Effect of Selected Conservation Tillage Practices on Soil Moisture Content and Sorghum Yield under Rainfed Conditions on Sandy Loam Soil

In arid and semi-arid regions, the key to increase crop production is maximizing infiltration at the expense of surface runoff. One way of achieving such objectives could be the introduction of conservation tillage practices using appropriate equipment. A field experiment was carried out for two consecutive seasons (2016%252F2017 and 2017%252F2018) at the demonstration farm of the Faculty of Natural Resources and Environmental Studies, University of Alsalam, El fula, Sudan. The objective was to observe the effect of selected conservation tillage practices on soil moisture content and sorghum grain yield on sandy loam soil under rain-fed conditions. The treatments consisted of five tillage practices viz%253A Chisel plowing, cultivator, offset disc harrowing, chisel plowing %2B offset disc harrowing and no-tillage (traditional) as a control. The experiment was laid out in a randomized complete block design with three replications (RCBD). The soil moisture content (%25) at three depths of 0-15 cm, 15-30 cm and 30-45 cm was measured. Sorghum grain yield (kg ha-1) was determined. The results of analysis showed that different tillage practices had no significant effect on soil moisture content at the three depths for both seasons, except at 0-15 cm depth during the first season. Whereas, no-tillage practice increased soil moisture content by 37.8 %25, 35.3 %25, 28.5 %25 and 13.3 %25 as compared to the chiseling, chiseling %2B harrowing, cultivator and harrowing, respectively. The results also indicated that sorghum grain yield was not influenced by conservation tillage practices in the first season. However, the chisel plowing and cultivator practices were significantly increased the sorghum grain yield by 28.3 %25 and 27.5 %25, respectively, as compared to no-tillage practice during the second season

Water storage changes and balances in Africa observed by GRACE and hydrologic models

AbstractContinental water storage plays a major role in Earth's climate system. However, temporal and spatial variations of continental water are poorly known, particularly in Africa. Gravity Recovery and Climate Experiment (GRACE) satellite mission provides an opportunity to estimate terrestrial water storage (TWS) variations at both continental and river-basin scales. In this paper, seasonal and secular variations of TWS within Africa for the period from January 2003 to July 2013 are assessed using monthly GRACE coefficients from three processing centers (Centre for Space Research, the German Research Centre for Geosciences, and NASA's Jet Propulsion Laboratory). Monthly grids from Global Land Data Assimilation System (GLDAS)-1 and from the Tropical Rainfall Measuring Mission (TRMM)-3B43 models are also used in order to understand the reasons of increasing or decreasing water storage. Results from GRACE processing centers show similar TWS estimates at seasonal timescales with some differences concerning inter-annual trend variations. The largest annual signals of GRACE TWS are observed in Zambezi and Okavango River basins and in Volta River Basin. An increasing trend of 11.60 mm/a is found in Zambezi River Basin and of 9 mm/a in Volta River Basin. A phase shift is found between rainfall and GRACE TWS (GRACE TWS is preceded by rainfall) by 2–3 months in parts of south central Africa. Comparing GLDAS rainfall with TRMM model, it is found that GLDAS has a dry bias from TRMM model

Computation Enhancement using Reconfigurable Computing

In light of the industry’s constant need for better computer performance, this project aims to choose and evaluate an approach for facing this issue. The targeted category of computers is single board computers (e.g. Raspberry Pi). The approach utilized for enhancing performance is the use of reconfigurable computing as to execute computationally expensive calculations on a runtime custom-tailored hardware. The objective of this project is the test of the potential this approach has for increasing computers performance through comparing a software implementation of an algorithm with an FPGA assisted implementation of the same algorithm. The platforms chosen for this project are the Rapsberry Pi and the Parallella P1602 board with its Zynq SoC for the software implementation and the FPGA assisted implementation in that order. The chosen algorithm is Fourier Fast Transform due to its part in many DSP applications and its suitability for the project objective. While the software solution worked successfully resulting in an asymptotic cost of O(N log N); the reconfigurable computing solution couldn’t be completed due to time constraints and lack of experience of the student. Future work should complete the experiment and add a multicore implementation of the same algorithm to add yet another class to the comparison

Terrorism:an analysis of the international legal framework, international and regional responses case study: Syria.

International law, as a discipline, is obsessed with crises, requiring reinterpretation of its basic principles to cope with them. Through this process of reinterpretation, it also creates new rules. Terrorism is one such ‘crisis’ which has impacted the international legal framework on the use of force, making it deviate from its basis established by the United Nations Charter. This thesis conducts a macro analysis of the changes in the legal framework for combating terrorism after 9/11 and the Arab Spring. It focuses on the Syrian conflict as a case study, analyzing the major actors and their different legal justifications. The Syrian conflict is a clear prototype of the changes that started to take place after 9/11. The development in the legal framework governing the use of force happened in three dimensions. The first is the broadening of existing rules (such as favoring a purpose-oriented interpretation of self-defense to include new forms such as anticipatory and pre-emptive self-defense). The second dimension is the creation of new rules through state practice that replaced existing codified ones, in an attempt to avoid the deadlock of the Security Council (SC) veto. For example, the “unwilling and unable†standard is used to justify unilateral interventions without the SC authorization to fight terrorists in other states. A third dimension is the gradual decline of the use of collective security under the UN system, giving way to unilateral action by States

