Focal Plane Metrology for the LSST Camera

Meeting the science goals for the Large Synoptic Survey Telescope (LSST) translates into a demanding set of imaging performance requirements for the optical system over a wide (3.5{sup o}) field of view. In turn, meeting those imaging requirements necessitates maintaining precise control of the focal plane surface (10 {micro}m P-V) over the entire field of view (640 mm diameter) at the operating temperature (T {approx} -100 C) and over the operational elevation angle range. We briefly describe the hierarchical design approach for the LSST Camera focal plane and the baseline design for assembling the flat focal plane at room temperature. Preliminary results of gravity load and thermal distortion calculations are provided, and early metrological verification of candidate materials under cold thermal conditions are presented. A detailed, generalized method for stitching together sparse metrology data originating from differential, non-contact metrological data acquisition spanning multiple (non-continuous) sensor surfaces making up the focal plane, is described and demonstrated. Finally, we describe some in situ alignment verification alternatives, some of which may be integrated into the camera's focal plane

Metagenome sequence analysis of filamentous microbial communities obtained from geochemically distinct geothermal channels reveals specialization of three aquificales lineages.

The Aquificales are thermophilic microorganisms that inhabit hydrothermal systems worldwide and are considered one of the earliest lineages of the domain Bacteria. We analyzed metagenome sequence obtained from six thermal ‘filamentous streamer’ communities (~40 Mbp per site), which targeted three different groups of Aquificales found in Yellowstone National Park (YNP). Unassembled metagenome sequence and PCR-amplified 16S rRNA gene libraries revealed that acidic, sulfidic sites were dominated by Hydrogenobaculum (Aquificaceae) populations, whereas the circumneutral pH (6.5 - 7.8) sites containing dissolved sulfide were dominated by Sulfurihydrogenibium spp. (Hydrogenothermaceae). Thermocrinis (Aquificaceae) populations were found primarily in the circumneutral sites with undetectable sulfide, and to a lesser extent in one sulfidic system at pH 8. Phylogenetic analysis of assembled sequence containing 16S rRNA genes as well as conserved protein-encoding genes revealed that the composition and function of these communities varied across geochemical conditions. Each Aquificales lineage contained genes for CO2 fixation by the reverse TCA cycle, but only the Sulfurihydrogenibium populations perform citrate cleavage using ATP citrate lyase (Acl). The Aquificaceae populations use an alternative pathway catalyzed by two separate enzymes, citryl CoA synthetase (Ccs) and citryl CoA lyase (Ccl). All three Aquificales lineages contained evidence of aerobic respiration, albeit due to completely different types of heme Cu oxidases (subunit I) involved in oxygen reduction. The distribution of Aquificales populations and differences among functional genes involved in energy generation and electron transport is consistent with the hypothesis that geochemical parameters (e.g., pH, sulfide, H2, O2) have resulted in niche specialization among members of the Aquificales

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Outcomes following small bowel obstruction due to malignancy in the national audit of small bowel obstruction

Introduction Patients with cancer who develop small bowel obstruction are at high risk of malnutrition and morbidity following compromise of gastrointestinal tract continuity. This study aimed to characterise current management and outcomes following malignant small bowel obstruction. Methods A prospective, multicentre cohort study of patients with small bowel obstruction who presented to UK hospitals between 16th January and 13th March 2017. Patients who presented with small bowel obstruction due to primary tumours of the intestine (excluding left-sided colonic tumours) or disseminated intra-abdominal malignancy were included. Outcomes included 30-day mortality and in-hospital complications. Cox-proportional hazards models were used to generate adjusted effects estimates, which are presented as hazard ratios (HR) alongside the corresponding 95% confidence interval (95% CI). The threshold for statistical significance was set at the level of P ≤ 0.05 a-priori. Results 205 patients with malignant small bowel obstruction presented to emergency surgery services during the study period. Of these patients, 50 had obstruction due to right sided colon cancer, 143 due to disseminated intraabdominal malignancy, 10 had primary tumours of the small bowel and 2 patients had gastrointestinal stromal tumours. In total 100 out of 205 patients underwent a surgical intervention for obstruction. 30-day in-hospital mortality rate was 11.3% for those with primary tumours and 19.6% for those with disseminated malignancy. Severe risk of malnutrition was an independent predictor for poor mortality in this cohort (adjusted HR 16.18, 95% CI 1.86 to 140.84, p = 0.012). Patients with right-sided colon cancer had high rates of morbidity. Conclusions Mortality rates were high in patients with disseminated malignancy and in those with right sided colon cancer. Further research should identify optimal management strategy to reduce morbidity for these patient groups

