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Cognitive impairment and decline in cognitively normal older adults with high amyloid-β: A meta-analysis
No full textAbstractIntroductionThis meta-analysis aimed to characterize the nature and magnitude of amyloid (Aβ)-related cognitive impairment and decline in cognitively normal (CN) older individuals.MethodMEDLINE Ovid was searched from 2012 to June 2016 for studies reporting relationships between cerebrospinal fluid or positron emission tomography (PET) Aβ levels and cognitive impairment (cross-sectional) and decline (longitudinal) in CN older adults. Neuropsychological data were classified into domains of episodic memory, executive function, working memory, processing speed, visuospatial function, semantic memory, and global cognition. Type of Aβ measure, how Aβ burden was analyzed, inclusion of control variables, and clinical criteria used to exclude participants, were considered as moderators. Random-effects models were used for analyses with effect sizes expressed as Cohen's d.ResultsA total of 38 studies met inclusion criteria contributing 30 cross-sectional (N = 5005) and 14 longitudinal (N = 2584) samples. Aβ-related cognitive impairment was observed for global cognition (d = 0.32), visuospatial function (d = 0.25), processing speed (d = 0.18), episodic memory, and executive function (both d's = 0.15), with decline observed for global cognition (d = 0.30), semantic memory (d = 0.28), visuospatial function (d = 0.25), and episodic memory (d = 0.24). Aβ-related impairment was moderated by age, amyloid measure, type of analysis, and inclusion of control variables and decline moderated by amyloid measure, type of analysis, inclusion of control variables, and exclusion criteria used.DiscussionCN older adults with high Aβ show a small general cognitive impairment and small to moderate decline in episodic memory, visuospatial function, semantic memory, and global cognition
Bacterial selection for biological control of plant disease: criterion determination and validation
No full textAbstractThis study aimed to evaluate the biocontrol potential of bacteria isolated from different plant species and soils. The production of compounds related to phytopathogen biocontrol and/or promotion of plant growth in bacterial isolates was evaluated by measuring the production of antimicrobial compounds (ammonia and antibiosis) and hydrolytic enzymes (amylases, lipases, proteases, and chitinases) and phosphate solubilization. Of the 1219 bacterial isolates, 92% produced one or more of the eight compounds evaluated, but only 1% of the isolates produced all the compounds. Proteolytic activity was most frequently observed among the bacterial isolates. Among the compounds which often determine the success of biocontrol, 43% produced compounds which inhibit mycelial growth of Monilinia fructicola, but only 11% hydrolyzed chitin. Bacteria from different plant species (rhizosphere or phylloplane) exhibited differences in the ability to produce the compounds evaluated. Most bacterial isolates with biocontrol potential were isolated from rhizospheric soil. The most efficient bacteria (producing at least five compounds related to phytopathogen biocontrol and/or plant growth), 86 in total, were evaluated for their biocontrol potential by observing their ability to kill juvenile Mesocriconema xenoplax. Thus, we clearly observed that bacteria that produced more compounds related to phytopathogen biocontrol and/or plant growth had a higher efficacy for nematode biocontrol, which validated the selection strategy used
Electrochemical ozone sensors: A miniaturised alternative for ozone measurements in laboratory experiments and air-quality monitoring
No full textAbstractOzone (O3) measurements are a critical component of air quality management and many atmospheric chemistry laboratory experiments. Conventional ozone monitoring devices based on UV absorption are relatively cumbersome and expensive, and have a relative high power consumption that limits their use to fixed sites. In this study electrochemical O3 sensors (OXB421, Alphasense) were used in a miniaturised O3 measurement device combined with LabJack and Labview data acquisition (DAQ). The device required a power supply of 5V direct current (VDC) with a total power consumption of approximately 5W. Total weight was less than 0.5kg, low enough for portable in situ field deployment. The electrochemical O3 sensors produced a voltage signal positively proportional to O3 concentrations over the range of 5ppb–10ppm. There was excellent agreement between the performances of two O3 sensors with a good linear coefficient (R2=0.9995). The influences of relative humidity (RH) and gas sample flow rate on sensor calibrations and sensitivities have been investigated separately. Coincident calibration curves indicate that sensor performances were almost identical even at different RHs and flow rates after a re-zeroing process to offset the sensor baseline drifts. Rapid RH changes (∼20%/min) generate significant and instant