerebellar origins of epilepsy is included.

Cerebellar Cortex↗

PubMed2003

Reannotation of the CELO genome characterizes a set of previously unassigned open reading frames and points to novel modes of host interaction in avian adenoviruses.

BACKGROUND: The genome of the avian adenovirus Chicken Embryo Lethal Orphan (CELO) has two terminal regions without detectable homology in mammalian adenoviruses that are left without annotation in the initial analysis. Since adenoviruses have been a rich source of new insights into molecular cell biology and practical applications of CELO as gene a delivery vector are being considered, this genome appeared worth revisiting. We conducted a systematic reannotation and in-depth sequence analysis of the CELO genome. RESULTS: We describe a strongly diverged paralogous cluster including ORF-2, ORF-12, ORF-13, and ORF-14 with an ATPase/helicase domain most likely acquired from adeno-associated parvoviruses. None of these ORFs appear to have retained ATPase/helicase function and alternative functions (e.g. modulation of gene expression during the early life-cycle) must be considered in an adenoviral context. Further, we identified a cluster of three putative type-1-transmembrane glycoproteins with IG-like domains (ORF-9, ORF-10, ORF-11) which are good candidates to substitute for the missing immunomodulatory functions of mammalian adenoviruses. ORF-16 (located directly adjacent) displays distant homology to vertebrate mono-ADP-ribosyltransferases. Members of this family are known to be involved in immuno-regulation and similiar functions during CELO life cycle can be considered for this ORF. Finally, we describe a putative triglyceride lipase (merged ORF-18/19) with additional domains, which can be expected to have specific roles during the infection of birds, since they are unique to avian adenoviruses and Marek's disease-like viruses, a group of pathogenic avian herpesviruses. CONCLUSIONS: We could characterize most of the previously unassigned ORFs pointing to functions in host-virus interaction. The results provide new directives for rationally designed experiments.

ADP Ribose Transferases↗

PubMed2003

Modern proteomic strategies in the study of complex neuropsychiatric disorders.

An insight into protein mechanisms involved in disease is critical to the discovery and design of new therapeutic tools. Direct protein analysis provides a method for studying the proteome of a tissue irrespective of an in-depth knowledge of its transcriptome. The development of a human central nervous system (CNS) proteome database ultimately will serve to accelerate the development of specific diagnostic and prognostic markers, neuropsychiatric disease markers, and the corresponding therapeutic tools. It may also reduce the uncertainties in in silico gene predictions by direct open reading frame verification and the ambiguities that experimental models of disease may provide. Advances in gel independent proteomic analyses by solid phase isotope tagging provide greater scope for the characterization of previously elusive membrane proteins; approximately half of all drug targets are key CNS membrane proteins. These advances hold great promise for improvements in the understanding, diagnosis, and therapy of central nervous system disorders.

Central Nervous System↗

PubMed2026

Benchmarking Assembly-Free K-mer Methods for Species Identification in Complex Plant Groups: A Case Study in Populus.

Species identification in taxonomically complex plant groups is frequently limited by the inadequacy of organellar markers, whose phylogenetic signal is disrupted by cytonuclear discordance and chloroplast capture. Using the taxonomically complex genus Populus as a model, we evaluated an assembly-free k-mer workflow against a curated SNP reference benchmark. Whole-genome resequencing data from 235 Populus individuals were curated to a 202-individual, 34-species reference dataset in which all retained species are strictly monophyletic in a genome-wide SNP analysis. Independent maximum likelihood analyses further confirmed that the 31 non-hybrid backbone species each maintained high-support monophyly, while taxa of documented reticulate origin showed placement patterns consistent with their reticulate histories. ABBA-BABA D-statistics detected widespread residual allele sharing within the backbone, though the strongest signals did not correspond to the species pairs responsible for the few k-mer identification failures. Against this benchmark, complete plastomes showed limited resolution, recovering only 3.0% species monophyly and 71.1% nearest-neighbor assignment. The optimized k-mer workflow, operating directly on raw reads without assembly or alignment, recovered 91.2% species monophyly, 99.0% nearest-neighbor assignment, and 98.0% group-average assignment. K-mer length was the primary accuracy-controlling parameter, with k = 31 falling within a stable accuracy plateau. Distance-based metrics reached near-saturation at 0.2× sequencing depth, indicating that low-coverage genome skimming can support scalable nuclear genome-based identification with standard computational resources. K-mer distance heatmaps also flagged unusual genomic affinities in hybrid-origin and outlier samples, providing a rapid screen for subsequent population genomic analyses. These results support assembly-free k-mer distances as an efficient tool for reference-based species identification and sample screening in complex plant groups, with residual limitations concentrated near recently diverged species boundaries. Model-based phylogenomic, coalescent, and network analyses remain necessary for resolving deeper species relationships and detailed introgression histories.

Populus↗

PubMedDate not supplied

An in-vitro evaluation of Kodak Insight and Ektaspeed Plus film with a CMOS detector for natural proximal caries: ROC analysis.

This study compared the diagnostic efficacy of Kodak Ektaspeed Plus film, Kodak Insight film, a newly introduced E/F-speed film, and Schick CMOS-APS digital sensor, with respect to caries detection in 92 proximal surfaces of extracted unrestored teeth, 51 of which were carious. Ground truth was evaluated histologically and the lesions classified as enamel or dentinal. Eight observers read the radiographs using a five-point confidence rating scale to record their diagnoses. Analyses using receiver operating characteristic curves revealed the areas under each curve that indicated the diagnostic accuracy (Ektaspeed Plus - 0.760, Insight - 0.778 and CMOS-APS sensor - 0.732). ANOVA revealed significant differences with respect to caries depth (p<0.031) and observers (p<0.0001). Weighted kappa analyses indicated moderate to substantial inter- and intra-observer agreement (0.42 and 0.66, respectively). The results suggest that none of the imaging modalities evaluated in this study differed in their diagnostic capabilities with respect to proximal decay detection and that the Insight film which was used with 20% less radiation exposure than Ektaspeed Plus film was as good as the other two sensors for this purpose.

Analysis of Variance↗