The ecosystem and evolutionary contexts of allelopathy

Plants can release chemicals into the environment that suppress the growth and establishment of other plants in their vicinity, a process known as ‘allelopathy’. However, chemicals with allelopathic functions have other ecological roles, such as plant defense, nutrient chelation, and regulation of soil biota in ways that affect decomposition and soil fertility. These ecosystem-scale roles of allelopathic chemicals can augment, attenuate or modify their community-scale functions. In this review we explore allelopathy in the context of ecosystem properties, and through its role in exotic invasions consider how evolution might affect the intensity and importance of allelopathic interactions

Very Large Array Observations of Ammonia in Infrared-Dark Clouds II: Internal Kinematics

Infrared-dark clouds (IRDCs) are believed to be the birthplaces of rich clusters and thus contain the earliest phases of high-mass star formation. We use the Green Bank Telescope (GBT) and Very Large Array (VLA) maps of ammonia (NH3) in six IRDCs to measure their column density and temperature structure (Paper 1), and here, we investigate the kinematic structure and energy content. We find that IRDCs overall display organized velocity fields, with only localized disruptions due to embedded star formation. The local effects seen in NH3 emission are not high velocity outflows but rather moderate (few km/s) increases in the line width that exhibit maxima near or coincident with the mid-infrared emission tracing protostars. These line width enhancements could be the result of infall or (hidden in NH3 emission) outflow. Not only is the kinetic energy content insufficient to support the IRDCs against collapse, but also the spatial energy distribution is inconsistent with a scenario of turbulent cloud support. We conclude that the velocity signatures of the IRDCs in our sample are due to active collapse and fragmentation, in some cases augmented by local feedback from stars.Comment: 15 pages, 12 figures, accepted for publication in Ap

Using SAP R/3 To Teach Fixed Asset Accounting And Business Process Reporting

This paper describes a simulation model specifically for the Financial Accounting Information Systems course – an SAP enabled course for junior Accounting majors.  Supporting and measuring the Supply Chain through technology is a key goal of Accounting and should therefore be reflected in an Accounting curriculum.  It will assist students to learn both the benefits, and costs, involved with implementing ERP software.  The purpose of this case is to present students with a set of business scenarios, and allow for the students to make educated and knowledgeable decisions using the SAP R/3 software.  The scenarios will act as a simplified replication of the business environment; thus, they will provide the students with an integrated learning experience.  Students make business decisions to ensure the profitability and cash flow of their respective product lines.  While making these decisions, students participate in the application and analysis provided by IDES, the simulated company integrated into the SAP system.  Eventually, they will need to justify the existence of their division by presenting profitability analysis.  To provide a “learning-by-doing” experience, the scenarios will be used to demonstrate the reporting functionality within IDES.  Today’s global economy is putting a premium on the ability of students to evaluate a broad range of decisions in collaboration with adaptive supply chains.  A critical component of the evolving accounting curriculum lies in the ability to extend students beyond the numbers to evaluate the effective and efficient delivery of these supply chains.  This paper includes our Fixed Asset Explorer Scenario, as well as a Capital Budgeting Analysis using Microsoft Excel

Very Large Array Observations of Ammonia in Infrared-dark Clouds. I. Column Density and Temperature Structure

We present Very Large Array observations of NH 3 (1,1) and (2,2) in a sample of six infrared-dark clouds (IRDCs) with distances from 2 to 5 kpc. We find that ammonia serves as an excellent tracer of dense gas in IRDCs, showing no evidence of depletion, and the average abundance in these clouds is 8.1 _ 10 –7 . Our sample consists of four IRDCs with 24 _m embedded protostars and two that appear starless. We calculate the kinetic temperature of the gas in IRDCs and find no significant difference between starless and star-forming IRDCs. We find that the bulk of the gas is between 8 and 13 K, indicating that any embedded or nearby stars or clusters do not affect the gas temperature dramatically. Though IRDCs have temperatures and volume densities on par with local star formation regions of lower mass, they consist of much more mass which induces very high internal pressures. In order for IRDCs to survive as coherent structures, the internal pressure must be balanced by a confining pressure provided by the high concentration of molecular clouds in the spiral arm in which they reside. The high molecular concentration and pressure are roughly consistent with gas dynamics of a bar galaxy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90758/1/0004-637X_736_2_163.pd

