359 research outputs found
Fabrication and characterizations of proton-exchanged LiNbO3 waveguides fabricated by inductively coupled plasma technique
This Letter reports the use of an inductively coupled plasma technique for fabrication of proton-exchanged (PE) LiNbO3 (LN) waveguides. Planar and stripe waveguides have been formed in Y-cut LN which are difficult to obtain with the conventional molten acid method due to the occurrence of surface damage. Secondary ion mass spectrometry, scanning electron microscopy, and infrared absorption spectrum characterization results revealed that a uniform vertical PE profile with a single low order crystal phase has been directly obtained as a result of this unique process. X-ray photoelectron spectroscopy characterization of the treated surface revealed the existence of NbO as the cause for a sometimes darkened surface and confirms the ability to completely restore the surface to LN by oxygen plasma treatment. Atomic force microscopy measurement confirms that good surface quality has been maintained after regeneration of the surface to LN
Tree-based intercropping: a land use for greenhouse gas mitigation in canadian agricultural systems
PosterIn tree-based intercropping (TBI) systems, the potential influence of trees in relation to carbon (C ) sequestration and Greenhouse Gas (GHG) emissions reduction has been documented but the mechanisms, remain poorly understood, especially for below-ground processes. Recently, several studies in this area were undertaken in Ontario, Canada under the auspices of Canada’s involvement in the Global Research Alliance.
C sequestration potential, nitrous oxide reduction potential and soil voids were quantified in a 25-year-old TBI system in southern Ontario for five tree species: hybrid poplar (Populus spp.), Norway spruce (Picae abies), red oak (Quercus rubra), black walnut (Juglans nigra), and white cedar (Thuja occidentalis) which were intercropped with soybean (Glycine max). Results were compared with a conventional agricultural system in which soybean was grown as the sole crop.
The net C flux for poplar, spruce, oak, walnut, cedar and the soybean sole-crop were + 2.1, + 1.6, + 0.8, + 1.8, +1.4 and – 1.2 t C ha-1, y-1, respectively. The results suggest a greater atmospheric CO2 sequestration potential for all five tree species when compared to a conventional agricultural system. DNA was also extracted from soil cores collected around four of the tree species (walnut, red oak, Norway spruce, poplar) and used for quantitative real-time PCR to determine the abundance of key functional genes in the nitrification and denitrification pathways. Results indicate that both tree species and proximity to the tree, can influence the abundance of key microbial groups associated with N2O production, particularly organisms associated with denitrification, nosZ and nirS. Soil void analysis showed that there was a positive correlation between x-ray bulk radio-density and soil bulk density, and a negative correlation between mean intra-aggregate x-ray radio-density and soil organic carbon (rs=-0.48, p=0.033), suggesting that the X-ray CT method could therefore be used to predict these soil properties
Tree-based intercropping: a land use for greenhouse gas mitigation in canadian agricultural systems
PosterIn tree-based intercropping (TBI) systems, the potential influence of trees in relation to carbon (C ) sequestration and Greenhouse Gas (GHG) emissions reduction has been documented but the mechanisms, remain poorly understood, especially for below-ground processes. Recently, several studies in this area were undertaken in Ontario, Canada under the auspices of Canada’s involvement in the Global Research Alliance.
C sequestration potential, nitrous oxide reduction potential and soil voids were quantified in a 25-year-old TBI system in southern Ontario for five tree species: hybrid poplar (Populus spp.), Norway spruce (Picae abies), red oak (Quercus rubra), black walnut (Juglans nigra), and white cedar (Thuja occidentalis) which were intercropped with soybean (Glycine max). Results were compared with a conventional agricultural system in which soybean was grown as the sole crop.
The net C flux for poplar, spruce, oak, walnut, cedar and the soybean sole-crop were + 2.1, + 1.6, + 0.8, + 1.8, +1.4 and – 1.2 t C ha-1, y-1, respectively. The results suggest a greater atmospheric CO2 sequestration potential for all five tree species when compared to a conventional agricultural system. DNA was also extracted from soil cores collected around four of the tree species (walnut, red oak, Norway spruce, poplar) and used for quantitative real-time PCR to determine the abundance of key functional genes in the nitrification and denitrification pathways. Results indicate that both tree species and proximity to the tree, can influence the abundance of key microbial groups associated with N2O production, particularly organisms associated with denitrification, nosZ and nirS. Soil void analysis showed that there was a positive correlation between x-ray bulk radio-density and soil bulk density, and a negative correlation between mean intra-aggregate x-ray radio-density and soil organic carbon (rs=-0.48, p=0.033), suggesting that the X-ray CT method could therefore be used to predict these soil properties
Tree-based intercropping: a land use for greenhouse gas mitigation in canadian agricultural systems
PosterIn tree-based intercropping (TBI) systems, the potential influence of trees in relation to carbon (C ) sequestration and Greenhouse Gas (GHG) emissions reduction has been documented but the mechanisms, remain poorly understood, especially for below-ground processes. Recently, several studies in this area were undertaken in Ontario, Canada under the auspices of Canada’s involvement in the Global Research Alliance.
