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https://www.readbyqxmd.com/read/27922826/phenotypic-spandrel-absolute-discrimination-and-ligand-antagonism
#1
Paul François, Mathieu Hemery, Kyle A Johnson, Laura N Saunders
We consider the general problem of sensitive and specific discrimination between biochemical species. An important instance is immune discrimination between self and not-self, where it is also observed experimentally that ligands just below the discrimination threshold negatively impact response, a phenomenon called antagonism. We characterize mathematically the generic properties of such discrimination, first relating it to biochemical adaptation. Then, based on basic biochemical rules, we establish that, surprisingly, antagonism is a generic consequence of any strictly specific discrimination made independently from ligand concentration...
December 6, 2016: Physical Biology
https://www.readbyqxmd.com/read/27921999/lift-calculations-based-on-accepted-wake-models-for-animal-flight-are-inconsistent-and-sensitive-to-vortex-dynamics
#2
Eric Gutierrez, Daniel B Quinn, Diana D Chin, David Lentink
There are three common methods for calculating the lift generated by a flying animal based on the measured airflow in the wake. However, these methods might not be accurate according to computational and robot-based studies of flapping wings. Here we test this hypothesis for the first time for a slowly flying Pacific parrotlet in still air using stereo particle image velocimetry recorded at 1000 Hz. The bird was trained to fly between two perches through a laser sheet wearing laser safety goggles. We found that the wingtip vortices generated during mid-downstroke advected down and broke up quickly, contradicting the frozen turbulence hypothesis typically assumed in animal flight experiments...
December 6, 2016: Bioinspiration & Biomimetics
https://www.readbyqxmd.com/read/27921142/intra-population-variability-of-ocean-acidification-impacts-on-the-physiology-of-baltic-blue-mussels-mytilus-edulis-integrating-tissue-and-organism-response
#3
L S Stapp, J Thomsen, H Schade, C Bock, F Melzner, H O Pörtner, G Lannig
Increased maintenance costs at cellular, and consequently organism level, are thought to be involved in shaping the sensitivity of marine calcifiers to ocean acidification (OA). Yet, knowledge of the capacity of marine calcifiers to undergo metabolic adaptation is sparse. In Kiel Fjord, blue mussels thrive despite periodically high seawater PCO2, making this population interesting for studying metabolic adaptation under OA. Consequently, we conducted a multi-generation experiment and compared physiological responses of F1 mussels from 'tolerant' and 'sensitive' families exposed to OA for 1 year...
December 5, 2016: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/27921069/reaching-200-ps-timing-resolution-in-a-time-of-flight-and-depth-of-interaction-positron-emission-tomography-detector-using-phosphor-coated-crystals-and-high-density-silicon-photomultipliers
#4
Sun Il Kwon, Alessandro Ferri, Alberto Gola, Eric Berg, Claudio Piemonte, Simon R Cherry, Emilie Roncali
Current research in the field of positron emission tomography (PET) focuses on improving the sensitivity of the scanner with thicker detectors, extended axial field-of-view, and time-of-flight (TOF) capability. These create the need for depth-of-interaction (DOI) encoding to correct parallax errors. We have proposed a method to encode DOI using phosphor-coated crystals. Our initial work using photomultiplier tubes (PMTs) demonstrated the possibilities of the proposed method, however, a major limitation of PMTs for this application is poor quantum efficiency in yellow light, corresponding to the wavelengths of the converted light by the phosphor coating...
October 2016: Journal of Medical Imaging
https://www.readbyqxmd.com/read/27920536/evaluation-of-potential-novel-variations-and-their-interactions-related-to-bipolar-disorders-analysis-of-genome-wide-association-study-data
#5
Cengizhan Acikel, Yesim Aydin Son, Cemil Celik, Husamettin Gul
BACKGROUND: Multifactor dimensionality reduction (MDR) is a nonparametric approach that can be used to detect relevant interactions between single-nucleotide polymorphisms (SNPs). The aim of this study was to build the best genomic model based on SNP associations and to identify candidate polymorphisms that are the underlying molecular basis of the bipolar disorders. METHODS: This study was performed on Whole-Genome Association Study of Bipolar Disorder (dbGaP [database of Genotypes and Phenotypes] study accession number: phs000017...
