Low Mortality in Tall Tropical Trees

The dynamics of the tallest trees in tropical forests are of special interest due to their carbon content, canopy dominance, and the large canopy gaps created when they die. Known ecological mechanisms that may influence tall tree survival lead to conflicting predictions. Hydraulic stress and exposure to high winds and desiccation should increase death rates, yet the tallest trees have the greatest access to light and escape damage caused by falling boles and branches. The uncertainty in tall tree mortality rates has been difficult to address due to their low density, which makes mortality rates challenging to estimate accurately. Here, we use a combination of LiDAR remote sensing and field measurements to show that the mortality rate over 8.5 years among individuals \u3e40 m tall in 444 ha of lowland Neotropical rain forest was 1.2% per year, less than half the landscape-scale average for all canopy trees (2.7% per year). The low mortality is likely explained by species-specific traits that decrease the mortality risk and/or ecological advantages of height that outweigh the risks. Regardless of the mechanisms, the low mortality rate has important implications for tropical forest carbon budgets, as we estimated that a single tall individual represents 2–11% of total live aboveground carbon stocks per hectare. Our findings suggest that height-specific dynamics may be surprisingly different from traditional diameter-specific dynamics, emphasizing the importance of extending ecological studies to investigate the role of tree height in forest dynamics

Linking Human Health to Biological Diversity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74648/1/j.1523-1739.1997.0110061459.x.pd

Análise dinâmica de sistemas de colheita e manuseio de biomassa para utilização como fonte de energia.

Desenvolveu-se um modelo matematico, em SLAM II, para simular colheita e transporte de palhada de milho, feno e cavacos de madeira para abastecer continuamente uma unidade de processamento de biomassa. Usaram-se dez anos de dados climatologicos e de producao do estado de Indiana, EUA, para quantificar o efeito do clima no desempenho do sistema, que foi analisado em diferentes situacoes. O clima mostrou ser variavel importante, especialmente na colheita de palhada de milho e feno. Houve casos em que foi preferivel alugar equipamento do que comprar, para diminuir custos de producao. Foram produzidas, em media, 3,3 t/ha e 1,9 t/ha de palhada de milho e feno, respectivamente. Cavacos de madeira vindos de corte de florestas naturais totalizaram 86 t/ha, de desbaste, 53 t/ha, e de plantacoes, 40 t/ha (100, 20 e 5 anos de rotacao respectivamente). Em ano de condicoes climatologicas medias, colheita e transporte de palhada de milho (fardos cilindricos) custaram 71% mais caro que de cavacos de madeira (corte de florestas naturais). Fardos retangulares e cilindricos equivaleram-se em custos de producao, mas transportar os cilindricos custou 55% a mais. Custos para produzir e transportar cavacos mostraram-se cerca de duas vezes maiores em florestas naturais, quando comparados com corte de plantacoes de arvores

Scavenging amphipods from the Wallaby-Zenith Fracture Zone : Extending the hadal paradigm beyond subduction trenches

Acknowledgements We would like to thank Nick Cuomo for assis- tance with lander deployments, Prof Darren Evans and Dr James Kitson (Newcastle University, UK) for bench space in the Molecular Diagno- sis Facility, Ed Hendrycks (Canadian Museum of Nature, Canada) for guidance on the Cleonardo sp. identification, and Dr Shannon Flynn (Newcastle University, UK) for constructive comments on manuscript drafts. We extend thanks to the Captain and crew on the 2017 R/V SONNE Expedition SO258 Leg 1, especially joint Chief Scientists Dr Reinhard Werner (GEOMAR, Germany) and Prof Hans-Joachim Wagner (University of Tübingen, Germany) and Oleg Lechenko and Julia Marinova (P.P. Shirshov Institute of Oceanology of the Russian Academy of Sciences, Russia) for the acquisition and processing of the bathymetric data. We are appreciative of the reviewers for their constructive comments and suggestions that improved the manuscript. Funding Participation on the R/V SONNE Expedition SO258 was sup- ported by Newcastle University’s Research Infrastructure Fund (RiF), Exploration of Extreme Ocean Environments, awarded to AJJ. The genetic analysis was funded by Newcastle University through internal funds to JNJW and the University of Aberdeen by the Natural Environment Research Council (NERC), UK Grant NE/N01149X/1, awarded to SBP.Peer reviewedPublisher PD

