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Studies that reveal detailed information about trilobite growth, particularly early developmental stages, are crucial for improving our understanding of the phylogenetic relationships within this iconic group of fossil arthropods. Here we document an essentially complete ontogeny of the trilobite Redlichia cf. versabunda from the Cambrian Series 2 (late Stage 4) Ramsay Limestone of Yorke Peninsula in South Australia, including some of the best-preserved protaspides (the earliest biomineralized trilobite larval stage) known for any Cambrian trilobite. These protaspid stages exhibit similar morphological characteristics to many other taxa within the Suborder Redlichiina, especially to closely related species such as Metaredlichia cylindrica from the early Cambrian period of China. Morphological patterns observed across early developmental stages of different groups within the Order Redlichiida are discussed. Although redlichiine protaspides exhibit similar overall morphologies, certain ontogenetic characters within this suborder have potential phylogenetic signal, with different superfamilies characterized by unique trait combinations in these early growth stages.
The aim of the current study was to explore the changing interrelationships among clinical variables through the stages of schizophrenia in order to assemble a comprehensive and meaningful disease model.
Twenty-nine centers from 25 countries participated and included 2358 patients aged 37.21 ± 11.87 years with schizophrenia. Multiple linear regression analysis and visual inspection of plots were performed.
The results suggest that with progression stages, there are changing correlations among Positive and Negative Syndrome Scale factors at each stage and each factor correlates with all the others in that particular stage, in which this factor is dominant. This internal structure further supports the validity of an already proposed four stages model, with positive symptoms dominating the first stage, excitement/hostility the second, depression the third, and neurocognitive decline the last stage.
The current study investigated the mental organization and functioning in patients with schizophrenia in relation to different stages of illness progression. It revealed two distinct “cores” of schizophrenia, the “Positive” and the “Negative,” while neurocognitive decline escalates during the later stages. Future research should focus on the therapeutic implications of such a model. Stopping the progress of the illness could demand to stop the succession of stages. This could be achieved not only by both halting the triggering effect of positive and negative symptoms, but also by stopping the sensitization effect on the neural pathways responsible for the development of hostility, excitement, anxiety, and depression as well as the deleterious effect on neural networks responsible for neurocognition.
This study examined the reasons for e-cigarette (EC) use, changes in self-efficacy and association between EC use and cessation of tobacco among Canadian young adult smokers over a 6-month period.
A secondary analysis was conducted using data from a randomised controlled trial (RCT) of young adult Canadian smokers. EC exposure was defined as persistent, transient and non-use of ECs at baseline and follow-up. The association between EC exposure and cessation was examined using logistic regression and adjusting for co-variates.
At 6-month follow-up, persistent EC use was associated with a lower cessation rate (13%) than transient (23%) or non-use (29%). After adjusting for covariates, non-use and transient use were associated with higher odds of cessation than persistent use (AOR = 3.23, 95% CI = 1.41–7.40, P < 0.01; AOR = 2.40, 95% CI = 1.01–5.58, P < 0.05). At 6-month follow-up, persistent users (68%) had high self-efficacy as compared to transient (15%) or non-use (12%). Top reasons for EC use included use as a quit aid (67%), perceived use as less harmful (52%) and taste (32%).
Among young adult Canadian smokers enrolled in a RCT of a cessation intervention, persistent and transient use of ECs was associated with a lower smoking cessation rate at 6 months.
A consensus workshop on low-calorie sweeteners (LCS) was held in November 2018 where seventeen experts (the panel) discussed three themes identified as key to the science and policy of LCS: (1) weight management and glucose control; (2) consumption, safety and perception; (3) nutrition policy. The aims were to identify the reliable facts on LCS, suggest research gaps and propose future actions. The panel agreed that the safety of LCS is demonstrated by a substantial body of evidence reviewed by regulatory experts and current levels of consumption, even for high users, are within agreed safety margins. However, better risk communication is needed. More emphasis is required on the role of LCS in helping individuals reduce their sugar and energy intake, which is a public health priority. Based on reviews of clinical evidence to date, the panel concluded that LCS can be beneficial for weight management when they are used to replace sugar in products consumed in the diet (without energy substitution). The available evidence suggests no grounds for concerns about adverse effects of LCS on sweet preference, appetite or glucose control; indeed, LCS may improve diabetic control and dietary compliance. Regarding effects on the human gut microbiota, data are limited and do not provide adequate evidence that LCS affect gut health at doses relevant to human use. The panel identified research priorities, including collation of the totality of evidence on LCS and body weight control, monitoring and modelling of LCS intakes, impacts on sugar reduction and diet quality and developing effective communication strategies to foster informed choice. There is also a need to reconcile policy discrepancies between organisations and reduce regulatory hurdles that impede low-energy product development and reformulation.
