19 research outputs found
Signatures of clumpy dark matter in the global 21 cm background signal
No full textWe examine the extent to which the self-annihilation of supersymmetric neutralino dark matter, as well as light dark matter, influences the rate of heating, ionization, and Lyman-alpha pumping of interstellar hydrogen and helium and the extent to which this is manifested in the 21 cm global background signal. We fully consider the enhancements to the annihilation rate from dark matter halos and substructures within them. We find that the influence of such structures can result in significant changes in the differential brightness temperature, delta T-b. The changes at redshifts z < 25 are likely to be undetectable due to the presence of the astrophysical signal; however, in the most favorable cases, deviations in delta T-b, relative to its value in the absence of self-annihilating dark matter, of up to similar or equal to 20 mK at z = 30 can occur. Thus we conclude that, in order to exclude these models, experiments measuring the global 21 cm signal, such as EDGES and CORE, will need to reduce the systematics at 50 MHz to below 20 mK
The indirect detection of non-Baryonic Dark Matter
No full textThe understanding of the nature of the dominant forms of matter and energy in the Universe is undoubtedly one of the most intriguing concepts within the vast domain of current scientific research. Current experimental evidence supports the notion that the dominant form of matter in the Universe is composed of a non-luminous, possibly exotic, material that is distinct from the familiar baryonic matter from which the luminous Universe is composed.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Impact of propagation uncertainties on the potential dark matter contribution to the Fermi LAT mid-latitude<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>γ</mml:mi></mml:math>-ray data
No full textDisciplining the Spectator: Subjectivity, the Body and Contemporary Spectatorship
No full textIn this thesis the author argues that although questions of the spectator’s corporeal engagement with film are much neglected by film theory, the body is nevertheless a central term within contemporary cinema, in its mode of address, as a locus of anxiety in media effects debate, and as site of disciplinary practices. And while the thesis begins by demonstrating both the socially and historically constructed nature of spectatorship, and the specific practices that work to create contemporary cinema’s corporeal address, the latter half of the dissertation devotes itself to revealing the regulatory implications of this physical address. That is, the author shows that cinema’s perceived capacity of affect the body of the spectator is a profound source of cultural anxiety. But more importantly, through an analysis of the films Funny Games, Irréversible, Wolf Creek, and the genre of ‘torture porn’ more generally, what is revealed in these final chapters is that the regulation of cinema in the contemporary era is less a question of the institutionalised censorship of texts, and more a question of regulating the ‘self’. In this respect, the author demonstrates the specific disciplinary practices that attempt to present the problem of violent, and sexually violent, imagery not as a textual issue per se, but a question of the formation of appropriate spectatorial relations. Moreover, this study begins the process of teasing out the ways in which the contemporary spectator is induced to see the problem of media violence as one that can be resolved through what
Foucault would term, techniques of the self
Is light neutralino as dark matter still viable?
No full text16 pages, 7 figures, 3 tablesMotivated by the recent re-confirmation by CoGENT of the low-energy excess of events observed last year, and the recent improved limits from the XENON-100 experiment that are in contention with the CoGENT data, we re-examine the low mass neutralino region of the Minimal Supersymmetric Standard Model and of the Next-to-Minimal Supersymmetric Standard Model, both without assuming gaugino mass unification. We make several focused scans for each model, determining conservative constraints on input parameters. We then determine how these constraints are made increasingly stringent as we re-invoke our experimental constraints involving the dark matter relic abundance, collider constraints from LEP and the Tevatron, and then from flavour physics, as a series of successive 2 sigma hard cuts. We find that for both models, when all relevant constraints are applied in this fashion, we do not generate neutralino LSPs that possess a spin-independent scattering cross section in excess of 10^-5 pb and a mass ~7 GeV < m_chi < ~9 GeV that is necessary in order to explain the CoGENT observations
A Systematic Review of the Efficacy and Toxicity of Brachytherapy Boost Combined with External Beam Radiotherapy for Nonmetastatic Prostate Cancer
No full textContext
The optimum use of brachytherapy (BT) combined with external beam radiotherapy (EBRT) for localised/locally advanced prostate cancer (PCa) remains uncertain.
Objective
To perform a systematic review to determine the benefits and harms of EBRT-BT.
