310 research outputs found
Induced resistance in rice, oryza sativa, to herbivores in the southern united states
The effects of herbivory and chemical applications as potential inducers of resistance to herbivores in rice, Oryza sativa L., were explored through a series of field, greenhouse, and laboratory experiments. Studies were conducted to investigate the preference and performance of several herbivore pests of rice with a focus on, Lissorhoptrus oryzophilus Kuschel, the rice water weevil (RWW), under conditions where rice plants had been stressed by previous herbivory or chemical applications. The effects of defoliation by Spodoptera frugiperda (J.E. Smith), the fall armyworm, on resistance and tolerance of rice to RWW under field conditions were examined. Herbivory by fall armyworm on rice may indirectly affect RWW in rice fields in the southeastern United States via changes in rice resistance and tolerance. Hypotheses were that defoliation by fall armyworm would alter the resistance of rice to subsequent infestation by RWW, and that defoliation would reduce the tolerance of rice to subsequent RWW injury. Additional experiments probed the effects of larval and adult feeding on rice tissues by RWW on subsequent adult RWW preference. Hypotheses were that prior feeding by either stage would alter plant resistance to subsequent adult infestation. These studies provided strong support for larval induced resistance to aboveground conspecific adults, while providing weaker support for adult induced resistance to subsequent RWW adults. Investigations of the effects of methyl jasmonate, a derivative of the plant hormone jasmonic acid, which is involved in the mechanisms underlying induced resistance to herbivores, were also studied at the greenhouse and field level. It was hypothesized that methyl jasmonate seed treatments would increase resistance in rice to RWW. Results indicated that while the compound did not provide protection equal to pyrethroid insecticides, it was capable of inducing resistance to RWW at the cost of delays in plant growth and potential reductions in yield. Finally, herbicide-induced resistance to major herbivores in LA rice was investigated at the field level. These herbivores included the RWW, a complex of stemborers (Lepidoptera:Crambidae) including Diatraea saccharalis (Fabricius), the sugarcane borer, Chilo plejadellus (Zincken), the rice stalk borer, and Eoreuma loftini (Dyar), the Mexican rice borer, as well as the rice stink bug, Oebalus pugnax (Fabricius). Hypotheses were that there would be both direct and indirect effects of herbicides on insect and weed densities in rice, and that these effects would translate to differences in rice yields between treatments. Overall results from this series of experiments indicate that herbicides are capable of altering pest densities of both weeds and insects, and the resulting changes in these communities can have impacts on yields. Collectively, this work documents the potential of plant stressors including herbivory, hormone seed treatments, and herbicide injury to influence resistance of rice to insect herbivores. The broader implications of the work presented are significant due to the potential impact this information may have on IPM and future research. It is important to note that rice in the southern U. S. can be used as a model for developing countries where pest management options are limited and pesticide safety is frequently eschewed
BUILDING THE NEST: HOW NATIVE ENGLISH SPEAKING TEACHERS (NESTs) IN THE TEFL FIELD DEVELOP INTERCULTURAL COMPETENCE
The role of an English foreign language teacher requires expertise in the English language and pedagogical skills to make the learning process approachable for a variety of students. There are certain characteristics that make a person ostensibly suitable for the role such as patience, intelligence, trustworthiness and creativity. However, the development of teachers is often shaped by their certification preparation, experiences in the field of education and the lessons they learn from their students. The purpose of this qualitative case study is to examine how native English speaking teachers (NESTs) in Costa Rica teaching English as a foreign language develop their knowledge, skills and critical awareness. This case study was guided by the following research questions: 1.) How do NESTsâ understanding of their studentsâ culture shape their teaching practice, and based on this understanding, how do teachers adapt to studentsâ needs and behavior?, 2.) How do NESTsâ perceptions of and adaptations to their host country shape their teaching practice?, and 3.) How do NESTs perceive and respond to the influences of English and U.S. American culture in Costa Rica? To answer these questions, six native English speaking teachers were interviewed regarding their experiences as English teachers. Additionally, documents from Teaching English as a Foreign Language (TEFL) certificate programs were collected and analyzed. The teachersâ responses and the documents collected were analyzed from a sociocultural theoretical perspective and a critical pedagogical lens while incorporating an intercultural communicative competence model. From this analysis three themes emerged that address how these six native English speaking teachers learned and developed during their time in Costa Rica. The themes are: 1.) Teachersâ perceptions of and adaptation to Costa Rica, 2.) Teachersâ perceptions of and interactions with their students, and 3.) Teachersâ attitudes towards TEFL and responses to studentsâ needs in the TEFL classroom. The findings suggest that teachers who travel to new countries learn from their new host communities, as well as their students, and adapt to the new environment. The teachers also adjusted their behaviors and manners of instruction to serve the needs of their students. The implications for the field of English foreign language education show a need for further intercultural competency training for native English speaking teachers, and a critical analysis of training materials that impact all TEFL teachers, administrators, and other stakeholders
Honoring Patient Do Not Resuscitate Wishes and Reducing Harm During Transitions of Care: A Quality Improvement Project
Objectives: The quality improvement project objectives were to honor documented Do Not Resuscitate wishes in emergency departments by examining and improving workflow during primary care to emergency department transitions. A location for advance care planning documentations was designated for advanced directives, yet not utilized.
Methods: Mixed method, pre-/post-comparison, and thematic design examined clinicians and patients in a primary care office and two emergency departments in a Midwest healthcare system. Data was collected from patient records, clinician surveys, and observation of workflow. Descriptive statistics, frequency counts and non-parametric tests were used to analyze data.