National prospective cohort study of the burden of acute small bowel obstruction

Background Small bowel obstruction is a common surgical emergency, and is associated with high levels of morbidity and mortality across the world. The literature provides little information on the conservatively managed group. The aim of this study was to describe the burden of small bowel obstruction in the UK. Methods This prospective cohort study was conducted in 131 acute hospitals in the UK between January and April 2017, delivered by trainee research collaboratives. Adult patients with a diagnosis of mechanical small bowel obstruction were included. The primary outcome was in‐hospital mortality. Secondary outcomes included complications, unplanned intensive care admission and readmission within 30 days of discharge. Practice measures, including use of radiological investigations, water soluble contrast, operative and nutritional interventions, were collected. Results Of 2341 patients identified, 693 (29·6 per cent) underwent immediate surgery (within 24 h of admission), 500 (21·4 per cent) had delayed surgery after initial conservative management, and 1148 (49·0 per cent) were managed non‐operatively. The mortality rate was 6·6 per cent (6·4 per cent for non‐operative management, 6·8 per cent for immediate surgery, 6·8 per cent for delayed surgery; P = 0·911). The major complication rate was 14·4 per cent overall, affecting 19·0 per cent in the immediate surgery, 23·6 per cent in the delayed surgery and 7·7 per cent in the non‐operative management groups (P < 0·001). Cox regression found hernia or malignant aetiology and malnutrition to be associated with higher rates of death. Malignant aetiology, operative intervention, acute kidney injury and malnutrition were associated with increased risk of major complication. Conclusion Small bowel obstruction represents a significant healthcare burden. Patient‐level factors such as timing of surgery, acute kidney injury and nutritional status are factors that might be modified to improve outcomes

Video colposcopy improves adherence to follow-up compared to regular colposcopy: a randomized trial

To assess and compare rates of adherence to follow-up in women undergoing video or regular colposcopy.Sixty patients with abnormal Pap smears were randomized to undergo video or regular colposcopy. All participants were given the same instructions and a follow-up appointment. If a patient did not keep her appointment and did not reschedule, this was considered a failure. Multivariate logistic regression was used for assessment of predictors of follow-up.The follow-up rate was significantly higher in the video colposcopy group compared to the regular colposcopy group (80 vs. 50%, p=0.014). After adjusting for results of previous and referral Pap smears, and previous treatment, multivariate analyses indicated that women undergoing video colposcopy were almost five times more likely to return for follow-up than women undergoing regular colposcopy (odds ratio=4.9, 95% confidence interval=[1.24, 19.39]).Colposcopy clinics with patient population similar to ours may consider the use of video colposcope

Evaluation of the relationship between endometrial thickness and failure of single-dose methotrexate in ectopic pregnancy

Objective: To test the hypothesis that endometrial stripe thicker than 12 mm increases treatment failure of single-dose methotrexate for the management of ectopic pregnancy. Study design: Seventy-three patients with ectopic pregnancy and measured pretreatment endometrial stripe were divided into two groups based on the endometrial stripe thickness (>12 mm or ≤12 mm). All patients were candidates for single-dose methotrexate treatment. Variables analyzed between the two groups were endometrial stripe thickness, initial beta human chorionic gonadotropin level (hCG), size of the ectopic mass, presence of fetal heart tones, previous ectopic pregnancy, and clinical outcomes. Results: Sixty patients had endometrial stripe thickness ≤12 mm and 13 patients >12 mm. The two groups were similar in initial hCG, size of ectopic mass, presence of fetal heart tones and rate of previous ectopic pregnancy. The failure rate was significantly higher in the group with endometrial stripe >12 mm compared to the group ≤ 12 mm (n=7, 53% vs. n=3, 5%, P12 mm compared to the group ≤12 mm (mean ± SD, 17.64±5.82 mm vs. 7.69±2.82 mm, P<0.01). Conclusion: Endometrial stripe thicker than 12 mm increases the risk for treatment failure with single-dose methotrexate

Risk factors for conversion to laparotomy during laparoscopic management of an ectopic pregnancy

To identify risk factors for conversion to laparotomy during laparoscopic management of ectopic pregnancy. A retrospective chart review of patients who underwent laparoscopy for treatment of ectopic pregnancy, during a 32-month period (6/1999-2/2002), at the University of Miami Jackson Memorial Hospital. We identified 229 patients; 201 had a successful laparoscopy (non-converted group) and 28 who were converted to laparotomy (converted group). Variables analyzed between the two groups were demographic data, patient-related risk factors available to the surgeon prior to the surgery (previous laparotomy, previous laparoscopy, history of PID, history of endometriosis, diameter of ectopic pregnancy as measured by ultrasound, amount of free fluid on ultrasound, BMI), and surgeons' experience. Out of the 229 laparoscopies, 28 were converted to laparotomy (12.2%). The rate of conversion was significantly higher for less experienced compared to experienced surgeon (OR = 6.1, 95% CI = 2.35-15.88). Significantly more women had a BMI > 30 kg/m2 in the converted group compared to the non-converted group (42% vs. 14%; OR = 4.28, 95% CI = 1.7-10.75) and the converted group had significantly higher rate of large free fluid reported on ultrasound compared to the non-converted group (21.42% vs. 7.46%; OR = 3.38, 95% CI = 1.04-10.61). Less experienced surgeon, BMI > 30 kg/m2, and large amount of free fluid on ultrasound increase the risk of conversion to laparotomy during laparoscopic management of ectopic pregnancy