Unpalatable Plants Protect Neighbors from Grazing and Increase Plant Community Diversity

Tasty plants can be protected from herbivores by unpalatable neighbors. We used experimental exclosures, removal of unpalatable species, and transplants of palatable and unpalatable species in subalpine meadows of the Caucasus Mountains of Georgia to study the effects of two unpalatable species on plant communities. We found that Cirsium obalatum and Veratrum lobelianum, two large native perennial herbs that invade after heavy grazing, had strong facilitative effects on communities through their indirect effects on livestock herbivores. These unpalatable invaders had different effects on community composition when livestock were present than when livestock were excluded. Furthermore, removing Cirsium and Veratrum where herbivory was permitted decreased the richness of associated communities, but inside a livestock exclosure removal of these species increased community richness. Transplanted palatable species (Anthoxanthum odoratum and Phleum alpinum) grew larger inside the exclosure, and in the exclosure Cirsium and Veratrum had no effect on their growth. However, outside of the exclosure, Cirsium and Veratrum had strong positive effects on the growth of A. odoratum and P. alpinum. Excluding livestock decreased the growth of Luzula pseudosudetica, another unpalatable species, and Cirsium and Veratrum had no effect on L. pseudosudetica outside the exclosure. In contrast, inside exclosures Cirsium and Veratrum had competitive effects on L. pseudosudetica. Our results indicate that Cirsium and Veratrum, which are in some ways undesirable rangeland weeds, may also play an important role in maintaining species and functional diversity of overgrazed plant communities in the Caucasus

Cost of Defense in the Context of Plant Competition: Brassica Rapa May Grow and Defend

Theory on costs of plant defense against herbivory in stressful environments predicts that costs should increase when competition is intense. This amplifies a fundamental dilemma that plants are thought to face: allocate limited resources to grow fast enough to compete, or invest these resources in secondary metabolites to maintain defense. We studied costs associated with genetic and environmental variation in secondary metabolite production of Brassica rapa in the presence and absence of the generalist competitor Lolium perenne. We used experimental quantitative genetics (artificial selection) to manipulate genetic variation, and herbivore-induction treatments to produce environmental variation in myrosinase and glucosinolate concentrations and resistance. Glucosinolates, and their byproducts after breakdown by myrosinase, are known to affect herbivory on plants in the Brassicaceae family. Defense costs were significant in the absence of competitors, but in contrast to theoretical predictions, costs of constitutive defense (measured as growth rates) were not detectable and the cost of induced defense remained the same in the competitive environment. To understand what factors made constitutive defense costs not detectable under competition we conducted several experiments to assess the effects of limited resources and allelopathy on costs and benefits of the defense chemicals. None of the experiments involving nutrient supply and weak competition supported the hypothesis that the lack of defense costs in competitive environments was due to limited resources. Instead, the breakdown products of the glucosinolate–myrosinase reaction appeared to function as allelopathic agents, which may benefit B. rapa plants in competition, thereby reducing net costs of chemical defense. We found that: (1) the effects of exogenous glucosinolates on Lolium root length depended on the presence of myrosinase. (2) In the absence of nutrients, Lolium root lengths were shorter when seeds germinated with B. rapa. (3) Genetic increases in glucosinolate concentration negatively affected Lolium seedling growth only when there were simultaneous genetic increases in myrosinase concentration. Activated carbon treatments designed to neutralize allelopathic effects and restore costs in the competitive environments were, however, not statistically significant. When plant defenses also function to benefit plants in competitive interactions, plants may evolve to compete and defend

The Influence of Visual Provenance Representations on Strategies in a Collaborative Hand-off Data Analysis Scenario

