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Biomedical subjects

M Anderson

Publications and source records attributed to M Anderson.

At least 19 recordsLinked to original sources
PubMed2007

Mesenchymal hamartoma of the liver in a late-term equine fetus.

Mesenchymal hamartoma of the liver is a rare congenital disorder of biliary tract development. During the necropsy of a late-term equine fetus, a markedly enlarged liver of more than two times normal weight was found. Light microscopic review revealed that the normal hepatic parenchyma had been obliterated, replaced, and expanded by abnormal bile ducts surrounded by abundant, myxoid stroma. The lesion was diagnosed as a mesenchymal hamartoma. Small portions of the liver had bridging septa of fibrosis and proliferations of small-caliber abnormal bile ducts, resembling another congenital biliary abnormality termed congenital hepatic fibrosis.

Animals↗
PubMed2006

Direct observation of dijets in central Au+Au collisions at sqrt[sNN]=200 GeV.

The STAR Collaboration at the Relativistic Heavy Ion Collider reports measurements of azimuthal correlations of high transverse momentum (pT) charged hadrons in Au+Au collisions at higher pT than reported previously. As (pT) is increased, a narrow, back-to-back peak emerges above the decreasing background, providing a clear dijet signal for all collision centralities studied. Using these correlations, we perform a systematic study of dijet production and suppression in nuclear collisions, providing new constraints on the mechanisms underlying partonic energy loss in dense matter.

Journal Article↗
PubMed2006

Identified baryon and meson distributions at large transverse momenta from Au + Au collisions at square root sNN=200 GeV.

Transverse momentum spectra of pi+/-, p, and p up to 12 GeV/c at midrapidity in centrality selected Au + Au collisions at square root sNN=200 GeV are presented. In central Au + Au collisions, both pi +/- and p(p) show significant suppression with respect to binary scaling at pT approximately >4 GeV/c. Protons and antiprotons are less suppressed than pi+/-, in the range 1.5 approximately < pT approximately < 6 GeV/c. The pi-/pi+ and p/p ratios show at most a weak pT dependence and no significant centrality dependence. The p/pi ratios in central Au + Au collisions approach the values in p + p and d + Au collisions at pT approximately >5 GeV/c. The results at high pT indicate that the partonic sources of pi+/-, p, and p have similar energy loss when traversing the nuclear medium.

Journal Article↗
PubMed2006

Strange baryon resonance production in sqrt s NN=200 GeV p+p and Au+Au collisions.

We report the measurements of Sigma(1385) and Lambda(1520) production in p+p and Au+Au collisions at sqrt[s{NN}]=200 GeV from the STAR Collaboration. The yields and the p(T) spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur.

Journal Article↗
PubMed2006

Measurements of the exclusive decays of the upsilon(5S) to meson final states and improved B(s)* mass measurement.

Using 420 pb(-1) of data collected on the upsilon(5S) resonance with the CLEO III detector, we reconstruct B mesons in 25 exclusive decay channels to measure or set upper limits on the decay rate of upsilon(5S) into B meson final states. We measure the inclusive B cross section to be sigma(upsilon(5S) --> BB(X)) = (0.177 +/- 0.030 +/- 0.016) nb and make the first measurements of the production rates of sigma(upsilon(5S) --> B*B*) = (0.131 +/- 0.025 +/- 0.014) nb and sigma(upsilon(5S) --> BB*) = (0.043 +/- 0.016 +/- 0.006) nb, respectively. We set 90% confidence level limits of sigma(upsilon(5S) -->BB) < 0.038 nb, sigma(upsilon(5S) --> B(*)B(*)pi) < 0.055 nb and sigma(upsilon(5S) --> BBpipi) < 0.024 nb. We also extract the most precise value of the B(s)* mass to date, M(B(s)*) = (5411.7 +/- 1.6 +/- 0.6) MeV/c2.

Journal Article↗
PubMed2006

Experimental limits on weak annihilation contributions to decays.

We present the first experimental limits on high-q2 contributions to charmless semileptonic decays of the form expected from the weak annihilation (WA) decay mechanism. Such contributions could bias determinations of /Vub/ from inclusive measurements of B-->Xulupsilon. Using a wide range of models based on available theoretical input we set a limit of GammaWA/Gammab-->u<7.4% (90% confidence level) on the WA fraction, and assess the impact on previous inclusive determinations of /Vub/.

Journal Article↗
PubMed2006

Dielectron widths of the Gamma(1S,2S,3S) resonances.

We determine the dielectron widths of the Gamma(1S), Gamma(2S), and Gamma(3S) resonances with better than 2% precision by integrating the cross section of e+e- -->Gamma over the e+e- center-of-mass energy. Using e+e- energy scans of the Gamma resonances at the Cornell Electron Storage Ring and measuring Gamma production with the CLEO detector, we find dielectron widths of 1.252+/-0.004(sigma(stat))+/-0.019(sigma(syst)) keV, 0.581+/-0.004+/-0.009 keV, and 0.413+/-0.004+/-0.006 keV for the Gamma(1S), Gamma(2S), and Gamma(3S), respectively.

