Estimating river flows across basins using water isotopes

Global warming is expected to dramatically alter the timing and quantity of water within the nation’s river systems; however, these impacts will be heterogeneous both within river basins and across regions. A detailed understanding of the spatial and temporal dynamics of water sources across river networks is therefore central to managing the impacts of climate change. Stable isotopes of water (2H:1H & 18O:16O) provide an emerging method for elucidating the contributions of varying water sources to rivers. Because the stable isotope composition of precipitation varies geographically, variation in the stable isotope composition of river water indicates the volume-weighted integration of source water within the watershed. During September 2017, we collected stable isotope samples across five river networks in the Pacific Northwest and SE Alaska that span a range of hydraulic and climatic conditions: the Snoqualmie, Green, Wenatchee, and Skagit Rivers as well as Cowee Creek. For each basin we regressed isotope values against computed spatial covariates such as elevation, mean annual precipitation, and geology to determine which covariates explained the greatest proportion of isotopic variation. We compared best-fit models for each basin to examine how major correlates of isotopic variation differed among river networks. Results indicate that rivers on the west side of the Cascades display a far stronger relationship to elevation than the Wenatchee. We then built spatial stream network models to display and communicate spatial patterns of isotopic variation within the Snoqualmie and Wenatchee basins. We also employed a mixing-model approach to determine where sources of water in the mainstems of each river originated (e.g. snow zone, rain-on-snow zone, or rain) during summer low flow conditions. Our results can be used by managers and watershed groups to estimate how river flows may shift in a changing climate

COVID-19 Risk Factors for Cancer Patients: A First Report with Comparator Data from COVID-19 Negative Cancer Patients

none32siSimple SummaryThe COVID-19 pandemic has had a detrimental impact on cancer patients globally. Whilst there are several studies looking at the potential risk factors for COVID-19 disease and related death, most of these include non-cancerous patients as the COVID-19 negative comparator group, meaning it is difficult to draw hard conclusions as to the implications for cancer patients. In our study, we utilized data from over 2000 cancer patients from a large tertiary Cancer Centre in London. In summary, our study found that patients who are male, of Black or Asian ethnicity, or with a hematological malignancy are at an increased risk of COVID-19. The use of cancer patients as the COVID-19 negative comparator group is a major advantage to the study as it means we can better understand the true impact of COVID-19 on cancer patients and identify which factors pose the biggest risk to their likelihood of infection with SARS-CoV2.Very few studies investigating COVID-19 in cancer patients have included cancer patients as controls. We aimed to identify factors associated with the risk of testing positive for SARS CoV2 infection in a cohort of cancer patients. We analyzed data from all cancer patients swabbed for COVID-19 between 1(st) March and 31(st) July 2020 at Guy's Cancer Centre. We conducted logistic regression analyses to identify which factors were associated with a positive COVID-19 test. Results: Of the 2152 patients tested for COVID-19, 190 (9%) tested positive. Male sex, black ethnicity, and hematological cancer type were positively associated with risk of COVID-19 (OR = 1.85, 95%CI:1.37-2.51; OR = 1.93, 95%CI:1.31-2.84; OR = 2.29, 95%CI:1.45-3.62, respectively) as compared to females, white ethnicity, or solid cancer type, respectively. Male, Asian ethnicity, and hematological cancer type were associated with an increased risk of severe COVID-19 (OR = 3.12, 95%CI:1.58-6.14; OR = 2.97, 95%CI:1.00-8.93; OR = 2.43, 95%CI:1.00-5.90, respectively). This study is one of the first to compare the risk of COVID-19 incidence and severity in cancer patients when including cancer patients as controls. Results from this study have echoed those of previous reports, that patients who are male, of black or Asian ethnicity, or with a hematological malignancy are at an increased risk of COVID-19.openRussell, Beth; Moss, Charlotte L; Palmer, Kieran; Sylva, Rushan; D'Souza, Andrea; Wylie, Harriet; Haire, Anna; Cahill, Fidelma; Steel, Renee; Hoyes, Angela; Wilson, Isabelle; Macneil, Alyson; Shifa, Belul; Monroy-Iglesias, Maria J; Papa, Sophie; Irshad, Sheeba; Ross, Paul; Spicer, James; Kordasti, Shahram; Crawley, Danielle; Zaki, Kamarul; Sita-Lumsden, Ailsa; Josephs, Debra; Enting, Deborah; Swampillai, Angela; Sawyer, Elinor; Fields, Paul; Wrench, David; Rigg, Anne; Sullivan, Richard; Van Hemelrijck, Mieke; Dolly, SaoirseRussell, Beth; Moss, Charlotte L; Palmer, Kieran; Sylva, Rushan; D'Souza, Andrea; Wylie, Harriet; Haire, Anna; Cahill, Fidelma; Steel, Renee; Hoyes, Angela; Wilson, Isabelle; Macneil, Alyson; Shifa, Belul; Monroy-Iglesias, Maria J; Papa, Sophie; Irshad, Sheeba; Ross, Paul; Spicer, James; Kordasti, Shahram; Crawley, Danielle; Zaki, Kamarul; Sita-Lumsden, Ailsa; Josephs, Debra; Enting, Deborah; Swampillai, Angela; Sawyer, Elinor; Fields, Paul; Wrench, David; Rigg, Anne; Sullivan, Richard; Van Hemelrijck, Mieke; Dolly, Saoirs