In light of rapid shifts in biodiversity associated with human impacts, there is an urgent need to understand how changing patterns in biodiversity impact ecosystem function. Functional redundancy is hypothesized to promote ecological resilience and stability, as ecosystem function of communities with more redundant species (those that perform similar functions) should be buffered against the loss of individual species. While functional redundancy is being increasingly quantified, few studies have linked differences in redundancy across communities to ecological outcomes. We conducted a review and meta‐analysis to determine whether empirical evidence supports the asserted link between functional redundancy and ecosystem stability and resilience. We reviewed 423 research articles and assembled a data set of 32 studies from 15 articles across aquatic and terrestrial ecosystems. Overall, the mean correlation between functional redundancy and ecological stability/resilience was positive. The mean positive effect of functional redundancy was greater for studies in which redundancy was measured as species richness within functional groups (vs. metrics independent of species richness), but species richness itself was not correlated with effect size. The results of this meta‐analysis indicate that functional redundancy may positively affect community stability and resilience to disturbance, but more empirical work is needed including more experimental studies, partitioning of richness and redundancy effects, and links to ecosystem functions.

In 3-D interconnect structures, process-induced thermal stresses around through-silicon-vias (TSVs) raise serious reliability issues such as Si cracking and performance degradation of devices. In this study, the thermo-mechanical reliability of 3-D interconnect was investigated using finite element analysis (FEA) combined with analytical methods. FEA simulation demonstrated that the thermal stresses in silicon decrease as a function of distance from an isolated TSV and increase with the TSV diameter. Additional simulation suggested that hybrid TSV structures can significantly reduce the thermal stresses. An analytical stress solution was introduced to deduce the stress distribution around an isolated TSV, which was further developed to deduce the stress interaction in TSV arrays based on linear superposition of the analytical solution. We calculated the crack driving force in TSV lines under a thermal load. The effects of TSV diameter, pitch size, and the line configuration on crack driving force were investigated.

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Deciphering molecular structures of dissolved organic matter (DOM) components is key to understanding the formation and transformation of this globally important carbon pool in aquatic environments. Such a task depends on the integrated use of complementary analytical techniques. We characterize the molecular structure of natural DOM using an ion mobility quadrupole time of flight liquid chromatography mass spectrometer (IM Q-TOF LC/MS), which provides multidimensional structural information on DOM molecules. Geometric conformation of DOM molecules is introduced into molecular-level analysis via the ion mobility (IM) in the system, and an actual measurement of isomers is achieved for the first time. Our data show that natural DOM molecules from several south Texas rivers and adjacent coastal waters have smaller geometric conformation compared with standard biomolecules. Furthermore, about 10% of all DOM molecules resolved within the detection limit of IM-MS had at least one but no more than four isomers. With acquired geometric and isomeric information, we established a multidimensional database containing 89 natural DOM compounds. This database provides a foundation to expand further, or compare, with DOM data from different seasons and locations.

Cyanobacterial harmful algal blooms (CyanoHABs) are enhanced by anthropogenic pressures, including excessive nutrient (nitrogen, N, and phosphorus, P) inputs and a warming climate. Severe eutrophication in aquatic systems is often manifested as non-N-fixing CyanoHABs (e.g., Microcystis spp.), but the biogeochemical relationship between N inputs/dynamics and CyanoHABs needs definition. Community biological ammonium (NH) demand (CBAD) relates N dynamics to total microbial productivity and NH deprivation in aquatic systems. A mechanistic conceptual model was constructed by combining nutrient cycling and CBAD observations from a spectrum of lakes to assess N cycling interactions with CyanoHABs. Model predictions were supported with CBAD data from a Microcystis bloom in Maumee Bay, Lake Erie, during summer 2015. Nitrogen compounds are transformed to reduced, more bioavailable forms (e.g., NH and urea) favored by CyanoHABs. During blooms, algal biomass increases faster than internal NH regeneration rates, causing high CBAD values. High turnover rates from cell death and remineralization of labile organic matter consume oxygen and enhance denitrification. These processes drive eutrophic systems to NH limitation or colimitation under warm, shallow conditions and support the need for dual nutrient (N and P) control.