Innovative interstellar explorer

An interstellar "precursor" mission has been under discussion in the scientific community for at least 30 years. Fundamental scientific questions about the interaction of the Sun with the interstellar medium can only be answered with in situ measurements that such a mission can provide. The Innovative Interstellar Explorer (IIE) and its use of Radioisotope Electric Propulsion (REP) is being studied under a NASA "Vision Mission" grant. Speed is provided by a combination of a high-energy launch, using current launch vehicle technology, a Jupiter gravity assist, and long-term, low-thrust, continuous acceleration provided by an ion thruster running off electricity provided by advanced radioisotope electric generators. A payload of ten instruments with an aggregate mass of ~35 kg and requiring ~30 W has been carefully chosen to address the compelling science questions. The nominal 20-day launch window opens on 22 October 2014 followed by a Jupiter gravity assist on 5 February 2016. The REP system accelerates the spacecraft to a "burnout" speed of 7.8 AU per year at 104 AU on 13 October 2032 (Voyager 1's current speed is ~3.6 AU/yr). The spacecraft will return at least 500 bits per second from at least 200 AU ~30 years after launch. Additional (backup) launch opportunities occur every 13 months to early 2018. In addition to addressing basic heliospheric science, the mission will ensure continued information on the far-heliospheric galactic cosmic ray population after the Voyagers have fallen silent and as the era of human Mars exploration begins

Technology requirements of exploration beyond Neptune by solar sail propulsion

This paper provides a set of requirements for the technology development of a solar sail propelled Interstellar Heliopause Probe mission. The mission is placed in the context of other outer solar systems missions, ranging from a Kuiper Belt mission through to an Oort cloud mission. Mission requirements are defined and a detailed parametric trajectory analysis and launch date scan performed. Through analysis of the complete mission trade space a set of critical technology development requirements are identified which include an advanced lightweight composite High-Gain Antenna, a high-efficiency Ka-band travelling-wave tube amplifier and a radioisotope thermoelectric generator with power density of approximately 12 W/kg. It is also shown that the Interstellar Heliopause Probe mission necessitates the use of a spinning sail, limiting the direct application of current hardware development activities. A Kuiper Belt mission is then considered as a pre-curser to the Interstellar Heliopause Probe, while it is also shown through study of an Oort cloud mission that the Interstellar Heliopause Probe mission is the likely end-goal of any future solar sail technology development program. As such, the technology requirements identified to enable the Interstellar Heliopause Probe must be enabled through all prior missions, with each mission acting as an enabling facilitator towards the next

Moisture Content Throughout the Pelleting Process and Subsequent Effects on Pellet Quality

This experiment was designed to evaluate the effects of steam addition to the condi­tioner on moisture content throughout the pelleting process and subsequent effects on pellet quality. Treatments consisted of diets pelleted with no steam and steam added to achieve conditioning temperatures of 145 and 190°F. Conditioner retention time was set at 30 s and diets were pelleted with a ¼ × 2 ½ inch pellet die. Pellet samples were collected and immediately placed in an experimental counterflow cooler for 15 min. All treatments were replicated at 3 separate time points to provide 3 replicates per treatment. Mash, conditioned mash, hot pellets, and cooled pellet samples were collected for moisture content analysis, and cooled pellets for pellet durability index (PDI). Data were analyzed with pelleting run as the experimental unit and time period as the blocking factor. Moisture samples were analyzed as a 3 × 4 factorial of steam-conditioning and sample location. There was a steam-conditioning × sample interaction (P \u3c 0.01) for moisture. Moisture in mash samples was similar for all treatments. For the no steam treatment, there was no difference in moisture content between the mash, conditioned mash, and hot pellets; however, moisture decreased in cooled pellets. For the 145°F treatment, there was an increase in moisture from mash to conditioned mash, followed by a decrease in both hot pellets and cooled pellets. For the 190°F treatment, moisture increased from mash to conditioned mash, and decreased in hot pellets and cooled pellets. Increasing conditioning temperature from no steam to 190°F increased (P \u3c 0.01) PDI from 3.3, 59.1, to 91.1%, respectively. In conclusion, increasing feed temperature from 97.2 to 190°F via steam addition increased the conditioned mash moisture content by 4.2%, resulting in improved pellet quality

