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Real-world data regarding the effectiveness, safety and immunogenicity of the Pfizer-BioNTech BNT162b2 mRNA vaccine are accumulating in the literature, suggesting that this vaccine generates high titres of S1-binding IgG antibodies that exhibit potent virus neutralization capacity. This is the first phase IV immunogenicity study to recruit a large number of Greek healthcare workers (n=425) including 63 previously-infected subjects. We measured titres of neutralizing IgGs against the receptor-binding domain of the S1 subunit of the spike protein of SARS-CoV-2 14 days post-immunization with the first dose, employing the SARS-CoV-2 IgG II Quant assay. A total of 92.24 % of our study cohort received a positive assay outcome and titres varied with age. Post-hoc analysis revealed that although titres did not significantly differ among participants aged 20–49 years, a significant decline was marked in the age group of 50–59 years, which was further accentuated in subjects aged over 60. Antibody titres escalated significantly among the previously-infected, indicating the potential booster effect of the first dose in that group.
Konstantina Kontopoulou; Alexandra Ainatzoglou; Athina Ifantidou; Christos T. Nakas; Georgia Gkounti; Vasilios Adamopoulos; Nikitas Papadopoulos; Georgios Papazisis. Immunogenicity after the first dose of the BNT162b2 mRNA Covid-19 vaccine: real-world evidence from Greek healthcare workers. Journal of Medical Microbiology 2021, 70, 001387 .
AMA StyleKonstantina Kontopoulou, Alexandra Ainatzoglou, Athina Ifantidou, Christos T. Nakas, Georgia Gkounti, Vasilios Adamopoulos, Nikitas Papadopoulos, Georgios Papazisis. Immunogenicity after the first dose of the BNT162b2 mRNA Covid-19 vaccine: real-world evidence from Greek healthcare workers. Journal of Medical Microbiology. 2021; 70 (8):001387.
Chicago/Turabian StyleKonstantina Kontopoulou; Alexandra Ainatzoglou; Athina Ifantidou; Christos T. Nakas; Georgia Gkounti; Vasilios Adamopoulos; Nikitas Papadopoulos; Georgios Papazisis. 2021. "Immunogenicity after the first dose of the BNT162b2 mRNA Covid-19 vaccine: real-world evidence from Greek healthcare workers." Journal of Medical Microbiology 70, no. 8: 001387.
This study monitored titers of neutralizing IgG against the receptor-binding domain of the SARS-CoV-2 S1 subunit 14 days post-injection of each dose of the BNT162b2 mRNA Covid-19 vaccine in 401 Greek healthcare workers aged 20–67. After the first dose, titers varied upon age and history of infection, being lower in the 50+ age group and significantly higher among the seropositive. After the second dose, immunogenicity was significantly boosted in the age 50+ and SARS-CoV-2-naïve individuals, indicating the effectuality of its timely administration, yet questioning its value among the seropositive.
Konstantina Kontopoulou; Alexandra Ainatzoglou; Christos T. Nakas; Athina Ifantidou; Georgia Goudi; Eleni Antoniadou; Vasilios Adamopoulos; Nikitas Papadopoulos; Georgios Papazisis. Second dose of the BNT162b2 mRNA vaccine: Value of timely administration but questionable necessity among the seropositive. Vaccine 2021, 39, 5078 -5081.
AMA StyleKonstantina Kontopoulou, Alexandra Ainatzoglou, Christos T. Nakas, Athina Ifantidou, Georgia Goudi, Eleni Antoniadou, Vasilios Adamopoulos, Nikitas Papadopoulos, Georgios Papazisis. Second dose of the BNT162b2 mRNA vaccine: Value of timely administration but questionable necessity among the seropositive. Vaccine. 2021; 39 (36):5078-5081.
Chicago/Turabian StyleKonstantina Kontopoulou; Alexandra Ainatzoglou; Christos T. Nakas; Athina Ifantidou; Georgia Goudi; Eleni Antoniadou; Vasilios Adamopoulos; Nikitas Papadopoulos; Georgios Papazisis. 2021. "Second dose of the BNT162b2 mRNA vaccine: Value of timely administration but questionable necessity among the seropositive." Vaccine 39, no. 36: 5078-5081.
FruiTemp is an open-source prototype developed to study the response of endophytic insect species such as fruit flies (Diptera: Tephrtidae) to variable temperature conditions including the controlled laboratory and fluctuating field settings. The system is a three-channel temperature sensor that consists of two precision thermistors that measure the temperature in the core and the surface of a fruit on a tree and a Harsh Environment thermistor that measures the air temperature surrounding the host at a rate of one measurement per 15 min. The sample rate can be adjusted according to the researcher’s needs. The system was successfully tested in field and laboratory experimental conditions using apples as the fruit model. The measurements on apples on trees lasted five consecutive days and produced a range of reliable data. After assessing statistical agreement and precision, the results revealed a differential bias of 0.331 °C and a proportional bias of a magnitude of 0.982. This work promotes open-source implementations allowing inexpensive solutions aiding experimentation procedures by significantly lowering operating costs.
Evmorfia Bataka; Vasilis Rodovitis; Kostas Zarpas; Nikos Papadopoulos; Christos Nakas. FruiTemp: Design, Implementation and Analysis for an Open-Source Temperature Logger Applied to Fruit Fly Host Experimentation. Applied Sciences 2021, 11, 6003 .
AMA StyleEvmorfia Bataka, Vasilis Rodovitis, Kostas Zarpas, Nikos Papadopoulos, Christos Nakas. FruiTemp: Design, Implementation and Analysis for an Open-Source Temperature Logger Applied to Fruit Fly Host Experimentation. Applied Sciences. 2021; 11 (13):6003.
Chicago/Turabian StyleEvmorfia Bataka; Vasilis Rodovitis; Kostas Zarpas; Nikos Papadopoulos; Christos Nakas. 2021. "FruiTemp: Design, Implementation and Analysis for an Open-Source Temperature Logger Applied to Fruit Fly Host Experimentation." Applied Sciences 11, no. 13: 6003.
