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This study aimed to evaluate the effects of an intervention including nutritional telemonitoring, nutrition education, and follow-up by a nurse on nutritional status, diet quality, appetite, physical functioning and quality of life of Dutch community-dwelling elderly. We used a parallel arm pre-test post-test design with 214 older adults (average age 80 years) who were allocated to the intervention group (n 97) or control group (n 107), based on the municipality. The intervention group received a 6-month intervention including telemonitoring measurements, nutrition education and follow-up by a nurse. Effect measurements took place at baseline, after 4·5 months, and at the end of the study. The intervention improved nutritional status of participants at risk of undernutrition (β (T1)=2·55; 95 % CI 1·41, 3·68; β (T2)=1·77; 95 % CI 0·60, 2·94) and scores for compliance with Dutch guidelines for the intake of vegetables (β=1·27; 95 % CI 0·49, 2·05), fruit (β=1·24; 95 % CI 0·60, 1·88), dietary fibre (β=1·13; 95 % CI 0·70, 1·57), protein (β=1·20; 95 % CI 0·15, 2·24) and physical activity (β=2·13; 95 % CI 0·98, 3·29). The intervention did not have an effect on body weight, appetite, physical functioning and quality of life. In conclusion, this intervention leads to improved nutritional status in older adults at risk of undernutrition, and to improved diet quality and physical activity levels of community-dwelling elderly. Future studies with a longer duration should focus on older adults at higher risk of undernutrition than this study population to investigate whether the impact of the intervention on nutritional and functional outcomes can be improved.
The Faint Sky Variability Survey (FSVS) is aimed at rinding photometrically and astrometrically variable objects. The main goal is to get a better understanding of binary evolution. This survey consists of 78 fields, which covers a total area of 21 deg2 in the sky and it is sensitive for objects in the magnitude range of 17 < V < 24. (For a description see Groot et al. 2003).
Lower prenatal exposure to n-3 PUFA relative to n-6 PUFA has been hypothesised to influence allergy development, but evidence remains largely inconsistent. In the Dutch Maastricht Essential Fatty Acid Birth (MEFAB) (n 293) and Greek RHEA Mother–Child (n 213) cohorts, we investigated whether cord blood phospholipid PUFA concentrations are associated with symptoms of wheeze, asthma, rhinitis and eczema at the age of 6–7 years. Information on allergy-related phenotypes was collected using validated questionnaires. We estimated relative risks (RR) and 95 % CI for associations of PUFA with child outcomes using multivariable generalised linear regression models. In pooled analyses, higher concentration of the n-3 long-chain EPA and DHA and a higher total n-3:n-6 PUFA ratio were associated with lower risk of current wheeze (RR 0·61; 95 % CI 0·45, 0·82 per sd increase in EPA+DHA and 0·54; 95 % CI 0·39, 0·75 per unit increase in the n-3:n-6 ratio) and reduced asthma risk (RR 0·50; 95 % CI 0·31, 0·79 for EPA+DHA and 0·43; 95 % CI 0·26, 0·70 for the n-3:n-6 ratio). No associations were observed for other allergy-related phenotypes. The results were similar across cohorts. In conclusion, higher EPA and DHA concentrations and a higher n-3:n-6 fatty acid ratio at birth were associated with lower risk of child wheeze and asthma. Our findings suggest that dietary interventions resulting in a marked increase in the n-3:n-6 PUFA ratio, and mainly in n-3 long-chain PUFA intake in late gestation, may reduce the risk of asthma symptoms in mid-childhood.
During and after hospitalisation, older adults are recommended to consume 1·2–1·5 g of protein/kg body weight per d (g/kg per d) to improve recovery. This randomised controlled trial studied the effectiveness of a 12-week intervention with protein-enriched foods and drinks by following-up seventy-five older patients (mean age: 76·8 (sd 6·9) years) during their first 6 months after hospital discharge. Primary outcomes were protein intake and physical performance (measured with Short Physical Performance Battery (SPPB)). Secondary outcomes for physical recovery were gait speed, chair-rise time, leg-extension strength, hand-grip strength, body weight, nutritional status (Mini Nutritional Assessment), independence in activities of daily living (ADL) and physical activity. The intervention group consumed more protein during the 12-week intervention period compared with the control group (P<0·01): 112 (sd 34) g/d (1·5 (sd 0·6) g/kg per d) v. 78 (sd 18) g/d (1·0 (sd 0·4) g/kg per d). SPPB total score, gait speed, chair-rise time, body weight and nutritional status improved at week 12 compared with baseline (time effect P<0·05), but were not different between groups. Leg-extension strength, hand-grip strength and independence in ADL did not change. In conclusion, protein-enriched products enabled older adults to increase their protein intake to levels that are higher than their required intake. In these older adults with already adequate protein intakes and limited physical activity, protein enrichment did not enhance physical recovery in the first 6 months after hospital discharge.
