A 64-channel transmitter for investigating parallel transmit MRI.

Multiple channel radiofrequency (RF) transmitters are being used in magnetic resonance imaging to investigate a number of active research topics, including transmit SENSE and B(1) shimming. Presently, the cost and availability of multiple channel transmitters restricts their use to relatively few sites. This paper describes the development and testing of a relatively inexpensive transmit system that can be easily duplicated by users with a reasonable level of RF hardware design experience. The system described here consists of 64 channels, each with 100 W peak output level. The hardware is modular at the level of four channels, easily accommodating larger or smaller channel counts. Unique aspects of the system include the use of vector modulators to replace more complex IQ direct digital modulators, 100 W MOSFET RF amplifiers with partial microstrip matching networks, and the use of digital potentiometers to replace more complex and costly digital-to-analog converters to control the amplitude and phase of each channel. Although mainly designed for B(1) shimming, the system is capable of dynamic modulation necessary for transmit SENSE by replacing the digital potentiometers controlling the vector modulators with commercially available analog output boards. The system design is discussed in detail and bench and imaging data are shown, demonstrating the ability to perform phase and amplitude control for B(1) shimming as well as dynamic modulation for transmitting complex RF pulses.

Bioprocess and bioreactor: next generation technology for production of potential plant-based antidiabetic and antioxidant molecules.

Globally, diabetes and obesity are two of the most common metabolic diseases of the 21(st) century. Increasingly, not only adults but children and adolescents are being affected. New approaches are needed to prevent and treat these disorders and to reduce the impact of associated disease-related complications. Industrial-scale production using plant-root cultures can produce quantities and quality of inexpensive bioactive small molecules with nutraceutical and pharmaceutical properties. Using this approach, and targeting these diseases, a next generation approach to tackling this emerging global health crisis may be developed. Adventitious roots cultured in bioreactors under controlled and reproducible conditions have been shown effective for production of natural products. The liquid-phase airlift bioreactor in particular has been used successfully for culturing roots on an industrial-scale and thus may provide an economical production platform for expressing promising plant-based antidiabetic and antioxidant molecules. This review focuses on a next-generation, scalable, bioprocessing approach for adventitious and hairy root cultures that are a pesticide-free, seasonally-independent, plant-based source of three molecules that have shown promise for the therapeutic management of diabetes and obesity: corosolic acid, resveratrol and ginsenosides.

Detection of Borrelia burgdorferi and Borrelia lonestari in birds in Tennessee.

Lyme disease in the United States is caused by the bacterial spirochete Borrelia burgdorferi s.s. (Johnson, Schmid, Hyde, Steigerwalt, and Brenner), which is transmitted by tick vectors Ixodes scapularis (Say) and I. pacificus (Cooley and Kohls). Borrelia lonestari, transmitted by the tick Amblyomma americanum L., may be associated with a related syndrome, southern tick-associated rash illness (STARI). Borrelia lonestari sequences, reported primarily in the southeastern states, have also been detected in ticks in northern states. It has been suggested that migratory birds may have a role in the spread of Lyme disease spirochetes. This study evaluated both migratory waterfowl and nonmigratory wild turkeys (Meleagris gallopavo silvestris, Eastern wild turkey) for B. burgdorferi and B. lonestari DNA sequences. A total of 389 avian blood samples (163 migratory birds representing six species, 125 wild turkeys harvested in habitats shared with migratory birds, 101 wild turkeys residing more distant from migratory flyways) were extracted, amplified, and probed to determine Borrelia presence and species identity. Ninety-one samples were positive for Borrelia spp. Among migratory birds and turkeys collected near migration routes, B. burgdorferi predominated. Among turkeys residing further away from flyways, detection of B. lonestari was more common. All A. americanum ticks collected from these areas were negative for Borrelia DNA; no I. scapularis were found. To our knowledge, this represents the first documentation of B. lonestari among any birds.

Estimating the exposure of small mammals at three sites within the Chernobyl exclusion zone--a test application of the ERICA Tool.

