1,132 research outputs found
An analysis of MRI derived cortical complexity in premature-born adults : regional patterns, risk factors, and potential significance
Premature birth bears an increased risk for aberrant brain development concerning its structure and function. Cortical complexity (CC) expresses the fractal dimension of the brain surface and changes during neurodevelopment. We hypothesized that CC is altered after premature birth and associated with long-term cognitive development.
One-hundred-and-one very premature-born adults (gestational age <32 weeks and/or birth weight <1500 g) and 111 term-born adults were assessed by structural MRI and cognitive testing at 26 years of age. CC was measured based on MRI by vertex-wise estimation of fractal dimension. Cognitive performance was measured based on Griffiths-Mental-Development-Scale (at 20 months) and Wechsler-Adult-Intelligence-Scales (at 26 years).
In premature-born adults, CC was decreased bilaterally in large lateral temporal and medial parietal clusters. Decreased CC was associated with lower gestational age and birth weight. Furthermore, decreased CC in the medial parietal cortices was linked with reduced full-scale IQ of premature-born adults and mediated the association between cognitive development at 20 months and IQ in adulthood.
Results demonstrate that CC is reduced in very premature-born adults in temporoparietal cortices, mediating the impact of prematurity on impaired cognitive development. These data indicate functionally relevant long-term alterations in the brain’s basic geometry of cortical organization in prematurity
Recommended from our members
Individual Differences in Reinforcement Learning: Behavioral, Electrophysiological, and Neuroimaging Correlates
During reinforcement learning, phasic modulations of activity in midbrain dopamine neurons are conveyed to the dorsal anterior cingulate Cortex (dACC) and basal ganglia (BG) and serve to guide adaptive responding. While the animal literature supports a role for the dACC in integrating reward history over time, most human electrophysiological Studies of dACC function have focused on responses to single positive and negative outcomes. The present electrophysiological study investigated the role of the dACC in probabilistic reward learning in healthy subjects using a task that required integration of reinforcement history over time. We recorded the feedback-related negativity (FRN) to reward feedback in subjects who developed a response bias toward a more frequently rewarded ("rich") stimulus ("learners") versus subjects who did not ("non-learners"). Compared to non-learners, learners showed more positive (i.e., smaller) FRNs and greater dACC activation upon receiving reward for correct identification of the rich stimulus. In addition, dACC activation and a bias to select the rich Stimulus were positively correlated. The same participants also completed a monetary incentive delay (MID) task administered during functional magnetic resonance imaging. Compared to non-learners, learners displayed stronger BG responses to reward in the MID task. These findings raise the possibility that learners in the probabilistic reinforcement task were characterized by stronger dACC and BG responses to rewarding outcomes. Furthermore, these results highlight the importance of the dACC to probabilistic reward learning in humans.Psycholog
Which Factors Influence the Adoption of Social Software? An Exploratory Study of Indian Information Technology Consultancy Firms
Kinked silicon nanowires-enabled interweaving electrode configuration for lithium-ion batteries
A tri-dimensional interweaving kinked silicon nanowires (k-SiNWs) assembly, with a Ni current collector co-integrated, is evaluated as electrode configuration for lithium ion batteries. The large-scale fabrication of k-SiNWs is based on a procedure for continuous metal assisted chemical etching of Si, supported by a chemical peeling step that enables the reuse of the Si substrate. The kinks are triggered by a simple, repetitive etch-quench sequence in a HF and H2O2-based etchant. We find that the inter-locking frameworks of k-SiNWs and multi-walled carbon nanotubes exhibit beneficial mechanical properties with a foam-like behavior amplified by the kinks and a suitable porosity for a minimal electrode deformation upon Li insertion. In addition, ionic liquid electrolyte systems associated with the integrated Ni current collector repress the detrimental effects related to the Si-Li alloying reaction, enabling high cycling stability with 80% capacity retention (1695 mAh/gSi) after 100 cycles. Areal capacities of 2.42 mAh/cm2 (1276 mAh/gelectrode) can be achieved at the maximum evaluated thickness (corresponding to 1.3 mgSi/cm2). This work emphasizes the versatility of the metal assisted chemical etching for the synthesis of advanced Si nanostructures for high performance lithium ion battery electrodes
