Facilitating bioinformatics reproducibility with QIIME 2 Provenance Replay.

Study reproducibility is essential to corroborate, build on, and learn from the results of scientific research but is notoriously challenging in bioinformatics, which often involves large data sets and complex analytic workflows involving many different tools. Additionally, many biologists are not trained in how to effectively record their bioinformatics analysis steps to ensure reproducibility, so critical information is often missing. Software tools used in bioinformatics can automate provenance tracking of the results they generate, removing most barriers to bioinformatics reproducibility. Here we present an implementation of that idea, Provenance Replay, a tool for generating new executable code from results generated with the QIIME 2 bioinformatics platform, and discuss considerations for bioinformatics developers who wish to implement similar functionality in their software.

Can Repetition-based Training in a High-fidelity Model Enhance Critical Trauma Surgical Skills Among Trainees and Attending Surgeons Equally?

BACKGROUND: The evolution of warfare has resulted in a surge of high-energy blast injuries predominantly involving the lower extremities. Once thought to impact only forward-deployed military, such mechanisms of injury are becoming a harsh reality even in civilian territory. Proficiency in surgical techniques for extremity damage control is vital for surgeons, regardless of specialty. To evaluate and train surgical residents and attending surgeons in critical limb-salvage techniques, Theater Hospital Operations Replication (THOR) has been proposed as a high-fidelity training platform to enhance extremity surgery teaching practices and assess proficiency in fasciotomy, vascular shunting, and knee-spanning external fixation in a simulated, resource-limited environment. QUESTIONS/PURPOSES: Given the importance of proficiency and efficiency in surgeon ability to perform fasciotomies, vascular shunting, and placement of external fixators, in this study, we proposed two research questions: (1) Does repetition-based training within the THOR model improve surgeon knowledge and technical skill? (2) Are there differences in skill outcome when utilizing the THOR model based on surgical specialty (orthopaedic versus general) and/or level in training (attending versus resident)? METHODS: This was an observational learning outcome study performed in the bioskills lab at a single institution, the Naval Medical Center Portsmouth, in which 26 surgeons completed a same-day course consisting of pretraining assessment, cadaver training on three damage-control surgery techniques in a high-fidelity THOR environment, and post-training assessment. The surgeons were either general surgeons or orthopaedic surgeons and consisted of both residents and attending surgeons. Subjects underwent a pretraining knowledge assessment, followed by two rounds of performing simulated surgery. The first round of surgery included guidance and instruction from board-certified orthopaedic surgeons. After a short break for the subjects to review the material, the second round was completed without instruction. To answer our first question of how repetition-based training impacts surgical skill, our metrics included: Objective Structured Assessment of Technical Skills (OSATS) scores (range 1 to 5, scored lowest to highest, where higher scores represent optimal skill performance), procedural accuracy, a 10-question knowledge assessment administered before and after training (scored 0 to 10, where higher scores represent competency of the anatomy and procedure steps), and total procedure time. To address our second question, data on demographic characteristics were collected on all participants, which included surgical specialty, year in training, and gender. RESULTS: The general surgery residents' cohort demonstrated improvement in both mean ± SD OSATS scores (2.4 ± 0.7 before training versus 3.6 ± 0.6 after training, mean difference 1.2 [95% CI 0.4 to 2.0]; p = 0.01) and procedure duration (23 ± 7 minutes before training versus 16 ± 5 minutes after training, mean difference 6 minutes [95% CI 4 to 9]; p = 0.001) for external fixator procedures after THOR. Similar results were seen in fasciotomies after THOR. The orthopaedic surgery residents' cohort showed similar improvements in reducing procedure duration when performing knee-spanning external fixator surgery, as well as exhibited improvements during vascular shunting procedures in both mean ± SD OSATS scores (previously 3.3 ± 0.9 versus 4.0 ± 0.9, mean difference 0.7 [95% CI 0.2 to 1.2]; p = 0.01) and procedure duration (23 ± 5 minutes versus 14 ± 8 minutes, mean difference 10 minutes [95% CI 4 to 15]; p = 0.003) after THOR. When we compared the cohorts, general surgery attending surgeons demonstrated an improvement in vascular shunting procedure duration after instruction with the THOR model (19 ± 3 minutes versus 12 ± 4 minutes, mean difference 7 minutes [95% CI 1 to 13]; p = 0.03) and in overall knowledge scores (4.3 + 0.5 versus 8.0 ± 1.6, mean difference 3.8 [95% CI 0.5 to 7.0]; p = 0.04). The orthopaedic surgery attending surgeons yielded no improvement for any metric, pretraining and post-training. Using the prescores as a covariate, for almost all metrics analyzed, there were no differences between surgeon groups based on specialty after completing the repeated training. CONCLUSION: Use of the high-fidelity THOR training model improved proficiency in the examined sample of extremity damage-control procedures, thus demonstrating its efficacy in enhancing surgical skills and short-interval knowledge retention while simultaneously highlighting the importance of cadaver simulation training in enhancing surgical preparedness for complex trauma. CLINICAL RELEVANCE: The high-fidelity THOR training model represents a promising modality for preparing surgeons for extremity combat trauma management in resource-limited, high-stress environments. Whether in a wartime environment or in the civilian sector, efficient and skilled intervention are crucial in managing patient morbidity. Differences of a few minutes per procedure can mean all the difference in damage control, especially when compounded in situations where vascular shunting, knee-spanning external fixation, and lower leg four-compartment fasciotomy have to be performed together by both orthopaedic and general surgeons. The observational period in this study spanned 1 day and thus does not provide information on retention of long-term skills or knowledge. A follow-on study can assess how time from initial training to final evaluation impacts overall skill competency and knowledge.

