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 email@example.com
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.
Despite efforts to improve maternal and child nutrition, undernutrition remains a major public health challenge in Ghana. The current study explored community perceptions of undernutrition and context-specific interventions that could improve maternal and child nutrition in rural Northern Ghana.
This exploratory qualitative study used ten focus group discussions to gather primary data. The discussions were recorded, transcribed and coded into themes using Nvivo 12 software to aid thematic analysis.
The study was conducted in rural Kassena-Nankana Districts of Northern Ghana.
Thirty-three men and fifty-one women aged 18–50 years were randomly selected from the community.
Most participants reported poverty, lack of irrigated agricultural land and poor harvests as the main barriers to optimal nutrition. To improve maternal and child nutrition, study participants suggested that the construction of dams at the community level would facilitate all year round farming including rearing of animals. Participants perceived that the provision of agricultural materials such as high yield seedlings, pesticides and fertiliser would help boost agricultural productivity. They also recommended community-based nutrition education by trained health volunteers, focused on types of locally produced foods and appropriate ways to prepare them to help improve maternal and child nutrition.
Drawing on these findings and existing literature, we argue that supporting community initiated nutrition interventions such as improved irrigation for dry season farming, provision of agricultural inputs and community education could improve maternal and child nutrition.
The coronavirus disease (COVID-19), while mild in most cases, has nevertheless caused significant mortality. The measures adopted in most countries to contain it have led to colossal social and economic disruptions, which will impact the medium- and long-term health outcomes for many communities. In this paper, we deliberate on the reality and facts surrounding the disease. For comparison, we present data from past pandemics, some of which claimed more lives than COVID-19. Mortality data on road traffic crashes and other non-communicable diseases, which cause more deaths each year than COVID-19 has so far, is also provided. The indirect, serious health and social effects are briefly discussed. We also deliberate on how misinformation, confusion stemming from contrasting expert statements, and lack of international coordination may have influenced the public perception of the illness and increased fear and uncertainty. With pandemics and similar problems likely to re-occur, we call for evidence-based decisions, the restoration of responsible journalism and communication built on a solid scientific foundation.
Analysis of the post-COVID world tends to gravitate to one of two poles. For some, the pandemic is a crisis that will reshuffle the decks, producing a fundamental reordering of global politics. For others, the basic principles of the international order are likely to remain much the same, driven largely by the emerging bipolar system between the US and China. We find both narratives dissatisfying, as the former overinterprets the causal role of the pandemic itself, while the latter underappreciates the critical ways in which global politics have been transformed beyond the state-centered system of the Cold War. We argue instead that the pandemic exposes underlying trends already at work and forces scholars to open the aperture on how we study globalization. Most centrally, we contend that globalization needs to be seen not just as a distributional game of winners and losers but rather a more profoundly transformational game that reshapes identities, redefines channels of power and authority, and generates new sites for contentious politics. We draw on emerging work to sketch out a theoretical frame for thinking about the politics of globalization, and assess some of the key policy arenas where COVID-19 is accelerating the transformative effects of globalization. In so doing, we suggest a roadmap to a post-pandemic research agenda for studying global markets that more fully captures these transformations and their implications for world politics.
Stictococcus vayssierei is a major pest of root and tuber crops in central Africa. However, data on its ecology are lacking. Here we provide an updated estimate of its distribution with the aim of facilitating the sustainable control of its populations. Surveys conducted in nine countries encompassing 13 ecological regions around the Congo basin showed that African root and tuber scale was present in Cameroon, Central African Republic, Congo, Democratic Republic of Congo, Equatorial Guinea, Gabon and Uganda. It was not found on the sites surveyed in Chad and Nigeria. The pest occurred in the forest and the forest-savannah mosaic as well as in the savannah where it was never recorded before. However, prevalence was higher in the forest (43.1%) where cassava was the most infested crop, compared to the savannah (9.2%) where aroids (cocoyam and taro) were the most infested crops. In the forest habitat, the pest was prevalent in all but two ecological regions: the Congolian swamp forests and the Southern Congolian forest-savanna mosaic. In the savannah habitat, it was restricted to the moist savannah highlands and absent from dry savannahs. The scale was not observed below 277 m asl. Where present, the scale was frequently (87.1% of the sites) attended by the ant Anoplolepis tenella. High densities (>1000 scales per plant) were recorded along the Cameroon–Gabon border. Good regulatory measures within and between countries are required to control the exchange of plant materials and limit its spread. The study provides information for niche modeling and risk mapping.
