2,715 research outputs found
An investigation of the relationship between BOLD and perfusion signal changes during epileptic generalised spike wave activity
In pathological conditions interpretation of functional magnetic resonance imaging (fMRI) results can be difficult. This is due to a reliance on the assumed coupling between neuronal activity and changes in cerebral blood flow (CBF) and oxygenation. We wanted to investigate the coupling between blood oxygen level dependant contrast (BOLD) and CBF time courses in epilepsy patients with generalised spike wave activity (GSW) to better understand the underlying mechanisms behind the EEG-fMRI signal changes observed, especially in regions of negative BOLD response (NBR). Four patients with frequent GSW were scanned with simultaneous electroencephalographic (EEG)-fMRI with BOLD and arterial spin labeling (ASL) sequences. We examined the relationship between simultaneous CBF and BOLD measurements by looking at the correlation of the two signals in terms of percentage signal change on a voxel-by-voxel basis. This method is not reliant on coincident activation. BOLD and CBF were positively correlated in patients with epilepsy during background EEG activity and GSW. The subject average value of the ΔCBF/ΔBOLD slope lay between +19 and +36 and also showed spatial variation which could indicate areas with altered vascular response. There was not a significant difference between ΔCBF/ΔBOLD during GSW, suggesting that neurovascular coupling to BOLD signal is generally maintained between states and, in particular, within areas of NBR
You Can Change the World With a Haircut”: Evaluating the Feasibility of a Barber-led Intervention for Men of Black and Ethnic Minority Heritage to Manage High Blood Pressure
Background:
People of Black, Asian and minority ethnic (BAME) heritage have a higher-than-average incidence of, and mortality from hypertension and stroke. Therefore, it is important to identify new settings for engaging people at risk of high blood pressure (BP).
Aim:
This feasibility study aimed to evaluate if barbers in a London borough can support and educate men of BAME heritage to manage their BP. Following UK Medical Research Council guidance, the RE-AIM (reach, effectiveness, adoption, implementation, maintenance) framework was used to guide study objectives and feasibility outcomes.
Methods:
We collaborated with 8 barbers who were part of an existing BAME barber network. Barbers were trained online (1.5 h) and face-to-face (3 h) to provide BP healthcare advice and take customers BP readings. Qualitative field notes were collected to assess how best to recruit and train barbers, and to understand how to maintain motivation and retention of barbers. BP readings were recorded between June 2021 and March 2022.
Results:
Both online and face-to-face training were effective, however, greater focus on how to start conversations about BP with clients was needed. We found that motivation, incentivization and regular contact with barbers were important for recruitment, retention, and sustained BP measurement. Obtaining BP readings was challenging due to client concerns about recording their data and the impracticalities of recording results. We captured 236 BP recordings, of which 39 (16.53%) were over 140/90 mmHg; of these, 5 were over 180/100 mmHg.
Conclusion:
The combined data showed that educating barbers to take BP readings and deliver healthcare advice about BP is a viable intervention for rollout in a large-scale study. It has demonstrated the need to identify strategies to motivate barbers for sustained recruitment and retention, as well as further efforts to build trust among customers for long-term BP surveillance
Enhancements of gravity wave amplitudes at midlatitudes during sudden stratospheric warmings in 2008
Timed Parity Games: Complexity and Robustness
We consider two-player games played in real time on game structures with
clocks where the objectives of players are described using parity conditions.
The games are \emph{concurrent} in that at each turn, both players
independently propose a time delay and an action, and the action with the
shorter delay is chosen. To prevent a player from winning by blocking time, we
restrict each player to play strategies that ensure that the player cannot be
responsible for causing a zeno run. First, we present an efficient reduction of
these games to \emph{turn-based} (i.e., not concurrent) \emph{finite-state}
(i.e., untimed) parity games. Our reduction improves the best known complexity
for solving timed parity games. Moreover, the rich class of algorithms for
classical parity games can now be applied to timed parity games. The states of
the resulting game are based on clock regions of the original game, and the
state space of the finite game is linear in the size of the region graph.
Second, we consider two restricted classes of strategies for the player that
represents the controller in a real-time synthesis problem, namely,
\emph{limit-robust} and \emph{bounded-robust} winning strategies. Using a
limit-robust winning strategy, the controller cannot choose an exact
real-valued time delay but must allow for some nonzero jitter in each of its
actions. If there is a given lower bound on the jitter, then the strategy is
bounded-robust winning. We show that exact strategies are more powerful than
limit-robust strategies, which are more powerful than bounded-robust winning
strategies for any bound. For both kinds of robust strategies, we present
efficient reductions to standard timed automaton games. These reductions
provide algorithms for the synthesis of robust real-time controllers
High prevalence of natural antibodies against Plasmodium falciparum 83-kilodalton apical membrane antigen (PF83/AMA-1) as detected by capture-enzyme-linked immunosorbent assay using full-length baculovirus recombinant PF83/AMA-1)
Novel Synthesis and High Pressure Behavior of Na0.3CoO2 x 1.3 H2O and Related Phases
We have prepared powder samples of NaxCoO2 x yH2O using a new synthesis
route. Superconductivity was observed in Na0.3CoO2 x 1.3H2O between 4 and 5K as
indicated by the magnetic susceptibility. The bulk compressibilities of
Na0.3CoO2 x 1.3H2O, Na0.3CoO2 x 0.6H2O and Na0.3CoO2 were determined using a
diamond anvil cell and synchrotron powder diffraction. Chemical changes
occurring under pressure when using different pressure transmitting media are
discussed and further transport measurements are advocated.Comment: 7 pages, 4 figures, PRrapid submitte
Assessing Student Participation at School: Developing a Multidimensional Scale
In the past few years there has been a growing interest in student participation at school, and in whether participation is connected with student wellbeing or with academic success. One problem when studying student participation is that it seems to mean different things to different people. For some people it is just about students attending school and going to lessons. For others it is about students making decisions about things that matter to them, or being part of “student voice” activities at school. Another problem is that we do not have good ways to measure how well schools are doing at student participation, with tools that take account of the different ways that students can participate. This article reports how a new tool has been created to measure student participation. The new tool is called the Student Participation Scale. It was created in New South Wales (NSW), Australia. The researchers read books and articles on student participation. They also talked to school staff and students to find out what student participation meant to them, and they asked them about what questions should go into the tool. Once they created the Student Participation Scale, the researchers tested it on 1,435 secondary school students. The Scale asks 38 questions to measure six types or “elements” of student participation:
Students working together with peers and school staff,
Students having a voice about schooling,
Students having a say with influential people at school,
Students having influence on decisions made at school,
Students having a voice about school activities outside of the classroom, and
Students having choice.
