249 research outputs found

    Simulated nature walks improve psychological well-being along a natural to urban continuum

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    Compared to urban environments, interactions with natural environments have been associated with several health benefits including psychological restoration and improved emotional well-being. However, dichotomizing environments as either natural or urban may emphasize between-category differences and minimize potentially important within-category variation (e.g., forests versus fields of crops; neighborhoods versus city centers). Therefore, the current experiment assessed how viewing brief videos of different environments, ranging along a continuum from stereotypically natural to stereotypically urban, influenced subjective ratings of mood, restoration, and well-being. Participants (n = 202) were randomly assigned to one of four video conditions, which depicted a simulated walk through a pine forest, a farmed field, a tree-lined urban neighborhood, or a bustling city center. Immediately before and after the videos, participants rated their current emotional states. Participants additionally rated the perceived restorativeness of the video. The results supported the idea that the virtual walks differentially influenced affect and perceived restoration, even when belonging to the same nominal category of natural or urban. The pine forest walk significantly improved happiness relative to both urban walks, whereas the farmed field walk did not. The bustling city center walk decreased feelings of calmness compared to all other walks, including the tree-lined neighborhood walk. The walks also differed on the perceived restorativeness measure of daydreaming in a graded fashion; however, the farmed field walk was found to be less fascinating than all other walks, including both urban walks. Taken together, these results suggest that categorizing environments as “natural versus urban” may gloss over meaningful within-category variability regarding the restorative potential of different physical environments

    Environmental influences on affect and cognition: A study of natural and commercial semi-public spaces

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    Research has consistently shown differences in affect and cognition after exposure to different physical environments. The time course of these differences emerging or fading during exploration of environments is less explored, as most studies measure dependent variables only before and after environmental exposure. In this within-subject study, we used repeated surveys to measure differences in thought content and affect throughout a 1-h environmental exploration of a nature conservatory and a large indoor mall. At each survey, participants reported on aspects of their most recent thoughts (e.g., thinking of the present moment vs. the future; thinking positively vs. negatively) and state affect. Using Bayesian multi-level models, we found that while visiting the conservatory, participants were more likely to report thoughts about the past, more positive and exciting thoughts, and higher feelings of positive affect and creativity. In the mall, participants were more likely to report thoughts about the future and higher feelings of impulsivity. Many of these differences in environments were present throughout the 1-h walk, however some differences were only evident at intermediary time points, indicating the importance of collecting data during exploration, as opposed to only before and after environmental exposures. We also measured cognitive performance with a dual n-back task. Results on 2-back trials replicated results from prior work that interacting with nature leads to improvements in working-memory performance. This study furthers our understanding of how thoughts and feelings are influenced by the surrounding physical environment and has implications for the design and use of public spaces

    Interactions of the EphA2 Kinase Domain with PIPs in Membranes: Implications for Receptor Function

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    EphA2 is a member of the receptor tyrosine kinase family. Interactions of the cytoplasmic region of EphA2 with the cell membrane are functionally important and yet remain incompletely characterized. Molecular dynamics simulations combined with biochemical studies reveal the interactions of the transmembrane, juxtamembrane (JM), and kinase domains with the membrane. We describe how the kinase domain is oriented relative to the membrane and how the JM region can modulate this interaction. We highlight the role of phosphatidylinositol phosphates (PIPs) in mediating the interaction of the kinase domain with the membrane and, conversely, how positively charged patches at the kinase surface and in the JM region induce the formation of nanoclusters of PIP molecules in the membrane. Integration of these results with those from previous studies enable computational reconstitution of a near complete EphA2 receptor within a membrane, suggesting a role for receptor-lipid interactions in modulation of EphA2

    Serological profile of foot-and-mouth disease in wildlife populations of West and Central Africa with special reference to Syncerus caffer subspecies

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    The role which West and Central African wildlife populations might play in the transmission dynamics of FMD is not known nor have studies been performed in order to assess the distribution and prevalence of FMD in wild animal species inhabiting those specific regions of Africa. This study reports the FMD serological profile extracted from samples (n = 696) collected from wildlife of West and Central Africa between 1999 and 2003. An overall prevalence of FMDV NSP reactive sera of 31.0% (216/696) was estimated, where a significant difference in seropositivity (p = 0.000) was reported for buffalo (64.8%) as opposed to other wild animal species tested (17.8%). Different levels of exposure to the FMDV resulted for each of the buffalo subspecies sampled (p = 0.031): 68.4%, 50.0% and 0% for Nile Buffalo, West African Buffalo and African Forest Buffalo, respectively. The characterisation of the FMDV serotypes tested for buffalo found presence of antibodies against all the six FMDV serotypes tested, although high estimates for type O and SAT 3 were reported for Central Africa. Different patterns of reaction to the six FMDV serotypes tested were recorded, from sera only positive for a single serotype to multiple reactivities. The results confirmed that FMDV circulates in wild ruminants populating both West and Central Africa rangelands and in particular in buffalo, also suggesting that multiple FMDV serotypes might be involved with type O, SAT 2 and SAT 1 being dominant. Differences in serotype and spill-over risk between wildlife and livestock likely reflect regional geography, historical circulation and differing trade and livestock systems

