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Electron microprobe trace element analysis is a significant challenge. Due to the low net intensity of peak measurements, the accuracy and precision of such analyses relies critically on background measurements, and on the accuracy of any pertinent peak interference corrections. A linear regression between two points selected at appropriate background positions is a classical approach for electron probe microanalysis (EPMA). However, this approach neglects the accurate assessment of background curvature (exponential or polynomial), and the presence of background interferences, a hole in the background, or an absorption edge can dramatically affect the results if underestimated or ignored. The acquisition of a quantitative wavelength-dispersive spectrometry (WDS) scan over the spectral region of interest remains a reasonable option to determine the background intensity and curvature from a fitted regression of background portions of the scan, but this technique can be time consuming and retains an element of subjectivity, as the analyst has to select areas in the scan which appear to represent background. This paper presents a new multi-point background (MPB) method whereby the background intensity is determined from up to 24 background measurements from wavelength positions on either side of analytical lines. This method improves the accuracy and precision of trace element analysis in a complex matrix through careful regression of the background shape, and can be used to characterize the background over a large spectral region covering several elements to be analyzed. The overall efficiency improves as systematic WDS scanning is not required to assess background interferences. The method is less subjective compared to methods that rely on WDS scanning, including selection of two interpolation points based on WDS scans, because “true” backgrounds are selected through an exclusion method of possible erroneous backgrounds. The first validation of the MPB method involves blank testing to ensure the method can accurately measure the absence of an element. The second validation involves the analysis of U-Th-Pb in several monazite reference materials of known isotopic age. The impetus for the MPB method came from efforts to refine EPMA monazite U-Th-Pb dating, where it was recognized that background errors resulting from interference or strong background curvature could result in errors of several tens of millions of years on the calculated date. Results obtained on monazite reference materials using two different microprobes, a Cameca SX-100 Ultrachron and a JEOL JXA-8230, yield excellent agreement with ages obtained by isotopic methods (Thermal Ionization Mass Spectrometry [TIMS], Sensitive High-Resolution Ion MicroProbe [SHRIMP], or Secondary Ion Mass Spectrometry [SIMS]). Finally, the MPB method can be used to model the background over a large spectrometer range to improve the accuracy of background measurement of minor and trace elements acquired on a same spectrometer, a method called the shared background measurement. This latter significantly improves the accuracy of minor and trace element analysis in complex matrices, as demonstrated by the analysis of Rare Earth Elements (REE) in REE-silicates and phosphates and of trace elements in scheelite.
Precision technologies and data have had relatively modest impacts in grass-based livestock ruminant production systems compared with other agricultural sectors such as arable. Precision technologies promise increased efficiency, reduced environmental impact, improved animal health, welfare and product quality. The benefits of precision technologies have, however, been relatively slow to be realised on pasture based farms. Though there is significant overlap with indoor systems, implementing technology in grass-based dairying brings unique opportunities and challenges. The large areas animals roam and graze in pasture based systems and the associated connectivity challenges may, in part at least, explain the comparatively lower adoption of such technologies in pasture based systems. With the exception of sensor and Bluetooth-enabled plate metres, there are thus few technologies designed specifically to increase pasture utilisation. Terrestrial and satellite-based spectral analysis of pasture biomass and quality is still in the development phase. One of the key drivers of efficiency in pasture based systems has thus only been marginally impacted by precision technologies. In contrast, technological development in the area of fertility and heat detection has been significant and offers significant potential value to dairy farmers, including those in pasture based systems. A past review of sensors in health management for dairy farms concluded that although the collection of accurate data was generally achieved, the processing, integration and presentation of the resulting information and decision-support applications were inadequate. These technologies’ value to farming systems is thus unclear. As a result, it is not certain that farm management is being sufficiently improved to justify widespread adoption of precision technologies currently. We argue for a user need-driven development of technologies and for a focus on how outputs arising from precision technologies and associated decision support applications are delivered to users to maximise their value. Further cost/benefit analysis is required to determine the efficacy of investing in specific precision technologies, potentially taking account of several yet to ascertained farm specific variables.