2016: Neuropsychiatric Disease and Treatment
https://www.readbyqxmd.com/read/27920211/outer-membrane-proteins-bb0405-and-bb0406-are-immunogenic-but-only-bb0405-is-required-for-borrelia-burgdorferi-infection
#6
Binu Shrestha, Melisha R Kenedy, Darrin R Akins
We recently identified the Borrelia burgdorferi outer membrane protein (OMP) BB0406 and found that the gene encoding this OMP was co-transcribed with the gene encoding the OMP BB0405. Interestingly, BB0405 and BB0406 share 59% similarity and are grouped into the same B. burgdorferi paralogous gene family. Given their overall similarity, it is plausible that both OMPs have similar or overlapping functions in this pathogenic spirochete. BB0405 has recently been shown to be required for mammalian infection despite the observations that BB0405 is poorly immunogenic and not recognized during mouse or human infection...
December 5, 2016: Infection and Immunity
https://www.readbyqxmd.com/read/27919675/individual-differences-in-internal-noise-are-consistent-across-two-measurement-techniques
#7
Greta Vilidaite, Daniel H Baker
Internal noise is a fundamental limiting property on visual processing. Internal noise has previously been estimated with the equivalent noise paradigm using broadband white noise masks and assuming a linear model. However, in addition to introducing noise into the detecting channel, white noise masks can suppress neural signals, and the linear model does not satisfactorily explain data from other paradigms. Here we propose estimating internal noise from a nonlinear gain control model fitted to contrast discrimination data...
December 2, 2016: Vision Research
https://www.readbyqxmd.com/read/27919503/binocular-low-contrast-letter-acuity-and-the-symbol-digit-modalities-test-improve-the-ability-of-the-multiple-sclerosis-functional-composite-to-predict-disease-in-pediatric-multiple-sclerosis
#8
Amy T Waldman, Salim Chahin, Amy M Lavery, Geraldine Liu, Brenda L Banwell, Grant T Liu, Laura J Balcer
BACKGROUND: Outcome measures to capture disability, such as the Multiple Sclerosis Functional Composite (MSFC), were developed to enhance outcome measurements for clinical trials in adults with multiple sclerosis (MS). The MSFC initially included three components: a timed 25-foot walk [T25FW], 9-hole peg test [9HPT], and the Paced Auditory Serial Addition Task [PASAT]. Modifications to the original MSFC, such as adding binocular low-contrast letter acuity (LCLA) or substituting the symbol digit modalities test (SDMT) for the PASAT, improved the capacity to capture neurologic impairment in adults...
November 2016: Multiple Sclerosis and related Disorders
https://www.readbyqxmd.com/read/27919490/quantitative-visual-tests-after-poorly-recovered-optic-neuritis-due-to-multiple-sclerosis
#9
Erin E Longbrake, Samantha Lancia, Nhial Tutlam, Kathryn Trinkaus, Robert T Naismith
BACKGROUND: Visual dysfunction in MS can be quantified using a variety of tests. Many vision tests have not been formally evaluated among MS patients with existing visual dysfunction. OBJECTIVE: Evaluate several versions of visual acuity and contrast sensitivity tests, measures of central and peripheral vision, retina structure, electrophysiologic function, and quality of life among MS patients with moderate/severe visual dysfunction. METHODS: Cross-sectional study of 46 patients with stable, incompletely recovered optic neuritis...
November 2016: Multiple Sclerosis and related Disorders
https://www.readbyqxmd.com/read/27919479/how-to-refer-to-people-with-disease-in-research-outputs-the-disconnection-between-academic-practise-and-that-preferred-by-people-with-multiple-sclerosis
#10
David Baker, Ananthi Anandhakrishnan, Katie A Tuite-Dalton, Hazel Lockart-Jones, Rodden M Middleton, David V Ford, Christina Crowe, Gavin Giovannoni
BACKGROUND: Increasingly, Government and Charity funders require public engagement in research. Invariably these research outputs describe the condition of someone with the disease of interest. We therefore sought to identify the preferred descriptor of someone with a disease, such as multiple sclerosis (MS) and to determine what descriptors are currently used by academics. METHODS: Several surveys were undertaken: one from the Research Network of the MS Society (MSSRN), a major MS Charity within the United Kingdom, who are involved in reviewing grant applications, priority setting and research governance (n=146), and surveys from both the United Kingdom MS register (MSR; n=1713) and the North American Research Committee on Multiple Sclerosis (NARCOMS) registry (n=518)...
