Correlated Interball/ground-based observations of isolated substorm: The pseudobreakup phase

International audienceWe study the isolated substorm that occurred after a long quiet period, which showed all of the substorm signatures except for the first half hour of the expansion phase, which could be characterized as a pseudobreakup sequence, rather than a full-scale substorm onset. During the considered event, the substorm's instability leads to a current disruption, which starts at the near-Earth plasma sheet and then propagates tailward. Based on auroral observations, the analysis of geosynchronous plasma injections, and the plasma sheet observations at ~15 RE at the meridian of auroral substorm development we show that (1) before and probably during "pseudobreakup phase", the plasma sheet stayed cold and dense, (2) during the pseudobreakup phase, particle injections at 6.6 RE were only seen in unusually low energy components, and (3) the electron precipitation into the ionosphere was very soft. We conclude that the basic difference between pseudobreakups and "real" substorm activations was found in the low energy of all manifestations. We suggest that high density and low electron temperature in the plasma sheet are the reasons for low energization in the magnetic reconnection operated on closed field lines in the plasma sheet, as well as the weak field-aligned acceleration, as predicted by the Knight's relationship. The low Hall conductivity could then be the reason for the weak ground magnetic effects observed. This explanation suggests that the role of the ionospheric conductivity is "passive" as the plasma sheet, rather than the ionosphere, controls the development of the magnetospheric instability

Информативность антеи интранатальных факторов риска развития бронхолегочной дисплазии у недоношенных новорожденных

Aim of the study. To identify the leading antenatal and intranatal risk factors for bronchopulmonary dysplasia based on the analysis of their prevalence and information contentMaterials and methods. We performed a prospective follow-up of 124 infants of gestational age of less than 32 weeks with the classical form of bronchopulmonary dysplasia (study group). The control group included 119 newborns with gestational age of less than 32 weeks without bronchopulmonary dysplasia. The parents of the compared groups were questioned, with the following assessment of the prevalence and informative value of antenatal and intranatal risk factors. Results. The leading antenatal and intranatal risk factors for the development of bronchopulmonary dysplasia are: acute respiratory viral infection in II-III trimester, threatened miscarriage, intrauterine growth retardation, Apgar score at the 1st (3 or less) and 5th minute (5 or less), body weight of less than 1400g at birth, body length less than 36 cm at birth, cesarean section, more then 6-hours waterless period. Conclusion. The combination of these intranatal and antenatal risk factors can be attributed to a group with high risk of bronchopulmonary dysplasia.Цель исследования. Выделение ведущих анте- и интранатальных факторов риска развития бронхолегочной дисплазии на основе анализа их распространенности и информативности.Материал и методы. Проведено проспективное наблюдение за 124 младенцами гестационного возраста менее 32 нед с классической формой бронхолегочной дисплазии (основная группа). Контролем служили 119 новорожденных со сроком гестации менее 32 нед без бронхолегочной дисплазии. На основе анкетирования проведен опрос родителей сравниваемых групп с последующей оценкой распространенности и информативности анте- и интранатальных факторов риска. Результаты. Ведущими анте- и интранатальными факторами риска развития бронхолегочной дисплазии служат присоединение острой респираторной вирусной инфекции во II-III триместре, угроза прерывания беременности, задержка внутриутробного развития плода, низкая оценка по шкале Апгар на 1-й (3 балла и менее) и 5-й (5 баллов и менее) минутах, масса тела при рождении менее 1400 г, длина тела при рождении менее 36 см, выполнение кесарева сечения, безводный промежуток более 6 ч. Заключение. Сочетание указанных интра- и антенатальных факторов дает основание отнести новорожденных к высокой группе риска формирования бронхолегочной дисплазии

Information value of ante- And intranatal risk factors for bronchopulmonary dysplasia in preterm newborns [Информативность анте- и интранатальных факторов риска развития бронхолегочной дисплазии у недоношенных новорожденных]

Aim of the study. To identify the leading antenatal and intranatal risk factors for bronchopulmonary dysplasia based on the analysis of their prevalence and information content Materials and methods. We performed a prospective follow-up of 124 infants of gestational age of less than 32 weeks with the classical form of bronchopulmonary dysplasia (study group). The control group included 119 newborns with gestational age of less than 32 weeks without bronchopulmonary dysplasia. The parents of the compared groups were questioned, with the following assessment of the prevalence and informative value of antenatal and intranatal risk factors. Results. The leading antenatal and intranatal risk factors for the development of bronchopulmonary dysplasia are: acute respiratory viral infection in II-III trimester, threatened miscarriage, intrauterine growth retardation, Apgar score at the 1st (3 or less) and 5th minute (5 or less), body weight of less than 1400g at birth, body length less than 36 cm at birth, cesarean section, more then 6-hours waterless period. Conclusion. The combination of these intranatal and antenatal risk factors can be attributed to a group with high risk of bronchopulmonary dysplasia. © 2019 National Academy of Pediatric Science and Innovation. All rights reserved