脱甲河氢氧同位素组分时空分布特征及其影响因素

河水氢氧稳定同位素特征是研究水体转化和示踪水循环过程的重要内容.为研究河水氢氧稳定同位素特征,揭示河水补给来源,于2017年4—8月对亚热带农业小流域脱甲河4级河段(S_1、S_2、S_3和S_4)水体氢(D)、氧(¹⁸O)稳定同位素进行了监测,分析其时空动态特征和过量氘(d-excess)的变化规律,并探讨了它们与降水、高程和水质等影响因子的相关关系.结果表明:δD、δ¹⁸O和d-excess的变化范围分别在-43.17‰^-26.43‰(-35.50‰±5.44‰)、-7.94‰^-5.70‰(-6.86‰±0.74‰)和16.77‰~23.49‰(19.39‰±1.95‰).受季风环流的影响,δD和δ¹⁸O具有明显的季节变化特征,即春季(δD和δ¹⁸O为-29.88‰±3.31‰和-6.18‰±0.57‰)>夏季(δD和δ¹⁸O为-39.25‰±2.65‰和-7.32‰±0.42‰);空间上,δD和δ¹⁸O表现出明显的沿程变化,随着采样点的位置到河流源头的距离波动增加,δD为S_118O为S_118O与水温呈显著负相关(δD:r=-0.92;δ¹⁸O:r=-0.88);δ¹⁸O与海拔呈显著负相关(r=-0.96);在空间上,δ¹⁸O与水温呈显著正相关(r=0.98);δD和δ¹⁸O与降水量呈不显著负相关.     

Effects of leaf water evaporative 2H‐enrichment and biosynthetic fractionation on leaf wax n‐alkane δ2H values in C3 and C4 grasses

Leaf wax n‐alkane δ²H values carry important information about environmental and ecophysiological processes in plants. However, the physiological and biochemical drivers that shape leaf wax n‐alkane δ²H values are not completely understood. It is particularly unclear why n‐alkanes in grasses are typically ²H‐depleted compared with plants from other taxonomic groups such as dicotyledonous plants and why C3 grasses are ²H‐depleted compared with C4 grasses. To resolve these uncertainties, we quantified the effects of leaf water evaporative ²H‐enrichment and biosynthetic hydrogen isotope fractionation on n‐alkane δ²H values for a range of C3 and C4 grasses grown in climate‐controlled chambers. We found that only a fraction of leaf water evaporative ²H‐enrichment is imprinted on the leaf wax n‐alkane δ²H values in grasses. This is interesting, as previous studies have shown in dicotyledonous plants a nearly complete transfer of this ²H‐enrichment to the n‐alkane δ²H values. We thus infer that the typically observed ²H‐depletion of n‐alkanes in grasses (as opposed to dicots) is because only a fraction of the leaf water evaporative ²H‐enrichment is imprinted on the δ²H values. Our experiments also show that differences in n‐alkane δ²H values between C3 and C4 grasses are largely the result of systematic differences in biosynthetic fractionation between these two plant groups, which was on average ?198‰ and?159‰ for C3 and C4 grasses, respectively.     

Estimation of Free‐Living Energy Expenditure Using a Novel Activity Monitor Designed to Minimize Obtrusiveness

