Why H Atom Prefers the On-Top Site and Alkali Metals Favor the Middle Hollow Site on the Basal Plane of Graphite

In this work, the different adsorption properties of H and alkali metal atoms on the basal plane of graphite are studied and compared using a density functional method on the same model chemistry level. The results show that H prefers the on-top site while alkali metals favor the middle hollow site of graphite basal plane due to the unique electronic structures of H, alkali metals, and graphite. H has a higher electronegativity than carbon, preferring to form a covalent bond with C atoms, whereas alkaline metals have lower electronegativity, tending to adsorb on the highest electrostatic potential sites. During adsorption, there are more charges transferred from alkali metal to graphite than from H to graphite.

The efficacy of a vitamin D-3 metabolite for improving the myofibrillar tenderness of meat from Bos indicus cattle

The influence of a once only administration of a metabolite of vitamin D-3 (HY center dot D-(R)-25-hydroxy vitamin D-3) on myofibrillar meat tenderness in Australian Brahman cattle was studied. Ninety-six Brahman steers of three phenotypes (indo-Brazil, US and US/European) and with two previous hormonal growth promotant (HGP) histories (implanted or not implanted with Compudose((R))) were fed a standard feedlot ration for 70 d. Treatment groups of 24 steers were offered daily 10 g/head HY center dot D-(R) (125 mg 25-hydroxyvitamin D-3) for 6, 4, or 2 d before slaughter. One other group of 24 steers was given the basal diet without HY center dot D-(R). Feed lot performance, blood and muscle samples and carcass quality data were collected at slaughter. Calcium, magnesium, potassium, sodium, iron and Vitamin D-3 metabolites were measured in plasma and longissimus dorsi muscle. Warner-Bratzler (WB) shear force (peak force, initial yield) and other objective meat quality measurements were made on the longissimus dorsi muscle of each steer after ageing for 1, 7 and 14 d post-mortem at 0-2 degrees C. There were no significant effects of HY center dot D-(R) supplements on average daily gain (ADG, 1.28-1.45 kg/d) over the experimental period. HY center dot D-(R) supplements given 6 d prior to slaughter resulted in significantly higher (P < 0.05) initial yield values compared to supplements given 2 d prior to slaughter. Supplementation had no significant effect on meat colour, ultimate pH, sarcomere length, cooking loss, instron compression or peak force. There was a significant treatment (HY center dot D-(R)) by phenotype/HGP interaction for peak force (P = 0.028), in which Indo-Brazil steers without previous HGP treatment responded positively (increased tenderness) to HY center dot D-(R) supplements at 2 d when compared with Indo-Brazil steers previously given HGP. There were no significant effects of treatment on other phenotypes. HY center dot D-(R) supplements did not affect muscle or plasma concentrations of calcium, potassium or sodium, but did significantly decrease plasma magnesium and iron concentrations when given 2 d before slaughter. There were no detectable amounts of 25-hydroxyvitamin D-3 in the blood or muscle of any cattle at slaughter. (c) 2005 Elsevier Ltd. All rights reserved.

Regional specialization in pyramidal cell structure in the limbic cortex of the vervet monkey (Cercopithecus pygerythrus): an intracellular injection study of the anterior and posterior cingulate gyrus

The pyramidal cell phenotype varies quite dramatically in structure among different cortical areas in the primate brain. Comparative studies in visual cortex, in particular, but also in sensorimotor and prefrontal cortex, reveal systematic trends for pyramidal cell specialization in functionally related cortical areas. Moreover, there are systematic differences in the extent of these trends between different primate species. Recently we demonstrated differences in pyramidal cell structure in the cingulate cortex of the macaque monkey; however, in the absence of other comparative data it remains unknown as to whether the neuronal phenotype differs in cingulate cortex between species. Here we extend the basis for comparison by studying the structure of the basal dendritic trees of layer III pyramidal cells in the posterior and anterior cingulate gyrus of the vervet monkey (Brodmann's areas 23 and 24, respectively). Cells were injected with Lucifer Yellow in flat-mounted cortical slices, and processed for a light-stable DAB reaction product. Size, branching pattern, and spine density of basal dendritic arbors were determined, and somal areas measured. As in the macaque monkey, we found that pyramidal cells in anterior cingulate gyrus (area 24) were more branched and more spinous than those in posterior cingulate gyrus (area 23). In addition, the extent of the difference in pyramidal cell structure between these two cortical regions was less in the vervet monkey than in the macaque monkey.

