cAMP/PKA-dependent increases in Ca Sparks, oscillations and SR Ca stores in retinal arteriolar myocytes after exposure to vasopressin.

PURPOSE: To investigate the effects of arginine vasopressin (AVP) on Ca(2+) sparks and oscillations and on sarcoplasmic reticulum (SR) Ca(2+) content in retinal arteriolar myocytes. METHODS: Fluo-4-loaded smooth muscle in intact segments of freshly isolated porcine retinal arteriole was imaged by confocal laser microscopy. SR Ca(2+) store content was assessed by recording caffeine-induced Ca(2+) transients with microfluorimetry and fura-2. RESULTS: The frequencies of Ca(2+) sparks and oscillations were increased both during exposure to, and 10 minutes after washout of AVP (10 nM). Caffeine transients were increased in amplitude 10 and 90 minutes after a 3-minute application of AVP. Both AVP-induced Ca(2+) transients and the enhancement of caffeine responses after AVP washout were inhibited by SR 49059, a V(1a) receptor blocker. Forskolin, an activator of adenylyl cyclase, also persistently enhanced caffeine transients. Rp-8-HA-cAMPS, a membrane-permeant PKA inhibitor, prevented enhancement of caffeine transients by both AVP and forskolin. Forskolin, but not AVP, produced a reversible, Rp-8-HA-cAMPS insensitive reduction in basal [Ca(2+)](i). CONCLUSIONS: AVP activates a cAMP/PKA-dependent pathway via V(1a) receptors in retinal arteriolar smooth muscle. This effect persistently increases SR Ca(2+) loading, upregulating Ca(2+) sparks and oscillations, and may favor prolonged agonist activity despite receptor desensitization.

A transit timing analysis of seven RISE light curves of the exoplanet system HAT-P-3

We present seven light curves of the exoplanet system HAT-P-3, taken as part of a transit timing programme using the rapid imager to search for exoplanets instrument on the Liverpool Telescope. The light curves are analysed using a Markov chain Monte Carlo algorithm to update the parameters of the system. The inclination is found to be i = 86.75+0.22-0.21°, the planet-star radius ratio to be Rp/R* = 0.1098+0.0010-0.0012 and the stellar radius to be R* = 0.834+0.018-0.026Rsolar, consistent with previous results but with a significant improvement in the precision. Central transit times and uncertainties for each light curve are also determined, and a residual permutation algorithm is used as an independent check on the errors. The transit times are found to be consistent with a linear ephemeris, and a new ephemeris is calculated as Tc(0) = 2454856.70118 +/- 0.00018 HJD and P = 2.899738 +/- 0.000007 d. Model timing residuals are fitted to the measured timing residuals to place upper mass limits for a hypothetical perturbing planet as a function of the period ratio. These show that we have probed for planets with masses as low as 0.33 and 1.81 M? in the interior and exterior 2:1 resonances, respectively, assuming the planets are initially in circular orbits.

An ingress and a complete transit of HD80606 b

We have used four telescopes at different longitudes to obtain near-continuous light-curve coverage of the star HD80606 as it was transited by its ~4-MJup planet. The observations were performed during the predicted transit windows around 2008 October 25 and 2009 February 14. Our data set is unique in that it simultaneously constrains the duration of the transit and the planet's period. Our Markov Chain Monte Carlo analysis of the light curves, combined with constraints from radial-velocity data, yields system parameters consistent with previously reported values. We find a planet-to-star radius ratio marginally smaller than previously reported, corresponding to a planet radius of Rp = 0.921 +/- 0.036RJup.