New dietary-based concepts are needed for treatment and effective prevention of overweight and obesity. The primary objective was to investigate if reduction in appetite is associated with improved weight loss maintenance. This cohort study was nested within the European Commission project Satiety Innovation (SATIN). Participants achieving ≥8% weight loss during an initial 8-week low-energy formula diet were included in a 12-week randomised double-blind parallel weight loss maintenance intervention. The intervention included food products designed to reduce appetite or matching controls along with instructions to follow national dietary guidelines. Appetite was assessed by ad libitum energy intake and self-reported appetite evaluations using visual analogue scales during standardised appetite probe days. These were evaluated at the first day of the maintenance period compared with baseline (acute effects after a single exposure of intervention products) and post-maintenance compared with baseline (sustained effects after repeated exposures of intervention products) regardless of randomisation. A total of 181 participants (forty-seven men and 134 women) completed the study. Sustained reduction in 24-h energy intake was associated with improved weight loss maintenance (R 0·37; P = 0·001), whereas the association was not found acutely (P = 0·91). Suppression in self-reported appetite was associated with improved weight loss maintenance both acutely (R −0·32; P = 0·033) and sustained (R −0·33; P = 0·042). Reduction in appetite seems to be associated with improved body weight management, making appetite-reducing food products an interesting strategy for dietary-based concepts.
In the territory between the Amazon and Orinoco rivers in the late sixteenth century, Sir Walter Raleigh observed natives use arrows with a “poison” so strong that its victims died, not by direct physical injury, but rather by the perishing effect of its poison. Curiosity in this substance by European explorers helped transform curare from an arrow poison to a surgical relaxant. The introduction of muscle relaxants revolutionized anesthetic practice as it allowed for improved surgical conditions, lower levels of volatile anesthetics, and improved tracheal intubation conditions.
The diurnal feeding patterns of dairy cows affects the 24 h robot utilisation of pasture-based automatic milking systems (AMS). A decline in robot utilisation between 2400 and 0600 h currently occurs in pasture-based AMS, as cow feeding activity is greatly reduced during this time. Here, we investigate the effect of a temporal variation in feed quality and quantity on cow feeding behaviour between 2400 and 0600 h as a potential tool to increase voluntary cow trafficking in an AMS at night. The day was allocated into four equal feeding periods (0600 to 1200, 1200 to 1800, 1800 to 2400 and 2400 to 0600 h). Lucerne hay cubes (CP = 19.1%, water soluble carbohydrate = 3.8%) and oat, ryegrass and clover hay cubes with 20% molasses (CP = 11.8%, water soluble carbohydrate = 10.7%) were offered as the ‘standard’ and ‘preferred’ (preference determined previously) feed types, respectively. The four treatments were (1) standard feed offered ad libitum (AL) throughout 24 h; (2) as per AL, with preferred feed replacing standard feed between 2400 and 0600 h (AL + P); (3) standard feed offered at a restricted rate, with quantity varying between each feeding period (20:10:30:60%, respectively) as a proportion of the (previously) measured daily ad libitum intake (VA); (4) as per VA, with preferred feed replacing standard feed between 2400 and 0600 h (VA + P). Eight non-lactating dairy cows were used in a 4 × 4 Latin square design. During each experimental period, treatment cows were fed for 7 days, including 3 days habituation and 4 days data collection. Total daily intake was approximately 8% greater (P < 0.001) for the AL and AL + P treatments (23.1 and 22.9 kg DM/cow) as compared with the VA and VA + P treatments (21.6 and 20.9 kg DM/cow). The AL + P and VA treatments had 21% and 90% greater (P < 0.001) dry matter intake (DMI) between 2400 and 0600 h, respectively, compared with the AL treatment. In contrast, the VA + P treatment had similar DMI to the VA treatment. Our experiment shows ability to increase cow feeding activity at night by varying feed type and quantity, though it is possible that a penalty to total DMI may occur using VA. Further research is required to determine if the implementation of variable feed allocation on pasture-based AMS farms is likely to improve milking robot utilisation by increasing cow feeding activity at night.
