Decay estimates for variable coefficient wave equations in exterior domains

In this article we consider variable coefficient, time dependent wave equations in exterior domains. We prove localized energy estimates if the domain is star-shaped and global in time Strichartz estimates if the domain is strictly convex.Comment: 15 pages. In the new version, some typos are fixed and a minor correction was made to the proof of Lemma 1

Ecological restoration alters nitrogen transformations in a ponderosa pine-bunchgrass ecosystem

Ponderosa pinebunchgrass ecosystems of the western United States were altered following Euro-American settlement as grazing and fire suppression facilitated pine invasion of grassy openings. Pine invasion changed stand structure and fire regimes, motivating restoration through forest thinning and prescribed burning. To determine effects of restoration on soil nitrogen (N) transformations, we replicated (0.25-ha plots) the following experimental restoration treatments within a ponderosa pinebunchgrass community near Flagstaff, Arizona: (1) partial restorationthinning to presettlement conditions, (2) complete restorationremoval of trees and forest floor to presettlement conditions, native grass litter addition, and a prescribed burn, and (3) control. Within treatments, we stratified sampling to assess effects of canopy cover on N transformations. Forest floor net N mineralization and nitrification were similar among treatments on an areal basis, but higher in restoration treatments on a mass basis. In the mineral soil (015 cm), restoration treatments had 23 times greater annual net N mineralization and 35 times greater annual net nitrification than the control. Gross N transformation measurements indicate that elevated net N mineralization may be due to increased gross N mineralization, while elevated net nitrification may be due to decreased microbial immobilization of nitrate. Net N transformation rates beneath relict grassy openings were twice those beneath postsettlement pines. These short-term (1 yr) results suggest that ecological restoration increases N transformation rates and that prescribed burning may not be necessary to restore N cycling processes

Stand-replacing wildfires increase nitrification for decades in southwestern ponderosa pine forests.

Stand-replacing wildfires are a novel disturbance within ponderosa pine (Pinus ponderosa) forests of the southwestern United States, and they can convert forests to grasslands or shrublands for decades. While most research shows that soil inorganic N pools and fluxes return to pre-fire levels within a few years, we wondered if vegetation conversion (ponderosa pine to bunchgrass) following stand-replacing fires might be accompanied by a long-term shift in N cycling processes. Using a 34-year stand-replacing wildfire chronosequence with paired, adjacent unburned patches, we examined the long-term dynamics of net and gross nitrogen (N) transformations. We hypothesized that N availability in burned patches would become more similar to those in unburned patches over time after fire as these areas become re-vegetated. Burned patches had higher net and gross nitrification rates than unburned patches (P < 0.01 for both), and nitrification accounted for a greater proportion of N mineralization in burned patches for both net (P < 0.01) and gross (P < 0.04) N transformation measurements. However, trends with time-after-fire were not observed for any other variables. Our findings contrast with previous work, which suggested that high nitrification rates are a short-term response to disturbance. Furthermore, high nitrification rates at our site were not simply correlated with the presence of herbaceous vegetation. Instead, we suggest that stand-replacing wildfire triggers a shift in N cycling that is maintained for at least three decades by various factors, including a shift from a woody to an herbaceous ecosystem and the presence of fire-deposited charcoal

Slow carbon and nutrient accumulation in trees established following fire exclusion in the southwestern United States.

Increasing tree density that followed fire exclusion after the 1880s in the southwestern United States may have also altered nutrient cycles and led to a carbon (C) sink that constitutes a significant component of the U.S. C budget. Yet, empirical data quantifying century-scale changes in C or nutrients due to fire exclusion are rare. We used tree-ring reconstructions of stand structure from five ponderosa pine-dominated sites from across northern Arizona to compare live tree C, nitrogen (N), and phosphorus (P) storage between the 1880s and 1990s. Live tree biomass in the 1990s contained up to three times more C, N, and P than in 1880s. However, the increase in C storage was smaller than values used in recent U.S. C budgets. Furthermore, trees that had established prior to the 1880s accounted for a large fraction (28-66%) of the C, N, and P stored in contemporary stands. Overall, our century-scale analysis revealed that forests of the 1880s were on a trajectory to accumulate C and nutrients in trees even in the absence of fire exclusion, either because growing conditions became more favorable after the 1880s or because forests in the 1880s included age or size cohorts poised for accelerated growth. These results may lead to a reduction in the C sink attributed to fire exclusion, and they refine our understanding of reference conditions for restoration management of fire-prone forests

Duration of Posttraumatic Amnesia Predicts Neuropsychological and Global Outcome in Complicated Mild Traumatic Brain Injury.

