Ablation on Barpu glacier, Karakoram Himalaya, Pakistan a study of melt processes on a faceted, debris-covered ice surface

ThesisThesis (M.A.), Wilfrid Laurier University, 198

The potential of unintended effects in potato glycoalkaloids

Unintended changes have long been considered as byproducts associated with genetic improvement of crop plants. The issue has been hotly debated during recent years following the identification of some unwanted characters in genetically engineered crop plants. In this context, the subject of unintended effects of plant transformation on known toxic compounds has been an area of immense interest. Compositional changes in these toxins may have a profound impact on human and animal health. Potato glycoalkaloids are known toxic compounds to humans and animals. These days, food safety evaluation tests of transgenic potato varieties are conducted on routine basis to keep the glycoalkaloid levels below a threshold level. Some transgenic potato varieties have been found with altered glycoalkaloid levels, which have created doubts on the process of transformation and tissue culture conditions. In this review, we summarize recent work on unintended effects in crop plants with special emphasis on compositional changes in potato glycoalkaloids as a result of genetic transformation.Keywords: Unintended effects, transgenic potato, glycoalkaloids, food safety, environmental stressAfrican Journal of Biotechnology Vol. 12(8), pp. 754-76

Comparison between endoscopic and microscopic approaches for surgery of pituitary tumours

Surgical techniques for resection of pituitary tumours have come a long way since it was first introduced in late 18th century. Nowadays, most pituitary surgeries are performed through trans-nasal trans-sphenoidal approach either using a microscope, or an endoscope. Herein the authors review the literature and compare these two instruments with regards to their outcomes when used for resection of pituitary tumours.

Diffuse low-grade glioma - Changing concepts in diagnosis and management: A review

Though diffuse low-grade gliomas (dLGGs) represent only 15% of gliomas, they have been receiving increasing attention in the past decade. Significant advances in knowledge of the natural history and clinical diversity have been documented, and an improved pathological classification of gliomas that integrates histological features with molecular markers has been issued by the WHO. Advances in the radiological assessment of dLGG, particularly new magnetic resonance imaging scanning sequences, allow improved diagnostic and prognostic information. The management paradigms are evolving from wait and watch of the past to more active interventional therapy to obviate the risk of malignant transformation. New surgical technologies allow more aggressive surgical resections with a reduction of morbidity. Many reports suggest the association of gross total resection with longer overall survival and progression-free survival in addition to better seizure control. The literature also shows the use of chemotherapeutics and radiation therapy as important adjuncts to surgery. The goals of management have has been increasing survival with increasing stress on quality of life. Our review highlights the recent advances in the molecular diagnosis and management of dLGG with trends toward multidisciplinary and multimodality management of dLGG with an aim to surgically resect the primary disease, followed by chemoradiation in cases of progressive or recurrent diseas

Role of 5-ALA in improving extent of tumour resection in patients with glioblastoma multiforme

Goal of surgery for patients with Glioblastoma Multiforme (GBM) is gross total resection with no new neurological deficits. Surgical resection is often restricted due the difficulty in differentiating the tumour from surrounding normal brain using either naked eye, or standard intra-operative white light microscopy. GBM uptakes orally administered 5-ALA becomes fluorescent when viewed by a special light, and this property has been used to improve intra-operative tumour identification. This technique should therefore allow better extent of tumour resection. The hypothesis has been tested through several studies and even though most studies are of low quality, they strongly favour the use of 5- ALA in improving the extent of resection when compared to white light microscopy. A systematic review on the topic had a similar conclusion. Few studies have also hinted on a high false negative rate with the use of this technique

Prognostic significance of IDH 1 mutation in patients with glioblastoma multiforme

