Radiological comparison of a FDNPP waste storage site during and after construction.

The clean-up effort that is occurring across the region affected by the 2011 Fukushima Daiichi Nuclear Power Plant accident is unprecedented in its magnitude as well as the financial cost that will eventually result. A major component of this remediation is the stripping of large volumes of material from the land surface, depositing this into large waste storage bags before placing these 1 cubic meter bags into specially constructed stores across Fukushima Prefecture. In this work, using an unmanned aerial vehicle to perform radiological surveys of a site, the time-resolved distribution of contamination during the construction of one of these waste storage sites was assessed. The results indicated that radioactive material was progressively leaching from the store into the surrounding environment. A subsequent survey of the site conducted eight months later revealed that in response to this survey and remedial actions, the contamination issue once existing on this site had been successfully resolved. Such results highlight the potential of low-altitude unmanned aerial systems to easily and rapidly assess site-wide changes over time - providing highly-visual results; therefore, permitting for prompt remedial actions to be undertaken as required. Use of UAV radiation mapping and airborne photogrammetry to produce a time-resolved assessment of remediation efforts within a Fukushima temporary storage facility.

Validation of a novel radiation mapping platform for the reduction of operator-induced shielding effects.

With extensive remediation currently ongoing because of the Fukushima Daiichi Nuclear Power Plant accident, there exists the even greater need to provide a system with which the distribution of radiation (specifically radiocesium) can be rapidly determined across extensive areas, yet at high (metre or sub-metre) spatial resolutions. Although a range of potential survey methods have been utilised (e.g. fixed-wing aircraft, helicopter, vehicular and more-recently unmanned aerial vehicle) to characterise the distribution of radiological contamination, ground-based (on-foot) methods that employ human operatives to traverse sites of interest remains one of the primary methods through which to perform routine radiological site surveys. Through the application of a newly-developed platform carried as a backpack-contained unit, it was possible to map sites at twice the rate previously possible-reducing not only the exposure time of the operator to ionising radiation, but also dramatically reducing the level of radiation attenuation (introduced by the operator) onto the detector. Like magnetometry platforms used during geological ore prospecting, this system was similarly boom-based, extending sideways away from the central operator. While conventional radiological survey platforms require a correction be performed on the data to account for the carrier (aircraft, vehicle or human) interception and attenuation incident radiation-this system is shown to not require such a retrospective correction.

Source identification of uranium-containing materials at mine legacy sites in Portugal.

Whilst prior nuclear forensic studies have focused on identifying signatures to distinguish between different uranium deposit types, this paper focuses on providing a scientific basis for source identification of materials from different uranium mine sites within a single region, which can then be potentially used within nuclear forensics. A number of different tools, including gamma spectrometry, alpha spectrometry, mineralogy and major and minor elemental analysis, have been utilised to determine the provenance of uranium mineral samples collected at eight mine sites, located within three different uranium provinces, in Portugal. A radiation survey was initially conducted by foot and/or unmanned aerial vehicle at each site to assist sample collection. The results from each mine site were then compared to determine if individual mine sites could be distinguished based on characteristic elemental and isotopic signatures. Gamma and alpha spectrometry were used to differentiate between samples from different sites and also give an indication of past milling and mining activities. Ore samples from the different mine sites were found to be very similar in terms of gangue and uranium mineralogy. However, rarer minerals or specific impurity elements, such as calcium and copper, did permit some separation of the sites examined. In addition, classification rates using linear discriminant analysis were comparable to those in the literature.

Application of airborne photogrammetry for the visualisation and assessment of contamination migration arising from a Fukushima waste storage facility.