Critical analysis of existing business process reengineering models: towards the development of a comprehensive integrated model

Over the past two decades, business process reengineering (BPR) has been one of the most popular approaches to improving the efficiency and effectiveness of an organisation. However, a review of the relevant literature reveals that available BPR models that have been widely in use have some serious limitations and fail to take into consideration the human factor and change management. The theoretical gap identified in academic research is also reflected in industrial practice. This article analyses existing BPR models in order to set the stage for the development of a comprehensive integrated model to address their theoretical deficiencies. The article will provide an overview of the main issues, limitations and challenges of existing BPR models. The limitations will then be itemised, described and analysed to provide evidence for the need of a more systematic model that would help organisations to successfully carry out BPR initiatives and projects.

The Effect of Using Reflective Teaching Strategies on Developing Classroom Performance of Prospective Teachers of English at Al-Aqsa University

هدفت هذه الدراسة إلى بحث أثر استخدام استراتيجيات التدريس التأملي على تطوير الأداء الصفي للطالبات المعلمات، تخصص اللغة الانجليزية. ولقد تبنت الدراسة المنهج شبه التجريبي. وتكونت عينة الدراسة من(٣٢) طالبة مقيدة بالمستوى الرابع في تخصص اللغة الانجليزية واساليب تدريسها بكلية التربية في جامعة الاقصى بغزة، وتم تقسيمهن عشوائيا إلى مجموعتين (ضابطة وتجريبية). اعتمدت المجموعة الضابطة على الطريقة المعتادة في أدائها، وهي تعليقات المشرفين فقط، بينما استخدمت المجموعة التجريبية استراتيجيات التدريس التأملي في فترة التربية العملية (2) حيث تم تدريب المجموعة التجريبية على استخدام استراتيجيتين للتدريس التأملي وهي: المذكرات اليومية، وملاحظة الزملاء أو الرفاق. ولقد تمت الاستعانة في هذا البحث بوسائل جمع البيانات وهي: قائمة ملاحظة بممارسات وأداء التدريس الصفي، ومقياس (متدرج) لتحليل وتقدير استراتيجيات التدريس التأملي. تم تحليل البيانات كمياً وكيفياً. واستخدمت الدراسة الإحصاء الوصفي (المتوسطات، والانحرافات المعيارية، والتكرارات، والرتب، والنسب المئوية واختبار "ت" في تحليل البيانات. ولمعرفة حجم التأثير الناتج عن استخدام استراتيجيات التدريس التأملي (المتغير المستقل) على الأداء الصفي للطالبات المعلمات (المتغير التابع) تم الاستعانة بمربع "إيتا". أظهرت نتائج الدراسة اهم ممارسات الأداء الصفي التي تحتاجها الطالبات المعلمات داخل الغرفة الصفية. كما اوضحت النتائج تحسنا ملحوظا في الأداء الصفي للمجموعة التجريبية. وعلاوة على ذلك، اظهرت نتائج الدراسة أن فروق ذات دلالة إحصائية عند مستوى 0.01) ) بين متوسطي درجات المجموعتين (التجريبية والضابطة) في التطبيق البعدي لقائمة معايير الأداء الصفي ككل وفي كل محور من المحاور الستة (توجيه التعليمات، استخدام تقنيات طرح الأسئلة المحفزة، استخدام التقنيات المناسبة لتصحيح الأخطاء، تعزيز الإجابات الصحيحة، الاستخدام المنظم للسبورة، واستخدام مصادر المعلومات والوسائل المتوفرة) لصالح المجموعة التجريبية. كذلك وتوصلت الدراسة إلى وجود فروق ذات دلالة إحصائية عند المستوى بين متوسط درجات المجموعة التجريبية في التطبيق القبلي والبعدي لقائمة معايير الأداء الصفي ككل وفي 0.01) ) كل محور من المحاور الستة السابق ذكرها وذلك لصالح التطبيق البعدي. وخلصت الدراسة إلى فعالية استخدام استراتيجيات التدريس التأملي خلال التربية العملية في تحسين الأداء الصفي للطالبات المعلمات تخصص اللغة الانجليزية واساليب تدريسها. وفي ضوء النتائج التي تم التوصل إليها، جاءت بعض التوصيات ومنها: وجوب دمج استراتيجيات التدريس التأملي في برامج إعداد معلمة اللغة الانجليزية، وفي مقررات طرق تدريس اللغة الانجليزية خاصة. وأنه من الضروري أن تتعرف الطالبة المعلمة على أساليب وطرق مختلفة ومتعددة للتأمل ٠ وقد أوصت الدراسة بإمكانية تطوير أداء المعلمات أثناء الخدمة باستخدام التدريس التأملي وأنشطته، بالإضافة إلى وجوب تدريب الطالبات المعلمات على استخدام الأدوات التي تدعم التفكير التأملي.This study aimed at investigating the effect of using the reflective teaching strategies on developing the classroom performance of prospective teachers of English at Al-Aqsa University. The Quasi-experimental design was adopted. The sample of the study consisted of 32 prospective female teachers of English enrolled at the Faculty of Education – Al-Aqsa University. They were randomly assigned to two groups (control and experimental). The control group received only the traditional supervisory practices while the experimental group was trained in using reflective teaching and introduced to three different activities of reflection which were journal writing, peer observation, and five-minute papers. Research instruments were interviews, checklist of classroom teaching practices, analytic scoring rubric of journal writing and peer classroom observation. Descriptive statistics (means, standard deviation, frequencies, ranks and percentages), independent and paired samples t-test (2-tailed) were used for data analysis. The effect size "d" was computed using Eta Squared (η2). Findings of the study showed the most important classroom teaching performance and practices in classroom in light of the checklist developed for that purpose. The results also demonstrated that a significant improvement  in  classroom  performance  of  the  experimental  group in the post-observation. The study findings also indicate that statistically significant differences at 0.01 level were found in overall classroom performance and in six dimensions namely:  giving  effective instructions,  using  motivated  question techniques,  choosing  suitable techniques for correcting mistakes, praising the correct answers, systematic handling of the blackboard, and making and using available audio-visual aids, in favor of the experimental group. Moreover, statistically significant differences at 0.01 level were also noted in overall classroom performance and in the six dimensions of classroom performance of the experimental group, in favor of those of the posttest.  The  study  concluded  that  the  reflective  teaching  strategies  can  be  used effectively with student teachers during the practicum period. It was recommended that it should be incorporated in EFL teacher education programs, specifically in the EFL methodology course. However, student teachers should make every effort to learn more about a variety of reflective activities.  The  reflective  teaching  strategies  could  be  used  on  developing  and  improving  the classroom performance of in-service teachers as well. Prospective teachers should be trained on methods of developing reflective thinking levels

