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To assess differences in cognition functions and gross brain structure in children seven years after an episode of severe acute malnutrition (SAM), compared with other Malawian children.
Prospective longitudinal cohort assessing school grade achieved and results of five computer-based (CANTAB) tests, covering three cognitive domains. A subset underwent brain MRI scans which were reviewed using a standardized checklist of gross abnormalities and compared with a reference population of Malawian children.
Children discharged from SAM treatment in 2006 and 2007 (n 320; median age 9·3 years) were compared with controls: siblings closest in age to the SAM survivors and age/sex-matched community children.
SAM survivors were significantly more likely to be in a lower grade at school than controls (adjusted OR = 0·4; 95 % CI 0·3, 0·6; P < 0·0001) and had consistently poorer scores in all CANTAB cognitive tests. Adjusting for HIV and socio-economic status diminished statistically significant differences. There were no significant differences in odds of brain abnormalities and sinusitis between SAM survivors (n 49) and reference children (OR = 1·11; 95 % CI 0·61, 2·03; P = 0·73).
Despite apparent preservation in gross brain structure, persistent impaired school achievement is likely to be detrimental to individual attainment and economic well-being. Understanding the multifactorial causes of lower school achievement is therefore needed to design interventions for SAM survivors to thrive in adulthood. The cognitive and potential economic implications of SAM need further emphasis to better advocate for SAM prevention and early treatment.
Predictions of the mechanical response of polycrystalline metals and underlying microstructure evolution and deformation mechanisms are critically important for the manufacturing and design of metallic components, especially those made of new advanced metals that aim to outperform those in use today. In this review article, recent advancements in modeling deformation processing-microstructure evolution and in microstructure–property relationships of polycrystalline metals are covered. While some notable examples will use standard crystal plasticity models, such as self-consistent and Taylor-type models, the emphasis is placed on more advanced full-field models such as crystal plasticity finite elements and Green’s function-based models. These models allow for nonhomogeneity in the mechanical fields leading to greater insight and predictive capability at the mesoscale. Despite the strides made, it still remains a mesoscale modeling challenge to incorporate in the same model the role of influential microstructural features and the dynamics of underlying mechanisms. The article ends with recommendations for improvements in computational speed.
In this work, the deformation mechanisms underlying the room temperature deformation of the pseudomorphic body centered cubic (BCC) Mg phase in Mg/Nb nanolayered composites are studied. Nanolayered composites comprised of 50% volume fraction of Mg and Nb were synthesized using physical vapor deposition with the individual layer thicknesses h of 5, 6.7, and 50 nm. At the lower layer thicknesses of h = 5 and 6.7 nm, Mg has undergone a phase transition from HCP to BCC such that it formed a coherent interface with the adjoining Nb phase. Micropillar compression testing normal and parallel to the interface plane shows that the BCC Mg nanolayered composite is much stronger and can sustain higher strains to failure than the HCP Mg nanolayered composite. A crystal plasticity model incorporating confined layer slip is presented and applied to link the observed anisotropy and hardening in the deformation response to the underlying slip mechanisms.
We present a multi-frequency study of the intermediate spiral SAB(r)bc type galaxy NGC 6744, using available data from the Chandra X-Ray telescope, radio continuum data from the Australia Telescope Compact Array and Murchison Widefield Array, and Wide-field Infrared Survey Explorer infrared observations. We identify 117 X-ray sources and 280 radio sources. Of these, we find nine sources in common between the X-ray and radio catalogues, one of which is a faint central black hole with a bolometric radio luminosity similar to the Milky Way’s central black hole. We classify 5 objects as supernova remnant (SNR) candidates, 2 objects as likely SNRs, 17 as H ii regions, 1 source as an AGN; the remaining 255 radio sources are categorised as background objects and one X-ray source is classified as a foreground star. We find the star-formation rate (SFR) of NGC 6744 to be in the range 2.8–4.7 M⊙~yr − 1 signifying the galaxy is still actively forming stars. The specific SFR of NGC 6744 is greater than that of late-type spirals such as the Milky Way, but considerably less that that of a typical starburst galaxy.
The aim of the present study was to compare dynamics of the bone healing process after different types of osteotomies. In total, 24 Wistar rats were subjected to different types of osteotomy performed with standard steel bur, piezosurgery, contact, and non-contact Erbium:yttrium-aluminum-garnet (Er:YAG) laser ablation. The animals were randomly divided into four groups, to be euthanized immediately after the procedure, or at 1, 2, or 3 weeks after surgery. The obtained bone samples were analyzed by scanning electron microscopy (SEM). Immediately after surgery, there were significant differences in the appearance of the bone defects, with presence of bone fragments and debris after standard steel bur preparation, compared with the clean smooth walls and relatively sharp edges in all other groups. The initial bone formation in defects prepared by piezosurgery was observed to be the most rapid. After 3 weeks, all bone defects were completely restored; although, differences in the healing pattern were noted, with a modest initial delay in healing after laser preparation. The first stage of the bone healing process was delayed when contact and non-contact Er:YAG laser modes were used and accelerated by piezosurgery; however, the results after 3 weeks demonstrated similar restitution of defects in all tested groups.
