scholarly journals Smelly feet are not always a bad thing: the relationship between cyprid footprint protein and the barnacle settlement pheromone

2006 ◽  
Vol 2 (3) ◽  
pp. 423-425 ◽  
Author(s):  
Catherine Dreanno ◽  
Richard R Kirby ◽  
Anthony S Clare
Keyword(s):  
Life Cycle ◽  
Protein Complex ◽  
Marine Invertebrates ◽  
Polyclonal Antibodies ◽  
Critical Phase ◽  
Suitable Substratum ◽  
The Relationship

A critical phase in the life cycle of sessile benthic marine invertebrates is locating a suitable substratum for settlement. For barnacles, it is the lecithotrophic cypris larva that makes this plankto–benthic transition. In exploring possible substrata for settlement, the cyprid leaves behind ‘footprints’ of a proteinaceous secretion that reportedly functions as a temporary adhesive, and also acts as a secondary cue in larval–larval interactions at settlement. Here, we show that two polyclonal antibodies raised against peptides localized at the N- and C-terminal regions of the adult settlement cue—the settlement-inducing protein complex (SIPC)—could both detect ‘temporary adhesive’ indicating that the SIPC is either a component of this secretion or that they are the same protein.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Phoronida

2017 ◽  
Author(s):  
Judith Fuchs
Keyword(s):  
Life Cycle ◽  
Small Group ◽  
Larval Stage ◽  
Intertidal Zone ◽  
Marine Invertebrates ◽  
Tree Of Life ◽  
General Morphology ◽  
Family Level ◽  
Planktonic Larval Stage

This chapter describes the taxonomy of Phoronida, a small group of exclusively marine invertebrates found in most of the world's oceans from the intertidal zone to about 400 metres depth. Phoronids are meroplanktonic with a planktonic larval stage usually less than 2 mm in length and a benthic adult whose length ranges from a few cm up to 50 cm. The chapter covers their life cycle, ecology, and general morphology. It includes a section that indicates the systematic placement of the taxon described within the tree of life, and lists the key marine representative illustrated in the chapter (usually to genus or family level). This section also provides information on the taxonomic authorities responsible for the classification adopted, recent changes which might have occurred, and lists relevant taxonomic sources.

Global temperature and life

2017 ◽  
Author(s):  
Andrew Clarke
Keyword(s):  
Life Cycle ◽  
Marine Invertebrates ◽  
Natural World ◽  
Death Valley ◽  
Cell Interior ◽  
Ground Temperatures ◽  
Thermal Limits ◽  
Air Temperatures ◽  
Continental Shelves ◽  
Multicellular Organisms

The extreme meteorological surface air temperatures recorded to date are –89.2 oC in Antarctica, and 56.7 oC in Death Valley, California. Ground temperatures can be higher or lower than these air temperatures. The bulk of oceanic water is cold (< 4 oC) and thermally stable. Whilst data on limits to survival attract considerable attention, the thermal limits to completion of the life cycle (which define the limits to life) are much less well known. Currently identified upper thermal limits for growth are 122 oC for archaeans, 100 oC for bacteria and ~60 oC for unicellular eukaryotes. No unicells appear to grow below –20 oC, a limit that is probably set by dehydration-linked vitrification of the cell interior. The lower thermal limits for survival in multicellular organisms in the natural world extend to at least –70 oC. However in all cases known to date, completion of the life cycle requires summer warmth and the lowest temperature for completion of a multicellular eukaryote life cycle appears to be ~0 oC for invertebrates in glacial meltwater and ~–2 oC for marine invertebrates and fish living on the continental shelves around Antarctica.

Innovation and Corporate Social Responsibility in SMEs

2015 ◽  
Vol 808 ◽  
pp. 359-363
Author(s):  
Cristina Feniser ◽  
Florin Lungu
Keyword(s):  
Corporate Social Responsibility ◽  
Life Cycle ◽  
Open Innovation ◽  
Social Goals ◽  
New Approach ◽  
Rational Management ◽  
Corporate Social ◽  
Qualitative Exploration ◽  
Whole Life Cycle ◽  
The Relationship

So far little attention has been given the differences or the compatibilities between CSR and innovation. Few works treats CSR in combination with innovation. What exactly is the relationship between CSR and innovation? Recent phenomena such as open innovation is based on the concept that the stakeholder's dialogue that overlaps with some dimensions of CSR. Being innovative means to bring organizational and technical improvements which will translate into a better position in the market. These improvements don't just aim the product, but the process by which it is obtained and its whole life-cycle. We're talking about a new approach to innovation, namely its orientation towards sustainability. Although SMEs have many features which facilitate implementation of CSR, activities of this type in such organizations are still limited. SMEs managers often make choices that are related to rational management. This leads to divergence between economical and social goals. Through a qualitative exploration of the concepts of CSR and innovation, we wanted to find out from some managers whether there is a link between innovation and CSR in SMEs and whether the activities corresponding to the two concepts overlap in a certain measure.

scholarly journals The survival of business takeovers and new venture start-ups

2020 ◽  
Vol 29 (3) ◽  
pp. 797-826
Author(s):  
Guoqian Xi ◽  
Jörn Block ◽  
Frank Lasch ◽  
Frank Robert ◽  
Roy Thurik
Keyword(s):  
Life Cycle ◽  
Survival Rate ◽  
Firm Survival ◽  
Organizational Ecology ◽  
New Venture ◽  
Firm Characteristics ◽  
Entry Modes ◽  
Survival Patterns ◽  
Start Ups ◽  
The Relationship

Abstract Business takeovers and new venture start-ups are two important and distinct entry modes of entrepreneurship. They differ from resource-based and organizational ecology perspectives. We compare firm survival patterns and determinants associated with the two entry modes. From two large French datasets, we find that business takeovers have a higher survival rate than new venture start-ups. However, these differences in survival probability reduce over the entrepreneurship life cycle and when controlling for different entrepreneur and firm characteristics. Moreover, we identify differences in determinants of survival for the two groups, highlighting a distinction between the two entrepreneurship entry modes. This work contributes to the literature on the relationship between entrepreneurship entry and firm survival, thereby contributing to both entrepreneurship and firm survival research.