2017 marked the 130th anniversary of the start of the Carte du Ciel project, an ambitious proposal by the Paris Observatory to map the entire sky using photographiy, which required the joint work of numerous observatories in the world. For this endeavour, an impressive organization was designed that included congresses, commissions and publications, which lasted through many years. The Carte du Ciel finally became one of the immediate antecedents of the International Astronomical Union, which in 2019 celebrates its first century. In Latin America, the observatories of Santiago de Chile, La Plata and Rio de Janeiro, the Argentine National Observatory and the Tacubaya Observatory, in Mexico, were involved in the project. In this presentation, we present part of the history of the failures and successes of one of the most important collaborative astronomical projects on the planet.
The astronomical community accepts the division of the celestial sphere into 88 constellations, according to what was established by the IAU. In the first Assembly of 1922 the use of Latin names for constellations and their abbreviations was resolved. The pending issue of the limits of the constellations was discussed in the next meeting and Eugène Delporte had the responsibility for the complete theoretical demarcation. For his work, Delporte took into account what was done half a century earlier in the famous work Uranometría Argentina, published in 1877 and 1879, under the supervition of Benjamin Gould. In ths presentation we discusse the situation at the moment when the constellation boundaries were proposed using arcs of RA circles and parallels of declination, choosing them in such a way that they did not deviate too much from those used in the most important celestial atlas of the time, and minimizing the changes of which constellations stars would belong to.
Achieving a consistent level of robot utilisation throughout 24 h maximises automatic milking system (AMS) utilisation. However, levels of robot utilisation in the early morning hours are typically low, caused by the diurnal feeding behaviour of cows, limiting the inherent capacity and total production of pasture-based AMS. Our objective was to determine robot utilisation throughout 24 h by dairy cows, based on milking frequency (MF; milking events per animal per day) in a pasture-based AMS. Milking data were collected from January and February 2013 across 56 days, from a single herd of 186 animals (Bos taurus) utilising three Lely A3 robotic milking units, located in Tasmania, Australia. The dairy herd was categorised into three equal sized groups (n=62 per group) according to the cow’s mean daily MF over the duration of the study. Robot utilisation was characterised by an interaction (P< 0.001) between the three MF groups and time of day, with peak milking time for high MF cows within one h of a fresh pasture allocation becoming available, followed by the medium MF and low MF cows 2 and 4 h later, respectively. Cows in the high MF group also presented for milking between 2400 and 0600 h more frequently (77% of nights), compared to the medium MF group (57%) and low MF group (50%). This study has shown the formation of three distinct groups of cows within a herd, based on their MF levels. Further work is required to determine if this finding is replicated across other pasture-based AMS farms.
The aim of this review is to synthesize empirical studies on undergraduate language learners’ experience abroad during a time period of a year or less. To help provide a framework to this synthesis, we begin our review by tracing the recent evolution of empirical mixed-method research on the learner, identifying problems and characteristics that language learners generally encounter in the study abroad (SA) experience. We take a closer look at variables related to individual difference such as anxiety, motivation, and attitudes to more recent views of learner identity in language learning. We highlight the shift to language learner agency, a topic that merits more discussion in SA literature. We then review how the SA learning environments are treated. This review takes a closer look at research informed by socially grounded theories. Finally, we review the role that SA plays in undergraduate language curricula, where the objectives of the experience are aligned with at-home (AH) curricula, a topic that has not been fully discussed in SA literature. The conclusions offer suggestions for keeping pace with the broader field of applied/educational linguistics.
In the UK, 11.8% of expectant mothers undergo an elective caesarean section (ELCS) representing 92 000 births per annum. It is not known to what extent this procedure has an impact on mental well-being in the longer term.
