bluuebunny/crossref_metadata_2025 huggingface dataset:
Phosphorylation of CREB in Ovine Pars Tuberalis is Regulated both by cyclic AMP‐Dependent and cyclic AMP‐Independent Mechanisms
Authors: McNulty S. , Ross A. W. , Shiu K. Y. , Morgan P. J. , Hastings M. H.
Published: October 2006

This study used a combination of Western blotting and immunocytochemistry to test whether signalling pathways independent of cyclic AMP have the potential to induce phospho‐CREB (pCREB)‐like immunoreactivity (‐ir) in the oPT. Western blot analysis of extracts of primary cultures of oPT using an antiserum against CREB, revealed a major band of CREB‐ir at 44 KDa. The intensity of this band did not vary systematically with treatment. In extracts from untreated cells, Western blot analysis revealed a major band of pCREB‐ir at 42 KDa which was not sensitive to agonist treatment. Treatment of cells with forskolin (10−6 M) increased the intensity of a number of other pCREB‐ir bands at between ca. 38 and 44 KDa. The band at 44 KDa probably represented native pCREB whilst the other bands induced by forskolin probably represented pCREB‐like proteins. Melatonin (10−6 M) alone had no effect on pCREB‐ir, but it did inhibit the effect of forskolin on the ca. 38 and 44 KDa pCREB‐ir bands. Treatment with lamb serum (1%) consistently increased the intensity of the ca. 38 and 44 KDa pCREB‐ir bands relative to control cells, as assessed by Western blot. However, Western blot analysis did not reveal a consistent effect of melatonin on the pCREB‐ir response to serum. The effect of serum on pCREB‐ir in oPT cells was characterized further by immunocytochemical analysis. In contrast to experiments utilizing Western blotting, untreated cells did not possess detectable pCREB‐ir. In serum‐starved oPT and oPD cultures, treatment with serum induced exclusively nuclear pCREB‐ir. A large majority of oPT cells (≥90%) were sensitive to serum (1%), and serum caused a time‐ and dose‐dependent increase of nuclear pCREB‐ir. Melatonin attenuated the response to serum in the oPT. This inhibition of the response to serum was not apparent in the oPD, demonstrating that the effect of melatonin was specific for a tissue known to express melatonin receptors. In oPT cultures, physiological concentrations of melatonin (10−9 M) partially reversed (ca. 70%) the inductive effect of 0.1% serum on nuclear pCREB‐ir. However, in contrast to studies applying forskolin, the induction of pCREB‐ir by serum occurred in the absence of measurable changes in the concentration of cyclic AMP, indicating that components of serum are able to stimulate the phosphorylation of CREB in the oPT through mechanisms independent of cyclic AMP. Both adenosine and prostaglandin E2 (PGE2) also induced nuclear pCREB‐ir in the absence of increased levels of cyclic AMP. These results demonstrate that transcriptional activities in the oPT which are under the control of CREB may be modulated by convergent cyclic AMP‐dependent and cyclic AMP‐independent pathways. Regulation of these pathways by melatonin and other factors present in serum may be an important control‐point in the generation of seasonal neuroendocrine cycles.
Prostaglandin E2 Acts via the Hypothalamus to Stimulate ACTH Secretion in the Fetal Sheep
Authors: Young I. Ross , Loose Jan M. , Kleftogiannis Fotini , Canny Benedict J.
Published: October 2006

Prostaglandin (PG) E2 is secreted into the fetal circulation during late gestation in the sheep. Exogenous infusion of PGE2 is associated with robust increases in the circulating concentrations of ACTH and cortisol and it has therefore been proposed that endogenous PGE2 modulates the activity of the fetal HPA axis, which is the primary determinant of parturition and essential for the maturation of vital organ systems. The sites of action of PGE2 within the HPA axis have not been clearly established. We have compared the effects of PGE2 infusion on ACTH and cortisol concentrations in intact fetuses and in those whose pituitaries were surgically disconnected from hypothalamic control (hypothalamo‐pituitary disconnected; HPD fetuses operated at 111–113 days gestational age). The effect of advancing gestational age on these responses was investigated by infusing PGE2 at 121, 131, 141 and 148 days of gestation. The functional integrity of the pituitary corticotrophs was tested by injecting CRH (1 μg) into intact and HPD fetuses at day 125. This test was repeated for the HPD fetuses at 160 days.The responsiveness of the adrenal glands was also tested by injecting 2.5 μg/kg synthetic ACTH1–24 (Synacthen) into both groups of fetuses at day 135, with the HPD group retested at day 155.
Morphine‐Induced Locomotor and Neurochemical Stimulation is Enhanced in Transgenic Mice with Impaired Glucocorticoid Receptor Function
Authors: Spanagel Rainer , Stöhr Thomas , Barden Nicholas , Holsboer Florian
Published: October 2006

