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https://www.readbyqxmd.com/read/28431369/the-temporal-paradox-of-hebbian-learning-and-homeostatic-plasticity
#1
REVIEW
Friedemann Zenke, Wulfram Gerstner, Surya Ganguli
Hebbian plasticity, a synaptic mechanism which detects and amplifies co-activity between neurons, is considered a key ingredient underlying learning and memory in the brain. However, Hebbian plasticity alone is unstable, leading to runaway neuronal activity, and therefore requires stabilization by additional compensatory processes. Traditionally, a diversity of homeostatic plasticity phenomena found in neural circuits is thought to play this role. However, recent modelling work suggests that the slow evolution of homeostatic plasticity, as observed in experiments, is insufficient to prevent instabilities originating from Hebbian plasticity...
April 18, 2017: Current Opinion in Neurobiology
https://www.readbyqxmd.com/read/28431348/evaluation-of-structural-effects-on-the-flocculation-performance-of-a-co-graft-starch-based-flocculant
#2
Zhouzhou Liu, Hua Wei, Aimin Li, Hu Yang
The molecular structure of a material substantially determines its final application performance. In this work, a series of starch-based flocculants with different charge densities and average graft chain lengths were prepared by the co-graft polymerization of acrylamide and [(2-methacryloyloxyethyl) trimethyl ammonium chloride] (St-g-PAM-co-PDMC). The flocculation performance of St-g-PAM-co-PDMC was studied systematically at neutral pH using kaolin suspension and sodium humate (NaHA) aqueous solution as synthetic wastewaters...
April 18, 2017: Water Research
https://www.readbyqxmd.com/read/28431056/long-term-outcome-of-transvenous-pacemaker-implantation-in-infants-a-retrospective-cohort-study
#3
Laura M Vos, Janneke A E Kammeraad, Matthias W Freund, Andreas C Blank, Johannes M P J Breur
Aim: Evaluation of long-term outcome of transvenous pacemaker (PM) implantation in infants. Methods and Results: A retrospective analysis of all transvenous PM implantations in infants <10 kg between September 1997 and October 2001 was made. Indications for PM implantation, age at implantation, and determinants of long-term outcome including cardiac function, PM function, and PM (system) complications were noted. Seven patients underwent transvenous VVI(R) PM implantation...
April 1, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28431049/nest-use-and-patterns-of-egg-laying-and-damage-by-4-strains-of-laying-hens-in-an-aviary-system1
#4
S Villanueva, A B A Ali, D L M Campbell, J M Siegford
Laying hens are strongly motivated to use nests for egg laying, and alternative production systems (e.g., aviaries) provide artificial sites to meet this need and ensure efficient collection of clean, undamaged eggs. However, nests are typically not provided to allow simultaneous use by all hens; therefore, competition or mislaid eggs can result. To understand the influence of strain on laying eggs outside nests and damage to eggs, we compared daily patterns of nests use and egg laying among 4 laying hen strains (Hy-Line Brown (HB), Bovans Brown (BB), DeKalb White (DW), and Hy-Line W36 (W36))...
April 20, 2017: Poultry Science
https://www.readbyqxmd.com/read/28431046/brg1-interacts-with-sox10-to-establish-the-melanocyte-lineage-and-to-promote-differentiation
#5
Himangi G Marathe, Dawn E Watkins-Chow, Matthias Weider, Alana Hoffmann, Gaurav Mehta, Archit Trivedi, Shweta Aras, Tupa Basuroy, Aanchal Mehrotra, Dorothy C Bennett, Michael Wegner, William J Pavan, Ivana L de la Serna
Mutations in SOX10 cause neurocristopathies which display varying degrees of hypopigmentation. Using a sensitized mutagenesis screen, we identified Smarca4 as a modifier gene that exacerbates the phenotypic severity of Sox10 haplo-insufficient mice. Conditional deletion of Smarca4 in SOX10 expressing cells resulted in reduced numbers of cranial and ventral trunk melanoblasts. To define the requirement for the Smarca4 -encoded BRG1 subunit of the SWI/SNF chromatin remodeling complex, we employed in vitro models of melanocyte differentiation in which induction of melanocyte-specific gene expression is closely linked to chromatin alterations...
