60 research outputs found
Degree Landscapes in Scale-Free Networks
We generalize the degree-organizational view of real-world networks with
broad degree-distributions in a landscape analogue with mountains (high-degree
nodes) and valleys (low-degree nodes). For example, correlated degrees between
adjacent nodes corresponds to smooth landscapes (social networks), hierarchical
networks to one-mountain landscapes (the Internet), and degree-disassortative
networks without hierarchical features to rough landscapes with several
mountains. We also generate ridge landscapes to model networks organized under
constraints imposed by the space the networks are embedded in, associated to
spatial or, in molecular networks, to functional localization. To quantify the
topology, we here measure the widths of the mountains and the separation
between different mountains.Comment: 4 pages, 5 figure
Retrospective analysis of health variables in a Reykjavík nursing home 1983-2002 (corrected)
Neðst á síðunni er að nálgast greinina í heild sinni með því að smella á hlekkinn View/OpenBACKGROUND: A municipal nursing home with 68 beds in Reykjavík, opened in mid-year 1982. OBJECTIVES: To analyse changes in demographic, health and outcome variables over 20 years. DESIGN: Retrospective analyses of data from medical records of all diseased persons with cross-sectional comparison of five four-year intervals. SETTING: Droplaugarstadir Nursing Home in Reykjavík. The nursing home is supervised by fully qualified nurses and provides maintenance rehabilitation. Medical services are delivered from a specialist geriatric hospital department. RESIDENTS: All residents who died 1983 to 2002 [corrected]. MEASUREMENTS: Demographic data, type of dwelling before admission, Nursing Home Pre-admission Assessment Score (NAPA), mobility- and cognitive score, drug usage and a list of medical diagnoses. All recorded health events during stay, falls and fractures, medical and specialist consultations. Advance directives, as recorded and end-of-life treatment, place of death, clinical diagnosis of cause of death and length of stay. RESULTS: The total number of medical records read numbered 385, including 279 females and 106 males. The mean age on admission was 85 (+/- 7) years. During the first 4 years the majority of residents came from their own private homes or residential settings but in the last four years, 60% were admitted directly from a hospital ward. The mortality rate was 17% per year in the first period and the majority died in a hospital. This ratio took a sharp turn as the mortality rate increased to 40%, and in the last period only 2 of 97 deaths took place in a hospital. Admission mobility- and cognitive scores showed increased disability with time. The most common diagnosis on admission was dementia (56%), ischemic heart disease (46%), fractures (35%) and strokes (27%). Parkinsonism and maturity onset diabetes had a low prevalence rate of 6%. A mean NHPA of 57 (+/- 17) points confirmed a high dependency selection. The mean number of drugs per patient was 5.3 (+/- 3), including 1.1 (+/- 1) for psychoactive drugs and sedatives. The most common health events during residents? stay were urinary and respiratory infections, heart failure, cardiac- and cerebral events and pulmonary disorders. Hip fractures occurred in 45 residents (12%) and other types of fractures in 47 during their stay in the nursing home. The number of medical visits and specialist referrals increased with time. Palliative care was the most common form of treatment at end of life. Pneumonia was most commonly recorded cause of death in medical notes. The yearly mortality rate was 29% and the mean length of stay was 3 (+/- 2,9) years for the whole period. LIMITATIONS: Retrospective analyses have many inherent drawbacks and the information in medical records tend to be scanty. Analyses of disabilities, as described in the medical record, can only be descriptive and health events are likely to be underreported. Statistical methods have a less meaningful role for interpretation as only diseased persons were included and survivors excluded. However, the length of time, uniform medical care and turnover rate of residents generate useful information on the patterns of the nursing home service during a time of considerable change. CONCLUSIONS: This retrospective analysis indicates increasing frailty in nursing home patients admitted over a period of 20 years. With time the residents are more often admitted directly from a hospital rather than from an individual dwelling. Most deaths took place in the nursing home and were preceded with