Airborne systems such as lightweight and highly portable unmanned aerial vehicles (UAVs) are becoming increasingly widespread in both academia and industry - with an ever-increasing range of applications, including (but not limited to), air quality sampling, wildlife monitoring and land-use mapping. In this work, high-resolution airborne photogrammetry obtained using a multi-rotor system operating at low survey altitudes, is combined with ground-based radiation mapping data acquired at an interim storage facility for wastes removed as part of the large-scale Fukushima clean-up program. The investigation aimed to assess the extent to which the remediation program at a specific site has contained the stored contaminants, as well as present a new methodology for rapidly surveying radiological sites globally. From the three-dimensional rendering of the site of interest, it was possible to not only generate a powerful graphic confirming the elevated radiological intensity existing at the location of the waste bags, but also to also illustrate the downslope movement of contamination due to species leakage from the large 1m3 storage bags. The entire survey took less than 1 h to perform, and was subsequently post-processed using graphical information software to obtain the renderings. The conclusions within this study not only highlight the usefulness of incorporating three-dimensional renderings within radiation mapping protocols, but also conclude that current methods of monitoring these storage facilities in the long term could be improved through the integration of UAVs within the standard protocol.

High-resolution radiation mapping to investigate FDNPP derived contaminant migration.

As of March 2016, five years will have passed since the earthquake and ensuing tsunami that crippled the Fukushima Daiichi Nuclear Power Plant on Japan's eastern coast, resulting in the explosive release of significant quantities of radioactive material. Over this period, significant time and resource has been expended on both the study of the contamination as well as its remediation from the affected environments. Presented in this work is a high-spatial resolution foot-based radiation mapping study using gamma-spectrometry at a site in the contaminated Iitate Village; conducted at different times, seventeen months apart. The specific site selected for this work was one in which consistent uniform agriculture was observed across its entire extent. From these surveys, obtained from along the main northwest trending line of the fallout plume, it was possible to determine the rate of reduction in the levels of contamination around the site attributable to the natural decay of the radiocesium, remediation efforts or material transport. Results from the work suggest that neither the natural decay of radiocesium nor its downward migration through the soil horizons were responsible for the decline in measured activity levels across the site, with the mobilisation of contaminant species likely adhered to soil particulate and the subsequent fluvial transport responsible for the measurable reduction in activity. This transport of contaminant via fluvial methods has already well studied implications for the input of contaminant material entering the neighbouring Pacific Ocean, as well as the deposition of material along rivers within previously decontaminated areas.

Low altitude unmanned aerial vehicle for characterising remediation effectiveness following the FDNPP accident.

On the 12th of March 2011, The Great Tohoku Earthquake occurred 70 km off the eastern coast of Japan, generating a large 14 m high tsunami. The ensuing catalogue of events over the succeeding 12 d resulted in the release of considerable quantities of radioactive material into the environment. Important to the large-scale remediation of the affected areas is the accurate and high spatial resolution characterisation of contamination, including the verification of decontaminated areas. To enable this, a low altitude unmanned aerial vehicle equipped with a lightweight gamma-spectrometer and height normalisation system was used to produce sub-meter resolution maps of contamination. This system provided a valuable method to examine both contaminated and remediated areas rapidly, whilst greatly reducing the dose received by the operator, typically in localities formerly inaccessible to ground-based survey methods. The characterisation of three sites within Fukushima Prefecture is presented; one remediated (and a site of much previous attention), one un-remediated and a third having been subjected to an alternative method to reduce emitted radiation dose.

The use of unmanned aerial systems for the mapping of legacy uranium mines.

Historical mining of uranium mineral veins within Cornwall, England, has resulted in a significant amount of legacy radiological contamination spread across numerous long disused mining sites. Factors including the poorly documented and aged condition of these sites as well as the highly localised nature of radioactivity limit the success of traditional survey methods. A newly developed terrain-independent unmanned aerial system [UAS] carrying an integrated gamma radiation mapping unit was used for the radiological characterisation of a single legacy mining site. Using this instrument to produce high-spatial-resolution maps, it was possible to determine the radiologically contaminated land areas and to rapidly identify and quantify the degree of contamination and its isotopic nature. The instrument was demonstrated to be a viable tool for the characterisation of similar sites worldwide.

