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J L Stone

Publications and source records attributed to J L Stone.

At least 19 recordsLinked to original sources
PubMed2006

Measurement of atmospheric neutrino flux consistent with tau neutrino appearance.

A search for the appearance of tau neutrinos from nu(mu) <--> nu(tau) oscillations in the atmospheric neutrinos has been performed using 1489.2 days of atmospheric neutrino data from the Super-Kamiokande-I experiment. A best fit tau neutrino appearance signal of 138+/-48(stat)-32(+15)(syst) events is obtained with an expectation of 78+/-26(syst). The hypothesis of no tau neutrino appearance is disfavored by 2.4 sigma.

Journal Article↗
PubMed2005

Rapid recent radiation of S-RNase lineages in Witheringia solanacea (Solanaceae).

Strong frequency-dependent selection as found in the self-incompatibility loci of flowering plants maintains allelic lineages for extremely long time scales, such that allelic genealogies can shed insight into long-term demographic patterns of species. Effective mutation rate, as well as demographic change such as population bottlenecks, can influence genealogical structure. In addition, loss of functionality at the self-incompatibility locus is likely to affect radiation rates. Partial sequences for 21 S-RNase alleles of the mid-elevation tropical species Witheringia solanacea were obtained in order to compare their substitution rates and genealogy with those of Witheringia maculata and two species in the closely related genus Physalis. Sequences for W. solanacea fell into the three clades within the Solanaceae already identified for the genus. Terminal branch lengths for W. solanacea, scaled to the total depth of its phylogeny, were intermediate between the unusually short terminal branches of W. maculata and those of the two Physalis species. In contrast to the Physalis species, where interspecific dN/dS for closely related alleles exceeded 1.0 to the same degree as did intraspecific dN/dS, in Witheringia only intraspecific comparisons showed an excess of nonsynonymous substitutions, suggesting postspeciation radiation of alleles. Alleles associated with lowered S-RNase production and self-compatibility showed extremely short terminal branches. In summary, it appears that rapid recent diversification of alleles characterizes the Witheringia lineages. In some cases, this rapid diversification can be attributed to relaxed constraints due to breakdown of self-incompatibility.

Alleles↗
PubMed2004

Evidence for an oscillatory signature in atmospheric neutrino oscillations.

Muon neutrino disappearance probability as a function of neutrino flight length L over neutrino energy E was studied. A dip in the L/E distribution was observed in the data, as predicted from the sinusoidal flavor transition probability of neutrino oscillation. The observed L/E distribution constrained nu(micro)<-->nu(tau) neutrino oscillation parameters; 1.9x10(-3) 0.90 at 90% confidence level.

Journal Article↗
PubMed2004

Search for electron neutrino appearance in a 250 km long-baseline experiment.

We present a search for electron neutrino appearance from accelerator-produced muon neutrinos in the K2K long-baseline neutrino experiment. One candidate event is found in the data corresponding to an exposure of 4.8 x 10(19) protons on target. The expected background in the absence of neutrino oscillations is estimated to be 2.4+/-0.6 events and is dominated by misidentification of events from neutral current pi(0) production. We exclude the nu(micro) to nu(e) oscillations at 90% C.L. for the effective mixing angle in the 2-flavor approximation of sin((2)2theta(microe)( approximately 1/2sin((2)2theta(13))>0.15 at Deltam(2)(microe)=2.8 x 10(-3) eV(2), the best-fit value of the nu(micro) disappearance analysis in K2K. The most stringent limit of sin((2)2theta(microe)<0.09 is obtained at Deltam(2)(microe)=6 x 10(-3) eV(2).

Journal Article↗
PubMed2004

Limits on the neutrino magnetic moment using 1496 days of Super-Kamiokande-I solar neutrino data.

A search for a nonzero neutrino magnetic moment has been conducted using 1496 live days of solar neutrino data from Super-Kamiokande-I. Specifically, we searched for distortions to the energy spectrum of recoil electrons arising from magnetic scattering due to a nonzero neutrino magnetic moment. In the absence of a clear signal, we found micro(nu)</=(3.6x10(-10))micro(B) at 90% C.L. by fitting to the Super-Kamiokande day-night spectra. The fitting took into account the effect of neutrino oscillation on the shapes of energy spectra. With additional information from other solar neutrino and KamLAND experiments constraining the oscillation region, a limit of micro(nu)</=(1.1x10(-10))micro(B) at 90% C.L. was obtained.

Journal Article↗
PubMed2004

Sheltered load associated with S-alleles in Solanum carolinense.

Bud pollinations allowed me to examine the effects of homozygosity at loci in the area of suppressed recombination around the S-locus in Solanum carolinense, whose S-alleles show surprisingly low diversification rates. The total number of seeds produced was lower for incompatible than compatible pollinations, revealing that self-incompatibility was only somewhat overcome by bud pollination. However, low seed set in incompatible crosses was not due solely to the incompatibility response; crosses between distinct plants sharing the same alleles at the S-locus led to dramatically high seed abortion, nearly equal to that found upon selfing. An excess of heterozygotes in the surviving progeny supports the supposition that these high abortion rates are due to sheltered load, that is, previously unexpressed load accumulated due to enforced heterozygosity and recombination suppression around the S-locus. Of the seven alleles examined in total, two showed evidence of severe load and five did not. The magnitude of load was consistent with terminal branch length in some, but not all, cases.

