Large invertebrate decomposers contribute to faster leaf litter decomposition in Fraxinus excelsior-dominated habitats: Implications of ash dieback.

Leaf litter decomposition is a major component of nutrient cycling which depends on the quality and quantity of the leaf material. Ash trees (Fraxinus excelsior, decay time âˆ¼ 0.4 years) are declining throughout Europe due to a fungal pathogen (Hymenoscyphus fraxineus), which is likely to alter biochemical cycling across the continent. The ecological impact of losing species with fast decomposing leaves is not well quantified. In this study we examine how decomposition of three leaf species with varying decomposition rates including ash, sycamore (Acer pseudoplatanus, decay time âˆ¼ 1.4 years), and beech (Fagus sylvatica, decay time âˆ¼ 6.8 years) differ in habitats with and without ash as the dominant overstorey species. Ten plots (40 m × 40 m) were set up in five locations representing ash dominated and non-ash dominated habitats. In each plot mesh bags (30 cm × 30 cm, 0.5 mm aperture) with a single leaf species (5 g) were used to include (large holes added) and exclude macrofauna invertebrates (with a focus on decomposer organisms such as earthworms, millipedes, and woodlice). The mesh bags were installed in October 2020 and retrieved without replacement at exponential intervals after 6, 12, 24 and 48 weeks. Total leaf mass loss was highest in the ash dominated habitat (ash dominated: 88.5%, non-ash dominated: 66.5%) where macrofauna were the main contributor (macrofauna: 96%, microorganisms/mesofauna: 4%). The difference between macrofauna vs microorganisms and mesofauna was less pronounced in the non-ash dominated habitat (macrofauna: 68%, microorganisms/mesofauna: 31%). Our results suggest that if ash dominated habitats are replaced by species such as sycamore, beech, and oak, the role of macrofauna decomposers will be reduced and leaf litter decomposition rates will decrease by 25%. These results provide important insights for future ash dieback management decisions.

Evaluating NetMHCpan performance on non-European HLA alleles not present in training data.

Bias in neural network model training datasets has been observed to decrease prediction accuracy for groups underrepresented in training data. Thus, investigating the composition of training datasets used in machine learning models with healthcare applications is vital to ensure equity. Two such machine learning models are NetMHCpan-4.1 and NetMHCIIpan-4.0, used to predict antigen binding scores to major histocompatibility complex class I and II molecules, respectively. As antigen presentation is a critical step in mounting the adaptive immune response, previous work has used these or similar predictions models in a broad array of applications, from explaining asymptomatic viral infection to cancer neoantigen prediction. However, these models have also been shown to be biased toward hydrophobic peptides, suggesting the network could also contain other sources of bias. Here, we report the composition of the networks' training datasets are heavily biased toward European Caucasian individuals and against Asian and Pacific Islander individuals. We test the ability of NetMHCpan-4.1 and NetMHCpan-4.0 to distinguish true binders from randomly generated peptides on alleles not included in the training datasets. Unexpectedly, we fail to find evidence that the disparities in training data lead to a meaningful difference in prediction quality for alleles not present in the training data. We attempt to explain this result by mapping the HLA sequence space to determine the sequence diversity of the training dataset. Furthermore, we link the residues which have the greatest impact on NetMHCpan predictions to structural features for three alleles (HLA-A*34:01, HLA-C*04:03, HLA-DRB1*12:02).

Delayed relapse in pseudotumor cerebri due to new stenosis after transverse sinus stenting.

A patient presented with recurrent severe pseudotumor cerebri (PTC). Transverse sinus stenting is a very effective treatment option, however stenosis and intracranial hypertension can recur. In our patient, stenting initially resulted in resolution of papilloedema. However, after 5 years, a new stenosis developed which required further stenting. This case highlights the fact that, in patients with PTC who undergo transverse sinus stenting, a small proportion require repeat treatment due to formation of a new stenosis, usually adjacent to the existing stent. Patients with severe disease, such as ours, may be at higher risk of recurrence. Regardless of the severity, all patients who undergo stenting should have regular ocular follow-up.

Delayed relapse in pseudotumor cerebri due to new stenosis after transverse sinus stenting.

A patient presented with recurrent severe pseudotumor cerebri (PTC). Transverse sinus stenting is a very effective treatment option, however stenosis and intracranial hypertension can recur. In our patient, stenting initially resulted in resolution of papilloedema. However, after 5 years, a new stenosis developed which required further stenting. This case highlights the fact that, in patients with PTC who undergo transverse sinus stenting, a small proportion require repeat treatment due to formation of a new stenosis, usually adjacent to the existing stent. Patients with severe disease, such as ours, may be at higher risk of recurrence. Regardless of the severity, all patients who undergo stenting should have regular ocular follow-up.

Anterior release of the elbow for extension loss.

BACKGROUND: There are many causes of elbow contracture. When nonoperative techniques fail to increase the arc of motion of the elbow, surgical intervention may be indicated. The purpose of this study was to report the outcomes of surgical correction, predominantly with an anterior release, of elbow flexion contractures. In addition, we evaluated the efficacy of continuous passive motion in the immediate postoperative period. METHODS: We retrospectively reviewed the outcomes of 106 consecutive patients who had undergone anterior elbow release for the treatment of a flexion contracture between July 1975 and June 2001. Twenty-nine patients were excluded because they had been followed for less than twelve months, leaving a study group of seventy-seven patients. Postoperatively, fifty-four of the seventy-seven patients were treated with continuous passive motion and the other twenty-three patients were treated with extension splinting. The average duration of follow-up was thirty-three months. The average patient age was thirty-four years. The results were evaluated on the basis of both preoperative and postoperative radiographs as well as clinical measurements of elbow motion, all performed by the same examiner using the same large (47-cm-long) goniometer. RESULTS: The mean preoperative extension in the seventy-seven patients was 52 degrees, which decreased to 20 degrees postoperatively. The mean flexion increased from 111 degrees preoperatively to 117 degrees postoperatively, and the mean total arc of motion increased from 59 degrees to 97 degrees. The total arc of motion in the patients treated with continuous passive motion increased 45 degrees, compared with an increase of 26 degrees in those treated with extension splinting. There were eleven complications in ten patients. The majority were traction neuropathies. There were two infections (one superficial and one deep), both of which resolved following treatment. CONCLUSIONS: Release of a pathologically thickened anterior elbow capsule through a predominantly anterior approach to correct diminished elbow extension is a safe and effective technique. Furthermore, compared with splinting in extension alone, the utilization of continuous passive motion during the postoperative period increases the total arc of motion.