Micromagnetic Tomography (MMT) is a new technique that allows the determination of magnetic moments of individual grains in volcanic rocks. Current MMT studies either showed that it is possible to ...obtain magnetic moments of relatively small numbers of grains in ideal sample material or provided important theoretical advances in MMT inversion theory and/or its statistical framework. Here, we present a large‐scale application of MMT on a sample from the 1907‐flow from Hawaii's Kilauea volcano producing magnetic moments of 1,646 grains. We produced 261,305 magnetic moments in total for these 1,646 grains, an increase of three orders of magnitude compared to earlier studies to assess the robustness of the MMT results, and a major step toward the number of grains that is necessary for paleomagnetic applications of MMT. Furthermore, we show that the recently proposed signal strength ratio is a powerful tool to scrutinize and select MMT results. Despite this progress, still only relatively large iron‐oxide grains with diameters >1.5–2 μm can be reliably resolved, impeding a reliable paleomagnetic interpretation. To determine the magnetic moments of smaller (<1 μm) grains that may exhibit pseudo‐single domain behavior and are therefore better paleomagnetic recorders, the resolution of the microcomputed tomography and magnetic scans necessary for MMT must be improved. Therefore, it is necessary to reduce the sample size in future MMT studies. Nevertheless, our study is an important step toward making MMT a useful paleomagnetic and rock‐magnetic technique.
Plain Language Summary
The magnetic information of volcanic rocks is an invaluable archive of the behavior of the Earth's magnetic field through time. Recently, a new technique, Micromagnetic Tomography, was proposed that promises to determine the magnetic signals of individual iron‐bearing grains in these rocks. This would greatly improve our ability to obtain and interpret the magnetic information stored in them. Here, we go beyond the proof‐of‐concept of this exciting new technique and show that it is indeed possible to obtain statistically robust results for a set of rather large grains, with diameters >1.5–2 μm, in a sample from the 1907‐flow from Hawaii's Kilauea volcano.
Key Points
We studied a sample from the 1907‐flow of Kilauea (Hawaii) with well‐known rock‐magnetic properties using Micromagnetic Tomography (MMT)
We performed 16,874 MMT inversions to characterize the magnetic moments of 1,646 grains, resulting in 261,305 magnetic moments
Magnetic moments were found only for grains >1.5–2 μm that exhibit multidomain behavior, but these MMT results are statistically robust
Purpose
To illustrate different causes of upper eyelid asymmetry and to stress that detection of any asymmetry is important in avoiding an unhappy patient.
Methods
Patients want an ‘upper eyelid ...correction’ and do not know the real cause of the asymmetry, or even did not notice any asymmetry. Different kind of asymmetric appearances of the upper eyelids will be shown and analyzed.
Results
The upper eyelid has several landmarks. Besides the palpebral aperture, the margin pupil distance and lid crease height, also the margin fold distance/tarsal show, the lid fullness and braw distance needs to be described. An asymmetric tarsal show is often perceived as ptosis. Also bony orbit, eye position, orbital fat and braw position are all important factors influencing the final upper eyelid shape. In some conditions a perfect upper eyelid symmetry is very difficult to achieve or sometimes impossible.
Conclusions
Good preoperative assessment is crucial in eyelid surgery, both in primary surgery and in correcting postoperative asymmetry. Good patient counseling is important to create realistic expectations.
Dune development along highly dynamic land–sea boundaries is the result of interaction between vegetation and dune size with sedimentation and erosion processes. Disentangling the contribution of ...vegetation characteristics from that of dune size would improve predictions of nebkha dune development under a changing climate, but has proven difficult due to the scarcity of spatially continuous monitoring data. This study explored the contributions of vegetation and dune size to dune development for locations differing in shelter from the sea. We monitored a natural nebkha dune field of 8 ha, along the coast of the island Texel, the Netherlands, for 1 year using an unmanned aerial vehicle (UAV) with camera. After constructing a digital surface model and orthomosaic we derived for each dune (1) vegetation characteristics (species composition, vegetation density, and maximum vegetation height), (2) dune size (dune volume, area, and maximum height), (3) degree of shelter (proximity to other nebkha dunes and the sheltering by the foredune). Changes in dune volume over summer and winter were related to vegetation, dune size and degree of shelter. We found that a positive change in dune volume (dune growth) was linearly related to initial dune volume over summer but not over winter. Big dunes accumulated more sand than small dunes due to their larger surface area. Exposed dunes increased more in volume (0.81 % per dune per week) than sheltered dunes (0.2 % per dune per week) over summer, while the opposite occurred over winter. Vegetation characteristics did not significantly affect dune growth in summer, but did significantly affect dune growth in winter. Over winter, dunes dominated by Ammophila arenaria, a grass species with high vegetation density throughout the year, increased more in volume than dunes dominated by Elytrigia juncea, a grass species with lower vegetation density (0.43 vs. 0.42 (m3 m−3) week−1). The effect of species was irrespective of dune size or distance to the sea. Our results show that dune growth in summer is mainly determined by dune size, whereas in winter dune growth was determined by vegetation type. In our study area the growth of exposed dunes was likely restricted by storm erosion, whereas growth of sheltered dunes was restricted by sand supply. Our results can be used to improve models predicting coastal dune development.
Cognitive behavioural therapy (CBT) is effective in reducing fatigue across long-term conditions (LTCs). This study evaluated whether cognitive and behavioural responses to symptoms: 1) differ ...between LTCs and 2) moderate and/or mediate the effect of CBT on fatigue.