The aim of this study was to investigate the ability of a novel activity monitor designed to be minimally obtrusive in predicting free‐living energy expenditure. Subjects were 18 men and 12 women (age: 41 ± 11 years, BMI: 24.4 ± 3 kg/m²). The habitual physical activity was monitored for 14 days using a DirectLife triaxial accelerometer for movement registration (Tracmor_D) (Philips New Wellness Solutions, Lifestyle Incubator, the Netherlands). Tracmor_D output was expressed as activity counts per day (Cnts/d). Simultaneously, total energy expenditure (TEE) was measured in free living conditions using doubly labeled water (DLW). Activity energy expenditure (AEE) and the physical activity level (PAL) were determined from TEE and sleeping metabolic rate (SMR). A multiple‐linear regression model predicted 76% of the variance in TEE, using as independent variables SMR (partial‐r² = 0.55, P < 0.001), and Cnts/d (partial r² = 0.21, P < 0.001). The s.e. of TEE estimates was 0.9 MJ/day or 7.4% of the average TEE. A model based on body mass (partial‐r² = 0.31, P < 0.001) and Cnts/d (partial‐r² = 0.23, P < 0.001) predicted 54% of the variance in TEE. Cnts/d were significantly and positively associated with AEE (r = 0.54, P < 0.01), PAL (r = 0.68, P < 0.001), and AEE corrected by body mass (r = 0.71, P < 0.001). This study showed that the Tracmor_D is a highly accurate instrument for predicting free‐living energy expenditure. The miniaturized design did not harm the ability of the instrument in measuring physical activity and in determining outcome parameters of physical activity such as TEE, AEE, and PAL.     

Seasonal Variation in Total Energy Expenditure and Physical Activity in Dutch Young Adults

Objective: The impact of season on energy expenditure and physical activity is not well quantified. This study focused on summer‐winter differences in total energy expenditure (TEE) and physical activity. Research Methods and Procedures: Twenty‐five healthy Dutch young adults, living in an urban environment, were measured in the summer season and the winter season. TEE was measured using doubly labeled water, and sleeping metabolic rate (SMR) was measured during an overnight stay in a respiration chamber. Subsequently, the physical activity level (PAL = TEE/SMR) and activity‐related energy expenditure [(0.9 × TEE) ? SMR] were calculated. Maximal mechanical power (W_max) was determined with an incremental test on a cycle ergometer. Body composition was measured with hydrostatic weighing and deuterium dilution using Siri's three‐compartment model. Results: There was no difference in TEE between seasons. PAL was higher in summer than in winter (1.87 ± 0.22 vs. 1.76 ± 0.18; p < 0.001), and the difference was higher for men than for women (0.20 ± 0.14 vs. 0.05 ± 0.16; p = 0.04). The difference in PAL between seasons was dependent on the initial activity level. There was a strong linear relation (R² = 0.48) between PAL and physical fitness (W_max/fat‐free mass), but W_max/fat‐free mass did not change between seasons in response to the lower PAL in winter. Discussion: The extent of the changes in PAL is of physiological significance, and seasonality in physical activity should be taken into account when studying physical activity patterns or relationships between physical activity and health.     

Significant Difference in Hydrogen Isotope Composition Between Xylem and Tissue Water in Populus Euphratica

Deuterium depletions between stem water and source water have been observed in coastal halophyte plants and in multiple species under greenhouse conditions. However, the location(s) of the isotope fractionation is not clear yet and it is uncertain whether deuterium fractionation appears in other natural environments. In this study, through two extensive field campaigns utilizing a common dryland riparian tree species Populus euphratica Oliv., we showed that no significant δ¹⁸O differences were found between water source and various plant components, in accord with previous studies. We also found that no deuterium fractionation occurred during P. euphratica water uptake by comparing the deuterium composition (δD) of groundwater and xylem sap. However, remarkable δD differences (up to 26.4‰) between xylem sap and twig water, root water and core water provided direct evidence that deuterium fractionation occurred between xylem sap and root or stem tissue water. This study indicates that deuterium fractionation could be a common phenomenon in drylands, which has important implications in plant water source identification, palaeoclimate reconstruction based on wood cellulose and evapotranspiration partitioning using δD of stem water.     