An extensive investigation of the visible stratigraphy, microparticle concentration, liquid conductivity, oxygen isotopes and beta-radioactivity was conducted in pits excavated at Amundsen-Scott South Pole station. The objectives of the investigation were to assess the spatial representativeness of the geochemical and physical records preserved within the snow strata and to ascertain the temporal resolution which can be obtained from such ice-core records. Accurate interpretation of the time scale and reconstruction of climatic conditions from these time series requires (1) the analysis of as many stratigraphic parameters as possible and (2) the synthesis of data from a suite of cores in the study area. For periods of 10 a or less, regionally representative accumulation rates cannot be obtained from annual accumulation time series reconstructed at a single site. Although the microparticle concentrations, liquid conductivity and oxygen isotopic abundances all exhibit a seasonal cycle in the firn, the construction of an accurate time scale requires all three parameters in conjunction with the beta-radioactivity. Absolute dating will be impossible for cores from South Pole where entire accumulation years may be missing. Nevertheless, for East Antarctica, where accumulation rates are low (<0.1 m a−1 water equivalent), the good temporal resolution and the preservation of a distinct annual signal in some geochemical parameters makes the South Pole a very attractive site for deep ice-core drilling.
The quality and utility of the records of oxygen-isotopic abundances, dust concentrations and anionic concentrations preserved in the ice at Siple Station (75°55′ S, 84° 15′ W) are assessed from four shallow (20 m) cores. The combination of high accumulation (0.56 m a−1 w.e.) and low mean annual temperature (—24°C) preserves the prominent seasonal variations in δ18Ο which are very spatially coherent. Sulfate concentrations vary seasonally and, in conjunction with δ18Ο, will allow accurate dating of deeper cores from Siple Station. The concentrations of insoluble dust are the lowest measured in Antarctica, making Siple Station an excellent location to examine large increases in atmospheric tubidity.
The seasonal variations and annual fluxes of the anions are examined for the last two decades (AD 1966–85) with regard to probable sources. An unusually high sulfate flux in 1976 may reflect the February 1975 eruption of Mount Ngauruhoe, New Zealand. No annual signal in nitrate concentration is confirmed and no unusually high nitrate fluxes support the suggestion of nitrate production by large solar flares. However, nitrate flux is higher for the latter half of the 1970s and early 1980s, possibly reflecting the recent loss of stratospheric ozone.
Finally, comparison of the δ18O record with available surface-temperature data (AD 1957–85) reveals that multi-year trends along the western coast of the Antarctic Peninsula are recorded at Siple. More importantly, comparison with areally weighted temperature reconstructions suggests that the δ18Ο record may reflect larger-scale, persistent trends in the high southern latitudes. The strong spatial coherence of the preserved records, the potential for accurate dating, and possible relevance to larger-scale processes make Siple Station an excellent site for paleoenvironmental reconstruction from ice cores.
The University of Washington Model FN tandem Van de Graaff accelerator is being used for the measurement of extremely small isotopic abundance ratios, notably 14C/12C and 10Be/9Be, in a joint project of the Nuclear Physics Laboratory (NPL) and the Quaternary Isotope Laboratory (QL). The experimental arrangements and technical developments are described, and some preliminary results on isotopic ratios in carbon and beryllium are presented.
Bones that have undergone burning at high temperatures (i.e. cremation) no longer contain organic carbon. Lanting et al. (2001) proposed that some of the original structural carbonate, formed during bioapatite formation, survives. This view is based on paired radiocarbon dating of cremated bone apatite and contemporary charcoal. However, stable carbon isotope composition of carbonate in cremated bones is consistently light compared to the untreated material and is closer to the δ13C values seen in C3 plant material. This raises the question of the origin of carbonate carbon in cremated bone apatite. That is, does the isotope signal reflect an exchange of carbon with the local cremation atmosphere and thus with carbon from the burning fuel, or is it caused by isotopic fractionation during cremation?
