An ecological perspective on water shedding from leaves

UB is funded by a Royal Society University Research Fellowship (UF150138) and Anne-Kristin Lenz is supported by a Royal Society Enhancement Award (RGF/EA/180059) held by UB.Water shedding from leaves is a complex process depending on multiple leaf traits interacting with rain, wind and air humidity, and with the entire plant and surrounding vegetation. Here, we synthesise the current knowledge of the physics of water shedding with implications for plant physiology and ecology. We argue that the drop retention angle is a more meaningful parameter to characterise the water shedding capacity of leaves than the commonly measured static contact angle. The understanding of the mechanics of water shedding is largely derived from laboratory experiments on artificial rather than natural surfaces, often on individual aspects such as surface wettability or drop impacts. In contrast, field studies attempting to identify the adaptive value of leaf traits linked to water shedding are largely correlative in nature, with inconclusive results. We make a strong case for taking the hypothesis-driven experimental approach of biomechanical lab studies into a real-world field setting to gain a comprehensive understanding of leaf water shedding in a whole-plant ecological and evolutionary context.Publisher PDFPeer reviewe

Combining global genome and transcriptome approaches to identify the candidate genes of small-effect quantitative trait loci in collagen-induced arthritis

Quantitative traits such as complex diseases are controlled by many small-effect genes that are difficult to identify. Here we present a novel strategy to identify the candidate genes for small-effect quantitative trait loci (QTL) in collagen induced arthritis (CIA) using global genome and transcriptome approaches. First, we performed genome linkage analysis in F2 progeny of the CIA susceptible and resistant strains to search for small-effect QTL. Second, we detected gene expression patterns of both strains during CIA. The candidate genes were identified using three criteria: they are located in a genomic region linked to CIA; they are disease-specific differentially expressed during CIA; and they are strain-specific differentially expressed regarding the two parental strains. Eight small-effect QTL controlling CIA severity were identified. Of 22,000 screened genes, 117 were both strain-specific and disease-specific differentially expressed during CIA. Of these 117 genes, 21 were located inside the support intervals of the 8 small-effect QTL and thus were considered as candidate genes

Interactive Effects of Parents’ Trait Verbal Aggressiveness and Situational Frustration on Parents’ Self‐Reported Anger

Examines the relationship between anger experienced by parents\u27 trait verbal aggressiveness and the frustrations, caused by the interaction with children. What was cited as an ordinary interaction between parents\u27 trait verbal aggressiveness and situational frustration; Process in which the examination was conducted; Exploration of a measure of trait verbal aggressiveness to parents; Discussion based on the results

Interactive Effects of Parents’ Trait Verbal Aggressiveness and Situational Frustration on Parents’ Self‐Reported Anger

Examines the relationship between anger experienced by parents\u27 trait verbal aggressiveness and the frustrations, caused by the interaction with children. What was cited as an ordinary interaction between parents\u27 trait verbal aggressiveness and situational frustration; Process in which the examination was conducted; Exploration of a measure of trait verbal aggressiveness to parents; Discussion based on the results

Polymerizing Phostones: A Fast Way to In-Chain Poly(phosphonate)s with Adjustable Hydrophilicity

Phostones, i.e., 2-alkoxy-2-oxo-1,3-oxaphospholanes, are accessible in a one-pot reaction from commercially available 1,3-dibromopropane and alkyl phosphites. These 5-membered cyclic phosphonic acid esters are used for the preparation of linear poly­(phosphonate)­s via ring-opening polymerization resulting in polymers with a hydrolytically stable P–C bond in the polymer backbone. Phostones have the stable P–C bond within the cycle, which leads to a dramatic increase of the monomer stability toward hydrolysis and long shelf-lives compared to other cyclic phosphoesters, which hydrolyze immediately at contact with water. Two phostone monomers containing ethoxy or butoxy pendant chains were prepared in a single-step synthesis from inexpensive starting materials avoiding the usage of SOCl₂ or POCl₃. Polymers with ethoxy side chains are water-soluble without a lower critical solution temperature, nontoxic to murine macrophages, and hydrolytically degradable under basic conditions. The polymerization kinetics for different catalyst systems were evaluated for both monomers in order to identify optimal polymerization conditions, resulting in polyphosphonates with molecular weights between 3000 and 25 100 g/mol with reasonable molecular weight dispersities (<1.6). Because of the ease of synthesis and distinct different hydrolysis kinetics compared to side-chain polyphosphonates, we believe that these new polyphostones represent a valuable addition to water-soluble biopolymers for future biomedical applications

