Fast and Efficient Root Phenotyping via Pose Estimation.

Image segmentation is commonly used to estimate the location and shape of plants and their external structures. Segmentation masks are then used to localize landmarks of interest and compute other geometric features that correspond to the plant's phenotype. Despite its prevalence, segmentation-based approaches are laborious (requiring extensive annotation to train) and error-prone (derived geometric features are sensitive to instance mask integrity). Here, we present a segmentation-free approach that leverages deep learning-based landmark detection and grouping, also known as pose estimation. We use a tool originally developed for animal motion capture called SLEAP (Social LEAP Estimates Animal Poses) to automate the detection of distinct morphological landmarks on plant roots. Using a gel cylinder imaging system across multiple species, we show that our approach can reliably and efficiently recover root system topology at high accuracy, few annotated samples, and faster speed than segmentation-based approaches. In order to make use of this landmark-based representation for root phenotyping, we developed a Python library (sleap-roots) for trait extraction directly comparable to existing segmentation-based analysis software. We show that pose-derived root traits are highly accurate and can be used for common downstream tasks including genotype classification and unsupervised trait mapping. Altogether, this work establishes the validity and advantages of pose estimation-based plant phenotyping. To facilitate adoption of this easy-to-use tool and to encourage further development, we make sleap-roots, all training data, models, and trait extraction code available at: https://github.com/talmolab/sleap-roots and https://osf.io/k7j9g/.

MRI-based prostate cancer classification using 3D efficient capsule network.

BACKGROUND: Prostate cancer (PCa) is the most common cancer in men and the second leading cause of male cancer-related death. Gleason score (GS) is the primary driver of PCa risk-stratification and medical decision-making, but can only be assessed at present via biopsy under anesthesia. Magnetic resonance imaging (MRI) is a promising non-invasive method to further characterize PCa, providing additional anatomical and functional information. Meanwhile, the diagnostic power of MRI is limited by qualitative or, at best, semi-quantitative interpretation criteria, leading to inter-reader variability. PURPOSES: Computer-aided diagnosis employing quantitative MRI analysis has yielded promising results in non-invasive prediction of GS. However, convolutional neural networks (CNNs) do not implicitly impose a frame of reference to the objects. Thus, CNNs do not encode the positional information properly, limiting method robustness against simple image variations such as flipping, scaling, or rotation. Capsule network (CapsNet) has been proposed to address this limitation and achieves promising results in this domain. In this study, we develop a 3D Efficient CapsNet to stratify GS-derived PCa risk using T2-weighted (T2W) MRI images. METHODS: In our method, we used 3D CNN modules to extract spatial features and primary capsule layers to encode vector features. We then propose to integrate fully-connected capsule layers (FC Caps) to create a deeper hierarchy for PCa grading prediction. FC Caps comprises a secondary capsule layer which routes active primary capsules and a final capsule layer which outputs PCa risk. To account for data imbalance, we propose a novel dynamic weighted margin loss. We evaluate our method on a public PCa T2W MRI dataset from the Cancer Imaging Archive containing data from 976 patients. RESULTS: Two groups of experiments were performed: (1) we first identified high-risk disease by classifying low + medium risk versus high risk; (2) we then stratified disease in one-versus-one fashion: low versus high risk, medium versus high risk, and low versus medium risk. Five-fold cross validation was performed. Our model achieved an area under receiver operating characteristic curve (AUC) of 0.83 and 0.64 F1-score for low versus high grade, 0.79 AUC and 0.75 F1-score for low + medium versus high grade, 0.75 AUC and 0.69 F1-score for medium versus high grade and 0.59 AUC and 0.57 F1-score for low versus medium grade. Our method outperformed state-of-the-art radiomics-based classification and deep learning methods with the highest metrics for each experiment. Our divide-and-conquer strategy achieved weighted Cohen's Kappa score of 0.41, suggesting moderate agreement with ground truth PCa risks. CONCLUSIONS: In this study, we proposed a novel 3D Efficient CapsNet for PCa risk stratification and demonstrated its feasibility. This developed tool provided a non-invasive approach to assess PCa risk from T2W MR images, which might have potential to personalize the treatment of PCa and reduce the number of unnecessary biopsies.