Self-calibrated Fourier transform spectrometer for laser-induced fluorescence spectroscopy with single-photon avalanche diode detection.

Fourier transform spectrometers are commonly used in scientific and industrial settings because of their ability to record complete spectra with high signal-to-noise ratios. Using a single-photon avalanche diode as the detector improves the sensitivity but adds complications in laser-induced fluorescence applications related to detector saturation and acquisition time exceeding the typical scan time. Here, we report a spectrometer for the detection of laser-induced fluorescence signal together with the excitation light, and use the second harmonic signal from the excitation light to correct the phase and calibrate the spectrum, removing the need for a separate calibration source. We achieve a resolution of 0.4cm-1 in the wavelength range of 1140.2 nm, and demonstrate detection of signals with powers as low as 377fW, with a noise floor of 172fW/cm-1.

Spin Susceptibility above the Superfluid Onset in Ultracold Fermi Gases.

Ultracold atomic Fermi gases can be tuned to interact strongly, which produces a display of spectroscopic signatures above the superfluid transition reminiscent of the pseudogap in cuprates. However, the extent of the analogy can be questioned since many thermodynamic quantities in the low temperature spin-imbalanced normal state can be described successfully using Fermi liquid theory. Here we present spin susceptibility measurements across the interaction strength-temperature phase diagram using a novel radio frequency technique with ultracold ^{6}Li gases. For all significant interaction strengths and at all temperatures we find the spin susceptibility is reduced compared to the equivalent value for a noninteracting Fermi gas. At unitarity, we can use the local density approximation to extract the integrated spin susceptibility for the uniform gas as a function of temperature, which at high temperatures is generally less than theoretically predicted. At low temperatures, our data lie within the range of theoretical predictions, although we can also describe the entire curve using a very simple one-parameter mean field model with monotonically increasing spin susceptibility.

Pleuropulmonary blastoma in children and adolescents: The EXPeRT/PARTNER diagnostic and therapeutic recommendations.

Pleuropulmonary blastoma (PPB) is a rare cancer occurring mainly during early childhood and often associated with germline DICER1 mutations. It is classified by the macroscopic appearance into three interrelated clinico-pathologic entities on a developmental continuum. Complete tumor resection is a main prognostic factor and can be performed at diagnosis or after neoadjuvant treatment that includes chemotherapy and in some cases radiotherapy. Optimal modalities of neo- or adjuvant treatments can be challenging taking into account potential long-term toxicities in this young population. This paper presents the recommendations for diagnosis and treatment of children and adolescents with PPB elaborated by the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) within the European Union-funded project PARTNER (Paediatric Rare Tumours Network - European Registry).

Kidney Histopathology and Prediction of Kidney Failure: A Retrospective Cohort Study.

