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This study investigated the characteristics of subjective memory complaints (SMCs) and their association with current and future cognitive functions.
A cohort of 209 community-dwelling individuals without dementia aged 47–90 years old was recruited for this 3-year study. Participants underwent neuropsychological and clinical assessments annually. Participants were divided into SMCs and non-memory complainers (NMCs) using a single question at baseline and a memory complaints questionnaire following baseline, to evaluate differential patterns of complaints. In addition, comprehensive assessment of memory complaints was undertaken to evaluate whether severity and consistency of complaints differentially predicted cognitive function.
SMC and NMC individuals were significantly different on various features of SMCs. Greater overall severity (but not consistency) of complaints was significantly associated with current and future cognitive functioning.
SMC individuals present distinctive features of memory complaints as compared to NMCs. Further, the severity of complaints was a significant predictor of future cognition. However, SMC did not significantly predict change over time in this sample. These findings warrant further research into the specific features of SMCs that may portend subsequent neuropathological and cognitive changes when screening individuals at increased future risk of dementia.
Antibiotics have been widely used in piglet diets to promote growth performance and reduce diarrhea incidence. However, the resistance of pathogens to antibiotics and the risk of residues of antibiotics in animal products induced a growing interest in the use of alternatives to in-feed antibiotics. Chito-oligosaccharide (COS), a natural alkaline polymer of glucosamine is currently being tested as a substitute for in-feed antibiotics. In weaned piglets, COS has positive effects on promoting growth, which may be related to its action on intestinal morphology, immune ability and beneficial microbiota. However, previous studies shown variable results with effective doses ranging from 30 mg/kg to 5 g/kg. Therefore, the goal of this study was to test the hypothesis that the use of COS can be an alternative to in-feed antibiotics by improve the intestinal morphology of piglets, using the jejunal explant model. The intestinal explants were exposed for 4 h to following treatments: control – only culture media and culture media with COS in doses of 0.025 mg/ml, 0.05 mg/ml, 0.1 mg/ml and 0.15 mg/ml. After the incubation period the explants were processed for histological and morphometrical analysis. The histological changes were evaluated using an adapted histological score based on the intensity and severity of lesions. Mild histological changes were observed in jejunal explants exposed to different treatments; however, no significant difference in the histological score, villi height, crypt depth or villus : crypt ratio were observed between the COS-groups and the control. In addition, goblet cells density in intestinal explants exposed to COS remained statistically similar to control group. Our results indicate that COS exposure in levels ranging from 0.025 to 0.15 mg/ml induced no effect on intestinal morphology of pig’s explants. The research will provide guidance on the low dosage of COS supplementation on weaning pigs.
Resource partitioning is considered one of the main processes driving diversification in ecological communities because it allows coexistence among closely related and ecologically equivalent species. We combined three complementary approaches, i.e. the evaluation of foraging behaviour, diet composition and nutritional condition (RNA:DNA ratio), to assess feeding by two closely related (sister) butterflyfishes that are syntopic in Puerto Rico. Chaetodon capistratus had a higher abundance and higher bite rate and selected octocorals and hard corals for feeding, whereas Chaetodon striatus fed preferentially on sandy substrates. Cnidarians and polychaetes were the most representative diet items for both species, but C. capistratus preferred the former (Feeding Index of 74.3%) and C. striatus the latter (Feeding Index of 60.4%). Similar RNA:DNA ratios for both species suggest that, although they differ in feeding rates and diet, C. capistratus and C. striatus have similar nutritional fitness. Therefore, these species are both zoobenthivores but show clear differences in their substrate selection. The differences in the use of foraging substrate by C. capistratus and C. striatus, despite their close phylogenetic relationship and similar diets, suggest that these species coexist by resource partitioning.
Individuals with chronic respiratory conditions may be at increased risk for pertussis. We conducted a retrospective administrative claims analysis to examine the incidence and economic burden of diagnosed pertussis among adolescents and adults in the USA with chronic obstructive pulmonary disease (COPD) or asthma. Patients aged ⩾11 years with diagnosed pertussis and pre-existing COPD (n = 343) or asthma (n = 1041) were matched 1:1 to patients with diagnosed pertussis but without COPD or asthma. Differences in all-cause costs (‘excess’ costs) during the 45-day and 3-month and 6-month periods before and after the pertussis index date were calculated; adjusted excess costs were estimated via multivariate regressions. The incidence of diagnosed pertussis was higher among patients with COPD or asthma than among matched patients. Compared with matched patients, patients with pertussis and pre-existing COPD or asthma accrued greater all-cause adjusted costs across study periods ($3694 and $1193 more, respectively, in the 45-day period; $4173 and $1301 more in the 3-month period; and $6154 and $1639 more in the 6-month period; all P < 0·0001). Patients with pre-existing COPD or asthma experience an increased economic burden after diagnosed pertussis and may especially benefit from targeted tetanus, diphtheria, and acellular pertussis vaccination strategies.