    Spinal Cord Injury Causes Sustained Disruption of the Blood-Testis Barrier in the Rat

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    There is a high incidence of infertility in males following traumatic spinal cord injury (SCI). Quality of semen is frequently poor in these patients, but the pathophysiological mechanism(s) causing this are not known. Blood-testis barrier (BTB) integrity following SCI has not previously been examined. The objective of this study was to characterize the effects of spinal contusion injury on the BTB in the rat. 63 adult, male Sprague Dawley rats received SCI (n = 28), laminectomy only (n = 7) or served as uninjured, age-matched controls (n = 28). Using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), BTB permeability to the vascular contrast agent gadopentate dimeglumine (Gd) was assessed at either 72 hours-, or 10 months post-SCI. DCE-MRI data revealed that BTB permeability to Gd was greater than controls at both 72 h and 10 mo post-SCI. Histological evaluation of testis tissue showed increased BTB permeability to immunoglobulin G at both 72 hours- and 10 months post-SCI, compared to age-matched sham-operated and uninjured controls. Tight junctional integrity within the seminiferous epithelium was assessed; at 72 hours post-SCI, decreased expression of the tight junction protein occludin was observed. Presence of inflammation in the testes was also examined. High expression of the proinflammatory cytokine interleukin-1 beta was detected in testis tissue. CD68+ immune cell infiltrate and mast cells were also detected within the seminiferous epithelium of both acute and chronic SCI groups but not in controls. In addition, extensive germ cell apoptosis was observed at 72 h post-SCI. Based on these results, we conclude that SCI is followed by compromised BTB integrity by as early as 72 hours post-injury in rats and is accompanied by a substantial immune response within the testis. Furthermore, our results indicate that the BTB remains compromised and testis immune cell infiltration persists for months after the initial injury

    ‘Triple wins’ or ‘triple faults’? Analysing the equity implications of policy discourses on climate-smart agriculture (CSA)

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    This paper analyses contrasting discourses of ‘climate-smart agriculture’ (CSA) for their implications on control over and access to changing resources in agriculture. One of the principal areas of contestation around CSA relates to equity, including who wins and who loses, who is able to participate, and whose knowledge and perspectives count in the process. Yet to date, the equity implications of CSA remain an under-researched area. We apply an equity framework centred on procedure, distribution and recognition, to four different discourses. Depending on which discourses are mobilised, the analysis helps to illuminate: (1) how CSA may transfer the burden of responsibility for climate change mitigation to marginalised producers and resource managers (distributive equity); (2) how CSA discourses generally fail to confront entrenched power relations that may constrain or block the emergence of more ‘pro-poor’ forms of agricultural development, adaptation to climate change, or carbon sequestration and storage (procedural equity); (3) how CSA discourses can have tangible implications for the bargaining power of the poorest and most vulnerable groups (recognition). The paper contributes to work showing the need for deeper acknowledgement of the political nature of the transformations necessary to address the challenges caused by a changing climate for the agricultural sector

    Activin enhances skin tumourigenesis and malignant progression by inducing a pro-tumourigenic immune cell response

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    Activin is an important orchestrator of wound repair, but its potential role in skin carcinogenesis has not been addressed. Here we show using different types of genetically modified mice that enhanced levels of activin in the skin promote skin tumour formation and their malignant progression through induction of a pro-tumourigenic microenvironment. This includes accumulation of tumour-promoting Langerhans cells and regulatory T cells in the epidermis. Furthermore, activin inhibits proliferation of tumour-suppressive epidermal γδ T cells, resulting in their progressive loss during tumour promotion. An increase in activin expression was also found in human cutaneous basal and squamous cell carcinomas when compared with control tissue. These findings highlight the parallels between wound healing and cancer, and suggest inhibition of activin action as a promising strategy for the treatment of cancers overexpressing this factor

    Specific Binding and Mineralization of Calcified Surfaces by Small Peptides

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    Several small (<25aa) peptides have been designed based on the sequence of the dentin phosphoprotein, one of the major noncollagenous proteins thought to be involved in the mineralization of the dentin extracellular matrix during tooth development. These peptides, consisting of multiple repeats of the tripeptide aspartate-serine-serine (DSS), bind with high affinity to calcium phosphate compounds and, when immobilized, can recruit calcium phosphate to peptide-derivatized polystyrene beads or to demineralized human dentin surfaces. The affinity of binding to hydroxyapatite surfaces increases with the number of (DSS)n repeats, and though similar repeated sequences—(NTT)n, (DTT)n, (ETT)n, (NSS)n, (ESS)n, (DAA)n, (ASS)n, and (NAA)n—also showed HA binding activity, it was generally not at the same level as the natural sequence. Binding of the (DSS)n peptides to sectioned human teeth was shown to be tissue-specific, with high levels of binding to the mantle dentin, lower levels of binding to the circumpulpal dentin, and little or no binding to healthy enamel. Phosphorylation of the serines of these peptides was found to affect the avidity, but not the affinity, of binding. The potential utility of these peptides in the detection of carious lesions, the delivery of therapeutic compounds to mineralized tissues, and the modulation of remineralization is discussed
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