Ethical allocation of scarce vaccine doses: the Priority-Equality protocol

Background: Whenever vaccines for a new pandemic or widespread epidemic are developed, demand greatly exceeds the available supply of vaccine doses in the crucial, initial phases of vaccination. Rationing protocols must then fulfill a number of ethical principles balancing equal treatment of individuals and prioritization of at-risk and instrumental subpopulations. For COVID-19, actual rationing methods used a territory-based first allocation stage based on proportionality to population size, followed by locally-implemented prioritization rules. The results of this procedure have been argued to be ethically problematic. Methods: We use a formal-analytical approach arising from the mathematical social sciences which allows to investigate whether any allocation methods (known or unknown) fulfill a combination of (ethical) desiderata and, if so, how they are formulated algorithmically. Results: Strikingly, we find that there exists one and only one method that allows to treat people equally while giving priority to those who are worse off. We identify this method down to the algorithmic level and show that it is easily implementable and it exhibits additional, desirable properties. In contrast, we show that the procedures used during the COVID-19 pandemic violate both principles. Conclusions: Our research delivers an actual algorithm that is readily applicable and improves upon previous ones. Since our axiomatic approach shows that any other algorithm would either fail to treat people equally or fail to prioritize those who are worse off, we conclude that ethical principles dictate the adoption of this algorithm as a standard for the COVID-19 or any other comparable vaccination campaigns

Ethical allocation of scarce vaccine doses: The Priority-Equality protocol

Background: Whenever vaccines for a new pandemic or widespread epidemic are developed, demand greatly exceeds the available supply of vaccine doses in the crucial, initial phases of vaccination. Rationing protocols must then fulfill a number of ethical principles balancing equal treatment of individuals and prioritization of at-risk and instrumental subpopulations. For COVID19, actual rationing methods used a territory-based first allocation stage based on proportionality to population size, followed by locally-implemented prioritization rules. The results of this procedure have been argued to be ethically problematic. Methods: We use a formal-analytical approach arising from the mathematical social sciences which allows to investigate whether any allocation methods (known or unknown) fulfill a combination of (ethical) desiderata and, if so, how they are formulated algorithmically. Results: Strikingly, we find that there exists one and only one method that allows to treat people equally while giving priority to those who are worse o. We identify this method down to the algorithmic level and show that it is easily implementable and it exhibits additional, desirable properties. In contrast, we show that the procedures used during the COVID-19 pandemic violate both principles. Conclusions: Our research delivers an actual algorithm that is readily applicable and improves upon previous ones. Since our axiomatic approach shows that any other algorithm would either fail to treat people equally or fail to prioritize those who are worse o, we conclude that ethical principles dictate the adoption of this algorithm as a standard for the COVID-19 or any other comparable vaccination campaigns

Analysis of the effect of clock drifts on frequency regulation and power sharing in inverter-based islanded microgrids

© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Local hardware clocks in physically distributed computation devices hardly ever agree because clocks drift apart and the drift can be different for each device. This paper analyses the effect that local clock drifts have in the parallel operation of voltage source inverters (VSIs) in islanded microgrids (MG). The state-of-the-art control policies for frequency regulation and active power sharing in VSIs-based MGs are reviewed and selected prototype policies are then re-formulated in terms of clock drifts. Next, steady-state properties for these policies are analyzed. For each of the policies, analytical expressions are developed to provide an exact quantification of the impact that drifts have on frequency and active power equilibrium points. In addition, a closed-loop model that accommodates all the policies is derived, and the stability of the equilibrium points is characterized in terms of the clock drifts. Finally, the implementation of the analyzed policies in a laboratory MG provides experimental results that confirm the theoretical analysis.Peer ReviewedPostprint (author's final draft

Criopreservação de embriões de camundongos e bovinos utilizando metanol como crioprotetor.