RATIONALE & OBJECTIVE: The use of kidney histopathology for predicting kidney failure is not established. We hypothesized that the use of histopathologic features of kidney biopsy specimens would improve prediction of clinical outcomes made using demographic and clinical variables alone. STUDY DESIGN: Retrospective cohort study and development of a clinical prediction model. SETTING & PARTICIPANTS: All 2,720 individuals from the Biopsy Biobank Cohort of Indiana who underwent kidney biopsy between 2002 and 2015 and had at least 2 years of follow-up. NEW PREDICTORS & ESTABLISHED PREDICTORS: Demographic variables, comorbid conditions, baseline clinical characteristics, and histopathologic features. OUTCOMES: Time to kidney failure, defined as sustained estimated glomerular filtration rate ≤ 10mL/min/1.73m2. ANALYTICAL APPROACH: Multivariable Cox regression model with internal validation by bootstrapping. Models including clinical and demographic variables were fit with the addition of histopathologic features. To assess the impact of adding a histopathology variable, the amount of variance explained (r2) and the C index were calculated. The impact on prediction was assessed by calculating the net reclassification index for each histopathologic variable and for all combined. RESULTS: Median follow-up was 3.1 years. Within 5 years of biopsy, 411 (15.1%) patients developed kidney failure. Multivariable analyses including demographic and clinical variables revealed that severe glomerular obsolescence (adjusted HR, 2.03; 95% CI, 1.51-2.03), severe interstitial fibrosis and tubular atrophy (adjusted HR, 1.99; 95% CI, 1.52-2.59), and severe arteriolar hyalinosis (adjusted HR, 1.53; 95% CI, 1.14-2.05) were independently associated with the primary outcome. The addition of all histopathologic variables to the clinical model yielded a net reclassification index for kidney failure of 5.1% (P < 0.001) with a full model C statistic of 0.915. Analyses addressing the competing risk for death, optimism, or shrinkage did not significantly change the results. LIMITATIONS: Selection bias from the use of clinically indicated biopsies and exclusion of patients with less than 2 years of follow-up, as well as reliance on surrogate indicators of kidney failure onset. CONCLUSIONS: A model incorporating histopathologic features from kidney biopsy specimens improved prediction of kidney failure and may be valuable clinically. Future studies will be needed to understand whether even more detailed characterization of kidney tissue may further improve prognostication about the future trajectory of estimated glomerular filtration rate.

Production and properties of a bioemulsifier obtained from a lactic acid bacterium.

In the present work, the production of bioemulsifier (BE) by a lactic acid bacterium (LAB) grown at 25 °C in lactic whey-based media for 24 h was evaluated. Maximum production was detected in a medium containing yeast extract, peptone and lactic whey (LAPLW medium), with a yield of 270 mg L-1. The BE proved to be more innocuous for Caco-2 cells, used as a toxicological indicator, than the non-ionic surfactant Triton X-100. In addition, the microbial product presented higher stability to changes in temperature (37 °C to 100 °C), pH (2-10), and salt concentration (5% and 20%, w/v) than the synthetic surfactant. Regarding emulsifying capacity tested against different hydrophobic substrates (kerosene, motor oil, diesel, sunflower oil, and grape oil), the BE displayed E24 values similar to or even better than those of Triton X-100. Finally, Triton X-100 caused irreversible modifications on the giant unilamellar vesicles (used as model membrane system), promoting the solubilization of the lipid bilayers. Nevertheless, BE induced temporary modifications of the membrane, which is associated with incorporation of the bioproduct in the outer layer. These results demonstrate the role of BE in biological processes, including reversible changes in microbial membranes to enhance the access to hydrophobic substrates.

Variability of outcome measures in trials of intravenous therapy in acute severe paediatric asthma: a systematic review.

OBJECTIVE: To determine the variability of primary and secondary outcomes used in trials of intravenous bronchodilators in children with acute severe paediatric asthma. METHODS: Systematic search of MEDLINE, EMBASE, Cochrane CENTRAL and the WHO International Clinical Trials Registry Platform for randomised trials in children (less than18 years) with acute severe paediatric asthma comparing intravenous bronchodilator therapy to another treatment. Initial search was performed on 7 January 2016 with an updated search performed on 6 September 2018. Primary and secondary outcomes were collated. RESULTS: We identified 35 published papers and four registered study protocols. 56 primary outcomes were found, the most common being a clinical asthma score (23/56; 41%). Other identified primary outcomes included bedside tests of respiratory function (11/56; 20%) and measures of length of stay (9/56; 16%). There were a total of 60 different secondary outcomes, the most common were various length of stay measures (24/60; 40%) and adverse events (11/60; 18%). CONCLUSION: Studies comparing intravenous treatment modalities for children with acute severe paediatric asthma exhibit great variation in the type, number and timing of outcome measures used. There are no patient or family-specific outcomes reported. There is a need to develop international consensus. TRIAL REGISTRATION NUMBER: CRD42017055331.

