From desert to deluge in the Mediterranean

Some time between five and six million years ago, the Mediterranean Sea became isolated from the Atlantic Ocean. In consequence some areas dried out -- hence the title of Kenneth Hsüs book The Mediterranean was a Desert 1 -- and large salty lakes recharged by rivers flowing through deep canyons replaced the previously marine basins. During this time, the remaining bodies of water were either too salty or not salty enough for normal marine fauna to flourish. This was the so-called Messinian salinity crisis. Because Messinian sediments are essentially devoid of marine fossils this dramatic geological event has been difficult to date or place accurately in the global stratigraphic record, meaning in turn that its causes and environmental impact have been unclear

Universal design for learning in inclusive education policy in South Africa

Background: South Africa has undertaken the implementation of inclusive education as a vehicle for achieving enhanced educational outcomes and equity. Universal Design for Learning (UDL) is an instructional design framework that takes into account the wide range of variations in skills and abilities that exist across all learners, and provides a research-based set of principles and guidelines for inclusive curriculum development and delivery. Objectives: To locate UDL within the specific inclusive education policy context of South Africa and consider how this approach can support policy implementation. We have argued that UDL could serve as a strategy to link policy imperatives with classroom practice, enabling effective communication between the different actors. Method: We reviewed fundamental inclusive education policies in South Africa and research relating to their implementation, and how they configure support and curriculum differentiation. We then compared this understanding with that proposed by UDL and considered what could be gained in adopting a UDL framework. Results: We noted that UDL has several advantages in that it allows for a common language between education stakeholders and gives new meaning to the interpretation of levels of support. Conclusion: The implementation of inclusive education in South Africa could be enhanced by introducing the concepts of UDL into policy, research and teaching practice as a common language and vehicle for packaging support systems

Nitric oxide donation lowers blood pressure in adrenocorticotrophic hormone-induced hypertensive rats.

Adrenocorticotrophic hormone (ACTH) elevates systolic blood pressure (SBP) and lowers plasma reactive nitrogen intermediates in rats. We assessed the ability of NO donation from isosorbide dinitrate (ISDN) to prevent or reverse the hypertension caused by ACTH. In the prevention study, male Sprague Dawley rats were treated with ACTH (0.2 mg/kg/day) or saline control for 8 days, with either concurrent ISDN (100 mg/kg/day) via the drinking water or water alone. Animals receiving ISDN via the drinking water were provided with nitrate-free water for 8 hours every day. In the reversal study ISDN (100 mg/kg) or vehicle was given as a single oral dose on day 8. SBP was measured daily by the indirect tail-cuff method in conscious, restrained rats. ACTH caused a significant increase in SBP compared with saline (P < 0.0015). In the prevention study, chronic administration of ISDN (100 mg/kg/day) did not affect the SBP in either group. In the reversal study, ISDN significantly lowered SBP in ACTH-treated rats at 1 and 2.5 hours (132 +/- 3 mmHg (1 h) and 131 +/- 2 mmHg (2.5 h) versus 143 +/- 3 mmHg (0 h), P < 0.002), but not to control levels. It had no effect in control (saline treated) rats. In conclusion, the lowering of SBP by NO donation is consistent with the notion that ACTH-induced hypertension involves an impaired bioavailability or action of NO in vivo

The implementation of inclusive education in South Africa: Reflections arising from a workshop for teachers and therapists to introduce Universal Design for Learning

South Africa has adopted an inclusive education policy in order to address barriers to learning in the education system. However, the implementation of this policy is hampered by the lack of teachers’ skills and knowledge in differentiating the curriculum to address a wide range of learning needs. In this paper we provided a background to inclusive education policy in South Africa and a brief exposition of an instructional design approach, Universal Design for Learning (UDL) that addresses a wide range of learning needs in a single classroom. We reported on a workshop conducted with teachers and therapists in South Africa as a first attempt to introduce UDL in this context. Knowledge of UDL was judged to be appropriate and useful by the course participants in the South African context as a strategy for curriculum differentiation in inclusive classrooms. Furthermore, knowledge of the UDL framework facilitates dialogue between teachers and therapists and provides a relatively simple and comprehensive approach for curriculum differentiation. We therefore conclude that there is potential for this approach that can be expanded through further teacher training

