Dataset for gastrointestinal tract segmentation on serial MRIs for abdominal tumor radiotherapy.

Purpose: Integrated MRI and linear accelerator systems (MR-Linacs) provide superior soft tissue contrast, and the capability of adapting radiotherapy plans to changes in daily anatomy. In this dataset, serial MRIs of the abdomen of patients undergoing radiotherapy were collected and the luminal gastro-intestinal tract was segmented to support an online segmentation algorithm competition. This dataset may be further utilized by radiation oncologists, medical physicists, and data scientists to further improve auto segmentation algorithms.

Increasing Supportive Care for Patients With COVID-19-Related Respiratory Deterioration in Non-ICU Settings.

Background: Prepandemic hospital guidelines were unable to support an acute influx of patients with respiratory deterioration. New processes for general care practice were needed to facilitate patient care.

Purpose: To develop and evaluate guidelines to safely treat patients with COVID-19 respiratory deterioration in the general care setting.

The Effect of Ocean Salinity on Climate and Its Implications for Earth's Habitability.

The influence of atmospheric composition on the climates of present-day and early Earth has been studied extensively, but the role of ocean composition has received less attention. We use the ROCKE-3D ocean-atmosphere general circulation model to investigate the response of Earth's present-day and Archean climate system to low versus high ocean salinity. We find that saltier oceans yield warmer climates in large part due to changes in ocean dynamics.

Human-Inspired Robotic Eye-Hand Coordination Enables New Communication Channels Between Humans and Robots.

This paper concerns human-inspired robotic eye-hand coordination algorithms using custom built robotic eyes that were interfaced with a Baxter robot. Eye movement was programmed anthropomorphically based on previously reported research on human eye-hand coordination during grasped object transportation. Robotic eye tests were first performed on a component level where accurate position and temporal control were achieved.

Improved Ipsilateral Breast and Chest Wall Sparing With MR-Guided 3-fraction Accelerated Partial Breast Irradiation: A Dosimetric Study Comparing MR-Linac and CT-Linac Plans.

Purpose: External beam accelerated partial breast irradiation (APBI) is subject to treatment uncertainties that must be accounted for through planning target volume (PTV) margin. We hypothesize that magnetic resonance-guided radiation therapy with reduced PTV margins enabled by real-time cine magnetic resonance image (MRI) target monitoring results in better normal tissue sparing compared with computed tomography (CT)-guided radiation therapy with commonly used clinical PTV margins. In this study, we compare the plan quality of ViewRay MRIdian Linac forward planned intensity modulated radiation therapy and TrueBeam volumetric modulated arc therapy for a novel 3-fraction APBI schedule.

Reduction of cardiac dose using respiratory-gated MR-linac plans for gastro-esophageal junction cancer.

Treatment of locally advanced adenocarcinoma of the gastroesophageal junction (GEJ) with chemoradiation may be associated with high rates of symptomatic cardiac toxicity. Large margins are typically required to ensure coverage of GEJ tumors with free-breathing volumetric modulated arc therapy (VMAT) radiotherapy. The purpose of this study is to determine whether treatment with tighter margins enabled by maximum-inhalation breath hold (MIBH)-gated intensity modulated radiation therapy (IMRT) on an integrated MRI-linear accelerator system (MR-linac) can decrease radiation doses to the heart and cardiac substructures.

A bacterial biosynthetic pathway for methylated furan fatty acids.

Fatty acids play many important roles in cells and also in industrial processes. Furan fatty acids (FuFAs) are present in the lipids of some plant, fish, and microbial species and appear to function as second messengers in pathways that protect cells from membrane-damaging agents. We report here the results of chemical, genetic, and synthetic biology experiments to decipher the biosynthesis of the monomethylated FuFA, methyl 9-(3-methyl-5-pentylfuran-2-yl) nonanoate (9M5-FuFA), and its dimethyl counterpart, methyl 9-(3,4-dimethyl-5-pentylfuran-2-yl) nonanoate (9D5-FuFA), in two α-proteobacteria.

Exoplanet Biosignatures: A Review of Remotely Detectable Signs of Life.

