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"Jarvis, A."
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Tempering of cocoa butter and chocolate using minor lipidic components
Chocolate manufacture includes a complex tempering procedure to direct the crystallization of cocoa butter towards the formation of fat crystal networks with specific polymorphism, nano- and microstructure, melting behavior, surface gloss and mechanical properties. Here we investigate the effects of adding various minor non-triglyceride lipidic components to refined cocoa butter and chocolate on their physical properties. We discover that addition of saturated phosphatidylcholine and phosphatidylethanolamine to neutralized and bleached cocoa butter or molten and recrystallized commercial chocolate at 0.1% (w/w) levels, followed by rapid cooling to 20 °C in the absence of shear, accelerates crystallization, stabilizes the desirable Form V polymorph and induces the formation of chocolate with an optimal microstructure, surface gloss and mechanical strength. Final chocolate structure and properties are comparable to those of a commercial tempered chocolate. Minor lipidic component addition represents an effective way to engineer chocolate material properties at different length scales, thus simplifying the entire tempering process.
In chocolate production, a complicated tempering process is used to guide the crystallization of cocoa butter towards its most desirable polymorph, which gives the chocolate proper melting behavior, gloss, and snap—hallmarks of good quality chocolate. Here, the authors find that simply adding a specific phospholipid also directs crystallization towards this polymorph, producing chocolate with comparable microstructure and properties to tempered chocolate.
Journal Article
Spinel-type lithium cobalt oxide as a bifunctional electrocatalyst for the oxygen evolution and oxygen reduction reactions
Development of efficient, affordable electrocatalysts for the oxygen evolution reaction and the oxygen reduction reaction is critical for rechargeable metal-air batteries. Here we present lithium cobalt oxide, synthesized at 400 °C (designated as LT-LiCoO
2
) that adopts a lithiated spinel structure, as an inexpensive, efficient electrocatalyst for the oxygen evolution reaction. The catalytic activity of LT-LiCoO
2
is higher than that of both spinel cobalt oxide and layered lithium cobalt oxide synthesized at 800 °C (designated as HT-LiCoO
2
) for the oxygen evolution reaction. Although LT-LiCoO
2
exhibits poor activity for the oxygen reduction reaction, the chemically delithiated LT-Li
1−x
CoO
2
samples exhibit a combination of high oxygen reduction reaction and oxygen evolution reaction activities, making the spinel-type LT-Li
0,5
CoO
2
a potential bifunctional electrocatalyst for rechargeable metal-air batteries. The high activities of these delithiated compositions are attributed to the Co
4
O
4
cubane subunits and a pinning of the Co
3+/4+
:3d energy with the top of the O
2−
:2p band.
The development of electrocatalysts for oxygen evolution and reduction is critical for rechargeable metal-air battery applications. Here, the authors synthesize and evaluate a delithiated spinel-type lithium cobalt oxide that exhibits promising performance for both processes.
Journal Article
Bridging the gap: Using reservoir ecology and human serosurveys to estimate Lassa virus spillover in West Africa
Forecasting the risk of pathogen spillover from reservoir populations of wild or domestic animals is essential for the effective deployment of interventions such as wildlife vaccination or culling. Due to the sporadic nature of spillover events and limited availability of data, developing and validating robust, spatially explicit, predictions is challenging. Recent efforts have begun to make progress in this direction by capitalizing on machine learning methodologies. An important weakness of existing approaches, however, is that they generally rely on combining human and reservoir infection data during the training process and thus conflate risk attributable to the prevalence of the pathogen in the reservoir population with the risk attributed to the realized rate of spillover into the human population. Because effective planning of interventions requires that these components of risk be disentangled, we developed a multi-layer machine learning framework that separates these processes. Our approach begins by training models to predict the geographic range of the primary reservoir and the subset of this range in which the pathogen occurs. The spillover risk predicted by the product of these reservoir specific models is then fit to data on realized patterns of historical spillover into the human population. The result is a geographically specific spillover risk forecast that can be easily decomposed and used to guide effective intervention. Applying our method to Lassa virus, a zoonotic pathogen that regularly spills over into the human population across West Africa, results in a model that explains a modest but statistically significant portion of geographic variation in historical patterns of spillover. When combined with a mechanistic mathematical model of infection dynamics, our spillover risk model predicts that 897,700 humans are infected by Lassa virus each year across West Africa, with Nigeria accounting for more than half of these human infections.