Human milk oligosaccharides (HMO) are involved in many biological functions influencing infant health. Although HMO act locally at the intestine, recent evidence has demonstrated that HMO are partially incorporated into the systemic circulation of breast-fed infants. In the last few years, a large amount of research has been conducted using preclinical models to uncover new biological functions of HMO. The aim of this study was to evaluate the absorption and urine excretion of HMO in rats. We administered a single oral dose of the following HMO: 2'-fucosyllactose (2'-FL), 6'-sialyllactose and lacto-N-neotetraose at different concentrations to adult rats. The time course of absorption of HMO into the bloodstream and their appearance in urine was studied. Our results showed that rats, similar to human infants, are able to effectively absorb a portion of HMO from the intestine into plasma and to excrete them in urine. On the basis of this, we also conducted a specific kinetic absorption study with 2'-FL, the most predominant HMO in human milk, in 9–11-d-old rat pups. Our results confirmed that a significant amount of 2'-FL was absorbed into the systemic circulation and subsequently excreted in urine during lactation in rats in a dose-depended manner. We also found basal levels of these HMO in plasma and urine of adult rats as well as rat pups as a natural result of nursing. Our data suggest that the rat may be a useful preclinical model that provides new insights into the metabolism and functions of HMO.
Two species of Catinaria with an unusual hepaticolous (i.e. growing on liverworts) lifestyle are described as new to science. Catinaria brodoana is described from species of Cheilolejeunea sect. Leucolejeunea (Lejeuneaceae) growing in south-eastern North America. Catinaria radulae is described from Radula flavifolia (Radulaceae) growing in the Cape Horn Archipelago of southernmost Chile, South America. The species are compared with the type of Catinaria (C. atropurpurea). In addition to occurring on hepatics, C. brodoana is characterized by its cellular exciple, warted ascospores and thallus composed of goniocysts, while C. radulae is characterized by its exciple of radiating hyphae, warted ascospores and absence of a lichenized thallus.
New radiocarbon calibration curves, IntCal04 and Marine04, have been constructed and internationally ratified to replace the terrestrial and marine components of IntCal98. The new calibration data sets extend an additional 2000 yr, from 0–26 cal kyr BP (Before Present, 0 cal BP = AD 1950), and provide much higher resolution, greater precision, and more detailed structure than IntCal98. For the Marine04 curve, dendrochronologically-dated tree-ring samples, converted with a box diffusion model to marine mixed-layer ages, cover the period from 0–10.5 cal kyr BP. Beyond 10.5 cal kyr BP, high-resolution marine data become available from foraminifera in varved sediments and U/Th-dated corals. The marine records are corrected with site-specific 14C reservoir age information to provide a single global marine mixed-layer calibration from 10.5–26.0 cal kyr BP. A substantial enhancement relative to IntCal98 is the introduction of a random walk model, which takes into account the uncertainty in both the calendar age and the 14C age to calculate the underlying calibration curve (Buck and Blackwell, this issue). The marine data sets and calibration curve for marine samples from the surface mixed layer (Marine04) are discussed here. The tree-ring data sets, sources of uncertainty, and regional offsets are presented in detail in a companion paper by Reimer et al. (this issue).
The radiocarbon calibration curve IntCal04 extends back to 26 cal kyr B P. While several high-resolution records exist beyond this limit, these data sets exhibit discrepancies of up to several millennia. As a result, no calibration curve for the time range 26–50 cal kyr BP can be recommended as yet, but in this paper the IntCal04 working group compares the available data sets and offers a discussion of the information that they hold.
The first meeting of the IntCal04 working group took place at Queen's University Belfast from April 15 to 17, 2002. The participants are listed as co-authors of this report. The meeting considered criteria for the acceptance of data into the next official calibration dataset, the importance of including reliable estimates of uncertainty in both the radiocarbon ages and the cal ages, and potential methods for combining datasets. This preliminary report summarizes the criteria that were discussed, but does not yet give specific recommendations for inclusion or exclusion of individual datasets.
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.
High-quality data from appropriate archives are needed for the continuing improvement of radiocarbon calibration curves. We discuss here the basic assumptions behind 14C dating that necessitate calibration and the relative strengths and weaknesses of archives from which calibration data are obtained. We also highlight the procedures, problems, and uncertainties involved in determining atmospheric and surface ocean 14C/12C in these archives, including a discussion of the various methods used to derive an independent absolute timescale and uncertainty. The types of data required for the current IntCal database and calibration curve model are tabulated with examples.
The IntCal09 and Marine09 radiocarbon calibration curves have been revised utilizing newly available and updated data sets from 14C measurements on tree rings, plant macrofossils, speleothems, corals, and foraminifera. The calibration curves were derived from the data using the random walk model (RWM) used to generate IntCal09 and Marine09, which has been revised to account for additional uncertainties and error structures. The new curves were ratified at the 21st International Radiocarbon conference in July 2012 and are available as Supplemental Material at www.radiocarbon.org. The database can be accessed at http://intcal.qub.ac.uk/intcal13/.
