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K Ford

Publications and source records attributed to K Ford.

At least 37 records · Page 2Linked to original sources

Measurements of the mass and width of the eta(c) meson and of an eta(c)(2S) candidate.

The mass m(eta(c)) and total width Gamma(eta(c))(tot) of the eta(c) meson have been measured in two-photon interactions at the SLAC e(+)e(-) asymmetric B Factory with the BABAR detector. With a sample of approximately 2500 reconstructed eta(c)-->K(0)(S)K+/-pi(-/+) decays in 88 fb(-1) of data, the results are m(eta(c))=2982.5+/-1.1(stat)+/-0.9(syst) MeV/c(2) and Gamma(eta(c))(tot)=34.3+/-2.3(stat)+/-0.9(syst) MeV/c(2). Using the same decay mode, a second resonance with 112+/-24 events is observed with a mass of 3630.8+/-3.4(stat)+/-1.0(syst) MeV/c(2) and width of 17.0+/-8.3(stat)+/-2.5(syst) MeV/c(2). This observation is consistent with expectations for the eta(c)(2S) state.

Journal Article↗

Search for lepton-flavor violation in the decay tau- --> l- l+ l-.

A search for the lepton-flavor-violating decay of the tau into three charged leptons has been performed using 91.5 fb(-1) of data collected at an e(+)e(-)center-of-mass energy around 10.58 GeV with the BABAR detector at the SLAC storage ring PEP-II. In all six decay modes considered, the numbers of events found in data are compatible with the background expectations. Upper limits on the branching fractions are set in the range (1-3)x10(-7) at 90% confidence level.

Journal Article↗

Measurement of the inclusive charmless semileptonic branching ratio of B mesons and determination of |V ub|.

We report a measurement of the inclusive charmless semileptonic branching fraction of B mesons in a sample of 89 x 10(6) (-)BB events recorded with the BABAR detector at the Upsilon(4S) resonance. Events are selected by fully reconstructing the decay of one B meson and identifying a charged lepton from the decay of the other B meson. The number of signal events is extracted from the mass distribution of the hadronic system accompanying the lepton and is used to determine the ratio of branching fractions B((-)B-->X(u)lnu;)/B((-)B-->Xlnu;)=[2.06+/-0.25(stat)+/-0.23(syst)+/-0.36(theo)]x10(-2). Using the measured branching fraction for inclusive semileptonic B decays, we find B((-)B-->X(u)lnu;)=[2.24+/-0.27(stat)+/-0.26(syst)+/-0.39(theo)]x10(-3) and derive the Cabibbo-Kobayashi-Maskawa matrix element |V(ub)|=[4.62+/-0.28(stat)+/-0.27(syst)+/-0.48(theo)]x10(-3).

Journal Article↗

Observation of B0-->omega K0, B+-->eta pi+, and B+-->eta K+ and study of related decays.

We present measurements of branching fractions and charge asymmetries for seven B-meson decays with an eta, eta', or omega meson in the final state. The data sample corresponds to 89x10(6) BB pairs produced from e(+)e(-) annihilation at the Upsilon(4S) resonance. We measure the following branching fractions in units of 10(-6): B(B+-->eta pi(+))=5.3+/-1.0+/-0.3, B(B+-->eta K+)=3.4+/-0.8+/-0.2, B(B0-->eta K0)=2.9+/-1.0+/-0.2 (<5.2, 90% C.L.), B(B+-->eta(')pi(+))=2.7+/-1.2+/-0.3 (<4.5, 90% C.L.), B(B+-->omega pi(+))=5.5+/-0.9+/-0.5, B(B+-->omega K+)=4.8+/-0.8+/-0.4, and B(B0-->omega K0)=5.9(+1.6)(-1.3)+/-0.5. The charge asymmetries are A(ch)(B+-->eta pi(+))=-0.44+/-0.18+/-0.01, A(ch)(B+-->eta K+)=-0.52+/-0.24+/-0.01, A(ch)(B+-->omega pi(+))=0.03+/-0.16+/-0.01, and A(ch)(B+-->omega K+)=-0.09+/-0.17+/-0.01.