: Worldwide, hospitals face pressure to reduce costs. Some respond by working with a reduced number of nurses or less qualified nursing staff. : This study aims at examining the relationship between mortality and patient exposure to shifts with low or high nurse staffing. : This longitudinal study used routine shift-, unit-, and patient-level data for three years (2015-2017) from one Swiss university hospital. Data from 55 units, 79,893 adult inpatients and 3646 nurses (2670 registered nurses, 438 licensed practical nurses, and 538 unlicensed and administrative personnel) were analyzed. After developing a staffing model to identify high- and low-staffed shifts, we fitted logistic regression models to explore associations between nurse staffing and mortality. : Exposure to shifts with high levels of registered nurses had lower odds of mortality by 8.7% [odds ratio 0.91 95% CI 0.89-0.93]. Conversely, low staffing was associated with higher odds of mortality by 10% [odds ratio 1.10 95% CI 1.07-1.13]. The associations between mortality and staffing by other groups was less clear. For example, both high and low staffing of unlicensed and administrative personnel were associated with higher mortality, respectively 1.03 [95% CI 1.01-1.04] and 1.04 [95% CI 1.03-1.06]. : This patient-level longitudinal study suggests a relationship between registered nurses staffing levels and mortality. Higher levels of registered nurses positively impact patient outcome (i.e. lower odds of mortality) and lower levels negatively (i.e. higher odds of mortality). Contributions of the three other groups to patient safety is unclear from these results. Therefore, substitution of either group for registered nurses is not recommended.
Sarah N. Musy; Olga Endrich; Alexander B. Leichtle; Peter Griffiths; Christos T. Nakas; Michael Simon. The association between nurse staffing and inpatient mortality: A shift-level retrospective longitudinal study. International Journal of Nursing Studies 2021, 120, 103950 .
AMA StyleSarah N. Musy, Olga Endrich, Alexander B. Leichtle, Peter Griffiths, Christos T. Nakas, Michael Simon. The association between nurse staffing and inpatient mortality: A shift-level retrospective longitudinal study. International Journal of Nursing Studies. 2021; 120 ():103950.
Chicago/Turabian StyleSarah N. Musy; Olga Endrich; Alexander B. Leichtle; Peter Griffiths; Christos T. Nakas; Michael Simon. 2021. "The association between nurse staffing and inpatient mortality: A shift-level retrospective longitudinal study." International Journal of Nursing Studies 120, no. : 103950.
Aims Lipoprotein(a) [Lp(a)] is a recognized causal risk factor for atherosclerotic cardiovascular disease but its role for acute ischaemic stroke (AIS) is controversial. In this study, we evaluated the association of Lp(a) with large artery atherosclerosis (LAA) stroke and risk of recurrent cerebrovascular events in AIS patients. Methods and results For this analysis of the prospective, observational, multicentre BIOSIGNAL cohort study we measured Lp(a) levels in plasma samples of 1733 primarily Caucasian (98.6%) AIS patients, collected within 24 h after symptom onset. Primary outcomes were LAA stroke aetiology and recurrent cerebrovascular events (ischaemic stroke or transient ischaemic attack) within 1 year. We showed that Lp(a) levels are independently associated with LAA stroke aetiology [adjusted odds ratio 1.48, 95% confidence interval (CI) 1.14-1.90, per unit log10Lp(a) increase] and identified age as a potent effect modifier (Pinteraction =0.031) of this association. The adjusted odds ratio for LAA stroke in patients aged <60 years was 3.64 (95% CI 1.76–7.52) per unit log10Lp(a) increase and 4.04 (95% CI 1.73–9.43) using the established cut-off ≥100 nmol/l. For 152 recurrent cerebrovascular events, we did not find a significant association in the whole cohort. However, Lp(a) levels ≥100 nmol/l were associated with an increased risk for recurrent events among patients who were either <60 years [adjusted hazard ratio (HR) 2.40, 95% CI 1.05–5.47], had evident LAA stroke aetiology (adjusted HR 2.18, 95% CI 1.08–4.40), or had no known atrial fibrillation (adjusted HR 1.60, 95% CI 1.03–2.48). Conclusion Elevated Lp(a) was independently associated with LAA stroke aetiology and risk of recurrent cerebrovascular events among primarily Caucasian individuals aged <60 years or with evident arteriosclerotic disease.
Markus Arnold; Juliane Schweizer; Christos T Nakas; Valerie Schütz; Laura P Westphal; Corinne Inauen; Thomas Pokorny; Andreas Luft; Alexander Leichtle; Marcel Arnold; Antonela Bicvic; Urs Fischer; Gian Marco De Marchis; Leo H Bonati; Mandy D Müller; Timo Kahles; Krassen Nedeltchev; Carlo W Cereda; Georg Kägi; Alejandro Bustamante; Joan Montaner; George Ntaios; Christian Foerch; Katharina Spanaus; Arnold von Eckardstein; Mira Katan. Lipoprotein(a) is associated with large artery atherosclerosis stroke aetiology and stroke recurrence among patients below the age of 60 years: results from the BIOSIGNAL study. European Heart Journal 2021, 42, 2186 -2196.
AMA StyleMarkus Arnold, Juliane Schweizer, Christos T Nakas, Valerie Schütz, Laura P Westphal, Corinne Inauen, Thomas Pokorny, Andreas Luft, Alexander Leichtle, Marcel Arnold, Antonela Bicvic, Urs Fischer, Gian Marco De Marchis, Leo H Bonati, Mandy D Müller, Timo Kahles, Krassen Nedeltchev, Carlo W Cereda, Georg Kägi, Alejandro Bustamante, Joan Montaner, George Ntaios, Christian Foerch, Katharina Spanaus, Arnold von Eckardstein, Mira Katan. Lipoprotein(a) is associated with large artery atherosclerosis stroke aetiology and stroke recurrence among patients below the age of 60 years: results from the BIOSIGNAL study. European Heart Journal. 2021; 42 (22):2186-2196.
Chicago/Turabian StyleMarkus Arnold; Juliane Schweizer; Christos T Nakas; Valerie Schütz; Laura P Westphal; Corinne Inauen; Thomas Pokorny; Andreas Luft; Alexander Leichtle; Marcel Arnold; Antonela Bicvic; Urs Fischer; Gian Marco De Marchis; Leo H Bonati; Mandy D Müller; Timo Kahles; Krassen Nedeltchev; Carlo W Cereda; Georg Kägi; Alejandro Bustamante; Joan Montaner; George Ntaios; Christian Foerch; Katharina Spanaus; Arnold von Eckardstein; Mira Katan. 2021. "Lipoprotein(a) is associated with large artery atherosclerosis stroke aetiology and stroke recurrence among patients below the age of 60 years: results from the BIOSIGNAL study." European Heart Journal 42, no. 22: 2186-2196.