Anatomical Structures at Risk in Percutaneous Preparation Talonavicular Fusion.

BACKGROUND: The stability of the hindfoot greatly relies on the integrity of the talonavicular joint. Pathologies affecting this joint often necessitate fusion. Our study explores the risks posed to neurovascular and tendon structures during simulated percutaneous talonavicular joint preparation for fusion. METHODS: In 9 fresh cadaver specimens, the talonavicular joint was accessed through two portals. A 2-mm Shannon burr was employed for joint surface preparation with distraction provided by a pin-based distractor. Dissections were performed to assess potential damage to critical structures, including the dorsalis pedis artery, superficial and deep peroneal nerves, extensor hallucis longus (EHL), and tibialis anterior (TA) tendons. RESULTS: The dorsal portal site was found to be significantly closer to important structures compared to the medial portal site. The Shannon burr made contact with various structures, with a single transection identified for both deep and superficial peroneal nerve branches. During the dorsal portal site approach, potential injury to the EHL tendon was identified as concern. CONCLUSION: This study sheds light on the potential risks associated with percutaneous dorsal and medial joint preparation approaches using a Shannon burr.Level of Evidence:Level V, mechanism-based reasoning..

Fast and efficient root phenotyping via pose estimation.

Image segmentation is commonly used to estimate the location and shape of plants and their external structures. Segmentation masks are then used to localize landmarks of interest and compute other geometric features that correspond to the plant's phenotype. Despite its prevalence, segmentation-based approaches are laborious (requiring extensive annotation to train), and error-prone (derived geometric features are sensitive to instance mask integrity). Here we present a segmentation-free approach which leverages deep learning-based landmark detection and grouping, also known as pose estimation. We use a tool originally developed for animal motion capture called SLEAP (Social LEAP Estimates Animal Poses) to automate the detection of distinct morphological landmarks on plant roots. Using a gel cylinder imaging system across multiple species, we show that our approach can reliably and efficiently recover root system topology at high accuracy, few annotated samples, and faster speed than segmentation-based approaches. In order to make use of this landmark-based representation for root phenotyping, we developed a Python library (sleap-roots) for trait extraction directly comparable to existing segmentation-based analysis software. We show that landmark-derived root traits are highly accurate and can be used for common downstream tasks including genotype classification and unsupervised trait mapping. Altogether, this work establishes the validity and advantages of pose estimation-based plant phenotyping. To facilitate adoption of this easy-to-use tool and to encourage further development, we make sleap-roots, all training data, models, and trait extraction code available at: https://github.com/talmolab/sleap-roots and https://osf.io/k7j9g/.

Unusual Arteriovenous Malformation in Total Hip Arthroplasty: Case Report of a Complicated Perioperative Course.

It is not common to encounter arteriovenous malformations (AVMs) during total hip arthroplasty (THA). We report the present case to draw attention to the possibility of an AVM during the direct anterior approach (DAA) for THA, which, if not borne in mind, may lead to the myriad of complications related to excessive bleeding. An 81-year-old female presented to the emergency department with a left femoral neck fracture. She elected to undergo a THA via the DAA. Abnormal appearing blood vessels were present near the ascending circumflex branches, which provided difficulty in achieving hemostasis. Excessive blood loss was noted, and the patient received one unit of packed red blood cells during the operation. Hemoglobin and hematocrit dropped in the days following surgery, requiring several additional transfusions of blood products. When the patient complained of progressive left leg swelling on postoperative day 3, a computed tomography revealed large hematomas within the left adductors and the left iliopsoas muscle. Active extravasation was identified arising from a branch of the left profunda femoral artery, as well as an arteriovenous fistula (AVF) in this area. Bleeding was controlled by selective endovascular coil embolization. As of current knowledge, this is the first reported intraoperative discovery of congenital arteriovenous malformation (AVM) with subsequent development of postoperative arteriovenous fistula and associated symptomatic hematomas in the setting of THA using the DAA. Early recognition and intervention of vascular malformations is essential in preventing potential limb- or life-threatening surgical complication.

Sparsity of higher-order landscape interactions enables learning and prediction for microbiomes.