Evaluation and reduction of magnetic resonance imaging artefacts induced by distinct plates for osseous fixation: an in vitro study @ 3 T

Objectives: To analyze MRI artefacts induced at 3 T by bioresorbable, titanium (TI) and glass fibre reinforced composite (GFRC) plates for osseous reconstruction.Methods: Fixation plates including bioresorbable polymers (Inion CPS, Inion Oy, Tampere, Finland; Rapidsorb, DePuy Synthes, Umkirch, Germany; Resorb X, Gebrueder KLS Martin GmbH, Tuttlingen, Germany), GFRC (Skulle Implants Oy, Turku, Finland) and TI plates of varying thickness and design (DePuy Synthes, Umkirch, Germany) were embedded in agarose gel and a 3 T MRI was performed using a standard protocol for head and neck imaging including T1W and T2W sequences. Additionally, different artefact reduction techniques (slice encoding for metal artefact reduction & ultrashort echo time) were used and their impact on the extent of artefacts evaluated for each material.Results: All TI plates induced significantly more artefacts than resorbable plates in T1W and T2W sequences. GFRCs induced the least artefacts in both sequences. The total extent of artefacts increased with plate thickness and height. Plate thickness had no influence on the percentage of overestimation in all three dimensions. TI-induced artefacts were significantly reduced by both artefact reduction techniques.Conclusions: Polylactide, GFRC and magnesium plates produce less susceptibility artefacts in MRI compared to TI, while the dimensions of TI plates directly influence artefact extension. Slice encoding for metal artefact reduction and ultrashort echo time significantly reduce metal artefacts at the expense of scan time or image resolution

Identification of imaging selection patterns in acute ischemic stroke patients and the influence on treatment and clinical trial enrolment decision making

For the STroke Imaging Research (STIR) and VISTA-Imaging Investigators The purpose of this study was to collect precise information on the typical imaging decisions given specific clinical acute stroke scenarios. Stroke centers worldwide were surveyed regarding typical imaging used to work up representative acute stroke patients, make treatment decisions, and willingness to enroll in clinical trials. STroke Imaging Research and Virtual International Stroke Trials Archive-Imaging circulated an online survey of clinical case vignettes through its website, the websites of national professional societies from multiple countries as well as through email distribution lists from STroke Imaging Research and participating societies. Survey responders were asked to select the typical imaging work-up for each clinical vignette presented. Actual images were not presented to the survey responders. Instead, the survey then displayed several types of imaging findings offered by the imaging strategy, and the responders selected the appropriate therapy and whether to enroll into a clinical trial considering time from onset, clinical presentation, and imaging findings. A follow-up survey focusing on 6 h from onset was conducted after the release of the positive endovascular trials. We received 548 responses from 35 countries including 282 individual centers; 78% of the centers originating from Australia, Brazil, France, Germany, Spain, United Kingdom, and United States. The specific onset windows presented influenced the type of imaging work-up selected more than the clinical scenario. Magnetic Resonance Imaging usage (27-28%) was substantial, in particular for wake-up stroke. Following the release of the positive trials, selection of perfusion imaging significantly increased for imaging strategy. Usage of vascular or perfusion imaging by Computed Tomography or Magnetic Resonance Imaging beyond just parenchymal imaging was the primary work-up (62-87%) across all clinical vignettes and time windows. Perfusion imaging with Computed Tomography or Magnetic Resonance Imaging was associated with increased probability of enrollment into clinical trials for 0-3 h. Following the release of the positive endovascular trials, selection of endovascular only treatment for 6 h increased across all clinical vignettes

Effect of the Pelleting Process on Diet Formulations with Varying Levels of Crystalline Amino Acids and Reducing Sugars on Digestibility in Growing Pigs