Impairment of adipose tissue in Prader-Willi syndrome rescued by growth hormone treatment.

BACKGROUND: Prader-Willi syndrome (PWS) results from abnormalities in the genomic imprinting process leading to hypothalamic dysfunction with an alteration of growth hormone (GH) secretion. PWS is associated with early morbid obesity and short stature which can be efficiently improved with GH treatment. OBJECTIVES: Our aims were to highlight adipose tissue structural and functional impairments in children with PWS and to study the modifications of those parameters on GH treatment. SUBJECTS AND METHODS: Plasma samples and adipose tissue biopsies were obtained from 23 research centers in France coordinated by the reference center for PWS in Toulouse, France. Lean controls (n=33), non-syndromic obese (n=53), untreated (n=26) and GH-treated PWS (n=43) children were enrolled in the study. Adipose tissue biopsies were obtained during scheduled surgeries from 15 lean control, 7 untreated and 8 GH-treated PWS children. RESULTS: Children with PWS displayed higher insulin sensitivity as shown by reduced glycemia, insulinemia and HOMA-IR compared with non-syndromic obese children. In contrast, plasma inflammatory cytokines such as TNF-α, MCP-1 and IL-8 were increased in PWS. Analysis of biopsies compared with control children revealed decreased progenitor cell content in the stromal vascular fraction of adipose tissue and an impairment of lipolytic response to ß-adrenergic agonist in PWS adipocytes. Interestingly, both of these alterations in PWS seem to be ameliorated on GH treatment. CONCLUSION: Herein, we report adipose tissue dysfunctions in children with PWS which may be partially restored by GH treatment.

Liver X Receptor: an oxysterol sensor and a major player in the control of lipogenesis.

De novo fatty acid biosynthesis is also called lipogenesis. It is a metabolic pathway that provides the cells with fatty acids required for major cellular processes such as energy storage, membrane structures and lipid signaling. In this article we will review the role of the Liver X Receptors (LXRs), nuclear receptors that sense oxysterols, in the transcriptional regulation of genes involved in lipogenesis.

Histopathologic findings in chickens experimentally infected with Gallibacterium anatis by nasal instillation.

Histologic findings in chickens experimentally infected by nasal instillation with reference strains of Gallibacterium anatis are described. No clinical signs were observed in experimentally infected birds; however, sequential histologic examinations of trachea, lung, air sacs, and liver revealed lesions in all infected chickens. Our observations suggest that the reference strains of G. anatis used in this experiment are capable of causing primary infection in chickens. Despite that the experimental birds were inoculated by intranasal route, lesions were detected in the liver, suggesting a probable bacteremia. Because several degrees of severity were established in histopathologic lesions, probable variations in virulence, among the experimental strains, also are discussed.

A minimal model for hepatic fatty acid balance during fasting: application to PPAR alpha-deficient mice.

The purpose of this study is to identify the hierarchy of importance amongst pathways involved in fatty acid (FA) metabolism and their regulators in the control of hepatic FA composition. A modeling approach was applied to experimental data obtained during fasting in PPARalpha knockout (KO) mice and wild-type mice. A step-by-step procedure was used in which a very simple model was completed by additional pathways until the model fitted correctly the measured quantities of FA in the liver. The resulting model included FA uptake by the liver, FA oxidation, elongation and desaturation of FA, which were found active in both genotypes during fasting. From the model analysis we concluded that PPARalpha had a strong effect on FA oxidation. There were no indications that this effect changes during the fasting period, and it was thus considered to be constant. In PPARalpha KO mice, FA uptake was identified as the main pathway responsible for FA variation in the liver. The models showed that FA were oxidized at a constant and small rate, whereas desaturation of FA also occurred during fasting. The latter observation was rather unexpected, but was confirmed experimentally by the measurement of delta-6-desaturase mRNA using real-time quantitative PCR (QPCR). These results confirm that mathematical models can be a useful tool in identifying new biological hypotheses and nutritional routes in metabolism.

