1,019 research outputs found
Morning quiet-time ionospheric current reversal at mid to high latitudes
The records of an array of magnetometers set up across the Australian mainland are examined. In addition to a well-defined current whorl corresponding to the ionospheric <i>S<sub>q</sub></i> current system, another system of eastward flowing currents is often found in the early morning. The system is most easily identified at observatories poleward of the focus of the <i>S<sub>q</sub></i> system, where a morning reversal from eastward to westward currents can be seen. The time of the reversal is usually later, sometimes up to 12h local noon, in June (Southern Winter) than in other seasons. There is some evidence of a similar current system at other longitudes and in the Northern Hemisphere. An important outcome of the study is that it enables identification of which features of a daily variation of the northward magnetic field &Delta;<i>X</i> relate to an <i>S<sub>q</sub></i> current whorl and which must be attributed to some other current system
Analytical models for Cross-correlation signal in Time-Distance Helioseismology
In time-distance helioseismology, the time signals (Doppler shifts) at two
points on the solar surface, separated by a fixed angular distance are
cross-correlated, and this leads to a wave packet signal. Accurately measuring
the travel times of these wave packets is crucial for inferring the sub-surface
properties in the Sun. The observed signal is quite noisy, and to improve the
signal-to-noise ratio and make the cross-correlation more robust, the temporal
oscillation signal is phase-speed filtered at the two points in order to select
waves that travel a fixed horizontal distance. Hence a new formula to estimate
the travel times is derived, in the presence of a phase speed filter, and it
includes both the radial and horizontal component of the oscillation
displacement signal. It generalizes the previously used Gabor wavelet that was
derived without a phase speed filter and included only the radial component of
the displacement. This is important since it will be consistent with the
observed cross-correlation that is computed using a phase speed filter, and
also it accounts for both the components of the displacement. The new formula
depends on the location of the two points on the solar surface that are being
cross correlated and accounts for the travel time shifts at different locations
on the solar surface.Comment: 27 pages, 8 figures, ApJ in pres
Anesthesia for thoracic surgery in infants and children
The management of infants and children presenting for thoracic surgery poses a variety of challenges for anesthesiologists. A thorough understanding of the implications of developmental changes in cardiopulmonary anatomy and physiology, associated comorbid conditions, and the proposed surgical intervention is essential in order to provide safe and effective clinical care. This narrative review discusses the perioperative anesthetic management of pediatric patients undergoing noncardiac thoracic surgery, beginning with the preoperative assessment. The considerations for the implementation and management of one-lung ventilation (OLV) will be reviewed, and as will the anesthetic implications of different surgical procedures including bronchoscopy, mediastinoscopy, thoracotomy, and thoracoscopy. We will also discuss pediatric-specific disease processes presenting in neonates, infants, and children, with an emphasis on those with unique impact on anesthetic management
Adam Smith and Colonialism
In the context of debates about liberalism and colonialism, the arguments of Adam Smith have been taken as illustrative of an important line of anti-colonial liberal thought. The reading of Smith presented here challenges this interpretation. It argues that Smith’s opposition to colonial rule derived largely from its impact on the metropole, rather than on its impact on the conquered and colonised; that Smith recognised colonialism had brought ‘improvement’ in conquered territories and that Smith struggled to balance recognition of moral diversity with a universal moral framework and a commitment to a particular interpretation of progress through history. These arguments have a wider significance as they point towards some of the issues at stake in liberal anti-colonial arguments more generally
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Factors affecting early identification of pregnant women by community health workers in Morogoro, Tanzania
Background: It is recommended that Antenatal Care (ANC) be initiated within the first trimester of pregnancy for essential interventions, such folic acid supplementation, to be effective. In Tanzania, only 24% of mothers attend their first ANC appointment during their first trimester. Studies have shown that women who have had contact with a health worker are more likely to attend their first antenatal care appointment earlier in pregnancy. Community health workers (CHWs) are in an opportune position to be this contact. This study explored CHW experiences with identifying women early in gestation to refer them to facility-based antenatal care services in Morogoro, Tanzania. Methods: This qualitative study employed 10 semi-structured focus group discussions, 5 with 34 CHWs and 5 with 34 recently delivered women in three districts in Morogoro, Tanzania. A thematic analytical approach was used to identify emerging themes among the CHW and RDW responses.ResultsStudy findings show CHWs play a major role in identifying pregnant women in their communities and linking them with health facilities. Lack of trust and other factors, however, affect early pregnancy identification by the CHWs. They utilize several methods to identify pregnant women, including: asking direct questions to households when collecting information on the national census, conducting frequent household visits and getting information about pregnant women from health facilities. Conclusions: We present a framework for the interaction of factors that affect CHWs' ability to identify pregnant women early in gestation. Further studies need to be conducted investigating optimal workload for CHWs, as well as reasons pregnant women might conceal their pregnancies.USAID through the Health Research Challenge for Impact (HRC) [GHS-A-00-09-00004-00]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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