Weitere biologische Literatur (eingeschränkter Zugriff)
345 search hits
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The seed surface morphology of the Gesneriaceae utilizing the scanning electron microscope and a new system for diagnosing seed morphology
(1983)
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Helen T. Beaufort-Murphy
- The seed collection of the species of the Gesneriaceae on which this
study is based was obtained, for the most part, during a number of visits to
the herbaria of the Smithsonian Institution, Washington, D.C., and the Royal
Botanical Garden of Kew, London, and Edinburgh, Scotland. The seed collection
comprises well over 800 samples of about 700 species of the Gesneriaceae,
representing 113 genera of the 127 in the family, and provides a good
taxonomic representation of the Gesneriaceae. Following an examination of
all the samples in the seed collection, over 300 species of the 113 genera
were selected to represent the wide range of seed morphology characters observed
among the examined species of the Gesneriaceae.
A system with which to analyze and diagnose seed surface morphology,
designed by the author, is based on a format of six major categories and 60
tertiary terms of seed morphology characters and a companion diagnostic
table. The categories are arranged in a sequence of increasingly smaller seed
characters, ranging from seed shape to the ultrastructural characters of the
individual cells. To ensure that the system would also apply to seed plants in
general, the seeds, achenes and nutlets of a wide variety of species from families
other than the Gesneriaceae were examined. Twenty species from 13
families other than the Gesneriaceae were then selected and are included in
this study and, together with the Gesneriaceae, represent eight of the ten
subclasses of the flowering plants (Cronquist 1968).
The seeds, achenes and nutlets of all the species included in this study are
illustrated with SEM photomicrographs on the 54 plates of the Seed Atlas,
and the seed morphology data of each species are recorded on the diagnostic
tables that face each of the Atlas Plates. To facilitate the comparison of the
taxa of the Gesneriaceae, and to assist in the identification of the seeds of
the examined species of the Gesneriaceae, the seed morphology data are also
recorded on a summary table at the genus, tribe, subfamily and family levels.
The seed morphology of the Gesneriaceae is compared and contrasted with
the current classifications of the family at the species, genus, tribe, subfamily
and family levels.
The seed analysis system designed for this study has proven to be a rapid,
efficient, uniform, objective method to deal with the analytical, diagnostic,
and taxonomic aspects of an investigation of seed morphology. In addition,
the system readily lends itself to the substitution or addition of terms and
categories if needed, or to programming for a computerized analysis of seed
morphology. It is hoped that the system will prove useful to other investigators,
as well as prove helpful to standardize future investigations of seed
morphology.
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Floral evolution in the Ranunculaceae
(1964)
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Elmar Emil Leppik
- Six clearly separable evolutionary levels in the floral evolution of the Ranunculaceae were found to
coincide with the six corresponding stages of sensory development of their pollinators as follows: amorphic -> haplomorphic -> actinomorphic -> pleomorphic -> stereomorphic-zygomorphic. This is a basic trend of floral evolution, fully recapitulated in a single family. Except for the first (amorphic), all upper levels are represented in the present-day floras as clearly separable type-classes. They are therefore accessible to direct observations and experimental study. Extensive
statistical data on flower visitors of the Ranunculaceae confirm the proposed theory of the mutual
interrelationship between the evolutionary levels of flower types and sensory stages of pollinating insects. The new picture, obtained by this study, gives us a better understanding of the evolutionary relationship between insects and plants and explains the extreme diversity in the floral structure of the Ranunculaceae.
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Australasian arachnology, Number 82, August 2011
(2011)
- Welcome to Issue 82 of Australasian
Arachnology. The last six months have been
extremely productive for the Australasian
Arachnological Society, with nine new
members and numerous new papers being
published by existing AAS members. It is
wonderful to see such a dynamic and growing
membership, and to witness the continuing
fascination elicited by our remarkable arachnid
fauna. Indeed, since the beginning of 2011, over
50 new species of arachnids have been
described from Australasia, including pseudoscorpions
and numerous spiders in the families
Selenopidae, Archaeidae, Amaurobiidae, Tetragnathidae
and Araneidae. The sheer diversity
of undescribed arachnid species in Australasia
has always posed a challenge to systematists
and ecologists, but major attempts are being
made to document the fauna. Take, for example,
Pinkfloydia, a new genus of Tetragnathidae
recently described from Western
Australia!