Effect of sward dry matter digestibility on methane production, ruminal fermentation, and microbial populations of zero-grazed beef cattle.

Increasing the digestibility of pasture for grazing ruminants has been proposed as a low-cost practical means of reducing ruminant CH(4) emissions. At high feed intake levels, the proportion of energy lost as CH(4) decreases as the digestibility of the diet increases. Therefore, improving forage digestibility may improve productivity as DM and energy intake are increased. A zero-grazing experiment was conducted to determine the effect of sward DM digestibility (DMD) on DMI, CH(4) emissions, and indices of rumen fermentation of beef animals. Twelve Charolais-cross heifers were assigned to 1 of 2 treatments, with 6 heifers per dietary treatment. Additionally, 4 cannulated Aberdeen Angus-cross steers were randomly allocated to each of these 2 treatments in a crossover design. Dietary treatments consisted of swards managed to produce (i) high digestibility pasture (high DMD) or (ii) pasture with less digestibility (low DMD), both offered for ad libitum intake. All animals were zero-grazed and offered freshly cut herbage twice daily. In vitro DMD values for the high and low DMD swards were 816 and 706 g/kg of DM. Heifers offered the high DMD grass had greater (P < 0.001) daily DMI of 7.66 kg compared with 5.38 kg for those offered the low DMD grass. Heifers offered the high DMD grass had greater (P = 0.003) daily CH(4) production (193 g of CH(4)/d) than those offered the low DMD grass (138 g of CH(4)/d). However, when corrected for DMI, digestible DMI, or ingested gross energy, there was no difference (P > 0.05) in CH(4) production between dietary treatments. For cannulated steers, intake tended (P = 0.06) to be greater for the high DMD grass (5.56 vs. 4.27 kg of DM/d), but rumen protozoa (4.95 x 10(4)/mL; P = 0.62); rumen ammonia (34 mg of N/L; P = 0.24); rumen total VFA (103 mM; P = 0.58), and rumen pH (6.8; P = 0.43) did not differ between treatments. There was no difference in total bacteria numbers, relative expression of the mcrA gene, and numbers of cycles to threshold for fungi when determined using quantitative PCR between dietary treatments with mean values of 73.0 ng/microL, 0.958, and 21.75 C(T), respectively. Results of this study demonstrate that there was no difference in CH(4) production when corrected for intake or rumen fermentation variables of beef cattle offered a high or low digestibility sward.

Noninvasive stimulation of human corticospinal axons innervating leg muscles.

These studies investigated whether a single electrical stimulus over the thoracic spine activates corticospinal axons projecting to human leg muscles. Transcranial magnetic stimulation of the motor cortex and electrical stimulation over the thoracic spine were paired at seven interstimulus intervals, and surface electromyographic responses were recorded from rectus femoris, tibialis anterior, and soleus. The interstimulus intervals (ISIs) were set so that the first descending volley evoked by cortical stimulation had not arrived at (positive ISIs), was at the same level as (0 ISI) or had passed (negative ISIs) the site of activation of descending axons by the thoracic stimulation at the moment of its delivery. Compared with the responses to motor cortical stimulation alone, responses to paired stimuli were larger at negative ISIs but reduced at positive ISIs in all three leg muscles. This depression of responses at positive ISIs is consistent with an occlusive interaction in which an antidromic volley evoked by the thoracic stimulation collides with descending volleys evoked by cortical stimulation. The cortical and spinal stimuli activate some of the same corticospinal axons. Thus it is possible to examine the excitability of lower limb motoneuron pools to corticospinal inputs without the confounding effects of changes occurring within the motor cortex.

Group III and IV muscle afferents differentially affect the motor cortex and motoneurones in humans.

