2,524 research outputs found

    Suitability of spiders and rove beetles as indicators for assessment of effects of cultivation-rearrangement from conventional to ecological farming

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    Im Gebiet des Ökohofes Seeben ließen sich im Verlauf von 4 Jahren arten- und individuenreiche Webspinnen- und Kurzflüglerzönosen registrieren (LÜBKE-AL HUSSEIN & AL HUSSEIN 1999; AL HUSSEIN 2002). Zu Beginn der Untersuchungen wurde die Arbeitshypothese formuliert: Die Fauna eines Agrar-Ökosystems wird durch die Intensität der Landbewirtschaftung sowie durch landschaftsräumliche Gliederung des Gebietes entscheidend geprägt. Die Umstellung eines bislang konventionell wirtschaftenden Betriebes auf ökologischen Landbau und die damit einhergehende Strukturierung ausgeräumter Flächen durch Feldraine, Hecken oder auch nur den streifenweisen Anbau mehrerer Kulturen auf einem Großschlag bewirkt eine Erhöhung der Faunendiversität. Die wachsende Diversität der Tierwelt begünstigt selbstregulative Prozesse der Agrozönose und wirkt dadurch stabilisierend auf das Ökosystem. Das Forschungsvorhaben kann als ein "Langzeit-Experiment" aufgefaßt werden, wobei die Anfangsbedingungen vor der Betriebsumstellung als referenzzustand dienen (HÜLSBERGEN & DIEPENBROCK, 2000). Webspinnen und Kurzflügelkäfer zählen zu den arten- und individuenreichsten Tiergruppen der Agrarlandschaft. Sie leben fast ausnahmslos räuberisch und spielen als Regulatoren von Schadinsektenpopulationen besonders im ökologischen Landbau eine bedeutende Rolle. Aufgrund ihrer Sensibilität gegenüber Umwelteinflüssen eignen sie sich als Indikatoren. Insbesondere Webspinnen werden für derartige Untersuchungen herangezogen. Einige können sogar als Zeigerarten angesehen werden. Bei vorliegenden Erhebungen galt es u. a. zu prüfen, inwieweit die weniger untersuchten Kurzflügler im Vergleich zu den Webspinnen zu derartigen Fragestellungen herangezogen werden können.From 1994 to 1997 investigations have been carried out on fields of the “Ökohof Seeben” in the North of Halle (Saale) refering to long-term effects of ecological farming on spiders and rove beetles. Two fields were selected in the northern part of the eco-farm representing different types of landscape. The question was whether ecological farming results in an increasing biodiversity over longer periods. For sampling of these arthropods pitfall traps were used. As a whole the communities of spiders and rove beetles were rich in species and individuals. The rearrangement from conventional to ecological agriculture did not provide the expected increase of biodiversity, but it showed positive tendencies such as the homogeneity of dominance structures and an increase of the number of species larger in size. The investigated parameters were influenced through different factors, e.g. the spiders more by field size and rove beetles especially by crop rotation. The occurrence of rove beetles depends on their high substrate specification and the existence of ecological niches, too. Such as these investigations should be carried out as long-term-experiments, because shorter experiments may lead to misinterpretations

    The Transport Properties of Cation Exchange Membranes in Bi-Ionic Forms

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    An Integrated Firewall System Model In A Multiclient-Server Environment

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    As the Internet grows, and the use of computers is getting more common, the need to secure networks and protect them from the Internet, while still being able to access it, is increasing. The easiest way to achieve a lot of this protection is through firewalls. Firewall technology is the most widely deployed security technology on the Internet. Firewalls have been around for several years. They are a fact of life on the Internet and it is not likely they will disappear in the future. Ongoing development and research in the field of firewall technology have shown a continually addition of features and services to conventional firewall systems.This thesis introduces a new concept for applying the security policy rules by both firewall administrators and users. The proposed firewall system solves some known problems which arise with the use of conventional firewalls residing at the networks perimeter. The developed firewall system integrates the main network firewall and the second-line firewalls into one system by the use of client/server technology to facilitate firewall configuration in a way that affords more convenience to users providing the new integrated firewall using multiclient-server scheme. It centralizes security functions in a single point, simplifying configuration and administration. The new system makes it easier to configure and administrate a firewall in a way in which it is not a source of annoyance to users which offering them higher level of flexibility by giving them the chance to participate in the process of configuration of the firewall using the client side of the system and without affecting the network security policy. It also makes the progress of configuration and administration of the firewall system smoother by reducing the administrator efforts to maintain the system. Good results have been achieved by using the program package. Results show that this system helps keeping the network traffic as low as possible, increasing the efficiency of the network and reducing the threats of malicious data passing in the network. It reduces the efforts and cost of overall system administration and maintenance as well. In addition, it affords users a system which is acceptable and preferable more than conventional firewall systems

