3,262 research outputs found
Producing energy while sequestering carbon? The relationship between biochar and agricultural productivity
A partial solution to problems associated with anthropogenic greenhouse gas (GHG) emissions could be the development and deployment of carbon-negative technologies, i.e., producing energy while reducing atmospheric carbon dioxide levels. Biofuels have been considered a possibility but have faced limitations due to competition with food production and GHG emissions through indirect land-use change (ILUC). In this article, we show how emissions from ILUC can potentially be reduced by producing food and bioenergy from biochar amended soils. The possibility of yield improvements from biochar would reduce the land requirement for crop production and thus, lead to a reduction in emissions from ILUC. In our application, biochar and bio-oil are produced via fast pyrolysis of corn stover. Bio-oil is subsequently upgraded into a fuel suitable for use in internal combustion engines. Applying the U.S. regulatory method used to determine biofuel life cycle emissions, our results show that a biochar-induced yield improvement in the U.S. Midwest ranging from 1% to 8% above trend can lead to an ILUC credit between 1.65 and 14.79 t CO2-equivalent haâ1 yearâ1 when future emissions are assessed over the next 30 years. The model is generalizable to other feedstocks and locations and illustrates the relationship between biochar and crop production
Effects of Low-Level Artificial Light at Night on Kentucky Bluegrass and Introduced Herbivore
Increasing evidence suggests that artificial light at night (ALAN) can negatively impact organisms. However, most studies examine the impacts of ALAN on a single species or under high levels of artificial light that are infrequent or unrealistic in urban environments. We currently have little information on how low levels of artificial light emanating from urban skyglow affect plants and their interactions with herbivores. We examined how low levels of ALAN affect grass and insects, including growth rate, photosynthesis, and stomatal conductance in grass, and foraging behavior and survival in crickets. We compared growth and leaf-level gas exchange of Kentucky Bluegrass (Poa pratensis) under low-levels of ALAN (0.3 lux) and starlight conditions (night light at 0.001 lux). Furthermore, each light treatment was divided into treatments with and without house crickets (Acheta domesticus). Without crickets present, bluegrass grown under artificial light at night for three weeks grew taller than plants grown under natural night light levels. Once crickets were introduced at the end of week three, grass height decreased resulting in no measurable effects of light treatment. There were no measurable differences in grass physiology among treatments. Our results indicate that low levels of light resulting from skyglow affect plant growth initially. However, with herbivory, ALAN effects on grass may be inconsequential. Gaining an understanding of how ALAN affects plant-insect interactions is critical to predicting ecological and evolutionary consequences of anthropogenic disturbance
Factors infuencing variation in investigations after a negative CT brain scan in suspected subarachnoid haemorrhage: A qualitative study
Introduction Variation in the approach to the patient with a possible subarachnoid haemorrhage (SAH) has been previously documented. The purpose of this study was to identify factors that influence emergency physiciansâ decisions about diagnostic testing after a normal CT brain scan for ED patients with a headache suspicious of a SAH.
Methods We conducted an interview-based qualitative study informed by social constructionist theory. Fifteen emergency physicians from six EDs across Queensland, Australia, underwent individual face-to-face or telephone interviews. Content analysis was performed whereby transcripts were examined and coded independently by two co-investigators, who then jointly agreed on the influencing factors.
Results Six categories of influencing factors were identified. Patient interaction was at the forefront of the identified factors. This shared decision-making process incorporated âwhat the patient wantsâ but may be biased by how the clinician communicates the benefits and harms of the diagnostic options to the patient. Patient risk profile, practice evidence and guidelines were also important. Other influencing factors included experiential factors of the clinician, consultation with colleagues and external influences where practice location and work processes impose constraints on test ordering external to the preferences of the clinician or patient. The six categories were organised within a conceptual framework comprising four components: the context, the evidence, the experience and the decision.
