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1.
Molecules ; 28(21)2023 Oct 29.
Article in English | MEDLINE | ID: mdl-37959750

ABSTRACT

Echinacea purpurea (L.) Moench is a medicinal plant commonly used for the treatment of upper respiratory tract infections, the common cold, sore throat, migraine, colic, stomach cramps, and toothaches and the promotion of wound healing. Based on the known pharmacological properties of essential oils (EOs), we hypothesized that E. purpurea EOs may contribute to these medicinal properties. In this work, EOs from the flowers of E. purpurea were steam-distilled and analyzed by gas chromatography-mass spectrometry (GC-MS), GC with flame-ionization detection (GC-FID), and chiral GC-MS. The EOs were also evaluated for in vitro antimicrobial and innate immunomodulatory activity. About 87 compounds were identified in five samples of the steam-distilled E. purpurea EO. The major components of the E. purpurea EO were germacrene D (42.0 ± 4.61%), α-phellandrene (10.09 ± 1.59%), ß-caryophyllene (5.75 ± 1.72%), γ-curcumene (5.03 ± 1.96%), α-pinene (4.44 ± 1.78%), δ-cadinene (3.31 ± 0.61%), and ß-pinene (2.43 ± 0.98%). Eleven chiral compounds were identified in the E. purpurea EO, including α-pinene, sabinene, ß-pinene, α-phellandrene, limonene, ß-phellandrene, α-copaene, ß-elemene, ß-caryophyllene, germacrene D, and δ-cadinene. Analysis of E. purpurea EO antimicrobial activity showed that they inhibited the growth of several bacterial species, although the EO did not seem to be effective for Staphylococcus aureus. The E. purpurea EO and its major components induced intracellular calcium mobilization in human neutrophils. Additionally, pretreatment of human neutrophils with the E. purpurea EO or (+)-δ-cadinene suppressed agonist-induced neutrophil calcium mobilization and chemotaxis. Moreover, pharmacophore mapping studies predicted two potential MAPK targets for (+)-δ-cadinene. Our results are consistent with previous reports on the innate immunomodulatory activities of ß-caryophyllene, α-phellandrene, and germacrene D. Thus, this study identified δ-cadinene as a novel neutrophil agonist and suggests that δ-cadinene may contribute to the reported immunomodulatory activity of E. purpurea.


Subject(s)
Anti-Infective Agents , Echinacea , Oils, Volatile , Humans , Oils, Volatile/chemistry , Calcium , Steam , Gas Chromatography-Mass Spectrometry , Anti-Infective Agents/chemistry
2.
Curr Res Toxicol ; 4: 100107, 2023.
Article in English | MEDLINE | ID: mdl-37332622

ABSTRACT

A growing public health concern, chronic Diesel Exhaust Particle (DEP) exposure is a heavy risk factor for the development of neurodegenerative diseases like Alzheimer's (AD). Considered the brain's first line of defense, the Blood-Brain Barrier (BBB) and perivascular microglia work in tandem to protect the brain from circulating neurotoxic molecules like DEP. Importantly, there is a strong association between AD and BBB dysfunction, particularly in the Aß transporter and multidrug resistant pump, P-glycoprotein (P-gp). However, the response of this efflux transporter is not well understood in the context of environmental exposures, such as to DEP. Moreover, microglia are seldom included in in vitro BBB models, despite their significance in neurovascular health and disease. Therefore, the goal of this study was to evaluate the effect of acute (24 hr.) DEP exposure (2000 µg/ml) on P-gp expression and function, paracellular permeability, and inflammation profiles of the human in vitro BBB model (hCMEC/D3) with and without microglia (hMC3). Our results suggested that DEP exposure can decrease both the expression and function of P-gp in the BBB, and corroborated that DEP exposure impairs BBB integrity (i.e. increased permeability), a response that was significantly worsened by the influence of microglia in co-culture. Interestingly, DEP exposure seemed to produce atypical inflammation profiles and an unexpected general downregulation in inflammatory markers in both the monoculture and co-culture, which differentially expressed IL-1ß and GM-CSF. Interestingly, the microglia in co-culture did not appear to influence the response of the BBB, save in the permeability assay, where it worsened the BBB's response. Overall, our study is important because it is the first (to our knowledge) to investigate the effect of acute DEP exposure on P-gp in the in vitro human BBB, while also investigating the influence of microglia on the BBB's responses to this environmental chemical.