    Investigations on the influence of conservation tillage strategies on the composition of the soil mesofauna by using the litter-bag-method

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    Elemente der Bodenmesofauna gehören gerade in pfluglosen Anbausystemen zu den bedeutendsten Primärzersetzern von Ernterückständen. Für den Rotteprozess, der nicht nur für die Pflanzengesundheit von größter Bedeutung ist, spielen sie damit eine entscheidende Rolle. Während Effekte der Bodenbearbeitung auf die mikrobielle Biomasse in den letzten Jahrzehnten Gegenstand zahlreicher Feldstudien waren, sind entsprechende Erhebungen zur Bodenmesofauna vergleichsweise rar und darüber hin in ihren Aussagen teilweise widersprüchlich. Positive Effekte auf Streuabbau durch reduzierte Intensität der Bodenbearbeitung konnten Heiber & Eisenbeis (1999) nachweisen. Vorliegende Untersuchungen sollten klären, welche Auswirkungen die Bodenbearbeitung auf die vielfältigen Zönosen der Bodenmesofauna eines intensiv ackerbaulich genutzten Lößstandortes hat.The soil mesofauna has an important role for the decomposition of organic materials in non-till cultivation systems. The investigations have been carried out on fields of Lüttewitz (Saxony, Germany). There were investigated 4 cultivation variants, which were still used on each plot more than 10 years: plough; mulch sowing with deep loosening; mulch till with shallow loosening and direct drilling. In each variant 20 litterbags (mesh size: 2 mm; litter weight: 20 g); (exposition period: spring till early summer 2006) were placed under the soil surface. To investigate the possible effects of the litter size on the colonization by the soil mesofauna, two litter variants (Maize chopped straw fine/cereals straw rough) were used. The litterbags were controlled at three times. At first a wet-extraction was carried out to estimate the dense of Enchytraeidae (Oligochaeta). Afterwards a dry extraction of the mesofauna with the Tullgren-method followed to find out the amount of mites (Oribatida and Acaridida) and Collembola, which are important for decomposition of the litter. Among the Oribatida the species Tectocepheus velatus and Oppiella nova reached high densities. The predatory Gamasina were dominated by the families Rhodacaridae, Parasitidae, Ascidae, Veigaiaidae, Macrochelidae and Zerconidae. All times the fine litter in all plots was stronger colonized. In rough litter the part of Gamasina as predators was lower than the decomposer groups. With the declining of the intensity of tillage the colonization of the litter-bags increased. In the variant mulch-till (with shallow loosening) the highest densities of individuals were found. The registered numbers often were higher as in the plots with direct drilling

    The Byzantine Eastern Church of Khirbet et-Tireh

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    Khirbet et-Tireh was inhabited during the Hellenistic, Roman, Byzantine and Early Islamic periods, and was later used as agricultural land throughout the Ottoman-Turkish period and down to modern times. The ancient settlement has been determined to cover a total area of approximately 30,000 square meters. However, 75 percent of its historic fortified space has been destroyed over the past few decades by the construction of roads, a school, a gas station and several residential structures on its northern part. The surviving architectural remains at the Khirbet include a system of fortifications, a Byzantine monastery, two Byzantine-era churches, a rock-cut reservoir, a cistern, water channels, a rock-cut olive press, several burial caves, a street (or a wide pathway corridor), and several dry-stone terrace walls. The unearthed part of the eastern church complex measures 28.8 m long along its east-west axis and a maximum of 25.5 m wide in its north-south dimension. It follows a basilical plan and consists of five main parts: four south side rooms, an atrium, a narthex, a main hall, and three northeast side rooms. The entire area of the church was once paved with mosaic carpets consisting of geometric and figurative designs, with the richly colored tesserae encompassing various shades of white, black, grey, yellow, orange, pink, wine red, green and blue. Furthermore, remains of two plaster layers were uncovered on the interior faces of the majority of the walls of the church complex. After the final consolidation and conservation of the mosaic pavements of the church, as a protective measure we are covering the mosaics with a permeable, plastic-mesh geotextile, topped by a layer of sieved soil 0.25 m thick.We are grateful to Al-Quds University and the Greek Orthodox Patriarchate for their generous financial assistance, which allowed for the further excavation and conservation of Khirbet et-Tireh over the summer of 2015, and to the Palestinian American Research Centre (PARC) for its financial assistance, which has made possible the publication of this research. I am indebted also to my B.A. archaeology students for their tireless efforts over the course of the excavation season. Thanks are also extended to Osama Hamdan, Raed Khalil, Rafat Khateeb, and Wisal Musa for their skilled, professional conservation of the unearthed mosaic pavements of the church. Finally, I would like to thank Tom Powers for his constructive proofreading and comments on the draft of this work