Statistical PT-symmetric lasing in an optical fiber network

PT-symmetry in optics is a condition whereby the real and imaginary parts of the refractive index across a photonic structure are deliberately balanced. This balance can lead to a host of novel optical phenomena, such as unidirectional invisibility, loss-induced lasing, single-mode lasing from multimode resonators, and non-reciprocal effects in conjunction with nonlinearities. Because PT-symmetry has been thought of as fragile, experimental realizations to date have been usually restricted to on-chip micro-devices. Here, we demonstrate that certain features of PT-symmetry are sufficiently robust to survive the statistical fluctuations associated with a macroscopic optical cavity. We construct optical-fiber-based coupled-cavities in excess of a kilometer in length (the free spectral range is less than 0.8 fm) with balanced gain and loss in two sub-cavities and examine the lasing dynamics. In such a macroscopic system, fluctuations can lead to a cavity-detuning exceeding the free spectral range. Nevertheless, by varying the gain-loss contrast, we observe that both the lasing threshold and the growth of the laser power follow the predicted behavior of a stable PT-symmetric structure. Furthermore, a statistical symmetry-breaking point is observed upon varying the cavity loss. These findings indicate that PT-symmetry is a more robust optical phenomenon than previously expected, and points to potential applications in optical fiber networks and fiber lasers.Comment: Submitted to Nature Communications, Pages 1-19: Main manuscript; Pages 20-38: Supplementary material

Allelopathic potential of Ficus retusa L. leaf litter on understory vegetation in urban gardens

Pruning Ficus trees in urban green spaces may lead to the accumulation and spread of their leaf litter on the understory vegetation. This study was conducted to evaluate the allelopathic effect of Ficus retusa L. leaf litter on the understory species in urban gardens. A field study showed that the plant cover and species richness of litter-affected plots were lower than those of litter-free areas. The litter-affected soils had substantially lower pH and higher electrical conductivity. In a greenhouse experiment, litter-affected soil significantly inhibited the emergence and growth of understory species selected for the purpose of this study: Melilotus indicus (L.) All., Trifolium resupinatum L. and Amaranthus viridis L. Osmotic potentials equivalent to those of the litter-affected soils did not affect emergence or growth of these species. A spectrophotometric analysis indicated that the litter-affected soils contained larger amounts of phenolics and flavonoids. An HPLC analysis revealed that the litter-affected soils contained higher concentrations of free phenolic and flavonoid allelochemicals. These results demonstrate that F. retusa leaf litter may reduce plant cover and species richness. The significant inhibition in both field and greenhouse experiments could be attributed to phenolic and flavonoid allelochemicals released from the tree litter, as the osmotic potential of the litter had no effect on the understory species. The allelopathic potential of F. retusa leaf litter plays at least a partial role in reducing urban vegetation

On the Gamma-Logistic Distribution

A new generalization of the logistic distribution is defined and studied, namely, the gamma-logistic distribution. Various properties of the gamma-logistic are obtained. The structural analysis of the distribution includes moments, mode, quantiles, skewness, kurtosis, Shannon\u27s entropy and order statistics. The method of maximum likelihood estimation is proposed for estimating the model parameters. For illustrative purposes, a real data set is analyzed as an application of the gamma-logistic distribution