While John Kingdon's Multiple Streams Approach (MSA) remains a key reference point in the public policy literature, few have attempted to assess MSA holistically. To assess its broader impact and ...trends in usage, we combine in‐depth analysis of representative studies, with comprehensive coverage of MSA‐inspired articles, to categorize its impact. We find that Kingdon's work makes two separate contributions. First, it has contributed to the development of “evolutionary” policy theories such as punctuated equilibrium. Second, it has prompted a large, dedicated, and often empirical, literature. However, most MSA empirical applications only engage with broader policy theory superficially. The two contributions are oddly independent of each other. We argue that these trends in application are due largely to its intuitive appeal and low “barrier to entry.” Drawing on other policy approaches, we offer suggestions to improve the MSA‐inspired literature.
A central goal of cognitive neuroscience is to decode human brain activity-that is, to infer mental processes from observed patterns of whole-brain activation. Previous decoding efforts have focused ...on classifying brain activity into a small set of discrete cognitive states. To attain maximal utility, a decoding framework must be open-ended, systematic, and context-sensitive-that is, capable of interpreting numerous brain states, presented in arbitrary combinations, in light of prior information. Here we take steps towards this objective by introducing a probabilistic decoding framework based on a novel topic model-Generalized Correspondence Latent Dirichlet Allocation-that learns latent topics from a database of over 11,000 published fMRI studies. The model produces highly interpretable, spatially-circumscribed topics that enable flexible decoding of whole-brain images. Importantly, the Bayesian nature of the model allows one to "seed" decoder priors with arbitrary images and text-enabling researchers, for the first time, to generate quantitative, context-sensitive interpretations of whole-brain patterns of brain activity.
Abstract
We present the most precise measurement of the z = 0 H i mass function (HIMF) to date based on the final catalogue of the ALFALFA (Arecibo Legacy Fast ALFA) blind H i survey of the nearby ...Universe. The Schechter function fit has a ‘knee’ mass $\log (M_{*}\,h^{2}_{70}/\mathrm{M_{{\odot }}}) = 9.94 \pm 0.01 \pm 0.05$, a low-mass slope parameter α = −1.25 ± 0.02 ± 0.1, and a normalization $\phi _{*} = (4.5 \,\pm \, 0.2\, \pm \, 0.8) \times 10^{-3} \, h^{3}_{70}\, \mathrm{Mpc^{-3}\,dex^{-1}}$, with both random and systematic uncertainties as quoted. Together these give an estimate of the H i content of the z = 0 Universe as $\Omega _{\mathrm{\rm{H\,\small {I}}} = (3.9 \pm 0.1 \pm 0.6) \times 10^{-4} \, h^{-1}_{70}$ (corrected for H i self-absorption). Our analysis of the uncertainties indicates that the ‘knee’ mass is a cosmologically fair measurement of the z = 0 value, with its largest uncertainty originating from the absolute flux calibration, but that the low-mass slope is only representative of the local Universe. We also explore large-scale trends in α and M* across the ALFALFA volume. Unlike with the 40 per cent sample, there is now sufficient coverage in both of the survey fields to make an independent determination of the HIMF in each. We find a large discrepancy in the low-mass slope (Δα = 0.14 ± 0.03) between the two regions, and argue that this is likely caused by the presence of a deep void in one field and the Virgo cluster in the other. Furthermore, we find that the value of the ‘knee’ mass within the Local Volume appears to be suppressed by 0.18 ± 0.04 dex compared to the global ALFALFA value, which explains the lower value measured by the shallower H i Parkes All Sky Survey (HIPASS). We discuss possible explanations and interpretations of these results and how they can be expanded on with future surveys.