    3D Hydrodynamic Model Development and Verification

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    A three-dimensional numerical model was developed to simulate hydrodynamic, temperature, and water quality distributions in rivers and lakes. In an attempt to get rid of the extra approximation and complexity, no coordinate transformation has been done and z-coordinate system has been employed. The governing equations are the continuity equation, free surface equation, momentum equations, and conservation equations of temperature and water quality. The model employs the time splitting technique which allows splitting the directions in which we end with two-dimensional governing equations and eventually the solution ends with a tri-diagonal matrix, which is easily solved by Thomas algorithm. The first step after developing a numerical model and before adding more features or applying the model to a real case, the model should be verified. The verification of the model was done by implementing the model to known solutions test cases in additional to evaluating whether the code preserves fluid mass. A series of test cases is performed by comparing the model results with the analytical solutions as proposed by many modelers. The model showed good agreement between the analytical and the numerical solution

    Development and initial validation of a postal survey evaluation of community pharmacists' opinion regarding falsified (counterfeit) medicines in Hampshire (UK)

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    Context: Falsified-medicines pose a worldwide problem to patients, healthcare professionals, pharmaceutical companies, and governments. Community pharmacists are usually the last points of contact with patients and can protect them by quarantining falsified medicines. Hence, their opinions are valuable in exploring how the profession can combat this. Aims: To explore the opinion of pharmacists with respect to falsified medicines. Methods: A postal survey was developed and distributed to 359 pharmacies via the local pharmaceutical committee in Hampshire, UK. Descriptive statistics and hypothesis testing was conducted. Hypothesis testing (95% CI, α = 0.05) will be conducted to identify any gender differences, differences based on years of experience and differences based on number of working hours per week. Results: A 14% response rate was achieved. Pharmacists surveyed believe that falsified-medicines pose a significant problem to the profession on a five-point Likert scale (4.02 ± 1.078). A pharmacist’s intervention can prevent or disrupt the supply to patients (4.12 ± 0.824) and training courses can improve pharmacist’s knowledge (4.06 ± 0.843). Pharmacists are not confident and capable in identifying falsified-medicines (2.62 ± 1.105). This is surprising and unexpected because pharmacists are medicines-expert. A 10-item scale is validated (72.2% Cronbach alpha). Conclusions: Falsified-medicines pose a small but significant and growing challenge to the profession. There is underutilization of the high street community pharmacist in identifying falsified-medicines. Healthcare professionals should report suspect counterfeits to the MHRA

    The impact of bank credit on investment and public spending in Iraq for the period (2005-2021)

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    Purpose: The current study aims at examining the reality of bank credit, analyzing, and estimating investment and public spending in Iraq. The research also aims at showing the impact of bank credit on investment and public spending in Iraq. Theoretical framework: Bank credit has an instrumental and effective part in financing most economic activities, which contributes to revitalizing the national economy by organizing and developing short, medium and long-term financing mechanisms. As for investment and public spending, they reflect the development of the economy and the extent of financial and monetary stability that the country has. Methodology: For reaching the research methodology, the inductive approach was adopted to study the total facts through formulating economic analysis descriptively by using modern standard tools in economic analysis to show the impact of bank credit on investment and public spending. Finding: It was concluded that bank credit has a key role, especially in financing investment projects that require great funds in order to create a favorable climate for investment. The relationship between bank credit and investment is a direct relationship. Research, scientific and social implications: The study identifies investment financing and public spending and how bank credit can meet this financing through the bank strategies. The study also determines which of the two variables, investment and public spending, is most affected by bank credit
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