This systematic review investigates evidence on the association between body image concerns and weight-related behaviours of adolescents and emerging adults. It includes peer-reviewed journal articles reporting research involving body image concerns and weight-related behaviours of adolescents and emerging adults, published between 2005–2017, and located through systematic searches from four databases. This review includes studies from 11 countries or regions: United States (n = 13), Asia (n = 9), Europe (n = 8), Middle East (n = 3), South America (Brazil; n = 3), Canada (n = 3), Australia (n = 1), New Zealand (n = 1), Trinidad (n = 1), Turkey (n = 1) and Seychelles (n = 1); 24 different countries (n = 1); three Asian countries and the United States (n = 1). Out of 46 studies included in this review, 45 studies reported a positive association between body image concerns and weight-related behaviours. Adolescents and emerging adults who misperceived their weight engaged in weight-related behaviours. Higher body dissatisfaction had a significant association in the development of eating disorders and extreme weight-loss behaviours. Body image concerns play a significant role in adolescents and emerging adults engaging in weight-related behaviours. Experimental research designs are required to determine the causality of this association. Evidence strongly suggests policy makers and public health practitioners contemplate strategies to promote positive body image and healthy weight-related behaviours among adolescents and emerging adults.
An outbreak of mumps within a student population in Scotland was investigated to assess the effect of previous vaccination on infection and clinical presentation, and any genotypic variation. Of the 341 cases, 79% were aged 18–24. Vaccination status was available for 278 cases of whom 84% had received at least one dose of mumps containing vaccine and 62% had received two. The complication rate was 5·3% (mainly orchitis), and 1·2% were admitted to hospital. Genetic sequencing of mumps virus isolated from cases across Scotland classified 97% of the samples as genotype G. Two distinct clusters of genotype G were identified, one circulating before the outbreak and the other thereafter, suggesting the virus that caused this outbreak was genetically different from the previously circulating virus. Whilst the poor vaccine effectiveness we found may be due to waning immunity over time, a contributing factor may be that the current mumps vaccine is less effective against some genotypes. Although the general benefits of the measles–mumps–rubella (MMR) vaccine should continue to be promoted, there may be value in reassessing the UK vaccination schedule and the current mumps component of the MMR vaccine.
Several outbreaks of hepatitis A in men who have sex with men (MSM) were reported in the 1980s and 1990s in Australia and other countries. An effective hepatitis A virus (HAV) vaccine has been available in Australia since 1994 and is recommended for high-risk groups including MSM. No outbreaks of hepatitis A in Australian MSM have been reported since 1996. In this study, we aimed to estimate HAV transmissibility in MSM populations in order to inform targets for vaccine coverage in such populations. We used mathematical models of HAV transmission in a MSM population to estimate the basic reproduction number (R0) and the probability of an HAV epidemic occurring as a function of the immune proportion. We estimated a plausible range for R0 of 1·71–3·67 for HAV in MSM and that sustained epidemics cannot occur once the proportion immune to HAV is greater than ~70%. To our knowledge this is the first estimate of R0 and the critical population immunity threshold for HAV transmission in MSM. As HAV is no longer endemic in Australia or in most other developed countries, vaccination is the only means of maintaining population immunity >70%. Our findings provide impetus to promote HAV vaccination in high-risk groups such as MSM.
Background: This study adds to the body of evidence regarding the theoretical underpinnings of interpersonal psychotherapy and the mechanisms through which it impacts upon depression in adolescents. Aims: The aims were to determine whether the interpersonal constructs proposed to underpin interpersonal psychotherapy do indeed change in response to this therapy and whether such changes are associated with changes in depression in young people. Method: Thirty-nine adolescents, aged 13–19 years, with a primary diagnosis of major depressive disorder, were randomly assigned in blocks to group or individual treatment. Assessments were conducted at pre and posttreatment, and 12-month follow-up. Results: The results supported the hypotheses, with significant improvements in social skills, social functioning, and the quality of parent-adolescent relationships, and an increase in secure attachment style and decrease in insecure attachment style being evident following treatment. Benefits were maintained at 12-month follow-up. Adolescents who showed greater reductions in depressive symptoms over this period tended to also show greater improvement in parent reported social skills, quality of the parent-adolescent relationship, and attachment style from pretreatment to 12-month follow-up. Conclusions: The findings are consistent with the proposed underpinnings of interpersonal psychotherapy. Adolescents showed significant improvements in interpersonal functioning and changes in attachment style following treatment, and changes in social skills, parent-adolescent conflict and attachment style were associated with reductions in depression. As such, the results add to the body of knowledge regarding the construct validity of interpersonal psychotherapy as an intervention for depression in young people. Clinical implications and directions for future research are discussed.
