75 research outputs found

    Impact of microvariability on classification and management of peatlands in Asia

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    Globally, wetlands occupy about 18.96 x 106 km2, of which 2% is made up of organic soils. In Asia, about 2.2 million km2 (~ 1.0%) of the land surface comprises peat or Histosols. The current global approach to agriculture places considerable emphasis on environmental quality, conservation of biodiversity and preservation of ecosystem while striving to achieve sustainable production in agroecosystems. In Asia, land use on the peatlands is low-input subsistence-based systems. In a few countries, such as Malaysia and Indonesia, rubber and oil-palm are cultivated on a plantation scale. Subsistence-based agricultural systems, understandably, would not be able to provide the level of input required for sustainable management of peat lands. The knowledge base for such systems is highly traditional in nature and is therefore vulnerable to the uncontrolled changes that occur in the evolution of the agro-ecosystem. Commercial-based agricultural systems appear to thrive in areas dominated by shallow peat. This system is technology-based, has a greater control over changes that may occur within the system but is perhaps still not in harmony with nature. Ignorance of the functions and value of such areas has lead to many forms of degradation. Therefore, sustainable development of the peat soils requires not only a holistic approach to the management but also dictates the need for a paradigm shift in resource characterization, research trends and land use policies.The paper elaborates on the paradigm shift in sustainable land management system and advocates a holistic approach wherein agronomic factors, environmental considerations as well as the much de-emphasized socioeconomic aspects, are all integrated into new research approaches. Research strategies needed to ensure sustainable agricultural development of organic soils include the urgent need for innovative measures to characterize the resource, evaluating and monitoring soil quality, assessing the potential of peat lands to release methane and other greenhouse gases upon drainage, and assessing the integrity of the ecosystem. Issues pertaining to productivity, assisting in the design of rational policies for development, promoting preservation of heritage, inculcating the ownership concept and developing better methods to gauge the economic viability of such projects are additional important factors that ensure sustainability. The most important factor differentiating peatlands from their mineral counterparts is microvariability; this, specifically in the context of small farms had not been addressed adequately and requires innovative approaches and technologies. Conventional soil surveys must be augmented with more innovative techniques as current methods suffer from various kinds of limitations

    Synchronization analysis of the uterine magnetic activity during contractions

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    BACKGROUND: Our objective was to quantify and compare the extent of synchronization of the spatial-temporal myometrial activity over the human uterus before and during a contraction using transabdominal magnetomyographic (MMG) recordings. Synchronization can be an important indicator for the quantification of uterine contractions. METHODS: The spatialtermporal myometrial activity recordings were performed using a 151-channel noninvasive magnetic sensor system called SARA. This device covers the entire pregnant abdomen and records the magnetic field corresponding to the electrical activity generated in the uterine myometrium. The data was collected at 250 samples/sec and was resampled with 25 samples/sec and then filtered in the band of 0.1–0.2 Hz to study the primary magnetic activity of the uterus related to contractions. The synchronization between a channel pair was computed. It was inferred from a statistical tendency to maintain a nearly constant phase difference over a given period of time even though the analytic phase of each channel may change markedly during that time frame. The analytic phase was computed after taking Hilbert transform of the magnetic field data. The process was applied on the pairs of magnetic field traces (240 sec length) with a stepping window of 20 sec duration which is long enough to cover two cycle of the lowest frequency of interest (0.1 Hz). The analysis was repeated by stepping the window at 10 sec intervals. The spatial patterns of the synchronization indices covering the anterior transabdominal area were computed. For this, regional coil-pairs were used. For a given coil, the coil pairs were constructed with the surrounding six coils. The synchronization indices were computed for each coil pair, averaged over the 21 coil-pairs and then assigned as the synchronization index to that particular coil. This procedure was tested on six pregnant subjects at the gestational age between 29 and 40 weeks admitted to the hospital for contractions. The RMS magnetic field for each coil was also computed. RESULTS: The results show that the spatial patterns of the synchronization indices change and follow the periodic pattern of the uterine contraction cycle. Spatial patterns of synchronization indices and the RMS magnetic fields show similarities in few window frames and also show large differences in few other windows. For six subjects, the average synchronization indices were: 0.346 ± 0.068 for the quiescent baseline period and 0.545 ± 0.022 at the peak of the contraction. DISCUSSION: These results show that synchronization indices and their spatial distributions depict uterine contractions and relaxations

    Soil micromorphology/ Stoops George (and Hari Eswaran (edt.)

