6,453 results match your criteria linear block


A time series analysis of the short-term association between climatic variables and acute respiratory infections in Singapore.

Int J Hyg Environ Health 2021 Apr 13;234:113748. Epub 2021 Apr 13.

Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, 12 Science Drive 2, 117549, Singapore; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, 10 Medical Drive, 117597, Singapore.

Background: Acute respiratory infections (ARIs) are among the most common human illnesses globally. Previous studies that examined the associations between climate variability and ARIs or ARI pathogens have reported inconsistent findings. Few studies have been conducted in Southeast Asia to date, and the impact of climatic factors are not well-understood. Read More

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Polysulfates block SARS-CoV-2 uptake via electrostatic interactions.

Angew Chem Int Ed Engl 2021 Apr 16. Epub 2021 Apr 16.

Freie Universitat Berlin, Dept. of Biology, Chemistry and Pharmacy, Takustr. 3, Institute for Chemistry and Biochemistry, 14195, Berlin, GERMANY.

Here we report that negatively charged polysulfates can bind to the spike protein of SARS-CoV-2 via electrostatic interactions. Using a plaque reduction assay, we compare inhibition of SARS-CoV-2 by heparin, pentosan sulfate, linear polyglycerol sulfate (LPGS) and hyperbranched polyglycerol sulfate (HPGS). Highly sulfated LPGS is the optimal inhibitor, with a half-maximal inhibitory concentration (IC 50 ) of 67 μg/mL (approx. Read More

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Mode of Anesthesia and Quality of Recovery After Breast Surgery: A Case Series of 100 Patients.

Cureus 2021 Mar 11;13(3):e13822. Epub 2021 Mar 11.

Anaesthesia, Guy's & St Thomas' National Health Service (NHS) Foundation Trust, London, GBR.

Purpose: Regional anesthesia techniques may improve patient recovery beyond treating postoperative pain alone and may facilitate patients in their return to functional, psychological as well as emotional baselines. We hypothesized that the quality of recovery (QoR) experienced by patients following breast surgery was associated with the type of anesthesia received as well as the use of a regional anesthesia technique during surgery.

Methods: We performed a single-center prospective, observational cohort study of patients undergoing elective breast procedures (both cancer and non-cancer surgery). Read More

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ENTRYWISE EIGENVECTOR ANALYSIS OF RANDOM MATRICES WITH LOW EXPECTED RANK.

Ann Stat 2020 Jun 17;48(3):1452-1474. Epub 2020 Jul 17.

Department of ORFE, Princeton University, Princeton, NJ 08544, USA.

Recovering low-rank structures via eigenvector perturbation analysis is a common problem in statistical machine learning, such as in factor analysis, community detection, ranking, matrix completion, among others. While a large variety of bounds are available for average errors between empirical and population statistics of eigenvectors, few results are tight for entrywise analyses, which are critical for a number of problems such as community detection. This paper investigates entrywise behaviors of eigenvectors for a large class of random matrices whose expectations are low-rank, which helps settle the conjecture in Abbe et al. Read More

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Effect of alternative income assistance schedules on drug use and drug-related harm: a randomised controlled trial.

Lancet Public Health 2021 Apr 12. Epub 2021 Apr 12.

Department of Medicine, University of British Columbia, Vancouver, BC, Canada; British Columbia Centre on Substance Use, Vancouver, BC, Canada.

Background: The synchronised monthly disbursement of income assistance, whereby all recipients are paid on the same day, has been associated with increases in illicit drug use and serious associated harms. This phenomenon is often referred to as the cheque effect. Because payment variability can affect consumption patterns, this study aimed to assess whether these harms could be mitigated through a structural intervention that varied income assistance payment timing and frequency. Read More

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The association between perceived patient-centered care and symptoms experienced by patients undergoing anti-cancer treatment.

Support Care Cancer 2021 Apr 14. Epub 2021 Apr 14.

The Cheryl Spencer Department of Nursing, Faculty of Social Welfare and Health Sciences, University of Haifa, 199 Aba Khoushy Avenue, Mount Carmel, 3498838, Haifa, Israel.

Purpose: Cancer patients undergoing active anti-cancer treatment experience multiple symptoms concurrently. Over the years, studies to improve patients' physical and psychological discomfort by focusing on patients' needs and preferences have reported promising outcomes. This study aims to explore perceived patient-centered care and its association to symptoms experienced by cancer patients undergoing active anti-cancer treatment. Read More

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The Interaction Mechanism of Intrinsically Disordered PP2A Inhibitor Proteins ARPP-16 and ARPP-19 With PP2A.

