2,295 research outputs found
Spatial and seasonal relationships between Pacific harbor seals (Phoca vitulina richardii) and their prey, at multiple scales
Knowing where pinnipeds forage is vital to managing and protecting their populations, and for assessing potential interactions with fisheries. We assessed the spatial
relationship between the seasonal distribution of Pacific harbor seals (Phoca vitulina richardii) outfitted with satellite transmitters and the seasonal distributions of potential harbor seal prey species in San Francisco Bay, California. Pearson’s correlation coefficients were calculated between the number of harbor seal locations in an area of the San Francisco Bay and the abundance of
specific prey species in the same area. The influence of scale on the analyses was assessed by varying the scale
of analysis from 1 to 10 km. There was consistency in the prey species targeted by harbor seals year-round, although there were seasonal differences between the most important
prey species. The highest correlations between harbor seals and their prey were found for seasonally abundant benthic species, located within about 10 km of the primary haul-out site. Probable foraging habitat for harbor seals was identified, based on areas with high abundances of prey species that were strongly correlated with harbor seal distribution. With comparable local data inputs, this
approach has potential application to pinniped management in other areas, and to decisions about the location of
marine reserves designed to protect these species
Conditional or unconditional? The effects of implementation intentions on driver behavior
Implementation intentions (IF-THEN plans) exert conditional effects on behavior, meaning that their ability to change behavior is conditional upon encountering the critical situation specified in the IF component of the plan. In the present study, we tested whether implementation intentions can exert unconditional effects on behavior. Consistent with the process of operant generalization, we hypothesized that implementation intentions would change behavior, not only in situations that are contextually identical to those specified in the IF component but also in contextually similar situations. Implementation intentions were not expected to generate behavior-change in contextually different situations to those specified. Participants (N = 139) completed questionnaires measuring speeding behavior and motivation to speed. Experimental participants then specified implementation intentions to avoid speeding in critical situations that were either contextually identical, similar or different to those subsequently encountered on a driving simulator. Control participants received educational information about the risks of speeding. All participants then drove on a driving simulator. Consistent with the hypotheses, participants in both the contextually identical and similar conditions exceeded the speed limit less frequently than did controls. There was no difference in speeding behavior between the contextually different and control conditions. Implications of the findings for behavior-change are discussed
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ELMO1 has an essential role in the internalization of Salmonella Typhimurium into enteric macrophages that impacts disease outcome.
Backgrounds and aims4-6 million people die of enteric infections each year. After invading intestinal epithelial cells, enteric bacteria encounter phagocytes. However, little is known about how phagocytes internalize the bacteria to generate host responses. Previously, we have shown that BAI1 (Brain Angiogenesis Inhibitor 1) binds and internalizes Gram-negative bacteria through an ELMO1 (Engulfment and cell Motility protein 1)/Rac1-dependent mechanism. Here we delineate the role of ELMO1 in host inflammatory responses following enteric infection.MethodsELMO1-depleted murine macrophage cell lines, intestinal macrophages and ELMO1 deficient mice (total or myeloid-cell specific) was infected with Salmonella enterica serovar Typhimurium. The bacterial load, inflammatory cytokines and histopathology was evaluated in the ileum, cecum and spleen. The ELMO1 dependent host cytokines were detected by a cytokine array. ELMO1 mediated Rac1 activity was measured by pulldown assay.ResultsThe cytokine array showed reduced release of pro-inflammatory cytokines, including TNF-α and MCP-1, by ELMO1-depleted macrophages. Inhibition of ELMO1 expression in macrophages decreased Rac1 activation (~6 fold) and reduced internalization of Salmonella. ELMO1-dependent internalization was indispensable for TNF-α and MCP-1. Simultaneous inhibition of ELMO1 and Rac function virtually abrogated TNF-α responses to infection. Further, activation of NF-κB, ERK1/2 and p38 MAP kinases were impaired in ELMO1-depleted cells. Strikingly, bacterial internalization by intestinal macrophages was completely dependent on ELMO1. Salmonella infection of ELMO1-deficient mice resulted in a 90% reduction in bacterial burden and attenuated inflammatory responses in the ileum, spleen and cecum.ConclusionThese findings suggest a novel role for ELMO1 in facilitating intracellular bacterial sensing and the induction of inflammatory responses following infection with Salmonella
Kinetochore alignment within the metaphase plate is regulated by centromere stiffness and microtubule depolymerases
During mitosis in most eukaryotic cells, chromosomes align and form a metaphase plate halfway between the spindle poles, about which they exhibit oscillatory movement. These movements are accompanied by changes in the distance between sister kinetochores, commonly referred to as breathing. We developed a live cell imaging assay combined with computational image analysis to quantify the properties and dynamics of sister kinetochores in three dimensions. We show that baseline oscillation and breathing speeds in late prometaphase and metaphase are set by microtubule depolymerases, whereas oscillation and breathing periods depend on the stiffness of the mechanical linkage between sisters. Metaphase plates become thinner as cells progress toward anaphase as a result of reduced oscillation speed at a relatively constant oscillation period. The progressive slowdown of oscillation speed and its coupling to plate thickness depend nonlinearly on the stiffness of the mechanical linkage between sisters. We propose that metaphase plate formation and thinning require tight control of the state of the mechanical linkage between sisters mediated by centromeric chromatin and cohesion