Background: The BNT162b2 mRNA Covid-19 vaccine that was recently launched exhibited high levels of efficacy and safety in a phase III RCT, along with robust immunogenicity in phase II trials. However, the release of phase IV studies verifying these preliminary findings by means of real-life evidence is essential. Methods: We measured titers of neutralizing IgGs against the receptor-binding domain (RBD) of the S1 subunit of the spike protein of SARS-CoV-2 14 days post-immunization of 425 healthcare providers utilizing the SARS-CoV-2 IgG II Quant assay and estimated the geometric mean concentration (GMC) of SARS-CoV-2-specific IgGs both in the previously-infected group and among the uninfected. The trial is registered on the International Standard Randomized Controlled Trial Number registry (study ID: ISRCTN61884303).Results: 392 of study participants 92.24% (95% CI:89.27, 94.43) had a positive SARS-CoV-2 IgG II Quant assay, while 33 subjects had an IgG concentration lower than 50 AU/ml (GMC 24.80303 AU/ml; 95% CI:19.190, 30.41612). All 63 previously-infected convalescent participants had very high SARS-CoV-2-specific antibody titers with a GMC of 19993,61AU/ml. Regarding age, antibody titers did not significantly differ in the range of 20-50 years, being however significantly lower in the 50-60 age group and dropping even further in subjects over the age of 60. Adverse reactions were overall mild, including pain at the site of the injection, fatigue, myalgias, headache and chills. No serious adverse events were reported in this study.Conclusion: To our knowledge, this is the first phase IV study in Greece presenting real-world evidence on the immunogenicity of the first dose of the BNT162b2 mRNA Covid-19 vaccine in a sample of 425 healthcare providers.
Konstantina Kontopoulou; Alexandra Ainatzoglou; Athina Ifantidou; Christos Nakas; Georgia Goudi; Eleni Antoniadou; Vasilios Adamopoulos; Nikitas Papadopoulos; Georgios Papazisis. Immunogenicity after the First Dose of the BNT162b2 mRNA COVID-19 Vaccine: Real-World Evidence from Greek Healthcare Workers. SSRN Electronic Journal 2021, 1 .
AMA StyleKonstantina Kontopoulou, Alexandra Ainatzoglou, Athina Ifantidou, Christos Nakas, Georgia Goudi, Eleni Antoniadou, Vasilios Adamopoulos, Nikitas Papadopoulos, Georgios Papazisis. Immunogenicity after the First Dose of the BNT162b2 mRNA COVID-19 Vaccine: Real-World Evidence from Greek Healthcare Workers. SSRN Electronic Journal. 2021; ():1.
Chicago/Turabian StyleKonstantina Kontopoulou; Alexandra Ainatzoglou; Athina Ifantidou; Christos Nakas; Georgia Goudi; Eleni Antoniadou; Vasilios Adamopoulos; Nikitas Papadopoulos; Georgios Papazisis. 2021. "Immunogenicity after the First Dose of the BNT162b2 mRNA COVID-19 Vaccine: Real-World Evidence from Greek Healthcare Workers." SSRN Electronic Journal , no. : 1.
Aim The aim of this study was to identify risk variants and haplotypes that impair dihydropyrimidine dehydrogenase (DPD) activity and are, therefore, candidate risk variants for severe toxicity to 5‐fluorouracil (5‐FU) chemotherapy. Method Plasma dihydrouracil/uracil (UH2/U) ratios were measured as a population marker for DPD activity in a total of 1'382 subjects from four independent studies. Genotype and haplotype correlations with UH2/U ratios were assessed. Results Significantly lower UH2/U ratios (panovaA (rs3918290), ‐46.0% for DPYD‐c.1679T>G (rs55886062), ‐37.1%, for DPYD‐c.2846A>T (rs67376798), and ‐13.2% for DPYD‐c.1129‐5923C>G (rs75017182). An additional variant, DPYD c.496A>G (rs2297595), was also associated with lower UH2/U ratios (pG, which consisted of the common variant c.85T>C (rs1801265) and the risk variant c.1129‐5923C>G. Both haplotypes carrying c.496A>G were associated with decreased UH2/U ratios (H3, p=0.003, MD: ‐9.6%; H5, p=0.002, MD: ‐16.9%). A haplotype carrying only the variant c.85T>C (H2) was associated with elevated ratios (p=0.004, MD: +8.6%). Conclusion Based on our data, DPYD‐c.496A>G is a strong candidate risk allele for 5‐FU toxicity. Our data suggest that DPYD‐c.85T>C might be protective; however, the deleterious impacts of the linked alleles c.496A>G and c.1129‐5923C>G likely limit this effect in patients. The possible protective effect of c.85T>C and LD with c.496A>G and c.1129‐5923C>G may have hampered prior association studies and should be considered in future clinical studies.
Seid Hamzic; Dominic Schärer; Steven M. Offer; Didier Meulendijks; Christos Nakas; Robert B. Diasio; Stefano Fontana; Marc Wehrli; Stefan Schürch; Ursula Amstutz; Carlo R. Largiadèr. Haplotype structure defines effects of common DPYD variants c.85T > C (rs1801265) and c.496A > G (rs2297595) on dihydropyrimidine dehydrogenase activity: Implication for 5‐fluorouracil toxicity. British Journal of Clinical Pharmacology 2021, 87, 3234 -3243.
AMA StyleSeid Hamzic, Dominic Schärer, Steven M. Offer, Didier Meulendijks, Christos Nakas, Robert B. Diasio, Stefano Fontana, Marc Wehrli, Stefan Schürch, Ursula Amstutz, Carlo R. Largiadèr. Haplotype structure defines effects of common DPYD variants c.85T > C (rs1801265) and c.496A > G (rs2297595) on dihydropyrimidine dehydrogenase activity: Implication for 5‐fluorouracil toxicity. British Journal of Clinical Pharmacology. 2021; 87 (8):3234-3243.
Chicago/Turabian StyleSeid Hamzic; Dominic Schärer; Steven M. Offer; Didier Meulendijks; Christos Nakas; Robert B. Diasio; Stefano Fontana; Marc Wehrli; Stefan Schürch; Ursula Amstutz; Carlo R. Largiadèr. 2021. "Haplotype structure defines effects of common DPYD variants c.85T > C (rs1801265) and c.496A > G (rs2297595) on dihydropyrimidine dehydrogenase activity: Implication for 5‐fluorouracil toxicity." British Journal of Clinical Pharmacology 87, no. 8: 3234-3243.
