1,279 research outputs found

    Practical Considerations in Developing Bioenergy Crops

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    Biofuels represent a significant challenge and opportunity for agriculture. Producing liquid fuels from cellulosic biomass affords a number of potential environmental benefits. Biofuels result in lower greenhouse gas emissions than fuels derived from petroleum. Growing perennial biomass crops reduces soil erosion and sequesters more carbon than annual crops grown for grain or biomass. Corn and sorghum are crops that have high near-term potential as annual biomass crops. Dedicated biomass crops with very high yields will produce more fuel per acre, helping to balance land for food and fuel. Switchgrass and Miscanthus are perennial species that have been broadly evaluated as potential biomass crops, but will benefit from further development for widespread use. New crops and cropping systems developed specifically for bioenergy production will be necessary to meet biofuel production targets. Bioenergy crops should be developed that use inputs efficiently, have high and stable productivity, have positive environment impact, and are compatible with existing cropping systems. Most importantly, biomass crop portfolios must be developed that allow for sustained energy supply throughout the year

    Experimental Evidence for the Interplay of Exogenous and Endogenous Factors on the Movement Ecology of a Migrating Songbird

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    Movement patterns during songbird migration remain poorly understood despite their expected fitness consequences in terms of survival, energetic condition and timing of migration that will carry over to subsequent phases of the annual cycle. We took an experimental approach to test hypotheses regarding the influence of habitat, energetic condition, time of season and sex on the hour-by-hour, local movement decisions of a songbird during spring stopover. To simulate arrival of nocturnal migrants at unfamiliar stopover sites, we translocated and continuously tracked migratory red-eyed vireos (Vireo olivaceus) throughout spring stopover with and without energetic reserves that were released in two replicates of three forested habitat types. Migrants moved the most upon release, during which time they selected habitat characterized by greater food abundance and higher foraging attack rates. Presumably under pressure to replenish fuel stores necessary to continue migration in a timely fashion, migrants released in poorer energetic condition moved faster and further than migrants in better condition and the same pattern was true for migrants released late in spring relative to those released earlier. However, a migrant\u27s energetic condition had less influence on their behavior when they were in poor quality habitat. Movement did not differ between sexes. Our study illustrates the importance of quickly finding suitable habitat at each stopover site, especially for energetically constrained migrants later in the season. If an initial period prior to foraging were necessary at each stop along a migrant\u27s journey, non-foraging periods would cumulatively result in a significant energetic and time cost to migration. However, we suggest behavior during stopover is not solely a function of underlying resource distributions but is a complex response to a combination of endogenous and exogenous factors

    Understanding Risk Perception and Xenophobic Attitudes during the Coronavirus Disease 2019 (COVID-19) Pandemic in the United States

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    Introduction: There have been over 87 million cases of Coronavirus Disease 2019 (COVID-19) in the United States (US). Objective: The objective of this study was to develop a novel questionnaire to assess risk perception of COVID-19 and xenophobic attitudes among adults in the US at the beginning of the pandemic. Methods: An anonymous self-report questionnaire was developed for this study in February 2020, and was distributed using convenience sampling from March 10 to March 25, 2020. The questionnaire assessed knowledge and risk perceptions of COVID-19, as well as attitudes toward individuals of various races and ethnicities. Results: 662 US adults completed the questionnaire. On a scale from 1 (low) to 5 (high), the mean risk perception was 3.44. Those with knowledge of COVID-19 and higher education levels reported higher risk perception and higher feelings of warmth towards Asian people. Forty percent of the sample had recently witnessed or experienced anti-Asian attitudes at the time of the survey. The majority of participants reported having heard about COVID-19 from news media, social media, and family or friends. Conclusions: Our sample had a moderate level of risk perception, potentially due to the time period of data collection (i.e., early in the pandemic course). The results suggest that knowledge about COVID-19 informed perceived risk and affected willingness to engage in healthy protective behaviors. Our study provides historic context of how people perceived the virus at the beginning of the pandemic, and gives insight into the aftermaths regarding quarantine and attitudes towards Asian Americans

    Developmental Morphology and Biomass Yield of Upland and Lowland Switchgrass Ecotypes Grown in Iowa

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    Sustainable development of the bioenergy industry will depend upon the amount and quality of bioenergy feedstock produced. Switchgrass (Panicum virgatum L.) is a model lignocellulosic bioenergy crop but critical information is lacking for improved management, growth, and development simulation model calibration. A field study was conducted near Ames, IA during 2012–2013 with the objective to evaluate upland (“Cave-in-Rock”, ‘Trailblazer’ and ‘Blackwell’) and lowland (“Kanlow” and “Alamo”) switchgrass ecotypes for harvest timing on morphology (i.e., phenology, leaf area index (LAI), and biomass yield). The experiment used a randomized complete block design, with three upland and two lowland varieties harvested at six dates annually. In both years, delaying harvest to later maturity increased biomass yield; lowland cultivars produced greater biomass yield (6.15 tons ha−1) than upland ecotypes (5.10 tons ha−1). Lowland ecotypes had delayed reproductive development compared with upland ecotypes. At the end of both growing seasons, upland ecotypes had greater mean stage count (MSC) than lowland ecotypes. “Cave-in-Rock” had greatest MSC and LAI, but did not produce the greatest biomass. Relationships were nonlinear between MSC and biomass yield, with significant cultivar–year interaction. The relationship between biomass yield and MSC will be useful for improving switchgrass, including cultivar selection, fertilizer application, and optimum harvest time

    The Incidence of Malignancy and the Preoperative Assessment of Women Undergoing Hysterectomy with Morcellation for Benign Indications

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    Background: The use of power morcellation in gynecologic surgery has come under scrutiny secondary to concerns for occult malignancy dissemination. The incidence of undiagnosed gynecologic malignancy when hysterectomy performed for benign indications is not definitive but has been quoted as high as 2.7% (1:37). There is not a standard recommended preoperative evaluation, and variation is anticipated by preoperative complaint or diagnosis. Objectives: To quantify the malignancy incidence in women undergoing hysterectomy for benign indications and to compare the preoperative evaluation of patients undergoing hysterectomy with and without morcellation. Methods: Retrospective cohort of women undergoing hysterectomies between October 2007 and June 2014 was identified by procedural codes through the hospital billing system. Exclusions included hysterectomies performed by gynecologic oncologists or non-gynecologic surgeons and surgeries performed outside the UMass healthcare system. Chart abstraction included demographics; pre-hysterectomy evaluation, including current cervical cytology, pathologic endometrial assessment (biopsy, dilation and curettage), and imaging (ultrasound, MRI, CT scan, sonohysterogram, or hysteroscopy); intraoperative factors; and final diagnosis. Results: Analytic cohort included 2,332 women undergoing hysterectomy with 396 (17.0%) including use of morcellation. The malignancy incidence on final pathology was 2.1% and was different between non-morcellated versus morcellated specimens (2.5% vs. 0.3%, p Conclusion: The incidence of malignancy at time ofhysterectomy performed by non­-oncology trained gynecologists was 2.1% overall, and 0.3% in morcellated cases. The pre-operative evaluation of patients undergoing hysterectomy with morcellation is similar to those without morcellation, except for lower rates of pathologic endometrial assessment. An argument could be made that a pathology assessment is indicated in this group due to risk of dissemination in the case of occult malignancy. The risk of occult malignancy is rare, but this should be discussed with patients and taken into account during the pre-operative evaluation
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