DHPLC analysis of patients with nevoid basal cell carcinoma syndrome reveals novel PTCH missense mutations in the serol-sensing domain

Nevoid Basal Cell Carcinoma Syndrome (NBCCS) is an autosomal dominant disorder characterised by multiple basal cell carcinomas, palmar and plantar pitting, odontogenic keratocysts of the jaws and bilamellar calcification of the falx. Mutations in the PTCH gene are responsible for NBCCS but most studies have found mutations in less than half of the cases tested. We used denaturing high performance liquid chromatography (DHPLC) to screen for PTCH mutations in 28 NBCCS cases, most of whom had been previously evaluated by single stranded conformation polymorphism analysis but found to be negative. Protein truncating (n = 10) and missense or indel (n = 4) mutations were found in 14/28 (50%) cases and one additional case carried an unclassified variant, c.2777G>C. Thirteen of the variants were novel. The mutation frequency was similar in inherited and de novo cases. Three of the missense and indel mutations were in the sterol-sensing domain, and one was in the sixth transmembrane domain.

Heterozygote effects in mice with partial truncations in the growth hormone receptor cytoplasmic domain: Assessment of growth parameters and phenotype

The GH receptor (GHR) is essential for normal postnatal growth and development, and the molecular basis of GHR action has been studied intensively. Clinical case studies and more recently mouse models have revealed the extensive phenotype of impaired GH action. We recently reported two new mouse models, possessing cytoplasmic truncations at position 569 (plus Y539/545-F) and 391, which were created to identify functional subdomains within the cytoplasmic signaling domain. In the homozygous state, these animals show progressively impaired postnatal growth coupled with complex changes in gene expression. We describe here an extended phenotype analysis encompassing the heterozygote state to identify whether single copies of these mutant receptors bring about partial or dominant-negative phenotypes. It appears that the retention of the ubiquitin-dependent endocytosis motif the N-terminal cytoplasmic domain permits turnover of these mutant receptors because no dominant-negative phenotype is seen. Nonetheless, we do observe partial impairment of postnatal growth in heterozygotes supporting limited haploinsufficiency. Reproductive function is impaired in these models in a progressive manner, in parallel with loss of signal transducer and activator of transcription-5 activation ability. In summary, we describe a more comprehensive phenotypic analysis of these mouse models, encompassing overall and longitudinal body growth, reproductive function, and hormonal status in both the heterozygote and homozygote state. Our results suggest that patients expressing single copies of similarly mutated GHRs would not display an obvious clinical phenotype.

Properties of a unique mutant of Helicoverpa armigera single-nucleocapsid nucleopolyhedrovirus that exhibits a partial many polyhedra and few polyhedra phenotype on extended serial passaging in suspension cell cultures

Serial passaging of wild-type Helicoverpa armigera, single-nucleocapsid (HaSNPV) in H. zea (HzAMI) illsect Cell Cultures results ill rapid selection for the few polyhedra (FP) phenotype. A unique HaSNPV mutant (ppC19) was isolated through plaque purification that exhibited a partial many polyhedra (MP) and FP phenotype. Oil serial passaging in suspension cell cultures, ppC19 produced fivefold more polyhedra than a typical FP mutant (FP8AS) but threefold less polyhedra than the wild-type virus. Most importantly, the polyhedra of ppC19 exhibited MP-like virion occlusion. Furthermore, ppC19 produced the same amount of budded virus (BV) as the FP mutant, which was fivefold higher than that of the wild-type virus. This selective advantage was likely to explain its relative stability in polyhedra production for six passages when compared with the wild-type Virus. However, subsequent passaging of ppC19 resulted in a steel) decline in both BV and polyhedra yields, which was also experienced by FP8AS and the wild-type virus Lit high passage numbers. Genomic deoxyribonueleic Licid profiling of the latter suggested that defective interfering particles (DIPS) were implicated in this phenomenon and represented another Undesirable mutation during serial passaging of HaSNPV Hence, a strategy to isolate HaSNPV Clones that exhibited MP-like polyhedra production but FP-like BV production, coupled with low multiplicities of infection during scale-up to avoid accumulation of DIPS, could prove commerically invaluable.