Conducting data analysis tasks rarely occur in isolation. Especially in intelligence analysis scenarios where different experts contribute knowledge to a shared understanding, members must communicate how insights develop to establish common ground among collaborators. The use of provenance to communicate analytic sensemaking carries promise by describing the interactions and summarizing the steps taken to reach insights. Yet, no universal guidelines exist for communicating provenance in different settings. Our work focuses on the presentation of provenance information and the resulting conclusions reached and strategies used by new analysts. In an open-ended, 30-minute, textual exploration scenario, we qualitatively compare how adding different types of provenance information (specifically data coverage and interaction history) affects analysts' confidence in conclusions developed, propensity to repeat work, filtering of data, identification of relevant information, and typical investigation strategies. We see that data coverage (i.e., what was interacted with) provides provenance information without limiting individual investigation freedom. On the other hand, while interaction history (i.e., when something was interacted with) does not significantly encourage more mimicry, it does take more time to comfortably understand, as represented by less confident conclusions and less relevant information-gathering behaviors. Our results contribute empirical data towards understanding how provenance summarizations can influence analysis behaviors.Comment: to be published in IEEE Vis 202

Telehealth Utilization in Response to the COVID-19 Pandemic: Current State of Medical Provider Training

Background: The COVID-19 pandemic accelerated the development of telehealth services and thus the need for telehealth education and training to support rapid implementation at scale. A national survey evaluating the current state of the telehealth landscape was deployed to organizational representatives, and included questions related to education and training. Materials and Methods: In the summer of 2020, 71 survey participants (31.8%) completed an online survey seeking to determine the utilization of telehealth services across institutional types and locations. This included data collected to specifically compare the rates and types of formal telehealth education provided before and during the pandemic. Results: Thirty percent of organizations reported no telehealth training before COVID-19, with those in suburban/rural settings significantly less likely to provide any training (55% vs. 82%) compared with urban. Pandemic-related training changes applied to 78% of organizations, with more change happening to those without any training before COVID-19 (95%). Generally, organizations offering training before the pandemic reported deploying COVID-19-related telehealth services, while a higher percentage of those without any training beforehand reported that they either did not plan on providing these services or were in the early planning stages. Discussion: Telehealth education is moving from elective to essential based on the need to prepare and certify the workforce to support high-quality telehealth services. Conclusions: As telehealth continues to evolve to meet the future health care service needs of patients and providers, education and training will advance to meet the needs of everyday clinical encounters and broader public health initiatives

Building Telehealth Teams of the Future Through Interprofessional Curriculum Development: A Five-Year Mixed Methodology Study

Building the next generation of telehealth enabled professionals requires a mixture of team-based, interprofessional practice with novel technologies that connect providers and patients. Effective telehealth education is critical for the development of multidisciplinary training curricula to ensure workforce preparedness. In this study, we evaluated the impact of a formal telehealth education curriculum for interprofessional students through an online elective. Over 12 semesters, 170 students self-selected to enroll in the 3-credit hour interprofessional elective and took part in structured didactic, experiential and interprofessional learning opportunities. Mixed-method assessments show significant knowledge and confidence gains with students reflecting on their roles as future healthcare providers. The results from five years’ worth of course data shows not only an opportunity to advance the individual knowledge of trainees, but a larger movement to facilitate changes in practice toward population health goals. Recent global health events have further highlighted the need for a rapid response to public health emergencies by highly trained provider teams who are able to utilize technology as the cornerstone for the continuity of care

Hurricane Impact on Emergency Services and Use of Telehealth to Support Prehospital Care

The impact of hurricanes on emergency services is well-known. Recent history demonstrates the need for prehospital and emergency department coordination to serve communities during evacuation, storm duration, and cleanup. The use of telehealth applications may enhance this coordination while lessening the impact on health-care systems. These applications can address triage, stabilization, and diversion and may be provided in collaboration with state and local emergency management operations through various shelters, as well as during other emergency medical responses