Evidence acquisition
Ovid MEDLINE, Embase, and EBM Reviews—Cochrane Central Register of Controlled Trials databases were systematically searched for studies published between January 1, 2000 and June 7, 2022, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Eligible studies compared low- or high-dose-rate EBRT-BT against EBRT ± androgen deprivation therapy (ADT) and/or radical prostatectomy (RP) ± postoperative radiotherapy (RP ± EBRT). The main outcomes were biochemical progression-free survival (bPFS), severe late genitourinary (GU)/gastrointestinal toxicity, metastasis-free survival (MFS), cancer-specific survival (CSS), and overall survival (OS), at/beyond 5 yr. Risk of bias was assessed and confounding assessment was performed. A meta-analysis was performed for randomised controlled trials (RCTs).
Evidence synthesis
Seventy-three studies were included (two RCTs, seven prospective studies, and 64 retrospective studies). Most studies included participants with intermediate-or high-risk PCa. Most studies, including both RCTs, used ADT with EBRT-BT. Generally, EBRT-BT was associated with improved bPFS compared with EBRT, but similar MFS, CSS, and OS. A meta-analysis of the two RCTs showed superior bPFS with EBRT-BT (estimated fixed-effect hazard ratio [HR] 0.54 [95% confidence interval {CI} 0.40–0.72], p < 0.001), with absolute improvements in bPFS at 5–6 yr of 4.9–16%. However, no difference was seen for MFS (HR 0.84 [95% CI 0.53–1.28], p = 0.4) or OS (HR 0.87 [95% CI 0.63–1.19], p = 0.4). Fewer studies examined RP ± EBRT. There is an increased risk of severe late GU toxicity, especially with low-dose-rate EBRT-BT, with some evidence of increased prevalence of severe GU toxicity at 5–6 yr of 6.4–7% across the two RCTs.
Conclusions
EBRT-BT can be considered for unfavourable intermediate/high-risk localised/locally advanced PCa in patients with good urinary function, although the strength of this recommendation based on the European Association of Urology guideline methodology is weak given that it is based on improvements in biochemical control.
Patient summary
We found good evidence that radiotherapy combined with brachytherapy keeps prostate cancer controlled for longer, but it could lead to worse urinary side effects than radiotherapy without brachytherapy, and its impact on cancer spread and patient survival is less clear
EAU-EANM-ESTRO-ESUR-SIOG Prostate Cancer Guideline Panel Consensus Statements for Deferred Treatment with Curative Intent for Localised Prostate Cancer from an International Collaborative Study (DETECTIVE Study)
No full textBackground
There is uncertainty in deferred active treatment (DAT) programmes, regarding patient selection, follow-up and monitoring, reclassification, and which outcome measures should be prioritised.
Objective
To develop consensus statements for all domains of DAT.
Design, setting, and participants
A protocol-driven, three phase study was undertaken by the European Association of Urology (EAU)-European Association of Nuclear Medicine (EANM)-European Society for Radiotherapy and Oncology (ESTRO)-European Association of Urology Section of Urological Research (ESUR)-International Society of Geriatric Oncology (SIOG) Prostate Cancer Guideline Panel in conjunction with partner organisations, including the following: (1) a systematic review to describe heterogeneity across all domains; (2) a two-round Delphi survey involving a large, international panel of stakeholders, including healthcare practitioners (HCPs) and patients; and (3) a consensus group meeting attended by stakeholder group representatives. Robust methods regarding what constituted the consensus were strictly followed.
Results and limitations
A total of 109 HCPs and 16 patients completed both survey rounds. Of 129 statements in the survey, consensus was achieved in 66 (51%); the rest of the statements were discussed and voted on in the consensus meeting by 32 HCPs and three patients, where consensus was achieved in additional 27 statements (43%). Overall, 93 statements (72%) achieved consensus in the project. Some uncertainties remained regarding clinically important thresholds for disease extent on biopsy in low-risk disease, and the role of multiparametric magnetic resonance imaging in determining disease stage and aggressiveness as a criterion for inclusion and exclusion.
Conclusions
Consensus statements and the findings are expected to guide and inform routine clinical practice and research, until higher levels of evidence emerge through prospective comparative studies and clinical trials.
Patient summary
We undertook a project aimed at standardising the elements of practice in active surveillance programmes for early localised prostate cancer because currently there is great variation and uncertainty regarding how best to conduct them. The project involved large numbers of healthcare practitioners and patients using a survey and face-to-face meeting, in order to achieve agreement (ie, consensus) regarding best practice, which will provide guidance to clinicians and researchers
Disability, access and design: a study of wheelchair access.
