Prospects for dendroanatomy in paleoclimatology – a case study on Picea engelmannii from the Canadian Rockies

The continuous development of new proxies as well as a refinement of existing tools are key to advances in paleoclimate research and improvements in the accuracy of existing climate reconstructions. Herein, we build on recent methodological progress in dendroanatomy – the analyses of wood anatomical parameters in dated tree rings – and introduce the longest (1585–2014 CE) dendroanatomical dataset currently developed for North America. We explore the potential of dendroanatomy of high-elevation Engelmann spruce (Picea engelmannii) as a proxy of past temperatures by measuring anatomical cell dimensions of 15 living trees from the Columbia Icefield area. There, X-ray maximum latewood density (MXD) and its blue intensity counterpart (MXBI) have previously been measured, which allows comparing the different parameters. Our findings highlight anatomical MXD and maximum radial cell wall thickness as the two most promising wood anatomical proxy parameters for past temperatures, each explaining 46 % and 49 %, respectively, of instrumental, high-pass filtered, July–August maximum temperatures over the 1901–1994 period. While both parameters display comparable climatic imprinting at higher frequencies to X-ray derived MXD, the anatomical dataset distinguishes itself from its predecessors by providing the most temporally stable warm-season temperature signal. For the long-term secular trends, discrepancies between anatomical MXD and maximum radial cell wall thickness chronologies were observed, where the former more closely follow the long-term variations of the X-ray based MXD. Further studies, including samples from more diverse age cohorts and the adaptation of RCS-based standardizations, are needed to disentangle the ontogenetic and climatic components of long-term signals stored in the wood anatomical traits and to more comprehensively evaluate the potential contribution of this new dataset to paleoclimate research.

Hydrocoel Morphogenesis Forming the Pentaradial Body Plan in a Sea Cucumber, Apostichopus Japonicus

Echinoderms constitute an animal phylum characterized by the pentaradial body plan. During the development from bilateral larvae to pentaradial adults, the formation of the multiple of five hydrocoel lobes, i.e., the buddings from the mesodermal coelom, is the firstly emerging pentameral character. The developmental mechanism underlying the hydrocoel-lobe formation should be revealed to understand the evolutionary process of this unique and highly derived body plan of echinoderms, although the morphogenetic mechanisms of hydrocoel lobes is largely uninvestigated. In this study, using the sea cucumber Apostichopus japonicus, in which the hydrocoel is easily observable, the developmental process of hydrocoel lobes was described in detail, focusing on the cell proliferation and rearrangement. Cell proliferation was not specifically distributed in the growing tips of the hydrocoel lobes and inhibition of the cell proliferation did not affect the lobe formation. During lobe formation, epithelium of the hydrocoel lobes were firstly stratified and then transformed into single-layered, suggesting that radial cell intercalation contributes to hydrocoel-lobe formation.

The Reduced Longitudinal Growth Induced by Overexpression of pPLAIIIγ Is Regulated by Genes Encoding Microtubule-Associated Proteins

There are three subfamilies of patatin-related phospholipase A (pPLA) group of genes: pPLAI, pPLAII, and pPLAIII. Among the four members of pPLAIIIs (α, β, γ, δ), the overexpression of three isoforms (α, β, and δ) displayed distinct morphological growth patterns, in which the anisotropic cell expansion was disrupted. Here, the least studied pPLAIIIγ was characterized, and it was found that the overexpression of pPLAIIIγ in Arabidopsis resulted in longitudinally reduced cell expansion patterns, which are consistent with the general phenotype induced by pPLAIIIs overexpression. The microtubule-associated protein MAP18 was found to be enriched in a pPLAIIIδ overexpressing line in a previous study. This indicates that factors, such as microtubules and ethylene biosynthesis, are involved in determining the radial cell expansion patterns. Microtubules have long been recognized to possess functional key roles in the processes of plant cells, including cell division, growth, and development, whereas ethylene treatment was reported to induce the reorientation of microtubules. Thus, the possible links between the altered anisotropic cell expansion and microtubules were studied. Our analysis revealed changes in the transcriptional levels of microtubule-associated genes, as well as phospholipase D (PLD) genes, upon the overexpression of pPLAIIIγ. Overall, our results suggest that the longitudinally reduced cell expansion observed in pPLAIIIγ overexpression is driven by microtubules via transcriptional modulation of the PLD and MAP genes. The altered transcripts of the genes involved in ethylene-biosynthesis in pPLAIIIγOE further support the conclusion that the typical phenotype is derived from the link with microtubules.

Experimental Study of Vaneless Diffuser Rotating Stall Development and Cell-Merging Phenomena

This paper describes the vaneless diffuser rotating stall (VDRS) development and cell-merging phenomena. A centrifugal compressor’s lifespan may be limited by flow instabilities occurring in off-design operation. One such instability is the VDRS, which generates oscillating, asymmetrical flow fields in the diffuser and, thus, undesired forces acting on the rotor. Understanding and prevention of VDRS behavior are crucial for achieving safe and undisturbed compressor operation. Experimental measurements of centrifugal compressors operating under the influence of VDRS have been presented. Two different approaches were used for the identification of VDRS: pressure measurements and two-dimensional (2D) particle image velocimetry (PIV). Frequency analysis based on spectral maps and cell development processes were investigated. The presented results showed that mass flowrate has an impact on the rotating frequency of both the entire structure and single cells. Additionally, it affects radial cell size, which grows with compressor throttling and ultimately reaches the length of the diffuser. During the experiments, the cell-merging phenomenon was observed which has not been widely described in the literature. The results presented in this paper allow a better understanding of vaneless diffuser rotating stall behavior. The phenomenon of the change of cell size and frequency could be very important for machine fatigue. Cell-merging could also have an impact on the machine’s vibrations and flow stability. Since it is believed that VDRS is one of the factors inducing surge, its understanding and prevention may have a positive influence on surge margins.