Temporal variation in the weight-size relationship of the mangrove crab Ucides cordatus L. (Decapoda: Ucididae) in relation to its life cycle phases

2014 ◽  
Vol 64 (4) ◽  
pp. 333-342 ◽  
Author(s):  
Marcos de Miranda Leão Leite ◽  
Cynthia Yuri Ogawa ◽  
Carla Ferreira Rezende ◽  
José Roberto Feitosa Silva
Keyword(s):  
Life Cycle ◽  
Condition Factor ◽  
River Estuary ◽  
Total Weight ◽  
Northeastern Brazil ◽  
Annual Life Cycle ◽  
Ucides Cordatus ◽  
Mangrove Crab ◽  
Significant Difference ◽  
The Relationship

The relationship between weight and size of individuals can be used to evaluate the status of a population, which is particularly useful for natural populations that are being exploited. Ucides cordatus occurs on the Atlantic coast of the American continent, from Florida (USA) to Santa Catarina (Brazil). This species is economically very important, most of all in the Northeastern area of Brazil, as well as in the Dominican Republic and Suriname. The objective of this study was to analyze life phases (‘fattening’, ‘matumba’, ‘milk-crab’, ‘maturation’ and ‘walking’) by use of the weight-length relationships, as well as temporal variations in this condition factor for each sex of U. cordatus. For this purpose, individuals were sampled monthly for twenty-four months at the Jaguaribe River estuary, Ceará State, Northeastern Brazil. The relationship between total weight and cephalothorax width was established using regression analysis, adjusted by a power equation. The dynamics of the condition factor were analyzed for each sex using the variation of its averages related to annual life cycle; this was done for each of the previously-mentioned phases. The relationship between total weight and cephalothorax width showed an isometric growth in males and negative allometric growth in females suggesting that, for the same reference size, males are heavier than females. When considering the average of the female condition factors, these were greater than those for males during the annual life cycle, except during the ‘maturation’ phase, which is the phase with a higher demand of energetic reserves for males. Annual variation of the condition factor in females presented no significant difference.

The morphology, formation and development of cysts of Entamoeba

Parasitology ◽  
1969 ◽  
Vol 59 (1) ◽  
pp. 41-53 ◽  
Author(s):  
Elspeth W. McConnachie
Keyword(s):  
Life Cycle ◽  
Present Knowledge ◽  
Comprehensive Review ◽  
Critical Phase

Parasitic amoebae of the genus Entamoeba are transmitted from one host to another as cysts. The active amoeboid forms are so adapted to life within their particular hosts that, outside the host, they soon die, but encysted stages survive conditions fatal to the unprotected amoebae. The cyst is an integral and critical phase in the life-cycle of Entamoeba; its attributes directly influence the dissemination of the organism, and are an important aspect in the epidemiology of amoebiasis. The following account of the morphology, formation and development of the cysts of Entamoeba is an assessment of present knowledge, and is not a comprehensive review of all available observations.

The Roles of Features and Abstraction in Mechanical Design

1994 ◽  
Author(s):  
LeRoy E. Taylor ◽  
Mark R. Henderson
Keyword(s):  
Life Cycle ◽  
Engineering Design ◽  
Design Process ◽  
Design Research ◽  
Mechanical Design ◽  
Product Modeling ◽  
Product Models ◽  
Mechanical Products ◽  
Unique Framework ◽  
The Relationship

Abstract This paper describes the roles of features and abstraction mechanisms in the mechanical design process, mechanical designs, and product models of mechanical designs. It also describes the relationship between functions and features in mechanical design. It is our experience that many research efforts exist in the areas of design and product modeling and, further, that these efforts must be cataloged and compared. To this end, this paper culminates with the presentation of a multi-dimensional abstraction space which provides a unique framework for (a) comparing mechanical engineering design research efforts, (b) relating conceptual objects used in the life cycle of mechanical products, and (c) defining a product modeling space.

scholarly journals Telomeric G-Quadruplexes: From Human to Tetrahymena Repeats

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Erika Demkovičová ◽  
Ľuboš Bauer ◽  
Petra Krafčíková ◽  
Katarína Tlučková ◽  
Petra Tóthova ◽  
...  
Keyword(s):  
Life Cycle ◽  
Base Substitution ◽  
Telomeric Dna ◽  
Purine Base ◽  
Telomeric Sequences ◽  
G Quadruplex ◽  
The Stability ◽  
Scientific Value ◽  
The Relationship ◽  
Adenine Base

The human telomeric and protozoal telomeric sequences differ only in one purine base in their repeats; TTAGGG in telomeric sequences; and TTGGGG in protozoal sequences. In this study, the relationship between G-quadruplexes formed from these repeats and their derivatives is analyzed and compared. The human telomeric DNA sequence G3(T2AG3)3 and related sequences in which each adenine base has been systematically replaced by a guanine were investigated; the result is Tetrahymena repeats. The substitution does not affect the formation of G-quadruplexes but may cause differences in topology. The results also show that the stability of the substituted derivatives increased in sequences with greater number of substitutions. In addition, most of the sequences containing imperfections in repeats which were analyzed in this study also occur in human and Tetrahymena genomes. Generally, the presence of G-quadruplex structures in any organism is a source of limitations during the life cycle. Therefore, a fuller understanding of the influence of base substitution on the structural variability of G-quadruplexes would be of considerable scientific value.

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