Greater Sudbury, Canada
Greater Sudbury, Canada

Laurentian University , which was incorporated on March 28, 1960, is a mid-sized bilingual university in Greater Sudbury, Ontario, Canada.While primarily focusing on undergraduate programming, Laurentian also features the east campus of Canada's newest medical school - the Northern Ontario School of Medicine, which opened in 2005. Its school of Graduate Studies offers a growing number of graduate-level degrees. Laurentian is the largest bilingual provider of distance education in Canada. Wikipedia.

Time filter

Source Type

Lesbarreres D.,Laurentian University | Fahrig L.,Carleton University
Trends in Ecology and Evolution | Year: 2012

Roads impede animal movement, which decreases habitat accessibility and reduces gene flow. Ecopassages have been built to mitigate this but there is little research with which to evaluate their effectiveness, owing to the difficulty in accessing results of existing research; the lack of scientific rigor in these studies; and the low priority of connectivity planning in road projects. In this article, we suggest that the imperative for improving studies of ecopassage effectiveness is that road ecology research should be included from the earliest stages of road projects onwards. This would enable before-after-control-impact (BACI) design research, producing useful information for the particular road project as well as rigorous results for use in future road mitigation. Well-designed studies on ecopassage effectiveness could help improve landscape connectivity even with the increasing number and use by traffic of roads. © 2012 Elsevier Ltd.

Walcarius A.,CNRS Laboratory of Physical Chemistry and Microbiology for the Environment | Mercier L.,Laurentian University
Journal of Materials Chemistry | Year: 2010

A review with ca. 400 references is provided dealing with the use of mesoporous silica and organically-modified silica-based materials for removal of inorganic and organic pollutants from aqueous solutions. After having briefly discussed the interest of functionalized mesoporous silica for environmental remediation purposes, the various synthetic methods to prepare such nanoengineered adsorbents are described. Then, their application to the removal of heavy metal species, toxic anions, radionuclides, and a wide range of organic pollutants is presented in a comprehensive way with the help of extensive tables and some illustrating figures. © 2010 The Royal Society of Chemistry.

Kamber B.S.,Laurentian University
Chemical Geology | Year: 2010

Ancient sediments that precipitated from seawater contain elemental and isotopic records that have yielded mutually exclusive conclusions regarding the supply of elements. Certain isotopic data (e.g. Sr and Nd) appear to imply a preponderance of hydrothermal flux while a number of elemental abundances (e.g. Eu and Y) apparently require a much greater flux from land. Refined insight into the origin of the marine rare earth element pattern is shown to strengthen the requirement for a significant elemental flux from the early Earth landmass. Here it is proposed that the Archean landmass included a significant fraction of emerged oceanic plateaus in addition to the continents. Alternatively, repeated volcanic resurfacing of the continents with mantle-derived basalt increased continental element flux.Model calculations for the Eo- to Neo-Archean marine rare earth element pattern require that ca. 20% of the planet was occupied by volcanic plateaus (compared to the 3% of today). Not only were the plateaus more extensive but they were also thicker. A tectonic picture emerges in which the Archean ocean basins may have consisted of lithosphere of lesser (similar to present day) thickness populated by relatively short-lived (several 100. Ma at most) plateaus of considerable thickness.One important feature that distinguishes the Archean from the modern land surface is the preponderance of freshly erupted volcanic rocks. Due to the instability of high-Mg rocks under weathering, a substantial land surface of this type would have had importance both for the supply of nutrients to the ocean, as well as a potential sink for water and atmospheric gases. For example, the disappearance of high-MgO land towards the end of the Archean may have reduced the supply of Ni to the ocean and brought to an end the supremacy of methanogens, ultimately leading to the great oxidation event. Furthermore, both the submarine and subaerial volcanic resurfacing of the continents and oceanic plateaus may have led to high 18O/16O alteration products and isotopically light seawater, removing the need for an unreasonably hot early Earth surface temperature.Hot mantle plumes capable of producing vast volcanic plateaus may thus have played a major role in regulating the composition of the early hydrosphere and biosphere and indirectly also the evolution of the atmosphere. © 2010 Elsevier B.V.

Cai M.,Laurentian University
Rock Mechanics and Rock Engineering | Year: 2010

By applying the Griffith stress criterion of brittle failure, one can find that the uniaxial compressive strength (σc) of rocks is eight times the value of the uniaxial tensile strength (σt). The Griffith strength ratio is smaller than what is normally measured for rocks, even with the consideration of crack closure. The reason is that Griffith's theories address only the initiation of failure. Under tensile conditions, the crack propagation is unstable so that the tensile crack propagation stress (σcd)t and the peak tensile strength rt are almost identical to the tensile crack initiation stress (σci) t. On the other hand, the crack growth after crack initiation is stable under a predominantly compressive condition. Additional loading is required in compression to bring the stress from the crack initiation stress rci to the peak strength σc. It is proposed to estimate the tensile strength of strong brittle rocks from the strength ratio of R = σc/|σt| = 8σc/ σci. The term σc/σci accounts for the difference of crack growth or propagation in tension and compression in uniaxial compression tests. σc/σci depends on rock heterogeneity and is larger for coarse grained rocks than for fine grained rocks. σci can be obtained from volumetric strain measurement or acoustic emission (AE) monitoring. With the strength ratio R determined, the tensile strength can be indirectly obtained from |σt| = σc/R = σci/8. It is found that the predicted tensile strengths using this method are in good agreement with test data. Finally, a practical estimate of the Hoek-Brown strength parameter mi is presented and a bi-segmental or multi-segmental representation of the Hoek-Brown strength envelope is suggested for some brittle rocks. In this fashion, the rock strength parameters like σt and mi, which require specialty tests such as direct tensile (or Brazilian) and triaxial compression tests for their determination, can be reasonably estimated from uniaxial compression tests. © Springer-Verlag 2009.