[The parapharyngeal adipose corpus: Surgical anatomy and imaging]. / Le corps adipeux parapharyngé : anatomie chirurgicale et imagerie.

The aim of this study is to define the parapharyngeal adiposis corpus (PAC) and its anatomical relationships originally described by P. Sebileau in 1892 to assess the potential clinical implications. MATERIALS AND METHODS: Seven frozen fresh cadavers were used, 3 of which after injection of latex neoprene colored in cervicocephalic arterial network. A MRI was performed in 10 patients without cervical pathology. The analysis was done on the frontal and transverse T1-weighted sections. RESULTS: The PAC, which is a yellowish fat formation, fills the paratonsillar space. It measures an average of 4.8cm (4.5 to 5.2cm) in length and 1.2cm (1.1 to 1.5cm) for subjects of varying size and sex. Its arterial supply is mainly provided by the ascending palatine artery, an early branch of the facial artery. A left-right symmetry was found on MRI analyses regardless of sex or age. It is found in all the medial and ventral cases on the pharyngeal extension of the parotid gland in homogeneous hyperintense T1. CONCLUSION: The PAC is a constant fat structure. Its vascularization depends mainly on the ascending palatine artery. Through its association with fatty peripharyngeal space, it could be a functionally sliding space. In imaging, it may be helpful in the interpretation of images of the pharyngeal extension of the parotid gland tumors.

Aneuploidy screening of embryonic stem cell clones by metaphase karyotyping and droplet digital polymerase chain reaction.

BACKGROUND: Karyotypic integrity is essential for the successful germline transmission of alleles mutated in embryonic stem (ES) cells. Classical methods for the identification of aneuploidy involve cytological analyses that are both time consuming and require rare expertise to identify mouse chromosomes. RESULTS: As part of the International Mouse Phenotyping Consortium, we gathered data from over 1,500 ES cell clones and found that the germline transmission (GLT) efficiency of clones is compromised when over 50 % of cells harbour chromosome number abnormalities. In JM8 cells, chromosomes 1, 8, 11 or Y displayed copy number variation most frequently, whilst the remainder generally remain unchanged. We developed protocols employing droplet digital polymerase chain reaction (ddPCR) to accurately quantify the copy number of these four chromosomes, allowing efficient triage of ES clones prior to microinjection. We verified that assessments of aneuploidy, and thus decisions regarding the suitability of clones for microinjection, were concordant between classical cytological and ddPCR-based methods. Finally, we improved the method to include assay multiplexing so that two unstable chromosomes are counted simultaneously (and independently) in one reaction, to enhance throughput and further reduce the cost. CONCLUSION: We validated a PCR-based method as an alternative to classical karyotype analysis. This technique enables laboratories that are non-specialist, or work with large numbers of clones, to precisely screen ES cells for the most common aneuploidies prior to microinjection to ensure the highest level of germline transmission potential. The application of this method allows early exclusion of aneuploid ES cell clones in the ES cell to mouse conversion process, thus improving the chances of obtaining germline transmission and reducing the number of animals used in failed microinjection attempts. This method can be applied to any other experiments that require accurate analysis of the genome for copy number variation (CNV).

Fluctuating stripes at the onset of the pseudogap in the high-T(c) superconductor Bi(2)Sr(2)CaCu(2)O(8+x).

Doped Mott insulators have a strong propensity to form patterns of holes and spins often referred to as stripes. In copper oxides, doping also gives rise to the pseudogap state, which can be transformed into a high-temperature superconducting state with sufficient doping or by reducing the temperature. A long-standing issue has been the interplay between the pseudogap, which is generic to all hole-doped copper oxide superconductors, and stripes, whose static form occurs in only one family of copper oxides over a narrow range of the phase diagram. Here we report observations of the spatial reorganization of electronic states with the onset of the pseudogap state in the high-temperature superconductor Bi(2)Sr(2)CaCu(2)O(8+x), using spectroscopic mapping with a scanning tunnelling microscope. We find that the onset of the pseudogap phase coincides with the appearance of electronic patterns that have the predicted characteristics of fluctuating stripes. As expected, the stripe patterns are strongest when the hole concentration in the CuO(2) planes is close to 1/8 (per copper atom). Although they demonstrate that the fluctuating stripes emerge with the onset of the pseudogap state and occur over a large part of the phase diagram, our experiments indicate that the stripes are a consequence of pseudogap behaviour rather than its cause.

