A Two-Stage Feature Selection Approach for Robust Evaluation of Treatment Effects in High-Dimensional Observational Data

A Randomized Control Trial (RCT) is considered as the gold standard for evaluating the effect of any intervention or treatment. However, its feasibility is often hindered by ethical, economical, and legal considerations, making observational data a valuable alternative for drawing causal conclusions. Nevertheless, healthcare observational data presents a difficult challenge due to its high dimensionality, requiring careful consideration to ensure unbiased, reliable, and robust causal inferences. To overcome this challenge, in this study, we propose a novel two-stage feature selection technique called, Outcome Adaptive Elastic Net (OAENet), explicitly designed for making robust causal inference decisions using matching techniques. OAENet offers several key advantages over existing methods: superior performance on correlated and high-dimensional data compared to the existing methods and the ability to select specific sets of variables (including confounders and variables associated only with the outcome). This ensures robustness and facilitates an unbiased estimate of the causal effect. Numerical experiments on simulated data demonstrate that OAENet significantly outperforms state-of-the-art methods by either producing a higher-quality estimate or a comparable estimate in significantly less time. To illustrate the applicability of OAENet, we employ large-scale US healthcare data to estimate the effect of Opioid Use Disorder (OUD) on suicidal behavior. When compared to competing methods, OAENet closely aligns with existing literature on the relationship between OUD and suicidal behavior. Performance on both simulated and real-world data highlights that OAENet notably enhances the accuracy of estimating treatment effects or evaluating policy decision-making with causal inference

Veränderung einer Kulturlandschaft infolge anthropogener Einflüsse auf Oberflächengewässer und Bedrohung von Mangrovenökosystemen am Beispiel der Sundarbans, Bangladesch