Journal Article↗

Observation of a significant excess of pi0pi0 events in B meson decays.

We present a study of the decay B0-->pi(0)pi(0) based on a sample of 124 x 10(6) BB pairs recorded by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We observe 46+/-13+/-3 events, where the first error is statistical and the second is systematic, corresponding to a significance of 4.2 standard deviations including systematic uncertainties. We measure the branching fraction B(B0-->pi(0)pi(0))=(2.1+/-0.6+/-0.3)x10(-6), averaged over B0 and B(0) decays.

Journal Article↗

Evidence for the rare decay B-->K*l+l- and measurement of the B-->Kl+l- branching fraction.

We present evidence for the flavor-changing neutral current decay B-->K*l+l- and a measurement of the branching fraction for the related process B-->K l+l-, where l+l- is either an epsilon+epsilon- or a mu+mu- pair. These decays are highly suppressed in the standard model, and they are sensitive to contributions from new particles in the intermediate state. The data sample comprises 123 x 10(6) Upsilon(4S)-->B(-)B decays collected with the BABAR detector at the SLAC PEP-II epsilon+epsilon- storage ring. Averaging over K(*) isospin and lepton flavor, we obtain the branching fractions B(B-->Kl+l-)=(0.65(+0.14)(-0.13)+/-0.04)x10(-6) and B(B-->K*l+l-)=(0.88(+0.33)(-0.29)+/-0.10)x10(-6), where the uncertainties are statistical and systematic, respectively. The significance of the B-->Kl+l- signal is over 8sigma, while for B-->K*l+l- it is 3.3sigma.

Journal Article↗

Measurements of branching fractions and CP-violating asymmetries in B0-->rho(+/-)h(-/+) decays.

We present measurements of branching fractions and CP-violating asymmetries in B0-->rho(+/-)pi(-/+) and B0-->rho-K+ decays. The results are obtained from a data sample of 88.9 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B Factory. From a time-dependent maximum likelihood fit we measure the branching fractions B(B0-->rho(+/-)pi(-/+))=[22.6+/-1.8 (stat)+/-2.2 (syst)]x10(-6) and B(B0-->rho-K+)=(7.3 -1.2( +1.3)+/-1.3)x10(-6), and the CP-violating charge asymmetries A(rhopi)(CP)=-0.18+/-0.08+/-0.03 and A(rhoK)(CP)=0.28+/-0.17+/-0.08, the direct CP violation parameter C(rhopi)=0.36+/-0.18+/-0.04 and the mixing-induced CP violation parameter S(rhopi)=0.19+/-0.24+/-0.03, and the dilution parameters DeltaC(rhopi)=0.28 -0.19( +0.18)+/-0.04 and DeltaS(rhopi)=0.15+/-0.25+/-0.03.

Journal Article↗

Rates, polarizations, and asymmetries in charmless vector-vector B meson decays.

With a sample of approximately 89 x 10(6) B(-)B pairs collected with the BABAR detector, we perform a search for B meson decays into pairs of charmless vector mesons (phi, rho, and K*). We measure the branching fractions, determine the degree of longitudinal polarization, and search for CP violation asymmetries in the processes B+-->phiK(*+), B0-->phiK(*0), B+-->rho(0)K(*+), and B+-->rho(0)rho(+). We also set an upper limit on the branching fraction for the decay B0-->rho(0)rho(0).

Journal Article↗

Comparison of memory- and visually guided saccades using event-related fMRI.

