Identify the similar geomorphological units to apply the same management based on desertification intensity (case study Sistan and Baluchestan province, Saravan)

After desertification mapping for proper management is very important to recognize the similar work units. Because, the two geomorphological units or two work units that have the same desertification intensity classes, do not necessarily require the same management. In this study, to identify the similar work units that need the same management, at first the intensity of desertification was evaluated according to 4 important criteria in the region (climate, soil, vegetation, and wind erosion) based on the IMDPA model and then classified and identified the similar work units using Cluster analysis method. The results of desertification intensity based on the IMDPA model showed that there are two classes of extreme and medium with the areas about 59.32 and 40.68 percent respectively. This is while the results of cluster analysis showed that all geomorphological units are classified in six different clusters. According to the results, two work units with the same desertification intensity are not necessarily in the same cluster, and work units with the same intensity are in different clusters. Therefore it can be said using the clustering method with desertification models to identify similar units for planning and implementation of management programs will have well efficiency

GIS and multi-criteria decision-making analysis assessment of land suitability for rapeseed farming in calcareous soils of semi-arid regions

To reverse the negative environmental properties effect on fertile lands for agriculture, land suitability evaluation is the first step in the designing the most sustainable land use and management systems. The aim of the present study was to develop and evaluate a land suitability model for rapeseed farming using topography factors, soil data and remote sensing data in calcareous soils of semi-arid regions northwestern Iran. For this purpose, stratified random sampling was used to select a set of 92 soil samples of agricultural land use from 0 to 30 cm depth. For land suitability assessment, the opinions of 19 local experts were used to make a decision for the weight of topography, soil data and remote sensing data factors by an analytic hierarchy process (AHP) from multi-criteria analysis. The input data including climate, topography, soil and remote sensing data were included that are related to rapeseed production. The results indicate the highest specific weight belongs to the soil texture (0.341), calcium carbonate equivalent (0.171) and elevation (0.114), respectively. Land suitability evaluation based on the United Nations Food and Agriculture Organization classification system indicated that 0.81% (420.8 ha) of the studied area was for high suitable (S1), 42.33% (21940.2 ha) was for moderately suitable (S2) and 11.78% (6104 ha) was for marginally suitable (S3) class. The 39.72% (20586.4) and 0.95% (492.1 ha) of studied area were located as currently not-suitable and permanently not-suitable for rapeseed productions, respectively

Assessment of Wind Erosion Intensity by IRIFR Model Case Study: Jazinak, Sistan, Iran

The main objective of this research is an investigation and preparing of wind erosion intensity map. IRIFR model used in this study which has been developed by Iranian researchers for Iran’s climatic conditions. At first, the working unit map was prepared Then nine effective factors in wind erosion such as Geological Formation, Landform and Topography, Wind and Climatic Conditions, Soil Surface, Plant Cover, Wind Erosion, Soil Moisture, Deposits of Wind and Management Process are determined for each working unit. Each factor scored according to IRIFR model and for each one a raster GIS layer was created. According to the results, active sand dunes and Saline Lands showed the highest value with the rate of annual sedimentation more than 3879.4 ton/km2 ,while medium sandy plain with low density showed the least value with an annual rate of sedimentation of 708.73 ton/km2. Also in whole area, 35.74 percent equivalent 46491.36 hectares are classified in high class and 63.73 percent equivalent 82902.43 hectares are classified in medium class of wind erosion

Hierarchical cluster analysis to identify the homogeneous desertification management units.

Since in most mapping models geometric mean of different criteria are used to determine the desertification intensity, one of the most important issues in desertification studies is understanding the similar areas, which require similar management after determining the desertification intensity map. Two similar classes of desertification intensity may require different management due to differences in the criteria that affect its desertification severity. Therefore, after determining the geomorphological facies as the working units in Sistan plain, we used hierarchical cluster analysis to identify the homogeneous environmental management units (HEMUs) based on indices of MEDALUS model. According to the MEDALUS model, the studied area was divided into two categories namely medium and high desertification classes. Working units (geomorphological facies) are classified into five clusters according to HEMUs analysis based on climate, soil, vegetation, and wind erosion criteria. The first cluster (C11) include six facies with moderate and severe desertification; in all of these units the main effective factor was wind erosion, so they need the same management decisions controlling wind erosion. Two working units (1 and 4) with the same desertification severity were placed in two different clusters due to the main factors affecting each other. The results of the Mann-Whitney test showed that the value of the test statistics was 79. Also, the value of Asymp.Sig was obtained to be 0.018, which is less than 0.025 (two-tailed test), and it can be concluded that the classification of work units in the two models, clustering and desertification, is not equal (P<0.05). So It seems that using cluster analysis to identify the same units, which need the same management decision after preparing the desertification intensity, is necessary

Postoperative continuous positive airway pressure to prevent pneumonia, re-intubation, and death after major abdominal surgery (PRISM): a multicentre, open-label, randomised, phase 3 trial

Background: Respiratory complications are an important cause of postoperative morbidity. We aimed to investigate whether continuous positive airway pressure (CPAP) administered immediately after major abdominal surgery could prevent postoperative morbidity. Methods: PRISM was an open-label, randomised, phase 3 trial done at 70 hospitals across six countries. Patients aged 50 years or older who were undergoing elective major open abdominal surgery were randomly assigned (1:1) to receive CPAP within 4 h of the end of surgery or usual postoperative care. Patients were randomly assigned using a computer-generated minimisation algorithm with inbuilt concealment. The primary outcome was a composite of pneumonia, endotracheal re-intubation, or death within 30 days after randomisation, assessed in the intention-to-treat population. Safety was assessed in all patients who received CPAP. The trial is registered with the ISRCTN registry, ISRCTN56012545. Findings: Between Feb 8, 2016, and Nov 11, 2019, 4806 patients were randomly assigned (2405 to the CPAP group and 2401 to the usual care group), of whom 4793 were included in the primary analysis (2396 in the CPAP group and 2397 in the usual care group). 195 (8\ub71%) of 2396 patients in the CPAP group and 197 (8\ub72%) of 2397 patients in the usual care group met the composite primary outcome (adjusted odds ratio 1\ub701 [95% CI 0\ub781-1\ub724]; p=0\ub795). 200 (8\ub79%) of 2241 patients in the CPAP group had adverse events. The most common adverse events were claustrophobia (78 [3\ub75%] of 2241 patients), oronasal dryness (43 [1\ub79%]), excessive air leak (36 [1\ub76%]), vomiting (26 [1\ub72%]), and pain (24 [1\ub71%]). There were two serious adverse events: one patient had significant hearing loss and one patient had obstruction of their venous catheter caused by a CPAP hood, which resulted in transient haemodynamic instability. Interpretation: In this large clinical effectiveness trial, CPAP did not reduce the incidence of pneumonia, endotracheal re-intubation, or death after major abdominal surgery. Although CPAP has an important role in the treatment of respiratory failure after surgery, routine use of prophylactic post-operative CPAP is not recommended