Quasi-model-independent search for new high p(T) physics at D0

We apply a quasi-model-independent strategy ("Sleuth") to search for new high p(T) physics in approximately 100 pb(-1) of pp collisions at square root of (s) = 1.8 TeV collected by the D0 experiment during 1992-1996 at the Fermilab Tevatron. We systematically analyze many exclusive final states and demonstrate sensitivity to a variety of models predicting new phenomena at the electroweak scale. No evidence of new high p(T) physics is observed.

Ratio of jet cross sections at square root of s = 630 GeV and 1800 GeV

The D0 Collaboration has measured the inclusive jet cross section in barpp collisions at square root of s = 630 GeV. The results for pseudorapidities (eta)<0.5 are combined with our previous results at square root of s = 1800 GeV to form a ratio of cross sections with smaller uncertainties than either individual measurement. Next-to-leading-order QCD predictions show excellent agreement with the measurement at 630 GeV; agreement is also satisfactory for the ratio. Specifically, despite a 10% to 15% difference in the absolute magnitude, the dependence of the ratio on jet transverse momentum is very similar for data and theory.

Ratios of multijet Cross Sections in p p collisions at radical(s) = 1.8 TeV

We report on a study of the ratio of inclusive three-jet to inclusive two-jet production cross sections as a function of total transverse energy in p&pmacr; collisions at a center-of-mass energy sqrt[s] = 1.8 TeV, using data collected with the D0 detector during the 1992-1993 run of the Fermilab Tevatron Collider. The measurements are used to deduce preferred renormalization scales in perturbative O(alpha(3)(s)) QCD calculations in modeling soft-jet emission.

Inclusive jet production in pp(macro) collisions

We report a new measurement of the pseudorapidity (eta) and transverse-energy ( E(T)) dependence of the inclusive jet production cross section in pp(macro) collisions at square root of s = 1.8 TeV using 95 pb(-1) of data collected with the D0 detector at the Fermilab Tevatron. The differential cross section d(2)sigma/(dE(T)d eta) is presented up to eta = 3, significantly extending previous measurements. The results are in good overall agreement with next-to-leading order predictions from QCD and indicate a preference for certain parton distribution functions.

Search for large extra dimensions in dielectron and diphoton production

We report a search for effects of large extra spatial dimensions in pp collisions at a center-of-mass energy of 1.8 TeV with the D0 detector, using events containing a pair of electrons or photons. The data are in good agreement with the expected background and do not exhibit evidence for large extra dimensions. We set the most restrictive lower limits to date, at the 95% C.L. on the effective Planck scale between 1.0 and 1.4 TeV for several formalisms and numbers of extra dimensions.

Percutaneous placement of an intercostal central venous catheter for chronic hyperalimentation guided by transhepatic venography

BACKGROUND AND METHODS

Increased utilization of central venous catheters for hyperalimentation has caused a rise in the incidence of central venous complications including occlusions and stenoses. When this occurs, the continued use of these catheters becomes more difficult. We describe a technique for catheter placement in a patient requiring access for total parenteral nutrition who had extensive central venous occlusion involving both internal jugular veins, both subclavian veins, and the infrorenal inferior vena cava (IVC).

RESULTS

A percutaneous transhepatic venous catheter had been placed in a patient with inferior vena caval, subclavian, and internal jugular venous occlusions. The Hickman catheter functioned well until the patient developed fungal sepsis and a large fibrin sheath around the catheter tip creating the need for a new access site. Placement of an intercostal venous catheter was performed using transhepatic venography to map patent collateral veins and microcatheters to access an intercostal route for Hickman placement.

CONCLUSIONS

Patients who require long-term central venous access often develop stenotic and occlusive complications in the central venous circulation. Individualized, unique and innovative routes to the central venous circulation must often be utilized to maintain venous access in these patients. Transhepatic venous mapping and microcatheter techniques aid in the finding of alternative sites in these patients with difficult access problems.

