1,134 research outputs found
Using air photos to parameterise landscape predictors of channel wetted width at baseflow
Evasion of carbon dioxide from the surface of freshwater channels accounts for a substantial proportion of its flux
from the terrestrial biosphere to the atmosphere; accurate estimates of channel wetted width (WW) are required
to improve predictions of this flux. We investigated which landscape and climate-related data were statistically
significant predictors of WW at baseflow across a large region (2200 km2) of north Wales and western England
(UK) where habitat surveys suggest the majority of channels are in a near natural state. We used 25 cm pixel
resolution air photos to measure channel WW at baseflow, and quantified the magnitude of the errors in these
measurements. We used flow information from local gauging stations to ensure that channels were at or close to
baseflow for the days on which the air photos were captured. The root mean squared difference between the fieldbased
and air photo measurements of WW (n=28 sites) was small (0.14 m) in comparison to the median channel
WW (3.07 m), and there was very little bias between the two sets of measurements (0.026 m).
We created a set of points along those sections of channels which were visible in air photos and used a digital terrain
model to create the drainage catchments for the points and computed their catchment area (CA).We removed points
with CA <1 km2 and selected a random subset from the remaining points (n=472). We measured channel WW at
these points from air photos and computed landscape and climate-related data for each of their catchments (mean
slope, mean annual rainfall, land cover type, elevation) and also mean BFIHOST, a quantitative index relating
to hydrological source of flow. We also computed the local slope at each of the selected points on the channel.
As these data were not independent random variables, we used the linear mixed model framework with WW as
the predictand and included the various landscape and climate-related data (including CA0:5) as fixed effects. We
included a spatial covariance function using residual maximum likelihood which computes unbiased estimates
of the predictors and accounts for clustering in the sample data. There was no evidence for retaining the spatial
covariance function and so we computed a linear model by ordinary least squares and selected predictors using a
stepwise procedure.With the exception of land cover, all the predictors were statistically significant and accounted
for 76% of the variance of channelWW. When CA0:5 alone was used as a predictor it captured 54% of the variance.
The vast majority of this difference was due to inclusion of an interaction between CA and hydrological source
of flow (BFIHOST). As catchment area increases, those channels with larger mean catchment BFIHOST values
(greater baseflow) have narrower channel WW by comparison to those with smaller mean BFIHOST for the same
CA
Extension Agents as Administrators of Volunteers: Competencies Needed for the Future
Extension faculty, in their role as administrators of volunteers, often lack the competencies to fully manage and utilize this tremendous resource. This article reports the findings of a nation-wide Delphi study that identified 33 competencies required by persons leading volunteers. These competencies included skills in the broad constructs of organizational and systems leadership, developing a positive organizational culture, personal skills that will help them in developing effective teams and managing change, and skills in daily management of volunteers. It is recommended that Extension devote greater time and resources to helping faculty acquire these competencies
Bringing Leadership Experiences to Inner-City Youth
Leadership skills are essential for young people to feel satisfaction and contribute to society. But how do you teach leadership skills to teens who only have a vague concept of leadership? Service learning offers teens the opportunity to practice leadership skills and reflect on the experience. 4-H Youth for Community Action (4-HYCA) is an after school leadership development program targeting teens in inner-city middle schools. The purpose of the program was to provide opportunities for inner city youth to learn and practice leadership skills in a service-learning environment. 4-HYCA participants actively engaged in problem-solving activities that taught decision-making, communication, and cooperation skills
A multiplex PCR assay for differentiating economically important gastrointestinal nematodes of cattle
A multiplex polymerase chain reaction (PCR) test was developed for identifying gastrointestinal (GI) nematodes that commonly infect cattle. This assay was developed using adult-derived genomic DNA and shown capable of discriminating parasite eggs from the feces of experimentally-infected animals at both the species and genus levels. Sequence data from internal (ITS) and external (ETS) transcribed spacers of the ribosomal DNA (rDNA) repeats as well as the 3′-end of the small subunit rDNA and 5′-end of the large subunit rDNA were used to generate five primer sets which, when used simultaneously in a multiplex PCR, produce a unique electrophoretic DNA banding pattern charac- terized by a single DNA fragment for Ostertagia ostertagi (257 bp), Haemonchus placei (176 bp),Oesophagostomum radiatum (329 bp), Trichostrongylus colubriformis (243 bp) and Cooperia on- cophora (151 bp). In a similar manner, the constructed primer sets amplified DNA from Ostertagia lyrata, Haemonchus contortus, Trichostrongylus axei, Cooperia surnabada and Cooperia punctata. With respect to H. contortus, a closely migrating doublet was generated suggesting size heterogene- ity in the ETS which is consistent with multiple rDNA repeat units within this species. PCR analyses using mixtures of monospecifically-purified nematode eggs indicated a sensitivity of less than 0.5 egg-DNA equivalent per species. Although, not designed as a quantitative technique, relative PCR signal intensities corresponded to relative egg burdens within the DNA samples from mixed species of eggs. Published by Elsevier Science B.V
Community Service Versus Service-Learning: Which Is Best for 4-H?
