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Over the past decade, the proliferation of entrepreneurial ventures and small firms with sustainable business models have pushed the sustainability agenda in the fashion industry. Despite prominent success stories, these companies often encounter significant operative challenges that hinder growth or even cause business failure. This paper adopts a qualitative research design and uses data gathered during 18 expert interviews with entrepreneurs and executive managers of 18 firms from 13 countries to identify and explore the dominant challenges that micro- and small-sized sustainable fashion companies struggle with. The results indicate that communicating with consumers is perceived as surprisingly difficult, especially because sustainable brands need to justify higher prices and explain the added benefits of their products. Second, resource constraints lead to operative friction and overburdening of the decision makers and their small management teams. Third, sustainable sourcing and production processes are economically difficult in an industry that continues to occupy a mass and low-cost logic. Against the background of these insights, a range of managerial recommendations are developed and contextualized in the framework of the Business Model Canvas. This novel approach makes the suggestions which are rooted in the resource-based view actionable and supports sustainable businesses to better manage their operations and achieve growth. For example, collaborative approaches with different stakeholders may mitigate constraints across all three identified problem areas.
Applications of pulsed electric fields for processing potatoes: Examples and equipment design
(2022)
In the last two decades, pulsed electric fields (PEF) have successfully been introduced into the food industry, as one of the most promising and "game changing" technologies. This review is devoted to the recent applications of pulsed electric fields used in processing potatoes. The potato processing market size was estimated to be ca. USD 24.83 billion (2018) and with an annual growth rate of 5.2%. The physicochemical characteristics of potatoes and the specificity of potato processing lines makes a pulsed electric field very versatile and flexible allowing one to achieve different technological aims by its implementation into technological lines. In this paper, a short analysis of the potato structure and its nutritional properties, applications of moderate electric fields, ohmic heating, and pulsed electric fields are presented. Moreover, the basic electroporation effects, metabolic responses, texture modification and different PEF assisted processes applied to the potato are discussed. Finally, some examples of commercial applications and a brief description of the available equipment for the PEF processing of potatoes are presented.
The impact of Pulsed Electric Field (PEF) processing pre-treatment on the texture and kinetics of in vitro starch digestibility of French fries made from two potato cultivars (Solanum tuberosum L.) containing dry matter content ranging from 19 to 22% was investigated. Whole and steam-peeled potato tubers were treated with a pilot scale PEF unit (electric field strength of 1.1 and 1.9 kV/cm with energy input <10 kJ/kg or ∼50 kJ/kg). This trial was carried out in a commercial French-fry plant using an industrial scale cutter, blancher, fryer and blast-freezer to prepare the frozen par-fried French fry samples. After subsequent final batch frying of the frozen fries, at 180 °C for 3 min to mimic the typical preparation practice at restaurant, retail and household, the outer crust of the fries produced from PEF-treated potatoes was significantly harder (9.4–16.3 N) than crust produced from untreated potatoes (6.9–8.5 N). High intensity (1.9 kV/cm with energy input ∼50 kJ/kg) PEF processing was found to cause defects (i.e. hollowness in the internal core) in the fries. A fractional conversion model was a good fit for the starch digestion kinetics of all French fry samples during the small intestinal phase (based on standardised INFOGEST static in vitro digestion assay). A lower % of total starch hydrolysis was predicted for French fries produced from high dry matter (>21%) tubers pretreated with PEF at electric field strength of 1.9 kV/cm. The findings generated in this study demonstrate PEF pretreatment may influence the texture of French fries and the extent of starch digestion that occurs.