We retrospectively assessed gluco‐regulatory hormones over 10 h (including two meals) of fully automated closed‐loop insulin delivery using faster (FA) versus standard insulin aspart (IAsp) in adults with type 2 diabetes [n = 15, age 59 ± 10 years, body mass index 34.5 ± 9.1 kg/m2, glycated haemoglobin 7.7 ± 1.2% (60 ± 13 mmol/mol)]. Plasma concentration of human insulin, IAsp, C‐peptide, glucagon, glucagon‐like peptide 1, glucose‐dependent insulinotropic peptide and peptide tyrosine tyrosine were measured every 15‐30 min. Endogenous insulin secretion was calculated using C‐peptide deconvolution and exposures to hormones were compared using their mean plasma concentrations. Ten‐hour exposure of IAsp was higher with FA versus IAsp (P = .037) in line with the 10% higher insulin requirements to achieve similar glucose control. No significant difference was found for total insulin exposure and endogenous insulin secretion. Similarly, other gluco‐regulatory hormones did not significantly differ. In conclusion, the faster pharmacokinetic profile and slightly higher aspart exposure of FA versus IAsp remained without significant effects on endogenous insulin secretion or other gluco‐regulatory hormones. Further studies are warranted to explore the metabolic and endocrine effects of novel insulins with accelerated pharmacokinetic properties.
David Herzig; David Studer; Christos T Nakas; Christina Kuenzli; Thomas P Stauffer; Roman Hovorka; Lia Bally. Effect of fully automated closed‐loop insulin delivery using faster aspart versus standard aspart on gluco‐regulatory hormones in type 2 diabetes. Diabetes, Obesity and Metabolism 2020, 23, 228 -233.
AMA StyleDavid Herzig, David Studer, Christos T Nakas, Christina Kuenzli, Thomas P Stauffer, Roman Hovorka, Lia Bally. Effect of fully automated closed‐loop insulin delivery using faster aspart versus standard aspart on gluco‐regulatory hormones in type 2 diabetes. Diabetes, Obesity and Metabolism. 2020; 23 (1):228-233.
Chicago/Turabian StyleDavid Herzig; David Studer; Christos T Nakas; Christina Kuenzli; Thomas P Stauffer; Roman Hovorka; Lia Bally. 2020. "Effect of fully automated closed‐loop insulin delivery using faster aspart versus standard aspart on gluco‐regulatory hormones in type 2 diabetes." Diabetes, Obesity and Metabolism 23, no. 1: 228-233.
The drained Karla basin in the Thessaly region of Central Greece has been used for decades as arable land without an existing policy that takes the significance of the former wetland into account. In order to reestablish the ecological balance of the area, however, an artificial lake was established and a series of technical works conducted. After the government's decision to restore the area, a policy of rural state-land allocation has been advocated to promote environmental and social sustainability. Agro-policies created for farmland holdings, crop suitability or crop diversification can profoundly affect the preferences of Greek farmers and regional social dynamics. In addition, negotiations between the state authorities, the farmers, and between the farmers themselves, can be used to reveal potential connections between the farmers' livelihoods and attitudes. This article, following a parallel mixed methods study, attempts to demonstrate the way in which land policy influences state-owned agricultural land distribution in the wetland area. By integrating farmers' opinions from six villages towards the current area's conditions, we attempt to highlight that stable political decisions are important for sustainable development.
Chrysafo-Anna Chatzipetrou; Christos T. Nakas. State farmland redistribution processes in Greece and farmers’ attitudes: A case study of the Karla basin. Journal of Rural Studies 2020, 79, 322 -333.
AMA StyleChrysafo-Anna Chatzipetrou, Christos T. Nakas. State farmland redistribution processes in Greece and farmers’ attitudes: A case study of the Karla basin. Journal of Rural Studies. 2020; 79 ():322-333.
Chicago/Turabian StyleChrysafo-Anna Chatzipetrou; Christos T. Nakas. 2020. "State farmland redistribution processes in Greece and farmers’ attitudes: A case study of the Karla basin." Journal of Rural Studies 79, no. : 322-333.
Fully automated closed‐loop insulin delivery may offer a novel way to manage diabetes in hospital. However, postprandial glycaemic control remains challenging. We aimed to assess the effect of nutritional intake on postprandial glucose control in hospitalized patients with type 2 diabetes receiving fully closed‐loop insulin therapy. The effects of different meal types and macronutrient composition on sensor glucose time in target (TIT, 3.9–10.0 mmol/L) and mean sensor glucose (MGL) were assessed with hierarchical linear models using a Bayesian estimation approach. TIT was lower, and MGL slightly higher, after breakfast compared to lunch and dinner whilst insulin dose was higher. Across meals, when carbohydrates were replaced by fat, or to a lesser extent by protein, postprandial glucose control improved. For breakfast, a 3.9% improvement in TIT was observed when 10% of the energy from carbohydrates was replaced by fat. Improvements were slightly lower during lunch and dinner (3.2 and 3.4%) or when carbohydrates were replaced by protein (2.2–2.7%). We suggest that reducing carbohydrate at the expense of fat or protein, could further improve glucose control during fully closed‐loop insulin therapy in hospital. This article is protected by copyright. All rights reserved.
Nicolas Banholzer; David Herzig; Camillo Piazza; Mario Álvarez‐Martínez; Christos T Nakas; Christophe Kosinski; Stefan Feuerriegel; Roman Hovorka; Lia Bally. Effect of nutrition on postprandial glucose control in hospitalized patients with type 2 diabetes receiving fully automated closed‐loop insulin therapy. Diabetes, Obesity and Metabolism 2020, 23, 234 -239.
AMA StyleNicolas Banholzer, David Herzig, Camillo Piazza, Mario Álvarez‐Martínez, Christos T Nakas, Christophe Kosinski, Stefan Feuerriegel, Roman Hovorka, Lia Bally. Effect of nutrition on postprandial glucose control in hospitalized patients with type 2 diabetes receiving fully automated closed‐loop insulin therapy. Diabetes, Obesity and Metabolism. 2020; 23 (1):234-239.
