Specific Conversion Factors Research Articles

Functional assessment of citral dietary supplementation on growth performance, intestinal parameters, and specific activity of the digestive enzymes of Sardinella brasiliensis reared in recirculating aquaculture system

This study evaluated the effects of dietary supplementation with citral on growth performance and intestinal parameters, and specific activity of the digestive enzymes of Sardinella brasiliensis. 240 juvenile S. brasiliensis were randomly distributed in a recirculating aquaculture system (RAS) composed of 12 circular tanks of 150 L (n = 20 per tank). A diet without citral addition (control) and three diets containing different levels of citral inclusion (0.5, 1.0 and 2.0 mL kg*feed–1) were used in the fish feeding management during 20 days. The indexes of zootechnical performance, survival, weight gain, specific growth rate, feed conversion and condition factor of the fish were verified, as well as digestive enzymes and histological analysis. A significant positive relationship was found between citral supplementation and fish survival. In the specific activity of digestive enzymes, dietary citral supplementation at 2.0 mL* kg feed–1 increased lipase and amylase activity. Citral supplementation positively influenced the number of villi and intestinal crypt depth. Furthermore, the inclusion of citral at 0.5 mL kg*feed–1 increased the intestine diameter of the fish. The results of the experiment suggest that the addition of citral as an additive in the diet of S. brasiliensis improved the survival of fish.

Comparison of Monte Carlo tally techniques for dosimetry in a transmission-type x-ray tube.

This study discussed comparing result accuracy and time cost under different tally methods using MCNP6 for a novel transmission x-ray tube which was designed for the Auger electron yield with specific material (e.g. iodine). The assessment included photon spectrum, percent depth dose, mass-energy absorption coefficient corresponding to air and water, and figure of merit comparison. The mean energy of in-air phantom was from 41.8 keV (0 mm) to 40.9 keV (100 mm), and the mean energy of in-water phantom was from 41.41 keV (0 mm) to 45.2 keV (100 mm). The specific dose conversion factors based mass-energy absorption coefficient corresponding to different materials was established and the difference was less than 2% for the dose conversion of FMESH comparing to measurement data. FMESH had better figure of merit (FOM) than the F6 tally for the dose parameter assessment, which mean the dose calculation that focused on the superficial region could be assessed with more calculation efficiency by FMESH tally for this novel transmission x-ray tube. The results of this study could help develop treatment planning system (TPS) to quickly obtain the calculated data for phase space data establishment and heterogeneous correction under different physical condition settings.

How much wood do we use and how do we use it? Estimating Danish wood flows, circularity, and cascading using national material flow accounts

Understanding how much wood we use and how we use it has important implications for forest management, economic policy, and climate action. While individual wood streams are documented by various sources, a comprehensive, economy-wide mapping of wood use has been lacking in Denmark.Our study set out to produce a comprehensive national wood flow analysis for all wood products, to include harvest, import, export, and domestic flows through the economy, as well as to assess the level of circular and cascading wood resource use. We used the Physical Supply-Use Tables compiled by Statistics Denmark in combination with other sources to construct wood flows in m3 solid wood equivalent (SWE), enabling comparison throughout the processing chain with the standing natural resource.We estimated total Danish use of wood fibre in 2018 to be around 17.7 million m3 SWE, of which more than 15 million m3 was used for energy production. Most wood used in Denmark is imported, with a net import of more than 11 million m3 SWE. Apart from energy use the domestic wood processing, construction, and furniture industries are the largest users.By using mass balancing principles, we identified significant undocumented flows of wood from nature to the economy which are currently used for energy purposes, representing more than 1 million m3 SWE per year from 2015 to 2021, and we estimated the output of secondary wood products from the wood industry to be around 400,000 m3 SWE in 2018.According to Eurostat's Circular Material Use rate indicator, 8.4% of wood used is recycled and reused domestically, though with imported wood for energy excluded, the rate would be higher, around 17.8%. The overall cascading factor for wood in the Danish economy was calculated to 1.44, indicating that wood is used almost one and a half times before oxidation or final consumption.Ongoing monitoring of Danish wood flows would permit further analysis of any changes in patterns of use and reuse, and our estimates of wood flows could likely be improved with investigation of currently undocumented streams and country specific conversion factors.