The influence of group III and IV muscle afferents on human motor pathways is poorly understood. We used experimental muscle pain to investigate their effects at cortical and spinal levels. In two studies, electromyographic (EMG) responses in elbow flexors and extensors to stimulation of the motor cortex (MEPs) and corticospinal tract (CMEPs) were evoked before, during, and after infusion of hypertonic saline into biceps brachii to evoke deep pain. In study 1, MEPs and CMEPs were evoked in relaxed muscles and during contractions to a constant elbow flexion force. In study 2, responses were evoked during elbow flexion and extension to a constant level of biceps or triceps brachii EMG, respectively. During pain, the size of CMEPs in relaxed biceps and triceps increased (by approximately 47% and approximately 56%, respectively; P < 0.05). MEPs did not change with pain, but relative to CMEPs, they decreased in biceps (by approximately 34%) and triceps (by approximately 43%; P < 0.05). During flexion with constant force, ongoing background EMG and MEPs decreased for biceps during pain (by approximately 14% and 15%; P < 0.05). During flexion with a constant EMG level, CMEPs in biceps and triceps increased during pain (by approximately 30% and approximately 26%, respectively; P < 0.05) and relative to CMEPs, MEPs decreased for both muscles (by approximately 20% and approximately 17%; P < 0.05). For extension, CMEPs in triceps increased during pain (by approximately 22%) whereas MEPs decreased (by approximately 15%; P < 0.05). Activity in group III and IV muscle afferents produced by hypertonic saline facilitates motoneurones innervating elbow flexor and extensor muscles but depresses motor cortical cells projecting to these muscles.

PPARalpha transcriptionally induces AhR expression in Caco-2, but represses AhR pro-inflammatory effects.

In this work we demonstrate that Caco-2 cell treatment with WY-14643 (a potent PPARalpha agonist) causes an increase in AhR expression. Luciferase assays and directed mutagenesis experiments showed that induction mainly occurred at transcriptional level and involved a PPRE site located within the AhR promoter. These results were further confirmed by the use of PPARalpha knockout mice in which AhR induction by WY14643 was abrogated. In addition to CYP1 regulation, AhR has been described as being involved in inflammation, so we also studied the effect of AhR regulation by PPARalpha on the expression of some inflammation target genes. 3-Methylcholanthrene (a potent AhR agonist) increased the expression (mRNA) of the major inflammatory targets IL-1beta and MMP9. WY-14643 co-treatment abrogated the 3-methylcholanthrene pro-inflammatory effect. Hence the anti-inflammatory effect of PPARalpha overrides the pro-inflammatory effect of AhR.

Clustering time-series gene expression data using smoothing spline derivatives.

Microarray data acquired during time-course experiments allow the temporal variations in gene expression to be monitored. An original postprandial fasting experiment was conducted in the mouse and the expression of 200 genes was monitored with a dedicated macroarray at 11 time points between 0 and 72 hours of fasting. The aim of this study was to provide a relevant clustering of gene expression temporal profiles. This was achieved by focusing on the shapes of the curves rather than on the absolute level of expression. Actually, we combined spline smoothing and first derivative computation with hierarchical and partitioning clustering. A heuristic approach was proposed to tune the spline smoothing parameter using both statistical and biological considerations. Clusters are illustrated a posteriori through principal component analysis and heatmap visualization. Most results were found to be in agreement with the literature on the effects of fasting on the mouse liver and provide promising directions for future biological investigations.

Muscle fatigue changes cutaneous suppression of propriospinal drive to human upper limb muscles.