Front Mol Biosci 2021 26;8:650881. Epub 2021 Mar 26.

Institute of Biomedicine, University of Turku, Turku, Finland.

Protein phosphatase 2A (PP2A) activity is critical for maintaining normal physiological cellular functions. PP2A is inhibited by endogenous inhibitor proteins in several pathological conditions including cancer. A PP2A inhibitor protein, ARPP-19, has recently been connected to several human cancer types. Read More

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High-Frequency Alternating Current Block Using Macro-Sieve Electrodes: A Pilot Study.

Cureus 2021 Mar 6;13(3):e13728. Epub 2021 Mar 6.

Department of Neurological Surgery, Washington University School of Medicine, St. Louis, USA.

Background and objective High-frequency alternating current (HFAC) can yield a rapid-acting and reversible nerve conduction block. The present study aimed to demonstrate the successful implementation of HFAC block delivery via regenerative macro-sieve electrodes (MSEs). Methods Dual-electrode assemblies in two configurations [dual macro-sieve electrode-1 (DMSE-I), DMSE-II] were fabricated from pairs of MSEs and implanted in the transected and subsequently repaired sciatic nerves of two male Lewis rats. Read More

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Impact of the Microstructure of CAD/CAM Blocks on the Bonding Strength and the Bonded Interface.

J Prosthodont 2021 Apr 9. Epub 2021 Apr 9.

Univ Lyon - Claude Bernard Lyon 1, UMR CNRS 5615, Laboratoire des Multimatériaux et Interfaces, Villeurbanne, France.

Purpose: To investigate the relationship between the microstructure of CAD/CAM blocks and the quality of adhesion as function of the surface treatment and resin cement type.

Materials And Methods: Two nano-ceramic composite resin CAD/CAM blocks, Lava Ultimate (LU) and Cerasmart (CS), and two Leucite-reinforced glass ceramic CAD/CAM IPS blocks, Empress® CAD (EM) and Initial LRF (IR), received either Hydrofluoric acid (HF) or sandblasting (SB) surface treatments. The blocks were then luted using two dual-cure resin cements, LinkForce (LF) and Multilink Automix (ML) with their corresponding silanes, resulting in 16 study groups. Read More

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Uniform Nanowires Containing a Heterogeneous π-Conjugated Core of Controlled Length, Composition and Morphology.

Chemistry 2021 Apr 8. Epub 2021 Apr 8.

Shanghai institute of organic chemistry, 345 lingling road, 200032, shanghai, CHINA.

We demonstrate for the first time that heterojunction nanowires consisting of a gradient and segmented-like heterogeneous π-conjugated core with controllable length, composition and morphology can be generated by co-self-seeding of oligo( p -phenylene vinylene) (OPV)- and oligo( p -phenylene ethynylene) (OPE)-containing block copolymers in despite of different chain lengths and molecular conformation for OPE and OPV. More importantly, on the basis of understanding about the formation of heterogeneous core by the co-self-seeding approach, we develop a "heating/cooling" seeded growth route, by which linear and branched heterojunction nanowires containing a segmented heterogeneous π-conjugated core of controlled length, composition and morphology can be obtained. This work provides a versatile platform to generate heterojunction nanowires with excellent controllability in length, composition and morphology. Read More

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Add on yoga treatment for negative symptoms of schizophrenia: A multi-centric, randomized controlled trial.

Schizophr Res 2021 Apr 5;231:90-97. Epub 2021 Apr 5.

National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.

The efficacy of antipsychotic medications in the treatment of negative symptoms of schizophrenia is modest at best. Preliminary studies suggest the beneficial effects of add on Yoga, a traditional Indian practice, in the treatment of schizophrenia. Hence, in this study, we examined the efficacy of yoga as an add-on treatment for negative symptoms of schizophrenia in a randomized, wait-list controlled design from two clinical institutes in south India. Read More

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Recognition of honeycomb lung in CT images based on improved MobileNet model.

Med Phys 2021 Apr 7. Epub 2021 Apr 7.

College of Information and Computer, Taiyuan University of Technology, Taiyuan, China.

Pupose: The research is to improve the efficiency and accuracy of recognition of honeycomb lung in CT images.

Methods: Deep learning methods are used to achieve automatic recognition of honeycomb lung in CT images, however, is time consuming and less accurate due to the large amount of structural parameters. In this paper, a novel recognition method based on MobileNetV1 network, multi-scale feature fusion method (MSFF) and dilated convolution are explored to deal with honeycomb lung in CT images classification. Read More

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Modulating the Molecular Geometry and Solution Self-Assembly of Amphiphilic Polypeptoid Block Copolymers by Side Chain Branching Pattern.

