Analyzing the sustainability of 28 ‘Blockchain for Good’ projects via affordances and constraints

Proponents of ‘Blockchain for Good’–blockchain efforts seeking to enable benefits to humans and the environment–have suggested that the technology can support sustainability. However, while previous research has addressed aspects of the sustainability affordances of Blockchain for Good projects, the constraints that these projects impose have not faced equal consideration. Furthermore, the theoretical concepts of sustainability ‘problems’ and ‘solutions’ implicit in these projects have not been made clear. In this exploratory study, we evaluate the sustainability of 28 Blockchain for Good projects that use cryptocurrencies or tradable tokens with regard to the UN sustainability goals. These projects span a range of goals, such as supply chain tracking, transparent charity, and fairer voting. Despite their admirable goals, we find that current Blockchain for Good projects are unlikely to contribute to a sustainable future due to technical limitations and a conceptual framing that favors the status quo rather than transformative change

Analyzing the sustainability of 28 ‘Blockchain for Good’ projects via affordances and constraints

Proponents of ‘Blockchain for Good’–blockchain efforts seeking to enable benefits to humans and the environment–have suggested that the technology can support sustainability. However, while previous research has addressed aspects of the sustainability affordances of Blockchain for Good projects, the constraints that these projects impose have not faced equal consideration. Furthermore, the theoretical concepts of sustainability ‘problems’ and ‘solutions’ implicit in these projects have not been made clear. In this exploratory study, we evaluate the sustainability of 28 Blockchain for Good projects that use cryptocurrencies or tradable tokens with regard to the UN sustainability goals. These projects span a range of goals, such as supply chain tracking, transparent charity, and fairer voting. Despite their admirable goals, we find that current Blockchain for Good projects are unlikely to contribute to a sustainable future due to technical limitations and a conceptual framing that favors the status quo rather than transformative change

Co-Occurrence of Asthma and Nephrolithiasis in Children

It has been proposed that epithelial dysfunction and inflammation may predispose patients to kidney stone formation. Asthma is another chronic condition related to epithelial dysfunction and inflammation. We hypothesized that pediatric patients with asthma would have an increased prevalence of nephrolithiasis. Furthermore, we investigated if asthma patients with nephrolithiasis have clinical characteristics and urine profiles that point to mechanisms of stone formation. We evaluated 865 pediatric patients who had a diagnosis of nephrolithiasis. Clinical/demographic data and 24 hour urine samples were compared between asthma + stone (n = 142) and stone only patients. Data from asthmatics without stone were also available for evaluation of medication differences among asthma + stone and asthma only patients. The prevalence of nephrolithiasis in the pediatric population at our institution was 0.08% vs. 0.31% in our pediatric asthmatic population. The prevalence of asthma in our pediatric population was 6.8% vs. 26.7% in our pediatric stone patients. Asthma + stone patients were more likely to be on a combination inhaled corticosteroid + long acting beta agonist inhaler as compared to age/gender/BMI matched asthma patients without stone (29.7% vs. 13.7%, p = 0.0012). 259 kidney stone patients had 24 hour urine samples for comparison. There was no difference in 24 hour urine profiles between asthma + stone and stone only patients. Children with asthma have a 4-fold greater prevalence of kidney stones than the general pediatric population. Similarly, children with kidney stones have a 4-fold greater prevalence of asthma. This correlation may suggest a mechanistic link between asthma and nephrolithiasis. Further investigation is needed to elucidate the pathophysiologic origin of this relationship

Development of an animal model of nephrocalcinosis via selective dietary sodium and chloride depletion

Background:Nephrocalcinosis (NC) is an important clinical problem seen in critically ill preterm neonates treated with loop diuretics. No reliable animal models are available to study the pathogenesis of NC in preterm infants. The purpose of this study was to develop a reproducible and clinically relevant animal model of NC for these patients and to explore the impact of extracellular fluid (ECF) volume contraction induced by sodium and chloride depletion in this process.Methods:Three-week-old weanling Sprague-Dawley rats were fed diets deficient in either chloride or sodium or both. A subgroup of rats from each dietary group was injected daily with furosemide (40 mg/kg i.p.).Results:Rats fed a control diet, with or without furosemide, or a chloride-depleted diet alone, did not develop NC. By contrast, 50% of the rats injected with furosemide and fed the chloride-depleted diet developed NC. Moreover, 94% of the rats fed the combined sodium- and chloride-depleted diet developed NC, independently of furosemide use. NC was associated with the development of severe ECF volume contraction; hypochloremic, hypokalemic, metabolic alkalosis; increased phosphaturia; and growth retardation.Conclusion:Severe ECF volume contraction induced by chronic sodium and chloride depletion appears to play an important role in the pathogenesis of NC. Copyright © 2013 International Pediatric Research Foundation, Inc

Hysteretic Dynamics of Multi-Stable Early Afterdepolarisations with Repolarisation Reserve Attenuation: A Potential Dynamical Mechanism for Cardiac Arrhythmias

Abstract Some cardiovascular and non-cardiovascular drugs frequently cause excessive prolongation of the cardiac action potential (AP) and lead to the development of early afterdepolarisations (EADs), which trigger lethal ventricular arrhythmias. Combining computer simulations in APs with numerical calculations based on dynamical system theory, we investigated stability changes of APs observed in a paced human ventricular myocyte model by decreasing and/or increasing the rapid (I Kr) and slow (I Ks) components of delayed rectifying K+ current. Upon reducing I Kr, the APs without EADs (no-EAD response) showed gradual prolongation of AP duration (APD), and were annihilated without AP configuration changes due to the occurrence of saddle-node bifurcations. This annihilation caused a transition to an AP with EADs as a new stable steady state. Furthermore, reducing repolarisation currents (repolarisation reserve attenuation) evoked multi-stable states consisting of APs with different APDs, and caused multiple hysteretic dynamics. Depending on initial ion circumstances within ventricular myocytes, these multi-stable AP states might increase the local/global heterogeneity of AP repolarisations in the ventricle. Thus, the EAD-induced arrhythmias with repolarisation reserve attenuation might be attributed to the APD variability caused by multi-stability in cardiac AP dynamics