Development of an Enhanced-Throughput Radial Cell Migration Device

It is often desirable to evaluate the ability of cells to move in an unrestricted manner in multiple directions without chemical gradients. By combining the standard radial migration assay with injection-molded gaskets and a rigid fixture, we have developed a highly reliable and sensitive method for observing and measuring radial cell migration. This method is adapted for use on high-throughput automated imaging systems. The use of injection-molded gaskets enables low-cost replacement of cell-wetted components. Moreover, the design enables secondary placement of attractants and co-cultures. This device and its enhanced throughput permit the use of therapeutic screening to evaluate phenotypic responses, for example, cancer cell migration response due to drugs or chemical signals. This approach is orthogonal to other 2D cell migration applications, such as scratch wound assays, although here we offer a noninvasive, enhanced-throughput device, which currently is not commercially available but is easily constructed. The proposed device is a systematic, reliable, rapid application to monitor phenotypic responses to chemotherapeutic screens, genetic alterations (e.g., RNAi and CRISPR), supplemental regimens, and other approaches, offering a reliable methodology to survey unbiased and noninvasive cell migration.

Experimental Study of Vaneless Diffuser Rotating Stall Development and Cell Merging Phenomena

This paper describes the vaneless diffuser rotating stall (VDRS) development and cell merging phenomena. A centrifugal compressor’s lifespan may be limited by flow instabilities occurring in off-design operation. One such instability is the VDRS, which generates oscillating, asymmetrical flow fields in the diffuser and, thus, undesired forces acting on the rotor. Understanding and prevention of VDRS behavior is crucial for achieving safe and undisturbed compressor operation. Experimental measurements of centrifugal compressors operating under the influence of VDRS have been presented. Two different approaches were used for the identification of VDRS: pressure measurements and 2D PIV. Frequency analysis based on spectral maps and cell development processes were investigated. The presented results showed that mass flow rate has an impact on the rotating frequency of both the entire structure and single cells. Additionally, it affects radial cell size, which grows with compressor throttling and ultimately reaches the length of the diffuser. During the experiments, the cell merging phenomenon was observed which has not been widely described in the literature. The results presented in this paper allow better understanding of vaneless diffuser rotating stall behavior. The phenomenon of the change of cell size and frequency could be very important for machine fatigue. Cell merging could also have an impact on the machine’s vibrations and flow stability. Since it is believed that VDRS is one of the factors inducing surge, its understanding and prevention may have positive influence on surge margins.

Synergus Hartig species group (Hymenoptera: Cynipidae: Synergini) with partially smooth mesopleurae from the New World

Inquiline oak gall wasps from the genus Synergus Hartig (Hymenoptera: Cynipidae: Synergini) that occur in the New World should be classified into the following morphological groups: i) species with the radial cell of fore wings open; ii) species with the radial cell of fore wings closed and mesopleurae completely sculptured, always with transversal striae covering its surface; iii) species with the radial cell of fore wings closed and mesopleurae partially smooth, with the speculum always shiny and not sculptured. The latter group, which appears to be unique to the New World’s fauna, is the focus of this study. An exhaustive taxonomical revision of all the Synergus species within this morphological group is carried out for the first time after the initial treatment by Lobato-Vila & Pujade-Villar (2017). Redescriptions, images and new distribution and biological data are provided. A new species from Mexico, Synergus aurofacies Lobato-Vila & Pujade-Villar, sp. nov., is here formally described and illustrated. Synergus variegatus McCracken & Egbert, 1922 is a junior synonym of S. flavens McCracken & Egbert, 1922 syn. nov.; S. profusus McCracken & Egbert, 1922 is a junior synonym of S. pacificus McCracken & Egbert, 1922 syn. nov.; and S. flavus Kieffer, 1904 and S. varicolor Fullaway, 1911 are junior synonyms of S. pomiformis (Ashmead, 1885) syn. nov. A key to species of this group is provided. The morphological traits of the species with partially smooth mesopleurae are discussed.

A new genus of railroad-worm beetles from the Atlantic Rainforest from Brazil (Coleoptera: Phengodidae, Mastinocerinae)

Here we describe a new genus, Cleidella gen. nov., and two new species, C. picea sp. nov. and C. silveirai sp. nov., all from Rio de Janeiro State, Brazil. The new genus is characterized by the interantennal distance subequal to scape length, antenna with 11 antennomeres, IV to X with two long symmetrical branches; mandibles long, projected and not crossed, pointed forward obliquely from head; maxillary palpi 4‑segmented, last segment digitiform; labial palpi 2‑segmented; posterior tentorial pit consisting of a single small fossa; elytron surpassing from the fourth to fifth abdominal segment, 3.3‑3.9× longer than wide; first tarsomere of protarsus with a ventral comb as long as the tarsomere length; wing with radial cell closed and transverse, vein r4 interrupted; aedeagus with paramere symmetrical, apex unevenly round, toothed inward, with short and scarce bristles. We provide a key to Mastinocerinae genera with 11 antennomeres, as well as illustrations for the diagnostic features for this new genus and a key to its species.