Tracing plant source water dynamics during drought by continuous transpiration measurements : An in-situ stable isotope approach

Publisher Copyright: © 2022 The Authors. Plant, Cell & Environment published by John Wiley & Sons Ltd.The isotopic composition of xylem water (δX) is of considerable interest for plant source water studies. In-situ monitored isotopic composition of transpired water (δT) could provide a nondestructive proxy for δX-values. Using flow-through leaf chambers, we monitored 2-hourly δT-dynamics in two tropical plant species, one canopy-forming tree and one understory herbaceous species. In an enclosed rainforest (Biosphere 2), we observed δT-dynamics in response to an experimental severe drought, followed by a 2H deep-water pulse applied belowground before starting regular rain. We also sampled branches to obtain δX-values from cryogenic vacuum extraction (CVE). Daily flux-weighted δ18OT-values were a good proxy for δ18OX-values under well-watered and drought conditions that matched the rainforest's water source. Transpiration-derived δ18OX-values were mostly lower than CVE-derived values. Transpiration-derived δ2HX-values were relatively high compared to source water and consistently higher than CVE-derived values during drought. Tracing the 2H deep-water pulse in real-time showed distinct water uptake and transport responses: a fast and strong contribution of deep water to canopy tree transpiration contrasting with a slow and limited contribution to understory species transpiration. Thus, the in-situ transpiration method is a promising tool to capture rapid dynamics in plant water uptake and use by both woody and nonwoody species.Peer reviewe

Schizophrenia and psychotic symptoms in families of two American Indian tribes

Abstract Background The risk of schizophrenia is thought to be higher in population isolates that have recently been exposed to major and accelerated cultural change, accompanied by ensuing socio-environmental stressors/triggers, than in dominant, mainstream societies. We investigated the prevalence and phenomenology of schizophrenia in 329 females and 253 males of a Southwestern American Indian tribe, and in 194 females and 137 males of a Plains American Indian tribe. These tribal groups were evaluated as part of a broader program of gene-environment investigations of alcoholism and other psychiatric disorders. Methods Semi-structured psychiatric interviews were conducted to allow diagnoses utilizing standardized psychiatric diagnostic criteria, and to limit cultural biases. Study participants were recruited from the community on the basis of membership in pedigrees, and not by convenience. After independent raters evaluated the interviews blindly, DSM-III-R diagnoses were assigned by a consensus of experts well-versed in the local cultures. Results Five of the 582 Southwestern American Indian respondents (prevalence = 8.6 per 1000), and one of the 331 interviewed Plains American Indians (prevalence = 3.02 per 1000) had a lifetime diagnosis of schizophrenia. The lifetime prevalence rates of schizophrenia within these two distinct American Indian tribal groups is consistent with lifetime expectancy rates reported for the general United States population and most isolate and homogeneous populations for which prevalence rates of schizophrenia are available. While we were unable to factor in the potential modifying effect that mortality rates of schizophrenia-suffering tribal members may have had on the overall tribal rates, the incidence of schizophrenia among the living was well within the normative range. Conclusion The occurrence of schizophrenia among members of these two tribal population groups is consistent with prevalence rates reported for population isolates and in the general population. Vulnerabilities to early onset alcohol and drug use disorders do not lend convincing support to a diathesis-stressor model with these stressors, commonly reported with these tribes. Nearly one-fifth of the respondents reported experiencing psychotic-like symptoms, reaffirming the need to examine sociocultural factors actively before making positive diagnoses of psychosis or schizophrenia.</p

Inverse plan optimization accounting for random geometric uncertainties with a multiple instance geometry approximation (MIGA)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135142/1/mp1016.pd

Better mental health in children of Vietnamese refugees compared with their Norwegian peers - a matter of cultural difference?

