489 research outputs found
Does fine sediment source as well as quantity affect salmonid embryo mortality and development?
Fine sediments are known to be an important cause of increased mortality in benthic spawning fish. To date, most of the research has focussed on the relationship between embryo mortality and the quantity of fine sediment accumulated in the egg pocket. However, recent evidence suggests a) that the source of fine sediment might also be important, and b) that fitness of surviving embryos post-hatch might also be impacted by the accumulation of fine sediments. In this paper, we report an experiment designed to simulate the incubation environment of brown trout (Salmo trutta) and Atlantic salmon (Salmo salar). During the experiment, the incubating embryos were exposed to different quantities of fine (< 63 ?m) sediment derived from four different sources; agricultural topsoils, damaged road verges, eroding river channel banks and tertiary level treated sewage. Results showed that mass and source are independently important for determining the mortality and fitness of alevin. Differences between species were observed, such that brown trout are less sensitive to mass and source of accumulated sediment. We demonstrate for the first time that sediment source is an additional control on the impact of fine sediment, and that this is primarily controlled by the organic matter content and oxygen consumption of the catchment source material
The significance of seniority for women managersâ interpretations of organizational restructuring
This paper examines the impact of restructuring within the transport and logistics sector on women managers working at senior and less senior (middle/junior management) levels of the organization. The majority of women experienced increased performance pressures and heavier workloads as well as an increase in working hours. At the same time, there were pressures to work at home (i.e. week-ends and evenings) and reduced opportunities to work from home (i.e. during normal office hours). Management level emerged as an important factor in how these changes were interpreted. Senior managers perceived more positive outcomes in terms of increased motivation and loyalty. Despite a longer working week, they were less likely to report low morale as an outcome from long hours. In fact, irrespective of management level, women working shorter hours were more likely to report low morale as an outcome. Results are discussed in relation to literature on restructuring and careers, in terms of perceptual framing and in relation to different levels of investment in the organization
Spin splitting in a polarized quasi-two-dimensional exciton gas
We have observed a large spin splitting between "spin" and
heavy-hole excitons, having unbalanced populations, in undoped GaAs/AlAs
quantum wells in the absence of any external magnetic field. Time-resolved
photoluminescence spectroscopy, under excitation with circularly polarized
light, reveals that, for high excitonic density and short times after the
pulsed excitation, the emission from majority excitons lies above that of
minority ones. The amount of the splitting, which can be as large as 50% of the
binding energy, increases with excitonic density and presents a time evolution
closely connected with the degree of polarization of the luminescence. Our
results are interpreted on the light of a recently developed model, which shows
that, while intra-excitonic exchange interaction is responsible for the spin
relaxation processes, exciton-exciton interaction produces a breaking of the
spin degeneracy in two-dimensional semiconductors.Comment: Revtex, four pages; four figures, postscript file Accepted for
publication in Physical Review B (Rapid Commun.
Management control â International Observatory 2014
International audienc
Neo/adjuvant chemotherapy does not improve outcome in resected primary synovial sarcoma: a study of the French Sarcoma Group
Background: There are only scarce data about the benefit of adjunctive chemotherapy in patients with localized synovial sarcoma (SS). Patients and methods: Data from 237 SS patients recorded in the database of the French Sarcoma Group were retrospectively analyzed. The respective impact of radiotherapy, neo-adjuvant chemotherapy and adjuvant chemotherapy on overall survival (OS), local recurrence-free survival (LRFS) and distant recurrence-free survival (DRFS) were assessed after adjustment to prognostic factors. Results: The median follow-up was 58 months (range 1-321). Adjuvant, neo-adjuvant chemotherapy and postoperative radiotherapy were administered in 112, 45 and 181 cases, respectively. In all, 59% of patients treated with chemotherapy received an ifosfamide-containing regimen. The 5-year OS, LRFS and DRFS rates were 64.0%, 70% and 57%, respectively. On multivariate analysis, age >35 years old, grade 3 and not-R0 margins were highly significant independent predictors of worse OS. After adjustment to prognostic factors, radiotherapy significantly improved LRFS but not DRFS or OS. Neither neo-adjuvant nor adjuvant chemotherapy had significant impact on OS, LRFS or DRFS. Conclusion: As for other high-grade soft-tissue sarcomas, well-planned wide surgical excision with adjuvant radiotherapy remains the cornerstone of treatment for SS. Neo-adjuvant or adjuvant chemotherapy should not be delivered outside a clinical trial settin
Use of urgent, emergency and acute care by mental health service users: a record-level cohort study
Background
People with serious mental illness experience worse physical health and greater mortality than the general population. Crude rates of A&E attendance and acute hospital admission are higher in people with serious mental illness than other hospital users. We aimed to further these findings by undertaking a standardised comparison of urgent and emergency care pathway use among users of mental health services and the general population.
