703 research outputs found

    170 GBit/s transmission in an erbium-doped waveguide amplifier on silicon

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    Signal transmission experiments were performed at 170 Gbit/s in an integrated Al2O3:Er3+Al_2O_3:Er^{3+} waveguide amplifier to investigate its potential application in high-speed photonic integrated circuits. Net internal gain of up to 11 dB was measured for a continuous-wave 1532 nm signal under 1480 nm pumping, with a threshold pump power of 4 mW. A differential group delay of 2 ps between the TE and TM fundamental modes of the 5.7-cm-long amplifier was measured. When selecting a single polarization open eye diagrams and bit error rates equal to those of the transmission system without the amplifier were observed for a 1550 nm signal encoded with a 170 Gbit/s return-to-zero pseudo-random 27−12^{7}-1 bit sequence

    Liver immune microenvironment and metastasis from colorectal cancer‐pathogenesis and therapeutic perspectives

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    A drastic difference exists between the 5‐year survival rates of colorectal cancer patients with localized cancer and distal organ metastasis. The liver is the most favorable organ for cancer metastases from the colorectum. Beyond the liver‐colon anatomic relationship, emerging evidence highlights the impact of liver immune microenvironment on colorectal liver metastasis. Prior to cancer cell dissemination, hepatocytes secrete multiple factors to recruit or activate immune cells and stromal cells in the liver to form a favorable premetastatic niche. The liver‐resident cells including Kupffer cells, hepatic stellate cells, and liver‐sinusoidal endothelial cells are co‐opted by the recruited cells, such as myeloid‐derived suppressor cells and tumor‐associated macrophages, to establish an immunosuppressive liver microenvironment suitable for tumor cell colonization and outgrowth. Current treatments including radical surgery, systemic therapy, and localized therapy have only achieved good clinical outcomes in a minority of colorectal cancer patients with liver metastasis, which is further hampered by high recurrence rate. Better understanding of the mechanisms governing the metastasis‐prone liver immune microenvironment should open new immuno‐oncology avenues for liver metastasis intervention

    Optimization viewpoint on Kalman smoothing, with applications to robust and sparse estimation

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    In this paper, we present the optimization formulation of the Kalman filtering and smoothing problems, and use this perspective to develop a variety of extensions and applications. We first formulate classic Kalman smoothing as a least squares problem, highlight special structure, and show that the classic filtering and smoothing algorithms are equivalent to a particular algorithm for solving this problem. Once this equivalence is established, we present extensions of Kalman smoothing to systems with nonlinear process and measurement models, systems with linear and nonlinear inequality constraints, systems with outliers in the measurements or sudden changes in the state, and systems where the sparsity of the state sequence must be accounted for. All extensions preserve the computational efficiency of the classic algorithms, and most of the extensions are illustrated with numerical examples, which are part of an open source Kalman smoothing Matlab/Octave package.Comment: 46 pages, 11 figure

    Sex differences in perceived risk and testing experience of HIV in an urban fishing setting in Ghana

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    The concept of neighborhood remains important in criminology but there is an increasing academic interest in the potential impact of the Modifiable Areal Unit Problem (MAUP) on neighborhood based studies. In the present study data over arson from the Swedish rescue services 2007-2012 have been employed to analyze MAUP in the city of Malmö, Sweden. The city has been divided into 50*50 meter pixels as micro-places (n=64540) which have been assigned a value for arson from frequency of arson within the pixel. The analysis is based on a comparison of two types of administrative geographical units alongside 40 randomly generated sets of thiessen polygon geographical units. Empty two-level hierarchical regression models with the micro-places as level 1 unit have been used to calculate Intra-Class Correlations (ICC) separately with each of the 42 different geographical units of analysis as level 2 units. The analysis is repeated with two alternative methods, kernel density and euclidian distance, to calculate a value for each micro-place. Results show that administrative geographical units of analysis in some cases just are marginally better than geographical units with random boundaries if the basic urban structure is taken into account

    Development of a Core Outcome Set for the research and assessment of inoperable malignant bowel obstruction

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    BackgroundMalignant bowel obstruction is experienced by 15% of people with advanced cancer, preventing them from eating and drinking and causing pain, nausea and vomiting. Surgery is not always appropriate. Management options include tube or stent drainage of intestinal contents and symptom control using medication. Published literature describing palliative interventions uses a broad range of outcome measures, few of which are patient-relevant. This hinders evidence synthesis, and fails to consider the perspectives of people undergoing treatment.AimsTo develop a Core Outcome Set for the assessment of inoperable malignant bowel obstruction with clinician, patient and caregiver involvement, using COMET methodology (Core Outcome Measures in Effectiveness Trials).MethodsA systematic review of clinical trials and observational studies, a rapid review of the qualitative literature and in-depth patient and clinician interviews were conducted to identify a comprehensive list of outcomes. Outcomes were compared and consolidated by the study Steering Group and Patient and Public Involvement contributors, and presented to an international clinical Expert Panel for review. Outcomes from the finalised list were rated for importance in a three-round international Delphi process: results of two survey rounds were circulated to respondents, and two separate consensus meetings were conducted with clinicians and with patients and caregivers via virtual conferencing, using live polling to reach agreement on a Core Outcome Set.Results130 unique outcomes were identified. Following the independent Expert Panel review, 82 outcomes were taken into round 1 of the Delphi survey; 24 outcomes reached criteria for critical importance across all stakeholder groups and none reached criteria for dropping. All outcomes rated critically important were taken forward for re-rating in round 2 and all other outcomes dropped. In round 2, all outcomes were voted critically important by at least one stakeholder group. Round 2 outcomes were presented again at online consensus meetings, categorised as high ranking (n = 9), middle ranking (n = 7) or low ranking (n = 8). Stakeholders reached agreement on 16 core outcomes across four key domains: Symptom control, Life impact, Treatment outcomes, and Communication and patient preferences.ConclusionUse of this Core Outcome Set can help to address current challenges in making sense of the evidence around treatment for inoperable malignant bowel obstruction to date, and underpin a more robust future approach. Clearer communication and an honest understanding between all stakeholders will help to provide a basis for responsible decision-making in this distressing situation in clinical practice