Cultural landscapes are areas of exceptional beauty, containing superlative natural phenomena and are of ecological importance. At present cultural landscapes and wetlands are the most spectacular global issues for economic growth and balancing of ecosystems. The Sundarbans has an outstanding universal value where the cultural landscape was shared by the indigenous pastoral society over thousand years ago and it is still visible. The site is representing significant ongoing ecological and biological processes in the evolution and development of mangrove ecosystems and communities of plants and animals. It is situated in the Ganges transboundary catchment which is known as the single largest stretch of productive mangrove ecosystems in the world. It covers 10,000 km² between Bangladesh and India. The Sundarbans portion of Bangladesh is about 62 % and covers an area of 6017 km². It was declared as world natural heritage site by the UNESCO in 1997 and as a Ramsar site in 1992 already. There is an agglomeration of biodiversity with 66 different species of mangroves growing there. For comparison: 70 species of mangroves are found in the world. A large part of mangrove wetlands in Bangladesh, almost 45 %, have disappeared within the last three decades. The Gorai River is the main tributary of the Ganges which supplies downstream freshwater to the Sundarbans and ensures the ecosystems balance in the coastal region. Since the diversion of the Ganges water at Farakka Barrage in India from early 1975, the salinity level has increased drastically in the south western part of the region. Due to the reduction of the Ganges flows the industries are facing serious problems. Inequality control of the products and fragile affects are demonstrating on agriculture, fisheries, navigation, and hydromorphology, quality of drinking water and mangrove wetlands ecosystems. As a result, about 170,000 hectares (20.4%) of new land has been affected by various degrees of salinity during the last three decades. 38 % of the country’s territory and 33 % of its population is already affected by salinity intrusions. The saline front defined by the 0.5 dS/m isohaline has penetrated in the Nabaganga River as far north as Magura is far from the coast (240 km). Similarly about 6 dS/m has penetrated 173 km from the Sea in the Atharobanka River to the vicinity of the off-take from the Madhumati River. The research findings are showing 10805-21610 dS/m salinity is the best productive range in Sundarbans, where only 20 % of the area is within 32415 dS/m range of salinity and 80 % of the area (4813.60 km²) has a salinity rate over 32414 dS/m. The dominant species Heritiera fomes and Ceriops decendra are affected by top-dying disease which is recognised as key management concern. Procedures of water salinity modelling of 13 rivers in the Sundarbans region lay out increasing salinity trends. Fourier Polynomial Models have been done on 13 rivers where the time series approach (4 years) has been considered. The results show that only one river has crossed the salinity threshold line of 20 ppt or 43,220 dS/m which was the maximum value in 2000. Whereas 6 rivers have crossed in 2001, 8 rivers have crossed in 2002 and important 11 rivers have crossed the water salinity threshold line in 2003. According to average peak values of river water salinity there are 4 rivers (basin 1, 2, 3 and 4) that are in good condition, two rivers (basin 7 and 9) carry the moderate situation and 7 rivers (basin 5, 6, 7, 8, 10, 12 and 13) carry the high salinity rate in the dry season, which are major threats for mangrove ecosystems in the Sundarbans. The high salinity zone is located in the south-western corner of the Sundarbans; the previous values were 38,898-54,025 dS/m while the present values are 54,025 – 69,152 dS/m. Furthermore the area has been extended from South to North and East to West direction. The Fourier Polynomial models show the cyclic increasing behaviour of water salinity in the Sundarbans Rivers. Considering the results of all models and threshold values of water salinity for the Sundarbans case, it is clearly indicated and forecasted the message that upstream fresh water supply is necessary and emergent for the protection of cultural landscapes and mangrove wetlands ecosystems in the Sundarbans region. As priority is given by surface water salinity modelling, statements are formulated to support planning activities and to protect a special natural heritage site. The findings of this study would be a potential contribution to make a comprehensive management plan for the long-term conservation and protection of the cultural landscape and mangrove wetlands ecosystem in the Sundarbans region.Kulturlandschaften sind oft Gebiete von außergewöhnlicher Schönheit, die sowohl natürliche Phänomene