Integrating major ion geochemistry, stable isotopes (O, H) and radioactive isotopes (Rn, C, Cl, H) to understand the interaction between catchment waters and an intermittent river.

Determining the locations and sources of baseflow and the transit times of water is important for understanding catchment behaviour and functioning. Major ion geochemistry, stable isotopes (O and H), and radioisotopes (Rn, H, C, and Cl) were used to investigate the sources and transit times of water in the upper catchment of the intermittent Avoca River in southeast Australia. Rn activities and Cl concentrations implied the presence of baseflow inputs and the distribution was mainly controlled by local topography.

Reference conditions and threshold values for nitrate-nitrogen in New Zealand groundwaters.

Management of groundwater quality is assisted by an understanding of reference conditions, which describe the concentration ranges expected for key substances in the absence of human impact. This study evaluates reference conditions for NO-N in New Zealand groundwater based on three complementary methods: hierarchical cluster analysis, relationships to groundwater age, and regression against a measure of land-use impact. The three methods result in very similar national-scale estimates of reference conditions for NO-N concentration in oxic, minimally impacted groundwater, with the 80th, 90th and 95th percentiles found to be 1.

Topographic Mapping of the Primary Sensory Cortex Using Intraoperative Optical Imaging and Tactile Irritation.

The determination of exact tumor boundaries within eloquent brain regions is essential to maximize the extent of resection. Recent studies showed that intraoperative optical imaging (IOI) combined with median nerve stimulation is a helpful tool for visualization of the primary sensory cortex (PSC). In this technical note, we describe a novel approach of using IOI with painless tactile irritation to demonstrate the feasibility of topographic mapping of different body regions within the PSC.

Characterization of cortical hemodynamic changes following sensory, visual, and speech activation by intraoperative optical imaging utilizing phase-based evaluation methods.

Alterations within cerebral hemodynamics are the intrinsic signal source for a wide variety of neuroimaging techniques. Stimulation of specific functions leads due to neurovascular coupling, to changes in regional cerebral blood flow, oxygenation and volume. In this study, we investigated the temporal characteristics of cortical hemodynamic responses following electrical, tactile, visual, and speech activation for different stimulation paradigms using Intraoperative Optical Imaging (IOI).

Molecular background of the undesired odor of polypropylene materials and insights into the sources of key odorants.

Screening the volatiles isolated from a standard polypropylene material consisting of a polypropylene homopolymer, the filler talcum, and a mixture of antioxidants, for odor-active compounds by application of an aroma extract dilution analysis revealed 30 odorants with flavor dilution factors ranging from 1 to 64. Eighteen odor-active compounds were subsequently quantitated by gas chromatography-mass spectrometry using stable isotopically substituted odorants as internal standards, and their odor activity values (OAVs) were calculated as ratios of the concentrations to the odor threshold values. Five odorants showed OAVs ≥1, among which were hex-1-en-3-one (OAV 12), butanoic acid (OAV 3), as well as 4-methylphenol, butan-1-ol, and 2-tert-butylphenol (all OAV 1).

The legacy and drivers of groundwater nutrients and pesticides in an agriculturally impacted Quaternary aquifer system.

Nutrient and pesticide pollution are among the major threats to groundwater quality in agriculturally impacted aquifers. Understanding their legacy effects and drivers are important to protect aquifers from exposures to contamination. However, the complexities of groundwater flowpaths make it difficult to predict the time-scales of groundwater flow and contaminant transport.

Workflow and hardware for intraoperative hyperspectral data acquisition in neurosurgery.

To prevent further brain tumour growth, malignant tissue should be removed as completely as possible in neurosurgical operations. Therefore, differentiation between tumour and brain tissue as well as detecting functional areas is very important. Hyperspectral imaging (HSI) can be used to get spatial information about brain tissue types and characteristics in a quasi-continuous reflection spectrum.

Mapping of language and motor function during awake neurosurgery with intraoperative optical imaging.

