1,174 research outputs found
Opportunities for Growing Short-Rotation Woody Crops in Agroforestry Practices
Technologies are readily available for growing hybrid poplars and willows in block plantings as short-rotation woody crops (SRWC) for fuel and fiber. SRWC species and technologies can also be incorporated into agricultural systems as agroforestry practices. Examples are windbreaks, living snowfences, “timberbelts”, riparian buffer strips, and wastewater treatment plantings. Fast growth, convenient propagation (see AF Note - 11), and compatibility with conventional farming methods make SRWC suitable for use in agroforestry practices to provide multiple benefits such as solid wood and wood fiber products, water quality improvement, crop and soil protection, wildlife habitat, and buffers for agricultural/community interfaces
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Effects of three plant growth regulators upon growth patterns in seedlings of three races of Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco
Populations of Douglas-fir seedlings from interior British
Columbia, Vancouver Island, and Arizona received six bi-weekly
foliar spray applications of the growth regulators IAA, CCC, and
B-995, each at three concentration levels under controlled environmental
conditions. Large differences were found among the three
populations in their responses to the growth regulators. The responses
to IAA treatments were as follows: height growth of interior
British Columbia seedlings was reduced markedly by all
three concentrations, Vancouver Island seedlings were unaffected
by all concentrations, and only the lowest concentration (75 ppm)
reduced the height growth of the Arizona seedlings; 300 ppm caused
twisting of leaders and a marked increase in the number of periods
of dormancy in all seedlings; and top dry weight was affected only
(Degree)
in interior British Columbia seedlings, particularly by 300 ppm.
Although the number of periods of dormancy was markedly increased
by 300 ppm IAA in the Vancouver Island and Arizona seedlings, height
growth was the same as in untreated seedlings. Root dry weights
varied in an inconsistent manner throughout the experiment. The
responses to CCC treatments were as follows: 2000 ppm reduced
height growth and top dry weight of interior British Columbia and
Vancouver Island seedlings but had no significant effect on the
Arizona seedlings. With increasing concentrations internodes became
progressively shorter and chlorosis more intense. CCC had
little effect upon number of periods of dormancy. The responses to
B-995 were as follows: height growth and number of periods of dormancy
were both decreased in Arizona seedlings; interior British
Columbia and Vancouver Island seedlings were affected to a lesser
degree. B-995 had no effects on top or root dry weight.
In a separate experiment, the effects of the high concentrations
of the three growth regulators upon the time of break of dormancy
were determined. Dormant 1-0 Douglas-fir seedlings lifted from a
nursery bed in mid-February were treated once or twice using either
two percent dimethyl sulfoxide (DMSO) or water as carrier. The
containers of seedlings were then transferred to a growth chamber
and exposed to an environment favorable toward growth initiation
(same environment as first experiment). Only 2000 ppm of CCC applied twice using water as carrier slowed the rate of growth
initiation significantly
High-latitude artificial aurora using the EISCAT high-gain HF facility
The EISCAT high-frequency (HF) transmitter facility at Ramfjord, Norway, has been used to accelerate F-region electrons sufficiently to excite the oxygen atoms and nitrogen molecules, resulting in optical emissions at 630, 557.7 and 427.8 nm. During O-mode transmissions at 5.423 MHz, using 630 MW effective radiated power, in the hours after sunset on 12 November 2001 several new observations were made, including: (1) The first high-latitude observation of an HF induced optical emission at 427.8 nm and (2) Optical rings being formed at HF on followed by their collapse into a central blob. Both discoveries remain unexplained with current theories
Farmers' awareness and application of banana Xanthomonas wilt control options: The case of Uganda and Kenya
Banana is a key staple and cash crop in east and central Africa. However, the recent outbreak of Banana Xanthomonas wilt (BXW) has threatened farmers whose livelihoods depend on the crop. Since 2002, stakeholders embarked on campaigns to sensitize farmers on the disease and its management. This study evaluated the effectiveness of these efforts by examining farmers' awareness of the disease, control options and their application in Uganda and Kenya. Data on BXW distribution and incidence, farmers' awareness of symptoms, mechanisms of spread and control options of the disease and banana production were collected through household surveys conducted in 2010. The results indicated that most farmers (> 90%) were aware of the disease and its symptoms and more than 50% were aware of the recommended control measures. Farmers obtained information on the disease from multiple sources but farmer-to-farmer interaction was the main source suggesting the key role rural social networks play in managing the disease. Not all affected farmers were able to apply control measures due to cost of intervention, lack of labour and inputs. The study recommends strengthening of linkages among stakeholders for better coordination of efforts and participatory development and promotion of farmer-oriented interventions that address farmer constraints
Structure and Thermodynamics of the Mixed Alkali Alanates
The thermodynamics and structural properties of the hexahydride alanates
(M2M'AlH6) with the elpasolite structure have been investigated. A series of
mixed alkali alanates (Na2LiAlH6, K2LiAlH6 and K2NaAlH6) were synthesized and
found to reversibly absorb and desorb hydrogen without the need for a catalyst.
