2,778 research outputs found
Stand Dynamics and Disturbance History of Champlain Valley Clayplain Forests
Studies of stand dynamics can explain how species interactions and disturbances drive forest structure and recruitment patterns of tree species. It is difficult to generate an understanding of stand dynamics and successional trends of forests in areas that have a long history of intense land use such as the Champlain Valley of Vermont, where over 230 years of agricultural activity has acutely and permanently influenced the landscape. The valley clayplain forest, a rare natural community containing endangered herbaceous plants and overstory tree species assemblages that are rare in Vermont, has been fragmented by agricultural use of the Champlain Valley. This study used dendroecological methods and assessments of forest structural conditions to describe the tree recruitment history and structural dynamics of two old-growth valley clayplain forest patches. Our results indicate that the valley clayplain forest has a species composition and recruitment history that has been heavily influenced by human land use throughout at least the past 230 years. We found that Quercus spp., typically considered characteristic of the valley clayplain forest, are being replaced by late-successional species such as Tsuga canadensis. Additionally, other human influences such as invasive species threaten to further alter the composition and dynamics of valley clayplain forests in the near future
ISIS2: Pixel Sensor with Local Charge Storage for ILC Vertex Detector
ISIS (In-situ Storage Imaging Sensor) is a novel CMOS sensor with multiple
charge storage capability developed for the ILC vertex detector by the Linear
Collider Flavour Identification (LCFI) collaboration. This paper reports test
results for ISIS2, the second generation of ISIS sensors implemented in a 0.18
micron CMOS process. The local charge storage and charge transfer were
unambiguously demonstrated.Comment: 11 pages, 16 figures, to be included in the Proceedings of
International Linear Collider Workshop 201
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Attempting to prevent postnatal depression by targeting the mother–infant relationship: a randomised controlled trial
Aim: The purpose of the study was to investigate whether a supportive psychotherapeutic intervention which focussed on enhancing the quality of the other-infant relationship would prevent the development of postnatal depression (PND) and the associated impairments in parenting and adverse effects on child development.
Background: Recent meta-analytic examinations report a modest preventive effect of psychological treatments for women vulnerable to the development of postnatal depression. However, given the strong evidence for an impact of PND on the quality of the mother-infant relationship and on child development, it is notable that there are limited data on the impact of preventive interventions on these outcomes. This is clearly a question that requires research attention. Accordingly, a randomized controlled trial was conducted of such a preventive intervention.
Methods: A large sample of pregnant women was screened to identify those at risk of PND.
91 were randomly assigned to the index intervention and received home visits from research health visitors, and 99 were assigned to a control group who received normal care. In an adjacent area 76 women received the index intervention from trained NHS health visitors. The index intervention involved 11 home visits, two antenatally and nine postnatally. They were supportive in nature, with specific measures to enhance maternal sensitivity to infant communicative signals. Independent assessments were made at18 weeks postpartum, and at 12 and 18 months postpartum of maternal mood, maternal sensitivity in mother-infant engagement, and infant behaviour problems, attachment and cognition.
Findings: The index intervention, whether delivered by research or NHS health visitors, had no discernible impact on maternal mood or the quality of the maternal parenting behaviours. Neither did it benefit the infant outcomes assessed. For girl children a benefit of the intervention was found for cognitive development. Overall the findings indicate that this approach to preventing PND cannot be recommended
Assessment of Imagining and Material Characteristics of a Radiopaque, Thermoresponsive Hydrogel for Intratumoral Administration to Solid Tumours
Introduction
Thermoresponsive hydrogels are gels which have different properties at varying temperatures. The objective of this study was to assess the material characteristics, imaging properties and chemotherapeutic drug release profile of a novel radiopaque thermoresponsive hydrogel, which is liquid at room temperature but solidifies at body temperature, to determine potential suitability for intratumoral delivery.
Materials and Methods
An iodinated radiopaque thermoresponsive hydrogel was formulated using iodixanol at a range of concentrations and assessed for sol-gel transition, radiopacity and imaging using CT and US. A lead formulation containing 9.22% w/w iodixanol was evaluated for injectability, disintegration and dual drug release of cisplatin and paclitaxel from the hydrogel formulation.
