Role of induced sputum with hypertonic saline in the early diagnosis of no / inadequate sputum or sputum smear negative suspected cases of pulmonary tuberculosis

Background: Pulmonary Tuberculosis is one of the common infections in the world, especially in developing countries like India and is a leading cause of morbidity and mortality worldwide. Therefore, early diagnosis and microbiological confirmation of pulmonary TB is important. This study was done to assess the role of induced sputum with hypertonic saline in suspected pulmonary TB patients who produce no or inadequate sputum or who are sputum for AFB smear negative.Methods: 100 patients with clinical and radiological evidence of pulmonary TB with no or inadequate sputum or who are smear negative with spontaneous sputum were included in the study. Sputum was induced with 5ml of 3% hypertonic saline delivered through nebulizer and then was sent for Ziehl Neelsen staining examination.Results: 96 patients could produce adequate sputum after sputum induction. In 47 patients, sputum for AFB smear was found positive after induction.Conclusions: Sputum induction is a safe, cheap and non-invasive procedure and offers an alternative or additional approach in the diagnosis of sputum smear-negative suspected pulmonary tuberculosis patients and would enhance sensitivity for the diagnosis of tuberculosis.

Spousal involvement and CPAP adherence: A dyadic perspective

Poor adherence to continuous positive airway pressure (CPAP) treatment is associated with substantial health care costs, morbidity and mortality, and has been a leading obstacle in the effective management of obstructive sleep apnea (OSA). Successful interventions to improve CPAP adherence may ultimately include a variety of components. For patients living with spouses (refers to all domestic partners), the spouse will likely be an integral component to any successful intervention. Developing understanding of the role of spouses in adherence to CPAP has been identified to be a critical research need. This review expands the investigation of CPAP adherence to a broader context, from an exclusive focus on individual patients to a dyadic perspective encompassing both patients and their spouses. A conceptual framework based on social support and social control theories is proposed to understand spousal involvement in CPAP adherence. Methodologies for future investigations are discussed, along with implications for developing interventions that engage both patients and their spouses to improve CPAP use

Role of Madden-Julian Oscillation and Its Modulation by the Sea Surface Temperature in El Niño—Southern Oscillation

A parameterization is designed to study the role of Madden-Julian Oscillation (MJO) and the modulation by sea surface temperature (SST) in El Niño—Southern Oscillation (ENSO). It is added to a coupled ocean-atmosphere model of intermediate complexity and to a coupled general circulation model (CGCM) that does not any generate internal MJO. The MJO parameters acquire values either additively, i.e. randomly from observed distributions, or multiplicatively, i.e. modulated by evolving model ENSO-SST, albeit with some stochasticity. Sensitivity tests using the intermediate model reveal the complexity of MJO-ENSO relationship: e.g. ENSO strengthens with increase in either the stochasticity of amplitude or the degree of its SST-modulation, but similar relationships are not evident for speed and zonal extent. Ensemble comparisons between simulations with and without SST-feedback suggest that SST feedback to the MJO acting in a stable regime can be responsible for the observed ENSO variance. The multiplicative case has a larger ensemble spread than the additive case, which manifests in a larger interdecadal variability of ENSO. Long-term simulations of the CGCM reveal that although the unrealistic 2-yr ENSO period is retained upon the inclusion of additive or multiplicative MJO, there is a disruption in the biennial regularity of ENSO. The timing and occurrence of El Niños become dependent on the timing of MJO activity, which manifests in unseasonal ENSO peaks and reduced interannual power. These constraints on El Niño are linked to the seasonal curtailment of eastward propagating upper ocean anomalies by the easterlies that intersperse MJO westerlies. The power is partially restored in the multiplicative case, where the enhancement of MJO westerlies during warming phase leads to stronger subsequent peaks. Re-simulations performed by switching the MJO presence or SST-dependence at a strategically chosen time demonstrate that the SST-feedback to the MJO has almost as much impact on the evolution of ENSO anomalies as the random component of the MJO.</p

