bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication and magnetoelectronic properties of field aligned CrO2 powders
Authors: Tripathy D. , Adeyeye A. O.
Published: January 2006

We have combined field alignment technique together with lithography to fabricate CrO2 powder based devices. A systematic study of the temperature‐dependent magnetoelectronic properties has been carried out. The devices exhibit strong anisotropy along the alignment direction at all temperatures. Temperature dependent analysis of the hysteresis loops shows that coercivity of the field aligned powders increases with decreasing temperature. The conduction mechanism has been examined in detail and a transition from tunneling across grain boundaries to inelastic hopping was observed at 215 K. This transition temperature shifts to 230 K in the presence of 10 kOe field cooling due to reduction of the spin‐independent hopping conductance channel. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Atmospheric pressure ionisation mass spectrometric fragmentation pathways of noscapine and papaverine revealed by multistage mass spectrometry and in‐source deuterium labelling
Authors: Wickens James R. , Sleeman Richard , Keely Brendan J.
Published: January 2006

Two opium alkaloids, noscapine and papaverine, show good response as [M+H]+ ions in positive ion electrospray mass spectrometry and atmospheric pressure chemical ionisation mass spectrometry. The two compounds exhibit markedly different fragmentation pathways and behaviour under multistage mass spectrometry (MSn), with papaverine displaying a wealth of ions in MS2 and noscapine providing a single dominant ion at each stage of MSn prior to MS4. Elucidation of the fragmentation pathways using the MSn capability of the ion trap was aided by spraying the analytes in 2H2O to incorporate an isotopic label. Simplex optimisation allowed optimum trapping and fragmentation parameters to be determined, leading to a six‐fold improvement in response for one transition and a seven‐fold improvement for one transition sequence. Copyright © 2006 John Wiley & Sons, Ltd.
On estimation of the variance in Cochran–Armitage trend tests for genetic association using case–control studies
Authors: Zheng Gang , Gastwirth Joseph L.
Published: January 2006

The Cochran–Armitage trend test has been used in case–control studies for testing genetic association. As the variance of the test statistic is a function of unknown parameters, e.g. disease prevalence and allele frequency, it must be estimated. The usual estimator combining data for cases and controls assumes they follow the same distribution under the null hypothesis. Under the alternative hypothesis, however, the cases and controls follow different distributions. Thus, the power of the trend tests may be affected by the variance estimator used. In particular, the usual method combining both cases and controls is not an asymptotically unbiased estimator of the null variance when the alternative is true. Two different estimates of the null variance are available which are consistent under both the null and alternative hypotheses. In this paper, we examine sample size and small sample power performance of trend tests, which are optimal for three common genetic models as well as a robust trend test based on the three estimates of the variance and provide guidelines for choosing an appropriate test. Copyright © 2006 John Wiley & Sons, Ltd.
Minimization of the energy storage requirements of a stand‐alone wind power installation by means of photovoltaic panels
Authors: Kaldellis J.K. , Kostas P. , Filios A.
Published: January 2006

Autonomous wind power systems are among the most interesting and environmentally friendly technological solutions for the electrification of remote consumers. In many cases, however, the battery contribution to the initial or the total operational cost is found to be dominant, discouraging further penetration of the available wind resource. This is basically the case for areas possessing a medium–low wind potential. On the other hand, several isolated consumers are located in regions having the regular benefit of an abundant and reliable solar energy supply. In this context the present study investigates the possibility of reducing the battery size of a stand‐alone wind power installation by incorporating a small photovoltaic generator. For this purpose an integrated energy production installation based exclusively on renewable energy resources is hereby proposed. Subsequently a new numerical algorithm is developed that is able to estimate the appropriate dimensions of a similar system. According to the results obtained by long‐term experimental measurements, the introduction of the photovoltaic panels considerably improves the operational and financial behaviour of the complete installation owing to the imposed significant battery capacity diminution. Copyright © 2006 John Wiley & Sons, Ltd.
Quantifying offshore wind resources from satellite wind maps: study area the North Sea
Authors: Hasager C. B. , Barthelmie R. J. , Christiansen M. B. , Nielsen M. , Pryor S. C.
Published: January 2006

Offshore wind resources are quantified from satellite synthetic aperture radar (SAR) and satellite scatterometer observations at local and regional scale respectively at the Horns Rev site in Denmark. The method for wind resource estimation from satellite observations interfaces with the wind atlas analysis and application program (WAsP). An estimate of the wind resource at the new project site at Horns Rev is given based on satellite SAR observations. The comparison of offshore satellite scatterometer winds, global model data and in situ data shows good agreement. Furthermore, the wake effect of the Horns Rev wind farm is quantified from satellite SAR images and compared with state‐of‐the‐art wake model results with good agreement. It is a unique method using satellite observations to quantify the spatial extent of the wake behind large offshore wind farms. Copyright © 2006 John Wiley & Sons, Ltd.
A novel toxin from the venom of the scorpion Tityus trivittatus, is the first member of a new α‐KTX subfamily
Authors: Abdel-Mottaleb Yousra , Coronas Fredy V. , de Roodt Adolfo R. , Possani Lourival D. , Tytgat Jan
Published: January 2006