An essential step in the development of any modelling tool is the validation of its predictions. This paper describes a study conducted within the Chernobyl exclusion zone to acquire data to conduct an independent test of the predictions of the ERICA Tool which is designed for use in assessments of radiological risk to the environment. Small mammals were repeatedly trapped at three woodland sites between early July and mid-August 2005. Thermoluminescent dosimeters mounted on collars were fitted to Apodemus flavicollis, Clethrionomys glareolus and Microtus spp. to provide measurements of external dose rate. A total of 85 TLDs were recovered. All animals from which TLDs were recovered were live-monitored to determine (90)Sr and (137)Cs whole-body activity concentrations. A limited number of animals were also analysed to determine (239,240)Pu activity concentrations. Measurements of whole-body activity concentrations and dose rates recorded by the TLDs were compared to predictions of the ERICA-Tool. The predicted (90)Sr and (137)Cs mean activity concentrations were within an order of magnitude of the observed data means. Whilst there was some variation between sites in the agreement between measurements and predictions this was consistent with what would be expected from the differences in soil types at the sites. Given the uncertainties of conducting a study such as this, the agreement observed between the TLD results and the predicted external dose rates gives confidence to the predictions of the ERICA Tool.

Factors contributing to radiocaesium variability in upland sheep flocks in west Cumbria (United Kingdom).

Following the Chernobyl accident in 1986, restrictions were placed on the movement and slaughter of sheep within upland areas of the UK because radiocaesium activity concentrations in their meat exceeded 1000 Bq kg(-1) fresh weight. Some farms remain under restriction in 2007. From 1991 to 1993 detailed studies were conducted on three sheep farms within the restricted area of west Cumbria to systematically assess the various parameters which may contribute to the observed variability in radiocaesium activity concentrations within sheep flocks. This paper reports the spatial variation in soil and vegetation activity concentrations across the grazed areas at these farms and determines the influence of grazing behaviour on variability in (137)Cs activity concentrations between individual sheep within the flocks. Together with previously reported results, these new data are used to draw conclusions on the factors determining variability within the three flocks. However, the factors are too site specific to be able to generalise the findings to other farms within the restricted areas of the UK.

The nonhomologous end joining factor Artemis suppresses multi-tissue tumor formation and prevents loss of heterozygosity.

Nonhomologous end joining (NHEJ) is a critical DNA repair pathway, with proposed tumor suppression functions in many tissues. Mutations in the NHEJ factor ARTEMIS cause radiation-sensitive severe combined immunodeficiency in humans and may increase susceptibility to lymphoma in some settings. We now report that deficiency for Artemis (encoded by Dclre1c/Art in mouse) accelerates tumorigenesis in several tissues in a Trp53 heterozygous setting, revealing tumor suppression roles for NHEJ in lymphoid and non-lymphoid cells. We also show that B-lineage lymphomas in these mice undergo loss of Trp53 heterozygosity by allele replacement, but arise by mechanisms distinct from those in Art Trp53 double null mice. These findings demonstrate a general tumor suppression function for NHEJ, and reveal that interplay between NHEJ and Trp53 loss of heterozygosity influences the sequence of multi-hit oncogenesis. We present a model where p53 status at the time of tumor initiation is a key determinant of subsequent oncogenic mechanisms. Because Art deficient mice represent a model for radiation-sensitive severe combined immunodeficiency, our findings suggest that these patients may be at risk for both lymphoid and non-lymphoid cancers.

"Blind" testing of models for predicting the 90Sr activity concentration in river systems using post-Chernobyl monitoring data.

Two different models for predicting the time-dependent mobility of (90)Sr in river systems have been evaluated using post-Chernobyl monitoring data for five large Belarusian rivers (Dnieper, Pripyat, Sozh, Besed and Iput) in the period between 1990 and 2004. The results of model predictions are shown to be in good agreement (within a factor of 5) with the measurements of (90)Sr activity concentration in river waters over a long period of time after the accident. This verifies the relatively good accuracy of the generalised input parameters of these models which were derived primarily from measurements of (90)Sr deposited after atmospheric nuclear weapons testing (NWT). For the cases studied here, the simpler AQUASCOPE model performed just as well as the more complex "Global" model which used GIS-based catchment data as an input. The reasons for this are discussed. Exponential decay equations were also curve-fitted to the data for each river to help assess the uncertainties in the predictive models.

Putative contributors to the secular increase in obesity: exploring the roads less traveled.