Mobile magnetic impurities in a Fermi superfluid: a route to designer molecules.

A magnetic impurity in a fermionic superfluid hosts bound quasiparticle states known as Yu-Shiba-Rusinov states. We argue here that, if the impurity is mobile (i.e., has a finite mass), the impurity and its bound Yu-Shiba-Rusinov quasiparticle move together as a midgap molecule, which has an unusual "Mexican-hat" dispersion that is tunable via the fermion density. We map out the impurity dispersion, which consists of an "atomic" branch (in which the impurity is dressed by quasiparticle pairs) and a "molecular" branch (in which the impurity binds a quasiparticle). We discuss the experimental realization and detection of midgap Shiba molecules, focusing on Li-Cs mixtures, and comment on the prospects they offer for realizing exotic many-body states.

Roton-maxon excitation spectrum of Bose condensates in a shaken optical lattice.

We present experimental evidence showing that an interacting Bose condensate in a shaken optical lattice develops a roton-maxon excitation spectrum, a feature normally associated with superfluid helium. The roton-maxon feature originates from the double-well dispersion in the shaken lattice, and can be controlled by both the atomic interaction and the lattice modulation amplitude. We determine the excitation spectrum using Bragg spectroscopy and measure the critical velocity by dragging a weak speckle potential through the condensate-both techniques are based on a digital micromirror device. Our dispersion measurements are in good agreement with a modified Bogoliubov model.

Topological surface states protected from backscattering by chiral spin texture.

Topological insulators are a new class of insulators in which a bulk gap for electronic excitations is generated because of the strong spin-orbit coupling inherent to these systems. These materials are distinguished from ordinary insulators by the presence of gapless metallic surface states, resembling chiral edge modes in quantum Hall systems, but with unconventional spin textures. A key predicted feature of such spin-textured boundary states is their insensitivity to spin-independent scattering, which is thought to protect them from backscattering and localization. Recently, experimental and theoretical efforts have provided strong evidence for the existence of both two- and three-dimensional classes of such topological insulator materials in semiconductor quantum well structures and several bismuth-based compounds, but so far experiments have not probed the sensitivity of these chiral states to scattering. Here we use scanning tunnelling spectroscopy and angle-resolved photoemission spectroscopy to visualize the gapless surface states in the three-dimensional topological insulator Bi(1-x)Sb(x), and examine in detail the influence of scattering from disorder caused by random alloying in this compound. We show that, despite strong atomic scale disorder, backscattering between states of opposite momentum and opposite spin is absent. Our observations demonstrate that the chiral nature of these states protects the spin of the carriers. These chiral states are therefore potentially useful for spin-based electronics, in which long spin coherence is critical, and also for quantum computing applications, where topological protection can enable fault-tolerant information processing.

Geometric scaling of Efimov states in a 6Li-¹³³Cs mixture.

In few-body physics, Efimov states are an infinite series of three-body bound states that obey universal discrete scaling symmetry when pairwise interactions are resonantly enhanced. Despite abundant reports of Efimov states in recent cold atom experiments, direct observation of the discrete scaling symmetry remains an elusive goal. Here we report the observation of three consecutive Efimov resonances in a heteronuclear Li-Cs mixture near a broad interspecies Feshbach resonance. The positions of the resonances closely follow a geometric series 1, λ, λ². The observed scaling constant λ(exp)=4.9(4) is in good agreement with the predicted value of 4.88.

The role of magnesium sulfate in acute asthma: does route of administration make a difference?

PURPOSE OF REVIEW: The role of magnesium sulfate (MgSO4) in the treatment of acute asthma is not clear. Four recent systematic reviews suggest a limited role of intravenous (i.v.) and inhaled nebulized treatment. The purpose of this review is to summarize the current literature, focus on two recent large multicenter randomized controlled trials, and discuss future research directions. RECENT FINDINGS: The Magnesium Nebulized Trial In Children (MAGNETIC) trial has shown little benefit to routine use of nebulized MgSO4 in children with acute asthma, but there may be a benefit in those with severe exacerbations and a shorter duration of symptoms. The 3Mg trial has shown no role for nebulized MgSO4 in adults and, at best a limited role for i.v. MgSO4 in only the most severe exacerbations. This is the only study with direct comparison of nebulized and i.v. MgSO4. SUMMARY: MgSO4 has a role in severe exacerbations of acute asthma and there is no evidence of benefit outside this clinical situation. Both nebulized and i.v. treatments are well tolerated and inexpensive. In adults, the most effective route of administration is i.v. There are no direct comparison studies in children. Further research should focus on more severe exacerbations.