The first example of a new sub‐family of toxins (α‐KTx20.1) from the scorpion Tityus trivittatus was purified, sequenced and characterized physiologically. It has 29 amino acid residues, three disulfide bridges assumed to adopt the cysteine‐stabilized α/β scaffold with a pI value of 8.98. The sequence identities with all the other known α‐KTx are less than 40%. Its effects were verified using seven different cloned K+ channels (vertebrate Kv1.1–1.5, Shaker IR and hERG) expressed in Xenopus leavis oocytes. The toxin‐induced effects show large differences among the different K+ channels and a preference towards Kv1.3 (EC50 = 7.9 ± 1.4 nM).
TbGPI16 is an essential component of GPI transamidase in Trypanosoma brucei
Authors: Hong Yeonchul , Nagamune Kisaburo , Ohishi Kazuhito , Morita Yasu S. , Ashida Hisashi , Maeda Yusuke , Kinoshita Taroh
Published: January 2006

Glycosylphosphatidylinositol (GPI) is widely used by eukaryotic cell surface proteins for membrane attachment. De novo synthesized GPI precursors are attached to proteins post‐translationally by the enzyme complex, GPI transamidase. TbGPI16, a component of the trypanosome transamidase, shares similarity with human PIG‐T. Here, we show that TbGPI16 is the orthologue of PIG‐T and an essential component of GPI transamidase by creating a TbGPI16 knockout. TbGPI16 forms a disulfide‐linked complex with TbGPI8. A cysteine to serine mutant of TbGPI16 was unable to fully restore the surface expression of GPI‐anchored proteins upon transfection into the knockout cells, indicating that its disulfide linkage with TbGPI8 is important for the full transamidase activity.
The heritability of perceived stress
Authors: FEDERENKO ILONA S. , SCHLOTZ WOLFF , KIRSCHBAUM CLEMENS , BARTELS MEIKE , HELLHAMMER DIRK H. , WÜST STEFAN
Published: January 2006

Background. Exploration of the degree to which perceived chronic stress is heritable is important as these self-reports have been linked to stress-related health outcomes. The aims of this study were to estimate whether perceived stress is a heritable condition and to assess whether heritability estimates vary between subjective stress reactivity and stress related to external demands.

Method. A sample of 103 monozygotic and 77 dizygotic twin pairs completed three questionnaires designed to measure perceived stress: the Perceived Stress Scale (PSS), the Measure for the Assessment of Stress Susceptibility (MESA) and the Trier Inventory for the Assessment of Chronic Stress (TICS). The TICS assesses the frequency of stressful experiences on six scales, the MESA assesses subjective stress reactivity, and the PSS takes both factors into account.

Results. A multivariate model-fitting procedure revealed that a model with common additive genetic and shared environmental factors best fit the eight scales (PSS, MESA, six TICS scales). Heritabilities for the best-fitting model varied between 5% and 45%, depending on the scale.

Conclusions. The present data suggest that perceived stress is in part heritable, that nearly half of the covariance between stress scales is due to genetic factors, and that heritability estimates vary considerably, depending on the questionnaire. Beyond methodological considerations that pertain to the validity of the questionnaires, these data suggest that studies assessing the heritability of perceived chronic stress should take the specific questionnaire focus into account.
Induction of strand breaks by low-energy electrons (8–68eV) in a self-assembled monolayer of oligonucleotides: Effective cross sections and attenuation lengths
Authors: Cai Zhongli , Dextraze Marie-Eve , Cloutier Pierre , Hunting Darel , Sanche Léon
Published: January 2006

Self-assembled monolayers of 5′-P32-labeled 3′-thiolated oligonucleotides chemisorbed on gold were bombarded by low-energy electrons (LEE) of 8–68eV. Shorter 5′-P32-oligonucleotides produced by LEE-induced strand breaks were separated with denaturing polyacrylamide gel electrophoresis and quantified by phosphor imaging. The yields of short oligonucleotides (y) decrease exponentially with their length (n), following the equation y=ae−bn, where a and b are constants, which are related to the average effective cross section per nucleotide for DNA strand break (σeff) and the attenuation length (AL=1∕b) of LEE, respectively. The AL decreases with LEE energies from 2.5±0.6nm at 8eVto0.8±0.1nm at 68eV, whereas σeff increases from (3±1)×10−18to(5.1±1.6)×10−17cm2 within the same energy range. The energy dependence of σeff shows a resonance peak of (2.8±0.9)×10−17cm2 at 18eV superimposed on a monotonically rising curve. Transient electron attachment to a σ* anion state of the deoxyribose group, followed by dipolar dissociation into H− and the corresponding positive-ion radical, leading to C–O bond cleavage, is proposed to account for this maximum.
Manganese doping and optical properties of ZnS nanoribbons by postannealing
Authors: Li Y. Q. , Zapien J. A. , Shan Y. Y. , Liu Y. K. , Lee S. T.
Published: January 2006

Manganese (Mn) doping of ZnS nanoribbons was achieved by simple thermal annealing. Upon heating ZnS nanoribbons with MnS powder up to 700°C, the intrinsic photoluminescence (PL) of the annealed nanoribbons disappeared and a new PL peak at 585nm gradually emerged. Significantly, the annealing process induced no detectable change in the morphology and uniform hexagonal wurtzite 2H structure of the single-crystal ZnS nanoribbons. The PL peak at 585nm is attributed to Mn dopant and confirms Mn incorporation in ZnS because (1) the peak appears only when ZnS ribbons were annealed with MnS, but does not appear without MnS, (2) its intensity increases with increasing annealing temperature, which is consistent with increased incorporation of Mn2+ ions, and (3) its position is similar to that of Mn-related emission in ZnS, and is independent of the measuring temperature and excitation power. This work demonstrates the capability of doping nanostructured materials by simple postannealing treatment.
Consequences of niobium doping for the ferromagnetism and microstructure of anatase Co:TiO2 films
Authors: Zhang S. X. , Ogale S. B. , Fu L. F. , Dhar S. , Kundaliya D. C. , Ramadan W. , Browning N. D. , Venkatesan T.
Published: January 2006