Duration of cannabis use - a novel phenotype?

Although cannabis is the most commonly used illicit drug, duration of cannabis use is typically short, with many of those who initiate cannabis use ceasing use by their late twenties. In this paper we analyze data from a volunteer Australian cohort of 6265 male and female twins to examine whether the duration of cannabis use is an informative phenotype for future genetic analyses. Genetic modeling indicated: (a) moderate genetic influences on duration of cannabis use in both males (41%; 95% CI = 31–51) and females (55%; 95% CI = 46–63); (b) strong genetic influences on cannabis dependence in both males (72%, 95% CI = 61–81) and females (62%, 95% CI = 48–74); (c) no evidence of shared environmental influences on duration of cannabis use or on cannabis dependence in either males or females. Importantly, this model fitting indicated that a substantial component of genetic influences (rg = .90, 95% CI = .77–.99 (males); .70, 95% CI = .57–.83 (females)) on duration of cannabis use was shared with those influencing liability to cannabis dependence. While there were high genetic correlations in both women and men, lifetime duration of cannabis may be uniquely informative in assessing components of liability to cannabis use.

A side order of stem cells: The SP phenotype

A defining property of murine hematopoietic stein cells (HSCs) is low fluorescence after staining with Hoechst 33342 and Rhodamine 123. These dyes have proven to be remarkably powerful tools in the purification and characterization of HSCs when used alone or in combination with antibodies directed against stem cell epitopes. Hoechst low cells are described as side population (SP) cells by virtue of their typical profiles in Hoechst red versus Hoechst blue bivariate fluorescent-activated cell sorting dot plots. Recently, excitement has been generated by the findings that putative stem cells from solid tissues may also possess this SP phenotype. SP cells have now been isolated from a wide variety of mammalian tissues based on this same dye efflux phenomenon, and in many cases this cell population has been shown to contain apparently multipotent stem cells. What is yet to be clearly addressed is whether cell fusion accounts for this perceived SP multipotency. Indeed, if low fluorescence after Hoechst staining is a phenotype shared by hematopoietic and organ-specific stem cells, do all resident tissue SP cells have bone marrow origins or might the SP phenotype be a property common to all stem cells? Subject to further analysis, the SP phenotype may prove invaluable for the initial isolation of resident tissue stem cells in the absence of definitive cell-surface markers and may have broad-ranging applications in stem cell biology, from the purification of novel stem cell populations to the development of autologous stem cell therapies.

Basal chromodorid sperm ultrastructure (Nudibranchia, Gastropoda, Mollusca)

The relationship between three genera considered basal in the Chromodorididae (Cadlina, Tyrinna, Cadlinella) has not yet been resolved by traditional morphological means. Here we examined the sperm ultrastructure of Tyrinna nobilis, Tyrinna evelinae, Cadlina flavomaculata and Cadlina cf. nigrobranchiata, with the expectation of finding phylogenetically informative characters. No Tyrinna or Cadlina species showed sperm similarities to Cadlinella. Both Cadlina species and Tyrinna nobilis (but not T. evelinae) exhibited coarse striations in the acrosomal pedestal. The putative fibers that occurred between the coarse striations of the pedestal are condensed into a layer in Cadlina and Tyrinna, but not in other species that also have coarse striations (Gymnodoris), and may constitute evidence for a close relationship. Tyrinna evelinae possessed fine acrosomal striations, which was shared with other Chromodorididae, Actinocyclidae and the cryptobranchs Rostanga and Aphelodoris. We also examined the sperm ultrastructure of 'Chromodoris' ambiguus, an animal which has shown molecular affinities to species of Cadlina, and not Chromodoris. The sperm of 'C'.' ambiguus did not exhibit the typical Cadlina characteristics, but also showed important differences to other investigated Chromodoris species.

