Abstract
The current research work was carried out to simulate monthly streamflow historical record using Soil and Water Assessment Tool (SWAT) and Artificial Neural Network (ANN) at the Astore ...Basin, Gilgit-Baltistan, Pakistan. The performance of SWAT and ANN models was assessed during calibration (1985–2005) and validation (2006–2010) periods via statistical indicators such as coefficient of determination (R2), Nash–Sutcliffe efficiency (NSE), percent bias (PBIAS), and root-mean-square error (RMSE). R2, NSE, PBIAS, and RMSE values for SWAT (ANN with Architecture (2,27,1)) models during calibration are 0.80 (0.88), 0.73 (0.82), 15.7 (0.008), and 79.81 (70.34), respectively, while during validation, the corresponding values are 0.71 (0.86), 0.66 (0.95), 17.3 (0.10), and 106.26 (75.92). The results implied that the ANN model is superior to the SWAT model based on the statistical performance indicators. The SWAT results demonstrated an underestimation of the high flow and overestimation of the low flow. Comparatively, the ANN model performed very well in estimating the general and extreme flow conditions. The findings of this research highlighted its potential as a valuable tool for accurate streamflow forecasting and decision-making. The current study recommends that additional machine learning models may be compared with the SWAT model output to improve monthly streamflow predictions in the Astore Basin.
Drug delivery via aerosolization for localized and systemic effect is a non-invasive approach to achieving pulmonary targeting. The aim of this study was to prepare spray-dried proliposome (SDP) ...powder formulations to produce carrier particles for superior aerosolization performance, assessed via a next generation impactor (NGI) in combination with a dry powder inhaler. SDP powder formulations (F1-F10) were prepared using a spray dryer, employing five different types of lactose carriers (Lactose monohydrate (LMH), lactose microfine (LMF), lactose 003, lactose 220 and lactose 300) and two different dispersion media. The first dispersion medium was comprised of water and ethanol (50:50% v/v ratio), and the second dispersion medium comprised wholly of ethanol (100%). In the first dispersion medium, the lipid phase (consisting of Soya phosphatidylcholine (SPC as phospholipid) and Beclomethasone dipropionate (BDP; model drug) were dissolved in ethanol and the lactose carrier in water, followed by spray drying. Whereas in second dispersion medium, the lipid phase and lactose carrier were dispersed in ethanol only, post spray drying. SDP powder formulations (F1-F5) possessed significantly smaller particles (2.89 ± 1.24-4.48 ± 1.20 μm), when compared to SDP F6-F10 formulations (10.63 ± 3.71-19.27 ± 4.98 μm), irrespective of lactose carrier type via SEM (scanning electron microscopy). Crystallinity of the F6-F10 and amorphicity of F1-F15 formulations were confirmed by XRD (X-ray diffraction). Differences in size and crystallinity were further reflected in production yield, where significantly higher production yield was obtained for F1-F5 (74.87 ± 4.28-87.32 ± 2.42%) then F6-F10 formulations (40.08 ± 5.714-54.98 ± 5.82%), irrespective of carrier type. Negligible differences were noted in terms of entrapment efficiency, when comparing F1-F5 SDP formulations (94.67 ± 8.41-96.35 ± 7.93) to F6-F10 formulations (78.16 ± 9.35-82.95 ± 9.62). Moreover, formulations F1-F5 demonstrated significantly higher fine particle fraction (FPF), fine particle dose (FPD) and respirable fraction (RF) (on average of 30.35%, 890.12 μg and 85.90%) when compared to counterpart SDP powder formulations (F6-F10). This study has demonstrated that when a combination of water and ethanol was employed as dispersion medium (formulations F1-F5), superior formulation properties for pulmonary drug delivery were observed, irrespective of carrier type employed.
Voluntary pro-environmental behaviors in the workplace such as organizational citizenship behavior towards environment (OCBE) are pertinent for the organizations striving to become environmentally ...responsible entities. The significance of OCBE for green organizational initiatives has led scholars to strive for expanding its nomological network. Approaching from the theoretical angle of the social information processing approach, this quantitative, survey-based study theoretically links and empirically tests the impact of environmental transformational leadership on organizational citizenship behavior towards environment (OCBE) via mediating mechanism of perceived meaningful work. Data from a sample of 311 employees working in Pakistan’s hospitality sector were collected and analyzed to test the hypothesized relationships using structural equation modelling. Results indicated the indirect effect of perceived meaningful work on the relationship between environmental transformational leadership and organizational citizenship behavior towards environment. Implications of both theoretical and practical nature are laid out in the relevant sections of the paper.
