507 research outputs found

    Mycorrhizal co-invasion and novel interactions depend on neighborhood context

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    © 2015 by the Ecological Society of America. Biological invasions are a rapidly increasing driver of global change, yet fundamental gaps remain in our understanding of the factors determining the success or extent of invasions. For example, although most woody plant species depend on belowground mutualists such as mycorrhizal fungi and nitrogen-fixing bacteria, the relative importance of these mutualisms in conferring invasion success is unresolved. Here, we describe how neighborhood context (identity of nearby tree species) affects the formation of belowground ectomycorrhizal partnerships between fungi and seedlings of a widespread invasive tree species, Pseudotsuga menziesii (Douglas-fir), in New Zealand.We found that the formation of mycorrhizal partnerships, the composition of the fungal species involved in these partnerships, and the origin of the fungi (co-invading or native to New Zealand) all depend on neighborhood context. Our data suggest that nearby ectomycorrhizal host trees act as both a reservoir of fungal inoculum and a carbon source for late-successional and native fungi. By facilitating mycorrhization of P. menziesii seedlings, adult trees may alleviate mycorrhizal limitation at the P. menziesii invasion front. These results highlight the importance of studying biological invasions across multiple ecological settings to understand establishment success and invasion speed

    Sensory experiences of children with autism spectrum disorder: In their own words

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    First-person perspectives of children with autism spectrum disorder (ASD) are rarely included in research, yet their voices may help more clearly illuminate their needs. This study involved phenomenological interviews with children with ASD (n=12, ages 4-13) used to gain insights about their sensory experiences. This article addresses two study aims: determining the feasibility of interviewing children with ASD and exploring how they share information about their sensory experiences during the qualitative interview process. With the described methods, children as young as four and across a broad range of autism severity scores successfully participated in the interviews. The manner with which children shared information about their sensory experiences included themes of normalizing, storytelling, and describing responses. The interviews also revealed the importance of context and the multisensory nature of children's experiences. These findings contribute strategies for understanding the sensory experiences of children with ASD with implications for practice and future research

    How Sensory Experiences of Children With and Without Autism Affect Family Occupations

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    We used a grounded theory approach to data analysis to discover what effect, if any, children's sensory experiences have on family occupations. We chose this approach because the existing literature does not provide a theory to account for the effect of children's sensory experiences on family occupations. Parents of six children who were typically developing and six children who had autism were interviewed. We analyzed the data using open, axial, and selective coding techniques. Children's sensory experiences affect family occupations in three ways: (1) what a family chooses to do or not do; (2) how the family prepares; and (3) the extent to which experiences, meaning, and feelings are shared

    Parent Reports of Sensory Experiences of Preschool Children With and Without Autism: A Qualitative Study

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    This study describes children’s “sensory experiences”, generates parents’ perceptions and explanations of these experiences, and compares these experiences across children with and without autism. Parents of 66 preschoolers (29 typically-developing; 37 with autism) were interviewed using a Critical Incident Technique. Parents described a situation where their child had a “good” sensory experience, a situation where their child had a “bad” sensory experience, and their own perception of how these situations felt to the child. The most common unpleasant experiences for both groups related to sound; the most common pleasant experiences involved touch and movement. Children with autism were reported to have more extreme and/or unusual experiences, and negative food-related experiences than typically-developing peers. Parental explanations for children’s responses focused on qualities of the child, stimulus, and/or context. Many parents had difficulty understanding the concept of sensory experiences. Parents of children with autism were more likely to recognize elements in their children’s experiences as being sensory, and likely to attribute these responses to aspects of autism. Parents’ positive response to the interview itself was an unexpected result with clinical relevance