Conclusions When clinicians are faced with a diagnostic challenge, such as the workup of a patient with suspected SAH, there are a number of influencing factors that can result in a variation in approach. These need to be considered in approaches to improve the appropriateness and consistency of medical care.No Full Tex
The New York City DOE/CUNY Library Collaborative: Bridging the Gap Between High School and College
This white paper presents the progression and the processes of the New York Collaborative Curriculum Revision Project (CCRP), a collaborative of high school teachers, college faculty, and librarians, formed to build upon the new Common Core State Standards designed to help students develop and become more adept at reading critically, conducting rigorous research, and being better prepared for postsecondary success. This paper presents CCRP as a model to be replicated, modified and strengthened. The DOE/CUNY Library Collaborative is central to the development of the model and shares its successes and hard-learned lessons in its steps to recruit, engage, and facilitate collaborative methods for improving educational outcomes
Radiological response heterogeneity is of prognostic significance in metastatic renal cell carcinoma treated with vascular endothelial growth factor-targeted therapy
Background:
Response evaluation criteria in solid tumours (RECIST) is widely used to assess tumour response but is limited by not considering disease site or radiological heterogeneity (RH).
Objective:
To determine whether RH or disease site has prognostic significance in patients with metastatic clear-cell renal cell carcinoma (ccRCC).
Design, setting, and participants:
A retrospective analysis was conducted of a second-line phase II study in patients with metastatic ccRCC (NCT00942877), evaluating 138 patients with 458 baseline lesions.
Intervention:
The phase II trial assessed vascular endothelial growth factor-targeted therapy ± Src inhibition.
Outcome measurements and statistical analysis:
RH at week 8 was assessed within individual patients with two or more lesions to predict overall survival (OS) using Kaplan-Meier method and Cox regression model. We defined a high heterogeneous response as occurring when one or more lesion underwent a â„10% reduction and one or more lesion underwent a â„10% increase in size. Disease progression was defined by RECIST 1.1 criteria.
Results and limitations:
In patients with a complete/partial response or stable disease by RECIST 1.1 and two or more lesions at week 8, those with a high heterogeneous response had a shorter OS compared to those with a homogeneous response (hazard ratio [HR] 2.01; 95% confidence interval [CI]: 1.39â2.92; p < 0.001). Response by disease site at week 8 did not affect OS. At disease progression, one or more new lesion was associated with worse survival compared with >20% increase in sum of target lesion diameters only (HR 2.12; 95% CI: 1.43â3.14; p < 0.001). Limitations include retrospective study design.
Conclusions:
RH and the development of new lesions may predict survival in metastatic ccRCC. Further prospective studies are required.
Patient summary:
We looked at individual metastases in patients with kidney cancer and showed that a variable response to treatment and the appearance of new metastases may be associated with worse survival. Further studies are required to confirm these findings
Design requirements for the Wide-field Infrared Transient Explorer (WINTER)
The Wide-field Infrared Transient Explorer (WINTER) is a 1x1 degree infrared survey telescope under devel- opment at MIT and Caltech, and slated for commissioning at Palomar Observatory in 2021. WINTER is a seeing-limited infrared time-domain survey and has two main science goals: (1) the discovery of IR kilonovae and r-process materials from binary neutron star mergers and (2) the study of general IR transients, including supernovae, tidal disruption events, and transiting exoplanets around low mass stars. We plan to meet these science goals with technologies that are relatively new to astrophysical research: hybridized InGaAs sensors as an alternative to traditional, but expensive, HgCdTe arrays and an IR-optimized 1-meter COTS telescope. To mitigate risk, optimize development efforts, and ensure that WINTER meets its science objectives, we use model-based systems engineering (MBSE) techniques commonly featured in aerospace engineering projects. Even as ground-based instrumentation projects grow in complexity, they do not often have the budget for a full-time systems engineer. We present one example of systems engineering for the ground-based WINTER project, featuring software tools that allow students or staff to learn the fundamentals of MBSE and capture the results in a formalized software interface. We focus on the top-level science requirements with a detailed example of how the goal of detecting kilonovae flows down to WINTERâs optical design. In particular, we discuss new methods for tolerance simulations, eliminating stray light, and maximizing image quality of a flyâs-eye design that slices the telescopeâs focus onto 6 non-buttable, IR detectors. We also include a discussion of safety constraints for a robotic telescope
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