Search

Integrating authentic research practices into introductory laboratory courses to prepare tomorrow's scientists has become increasingly prevalent over the past decade. However, an incomplete understanding of the nature of science (NOS) and authentic scientific inquiry (SI) precludes higher-level learning in undergraduate research experiences. In this article, we discuss a concise, low-cost, low-maintenance, hands-on activity--What's in the Box (WiB)--which is suitable for largeenrollment science courses at both the secondary and postsecondary levels and can help develop students' understanding of NOS and authentic SI. Analyses of the postlab reflective writing assignment showed a substantial increase in the students' appreciation for NOS and SI tenets; the top two NOS tenets were that scientific ideas are subject to change and that science demands evidence, identified in 20% and 18% of the reflective writings, respectively. The most appreciated authentic SI tenets were that SI is complex and iterative (reported in up to 32% of the reflective writings) and SI involves observation and exploration (reported in up to 12% of the reflective writings). [ABSTRACT FROM AUTHOR]

Background:Elevated anthropogenic nitrogen (N) deposition is an important cause of biodiversity decline and disruption of ecosystem function and services, yet these impacts on many globally important ecosystems remain poorly studied. The Western Ghats of India has a N deposition rate that is highest among the 34 world biodiversity hotspots, and is projected to increase to 3.3 g N m−2 year−1by 2050. Aims:This study aims to understand N addition effects on the plant community and ecosystem in the montane grasslands of the Nilgiris, Western Ghats. Methods:Plant and soil responses were measured in grassland plots subject to N addition (ambient, 2 and 8 g N m−2year−1) and N immobilisation (500 g sucrose N m−2 year−1) treatments in a region frequently subjected to fire disturbance – the study site was burned 6 months prior to the experiment. Results:Ecosystem responses were consistent with a N-limited system. Soil N availability and leaf tissue N concentration responded positively to N addition. Plant cover and biomass increased with N addition, whereas soil moisture decreased. Unexpectedly, N enrichment had a positive effect on species richness and diversity, although the cover of one important native grass was significantly reduced by the higher N level. Conclusions:These results suggest that there may be a complex interaction of N deposition and the direct and indirect effects of fire in this system, warranting more detailed and longer-term research in this ecosystem. [ABSTRACT FROM PUBLISHER]

Abstract: The spread of the exotic shrub Scotch broom in the montane grasslands of the Nilgiris is one of the major threats to biodiversity and ecosystem function there. It is likely that fire suppression over the past few decades is the proximate cause of expansion of broom populations. This study capitalizes on a wildfire event to examine fire effects on mature broom populations and soil seedbanks. Fire resulted in widespread death of mature broom stands but also stimulated broom soil seedbanks. However, this initial difference in seedling densities in burned and unburned plots was lost over time due to continuous recruitment in unburned plots. In a seed addition experiment, plots which were clipped prior to the fire showed higher germination success, possibly because fire temperature was moderated by biomass removal. In another experiment, non-dormant broom seeds were added to burned plots, which then received clipping treatments; there were no differences in broom seedling survival in clipped vs. unclipped plots. Overall, these results suggest that prescribed burning might contribute to the control of Scotch broom invasion by helping eliminate mature stands without significantly increasing regeneration from seed. [Copyright &y& Elsevier]

We investigated age and size class structures of Scotch broom stands, and the effects of invasion on the native plant community, in the high-altitude grasslands of the Nilgiris, South India. Girth, height and age of broom stems were recorded. Native vegetation cover was assessed under broom and in the surrounding grasslands. Age was positively correlated with girth and height of broom. Middle-age classes were better represented than the younger classes. Species richness and diversity of native plants were affected by invasion intensity, but not duration. [ABSTRACT FROM AUTHOR]

Animal behavior is a useful way to evaluate the environment and can be a predictive tool to assess not only the effects of treatments in a laboratory setting, but also the status of ecological habitats. As invasive species of crayfish encroach on territories of native species, the social behaviors and interactions can be informative for ecological studies. For a wider and more impactful effect, training community scientists using a scoring system to record the social interactions of crayfish that includes both the level of aggression and intensity would provide useable data to monitor the environment. Amateur scientists with little training were fairly reliable in their average scoring of the crayfish and the maximum behavior score with an expert as well as among themselves. However, the number of interactions was not as a reliable metric to compare with the expert or just among the amateurs. [ABSTRACT FROM AUTHOR]

The MYST protein lysine acetyltransferases are evolutionarily conserved throughout eukaryotes and acetylate proteins to regulate diverse biological processes including gene regulation, DNA repair, cell-cycle regulation, stem cell homeostasis and development. Here, we demonstrate that MYST protein acetyltransferase activity requires active site lysine autoacetylation. The X-ray crystal structures of yeast Esa1 (yEsa1/KAT5) bound to a bisubstrate H4K16CoA inhibitor and human MOF (hMOF/KAT8/MYST1) reveal that they are autoacetylated at a strictly conserved lysine residue in MYST proteins (yEsa1-K262 and hMOF-K274) in the enzyme active site. The structure of hMOF also shows partial occupancy of K274 in the unacetylated form, revealing that the side chain reorients to a position that engages the catalytic glutamate residue and would block cognate protein substrate binding. Consistent with the structural findings, we present mass spectrometry data and biochemical experiments to demonstrate that this lysine autoacetylation on yEsa1, hMOF and its yeast orthologue, ySas2 (KAT8) occurs in solution and is required for acetylation and protein substrate binding in vitro. We also show that this autoacetylation occurs in vivo and is required for the cellular functions of these MYST proteins. These findings provide an avenue for the autoposttranslational regulation of MYST proteins that is distinct from other acetyltransferases but draws similarities to the phosphoregulation of protein kinases. [ABSTRACT FROM AUTHOR]