Chicago/Turabian StyleNicolas Banholzer; David Herzig; Camillo Piazza; Mario Álvarez‐Martínez; Christos T Nakas; Christophe Kosinski; Stefan Feuerriegel; Roman Hovorka; Lia Bally. 2020. "Effect of nutrition on postprandial glucose control in hospitalized patients with type 2 diabetes receiving fully automated closed‐loop insulin therapy." Diabetes, Obesity and Metabolism 23, no. 1: 234-239.
Background Faster insulin aspart is a novel formulation of insulin aspart aiming to accelerate its subcutaneous absorption. The aim of the present study was to compare pharmacokinetics of faster insulin aspart versus standard insulin aspart in adults with type 2 diabetes during closed-loop insulin delivery. Methods We assessed the pharmacokinetics of faster (FA) and standard insulin aspart (A) from data obtained in a randomized double-blind crossover study evaluating fully closed-loop insulin delivery in adults with type 2 diabetes (n=13, age 59±10yrs, BMI 34.5±9.1kg/m2, HbA1c 7.7±1.2% [60±13mmol/mol]). Blood samples were collected every 15 to 30min over 10h to determine plasma insulin aspart concentration using liquid chromatography mass spectrometry. Time to peak plasma concentration (Tmax) was calculated using a two-compartment model, Results Tmax was 68.7±21.6min for FA and 89.7±31.8min for A (mean paired difference FA minus A -15.5min, 95% CI [-31.6; 0.6min], p=0.06). Metabolic clearance rate did not differ between the two insulins (p=0.61). Insulin amount delivered during closed-loop with FA positively correlated with Tmax (rS=0.73, p=0.01), whereas no statistically significant correlation was found with BMI, weight or HbA1C (all p>0.18). Conclusion In conclusion, Tmax tended to be shorter for FA vs A during fully automated closed-loop insulin delivery and correlated with the amount of insulin delivered.
David Herzig; Joachim Dehais; Jean-Christophe Prost; Christos T. Nakas; Christoph Stettler; Lia Bally; Roman Hovorka. Pharmacokinetics of Faster and Standard Insulin Aspart During Fully Closed-Loop Insulin Delivery in Type 2 Diabetes. Diabetes Technology & Therapeutics 2020, 22, 691 -696.
AMA StyleDavid Herzig, Joachim Dehais, Jean-Christophe Prost, Christos T. Nakas, Christoph Stettler, Lia Bally, Roman Hovorka. Pharmacokinetics of Faster and Standard Insulin Aspart During Fully Closed-Loop Insulin Delivery in Type 2 Diabetes. Diabetes Technology & Therapeutics. 2020; 22 (9):691-696.
Chicago/Turabian StyleDavid Herzig; Joachim Dehais; Jean-Christophe Prost; Christos T. Nakas; Christoph Stettler; Lia Bally; Roman Hovorka. 2020. "Pharmacokinetics of Faster and Standard Insulin Aspart During Fully Closed-Loop Insulin Delivery in Type 2 Diabetes." Diabetes Technology & Therapeutics 22, no. 9: 691-696.
OBJECTIVE While the adjustment of insulin is an established strategy to reduce the risk of exercise-associated hypoglycemia for individuals with type 1 diabetes, it is not easily feasible for those treated with ultra-long-acting basal insulin. The current study determined whether pre-exercise intake of fructose attenuates the risk of exercise-induced hypoglycemia in individuals with type 1 diabetes using insulin degludec. RESEARCH DESIGN AND METHODS Fourteen male adults with type 1 diabetes completed two 60-min aerobic cycling sessions with or without prior intake (30 min) of 20 g of fructose, in a randomized two-period crossover design. Exercise was performed in the morning in a fasted state without prior insulin reduction and after 48 h of standardized diet. The primary outcome was time to hypoglycemia (plasma glucose ≤3.9 mmol/L) during exercise. RESULTS Intake of fructose resulted in one hypoglycemic event at 60 min compared with six hypoglycemic events at 27.5 ± 9.4 min of exercise in the control condition, translating into a risk reduction of 87.8% (hazard ratio 0.12 [95% CI 0.02, 0.66]; P = 0.015). Mean plasma glucose during exercise was 7.3 ± 1.4 mmol/L with fructose and 5.5 ± 1.1 mmol/L in the control group (P < 0.001). Lactate levels were higher at rest in the 30 min following fructose intake (P < 0.001) but were not significantly different from the control group during exercise (P = 0.32). Substrate oxidation during exercise did not significantly differ between the conditions (P = 0.73 for carbohydrate and P = 0.48 for fat oxidation). Fructose was well tolerated. CONCLUSIONS Pre-exercise intake of fructose is an easily feasible, effective, and well-tolerated strategy to alleviate the risk of exercise-induced hypoglycemia while avoiding hyperglycemia in individuals with type 1 diabetes on ultra-long-acting insulin.
Christophe Kosinski; David Herzig; Céline Isabelle Laesser; Christos T. Nakas; Andreas Melmer; Andreas Vogt; Bruno Vogt; Markus Laimer; Lia Bally; Christoph Stettler. A Single Load of Fructose Attenuates the Risk of Exercise-Induced Hypoglycemia in Adults With Type 1 Diabetes on Ultra-Long-Acting Basal Insulin: A Randomized, Open-Label, Crossover Proof-of-Principle Study. Diabetes Care 2020, 43, 2010 -2016.
AMA StyleChristophe Kosinski, David Herzig, Céline Isabelle Laesser, Christos T. Nakas, Andreas Melmer, Andreas Vogt, Bruno Vogt, Markus Laimer, Lia Bally, Christoph Stettler. A Single Load of Fructose Attenuates the Risk of Exercise-Induced Hypoglycemia in Adults With Type 1 Diabetes on Ultra-Long-Acting Basal Insulin: A Randomized, Open-Label, Crossover Proof-of-Principle Study. Diabetes Care. 2020; 43 (9):2010-2016.
Chicago/Turabian StyleChristophe Kosinski; David Herzig; Céline Isabelle Laesser; Christos T. Nakas; Andreas Melmer; Andreas Vogt; Bruno Vogt; Markus Laimer; Lia Bally; Christoph Stettler. 2020. "A Single Load of Fructose Attenuates the Risk of Exercise-Induced Hypoglycemia in Adults With Type 1 Diabetes on Ultra-Long-Acting Basal Insulin: A Randomized, Open-Label, Crossover Proof-of-Principle Study." Diabetes Care 43, no. 9: 2010-2016.