Focus of brain tumour research is shifting towards tumour genesis and genetics, and possible development of individualized treatment plans. Genetic analysis shows recurrent mutation in isocitrate dehydrogenase (IDH1) gene in most Glioblastoma multiforme (GBM) cells. In this review we evaluated the prognostic significance of IDH 1 mutation on the basis of published evidence. Multiple retrospective clinical analyses correlate the presence of IDH1 mutation in GBM with good prognostic outcomes compared to wild-type IDH1. A systematic review reported similar results. Based on the review of current literature IDH1 mutation is an independent factor for longer overall survival (OS) and progression free survival (PFS) in GBM patients when compared to wild-type IDH1. The prognostic significance opens up new avenues for treatment

Mapping of randomly amplified polymorphic DNA primer (RAPD) on chromosome 2A of common wheat

Randomly amplified polymorphic DNA primers (RAPDs) were mapped on chromosomes 2A of wheat genotypes using “Chinese Spring” nullisomic-tetrasomic lines. One particular pair of chromosome was absent and another homologous pair was present in the extra dose. Genomic DNA was isolated from two genetic stocks viz; NT1D1B and NT2A2B. Polymerase chain reaction (PCR) were conducted using RAPD primers GLC-07 and GLB-11. PCR amplification using primer GLC-07 produced single band of approximately 1100 bp in both the genetic stocks, indicating that the primer was annealed to a loci other than chromosome 2A. RAPD primer GLB-11 amplified a polymorphic allele of approximately 500 bp which was present in NT1D1B but was absent in NT2A2B, indicating that the locus was present on chromosome 2A of common wheat. Hence, this marker (GLB-11) can reliably be used to keep track of chromosome 2A of wheat.Key words: Wheat, randomly amplified polymorphic DNA primer (RAPD), mapping, chromosomes, homologous, genomes

Role of intra-operative MRI (iMRI) in improving extent of resection and survival in patients with glioblastoma multiforme

Multiple intraoperative aids have been introduced to improve the extent of resection (EOR) in Glioblastoma Multiforme (GBM) patients, avoiding any new neurological deficits. Intraoperative MRI (iMRI) has been debated for its utility and cost for nearly two decades in neurosurgical literature. Review of literature suggests improved EOR in GBM patients who underwent iMRI assisted surgical resections leading to higher overall survival (OS) and progression free survival (PFS). iMRI provides real time intraoperative imaging with reasonable quality. Higher risk for new postoperative deficits with increased EOR is not reported in any study using iMRI. The level of evidence regarding prognostic benefits of iMRI is still of low quality

Resilience And Academic Achievement Of Male And Female Secondary Level Students In Pakistan

Resilience is the ability to succeed despite barriers that make it difficult for the students to succeed. The purpose of this study was to investigate the relationship between resilience and academic achievement of secondary level students of Gujranwala, Pakistan. A Resilience scale was used to collect data. The sample consisted of 127 secondary students, including 52 boys and 75 girls. The data revealed that there was no association between resilience and achievement as measured through marks obtained in 10th grade. The boys are more resilient than girls at the secondary level in Pakistan. &nbsp

Preparation of ZnO-SrO-B2O3 Glass Systems Doped with Dy2O3 for the White Light Emission Material Application

ZnO-SrO-B2O3 glasses doped with Dy3+ ions were prepared by a conventional melt quenching technique. The molar volume density and refractive index tends to increase with increasing of Dy2O3 concentration. The absorption bands show energy levels transition from 6H15/2 ground state to excited states such as 781 nm (6F3/2), 801 nm (6F5/2), 895 nm (6F7/2), 1083 nm (6F9/2), 1254 nm (6F11/2) and 1661 nm (6H11/2), and the intensity of the peak at 1254 nm is the highest. The excitation spectra of the 7 peaks glass sample were found in the wavelength range of 320-470 nm with the highest intensity peak at 386 nm. The emission spectra represent four emission bands, and all emission bands are over the visible range. The peak at 575 nm is the highest intensity peak. The CIE chromaticity (x,y) coordinates fall in the white light region of the CIE chromaticity diagram. The experimental decay time (τexp) of 6H13/2 transition of Dy3+ ions obtained from the measurement tends to increase with increasing of Dy2O3 concentration. These results show the potential for use in white LED applications