Size Specific Dose Estimate in Abdominal Computed Tomography by AAPM TG Report-204 and AAPM TG Report-220

Purpose: The AAPM Task Group (TG) reports 204 and 220 presented methods for evaluation of patient dose by announcing the SSDE. The TG reports provide the Size Specific Conversion factors that can be multiplied to CTDIvol to calculate the patient dose in terms of SSDE constructed from Deff (AAPM TG-204) and Dw (AAPM TG-220). Our study presents a comparison of the two TG reports on SSDE for the routine Abdominal Computed Tomography. Materials and Methods: The scan lengths of abdomen were measured from computed tomography (CT) topographic images and cross-section at the mid-slice of the abdomen were measured from tomographic images of 61 adults who had undergone abdominal CT using the GE Advance Workstation (AWS) software. The Deff and Dw was computed according to TG- 204 and TG-220 reports, respectively. Further, we performed the correlation analysis between Deff and BMI, Dw and BMI and SSDE and BMI for both the TG- reports. The Student’s paired t-test was performed to compare the two of SSDE calculation methods. Results: The results confirm that the mean value of SSDE is 13.04 (𝑚𝐺𝑦) and 13.60 (𝑚𝐺𝑦) for AAPM TG-220 and AAPM TG-204, respectively. And a good positive correlation was observed between Deff and BMI, Dw and BMI with r = 0.67 and r = 0.68 respectively. Also, the weak correlation was observed between SSDE and BMI for both the TG - reports. The Student’s paired t-test shows that the two means of SSDE calculation methods are significantly different (𝑝< 0.01) in abdominal computed tomography. Conclusion: We confirm the AAPM TG reports 204/220 using clinical data for SSDE calculation that the mean SSDE values computed from Deff and Dw in abdomenal computed tomography are significantly different and we conclude that the SSDE calculated by Dw method gives a more accurate evaluation of SSDE for the patients undergoing abdominal computed tomography scan then the SSDE calculated by Deff method.

Tissue composition and storage duration affect the usefulness of generic wet-to-dry mass conversion factors in toxicology studies

All ecosystems are exposed to a variety of anthropogenic contaminants. The potential threat posed by these contaminants to organisms has prompted scores of toxicology studies. Contaminant concentrations in wildlife toxicology studies are inconsistently expressed in wet or dry mass units, or even on a lipid-normalized basis, but tissue composition is rarely reported, and the conversion between dry and wet mass units, notably, is often based on assumed empirical moisture contents in tissues. However, diverse factors (e.g., tissue, storage conditions) may affect tissue composition and render comparisons between studies difficult or potentially biased. Here, we used data on the concentration of mercury, a global pollutant, in tissues of red foxes (Vulpes vulpes) to quantify the effects of diverse variables on moisture and lipid contents, and their consequences on contaminant concentration in different tissues, when converting between wet and dry mass units (lipid extracted or not). We found that moisture content differed largely between organs, enough to preclude the use of a single conversion factor, and decreased by 1% per year when stored at −80 °C. Although most fox tissues had low lipid concentrations, lipid content affected water content and their extraction affected the wet to dry mass conversion factor. We thus recommend reporting tissue composition (at least water and lipid contents) systematically in toxicology studies of mercury specifically and of contaminants in general, and using tissue/species specific conversion factors to convert between dry and wet mass concentration.

Application of the Greenhouse Gas Protocol (GHG Protocol) and the ISO 14064-1: 2006 standard for the estimation of the carbon footprint at the National University of Jaen in 2021

The objective of the study is to estimate the Carbon Footprint of the National University of Jaen (UNJ), for the period 2021. The direct Scope 1 (fuel consumption) and indirect Scope 2 (electricity consumption) greenhouse gas (GHG) emissions were calculated from CO2, CH4 and N2O produced in 29 administrative offices of the university campus. The methodology used was proposed by the GHG Protocol and ISO 14064-1:2006. For fuel emission factors, the indicators established by the Intergovernmental Panel on Climate Change (IPCC) were used, and for electrical energy: 1.56E-01 tCO2/MWh, 9.70E-06 tCH4/MWh, 1.20E-06 tN2O/MWh, and specific conversion factors established by the Ministry of the Environment (MINAM) were used. The results show that a total of 29.3937 tCO2eq were emitted, being CO2 the predominant GHG (23.1364 t). Scope 1 contributed 15,6827 tCO2eq, occupying the highest participation with 53.35 %.

