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The human ether-á-go-go-related gene (hERG1) channel conducts small outward K+ currents that are critical for cardiomyocyte membrane repolarization. The gain-of-function mutation N629D at the outer mouth of the selectivity filter (SF) disrupts inactivation and K+-selective transport in hERG1, leading to arrhythmogenic phenotypes associated with long-QT syndrome. Here, we combined computational electrophysiology with Markov state model analysis to investigate how SF-level gating modalities control selective cation transport in wild-type (WT) and mutant (N629D) hERG1 variants. Starting from the recently reported cryogenic electron microscopy (cryo-EM) open-state channel structure, multiple microseconds-long molecular-dynamics (MD) trajectories were generated using different cation configurations at the filter, voltages, electrolyte concentrations, and force-field parameters. Most of the K+ permeation events observed in hERG1-WT simulations occurred at microsecond timescales, influenced by the spontaneous dehydration/rehydration dynamics at the filter. The SF region displayed conductive, constricted, occluded, and dilated states, in qualitative agreement with the well-documented flickering conductance of hERG1. In line with mutagenesis studies, these gating modalities resulted from dynamic interaction networks involving residues from the SF, outer-mouth vestibule, P-helices, and S5-P segments. We found that N629D mutation significantly stabilizes the SF in a state that is permeable to both K+ and Na+, which is reminiscent of the SF in the nonselective bacterial NaK channel. Increasing the external K+ concentration induced "WT-like" SF dynamics in N629D, in qualitative agreement with the recovery of flickering currents in experiments. Overall, our findings provide an understanding of the molecular mechanisms controlling selective transport in K+ channels with a nonconventional SF sequence.

Aim: To demonstrate a case of Actinomyces infection in which ultrasound was used as a diagnostic aid tool. Materials and Methods: Description of a case of cervicofacial actinomycosis in a patient, whose treatment and long‐term evaluation were performed using ultrasound, a crucial tool to ensure accuracy and real‐time images, without exposing the patient to radiation, contributing to the success of treatment. Results: In the case of actinomycosis, the ultrasound findings consisted of hyperechoic foci surrounded by hypoechoic areas. Conclusions: Ultrasonography plays a broad role in dentistry, being able to assist in diagnosis, guided surgical interventions and post‐treatment monitoring. Furthermore, ultrasound is an accessible and portable examination that can be used at the patient's bedside, especially in critical cases, proving to be a promising tool in clinical management in a hospital environment. [ABSTRACT FROM AUTHOR]

The Lower Mississippi River has a floodplain that includes >1350 perennial lakes carved by shifts in river courses and other hydro‐fluvial processes over eons. Notwithstanding their similar provenances, these waterbodies exhibit an immense variety of morphologies and successional stages that illustrate their natural trajectory from aquatic to forested wetlands. A result of this geographical, morphological and temporal diversity is dynamic and varied fish communities. We examined how size structures of fish communities in these floodplain lakes were associated with key in‐lake and off‐lake environmental drivers.Fish lengths were collected with standardised procedures in a sample of 30 of these lakes to construct a lake‐by‐length group matrix. Likewise, in‐lake and off‐lake environmental descriptors were collected to construct a lake‐by‐covariate matrix. Distance‐based linear models were used to assess associations between fish size structure and environmental descriptors.Smaller fish were typically associated with increasing levels of turbidity, chlorophyll‐a, phycocyanin and surrounding agriculture. Shallow, hypereutrophic floodplain lakes associated with agricultural landscapes and reduced connectivity experience harsh physicochemical environments. These conditions appeared to hinder the formation of sustained fish communities but may confer a survival advantage to juveniles or small short‐lived species. Conversely, larger fish were associated with increasing lake depth, water clarity, connectivity, and extent of surrounding forests‐wetlands. Enhanced stability and size structure were observed in communities residing in deeper and clearer lakes, suggesting that these conditions facilitated the development of longer‐lived species spanning multiple age groups. The enhanced connectivity that facilitated this increased stability also permitted the presence of larger itinerant species.Size‐structure assessments can serve as a valuable ecological and biodiversity indicator in floodplain lakes.Size‐structure assessments could supplement and, depending on objectives, even supplant conventional taxonomic analyses, and enhance surveillance of this vast and important natural resource. [ABSTRACT FROM AUTHOR]

Background and aimThe identification of, and timely intervention for, patients with impaired nutritional status may reduce inflammatory bowel disease (IBD) complications. This study aimed to develop and validate an IBD-specific nutrition self-screening tool (IBD-NST) that identifies patients at nutrition risk.MethodsAn expert IBD panel was consulted to support development of an IBD-NST. The tool was assessed in different cohorts of patients attending IBD outpatient clinics for face, content and convergent validity and repeat reliability. The tool was compared with (i) the malnutrition universal screening tool to assess face validity and (ii) subjective global assessment (SGA), hand-grip strength (HGS) and mid-arm muscle circumference to assess convergent validity. Tool content was informed by agreement between assessment tools, sensitivity analysis and chi-squared tests. The IBD-NST was completed electronically twice, 1 week apart to assess repeat reliability using observed agreement and kappa statistic. Statistical significance assumed at p < 0.05.ResultsIn total, 282 IBD patients (175 with Crohn’s disease) were recruited to validate the IBD-NST. The final validated IBD-NST includes body mass index (BMI), weight loss and IBD-specific nutrition-focussed questions which were acceptable to patients. It identified patients at risk of malnutrition, moderately or severely malnourished patients and patients at nutritional risk. The IBD-NST identified 54/179 (30%) patients at moderate or high nutrition risk and had excellent repeat reliability in 85 patients [r = 0.77 (95% CI 0.669 to 0.746)].ConclusionThe IBD-NST is a self-screening tool, validated for use as either a paper or e-health version, that identifies patients at nutrition risk who are likely to benefit from dietetic assessment and intervention. Furthermore, patients with IBD symptoms who are concerned about their dietary intake can potentially access dietetic care more easily therefore encouraging greater self-management of IBD-related symptoms. The routine use of the IBD-NST as a self-screening tool would enable patient-led care in the outpatient setting and may facilitate timely access to dietetic care.

