To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Although both obesity and ageing are risk factors for cognitive impairment, there is no evidence in Chile on how obesity levels are associated with cognitive function. Therefore, the aim of the present study was to investigate the association between adiposity levels and cognitive impairment in older Chilean adults. This cross-sectional study includes 1384 participants, over 60 years of age, from the Chilean National Health Survey 2009–2010. Cognitive impairment was evaluated using the Mini-Mental State Examination. BMI and waist circumference (WC) were used as measures of adiposity. Compared with people with a normal BMI, the odds of cognitive impairment were higher in participants who were underweight (OR 4·44; 95 % CI 2·43, 6·45; P < 0·0001), overweight (OR 1·86; 95 % CI 1·06, 2·66; P = 0·031) and obese (OR 2·26; 95 % CI 1·31, 3·21; P = 0·003). The associations were robust after adjustment for confounding variables. Similar results were observed for WC. Low and high levels of adiposity are associated with an increased likelihood of cognitive impairment in older adults in Chile.
The use of additives such as ractopamine (Rac) in pregnant sows during early-mid pregnancy is an alternative to increase foetal and progeny growth and development. However, Rac supplementation in finishing pigs can lead to behavioural and physiological changes similar to the typical stress responses. The objective of this study was to evaluate the effects of dietary supplementation with Rac in pregnant sows from day 25 to 50 of gestation (pre-hyperplastic stage) on piglet’s vitality, blood parameters, number, diameter and perimeter of muscle fibres in semitendinosus muscle and developmental characteristics of piglets at birth to weaning. Forty-one hybrid sows were divided into three dietary treatments: (1) control diet without Rac (control), (2) addition of 10 mg/kg of Rac (Rac10) and (3) addition of 20 mg/kg of Rac (Rac20). Higher numbers of low-vitality piglets (P<0.05) were observed in Rac-fed sows, regardless of dose, compared with the control group. Very low-density lipoprotein levels were lower in the Rac10 group when compared with the Rac20 group at day 21. Haematocrit was greater, and the mean corpuscular haemoglobin concentration was lower in piglets from Rac-fed sows. No significant statistical differences were detected regarding piglets body weight, average daily gain, blood gasometry, complete blood count and muscle fibre measurements in semitendinosus muscle. The use of Rac in pregnant sows reduced the vitality parameters of piglets but did not improve the performance from birth until weaning and did not negatively influence the haematological parameter and lipid metabolism.
Parasitological analysis of coprolites has allowed exploring ecological relationships in ancient times. Ancient DNA analysis contributes to the identification of coprolites and their parasites. Pleistocene mammalian carnivore coprolites were recovered from paleontological and archaeological site Peñas de las Trampas 1.1 in the southern Puna of Argentina. With the aim of exploring ancient ecological relationships, parasitological analysis was performed to one of them, dated to 16 573–17 002 calibrated years BP, with 95.4% probability. Parasite eggs attributed to Toxascaris sp. by morphological characters were isolated. DNA of coprolite and eggs was extracted to molecular identification. Ancient mitochondrial DNA analysis confirmed the zoological origin of the coprolite as Puma concolor and that of parasite eggs as Toxascaris leonina. This is the oldest molecular parasite record worldwide, and it supports the presence of this parasite since the Pleistocene in America. These findings have implications for the biogeographic history of parasites and for the natural history of the region.
The bulk van der Waals crystal Mn3Si2Te6 (MST) has been irradiated with a proton beam of 2 MeV at a fluence of 1×1018 H+ cm-2. The temperature dependent magnetization measurements show a drastic decrease in the magnetization of 49.2% in the H//c direction observed in ferrimagnetic state. This decrease in magnetization is also reflected in the isothermal magnetization curves. No significant change in the ferrimagnetic transition temperature (75 K) was reflected after irradiation. Electron paramagnetic resonance (EPR) spectroscopy shows no magnetically active defects present after irradiation. Here, experimental findings gathered from MST bulk crystals via magnetic measurements, magnetocaloric effect, and heat capacity are discussed.