It is shown that dilute niobium doping has a significant effect on the ferromagnetism and microstructure of dilutely cobalt-doped anatase TiO2 films. Epitaxial films of anatase TiO2 with 3% Co, without and with 1% niobium doping were grown by pulsed-laser deposition at 875°C at different oxygen pressures. For growth at 10−5Torr niobium doping suppresses the ferromagnetism, while it enhances the same in films grown at 10−4Torr. High-resolution Z-contrast scanning transmission electron microscopy and electron energy loss spectroscopy show uniform surface segregation of cobalt-rich Ti1−x−yCoxNbyO2−δ phase, but without cobalt metal clusters.
Optical and structural changes of silver nanoparticles during photochromic transformation
Authors: Dahmen C. , Sprafke A. N. , Dieker H. , Wuttig M. , von Plessen G.
Published: January 2006

Silver nanoparticles embedded in titanium oxide change their color upon irradiation with visible light. Here we investigate the origin of this photochromic effect. The color change is found to result chiefly from a reduction of the optical extinction peak of the photoexcited particle plasmons. From a comparison with x-ray diffraction experiments, we conclude that this reduction is caused by a photoinduced decrease of the mean size of the silver nanocrystals.
Metabolism of lactate by mature boar spermatozoa
Authors: Jones A. R.
Published: January 2006

Boar sperm oxidatively metabolized fructose, glucose, glycerol, glycerol
3-phosphate and lactate to CO2 but pyruvate produced
only small amounts of CO2 and this was almost completely
prevented when endogenous glycolytic metabolism was inhibited. Lactate was the
preferred substrate over fructose, glycerol and glycerol 3-phosphate and when
lactate was offered in the presence of pyruvate, lactate was preferentially
oxidized to CO2. The rate of oxidation of fructose,
glycerol and glycerol 3-phosphate was approximately halved in the presence of
equi-molar concentrations of lactate and the metabolism of lactate was
progressively decreased in the presence of increasing concentrations of
mersalyl, an inhibitor of lactate transport. Sperm maintained a high energy
charge potential when incubated with lactate as substrate in the presence or
absence of bromopyruvate, an inhibitor of endogenous glycolytic metabolism.
This evidence confirms that it is lactate, rather than pyruvate, that enters
the mitochondria thereby constituting a lactate–pyruvate transport
system in these cells for regenerating cytoplasmic nicotinamide adenine
dinucleotide (NAD +). Electrophoretic examination of the
lactate dehydrogenase isozymes from sperm and several other tissues of the
boar showed that sperm contained almost entirely an isozyme which was not
present in the other tissues.
SRY and karyotypic status of one abnormal and two intersexual marsupials
Authors: Watson C. M. , Johnston P. G. , Rodger K. A. , McKenzie L. M. , O'Neill R. J. Waugh , Cooper D. W. , Cooper D. W.
Published: January 2006

An intersexual agile wallaby (Macropus agilis) with a
penis, a pouch and four teats had a sex-chromosome constitution of XXY in
lymphocytes and cultured fibroblasts; the sex-determining region Y
(SRY) gene was present, consistent with the presence of
a testis. An intersexual eastern grey kangaroo
(Macropus giganteus) with a small empty scrotum and no
penis, and an abnormal red kangaroo (Macropus rufus)
with no penis, pouch or teats, both had XX sex-chromosome complements; the SRY
gene was not present, consistent with testis absence. The agile wallaby and
grey kangaroo described here provide further evidence that scrotal development
in marsupials is independent of the Y chromosome. The cause of the
abnormalities in the XX individuals cannot be determined until candidate genes
are identified. These animals provide a basis for further genetic studies into
marsupial intersexuality and sex differentiation.
Fertilization of bovine oocytes grown in vitro
Authors: Osaki Shigeru , Matsumura Kenji , Yamamoto Ken , Miyano Takashi , Miyake Masashi , Kato Seishiro
Published: January 2006

Early antral follicles 0·5–0·7 mm in diameter were
dissected from bovine ovaries, and oocyte–cumulus complexes with pieces
of parietal granulosa (OCCGs) were then collected from the follicles. The
OCCGs containing oocytes of 90–99 m diameter (94·7 ±
2·8 µm, n = 196) were selected and
embedded in collagen gels and cultured for 14 days in TCM199 containing
10% fetal calf serum and 4 mM hypoxanthine. From cultured OCCGs, 144
surviving oocytes were recovered, of which 53 were granulosa cell-enclosed
oocytes and 91 were denuded oocytes. The mean diameter of the surviving
oocytes was 114·2 ± 8·4 µm, significantly larger
than that measured before culture (P < 0·05).
The granulosa cell-enclosed oocytes and denuded oocytes were further cultured
for maturation for 24 h. After culture, 72% (38/53) of the
granulosa cell-enclosed oocytes and 59% (54/91) of the denuded
oocytes showed normal morphology. These oocytes were then inseminated with
bovine spermatozoa. After 29 h of insemination, all of the denuded oocytes had
degenerated, while 32% (12/38) of the granulosa cell-enclosed
oocytes showed normal morphology. Of the 12 oocytes, 5 were penetrated by
spermatozoa, and 2 formed both male and female pronuclei. These results
demonstrate for the first time that bovine oocytes grown
in vitro acquire meiotic competence and can be
penetrated by spermatozoa.
Suppression of arousal by progesterone in fetal sheep
Authors: Crossley Kelly J. , Nicol Marcus B. , Hirst Jonathan J. , Walker David W. , Thorburn† Geoffrey D.
Published: January 2006