<p>Abstract</p> <p>Background</p> <p>There are conflicting results on whether immigrant children are at a heightened risk of mental health problems compared with native youth in the resettlement country.</p> <p>The objective of the study</p> <p>To compare the mental health of 94 Norwegian-born children from a community cohort of Vietnamese refugees, aged 4 - 18 years, with that of a Norwegian community sample.</p> <p>Methods</p> <p>The SDQ was completed by two types of informants; the children's self-reports, and the parents' reports, for comparison with Norwegian data from the Health Profiles for Children and Youth in the Akershus study.</p> <p>Results</p> <p>The self-perceived mental health of second-generation Vietnamese in Norway was better than that of their Norwegian compatriots, as assessed by the SDQ. In the Norwegian-Vietnamese group, both children and parents reported a higher level of functioning.</p> <p>Conclusion</p> <p>This surprising finding may result from the lower prevalence of mental distress in Norwegian-Vietnamese children compared with their Norwegian peers, or from biased reports and cultural differences in reporting emotional and behavioural problems. These findings may represent the positive results of the children's bi-cultural competencies.</p

Trauma, poverty and mental health among Somali and Rwandese refugees living in an African refugee settlement – an epidemiological study

Onyut LP, Neuner F, Ertl V, Schauer E, Odenwald M, Elbert T. Trauma, poverty and mental health among Somali and Rwandese refugees living in an African refugee settlement – an epidemiological study. Conflict and Health. 2009;3(1):6.Background: The aim of this study was to establish the prevalence of posttraumatic stress disorder (PTSD) and depression among Rwandese and Somali refugees resident in a Ugandan refugee settlement, as a measure of the mental health consequences of armed conflict, as well as to inform a subsequent mental health outreach program. The study population comprised a sample from 14400 (n = 519 Somali and n = 906 Rwandese) refugees resident in Nakivale refugee settlement in South Western Uganda during the year 2003. Methods: The Posttraumatic Diagnostic Scale (PDS) and the Hopkins Symptom Checklist 25 were used to screen for posttraumatic stress disorder and depression. Results: Thirty two percent of the Rwandese and 48.1% of the Somali refugees were found to suffer from PTSD. The Somalis refugees had a mean of 11.95 (SD = 6.17) separate traumatic event types while the Rwandese had 8.86 (SD = 5.05). The Somalis scored a mean sum score of 21.17 (SD = 16.19) on the PDS while the Rwandese had a mean sum score of 10.05 (SD = 9.7). Conclusion: Mental health consequences of conflict remain long after the events are over, and therefore mental health intervention is as urgent for post-conflict migrant populations as physical health and other emergency interventions. A mental health outreach program was initiated based on this study

Temporal changes in HCV genotype distribution in three different high risk populations in San Francisco, California

Abstract Background Hepatitis C virus (HCV) genotype (GT) has become an important measure in the diagnosis and monitoring of HCV infection treatment. In the United States (U.S.) HCV GT 1 is reported as the most common infecting GT among chronically infected patients. In Europe, however, recent studies have suggested that the epidemiology of HCV GTs is changing. Methods We assessed HCV GT distribution in 460 patients from three HCV-infected high risk populations in San Francisco, and examined patterns by birth cohort to assess temporal trends. Multiple logistic regression was used to assess factors independently associated with GT 1 infection compared to other GTs (2, 3, and 4). Results Overall, GT 1 was predominant (72.4%), however younger injection drug users (IDU) had a lower proportion of GT 1 infections (54.7%) compared to older IDU and HIV-infected patients (80.5% and 76.6%, respectively). Analysis by birth cohort showed increasing proportions of non-GT 1 infections associated with year of birth: birth before 1970 was independently associated with higher adjusted odds of GT 1: AOR 2.03 (95% CI: 1.23, 3.34). African-Americans as compared to whites also had higher adjusted odds of GT 1 infection (AOR: 3.37; 95% CI: 1.89, 5.99). Conclusions Although, HCV GT 1 remains the most prevalent GT, especially among older groups, changes in GT distribution could have significant implications for how HCV might be controlled on a population level and treated on an individual level

Examining the effects of social media in co-located classrooms: A case study based on SpeakUp

The broad availability of mobile computing devices has prompted the apparition of social media applications that support teaching and learning. However, so far, there is conflicting evidence as to whether the benefits such applications provide in terms of engagement and interaction, outweigh their potential cost as a source of distraction. To help in clarifying these issues, the present paper presents a case study on the impact of using SpeakUp (an app aimed at promoting student participation through anonymous chatrooms) in an authentic face-to-face learning scenario. Concretely, we focus on the connection between SpeakUp and the student engagement, distraction, social interaction, and the influence of the teachers' style. Our findings highlight that SpeakUp favored students' engagement and social interaction, but they also point towards its limitations in keeping students communicating about content relevant to the course