J Am Chem Soc 2021 Apr 6. Epub 2021 Apr 6.

Department of Chemistry and Macromolecular Studies Group, Louisiana State University, Baton Rouge, Louisiana 70803, United States.

Solution self-assembly of coil-crystalline diblock copolypeptoids has attracted increasing attention due to its capability to form hierarchical nanostructures with tailorable morphologies and functionalities. While the N-substituent (or side chain) structures are known to affect the crystallization of polypeptoids, their roles in dictating the hierarchical solution self-assembly of diblock copolypeptoids are not fully understood. Herein, we designed and synthesized two types of diblock copolypeptoids, i. Read More

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Implementation of the computer tomography parallel algorithms with the incomplete set of data.

PeerJ Comput Sci 2021 24;7:e339. Epub 2021 Feb 24.

Faculty of Applied Mathematics, Silesian Technical University of Gliwice, Gliwice, Śląskie, Poland.

Computer tomography has a wide field of applicability; however, most of its applications assume that the data, obtained from the scans of the examined object, satisfy the expectations regarding their amount and quality. Unfortunately, sometimes such expected data cannot be achieved. Then we deal with the incomplete set of data. Read More

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February 2021

Precise Synthesis and Thin Film Self-Assembly of PLLA--PS Bottlebrush Block Copolymers.

Molecules 2021 Mar 5;26(5). Epub 2021 Mar 5.

Laboratoire de Chimie des Polymères Organiques, Université de Bordeaux, CNRS, Bordeaux INP, LCPO, UMR 5629, F-33600 Pessac, France.

The ability of bottlebrush block copolymers (BBCPs) to self-assemble into ordered large periodic structures could greatly expand the scope of photonic and membrane technologies. In this paper, we describe a two-step synthesis of poly(l-lactide)--polystyrene (PLLA--PS) BBCPs and their rapid thin-film self-assembly. PLLA chains were grown from -5-norbornene-2-methanol via ring-opening polymerization (ROP) of l-lactide to produce norbornene-terminated PLLA. Read More

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Image Statistics Preserving Encrypt-then-Compress Scheme Dedicated for JPEG Compression Standard.

Entropy (Basel) 2021 Mar 31;23(4). Epub 2021 Mar 31.

Institute of Information Technology, Lodz University of Technology, 90-924 Lodz, Poland.

In this paper, the authors analyze in more details an image encryption scheme, proposed by the authors in their earlier work, which preserves input image statistics and can be used in connection with the JPEG compression standard. The image encryption process takes advantage of fast linear transforms parametrized with private keys and is carried out prior to the compression stage in a way that does not alter those statistical characteristics of the input image that are crucial from the point of view of the subsequent compression. This feature makes the encryption process transparent to the compression stage and enables the JPEG algorithm to maintain its full compression capabilities even though it operates on the encrypted image data. Read More

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Lessons Learned from Replicating a Randomized Control Trial Evaluation of an App-Based Sexual Health Program.

Int J Environ Res Public Health 2021 Mar 23;18(6). Epub 2021 Mar 23.

Child Trends, 7315 Wisconsin Avenue, Suite 1200W, Bethesda, MD 20814, USA.

This study presents findings from a randomized control trial replication evaluation of Pulse, an app-based pregnancy prevention program implemented with Black and Latinx women aged 18-20, a population with high rates of unplanned pregnancy. We used social media advertisements to enroll 1013 women online across the U.S. Read More

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Thiol-ene Reaction: An Efficient Tool to Design Lipophilic Polyphosphoesters for Drug Delivery Systems.

Molecules 2021 Mar 20;26(6). Epub 2021 Mar 20.

Center for Education and Research on Macromolecules (CERM), CESAM Research-Unit, University of Liège, Allée du 6 août 13, B6a, Sart-Tilman, 4000 Liège, Belgium.

Poly(ethylene glycol)--polyphosphoester (PEG--PPE) block copolymer nanoparticles are promising carriers for poorly water soluble drugs. To enhance the drug loading capacity and efficiency of such micelles, a strategy was investigated for increasing the lipophilicity of the PPE block of these PEG--PPE amphiphilic copolymers. A PEG--PPE copolymer bearing pendant vinyl groups along the PPE block was synthesized and then modified by thiol-ene click reaction with thiols bearing either a long linear alkyl chain (dodecyl) or a tocopherol moiety. Read More

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The Micellization of Well-Defined Single Graft Copolymers in Block Copolymer/Homopolymer Blends.

Polymers (Basel) 2021 Mar 9;13(5). Epub 2021 Mar 9.

Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, P.O. Box 1527, 71110 Heraklion Crete, Greece.

A series of well-defined (polyisoprene)(polystyrene), IS, single graft copolymers with similar total molecular weights but different compositions, , were blended with a low molecular weight polyisoprene homopolymer matrix at a constant concentration 2 wt%, and the micellar characteristics were studied by small-angle x-ray scattering. To investigate the effect of macromolecular architecture on the formation and characteristics of micelles, the results on the single graft copolymers were compared with those of the corresponding linear polystyrene--polyisoprene diblock copolymers, SI. The comparison reveals that the polystyrene core chains are more stretched in the case of graft copolymer micelles. Read More

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Research on Panoramic Stitching Algorithm of Lateral Cranial Sequence Images in Dental Multifunctional Cone Beam Computed Tomography.

Sensors (Basel) 2021 Mar 21;21(6). Epub 2021 Mar 21.

Medical Electronics and Information Technology Engineering Research Center, Chongqing University of Posts and Telecommunications, Chong Qing 400065, China.

In the design of dental multifunctional Cone Beam Computed Tomography, the linear scanning strategy not only saves equipment cost, but also avoids the demand for patients to be repositioned when acquiring lateral cranial sequence images. In order to obtain panoramic images, we propose a local normalized cross-correlation stitching algorithm based on Gaussian Mixture Model. Firstly, the Block-Matching and 3D filtering algorithm is used to remove quantum and impulse noises according to the characteristics of X-ray images; Then, the segmentation of the irrelevant region and the extraction of the region of interest are performed by Gaussian Mixture Model; The locally normalized cross-relation is used to complete the registration with the multi-resolution strategy based on wavelet transform and Particle Swarm Optimization algorithm; Finally, image fusion is achieved by the weighted smoothing fusion algorithm. Read More

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Pirfenidone in patients with progressive fibrotic interstitial lung diseases other than idiopathic pulmonary fibrosis (RELIEF): a double-blind, randomised, placebo-controlled, phase 2b trial.

Lancet Respir Med 2021 Mar 30. Epub 2021 Mar 30.

Center for Interstitial and Rare Lung Diseases, Justus-Liebig University Giessen, Giessen, Germany; Member of the German Center for Lung Research and Cardiopulmonary Institute, and Agaplesion Lung Clinic Waldhof-Elgershausen, Greifenstein, Germany.

Background: Pirfenidone has been shown to slow disease progression in patients with idiopathic pulmonary fibrosis (IPF). However, there are few treatment options for progressive fibrotic interstitial lung diseases (ILDs)) other than IPF. In view of the pathomechanistic and clinical similarities between IPF and other progressive fibrotic ILDs, we aimed to assess the efficacy and safety of pirfenidone in patients with four non-IPF progressive fibrotic ILDs. Read More

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Role of Charge Transfer in Halogen Bonding.

J Phys Chem A 2021 Apr 2;125(14):2944-2953. Epub 2021 Apr 2.

Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, North Carolina 27401, United States.

Halogen bonding has received intensive attention recently for its applications in the construction of supramolecular assemblies and crystal engineering and its implications and potentials in chemical and biological processes and rational drug design. Peculiarly, in intermolecular interactions, halogen atoms are known as electron-donating groups carrying partial negative charges in molecules due to its high electronegativity, but they can counterintuitively act as Lewis acids and bind with Lewis bases in the form of a halogen bond. The unsettling issue regarding the nature of the halogen bonding is whether the electrostatics or charge transfer interaction dominates. Read More

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Effect of body mass index (BMI) on phenotypic features of polycystic ovary syndrome (PCOS) in Singapore women: a prospective cross-sectional study.

BMC Womens Health 2021 Apr 1;21(1):135. Epub 2021 Apr 1.

Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, NUHS Tower Block, 1E Kent Ridge Road, Level 12, Singapore, Republic of Singapore, 119228.

Background: A diagnosis of Polycystic Ovary Syndrome (PCOS) and its related phenotypic features including increased hair growth can affect a woman's social and emotional well-being. We aim to determine firstly, if excess body weight affects menstrual cycle length, excessive hair growth and other phenotypic features in healthy women without PCOS and secondly, whether having PCOS exacerbates the effects of high body mass index (BMI).

Methods: A prospective cross-sectional study involving healthy women (21-45 years) recruited at an annual health screen for hospital staff and volunteers from the university community, and PCOS cases referred to tertiary gynecological clinics in Singapore. Read More

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Effects of different prosthetic instrumentations on tibial bone resection in total knee arthroplasty.

Sci Rep 2021 Mar 31;11(1):7297. Epub 2021 Mar 31.