November 2016: Multiple Sclerosis and related Disorders
https://www.readbyqxmd.com/read/27919371/a-machine-learning-based-framework-to-identify-type-2-diabetes-through-electronic-health-records
#11
Tao Zheng, Wei Xie, Liling Xu, Xiaoying He, Ya Zhang, Mingrong You, Gong Yang, You Chen
OBJECTIVE: To discover diverse genotype-phenotype associations affiliated with Type 2 Diabetes Mellitus (T2DM) via genome-wide association study (GWAS) and phenome-wide association study (PheWAS), more cases (T2DM subjects) and controls (subjects without T2DM) are required to be identified (e.g., via Electronic Health Records (EHR)). However, existing expert based identification algorithms often suffer in a low recall rate and could miss a large number of valuable samples under conservative filtering standards...
January 2017: International Journal of Medical Informatics
https://www.readbyqxmd.com/read/27919361/adverse-effects-on-insulin-secretion-of-replacing-saturated-fat-with-refined-carbohydrate-but-not-with-monounsaturated-fat-a-randomized-controlled-trial-in-centrally-obese-subjects
#12
Lin F Chang, Shireene R Vethakkan, Kalanithi Nesaretnam, Thomas A B Sanders, Kim-Tiu Teng
BACKGROUND: Current dietary guidelines recommend the replacement of saturated fatty acids (SAFAs) with carbohydrates or monounsaturated fatty acids (MUFAs) based on evidence on lipid profile alone, the chronic effects of the mentioned replacements on insulin secretion and insulin sensitivity are however unclear. OBJECTIVE: To assess the chronic effects of the substitution of refined carbohydrate or MUFA for SAFA on insulin secretion and insulin sensitivity in centrally obese subjects...
November 2016: Journal of Clinical Lipidology
https://www.readbyqxmd.com/read/27918951/subjective-alcohol-responses-in-a-cross-sectional-field-based-study-of-adolescents-and-young-adults-effects-of-age-drinking-level-and-dependence-consequences
#13
Hayley Treloar, Mark A Celio, Stephen A Lisman, Robert Miranda, Linda P Spear
BACKGROUND: Adolescents are physically, cognitively, socially, and emotionally different than adults in ways that may partially explain why alcohol misuse typically develops during this period. Ample animal-science evidence and nascent ecological evidence points toward developmentally limited differences in sensitivity to alcohol's stimulatory and sedative effects. Field-based research methods were used to test for such age-related differences in a sample of adolescents through young adults...
November 16, 2016: Drug and Alcohol Dependence
https://www.readbyqxmd.com/read/27918897/saturation-inversion-recovery-a-method-for-t1-measurement
#14
Hongzhi Wang, Ming Zhao, Jerome L Ackerman, Yiqiao Song
Spin-lattice relaxation (T1) has always been measured by inversion-recovery (IR), saturation-recovery (SR), or related methods. These existing methods share a common behavior in that the function describing T1 sensitivity is the exponential, e.g., exp(-τ/T1), where τ is the recovery time. In this paper, we describe a saturation-inversion-recovery (SIR) sequence for T1 measurement with considerably sharper T1-dependence than those of the IR and SR sequences, and demonstrate it experimentally. The SIR method could be useful in improving the contrast between regions of differing T1 in T1-weighted MRI...
November 27, 2016: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/27918532/developmentally-defined-forebrain-circuits-regulate-appetitive-and-aversive-olfactory-learning
#15
Nagendran Muthusamy, Xuying Zhang, Caroline A Johnson, Prem N Yadav, H Troy Ghashghaei
Postnatal and adult neurogenesis are region- and modality-specific, but the significance of developmentally distinct neuronal populations remains unclear. We demonstrate that chemogenetic inactivation of a subset of forebrain and olfactory neurons generated at birth disrupts responses to an aversive odor. In contrast, novel appetitive odor learning is sensitive to inactivation of adult-born neurons, revealing that developmentally defined sets of neurons may differentially participate in hedonic aspects of sensory learning...