The high rate of progesterone synthesis by the placenta in late gestation
exposes the ovine fetus to high concentrations of progesterone and its
metabolites that may affect activity of the fetal brain. The aim of this study
was to determine the effect of inhibiting maternal progesterone synthesis on
sleep–wake activity in fetal sheep. Fetal and maternal vascular
catheters, a fetal tracheal catheter, and electrodes for recording fetal
electrocortical (ECoG), electro-ocular (EOG) and nuchal muscle
electromyographic (EMG) activity were implanted. At 128–131 days
gestation, progesterone production was inhibited by an injection of trilostane
(50 mg), a 3β-hydroxysteroid dehydrogenase inhibitor. Vehicle solution or
progesterone (3 mg h -1 ) was then infused into the ewe
between 6 and 12 h after the trilostane treatment. Maternal progesterone
concentrations were significantly reduced from 1–24 h after trilostane
treatment (P < 0·05) when followed by vehicle
infusion. Fetal breathing movements (FBM), EOG, nuchal muscle EMG, and
behavioural arousal increased 12 h after trilostane treatment (P < 0
· 05). In contrast, there was no change in fetal arousal, EOG, EMG or
FBM activities when progesterone was infused after the trilostane treatment.
These findings show that progesterone can influence fetal behaviour, and
indicates that normal progesterone production tonically suppresses arousal, or
wakefulness in the fetus.
Reproductive health needs worldwide: constraints to fertility control
Authors: Kane Penny
Published: January 2006

Reproductive health, defined in the 1994 UN Cairo Conference on Population and
Development, is discussed and its limits identified. Mortality and morbidity
impacts of components of male and female reproductive health are quantified.
Use is made of survey data and the estimates of deaths and disease burdens
provided by the Global Burden of Disease Inquiry. Maternal causes are the
greatest contributors to the total disease burden among women aged
15–44 years. In developing countries, up to half of those who want
to delay or avoid further pregnancy are not using contraception. Worldwide,
induced abortion accounts for 61 000 deaths annually. Sexually transmitted
diseases and other illnesses also result from unsafe sexual practices,
resulting in at least 1 million deaths each year. These deaths—and
an overall disease burden of 50 million disability-adjusted life
years—are entirely preventable. Constraints include, lack a of
international commitment to improving reproductive health, social and economic
factors, lack of biomedical research, insensitive social science research, and
inadequate knowledge. Men and women have the right to demand better services
and the knowledge and conditions in which to use them. Those in the more
developed countries have the responsibility of ensuring adequate financial and
technical support to make reproductive health possible everywhere.
Lipid hydroperoxide and cGMP are not involved in nitric oxide inhibition of steroidogenesis in bovine granulosa cells
Authors: Basini G. , Grasselli F. , Ponderato N. , Bussolati S. , Tamanini C.
Published: January 2006

The present study was performed to explore two of the possible signalling
mechanisms through which nitric oxide (NO) inhibits steroidogenesis in bovine
granulosa cells. Because cGMP is generally known to play a pivotal role in NO
signal transduction, the first aim of the present study was to verify the
presence of a functional NO–cGMP signalling pathway. Because
non-cGMP-dependent pathways could be involved in the inhibition of
steroidogenesis by NO, we examined the formation of lipid hydroperoxides
(LPOs), possibly induced by NO. Using bovine granulosa cells collected from
small (< 5 mm) and large (> 8 mm) follicles, the effectiveness of the NO
donor s-nitroso-N-acetylpenicillamine (SNAP;
10–3, 10–4 and
10–5 M) in stimulating cGMP production and the
formation of LPOs was examined. The second aim of the present study was to
determine whether the effects of NO on steroidogenesis could be mimicked by
treatment of cells with a cGMP analogue (8-bromo-cGMP (8-Br-cGMP);
10–3, 10–4 and
10–5 M) and whether these effects could be
reversed by
[1H]-[1,2,3]oxadiaziolo[4,3a]quinoxaline-1-one
(ODQ; 10–5 and 10–4 M)
an inhibitor of NO-sensitive soluble guanylate cyclase. The highest dose of
SNAP used induced a significant (P<0.01) increase in
cGMP levels, while other concentrations tested were ineffective. Neither
concentration of ODQ used significantly inhibited basal cGMP output, while
both concentrations counteracted the stimulatory effect of SNAP. Treatment of
cells with 8-Br-cGMP and ODQ was ineffective in modifying steroidogenesis.
Treatment with SNAP, at the three concentrations tested, had no significant
effect on the level of LPOs. The present results suggest that NO inhibits
steroidogenesis in bovine granulosa cells without involving cGMP and LPOs.
Nitric oxide formation from glyceryl trinitrate in the developing guinea-pig hippocampus
Authors: Crowe Adrian C. , Chang Malcolm E. , McLaughlin Brian E. , Brien James F.
Published: January 2006