OBJECTIVE: To investigate plausible contributors to the obesity epidemic beyond the two most commonly suggested factors, reduced physical activity and food marketing practices. DESIGN: A narrative review of data and published materials that provide evidence of the role of additional putative factors in contributing to the increasing prevalence of obesity. DATA: Information was drawn from ecological and epidemiological studies of humans, animal studies and studies addressing physiological mechanisms, when available. RESULTS: For at least 10 putative additional explanations for the increased prevalence of obesity over the recent decades, we found supportive (although not conclusive) evidence that in many cases is as compelling as the evidence for more commonly discussed putative explanations. CONCLUSION: Undue attention has been devoted to reduced physical activity and food marketing practices as postulated causes for increases in the prevalence of obesity, leading to neglect of other plausible mechanisms and well-intentioned, but potentially ill-founded proposals for reducing obesity rates.

Prediction of spatial variation in global fallout of 137Cs using precipitation.

Deposition from atmospheric nuclear weapons tests (termed global fallout) has been shown to be proportional to the rate of precipitation. Here we describe methods for using precipitation and radionuclide deposition information for a reference site to estimate global fallout at other locations. These methods have been used to estimate global fallout in Iceland, identified during the Arctic Monitoring and Assessment Programme (AMAP) by Wright et al. [Wright, S.M., Howard, B.J., Strand, P., Nylén, T., Sickel, M.A.K., 1999. Prediction of 137Cs deposition from atmospheric nuclear weapons tests within the Arctic. Environ Pollut 104, 131-143.] as one of the Arctic areas which received the highest global fallout, but where measurements of contamination were sparse, and difficult to obtain due to the remote and inaccessible terrain of much of the country. Measurements of global fallout 137Cs deposition have been made in Iceland at sites close to meteorological stations to ensure that precipitation data were of high quality. The AMAP modeling approach, based on measured precipitation and radionuclide deposition data, was applied using a reference monitoring station located close to Reykjavik. The availability of good precipitation data and locally based estimates of time dependent ratios of 137Cs deposition to precipitation during the fallout period gave a better correlation between predicted and measured 137Cs global fallout (r2=0.96) than that achieved using the much more heterogeneous set of data collected by AMAP over the whole of the Arctic. Having obtained satisfactory results with the model for a number of calibration sites alongside meteorological stations we then produced a map of estimated 137Cs deposition based on a model of estimated precipitation. This deposition map was then successfully validated (r2=0.85) for sites where 137Cs deposition was measured; the associated uncertainty in predictions was also estimated.

Patterns and inventories of radioactive contamination of island sites of the Yenisey River, Russia.

The distribution of radioactive contamination at three island sites downstream from the Krasnoyarsk Mining and Chemical Combine (KMCC) was studied with the objectives of mapping contamination levels, interpreting radionuclide distributions through consideration of alluvial processes and determining radionuclide inventories. Contamination was measured using in situ gamma spectrometry and landforms characterised using topographic surveying methods. Maximum (137)Cs contamination densities (700 kBq m(-2)) were found on low- and middle-level floodplains and low-lying interconnecting areas of Beriozovy Island (16 km from the KMCC). On Mikhin Island (180 km from the KMCC) maximum total (60)Co, (152)Eu and (154)Eu activity concentrations (30-40 kBq m(-2)) occur in low-lying areas inundated during flooding. Maximum (137)Cs and total (60)Co, (152)Eu and (154)Eu contamination densities on Cheriomukhov Island (250 km from the KMCC) were 390 and 50 kBq m(-2), respectively. Estimated (137)Cs inventories were 145, 148 and 16GBq for Beriozovy, Mikhin and Cheriomukhov Islands, respectively.

Development of a case report review instrument.

Case reports are valued components of the medical literature. The assessment of case reports by editors of medical journals and peer reviewers is largely subjective. The purpose of this study was to develop a reliable instrument to evaluate the quality of written case reports. Instrument development involved review of the literature and the materials provided to peer reviewers who review manuscripts, communications with journal editors and discussions of the study team. After multiple amendments, the instrument was pilot tested on both published and unpublished case reports. Further revisions resulted in the final 11-item tool. Four independent reviewers evaluated 28 case reports in their original submission format that had been submitted to five medical journals. The reviewers were blinded to the specific journal that the manuscripts had been submitted and to whether the case reports had been accepted for publication. Inter-rater reliability was assessed using multirater kappa. Inter-rater reliability ranged from 0.03 to 0.90. The four variables with the highest agreement between raters were (i) rationale for writing the case report; (ii) implications of the case report; (iii) adequacy of the literature review; and (iv) overall impression about whether to accept or reject the manuscript (kappas of 0.67, 0.67, 0.90 and 0.67, respectively). Six of the instrument's first 10 variables were highly correlated with the reviewers' decision about whether to accept or reject the case report for publication (item 11) (all p < 0.001). No correlation existed between the reviewers' decision to accept or reject the manuscript and the actual decision that had been made by the various journals. The case report review instrument is the first such tool for objectively evaluating case reports and appears to have reasonable reliability. Medical journals may wish to incorporate the use of this instrument into the decision making about a case report's suitability for publication.