Abstract
Investigating the effects of climate and land-use changes on surface runoff is critical for water resources management. The majority of studies focused on projected climate change effects on ...surface runoff, while neglecting future land-use change. Therefore, the main aim of this article is to discriminate the impacts of projected climate and land-use changes on surface runoff using the Soil and Water Assessment Tool (SWAT) through the lens of the Upper Indus Basin, Pakistan. Future scenarios of the land-use and climate changes are predicted using cellular automata artificial neural network and four bias-corrected general circulation models, respectively. The historical record (2000–2013) was divided into the calibration period (2000–2008) and the validation period (2009–2013). The simulated results demonstrated that the SWAT model performed well. The results obtained from 2000 to 2013 show that climate change (61.61%) has a higher influence on river runoff than land-use change (38.39%). Both climate and land-use changes are predicted to increase future runoff depth in this basin. The influence of climate change (12.76–25.92%) is greater than land-use change (0.37–1.1%). Global weather data has good applicability for simulating hydrological responses in the region where conventional gauges are unavailable. The study discusses that both climate and land-use changes impact runoff depth and concludes with some suggestions for water resources managers to bring water environment sustainability.
Abstract
Streamflow forecasting is essential for planning, designing, and managing watershed systems. This research study investigates the use of artificial neural networks (ANN), recurrent neural ...networks (RNN), and adaptive neuro-fuzzy inference systems (ANFIS) for monthly streamflow forecasting in the Hunza River Basin of Pakistan. Different models were developed using precipitation, temperature, and discharge data. Two statistical performance indicators, i.e., root mean square error (RMSE) and coefficient of determination (R2), were used to assess the performance of machine learning techniques. Based on these performance indicators, the ANN model predicts monthly streamflow more accurately than the RNN and ANFIS models. To assess the performance of the ANN model, three architectures were used, namely 2-1-1, 2-2-1, and 2-3-1. The ANN architecture with a 2-3-1 configuration had higher R2 values of 0.9522 and 0.96998 for the training and testing phases, respectively. For each RNN architecture, three transfer functions were used, namely Tan-sig, Log-sig, and Purelin. The architecture with a 2-1-1 configuration based on tan-sig transfer function performed well in terms of R2 values, which were 0.7838 and 0.8439 for the training and testing phases, respectively. For the ANFIS model, the R2 values were 0.7023 and 0.7538 for both the training and testing phases, respectively. Overall, the findings suggest that the ANN model with a 2-3-1 architecture is the most effective for predicting monthly streamflow in the Hunza River Basin. This research can be helpful for planning, designing, and managing watershed systems, particularly in regions where streamflow forecasting is crucial for effective water resource management.
Lead (Pb) is one of the most abundant toxic heavy metals, which have a serious impact on the growth and yield of crop plants. Nitric oxide (NO) is a natural signaling molecule that regulates the ...growth and productivity of plants. Here, exogenous NO was found to enhance Pb tolerance in watermelon, which resulted in more Pb restriction in roots and less up-translocated Pb to aerial parts. Pb stress, however, led to an increase in shoot dry weight, root biomass, root relative water content, leaf malondialdehyde (MDA) content, and the total soluble protein content in leaves and roots. By contrast, shoot height and fresh weight, leaf biomass, and root MDA content were decreased under Pb stress. NO treatments alleviated Pb toxicity by decreasing Pb translocation, enhancing root growth (elongation and biomass), inducing antioxidant enzymes activities, and reducing root MDA contents in watermelon seedlings. In conclusion, our results provide useful insights into the mechanism of Pb tolerance in cucurbit crops and information for the cultivation management of watermelon in the presence of this heavy metal (Pb).