Glyceryl trinitrate (GTN) is classified as an organic nitrate vasodilator
drug. GTN is considered to be a prodrug because it undergoes biotransformation
at its site of action to form nitric oxide (NO) or a NO adduct, which produces
its pharmacologic effect. The objectives of this study were to determine
whether the hippocampus can biotransform GTN to NO using aerobic conditions,
and whether biotransformation of GTN to NO is age-dependent during postnatal
life. Time-dependent formation of NO occurred during the incubation of 100
µM GTN with 2.5% (w/v) homogenate of
guinea-pig hippocampus at 37°C using aerobic conditions. GTN-derived
NO formation was similar in magnitude for the three selected postnatal ages
that were studied, that is, postnatal days 10, 20 and > 60. The data
demonstrate that the capacity of the hippocampus for NO formation from GTN is
fully developed in the guinea-pig in early postnatal life. In view of these
findings, it is conceivable that a NO donor drug, selectively metabolized to
NO in the hippocampus, could be a useful therapeutic intervention to mitigate
structural and/or functional defects in this brain region resulting from
decreased NO formation or availability.
Antioxidants stimulate meiosis resumption, but inhibit mitogen-activated protein kinase phosphorylation and further cell cycle progression in porcine oocytes
Authors: Sun Q. Y. , Lai L. , Prather R. S. , Schatten H.
Published: January 2006

In the present study the effects of two cell-permeant antioxidants,
2(3)-tert-butyl-4-hydroxyanisole (BHA) and
nordihydroguaiaretic acid (NDGA), on porcine oocyte meiosis resumption,
chromatin behaviour and spindle assembly were investigated. The antioxidants
BHA and NDGA stimulated meiosis resumption in a dose-dependent manner in both
cumulus-enclosed and denuded porcine oocytes.
Afterin vitro culture for 8 h, few oocytes underwent
germinal vesicle breakdown (GVBD) in control groups, whereas GVBD occurred in
high percentages of oocytes treated with BHA or NDGA at concentrations that
inhibit GVBD in rodent oocytes, although mitogen-activated protein (MAP)
kinase was not phosphorylated as revealed by Western immunoblots. Orcein
staining and fluorescein isothiocyanate-anti-· -tubulin labelling
showed that chromosome and spindle formation, respectively, and further
meiosis progression were inhibited 20 and 25 h after culture. Instead,
chromatin was highly condensed or existed in scattered condensed clusters.
Correspondingly, MAP kinase phosphorylation was inhibited by both BHA and NDGA
in a dose-dependent manner. The inhibitory effects of BHA on meiosis
completion and MAP kinase phosphorylation was reversible. These results
suggest that, unlike in rodent oocytes, antioxidants stimulate GVBD in the
absence of MAP kinase activation, but inhibit MAP kinase phosphorylation,
meiotic apparatus formation and thus the further progression of the meiosis of
porcine oocytes.
Plasma progesterone concentrations during pregnancy in the dasyurid marsupial, Antechinus stuartii: relationship with differentiation of the embryo
Authors: Hinds LA , Selwood L
Published: January 2006

Antechinus stuartii females were sacrificed at various stages of pregnancy timed from the first day that epithelial cell numbers declined in the urine (day 0). Embryos were recovered and their developmental stage assessed, corpora lutea (CL) were fixed for histological sections and the plasma was taken for progesterone determination. The rate of development of the embryo appeared to parallel the formation of the CL and the plasma progesterone concentrations: cleavage (less than day 6) and the expansion of the unilaminar blastocyst (less than day 14), were periods of slow development, during which the formation of the CL was incomplete and plasma progesterone was low [less than 6 ng mL-1 (19.1 nmol L-1)] though steadily increasing. After day 14 the CL reached its maximum size and plasma progesterone was maximally elevated [greater than or equal to 15 ng mL-1 (47.7 nmol L-1)] until parturition on day 27. Rapid differentiation and growth of the embryo occurred between day 22 and day 27.
Roles of prolactin and the uterus in the control of luteal regression in the Bennett's wallaby (Macropus rufogriseus rufogriseus)
Authors: Loudon AS , Brinklow BR , Gulland FD , Boyle J , Flint AP
Published: January 2006

The factors responsible for controlling luteal regression in macropodid marsupials are unclear. Experiments were designed to examine the role of the uterus and the pre-partum prolactin pulse in this process. In experiment 1, two groups of adult female Bennett's wallabies were hysterectomized (n = 3) or sham-hysterectomized (n = 3) on Day 16 of a non-pregnant oestrous cycle and daily peripheral blood samples were collected between Days 10-37. In both groups, circulating progesterone concentrations declined to below 0.96 nmol L-1 at luteolysis on Days 28-33. Circulating prolactin concentrations remained low over the period of luteal regression. In experiment 2, two groups of animals, which were maintained in the presence of a fertile male and synchronized by the removal of pouch young (RPY), were treated on Day 16 after RPY with a single injection of long-acting bromocriptine (Parlodel LA, Sandoz Ltd, Basle, Switzerland; 50 mg per animal n = 5) or vehicle (n = 4). Vehicle-treated animals gave birth on Day 28 (n = 3) or Day 29 (n = 1) with a significant elevation of prolactin on Day 28. In contrast, 4 of the 5 bromocriptine-treated animals failed to give birth and one gave birth on Day 29. No comparable prolactin pulse was detected in any of them. Circulating progesterone concentrations declined later in the bromocriptine-treated group than in the controls. These data suggest that different mechanisms lead to luteolysis in pregnant and non-pregnant animals; in pregnancy the luteolytic signal is prolactin, whereas in the non-pregnant cycle another signal of non-uterine origin is involved.
Hormonal profiles in the tammar wallaby, Macropus eugenii, following FSH/LH superovulation
Authors: Jungnickel M. K. , Hinds L. A.
Published: January 2006

