Impacted maxillary canines and root resorptions of neighbouring teeth: a radiographic analysis using cone-beam computed tomography

The study analyses the location of impacted maxillary canines and factors influencing root resorptions of adjacent teeth using cone-beam computed tomography (CBCT). In addition, the interrater reliability between observers of two different dental specialties for radiographic parameters will be evaluated. CBCT images of patients who were referred for radiographic localization of impacted maxillary canines and/or suspicion of root resorptions of adjacent teeth were included. The study analysed the exact three-dimensional location of the impacted canines in the anterior maxilla, frequency and extent of root resorptions, and potential influencing factors. To assess interrater agreement, Cohen's correlation parameters were calculated. This study comprises 113 patients with CBCT scans, and 134 impacted canines were analysed retrospectively. In the patients evaluated, 69 impacted canines were located palatally (51.49 per cent), 41 labially (30.60 per cent), and 24 (17.91 per cent) in the middle of the alveolar process. Root resorptions were found in 34 lateral incisors (25.37 per cent), 7 central incisors (5.22 per cent), 6 first premolars (4.48 per cent), and 1 second premolar (0.75 per cent). There was a significant correlation between root resorptions on adjacent teeth and localization of the impacted canine in relation to the bone, as well as vertical localization of the canine. Interrater agreement showed values of 0.546-0.877. CBCT provides accurate information about location of the impacted canine and prevalence and degree of root resorption of neighbouring teeth with high interrater correlation. This information is of great importance for surgeons and orthodontists for accurate diagnostics and interdisciplinary treatment plannin

Endogenous biosynthesis of n-3 long-chain PUFA in Atlantic salmon

A more efficient utilisation of marine derived sources of dietary omega-3 long-chain polyunsaturated fatty acids (n-3 LC PUFA) in cultured Atlantic salmon could, amongst other strategies, be facilitated by nutritional strategies that maximise endogenous n-3 LC PUFA synthesis. The objective of the current study was to quantify the extent of n-3 LC PUFA biosynthesis and the resultant effect on fillet nutritional quality in large, market size Atlantic salmon. Four diets were manufactured providing altered levels of dietary omega-3 substrate, namely 18:3n-3, and end-products, namely, 20:5n-3 and 22:6n-3. After 283 days of feeding, fish grew to in excess of 3000g and no differences in growth performance or biometrical parameters were recorded. An analysis of fatty acid composition and in vivo metabolism revealed that post-smolt Atlantic salmon have the potential to endogenously produce n-3 LC PUFA when provided with a substantial amount of dietary omega-3 substrate. Moreover, the extent of endogenous production resulted in fillet levels of n-3 LC PUFA comparable to fish fed a diet with added fish oil. Another major finding was that the presence of abundant dietary omega-3 substrate with the addition of dietary omega-3 end-product (i.e. fish oil) had a positive effect on final fillet levels of n-3 LC PUFA. This was likely the result of the preferential β-oxidation of dietary C18 n-3 PUFA resulting in an apparent conservation of n-3 LC PUFA from catabolism. Ultimately, this study highlights the potential for endogenous synthesis of n-3 LC PUFA to, at least partially, support a substantial reduction, in the amount of dietary fish oil in diets for market sized Atlantic salmon reared in seawater

The impact of dietary protein: lipid ratio on growth performance, fatty acid metabolism, product quality and waste output in Atlantic salmon (Salmo salar)

A common strategy for aquafeed manufacturers has been the utilisation of relatively large amounts of terrestrial, both animal and plant, oil sources to produce diets with a high energy content. The provision of high fat diets is aimed at promoting the utilisation of energy from lipid, thus increasing the amount of dietary protein used for tissue synthesis. However, in recent years the cost of marine sourced dietary lipids has risen, at the same time, farming operations are under increasing pressure to limit environmental degradation associated with nitrogenous waste effluent. Currently there is limited information available regarding the environmental and economic impacts of an altered dietary protein: lipid ratio in diets for large Atlantic salmon (Salmo salar) reared in seawater, presenting a potential impediment for nutritional based solutions. Accordingly the present study compared two isoenergetic diets with varied protein: lipid ratios via an assessment of growth, fatty acid utilisation, human nutritional quality, nitrogenous waste output and economic considerations. The trial diets were fed to the fish for the final 150 days of an on-farm grow-out period and resulted in minimal differences in fish growth, fatty acid utilisation and fillet quality. A decreased dietary protein: lipid ratio resulted in a more efficient protein utilisation both in terms of digestibility and assimilation into fish and, therefore, nitrogenous waste output was reduced. However, due to small differences in feed utilisation, the cost of fish production was numerically higher

Altered levels of shorter vs long-chain omega-3 fatty acids in commercial diets for market-sized Atlantic salmon reared in seawater – Effects on fatty acid composition, metabolism and product quality