Precipitation, air temperature and Normalized Difference Vegetation Index (NDVI) data of 32 sites for a period of 1983 to till date in Pakistan were collected with the objective of studying the ...effects of vegetation on precipitation and air temperature in Pakistan. Spatial trends were assessed for NDVI, precipitation and air temperature (maximum and minimum). Increasing trends were observed at 18, 20, 24 and 26 number of monitoring stations for NDVI, precipitation and maximum and minimum temperature respectively. The trends of NDVI were compared with the trends of precipitation and maximum and minimum temperature in hilly and urban areas. NDVI and precipitation showed parallel trends in hilly areas at 64% of the monitoring stations. Whereas, only 53% of the stations displayed parallel trends in urban areas. 71% of the stations showed opposite NDVI and maximum temperature trends and 79% of the stations showed opposite NDVI and minimum temperature trends in hilly areas. However, in urban areas only 47% and 41% of the stations showed opposite trends of NDVI and maximum temperature and NDVI and minimum temperature respectively. Pearson’s correlation coefficients were calculated to determine the effects of vegetation on precipitation and air temperature (maximum and minimum) in hilly and urban areas. The results showed that there exists positive relationship between NDVI and precipitation and negative relationship between NDVI and temperature (maximum and minimum) in most of the hilly areas. However, in urban areas, the positive relationship between NDVI and precipitation exists only in 47% of the stations and negative relationships between NDVI and maximum temperature and between NDVI and minimum temperature exist only in 47% and 41% of the stations respectively. Results of the current study suggest afforestation practices at country level to reduce climate change effects.
Precipitation elasticity provides a basic estimate of the sensitivity of long-term streamflow to changes in long-term precipitation, and it is especially useful as the first assessment of climate ...change impact in land and water resource projects. This study estimated and compared the precipitation elasticity (εp) of streamflow in 86 catchments within Pakistan over 50 major rivers using three widely used analytical models: bivariate nonparametric (NP) estimator, multivariate NP analysis, and multivariate double logarithm (DL) model. All the three models gave similar values of elasticity in the range of 0.1–3.5 for over 70–75% of the catchments. This signifies that a 1% change in the annual mean precipitation compared to the long-term historic mean annual precipitation will amplify the streamflow by 0.1–3.5%. In addition, the results suggested that elasticity estimation of streamflow sensitivity using the multivariate DL model is more reliable and realistic. Precipitation elasticity of streamflow is observed high at altitudes ranging between 250 m and 1000 m while the longitudinal and latitudinal pattern of εp shows higher values in the range of 70–75 and 32–36 decimal degrees, respectively. The εp values were found to have a direct relationship with the mean annual precipitation and an inverse relationship with the catchment areas. Likewise, high εp values were noticed in areas where the mean annual temperature ranges between 15 and 24 °C.
Objective: To analyse the effect of pupil dilation on intraocular lens instrument IOLMaster 500 biometric measurements, and to determine the effect of these measurements on intraocular lens power ...calculations in Asian eyes.
Methods: The prospective study was conducted at the Aga Khan University Hospital, Karachi, between January and April 2017, and comprised all patients scheduled for cataract surgery who underwent scanning with IOLMaster 500. For each patient, pre-dilation and post-dilation measurements were taken. The intraocular lens power was determined through Sanders/Retzlaff/Kraff Theoretical, Holladay, and Hoffer Q formulae. Data was analysed using SPSS 24.
Results: There were 276 eyes of 138 participants who had a mean age of 59.7±11.1 years. Anterior chamber depth changed significantly with pupil dilation (p=0.001). No significant changes were observed in the axial length (p=0.410), keratometry measurements (p=0.931), and intraocular lens power calculations (p>0.05).
Conclusions: The change in anterior chamber depth, though significant, was perhaps clinically non-significant. intraocular lens power did not exhibit any significant differences post-mydriasis.
Key Words: Mydriasis, Lenses, Intraocular, Lens, Implantation, Phakic intraocular lenses, Biometry.
Cardiac devices with intra-ventricular leads are associated with a risk of perforation. This can be a diagnostic challenge given that there is a whole spectrum of clinical presentation from ...incidental discovery on imaging to large effusions and tamponade. Here we present a case where a patient with permanent pacemaker for complete heart block presented with worsening fatigue that deteriorated to syncopal episodes. Electrocardiogram revealed bradycardia with junctional escape and imaging revealed the tip of the right ventricular lead beyond the ventricular wall. The lead was replaced under fluoroscopic guidance without the need for surgical intervention and the patient was ready for discharge on post-procedure day one. Replacement under fluoroscopic guidance is not only safe, but also enables early discharge, which reduces the burden on health care facilities as well as minimizes the patient's number of days lost in the hospital.
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