informal or formal palliative care directives, which was a significant change over time. The data indicates growing efficiency in the nursing home selection processes due to the NHPA and improvements in holistic geriatric care. This development is in keeping with the Icelandic health care policy for elderly people to stay longer in their own home with access to a nursing home placement when needed.Tilgangur: Á síðustu árum hafa verið gerðar miklar skipulagsbreytingar á öldrunarþjónustu á Íslandi. Þessi afturvirka rannsókn beinist að því að meta áhrif þessara breytinga á lýðfræði og heilsufarsbreytur heimilismanna á Droplaugarstöðum, hjúkrunarheimili fyrir aldraða í Reykjavík. Efniviður og aðferðir: Lesnar voru sjúkraskrár allra vistmanna sem látist höfðu á árunum 1983-2002. Þessum 20 árum var skipt niður í fimm fjögurra ára tímabil. Skráð var aldur, kyn, hvaðan fólkið kom og stig á vistunarmati aldraðra. Metin var hreyfifærni og vitræn geta með fjögurra stiga kvarða, lyfjanotkun og sjúkdómsgreiningar við komu. Skráðar voru algengustu heilsufarsbreytur á dvalartíma, byltur og brot, vitjanir lækna og samráðskvaðningar. Stigun meðferðar, dánarstaður og dánarmein, meðalaldur og meðaldvalartími voru skráð. Niðurstöður: Rannsóknin náði til 385 heimilismanna, 279 kvenna og 106 karla. Meðalaldur við komu var 85 (± 7) ár fyrir bæði kynin og breyttist ekki marktækt á þessum 20 árum. Fyrstu fjögur árin komu flestir heimilismanna úr heimahúsum eða úr þjónustuíbúðum fyrir aldraða en á síðasta tímabilinu komu um 60% beint frá sjúkrahúsum. Hreyfihömlun og heilabilun voru talin algengustu vandamál heimilismanna við komu og algengi þeirra fór vaxandi með árunum. Algengustu sjúkdómsgreiningar við komu voru heilabilun (56%), kransæðasjúkdómar (46%), beinbrot (35%) og heilaáföll (27%). Parkinsonsjúkdómur og fullorðinssykursýki komu mun sjaldnar fyrir, eða í um 6% tilfella. Meðalfjöldi stiga á vistunarmati aldraðra (eftir 1991) var 57 stig (± 17), fjöldi lyfja á mann við komu voru 5,3 (± 3) og inntaka geð- og róandi lyfja 1,1 (±1). Algengustu heilsufarsáföll á dvalartíma voru sýkingar í þvagfærum og lungum, kviðverkir, hjartabilun, hjarta- og heilaáföll og lungnateppa. Mjaðmarbrot voru 45 (12%) og önnur beinbrot 47. Skráðar vitjanir lækna fóru vaxandi með árunum. Dánartíðni fór vaxandi fyrstu árin en var að meðaltali 29% á ári yfir allt tímabilið. Líknarmeðferð var algengasta meðferðarstig heimilismanna undir lokin. Fyrstu fjögur árin áttu 64% andláta heimilismanna sér stað á sjúkrahúsi en aðeins 2% síðustu árin. Algengasta skráða dánarmeinið var lungnabólga. Meðaldvalartími mældist lengstur á árunum 1991-94 en styttist og var 2,6 ár á síðasta tímabilinu. Ályktun: Þessi afturvirka rannsókn sýnir vaxandi hrumleika aldraðs fólks sem vistaðist á Droplaugarstöðum hjúkrunarheimili undanfarin 20 ár. Með árunum komu heimilismenn oftar beint frá legudeild á sjúkrahúsi. Á tímabilinu breyttist dánarstaður heimilismanna frá sjúkrahúsi yfir til heimilisins sjálfs í takt við breytt viðhorf til dánarferlis og samfara umræðu um útgefnar leiðbeiningar um lífslokameðferð. Niðurstöður benda til aukinnar skilvirkni í vistunarmati og heildrænni umönnunar á hjúkrunarheimilinu. Þessi þróun samræmist þeirri hugmyndafræði heilbrigðisyfirvalda að aldraðir búi sem lengst á eigin heimilum en hafi aðgang að hjúkrunarrýmum þegar allt um þrýtur heima
Modelling Eco-Driving Support System for Microscopic Traffic Simulation
Microscopic traffic simulation is an ideal tool for investigating the network level impacts of eco-driving in different networks and traffic conditions, under varying penetration rates and driver compliance rates. The reliability of the traffic simulation results however rely on the accurate representation of the simulation of the driver support system and the response of the driver to the eco-driving advice, as well as on a realistic modelling and calibration of the driver’s behaviour. The state-of-the-art microscopic traffic simulation models however exclude detailed modelling of the driver response to eco-driver support systems. This paper fills in this research gap by presenting a framework for extending state-of-the-art traffic simulation models with sub models for drivers’ compliance to advice from an advisory eco-driving support systems. The developed simulation framework includes among others a model of driver’s compliance with the advice given by the system, a gear shifting model and a simplified model for estimating vehicles maximum possible acceleration. Data from field operational tests with a full advisory eco-driving system developed within the ecoDriver project was used to calibrate the developed compliance models. A set of verification simulations used to illustrate the effect of the combination of the ecoDriver system and drivers’ compliance to the advices are also presented