Role of Stochastic Forcing in ENSO Variability in a Coupled GCM

A systematic procedure is designed to evaluate the role of stochastic forcing (SF) in El Nino ? Southern Oscillation (ENSO) exhibited by coupled ocean-atmosphere general circulation models (CGCMs). The procedure is applied on a 163-year run of a CGCM which has realistic representation of ENSO and SF. The realism of ENSO in the CGCM is determined by statistical comparison with a 29-year global reanalysis product. SF is extracted from both the CGCM and reanalysis as residual atmospheric variability uncoupled to the ocean. Further, the Madden-Julian Oscillation (MJO) and non-MJO components are isolated from SF. The CGCM stochastic components are compared to those from the reanalysis to validate their representation. A coupled ocean-atmosphere model of intermediate complexity is first forced with stochastic components from the reanalysis. The resulting ENSO is examined for realism to evaluate the strengths and weaknesses of the intermediate coupled model, which is then forced with the stochastic components from the CGCM. Results are diagnosed to investigate the role of SF. It is found that the SF can play an important role in ENSO in the CGCM, especially in its warm events. The role is similar to reanalysis SF in generating ENSO period and spring predictability barrier. However, unlike in case of the reanalysis, the seasonal dependence of ENSO variance in the CGCM does not seem to be originating from its SF. The contribution to statistics appears to be higher from the MJO component of SF compared to the non-MJO component. The intermediate model simulations also suggest that both in CGCM and nature, the SF operates on a weakly stable coupled system to produce ENSO variability.</p

Multiplicative MJO Forcing of ENSO

Abstract The Madden–Julian oscillation (MJO) is parameterized to study the role of the feedback it receives from sea surface temperature (SST) in its influence on El Niño–Southern Oscillation (ENSO). The parameterization describes MJO surface westerlies in terms of a few basic parameters that include amplitude, zonal propagation extent, propagation speed, and the interval between adjacent events. It is used to drive a coupled ocean–atmosphere model of intermediate complexity tuned to a marginally stable regime. The MJO parameters acquire values either additively (i.e., based on observed estimates of most probable value and stochasticity) or multiplicatively (i.e., modulated by an evolving model ENSO SST, albeit with some stochasticity). Simulations reveal that ENSO variance increases with the stochasticity of MJO amplitude but is insensitive to the stochasticity of zonal extent and speed, except that ENSO vanishes completely when the propagation speed is zero. Likewise, ENSO strengthens linearly with the SST modulation of MJO amplitude, but not of speed and zonal extent—even though the two are known to be significantly influenced by SST. Ensemble comparisons between simulations with and without SST feedback demonstrate that SST feedback to the MJO acting in a stable regime can be responsible for the observed ENSO variance. The multiplicative case has a larger ensemble spread than the additive case, which manifests in a larger interdecadal variability of ENSO. The results emphasize that ENSO reproduction in coupled models depends on correctly representing the MJO, especially its amplitude and SST feedback

Role of stochastic forcing in ENSO in observations and a coupled GCM

A procedure is presented to estimate the role of atmospheric stochastic forcing (SF) in El Niño–Southern Oscillation (ENSO) simulated by a coupled ocean–atmosphere general circulation model (CGCM), in direct comparison to observations represented by a global reanalysis product. SF is extracted from the CGCM and reanalysis as surface wind anomalies linearly independent of the sea-surface temperature anomalies. Madden–Julian Oscillation (MJO) is isolated from SF to quantify its role in ENSO. A coupled ocean–atmosphere model of intermediate complexity is forced with SF, as well as its MJO and non-MJO components, from the reanalysis and CGCM. The role of SF is estimated by comparing the original ENSO in observations and the CGCM with that reproduced by the intermediate model. ENSO statistics in both reanalysis and CGCM are better reproduced when the intermediate model is tuned to be weakly stable than unstable. The intermediate model driven by SF from the reanalysis reproduces most characteristics of observed ENSO, such as its spectrum, seasonal phase-locking, fast decorrelation of ENSO SST during boreal spring, and its lag-correlation with SF. In contrast, not all characteristics of ENSO in the CGCM are reproduced by the intermediate model when SF from the CGCM is used. The seasonal phase-locking of ENSO in the CGCM is not reproduced at all. ENSO, therefore, appears to be driven by SF to a lesser degree in the CGCM than in observations. Characteristics of observed ENSO reproduced by the intermediate model (driven by SF) can be largely attributed to the MJO; which, for instance, is responsible for the fast decorrelation of ENSO SST during boreal spring in both reanalysis and CGCM. The non-MJO component seems to be more responsible than the MJO for erroneous features of ENSO in the CGCM