The influence of air-sea fluxes on atmospheric aerosols during the summer monsoon over the tropical Indian Ocean

During the summer monsoon, the western tropical Indian Ocean is predicted to be a hot spot for dimethylsulfide emissions, the major marine sulfur source to the atmosphere, and an important aerosol precursor. Other aerosol relevant fluxes, such as isoprene and sea spray, should also be enhanced, due to the steady strong winds during the monsoon. Marine air masses dominate the area during the summer monsoon, excluding the influence of continentally derived pollutants. During the SO234-2/235 cruise in the western tropical Indian Ocean from July to August 2014, directly measured eddy covariance DMS fluxes confirm that the area is a large source of sulfur to the atmosphere (cruise average 9.1 μmol m−2 d−1). The directly measured fluxes, as well as computed isoprene and sea spray fluxes, were combined with FLEXPART backward and forward trajectories to track the emissions in space and time. The fluxes show a significant positive correlation with aerosol data from the Terra and Suomi-NPP satellites, indicating a local influence of marine emissions on atmospheric aerosol numbers

Discovery of a novel member of the histamine receptor family

We report the discovery, tissue distribution and pharmacological characterization of a novel receptor, which we have named H4. Like the three histamine receptors reported previously (H1, H2, and H3), the H4 receptor is a G protein-coupled receptor and is most closely related to the H3 receptor, sharing 58% identity in the transmembrane regions. The gene encoding the H4 receptor was discovered initially in a search of the GenBank databases as sequence fragments retrieved in a partially sequenced human genomic contig mapped to chromosome 18. These sequences were used to retrieve a partial cDNA clone and, in combination with genomic fragments, were used to determine the full-length open reading frame of 390 amino acids. Northern analysis revealed a 3.0-kb transcript in rat testis and intestine. Radioligand binding studies indicated that the H4 receptor has a unique pharmacology and binds [3H]histamine (K d = 44 nM) and [3H]pyrilamine (K d = 32 nM) and several psychoactive compounds (amitriptyline, chlorpromazine, cyproheptadine, mianserin) with moderate affinity (K i range of 33–750 nM). Additionally, histamine induced a rapid internalization of HA-tagged H4 receptors in transfected human embryonic kidney 293 cells

Development of a complex intervention to test the effectiveness of peer support in type 2 diabetes

BACKGROUND: Diabetes is a chronic illness which requires the individual to assume responsibility for their own care with the aim of maintaining glucose and blood pressure levels as close to normal as possible. Traditionally self management training for diabetes has been delivered in a didactic setting. In recent times alternatives to the traditional delivery of diabetes care have been investigated, for example, the concept of peer support which emphasises patient rather than professional domination. The aim of this paper is to describe the development of a complex intervention of peer support in type 2 diabetes for a randomised control trial in a primary care setting. METHODS: The Medical Research Council (MRC) framework for the development and evaluation of complex interventions for randomised control trials (RCT) was used as a theoretical guide to designing the intervention. The first three phases (Preclinical Phase, Phase 1, Phase 2) of this framework were examined in depth. The Preclinical Phase included a review of the literature relating to type 2 diabetes and peer support. In Phase 1 the theoretical background and qualitative data from 4 focus groups were combined to define the main components of the intervention. The preliminary intervention was conducted in Phase 2. This was a pilot study conducted in two general practices and amongst 24 patients and 4 peer supporters. Focus groups and semi structured interviews were conducted to collect additional qualitative data to inform the development of the intervention. RESULTS: The four components of the intervention were identified from the Preclinical Phase and Phase 1. They are: 1. Peer supporters; 2. Peer supporter training; 3. Retention and support for peer supporters; 4. Peer support meetings. The preliminary intervention was implemented in the Phase 2. Findings from this phase allowed further modeling of the intervention, to produce the definitive intervention. CONCLUSION: The MRC framework was instrumental in the development of a robust intervention of peer support of type 2 diabetes in primary care. TRIAL REGISTRATION: Current Controlled Trials ISRCTN42541690

Mutualism between harvester ants and a desert ephemeral: seed escape from rodents

DOI: 10.2307/1937419© Ecological Society of AmericaThe harvester ants Veromessor pergandei and Pogonomyrmex californicus modify the highly localized seed shadow of the Sonoran Desert ephemeral Datura discolor (Solanaceae) through (1) attraction to food bodies attached to seeds released beneath the parent plant, (2) immediate transport of disapores to the ant nest, (3) subsequent removal of the food body in underground granaries, and (4) final expulsion of intact seeds onto the colony midden. D. discolor seed without food bodies are not attractive to ants and remain beneath the parent canopy. At Nude Wash, California, USA, diaspore removal distances are generally small, averaging 2.3 m away from the nearest D. discolor canopy in March—May 1977. Two lines of evidence indicate that this limited transport has a large effect on seed detection and utilization by rodents: (1) seeds placed in ant—proof dishes beneath the D. discolor canopy were about 10 times more likely to be removed by nocturnally foraging rodents than seeds placed in locations similar to those where ants locate their nests; (2) using D. discolor as bait, significantly more rodents were trapped beneath the plant canopy than in open areas where seeds were transported by ants. Manipulation of the density of D. discolor seed in these tests suggests that seed utilization by rodents is distance—responsive to the parent canopy rather than dependent on the density of seeds. Disapore analyses indicate that investment in the transport system is relatively small and represents <5% of the total investment in seeds

Seasonal shifts in macronutrient preferences in supercolonies of the invasive Yellow Crazy Ant 'Anoplolepis gracilipes' (Smith, 1857) (Hymenoptera: Formicidae) on Christmas Island, Indian Ocean