Design of a Low-Resolution Gamma-ray Spectrometer for Monitoring Radioactive Levels of Wastewater

Wastewater containing radioactive materials is stored in decay tanks, which are typically installed in basements to restrict public access. Specific activity is measured by a gamma spectroscopy system or a gamma counter for several hours per sample before discharge. To simplify the sample collection and measurement procedures before draining, the specific activity conversion coefficient for converting a measured value from a 1.5″ NaI (Tl) detector installed on a tank into specific activity was calculated. The experimental calibration was performed in a test water tank with a volume of 14 L filled with diluted reference source 18F, which is most commonly used in hospitals. The specific activity of the test water was measured with a gamma spectroscopy system using a high-purity germanium detector calibrated with certified reference materials. The change in the conversion coefficient according to the change in the volume of the water tank was corrected based on a Monte Carlo calculation. Finally, it was determined whether the minimum detectable activity (MDA) of this system was lower than that of the draining standard. The counts for the specific activity conversion factor and MDA were evaluated as 5.5389 × 1010 and 2.09 × 105 for 18F and for the one-hour count, respectively. The MDA was lower than the standard value. Thus, this system can be used for discharge determination.

Size-Specific Dose Estimates for Thoracic and Abdominal Computed Tomography Examinations at Two Moroccan Hospitals.

Size-specific dose estimates (SSDE) are the latest topic of interest in patient radiation-dose studies in computed tomography (CT). The aim of this study is to calculate and evaluate the doses (SSDE) by measuring the effective diameter (ED) of cross-sectional images collected during CT examinations of the chest and abdomen in Moroccan hospitals. Doses (SSDE) were calculated based on cross-sectional images by measuring the effective diameters of 75 patients in both examinations (45 for the thorax and 30 for the abdomen). Specific conversion factors for (ED) were used to convert the registered CTDIvol to SSDE, according to the instruction in the American Association of Physicists (AAPM) Report 204. In thoracic CT, the CTDIvol and SSDE values ranged from 5.8 to 10.7mGy (mean: 8.08) and 9.55 to 15.37mGy (mean: 12.13), respectively. For abdominal CT, CTDIvol and SSDE values ranged from 4.8 to 12.2mGy (mean: 7.95) and 8.01 to 14.15mGy (mean: 11.31), respectively. The results show that the SSDE is a useful tool and could potentially educate CT operators on its effective use as a way to optimize radiation dose instead of CTDIvol, in particular to establish diagnostic reference levels.

Intercomparison of equivalent black carbon (eBC) and elemental carbon (EC) concentrations with three-year continuous measurement in Beijing, China

Due to the lack of black carbon (BC) measurement data in some cases, elemental carbon (EC) is often used as a surrogate of BC, with a simple assumption that they are interchangeable. Such assumption will inevitably lead to uncertainties in radiative forcing estimation and health impact assessment. In order to quantitatively and systematically evaluate the relationship between BC and EC as well as factors responsible for their difference, 3-year collocated equivalent BC (eBC) and EC measurements with 1-h resolution were performed in Beijing, China continuously from 2016 to 2019. EBC concentration was measured by the multi-wavelength aethalometer (AE-33) based on optical analysis, while EC concentration was determined by semi-continuous OC/EC analyzer with thermal-optical method. The results showed that around 90% of eBC concentration was higher than that of EC, with average difference between eBC and EC as 1.21 μg m−3 (accounting for 33% of average eBC in Beijing). EBC and EC concentrations exhibited strong correlation (r = 0.90) during the whole study period, but the slopes (or eBC/EC ratio) and correlation coefficients varied across seasons (spring: 1.67 and 0.94; summer: 0.91 and 0.65; fall: 1.15 and 0.88; winter: 1.09 and 0.91, respectively). Based on the information from shell/core ratios by Single Particle Soot Photometer (SP2), source apportionment results by positive matrix factorization model, and chemical composition of PM2.5, the differences between eBC and EC concentrations were found to be primarily related to BC aging process and secondary components as evidenced by strong positive correlation with secondary species (e.g., secondary organic carbon and nitrate). This study provided seasonal specific conversion factors of eBC and EC in Beijing and helpful reference for other areas, which will contribute new knowledge of carbonaceous aerosol and reduce uncertainty in assessing future climate change and health studies of BC.