Speckle Observations of Binary Stars with the WIYN Telescope. III. A Partial Survey of A, F, and G Dwarfs
Two hundred thirty nearby main-sequence stars with spectral types in the range of A to G have been observed by way of speckle interferometry using the WIYN 3.5 m telescope at Kitt Peak, Arizona. The stars had no previous mention of duplicity in the literature. Of those observed, 14 showed clear evidence of a companion, and 63 were classified as suspected nonsingle based on a power spectrum analysis. The remaining stars discussed show no evidence of duplicity to the limit of the detection system in high-quality observations
Clostridium difficile modulates host innate immunity via toxin-independent and dependent mechanism(s)
Clostridium difficile infection (CDI) is the leading cause of hospital and community-acquired antibiotic-associated diarrhoea and currently represents a significant health burden. Although the role and contribution of C. difficile toxins to disease pathogenesis is being increasingly understood, at present other facets of C. difficile-host interactions, in particular, bacterial-driven effects on host immunity remain less studied. Using an ex-vivo model of infection, we report that the human gastrointestinal mucosa elicits a rapid and significant cytokine response to C. difficile. Marked increase in IFN-γ with modest increase in IL-22 and IL-17A was noted. Significant increase in IL-8 suggested potential for neutrophil influx while presence of IL-12, IL-23, IL-1β and IL-6 was indicative of a cytokine milieu that may modulate subsequent T cell immunity. Majority of C. difficile-driven effects on murine bone-marrow-derived dendritic cell (BMDC) activation were toxin-independent; the toxins were however responsible for BMDC inflammasome activation. In contrast, human monocyte-derived DCs (mDCs) released IL-1β even in the absence of toxins suggesting host-specific mediation. Infected DC-T cell crosstalk revealed the ability of R20291 and 630 WT strains to elicit a differential DC IL-12 family cytokine milieu which culminated in significantly greater Th1 immunity in response to R20291. Interestingly, both strains induced a similar Th17 response. Elicitation of mucosal IFN-γ/IL-17A and Th1/Th17 immunity to C. difficile indicates a central role for this dual cytokine axis in establishing antimicrobial immunity to CDI
Examining Neolithic Building and Activity Areas through Historic Cultural Heritage in Jordan: A Combined Ethnographic, Phytolith and Geochemical Investigation
The INEA project (Identifying activity areas in Neolithic
sites through Ethnographic Analysis of phytoliths and
geochemical residues, https://research.bournemouth.
ac.uk/2014/07/inea-project-2/) develops and applies
a method that combines the analysis of plant remains
(silica phytoliths) and geochemical residues to inform
on construction methods and the use of space in recently
abandoned historical villages and Neolithic settlements. It
is a collaborative project based at Bournemouth University,
in partnership with the Council for British Research in the
Levant
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Associations of Mail Survey Length and Layout With Response Rates.
We assess the association between survey layout and response rates (RRs) in the 2017 Medicare Advantage Consumer Assessment of Healthcare Providers and Systems mail survey. Among 438 Medicare Advantage plans surveyed by six vendors, there was latitude in survey layout, and plans could add up to 12 supplemental items. Regression models predicted survey response from survey characteristics (page count, number of supplemental items, and survey attractiveness), and beneficiary sociodemographics. Beneficiary-age-by-survey-characteristic interactions assessed whether survey characteristics were more strongly related to RRs among older beneficiaries. We found that surveys with more supplemental items and less attractive layouts had lower adjusted odds of response. RRs were more sensitive to format among older beneficiaries. The difference in adjusted RRs for the most favorable versus the least favorable survey design was 14.5%. For a 65-year-old, this difference was 13.6%; for an 80-year-old, it was 21.0%. These findings suggest that even within a relatively standardized survey, formatting can substantially influence RRs
An application of the prototype willingness model to drivers' speeding behaviour
We tested the prototype willingness model (PWM). The participants (N=198) completed online questionnaire measures of PWM constructs (time 1) and subsequent speeding behaviour (time 2). Path analyses showed that the PWM accounted for 89% of the variance in subsequent (self-reported) speeding behaviour. This significantly exceeded the variance accounted for by the theory of planned behaviour. In line with the PWM, both behavioural intention and behavioural willingness had direct effects on behaviour. Behavioural willingness had a significantly larger effect. Attitude and subjective norm both had indirect effects on behaviour through both behavioural intention and behavioural willingness. Prototype (similarity) perceptions had indirect effects on behaviour through behavioural willingness only. The findings support the notion that driving is governed by reactive decision-making (willingness), underpinned by prototype perceptions, attitudes and subjective norms, to a greater extent than it is deliberative decision-making (intentions), underpinned by attitudes and subjective norms. The implications for safety interventions are discussed
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