The objective of this study was to determine the effect of thermal processing on the digestibility of amino acids (AA) in diets with or without increased concentrations of free amino acids and reducing sugars (RS). To measure AA digestibility, a total of eight individually housed barrows (initially 69.2 ± 6.8 lb) that had a T-cannula installed in the distal ileum were allotted to a replicated 8 × 8 Latin square design with 8 diets and eight 7-d periods. Thus, each pig was fed each diet in one period and no pig received the same diet more than once. Each period lasted 7 days with the initial 5 days being the adaptation period, and ileal digesta was collected for 9 hours on d 6 and 7. Treatments were arranged in a 2 × 2 × 2 factorial with main effects of crystalline AA concentration (low vs. high), reducing sugars (low vs. high), and diet form (mash vs. pellet). There was no feed form × crystalline AA inclusion × RS inclusion interaction for standardized ileal digestible (SID) AA. There was a feed form × RS interaction (P \u3c 0.026) for SID tryptophan. Feeding pelleted high RS diets resulted in decreased SID of tryptophan compared with mash high and low RS diets, and pelleted low RS diets. For the main effects of feed form, the SID of total AA, crude protein (CP), and indispensable AA increased (P \u3c 0.042) in pigs fed pelleted diets compared with those fed mash diets. For the main effects of crystalline AA inclusion, pigs fed low or high crystalline AA inclu­sion had similar SID of total AA and CP. Pigs fed high crystalline AA had increased (P = 0.007) SID of tryptophan compared with those fed low crystalline AA diets. The SID of lysine tended to increase (P = 0.076) in pigs fed high crystalline AA diets compared with those fed low crystalline AA inclusion diets. Pigs fed high crystalline AA had decreased (P = 0.050) SID histidine compared with those fed low crystalline AA diets. The SID of arginine and isoleucine tended to decrease (P \u3c 0.079), in pigs fed high crystalline AA. In pigs fed high crystalline AA, the SID of serine and glycine decreased (P \u3c 0.042) compared with those fed low crystalline AA. For the main effects of RS diets, pigs fed high RS diets had decreased (P \u3c 0.05) SID of total AA, CP, indispensable AA, alanine, aspartic acid, cysteine, glutamic acid, and serine. In conclu­sion, there was no evidence of interactions between diet types. Therefore, pelleting diets with increased concentration of crystalline AA or RS at the conditions reported herein did not reduce the AA digestibility. However, pelleting diets resulted in improved AA digestibility. Diets formulated with increased concentrations of crystalline AA had increased SID of tryptophan. Formulating diets with 20% DDGS and 15% bakery meal (high RS) resulted in decreased AA digestibility compared with the corn-soybean meal-based diets

Predictors of functional outcome vary by the hemisphere of involvement in major ischemic stroke treated with intra-arterial therapy: a retrospective cohort study

<p>Abstract</p> <p>Background</p> <p>Conflicting data exists regarding the effect of hemispheric lateralization on acute ischemic stroke outcome. Some of this variability may be related to heterogeneous study populations, particularly with respect to the level of arterial occlusion. Furthermore, little is known about the relationship between stroke lateralization and predictors of outcome. The purpose of this study was to characterize the impact of stroke lateralization on both functional outcome and its predictors in a well-defined population of anterior circulation proximal artery occlusions treated with IAT.</p> <p>Methods</p> <p>Thirty-five consecutive left- and 35 consecutive right-sided stroke patients with intracranial ICA and/or MCA occlusions who underwent IAT were retrospectively analyzed. Ischemic change on pre-treatment imaging was quantified. Reperfusion success was graded using the Mori scale. Good outcome at three months was defined as an mRS ≤ 2. Left- and right-sided strokes were compared for outcome and its predictors.</p> <p>Result</p> <p>Of 70 patients with median NIHSS score of 18 (IQR, 14-21), 19 (27.1%) had a good outcome. There were 21 terminal ICA and 49 MCA occlusions. There was no difference in the rate of good outcomes between left- (n = 9) and right-sided (n = 10) strokes (p = 0.99). There were no significant differences in occlusion level, age, ischemic change on initial imaging and degree of reperfusion between left- and right-sided strokes. Left-sided strokes had higher baseline NIHSS scores (p = 0.02) and lower admission SBP (p = 0.009). Independent predictors of outcome for left-sided strokes were NIHSS (p = 0.0002) and reperfusion (p = 0.006), and for right-sided strokes were age (p = 0.002) and reperfusion (p = 0.003). In univariate analysis, pre-treatment ischemic change on NCCT was associated with outcome only for left-sided strokes (p = 0.05).</p> <p>Conclusions</p> <p>In anterior circulation proximal artery occlusions treated with IAT, hemispheric lateralization influences the clinical and imaging predictors of outcome. Most notably, NIHSS predicts outcome only for the left-sided strokes in this population. This finding has important implications for outcome prediction in the acute setting and indicates a need for stroke severity scales more sensitive to right hemispheric deficits.</p