Some voluntary drive reaches human upper limb muscles via cervical propriospinal premotoneurones. Stimulation of the superficial radial nerve can inhibit these premotoneurones selectively and the resultant suppression of voluntary drive to motoneurones changes on-going electromyographic (EMG) activity. We investigated whether muscle fatigue changes this cutaneous-induced suppression of propriospinal drive to motoneurones of upper limb muscles. EMG was recorded from the extensors and flexors of the wrist and elbow. In the first study (n = 10 subjects), single stimuli (2 x perception threshold; 2PT) to the superficial radial nerve were delivered during contraction of the wrist extensors, before and after sustained fatiguing contractions of wrist extensors. In the second study (n = 10), similar stimuli were applied during elbow extension, before and during fatigue of elbow extensors. In the final study (n = 10), trains of three stimuli (2PT) were delivered during contractions of wrist extensors, before and while they were fatigued. With fatigue of either the wrist or elbow extensors, EMG suppression to single cutaneous stimuli increased significantly (by approximately 75%) for the fatigued muscle (P < 0.05). Conversely, in the other muscles, which were coactivated but not principally involved in the task, inhibition decreased or facilitation increased. Trains of stimuli produced greater suppression of on-going wrist extensor EMG than single stimuli and this difference persisted with fatigue. A control study of the H reflex in extensor carpi radialis showed that the mechanism responsible for the altered EMG suppression in fatigue was not at a motoneurone level. The findings suggest that the proportion of descending drive mediated via the disynaptic propriospinal pathway or the excitability of inhibitory interneurones projecting to propriospinal neurones increases substantially to fatigued muscles, but decreases to other active muscles. This pattern of changes may maintain coordination during multimuscle movements when one group of muscles is fatigued.

Theta burst stimulation does not reliably depress all regions of the human motor cortex.

OBJECTIVE: The excitability of the human motor cortex projecting to hand muscles can be reduced by theta burst transcranial magnetic repetitive stimulation (TBS). This study compared the magnitude and variability of changes evoked by TBS for a distal and proximal arm muscle. METHODS: Eight subjects participated in three studies. In each study, electromyographic responses (MEPs) to single-pulse transcranial magnetic stimulation assessed cortical excitability before and after 40s of TBS. In the first two studies, TBS (intensity, 80% active motor threshold) was delivered to the optimal locations for biceps or first dorsal interosseous (FDI). In the final study, weaker intensity TBS was delivered over the biceps representation. RESULTS: TBS targeting biceps produced highly variable results among subjects. For the group, MEPs were not significantly depressed. Repeat studies in individual subjects highlighted the variability of responses. For FDI, MEPs were significantly depressed 5min after TBS and remained depressed for >30min (p<0.05). No significant changes in biceps MEPs occurred with weaker TBS. CONCLUSIONS: The magnitude and reliability of TBS depends on the region of the cortex targeted. SIGNIFICANCE: Results obtained for the hand should not be considered indicative of changes that will occur in other regions of the motor cortex or the brain.

Output of human motoneuron pools to corticospinal inputs during voluntary contractions.

This study investigated transmission of corticospinal output through motoneurons over a wide range of voluntary contraction strengths in humans. During voluntary contraction of biceps brachii, motor evoked potentials (MEPs) to transcranial magnetic stimulation of the motor cortex grow up to about 50% maximal force and then decrease. To determine whether the decrease reflects events at a cortical or spinal level, responses to stimulation of the cortex and corticospinal tract (cervicomedullary motor evoked potentials, CMEPs) as well as maximal M-waves (M(max)) were recorded during strong contractions at 50 to 100% maximum. In biceps and brachioradialis, MEPs and CMEPs (normalized to M(max)) evoked by strong stimuli decreased during strong elbow flexions. Responses were largest during contractions at 75% maximum and both potentials decreased by about 25% M(max) during maximal efforts (P < 0.001). Reductions were smaller with weaker stimuli, but again similar for MEPs and CMEPs. Thus the reduction in MEPs during strong voluntary contractions can be accounted for by reduced responsiveness of the motoneuron pool to stimulation. During strong contractions of the first dorsal interosseous, a muscle that increases voluntary force largely by frequency modulation, MEPs declined more than in either elbow flexor muscle (35% M(max), P < 0.001). This suggests that motoneuron firing rates are important determinants of evoked output from the motoneuron pool. However, motor cortical output does not appear to be limited at high contraction strengths.