The development of cephalic armor in the tokay gecko (Squamata: Gekkonidae: Gekko gecko)

Armored skin resulting from the presence of bony dermal structures, osteoderms, is an exceptional phenotype in gekkotans (geckos and flap‐footed lizards) only known to occur in three genera: Geckolepis, Gekko, and Tarentola. The Tokay gecko (Gekko gecko LINNAEUS 1758) is among the best‐studied geckos due to its large size and wide range of occurrence, and although cranial dermal bone development has previously been investigated, details of osteoderm development along a size gradient remain less well‐known. Likewise, a comparative survey of additional species within the broader Gekko clade to determine the uniqueness of this trait has not yet been completed. Here, we studied a large sample of gekkotans (38 spp.), including 18 specimens of G. gecko, using X‐rays and high‐resolution computed tomography for visualizing and quantifying the dermal armor in situ. Results from this survey confirm the presence of osteoderms in a second species within this genus, Gekko reevesii GRAY 1831, which exhibits discordance in timing and pattern of osteoderm development when compared with its sister taxon, G. gecko. We discuss the developmental sequence of osteoderms in these two species and explore in detail the formation and functionality of these enigmatic dermal ossifications. Finally, we conducted a comparative analysis of endolymphatic sacs in a wide array of gekkotans to explore previous ideas regarding the role of osteoderms as calcium reservoirs. We found that G. gecko and other gecko species with osteoderms have highly enlarged endolymphatic sacs relative to their body size, when compared to species without osteoderms, which implies that these membranous structures might fulfill a major role of calcium storage even in species with osteoderms.Distribution of osteoderms in the skull of a large sized Tokay gecko (Gekko gecko).Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153558/1/jmor21092_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153558/2/jmor21092.pd

Perforin deficiency attenuates collagen-induced arthritis

Collagen-induced arthritis (CIA), an approved animal model for rheumatoid arthritis, is thought to be a T cell-dependent disease. There is evidence that CD8(+ )T cells are a major subset controlling the pathogenesis of CIA. They probably contribute to certain features of disease, namely tissue destruction and synovial hyperplasia. In this study we examined the role of perforin (pfp), a key molecule of the cytotoxic death pathway that is expressed mainly in CD8(+ )T cells, for the pathogenesis of CIA. We generated DBA/1J mice suffering from mutations of the pfp molecule, DBA/1J-pfp(-/-), and studied their susceptibility to arthritis. As a result, pfp-deficient mice showed a reduced incidence (DBA/1J-pfp(+/+), 64%; DBA/1J-pfp(-/-), 54%), a slightly delayed onset (onset of disease: DBA/1J-pfp(+/+), 53 ± 3.6; DBA/1J-pfp(-/-), 59 ± 4.9 (mean ± SEM), and milder form of the disease (maximum disease score: DBA/1J-pfp(+/+), 7.3 ± 1.1; DBA/1J-pfp(-/-), 3.4 ± 1.4 (mean ± SEM); P < 0.05). Concomitantly, peripheral T cell proliferation in response to the specific antigen bovine collagen II was increased in pfp(-/- )mice compared with pfp(+/+ )mice, arguing for an impaired killing of autoreactive T cells caused by pfp deficiency. Thus, pfp-mediated cytotoxicity is involved in the initiation of tissue damage in arthritis, but pfp-independent cytotoxic death pathways might also contribute to CIA