It has been suggested that the hypothalamic‐pituitary‐adrenocortical (HPA) system contributes to individual differences in sensitivity towards drug abuse. Therefore, we studied the effects of the prototypic drug morphine in transgenic mice with impaired glucocorticoid receptor function. This mouse model has a profoundly dysfunctional HPA feedback. Since morphine‐induced locomotor stimulation is positively correlated with the rewarding effects of morphine, we examined morphine‐induced locomotor activity of transgenic mice and control mice (B6C3F1), Because morphine‐induced locomotor activity depends on an intact mesolimbic system, dopaminergic (DAergic) neuronal activity was also estimated within the mesolimbic system. Results indicated that the activity after vehicle injection do not differ between these two mouse lines. Compared to vehicle injections, morphine (7.5 and 15mg/kg; i.p.) dose‐dependently increased motor activity for 3 h in control and transgenic mice. However, morphine‐induced locomotion was significantly more pronounced in transgenic mice. Further, morphine‐induced mesolimbic DAergic activity was enhanced in transgenic animals as compared to control animals. These results parallel endocrine data that show that the plasma ACTH level of transgenic mice reach higher levels compared to those levels observed in control mice after morphine injections. Altogether, this transgenic mouse line shows an enhanced locomotor‐stimulant effect to morphine, a response that is reflected by an enhanced DAergic activity within the mesolimbic system and is also associated with increased HPA activity. We submit that the dysregulation of the HPA system in these transgenic mice influences the enhanced vulnerability to drug‐seeking behavior.
Neural Regulation of Corticotropin Releasing Hormone (CRH) and CRH Receptor mRNA in the Hypothalamic Paraventricular Nucleus in the Rat
Authors: Kiss Alexander , Palkovits Miklos , Aguilera Greti
Published: October 2006

The role of afferent innervation to the hypothalamic paraventricular nucleus (PVN) on CRH mRNA and CRH receptor mRNA levels was studied in control and stressed rats. Groups of rats were subjected to unilateral transection of the stria terminalis (ST), the medial forebrain bundle at the rostral hypothalamic level (RMFB), or the lower brainstem through the medulla oblongata between the obex and the locus coeruleus (CBs). Twelve days after surgery, each group of rats was further divided into controls (basal conditions) and stressed (1 h immobilization), before collecting brains for mRNA analysis by in situ hybridization histochemistry. While ST and RMFB cuts had no effect on basal CRH mRNA levels in the PVN, CBs cut decreased CRH mRNA in the PVN ipsilaterally to the knife cut but it was without effect on the contralateral side (– 40% and –37%vs contralateral and sham‐operated, respectively, P&0.01). Acute stress (rats were killed 3 h after immobilization) increased CRH mRNA levels by about 30% bilaterally, an effect which was unchanged by any of the three hemisections. Under basal conditions, CRH receptor mRNA levels in the PVN were indistinguishable from the surrounding areas in sham‐operated controls, ST and RMFB operated rats. However, brainstem hemisection resulted in clear expression of CRH receptor mRNA in areas consistent with the dorsal, medial‐ventral and lateral parvicellular subdivisions of the PVN, ipsilateral to the transection. CRH neurons in these subdivisions project to the lower brainstem and the spinal cord. Expression of CRH receptor mRNA in the medial‐dorsal and anterior parvicellular divisions (CRH neurons with median eminence projections) was not affected by CBs cut. In these subdivisions, immobilization stress markedly increased CRH receptor mRNA levels but it did not influence CBs cut‐induced CRH receptor expression. ST and RMFB hemisections were without effect on PVN CRH receptor mRNA levels under basal or stress conditions. Oxytocin (OT) and vasopressin (VP) mRNA levels in the magnocellular subdivision of the PVN were unchanged after immobilization, or following ST, RMFB or CBs cuts, whereas OT mRNA in the medial‐ventral and caudal parvicellular subdivisions was decreased by 52% after CBs cut. The data demonstrate that: 1) basal CRH mRNA levels in the PVN are under tonic stimulatory influence of the lower brainstem (and/or spinal cord) afferents; 2) CRH receptor mRNA expression in PVN subdivisions (pituitary vs lower brainstem/spinal cord projecting neurons) is under different control mechanisms, and 3) immobilization‐induced changes in CRH mRNA and CRH receptor mRNA levels are mediated either by neural inputs from brain areas other than those investigated here, or by humoral factors.
Influence of Testosterone on LHRH Release, LHRH mRNA and Proopiomelanocortin mRNA in Male Sheep1
Authors: Hileman Stanley M. , Lubbers Laura S. , Petersen Sandra L. , Kuehl David E. , Scott Christopher J. , Jackson Gary L.
Published: October 2006

The mechanism whereby testosterone (T) reduces pulsatile LHRH and LH release is unknown. We tested the hypothesis that hypothalamic levels of LHRH mRNA decrease and proopiomelanocortin (POMC) mRNA increase coincident with reduced LHRH release induced by either long‐term or short‐term T treatment in male sheep. Experiment 1 examined the effect of long‐term T exposure on LHRH and LH release and LHRH and POMC mRNA levels. Yearling Suffolk rams were castrated and assigned to one of four treatments: 1) castrated (n = 4); 2) castrated, portal cannula (n = 5); 3) castrated +T (n = 4) and 4) castrated+T, portal cannula (n = 4). T‐treated males received ten 10‐cm silastic T‐implants immediately after castration. Surgical placement of devices for collecting hypophyseal‐portal blood occurred 2 to 3 months after castration. Seven to 10 days after surgery, blood samples were collected at 10‐min intervals for 8h from portal cannulated males or for 5 h from non‐cannulated males to assess pulsatile LHRH and/or LH release. Immediately after blood sample collection, hypothalamic tissue was collected for in situ measurement of LHRH or POMC mRNA. T‐treatment decreased (P < 0.01) mean LHRH and LH and decreased (P < 0.01) LHRH and LH pulse frequency. T did not significantly affect (P > 0.10) silver grain area per LHRH neuron, but decreased (P < 0.01) silver grain area per POMC neuron. Portal cannulation tended to decrease (P= 0.057) silver grain area per LHRH neuron without significantly affecting (P > 0.10) LHRH cell numbers while reducing (P < 0.01) silver grain area per POMC neuron and POMC cell numbers. A second experiment examined the effect of 72 h of T‐infusion on LHRH and POMC mRNA levels. Castrated yearling males were assigned to receive either vehicle (n = 4) or T (768 ug/kg/day;n=4). Blood samples were collected at 10 min intervals for 4h prior to and during the final 4 h of infusion. Infusion of T decreased (P < 0.01) mean LH and LH pulse frequency. T did not significantly affect (P > 0.10) silver grain area per LHRH neuron or LHRH cell numbers. T reduced (P < 0.01) silver grain area per POMC neuron without affecting (P > 0.10) POMC cell number. We reject our hypothesis and conclude that reduced LHRH or heightened POMC gene expression are not mechanisms whereby T reduces pulsatile LHRH release in male sheep.
Adrenergic Receptor Activation Hyperpolarizes the Caudal Neurosecretory Cells of the Flounder, Platichthys flesus
Authors: Hubbard P. C. , Balment R. J. , McCrohan C. R.
Published: October 2006