3.
Hum Factors ; : 187208231173263, 2023 May 01.
Article in English | MEDLINE | ID: mdl-37127397

ABSTRACT

OBJECTIVE: The present study investigated if the same users are vulnerable to phishing emails, scam text messages, and fake news headlines and if there are universal predictors of susceptibility for all three tasks. BACKGROUND: Theoretical research provides support for the notion that the same users likely fall for multiple forms of online deception. However, no research has directly compared susceptibility for various online deceptions (eg phishing, disinformation, scam text messages) within the same group of users. METHOD: Participants completed an online survey consisting of demographic questions, the Cognitive Reflection Test (ie impulsivity), and the Digital Literacy Scale, and classified 90 legitimate and deceptive emails, text messages, and news headlines. RESULTS: Results suggest that individuals who struggle to discriminate between deceptive and legitimate stimuli on one task experience similar difficulties on the other two tasks. Additionally, while lower levels of digital literacy and cognitive reflectiveness predicted poorer discrimination abilities across all three tasks, age did not predict performance. Interestingly, participants appeared to be the most susceptible to phishing emails. CONCLUSION: Overall, individuals who fall for one form of online deception appear to be more likely to fall for other forms of deception, and digital literacy and cognitive reflectiveness can predict widespread vulnerability to online deception. APPLICATION: Organizations may be able to identify potential vulnerabilities for a variety of online attacks by measuring digital literacy, cognitive reflectiveness, and performance in one online deception task. Additionally, training interventions may be the most needed for phishing emails.

4.
J Wildl Dis ; 58(4): 859-868, 2022 10 01.
Article in English | MEDLINE | ID: mdl-36288670

ABSTRACT

Steller's Jays (Cyanocitta stelleri) with swollen legs and feet resembling the signs of scaly leg have been commonly seen around Arcata, California, US. The clinical signs are thought to be caused by knemidokoptic mites, a group of parasites specialized on avian hosts. Between February 2019 and March 2020, we analyzed the long-term database of Steller's Jays collected by Humboldt State University for trends in the prevalence of signs of scaly leg, compared the gripping position in the feet of Steller's Jays with variable signs of this condition as an index of their ability to perch, identified the mites using a partial sequence of the cytochrome oxidase subunit I gene, and examined genetic distances between mites collected from different host species both sequenced in this study and from GenBank. Overall, 27% of jays recorded in the long-term database had shown signs of scaly leg. Jays with signs captured in this study had greater variability in and a reduced degree of contraction in the gripping position of their feet compared to jays without signs, suggesting that infestation may have an impact on the host's ability to perch. The cytochrome oxidase subunit I sequence (578 base pairs) from mites collected from Steller's Jays was compared to sequences from Knemidokoptes jamaicensis, Knemidokoptes derooi, and to unidentified Knemidokoptes spp. collected from different hosts. The mites from Steller's Jays were most closely related to Knemidokoptes jamaicensis but had a relatively high sequence divergence, 7.8%, supporting the possibility that the form infesting these jays may be an undescribed species.


Subject(s)
Electron Transport Complex IV , Animals , Electron Transport Complex IV/genetics
5.
Sci Rep ; 11(1): 24021, 2021 Dec 15.
Article in English | MEDLINE | ID: mdl-34912003

