Publications by authors named "Michael Maxwell"

Background matching, an important form of camouflage, can be challenging for animals that range across heterogeneously colored habitats. To remain cryptic in such habitats, animals may employ color change, background choice, or generalist coloration, and the efficacy of these strategies may be influenced by an animal's mobility. We examined camouflage strategies in the praying mantis .

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Background: Advancements in surgical planning, technique, and prosthesis design have improved adaptation to patient anatomy in reverse total shoulder arthroplasty (rTSA). Postoperative changes in deltoid and rotator cuff muscle length are important and may vary based on preoperative indications and prosthesis selection. The purpose of this study is to demonstrate the changes in deltoid and rotator cuff muscle length for planned rTSA using the spectrum of prosthesis configurations in both GHOA and RCA.

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  • Duchenne muscular dystrophy (DMD) leads to respiratory issues due to muscle injury and inflammation, ultimately causing respiratory failure.
  • A study was conducted to investigate the impact of long-term N-acetylcysteine (NAC) treatment on respiratory performance in a mouse model of DMD (mdx), after previous evidence suggested short-term benefits.
  • Results indicated that chronic NAC administration did not improve diaphragm function, breathing, or other respiratory metrics in mdx mice, implying that NAC treatment alone may have limited effectiveness for treating DMD in humans.
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  • The study explores the evolution of venom systems in stone centipedes, focusing on their defensive telopodal glandular organs, to understand the origins of novel traits in evolutionary biology.
  • Using various research methods like behavioral observations and molecular analyses, the researchers found that the telopodal organ and venom system share a similar developmental origin, suggesting a convergent evolutionary relationship.
  • The findings indicate that both systems evolved from the same type of gland, with overlapping biochemical components, highlighting the dynamism and innovation in biological traits across different systems.
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  • TLR signaling is crucial for innate immunity against pathogens but can lead to inflammation if overly activated, highlighting the need for specific inhibitors.
  • The small molecule o-vanillin has been identified as an inhibitor of TLR2 signaling, binding to and disrupting the assembly of the TLR adaptor protein MAL.
  • Research shows that o-vanillin forms a covalent bond with MAL and inhibits TLR2 exclusively, indicating it might modify TLR2 signaling complexes directly, potentially affecting various proteins in cells.
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  • Particle-induced osteolysis from polyethylene wear is a major issue causing implant failure in shoulder surgeries, prompting the development of vitamin E-enhanced highly cross-linked polyethylene (VEXPE) to improve wear resistance compared to traditional materials.!* -
  • The study assessed the wear properties of VEXPE against conventional ultrahigh-molecular-weight polyethylene (UHMWPE) under various testing conditions, recording mass loss and determining wear rates, demonstrating superior performance of VEXPE.!* -
  • Results showed that VEXPE glenoid had significantly lower wear rates than both highly cross-linked polyethylene and UHMWPE glenoids, suggesting it may reduce the risk of osteolysis and improve the longevity of shoulder implants.!*
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  • Bivalency is a natural mechanism in which two-domain peptides from animal venoms enhance receptor binding and potency, leading to unique pharmacological responses.
  • The study focuses on the structure and function of the bivalent peptide DkTx, a TRPV1 receptor agonist, revealing how its linker affects the orientation and interaction of its domains.
  • Findings show that the linker influences the potency and binding efficiency of DkTx, supporting a model where pre-organized domains yield better receptor engagement compared to a sequential binding approach.
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DFT calculations indicate that the F chemical shifts of aromatic rings containing single fluorine substituents are sensitive to the electric fields and electric field gradients at the position of the fluorine atom. The present work explores whether long-range structure restraints can be gained from changes in F chemical shifts following mutations of charged to uncharged residues. F chemical shifts of fluorotryptophan residues were measured in two different proteins, GB1 and the NT* domain, following mutations of single asparagine residues to aspartic acid.

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Despite profound diaphragm weakness, peak inspiratory pressure-generating capacity is preserved in young mdx mice revealing adequate compensation by extra-diaphragmatic muscles of breathing in early dystrophic disease. We hypothesised that loss of compensation gives rise to respiratory system compromise in advanced dystrophic disease. Studies were performed in male wild-type (n = 196) and dystrophin-deficient mdx mice (n = 188) at 1, 4, 8, 12 and 16 months of age.

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Exposure to acute intermittent hypoxia (AIH) elicits a form of respiratory plasticity known as long-term facilitation (LTF). Interest has grown in developing AIH interventions to treat ventilatory insufficiency, with promising results in spinal cord injury and amyotrophic lateral sclerosis. Therapeutic AIH may have application in neuromuscular disorders including muscular dystrophies.

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Background: Shoulder arthroplasty procedures are widely indicated, and the number of shoulder arthroplasty procedures has drastically increased over the years. Rapid expansion of the utilization of reverse total shoulder arthroplasty has outpaced the more modest growth of anatomic total shoulder arthroplasty (aTSA) while shoulder hemiarthroplasty (HA) has trended down. Recently, shoulder prostheses have transitioned to increasingly modular systems offering more individualized options with the potential for decreased pain and increased range of motion.

