670 research outputs found
Controls on continental shelf stratigraphy: Waiapu River, New Zealand
A quantitative understanding of the processes controlling sediment transport and deposition across the land/sea interface is crucial to linking terrestrial and marine environments and understanding the formation of marine stratigraphy. The nature and distribution of terrestrial-derived sediment preserved in shelf stratigraphy in turn provides insight into the complex linkages inherent in source-to-sink sediment dynamics. Located inboard of an actively subducting plate boundary and characterized by one of the highest sediment yields in the world, the open-shelf setting off of the Waiapu River in New Zealand presents an excellent location to improve our understanding of the factors controlling the formation of continental shelf stratigraphy and associated sediment transport. Over 850km of high-resolution seismic and swath bathymetry data ground-truthed by cores show significant stratigraphic spatial variation preserved on the Waiapu continental shelf. This spatial variation is likely controlled by regionally-specific sediment deposition and resuspension processes as well as antecedent geology. Chronostratigraphic control obtained from black carbon analysis reveals that deforestation of the Waiapu catchment is preserved as a distinct event in the adjacent inner shelf stratigraphy, and further indicates that the inner shelf is currently capturing a significant âŒ16-34% of the total Waiapu sediment budget. Shelf-wide stratigraphy shows that the thickest deposits of Holocene stratigraphy are found in tectonically-created accommodation spaces, highlighting the role of neotectonics in strata formation. The primary control on strata formation on the Waiapu continental shelf is presumed to be tectonically-steered, local sediment supply, which likely still influences modern-day sediment transport via the effects of small-scale bathymetric lows steering gravity-dependent sediment flows at the river mouth
Structure-stiffness relation of live mouse brain tissue determined by depth-controlled indentation mapping
The mechanical properties of brain tissue play a pivotal role in
neurodevelopment and neurological disorders. Yet, at present, there is no
consensus on how the different structural parts of the tissue contribute to its
stiffness variations. Here, we have gathered depth-controlled indentation
viscoelasticity maps of the hippocampus of isolated horizontal live mouse brain
sections. Our results confirm the highly viscoelestic nature of the material
and clearly show that the mechanical properties correlate with the different
morphological layers of the samples investigated. Interestingly, the relative
cell nuclei area seems to negatively correlate with the stiffness observed
Motor preparation of spatially and temporally defined movements: Evidence from startle
This article is available open access through the publisherâs website at the link below. Copyright © 2011 the American Physiological Society.Previous research has shown that the preparation of a spatially targeted movement performed at maximal speed is different from that of a temporally constrained movement (Gottlieb et al. 1989b). In the current study, we directly examined preparation differences in temporally vs. spatially defined movements through the use of a startling stimulus and manipulation of the task goals. Participants performed arm extension movements to one of three spatial targets (20°, 40°, 60°) and an arm extension movement of 20° at three movement speeds (slow, moderate, fast). All movements were performed in a blocked, simple reaction time paradigm, with trials involving a startling stimulus (124 dB) interspersed randomly with control trials. As predicted, spatial movements were modulated by agonist duration and timed movements were modulated by agonist rise time. The startling stimulus triggered all movements at short latencies with a compression of the kinematic and electromyogram (EMG) profile such that they were performed faster than control trials. However, temporally constrained movements showed a differential effect of movement compression on startle trials such that the slowest movement showed the greatest temporal compression. The startling stimulus also decreased the relative timing between EMG bursts more for the 20° movement when it was defined by a temporal rather than spatial goal, which we attributed to the disruption of an internal timekeeper for the timed movements. These results confirm that temporally defined movements were prepared in a different manner from spatially defined movements and provide new information pertaining to these preparation differences
Effects of strongly anisosmotic and NaCl deficient solutions on muscimol-and glutamate-evoked whole-cell currents in freshly dissociated hippocampal neurons
Supporting students with Tourette syndrome in secondary school: a survey of staff views
Tourette syndrome is a neurological condition involving involuntary movements and sounds (tics) and is thought to affect as many as 1% of school aged children. Some young people with Tourette syndrome experience educational difficulties and social difficulties. Current clinical guidelines suggest educators can play an important role in maximising learning potential and reducing the negative impact of this condition on studentsâ social adjustment. Secondary school staff (N = 63) with responsibilities for special educational needs or disabilities completed a survey about support strategies for students with Tourette syndrome. Participants were first asked to suggest potentially helpful strategies and then rated how easily 17 recommended strategies could be implemented in school. The survey participants suggested a range of support strategies that were categorised as (1) promoting knowledge and understanding in school, (2) helping the student to cope with his/her tics, (3) supporting the studentâs learning and (4) providing social and emotional support. All the recommended support strategies were rated as being easy to implement (or already in place) by the majority of respondents (e.g., increasing staff awareness and regular communication with home). The strategies that were identified as being least easy to implement were those requiring extra staff input (support from teaching assistants and individual/small group working). Additional challenges to providing support were also identified by the participants (e.g., getting input from outside agencies)
Systems approaches and algorithms for discovery of combinatorial therapies
Effective therapy of complex diseases requires control of highly non-linear
complex networks that remain incompletely characterized. In particular, drug
intervention can be seen as control of signaling in cellular networks.