Cross section for b-Jet production in &pmacr;p collisions at radicals = 1.8 TeV

Bottom-quark production in &pmacr;p collisions at sqrt[s] = 1.8 TeV is studied with 5 pb(-1) of data collected in 1995 by the D0 detector at the Fermilab Tevatron Collider. The differential production cross section for b jets in the central rapidity region ( | y(b)|<1) as a function of jet transverse energy is extracted from a muon-tagged jet sample. Within experimental and theoretical uncertainties, D0 results are found to be higher than, but compatible with, next-to-leading-order QCD predictions.

Patients' perspectives on services for epilepsy: a survey of patient satisfaction, preferences and information provision in 2394 people with epilepsy

The objectives of this study were to provide a comprehensive survey of satisfaction with care, care preferences and information provision for patients with epilepsy, and to formulate recommendations for the development of epilepsy services based on the findings. A questionnaire was distributed to 4620 patients who were currently receiving antiepileptic drugs for epilepsy, regardless of aetiology, duration or severity. Two different samples of patients with epilepsy were questioned: the first an unselected sample drawn from primary care, and the second consisting of consecutive patients drawn from hospital clinics. There were 2394 responses to the questionnaire. Satisfaction with primary and hospital care was high, both overall and for specific aspects. However, two major shortcomings were identified. First, few respondents felt that their care was shared between hospital and GP. Secondly, provision of information about epilepsy was perceived to be poor, particularly by the elderly. Younger patients and patients with severe epilepsy had a higher satisfaction with and preference for hospital care, whereas older age groups were more satisfied with and preferred primary care. Patients' main reasons for preferring primary care were that it was more personal and the GP was more familiar with them, and secondary care was preferred because the hospital doctor knew more about epilepsy. In conclusion, we have conducted the largest representative UK survey of patients' perceptions and views of the care available for epilepsy. Although patient satisfaction was high, information provision is poor and the shared care model is not operating effectively. We recommend that an emphasis be placed on methods for improving the interface between primary and secondary care. The setting up of hospital epilepsy centres, as recommended by the recently published Clinical Standards Advisory Group report on epilepsy, would provide a focus for these efforts and for information provision.

NHS services for epilepsy from the patient's perspective: a survey of primary, secondary and tertiary care access throughout the UK

The aims of this study were to estimate the proportion of patients with epilepsy who made primary care and/or hospital outpatient medical consultations within 1 year; to formulate a model of the explanatory variables that influence whether patients consult or not; and to estimate the frequency of referral to, and waiting time for, hospital outpatient clinics in patients with new-onset seizures. Suggestions are offered for improvement of epilepsy services based on the findings. A questionnaire was distributed to 3455 unselected patients identified at population level from primary care practices in all NHS regions of the UK. There were 1652 respondents with epilepsy of all types, irrespective of aetiology, duration or severity. Fifty-two per cent of the whole sample made at least one medical consultation of any type specifically for epilepsy (42.0% primary care, 30.5% hospital, 20.4% both). Most patients with controlled epilepsy (74.5%) had no consultations. Of patients with severe epilepsy, 27.5% made no primary care consultations, 43.4% no hospital consultations and 14.1% no consultations of either type. Gender did not influence the likelihood of either GP or hospital consultations in patients with either controlled or active epilepsy. Increasing seizure frequency was associated with a greater likelihood of one or more hospital consultations for epilepsy, whereas increasing duration of epilepsy was associated with a decreased likelihood of either type of consultation. Age affected consultation rates: of those patients over the age of 65 years, only 29.9% made a medical consultation for epilepsy, compared to 53.8% of young adults. Patients under the age of 17 years were less likely to have consulted a GP and more likely to have consulted a hospital doctor. Ninety percent of new-onset patients had been referred to a hospital doctor, and the mean wait was 6.5 weeks. In conclusion, many patients with epilepsy, including severe epilepsy, are not receiving specialist input, and a significant proportion are receiving no medical supervision. The elderly are over-represented in this group. Care tends to be polarized between hospital or primary care, falling short of the ideal of shared care. It will be important to address the influences on consultation seeking in epilepsy, particularly for those patients currently under no medical supervision.