Pressure-composition isotherms were measured to investigate the thermodynamics
of the absorption and desorption reactions with hydrogen. Isotherms for
catalyzed (4 mol% TiCl3) and uncatalyzed Na2LiAlH6 exhibited an increase in
kinetics, but no change in the bulk thermodynamics with the addition of a
dopant. A structural analysis using synchrotron x-ray diffraction showed that
these compounds favor the Fm-3m space group with the smaller ion (M') occupying
an octahedral site. These results demonstrate that appropriate cation
substitutions can be used to stabilize or destabilize the material and may
provide an avenue to improving the unfavorable thermodynamics of a number of
materials with promising gravimetric hydrogen densities.Comment: 6 pages, 7 figures,3 tables, submitted to PR
Import of cytochrome c into mitochondria
The import of cytochrome c into mitochondria can be resolved into a number of discrete steps. Here we report on the covalent attachment of heme to apocytochrome c by the enzyme cytochrome c heme lyase in mitochondria from Neurospora crassa.
A new method was developed to measure directly the linkage of heme to apocytochrome c. This method is independent of conformational changes in the protein accompanying heme attachment. Tryptic peptides of [35S]cysteine-labelled apocytochrome c, and of enzymatically formed holocytochrome c, were resolved by reverse-phase HPLC. The cysteine-containing peptide to which heme was attached eluted later than the corresponding peptide from apocytochrome c and could be quantified by counting 35S radioactivity as a measure of holocytochrome c formation. Using this procedure, the covalent attachment of heme to apocytochrome c, which is dependent on the enzyme cytochrome c heme lyase, could be measured. Activity required heme (as hemin) and could be reversibly inhibited by the analogue deuterohemin. Holocytochrome c formation was stimulated 5–10-fold by NADH > NADPH > glutathione and was independent of a potential across the inner mitochondrial membrane. NADH was not required for the binding of apocytochrome c to mitochondria and was not involved in the reduction of the cysteine thiols prior to heme attachment. Holocytochrome c formation was also dependent on a cytosolic factor that was necessary for the heme attaching step of cytochrome c import. The factor was a heat-stable, protease-insensitive, low-molecular-mass component of unknown function.
Cytochrome c heme lyase appeared to be a soluble protein located in the mitochondrial intermembrane space and was distinct from the previously identified apocytochrome c binding protein having a similar location. A model is presented in which the covalent attachment of heme by cytochrome c heme lyase also plays an essential role in the import pathway of cytochrome c
GEOYASGUI: THE GEOSPARQL QUERY EDITOR AND RESULT SET VISUALIZER
The Netherlands' Cadastre, Land Registry and Mapping Agency - in short Kadaster - collects and registers administrative and spatial data on property and the rights involved. This includes for ships, aircraft and telecommunications networks. Doing so, Kadaster protects legal certainty. The Kadaster publishes many large authoritative datasets including several key registers of the Dutch Government (Topography, Addresses and Buildings). Furthermore Kadaster is also developing and maintaining the PDOK shared service, in which about 100 spatial datasets are being published in several formats, including an incredible amount of detailed geospatial objects. Geospatial objects include all plots of land, all buildings, all roads and all lampposts. These objects are spatially and/or conceptually related, but are maintained by different data curators. As a result these datasets are syntactically and architecturally disjoint, and using them together currently requires non-trivial human labor. In response to this, Kadaster is currently publishing its geo-spatial data assets as Linked Open Data. The standardized query language for Linked Open Geodata is GeoSPARQL. Unfortunately, current tooling does not support writing and evaluating GeoSPARQL queries. This paper presents GeoYASGUI, a GeoSPARQL editor and result-set viewer with IDE capabilities. GeoYASGUI is not a new software product, but an integration of and a collection of updates to existing Open Source libraries. With GeoYASGUI it becomes possible to query the rich Open Data assets of the Kadaster
Determinants of farm-level adoption of cultural practices for banana xanthomonas wilt control in Uganda
Understanding the factors influencing farmers’adoption decisions of the disseminated Banana Xanthomonas wilt (BXW) control package is critical for successful management of the disease. This paper analysed the determinants of farmers’ decisions to adopt the control package by smallholder banana farmers in Uganda. A binomial Logit model is applied to household survey data collected from 350 households. Results from the study show that household labour availability, technology pack age attributes such as labour demand and perceived effectiveness of the practices in managing the disease; and agro-ecological location and banana production system significantly influence adoption decisions. These results suggest the need for adaptation of the technology package to better suit the needs and socio-economic conditions of smallholder farmers through a farmer participatory technology development approach that takes into account research findings, farmers’ indigenous knowledge and resource constraints to enhance adoption
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