There is a growing trend of ‘replacing’ long-chain omega-3 polyunsaturated fatty acid (n-3 LC PUFA) rich oils with C18 shorter-chain omega-3 polyunsaturated fatty acid rich oils in Atlantic salmon aquafeed formulations. n-3 LC PUFA, including 20:5n-3 and 22:6n-3, play contrasting physiological roles and are metabolised differently in comparison to C18 PUFA. Accordingly, the present study recorded the effect of replacing n-3 LC PUFA rich dietary fish oil with C18 n-3 PUFA rich camelina oil at two inclusion levels in commercial-like diets fed to market-sized Atlantic salmon. This assessment was achieved by an analysis of industry relevant production parameters including growth performance, fatty acid composition and metabolism, nutrient digestibility and consumer acceptance (liking and attribute analysis of fillet). The trial was conducted over the final 150 days of an on-farm grow-out period in seawater. The dietary replacement of n-3 LC PUFA with C18 n-3 PUFA resulted in a significant decrease in fillet n-3 LC PUFA and a poorer growth performance. However, in the absence of fish oil, the inclusion of camelina oil at high levels (40%) contributed to an improved n-6/n-3 ratio and partially ameliorated low dietary n-3 LC PUFA by providing added substrate for endogenous n-3 LC PUFA synthesis in comparison to a 20% camelina oil inclusion. Furthermore, consumer acceptance of Atlantic salmon was unaffected by the dietary addition of camelina oil

Repurposing environmental DNA samples—detecting the western pearlshell (Margaritifera falcata) as a proof of concept

Information on the distribution of multiple species in a common landscape is fundamental to effective conservation and management. However, distribution data are expensive to obtain and often limited to high-profile species in a system. A recently developed technique, environmental DNA (eDNA) sampling, has been shown to be more sensitive than traditional detection methods for many aquatic species. A second and perhaps underappreciated benefit of eDNA sampling is that a sample originally collected to determine the presence of one species can be re-analyzed to detect additional taxa without additional field effort. We developed an eDNA assay for the western pearlshell mussel (Margaritifera falcata) and evaluated its effectiveness by analyzing previously collected eDNA samples that were annotated with information including sample location and deposited in a central repository. The eDNA samples were initially collected to determine habitat occupancy by nonbenthic fish species at sites that were in the vicinity of locations recently occupied by western pearlshell. These repurposed eDNA samples produced results congruent with historical western pearlshell surveys and permitted a more precise delineation of the extent of local populations. That a sampling protocol designed to detect fish was also successful for detecting a freshwater mussel suggests that rapidly accumulating collections of eDNA samples can be repurposed to enhance the efficiency and cost-effectiveness of aquatic biodiversity monitoring

The International Surface Pressure Databank version 2

The International Surface Pressure Databank (ISPD) is the world's largest collection of global surface and sea-level pressure observations. It was developed by extracting observations from established international archives, through international cooperation with data recovery facilitated by the Atmospheric Circulation Reconstructions over the Earth (ACRE) initiative, and directly by contributing universities, organizations, and countries. The dataset period is currently 1768–2012 and consists of three data components: observations from land stations, marine observing systems, and tropical cyclone best track pressure reports. Version 2 of the ISPD (ISPDv2) was created to be observational input for the Twentieth Century Reanalysis Project (20CR) and contains the quality control and assimilation feedback metadata from the 20CR. Since then, it has been used for various general climate and weather studies, and an updated version 3 (ISPDv3) has been used in the ERA-20C reanalysis in connection with the European Reanalysis of Global Climate Observations project (ERA-CLIM). The focus of this paper is on the ISPDv2 and the inclusion of the 20CR feedback metadata. The Research Data Archive at the National Center for Atmospheric Research provides data collection and access for the ISPDv2, and will provide access to future versions

A systematic review and analysis of long-term growth trials on the effect of diet on omega-3 fatty acid levels in the fillet tissue of post-smolt Atlantic salmon

Elucidating the specific effects of diet on the fatty acid composition in Atlantic salmon (Salmo salar), particularly health beneficial omega-3 long-chain polyunsaturated fatty acids (n-3 LC PUFA), remains an area of intense commercial interest given the increasing market restrictions placed on the supply of fishmeal and fish oil. The present study conducted a systematic review and subsequent analysis of published nutritional data from long-term growth trials using post-smolt Atlantic salmon to provide a summary of currently available information and to identify the most significant drivers of omega-3 levels in Atlantic salmon fillet tissue. Overall, there were relatively few studies which met the selection criteria and this had implications for further explanation of some results. Statistically significant regression models were generated for fillet DHA and fillet n-3 LC PUFA. Fish weight was a significant predictor in both models, and dietary 22:6n-3 (DHA) was an intuitive predictor of fillet DHA. Furthermore, dietary EPA and dietary 22:1 isomers were significant predictors of fillet n-3 LC PUFA

Identification of Radiopure Titanium for the LZ Dark Matter Experiment and Future Rare Event Searches

The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a detector containing a total of 10 tonnes of liquid xenon within a double-vessel cryostat. The large mass and proximity of the cryostat to the active detector volume demand the use of material with extremely low intrinsic radioactivity. We report on the radioassay campaign conducted to identify suitable metals, the determination of factors limiting radiopure production, and the selection of titanium for construction of the LZ cryostat and other detector components. This titanium has been measured with activities of $^{238}$U$_{e}$~$<$1.6~mBq/kg, $^{238}$U$_{l}$~$<$0.09~mBq/kg, $^{232}$Th$_{e}$~$=0.28\pm 0.03$~mBq/kg, $^{232}$Th$_{l}$~$=0.25\pm 0.02$~mBq/kg, $^{40}$K~$<$0.54~mBq/kg, and $^{60}$Co~$<$0.02~mBq/kg (68\% CL). Such low intrinsic activities, which are some of the lowest ever reported for titanium, enable its use for future dark matter and other rare event searches. Monte Carlo simulations have been performed to assess the expected background contribution from the LZ cryostat with this radioactivity. In 1,000 days of WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute only a mean background of $0.160\pm0.001$(stat)$\pm0.030$(sys) counts.Comment: 13 pages, 3 figures, accepted for publication in Astroparticle Physic