Probing Balitsky-Fadin-Kuraev-Lipatov dynamics in the dijet cross section at large rapidity intervals in pp collisions at sqrt[s]=1800 and 630 GeV

Inclusive dijet production at large pseudorapidity intervals (Deltaeta) between the two jets has been suggested as a regime for observing Balitsky-Fadin-Kuraev-Lipatov (BFKL) dynamics. We have measured the dijet cross section for large Deltaeta in pp collisions at sqrt[s]=1800 and 630 GeV using the D0 detector. The partonic cross section increases strongly with the size of Deltaeta. The observed growth is even stronger than expected on the basis of BFKL resummation in the leading logarithmic approximation. The growth of the partonic cross section can be accommodated with an effective BFKL intercept of alphaBFKL(20 GeV)=1.65+/-0.07.

Measurement of the W-->taunu production cross section in pp collisions at square root s=1.8 TeV

We report on a measurement of sigma(pp-->W+X)B(W-->taunu) in pp collisions at sqrt[s]=1.8 TeV at the Fermilab Tevatron. The measurement is based on an integrated luminosity (lum) of 18 pb-1 of data collected with the D0 detector during 1994-1995. We find that sigma(pp-->W+X)B(W-->taunu)=2.22+/-0.09 (stat)+/-0. 10 (syst)+/-0.10 (lum) nb. Lepton universality predicts that the ratio of the tau and electron electroweak charged current couplings to the W boson, gWtau/gWe, be unity. We find gWtau/gWe=0.980+/-0.031, in agreement with lepton universality.

Small-angle muon and bottom-quark production in p&pmacr; collisions at radicals = 1.8 TeV

This Letter describes a measurement of the muon cross section originating from b-quark decay in the forward rapidity range 2.4<| y(&mgr;)|<3.2 in p&pmacr; collisions at sqrt[s] = 1.8 TeV. The data used in this analysis were collected by the D0 experiment at the Fermilab Tevatron. We find that next-to-leading-order QCD calculations underestimate b-quark production by a factor of 4 in the forward rapidity region.

Differential production cross section of Z bosons as a function of transverse momentum at sqrt

We present a measurement of the transverse momentum distribution of Z bosons produced in p&pmacr; collisions at sqrt[s] = 1.8 TeV from data collected by the DO experiment at the Fermilab Tevatron Collider. We find good agreement between our results and current resummation calculations, and also use our data to extract nonperturbative parameters for a particular version of the resummation formalism. The resulting values are significantly more precise than obtained in previous determinations.

Isolated photon cross section in p&pmacr; collisions at radicals = 1. 8 TeV

We report a new measurement of the cross section for the production of isolated photons with transverse energies ( E(gamma)(T)) above 10 GeV and pseudorapidities |eta|<2.5 in p&pmacr; collisions at sqrt[s] = 1.8 TeV. The results are based on a data sample of 107.6 pb(-1) recorded during 1992-1995 with the D0 detector at the Fermilab Tevatron collider. The background, predominantly from jets which fragment to neutral mesons, was estimated using the longitudinal shower shape of photon candidates in the calorimeter. The measured cross section is in good agreement with the next-to-leading order QCD calculation for E(gamma)(T) greater, similar36 GeV.

Search for second-generation leptoquark pairs in &pmacr;p collisions at radicals = 1.8 TeV

We have searched for second-generation leptoquark (LQ) pairs in the &mgr;&mgr;+jets channel using 94+/-5 pb(-1) of &pmacr;p collider data collected by the D0 experiment at the Fermilab Tevatron during 1993-1996. No evidence for a signal is observed. These results are combined with those from the &mgr;nu+jets and nunu+jets channels to obtain 95% confidence level (C.L.) upper limits on the LQ pair production cross section as a function of mass and beta, the branching fraction of a LQ decay into a charged lepton and a quark. Lower limits of 200(180) GeV/c(2) for beta = 1(1 / 2) are set at the 95% C.L. on the mass of scalar LQ. Mass limits are also set on vector leptoquarks as a function of beta.

Whole abdominal radiotherapy following second-look laparotomy for ovarian carcinoma

AIM

The safety and efficacy of whole abdominal radiotherapy was evaluated as salvage or consolidation treatment for ovarian cancer patients treated with primary surgery and chemotherapy, followed by second-look laparotomy (SLL). Overall survival and acute and late toxicity of treated patients were assessed.