The physiological factors that govern activity of the caudal neurosecretory system in teleost fish are poorly understood. Immunocytochemical evidence indicates that the neurosecretory Dahlgren cells are innervated by descending monoaminergic fibres. Using intracellular recording techniques in an isolated preparation of the posterior spinal cord of the flounder (Platichthys flesus) we have demonstrated that superfusion of adrenaline or noradrenaline (10−7–10−3 M) causes hyperpolarization of Dahlgren cells (up to −30 mV). This hyperpolarization is likely to reflect an inhibitory effect of noradrenergic nerves on the neurosecretory system in vivo, reducing the rate of hormone release. Fluctuations in the input resistance and membrane time constant suggest involvement of a multiplicity of cellular mechanisms, including the opening and closing of populations of ion‐selective channels. Superfusion with dopamine (10−7–10−3 M) had no effect. Superfusion with the β‐adrenoreceptor agonist, isoprenaline, caused hyperpolarization but to a markedly lesser extent than the maximum effect of adrenaline or noradrenaline, suggesting that their effects are mediated, only in part, by a β‐adrenoreceptor subtype. Superfusion of the preparation with a membrane permeable, non‐hydrolysable cyclic AMP analogue (8‐[4‐chlorophenylthio]‐cAMP) resulted in a slight hyperpolarization which was accompanied by a small, but significant, increase in input resistance. These data are consistent with at least part of the β‐adrenoreceptor mediated effect involving closure of cAMP‐sensitive ion channels. Superfusion with the β‐adrenoreceptor agonist, phenylephrine, had no effect on any electrophysiological parameter studied. However, the α2‐adrenoreceptor agonist, clonidine, caused hyperpolarization which again failed to reach the maximum level produced by adrenaline or noradrenaline. Together, these data suggest that the adrenergic inhibition of Dahlgren cell activity is mediated by both α2‐and β‐adrenoreceptor subtypes.
Complementary (secondary) metabolites in a soft coral: sex‐specific variability, inter‐clonal variability, and competition
Authors: Fleury Beatriz , Coll John , Sammarco Paul
Published: October 2006

Sex‐specific interactions involving competition for space between the dioecious alcyonacean soft coral Sarcophyton glaucum and the scleractinian coral Acropora robusta were assessed experimentally on Bald Rock, central region of the Great Barrier Reef. To examine this, plus inter‐clonal responses, one male colony of S. glaucum, known to produce sarcophytoxide as its predominant complementary (secondary) metabolite, was sectioned, producing 10 clones. The same was done for a female colony. These two sets of clones were then relocated to grids and placed in contact with Acropora clones. Relocated and non‐relocated controls were also monitored. High levels of tissue necrosis were observed in the hard coral under contact conditions with both the male and female clones after 20 days. The development of a protective polysaccharide layer in the alcyonacean was also observed. Differences observed in the concentrations of complementary metabolites within the two different S. glaucum colonies were related to sex. Both under competition and non‐competition conditions, females exhibited significantly higher concentrations of sarcophytoxide than males, and this increased with time. Fatty ester concentration was also higher in females than males, varying significantly through time, and falling dramatically just after spawning. Fatty ester concentrations decreased linearly through time in the male clones. When involved in competition for space, females possessed higher concentrations of fatty esters than males, both at the site of contact and in non‐contact sites, again, decreasing after spawning. No significant changes in sarcophytoxide levels were noted in the parental colonies, but such changes were observed in fatty esters, with the female producing higher concentrations until after spawning. The use of these two variates in the form of a ratio (sarcophytoxide concentration:fatty ester concentration) yielded a variable Rho (ρ) which was a more sensitive indicator of biochemical change than either of its components alone. These two sets of compounds appeared to have a negative association through time and varied highly significantly between sexes. The diterpene sarcophytoxide may be considered an allelopathic or stress metabolite, while the lipids act as energy storage metabolites.
Age and growth in olive ridley seaturtles (Lepidochelys olivacea) from the North‐central Pacific: a skeletochronological analysis
Authors: Zug George R. , Chaloupka Milani , Balazs George H.
Published: October 2006

The olive ridley is the most abundant seaturtle species in the world but little is known of the demography of this species. We used skeletochronological data on humerus diameter growth changes to estimate the age of North Pacific olive ridley seaturtles caught incidentally by pelagic longline fisheries operating near Hawaii and from dead turtles washed ashore on the main Hawaiian Islands. Two age estimation methods [ranking, correction factor (CF)] were used and yielded age estimates ranging from 5 to 38 and 7 to 24 years, respectively. Rank age‐estimates are highly correlated (r = 0.93) with straight carapace length (SCL), CF age estimates are not (r = 0.62). We consider the CF age‐estimates as biologically more plausible because of the disassociation of age and size. Using the CF age‐estimates, we then estimate the median age at sexual maturity to be around 13 years old (mean carapace size c. 60 cm SCL) and found that somatic growth was negligible by 15 years of age. The expected age‐specific growth rate function derived using numerical differentiation suggests at least one juvenile growth spurt at about 10–12 years of age when maximum age‐specific growth rates, c. 5 cm SCL year−1, are apparent.
Perception and modification of plant flavonoid signals by rhizosphere microorganisms
Authors: Shaw Liz J. , Morris Phil , Hooker John E.
Published: October 2006