Radiocaesium in lynx in relation to ground deposition and diet.

The European lynx (Lynx lynx) might be expected to have a high intake of radiocaesium in the parts of Sweden where the main prey of the lynx, namely reindeer and roe deer, have high activity concentrations of radiocaesium because of high ground deposition. We have measured (137)Cs in muscle samples from 733 lynx during 1996-2003. The aim was to quantify the extent to which radiocaesium is transferred from fallout deposition to lynx, to test whether the transfer was higher in areas where there are reindeer present, to see if there was any decline in radiocaesium over time, and to calculate the radiation dose to lynx. Most samples were collected in central and northern Sweden during January-April. Activity concentrations in lynx varied from 13 Bq kg(-1) to about 15 kBq kg(-1) fresh weight, with the highest value corresponding to a radiation dose at 18 mGy/year. Aggregated transfer coefficients (Tag), calculated by dividing the (137)Cs activity concentration in lynx muscle by the average ground deposition (total from Chernobyl and nuclear weapon tests) within a 50 km radius around the location of the lynx, varied from 0.004 to 1.3 m(2) kg(-1) and were significantly higher within the reindeer herding area than outside. The concentration ratio (CR) for lynx/reindeer was 2.6 on average, whilst the average for lynx/roe deer outside the reindeer herding area was lower at 1.3. Based on these results, a CR of around 2 could be considered representative for the general ratio between predator and prey. A long-term decline of radiocaesium in prey species was reflected in lynx, with an effective half-life of 7 years from 1996 to 2003. The study shows that the accumulation of radiocaesium in predators, especially predators of reindeer, makes them more vulnerable to high radiocaesium deposition than most other wild species.

Long-term consequences for Northern Norway of a hypothetical release from the Kola nuclear power plant.

The spatial and temporal variation in radiocaesium and (90)Sr doses to two population groups of the two Northernmost counties of Norway, Troms and Finnmark, following a hypothetical accident at the Kola nuclear power plant (KNPP) have been estimated using a model implemented within a geographical information system. The hypothetical accident assumes a severe loss of coolant accident at the KNPP coincident with meteorological conditions causing significant radionuclide deposition in the two counties. External doses are estimated from ground deposition and the behaviour of the different population groups, and internal doses from predicted food product activity concentrations and dietary consumption data. Doses are predicted for reindeer keepers and other Norwegian inhabitants, taking account of existing (137)Cs and (90)Sr deposition but not including the remedial effect of any countermeasures that might be used. The predicted doses, arising mainly from radiocaesium, confirm the Arctic Monitoring and Assessment Programme assessment that residents of the Arctic are particularly vulnerable to radiocaesium contamination, which could persist for many years. External doses are predicted to be negligible compared to ingestion doses. Ingestion doses for reindeer keepers are predicted to exceed 1 mSv y(-1) for several decades primarily due to their high consumption of reindeer meat. Other Norwegians would also be potentially exposed to doses exceeding 1 mSv y(-1) for several years, especially if they consume many local products. Whilst reindeer production is the most important exposure pathway, freshwater fish, lamb meat, dairy products, mushrooms and berries are also significant contributors to predicted ingestion doses. Radionuclide fluxes, defined as the total output of radioactivity in food from an area for a unit time, are dominated by reindeer meat. The results show the need for an effective emergency response, with appropriate countermeasures, should an accident of the scale considered in this paper occur at the KNPP.

Overcoming phase effects of voxel-sized coils in planar and cylindrical arrays.