As cuisine becomes globalized, large volumes of fresh produce are traded internationally. The potential exists for pathogens infecting fresh produce to hitchhike to new locations and perhaps to ...establish there. It is difficult to identify them using traditional methods if pathogens are novel, scarce, and/or unexpected. In an attempt to overcome this limitation, we used high-throughput sequencing technology as a means of detecting all RNA viruses infecting garlic (Allium sativum L.) bulbs imported into Australia from China, the USA, Mexico, Argentina and Spain, and those growing in Australia. Bulbs tested were grown over multiple vegetative generations and all were stably infected with one or more viruses, including two species not previously recorded in Australia. Present in various combinations from 10 garlic bulbs were 41 virus isolates representing potyviruses (Onion yellow dwarf virus, Leek yellow stripe virus), carlaviruses (Shallot latent virus, Garlic common latent virus) and allexiviruses (Garlic virus A, B, C, D, and X), for which 19 complete and 22 partial genome sequences were obtained, including the first complete genome sequences of two isolates of GarVD. The most genetically distinct isolates of GarVA and GarVX described so far were identified from Mexico and Argentina, and possible scenarios explaining this are presented. The complete genome sequence of an isolate of the potexvirus Asparagus virus 3 (AV3) was obtained in Australia from wild garlic (A. vineale L.), a naturalized weed. This is first time AV3 has been identified from wild garlic and the first time it has been identified beyond China and Japan. The need for routine generic diagnosis and appropriate legislation to address the risks to primary production and wild plant communities from pathogens spread through the international trade in fresh produce is discussed.
Damage to locus ceruleus neurons could play a part in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis because of impairment of ...the blood-brain barrier and enhanced neuroinflammation. The locus ceruleus has connections throughout the brain and spinal cord, so the characteristic widespread multifocal pathology in these disorders could be due to damage to different subsets of locus ceruleus neurons. Previous studies have shown that only certain locus ceruleus neurons accumulate the neurotoxic metal mercury. To find out if concentrations of other toxic metals or of essential trace elements also vary between individual locus ceruleus neurons, we used synchrotron X-ray fluorescence microscopy on frozen sections of locus ceruleus neurons taken from people with multiple sclerosis, in whom the locus ceruleus is structurally intact.
Paraffin embedded sections containing the locus ceruleus from seven people with multiple sclerosis were stained with autometallography that demonstrates accumulations of mercury, silver and bismuth. These were compared to maps of multiple elements obtained from frozen sections of locus ceruleus neurons from the same people using X-ray fluorescence microscopy. Neurons in the anterior pons from three of these donors were used as internal controls.
Autometallography staining was observed in scattered locus ceruleus neurons from three of the seven donors. X-ray fluorescence microscopy showed variations among individual locus ceruleus neurons in levels of mercury, selenium, iron, copper, lead, bromine, and rubidium. Variations between donors of locus ceruleus neuronal average levels of mercury, iron, copper, and bromine were also detected. Anterior pons neurons contained no mercury, had varied levels of iron, and had lower copper levels than locus ceruleus neurons.
Individual human locus ceruleus neurons contain varying levels of toxic metals and essential trace elements. In contrast, most toxic metals are absent or at low levels in nearby anterior pons neurons. The locus ceruleus plays a role in numerous central nervous system functions, including maintaining the blood-brain-barrier and limiting neuroinflammation. Toxic metals, or alterations in essential trace metals within individual locus ceruleus neurons, could be one factor determining the non-random destruction of locus ceruleus neurons in normal aging and neurodegenerative diseases, and subsequently the sites of the widespread multifocal central nervous system pathology in these disorders.
Examining chemical and structural characteristics of micro-features in complex tissue matrices is essential for understanding biological systems. Advances in multimodal chemical and structural ...imaging using synchrotron radiation have overcome many issues in correlative imaging, enabling the characterization of distinct microfeatures at nanoscale resolution in
ex vivo
tissues. We present a nanoscale imaging method that pairs X-ray ptychography and X-ray fluorescence microscopy (XFM) to simultaneously examine structural features and quantify elemental content of microfeatures in complex
ex vivo
tissues. We examined the neuropathological microfeatures Lewy bodies, aggregations of superoxide dismutase 1 (SOD1) and neuromelanin in human post-mortem Parkinson's disease tissue. Although biometals play essential roles in normal neuronal biochemistry, their dyshomeostasis is implicated in Parkinson's disease aetiology. Here we show that Lewy bodies and SOD1 aggregates have distinct elemental fingerprints yet are similar in structure, whilst neuromelanin exhibits different elemental composition and a distinct, disordered structure. The unique approach we describe is applicable to the structural and chemical characterization of a wide range of complex biological tissues at previously unprecedented levels of detail.