The impact of pulsed light (PL) treatment on naturally occurring microorganisms, mycotoxins, and on physicochemical properties in red pepper powder was investigated. Powder samples were exposed to different PL treatments up to 61 pulses, with fluence ranging from 1.0 to 9.1 J/cm2. The highest fluence applied (9.1 J/cm2, 61 pulses, 20 s) resulted in 2.7, 3.1, and 4.1 log CFU/g reduction of yeasts, molds, and total plate counts (TPC), where initial microbial loads were 4.6, 5.5, and 6.5 log CFU/g, respectively. At the same fluence intensity, a maximum reduction of 67.2, 50.9, and 36.9% of aflatoxin B1 (AFB1), total aflatoxins (AF), and ochratoxin A (OTA) were detected, respectively. Proportional increase in temperature of the samples was observed from the absorbed PL energy, reaching maximum of 59.8°C. The inactivation of investigated microorganisms and mycotoxins followed first-order kinetics (R2 > 0.95). The fluence intensity at 6.9 and 9.1 J/cm2 did not cause degradation, but rather a significant (p < .05) and apparent increase of total phenols. Total color difference (ΔE*) revealed only “slight differences,” compared to the untreated sample. In conclusion, higher reduction of microbial load and mycotoxins in red pepper powder could be achieved, when higher treatment intensity was applied. This suggests the PL as a potential technology for decontamination of red pepper powder and other spice powders.
Dieser Artikel befasst sich mit dem bundesweiten Niveau der Treibhausgas (THG)-Emissionen und des Ressourcenverbrauchs in der deutschen Gemeinschaftsverpflegung im Segment "Business" und deren Einsparpotenziale durch verschiedene Szenarien der ungestützten und gestützten Rezeptüberarbeitung. Unter "ungestützt" verstehen wir in dieser Arbeit die intuitive Optimierung von Rezepten durch die Mitarbeiter von Betrieben der Gemeinschaftsverpflegung. Die "unterstützten" Ansätze mussten dagegen bestimmte Zielvorgaben erfüllen, zum Beispiel der Deutschen Gesellschaft für Ernährung; engl. Deutschen Gesellschaft für Ernährung oder das nachhaltige Niveau. Konkret Konkret wird getestet, wie sich (A) eine ungestützte Rezeptüberarbeitung, (B) eine Rezeptüberarbeitung auf Basis von Ernährungsempfehlungen und (C) eine Rezeptüberarbeitung mit wissenschaftlicher Begleitung die Umweltauswirkungen eines Gerichtes beeinflussen. Als methodischer Rahmen diente eine Online-Befragung von Unternehmen der Gemeinschaftsverpflegung sowie eine Szenarioanalyse auf Menüebene und auf nationaler Ebene durchgeführt. Die Ergebnisse basieren zum einen auf empirischen Daten und zum anderen auf Hochrechnungen. Die Ergebnisse zeigen, dass die die bundesweite Umsetzung der Rezepturüberarbeitung nach wissenschaftlichen Vorgaben - wie konkrete Zielvorgaben für die THG Emissionen pro Portion - bis zu 44% des Ressourcenverbrauchs in der deutschen Betriebsgastronomie einsparen kann (das entspricht 3,4 Millionen Tonnen Ressourcen pro Jahr) und bis zu 40 % der THG-Emissionen (0,6 Millionen Tonnen THG-Emissionen pro Jahr) einsparen.
The study aimed to investigate inactivation of naturally occurring microorganisms and quality of red pepper paste treated by high pressure processing (HPP). Central composite rotatable design was employed to determine the impacts of pressure (100–600 MPa) and holding time (30–600 s). HPP at 527 MPa for 517 s reduced aerobic mesophilic bacteria count by 4.5 log CFU/g. Yeasts and molds counts were reduced to 1 log CFU/g at 600 MPa for 315 s. Total phenols, carotenoids and antioxidants activity ranged from 0.28 to 0.33 g GAE/100 g, 96.0–98.4 mg βc/100 g and 8.70–8.95 μmol TE/g, respectively. Increase (2.5–6.7%) in these variables was observed with increasing pressure and holding time. Total color difference (ΔE∗) values (0.2–2.8) were within the ranges of ‘imperceptible’ to ‘noticeable’. Experimental results were fitted satisfactorily into quadratic model with higher R2 values (0.8619–0.9863). Optimization process suggested treatment of red pepper paste at 536 MPa for 125 s for maximum desirability (0.622). Validation experiments confirmed comparable percentage of relative errors. Overall, this technique could be considered as an efficient treatment for the inactivation of microorganisms that naturally occur in red pepper paste with minimal changes in its characteristics.