This study investigated the effect of superovulation with exogenous porcine
FSH/LH on the normal hormonal milieu of the tammar wallaby
(Macropus eugenii). During seasonal and lactational
quiescence, groups of 6 females were treated with either multiple doses of
porcine follicle-stimulating hormone (FSH) (8 6 mg i.m., 12 h apart) followed
by a single subcutaneous injection of 4 mg porcine luteinizing hormone (LH) on
Day 5 or saline. Blood samples were collected throughout each 10-day
experimental period and each female was examined twice daily for signs of a
recent copulation. On Day 9, females were killed and their reproductive tracts
removed for examination and flushed for eggs. During both seasonal and
lactational quiescence, treatment with porcine FSH/LH induced circulating
concentrations of progesterone, porcine FSH and porcine LH that were within
the normal range of the natural tammar oestrous cycle. However, higher plasma
oestradiol concentrations (30–50 g mL–1)
than would be expected in a natural tammar preovulatory rise and the presence
of ‘highly stimulated’ ovaries in several of the treated animals
suggests that some degree of over-stimulation was occurring. During both
seasonal sampling periods, behavioural oestrus was detected in treated tammars
in the absence of a withdrawal of progesterone. This data suggests that plasma
progesterone is not the critical factor inducing behavioural oestrus.
Introduction to the 'Serono Symposium on Embryos, Embryonic Stem Cells and Transplantation'
Authors: Pera Martin F. , Trounson Alan O.
Published: January 2006

Cloning has a number of potential applications in human medicine and animal
breeding, but the efficiency of production of developmentally competent
embryos and healthy animal offspring needs to be improved. The primary
deficiency appears to be incomplete or abnormal nuclear reprogramming after
nuclear transfer, and it is hypothesized that epigenetic regulators of
transcription cannot always be converted to the embryonic pattern and this
leads to implantation failure, gestational abnormalities and poor health of
offspring. Research needs to be focused on this aspect of development for
nuclear transfer embryos. However, there is a gradual demand for commercial
application for cloning in animal production, transgenesis and animal
biopharmaceuticals, particularly in milk. These applications will expand in
the near future. There is little application of nuclear transfer in human
medicine at present, but important applications may be demonstrated for
prevention of the inheritance of mitochondrial mutations, prevention of
age-related aneuploidis in women, artificial gametes for sterile individuals
or couples and for therapeutic cloning to enable cell and gene therapies.
Clavulicium extendens sp. nov (Corticiaceae), a fungus spreading on twigs in Queensland rainforests
Authors: Hood Ian A. , Ramsden Michael
Published: January 2006

Clavulicium extendenssp. nov., is newly described from
Queensland. It occurs in rainforest and wet sclerophyll forest where it forms
an extensive, white, external, mycelial membrane on dead and living twigs and
stems, and spreads aerially between branches by means of attachment pads. No
evidence was found that C. extendens is able to
penetrate or injure living plant tissue, but it is not yet possible to
conclude that this fungus is non-pathogenic.
Ulva and Enteromorpha (Ulvales, Ulvophyceae, Chlorophyta) in eastern Australia: Comparison of morphological features and analyses of nuclear rDNA sequence data
Authors: Woolcott Geoffrey W. , King Robert J.
Published: January 2006

Specimens of Ulva Linnaeus and
Enteromorpha Link (Ulvales, Ulvophyceae, Chlorophyta)
were collected from 12 sites in eastern Australia and identified to species
level on the basis of morphological characters described in the major
Australian study of Womersley (1984). The species recognised were
Ulva australis Areschoug,
U. lactuca Linnaeus, U. fasciata
Delile, Enteromorpha compressa (Linnaeus) Greville,
E. flexuosa (Wulfen ex Roth) J.Agardh and
E. intestinalis (Linnaeus) Link. Species placement
within the genera Ulva and
Enteromorpha is problematic and features of DNA were
examined in order to assess their potential use as characters in species
determinations. Analyses were conducted on sequence data derived from the
internal transcribed spacer region ITS2, and the 5.8S gene. Groupings of the
12 isolates based on DNA analyses do not correlate with the species identified
using morphology nor with the two genera. Further work is required before
authoritative conclusions can be reached regarding the significance of
morphological plasticity in determination of differences within and between
Ulva and Enteromorpha species;
nevertheless, DNA studies may provide a backbone of characters upon which to
base such a study.
Structure and systematics of Hanguana, a monocotyledon of uncertain affinity
Authors: Rudall Paula J. , Stevenson Dennis W. , Linder H. Peter
Published: January 2006

Floral anatomy and some aspects of leaf and root anatomy of
Hanguana are described for the first time and reviewed
with respect to its systematic position in monocotyledons. Several characters
support its placement in the commelinoid clade, including cell wall ferulates,
silica bodies and tetracytic stomata with non-oblique cell divisions. Analysis
of morphological data indicates that Hanguana is the
sister taxon to Zingiberales. Characters supporting this association include
spinulate inaperturate pollen, plasmodial tapetum type, mucilage-secreting
intra-ovarian trichomes and modified septal nectaries. Gynoecial nectaries
were present in male flowers (probably modified septal nectaries, as in some
Zingiberales) and staminodial nectaries in female flowers examined.
Pyrrhoglossum and the small-spored species of Gymnopilus (Cortinariaceae) in eastern Australia
Authors: Rees B. J. , Ye J. L.
Published: January 2006

