Search results for: contrast stretching

Authors: Min Jung Kim

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Fe-(9, 19, 28, 37) wt%Cr alloys were corroded at 700 and 800 °C for 70 h under 1 atm of N₂, 1 atm of N₂/3.2%H₂O-mixed gas, and 1 atm of N₂/3.1%H₂O/2.42%H₂S-mixed gas. The corrosion rate of Fe-9Cr alloy increased with the addition of H₂O and increased further with the addition of H₂S in N₂/H₂O gas. Fe-9Cr alloy was non-protective in all gas types. In contrast, Fe-(19, 28, 37) wt%Cr alloys were protective in N₂ and N₂/H₂O-mixed gas because of the formation of the Cr₂O₃ layer. They were, however, non-protective in N₂/H₂O/H₂S-mixed gas because sulfidation dominated, forming the outer FeS layer and the inner Cr₂S₃ layer containing some FeCr₂S₄.

Keywords: Fe-(9, 19, 28, 37) wt%Cr alloys, corrosion, sulfidation, FeS

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Authors: Gabriela Wyszogrodzka, Przemyslaw Dorozynski, Barbara Gil, Maciej Strzempek, Bartosz Marszalek, Piotr Kulinowski, Wladyslaw Piotr Weglarz, Elzbieta Menaszek

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MOFs (Metal-Organic Frameworks) belong to a new group of porous materials with a hybrid organic-inorganic construction. Their structure is a network consisting of metal cations or clusters (acting as metallic centers, nodes) and the organic linkers between nodes. The interest in MOFs is primarily associated with the use of their well-developed surface and large porous. Possibility to build MOFs of biocompatible components let to use them as potential drug carriers. Furthermore, forming MOFs structure from cations possessing paramagnetic properties (e.g. iron cations) allows to use them as MRI (Magnetic Resonance Imaging) contrast agents. The concept of formation of particles that combine the ability to transfer active substance with imaging properties has been called theranostic (from words combination therapy and diagnostics). By building MOF structure from iron cations it is possible to use them as theranostic agents and monitoring the distribution of the active substance after administration in real time. In the study iron-MOF: Fe-MIL-101-NH2 was chosen, consisting of iron cluster in nodes of the structure and amino-terephthalic acid as a linker. The aim of the study was to investigate the possibility of applying Fe-MIL-101-NH2 as inhalable theranostic particulate system for the first-line anti-tuberculosis antibiotic – isoniazid. The drug content incorporated into Fe-MIL-101-NH2 was evaluated by dissolution study using spectrophotometric method. Results showed isoniazid encapsulation efficiency – ca. 12.5% wt. Possibility of Fe-MIL-101-NH2 application as the MRI contrast agent was demonstrated by magnetic resonance tomography. FeMIL-101-NH2 effectively shortening T1 and T2 relaxation times (increasing R1 and R2 relaxation rates) linearly with the concentrations of suspended material. Images obtained using multi-echo magnetic resonance imaging sequence revealed possibility to use FeMIL-101-NH2 as positive and negative contrasts depending on applied repetition time. MOFs micronization via ultrasound was evaluated by XRD, nitrogen adsorption, FTIR, SEM imaging and did not influence their crystal shape and size. Ultrasonication let to break the aggregates and achieve very homogeneously looking SEM images. MOFs cytotoxicity was evaluated in in vitro test with a highly sensitive resazurin based reagent PrestoBlue™ on L929 fibroblast cell line. After 24h no inhibition of cell proliferation was observed. All results proved potential possibility of application of ironMOFs as an isoniazid carrier and as MRI contrast agent in inhalatory treatment of tuberculosis. Acknowledgments: Authors gratefully acknowledge the National Science Center Poland for providing financial support, grant no 2014/15/B/ST5/04498.

Keywords: imaging agents, metal-organic frameworks, theranostics, tuberculosis

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Authors: M. H. Moreira da Silva, L. Valadao, F. Moreira da Silva

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In the present study, the fertilizing capacity of bovine spermatozoa was evaluated before and after its cryopreservation. For this, the testicles of 100 bulls slaughtered on Terceira Island were dissected, the epididymal tails were separated, and semen was recovered by the flotation method and then evaluated by phase contrast microscopy and by flow cytometry. For phase contrast microscopy, a drop of semen was used to evaluate the percentage of motile spermatozoa (from 0 to 100%) and motility (from 0 to 5). After determining the concentration and the abnormal forms, semen was diluted to a final concentration of 50 x 106 spz/ml and evaluated by flow cytometer for membrane and acrosome integrity using the conjugation of fluorescent probes propidium iodide (PI) and Arachis hypogea agglutinin (FITC-PNA). Freezing was carried out in a programmable semen freezer, using 0.25 ml straws, in a total of 20 x 106 viable sperm per straw with glycerol as a cryoprotectant in a final concentration of 0.58 M. It was observed that, on average, a total of 7.25 ml of semen was collected from each bull. The viability and vitality rates were respectively 83.22 ± 7.52% and 3.8 ± 0.4 before freezing, decreasing to 58.81 ± 11.99% and 3.6 ± 0.6, respectively, after thawing. Regarding cytoplasmic droplets, it was observed that a high percentage of spermatozoa had medial cytoplasmic droplets (38.47%), with only 3.32% and 0.15% presenting proximal and distal cytoplasmic drops, respectively. By flow cytometry, it was observed that before freezing, the percentage of sperm with the damaged plasma membrane and intact acrosome was 3.61 ± 0.99%, increasing slightly to 4.21 ± 1.86% after cryopreservation (p<0.05). Regarding spermatozoa with damaged plasma membrane and acrosome, the percentage before freezing was 3.37±1.87%, increasing to 4.34 ±1.16% after thawing, and no significant differences were observed between these two values. For the percentage of sperm with the intact plasma membrane and damaged acrosome, this value was 2.04 ± 2.34% before freezing, decreasing to 0.89 ± 0.48% after thawing (p<0.05). The percentage of sperm with the intact plasma membrane and acrosome before freezing was 90.99±2.75%, with a slight decrease to 90.57±3.15% after thawing (p<0.05). From this study, it can be clearly concluded that, after the slaughtering of bulls, the spermatozoa can be recovered from the epididymis and cryopreserved, maintaining an excellent rate of sperm viability and quality after thawing.