Defective p53 response and apoptosis associated with an ataxia-telangiectasia-like phenotype

Ataxia-telangiectasia mutated (ATM), the protein defective in ataxia-telangiectasia, plays a central role in DNA damage response and signaling to cell cycle checkpoints. We describe here a cell line from a patient with an ataxia-telangiectasia-like clinical phenotype defective in the p53 response to radiation but with normal ATM activation and efficient downstream phosphorylation of other ATM substrates. No mutations were detected in ATM cDNA. A normal level of interaction between p53 and peptidyl-prolyl-isomerase Pin1 suggests that posttranslational modification was intact in these cells but operating at reduced level. Defective p53 stabilization was accompanied by defective induction of p53 effector genes and failure to induce apoptosis in response to DNA-damaging agents. Continued association between p53 and murine double minute-2 (Mdm2) occurred in irradiated ATL2ABR cells in response to DNA damage, and incubation with Mdm2 antagonists, nutlins, increased the stabilization of p53 and its transcriptional activity but failed to induce apoptosis. These results suggest that ATM-dependent stabilization of p53 and induction of apoptosis by radiation involve an additional factor(s) that is defective in ATL2ABR cells.

Influence of incubation temperature on hatchling phenotype in reptiles

Incubation temperature influences hatchling phenotypes such as sex, size, shape, color, behavior, and locomotor performance in many reptiles, and there is growing concern that global warming might adversely affect reptile populations by altering frequencies of hatchling phenotypes. Here I overview a recent theoretical model used to predict hatchling sex of reptiles with temperature-dependent sex determination. This model predicts that sex ratios will be fairly robust to moderate global warming as long as eggs experience substantial daily cyclic fluctuations in incubation temperatures so that embryos are exposed to temperatures that inhibit embryonic development for part of the day. I also review studies that examine the influence of incubation temperature on posthatch locomotion performance and growth because these are the traits that are likely to have the greatest effect on hatchling fitness. The majority of these studies used artificial constant-temperature incubation, but some have addressed fluctuating incubation temperature regimes. Although the number of studies is small, it appears that fluctuating temperatures may enhance hatchling locomotor performance. This finding should not be surprising, given that the majority of natural reptile nests are relatively shallow and therefore experience daily fluctuations in incubation temperature.

Knockdown of zebrafish crim1 results in a bent tail phenotype with defects in somite and vascular development

The Crim1 gene encodes a transmembrane protein containing six cysteine-rich repeats similar to those found in the BMP antagonist, chordin (chd). To investigate its physiological role, zebrafish crim1 was cloned and shown to be both maternally and zygotically expressed during zebrafish development in sites including the vasculature, intermediate cell mass. notochord, and otic vesicle. Bent or hooked tails with U-shaped somites were observed in 85% of morphants from 12 hpf. This was accompanied by a loss of muscle pioneer cells. While morpholino knockdown of crim1 showed some evidence of ventralisation, including expansion of the intermediate cell mass (ICM), reduction in head size bent tails and disruption to the somites and notochord, this did not mimic the classically ventralised phenotype, as assessed by the pattern of expression of the dorsal markers chordin, otx2 and the ventral markers eve1, pax2.1, tall and gata1 between 75% epiboly and six-somites. From 24 hpf, morphants displayed an expansion of the ventral mesoderm-derived ICM, as evidenced by expansion of tall. Imo2 and crim1 itself. Analysis of the crim1 morphant phenotype in Tg(fli:EGFP) fish showed a clear reduction in the endothelial cells forming the intersegmental vessels and a loss of the dorsal longitudinal anastomotic vessel (DLAV). Hence, the primary role of zebrafish crim1 is likely to be the regulation of somitic and vascular development. (c) 2006 Elsevier Ireland Ltd. All rights reserved.