Microfluidic Device for Continuous Magnetophoretic Separation of Red Blood Cells
This paper presents a microfluidic device for magnetophoretic separation red
blood cells from blood under contionous flow. The separation method consist of
continous flow of a blood sample (diluted in PBS) through a microfluidic
channel which presents on the bottom "dots" of feromagnetic layer. By appling a
magnetic field perpendicular on the flowing direction, the feromagnetic "dots"
generates a gradient of magnetic field which amplifies the magnetic force. As a
result, the red blood cells are captured on the bottom of the microfluidic
channel while the rest of the blood is collected at the outlet. Experimental
results show that an average of 95 % of red blood cells are trapped in the
deviceComment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/handle/2042/16838
F-Theory GUT Vacua on Compact Calabi-Yau Fourfolds
We present compact three-generation F-theory GUT models meeting in particular
the constraints of D3-tadpole cancellation and D-term supersymmetry. To this
end we explicitly construct elliptically fibered Calabi-Yau fourfolds as
complete intersections in a toric ambient space. Toric methods enable us to
control the singular geometry of the SU(5) GUT model. The GUT brane wraps a
non-generic del Pezzo surface admitting GUT symmetry breaking via hypercharge
flux. It is contractible to a curve and we demonstrate the existence of a
consistent decoupling limit. We compute the Euler characteristic of the
singular Calabi-Yau fourfold to show that our three-generation flux solutions
obtained via the spectral cover construction are consistent with D3-tadpole
cancellation.Comment: 22+12 pages; v2: minor clarifications on decoupling limi
Use of a standardized education tool to increase patient selection of highly effective contraception
Purpose: The purpose of this project was to increase patient acceptance of LARC through the use of a standardized educational tool that has been demonstrated to be effective in assisting women to make informed decisions when choosing from among the most reliable and effective contraception methods available to them.
Summary: The Centers for Disease Control and Prevention recommend that all women use highly effective contraceptive methods, such as LARC to reduce unintended pregnancy. Research has demonstrated that standardized approaches to counseling are the most effective at increasing LARC use. In a small, private OB-GYN practice with one physician and two women\u27s health nurse practitioners, contraception counseling was not standardized and the selection of LARC was low among clients enrolled in the state Medicaid health insurance program. Providers and staff participated in a one hour in-service that included information about LARC and the benefits of standardized patient education for contraception. Patients of the practice that were enrolled in the state Medicaid health insurance program and expressed interest in changing or initiating contraception were invited to participate in the project. After obtaining consent, the participants were counseled about contraceptive methods using a standardized script tested in the Contraceptive CHOICE project. Chart reviews were completed, comparing patients\u27 contraceptive choices pre and post intervention
Outcomes: In the EBP project, 80% of participants chose LARC - a key comparison point with the CHOICE study where 75% chose LARC. Ethnicity was similar between the 2 studies. EBP project participants were older than CHOICE participants and were \u3e 50% more likely to be parous. Frequency of LARC uptake in pre and post-intervention chart reviews was analyzed and compared between those patients on AHCCCS, (Arizona\u27s Medicaid program) who received contraceptive counseling and chose LARC using the standardized education script with those patients on other insurance plans to identify any biases that could have impacted our data, such as the total number of patient visits or percentage of patients on AHCCCS that visited the clinic before and during the study time frame. The pre- and post- intervention groups were comparable so we don\u27t believe that selection bias or patient visit volume impacted the project outcomes.