C sequestration potential, nitrous oxide reduction potential and soil voids were quantified in a 25-year-old TBI system in southern Ontario for five tree species: hybrid poplar (Populus spp.), Norway spruce (Picae abies), red oak (Quercus rubra), black walnut (Juglans nigra), and white cedar (Thuja occidentalis) which were intercropped with soybean (Glycine max). Results were compared with a conventional agricultural system in which soybean was grown as the sole crop.
The net C flux for poplar, spruce, oak, walnut, cedar and the soybean sole-crop were + 2.1, + 1.6, + 0.8, + 1.8, +1.4 and – 1.2 t C ha-1, y-1, respectively. The results suggest a greater atmospheric CO2 sequestration potential for all five tree species when compared to a conventional agricultural system. DNA was also extracted from soil cores collected around four of the tree species (walnut, red oak, Norway spruce, poplar) and used for quantitative real-time PCR to determine the abundance of key functional genes in the nitrification and denitrification pathways. Results indicate that both tree species and proximity to the tree, can influence the abundance of key microbial groups associated with N2O production, particularly organisms associated with denitrification, nosZ and nirS. Soil void analysis showed that there was a positive correlation between x-ray bulk radio-density and soil bulk density, and a negative correlation between mean intra-aggregate x-ray radio-density and soil organic carbon (rs=-0.48, p=0.033), suggesting that the X-ray CT method could therefore be used to predict these soil properties
A gas sensor system for harsh environment applications
A novel low power, miniature gas sensor measuring system is presented for application in harsh environmental conditions, i.e. to detect carbon monoxide and oxygen at temperatures of up to +225oC and high relative humidities up to 95%. The gas sensors are fabricated using SOI high temperature technology and two full custom ASICs are embedded into a high-temperature circuit board interfaced to a low-cost general purpose microcontroller. The sensor system has been developed for a CO concentration range of 0 to 300 ppm, O2 concentration range of 0 to 21%, and monitors the humidity and temperature of the gas, as well as operating temperatures of micro-heaters within the two MOX gas sensors. Feedback control is built into the program of the micro-controller to compensate for temperature dependence of gas sensors. Preliminary experiments show promising results for the intended application within domestic boilers
Creating diamond color centers for quantum optical applications
Nitrogen vacancy (NV) centers in diamond have distinct promise as solid-state
qubits. This is because of their large dipole moment, convenient level
structure and very long room-temperature coherence times. In general, a
combination of ion irradiation and subsequent annealing is used to create the
centers, however for the rigorous demands of quantum computing all processes
need to be optimized, and decoherence due to the residual damage caused by the
implantation process itself must be mitigated. To that end we have studied
photoluminescence (PL) from NV, NV and GR1 centers formed by ion
implantation of 2MeV He ions over a wide range of fluences. The sample was
annealed at C to minimize residual vacancy diffusion, allowing for
the concurrent analysis of PL from NV centers and irradiation induced vacancies
(GR1). We find non-monotic PL intensities with increasing ion fluence,
monotonic increasing PL in NV/NV and GR1/(NV + NV) ratios, and
increasing inhomogeneous broadening of the zero-phonon lines with increasing
ion fluence. All these results shed important light on the optimal formation
conditions for NV qubits. We apply our findings to an off-resonant photonic
quantum memory scheme using vibronic sidebands
Spectral-domain optical coherence tomography of conjunctival mucosa-associated lymphoid tissue lymphoma with presumed choroidal involvement
Conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma has been well-described, but rarely do these lesions demonstrate intraocular involvement. We report a case of conjunctival MALT lymphoma with intraocular involvement and novel spectral-domain ocular coherence tomography (SD-OCT) findings.