Identification of control parameters presents an extreme challenge due to the
combinatorial explosion of control possibilities in combination therapy and to
the incomplete knowledge of the systems biology of cells. In this review paper
we describe the main current and proposed approaches to the design of
combinatorial therapies, including the empirical methods used now by clinicians
and alternative approaches suggested recently by several authors. New
approaches for designing combinations arising from systems biology are
described. We discuss in special detail the design of algorithms that identify
optimal control parameters in cellular networks based on a quantitative
characterization of control landscapes, maximizing utilization of incomplete
knowledge of the state and structure of intracellular networks. The use of new
technology for high-throughput measurements is key to these new approaches to
combination therapy and essential for the characterization of control
landscapes and implementation of the algorithms. Combinatorial optimization in
medical therapy is also compared with the combinatorial optimization of
engineering and materials science and similarities and differences are
delineated.Comment: 25 page
A varying threshold method for ChIP peak-calling using multiple sources of information
Motivation: Gene regulation commonly involves interaction among DNA, proteins and biochemical conditions. Using chromatin immunoprecipitation (ChIP) technologies, proteinâDNA interactions are routinely detected in the genome scale. Computational methods that detect weak protein-binding signals and simultaneously maintain a high specificity yet remain to be challenging. An attractive approach is to incorporate biologically relevant data, such as protein co-occupancy, to improve the power of protein-binding detection. We call the additional data related with the target protein binding as supporting tracks
Manufacture of functional surfaces through combined application of tool manufacturing processes and Robot Assisted Polishing
A sequence analysis of patterns in self-harm in young people with and without experience of being looked-after in care
Objectives: Young people in the public care system (âlooked-afterâ young people) have high levels of self-harm. Design: This paper reports the first detailed study of factors leading to self-harm over time in looked-after young people in England, using sequence analyses of the Card Sort Task for Self-harm (CaTS). Methods: Young people in care (looked-after group: n = 24; 14-21 years) and young people who had never been in care (contrast group: n = 21; 13-21 years) completed the CaTS, describing sequences of factors leading to their first and most recent episodes of self-harm. Lag sequential analysis determined patterns of significant transitions between factors (thoughts, feelings, behaviours, events) leading to self-harm across six months. Results: Young people in care reported feeling better immediately following their first episode of self-harm. However, fearlessness of death, impulsivity and access to means were reported most proximal to recent self-harm. Although difficult negative emotions were salient to self-harm sequences in both groups, young people with no experience of being in care reported a greater range of negative emotions and transitions between them. For the contrast group, feelings of depression and sadness were a significant starting point of the self-harm sequence six months prior to most recent self-harm. Conclusions: Sequences of factors leading to self-harm can change and evolve over time, so regular monitoring and assessment of each self-harm episode is needed. Support around easing and dealing with emotional distress is required. Restricting access to means to carry out potentially fatal self-harm attempts, particularly for the young persons with experience of being in care, is recommended
- âŠ