Development of a Diagnostic Genetic Test for Simplex and Autosomal Recessive Retinitis Pigmentosa

PURPOSE: Retinitis pigmentosa (RP) causes hereditary blindness in adults (prevalence, approximately 1 in 4000). Each of the more than 30 causative genes identified to date are responsible for only a small percentage of cases. Genetic diagnosis via traditional methods is problematic, and a single test with a higher probability of detecting the causative mutation would be very beneficial for the clinician. The goal of this study therefore was to develop a high-throughput screen capable of detecting both known mutations and novel mutations within all genes implicated in autosomal recessive or simplex RP. DESIGN: Evaluation of diagnostic technology. PARTICIPANTS AND CONTROLS: Participants were 56 simplex and autosomal recessive RP patients, with 360 population controls unscreened for ophthalmic disease. METHODS: A custom genechip capable of resequencing all exons containing known mutations in 19 disease-associated genes was developed (RP genechip). A second, commercially available arrayed primer extension (APEX) system was used to screen 501 individual previously reported variants. The ability of these high-throughput approaches to identify pathogenic variants was assessed in a cohort of simplex and autosomal recessive RP patients. MAIN OUTCOME MEASURES: Number of mutations and potentially pathogenic variants identified. RESULTS: The RP genechip identified 44 sequence variants: 5 previously reported mutations; 22 known single nucleotide polymorphisms (SNPs); 11 novel, potentially pathogenic variants; and 6 novel SNPs. There was strong concordance with the APEX array, but only the RP genechip detected novel variants. For example, identification of a novel mutation in CRB1 revealed a patient, who also had a single previously known CRB1 mutation, to be a compound heterozygote. In some individuals, potentially pathogenic variants were discovered in more than one gene, consistent with the existence of disease modifier effects resulting from mutations at a second locus. CONCLUSIONS: The RP genechip provides the significant advantage of detecting novel variants and could be expected to detect at least one pathogenic variant in more than 50% of patients. The APEX array provides a reliable method to detect known pathogenic variants in autosomal recessive RP and simplex RP patients and is commercially available. High-throughput genotyping for RP is evolving into a clinically useful genetic diagnostic tool.

Vasodilator-Stimulated Phosphoprotein Regulates Inside-Out Signaling of beta(2) Integrins in Neutrophils

The monomeric GTPase Rap1 controls functional activation of beta2 integrins in leukocytes. In this article, we describe a novel mechanism by which the chemoattractant fMLP activates Rap1 and inside-out signaling of beta2 integrins. We found that fMLP-induced activation of Rap1 in human polymorphonuclear leukocytes or neutrophils and differentiated PLB-985 cells was blocked by inhibitors of the NO/guanosine-3',5'-cyclic monophosphate-dependent protein kinase (cGKI) pathway [N-(3-(aminomethyl)benzyl)acetamidine, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, DT-3 peptide, 8-(4-chlorophenylthio)guanosine 3',5'-cyclic monophosphothioate, Rp-isomer triethylammonium salt-guanosine-3',5'-cyclic monophosphate], indicating that the downstream signaling events in Rap1 activation involve the production of NO and guanosine-3',5'-cyclic monophosphate, as well as the activation of cGKI. Silencing the expression of vasodilator-stimulated phosphoprotein (VASP), a substrate of cGKI, in resting PLB-985 cells or mice neutrophils led to constitutive activation of Rap1. In parallel, silencing VASP in differentiated PLB-985 cells led to recruitment of C3G, a guanine nucleotide exchange factor for Rap1, to the plasma membrane. Expression of murine GFP-tagged phosphodeficient VASP Ser235Ala mutant (murine serine 235 of VASP corresponds to human serine 239) in PLB-985 cells blunted fMLP-induced translocation of C3G to the membrane and activation of Rap1. Thus, bacterial fMLP triggers cGKI-dependent phosphorylation of human VASP on serine 239 and, thereby, controls membrane recruitment of C3G, which is required for activation of Rap1 and beta2 integrin-dependent antibacterial functions of neutrophils.

Retinopathy is reduced during experimental diabetes in a mouse model of outer retinal degeneration

PURPOSE. Diabetic patients who also have retinitis pigmentosa (RP) appear to have fewer and less severe retinal microvascular lesions. Diabetic retinopathy may be linked to increased inner retinal hypoxia, with the possibility that this is exacerbated by oxygen usage during the dark-adaptation response. Therefore, patients with RP with depleted rod photoreceptors may encounter proportionately less retinal hypoxia, and, when diabetes is also present, there may be fewer retinopathic lesions. This hypothesis was tested in rhodopsin knockout mice (Rho(-/-)) as an RP model in which the diabetic milieu is superimposed. The study was designed to investigate whether degeneration of the outer retina has any impact on hypoxia, to examine diabetes-related retinal gene expression responses, and to assess lesions of diabetic retinopathy.