Mouse embryos were collccted from superovulated animals on the fourth day after IICG injection. They were put directly into a solution of 3 M methanol in PBSS at room temperature during ten minutes. Thawing was carried out in a waterbath at 37 ºC during 20seconds. Embryos were placed directly into PBSS washed twice and put into culture using medium T6 supplemented with 10% fetal calf serum at 37 °C in a humid atmosphere of 5% CO2 , 5% 02 and 90% N2 . Bovine embryos were cultured under the same conditions, only using PBS supplemented with 20% fetal calf serum as culture medium. Of the 104 frozen mouse embryos, 48,2% continued developing in culture after thawing. None of the eight bovine embryos that were thawed and transferred directly to recipients resulted in pregnancy and none of the twelve bovine embryos that were thawed and put into culture continued to develop.Embriões de camundongos coletados no quarto dia após a injeção de HCG foram colocados diretamente em uma solução 3 M de metanol em PBS suplementado com 10% de soro fetal bovino (PBSS), à temperatura ambiente, durante dez minutos. Foram acondicionados em "paillets" de 0,25 ml e colocados diretamente a - 10 ºC durante cinco minutos antes e durante seis minutos depois de induzir a formação de gelo. O descongelainento foi realizado em banho-maria a 37 ºC durante 20 segundos. Os embriões foram colocados diretamente em P855, lavados duas vezes e colocados em cultura utilizando meio T 6 suplementado com 10% de soro fetal bovino, a 37 0C numa atmosfera umedecida dc 5% CO2, 5% 02 e 90% N2. Os embriões bovinos foram coletados de fêmeas superovuladas, sete dias após o cio, e processados da mesma maneira que os embriões de camundongo. Dos 104 embriões de camundongo criopreservados e descongelados, 48,2% continuaram seu desenvolvimento em cultura. Dos 20 embriões bovinos criopreservados e descongelados, oito foram transferidos diretamente a receptoras, e doze foram colocados em cultura. Nenhuma das receptoras ficou gestante e nenhum dos embriões continuou seu desenvolvimento em cultura

Requerimentos para uso de tratamentos hormonais e desmame temporário no controle da reprodução de vacas de corte com cria ao pé

A busca de alternativas locais para incremento da fertilidade em vacas de corte com cria ao pé tem sido efetuada através de estudos da fisiologia do pós-parto e do desenvolvimento de sistemas de indução de ovulação e cio durante o pósparto precoce. Embora seja possível a indução de ovulação durante o pós-parto, o balanço energético negativo nos primeiros meses após o parto, associado à amamentação e à carência de alimento nesse período são os principais fatores determinantes da baixa fertilidade de vacas de corte criadas sob condições extensivas. O objetivo foi o de identificar a condição corporal mínima para a utilização de tratamentos hormonais associados a desmame temporário em condições específicas de criação para a melhoria dos índices de reprodução de vacas com cria ao pé. Um total de 904 vacas oriundas de cruzamentos comerciais criadas em duas propriedades foram submetidas à inseminação e monta natural subsequente com duração de até 90 dias após a aplicação de separação dos terneiros por 96 horas, suplementação durante sete dias com progestágenos via intravaginal seguida ou não de uma injeção de estrógeno após 24 horas. As taxas de inseminação e prenhez foram analisadas através de logaritmo linear, considerando possíveis interações entre os fatores: condição corporal, propriedade, grupo de parição e tratamentos hormonais. Os resultados indicaram que apenas vacas em escore superior a 3 numa escala de 1 a 5 devem receber tratamento hormonal, devendo ser consideradas as interações entre os tratamentos e grupo de parição, bem como os efeitos diferenciais em cada unidade de produção

Body condition score to predict the postpartum fertility of crossbred beef cows

A relação entre as modificações no escore de condição corporal (BCS) e a fertilidade de vacas de corte durante o pós-parto foi examinada em grupos organizados em função das datas dos partos. Foram efetuadas quatro avaliações com início em torno de um mês pós-parto. Na segunda avaliação, as vacas receberam pessários impregnados com acetato de medroxi-progesterona e uma injeção de benzoato de estradiol. Na sua remoção, foi efetuada a terceira avaliação e separação dos terneiros durante quatro dias. Durante esse período foi observado cio duas vezes ao dia, sendo as inseminações realizadas 12 horas após. Depois do retorno dos terneiros às vacas, foram introduzidos touros até completar 60 dias de estação reprodutiva. As distribuições dos BCS diferiram significativamente entre grupos de parição e momentos de avaliação. Os resultados indicaram que apenas vacas com BCS 3 (escala de 1 a 5) em torno do primeiro mês pós-parto podem ser incluídas em programas de inseminação artificial com possibilidade de ficarem prenhas. Não foi observada diferença estatisticamente significativa entre grupos de parição quanto a taxa de prenhez. A evolução do BCS durante o pós-parto pode ser empregada para ajustar a estação reprodutiva à melhor época do ano, visando maiores taxas de gestação.The relationship between changes in body condition score (BCS) during the postpartum and fertility in beef cows suckling calves under extensive conditions were investigated. Cows were subjected to four BCS evaluations over the postpartum period, starting around one month after calving. In the second evaluation cows were treated with medroxy-progesterone acetate impregnated pessaries and received an injection of estradiol benzoate. At the third evaluation, pessaries were removed and calves were separated from the cows for 96 hours, during which time estrous was observed twice a day, and animals artificially inseminated 12 hours after detection. When calves returned to their dams, bulls were introduced until a 60-day mating period was reached. The distribution of BCS differed among calving groups and evaluations. Results indicated that only cows comprising a BCS 3 (1 to 5 scale) around the first month postpartum can be used in an artificial insemination program with possibilities of becoming pregnant. There was no statistical difference between the calving groups in pregnancy rate. The evolution of the BCS of the cows during postpartum can be used to adjust the start of the breeding season to coincide with the time of the year where herd pregnancy rates will be highest

