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Species-specific biomass drives macroalgal benthic primary production on temperate rocky reefs
Spector, Michael,Edwards, Matthew S. The Korean Society of Phycology 2020 ALGAE Vol.35 No.3
Temperate rocky reefs dominated by the giant kelp, Macrocystis pyrifera, support diverse assemblages of benthic macroalgae that provide a suite of ecosystem services, including high rates of primary production in aquatic ecosystems. These forests and the benthic macroalgae that inhabit them are facing both short-term losses and long-term declines throughout much of their range in the eastern Pacific Ocean. Here, we quantified patterns of benthic macroalgal biomass and irradiance on rocky reefs that had intact kelp forests and nearby reefs where the benthic macroalgae had been lost due to deforestation at three sites along the California, USA and Baja California, MEX coasts during the springs and summers of 2017 and 2018. We then modeled how the loss of macroalgae from these reefs impacted net benthic productivity using species-specific, mass-dependent rates of photosynthesis and respiration that we measured in the laboratory. Our results show that the macroalgal assemblages at these sites were dominated by a few species of stipitate kelps and fleshy red algae whose relative abundances were spatially and temporally variable, and which exhibited variable rates of photosynthesis and respiration. Together, our model estimates that the dominant macroalgae on these reefs contribute 15 to 4,300 mg C m<sup>-2</sup> d<sup>-1</sup> to net benthic primary production, and that this is driven primarily by a few dominant taxa that have large biomasses and high rates of photosynthesis and / or respiration. Consequently, we propose that the loss of these macroalgae results in the loss of an important contribution to primary production and overall ecosystem function.
Automation of Workplace Lifting Hazard Assessment for Musculoskeletal Injury Prevention
June T Spector,Max Lieblich,Stephen Bao,Kevin McQuade,Margaret Hughes 대한직업환경의학회 2014 대한직업환경의학회지 Vol.26 No.-
Objectives: Existing methods for practically evaluating musculoskeletal exposures such as posture and repetition in workplace settings have limitations. We aimed to automate the estimation of parameters in the revised United States National Institute for Occupational Safety and Health (NIOSH) lifting equation, a standard manual observational tool used to evaluate back injury risk related to lifting in workplace settings, using depth camera (Microsoft Kinect) and skeleton algorithm technology. Methods: A large dataset (approximately 22,000 frames, derived from six subjects) of simultaneous lifting and other motions recorded in a laboratory setting using the Kinect (Microsoft Corporation, Redmond, Washington, United States) and a standard optical motion capture system (Qualysis, Qualysis Motion Capture Systems, Qualysis AB, Sweden) was assembled. Error-correction regression models were developed to improve the accuracy of NIOSH lifting equation parameters estimated from the Kinect skeleton. Kinect-Qualysis errors were modelled using gradient boosted regression trees with a Huber loss function. Models were trained on data from all but one subject and tested on the excluded subject. Finally, models were tested on three lifting trials performed by subjects not involved in the generation of the model-building dataset. Results: Error-correction appears to produce estimates for NIOSH lifting equation parameters that are more accurate than those derived from the Microsoft Kinect algorithm alone. Our error-correction models substantially decreased the variance of parameter errors. In general, the Kinect underestimated parameters, and modelling reduced this bias, particularly for more biased estimates. Use of the raw Kinect skeleton model tended to result in falsely high safe recommended weight limits of loads, whereas error-corrected models gave more conservative, protective estimates. Conclusions: Our results suggest that it may be possible to produce reasonable estimates of posture and temporal elements of tasks such as task frequency in an automated fashion, although these findings should be confirmed in a larger study. Further work is needed to incorporate force assessments and address workplace feasibility challenges. We anticipate that this approach could ultimately be used to perform large-scale musculoskeletal exposure assessment not only for research but also to provide real-time feedback to workers and employers during work method improvement activities and employee training.
Kurokawa, Manabu,Kim, Jiyeon,Geradts, Joseph,Matsuura, Kenkyo,Liu, Liu,Ran, Xu,Xia, Wenle,Ribar, Thomas J.,Henao, Ricardo,Dewhirst, Mark W.,Kim, Wun-Jae,Lucas, Joseph E.,Wang, Shaomeng,Spector, Neil L AAAS 2013 Science signaling Vol.6 No.274
<P><B>Breaking Down to Build Resistance</B></P><P>Chemotherapeutic resistance often arises because of the rewiring of signaling pathways in cancer cells. Kurokawa <I>et al.</I> found that the ubiquitin E3 ligase MDM2 triggered the breakdown of another ubiquitin E3 ligase, HUWE1. In breast cancer cells that died when exposed to the HER2 (human epidermal growth factor receptor 2) EGFR (epidermal growth factor receptor) tyrosine kinase inhibitor lapatinib, MDM2 was degraded, which enabled HUWE1 to trigger the degradation of a prosurvival protein and promote assembly and activation of a protein complex required for the execution of cell death. However, MDM2 degradation did not occur in lapatinib-resistant breast cancer cells, and thus, the abundance of HUWE1 was decreased, promoting cell survival. In a mouse xenograft model, an inhibitor of MDM2 reduced the growth of tumors generated from lapatinib-resistant breast cancer cells. Thus, MDM2 could be targeted to circumvent resistance to lapatinib in breast cancers.</P>
Yee, J. C.,Udalski, A.,Sumi, T.,Dong, Subo,Kozłowski, S.,Bird, J. C.,Cole, A.,Higgins, D.,McCormick, J.,Monard, L. A. G.,Polishook, D.,Shporer, A.,Spector, O.,Szymań,ski, M. K.,Kubiak, M.,Pietrzy IOP Publishing 2009 The Astrophysical journal Vol.703 No.2
<P>We analyze the extreme high-magnification microlensing event OGLE-2008-BLG-279, which peaked at a maximum magnification of A similar to 1600 on 2008 May 30. The peak of this event exhibits both finite-source effects and terrestrial parallax, from which we determine the mass of the lens, M-l = 0.64 +/- 0.10 M-circle dot, and its distance, D-l = 4.0 +/- 0.6 kpc. We rule out Jupiter-mass planetary companions to the lens star for projected separations in the range 0.5-20 AU. More generally, we find that this event was sensitive to planets with masses as small as 0.2 M-circle dot similar or equal to 2 (MMars) with projected separations near the Einstein ring (similar to 3 AU).</P>