Comparison of methodologies for determining the carbon content in wood

New procedures seek to subsidize studies on biomass and carbon in forests and wood, mainly of tropical species. Thus, the work aimed to compare four methods of carbon determination in wood. A pre-dried sample of tropical wood was prepared and previously ground. In this sample, the carbon content was determined, applying four different methodologies, namely: conversion of organic matter, volumetric method, colorimetric method and dry combustion (LECO). The Tukey test was performed to determine the difference between the carbon levels obtained by each method. As a result, all methods differed statistically from each other: the colorimetric method underestimated the levels of organic carbon in a tropical wood; although widely used, the volumetric method has become obsolete; and the organic matter conversion method requires specific conversion factors for each material. So, from the environmental point of view and accuracy in obtaining data, the dry combustion method, in addition to being the closest to the standard, is also the one that generates less waste, being the most suitable to determinate carbon in wood.

Abstract 9731: Improved Risk Stratification with Vendor Independent Coronary Calcium Scores: Data from the Multi-Ethnic Study of Atherosclerosis (mesa)

Introduction: Coronary calcium score (CCS) plays a role in cardiovascular disease (CVD) risk calculators, but also reclassifies patients when considering statin therapy. However, CCS is still calculated following the Agatston methodology as developed on electron beam tomography (EBT) in the early 1990s. EBT has been replaced by multidetector computed tomography (MDCT). It is known that CCS differs substantially between MDCT-systems from different manufacturers, which can lead to risk reclassifications for 6.5% of examined individuals Aims: Our first aim was to identify CT system specific conversion factors to calculate a vendor-neutral Agatston score (rCCS). Second, we aimed to validate rCCS risk stratification for participants of the Multi-Ethnic Study of Atherosclerosis (MESA). Methods: As a first step, we calculated conversion factors between six state-of the-art CT systems and the reference EBT system used in the MESA study. For this purpose, we scanned two calcium-containing inserts, which were placed in a small and large anthropomorphic thorax phantom. Linear regression was used to find a model which converts vendor-specific CCS to vendor-independent rCCS. As a second step, we recalculated the non-zero Agatston scores of 550 MESA participants. Following the Youden method, we calculated an optimal cut-off point for rCCS. Results: The linear model for each CT system allowed for prediction of Agatston scores as measured on the EBT system (p=0.001). rCCS for GE LightSpeed, used in MESA, was calculated as rCCS=0.049+1.97xMESA Agatston score and rCCS=1.903+1.37xMESA Agatston score for small and large size, respectively. The median MESA Agatston score was 100.5 (26.3-379.5), and the median rCCS was 135.8 (35.6-508.6). Participants were assigned to a high Agatston category with Agatston scores exceeding 100 (50.2%) and 187 (43.1%) for CCS and rCCS, respectively. The hazard ratio for CVD of individuals with high Agatston scores increased from 1.88 (95%CI: 1.31-2.68, p=0.001) with MESA scores to 2.15 (95%CI: 1.52-3.05, p=0.001) with rCCS. rCCS reclassified 39 participants into the lower risk group, without statin therapy. Conclusions: In conclusion, based on these preliminary results, rCCS may improve patient classification for statin therapy.

