528 research outputs found

    THE GENUS MIMOSA WITH SPECIAL REFERENCE TOM. QUADRIVALVIS L. VAR. LEPTOCARPA (D.C.) EARNEDY, A NEW SPECIES RECORD FOR THE WEED FLORA IN MALAYSIA*)

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    An exploratory floristic survey of the genus Mimosa was conducted in 1993 to ascertain species diversity and their spatial patterns of distribution in Peninsular Malaysia. A new species record of uncertain indigene, M.. quadrivalvis was recorded for the first time in restricted localities along the roadsides in Pekan Darat and Bertam, Seberang Perai, Gurun and Bedong  in Kedah  in addition  to widely distributed and seemingly  ubiquitous presence of M. invisa Mart. ex. Colla and M. pudica L. The latter two species were mostly found in open, disturbed and derelict habitats, agricultural areas and ex-mining  lands. Both species exhibited  largely  contagious and overdispersed distribution patterns with positive peaks in pattern intensity values although regularity or underdispersed distribution patterns do manifest in certain localities. The giant mimosa, M. pigra inhabited in clustered thickets, large pockets of lands in the urban and sub-urban localities in the states of Penang, Perak, Kelantan, Kuala Lumpur and Negeri Sembilan. In other states, M. pigra was confined to a few localities in smaller patches. Except for M. quadrivalvis, the other species of Mimosa are serious weeds  in  the agricultural,  recreational and  residential and derelict areas. A key  to  the Mimosa species is constructed along with brief descriptions on their morphology and ecology.Key words: Malaysia/Weed ecology/Mimosa invisa/Mimosa pigra/Mimosa pudica/Mimosa quadrivalvis/ Weed distribution/Weed anatomy and morphology

    The Genus Mimosa with Special Reference Tom. Quadrivalvis L. Var. Leptocarpa (D.c.) Earnedy, a New Species Record for the Weed Flora in Malaysia*)

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    An exploratory floristic survey of the genus Mimosa was conducted in 1993 to ascertain species diversity and their spatial patterns of distribution in Peninsular Malaysia. A new species record of uncertain indigene, M.. quadrivalvis was recorded for the first time in restricted localities along the roadsides in Pekan Darat and Bertam, Seberang Perai, Gurun and Bedong in Kedah in addition to widely distributed and seemingly ubiquitous presence of M. invisa Mart. ex. Colla and M. pudica L. The latter two species were mostly found in open, disturbed and derelict habitats, agricultural areas and ex-mining lands. Both species exhibited largely contagious and overdispersed distribution patterns with positive peaks in pattern intensity values although regularity or underdispersed distribution patterns do manifest in certain localities. The giant mimosa, M. pigra inhabited in clustered thickets, large pockets of lands in the urban and sub-urban localities in the states of Penang, Perak, Kelantan, Kuala Lumpur and Negeri Sembilan. In other states, M. pigra was confined to a few localities in smaller patches. Except for M. quadrivalvis, the other species of Mimosa are serious weeds in the agricultural, recreational and residential and derelict areas. A key to the Mimosa species is constructed along with brief descriptions on their morphology and ecology

    Assessment of Allelopathic Potential of Melastoma malabathricum L. on Radish raphanus sativus L. and Barnyard Grass (Echinochloacrus-galli)

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    Melastoma malabathricum L. is a weedy invasive shrub in arable lands, abandoned farmlands, secondary forest openings and derelict areas in Malaysia. Some allelochemicals present in this plant extracts may, directly, prevent or promote germination when environmental conditions are conducive to growth and establishment. It may have an important role, indirectly, in determining plant community structures. The aqueous extract and methanol extracts , were assayed for the aqueous extract of fresh materials with concentrations of 0, 50,100,150 and 200 gl-1 and at aqueous of oven dried materials extract with concentrations of 40,80,120,160,and 200 gl-1 .The crude methanol extracts were prepared using extract concentrations of 10.8,14.28 ,18 and 30 gl-1 of shoot and root materials. The extracts were tested with the widely used radish seed barnyard grass seed. Radish seed germination was inhibited at concentrations ranging from 200 gl-1 in the extract aqueous of dried materials and in the methanol extract concentrations of 14.28 and 30 gl-1 .The inhibition of root and shoot growth was also observed in the Barnyard grass seed. Both species were susceptible to allelopathy by extracts isolated from shoot and root of M. malabathricum and also their rate of germination, root length and shoot length in were decreased upon the application of both type of extractions. The results from this study strongly suggest that allelopathy may be a possible mechanism controlling the timing of barnyard grass germination and seedling establishment

    Fundamental Role of Neurochemicals Aberration in the Pathogenesis of Autism Spectrum Disorders