Structural and chemical characterisation of microfeatures in unadulterated Parkinson's disease brain tissue using synchrotron nanoscale XFM and ptychography.
Age-related cognitive decline is common and may lead to substantial difficulties and disabilities in everyday life. We hypothesized that 10 hours of visual speed of processing training would prevent ...age-related declines and potentially improve cognitive processing speed.
Within two age bands (50-64 and ≥ 65) 681 patients were randomized to (a) three computerized visual speed of processing training arms (10 hours on-site, 14 hours on-site, or 10 hours at-home) or (b) an on-site attention control group using computerized crossword puzzles for 10 hours. The primary outcome was the Useful Field of View (UFOV) test, and the secondary outcomes were the Trail Making (Trails) A and B Tests, Symbol Digit Modalities Test (SDMT), Stroop Color and Word Tests, Controlled Oral Word Association Test (COWAT), and the Digit Vigilance Test (DVT), which were assessed at baseline and at one year. 620 participants (91%) completed the study and were included in the analyses. Linear mixed models were used with Blom rank transformations within age bands.
All intervention groups had (p<0.05) small to medium standardized effect size improvements on UFOV (Cohen's d = -0.322 to -0.579, depending on intervention arm), Trails A (d = -0.204 to -0.265), Trails B (d = -0.225 to -0.320), SDMT (d = 0.263 to 0.351), and Stroop Word (d = 0.240 to 0.271). Converted to years of protection against age-related cognitive declines, these effects reflect 3.0 to 4.1 years on UFOV, 2.2 to 3.5 years on Trails A, 1.5 to 2.0 years on Trails B, 5.4 to 6.6 years on SDMT, and 2.3 to 2.7 years on Stroop Word.
Visual speed of processing training delivered on-site or at-home to middle-aged or older adults using standard home computers resulted in stabilization or improvement in several cognitive function tests. Widespread implementation of this intervention is feasible.
ClinicalTrials.gov NCT-01165463.
Postpositive policy scholarship has long asserted the importance of narratives—or stories—in shaping public policy through public opinion. In part, the Narrative Policy Framework (NPF) was developed ...to empirically test this assertion. To assess the relationship between policy narratives and public opinion, NPF posits several causal mechanisms including narrative transportation. Narrative transportation is a measure used to assess the extent to which individuals exposed to a story are “transported” into that story. NPF hypothesizes that as narrative transportation increases the reader of the story will (i) have more positive affect for characters within the story; and (ii) will find the story more persuasive. Using an online experiment involving a nationally representative sample of over 1,700 respondents, this research tests narrative transportation hypotheses by exposing subjects to one of three Cultural Theory narratives about climate change, as well as a control list of scientifically agreed upon facts. While findings do not support that narratives are any more transportive than fact lists in terms of directly persuading respondents to accept specific climate change policies, the data do show that narrative transportation positively influences affect for hero characters, which extant research demonstrates indirectly influences the persuasiveness of a story.
Cell adhesion to the extracellular matrix (ECM) is required for normal cell cycle progression and accurate cell division. However, how cell adhesion to the wide range of ECM proteins found in human ...tissues influences the cell cycle is not fully understood. The composition and physical properties of the ECM can have profound effects on cell proliferation but can also promote cell cycle exit and quiescence. Furthermore, during tumor development and progression, changes in the ECM can drive both cancer cell proliferation and dormancy. Cell-matrix adhesion is primarily sensed via integrin-associated adhesion complexes, which in turn are regulated by the cell cycle machinery. In particular, cyclin-dependent kinase 1 (CDK1) has been shown to play a crucial role in regulating adhesion complexes during interphase and entry into mitosis. These reciprocal links between cell cycle progression and cell-matrix interactions are now being identified.
•ECM proteins can promote both cell proliferation and quiescence.•It is unclear how different ECM properties promote cell cycle outcomes.•ECM adhesion facilitates stem cell self-renewal and proliferation.•ECM proteins can promote cancer cell dormancy.•CDK1 regulates focal adhesions during interphase and mitosis.
PDF