ABSTRACT

Phosphonium ionic liquids with orthoborate anions have been studied in terms of their interfacial film formation, both physisorbed and sacrificial from chemical breakdown, in sheared contacts of varying harshness. The halogen-free anion architecture was varied through (i) the heteronuclear ring size, (ii) the hybridisation of the constituent atoms, and (iii) the addition of aryl functionalities. Time of Flight-Secondary Ion Mass Spectrometry analysis revealed the extent of sacrificial tribofilm formation allowing the relative stability of the ionic liquids under tribological conditions to be determined and their breakdown mechanisms to be compared to simple thermal decomposition. Overall, ionic liquids outperformed reference oils as lubricants; in some cases, sacrificial films were formed (with anion breakdown a necessary precursor to phosphonium cation decomposition) while in other cases, a protective, self-assembly lubricant layer or hybrid film was formed. The salicylate-based anion was the most chemically stable and decomposed only slightly even under the harshest conditions. It was further found that surface topography influenced the degree of breakdown through enhanced material transport and replenishment. This work thus unveils the relationship between ionic liquid composition and structure, and the ensuing inter- and intra-molecular interactions and chemical stability, and demonstrates the intrinsic tuneability of an ionic liquid lubrication technology.

6.
Phys Rev E ; 103(2-1): 023212, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33736071

ABSTRACT

While the majority of fusion energy research is focused on magnetic confinement, there have been several alternative confinement methods aimed at the development of smaller and less expensive reactors. A number of these alternative reactors are based on a spherically convergent beam of recirculating ions and include designs such as inertial electrostatic confinement (IEC), multigrid IEC, and the periodically oscillating plasma sphere concept. Here, a fully time-dependent GPU-based Vlasov solver was developed in order to study these spherically convergent devices. This code solves the Vlasov equation for a spherically symmetric system using a finite-volume method with a modified flux to account for electrode transparency. The solver accounts for secondary electron emission, interactions between the charged particles, and collisional effects such as ionization and charge exchange. This code was used to investigate a system similar to the ion-injected device described by Hirsch (see [R. L. Hirsch, J. Appl. Phys. 38, 4522 (1967)10.1063/1.1709162]), who had reported a neutron production rate for deuterium-deuterium reactions in the range of 10^{6}to10^{7} neutrons per second, which was attributed to the formation of a virtual electrode structure near the center of the chamber. Attempts to reproduce this experiment [B. J. Egle, Ph.D. thesis, 2010] yielded similar fusion rates, though the majority of the reactions were found not to occur near the center of the chamber. The results of this Vlasov solver, considering only beam-beam and beam-background fusion reactions, show that beam-background reactions would be dominant in such an ion-injected device. This result is consistent with work by Baxter and Stuart, who proposed a simplified steady-state Boltzmann model. However, the result of both models are inconsistent with the experimental results, which indicate a higher neutron production rate, and an inverse pressure scaling trend. It is shown that the higher experimental rates may be explained by beam-target fusion between the ion beam and deuterium embedded on the inner surface of the cathode.

7.
Phys Chem Chem Phys ; 20(24): 16558-16567, 2018 Jun 20.
Article in English | MEDLINE | ID: mdl-29873357

ABSTRACT

Solvate ionic liquids are a relatively new class of liquids produced by combining a coordinating solvent with a salt. They have a variety of uses and their suitability for such depends upon the ratio of salt to coordinating solvent. This work investigates the Kamlet-Taft solvent parameters of, NMR chemical shifts of nuclei in, and thermoelectrochemistry of a selected set of solvate ionic liquids produced from glymes (methyl terminated oligomers of ethylene glycol) and lithium bis(trifluoromethylsulfonyl)imide at two different compositions. The aim is to improve the understanding of the interactions occurring in these ionic liquids to help select suitable solvate ionic liquids for future applications.

8.
Ann Dyslexia ; 68(2): 104-125, 2018 07.
Article in English | MEDLINE | ID: mdl-29691707

ABSTRACT

Research demonstrates that phonological skills provide the basis of reading acquisition and are a primary processing deficit in dyslexia. This consensus has led to the development of effective methods of reading intervention. However, a single phonological deficit is not sufficient to account for the heterogeneity of individuals with dyslexia, and recent research provides evidence that supports a multiple-deficit model of reading disorders. Two studies are presented that investigate (1) the prevalence of phonological and cognitive processing deficit profiles in children with significant reading disability and (2) the effects of those same phonological and cognitive processing skills on reading development in a sample of children that received treatment for dyslexia. The results are discussed in the context of implications for identification and an intervention approach that accommodates multiple deficits within a comprehensive skills-based reading program.