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    AIM: The aim of this research was to establish the perturbation of reliable biomarkers implicated in the pathophysiology of autism to help in the early diagnosis and to be as targets in the treatment of autism spectrum disorders (ASDs) in children and to spotlight into the complex crosstalk between these biomarkers. PATIENS AND METHODS: This study included 90 autistic children aged from 2 to 7 years old, who were classified into two groups, the atypical autism of 30 children and the childhood autism. The childhood autism group was further divided into mild-moderate autism group and severe autism group each of 30 children. The control group included 30 matched healthy children. All the participants were subjected to full psychiatric examinations, psychological investigations, and biochemical measurements, including gamma-aminobutaric acid (GABA), serotonin, dopamine (DA) in plasma, and brain-derived neurotrophic factor (BDNF) in serum. RESULTS: The autistic groups showed a highly significant increase in GABA, serotonin, DA, and BDNF levels compared to the control. Of note, the levels of GABA, DA, and BDNF were significantly increased with the increased disease severity. Furthermore, a significant positive correlation between BDNF levels and both GABA and DA levels in the childhood autism group has been recorded. CONCLUSION: The present clinical setting provides new insight into the fundamental role of BDNF in the brain of autistic children as any alterations of its level due to GABA increment cause change in serotonin and DA levels which have empirical evidence in the pathophysiology of ASD. The results received in this research, create a fertile base for the setup of particular targets in the intervention of this ailment

    A Multiband Fractal Dipole Antenna for Wireless Communication Applications

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    mmunication applications. The proposed fractal antenna design is based onfractal geometry of the second level tent function transformation. Due to theresulting geometrical structures of a fractal tent function curve depend on thestarting angles of the initial tent function, many dipole antennas have beenmodeled and the corresponding radiation characteristics have been evaluated.Theoretical performance of these antennas has been calculated using the methodof moments (MoM) electromagnetic simulator, IE3D. Simulation results of manytent fractal dipole antennas which have been modeled show that all of theseantennas have multiband resonate behavior, but this resonate behavior is differentaccording to the starting angle for each antenna. The results have shown that theseantennas have acceptable performance for VSWR ≤ 2 (return loss ≤ -10 dB),using a 50W feed line, at most of the resonating frequencies. This feature providesantenna designer with more degree of freedom, and makes the proposed antenna(or its monopole counterpart) suitable for use in the modern multi-functionscommunication system

    Human papillomavirus mediated inhibition of DNA damage sensing and repair drives skin carcinogenesis

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    Background: The failure to mount an effective DNA damage response to repair UV induced cyclobutane pyrimidine dimers (CPDs) results in an increased propensity to develop cutaneous squamous cell carcinoma (cSCC). High-risk patient groups, such as organ transplant recipients (OTRs) frequently exhibit field cancerization at UV exposed body sites from which multiple human papillomavirus (HPV)-associated cSCCs develop rapidly, leading to profound morbidity and increased mortality. In vitro molecular evidence indicates that HPV of genus beta-papillomavirus (β-PV) play an important role in accelerating the early stages of skin tumorigenesis. Methods: We investigated the effects of UV induced DNA damage in murine models of β-PV E6 oncoprotein driven skin tumorigenesis by crossing K14-HPV8-E6wt mice (developing skin tumors after UV treatment) with K14-CPD-photolyase animals and by generating the K14-HPV8-E6-K136N mutant mouse strain. Thymine dimers (marker for CPDs) and γH2AX (a marker for DNA double strand breaks) levels were determined in the murine skin and organotypic skin cultures of E6 expressing primary human keratinocytes after UV-irradiation by immunohistochemistry and in cell lines by In Cell Western blotting. Phosphorylation of ATR/Chk1 and ATM were assessed in cell lines and organotypic skin cultures by Western blots and immunohistochemistry. Results: Skin tumor development after UV-irradiation in K14-HPV8-E6wt mice could completely be blocked through expression of CPD-photolyase. Through quantification of thymine dimers after UV irradiation in cells expressing E6 proteins with point mutations at conserved residues we identified a critical lysine in the

    EFFECTS OF NON-LINEAR MAGNETIC CHARGE ON INDUCTION FURNACE OPERATION DURING THE HEATING CYCLE

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    This research studying the electromagnetic behavior of the induction furnace when its core is a magnetic material taking into consideration the effect of the non-linear dependence of the magnetic flux induced in it due to the applied magnetizing force. Since the magnetic characteristics are severely affected by temperature rise in a non-linear way, so as the specific electric resistance of the charge material, this work deals with studying the effect of temperature on the non-linear characteristics of a magnetic core simultaneously with that on the specific electric resistance to show the electromagnetic behavior of the furnace during heating operation. The distribution of the current density, flux density and the magnetizing force at different temperatures inside the furnace and on the charge surfaces are determined for different temperatures. Also the flux distribution is plotted at these cases. This study will be the base for future work on the electromagnetic-thermal coupled analysis for the induction furnace