The Middle Horizon (ca. A.D. 600-1100) was a period of great change in the Andes, with much of Perú connected through long-distance exchange and widely shared Wari styles and practices. Recent research has begun to detail the transformations that occurred within the period, leading to questions about the development of the Wari state and its shifting relationships with outlying areas over time. This article expands this research by exploring the temporal differences within a funerary assemblage at La Real, a site in the Majes Valley of southern Perú. The artifacts and human remains from La Real are used to explore Middle Horizon dynamism in relation to both the surging interregional interaction of the period and emergent social stratification in the valley. Mortuary profiles and sublethal violence remain fairly constant throughout the period, but lethal violence significantly increases in the late Middle Horizon. There are also significant changes over time in the presence of exotic goods and other items, reflecting an increase in craft specialization, the adoption of Wari-related styles and practices, and the development of a more regionally oriented economy. The role of the Wari state in these changes, although unclear, may relate to attempts by Wari leaders to manipulate the long-distance movement of a restricted group of artifacts and resources.
This chapter provides an overview of Earth system models, the various model ‘flavours’, their state of development including model evaluation, benchmarking and optimization against observational data and their application to climate change issues.
The Earth system can be conceptualized as a suite of interacting physical, chemical, biological and anthropogenic processes that regulate the planet’s low of matter and energy. Earth system models (ESMs; Box 5.1 ) are built to mirror these processes. In fact, ESMs are the only tool available to the scientific community to investigate the system properties of the Earth, as we do not have an alternative planet to manipulate that could serve as a scientist’s laboratory.
The term ‘Earth system model’ is commonly used to describe coupled land–ocean–atmosphere models that include interactive biogeochemical components. Such models have developed progressively from the physical climate models first created in the 1960s and 1970s. Conventional climate models apply physical laws to simulate the general circulation of atmosphere and ocean. As our understanding of the natural and anthropogenic controls on climate has grown, and given the steady advances in computing power, global climate models have been extended to include more comprehensive representations of biological and geochemical processes, involving the addition of the various interacting components of the Earth system with their own feedback mechanisms. Figure 5.1 shows the conceptual differences between a conventional global coupled atmosphere–ocean general circulation model (AOGCM) and an ESM. In terms of the coupling between components, ESMs are more complex, and they have correspondingly higher computational demands.
This chapter provides a high-level summary of the state of knowledge regarding observations, processes and models of climate, terrestrial ecosystems and the global carbon cycle. We focus strongly on observations (at various timescales, including palaeo timescales as appropriate), and what can be learned from their interpretation in the light of the established principles of climate science and terrestrial ecosystem science. The field is very broad and therefore we have had to be highly selective. We discuss aspects pertinent to understanding recent and contemporary changes in climate and the global carbon cycle, with emphasis on the terrestrial component.
Observing and studying climate
Background and history of climate science
Like the weather, everyone has an interest in climate and knows something about it. Climate is generally understood as ‘average weather’. By definition, climate cannot change from year to year; but it can (and does) change over decades and centuries.
Until the 1970s, the study of climate was largely descriptive. The data were concentrated in certain regions, and often anecdotal. Nonetheless, as Lamb (1982) and others described, these data already showed the existence of a great deal of variability in climate on many timescales, and that this variability has had a pervasive impact on human societies.
Climate also has a dominant effect on ecosystems. The patterns of terrestrial biomes, from dense tropical forests to high-latitude and mountain tundra and deserts, reflect spatial patterns of average temperature and rainfall and show that climate has had a profound role in shaping the ecology and evolution of land plants. Relationships between vegetation and climate formed the basis for Köppen’s (1918) classification of world climates, which allowed climate to be inferred from vegetation at a time when direct climate observations were sparse.
Background: Patient involvement is widely acknowledged to be a valuable component in health technology assessment (HTA) and healthcare decision making. However, quantitative approaches to ascertain patients' preferences for treatment endpoints are not yet established. The objective of this study is to introduce the analytic hierarchy process (AHP) as a preference elicitation method in HTA. Based on a systematic literature review on the use of AHP in health care in 2009, the German Institute for Quality and Efficiency in Health Care (IQWiG) initiated an AHP study related to its HTA work in 2010.
Methods: The AHP study included two AHP workshops, one with twelve patients and one with seven healthcare professionals. In these workshops, both patients and professionals rated their preferences with respect to the importance of different endpoints of antidepressant treatment by a pairwise comparison of individual endpoints. These comparisons were performed and evaluated by the AHP method and relative weights were generated for each endpoint.
Results: The AHP study indicates that AHP is a well-structured technique whose cognitive demands were well handled by patients and professionals. The two groups rated some of the included endpoints of antidepressant treatment differently. For both groups, however, the same six of the eleven endpoints analyzed accounted for more than 80 percent of the total weight.
Conclusions: AHP can be used in HTA to give a quantitative dimension to patients' preferences for treatment endpoints. Preference elicitation could provide important information at various stages of HTA and challenge opinions on the importance of endpoints.
Anesthesia for complex spine surgery requires invasive monitoring, large-bore intravenous access, and awareness of the potential for disaster. Anesthesiologists involved in the care of patients undergoing complicated spine surgery should be cognitive of this infrequent but serious complication. This chapter presents a case study of a 75-year-old female who was scheduled for removal of instrumentation at L4-S1 and re-exploration of a previous posterior lumbar inter-body fusion. The intraoperative course was also complicated by significant coagulopathy from massive blood loss and transfusion. The postoperative course was complicated by nonoliguric renal failure, pneumonia, and urinary tract infection. The role of central venous monitoring is always debated in the context of major spine surgery. However, central venous pressure readings in the prone position may not reflect accurate data and large bore intravascular access and invasive blood pressure monitoring are probably more important in the hemodynamic management of these cases.