We assessed the performance of the factory‐calibrated, sixth‐generation continuous glucose monitoring (CGM) system Dexcom G6® (DexCom Inc., San Diego, California) during elective abdominal surgery. Twenty adults with (pre)diabetes undergoing abdominal surgery (>2 hours; 15 men, age 69 ± 13 years, glycated haemoglobin 53 ± 14 mmol/mol) wore the sensor from 1 week prior to surgery until hospital discharge. From induction of anaesthesia until 2 hours post‐surgery, reference capillary glucose values were obtained every 20 minutes using the Accu‐Chek® Inform II meter (Roche Diabetes Care, Mannheim, Germany). The primary endpoint was the mean absolute relative difference (ARD) between sensor and reference method during this period. In total, 1207 CGM/reference pairs were obtained. In the peri‐operative period (523 pairs), mean ± SD and median (interquartile range [IQR]) ARD were 12.7% ± 8.7% and 9.9 (6.3;15.9)%, respectively, and 67.4% of sensor readings were within International Organization of Standardization 15197:2013 limits. CGM overestimated reference glucose by 1.1 ± 0.8 mmol/L (95% limits of agreement −0.5;2.7 mmol/L). Clarke error grid zones A or B contained 99.2% of pairs (A: 78.8%; B: 20.4%). The median (IQR) peri‐operative sensor availability was 98.6 (95.9;100.0)%. No clinically significant adverse events occurred. In conclusion, the Dexcom G6 device showed consistent and acceptable accuracy during elective abdominal surgery, opening new avenues for peri‐operative glucose management.
Afroditi Tripyla; David Herzig; Dehais Joachim; Christos Nakas; Franziska Amiet; Andreas Andreou; Beat Gloor; Andreas Vogt; Lia Bally. Performance of a factory‐calibrated, real‐time continuous glucose monitoring system during elective abdominal surgery. Diabetes, Obesity and Metabolism 2020, 22, 1678 -1682.
AMA StyleAfroditi Tripyla, David Herzig, Dehais Joachim, Christos Nakas, Franziska Amiet, Andreas Andreou, Beat Gloor, Andreas Vogt, Lia Bally. Performance of a factory‐calibrated, real‐time continuous glucose monitoring system during elective abdominal surgery. Diabetes, Obesity and Metabolism. 2020; 22 (9):1678-1682.
Chicago/Turabian StyleAfroditi Tripyla; David Herzig; Dehais Joachim; Christos Nakas; Franziska Amiet; Andreas Andreou; Beat Gloor; Andreas Vogt; Lia Bally. 2020. "Performance of a factory‐calibrated, real‐time continuous glucose monitoring system during elective abdominal surgery." Diabetes, Obesity and Metabolism 22, no. 9: 1678-1682.
In receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) is undoubtedly the most widely used index of diagnostic accuracy for the assessment of the utility of a biomarker or for the comparison of competing biomarkers. Along with the AUC, the maximum of the Youden index, J, is often used both as an index of diagnostic accuracy and as a tool useful for the estimation of an optimal cutoff point that can be used for diagnostic purposes based on the biomarker under consideration. In this work, we study the utility of the length of the binormal model-based ROC curve (LoC) as an index of diagnostic accuracy for biomarker evaluation. Estimation procedures for LoC, described in this article, are based either on normality assumptions or on the same assumptions after a Box–Cox transformation to normality. Two simulation studies are considered. In the first, the estimation procedures for LoC are compared in terms of bias and root mean squared error, while in the second one, the performance of LoC is compared with approaches based on AUC and J, both for the case of the assessment of a single biomarker and for the comparison of two biomarkers, in a parametric framework. We provide an interpretation for the proposed index and illustrate with an application on biomarkers from a colorectal cancer study.
Alba M. Franco-Pereira; Christos Nakas; M. Carmen Pardo. Biomarker assessment in ROC curve analysis using the length of the curve as an index of diagnostic accuracy: the binormal model framework. AStA Advances in Statistical Analysis 2020, 104, 625 -647.
AMA StyleAlba M. Franco-Pereira, Christos Nakas, M. Carmen Pardo. Biomarker assessment in ROC curve analysis using the length of the curve as an index of diagnostic accuracy: the binormal model framework. AStA Advances in Statistical Analysis. 2020; 104 (4):625-647.
Chicago/Turabian StyleAlba M. Franco-Pereira; Christos Nakas; M. Carmen Pardo. 2020. "Biomarker assessment in ROC curve analysis using the length of the curve as an index of diagnostic accuracy: the binormal model framework." AStA Advances in Statistical Analysis 104, no. 4: 625-647.
Background and Purpose— MRproANP (midregional proatrial natriuretic peptide) is known to be independently associated with cardioembolic stroke cause and to improve risk stratification for 90-day mortality when measured within 24 to 72 hours after symptom onset in patients with acute ischemic stroke. However, the optimal time point for assessment remains unclear. This study aimed to evaluate prognostic utility of MRproANP at different time points during the first 5 days of hospitalization in patients with acute ischemic stroke. Methods— Samples of MRproANP were collected on admission ( Results— MRproANP levels modestly decease over the initial 5 days but remain highly predictive for cardioembolic stroke cause (odds ratio, 9.75 [95% CI, 3.2–29]; 10.62 [95% CI, 3.4–33.3]; 10.8 [95% CI, 3.1–37.1]; 19.4 [95% CI, 5.49–68.7] on admission, day 1, 3 and 5) and 90-day mortality (odds ratio, 59.4 [95% CI, 7.4–480.7]; 78.3 [95% CI, 7.9–772.6]; 14.5 [95% CI, 1.4–145]; 19.81 [95% CI, 2.7–143.4] on admission, day 1, 3, and 5). Change over time does not significantly modify the prognostic value of MRproANP ( P =0.65 and P =0.56 for the interaction term in the multivariate model). Conclusions— Independent prognostic value of MRproANP remains unaltered in the acute phase of stroke at least up to 5 days; repeated measurements do not improve the prognostic value.
Markus Arnold; Christos Nakas; Andreas Luft; Mirjam Christ-Crain; Alexander Leichtle; Mira Katan. Independent Prognostic Value of MRproANP (Midregional Proatrial Natriuretic Peptide) Levels in Patients With Stroke Is Unaltered Over Time. Stroke 2020, 51, 1873 -1875.