Keywords: bovine semen, epididymis, cryopreservation, fertility assessment

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Authors: Christos Konstantopoulos, Thomas Ussmueller

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Digital low drop-out regulators, in contrast to analog counterparts, provide an architecture of sub-1 V regulation with low power consumption, high power efficiency, and system integration. Towards an optimized integration in the ultra-low-power system-on-chip Internet of Things architecture that is operated through a radio frequency energy harvesting scheme, the D-LDO regulator should constitute the main regulator that operates the master-clock and rest loads of the SoC. In this context, we present a D-LDO with linear search coarse regulation and asynchronous fine regulation, which incorporates an in-regulator clock generation unit that provides an autonomous, self-start-up, and power-efficient D-LDO design. In contrast to contemporary D-LDO designs that employ ring-oscillator architecture which start-up time is dependent on the frequency, this work presents a fast start-up burst oscillator based on a high-gain stage with wake-up time independent of coarse regulation frequency. The design is implemented in a 55-nm Global Foundries CMOS process. With the purpose to validate the self-start-up capability of the presented D-LDO in the presence of ultra-low input power, an on-chip test-bench with an RF rectifier is implemented as well, which provides the RF to DC operation and feeds the D-LDO. Power efficiency and load regulation curves of the D-LDO are presented as extracted from the RF to regulated DC operation. The D-LDO regulator presents 83.6 % power efficiency during the RF to DC operation with a 3.65 uA load current and voltage regulator referred input power of -27 dBm. It succeeds 486 nA maximum quiescent current with CL 75 pF, the maximum current efficiency of 99.2%, and 1.16x power efficiency improvement compared to analog voltage regulator counterpart oriented to SoC IoT loads. Complementary, the transient performance of the D-LDO is evaluated under the transient droop test, and the achieved figure-of-merit is compared with state-of-art implementations.

Keywords: D-LDO, Internet of Things, RF energy harvesting, voltage regulators

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Authors: Maged Syed Ahamd, Manal Mohamed Yasser, Essam Sholkamy

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In this paper, we reported that selenium (Se) nanoparticles were firstly biosynthesized with a simple and eco-friendly biological method. Their shape, size, FTIR (Fourier Transform Infrared spectroscopy), UV–vis spectra, TEM (Transmission Electron Microscopy) images and EDS (Energy Dispersive Spectroscopy) pattern have been analyzed. TEM analyses of the samples obtained at different stages indicated that the formation of these Se nanostructures was governed by an incubation time (12- 24- 48 hours). The Se nanoparticles were initially generated and then would transform into crystal seeds for the subsequent growth of nanowires; however obtaining stable Se nanowire with a diameter of about 15-100 nm. EDS shows that Se nanoparticles are entirely pure. The IR spectra showed the peaks at 550 cm-1, 1635 cm-1, 1994 cm-1 and 3430 cm-1 correspond to the presence of Se-O bending and stretching vibrations. The concentrations of Se-NPs (0, 1, 2, 5 µg/ml) did not give significantly effect on both two cell lines while the highest concentrations (10- 100 µg/ml gave significantly effects on them. The lethal dose (ID50%) of Se-NPs on Hep2 G and MCF-7 cells was obtained at 75.96 and 61.86 µg/ml, respectively. Results showed that Se nanoparticles as anticancer agent against MCF-7 cells were more effective than Hep2 G cells. Our results suggest that Se-NPs may be a candidate for further evaluation as a chemotherapeutic agent for breast and liver cancers.

Keywords: selenium nanoparticle, Streptomyces bikiniensis, nanowires, chemotherapeutic agent

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Authors: Darius Diogo Barreto, Ajeet Kumar, Sushma Santapuri

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We present an axisymmetric variational formulation for coupled extension-torsion-inflation deformation in magnetoelastomeric thin tubes when both azimuthal and axial magnetic fields are applied. The tube's material is assumed to have a preferred magnetization direction which imparts helical magnetic anisotropy to the tube. We have also derived the expressions of the first derivative of free energy per unit tube's undeformed length with respect to various imposed strain parameters. On applying the thin tube limit, the two nonlinear ordinary differential equations to obtain the in-plane radial displacement and radial component of the Lagrangian magnetic field get converted into a set of three simple algebraic equations. This allows us to obtain simple analytical expressions in terms of the applied magnetic field, magnetization direction, and magnetoelastic constants, which tell us how these parameters can be tuned to generate positive/negative Poisson's effect in such tubes. We consider both torsionally constrained and torsionally relaxed stretching of the tube. The study can be useful in designing magnetoelastic tubular actuators.