Flavonoids are a diverse class of polyphenolic compounds that are produced as a result of plant secondary metabolism. They are known to play a multifunctional role in rhizospheric plant‐microbe and plant–plant communication. Most familiar is their function as a signal in initiation of the legume‐rhizobia symbiosis, but, flavonoids may also be signals in the establishment of arbuscular mycorrhizal symbiosis and are known agents in plant defence and in allelopathic interactions. Flavonoid perception by, and impact on, their microbial targets (e.g. rhizobia, plant pathogens) is relatively well characterized. However, potential impacts on ‘non‐target’ rhizosphere inhabitants (‘non‐target’ is used to distinguish those microorganisms not conventionally known as targets) have not been thoroughly investigated. Thus, this review first summarizes the conventional roles of flavonoids as nod gene inducers, phytoalexins and allelochemicals before exploring questions concerning ‘non‐target’ impacts. We hypothesize that flavonoids act to shape rhizosphere microbial community structure because they represent a potential source of carbon and toxicity and that they impact on rhizosphere function, for example, by accelerating the biodegradation of xenobiotics. We also examine the reverse question, ‘how do rhizosphere microbial communities impact on flavonoid signals?’ The presence of microorganisms undoubtedly influences the quality and quantity of flavonoids present in the rhizosphere, both through modification of root exudation patterns and microbial catabolism of exudates. Microbial alteration and attenuation of flavonoid signals may have ecological consequences for below‐ground plant‐microbe and plant–plant interaction. We have a lack of knowledge concerning the composition, concentration and bioavailability of flavonoids actually experienced by microbes in an intact rhizosphere, but this may be addressed through advances in microspectroscopic and biosensor techniques. Through the use of plant mutants defective in flavonoid biosynthesis, we may also start to address the question of the significance of flavonoids in shaping rhizosphere community structure and function.
Region‐dependent regulation of mesoaccumbens dopamine neuronsin vivoby the constitutive activity of central serotonin2C receptors
Authors: Navailles Sylvia , Moison Delphine , Ryczko Dimitri , Spampinato Umberto
Published: October 2006

Central serotonin2C receptors (5‐HT2CRs) control the mesoaccumbens dopamine (DA) pathway. This control involves the constitutive activity (CA) of 5‐HT2CRs, and is thought to engage regionally distinct populations of 5‐HT2CRs, leading to opposite functional effects. Here, usingin vivomicrodialysis in halothane‐anesthetized rats, we investigated the relative contribution of ventral tegmental area (VTA) and nucleus accumbens shell (NAc) 5‐HT2CRs in the phasic/tonic control of accumbal DA release, to specifically identify the nature (inhibition/excitation) of the control, and the role of the 5‐HT2CR CA. Intra‐VTA injections of the selective 5‐HT2CR antagonists SB 242084 and/or SB 243213 (0.1–0.5 µg/0.2 µL) prevented the decrease in accumbal DA outflow induced by the 5‐HT2CR agonist Ro 60–0175 (3 mg/kg, i.p), but did not affect the increase in DA outflow induced by the 5‐HT2CR inverse agonist SB 206553 (5 mg/kg, i.p). Intra‐NAc infusions of SB 242084 (0.1–1 µm) blocked Ro 60–0175‐ and SB 206553‐induced changes of DA outflow. Intra‐NAc, but not intra‐VTA administration of SB 206553 increased basal DA outflow. These findings demonstrate that both VTA and NAc 5‐HT2CRs participate in the inhibitory control exerted by 5‐HT2CRs on accumbal DA release, and that the NAc shell may represent a primary action site for the CA of 5‐HT2CRs.
Effects of Female Sex Hormones on Responses to CGRP, Acetylcholine, and 5‐HT in Rat Isolated Arteries
Authors: Gupta Saurabh , Mehrotra Suneet , Villalón Carlos , De Vries René , Garrelds Ingrid , Saxena Pramod , VanDenBrink Antoinette Maassen
Published: October 2006

Background.—Female sex hormones are implicated in the modulation of reactivity of a wide range of blood vessels under physiological as well as pathological conditions. Migraine, a neurovascular syndrome, is 3 times more prevalent in women during their reproductive period than in men.

Objective.—This study sets out to investigate the effects of the female sex steroids, 17β‐estradiol and progesterone (separately and in combination) on vasoactive responses to calcitonin gene‐related peptide (CGRP), acetylcholine, and 5‐hydroxytryptamine (5‐HT) in rat isolated mesenteric, caudal, and basilar arteries.

Methods.—Female Sprague‐Dawley rats were ovariectomized (Day 0) and 7 days later subcutaneously implanted with pellets releasing over a 21‐day period 17β‐estradiol (0.25 mg), progesterone (50 mg), their combination, or placebo. On days 25‐28, the animals were killed, arteries isolated and mounted in Mulvany myographs, and cumulative concentration response curves to CGRP, acetylcholine, and 5‐HT were constructed.

Results.—The relaxant responses to CGRP were significantly potentiated in mesenteric and caudal arteries from rats treated with 17β‐estradiol as compared to the placebo‐treated rats. Acetylcholine‐induced relaxations were potentiated in the caudal artery from rats treated with the combination of 17β‐estradiol and progesterone, as compared to that from placebo‐treated rats. The 5‐HT‐induced contractions in the 3 arteries were not significantly different in efficacy or potency.