In the coming years and decades, advanced space- and ground-based observatories will allow an unprecedented opportunity to probe the atmospheres and surfaces of potentially habitable exoplanets for signatures of life. Life on Earth, through its gaseous products and reflectance and scattering properties, has left its fingerprint on the spectrum of our planet. Aided by the universality of the laws of physics and chemistry, we turn to Earth's biosphere, both in the present and through geologic time, for analog signatures that will aid in the search for life elsewhere.

Perceptions and performance using computer-based testing: One institution's experience.

Background And Purpose: The purpose of this study was to evaluate student and faculty perceptions of the transition to a required computer-based testing format and to identify any impact of this transition on student exam performance.

Educational Activity And Setting: Separate questionnaires sent to students and faculty asked about perceptions of and problems with computer-based testing. Exam results from program-required courses for two years prior to and two years following the adoption of computer-based testing were compared to determine if this testing format impacted student performance.

Bone marrow suppression as a complication of total skin helical tomotherapy in the treatment of mycosis fungoides.

Background: Total skin electron beam therapy (TSEBT) is an effective treatment in mycosis fungoides. Total skin helical tomotherapy (TSHT) may be an alternative to TSEBT and may offer several dosimetric and treatment advantages. There are currently very few published treatment results using TSHT in place of TSEBT for treatment of mycosis fungoides.

Disequilibrium biosignatures over Earth history and implications for detecting exoplanet life.

Chemical disequilibrium in planetary atmospheres has been proposed as a generalized method for detecting life on exoplanets through remote spectroscopy. Among solar system planets with substantial atmospheres, the modern Earth has the largest thermodynamic chemical disequilibrium due to the presence of life. However, how this disequilibrium changed over time and, in particular, the biogenic disequilibria maintained in the anoxic Archean or less oxic Proterozoic eons are unknown.

False Negatives for Remote Life Detection on Ocean-Bearing Planets: Lessons from the Early Earth.

Ocean-atmosphere chemistry on Earth has undergone dramatic evolutionary changes throughout its long history, with potentially significant ramifications for the emergence and long-term stability of atmospheric biosignatures. Though a great deal of work has centered on refining our understanding of false positives for remote life detection, much less attention has been paid to the possibility of false negatives, that is, cryptic biospheres that are widespread and active on a planet's surface but are ultimately undetectable or difficult to detect in the composition of a planet's atmosphere. Here, we summarize recent developments from geochemical proxy records and Earth system models that provide insight into the long-term evolution of the most readily detectable potential biosignature gases on Earth-oxygen (O), ozone (O), and methane (CH).

Cyanobacterial Diazotrophy and Earth's Delayed Oxygenation.

The redox landscape of Earth's ocean-atmosphere system has changed dramatically throughout Earth history. Although Earth's protracted oxygenation is undoubtedly the consequence of cyanobacterial oxygenic photosynthesis, the relationship between biological O production and Earth's redox evolution remains poorly understood. Existing models for Earth's oxygenation cannot adequately explain the nearly 2.

Limited role for methane in the mid-Proterozoic greenhouse.

Pervasive anoxia in the subsurface ocean during the Proterozoic may have allowed large fluxes of biogenic CH to the atmosphere, enhancing the climatic significance of CH early in Earth's history. Indeed, the assumption of elevated pCH during the Proterozoic underlies most models for both anomalous climatic stasis during the mid-Proterozoic and extreme climate perturbation during the Neoproterozoic; however, the geologic record cannot directly constrain atmospheric CH levels and attendant radiative forcing. Here, we revisit the role of CH in Earth's climate system during Proterozoic time.

Earth's oxygen cycle and the evolution of animal life.

The emergence and expansion of complex eukaryotic life on Earth is linked at a basic level to the secular evolution of surface oxygen levels. However, the role that planetary redox evolution has played in controlling the timing of metazoan (animal) emergence and diversification, if any, has been intensely debated. Discussion has gravitated toward threshold levels of environmental free oxygen (O2) necessary for early evolving animals to survive under controlled conditions.