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Several important sensory physical quantities exist but are difficult to quantify, including food freshness. With the aid of a hyperspectral imaging system (HIS) and machine learning (ML), meat freshness is converted into a measurable physical quantity, i.e., freshness index (F. I.), in this study. F. I. is defined from meat fluorescence, which has a strong correlation with bacterial density, using a line-scan-type HIS stimulated at 365 nm. Combined with ML techniques, hyperspectral images are processed more efficiently. By employing linear discriminant and quadratic component analyses for hyperspectral images, F. I. can be estimated from its decision boundary after hyperspectral images are taken at an unknown freshness state. Advanced sensing versatility utilized by computational sensing systems allows hyper-personalization and hyper-customization of human life with the aid of home appliances and smartphones.

Measuring, recoding and analyzing of spectral information of materials as its unique finger print using a ubiquitous smart phone has been craved for by scientists and consumers. We demonstrated the concept of a spectral barcode in drug classification with a smartphone Raman spectrometer. The spectral barcode is a 2D Raman spectral intensity map captured with a CMOS-image sensor integrated with a periodic array of band-pass filters. We classified the type of each drug by capturing its spectrum and using a convolutional neural network (CNN) that we trained to identify 11 major spectral components. This yielded a prediction accuracy of 99%, including drugs in the same category but from different brands. The accuracy of identifying drugs by individual brand was 79.5%, which improved to 83.2% simultaneously using the spectral barcode and RGB image in the CNN. This inherent property-based labeling system will facilitate fundamental research and business opportunities.

The post-Umbrella Hong Kong is a site where the unprivileged memories are faced with a systematic eradication against the privileged and dominant memories of mainland China. A strong ‘archive drive’ exists in the scene which makes the memories of Hong Kong struggle to preserve themselves in defense to their obliteration. For memories to become archived, or an archive, they should go through two consecutive steps. First, they need to acquire a physical space where they can be preserved. Second, they need to be given a law, order, or way of interpretation and enunciation. While the privileged memories unquestioningly undergo the process, those of the unprivileged confront difficulties in both steps. By looking into the post-Umbrella Hong Kong’s omnibus film Ten Years, this essay will examine the archival struggle of Hong Kong memories where they show emotional anxiety and frustration, but also seek for an alternative way to become an actual archive.

South Korean studies on coronavirus disease-2019 (COVID-19) treatment have described the use of community treatment centers (CTCs), which combine elements of the home and hospital, to isolate and treat mild COVID-19 patients. While the number of South Koreans diagnosed with COVID-19 cases has varied greatly by season, the number of confirmed cases in foreign nationals has shown no seasonality, with an average of around 25 to 30 per day. For foreign patients, accommodation arrangements and travel routes may be difficult; they may also have difficulty accessing medical care, so require careful management. We discuss our experience in operating and managing a CTC for foreign COVID-19 patients arriving in South Korea with mild symptoms. We also propose guidelines for efficient use of resources with respect to treating these patients in CTCs. We present the clinical findings of patients treated at the CTC between 7 October and 22 November 2020, and make some recommendations. We quarantined and treated foreign patients with mild symptoms of COVID-19 at the Ansan CTC. Discharge is determined based on clinical symptoms rather than polymerase chain reaction results. Medical and administrative staff use building A, while building B is used for isolating patients. Medical rounds are in the form of twice-daily video calls. Three kinds of foods with medication are served according to the patient's country of origin. In total, 315 patients were admitted to the Ansan CTC between 7 October and 22 November 2020; 145 of them were discharged from the CTC and 26 were transferred to other hospitals. To utilize medical resources efficiently during the pandemic, it is desirable to reserve CTCs exclusively for foreign patients.