December 5, 2016: Nature Neuroscience
https://www.readbyqxmd.com/read/27918447/enhanced-antimicrobial-and-anticancer-activity-of-silver-and-gold-nanoparticles-synthesised-using-sargassum-incisifolium-aqueous-extracts
#16
Mokone Mmola, Marilize Le Roes-Hill, Kim Durrell, John J Bolton, Nicole Sibuyi, Mervin E Meyer, Denzil R Beukes, Edith Antunes
A detailed, methodical approach was used to synthesise silver and gold nanoparticles using two differently prepared aqueous extracts of the brown algae Sargassum incisifolium. The efficiency of the extracts in producing nanoparticles were compared to commercially available brown algal fucoidans, a major constituent of brown algal aqueous extracts. The nanoparticles were characterised using TEM, XRD and UV/Vis spectroscopy and zeta potential measurements. The rate of nanoparticle formation was assessed using UV/Vis spectroscopy and related to the size, shape and morphology of the nanoparticles as revealed by TEM...
December 2, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/27918237/gpx3-promoter-methylation-predicts-platinum-sensitivity-in-colorectal-cancer
#17
Lorraine Pelosof, Sashidhar Yerram, Todd Armstrong, Nina Chu, Ludmila Danilova, Breann Yanagisawa, Manuel Hidalgo, Nilofer Azad, James G Herman
Epigenetic control of gene expression is a major determinant of tumor phenotype and has been found to influence sensitivity to individual chemotherapeutic agents. Glutathione peroxidase 3 (GPX3, plasma glutathione peroxidase) is a key component of cellular antioxidant regulation and its gene has been reported to be methylated in specific tumor types. GPX3 role in oxidative damage has been associated with sensitivity to platinums in other tumors but its importance in colorectal cancer (CRC) has not been determined...
December 5, 2016: Epigenetics: Official Journal of the DNA Methylation Society
https://www.readbyqxmd.com/read/27917889/comparative-study-between-a-spectral-domain-and-a-high-speed-single-beam-swept-source-octa-system-for-identifying-choroidal-neovascularization-in-amd
#18
R Told, L Ginner, A Hecht, S Sacu, R Leitgeb, A Pollreisz, U Schmidt-Erfurth
This comparative study between a SD- and SS-OCTA system for visualizing neovascular patterns in AMD, also assessed the influence of cataract on OCTA imaging. 25 eyes with active CNV (AMD) were documented by FA, ICGA and SD-OCT. Two OCTA devices were used: A custom built SS-OCTA (1050 nm, 400,000 A-scans/s, 5 × 5 mm, no image segmentation); AngioVue (OptoVue, CA, USA) SD-OCTA (840 nm, 70.000 A-scans/s, 3 × 3 mm, SSADA technology). Two retina experts graded CNV types and vascular patterns. Cataract influence on OCTA image quality was reported for the superficial retinal plexus (6 eyes)...
December 5, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27917612/fear-of-falling-and-physical-function-in-older-adults-with-cataract-exploring-the-role-of-vision-as-a-moderator
#19
Anna Palagyi, Jonathon Q Ng, Kris Rogers, Lynn Meuleners, Peter McCluskey, Andrew White, Nigel Morlet, Lisa Keay
AIM: To examine fear of falling and associated factors in a cohort of older adults with cataract, and investigate the interplay of vision and physical function with respect to fear of falling. METHODS: We analyzed baseline data from a longitudinal study of adults aged ≥65 years referred for cataract surgery. Fear of falling was assessed by the Short Falls Efficacy Scale-International. Physical function was determined by the Short Physical Performance Battery...
December 4, 2016: Geriatrics & Gerontology International
https://www.readbyqxmd.com/read/27917530/visual-complications-in-diabetes-mellitus-beyond-retinopathy
#20
REVIEW
A Khan, I N Petropoulos, G Ponirakis, R A Malik
Diabetic retinopathy is the most common cause of vision loss in people with diabetes mellitus; however, other causes of visual impairment/loss include other retinal and non-retinal visual problems, including glaucoma, age-related macular degeneration, non-arteritic anterior ischaemic optic neuropathy and cataracts. Additionally, when a person with diabetes complains of visual disturbance despite a visual acuity of 6/6, abnormalities in refraction, contrast sensitivity, straylight and amplitude of accommodation should be considered...
December 5, 2016: Diabetic Medicine: a Journal of the British Diabetic Association
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