Previous functional imaging studies have shown an increased hemodynamic signal in several cortical areas when subjects perform memory-guided saccades than that when they perform visually guided saccades using blocked trial designs. It is unknown, however, whether this difference results from sensory processes associated with stimulus presentation, from processes occurring during the delay period before saccade generation, or from an increased motor signal for memory-guided saccades. We conducted fMRI using an event-related paradigm that separated stimulus-related, delay-related, and saccade-related activity. Subjects initially fixated a central cross, whose color indicated whether the trial was a memory- or a visually guided trial. A peripheral stimulus was then flashed at one of 4 possible locations. On memory-guided trials, subjects had to remember this location for the subsequent saccade, whereas the stimulus was a distractor on visually guided trials. Fixation cross disappearance after a delay period was the signal either to generate a memory-guided saccade or to look at a visual stimulus that was flashed on visually guided trials. We found slightly greater stimulus-related activation for visually guided trials in 3 right prefrontal regions and right rostral intraparietal sulcus (IPS). Memory-guided trials evoked greater delay-related activity in right posterior inferior frontal gyrus, right medial frontal eye field, bilateral supplementary eye field, right rostral IPS, and right ventral IPS but not in middle frontal gyrus. Right precentral gyrus and right rostral IPS exhibited greater saccade-related activation on memory-guided trials. We conclude that activation differences revealed by previous blocked experiments have different sources in different areas and that cortical saccade regions exhibit delay-related activation differences.

Adult↗

Measurement of time-dependent CP asymmetries and the CP-odd fraction in the decay B0-->D(*+)D(*-).

We present a measurement of time-dependent CP asymmetries and an updated determination of the CP-odd fraction in the decay B0-->D(*+)D(*-) using a data sample of 88x10(6)BB pairs collected by the BABAR detector at the PEP-II B Factory at SLAC. We determine the CP-odd fraction to be 0.063+/-0.055(stat)+/-0.009(syst). The time-dependent CP asymmetry parameters Im(lambda(+)) and /lambda(+)/ are determined to be 0.05+/-0.29(stat)+/-0.10(syst) and 0.75+/-0.19(stat)+/-0.02(syst), respectively. The standard model predicts these parameters to be -sin(2beta and 1, respectively, in the absence of penguin diagram contributions.

Journal Article↗

Limits on D0-macro D0 mixing and CP violation from the ratio of lifetimes for decay to K-pi+, K-K+, and pi- pi+.

We present a measurement of D0-macro D0 mixing parameters using the ratios of lifetimes extracted from samples of D0 mesons decaying to K-pi(+), K-K+, and pi(-)pi(+). Using 91 fb(-1) of data collected by the BABAR detector at the PEP-II asymmetric-energy B Factory, we obtain a value Y=[0.8+/-0.4(stat.)(+0.5)(-0.4)(syst.)]%, which, in the limit of CP conservation, corresponds to the mixing parameter y=Delta Gamma/2 Gamma. Using the difference in lifetimes of D0 and macro D0 mesons, we obtain the CP-violation parameter Delta Y=[-0.8+/-0.6(stat.)+/-0.2(syst.)]%.

Journal Article↗

Observation of a narrow meson state decaying to D(+)(s)pi(0) at a mass of 2.32 GeV/c(2).

We have observed a narrow state near 2.32 GeV/c(2) in the inclusive D(+)(s)pi(0) invariant mass distribution from e(+)e(-) annihilation data at energies near 10.6 GeV. The observed width is consistent with the experimental resolution. The small intrinsic width and the quantum numbers of the final state indicate that the decay violates isospin conservation. The state has natural spin-parity and the low mass suggests a J(P)=0(+) assignment. The data sample corresponds to an integrated luminosity of 91 fb(-1) recorded by the BABAR detector at the SLAC PEP-II asymmetric-energy e(+)e(-) storage ring.

Journal Article↗

Changes in defensive behaviors following olfactory bulbectomy in male and female rats.

The present study examined if olfactory bulbectomy (OBX) altered defensive behaviors on the elevated plus-maze and the open-field differently in male and female rats. Similar increases in defensive behaviors in male and female rats were observed in both tests following OBX. No significant correlations were detected between defensive behaviors and activity, supporting the hypothesis that some behavioral changes following OBX may be due to decreased defensive behaviors and not increased activity.

Aggression↗

Phase I trial of lobradimil (RMP-7) and carboplatin in children with brain tumors.