Alleles↗
PubMed2004

Perinatal outcomes in inflammatory bowel disease.

OBJECTIVE: To determine whether inflammatory bowel disease (IBD) is associated with increased risk for adverse perinatal outcome. METHODS: A case-control study of 116 singleton pregnancies with IBD compared to 56,398 singleton controls delivered between 1986 and 2001. RESULTS: Patients with IBD were slightly older (32.8 vs. 30.6 years, p < 0.001), more likely to be Caucasian or Asian than Black or Latino (92% vs. 57%, p < 0.001) and have private health insurance (33% vs. 3%, p < 0.001). IBD was associated with an increased risk for labor induction (32% vs. 24%, p = 0.002), chorioamnionitis (7% vs. 3%, p = 0.04) and Cesarean section (32% vs. 22%, p = 0.007), but there were no differences in neonatal outcomes. Subgroup analysis demonstrated an increased risk for low birth weight (LBW) in the ulcerative colitis group vs. the Crohn's disease group (19% vs. 0%, p = 0.002). Patients with prior surgery for IBD had a lower incidence of LBW (0% vs. 12%, p = 0.03). Flares during pregnancy were associated with an increased risk for preterm delivery (27% vs. 8%, p = 0.02) and LBW (32% vs. 3%, p = 0.003). CONCLUSION: IBD was an independent risk factor for Cesarean section but there was no increase in adverse perinatal outcome. Crohn's disease, prior IBD surgery and quiescent disease were associated with a lower risk for LBW.

Adult↗
PubMed2003

Search for nu(e) from the sun at Super-Kamiokande-I.

We present the results of a search for low energy nu(e) from the Sun using 1496 days of data from Super-Kamiokande-I. We observe no significant excess of events and set an upper limit for the conversion probability to nu(e) of the 8B solar neutrino. This conversion limit is 0.8% (90% C.L.) of the standard solar model's neutrino flux for total energy=8-20 MeV. We also set a flux limit for monochromatic nu(e) for E(nu(e))=10-17 MeV.

Journal Article↗
PubMed2003

Search for supernova relic neutrinos at Super-Kamiokande.

A search for the relic neutrinos from all past core-collapse supernovae was conducted using 1496 days of data from the Super-Kamiokande detector. This analysis looked for electron-type antineutrinos that had produced a positron with an energy greater than 18 MeV. In the absence of a signal, 90% C.L. upper limits on the total flux were set for several theoretical models; these limits ranged from 20 to 130 macro nu(e) cm(-2) s(-1). Additionally, an upper bound of 1.2 macro nu(e) cm(-2) s(-1) was set for the supernova relic neutrino flux in the energy region E(nu)>19.3 MeV.

Journal Article↗
PubMed2003

Indications of neutrino oscillation in a 250 km long-baseline experiment.

The K2K experiment observes indications of neutrino oscillation: a reduction of nu(mu) flux together with a distortion of the energy spectrum. Fifty-six beam neutrino events are observed in Super-Kamiokande (SK), 250 km from the neutrino production point, with an expectation of 80.1(+6.2)(-5.4). Twenty-nine one ring mu-like events are used to reconstruct the neutrino energy spectrum, which is better matched to the expected spectrum with neutrino oscillation than without. The probability that the observed flux at SK is explained by statistical fluctuation without neutrino oscillation is less than 1%.

Journal Article↗
PubMed2002

Percivall Pott and the miners of Cornwall.

Percivall Pott (1714-1788) was an astute and prolific mid-eighteenth century English surgeon with a strong interest in head injury. He was partial to the use of the trephine for all skull fractures and favoured early exploratory trephination when an intracranial collection could not be ruled out. If haemorrhage or abscess was beneath the dura, it was incised. Later in eighteenth century England and France, trephination fell out of favour. This was especially so in the crowded hospitals where putrid conditions were common. Surprisingly, on the remote southwestern English peninsula of Cornwall, where compound depressed skull fractures in miners were a frequent occurrence, Pott's principles prevailed unchanged. Generations of surgeons trephined early in suspected cranial fractures, without waiting for symptoms of compression or irritation. A large percentage of patients recovered. Those who died generally had diffuse injury, brain laceration, or a fractured base. The Atlantic breezes were believed beneficial to recovery. The operation of early 'preventive' trephination continued in the Cornish mining districts through the 1870s, when antiseptic methods were gradually adopted as elsewhere in England. Head injuries in miners became less common as mining reforms were introduced and head protection improved.

Coal Mining↗
PubMed2002

Molecular mechanisms underlying the breakdown of gametophytic self-incompatibility.