Microbiome engineering offers the potential to leverage microbial communities to improve outcomes in human health, agriculture, and climate. To translate this potential into reality, it is crucial to reliably predict community composition and function. But a brute force approach to cataloging community function is hindered by the combinatorial explosion in the number of ways we can combine microbial species. An alternative is to parameterize microbial community outcomes using simplified, mechanistic models, and then extrapolate these models beyond where we have sampled. But these approaches remain data-hungry, as well as requiring an a priori specification of what kinds of mechanisms are included and which are omitted. Here, we resolve both issues by introducing a mechanism-agnostic approach to predicting microbial community compositions and functions using limited data. The critical step is the identification of a sparse representation of the community landscape. We then leverage this sparsity to predict community compositions and functions, drawing from techniques in compressive sensing. We validate this approach on in silico community data, generated from a theoretical model. By sampling just [Formula: see text]1% of all possible communities, we accurately predict community compositions out of sample. We then demonstrate the real-world application of our approach by applying it to four experimental datasets and showing that we can recover interpretable, accurate predictions on composition and community function from highly limited data.

Universal abundance fluctuations across microbial communities, tropical forests, and urban populations.

The growth of complex populations, such as microbial communities, forests, and cities, occurs over vastly different spatial and temporal scales. Although research in different fields has developed detailed, system-specific models to understand each individual system, a unified analysis of different complex populations is lacking; such an analysis could deepen our understanding of each system and facilitate cross-pollination of tools and insights across fields. Here, we use a shared framework to analyze time-series data of the human gut microbiome, tropical forest, and urban employment. We demonstrate that a single, three-parameter model of stochastic population dynamics can reproduce the empirical distributions of population abundances and fluctuations in all three datasets. The three parameters characterizing a species measure its mean abundance, deterministic stability, and stochasticity. Our analysis reveals that, despite the vast differences in scale, all three systems occupy a similar region of parameter space when time is measured in generations. In other words, although the fluctuations observed in these systems may appear different, this difference is primarily due to the different physical timescales associated with each system. Further, we show that the distribution of temporal abundance fluctuations is described by just two parameters and derive a two-parameter functional form for abundance fluctuations to improve risk estimation and forecasting.

Methyl jasmonate influences ethylene formation, defense systems, nutrient homeostasis and carbohydrate metabolism to alleviate arsenic-induced stress in rice (Oryza sativa).

The plant growth regulator, jasmonic acid (JA) has emerged as important molecule and involved in key processes of plants. In this study, we investigated the role of methyl jasmonate (MeJA) in achieving tolerance mechanisms against arsenic (As) stress in rice (Oryza sativa). Arsenic toxicity is a major global concern that significantly deteriorate rice production. The application of MeJA (20 µM) and ethylene (150 µL L-1) both individually and/or in combination were found significant in protecting against As-induced toxicity in rice, and significantly improved defense systems. The study shown that the positive influence of MeJA in promoting carbohydrate metabolism, photosynthesis and growth under As stress were the result of its interplay with ethylene biosynthesis and reduced oxidative stress-mediated cellular injuries and cell deaths. Interestingly, the use of JA biosynthesis inhibitor, neomycin (Neo) and ethylene biosynthesis inhibitor, aminoethoxyvinylglycine (AVG) overturned the effects of MeJA and ethylene on plant growth under As stress. From the pooled data, it may also be concluded that Neo treatment to MeJA- treated rice plants restricted JA-mediated responses, implying that application of MeJA modulated ethylene- dependent pathways in response to As stress. Thus, the action of MeJA in As tolerance is found to be mediated by ethylene. The study will shed light on the mechanisms that could be used to ensure the sustainability of rice plants under As stress.