April 20, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28430715/computed-tomography-of-the-head-and-neck-region-for-tumor-staging-comparison-of-dual-source-dual-energy-and-low-kilovolt-single-energy-acquisitions
#6
Matthias Stefan May, Joscha Bruegel, Michael Brand, Marco Wiesmueller, Bernhard Krauss, Thomas Allmendinger, Michael Uder, Wolfgang Wuest
PURPOSE: The aim of this study was to intra-individually compare the image quality obtained by dual-source, dual-energy (DSDE) computed tomography (CT) examinations and different virtual monoenergetic reconstructions to a low single-energy (SE) scan. MATERIALS AND METHODS: Third-generation DSDE-CT was performed in 49 patients with histologically proven malignant disease of the head and neck region. Weighted average images (WAIs) and virtual monoenergetic images (VMIs) for low (40 and 60 keV) and high (120 and 190 keV) energies were reconstructed...
April 20, 2017: Investigative Radiology
https://www.readbyqxmd.com/read/28430427/performance-of-the-amoeba-water-model-in-the-vicinity-of-qm-solutes-a-diagnosis-using-energy-decomposition-analysis
#7
Yuezhi Mao, Yihan Shao, Jacek Dziedzic, Chris-Kriton Skylaris, Teresa Head-Gordon, Martin Head-Gordon
The importance of incorporating solvent polarization effects into the modeling of solvation processes has been well-recognized, and therefore a new generation of hybrid quantum mechanics/molecular mechanics (QM/MM) approaches that accounts for this effect is desirable. We present a fully self-consistent, mutually polarizable QM/MM scheme using the AMOEBA force field, in which the total energy of the system is variationally minimized with respect to both the QM electronic density and the MM induced dipoles. This QM/AMOEBA model is implemented through the Q-Chem/LibEFP code interface and then applied to the evaluation of solute-solvent interaction energies for various systems ranging from the water dimer to neutral and ionic solutes (NH3, NH4(+) , CN(-)) surrounded by increasing numbers of water molecules (up to 100)...
April 21, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28430390/chronic-toxicity-of-binary-metal-mixtures-of-cadmium-and-zinc-to-daphnia-magna
#8
Edgar Pérez, Tham C Hoang
The present study characterized the chronic effect of binary-metal mixtures of cadmium (Cd) and zinc (Zn) on Daphnia magna. The titration design was chosen to characterize the 21-d chronic effects of the binary-metal mixtures on survival, growth, reproduction, and metal accumulation in D. magna. Using this design, increasing concentrations of Zn (10, 20, 40, 80, 120, 160 and 200µg/L) were titrated against a constant concentration of 1.5µg/L Cd. The results demonstrated that Cd was highly toxic to D. magna...
April 21, 2017: Environmental Toxicology and Chemistry
https://www.readbyqxmd.com/read/28430292/failure-of-the-vascular-hypothesis-of-multiple-sclerosis-in-a-rat-model-of-chronic-cerebrospinal-venous-insufficiency
#9
Maha M A Zakaria, Shahira Y Mikhael, Azza K Abu Hussein, Rania A Salah El-Din, Hany W Abd El-Malak, Iman H Hewedi, Hany S Nadim
<i>Chronic cerebrospinal venous insufficiency (CCSVI) is a series of stenotic malformations in the cerebrospinal venous outflow routes, which is postulated to cause multiple sclerosis (MS). The hypotheses assumed that CCSVI leads to iron deposition which triggers inflammation and demyelination in MS. Invasive endovascular treatment of CCSVI was initiated based on the previous theory. The present study was designed to validate this hypothesis using a rat model of CCSVI. Bilateral jugular vein ligation (JVL) was performed on female albino rats (n = 15), and sham-operated rats (n = 15) were used as a control group...
2017: Folia Neuropathologica
https://www.readbyqxmd.com/read/28430182/evolution-of-choroidal-thickness-over-time-and-effect-of-early-and-sustained-therapy-in-birdshot-retinochoroiditis
#10
N Skvortsova, A Gasc, B Jeannin, C P Herbort
PurposeTo follow choroidal thickness (ChT) over time in birdshot retinochoroiditis (BRC) using enhanced depth imaging optical coherence tomography (EDI-OCT) and study the effect of early and sustained treatment on ChT.Patients and methodsEighteen patients were included and EDI-OCT measurements of ChT were analyzed retrospectively in five groups of patients with follow-up times ranging from 1 year to ≥15 years. The OCT images were evaluated and ChT was calculated under the foveola and 1500 μm temporal, nasal, superior, and inferior to the foveola...