Mean Glandular Dose Measurement in Three Mammography Centers in Kashan: An approach to Provide a Local DRL

Purpose: Mammography is the most important diagnostic modality for early detection of breast cancer, however, concerns related to the side effects induced by ionizing radiation are still present. In the current study, the Mean Glandular Dose (MGD) values for mammography examinations as well as a local Diagnostic Reference Level (DRL) were obtained for mammography centers in Kashan, Iran. Materials and Methods: Three mammography devices from three radiology centers were selected to obtain the MGD values of mammography examinations. To assess the MGD values, the technical parameters for patients’ imaging at these three radiology centers were extracted. Then, the incident air kerma (in mGy) value received by each patient was measured by a UNIDOS E electrometer (PTW, Germany) along with a SFD mammography ionization chamber (PTW, Germany). Finally, the incident air kerma values were converted to the MGD values by specific conversion factors. Based on the obtained MGD values, a local DRL was also established for mammography examinations. Results: Mean MGD values per exposure were obtained 2.39 ± 1.46 mGy for Right Craniocaudal (RCC), 2.64 ± 1.67 mGy for Left Craniocaudal (LCC), 2.82 ± 1.89 mGy for Right Mediolateral Oblique (RMLO), and 3.09 ± 1.90 mGy for left mediolateral oblique views. Moreover, a local DRL obtained from mammography examinations, which was established as the overall median of MGD value, was 1.72 mGy (1.91 mGy for digital and 1.32 mGy for analog mammography). Conclusion: The MGD values for different views obtained in this study are in the range of previously reported values. Considering the European guidelines for quality assurance in breast cancer screening and diagnosis, it can be mentioned that the obtained DRL was less than the recommended dose level (2.0 mGy).

CT pulmonary angiography in pregnancy: Specific conversion factors to estimate effective radiation dose from dose length product: A retrospective cross-sectional study across a multi-hospital integrated healthcare network

PurposeEffective dose describes radiation-related cancer risk from CT scans and is estimated using a readily available conversion factor (k-factor), which varies by body part and study type. To purpose of this study is to determine the specific k-factor for CTPA in pregnant patients and its predictive factors. MethodsThis retrospective cross-sectional study evaluates CTPA in pregnancy across a multihospital integrated healthcare network from January 2012 to April 2017. Patient and CTPA-related data were obtained from the electronic health record and a radiation dose index monitoring system. Each patient’s effective dose was determined by patient-specific Monte-Carlo simulation with Cristy phantoms and divided by patient dose-length-product to determine the k-factor. K-factor for pregnant patients was compared to the k-factor for adults of standard physique with a one-sample t-test. Bivariate and multivariable analyses were performed for patient and CT predictors of k-factor. ResultsA total of 534 patients were included. The mean k-factor for all patients was 0.0249 (mSv·mGy−1·cm−1), 78% greater than k-factor of 0.014 (p < 0.001) suggested for the general adult population. Multivariable analysis demonstrated lower k-factors with increasing pitch (p = 0.0002), patient size (p < 0.001), and scan length (p < 0.0001). The 120 kVp (p < 0.001) and 140 kVp (p = 0.0028) analyses showed a larger k-factor than 80 and 100 kVp studies combined. ConclusionsSpecific k-factor for CTPA in pregnant patients is greater than the previously used generic chest CT k-factor and should be used to estimate the effective dose for CTPA exams in pregnancy.

Assessment of Standardization and International Scale (IS) Alignment Efforts of BCR-ABL1 Testing By the Chinese CML Alliance in an International External Quality Assessment Program