Keywords: nonlinear magnetoelasticity, extension-torsion coupling, negative Poisson's effect, helical anisotropy, thin tube

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Authors: Xin Tong, Jin-sheng Xu, Xiong Chen, Ya Zheng

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The aim of this paper is to study the mechanical properties of HTPB (Hydroxyl-terminated polybutadiene) composite propellant under harsh conditions. It describes two tests involving uniaxial tensile tests of various strain rates (ranging from 0.0005 s^-1 to 1.5 s^-1), temperatures (ranging from 223 K to 343 K) and high-cycle fatigue tests under low-temperature (223 K, frequencies were set at 50, 100, 150 Hz) using DMA (Dynamic Mechanical Analyzer). To highlight the effect of small pre-strain on fatigue properties of HTPB propellant, quasi-static stretching was carried out before fatigue loading, and uniaxial tensile tests at constant strain rates were successively applied. The results reveal that flow stress of propellant increases with reduction in temperature and rise in strain rate, and the strain rate-temperature equivalence relationship could be described by TTSP (time-temperature superposition principle) incorporating a modified WLF equation. Moreover, the rate of performance degradations and damage accumulation of propellant during fatigue tests increased with increasing strain amplitude and loading frequencies, while initial quasi-static loading has a negative effect on fatigue properties by comparing stress-strain relations after fatigue tests.

Keywords: fatigue, HTPB propellant, tensile properties, time-temperature superposition principle

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Authors: L. C. Ding, Bradley G. Orr, K. Rahauoi, S. Truza, A. Date, A. Akbarzadeh

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The research on thermoelectric has been a blooming field of research for the latest decade, owing to large amount of heat source available to be harvested, being eco-friendly and static in operation. This paper provides the performance of thermoelectric generator (TEG) with bulk material of bismuth telluride, Bi2Te3. Later, the performance of the TEGs is evaluated by considering attaching the TEGs on a plastic (polyethylene sheet) in contrast to the common method of attaching the TEGs on the metal surface.

Keywords: electric power, heat transfer, renewable energy, thermoelectric generator

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Authors: Roxanne J. Kovacs

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This paper shows that political corruption in Ghana and Kenya does not, as is assumed by a considerable part of the academic literature, depend on the level of party competition as such, but rather on the kinds of issues that parties compete about. Party competition in Ghana revolves around party performance, which gives political leaders a strong incentive to control corruption. In contrast, party competition in Kenya revolves around ethnic identities, which directly reduces competition based on candidate quality and therefore fosters corruption.

Keywords: corruption, electoral competition, Kenya, Ghana

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Authors: Kirti, Samanta Sekhar Khora

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Inflation serves different purposes in different organisms and adds beauty to their behavioral attributes. Pufferfishes are also known as blowfish, swellfish, and globefish due to their remarkable ability to puff themselves up like a balloon when threatened. This ability to inflate can be correlated with anatomical features that are unique to pufferfishes. Pufferfish skin provides a rigid framework to support the body contents and a flexible covering to allow whatever changes are necessary for remarkable inflation mechanism. Skin, the outer covering of animals is made up of collagen fibers arranged in more or less ordered arrays. The ventral skin of pufferfish stretches more than dorsal skin during inflation. So, this study is of much of the interest in comparing the structure and mechanical properties of these two skin regions. The collagen fibers were found to be arranged in different ordered arrays for ventral and dorsal skin and concentration of fibers were also found to be different for these two skin parts. Scanning electron microscopy studies of the ventral skin showed a unidirectional arrangement of the collagen fibers, which provide more stretching capacity. Dorsal skin, on the other hand, has an orthogonal arrangement of fibers. This provides more stiffness to the ventral skin at the time of inflation. In this study, the possible role of collagen fibers was determined which significantly contributed to the remarkable inflation mechanism of pufferfishes.

Keywords: collagen, histology, inflation, pufferfish, scanning electron microscopy, Small-Angle X-Ray Scattering (SAXS), transmission electron microscopy

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Authors: Jing Zhang, Yvonne Reinwald, Nick Poulson, Alicia El Haj, Chung See, Mike Somekh, Melissa Mather

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Biomedical imaging of native tissue using light offers the potential to obtain excellent structural and functional information in a non-invasive manner with good temporal resolution. Image contrast can be derived from intrinsic absorption, fluorescence, or scatter, or through the use of extrinsic contrast. A major challenge in applying optical microscopy to in vivo tissue imaging is the effects of light attenuation which limits light penetration depth and achievable imaging resolution. Recently Selective Plane Illumination Microscopy (SPIM) has been used to map the 3D distribution of fluorophores dispersed in biological structures. In this approach, a focused sheet of light is used to illuminate the sample from the side to excite fluorophores within the sample of interest. Images are formed based on detection of fluorescence emission orthogonal to the illumination axis. By scanning the sample along the detection axis and acquiring a stack of images, 3D volumes can be obtained. The combination of rapid image acquisition speeds with the low photon dose to samples optical sectioning provides SPIM is an attractive approach for imaging biological samples in 3D. To date all implementations of SPIM rely on the use of fluorescence reporters be that endogenous or exogenous. This approach has the disadvantage that in the case of exogenous probes the specimens are altered from their native stage rendering them unsuitable for in vivo studies and in general fluorescence emission is weak and transient. Here we present for the first time to our knowledge a label-free implementation of SPIM that has downstream applications in the clinical setting. The experimental set up used in this work incorporates both label-free and fluorescent illumination arms in addition to a high specification camera that can be partitioned for simultaneous imaging of both fluorescent emission and scattered light from intrinsic sources of optical contrast in the sample being studied. This work first involved calibration of the imaging system and validation of the label-free method with well characterised fluorescent microbeads embedded in agarose gel. 3D constructs of mammalian cells cultured in agarose gel with varying cell concentrations were then imaged. A time course study to track cell proliferation in the 3D construct was also carried out and finally a native tissue sample was imaged. For each sample multiple images were obtained by scanning the sample along the axis of detection and 3D maps reconstructed. The results obtained validated label-free SPIM as a viable approach for imaging cells in a 3D gel construct and native tissue. This technique has the potential use in a near-patient environment that can provide results quickly and be implemented in an easy to use manner to provide more information with improved spatial resolution and depth penetration than current approaches.