Der Schwerpunkt des vorliegenden Papiers liegt auf der Nachfrageseite. In realen Labors verwenden wir einen standardisierten empirischen Ansatz, um verschiedene Nudging-Maßnahmen aus dem Bereich der physischen Umwelt und des Entscheidungsprozesses der Verbraucher zu vergleichen. Wir vergleichen die Auswirkungen ein und derselben Maßnahme in verschiedenen Umgebungen und die Auswirkungen verschiedener, aufeinander folgender Nudging-Maßnahmen in derselben Umgebung. Die Daten wurden in acht Betriebs- und Schulkantinen in Deutschland in zwei Projektdurchläufen (2016/2017; 2019/2020) erhoben. Es wurde ein ähnliches Interventionskonzept angewandt. Die Vergleichbarkeit wurde durch eine harmonisierte Speisekarte gewährleistet. Die erste Iteration des Projekts ergab, dass nur ein Nudge (oberste Menüposition, +22,5 %) zu einem signifikanten Anstieg der Wahl nachhaltiger Lebensmittel führte, während die Ergebnisse der zweiten Iteration zeigten, dass alle Nudge-Interventionen (beste Thekenposition, +11,6 %; oberste Menüposition, +6,9 %; Etikett plus Informationen, +15,9 %) die Wahl der Verbraucher positiv beeinflussten. Mögliche Erklärungen wie die striktere Einhaltung des Versuchsplans in den Cafeterien, aber auch gesellschaftliche Entwicklungen wie das Aufkommen der Fridays for Future-Bewegung werden diskutiert. Da die Ergebnisse je nach Standort und Umfeld variieren, legen unsere Ergebnisse nahe, dass Nudges situativen Bedingungen angepasst werden müssen, um die höchste Wirksamkeit zu erzielen.
The present study investigates properties of heat-induced, self-standing gels of globular proteins. Native egg white protein (EWP) with 9,8 wt% protein and 0,395 wt% NaCl content was adjusted to pH = 7,0 and heated from 25 to 85 °C via Ohmic heating (OH) and conventional heating (COV) with respective come-up times (CUT, 240 and 1200 s) and holding times (HOLD, 30 and 900 s). Gels heated under OH showed lower denaturation levels and less water holding capacity. When HOLD was short, the firmness of OH gels exceeded COV gel firmness but deceeded at long HOLD. Similarly, at short HOLD OH samples presented higher hydrophobic interactions whereas at long HOLD COV gels showed more hydrophobic interactions. This correlated with changes of intermolecular beta-sheet structures which increased with HOLD at COV but decreased or remained unchanged during OH. Furthermore, as an SDS-PAGE revealed the main EWP, ovalbumin, did not fully denature when heated via OH, this lead to the assumption that the oscillatory electric field partially interferes the complete denaturation and development of intermolecular beta-sheet structures and hydrophobic interactions during thermal gelation of this protein. Scanning electron microscopy also showed deviances in network structures between OH and COV as COV gels exhibited a denser and OH gels a more open and porous network structure.
Currently, the modelling of drying processes of plant tissues pre-treated by pulsed electric field (PEF) is following experimentally identified curves or separate heat and mass transfer and diffusion models with different levels of accuracy. This research had two major objectives: mathematical modeling and control of drying process of different vegetables pretreated by PEF during convective drying. The mathematical modeling was based on Luikov's heat and mass transfer model along with properties of different vegetables. Computer modelling was done using the difference method for predicting moisture and the temperature potentials of untreated and PEF-treated vegetables. The formulation and the solution procedures were applied to simulate the simultaneous heat and mass transfer in selected vegetables subjected to the convective drying. Suggested model had a good correlation with experimental results. Moreover, cell disintegration index can be used as a controllable parameter in heat and mass transfer models to predict drying behavior of potato, onion, and carrot tissues. Obtained drying models can be used as a mathematical tool to predict drying behavior for various types of agricultural products pre-treated by pulsed electric field.
