2,757 research outputs found
The prevalence and patterns of IgE-mediated food allergy and sensitisation in South African children with atopic dermatitis
Includes bibliographical references.Background: The prevalence of food allergy in South Africa is unknown, but previously thought to be low, particularly in black South Africans. We hypothesised that food allergies would be low in Xhosa patients, even those at increased risk of food allergy such as children with atopic dermatitis (AD). This study aimed to determine the prevalence of, patterns and risk factors for, IgE-mediated food allergy in South African children with moderate to severe AD. It is the first food allergy prevalence study in South Africa to utilise controlled food challenges and component analysis, and is unique for its comparison of food allergy patterns between ethnic groups in the same geographical area. Methodology: This was a prospective, observational study in a paediatric university hospital in Cape Town. Children with moderate to severe AD, aged 6 months to 10 years, were randomly recruited from the dermatology clinic. They were assessed for sensitisation and allergy by questionnaire, skin prick tests (SPT), Immuno Solid Phase Allergen Chip (ISAC) test and incremental food challenges. Sensitised patients were also tested for specific IgE by ImmunoCAP test. Results: One hundred participants (59 black Africans and 41 of mixed race) were enrolled, median age 42 months. There were high overall rates of food sensitisation (66%) and food allergy (40%). Egg (25%) and peanut (24%) were the most common allergies. Black participants had comparable sensitisation (69% vs 61%) but lower allergy rates (34% vs 46%) than mixed race participants. This was especially evident for peanut allergy (15% vs 37%, p=0.01). Early onset AD (< 6 months), severe eczema, and young age < 2 years were significant risk factors for food allergy. The ISAC test was less sensitive than SPT and ImmunoCAP tests. Only 42% of cases of perceived food allergy were confirmed as true food allergy
Conformational profiling of a G-rich sequence within the c-KIT promoter
G-quadruplexes (G4) within oncogene promoters are considered to be promising anticancer targets. However, often they undergo complex structural rearrangements that preclude a precise description of the optimal target. Moreover, even when solved structures are available, they refer to the thermodynamically stable forms but little or no information is supplied about their complex multistep folding pathway. To shed light on this issue, we systematically followed the kinetic behavior of a G-rich sequence located within the c-KIT proximal promoter (kit2) in the presence of monovalent cations K + and Na + . A very short-lived intermediate was observed to start the G4 folding process in both salt conditions. Subsequently, the two pathways diverge to produce distinct thermodynamically stable species (parallel and antiparallel G-quadruplex in K + and Na + , respectively). Remarkably, in K + -containing solution a branched pathway is required to drive the wild type sequence to distribute between a monomeric and dimeric G-quadruplex. Our approach has allowed us to identify transient forms whose relative abundance is regulated by the environment; some of them were characterized by a half-life within the timescale of physiological DNA processing events and thus may represent possible unexpected targets for ligands recognition
4th–5th Grade: English Level 2, Learning Packet #5 • Theme: Rainforests
Activities
Choose a Buddy
Packet #5 outline: rainforests
Sorting sight words
Sorting sight words match
Parts of a plant vocabulary
Read, label, and write
Life cycle of an apple tree
Sequence of a plant life cycle
Rainforest vocabulary
Rainforests
Rainforest vocabulary cards
Layers of the rainforest
My rainforest habitat
Rainforest report
Spelling my words
The Jaguar and the Mouse (adapted from Aesop\u27s fable)
Character\u27s feelings
Feelings chart
Creative writing
Nouns, adjectives, and verbs
Decimals to fractions
Rainforest fraction facts
Learn to draw bats
My Packet Journal
Reference Sheet
Answer Ke
4th–5th Grade: English Level 2, Learning Packet #2 • Theme: Habitats
Packet #2 outline: habitats
Choose a Buddy
Reading daily practice
Roll your sight words #2
Vocabulary cards: habitats
Habitats
Write and draw
Facts and opinions about habitats
Compound words
Vocabulary cut and paste
Writing a poem: acrostic
Math daily practice
Coordinate habitat
Goods from habitats
Lunchtime goods and services
Let\u27s take a break!