Multi-point estimation of total energy expenditure: a comparison between zinc-reduction and platinum-equilibration methodologies

Reducing water to hydrogen gas by zinc or uranium metal for determining D/H ratio is both tedious and time consuming. This has forced most energy metabolism investigators to use the "two-point" technique instead of the "Multi-point" technique for estimating total energy expenditure (TEE). Recently, we purchased a new platinum (Pt)-equilibration system that significantly reduces both time and labor required for D/H ratio determination. In this study, we compared TEE obtained from nine overweight but healthy subjects, estimated using the traditional Zn-reduction method to that obtained from the new Pt-equilibration system. Rate constants, pool spaces, and CO2 production rates obtained from use of the two methodologies were not significantly different. Correlation analysis demonstrated that TEEs estimated using the two methods were significantly correlated (r=0.925, p=0.0001). Sample equilibration time was reduced by 66% compared to those of similar methods. The data demonstrated that the Zn-reduction method could be replaced by the Pt-equilibration method when TEE was estimated using the "Multi-Point" technique. Furthermore, D equilibration time was significantly reduced.     

Identifying groundwater‐fed climate refugia in remote arid regions with citizen science and isotope hydrology

1. Groundwater and surface water‐fed systems act as biodiversity hotspots and ecological refuges and evolutionary refugia in arid regions. Groundwater‐dominated systems are sustained by underground aquifers that are recharged by rain that has fallen in the distant past, while surface water‐dominated systems are fed by recent local rain or floods. Some waterbodies are fed by a mixture of these sources. Perennial, groundwater‐dominated systems will act as refuges and refugia under future rainfall declines associated with global warming. We sought to identify climate refugia, based on groundwater dominance, by using isotope hydrology to characterise water samples collected by citizen scientists across arid central Australia.
2. There is a linear relationship between hydrogen isotopes (²H/¹H, δ²H) and oxygen isotopes (¹⁸O/¹⁶O, δ¹⁸O) in rainfall. This relationship is known as the meteoric water line (MWL). By comparing our samples with the Australian MWL, and developing a local evaporation line, we were able to test the hypotheses that groundwater‐dominated systems will follow the Australian MWL while temporary systems follow the local evaporation line, and, accordingly, distinguish between groundwater and surface water‐dominated systems. The isotopic composition of samples collected over a 36‐month period was determined using isotope ratio infrared spectrometry. The electrical conductivity of each sample was recorded to determine where freshwater is available for biota within this arid region.
3. Over 240 water samples were collected from 62 waterbodies and seven bores (groundwater wells) spanning an area of more than 250,000 km². Approximately 75% of the samples were collected by citizen scientists and 25% by research scientists.
4. Twenty groundwater‐dominated waterbodies, characterised by a small range of δ²H and δ¹⁸O values (c. ?55 to ?20‰ and c. ?9 to ?3‰, respectively) clustered around the long‐term mean composition of rainfall (δ²H = ?37.5‰, δ¹⁸O = ?6.4‰), were identified as future evolutionary refugia. These sites are likely to contain water through the most severe of droughts and will be critically important for the persistence of water‐dependent species.
5. Based on their isotopic composition, we identified 45 waterbodies (rockholes/waterholes) as temporary or ephemeral (δ²H c. ?40 to ?100‰ and δ¹⁸O c. ?4 to +25‰), that is, with no evidence of groundwater inflow. These, together with waterbodies supported by a mix of groundwater and surface water, can act as stepping stones and form part of the aquatic mosaic that is critical to supporting species in arid regions. Over two‐thirds of the waterholes sampled were very fresh (electrical conductivity <0.8 mS/cm), indicating that they provide the freshwater needed to support much of the regional aquatic and terrestrial fauna.
6. All evolutionary refugia are located within protected areas (i.e. national parks or Indigenous Protected Areas), but some are subject to the impacts of feral animal species and invasive plants. Our findings indicate where control programmes and restoration actions can be prioritised to support biodiversity conservation and climate change adaptation. Our approach, combining citizen science and isotope hydrology, can be used to identify future refugia in other remote and arid regions where water scarcity is likely to increase under global climate change.