Uncoupling antisense-mediated silencing and DNA methylation in the imprinted Gnas cluster.

There is increasing evidence that non-coding macroRNAs are major elements for silencing imprinted genes, but their mechanism of action is poorly understood. Within the imprinted Gnas cluster on mouse chromosome 2, Nespas is a paternally expressed macroRNA that arises from an imprinting control region and runs antisense to Nesp, a paternally repressed protein coding transcript. Here we report a knock-in mouse allele that behaves as a Nespas hypomorph. The hypomorph mediates down-regulation of Nesp in cis through chromatin modification at the Nesp promoter but in the absence of somatic DNA methylation. Notably there is reduced demethylation of H3K4me3, sufficient for down-regulation of Nesp, but insufficient for DNA methylation; in addition, there is depletion of the H3K36me3 mark permissive for DNA methylation. We propose an order of events for the regulation of a somatic imprint on the wild-type allele whereby Nespas modulates demethylation of H3K4me3 resulting in repression of Nesp followed by DNA methylation. This study demonstrates that a non-coding antisense transcript or its transcription is associated with silencing an overlapping protein-coding gene by a mechanism independent of DNA methylation. These results have broad implications for understanding the hierarchy of events in epigenetic silencing by macroRNAs.

Unraveling the mechanism of tip-enhanced molecular energy transfer.

Electronic Energy Transfer (EET) between chromophores is fundamental in many natural light-harvesting complexes, serving as a critical step for solar energy funneling in photosynthetic plants and bacteria. The complicated role of the environment in mediating this process in natural architectures has been addressed by recent scanning tunneling microscope experiments involving EET between two molecules supported on a solid substrate. These measurements demonstrated that EET in such conditions has peculiar features, such as a steep dependence on the donor-acceptor distance, reminiscent of a short-range mechanism more than of a Förster-like process. By using state of the art hybrid ab initio/electromagnetic modeling, here we provide a comprehensive theoretical analysis of tip-enhanced EET. In particular, we show that this process can be understood as a complex interplay of electromagnetic-based molecular plasmonic processes, whose result may effectively mimic short range effects. Therefore, the established identification of an exponential decay with Dexter-like effects does not hold for tip-enhanced EET, and accurate electromagnetic modeling is needed to identify the EET mechanism.

Clinical phenotype, laboratory features and genotype of 35 patients with heritable dysfibrinogenaemia.

Heritable dysfibrinogenaemia (HD) is a rare qualitative disorder of fibrinogen (FGN). To better describe the clinical, laboratory and genotypic spectrum of HD, we evaluated 35 subjects identified at two UK centres using laboratory criteria. 12/35(34%) subjects with HD experienced bleeding (bleeding score >1 at any site), 3/35(9%) thrombosis and 20/35(57%) were asymptomatic. Amongst subjects with bleeding, symptoms were typically mild, at one anatomical site and seldom occurred after invasive procedures. All subject showed dry clot weight within or above laboratory reference interval (median 3·2 g/l; range 1·9-5·1), reduced Clauss fibrinogen (median 0·52 g/l; range 0·21-1·3), and prolonged thrombin (median 30·7 s; range 21·3-45·7) and reptilase (median 42·0 s; range 20·0-68·0) times. In all subjects, the prothrombin time ratio (PTR), determined by Sysmex CA-1500 coagulometer and Innovin activator, was abnormal (median 1·42; range 1·22-1·61). The activated partial thromboplastin time ratio and PTR with other coagulometers and activators were comparatively insensitive to HD. All subjects with HD harboured heterozygous candidate nucleotide variations within known hotspots in the FGN genes. The HD variants identified in this cross-sectional study seldom have significant clinical manifestations and show similar laboratory features irrespective of genotype. Selection of coagulometer and PT activator may markedly affect the detection of new HD cases using coagulation screening tests.