The Impact of Global Warming and Anoxia on Marine Benthic Community Dynamics: an Example from the Toarcian (Early Jurassic)

The Pliensbachian-Toarcian (Early Jurassic) fossil record is an archive of natural data of benthic community response to global warming and marine long-term hypoxia and anoxia. In the early Toarcian mean temperatures increased by the same order of magnitude as that predicted for the near future; laminated, organic-rich, black shales were deposited in many shallow water epicontinental basins; and a biotic crisis occurred in the marine realm, with the extinction of approximately 5% of families and 26% of genera. High-resolution quantitative abundance data of benthic invertebrates were collected from the Cleveland Basin (North Yorkshire, UK), and analysed with multivariate statistical methods to detect how the fauna responded to environmental changes during the early Toarcian. Twelve biofacies were identified. Their changes through time closely resemble the pattern of faunal degradation and recovery observed in modern habitats affected by anoxia. All four successional stages of community structure recorded in modern studies are recognised in the fossil data (i.e. Stage III: climax; II: transitional; I: pioneer; 0: highly disturbed). Two main faunal turnover events occurred: (i) at the onset of anoxia, with the extinction of most benthic species and the survival of a few adapted to thrive in low-oxygen conditions (Stages I to 0) and (ii) in the recovery, when newly evolved species colonized the re-oxygenated soft sediments and the path of recovery did not retrace of pattern of ecological degradation (Stages I to II). The ordination of samples coupled with sedimentological and palaeotemperature proxy data indicate that the onset of anoxia and the extinction horizon coincide with both a rise in temperature and sea level. Our study of how faunal associations co-vary with long and short term sea level and temperature changes has implications for predicting the long-term effects of “dead zones” in modern oceans

Neurocognitive impairment associated with predominantly early stage HIV infection in Abuja, Nigeria

Detailed neuropsychological testing was performed on 134 HIV seropositive (SP) and 77 HIV seronegative (SN) individuals, 86% with early stage HIV infection in Nigeria, to determine the frequency of HIV-related neurocognitive impairment among the HIV-infected group. Twenty-two tests were administered to assess the following seven ability domains: speed of information processing (SIP); attention/working memory (AWM); executive functioning (EF); learning (LN); memory (MEM); verbal fluency (VF); and motor speed/dexterity (MSD). Demographically corrected individual test scores and scores for each domain or reflecting a global deficit (a global deficit score, or GDS) were compared for the SP and SN groups. SP participants were older, had fewer years of education, were more likely to be married, differed in ethnicity and had higher depression scores than SN individuals. On the testing, SP performed worse than SN on four tests that individually assessed LN, VF and MSD (the timed gait). SP subjects, however, performed better than SN on the finger-tapping test, also a motor task. Within the seven ability domains, SP performed worse than SN with respect to SIP, EF, LN, MEM and VF and also on the global measure. SP were also more frequently impaired on tests of SIP, and there was a borderline increase in the frequency of global impairment. Performance by SP subjects was not associated with CD4 counts. However, there were significant correlations between viral load measurements and individual tests of SIP, EF, LN and VF and with overall EF and a borderline correlation with the GDS. Depression scores for SP were associated with impairment on only a single test of EF. These results demonstrate that the ability of these assessments to identify areas of impairment that may be specifically linked to a history of HIV infection among individuals in Nigeria. Confirmation of these findings awaits analyses using data from a larger number of control subjects

Community-based interventions for enhancing access to or consumption of fruit and vegetables among five to 18-year olds: a scoping review

<p>Abstract</p> <p>Background</p> <p>Low fruit and vegetable ( FV) consumption is a key risk factor for morbidity and mortality. Consumption of FV is limited by a lack of access to FV. Enhanced understanding of interventions and their impact on both access to and consumption of FV can provide guidance to public health decision-makers. The purpose of this scoping review is to identify and map literature that has evaluated effects of community-based interventions designed to increase FV access or consumption among five to 18-year olds.</p> <p>Methods</p> <p>The search included 21 electronic bibliographic databases, grey literature, targeted organization websites, and 15 key journals for relevant studies published up to May 2011. Retrieved citations were screened in duplicate for relevance. Data extracted from included studies covered: year, country, study design, target audience, intervention setting, intervention strategies, interventionists, and reported outcomes.</p> <p>Results</p> <p>The search located 19,607 unique citations. Full text relevance screening was conducted on 1,908 studies. The final 289 unique studies included 30 knowledge syntheses, 27 randomized controlled trials, 55 quasi-experimental studies, 113 cluster controlled studies, 60 before-after studies, one mixed method study, and three controlled time series studies. Of these studies, 46 included access outcomes and 278 included consumption outcomes. In terms of target population, 110 studies focused on five to seven year olds, 175 targeted eight to 10 year olds, 192 targeted 11 to 14 year olds, 73 targeted 15 to 18 year olds, 55 targeted parents, and 30 targeted teachers, other service providers, or the general public. The most common intervention locations included schools, communities or community centres, and homes. Most studies implemented multi-faceted intervention strategies to increase FV access or consumption.</p> <p>Conclusions</p> <p>While consumption measures were commonly reported, this review identified a small yet important subset of literature examining access to FV. This is a critically important issue since consumption is contingent upon access. Future research should examine the impact of interventions on direct outcome measures of FV access and a focused systematic review that examines these interventions is also needed. In addition, research on interventions in low- and middle-income countries is warranted based on a limited existing knowledge base.</p

The value of open-source clinical science in pandemic response: lessons from ISARIC

International audienc