     

Cover plus: ways of measuring plant canopies and the terms used for them

Aim: To clarify the concepts and terms that have been used in recording plant canopies and the methods used for measuring them. Concepts: The concepts considered are cover, top cover, repeated cover, number of layers, proportion of repeated cover and leaf area index (LAI). Variants include canopy cover, basal area and leaf area density. Other terms have been used in the past, some are now ambiguous and some are counter‐intuitive. Measurement: Cover and its related concepts can be measured by point intercept, line intercept, angle sampling, charting and image analysis, canopy transmittance, complete enumeration, clipping and allometry. The common procedure of adding the cover of individual species to calculate a “total cover” is invalid: a nonsense number is produced. Other measures of abundance: Cover‐abundance, density, frequency, biomass and calorific values can also be used to measure abundance. They are related to cover. Especially, shoot frequency at a point is cover (the point intercept method). Subjective estimates: There are severe problems with cover‐abundance scales, such as that of Braun‐Blanquet. Estimation of abundance “by eye”, by “informed guess”, etc. has too often compromised results in vegetation science.     

Validation of the TracmorD Triaxial Accelerometer to Assess Physical Activity in Preschool Children

Objectives: To assess validity evidence of Tracmor_D to determine energy used for physical activity in 3‐4‐year‐old children. Design and Methods: Participants were randomly selected from GECKO Drenthe cohort (n = 30, age 3.4 ± 0.3 years). Total energy expenditure (TEE) was measured using the doubly labeled water method. Sleeping metabolic rate (SMR) was measured by indirect calorimetry (Deltatrac). TEE and SMR were used to calculate physical activity level (PAL) and activity energy expenditure (AEE). Physical activity was monitored using a DirectLife triaxial accelerometer, Tracmor_D with activity counts per minute (ACM) and activity counts per day (ACD) as outcome measures. Results: The best predictor for PAL was ACM with gender and weight, the best predictor for AEE was ACM alone (backward regression, R² = 0.50, P = 0.010 and R² = 0.31, P = 0.011, respectively). With ACD, the prediction model for PAL included ACD, height, gender, and sleep duration (R² = 0.48, P = 0.033), the prediction model for AEE included ACD, gender and sleep duration (R² = 0.39, P = 0.042). The accelerometer was worn for 5 days, but 3 days did not give a different estimated PAL. Conclusion: Tracmor_D provides moderate‐to‐strong validity evidence that supports its use to evaluate energy used for physical activity in 3‐4‐year‐old children.     

Body size estimation of small‐bodied humans: Applicability of current methods

Body size (stature and mass) estimates are integral to understanding the lifeways of past populations.Body size estimation of an archaeological skeletal sample can be problematic when the body size or proportions of the population are distinctive. One such population is that of the Holocene Later Stone Age (LSA) of southern Africa, in which small stature (mean femoral length = 407 mm, n = 52) and narrow pelves (mean bi‐iliac breadth = 210 mm, n = 50) produce a distinctive adult body size/shape, making it difficult to identify appropriate body size estimation methods. Material culture, morphology, and culture history link the Later Stone Age people with the descendant population collectively known as the Khoe‐San. Stature estimates based on skeletal “anatomical” linear measures (the Fully method) and on long bone length are compared, along with body mass estimates derived from “morphometric” (bi‐iliac breath/stature) and “biomechanical” (femoral head diameter) methods, in a LSA adult skeletal sample (n = 52) from the from coastal and near‐coastal regions of South Africa. Indices of sexual dimorphism (ISD) for each method are compared with data from living populations. Fully anatomical stature is most congruent with Olivier's femur + tibia method, although both produce low ISD. McHenry's femoral head body mass formula produces estimates most consistent with the bi‐iliac breadth/staturemethod for the females, although the males display higher degrees of disagreement among methods. These results highlight the need for formulae derived from reference samples from a wider range of body sizes to improve the reliability of existing methods. Am J Phys Anthropol, 2010. © 2009 Wiley‐Liss, Inc.     