repräsentieren, als auch von ökologischer Bedeutung sind. Kulturlandschaften und insbesondere Feuchtgebiete zählen zu den wichtigsten globalen Kernpunkten für Wirtschaftswachstum und für das Gleichgewicht von Ökosystemen. Das Ökosystem der Sundarbans hat einen überragenden universellen Wert. Bereits vor über tausend Jahren wurde diese Kulturlandschaft von der einheimischen Landbevölkerung genutzt. Dies ist auch heute noch sichtbar. Am Ökosystem der Sundarbans lassen sich die biologischen Prozesse und die ökologische Entwicklung der Mangrovenökosystem und der Lebensräume von Pflanzen und Tieren erkennen. Die Sundarbans liegen im Einzugsgebiet des die nationalen Grenzen überschreitenden Ganges. Sie sind weltweit bekannt als größtes und ergiebiges Mangrovenökosystem. Das Mangrovenökosystem umfasst eine Fläche von 10.000 km² zwischen Bangladesch und Indien. Der Anteil von Bangladesh an den Sundarbans beträgt 62% und umfasst ein Gebiet von 6017 km². Im Jahr 1997 wurde es von der UNESCO zum Weltnaturerbe erklärt und gemäß der Ramsar-Konvention als Ramsar-Feuchtgebiet im Jahr 1992. Das Gebiet schließt eine Artenvielfalt mit 66 Mangrovenarten ein. Zum Vergleich: Es gibt bislang 70 bekannte Mangrovenarten auf der Erde. Ein sehr großer Teil, fast 45 % der Mangrovenfeuchtgebiete von Bangladesch, sind in den letzten drei Dekaden verschwunden. Der Gorai-Fluß ist der Hauptarm des Ganges, der die Sundarbans stromabwärts mit Frischwasser versorgt und das Gleichgewicht des Ökosystems in der Küstenregion gewährleistet. Seit Anfang des Jahres 1975 wird der Ganges im Farakka Stauwehr (Indien) umgeleitet. Seitdem ist der Salzgehalt im westlichen Teil der Region drastisch gestiegen. Durch die Verringerung des Flussbetts des Ganges steht die Industrie vor ernsthaften Problemen bezüglich der Qualitätskontrolle der Produkte. Auswirkungen sind auch für die Landwirtschaft, die Fischerei, den Schiffsverkehr, die Hydromorphologie, die Qualität des Trinkwassers und die Ökosysteme der Feuchtgebiete der Mangrovenwälder zu verzeichnen. Durch die Versalzung sind bereits ca. 170,000 Hektar (20.4%) Neuland während der letzten drei Dekaden betroffen. Das entspricht 38 % des Hoheitsgebiets von Bangladesch. Die Versalzung hat sich bereits auf 33% der Bevölkerung ausgewirkt. Die Salzfront, die durch die 0.5 dS/m Isohaline definiert wird, ist bereits in den Nabaganga Fluss bis zur Stadt Magura, die 240 km von der Küste entfernt ist, eingedrungen. Im Atharobanka Fluss, der 173 Kilometer vom Meer entfernt ist, wird nahe des Abzweiges des Madhumati Rivers ein Salzgehalt von ca. 6 dS/m gemessen. Die Untersuchungsergebnisse zeigen, dass das Ökosystem der Sunderbans einen mittleren Salzgehalt von 10805-21610 dS/m aufweist, wobei 20 % des Gebietes einen Salzgehalt von 32415 dS/m und 80 % des Gebiets (4814 km²) einen Salzgehalt über 32414 dS/m aufweisen. Die dominierenden Arten Heritiera fomes und Ceriops decendra sind davon intensiv betroffen. Dies gilt als auffälligstes Ereignis in den Sundarbans. Die Modelle für den Salzgehalt von 13 Flüssen in der Region der Sundarbans zeigen steigende Tendenzen des Salzgehaltes. Die Ergebnisse der Fourier-Modelle zeigen, dass nur ein Fluss den Grenzbereich des Salzwassergehaltes (20 ppt oder 43,220 dS/m) im Jahr 2000 übersteigt. Dagegen überschreiten bereits im Jahr 2001 6 Fließgewässer, im Jahr 2002 8 Fließgewässer und im Jahr 2003 11 Fließgewässer den Grenzwert des Salzgehalts. Entsprechend den mittleren Höchstwerten des Salzgehaltes sind 4 Fließgewässer (Bassin 1, 2, 3 und 4) in gutem Zustand, 2 Fließgewässer (Bassin 7 und 9) im mittleren und 7 Fließgewässer (Bassin 5, 6, 7, 8, 10, 12 und 13) im schlechten Zustand während der trockenen Jahreszeit. Dies ist eine der Hauptbedrohungen für die Ökosysteme der Mangrovenwälder in den Sundarbans. Die Zone mit dem hohen Salzgehalt liegt im südwestlichen Teil der Sundarbans. Lagen die Werte früher bei 38898-54025 dS/m, so sind es aktuell Werte von 54025 - 69152 dS/m, des Weiteren hat sich das Gebiet von Süden nach Norden und von Osten nach Westen vergrößert. Die Fourier-Modelle zeigen eine kreisförmige Zunahme des Salzgehaltes in den Flüssen der Sundarbans. Fasst man die Ergebnisse der Dissertation zusammen, so lässt sich folgendes feststellen: 1. Es ist eindeutig zu erkennen, dass die Süßwasserversorgung lebenswichtig für den Schutz der Kulturlandschaft und des Ökosystems der Sundarbans ist. 2. Zur Vorhersage der Entwicklung der Sunderbans hat die Modellierung der Wassergüte, insbesondere des Salzgehaltes, höchste Priorität. 3. Administrative Anweisungen zum Schutz dieses Weltkulturerbes sind auszuarbeiten. 4. Die Erkenntnisse dieser Forschungsarbeit tragen dazu bei, einen langfristigen Managementplan für die Erhaltung und den Schutz der Kulturlandschaften und des Ökosystems der Sundarbans zu erstellen