Parallel imaging in MRI (using multiple coils to partially encode k-space) is currently the primary route to decreasing scan time. Single echo acquisition (SEA) imaging is a completely parallel imaging method recently developed by our group that collects a full image in a single echo. Phase encoding is eliminated and replaced by the spatial localization of long and very narrow coils. The fact that the coils are on the order of the voxel size for the first time in an MR application has led to an examination of the effect of the phase of the coil on the signal received from the voxel and how to most effectively manipulate it. Obtaining full signal from a voxel in planar arrays can be accomplished with a single gradient compensation pulse, but the phase effects in cylindrical arrays are more complex due to the changing coil angle with regard to the Cartesian axes of the gradients. This paper discusses the signal-phase interactions of planar and cylindrical arrays of voxel-sized coils and suggests methods for phase manipulation for optimization.

Applications of RF current sources for transmit phased array.

Current practice in MRI trends towards higher static magnetic field (B/sub 0/) because of the advantage of signal-to-noise ratio (SNR). However at high magnetic fields, the interaction between a coil and a load becomes significant, thus making current distribution on RF coils disturbed and causing transverse magnetic (B/sub 1/) field inhomogeneity. A novel approach to optimize B/sub 1/, field homogeneity is to use a transmit phased array and adjust the amplitudes and phases of the currents on each element independently. However, independent control is difficult to achieve in conventional arrays due to coupling between elements. In addition, the currents are generally load dependent. In this paper we show that a RF current source is an effective method for controlling the current on each element of the transmit phased array, and that the RF current source is much less sensitive to loading and a interelement coupling than a conventional 50Omega matched coil.

Monte-Carlo prediction of changes in areas of west Cumbria requiring restrictions on sheep following the Chernobyl accident.

Following the 1986 Chernobyl accident radiocaesium levels in sheep meat in some upland areas of the United Kingdom were above the national intervention limit. West Cumbria was one of these areas and restrictions are currently still in place. In addition to deposition from the Chernobyl accident, Cumbria has been subject to radiocaesium deposition from atmospheric nuclear weapons tests, the 1957 Windscale accident and routine releases from the Sellafield nuclear reprocessing plant. A Monte-Carlo approach has been used to try to predict areas in west Cumbria where radiocaesium activity concentrations in lamb meat would require the imposition of restrictions at different times after the Chernobyl accident. The approach models the transfer of radiocaesium from soil to vegetation, based upon soil organic matter, and from vegetation to lamb meat. Spatial inputs are soil organic matter and total post-Chernobyl (137)Cs and (134)Cs deposition; a ratio of Chernobyl (137)Cs to (134)Cs deposition has been used to differentiate Chernobyl and pre-Chernobyl (137)Cs deposition. Comparisons of predicted radiocaesium transfer from soil-vegetation and the spatial variation in lamb (137)Cs activity concentrations are good and predicted restricted areas with time after Chernobyl compare well to the restricted areas set by UK government. We predict that restrictions may be required until 2024 and that in some areas the contribution of pre-Chernobyl (137)Cs to predicted lamb radiocaesium activity concentrations is significant, such that restrictions may only have been required until 1994 as a consequence of Chernobyl radiocaesium deposition alone. This work represents a novel implementation of a spatial radioecological model using a Monte-Carlo approach.

Detection of Borrelia lonestari in Amblyomma americanum (Acari: Ixodidae) from Tennessee.

Genetic sequences characteristic of Borrelia lonestari (Barbour et al. 1996) were detected in two pools of adult Amblyomma americanum (L.) from Tennessee, corresponding to an estimated minimum field infection rate of 8.4 infected ticks/1000 adults. DNA amplification was conducted using primers derived from the B. lonestari flagellin gene that would also amplify Borrelia burgdorferi (Johnson, Schmid, Hyde, Steigerwalt, and Brenner). Species-specific, internal probes were then used to differentiate between genetic sequences of the spirochetes. Subsequent nucleotide sequencing confirmed the presence of B. lonestari in A. americanum; B. burgdorferi was not detected. This represents the first report of B. lonestari from Tennessee, and suggests that Lyme-like illness may occur in Tennessee.

Electrospray ionisation mass spectrometric analysis of lipid restructuring in the carp (Cyprinus carpio L.) during cold acclimation.