Unusual Arteriovenous Malformation in Total Hip Arthroplasty: Case Report of a Complicated Perioperative Course / Malformação arteriovenosa incomum em artroplastia total do quadril: relato de caso de um perioperatório de curso complicado

Abstract It is not common to encounter arteriovenous malformations (AVMs) during total hip arthroplasty (THA). We report the present case to draw attention to the possibility of an AVM during the direct anterior approach (DAA) for THA, which, if not borne in mind, may lead to the myriad of complications related to excessive bleeding. An 81-year-old female presented to the emergency department with a left femoral neck fracture. She elected to undergo a THA via the DAA. Abnormal appearing blood vessels were present near the ascending circumflex branches, which provided difficulty in achieving hemostasis. Excessive blood loss was noted, and the patient received one unit of packed red blood cells during the operation. Hemoglobin and hematocrit dropped in the days following surgery, requiring several additional transfusions of blood products. When the patient complained of progressive left leg swelling on postoperative day 3, a computed tomography revealed large hematomas within the left adductors and the left iliopsoas muscle. Active extravasation was identified arising from a branch of the left profunda femoral artery, as well as an arteriovenous fistula (AVF) in this area. Bleeding was controlled by selective endovascular coil embolization. As of current knowledge, this is the first reported intraoperative discovery of congenital arteriovenous malformation (AVM) with subsequent development of postoperative arteriovenous fistula and associated symptomatic hematomas in the setting of THA using the DAA. Early recognition and intervention of vascular malformations is essential in preventing potential limb- or life-threatening surgical complication.

Resumo Não é comum encontrar malformações arteriovenosas (MAV) durante a artroplastia total do quadril (ATQ). Relatamos o presente caso para chamar a atenção para a possibilidade de uma MAV durante a abordagem anterior direta (AAD) para ATQ, que se não for considerada, pode levar a uma miríade de complicações relacionadas ao sangramento excessivo. Uma mulher de 81 anos foi apresentada ao pronto-socorro com fratura no pescoço do fêmur esquerdo. Ela optou por se submeter a uma artroplastia total do quadril (ATQ) através da AAD. Vasos sanguíneos aparentemente anormais estavam presentes perto dos ramos circunflexos ascendentes, proporcionando dificuldade em alcançar hemostasia. A perda excessiva de sangue foi notada e a paciente recebeu uma unidade de glóbulos vermelhos embalados durante a operação. Hemoglobina e hematócrito caíram nos dias seguintes à cirurgia, exigindo várias transfusões adicionais de produtos sanguíneos. Quando a paciente reclamou de inchaço progressivo na perna esquerda no terceiro dia pós-operatório, a tomografia computadorizada revelou hematomas grandes dentro dos adutores esquerdos e do músculo iliopsoas esquerdo. A extravasão ativa foi identificada a partir de um ramo da artéria femoral esquerda, bem como de uma fístula arteriovenosa (FAV) nesta área. O sangramento foi controlado por embolização seletiva da bobina endovascular. A partir do conhecimento atual, esta é a primeira descoberta intraoperatória relatada de MAC congênita com desenvolvimento subsequente de FAV pós-operatória e hematomas sintomáticos associados no cenário de ATQ utilizando a AAD. O reconhecimento precoce e a intervenção de malformações vasculares são essenciais para prevenir possíveis complicações cirúrgicas de membros ou de risco de vida.

Functional convergence in slow-growing microbial communities arises from thermodynamic constraints.

The dynamics of microbial communities is complex, determined by competition for metabolic substrates and cross-feeding of byproducts. Species in the community grow by harvesting energy from chemical reactions that transform substrates to products. In many anoxic environments, these reactions are close to thermodynamic equilibrium and growth is slow. To understand the community structure in these energy-limited environments, we developed a microbial community consumer-resource model incorporating energetic and thermodynamic constraints on an interconnected metabolic network. The central element of the model is product inhibition, meaning that microbial growth may be limited not only by depletion of metabolic substrates but also by accumulation of products. We demonstrate that these additional constraints on microbial growth cause a convergence in the structure and function of the community metabolic network-independent of species composition and biochemical details-providing a possible explanation for convergence of community function despite taxonomic variation observed in many natural and industrial environments. Furthermore, we discovered that the structure of community metabolic network is governed by the thermodynamic principle of maximum free energy dissipation. Our results predict the decrease of functional convergence in faster growing communities, which we validate by analyzing experimental data from anaerobic digesters. Overall, the work demonstrates how universal thermodynamic principles may constrain community metabolism and explain observed functional convergence in microbial communities.

2D medical image synthesis using transformer-based denoising diffusion probabilistic model.