Sequential BCR-ABL1 mRNA level measurement by reverse transcription quantitative polymerase chain reaction (RT-qPCR) is embedded in management of chronic myeloid leukaemia (CML) patients.United Kingdom National External Quality Assessment Service for Leucocyte Immunophenotyping (UK NEQAS LI) has been providing External Quality Assessment (EQA)/Proficiency Testing (PT) to 200 laboratories undertaking BCR-ABL1 RT-qPCR analysis since 2007.The Chinese CML Alliance (CCA), established in 2011 for the purpose of the standardization of BCR-ABL1 measurement includes 58 laboratories to date. Peking University People's Hospital (PUPH), the Chinese regional reference centre, has acquired conversion factors (CFs) for reporting BCR-ABLIS through sample exchanges with the Adelaide IMVS reference laboratory. Other members acquired their laboratory specific CFs thorough sample exchange with PUPH, and their CFs were regularly revalidated through testing distributed samples by PUPH.We reviewed performance of CCA laboratories in UK NEQAS LI's BCR-ABL1 Quantification program to evaluate if technical standardization initiatives and local result alignment to the International Scale (IS) (defined as BCR-ABLIS) increased accuracy and precision of BCR-ABL1 measurement by CCA labs.MethodsThis study was facilitated by Diaceutics and Novartis. 5 CCA laboratories were included in 3 EQA/PT send-outs provided by UK NEQAS LI. Six standard samples and one additional educational sample were tested by CCA laboratories, alongside up to 207 other international participants. Samples comprised two lyophilized cell line mixtures containing dilutions of BCR-ABL1 (e14a2) positive K562 cells in a background of BCR-ABL1 negative HL60 cells.For each send-out, CCA laboratories were assessed against the IS robust mean BCR-ABLIS for each sample tested and their proximity to the robust mean log reduction between two standard trial samples tested, providing information on CCA laboratory IS alignment and assay linearity.ResultMedian BCR-ABLIS sample levels in this study (calculated from all participant data) ranged from 6.1% to 0.002% (Figure 1). All five CCA laboratories used in-house based methods to measure BCR-ABL1; 3 based their in-house method on the Europe Against Cancer protocols. ABL1 was detected in all samples by the 5 centres with 4 achieving ABL1 levels >100,000. Additionally, 4/5 detected BCR-ABL1 transcript in all seven samples but 1/5 laboratories failed to detect any transcript in 1 sample (the sample that had the lowest level of transcript (median BCR-ABLIS = 0.002%; ~MR 4.7)).4/5 laboratories measured BCR-ABL1IS levels within +2 SD of the robust means for individual sample and log reduction analysis undertaken between samples for each send-out.DiscussionThis study shows that efforts by the CCA to standardize BCR-ABL1 measurement and align local results to the IS have been successful. Satisfactory results (within +2SD of the robust mean) were obtained in 4/5 laboratories providing reassurance that patient testing in these laboratories is accurate and precise. A root cause analysis undertaken in the laboratory with results >+2SD from the robust mean found a pre-analytical sample transposition error that when reanalyzed was within the acceptable range for both individual sample and log reduction results.The study showed that some CCA laboratories omitted the BCR-ABL1 standard curve, something not recommended in technical guidelines (Foroni et al., 2011) as erroneous results may occur due to unrecoqnized assay drift or suboptimal amplification. Standard curves for both ABL1 and BCR-ABL1 should always be run; however it is acceptable to run a standard curve each day for multiple runs but these must use the same master mix used for the sample quantification (Foroni et al., 2011).Future studies will include more laboratories in the CCA network to assess if the use of internationally recognized calibrants can achieve even greater standardization.Figure 1. All participant BCR-ABLIS results for the 7 samples tested. Blue markers = non CCA laboratories; red marker = CCA laboratories. Long horizontal black lines = IS median. Short horizontal black lines = range.*Ya-Zhen Qin andStuart Scott contributed equally to this study. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Evaluating Total Organic Carbon Derived Algae Biomass Productivity Compared with Ash Free Dry Weight Measurement

Algae are the third generation feedstock for production of biofuels, high value chemicals, and antioxidants. Considering gradual depletion of fossil fuel, biofuel production from algae could be an attractive proposition. In recent years, biofuel production from algae has fascinated many researchers worldwide. Sustainability of this effort directly depends on daily areal productivity of biomass from cultivation, measured by dry weight (DW) or ash free dry weight (AFDW) basis. This method is based on the quantification of total suspended solids and volatile suspended solids using filtration, washing, drying and ashing of algal samples. However, AFDW method is time consuming, laborious, and expensive. Hence, an automated approach of using total organic carbon of centrifuged algae pellet (TOC-P) for calculating algal biomass productivity is evaluated. Accurate species specific conversion factors were determined to derive AFDW from TOC-P values using two different analytical methods, TOC-P and carbon per cent. A linear correlation was obtained between TOC-P and AFDW, carbon per cent of algae pellets was analysed by CHNS analyser for Picochlorum sp. and Chlorella sp. to establish species specific conversion factor. Once the TOC-P is measured in an algal sample, the AFDW can be calculated using the species specific conversion factors. The total organic carbon of algae pellets (TOC-P) estimation was found to be more than 11 times economical as compared to conventional gravimetric method (AFDW). The time and manpower required for AFDW measurement were estimated more than two times higher as compared to TOC-P. Thus, TOC-P is much more economic, quicker and convenient alternative method as compared to conventional AFDW for biomass productivity measurement.