The Antillean Cenozoic fossil record of asteroids comprises mainly dissociated ossicles. Most common among isolates from upper Oligocene deposits of Jamaica and Antigua are marginal ossicles of an extinct, indeterminate species of Pycinaster. This is the youngest known occurrence of the genus and the first from beyond Europe. A number of relatively complete fossils have been assigned to Pycinaster and (sub)familial status proposed for it together with Phocidaster. The latter proposition is based solely on a few marginals, but available diagnoses are judged insufficient to justify such recognition. The taxon Pycinasteridae is here synonymized with the Goniasteridae, although future study of added features (such as the ventral surface) might justify recognition at a higher taxonomic level. In addition to ossicles assigned to Pycinaster, many marginals are tentatively assigned to the surviving goniasterid Nymphaster. Numerous generic and many species names have been based on asteroid isolates, but the practice demands assumptions that are not readily justified. Linkage of discrete isolates under a single taxon name assumes derivation from a single source, an inference that can be verified only rarely (if ever), therefore reducing names to the single holotype ossicle. Availability of only isolates encourages comparison with extant taxa and biogeography, biasing interpretations with a Holocene overlay. Because of these constraints, a new nominal species of Pycinaster is not justified and assignment of ossicles to Nymphaster is tentative. However, given the importance of asteroids in marine communities, we emphasize the significance, largely ignored, of their presence in Cenozoic deposits of the wider Caribbean.
Obesity and its related non-communicable diseases (NCDs), such as type 2 diabetes, heart disease and cancer, impose huge burdens on society, particularly the healthcare system. Until recently, public health and policy were primarily focused on secondary prevention and treatment of NCDs. However, epidemiological and experimental evidence indicates that early-life exposures influence the risk of childhood obesity and related diseases later in life, and has now focused attention on the health of both mother and child. During pregnancy and the early neonatal period, individuals respond to their environment by establishing anatomical, physiological and biochemical trajectories that shape their future health. This period of developmental plasticity provides an early window of opportunity to mitigate the environmental insults that may increase an individual’s sensitivity to, or risk of, developing obesity or related diseases later in life. Although much investigation has already occurred in the area of Developmental Origins of Health and Disease research, the science itself is still in its infancy. It remains for researchers to tackle the important outstanding questions and translate their knowledge into workable solutions for the public good. The challenge, however, is to decide which areas to focus on. With these opportunities and challenges in mind, the 2014 Gravida Summit convened to examine how its early-life research program can determine which areas of research into mechanisms, biomarkers and interventions could contribute to the international research strategy to fight childhood obesity and its related diseases.
Background: This study adds to the limited evidence concerning the benefits of Interpersonal Psychotherapy (IPT) with depressed adolescents. It evaluates the long-term effects of group versus individual delivery of this treatment approach. Aims: To conduct a small-scale examination of the long-term efficacy of group versus individual delivery of IPT for depressed adolescents. Method: Thirty-nine adolescents, aged 13–19 years, with a primary diagnosis of Major Depressive Disorder, were randomly assigned in blocks to either group or individual delivery of IPT. Standardized clinical interview and questionnaire assessments were conducted at pre- and posttreatment, and 12-month follow-up. Results: Intent-to-treat (ITT) analyses indicated significant improvements in depression, anxiety, youth-reported internalizing problems, and global functioning from pre- to posttreatment for those receiving IPT, with no significant differences in outcome between group and individual formats of delivery. Improvements were maintained at 12-month follow-up. Completer analyses also revealed significant and sustained improvements on these measures for those receiving IPT, with no differences in outcome between therapy formats for most measures. Individual IPT showed significantly greater improvements than group IPT in parent-reported internalizing problems for the completer but not the ITT analyses. Conclusions: Both individual and group formats of IPT offer promise in producing long-term benefits in the treatment of depression among adolescents.
Maternal undernutrition during pregnancy increases offspring obesity and metabolic disease risk. We hypothesized that periconceptional undernutrition in sheep from 60 days before conception through to day 30 of gestation (UN) would decrease voluntary locomotor activity in adult offspring. Distance travelled was measured at 18 months of age for ∼48 h in the paddock. Data were analysed using multiple regression analysis, with explanatory variables including sex, nutrition group, birth weight, average time between GPS measurements and percentage of time during the measurement period spent in daylight. Mean (±s.e.) distance walked (m/h) was greater for control (CON) than UN animals, and greater for females than males [110.2 (6.5), CON females; 110.7 (6.3), CON males; 105.1 (5.3), UN females and 95.5 (5.8), UN males; P = 0.02 for nutrition group effect and for sex effect]. Periconceptional undernutrition may lead to a significant decrease in voluntary physical activity in adult offspring.