Time filter

Source Type

Phoenix, AZ, United States

Schumacher F.R.,University of Southern California | Schmit S.L.,University of Southern California | Jiao S.,Fred Hutchinson Cancer Research Center | Edlund C.K.,University of Southern California | And 109 more authors.
Nature Communications | Year: 2015

Genetic susceptibility to colorectal cancer is caused by rare pathogenic mutations and common genetic variants that contribute to familial risk. Here we report the results of a two-stage association study with 18,299 cases of colorectal cancer and 19,656 controls, with follow-up of the most statistically significant genetic loci in 4,725 cases and 9,969 controls from two Asian consortia. We describe six new susceptibility loci reaching a genome-wide threshold of P<5.0E-08. These findings provide additional insight into the underlying biological mechanisms of colorectal cancer and demonstrate the scientific value of large consortia-based genetic epidemiology studies. © 2015 Macmillan Publishers Limited.

Hamdan A.,Phoenix College | Schmeeckle M.,Arizona State University
Environmental Earth Sciences | Year: 2016

In this study, two ephemeral streams are compared in assessing bio-geomorphic change to channels intersected by the Central Arizona Project (CAP) canal. Water and sediment are fully or partially restricted to move downstream due to the CAP canal, which acts as a dam to these streams. Upstream of traversed channels, vegetation cover has increased over time causing the development of a green-up area. Along the canal, several channels remain longitudinally connected via culvert or overchute to the downstream sections of the stream channels. The two streams examined both had longitudinal connectivity, but only one of the streams had a green-up area upstream. Field work and channel surveys reveal that this is due to the culvert’s peak discharge outflow. The stream with a developed green-up area had a culvert size that is approximately three times less than the discharge of this ephemeral stream causing the partial damming upstream during flow events. Green-up zones slowly enlarge over time as bed levels and adjacent desert surface heights increase from continual sediment deposition upstream causing the floodplain to laterally increase due to overbank flooding. It is estimated that the green-up area for the partially dammed stream will increase by approximately 1570 m2 over the next 36 years. Suggestions for urban and agricultural development are presented in this paper in relation to these dynamic green-up areas. Understanding biogeomorphic processes along dammed ephemeral streams lends valuable insight to riparian conservation efforts and future urban development plans in desert regions. © 2015, Springer-Verlag Berlin Heidelberg.

Hamdan A.,Phoenix College | Stromberg J.C.,Arizona State University
Journal of Arid Environments | Year: 2016

The Central Arizona Project (CAP) is a large canal system that traverses hundreds of ephemeral stream channels in the Sonoran Desert. This longitudinal barrier alters flow during runoff events, causing water to pond behind the canal's wall. We asked: How has riparian vegetation of the ephemeral streams changed over the course of 35 years in response to canal construction? We compared field data (vegetation volume, woody plant stem density and size, and herbaceous cover) collected in distinct zones located upstream and downstream of the canal to unaltered controls. By ponding water and inducing sedimentation of fine particles, the canal has created areas that support dense vegetation. The wettest zone has the greatest vegetation volume and plant height, and supports densities of Prosopis velutina that are six times greater than in the control zone. Larrea tridentata and other desert shrubs are displaced to the border of the wettest zone, but have greater height and stem diameter than typically occur in the desert owing to increased frequency of soil wetting in the canal-associated anthropogenic-floodplain. This research aids in understanding the impacts of canal barriers on desert riparian vegetation, and can be used to predict future outcomes of proposed canals in desert environments. © 2015 Elsevier Ltd.

Perotti A.L.,Phoenix College | Lam K.C.,Research Support Instruments, Inc. | Bay R.C.,A.T. Still University
Journal of Sport Rehabilitation | Year: 2010

Context: Electrical stimulation is often used to control edema formation after acute injury. However, it is unknown whether its theoretical benefits translate to benefits in clinical practice. Objectives: To systematically review the basic-science literature regarding the effects of high-voltage pulsed stimulation (HVPS) for edema control. Evidence Acquisition: CINAHL (1982 to February 2010), PubMed (1966 to February 2010), Medline (1966 to February 2010), and SPORTDiscus (1980 to February 2010) databases were searched for relevant studies using the following keywordsedema, electrical stimulation, high-volt electrical stimulation, and combinations of these terms. Reference sections of relevant studies were hand-searched. Included studies investigated HVPS and its effect on acute edema formation and included outcome measures specific to edema. Eleven studies met the inclusion criteria. Methodological quality and level of evidence were assessed for each included study. Effect sizes were calculated for primary edema outcomes. Evidence Synthesis: Studies were critiqued by electrical stimulation treatment parameters: mode of stimulation, polarity, frequency, duration of treatment, voltage, intensity, number of treatments, and overall time of treatments. The available evidence indicates that HVPS administered using negative polarity, pulse frequency of 120 pulses/s, and intensity of 90% visual motor contraction may be effective at curbing edema formation. In addition, the evidence suggests that treatment should be administered in either four 30-min treatment sessions (30-min treatment, 30-min rest cycle for 4 h) or a single, continuous180-min session to achieve the edemasuppressing effects. Conclusions: These findings suggest that the basic-science literature provides a general list of treatment parameters that have been shown to successfully manage the formation of edema after acute injury in animal subjects. These treatment parameters may facilitate future research related to the effects of HVPS on edema formation in humans and guide practical clinical use. © 2010 Human Kinetics, Inc.

Wyche K.F.,The University of Oklahoma Health Sciences Center | Pfefferbaum R.L.,Phoenix College | Pfefferbaum B.,The University of Oklahoma Health Sciences Center | Norris F.H.,Dartmouth College | And 2 more authors.
American Journal of Orthopsychiatry | Year: 2011

Community resilience activities were assessed in workplace teams that became first responders for Hurricane Katrina survivors. Community resilience was assessed by a survey, focus groups, and key informant interviews. On the survey, 90 first responders ranked their team's disaster response performance as high on community resilience activities. The same participants, interviewed in 11 focus groups and 3 key informant interviews, discussed how their teams engaged in community resilience activities to strengthen their ability to deliver services. Specifically, their resilient behaviors were characterized by: shared organizational identity, purpose, and values; mutual support and trust; role flexibility; active problem solving; self-reflection; shared leadership; and skill building. The implications for research, policy, practice, and education of professionals are discussed. © 2011 American Orthopsychiatric Association.

Discover hidden collaborations