In 1999, the National 4-H Council (2000) reported that some 271,146 4-H members participated in service activities to their communities. These activities were categorized as volunteerism, community service, and service-learning--three distinctly different activities. To examine which activity is best in teaching leadership life skills, a randomized post-test only control group experiment utilizing a control group and two treatment groups was conducted to determine the effects of service-learning. This article distinguishes service service-learning from the other two activities, presents the results of the study, and discusses the implications of service learning for Extension
Angular two-photon interference and angular two-qubit states
Using angular-position-orbital-angular-momentum entangled photons, we study angular two-photon interference in a scheme in which entangled photons are made to pass through apertures in the form of double angular slits, and using this scheme, we demonstrate an entangled two-qubit state that is based on the angular-position correlations of entangled photons. The entanglement of the two-qubit state is quantified in terms of concurrence. These results provide an additional means for preparing entangled quantum states for use in quantum information protocols
Leadership Life Skills Demonstrated by State 4-H Council Members
The study discussed here examined the demonstration of leadership life skills by former State 4-H Council members. A purposive and snowball sampling technique was used to identify former council members. Traditional qualitative research methodologies were used to collect and triangulate data. The major finding was that State 4-H Council members demonstrated a command of the seven leadership life skill categories. Recommendations include developing a training method to expand the council members\u27 decision-making abilities and the opportunities for them to develop as a group, implement training in personality types and working with different types, and employ new ways of improving communication
A multiplex PCR assay for differentiating economically important gastrointestinal nematodes of cattle
A multiplex polymerase chain reaction (PCR) test was developed for identifying gastrointestinal (GI) nematodes that commonly infect cattle. This assay was developed using adult-derived genomic DNA and shown capable of discriminating parasite eggs from the feces of experimentally-infected animals at both the species and genus levels. Sequence data from internal (ITS) and external (ETS) transcribed spacers of the ribosomal DNA (rDNA) repeats as well as the 3′-end of the small subunit rDNA and 5′-end of the large subunit rDNA were used to generate five primer sets which, when used simultaneously in a multiplex PCR, produce a unique electrophoretic DNA banding pattern charac- terized by a single DNA fragment for Ostertagia ostertagi (257 bp), Haemonchus placei (176 bp),Oesophagostomum radiatum (329 bp), Trichostrongylus colubriformis (243 bp) and Cooperia on- cophora (151 bp). In a similar manner, the constructed primer sets amplified DNA from Ostertagia lyrata, Haemonchus contortus, Trichostrongylus axei, Cooperia surnabada and Cooperia punctata. With respect to H. contortus, a closely migrating doublet was generated suggesting size heterogene- ity in the ETS which is consistent with multiple rDNA repeat units within this species. PCR analyses using mixtures of monospecifically-purified nematode eggs indicated a sensitivity of less than 0.5 egg-DNA equivalent per species. Although, not designed as a quantitative technique, relative PCR signal intensities corresponded to relative egg burdens within the DNA samples from mixed species of eggs. Published by Elsevier Science B.V
Learning teaching: becoming an inspirational teacher
This essential and aspirational text is aimed at all beginning teachers whatever your training route, age phase and setting. It explicitly adopts and builds on a new metaphor for teachers' professional learning as interplay between the body of public knowledge and the practical wisdom of teachers within a particular school setting. It also accepts that 'telling' you how to teach is ineffective; you need to 'become a teacher' because it involves identity and practice. Enquiry-based critically reflective learning with a clear focus on the learning of pupils is proposed as the core strategy by which you can build your knowledge and skills to become an outstanding teacher. Core topics, including planning, inclusion, teaching, assessment and professional development, are tackled in an accessible and refreshing way, using key research informed evidence. The focus is relentlessly on 'learning' rather than performance, in order to support you becoming an excellent professional teacher, rather than a competent technician, who makes a difference to learners, colleagues, schools and policy. Think of this book as a temporary or additional mentor, challenging you with different ways of thinking about learning and providing strategies to guide your professional learning
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