METHODS

Patients were recruited between April 1981 and June 1994. All patients had SLL performed at Royal Prince Alfred Hospital after completion of primary chemotherapy. Data collected included demographic details, diagnosis, tumor stage, histology, grade, adjuvant chemotherapy, and radiotherapy. Radiation dose and fractionation, field size, boost volume and dose, failure to complete treatment and treatment interruptions, renal dose, and acute and late toxicity were recorded.

RESULTS

Fifty-one patients were evaluated; the median age was 51 years. Median follow-up for patients still alive was 62 months. Prior to 1988, chemotherapy comprised oral chlorambucil, with or without cisplatin (n = 25), while after this date all patients (n = 26) received primary cisplatin-based therapy. A radiation dose of 22. 5 Gy over 22 fractions was planned to the whole abdomen followed by a pelvic boost of 22 Gy in 11 fractions. Radiotherapy was completed in 37 (73%) patients. Treatment interruptions were necessary in 12 (24%) patients. Thrombocytopenia, neutropenia, nausea, vomiting, and diarrhea were the main causes of incomplete or interrupted treatment. Late bowel toxicity was seen in 6 (12%) patients, 2 of whom required laparotomy to relieve obstruction. There were no treatment-related deaths. Seven of the 51 patients are alive and free of disease, 2 died from other causes, and 2 are alive with evidence of recurrent or progressive disease. Mean follow-up time for surviving patients is 78.5 months. Overall survival at 2, 5, and 10 years was 65, 27, and 10%, respectively. Residual disease after primary surgery, smaller preirradiation tumor residuum, and completion of radiotherapy were independently associated with improved overall survival.

CONCLUSION

In this poor-prognosis group of patients, a combined approach of surgery, chemotherapy, and radiotherapy, while associated with acceptable toxicity, may not afford a prolongation of survival.

The caregiving system in mothers of infants: a comparison of divorcing and married mothers

This study was designed to investigate (1) the construct validity of a measure of the mother's internal representation of herself as a secure base in samples of married and divorcing mothers and infants, and (2) the relative contribution to infant security of this measure and a second representational measure, termed Psychological Protection, which focused specifically on the mother's responsiveness to the infant in the context of father visitation. There were 144 mothers and their first-born infants, age 12 to 20 months, who participated in the study. Of these, 51 dyads were from intact families; 93 were from families who had never married, had recently separated, or were in the process of divorce. Divorcing families were further divided into those in which the infant was participating in overnight timesharing arrangements with the father (n = 44) and those in which the infant was not (n = 49). Mothers completed questionnaires, they participated with their infants in the Strange Situation, and an hour-long, semi-structured Caregiving Interview was administered to them. Ratings of mothers on the Secure Base and Psychological Protection scales were based on verbatim transcripts of this interview. As predicted, mothers of securely attached infants in all family groups were discriminated from mothers of insecurely attached infants on the basis of Secure Base scores. Within the group of divorcing mothers, Secure Base scores were correlated with a rating of the mother's Psychological Protection of the infant in the context of visitation and both measures made independent contributions to infant attachment security. These findings are interpreted in terms of a more general model of the caregiving system. The manner in which the divorce context can disrupt the mothers' caregiving behavioral strategies and representations is also discussed.

Obstetric admissions to the intensive care unit

OBJECTIVE

To determine whether obstetric admissions to the intensive care unit (ICU) are useful quality-assurance indicators.

METHODS

We analyzed retrospectively obstetric ICU admissions at two tertiary care centers from 1991 to 1997.

RESULTS

The 131 obstetric admissions represented 0.3% of all deliveries. The majority (78%) of women were admitted to the ICU postpartum. Obstetric hemorrhage (26%) and hypertension (21%) were the two most common reasons for admission. Together with cardiac disease, respiratory disorders, and infection, they accounted for more than 80% of all admissions. Preexisting medical conditions were present in 38% of all admissions. The median Acute Physiology and Chronic Health Evaluation II score was 8.5. The predicted mortality rate for the group was 10.0%, and the actual mortality rate was 2.3%.

CONCLUSION

The most common precipitants of ICU admission were obstetric hemorrhage and uncontrolled hypertension. Improved management strategies for these problems may significantly reduce major maternal morbidity.