Nitrogen-to-Protein Conversion Factors for Edible Insects on the Swiss Market: T. molitor, A. domesticus, and L. migratoria.

With an increasing worldwide demand for animal protein, insects are becoming a promising sustainable option for meat protein replacement. However, reported protein contents of insects are often overestimated when calculated as “crude protein” = 6.25 × nitrogen content (N), compared to true protein contents quantified from the sum of amino acid (AA) residues. In this study, the main two types of usual nitrogen-to-protein conversion factors kp and kA were determined on the basis of true protein/total nitrogen and true protein/protein nitrogen, respectively, with focus on the three insect species legally sold on the Swiss food market. T. molitor (mealworm larvae), A. domesticus (house crickets), and L. migratoria (locusts) from various breeders were analyzed for total and amide nitrogen, chitin, and AA composition. Careful control experiments of insect samples spiked with a protein standard were conducted to establish the recovery of true protein, which was with >95% excellent. Mealworms, crickets, and locusts exhibited similar AA-profiles and true protein contents of 51, 55, and 47 g/100 g (dry weight basis), respectively. Specific conversion factors kp showed little variability between the three insect species with 5.41, 5.25, and 5.33 for mealworms, crickets, and locusts, respectively, and confirmed an average ~17% overestimation of protein contents when using 6.25 × N. The determined average kp of 5.33 is supported by extracted literature data and is suggested for general use instead of 6.25 × N to calculate more accurate insect protein contents, whereas the average pure protein conversion factor kA of 5.6 is proposed for use in the case of insect protein isolates.

Assessment of radiation doses received by patients during endoscopic retrograde cholangiopancreatography according to disease location.

patients are exposed to ionizing radiation during endoscopic retrograde cholangiopancreatography (ERCP). Radiation dose depends on multiple factors. The goal of this study was to assess fluoroscopy time (FT), radiation doses and effective dose (ED) during ERCP according to the condition being treated. a descriptive study was performed of 369 consecutive ERCPs from January 2017 to June 2019. Patient demographic and procedure data were collected. FT, cumulative dose area product (DAP), fluoroscopy DAP, DA fluoroscopy, air kerma, and number of radiographs were assessed. ED was estimated using specific conversion factors. the mean age was 73.34 years and 193 subjects were male. Mean FT was 4.56 ± 0.17 min, cumulative DAP was 2,056.73 ± 188.83 cGycm2, fluoroscopy DAP was 1,722.90 ± 82.26 cGycm2 and air kerma was 85.84 ± 4.93 mGy. The number of radiographs was 2.10 ± 0.07 and the mean ED was 5.34 ± 0.49 mSv. FT was significantly longer for choledocholithiasis (CL), proximal malignant biliary stricture (PMBS) and distal malignant biliary stricture (DMBS) versus others (OT). Cumulative DAP was higher for PMBS (p < 0.002). FT, cumulative DAP, fluoroscopy DAP and air kerma values were significantly higher for complicated CL as compared to simple CL. ED was higher for CL, DMBS and PMBS, but only significantly (p < 0.002) for PMBS. FT for ERCP is variable and increases with exploration difficulty. Thus, it is longer in the case of PMBS, as well as with the amount of radiation received by the patients and ED.

