Millimeter-wave Signature of Strange Matter Stars

One of the most important questions in the study of compact objects is the nature of pulsars, including whether they consist of neutron matter or strange quark matter (SQM). However, few mechanisms for distinguishing between these two possibilities have been proposed. The purpose of this paper is to show that a strange star (one made of SQM) will have a vibratory mode with an oscillation frequency of approximately 250 GHz (millimeter wave). This mode corresponds to motion of the center of the expected crust of normal matter relative to the center of the strange quark core, without distortion of either. Radiation from currents generated in the crust at the mode frequency would be a SQM signature. We also consider effects of stellar rotation, estimate power emission and signal-to-noise ratio, and discuss briefly possible mechanisms for exciting the mode.Comment: 13 pages, Latex, one figur

Is (poly-) substance use associated with impaired inhibitory control? A mega-analysis controlling for confounders.

Many studies have reported that heavy substance use is associated with impaired response inhibition. Studies typically focused on associations with a single substance, while polysubstance use is common. Further, most studies compared heavy users with light/non-users, though substance use occurs along a continuum. The current mega-analysis accounted for these issues by aggregating individual data from 43 studies (3610 adult participants) that used the Go/No-Go (GNG) or Stop-signal task (SST) to assess inhibition among mostly "recreational" substance users (i.e., the rate of substance use disorders was low). Main and interaction effects of substance use, demographics, and task-characteristics were entered in a linear mixed model. Contrary to many studies and reviews in the field, we found that only lifetime cannabis use was associated with impaired response inhibition in the SST. An interaction effect was also observed: the relationship between tobacco use and response inhibition (in the SST) differed between cannabis users and non-users, with a negative association between tobacco use and inhibition in the cannabis non-users. In addition, participants' age, education level, and some task characteristics influenced inhibition outcomes. Overall, we found limited support for impaired inhibition among substance users when controlling for demographics and task-characteristics

Brain Cancer in Workers Employed at a Laboratory Research Facility.

BACKGROUND:An earlier study of research facility workers found more brain cancer deaths than expected, but no workplace exposures were implicated. METHODS:Adding four additional years of vital-status follow-up, we reassessed the risk of death from brain cancer in the same workforce, including 5,284 workers employed between 1963, when the facility opened, and 2007. We compared the work histories of the brain cancer decedents in relationship to when they died and their ages at death. RESULTS:As in most other studies of laboratory and research workers, we found low rates of total mortality, total cancers, accidents, suicides, and chronic conditions such as heart disease and diabetes. We found no new brain cancer deaths in the four years of additional follow-up. Our best estimate of the brain cancer standardized mortality ratio (SMR) was 1.32 (95% confidence interval [95% CI] 0.66-2.37), but the SMR might have been as high as 1.69. Deaths from benign brain tumors and other non-malignant diseases of the nervous system were at or below expected levels. CONCLUSION:With the addition of four more years of follow-up and in the absence of any new brain cancers, the updated estimate of the risk of brain cancer death is smaller than in the original study. There was no consistent pattern among the work histories of decedents that indicated a common causative exposure

Cohort study of workers at a New Zealand agrochemical plant to assess the effect of dioxin exposure on mortality

OBJECTIVES: To describe how the exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) influenced mortality in a cohort of workers who were exposed more recently, and at lower levels, than other cohorts of trichlorophenol process workers.DESIGN: A cohort study.SETTING: An agrochemical plant in New Zealand PARTICIPANTS: 1,599 men and women working between 1 January 1969 and 1 November 1988 at a plant producing the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) with TCDD as a contaminant. Cumulative TCDD exposure was estimated for each individual in the study by a toxicokinetic model.PRIMARY OUTCOME MEASURES: Calculation of cause-specific standardised mortality ratios (SMRs) and 95% confidence intervals (95% CI's) compared those never and ever exposed to TCDD. Dose-response trends were assessed firstly through SMRs stratified in quartiles of cumulative TCCD exposure, and secondly with a proportional hazards model.RESULTS: The model intercept of 5.1 ppt of TCDD was consistent with background TCDD concentrations in New Zealand among older members of the population. Exposed workers had non-significant increases in all-cancer deaths (SMR=1.08, 95% CI 0.86 to 1.34), non-Hodgkin lymphoma (SMR=1.57, 95% CI: 0.32 to 4.59), soft tissue sarcoma (one death) (SMR=2.38, 95% CI: 0.06 to 13.26), diabetes (SMR=1.27, 95% CI: 0.55 to 2.50) and ischaemic heart disease (SMR=1.21, 95% CI: 0.96 to 1.50). Lung cancer deaths (SMR=0.95, 95% CI: 0.56 to 1.53) were fewer than expected. Neither the stratified SMR nor the proportional hazard analysis showed a dose-response relationship.CONCLUSION: There was no evidence of an increase in risk for 'all cancers', any specific cancer and no systematic trend in cancer risk with TCDD exposure. This argues against the carcinogenicity of TCDD at lower levels of exposure

Balloon-assisted occlusion of the internal iliac arteries in patients with placenta accreta/percreta.