    Antiretroviral Therapy in the Malawi Defence Force: Access, Treatment Outcomes and Impact on Mortality

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    BACKGROUND: HIV/AIDS affects all sectors of the population and the defence forces are not exempt. A national survey was conducted in all public and private sectors in Malawi that provide antiretroviral therapy (ART) to determine the uptake of ART by army personnel, their outcomes while on treatment, and the impact of ART on mortality in the Malawi Defence Force. METHODOLOGY/PRINCIPAL FINDINGS: A retrospective cohort analysis was carried out, collecting data on access and retention on treatment from all 103 public and 38 private sector ART clinics in Malawi, using standardised patient master cards and clinic registers. Observations were censored on December 31(st) 2006. Independent data on mortality trends in army personnel from all causes between 2002 and 2006 were available from army records. By December 31(st) 2006, there were 85,168 patients ever started on ART in both public and private sectors, of whom 547 (0.7%) were army personnel. Of these, 22% started ART in WHO clinical stage 1 or 2 with a CD4-lymphocyte count of <or=250/mm(3) and 78% started in stage 3 or 4. Treatment outcomes of army personnel by December 31(st) 2006 were:-365 (67%) alive and on ART at their registration facility, 98 (18%) transferred out to another facility, 71 (13%) dead, 9 (2%) lost to follow-up, and 4 (<1%) stopped treatment. The probability of being alive on ART at 6-, 12- and 18-months was 89.8%, 83.4% and 78.8% respectively. All-cause mortality in army personnel declined dramatically over the five year period from 2002-2006. CONCLUSION/SIGNIFICANCE: There has been a good access of army personnel to ART during the last five years with excellent outcomes, and this should serve as an example for other defence forces and large companies in the region

    Postoperative arginine-enriched immune modulating nutrition: Long-term survival results from a randomised clinical trial in patients with oesophagogastric and pancreaticobiliary cancer

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    Background and AimsImmune modulating nutrition (IMN) has been shown to reduce postoperative infectious complications and length of stay in patients with gastrointestinal cancer. Two studies study of IMN in patients undergoing surgery for head and neck cancer also suggested that this treatment might improve long-term survival and progression-free survival. In the present study, we analysed follow-up data from our previous randomised controlled trial of IMN, in patients undergoing surgery for oesophagogastric and pancreaticobiliary cancer, in order to evaluate the long-term impact on survival of postoperative IMN versus an isocaloric, isonitrogenous control feed.MethodsThis study included patients undergoing surgery for cancers of the pancreas, oesophagus and stomach, who had been randomised in a double-blind manner to receive postoperative jejunostomy feeding with IMN (Stresson, Nutricia Ltd.) or an isonitrogenous, isocaloric feed (Nutrison High Protein, Nutricia) for 10-15 days. The primary outcome was long-term overall survival.ResultsThere was complete follow-up for all 108 patients, with 54 patients randomised to each group. There were no statistically significant differences between groups by demographics [(age, p=0.63), sex (p=0.49) or site of cancer (p=0.25)]. 30-day mortality was 11.1% in both groups. Mortality in the intervention group was 13%, 31.5%, 70.4%, 85.2%, 88.9%, and 96.3% at 90 days, and 1, 5, 10, 15 and 20 years respectively. Corresponding mortality in the control group was 14.8%, 35.2%, 68.6%, 79.6%, 85.2% and 98.1% (p>0.05 for all comparisons).ConclusionEarly postoperative feeding with arginine-enriched IMN had no impact on long-term survival in patients undergoing surgery for oesophagogastric and pancreaticobiliary cancer

    How STRANGE are your study animals?

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    A new framework for studies of animal behaviour will help to avoid sampling bias— ten years on from the call to widen the pool of human participants in psychology research beyond the WEIRD.Publisher PDFNon peer reviewe

    Comment on Spracklandus Hoser, 2009 (Reptilia, Serpentes, ELAPIDAE): request for confirmation of the availability of the generic name and for the nomenclatural validation of the journal in which it was published (Case 3601; see BZN 70: 234–237; 71: 30–38, 133–135, 181–182, 252–253)

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