Simulating rewetting events in intermittent rivers and ephemeral streams: A global analysis of leached nutrients and organic matter

Climate change and human pressures are changing the global distribution and the ex‐ tent of intermittent rivers and ephemeral streams (IRES), which comprise half of the global river network area. IRES are characterized by periods of flow cessation, during which channel substrates accumulate and undergo physico‐chemical changes (precon‐ ditioning), and periods of flow resumption, when these substrates are rewetted and release pulses of dissolved nutrients and organic matter (OM). However, there are no estimates of the amounts and quality of leached substances, nor is there information on the underlying environmental constraints operating at the global scale. We experi‐ mentally simulated, under standard laboratory conditions, rewetting of leaves, river‐ bed sediments, and epilithic biofilms collected during the dry phase across 205 IRES from five major climate zones. We determined the amounts and qualitative character‐ istics of the leached nutrients and OM, and estimated their areal fluxes from riverbeds. In addition, we evaluated the variance in leachate characteristics in relation to selected environmental variables and substrate characteristics. We found that sediments, due to their large quantities within riverbeds, contribute most to the overall flux of dis‐ solved substances during rewetting events (56%–98%), and that flux rates distinctly differ among climate zones. Dissolved organic carbon, phenolics, and nitrate contrib‐ uted most to the areal fluxes. The largest amounts of leached substances were found in the continental climate zone, coinciding with the lowest potential bioavailability of the leached OM. The opposite pattern was found in the arid zone. Environmental vari‐ ables expected to be modified under climate change (i.e. potential evapotranspiration, aridity, dry period duration, land use) were correlated with the amount of leached sub‐ stances, with the strongest relationship found for sediments. These results show that the role of IRES should be accounted for in global biogeochemical cycles, especially because prevalence of IRES will increase due to increasing severity of drying event

Self-mutilation and suicide attempt: distinguishing features in prisoners

Nonlethal forms of self-injury are often discussed together with suicide attempts as though they belonged on a continuum of self-harm. Both types of self-injury are common in prisons, which have a predominantly male population; however, most studies of nonlethal self-injury have been done with female subjects. This exploratory study tested the hypothesis that prisoners who injured themselves without intending to die would differ clinically from prisoners who had attempted suicide. Inmates admitted to the prison unit of a public hospital for treatment of self-inflicted wounds or who had a history of previous self-injury were administered a standardized intake protocol by the first author, which included asking about their intent at the time they injured themselves. Patients were classified as self-mutilators or suicide attempters on the basis of intent. Fifteen patients reported that they had attempted to take their own lives, while 16 reported other reasons for harming themselves. Suicide attempt was associated with adult affective disorder 13/15 versus 2/16 mutilators); self-mutilation with a history of childhood hyperactivity (12/16 versus 1/15 suicide attempters) and a mixed dysthymia/anxiety syndrome that began in childhood or early adolescence (9/16). Prison self-mutilators and suicide attempters had very different clinical presentations and histories. The history of childhood hyperactivity in self-mutilators deserves further study in both correctional and noncorrectional populations

Burden of cancer in Malawi; common types, incidence and trends: National population-based cancer registry

Abstract Background Cancer is a leading cause of morbidity and mortality worldwide with a majority of cases and deaths occurring in developing countries. While cancer of the lung, breast, colorectum, stomach and prostate are the most common types of cancer globally, in east and southern Africa these are less common and comprehensive data to inform policies are lacking. Methods Nationwide cancer registry was conducted between September and October 2010 in Malawi. New cancer cases registered from 2007 to 2010 were identified from hospital and clinic registers of 81 out of 84 health facilities providing cancer diagnosis, treatment or palliative care services. Demographic and cancer data were extracted from registers and case notes using a standard form. Results A total of 18,946 new cases of cancer were registered in Malawi from 2007-2010. Of these 55.9% were females, 7.2% were children aged less than 15 years, 76.5% were adults aged 15-59 years and 16.4% were elderly aged 60 years or more. Only 17.9% of the cases had histologically verified diagnosis, 33.2% were diagnosed clinically and 49.6% based on clinical and some investigations. Amongst females, cancer of the cervix was the commonest accounting for 45.4% of all cases followed by Kaposi sarcoma (21.1%), cancer of the oesophagus (8.2%), breast (4.6%) and non-Hodgkin lymphoma (4.1%). In males, Kaposi sarcoma was the most frequent (50.7%) then cancer of oesophagus (16.9%), non-Hodgkin lymphoma (7.8), prostate (4.0%) and urinary bladder (3.7%). Age-standardised incidence rate per 100,000 population for all types of cancer in males increased from 31 in 1999-2002 to 56 in 2007-2010. In females it increased from 29 to 69. Kaposi sarcoma and cancer of the oesophagus, cervical cancer and Kaposi sarcoma were the main causes for the increased incidence in males and females respectively. It was estimated that, annually at least 8,151 new cases of cancer (all types) occur in Malawi. Conclusions This study provided data on common types and trends of cancer that could be used to focus prevention, treatment and control interventions in the context of limited resources. The problem of under-reporting and misdiagnosis of cancer cases has been highlighted.</p