Keywords: bioimaging, optics, selective plane illumination microscopy, tissue imaging

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Authors: Nona Mirzamohammadi, Bahram Nasernejad

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This work mainly focuses on studying the mechanism governing the adsorption of tetraethylammonium bromide, a short-chain quaternary ammonium salt, on the surface of natural zeolite and to characterize modified and raw zeolites in order to study the removal of nitrate anions from water. Natural clinoptilolite, as the most common zeolite, was chosen and modified in an ultrasonication process using tetraethylammonium bromide, subsequent to being contacted with NaCl solutions. FT-IR studies indicated a peak attributed to the stretching vibrations of the –CH₂ group in the molecule of tetraethylammonium bromide in the spectrum of the modified sample. Moreover, the SEM images showed some obvious changes in the surface morphology and crystallinity of clinoptilolite after being modified. Batch adsorption experiments show that the modified zeolite is capable of removing nitrate anions, and the predominant removal mechanism is suggested to be a combination of electrostatic attraction and ion exchange since the results from the zeta potential analysis showed a decrease in the net negative charge of clinoptilolite after modification, while bromide ions were detected in the modified sample in the µXRF analysis.

Keywords: adsorption, clinoptilolite, short-chain quaternary ammonium salt, tetraethylammoniumbromide, ultrasonication

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Authors: Francesca Alemanno

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As a complex socio-spatial phenomenon, migration is a practice that also contains a strong imaginative component with respect to the place that, through displacement, one person wants to reach. Every migrant has undertaken his journey having in his mind an image of the displacement he was about to make, of its implications and finally, of the place or city in which he was or would have liked to land. Often, however, the imaginary that has come to build before departure does not fully correspond to the reality of landing; this discrepancy, which can be more or less wide, plays an important role in the relationship that is established with the territory and in the evolution, therefore, of the city itself. In this sense, therefore, the clash that occurs between the imagined and the real is one of the factors that can contribute to making the entry of a migrant into new territory as critical as it can be. Starting from this perspective, the experiences of people who derive from a migratory context and who, over time, manage to create a bond with the land of reception, are taken into account as stories of resistance as they are necessarily charged with a force that is capable of driving difficult and articulated processes of change. The phenomenon of migrant entrepreneurship that is taken into consideration by this abstract plays a very important role because it highlights the story of many people who have managed to build such a close bond with the new territory of arrival that they can imagine and then realize the construction of their own personal business. The margin of contrast between the imagined city and the one that will be inhabited will be observed through the narratives of those who, through the realization of his business project has acted directly on the reality in which he landed. The margin of contrast that exists between the imagined city and the one actually inhabited, together with the implications that this may have on real life, has been observed and analyzed through a period of fieldwork, practicing ethnography, through the narratives of people who find themselves living in a new city as a result of a migration path, and has been contextualized with the support of semi-structured interviews and field notes. At the theoretical level, the research is inserted into a constructionist framework, particularly suited to detect and analyze processes of change, construction of the imaginary and its own modification, being able to capture the consequent repercussions of this process on the conceptual, emotional and practical level.

Keywords: entrepreneurship, imagination, migration, resistance

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Authors: Yifat Koren Carmi, Abed Agbarya, Hazem Khamaisi, Raymond Farah, Yelena Shechtman, Roman Korobochka, Jacob Gopas, Jamal Mahajna

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Ovarian cancer (OC), the second most common form of gynecological malignancy, has a poor prognosis and is frequently identified in its late stages. The recommended treatment for OC typically includes a platinum-based chemotherapy, like carboplatin. Nonetheless, OC treatment has proven challenging due to toxicity and development of acquired resistance to therapy. Chemoresistance is a significant obstacle to a long-lasting response in OC patients, believed to arise from alterations within the cancer cells as well as within the tumor microenvironments (TME). Malignant ascites is a presenting feature in more than one-third of OC patients. It serves as a reservoir for a complex mixture of soluble factors, metabolites, and cellular components, providing a pro-inflammatory and tumor-promoting microenvironment for the OC cells. Malignant ascites is also associated with metastasis and chemoresistance. In an attempt to elucidate the role of TME in chemoresistance of OC, we monitored the ability of soluble factors derived from ascites fluids to affect platinum sensitivity of OC cells. This research, compared ascites fluids from non-malignant cirrhotic patients to those from OC patients in terms of their ability to alter the platinum sensitivity of OC cells. Our findings indicated that exposure to OC ascites induces platinum chemoresistance on OC cells in 11 out of 13 cases (85%). In contrast, 75% of cirrhosis ascites (3 out of 4) failed to confer platinum chemoresistance to OC cells. Cytokine array analysis revealed that IL-6, and to a lesser extent HGF were enriched in OC ascites, whereas IL-22 was enriched in cirrhosis ascites. Pharmaceutical inhibitors that target the IL-6/JAK signaling pathway were mildly effective in overcoming the platinum chemoresistance induced by malignant ascites. In contrast, Crizotinib an HGF/c-MET inhibitor, and 2-hydroxyestradiol (2HE2) were effective in restoring platinum chemoresistance to OC. Our findings demonstrate the importance of OC ascites in supporting platinum chemoresistance as well as the potential of a combination therapy with Crizotinib and the estradiol metabolite 2HE2 to regain OC cells chemosensitivity.

