Monitoring Impacts of Urbanisation and Industrialisation on Air Quality in the Anthropocene Using Urban Pond Sediments

This is the final version of the article. Available from Frontiers Media via the DOI in this record.The release of toxic atmospheric pollutants since the Industrial Revolution is a major global challenge, driving climate change and damaging human health. Spatial health inequalities highlight the need to explore air pollution in different localities throughout the Anthropocene. Air quality monitoring programmes are spatially and temporally limited. We show how suitable urban sediment archives provide site specific records of long-term particulate matter (PM) releases, in cities and urban landscapes, that are or have been subjected to high pollution levels. High-resolution PM records spanning from the mid-20th century were reconstructed from an urban pond in Chongqing, southwest China, one of the fastest growing Chinese urban centres in the late 20th century. Temporal variations in pollution proxies including geomagnetic, geochemical and spheroidal carbonaceous particle trends correspond to key phases of industrial and urban developments, that are representative of the locality. Observed increases in air pollution proxies post-1960 coincide with the location of military-related industries to Chongqing and industrial intensification. Post-1997 pollution mirrors rapid urbanisation that occurred following the designation of Chongqing as a government-controlled municipality at this time and reveals a steadily increasing pollution trend to present day (2015). In comparison to Chongqing, an atmospheric depositional history was constructed from an urban pond in the Merseyside region of northwest England that has experienced a legacy of contamination since the early 19th century. In northwest England, changing characteristics of pollution are related to the establishment of localised, modern industries, power generation, urban sprawl, increased combustion-derived pollution post-1990 and effective pollution legislations. Whereas a reduction in air pollution has occurred post-2000 in Merseyside, in Chongqing, however, air pollution has continued to increase in spite of national efforts in pollution control. These urban sediments reveal the changing nature of air pollution in different urban landscapes, allowing us to assess air quality impacts of progressive industrial activity, increased road and air travel, urban expansion and the efficacy of pollution controls. It appears that air pollution remains an inevitable consequence of global industrialisation. It is therefore crucial to understand pollution histories in densely populated urban regions to determine environmental burdens of pollution on health over generational timescales.This research was supported by Halton Primary Care Trust (grant number CHCRD001 SE02), Edge Hill University (fund codes: RDWOR04, RDWOR05, RDWOR06, and RDWOR209), and the University of Exeter

Black love : exploring how a politicized care pedagogical approach supports youth establishment of rightful presence in STEM

Youth of color are severely underrepresented in STEM which is can be attributed to low socioeconomic status, lack of representation, varying levels of racism faced within different institutions and systems. Without proper support and representation, youth of color can begin to feel that STEM is not a field they identify with or feel they belong. However, Informal STEM programs have been found to be sites of non-traditional STEM learning that support youth of color. This dissertation, based on a three-year study within a local Boys and Girls Club in North Carolina, describes how an informal STEM educator’s politicized care pedagogical practice supports Black youth to reauthor their rightful presence in STEM. Using a participatory design-based research approach, I explore how critical relationality that focuses on the integration of youth voice and interest supports youth to develop their STEM-related onto-epistemologies. The findings of this dissertation indicate that the role of the informal STEM educator has a significant impact on how youth perceive themselves in STEM. This is presented through a multiple case study that focuses on how two Black boys co-created learning opportunities in coding, how informal STEM programs can serve as a Black educational space (a socio-spatial imaginary rooted in anti-Blackness), and a critical autoethnography that looks at what it means to be an informal STEM educator within a community-based setting. Through these findings I surface the criticality for informal STEM educators to have a relationship and develop community with the youth they work with

Neural representation of reward in recovered depressed patients

These findings support the view that abnormal neural responses to reward may be an endophenotype for depression and a potential target for intervention and prevention strategies