Background: There is limited evidence regarding the use of low FODMAP diet apps. This study aimed to evaluate the effectiveness of an app intended to reduce symptoms in FODMAP restriction and symptoms and tolerance of high FODMAP food challenges during FODMAP reintroduction and personalisation. Methods: Data were collected from 21,462 users of a low FODMAP diet app. Self-reported gut symptoms during FODMAP restriction, reintroduction, and personalisation and dietary triggers were identified from symptom response data for FODMAP food challenges. Results: Compared with baseline, at the end of FODMAP restriction, participants (n = 20,553) reported significantly less overall symptoms (11,689 (57%) versus 9105 (44%)), abdominal pain (8196 (40%) versus 6822 (33%)), bloating (11,265 (55%) versus 9146 (44%)), flatulence (10,318 (50%) 8272 (40%)), and diarrhoea (6284 (31%) versus 4961 (24%)) and significantly more constipation (5448 (27%) versus 5923 (29%)) (p < 0.001 for all). During FODMAP reintroduction, participants (n = 2053) completed 8760 food challenges; the five most frequent challenges and n/N (%) of dietary triggers identified were wheat bread 474/1146 (41%), onion 359/918 (39%), garlic 245/699 (35%), milk 274/687 (40%), and wheat pasta 222/548 (41%). The most frequently reported symptoms during food challenges were overall symptoms, abdominal pain, bloating, and flatulence. Conclusions: In a real-world setting, a low FODMAP diet app can help users improve gut symptoms and detect dietary triggers for long-term self-management.

Objective: Visual aids like length‐frequency histograms are widely used to examine fish population status and trends; however, comparing multiple histograms simultaneously becomes cumbersome and inefficient. Complicating matters further, overlaying covariates on histograms to highlight connections with length frequencies can be challenging. An alternative, and the subject of this Perspective, is to display length distributions as an ordination using similarity indexes; in many cases, this allows for improved visual organization and representation of relationships with covariates. Methods: I review the application of ordination methods for analysis of size structures using alternative visualizations that may facilitate the identification of connections that are concealed when analyzing a series of histograms. After a brief introduction to similarity indexes, types of ordinations, and sample sizes, I examine four case studies to illustrate size structure analysis via similarity indices: (1) unconstrained ordination to identify "bass‐crowded" populations in a set of 34 small fishing lakes, (2) unconstrained ordination to evaluate the effect of three consecutive length limits on a Largemouth Bass Micropterus nigricans population over a span of 28 years, (3) constrained ordination to assess the relationships between fish community size structure and in‐lake and off‐lake environmental descriptors in 30 oxbow lakes, and (4) constrained ordination to identify what aspects of Largemouth Bass size structure were related to six types of reservoir habitats. Result: Size structure analysis via similarity indexes enabled the exploration of extensive length‐frequency data. It is important to acknowledge that ordinations serve solely as a visual aid for assessing size structure—no statistical testing is involved. Conclusion: Ordination techniques and software are advancing at a quick pace, holding great promise for the future of size structure analysis via similarity indices. Impact statementLength ordinations provide a visual representation of complex size structure data, making it easier to understand patterns, relationships, and trends in size structure. The visual representation can facilitate the interpretation and communication of survey results to both experts and nonexperts. [ABSTRACT FROM AUTHOR]

Silver carp, Hypophthalmichthys molitrix, escaped into the Lower Mississippi River (LMR) over 50 years ago, established reproductive populations, and spread across much of the Mississippi River Basin. Demographic rates of silver carp are needed to inform decisions on control and management of this invasive species, but have not been published for the LMR. The purpose of this paper is to report silver carp age and growth estimates from fish collected in riverine (mainstem) and backwater (lake) habitats in the LMR during the period 2011-2019, to compare our results with populations from other geographic areas in the Upper Mississippi River drainage, and to evaluate latitudinal and habitat differences in demographic parameters. Silver carp gained weight with increasing length similarly throughout the lower and upper basin. However, annual growth rates were higher in the LMR compared to northern rivers including the Illinois, Wabash, Missouri, and Middle Mississippi rivers. In the LMR, regression analyses demonstrated that females were heavier in lakes than males or females in the mainstem and that females in lakes had the lowest instantaneous mortality (-0.186). Maximum age was 8 and 10 years for females and males, respectively. The largest male weighed 13.8 kg with a total length of 1022 mm, and was 7 years old. The largest female weighed 16.0 kg with a total length of 1034 mm TL, and was 7 years old. Rapid growth rates, larger sizes, and lower mortality in the LMR, in combination with limited commercial fishing, extensive river-floodplain connectivity, and vast amounts of spawning areas, ensure that LMR silver carp will continue to act as a source of fast-growing invasive individuals for other reaches and other rivers throughout the Mississippi River Basin. [ABSTRACT FROM AUTHOR]