OBJECTIVES: Examine the effects of posttraumatic amnesia (PTA) duration on neuropsychological and global recovery from 1 to 6 months after complicated mild traumatic brain injury (cmTBI). PARTICIPANTS: A total of 330 persons with cmTBI defined as Glasgow Coma Scale score of 13 to 15 in emergency department, with well-defined abnormalities on neuroimaging. METHODS: Enrollment within 24 hours of injury with follow-up at 1, 3, and 6 months. MEASURES: Glasgow Outcome Scale-Extended, California Verbal Learning Test II, and Controlled Oral Word Association Test. Duration of PTA was retrospectively measured with structured interview at 30 days postinjury. RESULTS: Despite all having a Glasgow Coma Scale Score of 13 to 15, a quarter of the sample had a PTA duration of greater than 7 days; half had PTA duration of 1 of 7 days. Both cognitive performance and Extended Glasgow Outcome Scale outcomes were strongly associated with time since injury and PTA duration, with those with PTA duration of greater than 1 week showing residual moderate disability at 6-month assessment. CONCLUSIONS: Findings reinforce importance of careful measurement of duration of PTA to refine outcome prediction and allocation of resources to those with cmTBI. Future research would benefit from standardization in computed tomographic criteria and use of severity indices beyond Glasgow Coma Scale to characterize cmTBI

Directed secondary interactions in transition metal complexes of tripodal pyrrole imine and amide ligands

Tripodal pyrrole imine and amide ligands provide platforms for combined primary and secondary coordination sphere interactions in square planar Pd and Cu, and octahedral Ti complexes.</p

Initial carbon, nitrogen, and phosphorus fluxes following ponderosa pine restoration treatments

Southwestern ponderosa pine forests were dramatically altered by fire regime disruption that accompanied Euro-American settlement in the 1800s. Major changes include increased tree density, diminished herbaceous cover, and a shift from a frequent lowintensity fire regime to a stand-replacing fire regime. Ecological restoration via thinning and prescribed burning is being widely applied to return forests to the pre-settlement condition, but the effects of restoration on ecosystem function are unknown. We measured carbon (C), nitrogen (N), and phosphorus (P) fluxes during the first two years after the implementation of a replicated field experiment comparing thinning and composite (thinning, forest floor fuel reduction, and prescribed burning) restoration treatments to untreated controls in a ponderosa pine forest in northern Arizona, USA. Total net primary productivity (260 g Cm22yr21) was similar among treatments because a 3050(percent) decrease in pine foliage and fine-root production in restored ecosystems was balanced by greater wood, coarse root, and herbaceous production. Herbaceous plants accounted for ,20(percent) of total plant C, N, and P uptake in the controls but from 25(percent) to 70(percent) in restored plots. Total plant N uptake was ;3 g Nm22yr21 in all treatments, but net N mineralization was just one-half and twothirds of this value in the control and composite restoration, respectively. Element flux rates in controls generally declined more in a drought year than rates in restoration treatments. In this ponderosa pine forest, ecological restoration that emulated pre-settlement stand structure and fire characteristics had a small effect on plant C, N, and P fluxes at the whole ecosystem level because lower pine foliage and fine-root fluxes in treated plots (compared to controls) were approximately balanced by higher fluxes in wood and herbaceous plants

Ecological and Genomic Attributes of Novel Bacterial Taxa That Thrive in Subsurface Soil Horizons.