The breakdown of self-incompatibility has occurred repeatedly throughout the evolution of flowering plants and has profound impacts on the genetic structure of populations. Recent advances in understanding of the molecular basis of self-incompatibility have provided insights into the mechanisms of its loss in natural populations, especially in the tomato family, the Solanaceae. In the Solanaceae, the gene that controls self-incompatibility in the style codes for a ribonuclease that causes the degradation of RNA in pollen tubes bearing an allele at the S-locus that matches either of the two alleles held by the maternal plant. The pollen component of the S-locus has yet to be identified. Loss of self-incompatibility can be attributed to three types of causes: duplication of the S-locus, mutations that cause loss of S-RNase activity, and mutations that do not cause loss of S-RNase activity. Duplication of the S-locus has been well studied in radiation-induced mutants but may be a relatively rare cause of the breakdown of self-incompatibility in nature. Point mutations within the S-locus that disrupt the production of S-RNase have been documented in natural populations. There are also a number of mutants in which S-RNase production is unimpaired, yet self-incompatibility is disrupted. The identity and function of these mutations is not well understood. Careful work on a handful of model organisms will enable population biologists to better understand the breakdown of self-incompatibility in nature.

Gene Duplication↗
PubMed2002

Proactive management of histopathology workloads: analysis of the UK Royal College of Pathologists' recommendations on specimens of limited or no clinical value on the workload of a teaching hospital gastrointestinal pathology service.

AIMS: To investigate the effect on the workload of a gastrointestinal pathology service of implementing the recommendations of the Royal College of Pathologists' (RCPath) working party on specimens of limited or no clinical value (LONCV). METHODS: All endoscopic gastrointestinal pathology reports for the first three months of 2001 at a large teaching hospital were reviewed against the RCPath recommendations. Specimens in the category of LONCV were recorded and the final histopathology diagnosis noted. RESULTS: The biopsies in the LONCV category were 30% of oesophageal, 61% of gastric, 0.5% of duodenal, and 7% of colorectal origin. CONCLUSIONS: Implementing the RCPath recommendations would reduce the number of requests for the examination of gastrointestinal endoscopic specimens by 3500 specimens each year in this department. None of the specimens in the LONCV category showed an abnormality that could not have been detected by a more efficient and less invasive method. In the UK, where there is a severe shortage of trained histopathologists, the implementation of these recommendations would ensure that these scarce resources are not misused.

Biopsy↗
PubMed2001

Solar 8B and hep neutrino measurements from 1258 days of Super-Kamiokande data.

Solar neutrino measurements from 1258 days of data from the Super-Kamiokande detector are presented. The measurements are based on recoil electrons in the energy range 5.0-20.0 MeV. The measured solar neutrino flux is 2.32+/-0.03(stat)+0.08-0.07(syst)x10(6) cm(-2) x s(-1), which is 45.1+/-0.5(stat)+1.6-1.4(syst)% of that predicted by the BP2000 SSM. The day vs night flux asymmetry (Phi(n)-Phi(d))/Phi(average) is 0.033+/-0.022(stat)+0.013-0.012(syst). The recoil electron energy spectrum is consistent with no spectral distortion. For the hep neutrino flux, we set a 90% C.L. upper limit of 40x10(3) cm(-2) x s(-1), which is 4.3 times the BP2000 SSM prediction.

Journal Article↗
PubMed2001

Constraints on neutrino oscillations using 1258 days of Super-Kamiokande solar neutrino data.

We report the result of a search for neutrino oscillations using precise measurements of the recoil electron energy spectrum and zenith angle variations of the solar neutrino flux from 1258 days of neutrino-electron scattering data in Super-Kamiokande. The absence of significant zenith angle variation and spectrum distortion places strong constraints on neutrino mixing and mass difference in a flux-independent way. Using the Super-Kamiokande flux measurement in addition, two allowed regions at large mixing are found.

Journal Article↗
PubMed2001

A five-year population study of persons involved in the mental health and local correctional systems: implications for service planning.

This study investigates the relationship between recipients of mental health services and incarceration within local jails. The analyses showed that male and female recipients of mental health services are incarcerated in local jails at a higher rate than the general community but that most are not long-term incarcerations. The study further showed that the rate of incarceration for recipients of mental health services decreases with age but the relative risk of incarceration, when compared with the general population, actually increases with age. In addition, across all age groups female recipients of mental health services were found to be at greater risk of incarceration than male recipients.

Adult↗
PubMed2001

Dr. Gottlieb Burckhardt--the pioneer of psychosurgery.

The first attempt at psychosurgery--intentional damage to the intact brain for the relief of mental illness--was undertaken in 1888 by the Swiss psychiatrist Gottlieb Burckhardt. Six chronic schizophrenic patients underwent localized cerebral cortical excisions. Most patients showed improvement and became easier to manage, although one died from the procedure and several had aphasia or seizures. Burckhardt, a learned neuropsychiatrist, presented his results in 1890 and in 1891 published his scientific rationale and detailed clinical outcome in a scholarly paper. Nevertheless his approach had shocked the medical community as reckless and irresponsible. Burckhardt was ridiculed, his academic endeavors ceased and his surgical endeavor largely ignored. Nevertheless he continued practice as a fine psychiatrist and mental hospital director. Burckhardt's career and interesting ideas on higher cerebral functions are reviewed and placed in perspective regarding the development of "modern" psychosurgery almost one-half century later.

History, 19th Century↗