Transcranial Magnetic Stimulation Intensities in Cognitive Paradigms

BACKGROUND: Transcranial magnetic stimulation (TMS) has become an important experimental tool for exploring the brain's functional anatomy. As TMS interferes with neural activity, the hypothetical function of the stimulated area can thus be tested. One unresolved methodological issue in TMS experiments is the question of how to adequately calibrate stimulation intensities. The motor threshold (MT) is often taken as a reference for individually adapted stimulation intensities in TMS experiments, even if they do not involve the motor system. The aim of the present study was to evaluate whether it is reasonable to adjust stimulation intensities in each subject to the individual MT if prefrontal regions are stimulated prior to the performance of a cognitive paradigm. METHODS AND FINDINGS: Repetitive TMS (rTMS) was applied prior to a working memory task, either at the 'fixed' intensity of 40% maximum stimulator output (MSO), or individually adapted at 90% of the subject's MT. Stimulation was applied to a target region in the left posterior middle frontal gyrus (pMFG), as indicated by a functional magnetic resonance imaging (fMRI) localizer acquired beforehand, or to a control site (vertex). Results show that MT predicted the effect size after stimulating subjects with the fixed intensity (i.e., subjects with a low MT showed a greater behavioral effect). Nevertheless, the individual adaptation of intensities did not lead to stable effects. CONCLUSION: Therefore, we suggest assessing MT and account for it as a measure for general cortical TMS susceptibility, even if TMS is applied outside the motor domain

Disrupted Functional Connectivity with Dopaminergic Midbrain in Cocaine Abusers

Background: Chronic cocaine use is associated with disrupted dopaminergic neurotransmission but how this disruption affects overall brain function (other than reward/motivation) is yet to be fully investigated. Here we test the hypothesis that cocaine addicted subjects will have disrupted functional connectivity between the midbrain (where dopamine neurons are located) and cortical and subcortical brain regions during the performance of a sustained attention task. Methodology/Principal Findings: We measured brain activation and functional connectivity with fMRI in 20 cocaine abusers and 20 matched controls. When compared to controls, cocaine abusers had lower positive functional connectivity of midbrain with thalamus, cerebellum, and rostral cingulate, and this was associated with decreased activation in thalamus and cerebellum and enhanced deactivation in rostral cingulate. Conclusions/Significance: These findings suggest that decreased functional connectivity of the midbrain interferes with the activation and deactivation signals associated with sustained attention in cocaine addicts

Detecting functional magnetic resonance imaging activation in white matter: Interhemispheric transfer across the corpus callosum

<p>Abstract</p> <p>Background</p> <p>It is generally believed that activation in functional magnetic resonance imaging (fMRI) is restricted to gray matter. Despite this, a number of studies have reported white matter activation, particularly when the corpus callosum is targeted using interhemispheric transfer tasks. These findings suggest that fMRI signals may not be neatly confined to gray matter tissue. In the current experiment, 4 T fMRI was employed to evaluate whether it is possible to detect white matter activation. We used an interhemispheric transfer task modelled after neurological studies of callosal disconnection. It was hypothesized that white matter activation could be detected using fMRI.</p> <p>Results</p> <p>Both group and individual data were considered. At liberal statistical thresholds (p < 0.005, uncorrected), group level activation was detected in the isthmus of the corpus callosum. This region connects the superior parietal cortices, which have been implicated previously in interhemispheric transfer. At the individual level, five of the 24 subjects (21%) had activation clusters that were located primarily within the corpus callosum. Consistent with the group results, the clusters of all five subjects were located in posterior callosal regions. The signal time courses for these clusters were comparable to those observed for task related gray matter activation.</p> <p>Conclusion</p> <p>The findings support the idea that, despite the inherent challenges, fMRI activation can be detected in the corpus callosum at the individual level. Future work is needed to determine whether the detection of this activation can be improved by utilizing higher spatial resolution, optimizing acquisition parameters, and analyzing the data with tissue specific models of the hemodynamic response. The ability to detect white matter fMRI activation expands the scope of basic and clinical brain mapping research, and provides a new approach for understanding brain connectivity.</p

Neural Basis of Self and Other Representation in Autism: An fMRI Study of Self-Face Recognition