Keywords: ovarian cancer, platinum chemoresistance, malignant ascites, tumor microenvironment, IL-6, 2-hydroxyestradiol, HGF, crizotinib

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Authors: Matthew Montebello

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The way e-learning effectiveness has been notoriously measured within an academic setting is by comparing the e-learning medium to the traditional face-to-face teaching methodology. In this paper, a simple yet innovative comparison methodology is introduced, whereby the effectiveness of next generation e-learning systems are assessed in contrast not only to the face-to-face mode, but also to the classical e-learning modality. Ethical and logistical issues are also discussed, as this three-way approach to compare teaching methodologies was applied and documented in a real empirical study within a higher education institution.

Keywords: e-learning effectiveness, higher education, teaching modality comparison

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Authors: M. Muneer, Waseem Raza

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Nano-crystalline materials of pure and metal-doped semiconducting materials have been successfully synthesized using sol gel and hydrothermal methods. The prepared materials were characterized by standard analytical techniques, i.e., XRD, SEM, EDX, UV–vis Spectroscopy and FTIR. The (XRD) analysis showed that the obtained particles are present in partial crystalline nature and exhibit no other impurity phase. The EDX and (SEM) images depicted that metals have been successfully loaded on the surface of the semiconductor. FTIR showed an additional absorption band at 910 cm−1, characteristic of absorption band indicating the incorporation of dopant into the lattice in addition to a broad and strong absorption band in the region of 410–580 cm−1 due to metal–O stretching. The UV–vis absorption spectra of synthesized particles indicate that the doping of metals into the lattice shift the absorption band towards the visible region. Thermal analysis, measurement of the synthesized sample showed that the thermal stability of pure semiconducting material is decreased due to increase in dopant concentration. The photocatalytic activity of the synthesized particles was studied by measuring the change in concentration of three different chromophoric dyes as a function of irradiation time. The photocatalytic activity of doped materials were found to increase with increase in dopant concentration.

Keywords: photocatalysis, metal doped semicondcutors, dye degradation, visible light active materials

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Authors: Syed Afrozuddin Ahmed, Junaid Saghir Siddiqi, Sabah Quaiser

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Various studies have reported that global warming causes unstable climate and many serious impact to physical environment and public health. The increasing incidence of dengue incidence is now a priority health issue and become a health burden of Pakistan. In this study it has been investigated that spatial pattern of environment causes the emergence or increasing rate of dengue fever incidence that effects the population and its health. The climatic or environmental structure data and the Dengue Fever (DF) data was processed by coding, editing, tabulating, recoding, restructuring in terms of re-tabulating was carried out, and finally applying different statistical methods, techniques, and procedures for the evaluation. Five climatic variables which we have studied are precipitation (P), Maximum temperature (Mx), Minimum temperature (Mn), Humidity (H) and Wind speed (W) collected from 1980-2012. The dengue cases in Karachi from 2010 to 2012 are reported on weekly basis. Principal component analysis is applied to explore the climatic variables and/or the climatic (structure) which may influence in the increase or decrease in the number of dengue fever cases in Karachi. PC1 for all the period is General atmospheric condition. PC2 for dengue period is contrast between precipitation and wind speed. PC3 is the weighted difference between maximum temperature and wind speed. PC4 for dengue period contrast between maximum and wind speed. Negative binomial and Poisson regression model are used to correlate the dengue fever incidence to climatic variable and principal component score. Relative humidity is estimated to positively influence on the chances of dengue occurrence by 1.71% times. Maximum temperature positively influence on the chances dengue occurrence by 19.48% times. Minimum temperature affects positively on the chances of dengue occurrence by 11.51% times. Wind speed is effecting negatively on the weekly occurrence of dengue fever by 7.41% times.

Keywords: principal component analysis, dengue fever, negative binomial regression model, poisson regression model

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Authors: Mustafa Hyder, Khalid Mahmood Iraqi, Sameen Mustafa

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They say if the leader limps, all the others will start limping too. Therefore, a very dynamic leadership at all levels within the IT Community is critical to the success of an organization. This paper is an attempt to study the relationship between Information Technology (IT) with leadership and assesses its relevancy in today's fast-paced hi-tech globalized environment. The paper strives to look into the essential qualities and knowledge as needed by today's IT leader, in contrast to essential characteristics common to all the leaders-past, present, and future.

Keywords: leadership, autocratic leaders, characteristics of IT leaders, skills of IT professionals, IT leadership

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Authors: A. H. M. Zehadul Karim

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Cameron Highlands (4°28’N, 101°23’E) is an attractive mountainous region with steep slopes located in the state of Pahang, Malaysia stretching between 1070 and 1830m above sea level with a total land area of 71,218ha. It is one of the few places in Malaysia that has a tropical highland climate as the mean annual temperature of it is 18 °C (64 °F) thus making the atmosphere perfect for specialized agriculture. Being ecologically suitable, Cameron Highlands has recently been identified as a very strategic farming area, producing multifarious vegetables, flowers and tea with a commercial motive of marketing them to Singapore and all over the urban areas of Malaysia to meet the domestic and international demands. The main intricacies of this plantation agriculture are fully dependent on the policies formulated by a group of emerging entrepreneurs who employ foreign labourers to make these agricultural activities a success in the agrarian sector in Malaysia. Based on the socio-anthropological perspective, the paper entirely relies on empirical field data generated by interviewing 10 farm owners and 200 foreign workers to find out the intricacies of this plantation agriculture which makes the research innovative and pragmatically significant. The paper deals with important issues relating to this productive plantation agriculture of Cameron Highlands and as such, narrates the various exceptional and holistic skills adopted for this type of farming.