Dysprosodic speech following basal ganglia insult: Toward a conceptual framework for the study of cerebral representation of prosody

Progress in understanding brain/behavior relationships in adult-acquired dysprosody has led to models of cortical hemispheric representation of prosodic processing based on functional (linguistic vs affective) or physical (timing vs pitch) parameters. These explanatory perspectives have not been reconciled, and also a number of neurobehavior syndromes that include dysprosody among their neurological signs have not yet been integrated. In addition to expanding the functional perspective on prosody, some of these syndromes have implicated a significant role of subcortical nuclei in prosodic competence. In this article, two patients with acquired dysprosodic speech following damage to basal ganglia nuclei were evaluated using behavioral, acoustic, cognitive, and radiographic approaches. Selective quantitative measures were performed on each individual’s performance to provide detailed verification and clarification of clinical observations, and to test hypotheses regarding prosodic function. These studies, combined with a review of related clinical research findings, exemplify the value of a broader perspective on the neurobehavioral dysfunction underlying acquired adult dysprosodic speech, and lead to a new, proposed conceptual framework for the cerebral representation of prosody.

Dramatic extension of tumor latency and correction of neurobehavioral phenotype in Atm-mutant mice with a nitroxide antioxidant

Mutations in the ATM gene (mutated in ataxia telangiectasia) in both humans and mice predispose to lymphoid tumors. A defect in this gene also causes neurodegeneration in humans and a less severe neurological phenotype in mice. There is some evidence that oxidative stress contributes to these defects, suggesting that antioxidants could alleviate the phenotype. We demonstrate here that the antioxidant 5-carboxy-1,1,3,3-tetramethylisoindolin-2-yloxyl (CTMIO) dramatically delays the onset of thymic lymphomas in Atm(-/-) mice which is not due to an enhancement of apoptosis by CTMIO. We also show that this compound corrects neurobehavioral deficits in these mice and reduces oxidative damage to Purkinje cells. The likely mechanism of action of CTMIO is due to a reduction in oxidative stress, which is protective against both the tumor progression and the development of neurological abnormalities. These data suggest that antioxidant therapy has considerable potential in the management of ataxia telangiectasia and possibly other neurodegenerative disorders where oxidative stress is implicated. (c) 2006 Elsevier Inc. All rights reserved.

Short root mutant of Lotus japonicus with a dramatically altered symbiotic phenotype

Legume plants carefully control the extent of nodulation in response to rhizobial infection. To examine the mechanism underlying this process we conducted a detailed analysis of the Lotus japonicus hypernodulating mutants, har1-1, 2 and 3 that define a new locus, HYPERNODULATION ABERRANT ROOT FORMATION (Har1), involved in root and symbiotic development. Mutations in the Har1 locus alter root architecture by inhibiting root elongation, diminishing root diameter and stimulating lateral root initiation. At the cellular level these developmental alterations are associated with changes in the position and duration of root cell growth and result in a premature differentiation of har1-1 mutant root. No significant differences between har1-1 mutant and wild-type plants were detected with respect to root growth responses to 1-aminocyclopropane1-carboxylic acid, the immediate precursor of ethylene, and auxin; however, cytokinin in the presence of AVG (aminoetoxyvinylglycine) was found to stimulate root elongation of the har1-1 mutant but not the wild-type. After inoculation with Mesorhizobium loti, the har1 mutant lines display an unusual hypernodulation (HNR) response, characterized by unrestricted nodulation (hypernodulation), and a concomitant drastic inhibition of root and shoot growth. These observations implicate a role for the Har1 locus in both symbiotic and non-symbiotic development of L. japonicus, and suggest that regulatory processes controlling nodule organogenesis and nodule number are integrated in an overall mechanism governing root growth and development.