Evaluating macroinvertebrate population and community level effects in outdoor microcosms: Use of in situ bioassays and multivariate analysis

1996 ◽  
Vol 15 (5) ◽  
pp. 608-617 ◽  
Author(s):  
Jennifer L. Shaw ◽  
Jeffrey P. Manning
2020 ◽  
Author(s):  
Zhou Zijuan ◽  
Su Peixi ◽  
Wu Xiukun ◽  
Shi Rui ◽  
Ding Xinjing

Abstract Background: The Tibetan Plateau is highly sensitive to elevated temperatures and has experienced significant climate warming in the last decades. While climate warming is known to greatly impact alpine ecosystems, the gas exchange responses at the leaf and community levels to climate warming in alpine meadow ecosystems remain unclear.Results: In this study, the alpine grass, Elymus nutans, and forb, Potentilla anserina, were grown in open-top chambers (OTCs) for three consecutive years to evaluate their response to warming. Gas exchange measurements were used to assess the effects of in-situ warming on leaf- and community-level photosynthetic carbon assimilation based on leaf traits and photosynthetic physiological parameters. We introduced a means of up-scaling photosynthetic measurements from the leaf level to the community level based on six easily-measurable parameters, including leaf net photosynthetic rate, fresh leaf mass per unit leaf area, fresh weight of all plant leaves, the percentage of healthy leaves, the percentage of received effective light by leaves in the community, and community coverage. The community-level photosynthetic carbon assimilation and productivity all increased with warming, and the net photosynthetic rate at the leaf level was significantly higher than at the community level. Under elevated temperature, the net photosynthetic rate of E. nutans decreased, while that of P. anserina increased.Conclusions: These results indicated that climate warming may significantly influence plant carbon assimilation, which could alter alpine meadow community composition in the future.


Author(s):  
Benoît J. D. Ferrari ◽  
Olivier Geffard ◽  
Arnaud Chaumot
Keyword(s):  

2010 ◽  
Vol 25 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Mark A. Rodriguez ◽  
Mark H. Van Benthem ◽  
David Ingersoll ◽  
Sven C. Vogel ◽  
Helmut M. Reiche

The electrochemical reaction behavior of a commercial Li-ion battery (LiFePO4-based cathode, graphite-based anode) has been measured via in situ neutron diffraction. A multivariate analysis was successfully applied to the neutron diffraction data set facilitating in the determination of Li bearing phases participating in the electrochemical reaction in both the anode and cathode as a function of state-of-charge (SOC). The analysis resulted in quantified phase fraction values for LiFePO4 and FePO4 cathode compounds as well as the identification of staging behavior of Li6, Li12, Li24, and graphite phases in the anode. An additional Li-graphite phase has also been tentatively identified during electrochemical cycling as LiC48 at conditions of ∼5% to 15% SOC.


1997 ◽  
Vol 51 (2) ◽  
pp. 247-252 ◽  
Author(s):  
Jeffrey F. Aust ◽  
Karl S. Booksh ◽  
Christopher M. Stellman ◽  
Richard S. Parnas ◽  
Michael L. Myrick

A method for real-time determination of the percent cure of epoxies via in situ fiber-optic Raman spectroscopy has been developed. This method utilizes a probe design developed for real-time monitoring of polymer curing and multivariate analysis to interpret the data and determine percent cure. This method was demonstrated to be reliable to ±0.54% of cure in laboratory samples over a 50–99% cure range. A preliminary study measuring cure percentage in an industrial, glass-reinforced composite has been shown to be reliable to ±0.82% in the 40–90% cure range.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e11533-e11533
Author(s):  
Cynthia Mayte Villarreal-Garza ◽  
Enrique Soto-Perez-de-Celis ◽  
Erika Sifuentes ◽  
Yanin Chavarri Guerra ◽  
Santiago Ruano ◽  
...  

e11533 Background: The most accurate definition of pathologic complete response (pCR) in HER2+ BC patients (pts) receiving T-based neoadjuvant chemotherapy associated with improved DFS is controversial, particularly regarding the role of residual ductal carcinoma in situ (ypTis) and focal invasive residuals (ypT1mic). The effect of pCR on DFS in various subgroups of HER2+ BC is also uncertain. Methods: Pts with localized HER2+ BC that received T-based neoadjuvant chemotherapy at NCI between January 2007 and May 2012 were identified. We conducted an exploratory analysis of DFS in pts according to their tumor response. DFS curves were derived from Kaplan-Meier estimates and compared by log-rank test. Multivariate analysis was performed using Cox’s regression model. Results: 243 pts were included for analysis. Median follow-up was 39 months (mo). 49% of pts had no invasive and no in situ residuals at surgery (ypT0), 14.4% had ypTis/ypT1mic residuals and 36.6% had gross residual BC. DFS was significantly superior in pts with both ypT0 and ypTis/ypT1mic (no gross invasive residual BC) compared with those with gross residual disease (60.6 and 62.7 mo respectively vs. 51.6 mo, p=0.011 and 0.017). There was no difference in DFS between ypT0 and ypTis/ypT1mic pts (p=0.402). The rate of no gross invasive residual BC was significantly superior in pts with ER-PR- tumors compared with patients with ER+/PR+ tumors (69.9% vs. 56.7%, p=0.034). No gross invasive residual BC was associated with improved DFS in pts with HER2+ ER-/PR- (60.3 vs. 49.0 mo; p=0.005), as opposed to HER2+ ER+/PR+ tumors (61.0 vs. 51.6 mo; p=0.100). Multivariate analysis showed that tumor size (p=0.013) and no gross invasive residual BC (p=0.13) were associated with improved DFS in all subgroups. Conclusions: The absence of gross invasive residual BC was associated with improved DFS in pts with HER2+ BC treated with T-based neoadjuvant chemotherapy, particularly in those with HER2+ ER-/PR- BC. Our data suggest a comparable DFS in HER2+ BC patients with no gross invasive residual BC regardless of the presence or absence of both ypTis and ypT1mic disease after neoadjuvant treatment.


1993 ◽  
Vol 50 (5) ◽  
pp. 902-912 ◽  
Author(s):  
Howard A. Simonin ◽  
Walter A. Kretser ◽  
Dale W. Bath ◽  
Mark Olson ◽  
James Gallagher

In situ bioassays were conducted using native Adirondack brook trout (Salvelinus fontinalis) and blacknose dace (Rhinichthys atratulus) in four headwater streams. Conductivity, pH, temperature, and stage height were monitored continuously, and water samples for laboratory analysis were collected during hydrologic episodes. Fish survived well during baseflow conditions, but during periods of spring snowmelt or large precipitation events, survival was poor. Blacknose dace were more sensitive than brook trout, and mortality was best correlated with the log of median inorganic monomeric aluminum (Alim) concentration. Brook trout mortality was best correlated with a two-variable model that included dissolved organic carbon (DOC) and a concentration–duration variable (median Alim during the episode times the duration of the episode). Brook trout mortality was inversely correlated with DOC. Bioassay fish that had been in the streams 15–24 d survived episodes better than fish that had either not become acclimatized or recovered from handling. Duration of exposure to acidic episodes was critical. Extended periods of poor water quality resulted in fish mortality and may be more important to native populations than short acidic episodes.


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