10,898 research outputs found
Foreground separation methods for satellite observations of the cosmic microwave background
A maximum entropy method (MEM) is presented for separating the emission due
to different foreground components from simulated satellite observations of the
cosmic microwave background radiation (CMBR). In particular, the method is
applied to simulated observations by the proposed Planck Surveyor satellite.
The simulations, performed by Bouchet and Gispert (1998), include emission from
the CMBR, the kinetic and thermal Sunyaev-Zel'dovich (SZ) effects from galaxy
clusters, as well as Galactic dust, free-free and synchrotron emission. We find
that the MEM technique performs well and produces faithful reconstructions of
the main input components. The method is also compared with traditional Wiener
filtering and is shown to produce consistently better results, particularly in
the recovery of the thermal SZ effect.Comment: 31 pages, 19 figures (bitmapped), accpeted for publication in MNRA
Quality of life of patients treated surgically for head and neck cancer
The quality of survival of 48 patients treated surgically for head and neck cancer was assessed using a problem-orientated self-administered questionnaire. The questionnaire was based on the European Organization for Research into the Treatment of Cancer (EORTC) core questionnaire to which a specific head and neck module was added. The following domains were studied: pain, fatigue, physical symptoms (gastrointestinal and 'other'), functional activity, psychological symptoms, overall physical condition and overall quality of life. For the analysis, five groups of patients were considered: laryngectomy (n = 15), pharyngolaryngoesophagectomy (n = 5), craniofacial procedure (n = 11), 'other operations' (n = 9) and patients with disease recurrence (n = 8). Each group identified different problem areas. Laryngectomees and 'other operation' patients reported relatively few problems, whereas patients with disease recurrence described difficulties in all of the domains examined. Symptoms of fatigue were common. Information collected in this way may facilitate improved rehabilitation and thus better quality of survival
Health information needs, source preferences and engagement behaviours of women with metastatic breast cancer across the care continuum: protocol for a scoping review
INTRODUCTION: The health information needs, information source preferences and engagement behaviours of women with metastatic breast cancer (mBC) depend on personal characteristics such as education level, prior knowledge, clinical complications, comorbidities and where they are in the cancer journey. A thorough understanding of the information behaviours of women living with mBC is essential to the provision of optimal care. A preliminary literature review suggests that there is little research on this topic, but that there may be lessons from a slightly broader literature. This review will identify what is known and what is not known about the health information needs, acquisition and influences of women with mBC across the care continuum. Findings will help to identify research needs and specific areas where in-depth systematic reviews may be feasible, as well as inform evidence-based interventions to address the health information needs of female patients with mBC with different demographics and characteristics and across the mBC journey. METHODS AND ANALYSIS: A scoping review will be performed using the guidelines of Arksey and O'Malley as updated by subsequent authors to systematically search scientific and grey literature for articles in English that discuss the health information needs, source preferences, engagement styles, and associated personal and medical attributes of women ≥18 years living with mBC at different stages of the disease course. A variety of databases (including Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed, Excerpta Medica Database (EMBASE), Academic Search Premier, Cochrane Database of Systematic Reviews, PsycINFO, Health Source: Nursing/Academic Edition, and PQDT Open), oncology, patient advocacy and governmental websites will be searched from inception to present day. Research and non-research literature will be included; no study designs will be excluded. The six-stage Arksey and O'Malley scoping review methodological framework involves: (1) identifying the research question; (2) searching for relevant studies; (3) selecting studies; (4) charting the data; (5) collating, summarising and reporting the results; and (6) consulting with stakeholders to inform or validate study findings (optional). Data will be extracted and analysed using a thematic chart and descriptive content analysis. ETHICS AND DISSEMINATION: Being a secondary analysis, this research will not require ethics approval. Results will be disseminated through patient support organisations and websites and publications targeting healthcare professionals, advocates and patients
Appreciating Complexity in Adolescent Self-Harm Risk Factors: Psychological Profiling in a Longitudinal Community Sample
Past research identifies a number of risk factors for adolescent self-harm, but often fails to account for overlap between these factors. This study investigated the underlying, broader concepts by identifying different psychological profiles among adolescents. We then compared new self-harm rates over a six-month period across different psychological profiles. Australian high school students (n = 326, 68.1% female) completed a questionnaire including a broad range of psychological and socioenvironmental risk and protective factors. Non-hierarchical cluster analysis produced six groups with different psychological profiles at baseline and rate of new self-harm at follow-up. The lowest rate was 1.4% in a group that appeared psychologically healthy; the highest rate was 37.5% in a group that displayed numerous psychological difficulties. Four groups with average self-harm had varied psychological profiles including low impulsivity, anxiety, impulsivity, and poor use of positive coping strategies. Identifying multiple profiles with distinct psychological characteristics can improve detection, guide prevention, and tailor treatment