The impact of Pulsed Electric Fields (PEF) on the peeling ability of different fruits and vegetables in particular tomatoes, peaches, peppers, and oranges were investigated. Samples were exposed to a fixed electric field strength of 2.15 kV/cm. The specific energy ranged from 0.6 kJ/kg to 50.3 kJ/kg. The treated raw materials were analysed regarding to the peeling ability, skin size and weight and firmness. The best result for tomatoes at a specific energy of 1.2 kJ/kg induced a high score of peeling ability that led to less product loss and could therefore increase the yield by 33.84%–41.53% compared to untreated samples. Moreover, an increased skin size by a factor of 3.7 was observed. However, PEF had no significant impact on peeling ability of oranges, peppers, and peaches. Although oranges showed an improvement in peeling ability by up to 32%, this cannot be traced back to the PEF treatment. The different properties and structures of the raw materials were discussed and provided indications about the limitation of PEF.
Background
Spinach is a nitrogen (N) demanding crop with a weekly N uptake of up to 60 kg ha–1. Consequently, a high N supply is required, which can temporarily lead to high quantities of nitrate (NO3–) being at risk of leaching.
Aims
The objective of this study was to develop a N fertilization approach to reduce the risk of NO3– leaching in field-grown spinach production without adversely affecting crop yield and quality at an early and late harvest stage.
Methods
Ten fertilization trials were conducted to compare different base fertilization rates and splits of top dressings. For top dressings, granulated fertilizers or foliar sprays were used. In a further treatment, N supply was reduced by withholding the second top dressing of 50–70 kg ha−1.
Results
Nitrate concentration at risk of leaching was considerably reduced by decreasing the base fertilizer rate as well as by splitting the top dressing. However, at an early harvest stage, total aboveground dry mass was reduced by, on average, 6% by these measures across all seasons. In contrast, at a later harvest stage, spinach was less affected by the fertilizer schedule. Urea foliar sprays proved to be insufficient in promoting plant growth and caused leaf necrosis. A reduced N supply led to impaired plant growth and yellowish leaves in both spring and winter.
Conclusions
Base N fertilization of spinach is only required in spring, but not in other seasons. Despite slight yield reduction, the top dressing should be split to reduce the risk of NO3− leaching after an early harvest.
Intensive care units (ICU) are often overflooded with alarms from monitoring devices which constitutes a hazard to both staff and patients. To date, the suggested solutions to excessive monitoring alarms have remained on a research level. We aimed to identify patient characteristics that affect the ICU alarm rate with the goal of proposing a straightforward solution that can easily be implemented in ICUs. Alarm logs from eight adult ICUs of a tertiary care university-hospital in Berlin, Germany were retrospectively collected between September 2019 and March 2021. Adult patients admitted to the ICU with at least 24 h of continuous alarm logs were included in the study. The sum of alarms per patient per day was calculated. The median was 119. A total of 26,890 observations from 3205 patients were included. 23 variables were extracted from patients' electronic health records (EHR) and a multivariable logistic regression was performed to evaluate the association of patient characteristics and alarm rates. Invasive blood pressure monitoring (adjusted odds ratio (aOR) 4.68, 95%CI 4.15–5.29, p < 0.001), invasive mechanical ventilation (aOR 1.24, 95%CI 1.16–1.32, p < 0.001), heart failure (aOR 1.26, 95%CI 1.19–1.35, p < 0.001), chronic renal failure (aOR 1.18, 95%CI 1.10–1.27, p < 0.001), hypertension (aOR 1.19, 95%CI 1.13–1.26, p < 0.001), high RASS (aOR 1.22, 95%CI 1.18–1.25, p < 0.001) and scheduled surgical admission (aOR 1.22, 95%CI 1.13–1.32, p < 0.001) were significantly associated with a high alarm rate. Our study suggests that patient-specific alarm management should be integrated in the clinical routine of ICUs. To reduce the overall alarm load, particular attention regarding alarm management should be paid to patients with invasive blood pressure monitoring, invasive mechanical ventilation, heart failure, chronic renal failure, hypertension, high RASS or scheduled surgical admission since they are more likely to have a high contribution to noise pollution, alarm fatigue and hence compromised patient safety in ICUs.