Autism is a developmental disorder characterized by decreased interest and engagement in social interactions and by enhanced self-focus. While previous theoretical approaches to understanding autism have emphasized social impairments and altered interpersonal interactions, there is a recent shift towards understanding the nature of the representation of the self in individuals with autism spectrum disorders (ASD). Still, the neural mechanisms subserving self-representations in ASD are relatively unexplored.We used event-related fMRI to investigate brain responsiveness to images of the subjects' own face and to faces of others. Children with ASD and typically developing (TD) children viewed randomly presented digital morphs between their own face and a gender-matched other face, and made "self/other" judgments. Both groups of children activated a right premotor/prefrontal system when identifying images containing a greater percentage of the self face. However, while TD children showed activation of this system during both self- and other-processing, children with ASD only recruited this system while viewing images containing mostly their own face.This functional dissociation between the representation of self versus others points to a potential neural substrate for the characteristic self-focus and decreased social understanding exhibited by these individuals, and suggests that individuals with ASD lack the shared neural representations for self and others that TD children and adults possess and may use to understand others

Evolution of active galactic nuclei

[Abriged] Supermassive black holes (SMBH) lurk in the nuclei of most massive galaxies, perhaps in all of them. The tight observed scaling relations between SMBH masses and structural properties of their host spheroids likely indicate that the processes fostering the growth of both components are physically linked, despite the many orders of magnitude difference in their physical size. This chapter discusses how we constrain the evolution of SMBH, probed by their actively growing phases, when they shine as active galactic nuclei (AGN) with luminosities often in excess of that of the entire stellar population of their host galaxies. Following loosely the chronological developments of the field, we begin by discussing early evolutionary studies, when AGN represented beacons of light probing the most distant reaches of the universe and were used as tracers of the large scale structure. This early study turned into AGN "Demography", once it was realized that the strong evolution (in luminosity, number density) of the AGN population hindered any attempt to derive cosmological parameters from AGN observations directly. Following a discussion of the state of the art in the study of AGN luminosity functions, we move on to discuss the "modern" view of AGN evolution, one in which a bigger emphasis is given to the physical relationships between the population of growing black holes and their environment. This includes observational and theoretical efforts aimed at constraining and understanding the evolution of scaling relations, as well as the resulting limits on the evolution of the SMBH mass function. Physical models of AGN feedback and the ongoing efforts to isolate them observationally are discussed next. Finally, we touch upon the problem of when and how the first black holes formed and the role of black holes in the high-redshift universe.Comment: 75 pages, 35 figures. Modified version of the chapter accepted to appear in "Planets, Stars and Stellar Systems", vol 6, ed W. Keel (www.springer.com/astronomy/book/978-90-481-8818-5). The number of references is limited upon request of the editors. Original submission to Springer: June 201

Cryptococcal meningitis: epidemiology, immunology, diagnosis and therapy.

HIV-associated cryptococcal meningitis is by far the most common cause of adult meningitis in many areas of the world that have high HIV seroprevalence. In most areas in Sub-Saharan Africa, the incidence of cryptococcal meningitis is not decreasing despite availability of antiretroviral therapy, because of issues of adherence and retention in HIV care. In addition, cryptococcal meningitis in HIV-seronegative individuals is a substantial problem: the risk of cryptococcal infection is increased in transplant recipients and other individuals with defects in cell-mediated immunity, and cryptococcosis is also reported in the apparently immunocompetent. Despite therapy, mortality rates in these groups are high. Over the past 5 years, advances have been made in rapid point-of-care diagnosis and early detection of cryptococcal antigen in the blood. These advances have enabled development of screening and pre-emptive treatment strategies aimed at preventing the development of clinical infection in patients with late-stage HIV infection. Progress in optimizing antifungal combinations has been aided by evaluation of the clearance rate of infection by using serial quantitative cultures of cerebrospinal fluid (CSF). Measurement and management of raised CSF pressure, a common complication, is a vital component of care. In addition, we now better understand protective immune responses in HIV-associated cases, immunogenetic predisposition to infection, and the role of immune-mediated pathology in patients with non-HIV associated infection and in the context of HIV-associated immune reconstitution reactions