Objective. Artificial intelligence (AI) methods have gained popularity in medical imaging research. The size and scope of the training image datasets needed for successful AI model deployment does not always have the desired scale. In this paper, we introduce a medical image synthesis framework aimed at addressing the challenge of limited training datasets for AI models.Approach. The proposed 2D image synthesis framework is based on a diffusion model using a Swin-transformer-based network. This model consists of a forward Gaussian noise process and a reverse process using the transformer-based diffusion model for denoising. Training data includes four image datasets: chest x-rays, heart MRI, pelvic CT, and abdomen CT. We evaluated the authenticity, quality, and diversity of the synthetic images using visual Turing assessments conducted by three medical physicists, and four quantitative evaluations: the Inception score (IS), Fréchet Inception Distance score (FID), feature similarity and diversity score (DS, indicating diversity similarity) between the synthetic and true images. To leverage the framework value for training AI models, we conducted COVID-19 classification tasks using real images, synthetic images, and mixtures of both images.Main results. Visual Turing assessments showed an average accuracy of 0.64 (accuracy converging to50%indicates a better realistic visual appearance of the synthetic images), sensitivity of 0.79, and specificity of 0.50. Average quantitative accuracy obtained from all datasets were IS = 2.28, FID = 37.27, FDS = 0.20, and DS = 0.86. For the COVID-19 classification task, the baseline network obtained an accuracy of 0.88 using a pure real dataset, 0.89 using a pure synthetic dataset, and 0.93 using a dataset mixed of real and synthetic data.Significance. A image synthesis framework was demonstrated for medical image synthesis, which can generate high-quality medical images of different imaging modalities with the purpose of supplementing existing training sets for AI model deployment. This method has potential applications in many data-driven medical imaging research.

Ecological landscapes guide the assembly of optimal microbial communities.

Assembling optimal microbial communities is key for various applications in biofuel production, agriculture, and human health. Finding the optimal community is challenging because the number of possible communities grows exponentially with the number of species, and so an exhaustive search cannot be performed even for a dozen species. A heuristic search that improves community function by adding or removing one species at a time is more practical, but it is unknown whether this strategy can discover an optimal or nearly optimal community. Using consumer-resource models with and without cross-feeding, we investigate how the efficacy of search depends on the distribution of resources, niche overlap, cross-feeding, and other aspects of community ecology. We show that search efficacy is determined by the ruggedness of the appropriately-defined ecological landscape. We identify specific ruggedness measures that are both predictive of search performance and robust to noise and low sampling density. The feasibility of our approach is demonstrated using experimental data from a soil microbial community. Overall, our results establish the conditions necessary for the success of the heuristic search and provide concrete design principles for building high-performing microbial consortia.

Tibiotalocalcaneal Arthrodesis with Intramedullary Fibular Strut Graft and Adjuvant Hardware Fixation.