Data were used from four Randomized Controlled Trials testing the efficacy of CBT for fatigue in Chronic Fatigue Syndrome/ME (N = 240), Multiple Sclerosis (N = 90), Type 1 Diabetes Mellitus (N = 120) and Q-fever fatigue syndrome (N = 155). Fatigue severity, assessed with the Checklist Individual Strength, was the primary outcome. Differences in fatigue perpetuating factors, assessed with the Cognitive Behavioural Responses to Symptoms Questionnaire (CBRQ), between diagnostic groups were tested using ANCOVAs. Linear regression and mediation analyses were used to investigate moderation and mediation by CBRQ scores of the treatment effect.
There were small to moderate differences in CBRQ scores between LTCs. Patients with higher scores on the subscales damage beliefs and avoidance/resting behaviour at baseline showed less improvement following CBT, irrespective of diagnosis. Reduction in fear avoidance, catastrophising and avoidance/resting behaviour mediated the positive effect of CBT on fatigue across diagnostic groups.
The same cognitive-behavioural responses to fatigue moderate and mediate treatment outcome across conditions, supporting a transdiagnostic approach to fatigue.
•Similar beliefs and behaviour moderate effect of CBT on fatigue across conditions.•The mediators of the effect of CBT on fatigue are also similar across conditions.•The findings support a transdiagnostic approach in the treatment of fatigue.
Genetic monitoring using noninvasive samples provides a complement or alternative to traditional population monitoring methods. However, next‐generation sequencing approaches to monitoring typically ...require high quality DNA and the use of noninvasive samples (e.g., scat) is often challenged by poor DNA quality and contamination by nontarget species. One promising solution is a highly multiplexed sequencing approach called genotyping‐in‐thousands by sequencing (GT‐seq), which can enable cost‐efficient genomics‐based monitoring for populations based on noninvasively collected samples. Here, we develop and validate a GT‐seq panel of 324 single nucleotide polymorphisms (SNPs) optimized for genotyping of polar bears based on DNA from noninvasively collected faecal samples. We demonstrate (1) successful GT‐seq genotyping of DNA from a range of sample sources, including successful genotyping (>50% loci) of 62.9% of noninvasively collected faecal samples determined to contain polar bear DNA; and (2) that we can reliably differentiate individuals, ascertain sex, assess relatedness, and resolve population structure of Canadian polar bear subpopulations based on a GT‐seq panel of 324 SNPs. Our GT‐seq data reveal spatial‐genetic patterns similar to previous polar bear studies but at lesser cost per sample and through use of noninvasively collected samples, indicating the potential of this approach for population monitoring. This GT‐seq panel provides the foundation for a noninvasive toolkit for polar bear monitoring and can contribute to community‐based programmes – a framework which may serve as a model for wildlife conservation and management for species worldwide.
Abstract Background In stroke and multiple sclerosis patients, gait is frequently hampered by a reduced ability to push-off with the ankle caused by weakness of the plantar-flexor muscles. To enhance ...ankle push-off and to decrease the high energy cost of walking, spring-like carbon-composite Ankle Foot Orthoses are frequently prescribed. However, it is unknown what Ankle Foot Orthoses stiffness should be used to obtain the most efficient gait. The aim of this simulation study was to gain insights into the effect of variation in Ankle Foot Orthosis stiffness on the amount of energy stored in the Ankle Foot Orthosis and the energy cost of walking. Methods We developed a two-dimensional forward-dynamic walking model with a passive spring at the ankle representing the Ankle Foot Orthosis and two constant torques at the hip for propulsion. We varied Ankle Foot Orthosis stiffness while keeping speed and step length constant. Findings We found an optimal stiffness, at which the energy delivered at the hip joint was minimal. Energy cost decreased with increasing energy storage in the ankle foot orthosis, but the most efficient gait did not occur with maximal energy storage. With maximum storage, push-off occurred too late to reduce the impact of the contralateral leg with the floor. Maximum return prior to foot strike was also suboptimal, as push-off occurred too early and its effects were subsequently counteracted by gravity. The optimal Ankle Foot Orthosis stiffness resulted in significant push-off timed just prior to foot strike and led to greater ankle plantar-flexion velocity just before contralateral foot strike. Interpretation Our results suggest that patient energy cost might be reduced by the proper choice of Ankle Foot Orthosis stiffness.
Disruption of the immune system during embryonic brain development by environmental chemicals was proposed as a possible cause of neurodevelopmental disorders. We previously found adverse effects of ...di-n-octyltin dichloride (DOTC) on maternal and developing immune systems of rats in an extended one-generation reproductive toxicity study according to the OECD 443 test guideline. We hypothesize that the DOTC-induced changes in the immune system can affect neurodevelopment. Therefore, we used in-vivo MRI and PET imaging and genomics, in addition to behavioral testing and neuropathology as proposed in OECD test guideline 443, to investigate the effect of DOTC on structural and functional brain development. Male rats were exposed to DOTC (0, 3, 10, or 30 mg/kg of diet) from 2 weeks prior to mating of the F0-generation until sacrifice of F1-animals. The brains of rats, exposed to DOTC showed a transiently enlarged volume of specific brain regions (MRI), altered specific gravity, and transient hyper-metabolism (
FFDG PET). The alterations in brain development concurred with hyper-responsiveness in auditory startle response and slight hyperactivity in young adult animals. Genomics identified altered transcription of key regulators involved in neurodevelopment and neural function (e.g.
,
,
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); and regulators involved in cell size, cell proliferation, and organ development, especially immune system development and functioning (e.g.
,
,
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). The results suggest the involvement of immunotoxicity in the impairment of the nervous system by DOTC and support the hypothesis of a close connection between the immune and nervous systems in brain development.
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