To study the changes in carbon isotopes (14C, 13C) of bone apatite during burning up to 800 °, a modern bovine bone was exposed to a continuous flow of an artificial atmosphere (basically a high-purity O2/N2 gas mix) under defined conditions (temperature, gas composition). To simulate the influence of the fuel carbon available under real cremation conditions, fossil CO2 was added at different concentrations. To yield cremated bone apatite properties similar to archaeological cremated bones, in terms of crystallographic criteria, water vapor had to be added to the atmosphere in the oven. Infrared vibrational spectra reveal large increases in crystal size and loss of carbonate upon cremation. The isotope results indicate an effective carbon exchange between bone apatite carbonate and CO2 in the combustion gases depending on temperature and CO2 concentration. 14C dates on archaeological cremated bone apatite may thus suffer from an old-wood effect. Paired 13C and 14C values indicate that in addition to this exchange, isotope fractionation between CO2 and carbonate, and admixture of carbon from other sources such as possibly collagen or atmospheric CO2, may play a role in determining the final composition of the apatite carbonate.
14C concentrations in the stem cellulose of a Sitka spruce from the Pacific coast of Washington respond to changes in atmospheric 14CO2 concentration within 5–6 weeks. δ14C values for cellulose were consistently lower than those of the corresponding clean troposphere during rapid increase in atmospheric 14C caused by nuclear weapons tests (1962–64). Possible reasons for this include: 1) a delay of days or weeks in incorporation of recent photosynthate, 2) the use of stored photosynthate, and 3) photo-assimilation of biospheric decay CO2. We estimate that the influence of process 1 is small or negligible. The respective contributions to the total carbon deposited as radial stem growth in our Sitka spruce then are 2) < 15% (possibly 0), and 3) 10%–23% (13%–28% if the possible effect of root respiration is included in the biosphere decay component). We plan to test this concept by looking for a vertical 14C gradient in the 1963 growth ring of a tree located in a dense forest canopy; we do not expect to find such a gradient in a similar tree from a strongly wind-washed location.
Ultrafiltration of bone collagen, dissolved as gelatin (M ~100,000 D), has received considerable attention as a means to remove small contaminants and thus produce more reliable dates (Brown et al. 1988; Bronk Ramsey et al. 2004; Higham et al. 2006; Mellars 2006). However, comparative dating studies have raised the question whether this cleaning step itself may introduce contamination with carbon from the filters used (Bronk Ramsey et al. 2004; Brock et al. 2007; Hüls et al. 2007).
Here, we present results of further ultrafiltration experiments with modern and fossil collagen samples using Vivaspin 20™ and Vivaspin 15R™ ultrafilters. Evidently, the Vivaspin 20 (VS 20) ultrafilter with a polyethersulfone (PES) membrane retains more material in the >30 kD fraction than the Vivaspin 15R (VS 15R) filter with a regenerated cellulose membrane (Hydrosat), which may be related to increased retention of proteins due to suboptimal electrostatic conditions during ultrafiltration with the PES membrane. In addition, this filter type shows clear evidence for contamination with fossil carbon, presumably from membrane fibers, in the <30 kD fraction. Radiocarbon measurements on ultrafiltrated fossil collagen seem to indicate small contributions of modern carbon via glycerin left on and within the filter membranes of both types. Although SEM pictures show film remnants on the fibrous filter structure of cleaned filter membranes, EDX analysis on the VS 20 membrane to not support the assumption this may be glycerin. Our observations indicate the risks and benefits of the use of ultrafiltration in cleaning collagen samples for 14C dating need to be further quantified, especially for the cleaning of fossil bone collagen of good quality samples.
We present 14C AMS measurements and discuss the extraction procedure used on pollen extracted from peat samples. Microscopic examination of the extracts shows that the procedure is sufficient to remove most non-pollen materials and results in an extract that is composed predominantly of pollen. The 14C dates that we obtained for pollen extracts from peat samples associated with the Mazama Ash layer are consistent with the range of bulk-sample dates obtained by others in previous studies. The limited measurement time and resulting precision (± 100 yr) of these initial measurements restrict our ability to draw firm conclusions from a comparison of the pollen extract dates with previous bulk-sample dates. We intend to adjust our procedure to improve the rejection of non-pollen materials and to increase the precision of our 14C measurements on pollen extracts from peat samples in future studies.
