383 research outputs found
Anterior Thalamic High Frequency Band Activity Is Coupled with Theta Oscillations at Rest
Cross-frequency coupling (CFC) between slow and fast brain rhythms, in the form of phaseâamplitude coupling (PAC), is proposed to enable the coordination of neural oscillatory activity required for cognitive processing. PAC has been identified in the neocortex and mesial temporal regions, varying according to the cognitive task being performed and also at rest. PAC has also been observed in the anterior thalamic nucleus (ATN) during memory processing. The thalamus is active during the resting state and has been proposed to be involved in switching between task-free cognitive states such as rest, in which attention is internally-focused, and externally-focused cognitive states, in which an individual engages with environmental stimuli. It is unknown whether PAC is an ongoing phenomenon during the resting state in the ATN, which is modulated during different cognitive states, or whether it only arises during the performance of specific tasks. We analyzed electrophysiological recordings of ATN activity during rest from seven patients who received thalamic electrodes implanted for treatment of pharmacoresistant focal epilepsy. PAC was identified between theta (4â6 Hz) phase and high frequency band (80â150 Hz) amplitude during rest in all seven patients, which diminished during engagement in tasks involving an external focus of attention. The findings are consistent with the proposal that thetaâgamma coupling in the ATN is an ongoing phenomenon, which is modulated by task performance
POTs: Protective Optimization Technologies
Algorithmic fairness aims to address the economic, moral, social, and
political impact that digital systems have on populations through solutions
that can be applied by service providers. Fairness frameworks do so, in part,
by mapping these problems to a narrow definition and assuming the service
providers can be trusted to deploy countermeasures. Not surprisingly, these
decisions limit fairness frameworks' ability to capture a variety of harms
caused by systems.
We characterize fairness limitations using concepts from requirements
engineering and from social sciences. We show that the focus on algorithms'
inputs and outputs misses harms that arise from systems interacting with the
world; that the focus on bias and discrimination omits broader harms on
populations and their environments; and that relying on service providers
excludes scenarios where they are not cooperative or intentionally adversarial.
We propose Protective Optimization Technologies (POTs). POTs provide means
for affected parties to address the negative impacts of systems in the
environment, expanding avenues for political contestation. POTs intervene from
outside the system, do not require service providers to cooperate, and can
serve to correct, shift, or expose harms that systems impose on populations and
their environments. We illustrate the potential and limitations of POTs in two
case studies: countering road congestion caused by traffic-beating
applications, and recalibrating credit scoring for loan applicants.Comment: Appears in Conference on Fairness, Accountability, and Transparency
(FAT* 2020). Bogdan Kulynych and Rebekah Overdorf contributed equally to this
work. Version v1/v2 by Seda G\"urses, Rebekah Overdorf, and Ero Balsa was
presented at HotPETS 2018 and at PiMLAI 201
Identification of Altered Evoked and Non-Evoked Responses in a Heterologous Mouse Model of Endometriosis-Associated Pain
The aim of this study was to develop and refine a heterologous mouse model of endometriosis-associated pain in which non-evoked responses, more relevant to the patient experience, were evaluated. Immunodeficient female mice (N = 24) were each implanted with four endometriotic human lesions (N = 12) or control tissue fat (N = 12) on the abdominal wall using tissue glue. Evoked pain responses were measured biweekly using von Frey filaments. Non-evoked responses were recorded weekly for 8 weeks using a home cage analysis (HCA). Endpoints were distance traveled, social proximity, time spent in the center vs. outer areas of the cage, drinking, and climbing. Significant differences between groups for von Frey response, climbing, and drinking were detected on days 14, 21, and 35 post implanting surgery, respectively, and sustained for the duration of the experiment. In conclusion, a heterologous mouse model of endometriosis-associated evoked a non-evoked pain was developed to improve the relevance of preclinical models to patient experience as a platform for drug testing
Structural shifts of aldehyde dehydrogenase enzymes were instrumental for the early evolution of retinoiddependent axial patterning in metazoans
Aldehyde dehydrogenases (ALDHs) catabolize toxic aldehydes and process the vitamin A-derived retinaldehyde into retinoic acid (RA), a small diffusible molecule and a pivotal chordate morphogen. In this study, we combine phylogenetic, structural, genomic, and developmental gene expression analyses to examine the evolutionary origins of ALDH substrate preference. Structural modeling reveals that processing of small aldehydes, such as acetaldehyde, by ALDH2, versus large aldehydes, including retinaldehyde, by ALDH1A is associated with small versus large substrate entry channels (SECs), respectively. Moreover, we show that metazoan ALDH1s and ALDH2s are members of a single ALDH1/2 clade and that during evolution, eukaryote ALDH1/2s often switched between large and small SECs after gene duplication, transforming constricted channels into wide opened ones and vice versa. Ancestral sequence reconstructions suggest that during the evolutionary emergence of RA signaling, the ancestral, narrow-channeled metazoan ALDH1/2 gave rise to large ALDH1 channels capable of accommodating bulky aldehydes, such as retinaldehyde, supporting the view that retinoid-dependent signaling arose from ancestral cellular detoxification mechanisms. Our analyses also indicate that, on a more restricted evolutionary scale, ALDH1 duplicates from invertebrate chordates (amphioxus and ascidian tunicates) underwent switches to smaller and narrower SECs. When combined with alterations in gene expression, these switches led to neofunctionalization from ALDH1-like roles in embryonic patterning to systemic, ALDH2-like roles, suggesting functional shifts from signaling to detoxification
Preclinical models of endometriosis and interstitial cystitis/bladder pain syndrome: an Innovative Medicines Initiative-PainCare initiative to improve their value for translational research in pelvic pain
Classification of patients with sepsis according to blood genomic endotype: a prospective cohort study
Center for Translational Molecular Medicine, Netherlands
parkin-induced defects in neurophysiology and locomotion are generated by metabolic dysfunction and not oxidative stress