Study of impulse-control disorders among alcohol-dependent patients

BACKGROUND

Impulse-control disorders (ICDs) include intermittent explosive disorder, kleptomania, trichotillomania, pyromania, and pathological gambling. Several studies have suggested that the incidence of pathological gambling is substantially higher in alcoholics than in the general population. The rate of co-occurrence of other ICDs and alcohol dependence has never been systematically investigated. In our study, we assessed the frequency of all ICDs in a population of alcohol-dependent patients. We also examined the possibility that the presence of an ICD can correspond to earlier onset and more severe forms of alcoholism, which have a greater association with antisocial personality.

METHOD

All patients hospitalized at our psychiatric unit for detoxification between January and August 1997 met DSM-IV criteria for alcohol dependence and were included in this study. Diagnosis of alcohol dependence was confirmed with the Mini-International Neuropsychiatric Interview. ICDs were investigated using the Minnesota Impulsive Disorders Interview. All patients completed the Michigan Alcoholism Screening Test.

RESULTS

Among the 79 patients included in the study, 30 (38.0%) met criteria for an ICD. Included in the study were 19 cases of intermittent explosive disorder, 7 cases of pathological gambling, 3 cases of kleptomania, and 1 case of trichotillomania. Patients with co-occurring ICDs were significantly younger than patients without an ICD (mean age = 40.7 vs. 44.5 years; p = .03). Patients with co-occurring pathological gambling were significantly younger at the onset of alcohol dependence than patients without ICDs (mean age = 19.5 vs. 25.9 years; p = .0008). Pathological gamblers had significantly longer duration of alcohol dependence compared with patients without ICDs (26.0 vs. 17.9 years; p = .02). Patients with co-occurring intermittent explosive disorder had the shortest duration of alcohol dependence of all patients (9.9 years). Prevalence of antisocial personality disorder was no different in patients with or without co-occurring ICDs.

CONCLUSION

Thirty-eight percent of the alcohol-dependent patients studied presented with an ICD. Patients with ICDs were younger than those without an ICD. The presence of an ICD was not associated with a specific form of alcohol dependence or with antisocial personality. Co-occurrence of pathological gambling, however, was associated with lower age at onset of alcohol dependence, a higher number of detoxifications, and a longer duration of alcohol dependence than was absence of an ICD.

The development of attachment in separated and divorced families. Effects of overnight visitation, parent and couple variables

This study represents the first systematic investigation of the effects on infant attachment to mother and to father of the increasingly common practice of overnight visitation (time-sharing) with the father in separated and divorced families. There were 145 infants (ages 12 to 20 months) and their mothers (and 83 fathers) who participated in the study. Parents completed questionnaires, were interviewed about their relationship with the baby, and were observed with their infants in the Strange Situation. Infants in separated/divorced families who had regular overnight visits with father (n = 44) were significantly less likely to be classified as secure and more likely to be classified as disorganized or unclassifiable in their attachment to mother than infants in a married comparison group (n = 52). Attachment classification to father was unrelated to visiting (time-sharing) arrangements, but infants were significantly more likely to be classified disorganized/unclassifiable with father in the separated/divorced groups (n = 39) than in dual-parent families (n = 44). Disorganized attachment to mother in the Overnight group was associated with maternal reports of low parent communication and high parent conflict, and with low maternal psychological protection of the infant, assessed from maternal interviews. Consistent with Bowlby's and Rutter's context-sensitive views of the effects of separation, the results suggest that repeated overnight separations from the primary caregiver are associated with disruption in mother-infant attachment when the conditions of visitation are poor, i.e. when parents are unable to provide adequate psychological support to the child.

Surgical treatment for chronic lower-leg compartment syndrome in young female athletes

Our experience in treating chronic lower-leg compartment syndrome suggests that women may be more susceptible to this injury than are men, an observation for which there is support in the literature. Furthermore, when we evaluated the 47 young female athletes (age range, 13 years 11 months to 21 years 10 months) from our practice on whom 78 separate surgeries were performed, we found a lower success rate than those generally reported in studies that combine male and female patients. We suspect, therefore, that for reasons as yet unclear, women may also respond less well than men to operative fasciotomy.