Conclusion.—Our results show that 17β‐estradiol potentiates CGRP‐induced relaxations in the mesenteric and caudal arteries, while the combination treatment enhances acetylcholine‐induced relaxations in the caudal artery. Although these in vitro experiments have been carried out in rats and a direct extrapolation to migraine in humans is not possible, our results may provide a new avenue to study the effects of sex steroids on vascular reactivity.
Cognitive Impairment Is Not Equal in Patients with Epileptic and Psychogenic Nonepileptic Seizures
Authors: Drane Daniel L. , Williamson David J. , Stroup Elizabeth S. , Holmes Mark D. , Jung Matthew , Koerner Erich , Chaytor Naomi , Wilensky Alan J. , Miller John W.
Published: October 2006

Summary:  Purpose: Patients with psychogenic nonepileptic seizures (PNES) and those with epileptic seizures (ES) purportedly have roughly equal neurocognitive deficits. However, recent findings suggest that patients with somatoform disorders exhibit more variable effort on neurocognitive testing than do controls. We reexamined neurocognitive function in patients with ESs and PNES by using symptom validity testing to control for variability in effort.

Methods: Patients referred for video‐EEG monitoring were administered the Word Memory Test (WMT), a measure of symptom validity, as part of neuropsychological evaluation. Patients classified with ictal video‐EEG recordings as having ES (n = 41) or PNES (n = 43) were compared on neurocognitive and WMT performance and demographic, psychiatric, and medical variables.

Results: Striking rates of WMT failure were observed in the PNES (51.2%) group, but not in the ES (8.1%) group (p = <0.001) after controlling for false‐positive errors. Although the PNES and ES groups reported equivalent neurologic histories, the PNES group exhibited less objective evidence of impairment as measured by valid neuropsychological testing, MRI of the brain, and video‐EEG monitoring.

Conclusions: Many patients with PNES do not put forth maximal effort during neuropsychological assessment. When patients with PNES put forth valid effort, they demonstrate less objective evidence of neuropathologic injury or disease than do patients with ES. The cognitive impairment reported by this group appears to be more a function of motivational (although not necessarily intentional) factors than of verifiable neuropathology.
Monazite Coatings on SiC Fibers II: Oxidation Protection
Authors: Mogilevsky P. , Boakye E. E. , Hay R. S. , Welter J. , Kerans R. J.
Published: October 2006

The effect of monazite on the oxidation of SiC was studied in laboratory and dry air. Monazite inhibited the oxidation of Tyranno‐SA™, Tyranno‐ZX™, Sylramic, and Hi‐Nicalon SiC fibers. Oxidation of pure chemical vapor deposition SiC and undoped SiC single crystals was not inhibited by monazite. Dry oxidation of both uncoated and monazite‐coated Tyranno‐SA™ fibers initially displayed parabolic kinetics with an activation energy of 180–190 kJ/mol. Subsequently, the oxidation rate of monazite‐coated fibers increased and the oxide‐scale growth rate approached that of the uncoated fibers. No differences in the composition or structure of the silica oxidation product could be detected between uncoated and coated fibers using transmission electron microscopy and energy‐dispersive spectroscopy. Possible mechanisms of the inhibition of SiC oxidation by monazite are discussed.
Morphology and Properties in Blended Cements with Ceramic Wastes as a Pozzolanic Material
Authors: Sánchez de Rojas M. I. , Marín F. , Rivera J. , Frías M.
Published: October 2006

This paper describes the research run on ceramic materials, and more specifically fired clay roof tiles, ground to a fineness suitable for use as an active replacement for portland cements (PCs). The utilization of waste products from calcined clay roof tiles as a pozzolanic material in the cement manufacture is studied. One of the first materials used as pozzolans in the history was thermal‐treated clay, a material similar to the calcined clay precast elements. For this study, the materials selected are clay products that have been eliminated for different reasons: a wrong temperature inside the kiln, dimensional and mechanical failures, and durability loss. The results showed that these products have good pozzolanic properties; at an early age, the pozzolanic activity was found to be higher than fly ash, although it was lower than silica fume. The morphology of clay tile–PC pastes are similar to the morphology of the pastes containing other pozzolanic materials. Hydrated calcium aluminate products are generated when the preparation method yields less compact pastes with a greater voids' volume to accommodate these products. The hydrated calcium aluminate phases were analyzed using scanning electronic microscopy and X‐ray diffraction techniques.
The Zirconia–Hafnia System: DTA Measurements and Thermodynamic Calculations
Authors: Wang Chong , Zinkevich Matvei , Aldinger Fritz
Published: October 2006

The equilibrium temperature (T0) at which the tetragonal and monoclinic phases of either ZrO2 or HfO2 coexist is generally defined by the middle temperature of As (the onset transformation temperature on heating) and Ms (the onset transformation temperature on cooling). It cannot be directly determined due to the athermal nature of the martensitic transformation. Practically, the determination of T0 is important for the prediction of As and Ms in ZrO2 or HfO2‐based materials. In this work, the ZrO2–HfO2 system was studied experimentally by differential thermal analysis (DTA) to obtain the martensitic tetragonal ⇔ monoclinic transformation temperatures in the temperature range of 1273–1973 K. The T0 temperatures obtained for ZrO2 and HfO2 are 1367±5 and 2052±5 K, respectively. They are adopted for the assessments of the Gibbs energy parameters of these two oxides. A reasonably calculated ZrO2−HfO2 phase diagram is presented.
Mechanical and Tribological Behavior of Polymer‐Derived Ceramics Constituted from SiCxOyNz
Authors: Cross Tsali , Raj Rishi , Prasad Somuri V. , Buchheit Thomas E. , Tallant David R.
Published: October 2006