Rapidly progressing and resistant warts in an immuno-competent male

Cutaneous warts are common skin conditions caused by different specific strains of the human papilloma virus (HPV), mostly affect children as localized lesion on the hands and feet. They are slowly progressing and disseminated lesions are found in immuno-compromised situations. Usually majority of warts disappear by few months to two years. This is a case of extensive, giant, rapidly progressing and resistant warts in an immuno-competent adult male.

Review on support vector machine (SVM) classifier for human emotion pattern recognition from EEG signals

This study reviewed the strategy in pattern classification for human emotion recognition system based on Support Vector Machine (SVM) classifier on Electroencephalography (EEG) signal. SVM has been widely used as a classifier and has been reported as having minimum error and produce accurate classification. However, the accuracy is influenced by many factors such as the electrode placement, equipment used, preprocessing techniques and selection of feature extraction methods. There are many types of SVM classifier such as SVM via Radial Basis Function (RBF), Linear Support Vector Machine (LSVM) and Multiclass Least Squares Support Vector Machine (MC-LS-SVM). SVM via RBF states the average accuracy rate of 92.73, 85.41, 93.80 and 67.40% using different features extraction method, respectively. The accuracy using LSVM and MC-LS-SVM classifier are 91.04 and 77.15%, respectively. Although, the accuracy rate influenced by many factors in the experimental works, SVM always shows their function as a great classifier. This study will discuss and summarize a few related works of EEG signals in classifying human emotion using SVM classifier

Properties Of Concrete By Using Bagasse Ash And Recycle Aggregate

Sustainable concrete structures which imply green building technology has been widely considering in modern structures. The objective of this study is to investigate the concrete properties by using recycle aggregate as a replacement of coarse aggregate and bagasse ash as the partial replacement of cement. Experimental investigation has been carried out by performing several tests which included slump test, compacting factor test, compressive strength test, rebound hammer test and concrete density test. A total of nine mix batches of concrete containing 0%, 25%, 50%, 75% and 100% of recycle aggregate and 0%, 10%, 15% and 20% of bagasse ash were tested to determine the increment of mechanical properties of concrete. It can be observed that significant decrease of concrete strength with the addition of recycle aggregate, and effective increment of concrete strength by using optimum percentage of bagasse ash might be possible. Finally, it can be concluded that recycle aggregate and bagasse ash with optimum percentage can be used to make recycle concrete and sustainable structures

Circular equivalent planar array- a new approach

In this paper, a new configuration of four elements circular equivalent planar array has been proposed to achieve high gain and directivity with lower sidelobe level. After being designed and simulated, the proposed antenna array has achieved high directivity of 15.3 dBi with 85 % radiation efficiency. Besides, the array has a maximum realized gain of 14.51 dB and low sidelobe level of – 16 dB. The proposed antenna array has been evaluated by comparing its performances with four elements of MIMO and planar antenna arrays. It is observed that the proposed array shows greater performances in terms of all parameters compared to the other two arrays. Also, the proposed array has maximum isolation of below – 35 dB between two nearby elements. In turn, the high directivity of the proposed antenna array resonating at 5.8 GHz with very minimum return loss which makes it suitable for Radar application

Customers' attitude towards agro based benefits provided by the telecommunication operators in Bangladesh

The main objective of this research is to find out attitude of users only towards agro based benefits provided by telecommunication operators in Bangladesh. Agriculture is the most important sector of the economy of Bangladesh which provides 63% employment and contributing 18.6% to the national GDP. But unfortunately the farmer's community is one of the most deprived ones in the country and frequent access to information remains one of the crying needs for a long time period. It can enable them to enhance their quality of life. It has been argued that telecommunication operators can come to aid in this respect. Telecommunications operators have already expanded their services and provided specialized agro-based services to the farmers. It also explored the characteristics of the user's and their perception. Data were collected from 120 respondents who were the users of telecommunication operators in Bangladesh. The data were collected through a structured interview schedule. Evidence from interviews suggests that most of the users were young, had little farming experience with small farm size and from small to medium families. These services were treated helpful to overcome their obstacles to information collection but still not efficient like the means they use to collect information traditionally. They want information in various fields of agriculture especially in the area of price, weather information, cultivation technique, disease treatment, fertilizer dose etc. Small farmers found it as a very effective any of information service especially in case of emergency situation and due to its cost effectiveness. But the mechanism need to use this services found sometimes difficult especially for the illiterate farmers. From this research, students other researchers and policy makers will get an insight about the ‘Users attitude towards agro based services provide by the telecommunication operators in Bangladesh. Key Words: Attitude, Agro, Services, Telecommunication, Bangladesh