Background
To detect changes in biological processes, samples are often studied at several time points. We examined expression data measured at different developmental stages, or more broadly, historical data. Hence, the main assumption of our proposed methodology was the independence between the examined samples over time. In addition, however, the examinations were clustered at each time point by measuring littermates from relatively few mother mice at each developmental stage. As each examination was lethal, we had an independent data structure over the entire history, but a dependent data structure at a particular time point. Over the course of these historical data, we wanted to identify abrupt changes in the parameter of interest - change points.
Results
In this study, we demonstrated the application of generalized hypothesis testing using a linear mixed effects model as a possible method to detect change points. The coefficients from the linear mixed model were used in multiple contrast tests and the effect estimates were visualized with their respective simultaneous confidence intervals. The latter were used to determine the change point(s). In small simulation studies, we modelled different courses with abrupt changes and compared the influence of different contrast matrices. We found two contrasts, both capable of answering different research questions in change point detection: The Sequen contrast to detect individual change points and the McDermott contrast to find change points due to overall progression. We provide the R code for direct use with provided examples. The applicability of those tests for real experimental data was shown with in-vivo data from a preclinical study.
Conclusion
Simultaneous confidence intervals estimated by multiple contrast tests using the model fit from a linear mixed model were capable to determine change points in clustered expression data. The confidence intervals directly delivered interpretable effect estimates representing the strength of the potential change point. Hence, scientists can define biologically relevant threshold of effect strength depending on their research question. We found two rarely used contrasts best fitted for detection of a possible change point: the Sequen and McDermott contrasts.
Background
A peripheral venous catheter (PVC) is the most widely used device for obtaining vascular access, allowing the administration of fluids and medication. Up to 25% of adult patients, and 50% of pediatric patients experience a first-attempt cannulation failure. In addition to patient and clinician characteristics, device features might affect the handling and success rates. The objective of the study was to compare the first-attempt cannulation success rate between PVCs with wings and a port access (Vasofix® Safety, B. Braun, abbreviated hereon in as VS) with those without (Introcan® Safety, B. Braun, abbreviated hereon in as IS) in an anesthesiological cohort.
Methods
An open label, multi-center, randomized trial was performed. First-attempt cannulation success rates were examined, along with relevant patient, clinician, and device characteristics with univariate and multivariate analyses. Information on handling and adherence to use instructions was gathered, and available catheters were assessed for damage.
Results
Two thousand three hundred four patients were included in the intention to treat analysis. First-attempt success rate was significantly higher with winged and ported catheters (VS) than with the non-winged, non-ported design (IS) (87.5% with VS vs. 78.2% with IS; PChi < .001). Operators rated the handling of VS as superior (rating of “good” or “very good: 86.1% VS vs. 20.8% IS, PChi < .001). Reinsertion of the needle into the catheter after partial withdrawal—prior or during the catheterization attempt—was associated with an increased risk of cannulation failure (7.909, CI 5.989–10.443, P < .001 and 23.023, CI 10.372–51.105, P < .001, respectively) and a twofold risk of catheter damage (OR 1.999, CI 1.347–2.967, P = .001).
Conclusions
First-attempt cannulation success of peripheral, ported, winged catheters was higher compared to non-ported, non-winged devices. The handling of the winged and ported design was better rated by the clinicians. Needle reinsertions are related to an increase in rates of catheter damage and cannulation failure.
Background: New ischaemic brain lesions on magnetic resonance imaging (MRI) are reported in up to 86% of patients after transcatheter edge-to-edge repair of the mitral valve (TEER-MV). Knowledge of the exact procedural step(s) that carry the highest risk for cerebral embolisation may help to further improve the procedure.
Aims: The aim of this study was to identify the procedural step(s) that are associated with an increased risk of cerebral embolisation during TEER-MV with the MitraClip system. Furthermore, the risk of overt stroke and silent brain ischaemia after TEER-MV was assessed.