Mean glandular dose in digital mamography in women with breast implants

Purpose: Mean Glandular Dose (MGD) is the quantity related to the risk of radiation-induced breast cancer. This study aimed to evaluate the MGD in screening mammography for women with breast implants. Methods: This retrospective study used data of 2680 mammographies of 335 asymptomatic women with mammary implants examined in a digital direct x-ray unit. Each woman had a total of eight images: four in standard views and four with posterior displacement of the implant (ID). Data on kV, mAs, target/filter combination, compressed breast thickness and MGD were obtained from the DICOM header of the stored images. Quantitative variables were presented through descriptive statistics for median (5th–95th percentiles); and the qualitative variables were presented by numbers and percentages. Mean glandular doses of standard views and ID views were compared and statistical analysis was used to assess the influence of implant position, breast glandularity and thickness on mean glandular doses. Results: Median MGD for standard views were 3.30 (2.60–4.00) mGy for CC and 3.31 (2.70–4.20) mGy for MLO. For ID views, median were 1.20 (0.90–2.20) mGy and 1.40 (0.97–3.74) mGy for CC and MLO views, respectively. Median MGD for the whole examination of women with breast implants was 9.60 (7.92–12.07) mGy, ranging from 6.25 to 21.50 mGy. When comparing MGD median for standard and ID views it was found a statistically significant difference (p < 0.05), with higher doses for the standard views due to the greater compressed breast thickness in these views. It was observed that, in the standard views, MGD decreases with increasing breast thickness due to the manual radiographic techniques used to expose the women. It was also observed that implant position does not affect MGD in breast augmentation mammography. Conclusion: Mammography of women with mammary implants gives higher radiation doses when compared with those without implants. For more accurate dose assessment in augmented breast mammography, it is necessary that specific conversion factors for the calculation of MGD based on air kerma at entrance of breasts with implants are made available.

Biological nitrogen fixation in peatlands: Comparison between acetylene reduction assay and 15N2 assimilation methods

Biological Nitrogen Fixation (BNF) is an essential microbial process supplying available nitrogen (N) to Sphagnum mosses in ombrotrophic peatlands. Acetylene Reduction Assay (ARA) and the 15N2 assimilation are the main methods used for the measurement of BNF. ARA is used as a proxy where the moles of ethylene (C2H4) produced from acetylene (C2H2) during incubation of mosses and peat are used to estimate the moles of N being fixed using a conversion factor (CF), thus relating the moles of C2H4 produced to the moles of N fixed. A theoretical CF of 3:1 originally developed for agricultural soils using pure nitrogenase enzymes is in use; in some cases a site specific CF is determined through parallel incubation of mosses and peat with ARA and 15N2 assimilation methods to enable the application of ARA for subsequent BNF measurement at high resolution and low cost. However, in recent literature, the reported site and/or species specific CF for peatlands varies by an order of magnitude, thus raising the question if measured CFs are robust and consistent enough for the estimation of BNF in peatlands. Thus, we measured BNF using the ARA and the direct 15N2 assimilation methods in three different peatlands across the UK during the growing season over two years. The incubations were carried out in parallel on the dominant Sphagnum spp. (S. cuspidatum, S. fallax, S. capillifolium, and S. papillosum) and top bulk peat (0–15 cm). Additional incubations were performed using the direct 15N2 assimilation method with and without C2H2 addition to evaluate if C2H2 was supressing N assimilation through BNF all together in peatlands. According to the results, the CF varied from 0.001 to 5.363, with a median CF of 0.028 for both mosses and peat, which is far lower than the theoretical 3:1 CF. The CF was also highly variable with differences up to 3 orders of magnitude across the different Sphagnum species. The measured CF between years for the same species and across the three peatland sites varied significantly suggesting an inconsistent performance of ARA against the 15N assimilation method. The generally low but highly varied CFs measured under this study shows that C2H2 differentially interferes with the activity of diazotrophic microbes, which results in an inconsistent CF at species, and site scales, and over time. In conclusion, ARA is not suitable as a proxy method for estimating and/or modelling BNF in peatlands.

Survival inequalities and redistribution in the Italian pension system

The public pension system in Italy is a defined contribution scheme based on the principle of actuarial fairness. The pension annuity is calculated starting from capitalised value and the Legislated Conversion Factors (LCFs) for each retirement age. The demographic parameters used by legislators in computing the LCFs are the survival probabilities of an average Italian, irrespective of gender or any characteristic except age. The aim of this paper is to analyse the impact of the differences in survival between men and women, and between individuals with different educational levels, on the calculation of the pension annuity, starting from the specific Conversion Factors (CFs). The gap between the LCFs and the factors obtained by allowing for differential survival across gender and socio-demographic groups (CFs) gives us a means of making a quantitative assessment of the implicit redistributive impacts of the annuity redistribution from individuals with a lower life expectancy to individuals with a higher life expectancy.