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Diagnosing HIV-Associated Neurocognitive Disorders (HAND) requires attributing neurocognitive impairment and functional decline at least partly to HIV-related brain effects. Depressive symptom severity, whether attributable to HIV or not, may influence self-reported functioning. We examined longitudinal relationships among objective global cognition, depressive symptom severity, and self-reported everyday functioning in people with HIV (PWH).
Methods:
Longitudinal data from 894 PWH were collected at a university-based research center (2002–2016). Participants completed self-report measures of everyday functioning to assess both dependence in instrumental activities of daily living (IADL) and subjective cognitive difficulties at each visit, along with depressive symptom severity (BDI-II). Multilevel modeling examined within- and between-person predictors of self-reported everyday functioning outcomes.
Results:
Participants averaged 6 visits over 5 years. Multilevel regression showed a significant interaction between visit-specific global cognitive performance and mean depression symptom severity on likelihood of dependence in IADL (p = 0.04), such that within-person association between worse cognition and greater likelihood of IADL dependence was strongest among individuals with lower mean depressive symptom severity. In contrast, participants with higher mean depressive symptom severity had higher likelihoods of IADL dependence regardless of cognition. Multilevel modelling of subjective cognitive difficulties showed no significant interaction between global cognition and mean depressive symptom severity (p > 0.05).
Conclusions:
The findings indicate a link between cognitive abilities and IADL dependence in PWH with low to moderate depressive symptoms. However, those with higher depressive symptoms severity report IADL dependence regardless of cognitive status. This is clinically significant because everyday functioning is measured through self-report rather than performance-based assessments.
Flumioxazin and S-metolachlor are widely used in conventional sweetpotato production in North Carolina and other states; however, some growers have recently expressed concerns about potential effects of these herbicides on sweetpotato yield and quality. Previous research indicates that activated charcoal has the potential to reduce herbicide injury. Field studies were conducted in 2021 and 2022 to determine whether flumioxazin applied preplant and S-metolachlor applied before and after transplanting negatively affect sweetpotato yield and quality when activated charcoal is applied with transplant water. The studies evaluated five herbicide treatments and two activated charcoal treatments. Herbicide treatments included two flumioxazin rates, one S-metolachlor rate applied immediately before and immediately after transplanting, and no herbicide. Charcoal treatments consisted of activated charcoal applied at 9 kg ha−1, and no charcoal. No visual injury from herbicides or charcoal was observed. Likewise, no effect of herbicide or charcoal treatment on no. 1, marketable (sum of no. 1 and jumbo grades), or total yield (sum of canner, no. 1, and jumbo grades) was observed. Additionally, shape analysis conducted on calculated length-to-width ratio (LWR) for no. 1 sweetpotato roots found no effect from flumioxazin at either rate on sweetpotato root shape. However, both S-metolachlor treatments resulted in lower LWR of no. 1 sweetpotato roots in 2021. Results are consistent with prior research and indicate that flumioxazin and S-metolachlor are safe for continued use on sweetpotato at registered rates.
Human societies are changing where and how water flows through the atmosphere. However, these changes in the atmospheric water cycle are not being managed, nor is there any real sense of where these changes might be headed in the future. Thus, we develop a new economic theory of atmospheric water management, and explore this theory using creative story-based scenarios. These scenarios reveal surprising possibilities for the future of atmospheric water management, ranging from a stock market for transpiration to on-demand weather. We discuss these story-based futures in the context of research and policy priorities in the present day.
Technical Summary
Humanity is modifying the atmospheric water cycle, via land use, climate change, air pollution, and weather modification. Historically, atmospheric water was implicitly considered a ‘public good’ since it was neither actively consumed nor controlled. However, given anthropogenic changes, atmospheric water can become a ‘common-pool’ good (consumable) or a ‘club’ good (controllable). Moreover, advancements in weather modification presage water becoming a ‘private’ good, meaning both consumable and controllable. Given the implications, we designed a theoretical framing of atmospheric water as an economic good and used a combination of methods in order to explore possible future scenarios based on human modifications of the atmospheric water cycle. First, a systematic literature search of scholarly abstracts was used in a computational text analysis. Second, the output of the text analysis was matched to different parts of an existing economic goods framework. Then, a group of global water experts were trained and developed story-based scenarios. The resultant scenarios serve as creative investigations of the future of human modification of the atmospheric water cycle. We discuss how the scenarios can enhance anticipatory capacity in the context of both future research frontiers and potential policy pathways including transboundary governance, finance, and resource management.
Social Media Summary
Story-based scenarios reveal novel future pathways for the management of the atmospheric water cycle.
We consider the role of gravity in solute transport when a thin droplet evaporates. Under the physically relevant assumptions that the contact line is pinned and the solutal Péclet number, ${Pe}$, is large, we identify two asymptotic regimes that depend on the size of the Bond number, ${Bo}$. When ${Bo} = O(1)$ as ${Pe}\rightarrow \infty$, the asymptotic structure of solute transport follows directly from the surface-tension-dominated regime, whereby advection drives solute towards the contact line, only to be countered by local diffusive effects, leading to the formation of the famous ‘coffee ring.’ In the distinguished limit in which ${Bo} = O({Pe}^{4/3})$ as ${Pe}\rightarrow \infty$, this interplay between advection and diffusion takes place alongside that between surface tension and gravity. In each regime, we perform a systematic asymptotic analysis of the solute transport and compare our predictions to numerical simulations. We identify the effect of gravity on the nascent coffee ring, providing quantitative predictions of the size, location and shape of the solute mass profile. In particular, for a fixed Péclet number, as the effect of gravity increases, the coffee ring is diminished in height and situated further from the contact line. Furthermore, for certain values of ${Bo}$, ${Pe}$ and the evaporation time, a secondary peak may exist inside the classical coffee ring. The onset of this secondary peak is linked to the change in type of the critical point in the solute mass profile at the droplet centre. Both the onset and the peak characteristics are shown to be independent of ${Pe}$.