Subject(s)
Dyslexia/diagnosis , Dyslexia/psychology , Early Intervention, Educational/methods , Reading , Child , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/epidemiology , Cognitive Dysfunction/psychology , Dyslexia/epidemiology , Early Intervention, Educational/trends , Female , Humans , Male , Phonetics
9.
Ann Dyslexia ; 67(3): 383-400, 2017 Oct.
Article in English | MEDLINE | ID: mdl-29134479

ABSTRACT

Thirty years ago in this journal, Aylett Royall Cox reported on the development of Alphabetic Phonics, a revision of the existing Orton Gillingham treatment for children with dyslexia. This paper continues that discussion and reports on the evolution of that curriculum as it is represented in a comprehensive dyslexia treatment program informed by intervention research. The paper describes the curriculum and reports data from a hospital-based learning disabilities clinic that provides qualified support for treatment efficacy and the value of added comprehension instruction. The results are then discussed in the context of current and future issues in dyslexia intervention.


Subject(s)
Curriculum/trends , Dyslexia/therapy , Early Intervention, Educational/methods , Early Intervention, Educational/trends , Reading , Adolescent , Child , Cohort Studies , Comprehension/physiology , Dyslexia/psychology , Female , Humans , Male
10.
Psychopharmacol Bull ; 47(4): 59-63, 2017 09 15.
Article in English | MEDLINE | ID: mdl-28936010

ABSTRACT

Dextromethorphan (3-methoxy-N-methylmorphinan), also known as "DXM" and "the poor man's PCP," is a synthetically produced drug that is available in more than 140 over-the-counter cough and cold preparations. Dextromethorphan (DXM) has overtaken codeine as the most widely used cough suppressant due to its availability, efficacy, and safety profile at directed doses. However, DXM is subject to abuse. When consumed at inappropriately high doses (over 1500 mg/day), DXM can induce a state of psychosis characterized by Phencyclidine (PCP)-like psychological symptoms, including delusions, hallucinations, and paranoia. We report a noteworthy case of severe dextromethorphan use disorder with dextromethorphan-induced psychotic disorder in a 40-year-old Caucasian female, whose symptoms remitted only following treatment with a combination of an antipsychotic and mood stabilizer. While some states have begun to limit the quantity of DXM sold or restrict sales to individuals over 18-years of age, there is currently no federal ban or restriction on DXM. Abuse of DXM, a readily available and typically inexpensive agent that is not detected on a standard urine drug screen, may be an under-recognized cause of substance-induced psychosis. It is imperative that clinicians are aware of the potential psychiatric sequelae of recreational DXM use.


Subject(s)
Antitussive Agents/adverse effects , Dextromethorphan/adverse effects , Psychoses, Substance-Induced/etiology , Substance-Related Disorders/complications , Adult , Antimanic Agents/administration & dosage , Antipsychotic Agents/administration & dosage , Antitussive Agents/administration & dosage , Dextromethorphan/administration & dosage , Female , Humans , Nonprescription Drugs , Psychoses, Substance-Induced/drug therapy
11.
Phys Chem Chem Phys ; 19(35): 24255-24263, 2017 Sep 13.
Article in English | MEDLINE | ID: mdl-28848948

ABSTRACT

Entropic changes inherent within a redox process typically result in significant temperature sensitivity. This can be utilised positively or can be a detrimental process. This study has investigated the thermoelectrochemical properties (temperature-dependant electrochemistry) of the ferrocenium|ferrocene redox couple in an ionic liquid, and in particular the effect of covalently tethering this redox couple to fixed positive or negative charges. As such, the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide was employed to dissolve ferrocene, as well as cationic-tethered ferrocene (the 1-ethyl-3-(methylferrocenyl)imidazolium cation) and anionic-tethered ferrocene (the ferrocenylsulfonyl(trifluoromethylsulfonyl)imide anion). These systems were characterised in terms of their voltammetry (apparent formal potentials, diffusion coefficients and electron transfer rate constants) and thermoelectrochemistry (temperature coefficients of the cell potential or 'Seebeck coefficients', short circuit current densities and power density outputs). The oxidised cationic species behaved like a dicationic species and was thus 6-fold more effective at converting waste thermal energy to electrical power within a thermoelectrochemical cell than unmodified ferrocene. This was almost exclusively due to a significant boost in the Seebeck coefficient of this redox couple. Conversely, the oxidised anionic species was formally a zwitterion, but this zwitterionic species behaved thermodynamically like a neutral species. The inverted entropic change upon going from ferrocene to anion-tethered ferrocene allowed development of a largely temperature-insensitive reference potential based upon a mixture of acetylferrocene and ferricenyl(iii)sulfonyl(trifluoromethylsulfonyl)imide.