AMA StyleMarkus Arnold, Christos Nakas, Andreas Luft, Mirjam Christ-Crain, Alexander Leichtle, Mira Katan. Independent Prognostic Value of MRproANP (Midregional Proatrial Natriuretic Peptide) Levels in Patients With Stroke Is Unaltered Over Time. Stroke. 2020; 51 (6):1873-1875.
Chicago/Turabian StyleMarkus Arnold; Christos Nakas; Andreas Luft; Mirjam Christ-Crain; Alexander Leichtle; Mira Katan. 2020. "Independent Prognostic Value of MRproANP (Midregional Proatrial Natriuretic Peptide) Levels in Patients With Stroke Is Unaltered Over Time." Stroke 51, no. 6: 1873-1875.
Alternative hypotheses for order restrictions, such as umbrella or inverse umbrella (a.k.a tree) orderings, have been studied extensively in the literature, although less so when the studied response for each individual is the presence or absence of the event of interest. Two families of test statistics for solving the problem of testing against an umbrella or a tree ordering when the responses are binomial proportions are studied in this work and their asymptotic distributions are derived. A simulation study is conducted to compare the empirical power of some members of the derived families of test statistics with competing approaches. The methodology developed here was driven by an applied problem arising in stored products research where despite universal mortality in the case of doses of 1000 ppm of the insecticide phosphine, unexpected survival was noted at higher doses.
A. M. Franco‐Pereira; C. T. Nakas; C. G. Athanassiou; M. C. Pardo. Testing against umbrella or tree orderings for binomial proportions with an adaptation of an insect resistance case. Biometrical Journal 2020, 62, 1574 -1588.
AMA StyleA. M. Franco‐Pereira, C. T. Nakas, C. G. Athanassiou, M. C. Pardo. Testing against umbrella or tree orderings for binomial proportions with an adaptation of an insect resistance case. Biometrical Journal. 2020; 62 (6):1574-1588.
Chicago/Turabian StyleA. M. Franco‐Pereira; C. T. Nakas; C. G. Athanassiou; M. C. Pardo. 2020. "Testing against umbrella or tree orderings for binomial proportions with an adaptation of an insect resistance case." Biometrical Journal 62, no. 6: 1574-1588.
Background Variations in patient demand increase the challenge of balancing high-quality nursing skill mixes against budgetary constraints. Developing staffing guidelines that allow high-quality care at minimal cost requires first exploring the dynamic changes in nursing workload over the course of a day. Objective Accordingly, this longitudinal study analyzed nursing care supply and demand in 30-minute increments over a period of 3 years. We assessed 5 care factors: patient count (care demand), nurse count (care supply), the patient-to-nurse ratio for each nurse group, extreme supply-demand mismatches, and patient turnover (ie, number of admissions, discharges, and transfers). Methods Our retrospective analysis of data from the Inselspital University Hospital Bern, Switzerland included all inpatients and nurses working in their units from January 1, 2015 to December 31, 2017. Two data sources were used. The nurse staffing system (tacs) provided information about nurses and all the care they provided to patients, their working time, and admission, discharge, and transfer dates and times. The medical discharge data included patient demographics, further admission and discharge details, and diagnoses. Based on several identifiers, these two data sources were linked. Results Our final dataset included more than 58 million data points for 128,484 patients and 4633 nurses across 70 units. Compared with patient turnover, fluctuations in the number of nurses were less pronounced. The differences mainly coincided with shifts (night, morning, evening). While the percentage of shifts with extreme staffing fluctuations ranged from fewer than 3% (mornings) to 30% (evenings and nights), the percentage within “normal” ranges ranged from fewer than 50% to more than 80%. Patient turnover occurred throughout the measurement period but was lowest at night. Conclusions Based on measurements of patient-to-nurse ratio and patient turnover at 30-minute intervals, our findings indicate that the patient count, which varies considerably throughout the day, is the key driver of changes in the patient-to-nurse ratio. This demand-side variability challenges the supply-side mandate to provide safe and reliable care. Detecting and describing patterns in variability such as these are key to appropriate staffing planning. This descriptive analysis was a first step towards identifying time-related variables to be considered for a predictive nurse staffing model.
Michael Smith; Jae-Ho Lee; Sarah N. Musy; Olga Endrich; Alexander B. Leichtle; Peter Griffiths; Christos T. Nakas; Michael Simon. Longitudinal Study of the Variation in Patient Turnover and Patient-to-Nurse Ratio: Descriptive Analysis of a Swiss University Hospital. Journal of Medical Internet Research 2020, 22, e15554 .
AMA StyleMichael Smith, Jae-Ho Lee, Sarah N. Musy, Olga Endrich, Alexander B. Leichtle, Peter Griffiths, Christos T. Nakas, Michael Simon. Longitudinal Study of the Variation in Patient Turnover and Patient-to-Nurse Ratio: Descriptive Analysis of a Swiss University Hospital. Journal of Medical Internet Research. 2020; 22 (4):e15554.
Chicago/Turabian StyleMichael Smith; Jae-Ho Lee; Sarah N. Musy; Olga Endrich; Alexander B. Leichtle; Peter Griffiths; Christos T. Nakas; Michael Simon. 2020. "Longitudinal Study of the Variation in Patient Turnover and Patient-to-Nurse Ratio: Descriptive Analysis of a Swiss University Hospital." Journal of Medical Internet Research 22, no. 4: e15554.
Background Quantification of dietary intake is key to the prevention and management of numerous metabolic disorders. Conventional approaches are challenging, laborious, and lack accuracy. The recent advent of depth-sensing smartphones in conjunction with computer vision could facilitate reliable quantification of food intake. Objective The objective of this study was to evaluate the accuracy of a novel smartphone app combining depth-sensing hardware with computer vision to quantify meal macronutrient content using volumetry. Methods The app ran on a smartphone with a built-in depth sensor applying structured light (iPhone X). The app estimated weight, macronutrient (carbohydrate, protein, fat), and energy content of 48 randomly chosen meals (breakfasts, cooked meals, snacks) encompassing 128 food items. The reference weight was generated by weighing individual food items using a precision scale. The study endpoints were (1) error of estimated meal weight, (2) error of estimated meal macronutrient content and energy content, (3) segmentation performance, and (4) processing time. Results In both absolute and relative terms, the mean (SD) absolute errors of the app’s estimates were 35.1 g (42.8 g; relative absolute error: 14.0% [12.2%]) for weight; 5.5 g (5.1 g; relative absolute error: 14.8% [10.9%]) for carbohydrate content; 1.3 g (1.7 g; relative absolute error: 12.3% [12.8%]) for fat content; 2.4 g (5.6 g; relative absolute error: 13.0% [13.8%]) for protein content; and 41.2 kcal (42.5 kcal; relative absolute error: 12.7% [10.8%]) for energy content. Although estimation accuracy was not affected by the viewing angle, the type of meal mattered, with slightly worse performance for cooked meals than for breakfasts and snacks. Segmentation adjustment was required for 7 of the 128 items. Mean (SD) processing time across all meals was 22.9 seconds (8.6 seconds). Conclusions This study evaluated the accuracy of a novel smartphone app with an integrated depth-sensing camera and found highly accurate volume estimation across a broad range of food items. In addition, the system demonstrated high segmentation performance and low processing time, highlighting its usability.