Cold acclimation of carp from 30 degrees C to 10 degrees C causes a restructuring of liver microsomal phospholipids characterised by increased proportions of monounsaturated fatty acid in phosphatidylcholine (PC) and phosphatidylethanolamine (PE). Here, we have used electrospray ionisation mass spectrometry (ESI-MS) to determine the patterns of alteration to individual molecular species compositions of PC, PE and phosphatidylinositol (PI) in response to gradually decreasing temperature. The results demonstrate that cold induces precise changes to a limited number of phospholipid species, and that these changes are distinct and different for each phospholipid class. The major change for PC was increased 16:1/22:6, but for PE the species that increased was 18:1/22:6. By contrast, the PI species that increased during cold acclimation were characterised by an sn-1 monounsaturated fatty acid in combination with arachidonoyl or eicosapentaenoyl fatty acid at the sn-2 position. Analysis of acyl distribution indicates that cold only caused the accumulation of monounsaturated fatty acids at the sn-1 and not at the sn-2 position of phospholipids. These results highlight the tight and restricted range of modifications that membranes make to their phospholipid composition in response to thermal stress.

Predictions of in situ solid/liquid distribution of radiocaesium in soils.

Previous work has demonstrated that plant uptake of radiocaesium (RCs) is related to the activity concentration of RCs in soil solution, which is linked to the soil/soil solution distribution coefficient, K(D). The solid-liquid distribution of RCs is generally studied in soil suspensions in the laboratory and there are few reported measurements for in situ soil solutions. From a data set of 53 different soils (contaminated with either 134CsCl or 137CsCl) used in pot trials to investigate grass uptake of RCs, we analysed the variation of in situ K(D) with measured soil properties. The soils differed widely in % clay (0.5-58%), organic matter content (1.9-96%) and pH (2.4-7.0, CaCl2). The K(D) varied between 29 and 375,000 L kg-' (median 1460 L kg(-1)). Stepwise multiple regression analysis showed a significant correlation between the log K(D) and pH (p < 0.001), log %clay (p < 0.01) and log exchangeable K (p < 0.001) (overall R2 = 0.70). The in situ K(D) values were further compared to K(D)S predicted using an existing model, which assumes that RCs sorption occurs on specific sites and regular ion-exchange sites on the soil solid phase. Sorption of RCs on specific sites was quantified from the radiocaesium interception potential (RIP) measured for each soil and the soil solution concentrations of K+ and NH4+. The in situ log K(D) correlated well with the predicted K(D) (R2 = 0.85 before plant growth, R2 = 0.83 after plant growth). However, the observations were fivefold to eightfold higher than the predictions, particularly for the mineral soils. We attribute the under-prediction to the long contact times (minimum 4 weeks) between the RCs tracers and our experimental soils relative to the short (24 h) contact times used in RIP measurements. We conclude that our data confirmed the model but that ageing of RCs in soil is a factor that needs to be considered to better predict in situ KD values.

Bovine immunodeficiency virus expression in vitro is reduced in the presence of beta-chemokines, MIP-1alpha, MIP-1beta and RANTES.

The inhibition of HIV expression in vitro by a cocktail of the beta-chemokines MIP-1alpha, MIP-1beta and RANTES provided the initial evidence that HIV utilizes chemokine receptors as co-receptors for infection of cells. Bovine immunodeficiency virus (BIV), a lentivirus, infects a wide variety of leukocyte populations, but the cellular receptor(s) utilized by this virus for infection of cells is not known. The purpose of this study was to determine whether MIP-1alpha, MIP-1beta and RANTES affect BIV expression in vitro, as a prelude to identifying the cellular receptors utilized by this virus. Fetal bovine lung (FBL) cells were pretreated with serial dilutions of a cocktail of the chemokines, and then the cells were infected with BIV. Virus expression in these cells was determined by counting the syncytia that had developed in the cultures by five days after infection. A significant decrease in syncytium formation, corresponding to increasing concentrations of the chemokines, was the result. Reacting the chemokines with chemokine-specific neutralizing antibodies prior to treatment of the cells neutralized the effect of the chemokines on virus replication in a dose-dependent manner, restoring viral expression to a level similar to that of untreated cells. The presence of a CCR5 homologue on the surface of FBL cells was confirmed using an anti-CCR5 monoclonal antibody and FACS analysis. Collectively, these data provide preliminary evidence that BIV may utilize the CCR5 receptor for infection of cells in vitro, but additional studies are necessary to confirm this.