Depending on the cone half-angle and the inverse normal-shock density ratio
, hypersonic flow over a spherically blunted cone exhibits two regimes separated by an almost discontinuous jump of the body end of the sonic line from a point on the spherical nose to the shoulder of the cone, here called sphere behaviour and cone behaviour. The inflection point of the shock wave in sphere behaviour is explained. In Part 1 we explore the two elements of the capsule shape, the sphere and the sharp cone with detached shock, theoretically and computationally, in order to put the treatment of the full capsule shape on a sound basis. Starting from the analytical expression for the shock detachment angle of a cone given by Hayes & Probstein (Hypersonic Flow Theory, 1959, Academic Press) we make a hypothesis for the sharp cone, about the functional form of the dependence of dimensionless quantities on
and a cone angle parameter,
. In the critical part of atmospheric entry the shock shape and drag of the capsule are insensitive to viscous effects, so that much can be learned from inviscid studies. Accordingly, the hypothesis is tested by making a large number of Euler computations to cover the parameter space: Mach number, specific heat ratio and cone angle. The results confirm the hypothesis in the case of the dimensionless shock stand-off distance as well as for the drag coefficient, yielding accurate analytical functions for both. This reduces the number of independent parameters of the problem from three to two. A functional form of the shock stand-off distance is found for the transition from the
cone to the sphere. Although the analysis assumes a calorically perfect gas, the results may be carried over to the high-enthalpy real-gas situation if the normal-shock density ratio is replaced by the density ratio based on the average density along the stagnation streamline (see e.g. Stulov, Izv. AN SSSR Mech. Zhidk. Gaza, vol. 4, 1969, pp. 142–146; Hornung, J. Fluid Mech., vol. 53, 1972, pp. 149–176; Wen & Hornung, J. Fluid Mech., vol. 299, 1995, pp. 389–405).
This study examined (1) the association of dietary energy density from solid (EDS) and solid plus liquids (EDSL) with adiposity and cardiometabolic risk factors (CRF) in children with overweight and obesity, (2) the effect of under-reporting on the mentioned associations and (3) whether the association between ED and body composition and CRF is influenced by levels of physical activity. In a cross-sectional design, 208 overweight and obese children (8–12-year-old; 111 boys) completed two non-consecutive 24 h recalls. ED was calculated using two different approaches: EDS and EDSL. Under-reporters were determined with the Goldberg method. Body composition, anthropometry and fasting blood sample measurements were performed. Moderate to vigorous physical activity (MVPA) was registered with accelerometers (7-d-register). Linear regressions were performed to evaluate the association of ED with the previously mentioned variables. Neither EDS nor EDSL were associated with body composition or CRF. However, when under-reporters were excluded, EDS was positively associated with BMI (P=0·019), body fat percentage (P=0·005), abdominal fat (P=0·008) and fat mass index (P=0·018), while EDSL was positively associated with body fat percentage (P=0·008) and fat mass index (P=0·026). When stratifying the group according to physical activity recommendations, the aforementioned associations were only maintained for non-compliers. Cluster analysis showed that the low-ED and high-MVPA group presented the healthiest profile for all adiposity and CRF. These findings could partly explain inconsistencies in literature, as we found that different ED calculations entail distinct results. Physical activity levels and excluding under-reporters greatly influence the associations between ED and adiposity in children with overweight and obesity.
We have developed a technique for determining the atomic elastic constants from measurements of the Debye-Waller factors. The Debye-Waller factors are obtained by Rietveld refinement of time-of-flight neutron diffraction data and interpreted in terms of an atomic Debye-Waller temperature. The method is applicable to powders and to materials that must be encapsulated for safety or environmental reasons. We will illustrate our technique with applications to actinide metals, to metallic hydrides and to high-temperature superconductors.
Hydrogels made of sodium 2-acrylamide-2-methypropanesulfonate were synthesized with the goal of creating a polymer for tissue engineering applications. The hydrogels were doped with silver nanoparticles to create hydrogel/Ag with possible antibacterial properties. We varied the weight/volume percentage of Laponite from 3 to 10 w/v% to alter the rheological properties of the hydrogels. Raman spectroscopy was used to study the progress of the chemical reaction at different polymerization times under ultraviolet radiation. By comparing the changes in the intensities of the Raman bands corresponding to C=C and C–C bonds with reaction time, we found that the optimal polymerization time to obtain chains of poly(2-acrylamide-2-methylpropanesulfonate) was 3 to 4 h. Characterization of the hydrogels with scanning electron microscopy indicated pore sizes of 1 to 6 µm.
A great deal of research has focused on acculturation and enculturation, which represent the processes of adapting to a new culture. Despite this growing literature, results have produced inconsistent findings that may be attributable to differences in terms of the instruments used to assess acculturation and enculturation. Utilizing a 3-year longitudinal data set (with 1-year lags between assessments), the present study explored the psychometric properties of the Bicultural Involvement Questionnaire—Short Version (BIQ-S) and the Acculturation Rating Scale for Mexican Americans II (ARSMA-II) and examined the overlap between changes in these measures as they relate to internalizing and externalizing problem behavior. The present sample consisted of 216 immigrant Latino youth (43% boys; mean age 13.6 years at baseline; SD = 1.44 years, range 10 to 17). Exploratory structural equation modeling identified factor structures for the BIQ-S and ARSMA-II that diverged from their hypothesized structure. Growth curve models also indicate divergence between the BIQ-S and ARSMA-II in terms of change in acculturation and enculturation processes. Finally, the present findings emphasized that measures of acculturation and enculturation are not equivalent in terms of their effects on internalizing and externalizing problems.