BACKGROUND: Placenta accreta/percreta is a leading cause of third trimester hemorrhage and postpartum maternal death. The current treatment for third trimester hemorrhage due to placenta accreta/percreta is cesarean hysterectomy, which may be complicated by large volume blood loss. PURPOSE: To determine what role, if any, prophylactic temporary balloon occlusion and transcatheter embolization of the anterior division of the internal iliac arteries plays in the management of patients with placenta accreta/percreta. METHODS: The records of 28 consecutive patients with a diagnosis of placenta accreta/percreta were retrospectively reviewed. Patients were divided into two groups. Six patients underwent prophylactic temporary balloon occlusion, followed by cesarean section, transcatheter embolization of the anterior division of the internal iliac arteries and cesarean hysterectomy (n = 5) or uterine curettage (n = 1). Twenty-two patients underwent cesarean hysterectomy without endovascular intervention. The following parameters were compared in the two groups: patient age, gravidity, parity, gestational age at delivery, days in the intensive care unit after delivery, total hospital days, volume of transfused blood products, volume of fluid replacement intraoperatively, operating room time, estimated blood loss, and postoperative morbidity and mortality. RESULTS: Patients in the embolization group had more frequent episodes of third trimester bleeding requiring admission and bedrest prior to delivery (16.7 days vs. 2.9 days), resulting in significantly more hospitalization time in the embolization group (23 days vs. 8.8 days) and delivery at an earlier gestational age than in those in the surgical group (32.5 weeks). There was no statistical difference in mean estimated blood loss, volume of replaced blood products, fluid replacement needs, operating room time or postoperative recovery time. CONCLUSION: Our findings do not support the contention that in patients with placenta accreta/percreta, prophylactic temporary balloon occlusion and embolization prior to hysterectomy diminishes intraoperative blood loss

Observed (Obs) and expected (Exp) number of malignant primary brain cancer deaths, standardized mortality ratio (SMR), and 95% confidence interval (95% CI) in original study (Alexander et al.) and current update, relying only on NDI and death certificates for cause of death information or relying on additional information not included on death certificates, as computed for follow-up through 2007 or 2011.

<p>^*Computed using Life Table Analysis System (LTAS).</p>†<p>We present these values for the convenience of the reader. Alexander et al. did not present an analysis with this observed number, which excludes three deaths with incomplete or modified death certificate information.</p>‡<p>Computed using Occupational Cohort Mortality Analysis Program (OCMAP).</p>§<p>We present these values for the convenience of the reader. Relying on additional information not included on death certificates provides a more accurate count of deaths in the study cohort, but this approach introduces an information bias relative to the comparison population. We do not consider the ratio of these observed and expected numbers to constitute valid SMR estimates.</p><p>Observed (Obs) and expected (Exp) number of malignant primary brain cancer deaths, standardized mortality ratio (SMR), and 95% confidence interval (95% CI) in original study (Alexander et al.) and current update, relying only on NDI and death certificates for cause of death information or relying on additional information not included on death certificates, as computed for follow-up through 2007 or 2011.</p

Years worked at the Spring House facility, death date, and age at death for workers identified as having died of brain cancer relying only on NDI and death certificates for cause of death information or relying on additional information not included on death certificates.

<p>Gray bars represent years worked at the Spring House facility. The vertical black lines indicate the death date. The numbers specify age at death. The International Classification of Disease (ICD) codes provided were provided by the National Death Index (NDI) or coded by a nosologist according to the ICD revision in effect when the death occurred. ICD code translations are provided along with the type of brain cancer as determined by Alexander et al. in the original Spring House mortality study.</p

Standardized mortality ratios (SMR) and 95% confidence intervals (95% CI) for studies of laboratory or research workers which report brain cancers.

<p>Standardized mortality ratios (SMR) and 95% confidence intervals (95% CI) for studies of laboratory or research workers which report brain cancers.</p

Cohort size, follow-up, and results of vital status tracing in original study (Alexander et al.) and current update.

<p>^*This category includes 77 persons lost to follow-up (vital status unknown) and 4 foreign or war deaths. Follow-up for decedents was censored at date of death.</p><p>Cohort size, follow-up, and results of vital status tracing in original study (Alexander et al.) and current update.</p