Results
Radiopacity of the hydrogel increased in a concentration dependent manner but higher concentrations of iodixanol adversely affected the sol-gel transition of the hydrogel, therefore 9.22%w/w iodixanol hydrogel was identified as the lead formulation. This formulation was readily visible on both CT and US. The formulation was hand-injectable through a range of clinically relevant devices, had a sustained disintegration profile for up to 28 days, and was able to deliver a sustained release of chemotherapeutic drug for up to 10 days.
Discussion
Favourable imaging and material characteristics of this thermoresponsive gel are demonstrated, suggesting potential interventional oncology applications for image-guided intratumoral delivery of sustained-release chemotherapy
A Custom Radiopaque Thermoresponsive Chemotherapy-Loaded Hydrogel for Intratumoural Injection: An In Vitro and Ex Vivo Assessment of Imaging Characteristics and Material Properties
Purpose Thermoresponsive hydrogels are gels which have different properties at varying temperatures. The objective of this study was to assess the material characteristics, imaging properties and chemotherapeutic drug release profile of a novel radiopaque thermoresponsive hydrogel in vitro, which is liquid at room temperature but solidifies at body temperature, to determine potential suitability for intratumoural delivery. Materials and Methods An iodinated radiopaque thermoresponsive hydrogel was formulated using iodixanol at a range of concentrations and assessed for sol–gel transition, radiopacity and imaging using CT and US. A lead formulation containing iodixanol at a concentration of 9.22% weight by weight (w/w, g of iodixanol per g of hydrogel) was evaluated in vitro for injectability, disintegration and dual drug release of cisplatin and paclitaxel from the hydrogel formulation. Results Radiopacity of the hydrogel increased in a concentration- dependent manner, but the highest concentration of iodixanol evaluated in this study (13.83% w/w) adversely affected the sol–gel transition of the hydrogel; therefore, 9.22% w/w iodixanol hydrogel was identified as the lead formulation. This formulation was readily visible on both CT and US. The formulation was hand injectable through a range of clinically relevant devices, had a sustained disintegration profile for up to 28 days and was able to deliver a sustained release of chemotherapeutic drug for up to 10 days. Conclusions Favourable in vitro and ex vivo imaging and material characteristics of this thermoresponsive gel are demonstrated, suggesting potential interventional oncology applications for image-guided intratumoural delivery of sustained-release chemotherapy
Screening for EGFR Mutations in Patients with Head and Neck Cancer Treated with Gefitinib on a Compassionate-Use Program: A Hellenic Cooperative Oncology Group Study
Background and Aim. EGFR is commonly expressed in cancers of the head and neck (H and N), and anti-EGFR agents have demonstrated improvements in outcomes (TTP and OS). The aim of this study was to determine EGFR gene status in H and N cancer patients treated with gefitinib and to correlate mutational status with clinico-pathological data and response. Patients and Methods. Patients with histologically confirmed H and N cancer having failed prior treatment for advanced disease entered this compassionate-use-program. Nineteen patients received gefitinib. EGFR expression was assessed by IHC, gene copy number by FISH, and mutation analysis was conducted for EGFR (18-21), KRAS, BRAF (V600E), and HER-2 exon 20. An additional TKI naive cohort of 73 patients was also screened. Results. Mutations were detected in 6/19 patients (3× EGFR, 1× KRAS, and 2× HER2-exon 20). There were no significant differences in TTP or OS for patients with somatic EGFR mutations. No BRAF mutations were detected. Conclusions. The incidence of EGFR mutations in H and N cancer in this study was 5.3%. No statistically relevant correlations between mutation or gene gain and response or survival were observed. Due to the limited number of patients and low incidence of genetic aberrations in the genes analyzed, additional studies are warranted
Titania-doped tantala/silica coatings for gravitational-wave detection
Reducing thermal noise from optical coatings is crucial to reaching the required sensitivity in next generation interferometric gravitational-wave detectors. Here we show that adding TiO2 to Ta2O5 in Ta2O5/SiO2 coatings reduces the internal friction and in addition present data confirming it reduces thermal noise. We also show that TiO2-doped Ta2O5/SiO2 coatings are close to satisfying the optical absorption requirements of second generation gravitational-wave detectors
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