While most bacterial and archaeal taxa living in surface soils remain undescribed, this problem is exacerbated in deeper soils, owing to the unique oligotrophic conditions found in the subsurface. Additionally, previous studies of soil microbiomes have focused almost exclusively on surface soils, even though the microbes living in deeper soils also play critical roles in a wide range of biogeochemical processes. We examined soils collected from 20 distinct profiles across the United States to characterize the bacterial and archaeal communities that live in subsurface soils and to determine whether there are consistent changes in soil microbial communities with depth across a wide range of soil and environmental conditions. We found that bacterial and archaeal diversity generally decreased with depth, as did the degree of similarity of microbial communities to those found in surface horizons. We observed five phyla that consistently increased in relative abundance with depth across our soil profiles: Chloroflexi, Nitrospirae, Euryarchaeota, and candidate phyla GAL15 and Dormibacteraeota (formerly AD3). Leveraging the unusually high abundance of Dormibacteraeota at depth, we assembled genomes representative of this candidate phylum and identified traits that are likely to be beneficial in low-nutrient environments, including the synthesis and storage of carbohydrates, the potential to use carbon monoxide (CO) as a supplemental energy source, and the ability to form spores. Together these attributes likely allow members of the candidate phylum Dormibacteraeota to flourish in deeper soils and provide insight into the survival and growth strategies employed by the microbes that thrive in oligotrophic soil environments.IMPORTANCE Soil profiles are rarely homogeneous. Resource availability and microbial abundances typically decrease with soil depth, but microbes found in deeper horizons are still important components of terrestrial ecosystems. By studying 20 soil profiles across the United States, we documented consistent changes in soil bacterial and archaeal communities with depth. Deeper soils harbored communities distinct from those of the more commonly studied surface horizons. Most notably, we found that the candidate phylum Dormibacteraeota (formerly AD3) was often dominant in subsurface soils, and we used genomes from uncultivated members of this group to identify why these taxa are able to thrive in such resource-limited environments. Simply digging deeper into soil can reveal a surprising number of novel microbes with unique adaptations to oligotrophic subsurface conditions

IPR Policy Brief - Protecting Palestinian children from political violence

Violence has shaped the setting in which successive generations of children living in the occupied territories of Gaza, the West Bank and East Jerusalem, have grown up. Although numerous UN and international non-governmental agencies have worked for many years with the aim of protecting children from this violence and realising their basic human rights, the limits of their capacity to achieve this aim have been all too apparent.Research conducted by Dr Jason Hart (University of Bath) and Claudia Lo Forte (Independent Researcher), has explored and identified the reasons for the failures of these organisations. They argue that international agencies and their donors have been constrained in their ability to properly protect Palestinian children because of serious flaws in their understanding of and willingness to address the political situation in the occupied Palestinian territory (oPt).As a result of the tendency to deal with the effects rather than the causes of the suffering of children, efforts remain technocratic and ameliorative (aimed at increasing the capacity of Palestinian families to cope better and longer with Israeli violations), rather than principled and preventative. The research recommends that international agencies and their donors engage in, and are judged against, a concerted and multi-level solution rooted in the realisation of human rights and child protection principles

Learning Intentions, Success Criteria, and Metacognition: The Influence of a Professional Development for Grades Three to Five Teachers

Formative assessment is a strategy that teachers use to improve student learning. This study explored how professional development focused on assessment for learning practices (AFL), with the main emphasis on learning intentions and success criteria, influences teacher use of those strategies and changes in teacher and student metacognition. The overarching research question was: How does professional development on AFL practices influence teachers\u27 reported use of AFL practices and teacher and student metacognition? This study utilized a mixes-methods research design and provided professional development on AFL practices to 16 in-service elementary mathematics teachers and measured changes to their AFL practices and metacognition using two surveys: the AfLMi for AFL and the MAIT for metacognition. Five teachers were selected to participate in a case study to explore how they understood their professional development on AFL strategies using semi-structured interviews. Ten students were interviewed to triangulate the findings. The results found that the teacher\u27s AfLMi scores showed a statistically significant decrease, and the MAIT scores saw a non-statistically significant increase. The teacher and student interviews indicated that the teachers did not reduce their use of formative assessment practices but did change their perspective of why they used them. Teachers and students identified multiple effective practices with formative assessment and noted novel approaches in regard to formative assessment practices. Teacher interviews demonstrated teachers showing a change in what they were metacognitive about. Students also showed some increase in their metacognition, becoming more aware of their teacher\u27s formative assessment practices