Keywords: Cameron Highlands Malaysia, plantation agriculture, issues and challenges, mechanisms

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Authors: Jie Yang, Jian-Min Meng

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A GPU-based floating object detection scheme is presented in this paper which is designed for floating mine detection tasks. This system uses contrast and motion information to eliminate as many false positives as possible while avoiding false negatives. The GPU computation platform is deployed to allow detecting objects in real-time. From the experimental results, it is shown that with certain configuration, the GPU-based scheme can speed up the computation up to one thousand times compared to the CPU-based scheme.

Keywords: object detection, GPU, motion estimation, parallel processing

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Authors: Mohua Chatterjee, Rajib De

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Introduction: Bone Marrow Transplant (BMT) is often performed to treat patients with various types of leukemia. A majority of these patients develop complications like chronic musculoskeletal GVHD post-BMT where patients get scleroderma, pain and restricted range of motion of joints of hand. If not treated early, it may cause permanent deformity of hand. This study was done to find the effectiveness of physiotherapy in hand dysfunction caused due to chronic musculoskeletal GVHD of leukemia patients after BMT. Methodology: 23 patients diagnosed with leukemia and having musculoskeletal GVHD were treated with a set of exercises including active exercises and stretching. The outcome was measured by Cochin Hand Function Scale (CHFS) at baseline and after four weeks of intervention. Results: Two patients were not able to carry out exercises beyond two weeks due to relapse of disease and one patient defaulted. It was found that all the patients who received physiotherapy had significant improvement in hand function. Mean CHFS decreased from 63.67 to 27.43 (P value < 0.001) indicating improvement in hand function after four weeks of physiotherapy. Conclusion: Early intervention of physiotherapy is effective in reducing hand dysfunction of leukemia patients with musculoskeletal GVHD post-BMT.

Keywords: bone marrow transplant, hand dysfunction, leukemia, musculoskeletal graft versus host disease, physiotherapy

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Authors: Parimalah Velo, Ahmad Zakaria

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Introduction: Monte Carlo simulations of preclinical imaging systems allow opportunity to enable new research that could range from designing hardware up to discovery of new imaging application. The simulation system which could accurately model an imaging modality provides a platform for imaging developments that might be inconvenient in physical experiment systems due to the expense, unnecessary radiation exposures and technological difficulties. The aim of present study is to validate the Monte Carlo simulation of thyroid phantom imaging using Geant4-GATE for Siemen’s e-cam single head gamma camera. Upon the validation of the gamma camera simulation model by comparing physical characteristic such as energy resolution, spatial resolution, sensitivity, and dead time, the GATE simulation of thyroid phantom imaging is carried out. Methods: A thyroid phantom is defined geometrically which comprises of 2 lobes with 80mm in diameter, 1 hot spot, and 3 cold spots. This geometry accurately resembling the actual dimensions of thyroid phantom. A planar image of 500k counts with 128x128 matrix size was acquired using simulation model and in actual experimental setup. Upon image acquisition, quantitative image analysis was performed by investigating the total number of counts in image, the contrast of the image, radioactivity distributions on image and the dimension of hot spot. Algorithm for each quantification is described in detail. The difference in estimated and actual values for both simulation and experimental setup is analyzed for radioactivity distribution and dimension of hot spot. Results: The results show that the difference between contrast level of simulation image and experimental image is within 2%. The difference in the total count between simulation and actual study is 0.4%. The results of activity estimation show that the relative difference between estimated and actual activity for experimental and simulation is 4.62% and 3.03% respectively. The deviation in estimated diameter of hot spot for both simulation and experimental study are similar which is 0.5 pixel. In conclusion, the comparisons show good agreement between the simulation and experimental data.

Keywords: gamma camera, Geant4 application of tomographic emission (GATE), Monte Carlo, thyroid imaging

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Authors: Ahmed Elwaleed, Huiho Jeong, Ali H. Abdelbagi, Nguyen Thi Quynh, Koji Arizono, Yasuhiro Ishibashi

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Artisanal and small-scale gold mining (ASGM) poses substantial risks to both human health and the environment, particularly through contamination of soil, water, and air. Prolonged exposure to ASGM-contaminated soils can lead to acute or chronic mercury toxicity. This study assesses the human health risks associated with mercury-contaminated soils and tailings in the Alebediah mining community in Sudan. Soil samples were collected from various locations within Alebediah, including ASGM areas, farmlands, and residential areas, along with tailings samples commonly found within ASGM sites. The evaluation of potential health risks to humans included the computation of the estimated daily intake (AvDI), the hazard quotient (HQ), and the hazard index (HI) for both adults and children. The primary exposure route identified as potentially posing a significant health risk was the volatilization of mercury from tailings samples, where mercury concentrations reached up to 25.5 mg/kg. In contrast, other samples within the ASGM area showed elevated mercury levels but did not present significant health risks, with HI values below 1. However, all areas indicated HI values above 1 for the remaining exposure routes. The study observed a decrease in mercury concentration with increasing distance from the ASGM community. Additionally, soil samples revealed elevated mercury levels exceeding background values, prompting an assessment of contamination levels using the enrichment factor (EF). The findings indicated that farmlands and residential areas exhibited depleted EF, while areas surrounding the ASGM community showed none to moderate pollution. In contrast, ASGM areas exhibited significant to extreme pollution. A GIS map was generated to visually depict the extent of mercury pollution, facilitating communication with stakeholders and decision-makers.