April 21, 2017: Eye
https://www.readbyqxmd.com/read/28429938/high-resolution-accurate-mass-mass-spectrometry-enables-in-depth-characterization-of-in-vivo-biotransformations-for-intact-antibody-drug-conjugates
#11
Jintang He, Dian Su, Carl K Ng, Luna Liu, Shang-Fan Yu, Thomas H Pillow, Geoffrey Del Rosario, Martine Darwish, Byoung-Chul Lee, Rachana Ohri, Hongxiang Zhou, Xueji Wang, Jiawei Lu, Surinder Kaur, Keyang Xu
Antibody-drug conjugates (ADCs) represent a promising class of therapeutics for the targeted delivery of highly potent cytotoxic drugs to tumor cells to improve bioactivity while minimizing side effects. ADCs are composed of both small and large molecules, and therefore have complex molecular structures. In vivo biotransformations may further increase the complexity of ADCs, representing a unique challenge for bioanalytical assays. Quadrupole time-of-flight mass spectrometry (Q-TOF MS) with electrospray ionization has been widely used for characterization of intact ADCs...
April 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28429905/maintenance-vitamin-d3-dosage-requirements-in-chinese-women-with-post-menopausal-osteoporosis-living-in-the-tropics
#12
Yogeswari Venugopal, Sharifah F Wan Muhamad Hatta, Nurbazlin Musa, Siti Abdul Rahman, Jeyakantha Ratnasingam, Sharmila Sunita Paramasivam, Lee Ling Lim, Luqman Ibrahim, Karen Choong, Alexander Tb Tan, Karuthan Chinna, Siew Pheng Chan, Shireene R Vethakkan
BACKGROUND AND OBJECTIVES: Vitamin D3 (cholecalciferol) dose required to maintain sufficiency in non- Caucasian women with postmenopausal osteoporosis (PMO) inthe tropics has not been well studied. Some guidelines mandate 800-1000 IU vitamin D/day but the Endocrine Society (US) advocates 1500-2000 IU/day to maintain 25-hydroxyvitamin-D (25(OH)D) concentration at >75 nmol/L. We aimed to establish oral cholecalciferol dose required to maintain 25(OH)D concentration at >75 nmol/L in PMO Chinese Malaysian women, postulating lower dose requirements amongst light-skinned subjects in the tropics...
May 2017: Asia Pacific Journal of Clinical Nutrition
https://www.readbyqxmd.com/read/28429878/a-systematic-review-of-ultrasound-imaging-as-a-tool-for-evaluating-haemophilic-arthropathy-in-children-and-adults
#13
REVIEW
C C Ligocki, A Abadeh, K C Wang, T Adams-Webber, V S Blanchette, A S Doria
The purpose of this study was to semi-quantitatively assess the evidence on the value of ultrasound (US) for assessment of haemophilic arthropathy (HA) in children and adults based on the following questions: (1) Does early diagnosis of pathological findings, using available US techniques, impact the functional status of the joint? (2) Do current available US techniques have the ability to accurately detect pathological changes in target joints in haemophilic patients? (3) Does treatment (prophylaxis) improve US evidence of haemophilic arthropathy in children and adults? (4) Is there any association between various US scoring systems and other clinical/radiological constructs? Of the 6880 citations identified searching databases such as MEDLINE, Embase, CENTRAL and Web of Science, 20 articles investigating either the diagnostic accuracy of US and/or US scanning protocols and scoring systems for assessment of HA met the inclusion criteria for the study...
April 21, 2017: Haemophilia: the Official Journal of the World Federation of Hemophilia
https://www.readbyqxmd.com/read/28429817/investigation-of-bacterial-viability-from-incubated-saliva-by-application-of-flow-cytometry-and-hyphenated-separation-techniques
#14
Bogusław Buszewski, Maciej Milanowski, Tomasz Ligor, Paweł Pomastowski
The aim of the study was determination of bacterial viability in saliva samples and finding a correlation between microbiological and volatile profiles of saliva depending on incubation time. Bacteria colonizing healthy oral cavities were also identified. Twelve healthy adults donated unstimulated saliva samples. Flow cytometry, optical density measurements and colony-forming unit (CFU) counting method were employed for analyses of native and inoculated saliva after 0, 1, 2, 24 and 48 h of incubation. Volatile profiles were acquired using headspace-solid phase microextraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS)...