Methods: In this prospective, pre-specified observational study, all patients underwent continuous transcranial Doppler examination during TEER-MV to detect microembolic signals (MES). MES were assigned to specific procedural steps: (1) transseptal puncture and placement of the guide, (2) advancing and adjustment of the clip in the left atrium, (3) device interaction with the MV, and (4) removal of the clip delivery system and the guide. Neurological examination using the National Institutes of Health Stroke Scale (NIHSS) and cerebral MRI were performed before and after TEER-MV.
Results: Fifty-four patients were included. The number of MES differed significantly between the procedural steps with the highest numbers observed during device interaction with the MV. Mild neurological deterioration (NIHSS ≤3) occurred in 9/54 patients. New ischaemic lesions were detected in 21/24 patients who underwent MRI. Larger infarct volume was significantly associated with neurological deterioration.
Conclusions: Cerebral embolisation is immanent to TEER-MV and predominantly occurs during device interaction with the MV. Improvements to the procedure may focus on this procedural step.
During gestation, the most drastic change in oxygen supply occurs with the onset of ventilation after birth. As the too early exposure of premature infants to high arterial oxygen pressure leads to characteristic diseases, we studied the adaptation of the oxygen sensing system and its targets, the hypoxia-inducible factor- (HIF-) regulated genes (HRGs) in the developing lung. We draw a detailed picture of the oxygen sensing system by integrating information from qPCR, immunoblotting, in situ hybridization, and single-cell RNA sequencing data in ex vivo and in vivo models. HIF1α protein was completely destabilized with the onset of pulmonary ventilation, but did not coincide with expression changes in bona fide HRGs. We observed a modified composition of the HIF-PHD system from intrauterine to neonatal phases: Phd3 was significantly decreased, while Hif2a showed a strong increase and the Hif3a isoform Ipas exclusively peaked at P0. Colocalization studies point to the Hif1a-Phd1 axis as the main regulator of the HIF-PHD system in mouse lung development, complemented by the Hif3a-Phd3 axis during gestation. Hif3a isoform expression showed a stepwise adaptation during the periods of saccular and alveolar differentiation. With a strong hypoxic stimulus, lung ex vivo organ cultures displayed a functioning HIF system at every developmental stage. Approaches with systemic hypoxia or roxadustat treatment revealed only a limited in vivo response of HRGs. Understanding the interplay of the oxygen sensing system components during the transition from saccular to alveolar phases of lung development might help to counteract prematurity-associated diseases like bronchopulmonary dysplasia.
Objectives: To measure and assess the economic impact of adherence to a single quality indicator (QI) regarding weaning from invasive ventilation.
Design: Retrospective observational single-centre study, based on electronic medical and administrative records.
Setting: Intensive care unit (ICU) of a German university hospital, reference centre for acute respiratory distress syndrome.
Participants: Records of 3063 consecutive mechanically ventilated patients admitted to the ICU between 2012 and 2017 were extracted, of whom 583 were eligible adults for further analysis. Patients’ weaning protocols were evaluated for daily adherence to quality standards until ICU discharge. Patients with <65% compliance were assigned to the low adherence group (LAG), patients with ≥65% to the high adherence group (HAG).
Primary and secondary outcome measures: Economic healthcare costs, clinical outcomes and patients’ characteristics.
Results: The LAG consisted of 378 patients with a median negative economic results of −€3969, HAG of 205 (−€1030), respectively (p<0.001). Median duration of ventilation was 476 (248; 769) hours in the LAG and 389 (247; 608) hours in the HAG (p<0.001). Length of stay (LOS) in the LAG on ICU was 21 (12; 35) days and 16 (11; 25) days in the HAG (p<0.001). LOS in the hospital was 36 (22; 61) days in the LAG, and within the HAG, respectively, 26 (18; 48) days (p=0.001).
Conclusions: High adherence to this single QI is associated with better clinical outcome and improved economic returns. Therefore, the results support the adherence to QI. However, the examined QI does not influence economic outcome as the decisive factor.