PURPOSE: To determine the maximum tolerated dose (MTD), the incidence and severity of toxicities, and the pharmacokinetics of lobradimil administered intravenously over 10 min in combination with carboplatin in children with refractory brain tumors. METHODS: A group of 25 children with primary brain tumors received carboplatin and lobradimil on two consecutive days every 28 days. The 10-min lobradimil infusion began 5 min before the end of the carboplatin infusion. Four lobradimil dose levels (100, 300, 450 and 600 ng/kg ideal body weight, IBW) were studied in cohorts of 4 to 13 patients. Carboplatin was adaptively dosed based on the glomerular filtration rate to achieve a target plasma area under the concentration-time curve (AUC) of 7.0 mg min/ml per course (5.0 mg min/ml for patients who had previously received craniospinal radiation or myeloablative chemotherapy). RESULTS: Lobradimil toxicity was immediate, tolerable and rapidly reversible. The most frequent toxicities were hypotension, flushing, headache and gastrointestinal complaints. One patient on the 600 ng/kg dose level had a seizure during the lobradimil infusion. The incidence and severity of lobradimil toxicities were not dose-related and the lobradimil dose was not escalated beyond the 600 ng/kg IBW dose level. Two patients had partial responses and ten patients had stable disease. Myelosuppression (thrombocytopenia more prominent than neutropenia) was the primary toxicity attributed to carboplatin. Lobradimil pharmacokinetics were characterized by rapid clearance from the plasma compartment and substantial interpatient variability. CONCLUSIONS: The combination of carboplatin and lobradimil is safe and tolerable. An MTD for lobradimil was not defined because toxicity was not dose-related. The recommended pediatric phase II dose of lobradimil is 600 ng/kg IBW.

Adolescent↗

Stories seldom told: paediatric nurses' experiences of caring for hospitalized children with special needs and their families.

AIMS OF THE STUDY: This study explored paediatric nurses' experiences of caring for children with special needs and their families in an acute care setting. The aim of the study was to increase understanding of nurses' experiences of caring for these children and their families. The study was designed to reveal the caring practices embedded within these relationships through exploring nurses' stories. STUDY DESIGN/METHODS: Gadamerian hermeneutic phenomenology and feminist research principles were the approaches used to guide the study. Interviews were held with experienced paediatric nurses and interpretation of interview transcripts using a Gadamerian hermeneutic phenomenological approach resulted in the identification of four themes. FINDINGS: The four themes revealed were: Special Relationships; Multiple Dimensions of Who is Expert; Development of Trust Between Nurses and Families; and Feelings of Frustration and Guilt. CONCLUSIONS: The study emphasized the context-specific nature of relationships between nurses and children and their families. The nurses spoke about the difficulties they encountered in their practice and some of the ways that they dealt with these problems. They discussed the things that they valued and those that made them feel guilty and frustrated. In doing so, they revealed their warmth, strength, humanity and caring.

Acute Disease↗

Regional dendritic and spine variation in human cerebral cortex: a quantitative golgi study.

The present study explored differences in dendritic/spine extent across several human cortical regions. Specifically, the basilar dendrites/spines of supragranular pyramidal cells were examined in eight Brodmann's areas (BA) arranged according to Benson's (1993, Behav Neurol 6:75-81) functional hierarchy: primary cortex (somatosensory, BA3-1-2; motor, BA4), unimodal cortex (Wernicke's area, BA22; Broca's area, BA44), heteromodal cortex (supple- mentary motor area, BA6beta; angular gyrus, BA39) and supramodal cortex (superior frontopolar zone, BA10; inferior frontopolar zone, BA11). To capture more general aspects of regional variability, primary and unimodal areas were designated as low integrative regions; heteromodal and supramodal areas were designated as high integrative regions. Tissue was obtained from the left hemisphere of 10 neurologically normal individuals (M(age) = 30 +/- 17 years; five males, five females) and stained with a modified rapid Golgi technique. Ten neurons were sampled from each cortical region (n = 800) and evaluated according to total dendritic length, mean segment length, dendritic segment count, dendritic spine number and dendritic spine density. Despite considerable inter-individual variation, there were significant differences across the eight Brodmann's areas and between the high and low integrative regions for all dendritic and spine measures. Dendritic systems in primary and unimodal regions were consistently less complex than in heteromodal and supramodal areas. The range within these rankings was substantial, with total dendritic length in BA10 being 31% greater than that in BA3-1-2, and dendritic spine number being 69% greater. These findings demonstrate that cortical regions involved in the early stages of processing (e.g. primary sensory areas) generally exhibit less complex dendritic/spine systems than those regions involved in the later stages of information processing (e.g. prefrontal cortex). This dendritic progression appears to reflect significant differences in the nature of cortical processing, with spine-dense neurons at hierarchically higher association levels integrating a broader range of synaptic input than those at lower cortical levels.