Ultrasonic NDE of Green-State Ceramics by Focused Through-Transmission
Reliable NDE techniques for green-state (unfired) ceramics are needed (1) to evaluate ceramic powder processing and compaction methods and (2) to screen out defective ceramic components prior to the costly densification process. Past work in the application of ultrasonic NDE to green-state ceramics has been hampered by the lack of an efficient yet safe means to obtain ultrasonic coupling, since conventional coupling fluids (water, gels, oils, etc.) have a detrimental effect on fragile green-state materials. In early work, direct contact pressure was used to obtain dry coupling between transducer and specimen [1]. This approach was later improved upon by placing an elastomer membrane between the transducer and specimen; this method provided efficient coupling at significantly lower contact pressures [2]. In the study presented here, an acoustically transparent plastic membrane was held against the ceramic specimen by atmospheric pressure [3]. The advantage of this technique is that it allows the use of ultrasonic immersion techniques as well as contact transducers
Event-related potentials following contraction of respiratory muscles in pre-term and full-term infants
Objective: Involuntary isolated body movements are prominent in pre-term and full-term infants. Proprioceptive and tactile afferent feedback following limb muscle contractions is associated with somatotopic EEG responses. Involuntary contractions of respiratory muscles, primarily the diaphragm – hiccups – are also frequent throughout the human perinatal period during active behavioural states. Here we tested whether diaphragm contraction provides afferent input to the developing brain, as following limb muscle contraction. /
Methods: In 13 infants on the neonatal ward (30–42 weeks corrected gestational age), we analysed EEG activity (18-electrode recordings in six subjects; 17-electrode recordings in five subjects; 16-electrode recordings in two subjects), time-locked to diaphragm contractions (n = 1316) recorded with a movement transducer affixed to the trunk. /
Results: All bouts of hiccups occurred during wakefulness or active sleep. Each diaphragm contraction evoked two initial event-related potentials with negativity predominantly across the central region, and a third event-related potential with positivity maximal across the central region. /
Conclusions: Involuntary contraction of the diaphragm can be encoded by the brain from as early as ten weeks prior to the average time of birth. /
Significance: Hiccups – frequently observed in neonates – can provide afferent input to developing sensory cortices in pre-term and full-term infants
Altered cortical processing of somatosensory input in pre-term infants who had high-grade germinal matrix-intraventricular haemorrhage
High-grade (large) germinal matrix-intraventricular haemorrhage (GM-IVH) is one of the most common causes of somatomotor neurodisability in pre-term infants. GM-IVH presents during the first postnatal week and can impinge on somatosensory circuits resulting in aberrant somatosensory cortical events straight after injury. Subsequently, somatosensory circuits undergo significant plastic changes, sometimes allowing the reinstatement of a somatosensory cortical response. However, it is not known whether this restructuring results in a full recovery of somatosensory functions. To investigate this, we compared somatosensory responses to mechanical stimulation measured with 18-channels EEG between infants who had high-grade GM-IVH (with ventricular dilatation and/or intraparenchymal lesion; n = 7 studies from 6 infants; mean corrected gestational age = 33 weeks; mean postnatal age = 56 days) and age-matched controls (n = 9 studies from 8 infants; mean corrected gestational age = 32 weeks; mean postnatal age = 36 days). We showed that infants who had high-grade GM-IVH did not recruit the same cortical source configuration following stimulation of the foot, but their response to stimulation of the hand resembled that of controls. These results show that somatosensory cortical circuits are reinstated in infants who had GM-IVH, during the several weeks after injury, but remain different from those of infants without brain injury. An important next step will be to investigate whether these evidences of neural reorganisation predict neurodevelopmental outcome
Application of a multiple attribute group decision making (MAGDM) model for selecting appropriate maintenance strategy for marine and offshore machinery operations
The process of selecting appropriate maintenance strategy to enhance the operational efficiency of marine and offshore machinery under an uncertain environment is challenging due to the many criteria that need to be considered and modelled. In addition, the design of such complex machinery on-board a vessel consists of many subjective and imprecise parameters contained in different quantitative and qualitative forms. This paper proposes a strategic multi-attribute group decision-making (MAGDM) methodology for the concise and straightforward selection of an appropriate maintenance strategy. The decision support structure allows the use of multiple decision makers to incorporate and aggregate their subjective opinions transparently. In the analysis, a Technique for Order Preference by Similarity to Ideal Situation (TOPSIS) was employed to rank the maintenance strategies with respect to costs and benefits for their subsequent implementation. The purpose of using MAGDM in this paper is to aggregate and synthesise opinions of experts, thus, guiding them in decision making when they are planning to implement a cost effective maintenance investment. © 2019 Elsevier Lt
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