Anchoring on Utopia: a generalization of the Kalai–Smorodinsky solution

Many bargaining solutions anchor on disagreement, allocating gains with respect to the worst-case scenario. We propose here a solution anchoring on utopia (the ideal, maximal aspirations for all agents), but yielding feasible allocations for any number of agents. The negotiated aspirations solution proposes the best allocation in the direction of utopia starting at an endogenous reference point which depends on both the utopia point and bargaining power. The Kalai–Smorodinsky solution becomes a particular case if (and only if) the reference point lies on the line from utopia to disagreement. We provide a characterization for the two-agent case relying only on standard axioms or natural restrictions thereof: strong Pareto optimality, scale invariance, restricted monotonicity, and restricted concavity. A characterization for the general (n-agent) case is obtained by relaxing Pareto optimality and adding the (standard) axiom of restricted contraction independence, plus the minimal condition that utopia should be selected if available

Utilidade do benzoato de estradiol após a suplementação com gestágeno na sincronização de cios de novilhas de corte

Existem evidências de que a associação de benzoato de estradiol (ODB) após a suplementação com progesterona concentra a manifestação de cios em sistemas de sincronização de cios para bovinos. O objetivo deste experimento foi de verificar o efeito do uso de diferentes dosagens de ODB injetadas 24 horas após a retirada do progestágeno, em novilhas de 14 e 24 meses de idade. Foram utilizadas 376 novilhas que receberam esponjas vaginais durante 7 dias e na colocação dos pessários 5,0 mg de ODB i.m.. Na retirada das esponjas foram distribuídas em três tratamentos: 0,0 ODB, que não receberam o estrógeno; 0,5 ODB, com 0,5 mg e 1,0 ODB, com 1,0 mg de estrógeno i.m. 24 h após a retirada do pessário. As variáveis medidas foram: cio (presença ou não), 2º cio (taxa de segundo serviço) e prenhez, ao final da temporada reprodutiva. Nas novilhas de 24 meses que receberam ODB foi observada maior freqüência de cios na propriedade A, em contraste, na propriedade B a taxa de 2º cio foi superior. No geral foi observada uma taxa de cio de 84%, 96% e 96% e de 2º cio de 19%, 35% e 45%, respectivamente para 0,0 ODB, 0,5 ODB e 1,0 ODB. As novilhas de 14 meses tratadas com ODB manifestam um maior percentual de cios, sem modificação significativa na taxa de retorno. A associação de 0,5 mg de ODB à suplementação com o progestágeno promove maior incidência de cio em novilhas de 24 meses, porém, com redução da fertilidade em algumas situações. A utilidade da associação com esteróides é maior em novilhas de 14 meses, nas quais as taxas de concepção foram semelhantes as que não receberam o estrógeno

Polychlorinated trityl radicals for dynamic nuclear polarization: the role of chlorine nuclei

Polychlorinated trityl radicals bearing carboxylate substituents are water soluble persistent radicals that can be used for dynamic nuclear polarization. In contrast to other trityl radicals, the polarization mechanism differs from the classical solid effect. DFT calculations performed to rationalize this behaviour support the hypothesis that polarization is transferred from the unpaired electron to chlorine nuclei and from these to carbon by spin diffusion. The marked differences observed between neutral and anionic forms of the radical will be discussed

Selective harmonic-compensation control for single-phase active power filter with high harmonic rejection

(c) 2009 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.This paper presents a linear current control scheme for single-phase active power filters. The approach is based on an outer voltage loop, an inner current loop, and a resonant selective harmonic compensator. The design of the control parameters is carried out using conventional linear techniques (analysis of loop gain and other disturbance-rejection transfer functions). The performance of the proposed controller is evaluated and compared with two reference controllers: a basic control and an advanced repetitive control. In comparison with these controllers, the proposed control scheme provides additional attenuation to the harmonics coming from the load current, the grid voltage, and the reference signal, resulting in a grid current with lower harmonic distortion. Experimental results are reported in order to validate this paper.Peer ReviewedPostprint (updated version