Algal plankton survived darkness and reconquered the oceans by resorting to hunting after the end-Cretaceous asteroid impact., The end-Cretaceous bolide impact triggered the devastation of marine ecosystems. However, the specific kill mechanism(s) are still debated, and how primary production subsequently recovered remains elusive. We used marine plankton microfossils and eco-evolutionary modeling to determine strategies for survival and recovery, finding that widespread phagotrophy (prey ingestion) was fundamental to plankton surviving the impact and also for the subsequent reestablishment of primary production. Ecological selectivity points to extreme post-impact light inhibition as the principal kill mechanism, with the marine food chain temporarily reset to a bacteria-dominated state. Subsequently, in a sunlit ocean inhabited by only rare survivor grazers but abundant small prey, it was mixotrophic nutrition (autotrophy and heterotrophy) and increasing cell sizes that enabled the eventual reestablishment of marine food webs some 2 million years later.

Importance There is limited information about the clinical course and viral load in asymptomatic patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Objective To quantitatively describe SARS-CoV-2 molecular viral shedding in asymptomatic and symptomatic patients. Design, Setting, and Participants A retrospective evaluation was conducted for a cohort of 303 symptomatic and asymptomatic patients with SARS-CoV-2 infection between March 6 and March 26, 2020. Participants were isolated in a community treatment center in Cheonan, Republic of Korea. Main Outcomes and Measures Epidemiologic, demographic, and laboratory data were collected and analyzed. Attending health care personnel carefully identified patients’ symptoms during isolation. The decision to release an individual from isolation was based on the results of reverse transcription–polymerase chain reaction (RT-PCR) assay from upper respiratory tract specimens (nasopharynx and oropharynx swab) and lower respiratory tract specimens (sputum) for SARS-CoV-2. This testing was performed on days 8, 9, 15, and 16 of isolation. On days 10, 17, 18, and 19, RT-PCR assays from the upper or lower respiratory tract were performed at physician discretion. Cycle threshold (Ct) values in RT-PCR for SARS-CoV-2 detection were determined in both asymptomatic and symptomatic patients. Results Of the 303 patients with SARS-CoV-2 infection, the median (interquartile range) age was 25 (22-36) years, and 201 (66.3%) were women. Only 12 (3.9%) patients had comorbidities (10 had hypertension, 1 had cancer, and 1 had asthma). Among the 303 patients with SARS-CoV-2 infection, 193 (63.7%) were symptomatic at the time of isolation. Of the 110 (36.3%) asymptomatic patients, 21 (19.1%) developed symptoms during isolation. The median (interquartile range) interval of time from detection of SARS-CoV-2 to symptom onset in presymptomatic patients was 15 (13-20) days. The proportions of participants with a negative conversion at day 14 and day 21 from diagnosis were 33.7% and 75.2%, respectively, in asymptomatic patients and 29.6% and 69.9%, respectively, in symptomatic patients (including presymptomatic patients). The median (SE) time from diagnosis to the first negative conversion was 17 (1.07) days for asymptomatic patients and 19.5 (0.63) days for symptomatic (including presymptomatic) patients (P = .07). The Ct values for the envelope (env) gene from lower respiratory tract specimens showed that viral loads in asymptomatic patients from diagnosis to discharge tended to decrease more slowly in the time interaction trend than those in symptomatic (including presymptomatic) patients (β = −0.065 [SE, 0.023];P = .005). Conclusions and Relevance In this cohort study of symptomatic and asymptomatic patients with SARS-CoV-2 infection who were isolated in a community treatment center in Cheonan, Republic of Korea, the Ct values in asymptomatic patients were similar to those in symptomatic patients. Isolation of asymptomatic patients may be necessary to control the spread of SARS-CoV-2.

An impact with a dash of volcanism Around the time of the end-Cretaceous mass extinction that wiped out dinosaurs, there was both a bolide impact and a large amount of volcanism. Hull et al. ran several temperature simulations based on different volcanic outgassing scenarios and compared them with temperature records across the extinction event. The best model fits to the data required most outgassing to occur before the impact. When combined with other lines of evidence, these models support an impact-driven extinction. However, volcanic gases may have played a role in shaping the rise of different species after the extinction event. Science , this issue p. 266

We used geographic information system applications and statistical analyses to classify young, premature forest areas in southeastern Georgia using combined data from Landsat TM 5 satellite imagery and ground inventory data. We defined premature stands as forests with trees up to 15 years old. We estimated the premature forest areas using three methods: maximum likelihood classification (MLC), regression analysis, and k-nearest neighbor (kNN) modeling. Overall accuracy (OA) of classifying the premature forest using MLC was 82% and the Kappa coefficient of agreement was 0.63, which was the highest among the methods that we have tested. The kNN approach ranked second in accuracy with OA of 61% and a Kappa coefficient of agreement of 0.22. Regression analysis yielded an OA of 57% and a Kappa coefficient of 0.14. We conclude that Landsat imagery can be effectively used for estimating premature forest areas in combination with image processing classifiers such as MLC.