Solid state batteries are an emerging alternative to traditional liquid electrolyte cells that provide potential for safe and high-energy density power sources. This report describes a self-forming, solid state battery based on the Li/I2 couple using an LiI-rich LiI(3-hydroxypropionitrile)2 electrolyte (LiI–LiI(HPN)2). As the negative and positive active materials are generated in situ, the solid electrolyte–current collector interfaces play a critical role in determining the electrochemical response of the battery. Herein, we report the investigation of solid electrolyte–current collector interfaces with a self-forming LiI–LiI(HPN)2 solid electrolyte and the role of varying interface design in reducing resistance during cycling.
Cognitive impairment is a core feature of psychotic disorders, but the profile of impairment across adulthood, particularly in African-American populations, remains unclear.
Using cross-sectional data from a case–control study of African-American adults with affective (n = 59) and nonaffective (n = 68) psychotic disorders, we examined cognitive functioning between early and middle adulthood (ages 20–60) on measures of general cognitive ability, language, abstract reasoning, processing speed, executive function, verbal memory, and working memory.
Both affective and nonaffective psychosis patients showed substantial and widespread cognitive impairments. However, comparison of cognitive functioning between controls and psychosis groups throughout early (ages 20–40) and middle (ages 40–60) adulthood also revealed age-associated group differences. During early adulthood, the nonaffective psychosis group showed increasing impairments with age on measures of general cognitive ability and executive function, while the affective psychosis group showed increasing impairment on a measure of language ability. Impairments on other cognitive measures remained mostly stable, although decreasing impairments on measures of processing speed, memory and working memory were also observed.
These findings suggest similarities, but also differences in the profile of cognitive dysfunction in adults with affective and nonaffective psychotic disorders. Both affective and nonaffective patients showed substantial and relatively stable impairments across adulthood. The nonaffective group also showed increasing impairments with age in general and executive functions, and the affective group showed an increasing impairment in verbal functions, possibly suggesting different underlying etiopathogenic mechanisms.
The earliest phases of star formation are characterised by intense mass accretion from the circumstellar disk to the central star. One group of young stellar objects, the FU Orionis-type stars exhibit accretion rate peaks accompanied by bright eruptions. The occurance of these outbursts might solve the luminosity problem of protostars, play a key role in accumulating the final star mass, and have a significant effect on the parameters of the envelope and the disk. In the framework of the Structured Accretion Disks ERC project, we are conducting a systematic investigation of these sources with millimeter interferometry to examine whether they represent normal young stars in exceptional times or they are unusual objects. Our results show that FU Orionis-type stars can be similar to both Class I and Class II systems and may be in a special evolutionary phase between the two classes with their infall-driven episodic eruptions being the main driving force of the transition.
The origin of optical-infrared variability in young, intermediate mass Herbig Ae/Be stars is linked to their circumstellar disk. Therefore, variability could serve as a diagnostic tool to constrain the structure and dynamics of the (inner) disk. Here we discuss this diagnostic potential, and report some preliminary results from our coordinated BV RIJHKs and Spitzer monitoring observations of nine Herbig Ae stars. We aim to understand the response of the inner disks thermal emission on the changing stellar irradiation, and to separate it from UX Orionis-type fading events, which also provide information on the disk. This project is a pilot study for the era of time domain astronomy of young stars, opened by Kepler K2, Gaia, ASAS-SN, TESS, Spitzer, WISE, and JWST.
DQ Tau is a young low-mass spectroscopic binary, consisting of two almost equal-mass stars on a 15.8 day period surrounded by a circumbinary disk. We analyzed DQ Tau’s light curves obtained by Kepler K2, the Spitzer Space Telescope, and ground-based facilities. We observed variability phenomena, including rotational modulation by stellar spots, energetic stellar flares, brightening events around periastron due to increased accretion, and short dips due to temporary circumstellar obscuration. The study on DQ Tau will help in discovering and understanding the formation and evolution of other real-world examples of “Tatooine-like” systems. This is especially important because more and more evidence points to the possibility that all Sun-like stars were born in binary or multiple systems that broke up later due to dynamical interactions.
Young stellar objects often show photometric variability, which is well examined at optical wavelengths, but more and more infrared data are also available. The wavelength dependence of the variability carries information on the physical cause of the changing brightness. Here, we examine seven T Tauri-type stars known for their large amplitude variability selected from the Campaign 13 field of the Kepler K2 mission. We complemented the K2 light curves by multifilter optical monitoring observations made with the 90 cm Schmidt telescope of Konkoly Observatory, and by 3.6 and 4.5 μm infrared photometry with a 20 hours cadence using the Spitzer Space Telescope. We found that the wavelength dependence of the observed variability is not consistent with changing interstellar extinction. We suggest that the brightness changes are due to variable accretion, causing a variable illumination of the inner disk.
