102 research outputs found
Positive affect and behavior change
Affect and emotion have potent motivational properties that can be leveraged to promote desirable behavior change. Although interventions often employ fear appeals in an effort to motivate change, both theory and a growing body of empirical evidence suggest that positive affect and emotions can promote change by serving as proximal rewards for desired behaviors. This article reviews examples of such efforts in the domains of healthy diet and exercise, prosocial behavior, and pro-environmental behavior, documenting the strong potential offered by behavioral interventions using this approach. The extent to which positive affect experience prospectively drives behavior change (as distinct from rewarding the desired behavior) is less clear. However, a variety of possible indirect pathways involving incidental effects of positive affect and specific positive emotions deserve rigorous future study
Modelling the sulfate capacity of simulated radioactive waste borosilicate glasses
The capacity of simulated high-level radioactive waste borosilicate glasses to incorporate sulfate has been studied as a function of glass composition. Combined Raman, 57Fe Mössbauer and literature evidence supports the attribution of coordination numbers and oxidation states of constituent cations for the purposes of modelling, and results confirm the validity of correlating sulfate incorporation in multicomponent borosilicate radioactive waste glasses with different models. A strong compositional dependency is observed and this can be described by an inverse linear relationship between incorporated sulfate (mol% SO42−) and total cation field strength index of the glass, Σ(z/a2), with a high goodness-of-fit (R2 ≈ 0.950). Similar relationships are also obtained if theoretical optical basicity, Λth (R2 ≈ 0.930) or non-bridging oxygen per tetrahedron ratio, NBO/T (R2 ≈ 0.919), are used. Results support the application of these models, and in particular Σ(z/a2), as predictive tools to aid the development of new glass compositions with enhanced sulfate capacities
Alveolar macrophage apoptosis-associated bacterial killing helps prevent murine pneumonia
RATIONALE: Antimicrobial resistance challenges therapy of pneumonia. Enhancing macrophage microbicidal responses would combat this problem but is limited by our understanding of how alveolar macrophages (AM) kill bacteria. OBJECTIVES: To define the role and mechanism of AM apoptosis-associated bacterial killing in the lung. METHODS: We generated a unique CD68.hMcl-1 transgenic mouse with macrophage-specific over-expression of the human anti-apoptotic Mcl-1 protein, a factor upregulated in AM from patients at increased risk of community-acquired pneumonia, to address the requirement for apoptosis-associated killing. MEASUREMENTS AND MAIN RESULTS: Wild-type and transgenic macrophages demonstrated comparable ingestion and initial phagolysosomal killing of bacteria. Continued ingestion (for > 12 h) overwhelmed initial killing and a second late-phase microbicidal response killed viable bacteria in wild-type macrophages, but this response was blunted in CD68.hMcl-1 transgenic macrophages. The late-phase of bacterial killing required both caspase-induced generation of mitochondrial reactive oxygen species (mROS) and nitric oxide (NO), whose peak generation coincided with the late-phase of killing. The CD68.hMcl-1 transgene prevented mROS but not NO generation. Apoptosis-associated killing enhanced pulmonary clearance of Streptococcus pneumoniae and Haemophilus influenzae in wild-type but not CD68.hMcl-1 transgenic mice. Bacterial clearance was enhanced in vivo in CD68.hMcl-1 transgenic mice by reconstitution of apoptosis with BH3 mimetics or clodronate-encapsulated liposomes. Apoptosis-associated killing was not activated during Staphylococcus aureus lung infection. CONCLUSIONS: Mcl-1 upregulation prevents macrophage apoptosis-associated killing and establishes that apoptosis-associated killing is required to allow AM to clear ingested bacteria. Engagement of macrophage apoptosis should be investigated as a novel host-based antimicrobial strategy
The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets
This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all objects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sun’s centre, equal to half of Mercury’s perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground- and space-based facilities that will allow us to address those science topics
Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy
We review HB stars in a broad astrophysical context, including both variable
and non-variable stars. A reassessment of the Oosterhoff dichotomy is
presented, which provides unprecedented detail regarding its origin and
systematics. We show that the Oosterhoff dichotomy and the distribution of
globular clusters (GCs) in the HB morphology-metallicity plane both exclude,
with high statistical significance, the possibility that the Galactic halo may
have formed from the accretion of dwarf galaxies resembling present-day Milky
Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the
second-parameter problem is presented. A technique is proposed to estimate the
HB types of extragalactic GCs on the basis of integrated far-UV photometry. The
relationship between the absolute V magnitude of the HB at the RR Lyrae level
and metallicity, as obtained on the basis of trigonometric parallax
measurements for the star RR Lyrae, is also revisited, giving a distance
modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are
studied. Finally, the conductive opacities used in evolutionary calculations of
low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and
Space Scienc
Designing Social Agents with Empathic Understanding
Abstract. This paper addresses the design of an agent model for a social agent capable of understanding other agents in an empathic way. The model describes how the empathic agent deals with another agent’s mental states and the associated feelings, thus not only understanding the other agent’s mental state but at the same time feeling the accompanying emotion of the other agent.