Journal Article↗
PubMed2006

Measurement of sigma(e+e- -->psi(3770)-->hadrons) at Ec.m.=3773 MeV.

We measure the cross section for e+e- -->psi(3770) -->hadrons at Ec.m.=3773 MeV to be (6.38+/-0.08(+0.41)(-0.30) nb using the CLEO detector at the CESR e+e- collider. The difference between this and the e+e- -->psi(3770) -->DD cross section at the same energy is found to be (-0.01+/-0.08(+0.41)(-0.30) nb. With the observed total cross section, we extract Gamma(ee)(psi(3770))=(0.204+/-0.003(+0.041)(-0.027) keV. Uncertainties shown are statistical and systematic, respectively.

Journal Article↗
PubMed2006

Observation of psi(3770) --> pi pi J/psi and measurement of Gamma ee[psi(2S)].

We observe signals for the decays psi(3770) --> XJ/psi from data acquired with the CLEO detector operating at the CESR e+ e- collider with square root of s = 3773 MeV. We measure the following branching fractions Beta(psi(3770) --> XJ/psi and significances: (189 +/- 20 +/- 20) x 10(-5) (11.6sigma) for X = pi+ pi-, (80 +/- 25 +/- 16) x 10(-5) (3.4sigma) for X = pi0 pi0, and (87 +/- 33 +/- 22) x 10(-5) (3.5sigma) for X = eta, where the errors are statistical and systematic, respectively. The radiative return process e+ e- --> gamma psi(2S) populates the same event sample and is used to measure Gamma ee[psi(2S)] = (2.54 +/- 0.03 +/- 0.11) keV.

Journal Article↗
PubMed2006

New measurements of Cabibbo-suppressed decays of mesons with the CLEO-c detector.

Using of data collected with the CLEO-c detector, we report on first observations and measurements of Cabibbo-suppressed decays of D mesons in the following six decay modes: pi+ pi- pi0 pi0, pi+ pi+ pi- pi- pi0, pi+ pi0 pi0, pi+ pi+ pi- pi0, eta pi0, and omega pi+ pi-. Improved branching fraction measurements in eight other multipion decay modes are also presented. The measured D --> pi pi rates allow us to extract the ratio of isospin amplitudes A(DeltaI = (3/2) / A(DeltaI = (1/2)) = 0.420 +/- 0.014(stat) +/- 0.016(syst) and the strong phase shift of delta1 = (86.4 +/- 2.8 +/- 3.3) degrees, which is quite large and now more precisely determined.

Journal Article↗
PubMed2006

Selection for faster development does not bias sex ratios resulting from blastocyst embryo transfer.

Concerns of possible male biased sex ratios with IVF exist due to reports of faster preimplantation development for male relative to female embryos in a variety of mammals, including humans. This study reports the first direct test of the hypothesis that selection for faster preimplantation development to the blastocyst stage increases the likelihood of a male birth. Gender outcomes of all live births resulting from blastocyst stage embryo transfer within a large assisted reproduction practice were reviewed, along with associated embryological records. The developmental stage of transferred embryos relative to the average developmental stage of all viable embryos in each cohort was related to gender outcomes by logistic regression analysis. Gender data were available for 1,184 children born from 815 pregnancies resulting from blastocyst stage embryo transfer during the study period. Data on preimplantation embryonic development were available for 737 cycles resulting in the birth of 1,075 children. There was no relationship between selection for developmental rate and the gender of resulting children. Numbers of male and female children were nearly identical within this patient population (593 male versus 591 female). These results indicate that offspring gender is unrelated to selection for developmental rate among blastocyst transfer cycles.

Blastocyst↗
PubMed2006

The national suicide prevention strategy for England: the reality of a national strategy for the nursing profession.

Suicide is recognized as a global phenomenon and many countries now have national suicide prevention strategies. International guidance on suicide prevention and accepted epidemiological and treatment-based research underpins healthcare policy relating to suicide reduction. There has been an established comprehensive strategy in England since 2002. However, the rate of suicide continues to be a concern and nurses hold a key role in the implementation of national, regional and local policy into practice. The aim of this paper is to consider the current implications of the national suicide prevention strategy in England for nursing. This discussion paper draws upon both empirical evidence-based literature, governmental guidance and policy-related documentation. The national suicide prevention strategy for England currently continues to have a multifaceted impact on the nursing profession. This ranges from clinical practice issues such as risk assessment through to broader public health responsibilities. If nurses and allied health professionals are to be effective in their role within suicide prevention, they will need to be supported in building awareness of the wider context of the national policy. In particular, this will mean working effectively and collaboratively with the voluntary sector, service users and other non-medical agencies.

Cooperative Behavior↗
PubMed2006

A randomized trial of teaching clinical skills using virtual and live standardized patients.