Journal Article
The relative age effect reversal among the National Hockey League elite
Like many sports in adolescence, junior hockey is organized by age groups. Typically, players born after December 31st are placed in the subsequent age cohort and as a result, will have an age advantage over those players born closer to the end of the year. While this relative age effect (RAE) has been well-established in junior hockey and other professional sports, the long-term impact of this phenomenon is not well understood. Using roster data on North American National Hockey League (NHL) players from the 2008-2009 season to the 2015-2016 season, we document a RAE reversal-players born in the last quarter of the year (October-December) score more and command higher salaries than those born in the first quarter of the year. This reversal is even more pronounced among the NHL \"elite.\" We find that among players in the 90th percentile of scoring, those born in the last quarter of the year score about 9 more points per season than those born in the first quarter. Likewise, elite players in the 90th percentile of salary who are born in the last quarter of the year earn 51% more pay than players born at the start of the year. Surprisingly, compared to players at the lower end of the performance distribution, the RAE reversal is about three to four times greater among elite players.
Journal Article
Orally delivered MK-4482 inhibits SARS-CoV-2 replication in the Syrian hamster model
The COVID-19 pandemic progresses unabated in many regions of the world. An effective antiviral against SARS-CoV-2 that could be administered orally for use following high-risk exposure would be of substantial benefit in controlling the COVID-19 pandemic. Herein, we show that MK-4482, an orally administered nucleoside analog, inhibits SARS-CoV-2 replication in the Syrian hamster model. The inhibitory effect of MK-4482 on SARS-CoV-2 replication is observed in animals when the drug is administered either beginning 12 h before or 12 h following infection in a high-risk exposure model. These data support the potential utility of MK-4482 to control SARS-CoV-2 infection in humans following high-risk exposure as well as for treatment of COVID-19 patients.
While vaccines protecting against SARS-CoV-2 infection are approved, currently, there are no drugs suitable for high-risk exposure use against SARS-CoV-2. Here, Rosenke et al. provide evidence that orally delivered MK-4482, a nucleoside analog, inhibits SARS-CoV-2 replication in the Syrian hamster model.
Journal Article
Revealing the Application of Synchrotron‐Based X‐Ray Computed Tomography in Healthy Versus Unhealthy Interior Lodgepole Pine (Pinus contorta var. latifolia) Conelets
The reproductive cycle of interior lodgepole pine spans approximately 26 months, with seed cones initiating in late summer, followed by pollen conelets emerging the next spring when pollination occurs. Fertilization and cone maturation occur in the subsequent spring and fall. Successful pollination, critical for seed conelet retention, requires an ~80% success rate. In June 2020, 30 pine clones (genotypes), with contrasting conelet abortion rates, were selected from a production seed orchard in Alberta, Canada. Sixty conelets per clone (30 aborted and 30 healthy) were collected for synchrotron radiation–based microcomputed tomography (SR‐μCT) analysis. A subset of two contrasting clones (1401 and 596) was selected for detailed study. Conelets were transported to the Canadian Light Source in Saskatoon, Saskatchewan, for SR‐μCT Phase Contrast Imaging (PCI), where samples were mounted and scanned using a PCO Edge 5.5 sCMOS camera and analyzed using Avizo software to visualize internal structures. Results showed that healthy conelets in clones 1401 and 596 had greater tissue volume (248.8 and 251.9 mm3, respectively) and more organized cavity spaces than aborted conelets (64.7 and 102.1 mm3, respectively), with differential internal air space volume (clone 1401: 8.7 mm3 in aborted vs. 17.5 mm3 in healthy; clone 596: 6.9 mm3 in aborted vs. 11.5 mm3 in healthy). Overall, SR‐μCT imaging demonstrated significant advantages over traditional methods of visualization by providing a nondestructive, high‐resolution analysis of internal structures. In addition, this technology enhances our understanding of pine reproductive processes, improving management practices in seed orchards—the delivery system for tree improvement programs.