The apple fruit (Malus domestica L. Borkh) is one of the most popular fruits worldwide. Beyond their beneficial properties, apples contain proteins that trigger allergic reactions in susceptible consumers. Mal d1 to d4 are allergens present in a variety of different isoforms in apples. In this study, we used proteomics to quantify all four Mal d proteins in 52 apple genotypes with varying allergenic potentials. A total of 195, 17, 14, and 18 peptides were found to be related to Mal d1, d2, d3, and d4 proteins, respectively of which 25 different Mal d proteins could be unambiguously identified. The allergenic potential of the Mal d isoforms was characterized by comparing the isoform abundance with the allergenic score of genotypes from oral challenge tests. The detected Mal d peptides presumably have different IgE binding properties and could be used as potential molecular markers to discriminate between hypoallergenic and hyperallergenic cultivars.
Currently, only non-imaging chlorophyll fluorescence measurements are used to identify the Lower Oxygen Limit (LOL) in Dynamic Controlled Atmosphere - Chlorophyll Fluorescence (DCA-CF) storage. The disadvantage of non-imaging fluorescence is that no statement can be made about the spatial heterogeneity of the sample. In contrast, chlorophyll fluorescence imaging can detect spatial heterogeneity of photosynthetic activity and has been established in research for some decades because the information benefit is higher. In this study, the chlorophyll fluorescence (Fo, Fm, Fv, Fv/Fm) of apples (Malus x domestica, BORKH.) was measured with a fluorescence imaging system in situ during storage. Intact apples of ‘Braeburn’ and ‘Golden Delicious’ were stored under low-oxygen stress conditions (< 1 kPa). The metabolic shift from aerobic to fermentative metabolism was made visible with the chlorophyll fluorescence imaging and was spatially localized on the sample. Furthermore, a method was developed to identify the LOL based on the chlorophyll fluorescence imaging combined with the histogram division method. This method considers the heterogeneity of the fluorescence and bundles the measured Fo data as histograms. Our results showed that the fluorescence imaging combined with the histogram division method can be a powerful tool for identifying the LOL.
Background:
Contact tracing apps are potentially useful tools for supporting national COVID-19 containment strategies. Various national apps with different technical design features have been commissioned and issued by governments worldwide.
Objective:
Our goal was to develop and propose an item set that was suitable for describing and monitoring nationally issued COVID-19 contact tracing apps. This item set could provide a framework for describing the key technical features of such apps and monitoring their use based on widely available information.
Methods:
We used an open-source intelligence approach (OSINT) to access a multitude of publicly available sources and collect data and information regarding the development and use of contact tracing apps in different countries over several months (from June 2020 to January 2021). The collected documents were then iteratively analyzed via content analysis methods. During this process, an initial set of subject areas were refined into categories for evaluation (ie, coherent topics), which were then examined for individual features. These features were paraphrased as items in the form of questions and applied to information materials from a sample of countries (ie, Brazil, China, Finland, France, Germany, Italy, Singapore, South Korea, Spain, and the United Kingdom [England and Wales]). This sample was purposefully selected; our intention was to include the apps of different countries from around the world and to propose a valid item set that can be relatively easily applied by using an OSINT approach.
Results:
Our OSINT approach and subsequent analysis of the collected documents resulted in the definition of the following five main categories and associated subcategories: (1) background information (open-source code, public information, and collaborators); (2) purpose and workflow (secondary data use and warning process design); (3) technical information (protocol, tracing technology, exposure notification system, and interoperability); (4) privacy protection (the entity of trust and anonymity); and (5) availability and use (release date and the number of downloads). Based on this structure, a set of items that constituted the evaluation framework were specified. The application of these items to the 10 selected countries revealed differences, especially with regard to the centralization of the entity of trust and the overall transparency of the apps’ technical makeup.
Conclusions:
We provide a set of criteria for monitoring and evaluating COVID-19 tracing apps that can be easily applied to publicly issued information. The application of these criteria might help governments to identify design features that promote the successful, widespread adoption of COVID-19 tracing apps among target populations and across national boundaries.