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Objective: To determine whether the Institute Of Medicine's (IOM) 2009 guidelines for weight-gain during pregnancy are predictive of maternal and infant outcomes in ethnic minority populations. Methods: We designed a population-based study using administrative data on 181,948 women who delivered live singleton births in Washington State between 2006–2008. We examined risks of gestational hypertension, preeclampsia/eclampsia, cesarean delivery, and extended hospital stay in White, Black, Native-American, East-Asian, Hispanic, South-Asian and Hawaiian/Pacific islander women according to whether they gained more or less weight during pregnancy than recommended by IOM guidelines. We also examined risks of neonatal outcomes including Apgar score <7 at 5 min, admission to NICU, requirement for ventilation, and a diagnosis of small or large for gestational age at birth. Results: Gaining too much weight was associated with increased odds for gestational hypertension (adjusted OR (aOR) ranged between 1.53–2.22), preeclampsia/eclampsia (aOR 1.44–1.81), cesarean delivery (aOR 1.07–1.38) and extended hospital stay (aOR 1.06–1.28) in all ethnic groups. Gaining too little weight was associated with decreased odds for gestational hypertension and delivery by cesarean section in Whites, Blacks and Hispanics. Gaining less weight or more weight than recommended was associated with increased odds for small for gestational age and large for gestational age infants respectively, in all ethnic groups. Conclusions: Adherence to the 2009 IOM guidelines for weight gain during pregnancy reduces risk for various adverse maternal outcomes in all ethnic groups studied. However, the guidelines were less predictive of infant outcomes with the exception of small and large for gestational age.

The purpose of this study is to investigate the transient behavior of various radiating elements used in phased array systems such as the dipole, the loop, the log-periodic, the slot, the horn, and the spiral antennas. Both the driving point impulse response and the step modulated response in the far field are to be evaluated experimentally and theoretically. This report treats the analysis of the cylindrical and biconical dipole radiating elements. In addition, a general theory for determining radiation from bent wires is presented. Both the theoretical and experimental portion of this study employ a time domain analysis as opposed to the conventional frequency domain approach. It is shown that a time domain analysis yields considerable insight and suggests network modles which can be verified experimentally. (Author)

The purpose of this study is to investigate the transient behavior of various radiating elements used in radar phased array systems such as the dipole, the loop, the log-periodic, the slot, the horn, and the spiral antennas. Both the driving point impulse response and the step modulated response in the far field are evaluated experimentally and theoretically. The radiating elements are divided into two classes: the bent wire radiators and the aperture type antennas (for example - the dipole and the waveguide horn, respectively). A new empirical theory of radiation and reflection from bent wire antennas is presented and computer programs are offered. The dp and far field responses of certain bent wire elements, namely the monopole, the dipole above a ground plane (the element used frequently in array systems), the loop, the log-periodic and the spiral are evaluated. In addition, the dp responses of a biconical antenna waveguide horn and slot radiators are presented. Both the theoretical and experimental portions of this study employ a time domain analysis as opposed to the conventional frequency domain approach. It is shown that a time domain analysis yields considerable insight and suggests network models which can be verified experimentally.

BACKGROUND: The diagnosis of labor onset has been described as one of the most important judgments in maternity care. There is compelling evidence that the duration of both latent and active phase labor are clinically important and require consistent approaches to measurement. In order to measure the duration of labor phases systematically, we need standard definitions of their onset. We reviewed the literature to examine definitions of labor onset and the evidentiary basis provided for these definitions. METHODS: Five electronic databases were searched using predefined search terms. We included English, French and German language studies published between January 1978 and March 2014 defining the onset of latent labor and/or active labor in a population of healthy women with term births. Studies focusing exclusively on induced labor were excluded. RESULTS: We included 62 studies. Four 'types' of labor onset were defined: latent phase, active phase, first stage and unspecified. Labor onset was most commonly defined through the presence of regular painful contractions (71 % of studies) and/or some measure of cervical dilatation (68 % of studies). However, there was considerable discrepancy about what constituted onset of labor even within 'type' of labor onset. The majority of studies did not provide evidentiary support for their choice of definition of labor onset. CONCLUSIONS: There is little consensus regarding definitions of labor onset in the research literature. In order to avoid misdiagnosis of the onset of labor and identify departures from normal labor trajectories, a consistent and measurable definition of labor onset for each phase and stage is essential. In choosing standard definitions, the consequences of their use on rates of maternal and fetal morbidity must also be examined.