The dynamics of thin, non-circular droplets evaporating in the diffusion-limited regime is examined. The challenging non-rectilinear mixed boundary problem this poses is solved using a novel asymptotic approach and an asymptotic expansion for the evaporative flux from the free surface of the droplet is found. While theoretically valid only for droplets that are close to circular, it is demonstrated that the methodology can successfully be applied to droplets with a wide variety of footprint shapes, including polygons and highly non-convex domains. As our solution for the flux fundamentally represents a novel result in potential theory, the applications are numerous, as the mixed boundary value problem arises in fields as diverse as electrostatics and contact mechanics. Here, we demonstrate the practicality of our result by considering the analytically tractable case of deposition of solute from large droplets in detail, including a matched asymptotic analysis to resolve the pressure, streamlines and deposition up to second order.
The first demonstration of laser action in ruby was made in 1960 by T. H. Maiman of Hughes Research Laboratories, USA. Many laboratories worldwide began the search for lasers using different materials, operating at different wavelengths. In the UK, academia, industry and the central laboratories took up the challenge from the earliest days to develop these systems for a broad range of applications. This historical review looks at the contribution the UK has made to the advancement of the technology, the development of systems and components and their exploitation over the last 60 years.
Bayesian analysis of radiocarbon (14C) dates in North American archaeology is increasing, especially among archaeologists working in deeper time. However, historical archaeologists have been slow to embrace these new techniques, and there have been only a few examples of the incorporation of calendar dates as informative priors in Bayesian models in such work in the United States. To illustrate the value of Bayesian approaches to sites with both substantial earlier Native American occupations as well as a historic era European presence, we present the results of our Bayesian analysis of 14C dates from the earlier Guale village and the Mission period contexts from the Sapelo Shell Ring Complex (9MC23) in southern Georgia. Jefferies and Moore have explored the Spanish Mission period deposits at this site to better understand the Native American interactions with the Spanish during the 16th and 17th centuries along the Georgia Coast. Given the results of our Bayesian modeling, we can say with some degree of confidence that the deposits thus far excavated and sampled contain important information dating to the 17th-century mission on Sapelo Island. In addition, our modeling of new dates suggests the range of the pre-Mission era Guale village. Based on these new dates, we can now say with some degree of certainty which of the deposits sampled likely contain information that dates to one of the critical periods of Mission period research, the AD 1660–1684 period that ushered in the close of mission efforts on the Georgia Coast.
The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.
Synchrotron X-ray topography was the principal perfection-assessment method employed. X-ray wavelengths were chosen that gave optimum penetration and diffraction contrast characteristics for the size of crystals examined. Two colourles transparent specimens were selected for comprehensive study. Both were of simple habit consisting of the prism {101̄0} terminated at each end by major and minor rhombohedral facets only. The larger specimen, volume ≈250 mm3, contained a moderately high but non-uniformly distributed dislocation population, totalling ≈103, all emanating from a roughly centrally located small nuclear volume. One apical region was dislocation-free. Optical microscopic observations including Nomarski interference contrast of features on one major rhombohedral facet in this region are described. The smaller specimen, volume ≈30 mm3, was remarkable for its low dislocation content, ≈20 in total, all radiating from a central point. Enhancement of dislocation image visibility relative to diffraction contrast images of severe surface damage on this crystal was demonstrated using higher-order X-ray reflections. Neither of the specimens studied in detail contained twinning or evident diffraction contrast from impurity zoning. Their lack of a microscopically visible or X-ray topographically detectable nucleating body favours a homogenous nucleation origin of these crystals.
Animal models of early postnatal mother–infant interactions have highlighted the importance of tactile contact for biobehavioral outcomes via the modification of DNA methylation (DNAm). The role of normative variation in contact in early human development has yet to be explored. In an effort to translate the animal work on tactile contact to humans, we applied a naturalistic daily diary strategy to assess the link between maternal contact with infants and epigenetic signatures in children 4–5 years later, with respect to multiple levels of child-level factors, including genetic variation and infant distress. We first investigated DNAm at four candidate genes: the glucocorticoid receptor gene, nuclear receptor subfamily 3, group C, member 1 (NR3C1), μ-opioid receptor M1 (OPRM1) and oxytocin receptor (OXTR; related to the neurobiology of social bonds), and brain-derived neurotrophic factor (BDNF; involved in postnatal plasticity). Although no candidate gene DNAm sites significantly associated with early postnatal contact, when we next examined DNAm across the genome, differentially methylated regions were identified between high and low contact groups. Using a different application of epigenomic information, we also quantified epigenetic age, and report that for infants who received low contact from caregivers, greater infant distress was associated with younger epigenetic age. These results suggested that early postnatal contact has lasting associations with child biology.
MR is a powerful modality. At its most advanced, it can be used not just to image anatomy and pathology, but to investigate organ function, to probe in vivo chemistry, and even to visualise the brain thinking. However, clinicians, technologists and scientists struggle with the study of the subject. The result is sometimes an obscurity of understanding, or a dilution of scientific truth, resulting in misconceptions. This is why MRI from Picture to Proton has achieved its reputation for practical clarity. MR is introduced as a tool, with coverage starting from the images, equipment and scanning protocols and traced back towards the underlying physics theory. With new content on quantitative MRI, MR safety, multi-band excitation, Dixon imaging, MR elastography and advanced pulse sequences, and with additional supportive materials available on the book's website, this new edition is completely revised and updated to reflect the best use of modern MR technology.