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Australasian arachnology, Number 83, February 2012
(2012)
- Welcome to Issue 83 of Australasian
Arachnology. I’d like to begin this editorial by
once again noting the steady stream of new
members who are joining the society, and
observing (as always) the exemplary recent
research outputs in the Australasian region. The
Australasian arachnological community continues
to maintain a strong interest in our
remarkable arachnid fauna, and continues to
promote arachnology throughout the region.
This is by no means a straightforward task,
given the negative public perceptions that often
accompany our eight-legged friends, and given
the sometimes challenging research funding
environment for taxonomic and biodiversity
research. Certainly, having watched the society
grow over the last twenty years, and having
seen perceptions of the Australasian fauna
change during that time, it is both reassuring
and exciting to look ahead. With unparalleled
population growth throughout the region and
the world, and unprecedented pressures on our
natural landscapes, habitats and remaining
natural biomes, it is critical that arachnids (and
indeed all invertebrates) continue to receive the
growing recognition they deserve among
ecologists, conservation biologists, legislators
and the public at large. The 10th Invertebrate
Biodiversity and Conservation Conference in
Melbourne in December 2011 confirmed just
how active research in this field is, and there is
no doubt that Australasian arachnids will
continue to be the focus of much positive
attention over the next few years.
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Australasian arachnology, Number 84, August 2012
(2012)
- Welcome to Issue 84 of Australasian
Arachnology. I’d like to begin this editorial by
first making special mention of the late Doug
Wallace OAM (1923-2012), who passed away
in June this year. Doug was a founding member
of the Australasian Arachnological Society, and
would be further known to many as the founder
and President of the long-running Rockhampton
Arachnological Society. Robert Raven and I
have written a small notice re. Doug’s passing
in the General Announcements section (below),
and Robert will contribute a full obituary for
Doug in the following issue of the newsletter.
Vale Doug – you will be sorely missed.
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Generation of recombinant antibodies against membrane proteins by phage display
(2007)
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Syed Hussain Mir
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Effect of the histone deacetylase inhibitor LAQ824 in colon cancer cells
(2007)
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Ignacio Portero Robles
- Colorectal cancer is one of the most cause of cancer and death in Western societies. Recently, histone deacetylase inhibitors (HDIs), which regulate transcription through modification of chromatin structure, received considerable interest on the ground of they ability to stop the growth and induce cell death in colon cancer tumours, representing a promising transcriptional cancer therapy. This kind of cancer initiates with an activating mutation in the Wnt cascade, allowing the nuclear import of ß-catenin binding to LEF/TCF. This induces the overexpression of growthpromoting oncogenes affecting the cell cycle arrest, lineage-specific cell differentiation and apoptosis processes. In addition, ß-catenin also participates in cell-cell adhesion via interactions with E-cadherin, which can be repressed by families of transcription factors Snail and ZEB. This, and gain of vimentin has been closely correlated with local invasion and metastasis since they avoid the induction of apoptosis through the loss of cell anchorage, a phenomenon called anoikis. In this process the inactivation of the kinases Src an FAK provoking disruption of focal adhesion complexes through is involved. LAQ824 is a HDAC inhibitor derivative of hydroxamic acid, which present antitumor effect in colon and other cancer cells. The aim of this study is to analyse the effect of LAQ824 in cell proliferation, apoptosis, motility and tumour invasion in a colon carcinoma model based on the adenoma-carcinoma sequence descrying trough which pathways LAQ824 is able to cause these effects. Here I demonstrate for the first time that a HDAC inhibitor, LAQ824, induces detachmentinduced cell death of colon cancer cell lines HCT116 and HT-29, a phenomenon called anoikis, in a caspase-dependent and p53-independent manner. In this process the component of the Wnt signalling pathway ß-catenin is involved. Furthermore LAQ824 upregulates the adhesion molecule E-cadherin expression in these cell lines independently of its repressor Snail, but probably mediated by the repressor ZEB. In addition LAQ824-induced anoikis is caused by disruption of focal adhesion complexes through inhibition of the activity of the kinases FAK and Src inhibiting cell motility indicating a strong antimetastatic potential for LAQ824.
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Structural genomics on prokaryotic membrane proteins
(2007)
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Sachin Badrinath Surade
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An essential role of chloride in prokaryotes : osmoregulation in the moderately halophilic bacterium Halobacillus halophilus
(2007)
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Stephan H. Saum
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Functional characterization of TRPV4
(2007)
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Daniel Becker