changes in sensor signal, and the sensors consistently take up to 40min to recover their original values after such a rapid RH change. In contrast, slow RH changes (∼0.1%/min) had little effect on sensor response. To test the performance of the miniaturised O3 device for real-world applications, the O3 sensors were employed for (i) laboratory experiments to measure O3 loss by seawater uptake and (ii) air quality monitoring over an 18-day period. It was found that ozone uptake by seawater was linear to the volume of linoleic acid on a sea surface microlayer and the calculated uptake coefficients based on sensor measurements were close to those from previous studies. For the 18-day period of air quality monitoring the corrected data from the O3 sensor was in a good agreement with those obtained by reference UV O3 analyser with an r2 of 0.83 (n=8502). The novelty of this study is that the electrochemical O3 sensor was comprehensively investigated in O3 measurements in both laboratory and ambient air quality monitoring and it can to be a miniaturised alternative for conventional O3 monitoring devices due to its low cost, low power-consumption, portable and simple-conduction properties
Synthesis of 2,4,5-triarylated imidazoles via three-component domino reaction under catalyst-free conditions
No full textAbstractA one-pot synthesis of 2,4,5-triarylated imidazoles via three-component domino reaction of 2,2-dibromo-1,2-diarylethanones, ammonium acetate, and aryl aldehydes under catalyst-free conditions is developed. The scope of this reaction is studied. A possible mechanism is proposed based on experimental results
The 5-HT6 receptor antagonist idalopirdine potentiates the effects of donepezil on gamma oscillations in the frontal cortex of anesthetized and awake rats without affecting sleep-wake architecture
No full textAbstractThe 5-HT6 receptor is a promising target for cognitive disorders, in particular for Alzheimer's disease (AD). The high affinity and selective 5-HT6 receptor antagonist idalopirdine (Lu AE58054) is currently in development for mild-moderate AD as adjunct therapy to acetylcholinesterase inhibitors (AChEIs). We studied the effects of idalopirdine alone and in combination with the AChEI donepezil on cortical function using two in vivo electrophysiological methods. Neuronal network oscillations in the frontal cortex were measured during electrical stimulation of the brainstem nucleus pontis oralis (nPO) in the anesthetized rat and by an electroencephalogram (EEG) in the awake, freely moving rat. In conjunction with the EEG study, we investigated the effects of idalopirdine and donepezil on sleep-wake architecture using telemetric polysomnography. Idalopirdine (2 mg/kg i.v.) increased gamma power in the medial prefrontal cortex (mPFC) during nPO stimulation. Donepezil (0.3 and 1 mg/kg i.v.) also increased cortical gamma power and pretreatment with idalopirdine (2 mg/kg i.v.) potentiated and prolonged the effects of donepezil. Similarly, donepezil (1 and 3 mg/kg s.c.) dose-dependently increased frontal cortical gamma power in the freely moving rat and pretreatment with idalopirdine (10 mg/kg p.o.) augmented the effect of donepezil 1 mg/kg. Analysis of the sleep-wake architecture showed that donepezil (1 and 3 mg/kg s.c.) dose-dependently delayed sleep onset and decreased the time spent in both REM and non REM sleep stages. In contrast, idalopirdine (10 mg/kg p.o.) did not affect sleep-wake architecture nor the effects of donepezil. In summary, we show that idalopirdine potentiates the effects of donepezil on frontal cortical gamma oscillations, a pharmacodynamic biomarker associated with cognition, without modifying the effects of donepezil on sleep. The increased cortical excitability may contribute to the procognitive effects of idalopirdine in donepezil-treated AD patients
Approximate solutions for solving the Klein–Gordon and sine-Gordon equations
No full textAbstractIn this paper, we practiced relatively new, analytical method known as the variational homotopy perturbation method for solving Klein–Gordon and sine-Gordon equations. To present the present method’s effectiveness many examples are given. In this study, we compare numerical results with the exact solutions, the Adomian decomposition method (ADM), the variational iteration method (VIM), homotopy perturbation method (HPM), modified Adomian decomposition method (MADM), and differential transform method (DTM). The results reveal that the VHPM is very effective
Structures and mechanisms of CRISPR RNA-guided effector nucleases