    Multi-institutional expert update on the use of laparoscopic bile duct exploration (LBDE) in the management of choledocholithiasis: lesson learned from 3950 procedures

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    Background: Recently there has been a growing interest in the laparoscopic management of common bile duct stones with gallbladder in situ (LBDE), which is favoring the expansion of this technique. Our study identified the standardization factors of LBDE and its implementation in the single-stage man agement of choledocholithiasis. Methods: A retrospective multi-institutional study among 17 centers with proven experience in LBDE was performed. A cross-sectional survey consisting of a semi-structured pretested questionnaire was distributed covering the main aspects on the use of LBDE in the management of choledocholithiasis. Results: A total of 3950 LBDEs were analyzed. The most frequent indication was jaundice (58.8%). LBDEs were performed after failed ERCP in 15.2%. The most common approach used was the transcystic (63.11%). The overall series failure rate of LBDE was 4% and the median rate for each center was 6% (IQR, 4.5-12.5). Median operative time ranged between 60-120 min (70.6%). Overall morbidity rate was 14.6%, with a postoperative bile leak and complications ≥3a rate of 4.5% and 2.5%, respectively. The operative time decreased with experience (P = .03) and length of hospital stay was longer in the presence of a biliary leak (P = .04). Current training of LBDE was defined as poor or very poor by 82.4%. Conclusion: Based on this multicenter survey, LBDE is a safe and effective ap proach when performed by experienced teams. The generalization of LBDE will be based on developing training programs

    Structural, thermal, and optical analysis of zinc boro-aluminosilicate glasses containing different alkali and alkaline modifier ions

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    In this article, structural, thermal, and optical properties of zinc boro-aluminosilicate glasses with addition of different alkali (Li, Na, and K) and alkaline oxides (Mg, Ca, Sr, and Ba) have been reported. 10 mol% of alkali and alkaline oxides were incorporated into Zinc boro-aluminosilicate glasses and all these glasses possess high optical quality. Samples were characterized using X-ray diffraction (XRD), scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDAX), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, Raman spectroscopy, thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), and optical absorption spectroscopy. The XRD and SEM measurements demonstrated the amorphous origin for all the prepared glasses and EDAX confirms that all the elements are presented in the prepared glasses. The presence of various functional groups such as triangular and tetrahedral-borate (BO3 and BO4) was confirmed by ATR-FTIR and Raman spectra, and both of the ATR-FTIR and Raman spectra show lower phonon energy for H3 (K2O) in alkali series, and H7 (BaO) for alkaline. From TGA analysis we found a lower weight loss < 0.1% in K2O, MgO, and BaO; and from the DSC profiles the glass transition temperature (Tg), onset crystallization temperature (Tx), crystallization temperature (Tc), and melting temperature (Tm) were identified and related different thermal parameters are evaluated. Alkali and alkaline influenced Zinc boro-aluminosilicate glasses demonstrate excellent glass stability. From the optical absorption spectra, we calculated cut-off wavelength and it shows spectral shifting to longer wavelength with alkali (Li → Na → K), and alkaline (Mg → Ca → Sr → Ba) modifiers. We investigated optical band gap energy also for allowed transitions in UV–visible region using three methods; direct, indirect, and absorption spectrum fitting (ASF)

    Germanate Oxide Impacts on the Optical and Gamma Radiation Shielding Properties of TeO2-ZnO-Li2O Glass System

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    In this work, a series of tellurite glass combined with various concentrations of germanium oxide was fabricated according to the formula of (70-x)TeO2-xGeO2–20ZnO-10Li2O where x = 5, 10, 15 and 20 mol% via utilizing the melt-quench method for possible use in a radiation shielding applications. X-ray diffraction and Attenuated Total Reflectance Fourier Transform Infrared was employed to investigate the structure of the synthesized glasses. The density and Poisson's ratio for current samples reduced gradually from 5.221–5.008 g.cm−3 and 0.134–0.131, respectively, while the enhancement in bandgap values from 3.700–3.872 eV with addition of GeO2 is observed. The linear attenuation coefficient values at 0.015 MeV are 230.123 and 236.832 cm−1 for samples TG1 and TG4, respectively. Moreover, the lowest half-value layer attained via TG1 and raises from 0.0030 to 3.6684 cm while the highest HVL attained by TG4 and raises from 0.0029 to 3.9696 cm. © 2020 Elsevier B.V.All Authors present their grateful acknowledge to the Universiti Putra Malaysia (UPM), for supporting this work by chemicals and services, which granted by UPM under IPB-9554200. Also, the authors present their grateful acknowledge to the university of Tabuk, Tabuk, Saudi Arabia for supporting this work by some chemicals
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