BACKGROUND: We developed computer-based virtual patient (VP) cases to complement an interactive continuing medical education (CME) course that emphasizes skills practice using standardized patients (SP). Virtual patient simulations have the significant advantages of requiring fewer personnel and resources, being accessible at any time, and being highly standardized. Little is known about the educational effectiveness of these new resources. We conducted a randomized trial to assess the educational effectiveness of VPs and SPs in teaching clinical skills. OBJECTIVE: To determine the effectiveness of VP cases when compared with live SP cases in improving clinical skills and knowledge. DESIGN: Randomized trial. PARTICIPANTS: Fifty-five health care providers (registered nurses 45%, physicians 15%, other provider types 40%) who attended a CME program. INTERVENTIONS: Participants were randomized to receive either 4 live cases (n=32) or 2 live and 2 virtual cases (n=23). Other aspects of the course were identical for both groups. RESULTS: Participants in both groups were equivalent with respect to pre-post workshop improvement in comfort level (P=.66) and preparedness to respond (P=.61), to screen (P=.79), and to care (P=.055) for patients using the skills taught. There was no difference in subjective ratings of effectiveness of the VPs and SPs by participants who experienced both (P=.79). Improvement in diagnostic abilities were equivalent in groups who experienced cases either live or virtually. CONCLUSIONS: Improvements in performance and diagnostic ability were equivalent between the groups and participants rated VP and SP cases equally. Including well-designed VPs has a potentially powerful and efficient place in clinical skills training for practicing health care workers.

Adult↗
PubMed2006

Ascertainment of intimate partner violence using two abuse measurement frameworks.

OBJECTIVE: To estimate prevalence of intimate partner violence (IPV) according to two abuse ascertainment tools, and agreement between the tools. METHODS: 2504 women randomly selected from a health maintenance organization were asked about IPV exposure in their most recent intimate relationship using five questions on physical and sexual abuse, and fear due to partner's threats and controlling behavior from the Behavioral Risk Factor Surveillance Survey (BRFSS) and 10 questions from the Women's Experience with Battering (WEB) scale. IPV prevalence was estimated according to the BRFSS and WEB, and the proportion of women who were WEB+/BRFSS+, WEB-/BRFSS-, WEB-/BRFSS+, and WEB+/BRFSS-. RESULTS: In their most recent relationship, 14.7% of women reported abuse of any type on the BRFSS versus 7.0% on the WEB scale. In direct comparisons of the WEB and BRFSS questions, a higher percentage of abused women reported any IPV on the five BRFSS questions (88.4%) compared to the 10 WEB questions (42.0%). However, both the BRFSS and WEB identified some women as abused that would have been missed by the other instrument. CONCLUSIONS: Intimate partner violence prevalence depends on how women are asked about abuse. Resources permitting, more than one abuse ascertainment strategy (for example, both the BRFSS and WEB questions) should be tried in order to broadly identify as many women as possible who interpret themselves as abused.

Adolescent↗
PubMed2006

Xenotransplantation: a bioethical evaluation.

Allograft shortage is a formidable obstacle in organ transplantation. Xenotransplantation, the interspecies transplantation of cells, tissues, and organs, or ex vivo interspecies exchange between cells, tissues, and organs is a frequently suggested alternative to this allograft shortage. As xenotransplantation steadily improves into a viable allotransplantation alternative, several bioethical considerations coalesce. Such considerations include the Helsinki declaration's guarantee of patients' rights to privacy; political red tape that may select for undermined socioeconomic groups as the first recipients of xenografts; industry incentives in xenotransplantation investments; conflicts of interest when a clinician supervises a patient as a research subject; the psychosocial impact of transplantation on the xenograft recipient, and the rights of animals. This review illuminates these issues through a conglomeration of expert opinion and relevant experimental studies.

Animal Rights↗
PubMed2005

Precision measurements of the timelike electromagnetic form factors of pion, kaon, and proton.

Using 20.7 pb(-1) of e(+)e(-) annihilation data taken at sq.rt(r) = 3.671 GeV with the CLEO-c detector, precision measurements of the electromagnetic form factors of the charged pion, charged kaon, and proton have been made for timelike momentum transfer of |Q(2)| = 13.48 GeV(2) by the reaction e(+)e(-) --> h(+)h(-). The measurements are the first ever with identified pions and kaons of |Q(2)| > 4 GeV(2), with the results F(13.48 GeV(2)) = 0.075 +/- 0.008(stat) +/- 0.005(syst) and F(K)(13.48 GeV(2)) = 0.063 +/- 0.004(stat) +/- 0.001(syst). The result for the proton, assuming G(p)(E) = G(p)(M), is G(p)(M)(13.48 GeV(2)) = 0.014 +/- 0.002(stat) +/- 0.001(syst), which is in agreement with earlier results.

Journal Article↗
PubMed2005

Anesthetist to patient transmission of hepatitis C virus associated with non exposure-prone procedures.

A 44-year-old lady was diagnosed with acute hepatitis C virus (HCV) infection 8 weeks after hysterectomy at which the attending anesthetist was known to be hepatitis C seropositive. Comparative nucleotide sequence analysis and phylogenetic comparison proved that transmission had occurred from the anesthetist to the patient. The patient had received general anesthesia with endotracheal intubation and peripheral intravenous cannulation. No exposure-prone anesthetic procedures had been performed. This is the first case described in UK involving transmission from an anesthetist to a patient during anesthesia where no exposure prone procedures were carried out. It is the first example in which the anesthetist was known to be seropositive for hepatitis C prior to the operation.

Adult↗