Bioprocesses

The application of remote sensing techniques to the study of eutrophication in natural waters and the location and characterization of fronts is considered. The specific problem to be studied is examined along with the feasibility and capabability of remote sensing techniques for each application

Acute Sensitivity of Landslide Rates to Initial Soil Porosity

Some landslides move imperceptibly downslope, whereas others accelerate catastrophically. Experimental landslides triggered by rising pore water pressure moved at sharply contrasting rates due to small differences in initial porosity. Wet sandy soil with porosity of about 0.5 contracted during slope failure, partially liquefied, and accelerated within 1 second to speeds over 1 meter per second. The same soil with porosity of about 0.4 dilated during failure and slipped episodically at rates averaging 0.002 meter per second. Repeated slip episodes were induced by gradually rising pore water pressure and were arrested by pore dilation and attendant pore pressure decline

Why tic severity changes from then to now and from here to there

Much of the research regarding Tourette\u27s syndrome (TS) has focused on why certain individuals develop tics while others do not. However, a separate line of research focuses on the momentary influences that cause tics to increase or decrease in patients who are already known to have TS or another chronic tic disorder (CTD). Environmental and internal variables such as fatigue, anxiety, and certain types of thoughts all have been shown to worsen tic severity and may even overcome the positive effects of treatment. Other influences such as stress, distraction, and being observed have had mixed effects in the various studies that have examined them. Still, other variables such as social media exposure and dietary habits have received only minimal research attention and would benefit from additional study. Understanding the impact of these environmental and internal influences provides an opportunity to improve behavioral treatments for TS/CTD and to improve the lives of those living with these conditions. This review will examine the current literature on how these moment-to-moment influences impact tic expression in those with TS/CTD

Gesture and speech in maternal input to children with Down's syndrome

Background: Despite recent interest in relationships between maternal gesture and speech and communicative development in typically developing (M) children, little work has examined either speech or gesture in mothers of children with Down's syndrome (DS). Aims: To compare aspects of speech and gesture production by mothers of children with DS with that of mothers of TD children. Methods & Procedures: Participants were five mothers of children with DS (mean chronological age (CA)=47.6 months; mean mental age (MA,)=22.4 months) and five mothers of TD children. To equate for expressive language ability, children in the TD and DS groups were individually matched on the basis of: (1) gender; (2) correspondence between the TD child's chronological age and the DS child's language age; and (3) observed expressive vocabulary size. Each mother-child dyad was videotaped for approximately 30 min during free play. Data analyses focused on: (1) the number and types (speech only, gesture only, mixed) of maternal utterances; (2) the gesture types (deictic, iconic, conventional, emphatic); and (3) for mixed utterances, the structure and the temporal patterning of spoken and gestured components. Outcomes & Results: Relative to mothers of TD children, mothers of children with DS produced significantly fewer utterances overall, but the distribution of utterance types did not differ between the two groups. Relative to mothers of TD children, mothers of children with DS used proportionately more deictic gestures and made more frequent use of SHOWING. Mothers of TD children produced more POINTING gestures. Finally, mothers of children with DS produced a significantly higher proportion of utterances consisting of a single gesture and a single verbal utterance; in contrast to mothers of TD children, more complex structures (one gesture with multiple verbal utterances, one verbal utterance with multiple gestures) were never observed. Within the category of utterances consisting of a gesture and a single verbal utterance, mothers of children with DS tended to produce gestures that were held throughout the complete verbal utterance, while the gestures of mothers of TD children tended to co-occur with only a portion of the utterance. Conclusions: The findings suggest that mothers of children with DS adjust their communication to the developmental status of their child. Results are discussed in terms of the role of gesture in maternal communication and in the regulation of mother-child interaction

Avalanche Dynamics in Wet Granular Materials

We have studied the dynamics of avalanching wet granular media in a rotating drum apparatus. Quantitative measurements of the flow velocity and the granular flux during avalanches allow us to characterize novel avalanche types unique to wet media. We also explore the details of viscoplastic flow (observed at the highest liquid contents) in which there are lasting contacts during flow, leading to coherence across the entire sample. This coherence leads to a velocity independent flow depth at high rotation rates and novel robust pattern formation in the granular surface.Comment: 5 pages, 3 figures in color, REVTeX4, for smaller pdfs see http://angel.elte.hu/~tegzes/condmat.htm

The Importance of the Northeastern Gulf of Mexico to Foraging Loggerhead Sea Turtles

Identification of high-use foraging sites where imperiled sea turtles are resident remains a globally-recognized conservation priority. In the biodiverse Gulf of Mexico (GoM), recent telemetry studies highlighted post-nesting foraging sites for federally threatened loggerhead turtles (Caretta caretta). Our aim here was to discern loggerhead use of additional northern GoM regions that may serve as high-use foraging sites. Thus, we used satellite tracking and switching state-space modeling to show that the Big Bend region off the northwest Florida coast is a coastal foraging area that supports imperiled adult female loggerhead turtles tracked from different nesting subpopulations. From 2011 to 2016, we satellite-tagged 15 loggerheads that nested on four distinct beaches around the GoM: Dry Tortugas National Park, FL; Everglades National Park, FL; St. Joseph Peninsula, FL; and Gulf Shores, AL. Turtles arrived at their foraging ground in the Big Bend region between June and September and remained resident in their respective foraging sites for an average of 198 tracking days, where they established mean home ranges (95% kernel density estimate) 232.7 km2. Larger home ranges were in deeper water; 50% kernel density estimate centroid values were a mean 26.4 m deep and 52.7 km from shore. The Big Bend region provides a wide area of suitable year-round foraging habitat for loggerheads from at least 3 different nesting subpopulations. Understanding where and when threatened loggerheads forage and remain resident is key for designing both surveys of foraging resources and additional protection strategies that can impact population recovery trajectories for this imperiled species

Soft-bed experiments beneath Engabreen, Norway: regelation infiltration, basal slip and bed deformation

To avoid some of the limitations of studying soft-bed processes through boreholes, a prism of simulated till (1.8 m × 1.6 m × 0.45 m) with extensive instrumentation was constructed in a trough blasted in the rock bed of Engabreen, a temperate glacier in Norway. Tunnels there provide access to the bed beneath 213 m of ice. Pore-water pressure was regulated in the prism by pumping water to it. During experiments lasting 7–12 days, the glacier regelated downward into the prism to depths of 50– 80 mm, accreting ice-infiltrated till at rates predicted by theory. During periods of sustained high pore water pressure (70–100% of overburden), ice commonly slipped over the prism, due to a water layer at the prism surface. Deformation of the prism was activated when this layer thinned to a sub-millimeter thickness. Shear strain in the till was pervasive and decreased with depth. A model of slip by ploughing of ice-infiltrated till across the prism surface accounts for the slip that occurred when effective pressure was sufficiently low or high. Slip at low effective pressures resulted from water-layer thickening that increased non-linearly with decreasing effective pressure. If sufficiently widespread, such slip over soft glacier beds, which involves no viscous deformation resistance, may instigate abrupt increases in glacier velocity

Editorial: Understanding Trajectories and Promoting Change From Early to Complex Skills in Typical and Atypical Development: A Cross-Population Approach

This Research Topic focuses on new research perspectives, methodologies, and protocols to understand trajectories and promote change in typical, at-risk, and atypical development. The interplay between early skills and the environment and the connections between theoretical and interventionmodels with an interdisciplinary, cross-domain and cross-population approach are addressed. These findings have important implications for clinicians and practitioners, who should take into account the specific characteristics of individual and interacting learning processes in planning interventions