Results: Patient charts were audited (N=261 [pre=124; post=137]), mean age 79.2 years, 59% female. Clinician surveys included 32 emergency department providers (30=pre; 2=post) and 59 registered nurses (38=pre; 21=post). Patient chart audit (N=137) found 97% had a primary care code status with 2.9% in emergency department records. Provider (mean 2.93) and registered nurse (mean 3.14) moral distress was moderate. Pre/post barriers to discuss advanced directives increased from 80.2% to 100%; comfort discussing advanced directives improved from 43.2% to 100%; and providers (13.3-100%) and registered nurses (3-19%) were more aware of where to document advanced directives.
Conclusions: Gaps in care placed patients with Do Not Resuscitate at risk for harm due to challenges with documentation. Post-implementation knowledge improved yet workflow and placement of Do Not Resuscitate orders in the record did not change. A clinically significant improvement in clinician knowledge of patient safety and location of advance care planning documents may lead to improved care
Recommended from our members
Foundations of High Performance Computing Micro-credential Checklist - Emily Kraus
This micro-credentialed course provides a foundation for addressing computing-, memory-, or storage-intensive research problems using high-performance computing (HPC). Participants who complete the course will be able to navigate the Linux command line, apply data transfer protocols, find and use software on HPC, and use a scheduler to run batch and interactive jobs. Skills acquired in the course can greatly accelerate problem solving in the computational realm.</p
Asymmetric radiating brane-world
At high energies on a cosmological brane of Randall-Sundrum type, particle
interactions can produce gravitons that are emitted into the bulk and that can
feed a bulk black hole. We generalize previous investigations of such radiating
brane-worlds by allowing for a breaking of Z_2-symmetry, via different bulk
cosmological constants and different initial black hole masses on either side
of the brane. One of the notable features of asymmetry is a suppression of the
asymptotic level of dark radiation, which means that nucleosynthesis
constraints are easier to satisfy. There are also models where the radiation
escapes to infinity on one or both sides, rather than falling into a black
hole, but these models can have negative energy density on the brane.Comment: sign error in eq. (34) corrected; version to appear Phys. Rev.
A New Look at an Old Cluster: The Membership, Rotation, and Magnetic Activity of Low-Mass Stars in the 1.3-Gyr-Old Open Cluster NGC 752
The nearby open cluster NGC 752 presents a rare opportunity to study stellar
properties at ages >1 Gyr. However, constructing a membership catalog for it is
challenging; most surveys have been limited to identifying its giants and dwarf
members earlier than mid-K. We supplement past membership catalogs with
candidates selected with updated photometric and proper-motion criteria,
generating a list of 258 members, a >50% increase over previous catalogs. Using
a Bayesian framework to fit MESA Isochrones & Stellar Tracks evolutionary
models to literature photometry and the Tycho-Gaia Astrometric Solution data
available for 59 cluster members, we infer the age of, and distance to, NGC
752: 1.340.06 Gyr and 438 pc. We also report the results of
our optical monitoring of the cluster using the Palomar Transient Factory. We
obtain rotation periods for 12 K and M cluster members, the first periods
measured for such low-mass stars with a well-constrained age >1 Gyr. We compare
these new periods to data from the younger clusters Praesepe and NGC 6811, and
to a theoretical model for angular-momentum loss, to examine stellar spin down
for low-mass stars over their first 1.3 Gyr. While on average NGC 752 stars are
rotating more slowly than their younger counterparts, the difference is not
significant. Finally, we use our spectroscopic observations to measure Halpha
for cluster stars, finding that members earlier than M2 are
magnetically inactive, as expected at this age. Forthcoming Gaia data should
solidify and extend the membership of NGC 752 to lower masses, thereby
increasing its importance for studies of low-mass stars.Comment: Accepted to ApJ. This version 23 pages, 15 figures; on-line version
will include 11 more figures as well as light curve data for the 12 rotators
we identif
First record of an indigenous South African parasitoid wasp on an imported biological control agent, the water hyacinth hopper
Water hyacinth, Pontederia crassipes (Martius) [âĄEichhornia crassip es (Martius) Solms-Laubach] (Pontederiaceae), is native to South America, but has expanded its range to many other regions of the world including South Africa. Megamelus scutellaris Berg (Hemiptera: Delphacidae) was released as a biological control agent and has established in several regions. Recently, the indigenous species Echthrodelphax migratorius Benoit, (Hymenoptera: Dryinidae) was discovered in South Africa parasitising M. scutellaris. This newly discovered relationship might have repercussions for the efficacy of biological control of water hyacinth by the delphacid. The wasp may negatively impact M. scutellaris populations making it difficult for the agent to successfully manage the invasive weed. Contrarily, the parasitoid may be beneficial by keeping the M. scutellaris populations stable, serving as a natural enemy
First record of an indigenous South African parasitoid wasp on an imported biological control agent, the water hyacinth hopper
Water hyacinth, Pontederia crassipes (Martius) [âĄEichhornia crassip es (Martius) Solms-Laubach] (Pontederiaceae), is native to South America, but has expanded its range to many other regions of the world including South Africa. Megamelus scutellaris Berg (Hemiptera: Delphacidae) was released as a biological control agent and has established in several regions. Recently, the indigenous species Echthrodelphax migratorius Benoit, (Hymenoptera: Dryinidae) was discovered in South Africa parasitising M. scutellaris. This newly discovered relationship might have repercussions for the efficacy of biological control of water hyacinth by the delphacid. The wasp may negatively impact M. scutellaris populations making it difficult for the agent to successfully manage the invasive weed. Contrarily, the parasitoid may be beneficial by keeping the M. scutellaris populations stable, serving as a natural enemy
- âŠ