Taxon-specific variation in the stable isotopic signatures (δ13C and δ15N) of lake phytoplankton

1. The variability in the stable isotope signatures of carbon and nitrogen (δ¹³C and δ¹⁵N) in different phytoplankton taxa was studied in one mesotrophic and three eutrophic lakes in south‐west Finland. The lakes were sampled on nine to 16 occasions over 2–4 years and most of the time were dominated by cyanobacteria and diatoms. A total of 151 taxon‐specific subsamples covering 18 different phytoplankton taxa could be isolated by filtration through a series of sieves and by flotation/sedimentation, followed by microscopical identification and screening for purity. 2. Substantial and systematic differences between phytoplankton taxa, seasons and lakes were observed for both δ¹³C and δ¹⁵N. The values of δ¹³C ranged from ?34.4‰ to ?5.9‰ and were lowest in chrysophytes (?34.4‰ to ?31.3‰) and diatoms (?30.6‰ to ?26.6‰). Cyanobacteria were most variable (?32.4‰ to ?5.9‰), including particularly high values in the nostocalean cyanobacterium Gloeotrichia echinulata (?14.4‰ to ?5.9‰). For δ¹³C, the taxon‐specific amplitude of temporal changes within a lake was usually <1–8‰ (<1–4‰ for microalgae alone and <1–8‰ for cyanobacteria alone), whereas the amplitude among taxa within a water sample was up to 31‰. 3. The values of δ¹⁵N ranged from ?2.1‰ to 12.8‰ and were high in chrysophytes, dinophytes and diatoms, but low in the nitrogen‐fixing cyanobacteria Anabaena spp., Aphanizomenon spp. and G. echinulata (?2.1‰ to 1.6‰). Chroococcalean cyanobacteria ranged from ?1.4‰ to 8.9‰. For δ¹⁵N, the taxon‐specific amplitude of temporal changes within a lake was 2–6‰, (2–6‰ for microalgae alone and 2–4‰ for cyanobacteria alone) and the amplitude among taxa within a water sample was up to 11‰. 4. The isotopic signatures of phytoplankton changed systematically with their physical and chemical environment, most notably with the concentrations of nutrients, but correlations were non‐systematic and site‐specific. 5. The substantial variability in the isotopic signatures of phytoplankton among taxa, seasons and lakes complicates the interpretation of isotopic signatures in lacustrine food webs. However, taxon‐specific values and seasonal patterns showed some consistency among years and may eventually be predictable.     

Accuracy and precision of age determination using growth layer groups for California sea lions (Zalophus californianus) with known ages

Age determination from counts of growth layer groups (GLGs) in tooth dentine is a common method for aging marine mammals. Using known‐aged animals, we validated this method for acid etched teeth of California sea lions (CSLs), Zalophus californianus. Between 1991 and 2013, the upper left canine (n = 33) was collected opportunistically during necropsy from animals tagged or branded as pups that later died. Overall, 55%–61% of age estimates by GLG counting were within 1 yr of the known‐age in the sample of 1–30‐yr‐old CSLs. Accuracy of age estimates was found to be dependent on age of the CSLs, however. 71%–79% of age estimates were within 1 yr of the known‐age in CSLs <10 yr old. These findings support the validity of counting GLGs to estimate age for CSLs <10 yr old to within 1 yr of accuracy.     

Bioimpedance for severe obesity: comparing research methods for total body water and resting energy expenditure