    Renewing Criminalized and Hegemonic Cultural Landscapes

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    The Mafia's long historical pedigree in Mezzogiorno, Southern Italy, has empowered the Mafioso as a notorious, uncontested, and hegemonic figure. The counter-cultural resistance against the mafiosi culture began to be institutionalized in the early 1990s. Today, Libera Terra is the largest civil society organization in the country that uses the lands confiscated from the Mafia as a space of cultural repertoire to realize its ideals. Deploying labor force through volunteer participation, producing biological fruits and vegetables, and providing information to the students on the fields are the principal cultural practices of this struggle. The confiscated lands make the Italian experience of anti-Mafia resistance a unique example by connecting the land with the ideals of cultural change. The sociocultural resistance of Libera Terra conveys a political message through these practices and utters that the Mafia is not invincible. This study draws the complex panorama of the Mafia and anti-Mafia movement that uses the ‘confiscated lands’ as cultural and public spaces for resistance and socio-cultural change. In doing so, this article sheds new light on the relationship between rural criminology and crime prevention policies in Southern Italy by demonstrating how community development practice of Libera Terra changes the meaning of landscape through iconographic symbolism and ethnographic performance

    Circuit dissection of the role of somatostatin in itch and pain

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    Stimuli that elicit itch are detected by sensory neurons that innervate the skin. This information is processed by the spinal cord; however, the way in which this occurs is still poorly understood. Here we investigated the neuronal pathways for itch neurotransmission, particularly the contribution of the neuropeptide somatostatin. We find that in the periphery, somatostatin is exclusively expressed in Nppb+ neurons, and we demonstrate that Nppb+somatostatin+ cells function as pruriceptors. Employing chemogenetics, pharmacology and cell-specific ablation methods, we demonstrate that somatostatin potentiates itch by inhibiting inhibitory dynorphin neurons, which results in disinhibition of GRPR+ neurons. Furthermore, elimination of somatostatin from primary afferents and/or from spinal interneurons demonstrates differential involvement of the peptide released from these sources in itch and pain. Our results define the neural circuit underlying somatostatin-induced itch and characterize a contrasting antinociceptive role for the peptide

    Eurocity London: a qualitative comparison of graduate migration from Germany, Italy and Latvia

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    This paper compares the motivations and characteristics of the recent migration to London of young-adult graduates from Germany, Italy and Latvia. Conceptually the paper links three domains: the theory of core–periphery structures within Europe; the notion of London as both a global city and a ‘Eurocity’; and the trope of ‘crisis’. The dataset analysed consists of 95 in-depth biographical interviews and the paper’s main objective is to tease out the narrative similarities and differences between the three groups interviewed. Each of the three nationalities represents a different geo-economic positioning within Europe. German graduates move from one economically prosperous country to another; they traverse shallow economic and cultural boundaries. Italian graduates migrate from a relatively peripheral Southern European country where, especially in Southern Italy, employment and career prospects have long been difficult, and have become more so in the wake of the financial crisis. They find employment opportunities in London which are unavailable to them in Italy. Latvian graduates are from a different European periphery, the Eastern one, post-socialist and post-Soviet. Like the Italians, their moves are economically driven whereas, for the Germans, migration is more related to lifestyle and life-stage. For all three groups, the chance to live in a large, multicultural, cosmopolitan city is a great attraction. And for all groups, thoughts about the future are marked by uncertainty and ambiguity

    Diversity of inhibitory and excitatory parvalbumin interneuron circuits in the dorsal horn

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    Parvalbumin-expressing interneurons (PVINs) in the spinal dorsal horn are found primarily in laminae II inner and III. Inhibitory PVINs (iPVINs) play an important role in segregating innocuous tactile input from pain-processing circuits through presynaptic inhibition of myelinated low-threshold mechanoreceptors and postsynaptic inhibition of distinct spinal circuits. By comparison, relatively little is known of the role of excitatory PVINs (ePVINs) in sensory processing. Here we use neuroanatomical and optogenetic approaches to show that ePVINs comprise a larger proportion of the PVIN population than previously reported, and that both ePVIN and iPVIN populations form synaptic connections amongst (and between) themselves. We find that these cells contribute to neuronal networks that influence activity within several functionally distinct circuits, and that aberrant activity of ePVINs under pathological conditions is well placed to contribute to the development of mechanical hypersensitivity
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