Background: In patients with irreparable damage to the articular surfaces of the hindfoot, hindfoot arthrodesis is frequently chosen to provide pain relief and improve activities of daily living. Common etiologies leading to hindfoot arthrodesis procedures include osteonecrosis, failed total ankle arthroplasty, and deformities resulting from Charcot arthropathy or rheumatoid arthritis. Traditionally, this operation utilizes an intramedullary nail to obtain fusion of the tibiotalocalcaneal joint. Although 80% to 90% of patients achieve postoperative union, the remaining 10% to 20% experience nonunion1-3. Factors affecting the rate of nonunion include Charcot neuroarthropathy, use of nonsteroidal anti-inflammatory drugs or methotrexate, osteopenic bone, and smoking4. In the present video article, we describe a tibiotalocalcaneal arthrodesis performed with use of a fibular strut autograft for repeat arthrodesis following failure of primary tibiotalocalcaneal arthrodesis or as a salvage operation in end-stage pathologies of the hindfoot. Our surgical technique yields union rates of approximately 80% and provides surgeons with a viable surgical technique for patients with complex hindfoot pathologies or fusion failure. Description: The patient is placed in the supine position, and a 10-cm curvilinear incision is made including the distal 6 to 8 cm of the fibula. The incision is centered directly lateral on the fibula proximally and transitions to the posterolateral aspect of the fibula distally. As the incision continues distally, it extends inferiorly and anteriorly over the sinus tarsi and toward the base of the 4th metatarsal, using an internervous plane between the superficial peroneal nerve anteriorly and the sural nerve posteriorly. Exposure of the periosteum is carried out through development of full-thickness skin flaps. The periosteum is stripped, and a sagittal saw is used to make a beveled cut on the fibula at a 45° angle, approximately 6 to 8 cm proximal to the ankle. The fibular strut is decorticated, drilled, and stripped of the cartilage on the distal end. Preparation of the tibiotalar and subtalar joints for arthrodesis are completed through the lateral incision. The foot is placed in 0° of dorsiflexion, 5° of external rotation in relation to the tibial crest, and 5° of hindfoot valgus while maintaining a plantigrade foot. This placement can be temporarily maintained with Kirschner wires if needed. Next, the plantar surface overlying the heel pad is incised, and a guidewire is passed through the center of the calcaneus and into the medullary cavity of the tibia. Correct alignment of the guidewire is then confirmed on fluoroscopy. The fibular strut autograft is prepared for insertion while the tibiotalocalcaneal canal is reamed to 1 to 2 mm larger than the graft. The graft is tapped into position, followed by placement of two 6.5-mm cancellous screws to immobilize the joint, taking care to avoid excess contact of the fibular graft with the screws. Alternatives: Alternatives to this procedure include traditional arthrodesis techniques, nonoperative treatment (such as rehabilitation or bracing), or no intervention. Patients with failed primary hindfoot arthrodesis may undergo an additional traditional arthrodesis, but may face an increased risk of complications and failure1,2. Rationale: A recent study1 has shown that the use of a fibular strut autograft for tibiotalocalcaneal arthrodesis produces union rates similar to those seen with the traditional intramedullary nailing technique4,5. These results are important to note, as the presently described technique, which is used as a salvage procedure, produces outcomes that are equivalent to those observed for primary tibiotalocalcaneal arthrodesis with nailing, which is used for the treatment of severe trauma, extensive bone loss, or severe hindfoot pathologies. We recommend using this technique particularly in cases of failed primary tibiotalocalcaneal arthrodesis or in patients with end-stage hindfoot pathologies. The fibular strut autograft is a viable salvage option to decrease daily pain and provide quality improvement in patient activities of daily living. Expected Outcomes: Tibiotalocalcaneal arthrodesis with a fibular strut autograft has been shown to produce a union rate (81.2%) similar to that of the traditional arthrodesis technique with intramedullary nailing (74.4% to 90%). The strut graft provides an osteoinductive environment for healing and increases the post-arthrodesis load tolerance1. Mean visual analog scale pain scores improved from 6.9 preoperatively to 1.2 postoperatively with use of this procedure1. The most common complication was wound dehiscence requiring additional wound care (37.5%); its rate was higher than the rates reported in other studies of tibiotalocalcaneal arthrodesis, possibly because of the small sample size of patients undergoing such a complex procedure for a complex medical issue2,11. Although 7 patients required a reoperation, all ultimately experienced a union and recovered postoperatively. All non-retired patients were all able to return to work1. Important Tips: Place your incision precisely to allow adequate exposure of both the tibiotalar and subtalar joints.Curvilinear incision should begin 6 to 8 cm proximal to, and directly lateral to, the distal end of the fibula. It should continue posterolaterally to the fibula distally and extend inferiorly and anteriorly over the sinus tarsi, toward the base of the 4th metatarsal.Prepare the tibiotalar and subtalar joints this same incision.Decorticate the fibular strut autograft; this plays a key role in obtaining fusion.Harvest the fibula 6 to 8 cm above the ankle joint line. Once the graft is harvested, smooth the edges of the fibula with a burr; this facilitates graft insertion.Finally, when immobilizing the joint, take care to avoid excessive perforation of the graft as this increases the likelihood of fracture. Acronyms and Abbreviations: OR = operating roomIM = intramedullaryCT = computed tomographyTTCA = tibiotalocalcaneal arthrodesisTTC = tibiotalocalcanealK-wire - Kirschner wire.

Mission Indradhanush and Intensified Mission Indradhanush-Success Story of India's Universal Immunization Program and the Role of Mann Ki Baat in Bridging the Immunization Gap.