Polymer‐derived ceramics (PDCs) are a new class of ceramics that are obtained from direct pyrolysis of densely crosslinked polymers. In this article, we report the mechanical and tribological properties of silicon‐based PDCs. The density, the elastic modulus, the hardness, and the fracture toughness of silicon oxycarbonitride ceramics are related to their tribological (friction and wear) behavior. The mechanical properties show a strong relationship with the oxygen/nitrogen ratio in the ceramic, which was varied by annealing the specimens in nitrogen at high temperatures and pressure. The properties are enhanced by a higher nitrogen‐to‐oxygen ratio. In dry environments, the tribological behavior is divided into two regimes: a low‐friction regime with a coefficient of friction, μ, of about 0.2, and a high‐friction regime with μ∼0.7. The transition occurs at a critical value of contact stress. This transition stress appears to be related to the onset of fracture of the ceramic, and moves to a higher value with higher modulus and hardness of the ceramic. The transition stress is successfully analyzed in terms of the influence of the elastic modulus on the fracture stress. The analysis leads to the suggestion of a residual tensile stress in the surface of the specimens of approximately 1 GPa equivalent of the contact stress. In a humid environment, the transition stress apparently moves beyond the experimentally accessible regime. In this environment, the coefficient of friction remains unchanged at μ∼0.2. Two hypotheses, one related to the effect of humidity on the work of fracture, and the other to the formation of a hydrated film on the surface of silicon nitride, the counterface in the tribological experiments, are proposed for this behavior.
Vegetation and Environment History for the Past 14 000 yr BP from Dingnan, Jiangxi Province, South China
Authors: Dodson John Richard , Hickson Shirene , Khoo Rachel , Li Xiao‐Qiang , Toia Jemina , Zhou Wei‐Jian
Published: October 2006

A Late Pleistocene‐Holocene pollen, phosphorus, and charcoal record was reconstructed from a peatland in southern Jiangxi Province in southern China. The area today has a mountainous and rolling landscape with villages, small towns, and agriculture dominated by rice paddies, vegetable, and fruit gardens, as well as areas of secondary forest and pine re‐afforestation. The record opens before 14 300 yr BP, with Alnus woodland dominating the wetland areas and with an open Quercus woodland on the surrounding slopes. The forest area becomes more complex from approximately 12 800 yr BP and further from 9 000 yr BP. At approximately 6 000 yr BP, there is evidence of clearing and, by 4500–4000 yr BP, a complete collapse in the wetland Alnus and terrestrial forest as the low‐lying areas are converted to rice production. For much of the record, the occurrence of fire around the site was low, although there is evidence of regional fires. Fire was used as a tool in clearing and then used in the annual cycles of stubble burning after rice harvest. Nutrient levels, as reflected by total phosphorus in the sediment, seem to be closely related to forest changes and high values in the surface layers probably result from land‐management techniques associated with agriculture. Therefore, human impact greatly altered forest cover, fire frequency, and nutrient dynamics; this has been evident for approximately 6 000 yr BP and then intensifies towards the present day.

(Managing editor: Ya‐Qin Han)
Development of Diagnostic Microscopic and Chemical Markers of Some Euphorbia Latexes
Authors: Mallavadhani Uppuluri Venkata , Satyanarayana Kantamreddi Venkata Siva , Mahapatra Anita , Sudhakar Akella Venkata Subrahmanya , Narasimhan Kilambi , Pandey Devendar Kumar , Thirunavokkarasu Manikkannan
Published: October 2006

The latexes of the three Euphorbia species, namely E. antiquorum L., E. nerifolia L., and E. tirucalli L., are highly valued in the Indian system of medicine as purgatives, in addition to their specific and distinct therapeutic activities. In order to distinguish these latexes and develop their diagnostic microscopic and chemical markers, we performed extensive chemical and microscopic studies. The three latexes differ significantly in their microscopic features by exhibiting characteristic starch grain patterns. Although amoebic structures were found to be characteristic of E. antiquorum, dumb‐bell and oval structures are characteristic of E. nerifolia and E. tirucalli, respectively. In addition, these latexes showed bone‐shaped structures as a common feature, but these differed considerably in their length (10–60, 30–55, and 50–70 μm in length in E. antiquorum, E. nerifolia, and E. tirucalli, respectively). The chemical markers nerifoliene and euphol were found to be common to both E. antiquorum and E. nerifolia, whereas euphol is the only marker for E. tirucalli. A reverse‐phase high‐performance thin‐layer chromatographic (HPTLC) method was developed to distinguish these three latexes and to generate their standard fingerprinting patterns. Most significantly, the markers nerifoliene and euphol could be resolved by RP‐18 F254s precoated aluminium plates and the latexes have been quantitatively estimated with respect to these markers. The developed microscopic, chemical and HPTLC patterns can be used to distinguish the three latexes.

(Managing editor: Wei Wang)
Overexpression of the Wounding‐Responsive Gene AtMYB15 Activates the Shikimate Pathway in Arabidopsis
Authors: Chen Yanhui , Zhang Xiangbo , Wu Wei , Chen Zhangliang , Gu Hongya , Qu Li‐Jia
Published: October 2006

The MYB transcription factor genes play important roles in many developmental processes and various defense responses of plants. The shikimate pathway is a major biosynthetic pathway for the production of three aromatic amino acids and other aromatic compounds that are involved in multiple responses of plants, including protection against UV and defense. Herein, we describe the characterization of the R2R3‐MYB gene AtMYB15 as an activator of the shikimate pathway in Arabidopsis. The AtMYB15 protein is nuclear localized and a transcriptional activation domain is found in its C‐terminal portion. Northern blots showed that AtMYB15 is an early wounding‐inducible gene. Resutls of microarray analysis, confirmed using quantitative real‐time polymerase chain reaction, showed that overexpression of AtMYB15 in transgenic plants resulted in elevated expression of almost all the genes involved in the shikimate pathway. Bioinformatics analysis showed that one or more AtMYB15‐binding AC elements were detected in the promoters of these upregulated genes. Furthermore, these genes in the shikimate pathway were also found to be induced by wounding. These data suggest an important role of AtMYB15 as a possible direct regulator of the Arabidopsis shikimate pathway in response to wounding.