12.
Phys Chem Chem Phys ; 18(30): 20768-77, 2016 Jul 27.
Article in English | MEDLINE | ID: mdl-27412130

ABSTRACT

Thermoelectrochemistry offers a simple, scalable technique for direct conversion of waste heat into useful electricity. Here the thermoelectrochemical properties of lithium-glyme solvate ionic liquids, as well as their dilute electrolyte analogues, have been investigated using mixtures of tetraglyme (G4, tetraethylene glycol dimethyl ether) and lithium bis(trifluoromethylsulfonyl)imide (Li[NTf2]). The thermoelectrochemical process is entropically-driven by release of the glyme from the lithium-glyme complex cation, due to electrodeposition of lithium metal at the hotter lithium electrode with concomitant electrodissolution at the cooler lithium electrode. The optimum ratio for thermochemical electricity generation is not the solvate ionic liquid (equimolar mixture of Li[NTf2] and glyme), but rather one Li[NTf2] to four G4, due to the mixtures relatively high ionic conductivity and good apparent Seebeck coefficient (+1.4 mV K(-1)). Determination of the lithium-glyme mixture thermal conductivity enabled full assessment of the Figure of Merit (ZT), and the efficiency relative to the Carnot efficiency to be determined. As the lithium electrodeposits are porous, alternating the temperature gradient results in a system that actually improves with repeated use.

13.
Dev Neuropsychol ; 41(3): 145-61, 2016 04.
Article in English | MEDLINE | ID: mdl-27028067

ABSTRACT

An object rhyming task that does not require text reading and is suitable for younger children was used to predict gains in word level reading skills following an intensive 2-year reading intervention for children with developmental dyslexia. The task evoked activation in bilateral inferior frontal regions. Growth in untimed pseudoword reading was associated with increased pre-intervention activation of the left inferior frontal gyrus, and growth in timed word reading was associated with pre-intervention activation of the left and right inferior frontal gyri. These analyses help identify pre-intervention factors that facilitate reading skill improvements in children with developmental dyslexia.


Subject(s)
Dyslexia/therapy , Functional Neuroimaging , Learning/physiology , Reading , Brain/physiology , Brain/physiopathology , Brain Mapping , Child , Dyslexia/diagnosis , Dyslexia/physiopathology , Frontal Lobe/physiopathology , Humans , Magnetic Resonance Imaging
14.
Anim Cogn ; 18(1): 95-8, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25001401

ABSTRACT

Steller's jays (Cyanocitta stelleri) often store food and return to retrieve the stored items at a later time. Between caching and consumption, stored food has the potential to be pilfered by conspecific observers. We investigated whether individually marked Steller's jays in suburban neighborhoods of Arcata, California, USA, adjusted cache concealment effort when in the presence of conspecifics. Both male and female jays traveled the shortest distances to cache when alone, traveled further when a mate was present, and traveled furthest when neighbors from adjacent territories were present. These results suggest that Steller's jays recognize and respond to social contexts when concealing food items.


