Natural history and ecological niche modelling of coastal Atyphella Olliff Larvae (Lampyridae: Luciolinae) in Vanuatu

ABSTRACT

The genus Atyphella Olliff includes several coastal species with larvae that were collected on coastal rock within the intertidal zone. Recent fieldwork in Vanuatu has expanded the distribution of these insects and begun to provide insight into how they are able to survive in such a unique environment. An ecological niche model is produced using Maxent to predict additional locations of coastal Atyphella in the South Pacific. Larval instars for the two species of Atyphella in Vanuatu are estimated using protergum shield width measurements. Additionally, submersion tests were performed on larvae to determine survivability in saltwater and freshwater environments. These data provide evidence for previously unknown aspects of their natural history that strongly suggest the species are multivoltine and spend a large portion of their larval stage in the intertidal zone.     

Distributional changes and population status of amphibians in the eastern Mojave Desert

Several amphibian species historically inhabited sparsely distributed wetlands in the Mojave Desert of western North America, habitats that have been dramatically altered or eliminated as a result of human activities. The population status and distributional changes of amphibians were investigated over a 20,000-km 2 area in the eastern Mojave Desert in 2 ways. For upland sites (i.e., sites outside of major valleys and river floodplains), where wetland habitat is almost exclusively springs, encounter surveys were conducted at 128 sites in 1997-1999, and results were compared to historical (pre-1970) locality records. For lowland sites (i.e., sites within major valleys and river floodplains), locality records and field surveys in 1995-2004 were reviewed to detect changes in distribution over time. Amphibians were found at 79% of upland sites. By far the most common species was the red-spotted toad ( Bufo punctatus , 73% of sites), followed by the Pacific chorus frog ( Pseudacris regilla ), Woodhouse's toad ( B. woodhousii ), relict leopard frog ( Rana onca ), and the introduced American bullfrog ( R. catesbeiana ). Taxa observed or collected in the lowlands since 1990 were Woodhouse's toad, Pacific chorus frog, American bullfrog, and the introduced tiger salamander ( Ambystoma tigrinum ). Four taxa (Vegas Valley leopard frog [ Rana sp.], Arizona toad [ B. microscaphus ], Great Plains toad [ B. cognatus ], and Great Basin spadefoot [ Spea intermontana ]) had historical records but no evidence of occurrence in the study area within the past 5 decades. The amphibian fauna of the study area has changed dramatically in the past century, primarily at lowland sites where habitat loss and modification have been extreme. Striking changes are the nearly complete replacement of native leopard frogs (i.e., Vegas Valley and relict leopard frogs) with the introduced bullfrog, and the complete replacement of the Arizona toad in Las Vegas Valley with Woodhouse's toad or hybrids with predominantly Woodhouse's traits. In contrast, the distributions of 2 species characteristic of upland springs, red-spotted toad and Pacific chorus frog, appear to have changed little from their historical distributions, despite habitat modification at many sites.     

Corrosion Protection Properties of Organofunctional Silanes——An Overview

The aim of this paper is to review the development and state of the art in the application of certain organosilicon compounds known as trialkoxysilanes （or simply silanes） to the problems of the metal finishing industry. The ultimate goal of this work is the replacement of chromate passivation and paint pretreatments, as well as overcoming the shortcomings of organic coatings formulated in the modern environmentally friendly world, thus without chromate or chromated pigments, volatile organic carbon （VOC） containing compounds or harazardous air pollutants （HAPs）.     

Cell-specific mitotic defect and dyserythropoiesis associated with erythroid band 3 deficiency

Most eukaryotic cell types use a common program to regulate the process of cell division. During mitosis, successful partitioning of the genetic material depends on spatially coordinated chromosome movement and cell cleavage. Here we characterize a zebrafish mutant, retsina (ret), that exhibits an erythroid-specific defect in cell division with marked dyserythropoiesis similar to human congenital dyserythropoietic anemia. Erythroblasts from ret fish show binuclearity and undergo apoptosis due to a failure in the completion of chromosome segregation and cytokinesis. Through positional cloning, we show that the ret mutation is in a gene (slc4a1) encoding the anion exchanger 1 (also called band 3 and AE1), an erythroid-specific cytoskeletal protein. We further show an association between deficiency in Slc4a1 and mitotic defects in the mouse. Rescue experiments in ret zebrafish embryos expressing transgenic slc4a1 with a variety of mutations show that the requirement for band 3 in normal erythroid mitosis is mediated through its protein 4.1R-binding domains. Our report establishes an evolutionarily conserved role for band 3 in erythroid-specific cell division and illustrates the concept of cell-specific adaptation for mitosis.     

Observations on body mass of prairie dogs in urban habitat

The black-tailed prairie dog is an important component of prairie and steppe ecosystems. Currently many prairie dog colonies are fragmented by, or adjacent to, urban development, but little is known about what effects urbanization may have on these animals. I compare body weights and sex ratios of prairie dogs in isolated urban habitat in Denver, Colorado, to published data for black-tailed prairie dogs at the same time of year. Prairie dogs in this study had summer weights similar to those reported in the literature, although males apparently gained weight earlier in the year, and observed sex ratios were not significantly different from 1:1. Although prairie dogs in urban areas face numerous threats, my study provides no evidence that urban forage is limited enough to result in decreased body mass or skewed sex ratios of urban prairie dogs.     

Seismology: speed and size of the Sumatra earthquake

Our seismological results reveal that Indonesia's devastating Sumatra-Andaman earthquake on 26 December 2004 was 2.5 times larger than initial reports suggested--second only to the 1960 Chilean earthquake in recorded magnitude. They indicate that it slowly released its energy by slip along a 1,200-km fault, generating a long rupture that contributed to the subsequent tsunami. Now that the entire rupture zone has slipped, the strain accumulated from the subduction of the Indian plate beneath the Burma microplate has been released, and there is no immediate danger of a similar tsunami being generated on this part of the plate boundary, although large earthquakes on segments to the south still present a threat.     

Cascades of multisite phosphorylation control Sic1 destruction at the onset of S phase

Multisite phosphorylation of proteins has been proposed to transform a graded protein kinase signal into an ultrasensitive switch-like response. Although many multiphosphorylated targets have been identified, the dynamics and sequence of individual phosphorylation events within the multisite phosphorylation process have never been thoroughly studied. In Saccharomyces cerevisiae, the initiation of S phase is thought to be governed by complexes of Cdk1 and Cln cyclins that phosphorylate six or more sites on the Clb5-Cdk1 inhibitor Sic1, directing it to SCF-mediated destruction. The resulting Sic1-free Clb5-Cdk1 complex triggers S phase. Here, we demonstrate that Sic1 destruction depends on a more complex process in which both Cln2-Cdk1 and Clb5-Cdk1 act in processive multiphosphorylation cascades leading to the phosphorylation of a small number of specific phosphodegrons. The routes of these phosphorylation cascades are shaped by precisely oriented docking interactions mediated by cyclin-specific docking motifs in Sic1 and by Cks1, the phospho-adaptor subunit of Cdk1. Our results indicate that Clb5-Cdk1-dependent phosphorylation generates positive feedback that is required for switch-like Sic1 destruction. Our evidence for a docking network within clusters of phosphorylation sites uncovers a new level of complexity in Cdk1-dependent regulation of cell cycle transitions, and has general implications for the regulation of cellular processes by multisite phosphorylation.