Keywords: mercury pollution, artisanal and small-scale gold mining, health risk assessment, hazard index, soil and tailings, enrichment factor

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Authors: Rika Aoki

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The aim of this paper is to investigate whether being bilinguals facilitates or impedes the perception of a third language. The present study conducted a perception experiment in which Mandarin-Japanese bilinguals categorized a Voice-Onset-Time (VOT) continuum into English /b/ or /p/. The results show that early bilinguals were influenced by both Mandarin and Japanese, while late bilinguals behaved in a similar manner to Mandarin monolinguals Thus, it can be concluded that in the present study having two languages did not help bilinguals to perceive L3 stop contrast native-likely.

Keywords: bilinguals, perception, third language acquisition, voice-onset-time

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Authors: Yasir Alotaibi

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The aim of this paper is to discuss the syntactic analysis of aspectual or phasal verbs in Modern Standard Arabic (MSA). Aspectual or phasal verbs refer to a class of verbs that require a verbal complement and denote the inception, duration, termination ...etc. of a state or event. This paper will discuss two groups of aspectual verbs in MSA. The first group includes verbs such as ̆gacala, tafiqa, ?akhatha, ?ansha?a, sharaca and bada?a and these verbs are used to denote the inception of an event. The second group includes verbs such as ?awshaka, kaada and karaba and the meaning of these verbs is equivalent to be near/almost . The following examples illustrate the use of the verb bada?a ‘begin’ which is from the first group: a. saalim-un bada?a yuthaakiru. Salem-NOM begin.PFV.3SGM study.IPFV.3SGM ‘Salem began to study’ b.*saalim-un bada?a ?an yuthaakiru. Salem-NOM begin.PFV.3SGM COMP study.IPFV.3SGM ‘Salem began to study’ The example in (1a) is grammatical because the aspectual verb is used with a verbal complement that is not introduced by a complementizer. In contrast, example (1b) is not grammatical because the verbal complement is introduced by the complementizer ?an ‘that’. In contrast, the following examples illustrate the use of the verb kaada ‘be almost’ which is from the second group. However, the two examples are grammatical and this means that the verbal complement of this verb can be without (as in example (2a)) or with ( as in example (2b)) a complementizer. (2) a. saalim-un kaada yuthaakiru. Salem-NOM be.almost.PFV.3SGM study.IPFV.3SGM ‘Salem was almost to study’ b. saalim-un kaada ?an yuthaakiru. Salem-NOM be.almost.PFV.3SGM COMP study.IPFV.3SGM ‘Salem was almost to study’ The salient properties of this class of verbs are that they require a verbal complement, there is no a complementizer that can introduce the complement with the first group while it is possible with the second and the aspectual verb and the embedded verb share and agree with the same subject. To the best of knowledge, aspectual verbs in MSA are discussed in traditional grammar only and have not been studied in modern syntactic theories. This paper will consider the analysis of aspectual verbs in MSA within the Lexical Functional Grammar (LFG) framework. It will use some evidence such as modifier or negation to find out whether these verbs have PRED values and head their f-structures or they form complex predicates with their complements. If aspectual verbs show the properties of heads, then the paper will explore what kind of heads they are. In particular, they should be raising or control verbs. The paper will use some tests such as agreement, selectional restrictions...etc. to find out what kind of verbs they are.

Keywords: aspectual verbs, biclausal, monoclausal, raising

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Authors: Amany Mohamed, Alaa Balbaa, Magdoline Mishel

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Background: Pain in the neck or scapular region is one of the most frequent symptoms in cervical radiculopathy, which is commonly caused by degenerative process in the spine. Purpose: To determine the effect of scapular stabilization exercises in the treatment of chronic neck pain regarding pain and disability and limitation in the range of motion. Patients and Methods: Thirty male and female patients with chronic neck pain were involved. Aged between 30-50 years old. They were randomly assigned into two groups. In group (A), patients received physical therapy program in the form of infrared, transcutaneous electrical nerve stimulation (TENS), Stretching and cervical stabilization exercises. In group (B), patients received scapular stabilization exercises in addition to the same physical therapy program. Treatment was given 3 times a week for 4 weeks. Range of motion of the cervical spine, range of motion of the scapula, neck pain and disability were assessed before and after treatment. Results: There was significant improvement in both groups (A and B) in cervical range of motion, pain and disability. Group (B) showed more significant improvement than group (A) in cervical range of motion and pain and disability. There was no significant improvement in both groups in scapular range of motion. Conclusion: Scapular stabilization exercises should be used as an integral part in the rehabilitation program

Keywords: Neck pain, neck stabilization exercise, scapular stabilization exercise, chronic neck pain

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Authors: Reem Alshiha, Tanzila Saba