The Southern Hemisphere SHCal04 radiocarbon calibration curve has been updated with the addition of new data sets extending measurements to 2145 cal BP and including the ANSTO Younger Dryas Huon pine data set. Outside the range of measured data, the curve is based upon the ern Hemisphere data sets as presented in IntCal13, with an interhemispheric offset averaging 43 ± 23 yr modeled by an autoregressive process to represent the short-term correlations in the offset.
The final season of the three-year programme to survey the central Tripolitanian pre-desert examined the region to the west of the regions of the Wadis Sofeggin and Zem Zem, casting important light on the route between the interior of Libya and the coast during the prehistoric and Roman periods. In particular, a detailed account is given of the archaeological sites of the Bir Scedua Basin and of the Severan fort at Gheriat el-Garbia.
Two new species in Leptogium are described and illustrated from the Cape Horn region: L. auriculatum and L. adnatum both grow on wet rocks, the former by a river, the latter on coastal rocks. In addition to the special habitat the latter is easily identified on the closely appressed thallus which centrally often have densely packed squamules in intricately folded structures. Leptogium auriculatum is characterized by the regular, rounded lobes with thickened margins carrying granular isidia. The total number of Leptogium species known in the region at present is 19, including the previously doubtful L. patagonicum Zahlbr., which is here confirmed as a distinct species.
Results for a radiolysis model sensitivity study of radiolytically produced H2O2 are presented as they relate to Spent (or Used) Light Water Reactor uranium oxide (UO2) nuclear fuel (UNF) oxidation in a low oxygen environment. The model builds on previous reaction kinetic studies to represent the radiolytic processes occurring at the nuclear fuel surface. Hydrogen peroxide (H2O2) is the dominant oxidant for spent nuclear fuel in an O2-depleted water environment. The most sensitive parameters have been identified with respect to predictions under typical conditions. As compared with the full model with about 100 reactions, it was found that only 30 to 40 of the reactions are required to determine [H2O2] to one part in 10–5 and to preserve most of the predictions for major species. This allows a systematic approach for model simplification and offers guidance in designing experiments for validation.
Pyrochlore-rich ceramics containing additional zirconolite, brannerite and rutile have been developed for immobilizing excess weapons plutonium. This study reports data for a ceramic containing small amounts of Al and Mo in addition to the major oxide components of Ti, U, Ca, Hf, Gd and Ce. Hafnium and Gd are added as neutron absorbers, Al and Mo represent impurities. Quantitative electron microprobe data demonstrate that UO2 is strongly partitioned into brannerite (45 wt%), which is present as euhedral crystals with inclusions of unreacted UO2. Pyrochlore forms the groundmass and has an average UO2 content of 28 wt%. Zirconolite contains only 15 wt% UO2, but is significantly more effective in accommodating Hf and Gd than both brannerite and pyrochlore. Zirconolite incorporates U together with Hf and Ce in one structural site, whereas brannerite and pyrochlore accommodate U with Gd in a site that is distinct from that occupied by Hf. Incorporation of Gd into zirconolite takes place via a coupled substitution involving Al, thus explaining the high Al2O3 contents (3 wt%). Molybdenum was not detected in the major oxides, and it might be present in the accessory rutile. Although the studied waste form was designed to incorporate Pu, the present dataset is also valuable because immobilization of highly fissile U (e.g., U-233) might need to be considered in the future.
In this study, the oxidation state of uranium was investigated with Electron Energy-Loss Spectroscopy on the Transmission Electron Microscope. The oxygen K edge in a series of uranium-bearing phases was investigated and this technique was compared to an alternative method of using the relative intensities of the M4,5- edges of the actinides. Under controlled conditions, it is possible to obtain reliable oxidation state data on uranium solids; however, mixtures of oxidation states in a single compound cannot be distinguished with certainty.
Microlite, a Ta-rich member of the pyrochlore group, occurs in 440 Ma old lithium pegmatites in Mozambique and exhibits a pronounced growth zoning, with a U-free core surrounded by a U-rich rim (UO2 ≤ 17 wt%). Subsequent to the uplift of the host rock, microlite was subjected to intense low-temperature alteration during which Na, Ca and F were leached from the microlite crystals. This alteration, resulting from exposure to tropical conditions, also led to localized redistribution of radiogenic Pb (formation of plumbomicrolite) and to hydration of microlite, but U remained immobile. The low-temperature alteration effects are only observed in the U-rich rim, which is characterized by abundant microfractures. As demonstrated by electron diffraction images and powder X-ray patterns, the U-rich rim is largely metamict. Our investigation illustrates the importance of natural analogues in evaluating the durability of pyrochlore-based nuclear waste-form materials over geologic time.