The effects of immediate vision on implicit hand maps

Perceiving the external spatial location of the limbs using position sense requires that immediate proprioceptive afferent signals be combined with a stored body model specifying the size and shape of the body. Longo and Haggard (Proc Natl Acad Sci USA 107:11727–11732, 2010) developed a method to isolate and measure this body model in the case of the hand in which participants judge the perceived location in external space of several landmarks on their occluded hand. The spatial layout of judgments of different landmarks is used to construct implicit hand maps, which can then be compared with actual hand shape. Studies using this paradigm have revealed that the body model of the hand is massively distorted, in a highly stereotyped way across individuals, with large underestimation of finger length and overestimation of hand width. Previous studies using this paradigm have allowed participants to see the locations of their judgments on the occluding board. Several previous studies have demonstrated that immediate vision, even when wholly non-informative, can alter processing of somatosensory signals and alter the reference frame in which they are localised. The present study therefore investigated whether immediate vision contributes to the distortions of implicit hand maps described previously. Participants judged the external spatial location of the tips and knuckles of their occluded left hand either while being able to see where they were pointing (as in previous studies) or while blindfolded. The characteristic distortions of implicit hand maps reported previously were clearly apparent in both conditions, demonstrating that the distortions are not an artefact of immediate vision. However, there were significant differences in the magnitude of distortions in the two conditions, suggesting that vision may modulate representations of body size and shape, even when entirely non-informative

Penumbral Rescue by normobaric O = O administration in patients with ischemic stroke and target mismatch proFile (PROOF): Study protocol of a phase IIb trial.

Oxygen is essential for cellular energy metabolism. Neurons are particularly vulnerable to hypoxia. Increasing oxygen supply shortly after stroke onset could preserve the ischemic penumbra until revascularization occurs. PROOF investigates the use of normobaric oxygen (NBO) therapy within 6 h of symptom onset/notice for brain-protective bridging until endovascular revascularization of acute intracranial anterior-circulation occlusion. Randomized (1:1), standard treatment-controlled, open-label, blinded endpoint, multicenter adaptive phase IIb trial. Primary outcome is ischemic core growth (mL) from baseline to 24 h (intention-to-treat analysis). Secondary efficacy outcomes include change in NIHSS from baseline to 24 h, mRS at 90 days, cognitive and emotional function, and quality of life. Safety outcomes include mortality, intracranial hemorrhage, and respiratory failure. Exploratory analyses of imaging and blood biomarkers will be conducted. Using an adaptive design with interim analysis at 80 patients per arm, up to 456 participants (228 per arm) would be needed for 80% power (one-sided alpha 0.05) to detect a mean reduction of ischemic core growth by 6.68 mL, assuming 21.4 mL standard deviation. By enrolling endovascular thrombectomy candidates in an early time window, the trial replicates insights from preclinical studies in which NBO showed beneficial effects, namely early initiation of near 100% inspired oxygen during short temporary ischemia. Primary outcome assessment at 24 h on follow-up imaging reduces variability due to withdrawal of care and early clinical confounders such as delayed extubation and aspiration pneumonia. ClinicalTrials.gov: NCT03500939; EudraCT: 2017-001355-31