Moose Browsing Tends Spruce Plantations More Efficiently Than a Single Mechanical Release

Forest vegetation management can improve planted seedling survival and growth and is thus widely used in plantation silviculture. In some jurisdictions, mechanical release using brushsaws has replaced the traditional use of chemical herbicides for forest vegetation management purposes. However, its associated costs and the increasing difficulty of finding qualified labor represent a challenge. The browsing of competition by large herbivores may represent an alternative to mechanical release when planted seedlings are resistant to browsing. Here, we compare the efficacy of moose browsing relative to mechanical release in controlling competing vegetation and in promoting white spruce growth in plantations. In a high moose density region, we used an experimental design consisting of four pairs of moose exclosures and unfenced plots; fifty percent of both the access-restricted and unrestricted study areas received a mechanical release treatment. Moose browsing was more efficient than mechanical release in diminishing the sapling density and basal area of competing species. Mechanical release only reduced the sapling density of taller competitors (height > 201 cm), whereas browsing reduced the sapling densities of competitors across a greater size range (height > 130 cm). These effects of moose browsing on competition translated into a greater positive effect of moose browsing on the basal area of planted spruces. We attribute the higher effectiveness of moose browsing relative to mechanical release to its chronic nature. Moose browsed continuously throughout the year and for multiple years, whereas mechanical release was applied only one time between the second and fourth years after planting. Our results suggest that pairing wildlife management and silviculture decisions could be in the best interest of both the hunting and forestry industries in regions where plantations are frequent and use browse-resistant crop trees. Favouring browsers in controlling the density of competing species could increase the hunting experience and income, while providing an effective, cost-free, and socially acceptable forest vegetation management service.

Separations-encoded microparticles for single-cell western blotting

Direct measurement of proteins from single cells has been realized at the microscale using microfluidic channels, capillaries, and semi-enclosed microwell arrays. Although powerful, these formats are constrained, with the enclosed geometries proving cumbersome for multistage assays, including electrophoresis followed by immunoprobing. We introduce a hybrid microfluidic format that toggles between a planar microwell array and a suspension of microparticles. The planar array is stippled in a thin sheet of polyacrylamide gel, for efficient single-cell isolation and protein electrophoresis of hundreds-to-thousands of cells. Upon mechanical release, array elements become a suspension of separations-encoded microparticles for more efficient immunoprobing due to enhanced mass transfer. Dehydrating microparticles offer improved analytical sensitivity owing to in-gel concentration of fluorescence signal for high-throughput single-cell targeted proteomics.

Advances in Temporary Bonding and Debonding Technologies for use with Wafer-Level System-in-Package (WLSiP) and Fan-Out Wafer-Level Packaging (FOWLP) Processes

Today's complex fan-out wafer-level packaging (FOWLP) processes include the use of redistribution layers (RDL) and reconstituted wafers with epoxy mold compound (EMC) for use in heterogeneous integration [1]. Wafer-level system-in-package (WLSiP) uses fan-out wafer-level packaging (FOWLP) to build the system-in-package (SiP) by attaching know-good die (KGD) in a chip-first process to a tape laminated temporary carrier. If the dies are attached in a die-up configuration (active area facing up) and then over-molded with EMC, contact pads on the embedded die are exposed during the backside grind process. During the RDL build, the temporary carrier supplies mechanical support for the thinned substrate. In a die-down configuration with the active area facing down (eWLB), the temporary carrier is removed after the molding process thus exposing the contact pads for RDL build and solder ball mount. The ideal chip attachment scheme should minimize lateral movement of the die during over-mold (die shift) and also minimize vertical deformation of the bonding material. Thermal release tape provides a convenient way to attach die to a carrier prior to over-molding with EMC. However, not all bonding materials are suitable for presentation in tape form, so the material used in the tape may not be the optimal choice. An alternative method is to directly apply temporary bonding material to the carrier substrate. This enables the use of bonding materials with higher melt viscosity and improved thermal stability, resulting in less vertical deformation during die placement, and reduced die shift during over-molding. The bonding material will ideally have high adhesion to the EMC wafer to prevent delamination in the bond line during downstream processing. Stack stress and warpage is a major concern which causes handling and alignment problems during processing. The bonding material and carrier will need to be specifically suited to minimize the effects of stress in the compound wafer. Such material must balance rigidity with warp to prevent lateral die shift and deformation induced by coefficient of thermal expansion (CTE) mismatch between the carrier and EMC material [2]. Bonding materials must also have enough adhesion to the EMC material to overcome such stress without bond failure for an associated debond path (such as laser or mechanical release). In this experiment, we will examine a thermoplastic bonding material in combination with different release materials, addressing die shift, and deformation after EMC processing. Successful pairs will then undergo carrier release using either mechanical release or laser ablation release technology.