Murine model of autosomal dominant retinitis pigmentosa generated by targeted deletion at codon 307 of the rds-peripherin gene

We introduced a targeted single base deletion at codon 307 of the rds-peripherin gene in mice, similar mutations being known to cause autosomal dominant retinitis pigmentosa (RP) in man. Histopathological and electroretinographic analysis indicate that the retinopathy in mice homozygous for the codon 307 mutation appears more rapid than that in the naturally occurring null mutant, the rds(-/-) mouse, suggesting that the rds-307 mutation displays a dominant negative phenotype in combination with that due to haplosufficiency. RP is the most prevalent cause of registered visual handicap in those of working age in developed countries, the 50 or so mutations so far identified within the RDS-peripherin gene accounting for up to 10% of dominant cases of the disease. Given the sequence homologies that exist between the murine rds-peripherin and the human RDS-peripherin gene, this disease model, the first to be generated for peripherin-based RP using gene targeting techniques, should in principle be of value in the work-up in mice of therapeutics capable of targeting transcripts derived from the human gene.

WASP-25b: a 0.6 MJ planet in the Southern hemisphere

We report the detection of a 0.6 MJ extrasolar planet by WASP-South, WASP-25b, transiting its solar-type host star every 3.76 d. A simultaneous analysis of the WASP, FTS and Euler photometry and CORALIE spectroscopy yields a planet of Rp= 1.22 RJ and Mp= 0.58 MJ around a slightly metal-poor solar-type host star, [Fe/H]=- 0.05 ± 0.10, of R*= 0.92 Rsun and M*= 1.00 Msun. WASP-25b is found to have a density of ?p= 0.32 ?J, a low value for a sub-Jupiter mass planet. We investigate the relationship of planetary radius to planetary equilibrium temperature and host star metallicity for transiting exoplanets with a similar mass to WASP-25b, finding that these two parameters explain the radii of most low-mass planets well.

WASP-34b: a near-grazing transiting sub-Jupiter-mass exoplanet in a hierarchical triple system

We report the discovery of WASP-34b, a sub-Jupiter-mass exoplanet transiting its 10.4-magnitude solar-type host star (1SWASP J110135.89-235138.4; TYC 6636-540-1) every 4.3177 days in a slightly eccentric orbit (e = 0.038±0.012). We find a planetary mass of 0.59±0.01 MJup and radius of 1.22-0.08+0.11 RJup. There is a linear trend in the radial velocities of 55±4 m s-1 y-1 indicating the presence of a long-period third body in the system with a mass ?0.45 MJup at a distance of ?1.2 AU from the host star. This third-body is either a low-mass star, a white dwarf, or another planet. The transit depth ((RP/Rstar)2 = 0.0126) and high impact parameter (b = 0.90) suggest that this could be the first known transiting exoplanet expected to undergo grazing transits, but with a confidence of only 80%. Radial velocity and photometric data are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/526/A130

A lower mass for the exoplanet WASP-21b

We present high-precision transit observations of the exoplanet WASP-21b, obtained with the Rapid Imager to Search for Exoplanets instrument mounted on the 2.0-m Liverpool Telescope. A transit model is fitted, coupled with a Markov chain Monte Carlo routine, to derive accurate system parameters. The two new high-precision transits allow us to estimate the stellar density directly from the light curve. Our analysis suggests that WASP-21 is evolving off the main sequence which led to a previous overestimation of the stellar density. Using isochrone interpolation, we find a stellar mass of 0.86 ± 0.04 Msun, which is significantly lower than previously reported (1.01 ± 0.03 Msun). Consequently, we find a lower planetary mass of 0.27 ± 0.01 MJup. A lower inclination (87?4 ± 0?3) is also found for the system than previously reported, resulting in a slightly larger stellar (R*= 1.10 ± 0.03 Rsun) and planetary radius (Rp= 1.14 ± 0.04 RJup). The planet radius suggests a hydrogen/helium composition with no core which strengthens the correlation between planetary density and host star metallicity. A new ephemeris is determined for the system, i.e. T0= 245 5084.519 74 ± 0.000 20 (HJD) and P= 4.322 5060 ± 0.000 0031 d. We found no transit timing variations in WASP-21b.