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    xvii, 345 hal.: ill.; 26 cm

    Graphical passwords effects of tolerance password, image choice and OTP login security

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    In this framework a spelling based Puzzle framework, named and secret key spell. The proposed plot, we exhibit another security primitive in view of hard AI issues Click spell, not just tries to enhance both security and convenience of Puzzle , additionally expects to grow the appropriateness of Puzzle CAPTCHA. Click spell endeavour to accomplish taking after objectives.Security: Puzzle Login utilizing bubble sort.Usability: To expand the rate of finishing the test.Extensibility: To give a lexicon capacity to clients to find out about the significance and the spelling of words. What's more, an ad can be set on the highest point of CAPTCHA pictures. Security: Image Puzzle settling Using AES Algorithm OTP Generation

    Editorial: soils and sediments in the anthropocene

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    A Research Strategy to Secure Energy, Water, and Food via Developing Sustainable Land and Water Management in Turkey

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    One of the basic contentions of the neo-realist worldview has been the argument that states have to survive in a dangerously competitive and ruthlessly conflictual environment (Waltz 2002: 29)

    Multiscale forward electromagnetic model of uterine contractions during pregnancy

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    BACKGROUND: Analyzing and monitoring uterine contractions during pregnancy is relevant to the field of reproductive health assessment. Its clinical importance is grounded in the need to reliably predict the onset of labor at term and pre-term. Preterm births can cause health problems or even be fatal for the fetus. Currently, there are no objective methods for consistently predicting the onset of labor based on sensing of the mechanical or electrophysiological aspects of uterine contractions. Therefore, modeling uterine contractions could help to better interpret such measurements and to develop more accurate methods for predicting labor. In this work, we develop a multiscale forward electromagnetic model of myometrial contractions during pregnancy. In particular, we introduce a model of myometrial current source densities and compute its magnetic field and action potential at the abdominal surface, using Maxwell’s equations and a four-compartment volume conductor geometry. To model the current source density at the myometrium we use a bidomain approach. We consider a modified version of the Fitzhugh-Nagumo (FHN) equation for modeling ionic currents in each myocyte, assuming a plateau-type transmembrane potential, and we incorporate the anisotropic nature of the uterus by designing conductivity-tensor fields. RESULTS: We illustrate our modeling approach considering a spherical uterus and one pacemaker located in the fundus. We obtained a travelling transmembrane potential depolarizing from −56 mV to −16 mV and an average potential in the plateau area of −25 mV with a duration, before hyperpolarization, of 35 s, which is a good approximation with respect to the average recorded transmembrane potentials at term reported in the technical literature. Similarly, the percentage of myometrial cells contracting as a function of time had the same symmetric properties and duration as the intrauterine pressure waveforms of a pregnant human myometrium at term. CONCLUSIONS: We introduced a multiscale modeling approach of uterine contractions which allows for incorporating electrophysiological and anatomical knowledge of the myometrium jointly. Our results are in good agreement with the values reported in the experimental technical literature, and these are potentially important as a tool for helping in the characterization of contractions and for predicting labor using magnetomyography (MMG) and electromyography (EMG)

    Estimating uterine source current during contractions using magnetomyography measurements.

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    Understanding the uterine source of the electrophysiological activity of contractions during pregnancy is of scientific interest and potential clinical applications. In this work, we propose a method to estimate uterine source currents from magnetomyography (MMG) temporal course measurements on the abdominal surface. In particular, we develop a linear forward model, based on the quasistatic Maxwell's equations and a realistic four-compartment volume conductor, relating the magnetic fields to the source currents on the uterine surface through a lead-field matrix. To compute the lead-field matrix, we use a finite element method that considers the anisotropic property of the myometrium. We estimate the source currents by minimizing a constrained least-squares problem to solve the non-uniqueness issue of the inverse problem. Because we lack the ground truth of the source current, we propose to predict the intrauterine pressure from our estimated source currents by using an absolute-value-based method and compare the result with real abdominal deflection recorded during contractile activity. We test the feasibility of the lead-field matrix by displaying the lead fields that are generated by putative source currents at different locations in the myometrium: cervix and fundus, left and right, front and back. We then illustrate our method by using three synthetic MMG data sets, which are generated using our previously developed multiscale model of uterine contractions, and three real MMG data sets, one of which has simultaneous real abdominal deflection measurements. The numerical results demonstrate the ability of our method to capture the local contractile activity of human uterus during pregnancy. Moreover, the predicted intrauterine pressure is in fair agreement with the real abdominal deflection with respect to the timing of uterine contractions
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