Updated several times a week with posts by a wide variety of authors, AJN's blog Off the Charts allows us to provide more timely-and often more personal-perspectives on professional, policy, and clinical issues. Best of the Blog is a regular column to draw the attention of AJN readers to posts we think deserve a wider audience. To read more, please visit: www.ajnoffthecharts.com.

The Chicxulub bolide impact 66 million years ago drove the near-instantaneous collapse of ocean ecosystems. The devastating loss of diversity at the base of ocean food webs probably triggered cascading extinctions across all trophic levels1–3 and caused severe disruption of the biogeochemical functions of the ocean, and especially disrupted the cycling of carbon between the surface and deep sea4,5. The absence of sufficiently detailed biotic data that span the post-extinction interval has limited our understanding of how ecosystem resilience and biochemical function was restored; estimates6–8 of ecosystem ‘recovery’ vary from less than 100 years to 10 million years. Here, using a 13-million-year-long nannoplankton time series, we show that post-extinction communities exhibited 1.8 million years of exceptional volatility before a more stable equilibrium-state community emerged that displayed hallmarks of resilience. The transition to this new equilibrium-state community with a broader spectrum of cell sizes coincides with indicators of carbon-cycle restoration and a fully functioning biological pump9. These findings suggest a fundamental link between ecosystem recovery and biogeochemical cycling over timescales that are longer than those suggested by proxies of export production7,8, but far shorter than the return of taxonomic richness6. The fact that species richness remained low as both community stability and biological pump efficiency re-emerged suggests that ecological functions rather than the number of species are more important to community resilience and biochemical functions. After the Cretaceous/Palaeogene mass extinction event, nannoplankton communities exhibited volatility for 1.8 million years before a more stable community emerged, coinciding with restoration of the carbon cycle and a fully functioning biological pump between the surface and deep sea.

The thermochemical properties of Sr-Sn alloys were determined by electromotive force (emf) measurements to evaluate liquid tin as an interacting electrode material for separating alkaline-earth elements from molten salt solutions. A Sr(s)|CaF2-SrF2|Sr(in Sn) cell was used to measure emf values for twelve Sr-Sn alloys at mole fractions xSr = 0.02‒0.43, allowing the determination of thermochemical properties such as activity and partial molar quantities of Gibbs energy, entropy, and enthalpy of Sr at 730‒1110 K. Activity values of Sr in liquid Sn were as low as 6.9×10‒12 at 800 K and xSr = 0.02 indicating highly non-ideal solution behavior between Sr and Sn. Phase transitions were also determined from the emf data and were validated via differential scanning calorimetry (DSC). Through the combination of emf measurements for thermochemical properties, X-ray diffraction (XRD) for phase constituents, and DSC measurements for phase transitions, this work established more complete thermodynamic properties of the Sr-Sn binary system.

In this study we analyzed forest carbon models that use growth yield curve: CBM-CFS3, CO2FIX, CASMOFOR, and EFISCEN. Relatively speaking, CBM-CFS3 is expected to give high accuracy in the estimation of forest carbon with diverse inputs and detailed compartments in biomass pools and dead organic matter pools, and handle C dynamics which is related to disturbance and land-use changes deeply in both small-scale and large-scale forests. CO2FIX has various extended modules based on a cohort approach, which is suitable for those interested in wide-ranging factors related to carbon dynamics in small-scale forests. CASMOFOR presents various pools with related processes and, especially, makes afforestation a major issue in both small- and large-scale forests. EFISCEN can project forest carbon dynamics in combination with diverse scenarios driven from multiple models, with matrix structure large-scale forest ecosystem processes described simply and efficiently.