Cai M.,Laurentian University
Tunnelling and Underground Space Technology | Year: 2013

Rock support in burst-prone ground requires a good understanding of rock mass behavior under high stress conditions and the behavior and functionality of each rock support element as well as the behavior of the rock support system. Seven principles which can lead to making the right judgment and decision with regards to rock support design in burst-prone ground are presented in this paper. A good understanding of these principles helps ground control engineers to master the art of rock support in burst-probe grounds so as to develop useful methodology for design. © 2013 Elsevier Ltd.

Persinger M.A.,Laurentian University
Current Medicinal Chemistry | Year: 2010

The myriads of molecular pathways that have been measured to understand the physical bases of neuronal and other cellular functions have exceeded classical comprehension. In the tradition of Bohr and Schrodinger, the hypothesis is developed that molecular pathways are simply epiphenomenal transports of quanta with increments in the order of 10-20 J. Experimental measurements of photon emissions from cell cultures and the serial steps of phosphorylation in general molecular pathways and transformations in chromophores supported this contention. This discrete value is also associated with action potentials, intersynaptic events, the biophysical bases of membrane potentials, the numbers of action potentials per cell from magnetic energy potential, and the interionic distances around membranes. Consideration of information as discrete increments of energy may allow greater experimental control and external intervention of pathways relevant to medicinal chemistry. © 2010 Bentham Science Publishers Ltd.

Cancerous tumours vary significantly in their response to chemotherapy agents. Currently, it is difficult to reliably assess the level of tumour responsiveness to a chemotherapy regimen during or post-administration. Biomarkers of tumour sensitivity to chemotherapy agents have hitherto been unknown. Such a biomarker would expedite identification of nonresponsive patients, who may then switch to other, possibly more effective regimens. The present invention provides a method for determining tumour responsiveness to a chemotherapy agent, wherein RNA is isolated from tumour cells of a patient before, during, and after chemotherapy. The quality of the RNA can be determined by capillary electrophoresis and assignment of an RNA integrity number (RIN). RIN values during and/or after chemotherapy are inversely proportionate to the level of tumour responsiveness. The tumour RIN is an easily accessed biomarker of tumour responsiveness to chemotherapy. The tumour RIN may also be used to assess the efficacy of a chemotherapy regimen.

Systems and methods are provided for the detection of conductive bodies using three-component electric or magnetic dipole transmitters. The fields from multiple transmitters can be combined to enhance fields at specific locations and in specific orientation. A one- two- or three-component receiver or receiver array is provided for detecting the secondary field radiated by a conductive body. The data from multiple receivers can be combined to enhance the response at a specific sensing location with a specific orientation. Another method is provided in which a three-component transmitter and receiver are separated by an arbitrary distance, and where the position and orientation of the receiver relative to the transmitter are calculated, allowing the response of a highly conductive body to be detected.

Laurentian University | Date: 2014-01-28

Compositions described herein are purposed to attract gravid mosquitoes to oviposit in a preferred environment. The composition for directing the oviposition of mosquitoes comprises one or more attractants and NPK additive, wherein the NPK additive is mixture that contain chemical elements nitrogen, phosphorus and potassium. The attractants can be modified to provide a composition for facilitating the oviposition of different kind of mosquito. The composition described above, can be modified to provide a composition for facilitating the oviposition of the Anopheles species of Culicidae. The composition can also include cooked whey, n-heneicosane and/or tetradecanoic acid methyl ester to provide a composition for facilitating the oviposition of the Aedes species of Culicidae. The composition can also be modified to provide a composition for facilitating the oviposition of the Culex species of Culicidae.

Cai M.,Laurentian University
Rock Mechanics and Rock Engineering | Year: 2013

In the present study, fracture initiation and propagation from a pre-existing plane interface in a Brazilian disc is investigated using a finite-discrete element combined method. Different fracture patterns, depending on the frictional resistance of the pre-existing crack or interface, are observed from the numerical simulation. It is found that when there is no or very little frictional resistance on the surfaces of the pre-existing crack, the primary fractures (wing cracks), which are tensile in nature and are at roughly right angles to the pre-existing crack, start from the tips of the pre-existing crack. As the friction coefficient increases, the wing cracks' initiation locations deviate from the crack tips and move toward the disc center. Secondary fractures, which are also tensile in nature, initiate from the disc boundary and occur only when the length of the pre-existing crack is sufficiently long. The secondary fractures are roughly sub-parallel to the pre-existing crack. The failure load is found to be influenced by the friction coefficient of the pre-existing crack. A 38 % failure load increase can result when the friction coefficient changes from 0 to 1. A good understanding of the fracture initiation and propagation in the forms of primary and secondary fractures provides insight into explaining some fracture patterns observed underground. © 2012 Springer-Verlag Wien.

Loading Laurentian University collaborators
Loading Laurentian University collaborators