Interactions between functional networks in Parkinson's disease mild cognitive impairment.

The study of mild cognitive impairment (MCI) is critical to understand the underlying processes of cognitive decline in Parkinson's disease (PD). Functional connectivity (FC) disruptions in PD-MCI patients have been observed in several networks. However, the functional and cognitive changes associated with the disruptions observed in these networks are still unclear. Using a data-driven methodology based on independent component analysis, we examined differences in FC RSNs among PD-MCI, PD cognitively normal patients (PD-CN) and healthy controls (HC) and studied their associations with cognitive and motor variables. A significant difference was found between PD-MCI vs PD-CN and HC in a FC-trait comprising sensorimotor (SMN), dorsal attention (DAN), ventral attention (VAN) and frontoparietal (FPN) networks. This FC-trait was associated with working memory, memory and the UPDRS motor scale. SMN involvement in verbal memory recall may be related with the FC-trait correlation with memory deficits. Meanwhile, working memory impairment may be reflected in the DAN, VAN and FPN interconnectivity disruptions with the SMN. Furthermore, interactions between the SMN and the DAN, VAN and FPN network reflect the intertwined decline of motor and cognitive abilities in PD-MCI. Our findings suggest that the memory impairments observed in PD-MCI are associated with reduced FC within the SMN and between SMN and attention networks.

Evaluation of sample processing methods to improve the detection of Bacillus anthracis in difficult sample matrices.

Large area sampling approaches have been developed and implemented by the US Environmental Protection Agency (EPA) to increase sample sizes, and potentially representativeness, in outdoor urban environments (e.g., concrete, asphalt, grass/landscaping). These sampling approaches could be implemented in response to an outdoor biological contamination incident or bioterrorism attack to determine the extent of contamination and for clearance following remediation. However, sample collection over large areas often contains an extensive amount of co-collected debris and native background microorganisms that interfere with the detection of biological threat agents. Sample processing methods that utilize basic laboratory equipment amenable to field deployment were selected and applied to turbid aqueous samples (TAS) to reduce particulates and native environmental organisms prior to culture and rapid viability-polymerase chain reaction (RV-PCR) analytical methods. Bacillus anthracis Sterne (BaS) spores were spiked into TAS collected by soil grab, wet vacuum collection from an outdoor concrete surface, or storm water runoff from an urban parking lot. The implementation of a sample processing method improved the sensitivity of culture and RV-PCR analytical methods for BaS spore detection in soil and wet vacuum TAS samples compared to baseline (minimal to no field processing methods applied). For soil, when the processing method was applied, samples with 15 colony forming units (CFU)/ml (60 CFU/g) and 1.5 CFU/mL (6 CFU/g) BaS spore load were detected using culture and RV-PCR, respectively. Most notably, the processing methods greatly improved the sensitivity of the RV-PCR analytical method for the wet vacuum TAS from no detection at the 1500 CFU/mL BaS spore load level to as low as 1.5 CFU/mL BaS spore load.

Evaluation of a modified rapid viability-polymerase chain reaction method for Bacillus atrophaeus spores in water matrices.

A rapid method that provides information on the viability of organisms is needed to protect public health and ensure that remediation efforts following a release of a biological agent are effective. The rapid viability-polymerase chain reaction (RV-PCR) method combines broth culture and molecular methods to provide results on whether viable organisms are present in less than 15 h. In this study, a modified RV-PCR (mRV-PCR) method was compared to a membrane-filtration culture method for the detection of viable Bacillus spores in water matrices. Samples included small and large volumes of chlorine and non­chlorine treated tap water. Large volume water samples (up to 100 L), were processed by ultrafiltration using a semi-automated waterborne pathogen concentrator, followed by centrifugation as a secondary concentration technique. The concentrated samples were analyzed by mRV-PCR and culture methods. The overall agreement between the mRV-PCR and culture methods when seed concentrations were greater than 10 spores per sample volume analyzed was 96%. The total time from the start of sample processing to the final sample result for the mRV-PCR method was decreased by approximately 2 h, in comparison to the previously published RV-PCR method because of the incorporation of shorter, more efficient primary and secondary concentration steps and a shorter DNA extraction technique. Overall, this study confirmed that RV-PCR is a promising approach for identifying viable Bacillus spores in small- and large-volume water samples and for producing results in less time than traditional culture methods.