Subject(s)
Feeding Behavior/psychology , Passeriformes , Social Behavior , Animals , Female , Food , Male
15.
PLoS One ; 9(8): e105257, 2014.
Article in English | MEDLINE | ID: mdl-25148039

ABSTRACT

Genetic analysis of avian mating systems has revealed that more than 70% of monogamous species show incidence of offspring parentage that does not match the social partner. Extra-pair parentage (EPP) has been linked to a variety of factors, including size and symmetry of ornamental traits, coloration, resource availability, and local conspecific density. We examined how ornamental plumage traits of individual Steller's jays (Cyanocitta stelleri) and territory characteristics influence genetic fidelity of socially monogamous pairs. We used seven highly polymorphic microsatellite markers to assign paternity to 79 offspring, and identified 12 (15.2%) as extra-pair young (EPY). Steller's jays with extra-pair young had significantly lower values of feather brightness and hue, indicating more ultraviolet-blue shifted coloration, and nested in closer proximity to the forest edge than Steller's jays with no detected EPY. Body size, crest height, asymmetry of ornamental crest stripes, as well as vegetative composition of territories and their proximity to supplemental feeders appeared to have little relationship to EPP. These results indicate that extra-pair parentage plays a role in the evolution of secondary sexual characteristics in both sexes, and suggest local density and availability of resources may influence Steller's jay mating dynamics.


Subject(s)
Birds/physiology , Mating Preference, Animal , Animals , Female , Male , Microsatellite Repeats , Reproduction/genetics , Selection, Genetic
16.
Ecol Appl ; 22(6): 1743-61, 2012 Sep.
Article in English | MEDLINE | ID: mdl-23092012

ABSTRACT

Managers need to predict how animals will respond to habitat redistributions caused by climate change. Our objective was to model the effects of sea level rise on total eelgrass (Zostera marina) habitat area and on the amount of that area that is accessible to Brant geese (Branta bernicla), specialist grazers of eelgrass. Digital elevation models were developed for seven estuaries from Alaska, Washington, California (USA), and Mexico. Scenarios of future total eelgrass area were derived from combinations of estuarine specific sediment and tectonic rates (i.e., bottom change rate) with three rates of eustatic sea level rise (ESLR). Percentages of total eelgrass areas that were accessible to foraging Brant were determined for December when the birds overwinter at more southerly sites and in April as they move north to sites where they build body stores on their way to nesting areas in Alaska. The modeling showed that accessible eelgrass area could be lower than total area due to how daytime low-tide height, eelgrass shoot length, and the upper elevation of eelgrass determined Brant-reaching depth. Projections of future eelgrass area indicated that present-day ESLR (2.8 mm/yr) and bottom change rates should sustain the current pattern of estuarine use by Brant except in Morro Bay, where use should decrease because eelgrass is being ejected from this estuary by a positive bottom change rate. Higher ESLR rates (6.3 and 12.7 mm/yr) should result in less Brant use of estuaries at the northern and southern ends of the flyway, particularly during the winter, but more use of mid-latitude estuaries. The capacity of mid-latitude estuaries to function as Brant feeding refugia, or for these estuaries and Izembek Lagoon to provide drift rather than attached leaves, is eventually limited by the decrease in total eelgrass area, which is a result of a light extinction affect on the eelgrass, or the habitat being pushed out of the estuary by positive tectonic rates. Management responses are limited to the increase or decrease of sediment supply and the relocation of levees to allow for upslope migration of eelgrass habitat.


Subject(s)
Feeding Behavior/physiology , Geese/physiology , Zosteraceae/physiology , Animals , Demography , Ecosystem , Environmental Monitoring , Global Warming , Models, Biological , Pacific Ocean , Time Factors
17.
Neurocase ; 17(5): 425-39, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21590585

ABSTRACT

Individuals with dyslexia often demonstrate bilateral inferior frontal lobe activation while performing basic reading tasks. To investigate these findings, functional connectivity analyses were conducted on fMRI data collected from children with dyslexia, who did and did not respond well to treatment, and from non-impaired readers. Analysis of active and resting-state fMRI data across 15 participants revealed functional connections between the inferior frontal regions in non-impaired readers and treatment responders, but not in treatment non-responders. Analyses incorporating DTI data revealed associations with anterior corpus callosum structures. These results suggest that bilateral frontal functional connectivity is normative and may facilitate treatment response.