A multi-center study on the attitudes of Malaysian emergency health care staff towards allowing family presence during resuscitation of adult patients
BACKGROUND
The practice of allowing family members to witness on-going active resuscitation has been gaining ground in many developed countries since it was first introduced in the early 1990s. In many Asian countries, the acceptability of this practice has not been well studied.
AIM
We conducted a multi-center questionnaire study to determine the attitudes of health care professionals in Malaysia towards family presence to witness ongoing medical procedures during resuscitation.
METHODS
Using a bilingual questionnaire (in Malay and English language), we asked our respondents about their attitudes towards allowing family presence (FP) as well as their actual experience of requests from families to be allowed to witness resuscitations. Multiple logistic regression was used to analyze the association between the many variables and a positive attitude towards FP.
RESULTS
Out of 300 health care professionals who received forms, 270 responded (a 90% response rate). Generally only 15.8% of our respondents agreed to allow relatives to witness resuscitations, although more than twice the number (38.5%) agreed that relatives do have a right to be around during resuscitation. Health care providers are significantly more likely to allow FP if the procedures are perceived as likely to be successful (e.g., intravenous cannulation and blood taking as compared to chest tube insertion). Doctors were more than twice as likely as paramedics to agree to FP (p-value = 0.002). This is probably due to the Malaysian work culture in our health care systems in which paramedics usually adopt a 'follow-the-leader' attitude in their daily practice.
CONCLUSION
The concept of allowing FP is not well accepted among our Malaysian health care providers
Soil health: looking for suitable indicators. What should be considered to assess the effects of use and management on soil health?
The effect of material property variations on the failure probability of an AGR moderator brick subject to irradiation induced self stress
SIGLEAvailable from British Library Document Supply Centre- DSC:DXN002169 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Cerebral Amyloid Angiopathy in the Aetiology of Alzheimer’s disease and its effect on Therapy.
Amyloid is deposited in the walls of arteries and capillaries as cerebral amyloid angiopathy (CAA) in the brains of older individuals and of those with Alzheimer disease (AD). CAA in AD reflects an age-related failure of elimination of amyloid-beta (A?) from the brain along perivascular lymphatic drainage pathways. In the absence of conventional lymphatic vessel in the brain, interstitial fluid and solutes drain from the brain to cervical lymph nodes along narrow basement membranes in the walls of capillaries and arteries, a pathway that is largely separate from the cerebrospinal fluid. In this review we focus on the pathology and pathogenesis of CAA, its role in the aetiology of AD and its impact on immunotherapy for AD. The motive force for lymphatic drainage of the brain appears to be generated by arterial pulsations. Failure of elimination of A? along perivascular pathways coincides with a reduction in enzymic degradation of A?, reduced absorption of A? into the blood and age-related stiffening of artery walls that appears to reduce the motive force for lymphatic drainage. Reduced clearances of A? and CAA are associated with the accumulation of insoluble and soluble A?s in the brain in AD and the probable loss of homeostasis of the neuronal environment due to retention of soluble metabolites within the brain. Tau metabolism may also be affected. Immunotherapy has been successful in removing insoluble plaques of A? from the brain in AD but with little effect on cognitive decline. One major problem is the increase in CAA in immunised patients that probably prevents the complete removal of A? from the brain. Increased knowledge of the physiology and structural and genetic aspects of the lymphatic drainage of A? from the brain will stimulate the development of therapeutic strategies for the prevention and treatment of A
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