Three new species of Gymnopilus subgenusGymnopilus section Microspori aredescribed from eastern Australia. These areGymnopilus marginatus,Gymnopilus patriae andGymnopilus parvisporus. Because of their frequently excentrically stipitate habit and small spore size, the species are comparedwith Pyrrhoglossum pyrrhum (Berk. & M.A.Curtis)Singer, the type species of the genus Pyrrhoglossum,whose presence is also recorded from Australia for the first time. Pigment content of all four species has been examined by thin layer chromatography.Styrylpyrone pigments bis-noryangonin and hispidin were detected in only two of the three Gymnopilus species.Although yellow pigment can be extracted fromPyrrhoglossum pyrrhum, it does not containbis-noryangonin or hispidin.
Brachyscias (Apiaceae): a new genus from south-west Western Australia
Authors: Hart J. M. , Henwood M. J.
Published: January 2006

The new monotypic genus Brachyscias (Apiaceae) isdescribed from south-west Western Australia.Brachyscias verecundus J.M.Hart & M.J.Henwoodshowsclosest affinities to the endemic genusChlaenosciadium,but differs from this genus in itspossession of glabrous, ternately divided leaves, its foliaceous involucralbracts and bracteoles (with no whorl of bracts around flowers between therays) and by its nectaries being adnate to the styles. The undulate surfacetexture of the fruit of Brachyscias further separates itfrom Chlaenosciadium.
Sirodotia (Batrachospermales, Rhodophyta) in Australia and New Zealand
Authors: Entwisle Timothy J. , Foard Helen J.
Published: January 2006

Two species of Sirodotia from Australia and New Zealand
are documented, including descriptions, photomicrographs, maps and keys.
Sirodotia goebelii sp. nov., known only from a single
nineteenth century collection from south-western Western Australia, has
carpogonia with a broad base and usually pedicellate and deflexed trichogyne,
long and profusely branched erect gonimoblasat filaments, and longer, elongate
carposporangia. Sirodotia suecica Kylin is widespread in
Australia and New Zealand, including a number of noteworthy variants. All
other species of Sirodotia reported from the region are
referred to S. suecica.
Lactarius (Basidiomycota) in Papua New Guinea. 1. Species of tropical lowland habitats
Authors: Verbeken A. , Horak E.
Published: January 2006

The extant herbarium material of the genus Lactarius
(L. novoguineensis P.Henn.) collected in tropical Papua
New Guinean lowland forests is studied. In addition, four new taxa,
L. leucophaeus, L. paleus,
L. leoninus and L. walleynii are
introduced. A key to the five species, illustrations and discussionabout their
infrageneric position are presented.
INTRODUCING The L. A. S. Johnson review series in
ASB
Authors: Farrer Simone , Advisory Committee Editorial
Published: January 2006

On behalf of the Editorial Advisory Committee of the journal, I have much pleasure in
announcing the introduction of the publication of an important series of reviews in
Australian Systematic Botany, to be known as The L. A. S. Johnson Reviews.

Our aim for The L. A. S. Johnson Reviews is to provide critical state-of-the-art
evaluations that advance knowledge in current key areas of systematic botanical research.
The series will be commissioned by invitation, and will be numbered in sequence. The
journal will provide 75 reprints free of charge. The author will also receive a free copy of
the issue in which the paper is published. Normal refereeing processes apply.
Characterization of the Yeast Amphiphysins Rvs161p and Rvs167p Reveals Roles for the Rvs Heterodimer In Vivo
Authors: Friesen Helena , Humphries Christine , Ho Yuen , Schub Oliver , Colwill Karen , Andrews Brenda
Published: January 2006

We have used comprehensive synthetic lethal screens and biochemical assays to examine the biological role of the yeast amphiphysin homologues Rvs161p and Rvs167p, two proteins that play a role in regulation of the actin cytoskeleton, endocytosis, and sporulation. We found that unlike some forms of amphiphysin, Rvs161p-Rvs167p acts as an obligate heterodimer during vegetative growth and neither Rvs161p nor Rvs167p forms a homodimer in vivo. RVS161 and RVS167 have an identical set of 49 synthetic lethal interactions, revealing functions for the Rvs proteins in cell polarity, cell wall synthesis, and vesicle trafficking as well as a shared role in mating. Consistent with these roles, we show that the Rvs167p-Rvs161p heterodimer, like its amphiphysin homologues, can bind to phospholipid membranes in vitro, suggesting a role in vesicle formation and/or fusion. Our genetic screens also reveal that the interaction between Abp1p and the Rvs167p Src homology 3 (SH3) domain may be important under certain conditions, providing the first genetic evidence for a role for the SH3 domain of Rvs167p. Our studies implicate heterodimerization of amphiphysin family proteins in various functions related to cell polarity, cell integrity, and vesicle trafficking during vegetative growth and the mating response.
Protein Kinase Cγ Regulates Myosin IIB Phosphorylation, Cellular Localization, and Filament Assembly
Authors: Rosenberg Michael , Ravid Shoshana
Published: January 2006