Subject(s)
Dyslexia/physiopathology , Frontal Lobe/anatomy & histology , Frontal Lobe/physiology , Neural Pathways/physiology , Reading , Adolescent , Child , Female , Frontal Lobe/physiopathology , Humans , Magnetic Resonance Imaging/methods , Male , Neural Pathways/anatomy & histology , Neuropsychological Tests
18.
J Environ Radioact ; 102(3): 235-43, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21216054

ABSTRACT

A survey of radioactivity in groundwater (110 sites) was conducted as a precursor to providing a baseline of radiation exposure in rural and remote communities in Queensland, Australia, that may be impacted upon by exposure pathways associated with the supply, treatment, use and wastewater treatment of the resource. Radionuclides in groundwater, including ²³8U, ²²6Ra, ²²²Rn, ²²8Ra, ²²4Ra and 4°K were measured and found to contain activity concentration levels of up to 0.71 BqL⁻¹, 0.96 BqL⁻¹, 108 BqL⁻¹, 2.8 BqL⁻¹, 0.11 BqL⁻¹ and 0.19 BqL⁻¹ respectively. Activity concentration results were classified by aquifer lithology, showing correlation between increased radium isotope concentration and basic volcanic host rock. The groundwater survey and mapping results were further assessed using an investigation assessment tool to identify seven remote or rural communities that may require additional radiation dose assessment beyond that attributed to ingestion of potable water.


Subject(s)
Radiation Monitoring/methods , Water Supply/analysis , Australia , Radium/analysis , Radon/analysis , Uranium/analysis
19.
Neuropsychologia ; 47(8-9): 1972-7, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19428430

ABSTRACT

Diffusion Tensor Imaging (DTI) was used to investigate the relationship between white matter and reading abilities in reading impaired and non-reading impaired children. Seventeen children (7 non-reading impaired, 10 reading impaired) participated in this study. DTI was performed with 2mm isotropic resolution to cover the entire brain along 30 noncollinear directions. Voxelwise analyses were conducted on data processed through Tract Based Spatial Statistics (TBSS). The data replicated previous results seen across multiple studies and extended findings to include measures of both real word and pseudoword decoding. Negative correlations were observed in the left posterior corpus callosum between fractional anisotropy (FA) values and both measures of decoding. Positive correlations between FA values and real word and pseudoword decoding were observed in the left superior corona radiata. This extension of findings regarding correlations between the corona radiata and reading skills suggests an important direction for future research into the neurological substrates of reading.


Subject(s)
Brain Mapping , Brain/physiopathology , Dyslexia/pathology , Reading , Adolescent , Anisotropy , Child , Diffusion Magnetic Resonance Imaging/methods , Dyslexia/physiopathology , Female , Functional Laterality , Humans , Image Processing, Computer-Assisted/methods , Language , Male , Neuropsychological Tests , Recognition, Psychology/physiology , Statistics as Topic
20.
J Am Acad Audiol ; 19(1): 33-45, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18637408

ABSTRACT

Functional magnetic resonance images were acquired while children with and without dyslexia identified incongruous words embedded within fairy tale segments in a quasidichotic listening task. All children produced greater activation in the left hemisphere than in the right hemisphere during the binaural separation listening task. Children with dyslexia, who had a higher incidence of a dichotic left ear deficit from prescanning behavioral tests, produced fewer hits and more misses than control children while monitoring their left ears in the scanner. Control children produced stronger left hemispheric activation for ipsilateral left ear input than right hemispheric activation for ipsilateral right ear input, but ipsilateral activation patterns in children with dyslexia were symmetrical. Children with dyslexia who monitored their right ears first produced the lowest left hemispheric activation overall, suggesting that priming of the right ear may have inhibited the ability of children with a left ear deficit to adequately identify target words presented toward their left ears while in the scanner.


Subject(s)
Auditory Cortex/physiology , Dichotic Listening Tests , Dyslexia/physiopathology , Magnetic Resonance Imaging , Sound Localization/physiology , Acoustic Stimulation , Auditory Cortex/blood supply , Child , Dominance, Cerebral/physiology , Dyslexia/diagnosis , Humans , Reading
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