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Multivalent ligands of ion channels have proven to be both very rare and highly valuable in yielding unique insights into channel structure and pharmacology. Here, we describe a bivalent peptide from the venom of Xibalbanus tulumensis, a troglobitic arthropod from the enigmatic class Remipedia, that causes persistent calcium release by activation of ion channels involved in muscle contraction. The high-resolution solution structure of φ-Xibalbin3-Xt3a reveals a tandem repeat arrangement of inhibitor-cysteine knot (ICK) domains previously only found in spider venoms.

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  • - Receptor avidity through multivalency is important for ligands, but creating synthetic versions of this property is difficult, unlike the natural bivalent antibodies found in nature.
  • - Researchers discovered bivalent venom peptides that consist of two independently folded domains in tandem, leading to a new understanding of how to engineer multivalency in biomolecules, and these were classified as secreted cysteine-rich repeat-proteins (SCREPs).
  • - The newly created online resource ScrepYard helps scientists identify and characterize SCREP sequences, revealing that two-domain tandem repeats are common, and showcasing the tool's ability to discover new multivalent peptides, such as a serine protease inhibitor.
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The paramagnetism of a lanthanoid tag site-specifically installed on a protein provides a rich source of structural information accessible by nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopy. Here we report a lanthanoid tag for selective reaction with cysteine or selenocysteine with formation of a (seleno)thioether bond and a short tether between the lanthanoid ion and the protein backbone. The tag is assembled on the protein in three steps, comprising (i) reaction with 4-fluoro-2,6-dicyanopyridine (FDCP); (ii) reaction of the cyano groups with -cysteine, penicillamine or -cysteine to complete the lanthanoid chelating moiety; and (iii) titration with a lanthanoid ion.

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Digital pathology platforms with integrated artificial intelligence have the potential to increase the efficiency of the nonclinical pathologist's workflow through screening and prioritizing slides with lesions and highlighting areas with specific lesions for review. Herein, we describe the comparison of various single- and multi-magnification convolutional neural network (CNN) architectures to accelerate the detection of lesions in tissues. Different models were evaluated for defining performance characteristics and efficiency in accurately identifying lesions in 5 key rat organs (liver, kidney, heart, lung, and brain).

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This paper presents a set of eleven functional Dynamic Neuromuscular Stabilization (DNS) tests corresponding with specific infantile developmental stages, clarifying desired postural-locomotion patterns from a developmental perspective, while also describing frequently-observed disturbances of these patterns.

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The natural flight response in shrimp is powered by rapid contractions of the abdominal muscle fibres to propel themselves backwards away from perceived danger. This muscle contraction is dependent on repetitive depolarization of muscle plasma membrane, triggering tightly spaced cytoplasmic [Ca] transients and rapidly rising tetanic force responses. To achieve such high amplitude and high frequency of Ca transients requires a high abundance of sarcoplasmic/endoplasmic reticulum Ca ATPase (SERCA) to rapidly clear cytoplasmic Ca between each transient and an efficient Ca release system consisting of the Ryanodine Receptor (RyR), and voltage gated Ca channels (Cas).

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Peptide toxins isolated from animal venom secretions have proven to be useful pharmacological tools for probing the structure and function of a number of molecular receptors. Their molecular structures are stabilized by posttranslational formation of multiple disulfide bonds formed between sidechain thiols of cysteine residues, resulting in high thermal and chemical stability. Many of these peptides have been found to be potent modulators of ion channels, making them particularly influential in this field.

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Although subjects with recurrent low back pain (LBP) demonstrate altered trunk control, the kinematic and kinetic responses of the trunk have not been carefully investigated. This study was conducted to compare the standing time, spine range of motion (ROM), and dynamic postural steadiness index (DPSI) based on visual condition between subjects with and without recurrent LBP during upright one leg standing. Sixty-three individuals participated in the study, including 34 control subjects and 29 subjects with recurrent LBP.

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A photochemical method for the direct synthesis of 1H-pyrazoles from pyridazine N-oxides was developed. This chemistry features a regioselective approach to nonsymmetrically substituted pyridazine N-oxides. Herein, we highlight the first strategic use of photoinduced ring-opening reactions of 1,2-diazine N-oxides for the preparative synthesis of nitrogen heterocycles.

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The conversion of readily available silylalkynes, iodobenzene diacetate, and azide anions was utilized to form and react cyanocarbenes. A copper(II)-catalyzed reaction was found to react in a different manner. Both of these methods benefit from the formation and in situ reaction of hypervalent iodonium alkynyl triflates in O-H insertion reactions.

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Stagmomantis is a remarkable genus within the Mantodea, being relatively species-rich and geographically widespread.  Yet, the number of species within the genus remains curiously unresolved.  The present synoptic review surveys the literature on Stagmomantis to identify named species for which scientific consensus exists, as well as to summarize basic biological information for each species, including geographic distribution, morphological features, and sex-specific biometric data.

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