Child immunization is crucial for reducing the morbidity and mortality associated with vaccine-preventable diseases (VPDs). The program grew over the years, however, progress towards full immunization coverage (FIC) remained slow, with only 44% of children fully immunized in 1992-1993, and 62% in 2015-2016, as reported in the National Family Health Survey. To address this challenge, Government of India launched Routine Immunization intensification drive- Mission Indradhanush (MI) in 2014, with the aim of achieving 90% FIC. The success of MI led to the launch of Intensified Mission Indradhanush (IMI) in 2017, with more intensive planning, monitoring, review, and inter-sectoral partnerships.

Reconstruction of Superficial Medial Collateral Ligament: Modified Danish Technique with Dual Adjustable Loop Suspensory Fixation.

Injury to the superficial medial collateral ligament (MCL) is treated conservatively for low-grade injury and with surgery for high-grade injury, especially in association with cruciate ligament injury. Acute injuries are treated with MCL repair, and chronic injury requires reconstruction. Anatomic MCL reconstruction can be done using free allograft or autograft and fixed using screws or suspensory fixation. We describe here an anatomic technique that is a modification of a Danish technique in which we reroute the semitendinosus, keeping its tibial attachment intact. The semitendinosus is rerouted anatomically in the tibial tunnel, and a graft is then passed anatomically in the femoral tunnel. The graft is fixed in both tunnels with adjustable loop suspensory fixation, which gives the unique advantage of controlled tensioning of the graft for MCL reconstruction. In this technique further re-tensioning is possible if the knee is unstable in valgus stress, even after final fixation.

Incidence and predictors of toxicity in the management of vulvar squamous cell carcinoma treated with radiation therapy.

Purpose/Objective: Given the rarity of vulvar cancer, data on the incidence of acute and late severe toxicity and patients' symptom burden from radiotherapy (RT) are lacking. Materials/Methods: This multi-center, single-institution study included patients with vulvar squamous cell carcinoma treated with curative intent RT between 2009 and 2020. Treatment-related acute and late grade ≥ 3 toxicities and late patient subjective symptoms (PSS) were recorded. Results: Forty-two patients with predominantly stage III/IV disease (n = 25, 59.5 %) were treated with either definitive (n = 25, 59.5 %) or adjuvant (n = 17, 40.5 %) external beam RT to a median dose of 64 Gy and 59.4 Gy, respectively. Five patients received a brachytherapy boost with a median total dose of 84.3 Gy in 2 Gy-equivalent dose (EQD2). Intensity-modulated RT was used in 37 (88.1 %) of patients, and 25 patients (59.5 %) received concurrent chemotherapy. Median follow-up was 27 months. Acute grade ≥ 3 toxicity occurred in 17 patients (40.5 %), including 13 (31.0 %) acute grade 3 skin events. No factors, including total RT dose (p = 0.951), were associated with acute skin toxicity. Eleven (27.5 %) patients developed late grade ≥ 3 toxicity events, including 10 (23.8 %) late grade ≥ 3 skin toxicity events. Patients with late grade ≥ 3 skin toxicity had a higher mean body-mass index (33.0 vs 28.2 kg/m2; p = 0.009). Common late PSS included vaginal pain (n = 15, 35.7 %), skin fibrosis (n = 10, 23.8 %), and requirement of long-term opiates (n = 12, 28.6 %). Conclusion: RT for vulvar cancer is associated with considerable rates of severe acute and late toxicity and PSS burden. Larger studies are needed to identify risk factors, explore toxicity mitigation strategies, and assess patient-reported outcomes.

Patient and Surgical Factors Affecting Fusion Rates After Arthroscopic and Open Ankle Fusion: A Review of a High-Risk Cohort.