It is now almost 10 yr since radiocarbon dating of cremated bone was first developed using the small carbonate component contained within the hydroxyapatite-based inorganic fraction. Currently, a significant number of 14C laboratories date cremated bone as part of their routine dating service. As a general investigation of cremated bone dating since this initial development, a small, cremated bone intercomparison study took place in 2005, involving 6 laboratories. Six cremated bone samples (including 2 sets of duplicates), with ages spanning approximately 1500–2800 BP, were sent to the laboratories. The results, which showed relatively good agreement amongst the laboratories and between the duplicate samples, are discussed in detail.
We report AMS 14C measurements on subannual samples of coral from the Galapagos Islands that span the period, 1970–1973. Both the major 1972 El Niño/Southern Oscillation event and intra-annual changes in regional upwelling of 14C-depleted waters associated with alternation of surface-ocean current patterns are evident in the record. Our data show that the corals preserve a detailed record of past intra-annual variations of the 14C content of surface ocean water.
During the past year we have continued to work toward greater stability and flexibility in nearly all elements of our accelerator mass spectrometry (AMS) system, which is based upon an FN tandem Van de Graaff accelerator, and have carried out measurements of 14C/12C and 10Be/9Be isotopic abundance ratios in natural samples. The principal recent developments and improvements in the accelerator system and in our sample preparation techniques for carbon and beryllium are discussed, and the results of a study of 10Be cross-contamination of beryllium samples in the sputter ion source are presented.
We here report on two technical research projects of the Quaternary Isotope Laboratory (QL) vis, (1) the use of thermal diffusion isotopic enrichment to extend the technical range of 14C dating, (2) the preparation of samples for ion counting using a Van de Graaff tandem accelerator. The second project is carried out in cooperation with, and partly at, the Nuclear Physics Laboratory.
A gain in dating range of 3 to 4 half-lives can routinely be obtained with the QL and the Groningen enrichment systems. The same gain in age range can be obtained for ion counting with a simplified system that requires only 0.5 to 2g of carbon and 3 to 7 days enrichment time.
A method to convert CO2 quantitatively via CO into carbon is described. For short intervals the carbon deposit yields good 12C— beams. We also give a different procedure to make graphite-like carbon samples. The preparation of beryllium metal samples is given last.
Our accelerator mass spectrometry (AMS) system shows a one-to-one relationship between sample 14C concentrations determined by AMS - and by β-counting. Measurements of unknown samples against a standard indicate that 14C concentration measurements to better than 2% can be made. For a 30-second data collection interval in a typical run of 100 intervals, the variability of the beam injected into the accelerator is ca 2%, that of the machine transmission is ca 4%, and counting statistics give 4.7% standard deviation for a sample of 80% of modern carbon.
The IntCal04 and Marine04 radiocarbon calibration curves have been updated from 12 cal kBP (cal kBP is here defined as thousands of calibrated years before AD 1950), and extended to 50 cal kBP, utilizing newly available data sets that meet the IntCal Working Group criteria for pristine corals and other carbonates and for quantification of uncertainty in both the 14C and calendar timescales as established in 2002. No change was made to the curves from 0–12 cal kBP. The curves were constructed using a Markov chain Monte Carlo (MCMC) implementation of the random walk model used for IntCal04 and Marine04. The new curves were ratified at the 20th International Radiocarbon Conference in June 2009 and are available in the Supplemental Material at www.radiocarbon.org.
Since our first report on the performance of the Kiel accelerator mass spectrometry (AMS) system and our early work on sample preparation, systems have been built to improve the sample quality and throughput of the laboratory. Minor modifications were also made on the AMS system, mainly in order to reduce the amount of work and time needed to maintain the system in optimal condition. The design and performance of a 20-port reduction system, a pneumatic target press, and a remote alarm unit for the AMS system are discussed, along with an overview of the results obtained during the last year and the procedure used to obtain them. Statistical analysis shows that the contribution of the AMS system to the measuring uncertainty at our current level (0.3% for a modern sample) is negligible.