To examine level of participation and satisfaction with the Healthy Savings Program (HSP), a programme that provides price discounts on healthier foods.
For Study 1, a survey was distributed to a random sample of adults who were invited to participate in a version of the HSP that provided a discount for the purchase of fresh produce and discounts on other healthier foods. In Study 2, interviews were conducted with a convenience sample of adults invited to participate in a version of the HSP that provided price discounts on specific products only (no fresh produce discount).
The HSP is provided to all employer-based insurance plan members of a large health plan. Employers can choose to enhance the version of the HSP that their employees receive by paying for a weekly discount on fresh produce.
Employees in employer groups that received the enhanced HSP (Study 1) and employees in an employer group (Study 2) that received the standard HSP.
Among survey respondents in Study 1, 69·3 % reported using the HSP card. Most were satisfied with the fresh produce discount and ease of use of the HSP card. Satisfaction was lower for selection of participating stores, amounts of discounts and selection of discounted products. In Study 2, barriers to the use of the HSP card cited included the limited number of participating stores and the limited selection of discounted products.
Satisfaction with some elements of the HSP was high while other elements may need improvement to increase programme use.
To compare the dosimetric outcomes of linear accelerator-based stereotactic radiotherapy (SRT) techniques—static conformal field (SCF), static conformal arc (SCA) and dynamic conformal arc (DCA), for treating pituitary adenoma and craniopharyngioma.
Materials and methods
Computer image sets of 20 patients with pituitary adenoma or craniopharyngioma and treated with post-operative SRT were selected for this study. For each dataset, three SRT plans, with SCF, SCA and DCA techniques were generated using Brain LAB, iPlan RT V.4.5.3, TPS software. The conformity index (CI), homogeneity index (HI), quality of coverage of the target, dose–volume histograms for the target and organs at risk (OARs) and the time taken to deliver treatment was compared across three sets of plan.
There were 12 patients with pituitary adenoma and eight with craniopharyngioma. The CI and HI were comparable across three techniques. The quality of coverage was superior in DCA technique. OARs were better spared in SCF and DCA techniques. Time taken to deliver treatment was least in SCF technique.
The linac-based SRT techniques SCF, SCA and DCA are efficient in delivering highly conformal and homogenous dose to the target in pituitary adenoma and craniopharyngioma. Among these three techniques, SCF and DCA had acceptable quality of coverage. The dose received by OARs was least in the SCF technique.
Pixelated vision or visual snow has been associated with schizophrenia (Silverstein 2011). The impact of viewing a 3D motion picture on such a visualphenomenon has not heretofore been described.
Case Study: A 28 year old right handed single male three years prior to presentation noticed that all his vision was pixelated. The pixelated vision is panoramic, involving the entire visual field. The pixels are characterized by 10,000 flat white and gray dots measuring 1mm x 1mm. No changes in color, shape, or size were noted in high and low intensity light. White, dark, gray, or multicolored backgrounds had no effect on his vision. The visual distortions are not impacted by head movements, emotions, degree of tiredness, driving, or his hedonic perception of the object being visualized. The pixels were noted to disappear upon closure of both eyes but persisted during monocular vision with either eye. These visual hallucinations were sporadic during the first year and became continuous over the following two years. Two weeks after onset ofpixelated vision he developed auditory hallucinations and hyperacusis. These increased in intensity and frequency to 500-600 times per day. He denied palinopsia, migraines, tinnitus, and photophobia. These hallucinations persisted despite treatment with aripiprazole, paliperidone, lurasidone, olanzapine, clozapine, ziprasidone, benztropine, bupropion, lamotrigine, modafinil, trazodone, atomoxetine, and amphetamine.
Abnormalities in Examination: Hypoverbal, blunted affect, impaired concentration, preoccupied with racing thoughts. Admitted to actively having auditory and visualhallucinations, without suicidal or homicidal ideations. Memory testing: Able to recall 2 out of 4 objects in 3 minutes and 3 out of 4 with reinforcement. Similarities interpreted concretely. Visual Acuity: 20/20 OU. Retinal examination: Normal. Intraocular Pressure: 19 mm OD, 20 mm OS (normal). Automotive Perimetry Testing: Normal. Cover/Uncover: Normal. Near Convergence: 3 inches (normal). Lens or filtered prism have no effect on visual snow. MRI of his brain, EEG, BAER, liver function tests, CBC, vitamin B12, folate, and thyroid function tests were normal. MRA: mild hypoplasia of distal right vertebral artery.