(Managing editor: Ya‐Qin Han)
Comparative Analysis of the Endosperm Proteins Separated by 2‐D Electrophoresis for Two Cultivars of Hybrid Rice (Oryza sativa L.)
Authors: Yang Pingfang , Shen Shihua , Kuang Tingyun
Published: October 2006

Liangyoupeijiu is a two‐parental‐line, and Shanyou63 is a three‐parental‐line hybrid rice (Oryza sativa L.). Although both belong to the indica subspecies, they have obvious differences with respect to morphology, physiology and grain quality. Variations in endosperm protein compositions were studied by comparing the 2‐D electrophoresis (2‐DE) maps for these two cultivars of hybrid rice. After matrix‐assisted laser desorption/ionization time of flight mass spectrometry (MALDI‐TOF/MS) analysis, a 21‐kDa precursor of 19‐kDa globulin was identified as the major storage protein for both cultivars. Some isoforms of peroxiredoxin and seed maturation protein were found to only exist in Shanyou63, whereas aldose reductase and starch granule‐bound starch synthase were only detected in Liangyoupeijiu. These data might provide a foundation for further comparative studies of these two cultivars of hybrid rice.

(Managing editor: Ping He)
Characterization of Interspecific Hybrids Between Oryza sativa L. and Three Wild Rice Species of China by Genomic In Situ Hybridization
Authors: Tan Guang‐Xuan , Xiong Zhi‐Yong , Jin Hua‐Jun , Li Gang , Zhu Li‐Li , Shu Li‐Hui , He Guang‐Cun
Published: October 2006

In the genus Oryza, interspecific hybrids are useful bridges for transferring the desired genes from wild species to cultivated rice (Oryza sativa L.). In the present study, hybrids between O. sativa (AA genome) and three Chinese wild rices, namely O. rufipogon (AA genome), O. officinalis (CC genome), and O. meyeriana (GG genome), were produced. Agricultural traits of the F1 hybrids surveyed were intermediate between their parents and appreciably resembled wild rice parents. Except for the O. sativa× O. rufipogon hybrid, the other F1 hybrids were completely sterile. Genomic in situ hybridization (GISH) was used for hybrid verification. Wild rice genomic DNAs were used as probes and cultivated rice DNA was used as a block. With the exception of O. rufipogon chromosomes, this method distinguished the other two wild rice and cultivated rice chromosomes at the stage of mitotic metaphase with different blocking ratios. The results suggest that a more distant phylogenetic relationship exists between O. meyeriana and O. sativa and that O. rufipogon and O. sativa share a high degree of sequence homology. The average mitotic chromosome length of O. officinalis and O. meyeriana was 1.25‐and 1.51‐fold that of O. sativa, respectively. 4′,6′‐Diamidino‐2‐phenylindole staining showed that the chromosomes of O. officinalis and O. meyeriana harbored more heterochromatin, suggesting that the C and G genomes were amplified with repetitive sequences compared with the A genome. Although chromocenters formed by chromatin compaction were detected with wild rice‐specific signals corresponding to the C and G genomes in discrete domains of the F1 hybrid interphase nuclei, the size and number of O. meyeriana chromocenters were bigger and greater than those of O. officinalis. The present results provide an important understanding of the genomic relationships and a tool for the transfer of useful genes from three native wild rice species in China to cultivars.

(Managing editor: Li‐Hui Zhao)
Biology and life table parameters of the mushroom pest, Pediculaster fletchmanni (Acari: Siteroptidae), at three constant temperatures
Authors: KHERADMAND KATAYUN , KAMALI KARIM , FATHIPOUR YAGHOUB , GOLTAPEH EBRAHIM MOHAMMADI , CAMERIK A. M.
Published: October 2006

Abstract
This paper is concerned with the bionomics and demography of Pediculaster fletchmanni Wicht (Acari: Siteroptidae) under controlled conditions (20 ± 1, 22 ± 1 and 25 ± 1°C, 70%± 5% relative humidity and a photoperiod of 16L : 8D hours). Glass Petri dishes inoculated with Trichoderma sp. mycelia were used as substrate and food source. The mean developmental time of the egg and the active larva did not differ significantly at the various constant temperatures, but these periods were significantly different for the quiescent larval stage. The preoviposition period ranged from 2.3 to 2.8 days, the ovipositional period increased with temperature increase, and all females died immediately after oviposition. The development of active larvae was the fastest of all life stages. The developmental threshold ranged between 5.25–14.22°C the highest value being observed for the quiescent larval development. For immature development required 89.29 degree‐days. Values of rm (intrinsic rate of increase) were 0.229, 0.398 and 0.386 for 20, 22 and 25°C respectively. Finite rates of increase (λ) increased along with increasing temperature from 20–25°C consequently the population doubling time (Dt) and mean generation time (Tc) showed significant differences with increasing temperature.
The Ins and Outs of Introspection
Authors: Robbins Philip
Published: October 2006

Introspection admits of several varieties, depending on which types of mental events are introspected. I distinguish three kinds of introspection (primary, secondary, and tertiary) and three explanations of the general capacity: the inside access view, the outside access view, and the hybrid view. Drawing on recent evidence from clinical and developmental psychology, I argue that the inside view offers the most promising account of primary and secondary introspection.
How we do it: The Dutch functional hearing–screening tests by telephone and internet
Authors: Smits C. , Merkus P. , Houtgast T.
Published: October 2006

Keypoints

• The Dutch National Hearing Test is a reliable and very successful functional hearing–screening test by telephone. An internet version of the National Hearing Test was also implemented.