Objective: As the acceptance of surgical procedures for weight loss in morbid obesity is increasing, clinically useful baseline and follow‐up measures of total body water (TBW) and resting energy expenditure (REE) are important. Research methods such as deuterium (D²O) dilution and metabolic carts are problematic in the clinical setting. We compared bioimpedance analysis (BIA) predicted (Tanita TBF‐310) and measured TBW and REE. Methods and Procedures: Forty‐two paired presurgery studies were completed using BIA and D²O in patients with BMI (mean ± s.d.) 50.2 ± 8.8 kg/m² for TBW, and 30 patients with BMI 51.0 ± 13 kg/m² completed paired determinations of REE with metabolic carts and the Tanita balance with weight, height, sex, and age modifiers. Regression analysis and Bland‐Altman plots were applied. Results: When regression analysis was completed for TBW, regression line was consistent with the identity line “y = x.” The intercept was not different from 0 (95% confidence interval ?2.5 ± 7.0). The slope of the line was not different from 1.0 ± 0.1. The measured TBW 51.2 ± 10.1 l had a correlation with the predicted 49.5 ± 11.27 l of 0.92. There also was no significant difference (P = 0.33) between predicted (2,316 ± 559 kcal/day) and measured REE (2,383 ± 576 kcal/day);δ 66.7 ± 273 kcal/day. The two measures were highly correlated (r = 0.88) with no bias detected. Discussion: These observations support the use of the BIA system calibration in subjects with severe obesity. Without the use of complex, costly equipment and invasive procedures, BIA measurements can easily be obtained in clinical practice to monitor patient responses to treatment.     

Validation of a quantitative magnetic resonance method for measuring human body composition

Objective: To evaluate a novel quantitative magnetic resonance (QMR) methodology (EchoMRI‐AH, Echo Medical Systems) for measurement of whole‐body fat and lean mass in humans. Methods and Procedures: We have studied (i) the in vitro accuracy and precision by measuring 18 kg Canola oil with and without 9 kg water (ii) the accuracy and precision of measures of simulated fat mass changes in human subjects (n = 10) and (iii) QMR fat and lean mass measurements compared to those obtained using the established 4‐compartment (4‐C) model method (n = 30). Results: (i) QMR represented 18 kg of oil at 40°C as 17.1 kg fat and 1 kg lean while at 30°C 15.8 kg fat and 4.7 kg lean were reported. The s.d. of repeated estimates was 0.13 kg for fat and 0.23 kg for lean mass. Adding 9 kg of water reduced the fat estimates, increased misrepresentation of fat as lean, and degraded the precision. (ii) the simulated change in the fat mass of human volunteers was accurately represented, independently of added water. (iii) compared to the 4‐C model, QMR underestimated fat and over‐estimated lean mass. The extent of difference increased with body mass. The s.d. of repeated measurements increased with adiposity, from 0.25 kg (fat) and 0.51 kg (lean) with BMI <25 kg/m² to 0.43 kg and 0.81 kg respectively with BMI >30 kg/m². Discussion: EchoMRI‐AH prototype showed shortcomings in absolute accuracy and specificity of fat mass measures, but detected simulated body composition change accurately and with precision roughly three times better than current best measures. This methodology should reduce the study duration and cohort number needed to evaluate anti‐obesity interventions.     

Hydrogen isotope fractionation during H2/CO2 acetogenesis: hydrogen utilization efficiency and the origin of lipid-bound hydrogen

Hydrogen metabolism was studied in the anaerobic bacterium, Sporomusa sp. strain DMG 58, by measuring natural abundance levels of deuterium in H₂, H₂O, and individual fatty acids during acetogenic growth on H₂/CO₂. Four cultures were grown, each in medium with a distinct hydrogen‐isotopic composition (δD‐H₂O). The δD value of H₂ was quantified in the residual gas exiting the growth chambers and found to decrease concurrently with net H₂ consumption, indicating rapid isotope exchange between H₂ and H₂O. An isotopic mass balance was used to constrain the efficiency with which H₂ was activated by the cell and the reducing equivalents catabolized, which we term the H₂ utilization efficiency. Results indicate that H₂ utilization efficiency in these cultures is less than 20% during the growth phase, and less than 2% after the growth phase. The gross rate of cellular H₂ activation was similar in the growth phase and afterward. Biomass harvested at the end of each experiment was used to analyse the D/H of individual membrane lipids. Values of δD were highly correlated between lipids and water (δD‐lipids = 0.59 × δD‐water – 381‰; R² = 0.995), indicating the source of lipid hydrogen is in isotopic equilibrium with water. Results are consistent with two possibilities: (i) water is the sole source of hydrogen to lipids, and the fractionation during biosynthesis is significantly larger than previously observed (α = 0.59), or (ii) hydrogen from H₂ is incorporated into lipids, but only after reaching isotopic equilibrium with H₂O. Fatty acids were strongly depleted in deuterium relative to all other organisms studied thus far, and such large depletions may prove useful as biomarkers for studying H₂ cycling in anoxic environments as well as in the geological record.     