Methods
Retrospective cohort analysis using routine data from 2013â2016 from the CUREd dataset for urgent and emergency care contacts (NHS 111, ambulance, A&E and acute admissions) and linked mental health trust data for Sheffield, England. We compared annual age- and sex-standardised usage rates for each urgent and emergency care service between users of mental health services and those without a recent history of mental health service use.
Results
We found marked differences in usage rates for all four urgent and emergency care services between the general population and users of mental health services. Usage rates and the proportion of users were 5â6 times and 3â4 times higher in users of mental health services, respectively, for all urgent and emergency care services. Users of mental health services were often more likely to experience the highest or lowest acuity usage characteristics.
Conclusions
Current users of mental health services were heavily over-represented among urgent and emergency care users, and they made more contacts per-person. Higher service use among users of mental health services could be addressed by improved community care, more integrated physical and mental health support, and more proactive primary care. A complex pattern of service use among users of mental health services suggests this will need careful targeting to reduce avoidable contacts and optimise patient outcomes
Exciton Spin Dynamics in Semiconductor Quantum Wells
In this paper we will review Exciton Spin Dynamics in Semiconductor Quantum
Wells. The spin properties of excitons in nanostructures are determined by
their fine structure. We will mainly focus in this review on GaAs and InGaAs
quantum wells which are model systems.Comment: 55 pages, 27 figure
Work-Unit Absenteeism: Effects of Satisfaction, Commitment, Labor Market Conditions, and Time
Prior research is limited in explaining absenteeism at the unit level and over time. We developed and tested a model of unit-level absenteeism using five waves of data collected over six years from 115 work units in a large state agency. Unit-level job satisfaction, organizational commitment, and local unemployment were modeled as time-varying predictors of absenteeism. Shared satisfaction and commitment interacted in predicting absenteeism but were not related to the rate of change in absenteeism over time. Unit-level satisfaction and commitment were more strongly related to absenteeism when units were located in areas with plentiful job alternatives
Optimizing Clinical Benefits of Bisphosphonates in Cancer Patients with Bone Metastases
Malignant bone disease is common in patients with advanced solid tumors or multiple myeloma. Bisphosphonates have been found to be important treatments for bone metastases. A positive benefit-risk ratio for bisphosphonates has been established, and ongoing clinical trials will determine whether individualized therapy is possible
Final analysis of the phase III non-inferiority COLUMBA study of subcutaneous versus intravenous daratumumab in patients with relapsed or refractory multiple myeloma
In the primary analysis of the phase III COLUMBA study, daratumumab by subcutaneous administration (DARA SC) demonstrated non-inferiority to intravenous administration (DARA IV) for relapsed or refractory multiple myeloma (RRMM). Here, we report the final analysis of efficacy and safety from COLUMBA after a median of 29.3 months follow-up (additional 21.8 months after the primary analysis). In total, 522 patients were randomized (DARA SC, n=263; DARA IV, n=259). With longer follow-up, DARA SC and DARA IV continued to show consistent efficacy and maximum trough daratumumab concentration as compared with the primary analysis. The overall response rate was 43.7% for DARA SC and 39.8% for DARA IV. The maximum mean (standard deviation [SD]) trough concentration (cycle 3, day 1 pre-dose) of serum DARA was 581 (SD, 315) ”g/mL for DARA SC and 496 (SD, 231) ”g/mL for DARA IV. Median progression-free survival was 5.6 months for DARA SC and 6.1 months for DARA IV; median overall survival was 28.2 months and 25.6 months, respectively. Grade 3/4 treatment-emergent adverse events occurred in 50.8% of patients in the DARA SC group and 52.7% in the DARA IV group; the most common (â„10%) were thrombocytopenia (DARA SC, 14.2%; DARA IV, 13.6%), anemia (13.8%; 15.1%), and neutropenia (13.1%; 7.8%). The safety profile remained consistent with the primary analysis after longer follow-up. In summary, DARA SC and DARA IV continue to demonstrate similar efficacy and safety, with a low rate of infusion-related reactions (12.7% vs. 34.5%, respectively) and shorter administration time (3-5 minutes vs. 3-7 hours) supporting DARA SC as a preferable therapeutic choice
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