Parkinson's disease (PD) is characterized by movement disorders, including bradykinesia. Analysis of inherited, juvenile PD, identified several genes linked via a common pathway to mitochondrial dysfunction. In this study, we demonstrate that the larva of the Drosophila parkin mutant faithfully models the locomotory and metabolic defects of PD and is an excellent system for investigating their inter-relationship. parkin larvae displayed a marked bradykinesia that was caused by a reduction in both the frequency of peristalsis and speed of muscle contractions. Rescue experiments confirmed that this phenotype was due to a defect in the nervous system and not in the muscle. Furthermore, recordings of motoneuron activity in parkin larvae revealed reduced bursting and a striking reduction in evoked and miniature excitatory junction potentials, suggesting a neuronal deficit. This was supported by our observations in parkin larvae that the resting potential was depolarized, oxygen consumption and ATP concentration were drastically reduced while lactate was increased. These findings suggest that neuronal mitochondrial respiration is severely compromised and there is a compensatory switch to glycolysis for energy production
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
An ethnographic study of knowledge sharing across the boundaries between care processes, services and organisations: the contributions to âsafeâ hospital discharge
Background
Hospital discharge is a vulnerable stage in the patient pathway. Research highlights communication failures and the problems of co-ordination as resulting in delayed, poorly timed and unsafe discharges. The complexity of hospital discharge exemplifies the threats to patient safety found âbetweenâ care processes and organisations. In developing this perspective, safe discharge is seen as relying upon enhanced knowledge sharing and collaboration between stakeholders, which can mitigate system complexity and promote safety.
Aim
To identify interventions and practices that support knowledge sharing and collaboration in the processes of discharge planning and care transition.
Setting
The study was undertaken between 2011 and 2013 in two English health-care systems, each comprising an acute health-care provider, community and primary care providers, local authority social services and social care agencies. The study sites were selected to reflect known variations in local population demographics as well as in the size and composition of the care systems. The study compared the experiences of stroke and hip fracture patients as exemplars of acute care with complex discharge pathways.
Design
The study involved in-depth ethnographic research in the two sites. This combined (a) over 180 hours of observations of discharge processes and knowledge-sharing activities in various care settings; (b) focused âpatient trackingâ to trace and understand discharge activities across the entire patient journey; and (c) qualitative interviews with 169 individuals working in health, social and voluntary care sectors.
Findings
The study reinforces the view of hospital discharge as a complex system involving dynamic and multidirectional patterns of knowledge sharing between multiple groups. The study shows that discharge planning and care transitions develop through a series of linked âsituationsâ or opportunities for knowledge sharing. It also shows variations in these situations, in terms of the range of actors, forms of knowledge shared, and media and resources used, and the wider culture and organisation of discharge. The study also describes the threats to patient safety associated with hospital discharge, as perceived by participants and stakeholders. These related to falls, medicines, infection, clinical procedures, equipment, timing and scheduling of discharge, and communication. Each of these identified risks are analysed and explained with reference to the observed patterns of knowledge sharing to elaborate how variations in knowledge sharing can hinder or promote safe discharge.
Conclusions
The study supports the view of hospital discharge as a complex system involving tightly coupled and interdependent patterns of interaction between multiple health and social care agencies. Knowledge sharing can help to mitigate system complexity through supporting collaboration and co-ordination. The study suggests four areas of change that might enhance knowledge sharing, reduce system complexity and promote safety. First, knowledge brokers in the form of discharge co-ordinators can facilitate knowledge sharing and co-ordination; second, colocation and functional proximity of stakeholders can support knowledge sharing and mutual appreciation and alignment of divergent practices; third, local cultures should prioritise and value collaboration; and finally, organisational resources, procedures and leadership should be aligned to fostering knowledge sharing and collaborative working. These learning points provide insight for future interventions to enhance discharge planning and care transition. Future research might consider the implementation of interviews to mediate system complexity through fostering enhanced knowledge sharing across occupational and organisational boundaries. Research might also consider in more detail the underlying complexity of both health and social care systems and how opportunities for knowledge sharing might be engendered to promote patient safety in other areas
Exposure to p,pâČ-DDE: A Risk Factor for Type 2 Diabetes
BACKGROUND: Persistent organic pollutants (POPs), such as PCBs, DDT and dioxins have in several cross-sectional studies shown strong associations with type 2 diabetes mellitus. Reversed causality can however not be excluded. The aim of this case-control study was to evaluate whether POPs concentration is a risk factor for type 2 diabetes. METHODOLOGY/PRINCIPAL FINDINGS: A case-control study was performed within a well-defined cohort of women, age 50-59 years, from the Southern part of Sweden. Biomarkers for POP exposure, 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) and 1,1-dichloro-2,2-bis (p-chlorophenyl)-ethylene (p,p'-DDE) were analyzed in stored serum samples, which were collected at the baseline examination when the cohort was established. For 107 out of the 371 cases, serum samples were stored at least three years before their type 2 diabetes was diagnosed. In this data set, CB-153 and p,p'-DDE were not associated with an increased risk to develop type 2 diabetes. However, when only the cases (n = 39) that were diagnosed more than six years after the baseline examination and their controls were studied, the women in the highest exposed quartile showed an increased risk to develop type 2 diabetes (OR of 1.6 [95% 0.61, 4.0] for CB-153 and 5.5 [95% CI 1.2, 25] for p,p'-DDE). CONCLUSIONS/SIGNIFICANCE: The results from the present case-control study, including a follow-up design, confirms that p,p'-DDE exposure can be a risk factor for type 2 diabetes
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