Sporophyte recrultment, holclfast growth and mortality of giant kelp Macrocyst~spynfera were measured seasonally on permanent transects at 3 sltes [protected Intermediate and exposed) along a wave exposure gradient on the Monterey Peninsula, c e n t~a l Cal~fornia (USA) between 1988 and 1991 The constant presence of cold, nutnent-nch water and the relative absence of o t h e~ kelps and large grazers allowed the dynanucs of M pynfera populations to be examined under conditions in which wave exposure was highly vanable and ~nfluences of other abiotlc and biotic factors were minimized Recovery of M pynfera populations fiom decreased adult density (presumably due to stormlnduced mortality, adult density was negatively correlated with storm activity) was a 2-stage process requiring the establishment of luvenile populations and condit~ons suitable for ]uvenile growth to adult size Sporophyte recrultment was negatively correlated with M pynfera canopy cover, and thus appeared to be related to irradiance Recruitment was low and continuous under a temporally stable M pyrifera canopy at the protected slte At the intermediate and exposed sites, canopy cover was more variable, canopy loss was greater, and durdt~ons of low canopy cover were longer than at the protected site resulting in episodic sporophyte recruitment These distinct patterns in sporophyte lecruitment resulted In continuous luvenile populations at the protected site and intermittent luvenlle populations at the intermediate and exposed sites Growth of luveniles to adult size required additional irrad~ance probably d u e to gleater light requirements for luvenlle growth than for sporophyte recrultment We observed that luveniles grew to adult slze when canopy cover was low and adults were below a threshold denslty estimated at -10 plants 100 m 2 , but ~uveniles also occasionally grew to adult size following periods of low canopy cover only Ep~sodic sporophyte recruitment at the intermediate and exposed sites resulted in decreased coincidence of the 2 recovery stages, adult dens~ties were often decreased below threshold piior to the establishment of luvenile populations Recovery time, that required by populations to return to densities above threshold was equal to the time lag between occurrence of the 2 recovery stages and was therefore greatest at the more exposed sites Compansons between central and southern Cal~tornia M pyl~fera populat~ons suggest that by altering recovery time variable frequency and magnitude of storm disturbance may result in different periodlclties of adult population cycles K E Y WORDS. Glant kelp. Macrocyst~spyr~fera . Wave exposure. Demography. Recruitment. Recovery
Remotely operated vehicle (ROV) surveys were conducted over a 3-year period to evaluate the importance of macroalgal drift exported from nearshore forests of giant kelp (Macrocystis pyrifera) to adjacent submarine-canyon and continental-shelf benthic habitats. Abundant macroalgal drift was found in the Carmel Submarine Canyon (153-454-m depth) but was rare at Pt. Joe, a continental shelf habitat 9 km away (87-357-m depth). Most of the drift parcels consisted of brown algae, but 10 other categories were found, including green and red algae and the surfgrass Phyllospadix spp. M. pyrifera drift accounted for as much as 20% of the density of drift parcels in the Carmel Submarine Canyon, and up to 50% of the drift parcels at Pt. Joe. From previously determined turnover rates of drift M. pyrifera and the standing stock estimates from the present study, we estimated that the rate of carbon flux associated with drift M. pyrifera to the benthos of the Cannel Submarine Canyon was 45.2 mg C m z d I. Based on published estimates of carbon flux from vertically sinking particulate organic carbon at 400-m depth in the nearby Monterey Submarine Canyon, and our estimates of kelp-derived carbon flux, drift M. pyrifera can account for 20-83% of the total particulate organic carbon reaching the sea floor in the Carmel Submarine Canyon. We conclude that drift macrophytes provide significant enrichment of organic carbon to the benthos above that provided by vertically sinking particulate organic material. The extent to which this alters the structure of benthic communities compared to areas without organic enrichment by drift macrophytes remains unknown and awaits further study.
As hospitals move towards providing in-house 24×7 services, there is an increasing need for information systems to be available around the clock. This study investigates one organization's need for a workflow continuity solution that provides around the clock availability for information systems that do not provide highly available services. The organization investigated is a large multifacility healthcare organization that consists of 20 hospitals and more than 30 imaging centers. A case analysis approach was used to investigate the organization's efforts. The results show an overall reduction in downtimes where radiologists could not continue their normal workflow on the integrated Picture Archiving and Communications System (PACS) solution by 94 % from 2008 to 2011. The impact of unplanned downtimes was reduced by 72 % while the impact of planned downtimes was reduced by 99.66 % over the same period. Additionally more than 98 h of radiologist impact due to a PACS upgrade in 2008 was entirely eliminated in 2011 utilizing the system created by the workflow continuity approach. Workflow continuity differs from high availability and business continuity in its design process and available services. Workflow continuity only ensures that critical workflows are available when the production system is unavailable due to scheduled or unscheduled downtimes. Workflow continuity works in conjunction with business continuity and highly available system designs. The results of this investigation revealed that this approach can add significant value to organizations because impact on users is minimized if not eliminated entirely.
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