Implications for Women\u27s Health: Unintended pregnancy is associated with adverse effects for women and children. Increasing the use of highly effective contraceptives such as LARC is recommended for women as the most effective means of reducing unintended pregnancies. Offering women complete and accurate information about the most effective and reliable contraceptive methods is a critical first step to assisting women to carry out their reproductive life plans. Nurse Practitioners who provide primary care and women\u27s health care to women of childbearing age may find standardized contraception education tools helpful when collaborating with patients to help them make the best choices for themselves and their families
Energy-efficient scheduling of flexible flow shop of composite recycling
Composite recycling technologies have been developed to tackle the increasing use of composites in industry and as a result of restrictions placed on landfill disposal. Mechanical, thermal and chemical approaches are the existing main recycling techniques to recover the fibres. Some optimisation work for reducing energy consumed by above processes has also been developed. However, the resource efficiency of recycling composites at the workshop level has never been considered before. Considering the current trend of designing and optimising a system in parallel and the future needs of the composite recycling business, a flexible flow shop for carbon fibre reinforced composite recycling is modelled. Optimisation approaches based on non-dominated sorting genetic algorithm II (NSGA-II) have been developed to reduce the time and energy consumed for processing composite wastes by searching for the optimal sub-lot splitting and resource scheduling plans. Case studies on different composite recycling scenarios have been conducted to prove the feasibility of the model and the developed algorithm
Infant regulatory problems, parenting quality and childhood attention problems
Background and aims
To determine the combined impact of infant multiple/persistent regulatory problems (RPs), parenting quality and maternal mental health on childhood attention problems.
Study design
A prospective, population-based cohort study including 16 paediatric hospitals in Southern Bavaria (Germany).
Subjects
1459 infants were followed from birth to 8 years of age.
Outcome measures
RPs were assessed at 5 and 20 months using interviews by trained paediatricians; parenting quality was assessed between birth and 5 months using parent interviews and nurses' observations; maternal mental health was assessed at birth and 5 months using standardized parents' interviews; childhood data on attention problems were collected at 8 years, using parent reports and expert behaviour observation ratings.
Results
After correction for gestational age, sex, and socioeconomic status, early RPs (β = 0.079) and low parenting quality (β = 0.175) predicted later attention problems (R2 = 0.272). Their impact was additive, such that infants with both multiple/persistent RPs and poor parenting quality showed the highest attention problems 8 years later. However, the impact of RPs on attention was strongest for preterm children. Maternal mental health was a significant moderator of the relationship between parenting quality and attention problems. With adequate maternal mental health, good parenting quality was related to lower attention problems, yet with mental health problems present, the effect of good parenting on attention problems diminished.
Conclusions
Guidance and support for parents of infants with multiple/persistent crying, sleeping or feeding problems may be essential to prevent the development of childhood attention problems, especially when maternal mental health problems are present
Recommended from our members
Reduced Caudate and Nucleus Accumbens Response to Rewards in Unmedicated Subjects with Major Depressive Disorder
Objective: Major depressive disorder is characterized by impaired reward processing, possibly due to dysfunction in the basal ganglia. However, few neuroimaging studies of depression have distinguished between anticipatory and consummatory phases of reward processing. Using functional MRI (fMRI) and a task that dissociates anticipatory and consummatory phases of reward processing, the authors tested the hypothesis that individuals with major depression would show reduced reward-related responses in basal ganglia structures. Method: A monetary incentive delay task was presented to 30 unmedicated individuals with major depressive disorder and 31 healthy comparison subjects during fMRI scanning. Whole-brain analyses focused on neural responses to reward-predicting cues and rewarding outcomes (i.e., monetary gains). Secondary analyses focused on the relationship between anhedonic symptoms and basal ganglia volumes. Results: Relative to comparison subjects, participants with major depression showed significantly weaker responses to gains in the left nucleus accumbens and the caudate bilaterally. Group differences in these regions were specific to rewarding outcomes and did not generalize to neutral or negative outcomes, although relatively reduced responses to monetary penalties in the major depression group emerged in other caudate regions. By contrast, evidence for group differences during reward anticipation was weaker, although participants with major depression showed reduced activation to reward cues in a small sector of the left posterior putamen. In the major depression group, anhedonic symptoms and depression severity were associated with reduced caudate volume bilaterally. Conclusions: These results suggest that basal ganglia dysfunction in major depression may affect the consummatory phase of reward processing. Additionally, morphometric results suggest that anhedonia in major depression is related to caudate volume.Psycholog
- …