These elements of student participation were the same for boys and girls, for different grade or year groups, for students who spoke English as a second language, for students from an Indigenous background, and for students with a disability. The Scale was also consistent and valid. That is, it measured what the researchers said it would measure. The Student Participation Scale is easy and free for schools to use. It can be used to measure which elements of participation are happening most, and which ones schools might try to improve. There is also a guidebook that has instructions and tips for using the Scale in schools
The efficacy of recombinant thrombopoietin in murine and nonhuman primate models for radiation-induced myelosuppression and stem cell transplantation
Radiation-induced pancytopenia proved to be a suitable model system in
mice and rhesus monkeys for studying thrombopoietin (TPO) target cell
range and efficacy. TPO was highly effective in rhesus monkeys exposed to
the mid-lethal dose of 5 Gy (300 kV x-rays) TBI, a model in which it
alleviated thrombocytopenia, promoted red cell reconstitution, accelerated
reconstitution of immature CD34+ bone marrow cells, and potentiated the
response to growth factors such as GM-CSF and G-CSF. In contrast to the
results in the 5 Gy TBI model, TPO was ineffective following
transplantation of limited numbers of autologous bone marrow or highly
purified stem cells in monkeys conditioned with 8 Gy TBI. In the 5 Gy
model, a single dose of TPO augmented by GM-CSF 24 h after TBI was
effective in preventing thrombocytopenia. The strong erythropoietic
stimulation may result in iron depletion, and TPO treatment should be
accompanied by monitoring of iron status. This preclinical evaluation thus
identified TPO as a potential major therapeutic agent for counteracting
radiation-induced pancytopenia and demonstrated pronounced stimulatory
effects on the reconstitution of immature CD34+ hemopoietic cells with
multilineage potential. The latter observation explains the potentiation
of the hematopoietic responses to G-CSF and GM-CSF when administered
concomitantly. It also predicts the effective use of TPO to accelerate
reconstitution of immature hematopoietic cells as well as possible
synergistic effects in vivo with various other growth factors acting on
immature stem cells and their direct lineage-committed progeny. The
finding that a single dose of TPO might be sufficient for a clinically
significant response emphasizes its potency and is of practical relevance.
The heterogeneity of the TPO response encountered in the various models
used for evaluation points to multiple mechanisms operating on the TPO
response and heterogeneity of its target cells. Mechanistic mouse studies
made apparent that the response of multilineage cells shortly after TBI to
a single administration of TPO is quantitatively more important for
optimal efficacy than the lineage-restricted response obtained at later
intervals after TBI and emphasized the importance of a relatively high
dose of TPO to overcome initial c-mpl-mediated clearance. Further
elucidation of mechanisms determining efficacy might very well result in a
further improvement, e.g., following transplantation of limited numbers of
stem cells. Adverse effects of TPO administration to myelosuppressed or
stem cell transplanted experimental animals were not observed
Geologic mapping of the Urvara and Yalode Quadrangles of Ceres
We conducted geologic mapping of the Urvara (Ac-13) and Yalode (Ac-14) Quadrangles (21–66°S, 180–360°E) of the dwarf planet Ceres utilizing morphologic, topographic, and compositional information acquired by NASA's Dawn mission. The geologic characteristics of the two large impact basins Urvara (170 km diameter) and Yalode (260 km diameter) and their surroundings were investigated using Dawn Framing Camera datasets, including Survey (415 m/pixel), HAMO (140 m/pixel), and LAMO (35 m/pixel) images and mosaics, color and color ratio images, and DTMs derived from stereo-photogrammetry. Geologic mapping demonstrates that impact cratering has dominated the geologic history of the Urvara and Yalode Quadrangles, with early cratered terrain formation followed by formation of the large basins and widespread emplacement of basin-related smooth material. Impact craters display a wide range of preservation states from nearly completely buried/degraded forms to more recent pristine craters with terraced inner walls and lobate ejecta deposits. Cross-cutting relationships and morphologic signatures show that the Urvara impact followed the Yalode impact, consistent with ages derived from crater size-frequency distributions (580 ± 40 Ma for Yalode and 550 ± 50 Ma for Urvara). Observed differences in basin materials and rim morphology suggest heterogeneities in the substrate excavated by impact. Smooth deposits that cover large areas of the quadrangles, including the basin floors, rims, and exterior zones, are interpreted to be dominated by Urvara ejecta but Yalode ejecta and localized ice-rich flow material may be minor components. Geologic mapping results and simulations of ejecta emplacement suggest that Urvara and Yalode ejecta deposits extend for large distances (more than two crater diameters from the basin centers) and may serve as important stratigraphic markers for the geologic record of Ceres
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