The molecular form of mercury in biota:identification of novel mercury peptide complexes in plants

The molecular structure of a variety of novel mercury-phytochelatin complexes was evidenced in rice plants exposed to inorganic mercury (Hg2+) using RP-HPLC with simultaneous detection via ICP-MS and ES-MS.

Class, Factionalism, and the Radical Retreat: Black Laborers and the Republican Party in South Carolina, 1865-1900

a chapter-length piece in a collection which I've co-edited and written the introduction for, which examines class and other tensions in the ranks of the Republican party during and after Reconstruction in South Carolina, with a focus on the confrontation between insurgent former slaves and Party moderates over the social content of the RP programme.

Development of a genotyping microarray for Usher syndrome

Usher syndrome, a combination of retinitis pigmentosa (RP) and sensorineural hearing loss with or without vestibular dysfunction, displays a high degree of clinical and genetic heterogeneity. Three clinical subtypes can be distinguished, based on the age of onset and severity of the hearing impairment, and the presence or absence of vestibular abnormalities. Thus far, eight genes have been implicated in the syndrome, together comprising 347 protein-coding exons.

Next generation sequencing-based molecular diagnosis of retinitis pigmentosa: identification of a novel genotype-phenotype correlation and clinical refinements

Retinitis pigmentosa (RP) is a devastating form of retinal degeneration, with significant social and professional consequences. Molecular genetic information is invaluable for an accurate clinical diagnosis of RP due to its high genetic and clinical heterogeneity. Using a gene capture panel that covers 163 of the currently known retinal disease genes, including 48 RP genes, we performed a comprehensive molecular screening in a collection of 123 RP unsettled probands from a wide variety of ethnic backgrounds, including 113 unrelated simplex and 10 autosomal recessive RP (arRP) cases. As a result, 61 mutations were identified in 45 probands, including 38 novel pathogenic alleles. Interestingly, we observed that phenotype and genotype were not in full agreement in 21 probands. Among them, eight probands were clinically reassessed, resulting in refinement of clinical diagnoses for six of these patients. Finally, recessive mutations in CLN3 were identified in five retinal degeneration patients, including four RP probands and one cone-rod dystrophy patient, suggesting that CLN3 is a novel non-syndromic retinal disease gene. Collectively, our results underscore that, due to the high molecular and clinical heterogeneity of RP, comprehensive screening of all retinal disease genes is effective in identifying novel pathogenic mutations and provides an opportunity to discover new genotype-phenotype correlations. Information gained from this genetic screening will directly aid in patient diagnosis, prognosis, and treatment, as well as allowing appropriate family planning and counseling.

Causal Models of Clinically Significant Behaviors in Angelman, Cornelia de Lange, Prader-Willi and Smith-Magenis Syndromes

The operant learning theory account of behaviors of clinical significance in people with intellectual disability (ID) has dominated the field for nearly 50 years. However, in the last two decades, there has been a substantial increase in published research that describes the behavioral phenotypes of genetic disorders and shows that behaviors such as self-injury and aggression are more common in some syndromes than might be expected given group characteristics. These cross-syndrome differences in prevalence warrant explanation, not least because this observation challenges an exclusively operant learning theory account. To explore this possible conflict between theoretical account and empirical observation, we describe the genetic cause and physical, social, cognitive and behavioral phenotypes of four disorders associated with ID (Angleman, Cornelia de Lange, Prader-Willi and Smith-Magenis syndromes) and focus on the behaviors of clinical significance in each syndrome. For each syndrome we then describe a model of the interactions between physical characteristics, cognitive and motivational endophenotypes and environmental factors (including operant reinforcement) to account for the resultant behavioral phenotype. In each syndrome it is possible to identify pathways from gene to physical phenotype to cognitive or motivational endophenotype to behavior to environment and back to behavior. We identify the implications of these models for responsive and early intervention and the challenges for research in this area. We identify a pressing need for meaningful dialog between different disciplines to construct better informed models that can incorporate all relevant and robust empirical evidence.