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Physical rehabilitation is the process of helping people to recover and be able to go back to their former activities that have been delayed due to external factors such as car accidents, old age and victims of strokes (chronic diseases and accidents, and those related to sport activities).The cost of hiring a personal nurse or driving the patient to and from the hospital could be costly and time-consuming. Also, there are other factors to take into account such as forgetfulness, boredom and lack of motivation. In order to solve this dilemma, some experts came up with rehabilitation software to be used with Microsoft Kinect to help the patients and their families for in-home rehabilitation. In home rehabilitation software is becoming more and more popular, since it is more convenient for all parties affiliated with the patient. In contrast to the other costly market-based systems that have no portability, Microsoft’s Kinect is a portable motion sensor that reads body movements and interprets it. New software development has made rehabilitation games available to be used at home for the convenience of the patient. The game will benefit its users (rehabilitation patients) in saving time and money. There are many software's that are used with the Kinect for rehabilitation, but the software that is chosen in this research is Kinectotherapy. Kinectotherapy software is used for rehabilitation patients in Riyadh clinics to test its acceptance by patients and their physicians. In this study, we used Kinect because it was affordable, portable and easy to access in contrast to expensive market-based motion sensors. This paper explores the importance of in-home rehabilitation by using Kinect with Kinectotherapy software. The software targets both upper and lower limbs, but in this research, the main focus is on upper-limb functionality. However, the in-home rehabilitation is applicable to be used by all patients with motor disability, since the patient must have some self-reliance. The targeted subjects are patients with minor motor impairment that are somewhat independent in their mobility. The presented work is the first to consider the implementation of in-home rehabilitation with real-time feedback to the patient and physician. This research proposes the implementation of in-home rehabilitation in Riyadh, Saudi Arabia. The findings show that most of the patients are interested and motivated in using the in-home rehabilitation system in the future. The main value of the software application is due to these factors: improve patient engagement through stimulating rehabilitation, be a low cost rehabilitation tool and reduce the need for expensive one-to-one clinical contact. Rehabilitation is a crucial treatment that can improve the quality of life and confidence of the patient as well as their self-esteem.

Keywords: x-box, rehabilitation, physical therapy, rehabilitation software, kinect

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Authors: Ahmed M. F. El Shiwi

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Background: Low back pain affects about 60% to 90% of the working-age population in modern industrial society. Myofascial pain syndrome is a condition characterized by muscles shortening with increased tone and associated with trigger points that aggravated with the activity of daily living. Purpose: To examine the effects of magnetic field therapy in patients with lower back myofascial pain syndrome. Methods: Thirty patients were assigned randomly into two groups. Subjects in the experimental group (n=15) with main age of 36.73 (2.52) received traditional physical therapy program (Infrared radiation, ultrasonic, stretching and strengthening exercises for back muscles) as well as magnetic field, and control group (n=15) with main age of 37.27 (2.52) received traditional physical therapy only. The following parameters including pain severity, functional disability and lumbar range of motion (flexion, extension, right side bending, and left side bending) were measured before and after four weeks of treatment. Results: The results showed significant improvement in all parameters in the experimental group compared with those in the control group. Interpretation/Conclusion: By the present date, it is possible to conclude that a magnetic field is effective as a method of treatment for lower back myofascial pain syndrome patients with the parameters used in the present study.

Keywords: magnetic field, lower back pain, myofascial pain syndrome, biological systems engineering

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Authors: Mateusz Hermyt, Pawel Kaczmarek, Weronika Rupik

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The egg tooth is a crucial structure during hatching of lizards and snakes. In contrast to birds, turtles, crocodiles, and monotremes, egg tooth of squamate reptiles is a true tooth sharing common features of structure and development with all the other teeth of vertebrates. The egg tooth; however, due to its function, exhibits structural differences in relation to regular teeth. External morphology seems to be important in the context of phylogenetic relationships within Squamata but up to date, there is scarce information concerning structure and development of the egg tooth at the submicroscopical level. In presented studies detailed analysis of the egg tooth development in grass snake has been performed with the usage of light (including fluorescent), transmission and scanning electron microscopy. Grass snake embryo’s heads have been used in our studies. Grass snake is common snake species occurring in most of Europe including Poland. The grass snake is characterized by the presence of single unpaired egg tooth (as in most squamates) in contrast to geckos and dibamids possessing paired egg teeth. Studies show changes occurring on the external morphology, tissue and cellular levels of differentiating egg tooth. The egg tooth during its development changes its curvature. Initially, faces directly downward and in the course of its differentiation, it gradually changes to rostro-ventral orientation. Additionally, it forms conical dentinal protrusions on the sides. Histological analysis showed that egg tooth development occurs in similar steps in relation to regular teeth. It undergoes initiation, bud, cap and bell morphological stages. Analyses focused on describing morphological changes in hard tissues (mainly dentin and predentin) of egg tooth and in cells which enamel organ consists of. It included: outer enamel epithelium, stratum intermedium, inner enamel epithelium, odontoblasts, and cells of dental pulp. All specimens used in the study were captured according to the Polish regulations concerning the protection of wild species. Permission was granted by the Local Ethics Commission in Katowice (41/2010; 87/2015) and the Regional Directorate for Environmental Protection in Katowice (WPN.6401.257.2015.DC).

Keywords: hatching, organogenesis, reptile, Squamata

Procedia PDF Downloads 155

Authors: June Tay, Ivy Chia

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There are numerous changes, both mental and physical, taking place when people age. We need to understand the different aspects required for healthy living, including meeting nutritional needs, regular physical activities to keep agility, sufficient rest and sleep to have physical and mental well-being, social engagement to avoid the risk of social isolation and depression, and access to healthcare to detect and manage chronic conditions. Promoting physical activities for an ageing population is necessary as many may have enjoyed sedentary lifestyles for some time. In our study, we evaluate the considerations when designing a computer vision video game for the elderly. We need to design some low-impact activities, such as stretching and gentle movements, because some elderly individuals may have joint pains or mobility issues. The exercise game should consist of simple movements that are easy to follow and remember. It should be fun and enjoyable so that they can be motivated to do some exercise. Social engagement can keep the elderly motivated and competitive, and they are more willing to engage in game exercises. Elderly citizens can compare their game scores and try to improve them. We propose a computer vision-based video game for the elderly that will capture and track the movement of the elderly hand pushing a ball on the screen into a circle. It can be easily set up using a PC laptop with a webcam. Our video game adhered to the design framework we employed, and it encompassed ease of use, a simple graphical interface, easy-to-play game exercise, and fun gameplay.

Keywords: about computer vision, video games, gerontology technology, caregiving

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