Intraoperative optical imaging (IOI) is a marker-free, contactless, and noninvasive imaging technique that is able to visualize metabolic changes of the brain surface following neuronal activation. Although it has been used in the past mainly for the identification of functional brain areas under general anesthesia, the authors investigated the potential of the method during awake surgery. Measurements were performed in 10 patients who underwent resection of lesions within or adjacent to cortical language or motor sites.

Evaluating anthropogenic and environmental tritium effects using precipitation and Hokkaido snowpack at selected coastal locations in Asia.

Tritium dating requires a good understanding of the tritium and water inputs into hydrologic systems, including their main trends due to latitudinal, seasonal and altitudinal effects. Although tritium reached ambient levels at the end of the 20th century, tritium released from nuclear facilities and bomb tests since then has the potential to confound use of tritium for age dating. We therefore collected precipitation and snowpack samples for tritium analysis to confirm that tritium levels in Japanese precipitation had not exceeded ambient levels following the North Korean nuclear tests in January 6th 2016 and September 3rd 2017.

The influence of unsaturated zone drainage status on denitrification and the redox succession in shallow groundwater.

Since nitrate is a major agricultural freshwater contaminant, denitrification is the environmentally most important step in the ecological succession of redox processes that can occur in groundwater. Understanding where and to what extent denitrification occurs would enable spatially differentiated land management and regulation. We investigated in a dairy farming catchment in the North Island of New Zealand the influence of the unsaturated zone's drainage status on the redox succession in shallow groundwater along a well transect spanning drainage conditions from well drained to very poorly drained.

Modulation of Cosmogenic Tritium in Meteoric Precipitation by the 11-year Cycle of Solar Magnetic Field Activity.

The relationship between the atmospheric concentration of cosmogenic isotopes, the change of solar activity and hence secondary neutron flux has already been proven. The temporal atmospheric variation of the most studied cosmogenic isotopes shows a significant anti-correlation with solar cycles. However, since artificial tritium input to the atmosphere due to nuclear-weapon tests masked the expected variations of tritium production rate by three orders of magnitude, the natural variation of tritium in meteoric precipitation has not previously been detected.

Vertical stratification of redox conditions, denitrification and recharge in shallow groundwater on a volcanic hillslope containing relict organic matter.

Natural denitrification in groundwater systems has been recognised as an ecosystem service that reduces the impact of agriculturally-derived nitrate inputs to surface waters. Identification of this ecosystem service within the landscape would permit spatially differentiated land management and legislation. However, spatial variation in groundwater redox conditions poses a significant challenge to such a concept.

Intraoperative optical imaging of metabolic changes after direct cortical stimulation - a clinical tool for guidance during tumor resection?

Brain tumor resection is even today one of the most challenging disciplines in neurosurgery. The current state of the art for the identification of tumor tissue during the surgical procedure comprises a wide variety of different tools, each with its own limitations and drawbacks. In this paper, we present a novel approach, the use of optical imaging in connection with direct electrical cortical stimulation (DCS), for identification of impaired tumor tissue and functional intact normal brain tissue under intraoperative conditions.

Assessing the recharge of a coastal aquifer using physical observations, tritium, groundwater chemistry and modelling.

Assessing recharge is critical to understanding groundwater and preventing pollution. Here, we investigate recharge in an Australian coastal aquifer using a combination of physical, modelling and geochemical techniques. We assess whether recharge may occur through a pervasive layer of floodplain muds that was initially hypothesized to be impermeable.

Thermodynamic and hydrochemical controls on CH4 in a coal seam gas and overlying alluvial aquifer: new insights into CH4 origins.