Clinical management of seizures in patients with meningiomas: Efficacy of surgical resection for seizure control and patient-tailored postoperative anti-epileptic drug management

Meningiomas are the most common primary intracranial tumor. They are slow growing and often incidentally found tumors that arise from the arachnoid villi. As they grow, they have a greater likelihood of becoming symptomatic with seizures being one of the most clinically significant symptoms. Seizures are more likely to present as a symptom of larger meningiomas and meningiomas that compress cortical areas particularly those in non-skull base locations. These seizures are often managed medically, utilizing the same anti-seizure medications that are used to treat other causes of epilepsy. We discuss common anti-seizure medications used including valproate, phenobarbital, carbamazepine, phenytoin, lacosamide, lamotrigine, levetiracetam and topiramate and their common adverse effects. The goal of pharmacotherapy for seizure control is to maximize seizure control while minimizing the adverse effects of the medication. The decision to provide medical management is dependent on individual seizure history and plans for surgical treatment. Patients who did not require seizure prophylaxis before surgery are commonly prescribed seizure prophylaxis postoperatively. Symptomatic meningiomas not controlled by medical management alone are commonly evaluated for surgical resection. The efficacy of surgical resection in providing seizure freedom is dependent on several features of the tumor including tumor size, the extent of the peritumoral edema, the number of tumors, sinus infiltration and the degree of resection

Clinical Effectiveness of the Queen Square Intensive Comprehensive Aphasia Service for Patients With Poststroke Aphasia

BACKGROUND AND PURPOSE: Poststroke aphasia has a major impact on peoples' quality of life. Speech and language therapy interventions work, especially in high doses, but these doses are rarely achieved outside of research studies. Intensive Comprehensive Aphasia Programs (ICAPs) are an option to deliver high doses of therapy to people with aphasia over a short period of time. METHODS: Forty-six people with aphasia in the chronic stage poststroke completed the ICAP over a 3-week period, attending for 15 days and averaging 6 hours of therapy per day. Outcome measures included the Comprehensive Aphasia Test, an impairment-based test of the 4 main domains of language (speaking, writing, auditory comprehension, and reading) which was measured at 3 time points (baseline, immediately posttreatment at 3 weeks and follow-up at 12-week post-ICAP); and, the Communicative Effectiveness Index, a carer-reported measure of functional communication skills collected at baseline and 12 weeks. RESULTS: A 2-way repeated measures multivariate ANOVA was conducted. We found a significant domain-by-time interaction, F=12.7, P<0.0005, indicating that the ICAP improved people with aphasia's language scores across all 4 domains, with the largest gains in speaking (Cohen's d=1.3). All gains were maintained or significantly improved further at 12-week post-ICAP. Importantly, patients' functional communication, as indexed by changes on the Communicative Effectiveness Index, also significantly improved at 12-week post-ICAP, t=5.4, P<0.0005, also with a large effect size (Cohen's d=0.9). CONCLUSIONS: People with aphasia who participated in the Queen Square ICAP made large and clinically meaningful gains on both impairment-based and functional measures of language. Gains were sustained and in some cases improved further over the subsequent 12 weeks

Radio-frequency discharges in Oxygen. Part 1: Modeling

In this series of three papers we present results from a combined experimental and theoretical effort to quantitatively describe capacitively coupled radio-frequency discharges in oxygen. The particle-in-cell Monte-Carlo model on which the theoretical description is based will be described in the present paper. It treats space charge fields and transport processes on an equal footing with the most important plasma-chemical reactions. For given external voltage and pressure, the model determines the electric potential within the discharge and the distribution functions for electrons, negatively charged atomic oxygen, and positively charged molecular oxygen. Previously used scattering and reaction cross section data are critically assessed and in some cases modified. To validate our model, we compare the densities in the bulk of the discharge with experimental data and find good agreement, indicating that essential aspects of an oxygen discharge are captured.Comment: 11 pages, 10 figure