Groundwater shapes sediment biogeochemistry and microbial diversity in a submerged Great Lake sinkhole.

For a large part of earth's history, cyanobacterial mats thrived in low-oxygen conditions, yet our understanding of their ecological functioning is limited. Extant cyanobacterial mats provide windows into the putative functioning of ancient ecosystems, and they continue to mediate biogeochemical transformations and nutrient transport across the sediment-water interface in modern ecosystems. The structure and function of benthic mats are shaped by biogeochemical processes in underlying sediments. A modern cyanobacterial mat system in a submerged sinkhole of Lake Huron (LH) provides a unique opportunity to explore such sediment-mat interactions. In the Middle Island Sinkhole (MIS), seeping groundwater establishes a low-oxygen, sulfidic environment in which a microbial mat dominated by Phormidium and Planktothrix that is capable of both anoxygenic and oxygenic photosynthesis, as well as chemosynthesis, thrives. We explored the coupled microbial community composition and biogeochemical functioning of organic-rich, sulfidic sediments underlying the surface mat. Microbial communities were diverse and vertically stratified to 12 cm sediment depth. In contrast to previous studies, which used low-throughput or shotgun metagenomic approaches, our high-throughput 16S rRNA gene sequencing approach revealed extensive diversity. This diversity was present within microbial groups, including putative sulfate-reducing taxa of Deltaproteobacteria, some of which exhibited differential abundance patterns in the mats and with depth in the underlying sediments. The biological and geochemical conditions in the MIS were distinctly different from those in typical LH sediments of comparable depth. We found evidence for active cycling of sulfur, methane, and nutrients leading to high concentrations of sulfide, ammonium, and phosphorus in sediments underlying cyanobacterial mats. Indicators of nutrient availability were significantly related to MIS microbial community composition, while LH communities were also shaped by indicators of subsurface groundwater influence. These results show that interactions between the mats and sediments are crucial for sustaining this hot spot of biological diversity and biogeochemical cycling.

A national survey of parent perspectives on use of patient portals for their children's health care.

OBJECTIVES: To assess parents' current utilization and future willingness to use patient portals to interact with their child's health care provider. METHODS: A cross-sectional survey of a nationally representative sample of US parents was conducted using an established online panel. Bivariate analyses assessed associations between current utilization and future willingness to use patient portals, parental concerns, and demographic variables. RESULTS: Among the 1,420 parent respondents, 40% did not know whether their child's health practice offers the option of setting up a patient portal for their child. Of the 21% of parents who reported being offered the option of setting up a patient portal for their child, 59% had done so. Among parents who had the option but chose not to set up a patient portal for their child, lack of time and low perceived need were the main reasons cited. Current use and likelihood of future use was highest for viewing lab results and immunization records. The most common concern about patient portals was the security of the child portal system. CONCLUSIONS: Current use of patient portals by parents is low. Only about half of parents currently using or likely to use a portal perceive value in using portals for certain tasks, which suggests that providers will need to continue traditional communication mechanisms to reach their entire patient population.

A Model for a Policy on HIV/AIDS and Athletics.

Human immunodeficiency virus (HIV)-infected athletes exist at the collegiate level and are engaging in competitive sports, as was revealed by a 1993 NCAA survey. Unfortunately, there is a void when the issue of policy for the HIV- positive athlete and his or her participation rights at the collegiate level is addressed. Given the controversial nature of opinion on HIV and the resultant acquired immunodeficiency syndrome (AIDS), it is recommended that a policy be in place for an HIV-infected athlete before it is needed. Ithaca College has recently developed such a policy, and it is offered here to other educational institutions as a model. It is emphasized throughout the policy that HIV-positive athletes should not be restricted from athletic participation for the reason of infection alone, that strict confidentiality guidelines should be followed, and that mandatory testing of athletes for HIV is not justified.

Neurovirulence mutant of vesicular stomatitis virus with an altered target cell tropism in vivo.

Intracerebral infection of weanling Swiss mice with a temperature-sensitive (ts) mutant of vesicular stomatitis virus (VSV), ts pi364, resulted in a unique neuropathological syndrome not previously described with other VSV mutants. Mice infected with wild-type VSV died from an acute encephalitis characterized by neuronal necrosis and efficient virus replication in both brain and spinal cord. In contrast, with VSV ts pi364, the most prominent histopathological feature was destruction of the ependyma of the lateral ventricles. Virus antigen was also limited to the leptomeninges and the lateral ventricles. Infected mice survived and developed hydrocephalus. Replication of ts pi364 in the brain was 10- to 100- fold less than that of wild-type VSV, and appearance of virus in the spinal cord was delayed. VSV ts pi364 was isolated from mouse cells persistently infected with VSV. Another VSV ts pi mutant, isolated from the same persistent infection, behaved in vivo like wild-type VSV, even though both mutants were very similar in plaque size, reversion frequency, cut-off temperature, and synthesis of virus-specific proteins at semipermissive temperature. These results strongly suggest that VSV ts pi364 has a second, non-ts mutation which results in a restricted target cell range in vivo; wild-type VSV can infect both neurons and ependymal cells, whereas ts pi364 does not replicate in neurons.