Health conditions and support needs of persons living in residential facilities for adults with intellectual disability in Western Cape Province

Background: Intellectual disability (ID) is a relatively high-incidence disability, with an increased risk of poor physical and mental health. Persons with ID also have lifelong support needs that must be met if they are to achieve an acceptable quality of life. Little is known about these health conditions and support needs in the African context. This study examines persons over the age of 18 years with ID in residential facilities in Western Cape Province. OBJECTIVE: To analyse the health conditions and support needs of persons with ID in Western Cape Province. METHOD: A survey of residents' health conditions and support needs was conducted in face-to-face interviews with the managers of 37 out of 41 identified facilities. RESULTS AND CONCLUSION: The survey comprised 2 098 residents (54% of them female), representing less than 2% of the estimated population of persons with ID in the province. The survey suggests that such persons experience a wide range of health conditions (notably mental health and behavioural issues) but have limited access to general health care and rehabilitation services. Furthermore, the daily living supports required for an acceptable quality of life are limited. The findings highlight the need for better health and support provision to persons with ID

Biomineralization of carbonate and phosphate by moderately halophilic bacteria

We investigated the precipitation of carbonate and phosphate minerals by 19 species of moderately halophilic bacteria using media with variable Mg2+/Ca2+ ratios. The precipitated minerals were calcite, magnesium (Mg) calcite, and struvite (MgNH4PO4·6H2O) in variable proportions depending on the Mg2+/Ca2+ ratio of the medium. The Mg content of the Mg-calcite decreased with increasing Ca2+ concentration in the medium. According to the saturation indices, other minerals could also have precipitated. We observed important differences between the morphology of carbonate and phosphate, which may help us to recognize these minerals in natural systems. We studied the growth and pH curves of four bacteria in media specific for carbonate and struvite precipitation. We consider the biomineralization processes that produce carbonate and phosphate minerals, and propose a hypothesis for the lack of struvite in natural environments and ancient rock

The importance of microbial mats for dolomite formation in the Dohat Faishakh sabkha, Qatar

The Dohat Faishakh sabkha in Qatar is one of the rare modern environments where it is possible to study the formation of dolomite, a mineral whose origin has been long debated. In previous studies, dolomite formation in this area was considered to be the result of a penecontemporaneous replacement of aragonite, occurring in the presence of Mg-rich evaporated pore-waters. However, a re-investigation of the sabkha revealed that dolomite is not forming exclusively under the evaporitic conditions that characterize the supratidal zone, but also in microbial mats that colonize the lower intertidal zone, indicating that evaporated pore-waters are not a strict requirement for the mineralization process. Moreover, in the supratidal zone, portions of the sediment that are rich in dolomite are also relatively richer in organic material, which derives from partially degraded microbial mats buried in the sediments. Extracellular polymeric substances (EPS) that constitute microbial mats are recognized as an important component for the formation of Mg-rich carbonates. The presence of living and decaying microbial mats comprising EPS, rather than a replacement process, may be the key factor for dolomite formation in the Dohat Faishakh sabkha.Swiss National Science Foundatio

Fifty Years of Scientific Ocean Drilling

Author Posting. © Oceanography Society , 2019. This article is posted here by permission of Oceanography Society for personal use, not for redistribution. The definitive version was published in Becker, K., Austin, J. A., Jr., Exon, N., Humphris, S., Kastner, M., McKenzie, J. A., Miller, K. G., Suyehiro, K., & Taira, A. Fifty years of scientific ocean drilling. Oceanography, 32(1), (2019):17-21, doi:10.5670/oceanog.2019.110.Nearly a century after the first systematic study of the global ocean and seafloor by HMS Challenger (1871–1876), US scientists began to drill beneath the seafloor to unlock the secrets of the ~70% of Earth’s surface covered by the seas. Fifty years of scientific ocean drilling by teams of international partners has provided unparalleled advancements in Earth sciences. Here, we briefly review the history, impacts, and scientific achievements of five decades of coordinated scientific ocean drilling