Visual snow has been anecdotally described as static, continuous, and independent of the specific visual environment (McKendrick, 2017). However, thepersistence of visual snow in the presence of 3D movies has never been reported. The visual snow paralleled auditory hallucinations and hyperacusis in frequency and intensity, which suggests there may be generalized hyperexcitability of the brain inducing both auditory and visual hallucinations. Agents that reduce cortical hyperexcitability (i.e., anticonvulsants, anxiolytics) may have efficacy. Treatment with these agents has been described (Ghannam, 2017), warrants further investigation.
Predicting mango mealybug, Rastrococcus iceryoides (Green) (Hemiptera: Pseudococcidae), populations in an organic mango (Mangiferaindica Linnaeus; Anacardiaceae) ecosystem well in advance with reasonable accuracy, will facilitate biological control. In this study, an attempt was made to predict the population of mango mealybug using abiotic weather parameters as independent variables. The study was conducted at the Indian Council of Agricultural Research – Indian Institute of Horticultural Research, Bengaluru, India (12°8'N; 77°35'E). Among the abiotic variables, maximum temperature was found relevant for predicting the population of the mealybug based on significant correlations. It was found that a prediction model using maximum temperature as independent variable with R2 is most ideal. This prediction model, when considered three to four weeks in advance of an infestation, could help farmers to gear up with biological control.
Kefir is a fermented milk obtained by the activity of kefir grains which are composed of lactic and acetic acid bacteria, and yeasts. Many beneficial health effects have been associated with kefir consumption such as stimulation of the immune system and inhibition of pathogenic microorganisms. The biological activity of kefir may be attributed to the presence of a complex microbiota as well as the microbial metabolites that are released during fermentation. The aim of this work was to characterise the non-microbial fraction of kefir and to study its antagonism against Escherichia coli, Salmonella spp. and Bacillus cereus. During milk fermentation there was a production of organic acids, mainly lactic and acetic acid, with a consequent decrease in pH and lactose content. The non-microbial fraction of kefir added to nutrient broth at concentrations above 75% v/v induced a complete inhibition of pathogenic growth that could be ascribed to the presence of un-dissociated lactic acid. In vitro assays using an intestinal epithelial cell model indicated that pre-incubation of cells with the non-microbial fraction of kefir did not modify the association/invasion of Salmonella whereas pre-incubation of Salmonella with this fraction under conditions that did not affect their viability significantly decreased the pathogen's ability to invade epithelial cells. Lactate exerted a protective effect against Salmonella in a mouse model, demonstrating the relevance of metabolites present in the non-microbial fraction of kefir produced during milk fermentation.
We present our approach of visibility modeling of disks around low-mass (< 2 M⊙) young stellar objects (YSOs). We compiled an atlas based on mid-infrared interferometric observations from the MIDI instrument at the VLTI. We use three different models to fit the data. These models allow us to determine overall sizes (and the extent of the inner gaps) of the modeled circumstellar disks.
We present the first quantitative assessment of combustion dynamics of on-chip porous silicon (PS) energetic material using sulfur and nitrate-based oxidizers with potential for improved moisture stability and/or minimized environmental impact compared to sodium perchlorate (NaClO4). Material properties of the PS films were characterized using gas adsorption porosimetry, and profilometry to calculate specific surface area, porosity and etch depth. The PS/sulfur energetic composite was formed using three pore loading techniques, where the combustion speeds ranged from 2.9 – 290 m/s. The nitrate-based oxidizers were solution-deposited using different compatible solvents, and depending on the metal-nitrate yielded combustion speeds of 3.1 – 21 m/s. Additionally, the combustion enthalpies from bomb calorimetry experiments are reported for the alternative PS/oxidizer systems in both nitrogen and oxygen environments.
Atomic force microscopy is employed to study the structural changes in the morphology and physical characteristics of asphaltene aggregates as a function of temperature. The exotic fractal structure obtained by evaporation-driven asphaltene aggregates shows an interesting dynamics for a large range of temperatures from 25°C to 80°C. The changes in the topography, surface potential and adhesion are unnoticeable until 70°C. However, a significant change in the dynamics and material properties is displayed in the range of 70°C - 80°C, during which the aspahltene aggregates acquire ‘liquid-like’ mobility and fuse together. This behaviour is attributed to the transition from the pure amorphous phase to a crystalline liquid phase which occurs at approximately 70°C as shown by using Differential Scanning Calorimetry (DSC). Additionally, the charged nature of asphaltenes and bitumen is also explored using kelvin probe microscopy. Such observations can lead to the development of a rational approach to the fundamental understanding of asphaltene aggregation dynamics and may help in devising novel techniques for the handling and separation of asphaltene aggregates using dielectrophoretic methods.