My Packet Journal
Reference Sheet
Answer Key
6th–8th Grade: English Level 1, Learning Packet #3 • Theme: School
Reading daily practice
Roll your sight words
School vocabulary
Write and draw
Try the words in a sentence
Class vocabulary
Matching vocabulary
Class schedule
My schedule
School actions
Prepositions introduction
Vocabulary cards: prepositions
People at school
Job description
Drawing prepositions
How to open a lock
Lock combination
Make a safety plan
Your turn!
Similarities and differences
Facts and opinions about classrooms
Compare and contrast
Safety and school
Vocabulary dictionary
Essential question
Angles and polygons
Let\u27s take a break!
My Packet Journal
Reference Sheet
Answer Key
Do riparian forest fragments provide ecosystem services or disservices in surrounding oil palm plantations?
Agricultural expansion across tropical regions is causing declines in biodiversity and altering ecological processes. However, in some tropical agricultural systems, conserving natural habitat can simultaneously protect threatened species and support important ecosystem services. Oil palm cultivation is expanding rapidly throughout the tropics but the extent to which non-crop habitat supports biodiversity and ecosystem services in these landscapes is poorly documented. We investigated whether riparian forest fragments (riparian reserves) provide a pest control service or increase pest activity (disservice) within oil palm dominated landscapes in Sabah, Malaysian Borneo. We assessed the activity of potential predators of pest herbivores using plasticine caterpillar mimics and quantified herbivory rates on oil palm fronds in areas with and without riparian reserves. We also manipulated the shape and colour of the mimics to assess the extent to which artificial pest mimics reflect a predatory response. The presence of riparian reserves increased the attack rate on mimics by arthropods, but not by birds. Our methodological study suggested attacks on artificial pest mimics provide a better indication of predatory activity for birds than for arthropod predators. Herbivory rates were also not significantly affected by the presence of a riparian reserve, but we found some evidence that herbivory rates may decrease as the size of riparian reserves increases. Overall, we conclude that riparian forest fragments of 30 – 50 m width on each side of the river are unlikely to provide a pest control service. Nevertheless, our results provide evidence that these riparian buffer strips do not increase the density of defoliating pests, which should reassure managers concerned about possible negative consequences of preserving riparian buffers
Food security, farming, and climate change to 2050: Scenarios, results, policy options
As the global population grows and incomes in poor countries rise, so too, will the demand for food, placing additional pressure on sustainable food production. Climate change adds a further challenge, as changes in temperature and precipitation threaten agricultural productivity and the capacity to feed the world's population. This study assesses how serious the danger to food security might be and suggests some steps policymakers can take to remedy the situation.global food security, Climate change, Food prices, Agricultural productivity,
Spatial ecology of the endangered and endemic Sagalla caecilian (Boulengerula niedeni) in the Eastern Arc Mountains of Kenya
Caecilians (Order Gymnophiona) are generalist predators of soil invertebrates, and may therefore play an important role in tropical soil ecosystems. However, their fossorial lifestyle and the associated difficulties in surveying them have caused a deficit in data for the majority of species. We applied a systematic approach and an intensive sampling strategy to an Endangered and evolutionarily distinct caecilian from the Eastern Arc Mountains, the Sagalla caecilian Boulengerula niedeni. We investigated the association between habitat type and caecilian occupancy across its entire range, the Sagalla Hill, Kenya, and explored the relationship between several variables (land use type, surface soil temperature, soil compactness and landowner prediction of caecilian presence) and its presence in different habitats. We found no significant effects of any of the investigated variables in predicting caecilian presence across the Sagalla landscape. Instead, our findings suggest that the species survives at least as well in agricultural landscapes as it does in areas with indigenous vegetation, with an estimated density of around 900 caecilians per hectare. A bimodal distribution of sizes and weights of captured specimens suggests ongoing successful breeding and recruitment. This suggests that there is a case for cautious optimism with regard to the status of B. niedeni. Our work could act as a useful pilot for further, improved caecilian surveys in the Eastern Arc Mountains and beyond, to improve our understanding and conservation of these overlooked fossorial amphibians
- …