Flow‐injection determination of manganese (II) using surfactant enhanced diperiodatonickelate (IV)‐rhodamine 6G chemiluminescence

Chemiluminescence (CL) of the rhodamine 6‐G‐diperiodatonickelate (IV) (Rh6‐G‐Ni(IV) complex) in the presence of Brij‐35 was examined in an alkaline medium and implemented using flow‐injection analysis to analyze Mn(II) in natural waters. Brij‐35 was identified as the surfactant of choice that enhanced CL intensity by about 62% of the reaction. The calibration curves were linear in the range 1.7 × 10^?3 – 0.2 (0.9990, n = 7) and 8.0 × 10^?4 – 0.1 μg ml^?1 (0.9990, n = 7) with limits of detection (LODs) (S:N = 3) of 5.0 × 10^?4 and 2.4 × 10^?4 μg ml^?1 without and with using an in‐line 8‐hydroxyquinoline (8‐HQ) resin mini‐column, respectively. The sample throughput and relative standard deviation were 200 h^?1 and 1.7–2.2% in the range studied respectively. Mn(II) concentrations in certified reference materials and natural water samples was successfully determined. A brief discussion about the possible CL reaction mechanism is also given. In addition, analysis of V(III), Cr(III) and Fe(II) was also performed without and with using an in‐line 8–HQ column and selective elution of each metal ion was achieved by adjusting the pH of the sample carrier stream with aqueous HCl solution.     

Measuring Free‐Living Energy Expenditure and Physical Activity with Triaxial Accelerometry

Objective: To investigate the ability of a newly developed triaxial accelerometer to predict total energy expenditure (EE) (TEE) and activity‐related EE (AEE) in free‐living conditions. Research Methods and Procedures: Subjects were 29 healthy subjects between the ages of 18 and 40. The Triaxial Accelerometer for Movement Registration (Tracmor) was worn for 15 consecutive days. Tracmor output was defined as activity counts per day (ACD) for the sum of all three axes or each axis separately (ACD‐X, ACD‐Y, ACD‐Z). TEE was measured with the doubly labeled water technique. Sleeping metabolic rate (SMR) was measured during an overnight stay in a respiration chamber. The physical activity level was calculated as TEE × SMR^?1, and AEE was calculated as [(0.9 × TEE) ? SMR]. Body composition was calculated from body weight, body volume, and total body water using Siri's three‐compartment model. Results: Age, height, body mass, and ACD explained 83% of the variation in TEE [standard error of estimate (SEE) = 1.00 MJ/d] and 81% of the variation in AEE (SEE = 0.70 MJ/d). The partial correlations for ACD were 0.73 (p < 0.001) and 0.79 (p < 0.001) with TEE and AEE, respectively. When data on SMR or body composition were used with ACD, the explained variation in TEE was 90% (SEE = 0.74 and 0.77 MJ/d, respectively). The increase in the explained variation using three axes instead of one axis (vertical) was 5% (p < 0.05). Discussion: The correlations between Tracmor output and EE measures are the highest reported so far. To measure daily life activities, the use of triaxial accelerometry seems beneficial to uniaxial.     