To determine the prevalence and postpartum progression of anxiety and depression symptoms in women undergoing ELCS in Wales.
Prevalence of depression and anxiety were determined in women at University Hospital Wales (2015–16; n = 308) through completion of the Edinburgh Postnatal Depression Scale (EPDS; ≥13) and State-Trait Anxiety Inventory (STAI; ≥40) questionnaires 1 day prior to ELCS, and three postpartum time points for 1 year. Maternal characteristics were determined from questionnaires and, where possible, confirmed from National Health Service maternity records.
Using these criteria the prevalence of reported depression symptoms was 14.3% (95% CI 10.9–18.3) 1 day prior to ELCS, 8.0% (95% CI 4.2–12.5) within 1 week, 8.7% (95% CI 4.2–13.8) at 10 weeks and 12.4% (95% CI 6.4–18.4) 1 year postpartum. Prevalence of reported anxiety symptoms was 27.3% (95% CI 22.5–32.4), 21.7% (95% CI 15.8–28.0), 25.3% (95% CI 18.5–32.7) and 35.1% (95% CI 26.3–44.2) at these same stages. Prenatal anxiety was not resolved after ELCS more than 1 year after delivery.
Women undergoing ELCS experience prolonged anxiety postpartum that merits focused clinical attention.
The primary objectives of the ExoplANETS-A project are to: establish new knowledge on exoplanet atmospheres; establish new insight on influence of the host star on the planet atmosphere; disseminate knowledge, using online, web-based platforms. The project, funded under the EU’s Horizon-2020 programme, started in January 2018 and has a duration ∼3 years. We present an overview of the project, the activities concerning the host stars and some early results on the host stars.
Certain forestry and agricultural practices are known to affect arbuscular mycorrhizal (AM) fungal communities, but the effects of deforestation – including slash-and-burn management and other more severe disturbances – in tropical rain forests are poorly understood. We addressed the effects of anthropogenic disturbance on rain-forest AM fungal communities in French Guiana, by comparing mature tropical rain forest, slash-and-burn (5 y old) and clearcut areas (8 y old). A total of 36 soil samples were collected in six plots and sequenced using a high throughput 454-pyrosequencing platform. A total of 32649 sequences from 103 AM fungal virtual taxa (VT) were recorded. Whereas alpha diversity of AM fungi did not decrease due to land-use intensification, with average richness ranging from 17 to 21 taxa per plot, beta diversity (average distance to multivariate centroid) dropped by 28% from 0.46 in rain forest to 0.33 under clearcutting. AM fungal community composition was correlated with land use and soil chemical properties. Clearcut areas were characterized by the more frequent occurrence of specialist AM fungi, compared with mature forest or slash-and-burn areas. Specifically, clearcuts contained the highest proportions of VT that were geographic (21%), habitat (31%), abundance (97%) or host (97%) specialists based on VT metadata contained in the MaarjAM database. This suggests that certain AM fungi with narrow ecological niches have traits that allow them to exploit conditions of severe disturbance. In conclusion, slash-and-burn management appears to allow diverse AM fungal communities to persist, and may favour regeneration of tropical rain forest after abandonment. More severe disturbance in the form of clearcutting resulted in marked changes in AM fungal communities.
Metamaterials offer the possibility to control and manipulate electromagnetic radiation. Spoof surface plasmon metamaterials are the focus of this Element of the Metamaterials Series. The fundamentals of spoof surface plasmons are reviewed, and advances on plasmonic metamaterials based on spoof plasmons are presented. Spoof surface plasmon metamaterials on a wide range of geometries are discussed: from planar platforms to waveguides and localized modes, including cylindrical structures, grooves, wedges, dominos or conformal surface plasmons in ultrathin platforms. The Element closes with a review of recent advances and applications such as Terahertz sensing or integrated devices and circuits.
We argue that although objectivist moral attitudes may facilitate cooperation, they are not necessary for the high levels of cooperation in humans. This is implied by evolutionary models that articulate a mechanism underlying Stanford's account, and is also suggested by the ability of merely conventional social norms to explain extreme human behaviors.