A 75-year-old woman with biopsy-proven MALT lymphoma of the conjunctiva presented with ipsilateral yellowish diffuse choroidal infiltrates on fundoscopic examination. Choroidal involvement was documented clinically, on ultrasonography, on fluorescein angiography, and by SD-OCT. Treatment consisted of 3 weeks of oral doxycycline and six cycles of systemic chemotherapy with cyclophosphamide, vincristine, prednisone, and rituximab.
There was no evidence of progression or recurrence of MALT lymphoma after 9 months of follow-up. Despite complete resolution of clinical findings, ultrasound, and fluorescein angiography, the choroidal lesions remained unchanged on SD-OCT.
Choroidal involvement of conjunctival MALT is rare, and can be successfully treated. Persistence of irregularities on SD-OCT did not influence management in the presence of clinical improvement and resolution on ultrasonography and fluorescein angiography
The relationship between the body and air temperature in a terrestrial ectotherm
This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement:The data and code supporting this manuscript are available in Zenodo: DOI 10.5281/zenodo.8383661Ectotherms make up the majority of terrestrial biodiversity, so it is important to understand their potential responses to climate change. Often, models aiming to achieve this understanding correlate species distributions with ambient air temperature. However, this assumes a constant relationship between the air temperature and body temperature, which determines an ectotherm's thermal performance. To test this assumption, we develop and validate a method for retrospective estimation of ectotherm body temperature using heat exchange equations. We apply the model to predict the body temperature of wild field crickets (Gryllus campestris) in Northern Spain for 1985-2019 and compare these values to air temperature. We show that while air temperature impacts ectotherm body temperature, it captures only a fraction of its thermal experience. Solar radiation can increase the body temperature by more than 20°C above air temperature with implications for physiology and behaviour. The effect of solar radiation on body temperature is particularly important given that climate change will alter cloud cover. Our study shows that the impacts of climate change on species cannot be assumed to be proportional only to changing air temperature. More reliable models of future species distributions require mechanistic links between environmental conditions and thermal ecophysiologies of species.Natural Environment Research Council (NERC
Clinical impact of recurrently mutated genes on lymphoma diagnostics
Similar to the inherent clinical heterogeneity of most, if not all, lymphoma entities, the genetic landscape of these tumors is markedly complex in the majority of cases, with a rapidly growing list of recurrently mutated genes discovered in recent years by next-generation sequencing technology. Whilst a few genes have been implied to have diagnostic, prognostic and even predictive impact, most gene mutations still require rigorous validation in larger, preferably prospective patient series, to scrutinize their potential role in lymphoma diagnostics and patient management. In selected entities, a predominantly mutated gene is identified in almost all cases (e.g. Waldenström's macroglobulinemia/lymphoplasmacytic lymphoma and hairy-cell leukemia), while for the vast majority of lymphomas a quite diverse mutation pattern is observed, with a limited number of frequently mutated genes followed by a seemingly endless tail of genes with mutations at a low frequency. Herein, the European Expert Group on NGS-based Diagnostics in Lymphomas (EGNL) summarizes the current status of this ever-evolving field, and, based on the present evidence level, segregates mutations into the following categories: i) immediate impact on treatment decisions, ii) diagnostic impact, iii) prognostic impact, iv) potential clinical impact in the near future, or v) should only be considered for research purposes. In the coming years, coordinated efforts aiming to apply targeted next-generation sequencing in large patient series will be needed in order to elucidate if a particular gene mutation will have an immediate impact on the lymphoma classification, and ultimately aid clinical decision making
Gastric adenocarcinoma in a patient re-infected with H. pylori after regression of MALT lymphoma with successful anti-H. pylori therapy and gastric resection: a case report
BACKGROUND: Helicobacter pylori (H. pylori) has been etiologically linked with primary gastric lymphoma (PGL) and gastric carcinoma (GC). There are a few reports of occurrence of both diseases in the same patient with H. pylori infection. CASE PRESENTATION: We report a patient with PGL in whom the tumor regressed after surgical resection combined with eradication of H. pylori infection. However, he developed GC on follow up; this was temporally associated with recrudescence / re-infection of H. pylori. This is perhaps first report of such occurrence. CONCLUSIONS: Possible cause and effect relationship between H. pylori infection and both PGL and GC is discussed. This case also documents a unique problem in management of PGL in tropical countries where re-infection with H. pylori is supposed to be high
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