Using a comprehensive data set (dissolved CH4, δ(13)C-CH4, δ(2)H-CH4, δ(13)C-DIC, δ(37)Cl, δ(2)H-H2O, δ(18)O-H2O, Na, K, Ca, Mg, HCO3, Cl, Br, SO4, NO3 and DO), in combination with a novel application of isometric log ratios, this study describes hydrochemical and thermodynamic controls on dissolved CH4 from a coal seam gas reservoir and an alluvial aquifer in the Condamine catchment, eastern Surat/north-western Clarence-Moreton basins, Australia. δ(13)C-CH4 data in the gas reservoir (-58‰ to -49‰) and shallow coal measures underlying the alluvium (-80‰ to -65‰) are distinct. CO2 reduction is the dominant methanogenic pathway in all aquifers, and it is controlled by SO4 concentrations and competition for reactants such as H2.

Assessing the eligibility of a non-invasive continuous blood pressure measurement technique for application during total intravenous anaesthesia.

Objective: To assess the eligibility for replacement of invasive blood pressure as measured "within" the arterial vessel (IBP) with non-invasive continuous arterial blood pressure (cNIP) monitoring during total intravenous anaesthesia (TIVA), the ability of cNiP to track fast blood pressure changes needs to be quantified. A new method of statistical data analysis is developed for this purpose.

Methods: In a pilot study on patients undergoing neurosurgical anaesthesia, mean arterial pressure MAPIBP measured with IBP was compared to MAPCNP measured by the CNAP Monitor 500 in ten patients (age: 63±13 a).

[Concentration enhancement for retaining daily living competence in dementia].

Background: Dementia is characterized by reduced memory and concentration abilities leading to a decrease in activities of daily living. Various studies have shown that various forms of physical exercise have a positive therapeutic effect at an early stage of dementia.

Objective: In the present study the effects of an exercise-based Brain-Gym concept on the concentration and routine daily competences were evaluated in dementia patients.

Improved visualization of intracranial vessels with intraoperative coregistration of rotational digital subtraction angiography and intraoperative 3D ultrasound.

Introduction: Ultrasound can visualize and update the vessel status in real time during cerebral vascular surgery. We studied the depiction of parent vessels and aneurysms with a high-resolution 3D intraoperative ultrasound imaging system during aneurysm clipping using rotational digital subtraction angiography as a reference.

Methods: We analyzed 3D intraoperative ultrasound in 39 patients with cerebral aneurysms to visualize the aneurysm intraoperatively and the nearby vascular tree before and after clipping.

Intraoperative optical imaging of intrinsic signals: a reliable method for visualizing stimulated functional brain areas during surgery.

Object: Intraoperative optical imaging (IOI) is an experimental technique used for visualizing functional brain areas after surgical exposure of the cerebral cortex. This technique identifies areas of local changes in blood volume and oxygenation caused by stimulation of specific brain functions. The authors describe a new IOI method, including innovative data analysis, that can facilitate intraoperative functional imaging on a routine basis.

Autostereoscopic 3D visualization and image processing system for neurosurgery.

A demonstrator system for planning neurosurgical procedures was developed based on commercial hardware and software. The system combines an easy-to-use environment for surgical planning with high-end visualization and the opportunity to analyze data sets for research purposes. The demonstrator system is based on the software AMIRA.

Quantitative fluorescence angiography for neurosurgical interventions.

Present methods for quantitative measurement of cerebral perfusion during neurosurgical operations require additional technology for measurement, data acquisition, and processing. This study used conventional fluorescence video angiography--as an established method to visualize blood flow in brain vessels--enhanced by a quantifying perfusion software tool. For these purposes, the fluorescence dye indocyanine green is given intravenously, and after activation by a near-infrared light source the fluorescence signal is recorded.

Evaluation of the clinical practicability of intraoperative optical imaging comparing three different camera setups.

Intraoperative optical imaging (IOI) is a method to visualize functional activated brain areas during brain surgery using a camera system connected to a standard operating microscope. Three different high-resolution camera systems (Hamamatsu EB-CCD C7190-13W, Hamamatsu C4742-96-12G04, and Zeiss AxioCam MRm) have been evaluated for suitability to detect activated brain areas by detecting stimulation-dependent blood volume changes in the somatosensory cerebral cortex after median nerve stimulation. The image quality of the camera systems was evaluated in 14 patients with tumors around the somatosensory cortex.