Effects of Chronic Electronic Cigarette Use on Glucose Metabolism

Traditional cigarette usage has been linked to a number of nefarious metabolic effects, including insulin resistance; however, the effects of electronic cigarettes (E-cigs) are not currently known. Advertised as a safe alternative for traditional tobacco cigarettes, E-cigs still contain some of the same harmful chemicals as tobacco cigarettes. Through this study, we hope to gain perspective on whether e-cigs play into the development of altered glucose homeostasis. C57BL/6 mice were divided between E-cig (n=15) and control (n=15) groups and exposed to either cappuccino flavored E-cig vapor or filtered air for 4 h/d, 5 d/wk for 8 months. Fasting blood glucose (FBG) and glucose tolerance were observed after 6 months of exposure. Glucose was administered either orally or IP at 2g glucose/kg body mass. Following an overnight fast, an oral glucose tolerance test (OGTT) was performed prior to E-cig exposure; on a separate day another OGT was performed immediately after a 4-hour exposure period. In addition, an intraperitoneal glucose tolerance test (IPGTT) was performed immediately after a 4-hour exposure period in a subset of mice (N=4).;At the conclusion of 8 months of exposure, pancreas tissue was harvested and assessed in a subset of mice (n=6). Total body mass was similar between E-cig and air exposed groups at six months (E-cig: 28.7 +/-1.1g vs Control: 28.8 +/-1.45g) and eight months (E-cig: 29.5+/-1.62g vs Control: 28.9+/-1.06g). FBG prior to E-cig exposure tended to be higher in E-cig vs control mice (p=.13), while glucose following exposure were increased in the E-cig group (143.8+/-6mg/dL vs. 118.8+/-8mg/dL, p=0.05). During the IPGTT, E-cig animals presented with a higher peak blood glucose (225+/-7mg/dL vs. 180+/-15mg/dL, p=0.03), as well as a higher total area under the curve (AUC) than controls (18228 +/- 742 vs 15069 +/- 667 respectively, p=0.02). E-cig animals did not have a different ?-cell density, insulin positive area, or number of SIRT1(+) nuclei. However, SIRT1 density (determined by number of SIRT1(+) nuclei/islet area) was lower in E-cig mice versus control (E-cig: 2.8E-4 +/- 5.0E-5 nuclei/?m vs Controls: 4.4E-4 +/- 5.0E-5 nuclei/?m, p=0.05). Total SIRT1 (E-cig: 1449 +/- 301ng vs Control: 1297 +/- 251ng) and UCP2 (E-cig: 0.08 +/- 0.009 vs. Control: 0.10 +/- 0.01, AU) protein in the pancreas was not different between groups. In conclusion, chronic exposure to E-cig vapor resulted in modestly higher resting and stimulated blood glucose. Although total pancreatic SIRT1 protein levels were not affected, the density of SIRT1 positive ?-cells was reduced in E-cig animals. Future research needs to determine if other pancreatic proteins and mechanisms are negatively affected because of E-cig exposure

Agricultural Transformation in Rural Western Kenya: The Maize Crop in the Mt. Elgon Region, 1930-1950

Between 1930 and 1950 the Kenyan colonial government began an experiment with maize by attempting to introduce it as a major cash crop in the Mt. Elgon geographical region of Western Kenya. Part of a larger campaign concerning African agriculture in general, the colonial government pursued various policies aimed at raising the price of African-grown maize and improving its production. Just as these policies began to provide an atmosphere favorable to African maize export growth, however, the colonial government reversed several of these policies. Using the case of maize in the Mt. Elgon region, this research illustrates how the failure of economic development policies in colonized or less-developed countries is often due to contradictory or unfit governmental policies. This is in contrast to standard perceptions regarding the inability of the colonized or less-developed peoples to adapt to the policies

The effects of soaking and storage on the radiosensitivity of barley seeds

The purpose of this study was to determine the extent to which the effects of irradiation on barley seed could be modified by varying the moisture content of the seed and the storage time

Band Gaps and Localization in Acoustic Propagation in Water with Air-cylinders

Multiple scattering of waves leads to many peculiar phenomena such as complete band gaps in periodic structures and wave localization in disordered media. Within a band gap excitations are evanescent; when localized they remain confined in space until dissipated. Here we report acoustic band gap and localization in a 2D system of air-cylinders in water. Exact numerical calculations reveal the unexpected result that localization is relatively independent of the precise location or organization of the scatterers. Localization occurs within a finite region of frequencies, coincident with the complete band gap predicted by a conventional band structure calculation for a periodic lattice of scatterers. Inside the gap or localization regime, a previously uninvestigated stable collective behavior of the cylinders appears.Comment: 10 pages, 4 figure