No full textIn the prokaryotic CRISPR-Cas adaptive immune systems, a CRISPR RNA (crRNA) assembles with multiple or single Cas proteins to form crRNA ribonucleoprotein (crRNP) effector complexes, responsible for the destruction of invading genetic elements. Although the mechanisms of target recognition and cleavage by the crRNP effectors are quite diverse among the different types of CRISPR-Cas systems, the basic action principles of these crRNA-guided effector nucleases are highly conserved. In all of the crRNP effectors, the repeat-derived invariant and spacer-derived variable segments of the crRNA are recognized by the Cas protein(s) in sequence-dependent and sequence-independent manners, respectively, with the spacer-derived guide segment available for base pairing with target nucleic acids. Over the past few years, intensive studies have provided an atomic view of the crRNA-guided target interference mechanisms in different types of CRISPR-Cas systems. Here, we review the recent progress toward structural and mechanistic understanding of the diverse crRNP effector nucleases
Fetal growth and air pollution - A study on ultrasound and birth measures
No full textAbstractAir pollution has been suggested to affect fetal growth, but more data is needed to assess the timing of exposure effects by using ultrasound measures. It is also important to study effects in low exposure areas to assess eventual thresholds of effects.The MAPSS (Maternal Air Pollution in Southern Sweden) cohort consists of linked registry data for around 48,000 pregnancies from an ultrasound database, birth registry and exposure data based on residential addresses. Measures of air pollution exposure were obtained through dispersion modelling with input data from an emissions database (NOx) with high resolution (100–500m grids). Air pollution effects were assessed with linear regressions for the following endpoints; biparietal diameter, femur length, abdominal diameter and estimated fetal weight measured in late pregnancy and birth weight and head circumference measured at birth.We estimated negative effects for NOx; in the adjusted analyses the decrease of abdominal diameter and femur length were −0.10 (−0.17, −0.03) and −0.13 (−0.17, −0.01)mm, respectively, per 10µg/m3 increment of NOx. We also estimated an effect of NOx-exposures on birth weight by reducing birth weight by 9g per 10µg/m3 increment of NOx.We estimated small but statistically significant effects of air pollution on late fetal and birth size and reduced fetal growth late in pregnancy in a geographic area with levels below current WHO air quality guidelines
Integrated control of white rot disease on beans caused by Sclerotinia sclerotiorum using Contans® and reduced fungicides application
No full textAbstractThis study was conducted to determine the compatibility of Contans® (Coniothyrium minitans) with fungicides against Sclerotinia sclerotiorum. Results showed that both Contans® and Topsin® significantly reduced the disease incidence caused by S. sclerotiorum by 90% and 95% survival plants, respectively when they were individually applied and compared to control. While, soil application of Contans® and Sumisclex mixture was the most effective in suppressing the white rot disease incidence that produced 100% survival plants, application of C. minitans combined with the reduced doses of fungicides would be advantageous in saving labor cost, thus increasing production efficiency of bean
Geographic Variation and US County Characteristics Associated With Rapid Kidney Function Decline
No full textIntroductionGeographic variation in the prevalence of chronic kidney disease and incidence of end-stage renal disease has been previously reported. However, the geographic epidemiology of rapid estimated glomerular filtration rate (eGFR) decline has not been examined.MethodsWe built a longitudinal cohort of 2,107,570 US veterans to characterize the spatial epidemiology of and examine the associations between US county characteristics and rapid eGFR decline.ResultsThere were 169,029 (8.02%) with rapid eGFR decline (defined as eGFR slope < –5 ml/min per 1.73 m2/year). The prevalence of rapid eGFR decline adjusted for age, race, gender, diabetes, and hypertension varied by county from 4.10%–6.72% in the lowest prevalence quintile to 8.41%–22.04% in the highest prevalence quintile (P for heterogeneity < 0.001). Examination of adjusted prevalence showed substantial geographic variation in those with and without diabetes and those with and without hypertension (P for heterogeneity < 0.001). Cohort participants had higher odds of rapid eGFR decline when living in counties with unfavorable characteristics in domains including health outcomes (odds ratio [OR] = 1.15; confidence interval [CI] = 1.09–1.22), health behaviors (OR = 1.08; CI = 1.03–1.13), clinical care (OR = 1.11; CI = 1.06–1.16), socioeconomic conditions (OR = 1.15; CI = 1.09–1.22), and physical environment (OR = 1.15; CI = 1.01–1.20); living in counties with high percentage of minorities and immigrants was associated with rapid eGFR decline (OR = 1.25; CI = 1.20–1.31). Spatial analyses suggest the presence of cluster of counties with high prevalence of rapid eGFR decline.DiscussionOur findings show substantial geographic variation in rapid eGFR decline among US veterans; the variation persists in analyses stratified by diabetes and hypertension status; results show associations between US county characteristics in domains capturing health, socioeconomic, environmental, and diversity conditions, and rapid eGFR decline