Adult↗

The Bali STD/AIDS study: association between vaginal hygiene practices and STDs among sex workers.

OBJECTIVES: To assess the association between genital cleansing practices and the prevalence of sexually transmitted diseases and of sexual health knowledge among female sex workers in Bali, Indonesia. METHODS: Low priced commercial sex workers (CSWs) participated in the Bali STD/AIDS Study, a 3 year educational project evaluating the effect of education on the subsequent use of condoms and the prevalence of STDs and AIDS. Structured interviews, genital evaluation, laboratory evaluation for STDs, and treatment were performed. Vaginal cleansing characteristics including frequency, type, and reasons for use, were evaluated. Associations between these characteristics and the presence of bacterial and viral genital infections were assessed. RESULTS: Of 625 female sex workers evaluated between May and July 1998, 99.1% used substances, such as soap and toothpaste, to clean the vagina at least daily, with 69.3% performing this after each intercourse. The women using such cleansers after each client did not differ from those using them once or less daily in education, AIDS and condom use knowledge, time working as a CSW, or number of clients in the previous day. However, they were younger than those using vaginal cleansers daily or less, and reported lower condom usage in the past week. Several genital symptoms, such as discoloured discharge and odour, were reported less by women with the highest frequency of vaginal cleanser use. Prevalence of genital infections in this population of women was substantial, with bacterial infections more prevalent than viral infections. Infections were not associated with the type of cleanser used, using a genital cleanser on the day of examination, or using a cleanser after each client versus daily or less, except for candida colonisation, which was more prevalent in women cleansing after each client (OR=1.87, 95% CI 1.21, 2.90). However, symptomatic candida vulvovaginitis (positive culture plus presence of symptoms) was not associated with the prevalence of genital cleansing. Women using genital cleansing in part for "infection avoidance" (39.7%) were more likely to have heard of STDs and AIDS, but were less knowledgeable about these infections, compared with women not citing this reason for genital cleansing. CONCLUSION: Commercial sex workers in low priced brothels in Bali have a high rate of genital infections, with lower rates of viral compared with bacterial infections. Genital cleansers, on a daily or after each intercourse schedule, are used routinely. Although genital cleansing after each intercourse was associated with fewer genital symptoms, the prevalence of STDs did not differ significantly based on this frequency, and the women's knowledge of STDs and AIDS was less than that of women cleansing less often. The effect of genital cleansing in general on STD and AIDS prevalence could not be assessed in this population owing to the lack of a non-cleansing cohort. Further study to elucidate the effect of vaginal cleansing practices on STD prevalence and resistance is needed.

Acquired Immunodeficiency Syndrome↗

Aids knowledge and risk behaviors among Midwest migrant farm workers.

The objectives of this study were to investigate the AIDS/HIV knowledge of Latino adolescent and adult migrant farm workers in Michigan, to determine risk behaviors related to HIV, and to determine differences in generational norms regarding sexual activity. For the most part, the Latino migrant population seemed knowledgeable about sexual modes of HIV transmission, although casual contact, through kissing and going to school or work with an infected individual, was also seen as a possible route of transmission for some. Several condom beliefs were identified that may be barriers to use, including the beliefs that condoms are only for use with prostitutes (35 % agreed) and that condoms are only for gay men (54% agreed). Only a small proportion (10%) agreed that condoms were good protection from AIDS. Most respondents knew what condoms were, although only 51% of the sample knew friends who used them. Adolescent females in the camps generally disapproved of premarital sex, while males and older females were more accepting. All these factors make it pertinent to implement HIV/AIDS education programs that are culturally sensitive, gender-specific, and effective in both generations.

Adolescent↗