The use of block counts,mark-resight and distance sampling to estimate population size of a mountain-dwelling ungulate

Population size estimates represent indispensable tools for many research programs and for conservation or management issues. Mountain ungulates in open areas are often surveyed through ground counts that normally underestimate population size. While the use of sample counts is desirable, few studies have compared different probabilistic approaches to estimate population size in this taxon. We compared the size estimates of a male population of Alpine chamois using mark-resight and line transect sampling methods, while block counts were used to obtain the minimum number of males alive in the study area. Surveys were conducted within the Gran Paradiso National Park (Italy), in August–September 2013, using block counts along purposely selected trails and vantage points, mark-resight over 5 consecutive resightings from vantage points and trails, and line transect sampling along 12 transects repeated 8 times. Block counts yielded a minimum number of males alive in the population of n = 72 individuals. This value was greater than the upper bound of the 95 % confidence interval achieved using line transect sampling {n = 54, CV = 14 % [95 % CI (40, 71)]} while mark-resight yielded a more realistic result of n = 93 individuals {CV = 18 % [95 % CI (63, 137)]}. Our results suggest that line transect sampling performed poorly in the Alpine environment, leading to underestimates of population size, likely due to violations of some assumptions imposed by the rugged nature of the terrain. The mark-resight yielded lower precision, possibly due to the limited number of marked individuals and resighting occasions, but it provided robustness and accurate estimates as marks were evenly distributed among animals.     

A comparison of single‐sample effective size estimators using empirical toad (Bufo calamita) population data: genetic compensation and population size‐genetic diversity correlations

The accuracy and precision of four single‐sample estimators of effective population size, N_e (heterozygote excess, linkage disequilibrium, Bayesian partial likelihood and sibship analysis) were compared using empirical data (microsatellite genotypes) from multiple natterjack toad (Bufo calamita) populations in Britain (n = 16) and elsewhere in Europe (n = 10). Census size data were available for the British populations. Because toads have overlapping generations, all of these methods estimated the number of effective breeders N_b rather than N_e. The heterozygote excess method only provided results, without confidence limits, for nine of the British populations. Linkage disequilibrium gave estimates for 10 British populations, but only six had finite confidence limits. The Bayesian and sibship methods both produced estimates with finite confidence limits for all the populations. Although the Bayesian method was the most precise, on most criteria (insensitivity to locus number, correlation with other effective and census size estimates and correlation with genetic diversity) the sibship method performed best. The results also provided evidence of genetic compensation in natterjack toads, and highlighted how the relationship between effective size and genetic diversity can vary as a function of geographical scale.     

Evaluation of methodology for detection of human adenoviruses in wastewater,drinking water,stream water and recreational waters

Aims: This study evaluates dialysis filtration and a range of PCR detection methods for identification and quantification of human adenoviruses in a range of environmental waters. Methods and Results: Adenovirus was concentrated from large volumes (50–200 l) of environmental and potable water by hollow fibre microfiltration using commercial dialysis filters. By this method, an acceptable recovery of a seeded control bacteriophage MS2 from seawater (median 95·5%, range 36–98%, n = 5), stream water (median 84·7%, range 23–94%, n = 5) and storm water (median 59·5%, range 6·3–112%, n = 5) was achieved. Adenovirus detection using integrated cell culture PCR (ICC‐PCR), direct PCR, nested PCR, real‐time quantitative PCR (qPCR) and adenovirus group F‐specific direct PCR was tested with PCR products sequenced for confirmation. Adenovirus was routinely detected from all water types by most methods, with ICC‐PCR more sensitive than direct‐nested PCR or qPCR. Group F adenovirus dominated in wastewater samples but was detected very infrequently in environmental waters. Conclusions and Implications: Human adenoviruses (HAdv) proved relatively common in environmental and potable waters when assessed using an efficient concentration method and sensitive detection method. ICC‐PCR proved most sensitive, could be used semiquantitatively and demonstrated virus infectivity but was time consuming and expensive. qPCR provided quantitative results but was c. ten‐fold less sensitive than the best methods.