Nonmuscle myosin II is an important component of the cytoskeleton, playing a major role in cell motility and chemotaxis. We have previously demonstrated that, on stimulation with epidermal growth factor (EGF), nonmuscle myosin heavy chain II-B (NMHC-IIB) undergoes a transient phosphorylation correlating with its cellular localization. We also showed that members of the PKC family are involved in this phosphorylation. Here we demonstrate that of the two conventional PKC isoforms expressed by prostate cancer cells, PKCβII and PKCγ, PKCγ directly phosphorylates NMHC-IIB. Overexpression of wild-type and kinase dead dominant negative PKCγ result in both altered NMHC-IIB phosphorylation and subcellular localization. We have also mapped the phosphorylation sites of PKCγ on NMHC-IIB. Conversion of the PKCγ phosphorylation sites to alanine residues, reduces the EGF-dependent NMHC-IIB phosphorylation. Aspartate substitution of these sites reduces NMHC-IIB localization into cytoskeleton. These results indicate that PKCγ regulates NMHC-IIB phosphorylation and cellular localization in response to EGF stimulation.
Role of Numb in Dendritic Spine Development with a Cdc42 GEF Intersectin and EphB2
Authors: Nishimura Takashi , Yamaguchi Tomoya , Tokunaga Akinori , Hara Akitoshi , Hamaguchi Tomonari , Kato Katsuhiro , Iwamatsu Akihiro , Okano Hideyuki , Kaibuchi Kozo
Published: January 2006

Numb has been implicated in cortical neurogenesis during nervous system development, as a result of its asymmetric partitioning and antagonizing Notch signaling. Recent studies have revealed that Numb functions in clathrin-dependent endocytosis by binding to the AP-2 complex. Numb is also expressed in postmitotic neurons and plays a role in axonal growth. However, the functions of Numb in later stages of neuronal development remain unknown. Here, we report that Numb specifically localizes to dendritic spines in cultured hippocampal neurons and is implicated in dendritic spine morphogenesis, partially through the direct interaction with intersectin, a Cdc42 guanine nucleotide exchange factor (GEF). Intersectin functions as a multidomain adaptor for proteins involved in endocytosis and cytoskeletal regulation. Numb enhanced the GEF activity of intersectin toward Cdc42 in vivo. Expression of Numb or intersectin caused the elongation of spine neck, whereas knockdown of Numb and Numb-like decreased the protrusion density and its length. Furthermore, Numb formed a complex with EphB2 receptor-type tyrosine kinase and NMDA-type glutamate receptors. Knockdown of Numb suppressed the ephrin-B1-induced spine development and maturation. These results highlight a role of Numb for dendritic spine development and synaptic functions with intersectin and EphB2.
THE DECREASING INFLUENCE OF DOMESTIC MARKET STRUCTURE ON RACIAL EARNINGS DIFFERENTIALS: 1984 TO 1996
Authors: AGESA JACQUELINE , MONACO KRISTEN
Published: January 2006

This study investigates the market concentration/racial earnings discrimination relationship in two periods: 1984–90 and 1991–96. In each period, the racial wage gap and the residual wage gap are compared for union and nonunion workers in monopolistic and competitive industries. The authors find no evidence of market structure–driven discrimination for union workers in either period. However, from the first to the second period they find evidence of increased racial earnings differentials for nonunion workers, yet market structure–driven discrimination decreases. The authors suggest that concentration has become a less effective measure of market power and firms' latitude to discriminate. (JEL J31, J71)
Pyramids of Trust: Social Embeddedness and Political Culture in Two Italian Gold Jewelry Districts
Authors: Gaggio Dario
Published: January 2006

This article demonstrates the usefulness of the notion of embeddedness to the historical study of Italian industrial districts of small firms and of local economic change more generally. The development of gold jewelry production in two Italian towns, Valenza Po and Arezzo, shows that vertical disintegration was enabled by the creation of networks of heterogeneous social relations. In both towns, social and political ties led to the creation of institutions of collective governance, which in turn produced a workable level of trust between economic actors. The production of trust, however, never ceased to be a contentious process, endowed with multiple and often contradictory meanings embedded in specific networks and contexts, ranging from collective projects of modernization in Valenza Po to the cementing of a secretive informal economy in Arezzo. The embeddedness approach to economic action is superior both to the communitarian arguments of much of the literature on the Italian industrial districts and to transaction-cost theories, which tend to view institutions in instrumental and functionalist ways.
Local Recurrence after CO2 Laser Cordectomy for Early Glottic Carcinoma
Authors: Mortuaire G , Francois J , Wiel E , Chevalier D
Published: January 2006

Objectives: To point out prognosis factors of local recurrence after endoscopic cordectomies for Tis, T1a, T1b, and T2 glottic squamous cell carcinomas.

Study Design: A cohort of 110 patients treated from January 1990 to December 2000 at a single institution was retrospectively analyzed: 21 had Tis, 76 T1a, 7 T1b, and 6 T2 (mean follow‐up 42 mo; range 1–160 mo).

Methods: The depth and extension of the excision were graded according to the European Laryngological Society Classification. Univariate analysis was used to review the impact on disease‐free survival of factors related to the host, the tumor, and the treatment.

Results: According to the Kaplan‐Meier method, the 5 year overall survival and the disease‐free survival were 87% and 75%, respectively. The rates of cause‐specific survival, ultimate local control with laser alone, and laryngeal preservation were 97%, 84%, and 90%, respectively. Univariate analysis by the log rank test revealed that vocal muscle infiltration (P = .001) and subglottic involvement (P = .02) have a significant impact on disease‐free survival. Of the 22 patients with local recurrence (17 T1a, 1 T1b, and 4 T2), 9 were managed with total laryngectomy, 5 with partial laryngectomy, 4 with further laser cordectomy, 2 with radiotherapy, and 2 had no curative treatment.

Conclusion: Transoral laser surgery for early glottic carcinoma is a valid alternative to radiotherapy and partial laryngectomy in terms of oncologic results. It offers low morbidity and excellent retreatment options in case of local failure. Careful patient selection for laser surgery is essential to secure good results.