Journal Article
Imaging radiation dose in breast radiotherapy by X-ray CT calibration of Cherenkov light
Imaging Cherenkov emission during radiation therapy cancer treatments can provide a real-time, non-contact sampling of the entire dose field. The emitted Cherenkov signal generated is proportional to deposited dose, however, it is affected by attenuation from the intrinsic tissue optical properties of the patient, which in breast, ranges from primarily adipose to fibroglandular tissue. Patients being treated with whole-breast X-ray radiotherapy (
n
= 13) were imaged for 108 total fractions, to establish correction factors from the linear relationships between Cherenkov light and CT number (HU). This study elucidates this relationship in vivo, and a correction factor approach is used to scale each image to improve the linear correlation between Cherenkov emission intensity and dose (
R
6
X
2
=
0.85
,
R
10
X
2
=
0.95
). This study provides a major step towards direct quantitative radiation dose imaging in humans by utilizing non-contact camera sensing of Cherenkov emission during the radiation therapy treatment.
Imaging Cherenkov emission during radiotherapy can provide information on the delivered radiation dose, but is attenuated by optical properties of the tissue. Here the authors derive a correction factor applicable to breast X-ray radiotherapy in human subjects to improve the correlation between Cherenkov emission intensity and dose.
Journal Article
Quantifying the benefit of early climate change mitigation in avoiding biodiversity loss
Climate change is expected to significantly influence biodiversity, but the performance of climate change mitigation strategies in reducing these impacts is not yet known. Simulations of the future ranges of common and widespread species indicate that mitigation could reduce range loss by 60% if emissions peak in 2016, or by 40% if emissions peak in 2030.
Climate change is expected to have significant influences on terrestrial biodiversity at all system levels, including species-level reductions in range size and abundance, especially amongst endemic species
1
,
2
,
3
,
4
,
5
,
6
. However, little is known about how mitigation of greenhouse gas emissions could reduce biodiversity impacts, particularly amongst common and widespread species. Our global analysis of future climatic range change of common and widespread species shows that without mitigation, 57±6% of plants and 34±7% of animals are likely to lose ≥50% of their present climatic range by the 2080s. With mitigation, however, losses are reduced by 60% if emissions peak in 2016 or 40% if emissions peak in 2030. Thus, our analyses indicate that without mitigation, large range contractions can be expected even amongst common and widespread species, amounting to a substantial global reduction in biodiversity and ecosystem services by the end of this century. Prompt and stringent mitigation, on the other hand, could substantially reduce range losses and buy up to four decades for climate change adaptation.
Journal Article
Defining the Syrian hamster as a highly susceptible preclinical model for SARS-CoV-2 infection
Following emergence in late 2019, SARS-CoV-2 rapidly became pandemic and is presently responsible for millions of infections and hundreds of thousands of deaths worldwide. There is currently no approved vaccine to halt the spread of SARS-CoV-2 and only very few treatment options are available to manage COVID-19 patients. For development of preclinical countermeasures, reliable and well-characterized small animal disease models will be of paramount importance. Here we show that intranasal inoculation of SARS-CoV-2 into Syrian hamsters consistently caused moderate broncho-interstitial pneumonia, with high viral lung loads and extensive virus shedding, but animals only displayed transient mild disease. We determined the infectious dose 50 to be only five infectious particles, making the Syrian hamster a highly susceptible model for SARS-CoV-2 infection. Neither hamster age nor sex had any impact on the severity of disease or course of infection. Finally, prolonged viral persistence in interleukin 2 receptor gamma chain knockout hamsters revealed susceptibility of SARS-CoV-2 to adaptive immune control. In conclusion, the Syrian hamster is highly susceptible to SARS-CoV-2 making it a very suitable infection model for COVID-19 countermeasure development.
Journal Article