Using the Geology of Your Neighbourhood and City for Geoscience Outreach

Most Canadians live, work and attend school in urban areas. Your neighbour-hood has wonders such as snow-bank stratigraphy, sidewalk sedimentology, and building stone. Urban fieldtrips require little money and little time to run and they can inspire participants. An inner-city school teacher confirmed my belief in urban fieldtrips when she said, “I’ve never been able to take my students anywhere but we can now take a city bus downtown and see the world. Thank You!” So open your eyes to the grand world of geology around you. Take others on a neighbourhood trip; you will inspire, motivate and educate them. SOMMAIRE La majorité des Canadiens vivent, travaillent et étudient en milieu urbain. Votre voisinage même offre des occasions d’émerveillement comme des exemples de stratigraphie de bancs de neige, de sédimentologie des trottoirs, et de pierres de construction. Les excursions urbaines sont peu coûteuses, prennent peu de temps et peu-vent s’avérer stimulantes pour leurs participants. Une enseignante d’une école en milieu urbain a confirmé mes idées sur les excursions urbaines lorsqu’elle a déclaré, « Je n’avais jamais pu sortir mes élèves, mais maintenant, nous pouvons prendre l’autobus et voir le monde, grâce à vous. » Soyez donc à l’affût de l’univers géologique qui pointe dans votre milieu. Amener les gens de votre entourage en excursion; vous les aurez intéressés, motivés et éduqués

Twisted Sector Yukawa Couplings For The ZM×ZN{\bf Z}_M\times {\bf Z}_N Orbifolds

The moduli dependent Yukawa couplings between twisted sectors of ${\bf Z}_M\times {\bf Z}_N$ Coxeter orbifolds are studied.Comment: 40 pages, SUSX-TH-92/1

Background Symmetries In Orbifolds With Discrete Wilson Lines

Target space symmetries are studied for orbifold compactified string theories containing Wilson line background fields. The symmetries determined are for those moduli which contribute to the string loop threshold corrections of the gauge coupling constants. The groups found are subgroups of the modular group $PSL(2, Z)$ and depend on the choice of discrete Wilson lines and the shape of the underlying six-dimensional lattice.Comment: 31 pages, QMW--TH--94/0

Yukawa Couplings involving Excited Twisted Sector States for ZM×ZN{\bf Z}_M\times {\bf Z}_N Orbifolds

A study is made for ${\bf Z}_M\times {\bf Z}_N$ orbifolds of the modification of the form of the twisted sector Yukawa couplings when some of the states involved are excited twisted sectors rather than twisted sector ground states.Comment: 15 pages, SUSX--TH--93/1

Yukawa Couplings involving Excited Twisted Sector States for ZN{\bf Z}_N and ZM×ZN{\bf Z}_M\times {\bf Z}_N Orbifolds

We study the Yukawa couplings among excited twist fields which might arise in the low-energy effective field theory obtained by compactifying the heterotic string on ${\bf Z}_N$ and ${\bf Z}_M\times {\bf Z}_N$ orbifolds.Comment: SUSX--TH--93/12, 31 page

From Yang-Mills Lagrangian to MHV Diagrams

We prove the equivalence of a recently suggested MHV-formalism to the standard Yang-Mills theory. This is achieved by a formally non-local change of variables. In this note we present the explicit formulas while the detailed proofs are postponed to a future publication.Comment: Latex,11 pages, minor changes, reference added, version to appear in JHE

Gauge Coupling Constant Unification With Planck Scale Values Of Moduli

Convergence of the standard model gauge coupling constants to a common value at around $2\times 10^{16}$ GeV is studied in the context of orbifold theories where the modular symmetry groups for $T$ and $U$ moduli are broken to subgroups of $PSL(2, Z)$. The values of the moduli required for this unification of coupling constants are studied for this case and also for the case where string unification is accompanied by unification to a gauge group larger then $SU(3)\times SU(2)\times U(1).$Comment: Tex, 15 pages, minor typos corrected and some references adde

Appraisal and composition of some traditional complementary foods for infant nutrition in Sierra Leone

Open Access Article; Published online: 09 Mar 2020Malnutrition among infants in Sierra Leone still ranks one of the highest globally. Potency of some locally-formulated complementary food at resolving the problem had been proven. The experiment aimed at evaluating nutrient contents in traditional complementary foods consumed by infants in Eastern and Northern regions of Sierra Leone was carried out between 2016 and 2018. Ten common recipes identified through semi-structured questionnaire were standardized and analyzed using standard laboratory methods. Data were analyzed using SAS statistical package while means were separated using the new Duncan’s Multiple Range Test. Results showed that Bennie-mix, pamahun, as well as pap prepared from rice, millet and rice-one pot are richer in protein content (9.92% – 16.87%) and essential micronutrients (Iron ranged from 0.45mg – 3.58mg and zinc ranged from 1.24mg – 4.38mg). phytate (0.61mg – 3.76mg) and trypsin inhibitors (0.26mg – 5.79mg) which were low in all the selected samples as recommended by WHO. It can be concluded that four out of the ten standardized traditional complementary foods are rich in macronutrient but required enhancement of the micronutrients

A thermoresponsive and magnetic colloid for 3D cell expansion and reconfiguration

A dual thermoresponsive and magnetic colloidal gel matrix is described for enhanced stem-cell culture. The combined properties of the material allow enzyme-free passaging and expansion of mesenchymal stem cells, as well as isolation of cells postculture by the simple process of lowering the temperature and applying an external magnetic field. The colloidal gel can be reconfigured with thermal and magnetic stimuli to allow patterning of cells in discrete zones and to control movement of cells within the porous matrix during culture

Localized anomalies in orbifold gauge theories

We apply the path-integral formalism to compute the anomalies in general orbifold gauge theories (including possible non-trivial Scherk-Schwarz boundary conditions) where a gauge group G is broken down to subgroups H_f at the fixed points y=y_f. Bulk and localized anomalies, proportional to \delta(y-y_f), do generically appear from matter propagating in the bulk. The anomaly zero-mode that survives in the four-dimensional effective theory should be canceled by localized fermions (except possibly for mixed U(1) anomalies). We examine in detail the possibility of canceling localized anomalies by the Green-Schwarz mechanism involving two- and four-forms in the bulk. The four-form can only cancel anomalies which do not survive in the 4D effective theory: they are called globally vanishing anomalies. The two-form may cancel a specific class of mixed U(1) anomalies. Only if these anomalies are present in the 4D theory this mechanism spontaneously breaks the U(1) symmetry. The examples of five and six-dimensional Z_N orbifolds are considered in great detail. In five dimensions the Green-Schwarz four-form has no physical degrees of freedom and is equivalent to canceling anomalies by a Chern-Simons term. In all other cases, the Green-Schwarz forms have some physical degrees of freedom and leave some non-renormalizable interactions in the low energy effective theory. In general, localized anomaly cancellation imposes strong constraints on model building.Comment: 30 pages, 4 figures. v2: reference adde