Abstract: We present a case series with the objective of identifying risk factors for nonunion after open and arthroscopic primary ankle arthrodesis. Eighty-seven patients who underwent primary ankle arthrodesis and met inclusion criteria were divided into open (N = 46) and arthroscopic (N = 41) groups. Patient and operative characteristics were retrospectively analyzed as possible risk factors for nonunion within each technique. The nonunion rate was 11% in the open and 12% in the arthroscopic group. Obesity, smoking, and ASA class 3 were highly prevalent in both groups. In the arthroscopic group, a remote history of infection and the use of headed screws had notably higher risk of nonunion, though not statistically significant. In the open group, use of bone graft trended toward lower risk of nonunion, though also not statistically significant. The results of this study demonstrated, nonunion rates are comparable between open and arthroscopic ankle arthrodesis in high-risk patients. For patients with a remote history of infection, open ankle arthrodesis may be preferable, and bone graft importance may vary with open versus arthroscopic technique. Level of evidence: III.

Protein cost minimization promotes the emergence of coenzyme redundancy.

SignificanceMetabolism relies on a small class of molecules (coenzymes) that serve as universal donors and acceptors of key chemical groups and electrons. Although metabolic networks crucially depend on structurally redundant coenzymes [e.g., NAD(H) and NADP(H)] associated with different enzymes, the criteria that led to the emergence of this redundancy remain poorly understood. Our combination of modeling and structural and sequence analysis indicates that coenzyme redundancy may not be essential for metabolism but could rather constitute an evolved strategy promoting efficient usage of enzymes when biochemical reactions are near equilibrium. Our work suggests that early metabolism may have operated with fewer coenzymes and that adaptation for metabolic efficiency may have driven the rise of coenzyme diversity in living systems.

Installation and imaging of thousands of minirhizotrons to phenotype root systems of field-grown plants.

BACKGROUND: Roots are vital to plant performance because they acquire resources from the soil and provide anchorage. However, it remains difficult to assess root system size and distribution because roots are inaccessible in the soil. Existing methods to phenotype entire root systems range from slow, often destructive, methods applied to relatively small numbers of plants in the field to rapid methods that can be applied to large numbers of plants in controlled environment conditions. Much has been learned recently by extensive sampling of the root crown portion of field-grown plants. But, information on large-scale genetic and environmental variation in the size and distribution of root systems in the field remains a key knowledge gap. Minirhizotrons are the only established, non-destructive technology that can address this need in a standard field trial. Prior experiments have used only modest numbers of minirhizotrons, which has limited testing to small numbers of genotypes or environmental conditions. This study addressed the need for methods to install and collect images from thousands of minirhizotrons and thereby help break the phenotyping bottleneck in the field. RESULTS: Over three growing seasons, methods were developed and refined to install and collect images from up to 3038 minirhizotrons per experiment. Modifications were made to four tractors and hydraulic soil corers mounted to them. High quality installation was achieved at an average rate of up to 84.4 minirhizotron tubes per tractor per day. A set of four commercially available minirhizotron camera systems were each transported by wheelbarrow to allow collection of images of mature maize root systems at an average rate of up to 65.3 tubes per day per camera. This resulted in over 300,000 images being collected in as little as 11 days for a single experiment. CONCLUSION: The scale of minirhizotron installation was increased by two orders of magnitude by simultaneously using four tractor-mounted, hydraulic soil corers with modifications to ensure high quality, rapid operation. Image collection can be achieved at the corresponding scale using commercially available minirhizotron camera systems. Along with recent advances in image analysis, these advances will allow use of minirhizotrons at unprecedented scale to address key knowledge gaps regarding genetic and environmental effects on root system size and distribution in the field.

Complementary resource preferences spontaneously emerge in diauxic microbial communities.

Many microbes grow diauxically, utilizing the available resources one at a time rather than simultaneously. The properties of communities of microbes growing diauxically remain poorly understood, largely due to a lack of theory and models of such communities. Here, we develop and study a minimal model of diauxic microbial communities assembling in a serially diluted culture. We find that unlike co-utilizing communities, diauxic community assembly repeatably and spontaneously leads to communities with complementary resource preferences, namely communities where species prefer different resources as their top choice. Simulations and theory explain that the emergence of complementarity is driven by the disproportionate contribution of the top choice resource to the growth of a diauxic species. Additionally, we develop a geometric approach for analyzing serially diluted communities, with or without diauxie, which intuitively explains several additional emergent community properties, such as the apparent lack of species which grow fastest on a resource other than their most preferred resource. Overall, our work provides testable predictions for the assembly of natural as well as synthetic communities of diauxically shifting microbes.