The use of hollow fiber dialysis filters operated in axial flow mode for recovery of microorganisms in large volume water samples with high loadings of particulate matter.

Ultrafiltration concentration of microorganisms in large volume water samples containing high levels of particulate matter was evaluated in a proof of concept study. The organisms tested were Bacillus atrophaeus subspecies globigii spores and MS2 bacteriophage. To produce the large volume samples, fresh water sediment of a known particle size was added to 51 l of tap water. Five different concentrations of particulate matter were studied: 0, 50, 100, 150 and 750 mg solids/l. The concentration procedure used a dialysis filter as the ultrafilter configured for axial flow, either with or without recirculation. The target number of organisms spiked was 1 × 105 of either spores or bacteriophage per 51 l. After concentration, the filters were dissected to retrieve the fibers which were then washed using surfactant solution which was then analyzed for the target organisms. Two washes of the filter fibers were carried out sequentially. For axial flow with recirculation, the first wash produced statistically greater recovery of B. globigii spores (26-40% of spike) compared to the second wash (8-13% of spike). Total recovery (the sum of the recoveries for the first and second washes) ranged from 35 to 53%. Recovery increased as the solids level increased from 0 to 150 mg solids/l. Recovery at the 100 and 150 mg solids/L loadings was statistically higher at the P < .05 level than recovery at 0 mg/L solids. At 150 mg solids/L, axial flow without recirculation (dead end) yielded lower recovery than axial flow with recirculation, however the difference was not significant at the P < .05 level. Recovery of B. globigii at 750 mg solids/L averaged 38% using dead end axial flow. The average recovery of MS2 bacteriophage was 45% at a solids concentration of 150 mg/L using axial flow with recirculation. PhiX174 and Phi8 were also studied, however these bacteriophage appeared to be inactivated in the matrix of concentrated wash water. One hundred liters of water containing 750 mg solids/L was concentrated using dead end axial flow, and only minimal problems with filter clogging were observed. Results described herein suggest axial flow ultrafiltration is an effective concentration method for microorganisms in water containing high levels of particulate matter.

Prediction of central neuropathic pain in spinal cord injury based on EEG classifier.

OBJECTIVES: To create a classifier based on electroencephalography (EEG) to identify spinal cord injured (SCI) participants at risk of developing central neuropathic pain (CNP) by comparing them with patients who had already developed pain and with able bodied controls. METHODS: Multichannel EEG was recorded in the relaxed eyes opened and eyes closed states in 10 able bodied participants and 31 subacute SCI participants (11 with CNP, 10 without NP and 10 who later developed pain within 6 months of the EEG recording). Up to nine EEG band power features were classified using linear and non-linear classifiers. RESULTS: Three classifiers (artificial neural networks ANN, support vector machine SVM and linear discriminant analysis LDA) achieved similar average performances, higher than 85% on a full set of features identifying patients at risk of developing pain and achieved comparably high performance classifying between other groups. With only 10 channels, LDA and ANN achieved 86% and 83% accuracy respectively, identifying patients at risk of developing CNP. CONCLUSION: Transferable learning classifier can detect patients at risk of developing CNP. EEG markers of pain appear before its physical symptoms. Simple and complex classifiers have comparable performance. SIGNIFICANCE: Identify patients to receive prophylaxic treatment of CNP.

Inactivation of Bacillus Spores in Wash Waters Using Dilute Chlorine Bleach Solutions at Different Temperatures and pH Levels.

Inactivation of Bacillus globigii spores in wash water was studied to simulate chlorine inactivation of Bacillus anthracis spores in water generated during biological cleanups. Eight waters were studied, with six containing detergent. Chlorine levels were approximately 3000 mg/L. Results across different waters showed decreasing inactivation with increasing pH. Inactivation did not appear to be influenced by chemical oxygen demand, suspended solids, turbidity, or dissolved solids. Inactivation efficacy was expressed as the time calculated to yield 6 log10 inactivation at 3000 mg NaOCl/L. This time ranged from 5 to 51 minutes at ~21 °C and from 11 to 209 minutes at ~5 °C. For one wash water, inactivation was conducted when there was no pH adjustment, and when the pH was buffered at 7 and 8. Inactivation in these buffered waters was rapid, but inactivation decreased sharply at a pH above ~9.3.