David Herzig; Christos T Nakas; Janine Stalder; Christophe Kosinski; Céline Laesser; Joachim Dehais; Raphael Jaeggi; Alexander Benedikt Leichtle; Fried-Michael Dahlweid; Christoph Stettler; Lia Bally. Volumetric Food Quantification Using Computer Vision on a Depth-Sensing Smartphone: Preclinical Study. JMIR mHealth and uHealth 2020, 8, e15294 .
AMA StyleDavid Herzig, Christos T Nakas, Janine Stalder, Christophe Kosinski, Céline Laesser, Joachim Dehais, Raphael Jaeggi, Alexander Benedikt Leichtle, Fried-Michael Dahlweid, Christoph Stettler, Lia Bally. Volumetric Food Quantification Using Computer Vision on a Depth-Sensing Smartphone: Preclinical Study. JMIR mHealth and uHealth. 2020; 8 (3):e15294.
Chicago/Turabian StyleDavid Herzig; Christos T Nakas; Janine Stalder; Christophe Kosinski; Céline Laesser; Joachim Dehais; Raphael Jaeggi; Alexander Benedikt Leichtle; Fried-Michael Dahlweid; Christoph Stettler; Lia Bally. 2020. "Volumetric Food Quantification Using Computer Vision on a Depth-Sensing Smartphone: Preclinical Study." JMIR mHealth and uHealth 8, no. 3: e15294.
Although the complexity and length of treatment is connected to the newborn's maturity and birth weight, most case-mix grouping schemes classify newborns by birth weight alone. The objective of this study was to determine whether the definition of thresholds based on a changepoint analysis of variability of birth weight and gestational age contributes to a more homogenous classification. This retrospective observational study was conducted at a Tertiary Care Center with Level III Neonatal Intensive Care and included neonate cases from 2016 through 2018. The institutional database of routinely collected health data was used. The design of this cohort study was explorative. The cases were categorized according to WHO gestational age classes and SwissDRG birth weight classes. A changepoint analysis was conducted. Cut-off values were determined. When grouping the cases according to the calculated changepoints, the variability within the groups with regard to case related costs could be reduced. A refined grouping was achieved especially with cases of >2500 g birth weight. An adjusted Grouping Grid for practical purposes was developed. A novel method of classification of newborn cases by changepoint analysis was developed, providing the possibility to assign costs or outcome indicators to grouping mechanisms by gestational age and birth weight combined.
Olga Endrich; Karen Triep; Nenad Torbica; Christos Nakas; Mathias Nelle; Martin Fiedler; Luigi Raio. Changepoint analysis of gestational age and birth weight: proposing a refinement of Diagnosis Related Groups. Pediatric Research 2019, 87, 910 -916.
AMA StyleOlga Endrich, Karen Triep, Nenad Torbica, Christos Nakas, Mathias Nelle, Martin Fiedler, Luigi Raio. Changepoint analysis of gestational age and birth weight: proposing a refinement of Diagnosis Related Groups. Pediatric Research. 2019; 87 (5):910-916.
Chicago/Turabian StyleOlga Endrich; Karen Triep; Nenad Torbica; Christos Nakas; Mathias Nelle; Martin Fiedler; Luigi Raio. 2019. "Changepoint analysis of gestational age and birth weight: proposing a refinement of Diagnosis Related Groups." Pediatric Research 87, no. 5: 910-916.
Response of endophytic fruit fly species (Tephritidae) to larval crowding is a form of scramble competition that may affect important life history traits of adults, such as survival and reproduction. Recent empirical evidence demonstrates large differences in adult life history traits, especially longevity, among Mediterranean fruit fly (Ceratitis capitata; "medfly") biotypes obtained from different regions of the world. However, whether the evolution of long lifespan is associated with response to stress induced by larval crowding has not been fully elucidated. We investigated, under constant laboratory conditions, the response of a short‐ and a long‐lived medfly biotypes to stress induced by larval crowding. Survival and development of larvae and pupae and the size of resulting pupae were recorded. The lifespan and age‐specific egg production patterns of the obtained adults were recorded. Our findings reveal that increased larval density reduced immature survival (larvae and pupae) in the short‐lived biotype but had rather neutral effects on the longed‐lived one. Only larvae of the long‐lived biotype were capable of prolonging their developmental duration under the highest crowding regime to successfully pupate and emerge as adults. Response of emerging adults to larvae crowding conditions was similar in the two medfly biotypes. Those individuals emerging from high larval density regimes had reduced longevity and fecundity. Long‐lived biotype individuals, however, appeared to suffer a higher cost in longevity compared with the short‐lived one. The importance of our findings to understand the evolution of long lifespan is discussed.
Alexandros D. Diamantidis; Charalampos S. Ioannou; Christos Nakas; James R. Carey; Nikos T. Papadopoulos. Differential response to larval crowding of a long‐ and a short‐lived medfly biotype. Journal of Evolutionary Biology 2019, 33, 329 -341.
AMA StyleAlexandros D. Diamantidis, Charalampos S. Ioannou, Christos Nakas, James R. Carey, Nikos T. Papadopoulos. Differential response to larval crowding of a long‐ and a short‐lived medfly biotype. Journal of Evolutionary Biology. 2019; 33 (3):329-341.
Chicago/Turabian StyleAlexandros D. Diamantidis; Charalampos S. Ioannou; Christos Nakas; James R. Carey; Nikos T. Papadopoulos. 2019. "Differential response to larval crowding of a long‐ and a short‐lived medfly biotype." Journal of Evolutionary Biology 33, no. 3: 329-341.