• The National Hearing Test is a fully automatic adaptive speech‐in‐noise test that uses digit‐triplets as speech material. The result of the test is given as ‘good,’‘insufficient,’ or ‘poor.’

• The test by telephone performs better in reaching older subjects, who are more likely to suffer from hearing loss, than the test by internet.

• More than 50% of the participants who scored ‘insufficient’ or ‘poor’ followed the recommendation to visit a GP, hearing‐aid dispenser, ENT specialist or Audiological Center.

• The tests contribute to increase the identification and treatment of older hearing‐impaired subjects.
Anatomical and surgical considerations of the external branch of the superior laryngeal nerve: a systematic review
Authors: Morton R.P. , Whitfield P. , Al‐Ali S.
Published: October 2006

Keypoints

• The anatomical course of the external branch of the superior laryngeal nerve (EBSLN) is variable, and a consistent approach to its preservation during thyroid surgery is needed to reduce risk of post‐operative voice impairment.

• Despite agreement that careful dissection in the region of the superior thyroid pole is required, there is no accepted ‘best’ approach, nor any universal acknowledgement that location of the EBSLN is actually necessary.

• The popular cernea classification of EBSLN has limitations, including its decreased reliability with increased thyroid size and its irrelevance in cases of ‘buried’ variants.

• Recent work has identified factors such as ethnicity and stature in the prevalence of EBSLN variants.

• Consistent approaches to the post‐operative detection of EBSLN injury are needed to build an accurate picture of the incidence of surgical nerve injury. Then a standardised approach to EBSLN preservation may emerge.
Quality of life assessment after non‐laser endonasal dacryocystorhinostomy
Authors: Ho A. , Sachidananda R. , Carrie S. , Neoh C.
Published: October 2006

Objective:  There has been a lack of patient‐centred evidence in the Otolaryngology literature, that non‐laser endonasal dacryocystorhinostomy improves the quality of life of patients. Many studies demonstrate successful outcomes based on non‐validated subjective patient reporting. The aim of this survey was to evaluate the impact of non‐laser endonasal dacryocystorhinostomy on the quality of life of patients using a validated questionnaire, the Glasgow Benefit Inventory (GBI).

Design:  Prospective non‐randomised case series.

Setting:  Secondary otorhinolaryngology–ophthalmology centre, single centre.

Participants:  Sixty‐five consecutive patients undergoing non‐laser endonasal dacryocystorhinostomy were asked to complete a questionnaire at their follow‐up clinic appointment. All patients had a minimum of 9 months follow‐up.

Main outcome measures:  A consultant ophthalmologist reviewed each patient six months after surgery and recorded the outcomes as ‘cure’, ‘better’, ‘no change’ or ‘worse’. We defined ‘success’ as cured or better. ‘Failure’ suggests no improvement or worsening epiphora. The validated 18‐item GBI was used.

Results:  Fully completed questionnaires were received from 55 patients. Mean total GBI scores were +34 for successful non‐laser endonasal dacryocystorhinostomy and −19 for failed non‐laser endonasal dacryocystorhinostomy (Mann–Whitney z = 3.8, P < 0.001).

Conclusion:  Successful non‐laser endonasal dacryocystorhinostomy does confer significant quality of life improvement.
Validation of a voice prosthesis questionnaire to assess valved speech and its related issues in patients following total laryngectomy
Authors: Kazi R. , Singh A. , De Cordova J. , Al‐Mutairy A. , Clarke P. , Nutting C. , Rhys‐Evans P. , Harrington K.
Published: October 2006

Objectives:  To establish the reliability and validity of a new self‐administered questionnaire to assess valved speech and its related issues in patients who have undergone a total laryngectomy operation.

Design:  Cross‐sectional psychometric validation study.

Setting:  Tertiary cancer care centre.

Patients:  We identified sixty‐one total laryngectomy patients with no sign of recurrent disease and using voice prothesis from the speech and language therapy database of the Royal Marsden Hospital. The patients were assessed using a postal self‐administered voice prosthesis questionnaire concerning the voice valve and it's related issues. Patients were also asked to complete the University of Michigan voice related quality of life and University of Washington head and neck quality of life (version 4) questionnaires.

Main outcome measures:  Test‐retest and internal consistency reliability; content; criterion and construct validity.

Results:  We received completed questionnaires from fifty‐one of the sixty‐one total laryngectomy patients identified for the study providing a response rate of 84%. The median age of the group was 65 years (range: 40–85) with thirty‐seven males and fourteen females. The internal consistency reliability using the Cronbach's alpha coefficient was 0.87 (range: 0.85 to 0.89). Test‐retest reliablility showed that more than 75% of patients had a score on re‐test that was within 1 point of their original score. Content validity was ensured during the design process. The median Spearman correlation coefficient was 0.25 for convergent construct validity with the University of Washington head and neck quality of life questionnaire and 0.64 for criterion valididty on comparison with the University of Michigan voice related quality of life scale.

Conclusions:  The voice prosthesis questionnaire is the first validated and reliable self‐administered questionnaire designed specifically for evaluating valved speech and its related issues in patients who have undergone total laryngectomy. The voice prosthesis questionnaire has significant utility for audit, outcomes research and monitoring in this unique group of patients.