No full textThe aim of this study is to determine wheelchair user's views about access and ascertain whether designers are able to contribute to issues pertaining to inclusion through design solutions. Popular constructions of disability have established a relatively powerless and deviant status for the disabled population when compared to their able bodied peers. Regulatory controls and legislation require that builders and designers are sensitised to the needs of disabled people, but there is no legislative process to endorse disabled peoples request for a fully inclusive and accessible lifestyle. The enquiry is divided into two phases. The first phase considers access issues from a
sample of wheelchair users via the use of focus groups and individual interviews. The data attained and information collated for the literature review leads the author to
conclude that designers should consult with end users throughout the design process. During the second phase of the study the author proposes a model of inclusive design
and an associated design resource. The author advocates that this is to be used by designers and development professionals to ensure inclusion within society is attained
for all sectors of the community. The study concludes that, historically, society has responded to the needs of the disabled by providing separate and special services based on each individual's impairment, as opposed to the promotion of an equitable lifestyle for all. Inclusive design focuses on the design of the environment and not individual impairments. It is a process that promotes inclusivity for all sectors of society regardless of age, race, gender, sexuality or disability. Its principles consider diversity, and provides for an inclusive environment that can help break down barriers and exclusion as everyone will benefit from the end result
Experiment on the effect of an interaction of heat and hypoosmotic stress on the growth and photosynthetic performance of tropical seagrass species Thalassia testudinum: growth parameters
No full textThis study examined the response of tropical seagrass species Thalassia testudinum to a combination of heat and hypoosmotic stress. These two stressors are of major importance, as studies predict a rise in sea surface temperatures, as well as in increase in precipitation in the Caribbean region. Field-studies revealed the plant to exhibit a slow stress response to e.g. elevated temperatures and changes in salinity, however, they also showed the severity in changes in these factors. While in-situ observations allow for a good setting of treatment levels, there is a scarcity of in-culture experiments exposing T. testudinum to heat and osmotic stress, especially in combination. These experiments are essential to precisely delineate the effects and establish causality, thereby eliminating potential confounding factors. This in-culture experiment was performed in the culturing facilities of the GEOMAR building (54°19'48N 10°08'54E) using a culture of four T. testudinum clones. Plants were originally collected in 2017 from waters in front of the Smithsonian Tropical Research Institute in Bocas del Toro, Panama (9°21'04N 82°15'26W). Subsequently, they were cultivated in the GEOMAR culturing facilities under water temperatures of 28°C and salinities levels between 31-34. For the experiment, plants were replanted in February 2023 to fit a fully factorial experiment comprising all four clones crossed over four treatments: control (T=28°C; S=32.5), heat stress (T=34°C; S=32.5), hypoosmotic stress (T=28°C; S=27) and combined heat and hypoosmotic stress (T=34°C; S=27). Each treatment held three replicates (100 L aquaria), which in turn held two boxes of each clone with a starting number of two shoots each. Plants were given sufficient time to establish until overall net new growth in form of new shoot production was observed. After this initial establishment, a one week warming phase for heat treatments preceded the four-week stress period throughout August 2023, followed by cool-down phase and subsequently a total of six weeks recovery. During the stress period heat stress was a permanent stressor, while hypoosmotic stress was induced in pulsed salinity drops to simulated inflow events. For this, filtered (Aqua Medic Antiphos FE) water (50/50 VE and tap water) was added to the aquaria over two to three hours until the desired salinity of 27 was reached. The same water was used to refill evaporated water in the other treatments to keep salinity levels at 32.5. Growth parameters of T. testudinum were measured at the start and end of the stress period, three weeks into the recovery phase, and again after six weeks. Measurements involved using a ruler to carefully determine the length (centimeters) of the youngest and second youngest leaves (sheath to tip of the leaf) within a four-day interval to calculate the average growth rate per day. Additionally, the number of leaves of the measured shoot was recorded. Newly formed leaves withing the measurement interval were noted as well. Prior to the first measurement, shoots were chosen randomly within the samples and assigned a location code to ensure the same shoot was measured every time. A total of five shoots per clone per treatment were measured, resulting in a total of 20 samples per treatment