The timing and duration of sexual brood production in ants can affect their rate of spread and colony growth. Because protein is key to larval growth, queen survival and fecundity, macronutrient collection by foraging workers is expected to favour protein prior to and throughout gyne production. However, food preference driven by the production of gynes may be overridden by a preference associated with worker production, especially if investment in workers vastly outweighs that of sexual brood and workers are produced on different schedules. Food preferences alone may not indicate the availability of that food type in the environment. On Christmas Island, Indian Ocean, sexual brood of the invasive Yellow Crazy Ant, 'Anoplolepis gracilipes' (Smith, 1857), was produced annually during a single period associated with the onset of the wet season. However, workers were produced continuously throughout the year and colony investment to worker production measured by the standing biomass of eggs, larvae and pupae, typically exceeded 98%. High, aseasonal investment in worker production, together with aseasonal worker activity, would suggest that there should be no seasonal preference shown by workers at food stations containing both protein and carbohydrate. However, workers showed a preference for one food type over another on 46 of 61 occasions at one site and on 31 of 41 occasions at another. When a preference was shown, it was predominantly for protein-rich food during the dry season and almost always for carbohydrate at the onset and during the wet season. We suggest that these preferences reflect seasonal shortages in key resources when invertebrates (protein-rich) are scarce during the dry season and honeydew from scale insects (carbohydrate) is depleted by rain during the wet season. On Christmas Island, timing and duration of the dry season preference for protein has been exploited by the control program for A. gracilipes supercolonies, which deploys a toxin in a proteinaceous bait matrix during dry periods

First record of Pulvinaria urbicola Cockerell (Hemiptera: Coccidae), a potentially damaging scale insect, on Christmas Island, Indian Ocean

Pulvinaria urbicola Cockerell, a pulvinariine soft scale (Hemiptera: Coccidae), is a broad host-plant generalist, produces honeydew and is commonly tended by ants, including the invasive yellow crazy ant Anoplolepis gracilipes Smith and big-headed ant Pheidole megacephala (Fabricius). Pu. urbicola is implicated in dieback of forest dominated by Pisonia grandis (Nyctaginaceae) on many Indo-Pacific islands. Here we report detection of Pu. urbicola on Christmas Island (Indian Ocean), describe the potential impacts of the association of this trophobiont with introduced ants, and briefly outline biosecurity and management issues. On Christmas Island, Pu. urbicola represents a threat to stands of Pi. grandis, potentially threatens the dominant forest tree Pi. umbellifera, and could exacerbate supercolony formation and impacts of the yellow crazy ant

Diversity, endemism and origins of scale insects on a tropical oceanic island: Implications for management of an invasive ant

Detailed assessment of scale insect (Hemiptera: Coccoidea) faunas on islands may help predict impacts of invasive ants (Hymenoptera: Formicidae) and inform options for their management, including biological control. Mutualism between scale insects and the invasive ant Anoplolepis gracilipes on Christmas Island, Indian Ocean, threatens the conservation of the island's endemic land crab fauna, alters rainforest structure and composition, and disrupts ecosystem processes. Diversity and endemism of the scale insect fauna were assessed through broad survey across rainforest, targeted search on endemic plant species, and inspection of ornamental and horticultural plants in settled areas. Emphasis was placed on honeydew-producing species that sustain ant supercolonies and detection of endemic scale insects that could be non-target species in a biological control programme for honeydew-producing scale insects. Origins of the fauna were inferred using scale insect databases and interception records at Ports-of-Entry for the United States and Korea. Twenty-eight scale insect species in seven families are identified for the island. Four honeydew-producing species, the lac scale Tachardina aurantiaca (Kerriidae) and three soft scale species (Coccidae), are abundant in rainforest and tended by ants. No endemic species were found. Compositionally, the scale insect fauna resembles that of many other tropical islands: almost all species are biogeographically widespread, host-plant generalists, and routinely intercepted in human-mediated dispersal pathways. The likely source bioregion is Sundaland where 27 of the 28 species on the island have been recorded and which has been the major pathway for movement of plant material to the island for over a century

Invasional meltdown: Invader-invader mutualism facilitates a secondary invasion

In multiply invaded ecosystems, introduced species should interact with each other as well as with native species. Invader-invader interactions may affect the success of further invaders by altering attributes of recipient communities and propagule pressure. The invasional meltdown hypothesis (IMH) posits that positive interactions among invaders initiate positive population-level feedback that intensifies impacts and promotes secondary invasions. IMH remains controversial: few studies show feedback between invaders that amplifies their effects, and none yet demonstrate facilitation of entry and spread of secondary invaders. Our results show that supercolonies of an alien ant, promoted by mutualism with introduced honeydew-secreting scale insects, permitted invasion by an exotic land snail on Christmas Island, Indian Ocean. Modeling of land snail spread over 750 sites across 135 km² over seven years showed that the probability of land snail invasion was facilitated 253-fold in ant supercolonies but impeded in intact forest where predaceous native land crabs remained abundant. Land snail occurrence at neighboring sites, a measure of propagule pressure, also promoted land snail spread. Site comparisons and experiments revealed that ant super colonies, by killing land crabs but not land snails, disrupted biotic resistance and provided enemy-free space. Predation pressure on land snails was lower (28.6%), survival 115 times longer, and abundance 20-fold greater in supercolonies than in intact forest. Whole-ecosystem suppression of supercolonies reversed the probability of land snail invasion by allowing recolonization of land crabs; land snails were much less likely (0.79%) to invade sites where supercolonies were suppressed than where they remained intact. Our results provide strong empirical evidence for IMH by demonstrating that mutualism between invaders reconfigures key interactions in the recipient community. This facilitates entry of secondary invaders and elevates propagule pressure, propagating their spread at the whole-ecosystem level. We show that identification and management of key facilitative interactions in invaded ecosystems can be used to reverse impacts and restore resistance to further invasions