Adsorption of Malathion onto Copper and Iron Surfaces Relevant to Water Infrastructure.

This study investigated the adsorption of malathion to copper and iron surfaces including microspheres and pipe specimens similar to those in drinking water infrastructure. The solid phase concentration of malathion on the virgin and used copper pipe specimens was generally between 0.2 - 1 mg/g. The adsorption capacity for copper and iron microspheres were greater than those of the pipe specimens because of their higher surface area-to-volume ratios. Copper materials adsorbed more malathion than comparable iron materials. XPS analysis of copper and iron surfaces revealed peaks at 164 eV (S 2p) and 135 eV (P 2p), which suggests that malathion chemically bonded to the surfaces of the specimens. Metal oxides likely formed stable bonds with phosphorus through pi conjugation. These findings are the first to show that malathion can chemically adhere to copper and iron pipe materials. This insight is critical for understanding the decontamination strategies needed for water networks.

A Method Detection Limit for Bacillus anthracis Spores in Water Using an Automated Waterborne Pathogen Concentrator.

The method detection limit (MDL, 99% chance of detecting a positive result in a single replicate), as per the United States Code of Federal Regulations, was determined for a protocol using an ultrafiltration based automated waterborne pathogen concentration device. Bacillus anthracis Sterne strain spores were seeded at low levels into 100 L reagent water samples. Suspect colonies were confirmed through morphological, chemical, and genetic tests. Samples of 100 L (n=14) of reagent water were seeded with five B. anthracis CFUs each. To confirm the estimated detection limit, a second set (n=19) of 100 L reagent water samples were seeded at a higher level (7 CFUs). The second estimate of the MDL could not be pooled with the first, due to significant difference in variance. A third trial (n=7) seeded with 10 CFUs produced an estimate of the MDL that could be pooled with the higher previous estimate. Another trial consisting of eight 100 L samples of tap water were seeded with approximately 7 CFUs. Recovery in these samples was not significantly different from the pooled MDL. Theoretically a concentration of 4.6 spores/100 L would be required for detection 95% of the time, based on a Poisson distribution. The calculated pooled MDL, based on experimental data was approximately 6 B. anthracis CFU/100 L (95% confidence interval 4.8 to 8.4). Detection at this level was achieved in municipal water samples.

Comparison of filters for concentrating microbial indicators and pathogens in lake water samples.

Bacterial indicators are used to indicate increased health risk from pathogens and to make beach closure and advisory decisions; however, beaches are seldom monitored for the pathogens themselves. Studies of sources and types of pathogens at beaches are needed to improve estimates of swimming-associated health risks. It would be advantageous and cost-effective, especially for studies conducted on a regional scale, to use a method that can simultaneously filter and concentrate all classes of pathogens from the large volumes of water needed to detect pathogens. In seven recovery experiments, stock cultures of viruses and protozoa were seeded into 10-liter lake water samples, and concentrations of naturally occurring bacterial indicators were used to determine recoveries. For the five filtration methods tested, the highest median recoveries were as follows: glass wool for adenovirus (4.7%); NanoCeram for enterovirus (14.5%) and MS2 coliphage (84%); continuous-flow centrifugation (CFC) plus Virocap (CFC+ViroCap) for Escherichia coli (68.3%) and Cryptosporidium (54%); automatic ultrafiltration (UF) for norovirus GII (2.4%); and dead-end UF for Enterococcus faecalis (80.5%), avian influenza virus (0.02%), and Giardia (57%). In evaluating filter performance in terms of both recovery and variability, the automatic UF resulted in the highest recovery while maintaining low variability for all nine microorganisms. The automatic UF was used to demonstrate that filtration can be scaled up to field deployment and the collection of 200-liter lake water samples.