Osteonecrosis and Joint Reconstruction Ward, Department of Joint Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, 710054, Shaanxi, People's Republic of China.

Our aim was to assess the accuracy of the obtained posterior tibial slope (PTS) with a fixed angle cutting block. 247 TKAs in 213 patients were reviewed. We included 104 Legion Prosthesis, 76 U2 Knee Prosthesis, 46 NexGen LPS-Flex Prosthesis, and 21 Vanguard Knee System products. Read More

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International trends in grant and fellowship funding awarded to women in neurosurgery.

Neurosurg Focus 2021 Mar;50(3):E5

1Mayo Clinic Department of Neurologic Surgery, and.

Objective: Metric tracking of grant funding over time for academic neurosurgeons sorted by gender informs the current climate of career development internationally for women in neurosurgery.

Methods: Multivariate linear trend analysis of grant funding awarded to neurosurgeons in the NIH and World Research Portfolio Online Reporting Tools Expenditures and Results (RePORTER) was performed. Traveling fellowships for international neurosurgery residents sponsored by the AANS and Congress of Neurological Surgeons (CNS) were also analyzed. Read More

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Block Search Stochastic Simulation Algorithm (BlSSSA): A Fast Stochastic Simulation Algorithm for Modeling Large Biochemical Networks.

IEEE/ACM Trans Comput Biol Bioinform 2021 Mar 31;PP. Epub 2021 Mar 31.

Stochastic simulation algorithms are extensively used for exploring stochastic behavior of biochemical pathways/networks. Computational cost of these algorithms is high in simulating real biochemical systems due to their large size, complex structure and stiffness. In order to reduce the computational cost, several algorithms have been developed. Read More

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A connectome-based approach to assess motor outcome after neonatal arterial ischemic stroke.

Ann Clin Transl Neurol 2021 Mar 30. Epub 2021 Mar 30.

Université d'Angers, Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS) EA7315, Angers, 49000, France.

Objective: Studies of motor outcome after Neonatal Arterial Ischemic Stroke (NAIS) often rely on lesion mapping using MRI. However, clinical measurements indicate that motor deficit can be different than what would solely be anticipated by the lesion extent and location. Because this may be explained by the cortical disconnections between motor areas due to necrosis following the stroke, the investigation of the motor network can help in the understanding of visual inspection and outcome discrepancy. Read More

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Modelling the effect of light through commercially available blue-blocking lenses on the human circadian system.

Clin Exp Optom 2021 Mar 27:1-6. Epub 2021 Mar 27.

School of Optometry and Vision Science, The University of New South Wales, Sydney, Australia.

Clinical Relevance: Wearing blue-blocking lenses (BBLs) in the evening hours may not be effective in improving sleep quality. Optometrists need to be informed in prescribing BBLs by highlighting the consequences of their wear to the circadian system.

Background: Excessive exposure to artificial light, particularly at short wavelengths, during the evening, may disrupt normal nocturnal melatonin production, which is a natural process of the circadian rhythm and affect sleep quality. Read More

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Posterior Cranial Vault Distraction Osteogenesis Utilizing a Posterior-Superior Distraction Vector in the Treatment of Mercedes Benz Pattern Craniosynostosis.

J Craniofac Surg 2021 Mar 24. Epub 2021 Mar 24.

Department of Plastic Surgery, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center Department of Plastic Surgery, University of Pittsburgh School of Medicine University of Pittsburgh School of Medicine, Pittsburgh, PA.

Abstract: Bilateral lambdoid and sagittal synostosis, or Mercedes Benz Syndrome, is a rare complex craniosynostosis resulting in frontal bossing, a tapered posterior fossa, and an anteriorly displaced cranial vertex. Its ideal surgical correction must result in posterior expansion, skull elongation, and caudal repositioning of the vertex. We present a craniometric analysis of skull changes with posterior-superior distraction and introduce a novel craniometric measure: vertex position. Read More

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Analysing detection gaps in acoustic telemetry data to infer differential movement patterns in fish.

Ecol Evol 2021 Mar 10;11(6):2717-2730. Epub 2021 Feb 10.

Institute of Zoology Zoological Society of London London UK.

A wide array of technologies are available for gaining insight into the movement of wild aquatic animals. Although acoustic telemetry can lack the fine-scale spatial resolution of some satellite tracking technologies, the substantially longer battery life can yield important long-term data on individual behavior and movement for low per-unit cost. Typically, however, receiver arrays are designed to maximize spatial coverage at the cost of positional accuracy leading to potentially longer detection gaps as individuals move out of range between monitored locations. Read More

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