April 21, 2017: Electrophoresis
https://www.readbyqxmd.com/read/28429748/the-pre-argo-ocean-reanalyses-may-be-seriously-affected-by-the-spatial-coverage-of-moored-buoys
#15
S Sivareddy, Arya Paul, Travis Sluka, M Ravichandran, Eugenia Kalnay
Assimilation methods, meant to constrain divergence of model trajectory from reality using observations, do not exactly satisfy the physical laws governing the model state variables. This allows mismatches in the analysis in the vicinity of observation locations where the effect of assimilation is most prominent. These mismatches are usually mitigated either by the model dynamics in between the analysis cycles and/or by assimilation at the next analysis cycle. However, if the observations coverage is limited in space, as it was in the ocean before the Argo era, these mechanisms may be insufficient to dampen the mismatches, which we call shocks, and they may remain and grow...
April 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28429711/single-photon-test-of-hyper-complex-quantum-theories-using-a-metamaterial
#16
Lorenzo M Procopio, Lee A Rozema, Zi Jing Wong, Deny R Hamel, Kevin O'Brien, Xiang Zhang, Borivoje Dakić, Philip Walther
In standard quantum mechanics, complex numbers are used to describe the wavefunction. Although this has so far proven sufficient to predict experimental results, there is no theoretical reason to choose them over real numbers or generalizations of complex numbers, that is, hyper-complex numbers. Experiments performed to date have proven that real numbers are insufficient, but the need for hyper-complex numbers remains an open question. Here we experimentally probe hyper-complex quantum theories, studying one of their deviations from complex quantum theory: the non-commutativity of phases...
April 21, 2017: Nature Communications
https://www.readbyqxmd.com/read/28429558/is-there-a-role-or-target-value-for-nutritional-vitamin-d-in-chronic-kidney-disease
#17
Wai H Lim, Emma L Duncan
Vitamin D is important for bone health in the general population but the value of vitamin D supplementation, and the role of 25-hydroxyvitamin D independently of 1,25-dihydroxyvitmain D, in individuals with chronic kidney disease (CKD), particularly in those who require dialysis, remains uncertain. Supplementation may improve some biochemical parameters, such as reducing PTH levels in patients to CKD-stage 4 who have vitamin D deficiency; but it remains to be established whether the role of nutritional vitamin D in maintaining bone health in the general population can be extrapolated to the CKD population...
March 2017: Nephrology
https://www.readbyqxmd.com/read/28429459/nitric-oxide-donors-nitrates-l-arginine-or-nitric-oxide-synthase-inhibitors-for-acute-stroke
#18
REVIEW
Philip Mw Bath, Kailash Krishnan, Jason P Appleton
BACKGROUND: Nitric oxide (NO) has multiple effects that may be beneficial in acute stroke, including lowering blood pressure, and promoting reperfusion and cytoprotection. Some forms of nitric oxide synthase inhibition (NOS-I) may also be beneficial. However, high concentrations of NO are likely to be toxic to brain tissue. This is an update of a Cochrane review first published in 1998, and last updated in 2002. OBJECTIVES: To assess the safety and efficacy of NO donors, L-arginine, and NOS-I in people with acute stroke...
April 21, 2017: Cochrane Database of Systematic Reviews
https://www.readbyqxmd.com/read/28429032/obstructive-sleep-apnoea-and-type-2-diabetes-mellitus-are-they-connected
#19
Yingjuan Mok, Chee Wei Tan, Hang Siang Wong, Choon How How, Kah Leong Alvin Tan, Pon Poh Hsu
Obstructive sleep apnoea (OSA), a sleep-related breathing condition, is diagnosed based on a patient's apnoea-hypopnea index from a sleep study, and the presence or absence of symptoms. Diabetes mellitus (DM) and OSA share a significant common risk factor, obesity, with all three conditions contributing to the risk of developing cardiovascular diseases. The pathophysiological links between OSA and DM are still unclear, but intermittent hypoxia may be an important mechanism. More awareness of the possible link between OSA and DM is needed, given their increasing prevalence locally and worldwide...
April 2017: Singapore Medical Journal
https://www.readbyqxmd.com/read/28428905/deep-brain-stimulation-target-selection-in-an-advanced-parkinson-s-disease-patient-with-significant-tremor-and-comorbid-depression
#20
Amar S Patel
CLINICAL VIGNETTE: A 67-year-old female with advanced Parkinson's disease (PD), medically refractory tremor, and a history of significant depression presented for evaluation of deep brain stimulation (DBS) candidacy. CLINICAL DILEMMA: Traditionally, the subthalamic nucleus (STN) has been preferred over the globus pallidus interna (GPi) as a DBS target for PD patients with levodopa-responsive fluctuations in rigidity and akinesia, for whom tremor is also a significant source of impairment...
2017: Tremor and Other Hyperkinetic Movements
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