Statistical Laws Governing Fluctuations in Word Use from Word Birth to Word Death
We analyze the dynamic properties of 10^7 words recorded in English, Spanish
and Hebrew over the period 1800--2008 in order to gain insight into the
coevolution of language and culture. We report language independent patterns
useful as benchmarks for theoretical models of language evolution. A
significantly decreasing (increasing) trend in the birth (death) rate of words
indicates a recent shift in the selection laws governing word use. For new
words, we observe a peak in the growth-rate fluctuations around 40 years after
introduction, consistent with the typical entry time into standard dictionaries
and the human generational timescale. Pronounced changes in the dynamics of
language during periods of war shows that word correlations, occurring across
time and between words, are largely influenced by coevolutionary social,
technological, and political factors. We quantify cultural memory by analyzing
the long-term correlations in the use of individual words using detrended
fluctuation analysis.Comment: Version 1: 31 pages, 17 figures, 3 tables. Version 2 is streamlined,
eliminates substantial material and incorporates referee comments: 19 pages,
14 figures, 3 table
Size-Dependency of Income Distributions and Its Implications
This paper highlights the size-dependency of income distributions, i.e. the
income distribution curves versus the population of a country systematically.
By using the generalized Lotka-Volterra model to fit the empirical income data
in the United States during 1996-2007, we found an important parameter
can scale with a power of the size (population) of U.S. in
that year. We pointed out that the size-dependency of the income distributions,
which is a very important property but seldom addressed by previous studies,
has two non-trivial implications: (1) the allometric growth pattern, i.e. the
power law relationship between population and GDP in different years, which can
be mathematically derived from the size-dependent income distributions and also
supported by the empirical data; (2) the connection with the anomalous scaling
for the probability density function in critical phenomena since the re-scaled
form of the income distributions has the exactly same mathematical expression
for the limit distribution of the sum of many correlated random variables
asymptotically.Comment: 4 figures, 4 page
Drug sensitivity testing on patient-derived sarcoma cells predicts patient response to treatment and identifies c-Sarc inhibitors as active drugs for translocation sarcomas
BACKGROUND: Heterogeneity and low incidence comprise the biggest challenge in sarcoma diagnosis and treatment. Chemotherapy, although efficient for some sarcoma subtypes, generally results in poor clinical responses and is mostly recommended for advanced disease. Specific genomic aberrations have been identified in some sarcoma subtypes but few of them can be targeted with approved drugs. METHODS: We cultured and characterised patient-derived sarcoma cells and evaluated their sensitivity to 525 anti-cancer agents including both approved and non-approved drugs. In total, 14 sarcomas and 5 healthy mesenchymal primary cell cultures were studied. The sarcoma biopsies and derived cells were characterised by gene panel sequencing, cancer driver gene expression and by detecting specific fusion oncoproteins in situ in sarcomas with translocations. RESULTS: Soft tissue sarcoma cultures were established from patient biopsies with a success rate of 58%. The genomic profile and drug sensitivity testing on these samples helped to identify targeted inhibitors active on sarcomas. The cSrc inhibitor Dasatinib was identified as an active drug in sarcomas carrying chromosomal translocations. The drug sensitivity of the patient sarcoma cells ex vivo correlated with the response to the former treatment of the patient. CONCLUSIONS: Our results show that patient-derived sarcoma cells cultured in vitro are relevant and practical models for genotypic and phenotypic screens aiming to identify efficient drugs to treat sarcoma patients with poor treatment options.Peer reviewe
Study protocol: a mixed methods feasibility study for a loaded self-managed exercise programme for patellofemoral pain
Background: Patellofemoral pain (PFP) is one of the most common forms of knee pain in adults under the age of 40, with a prevalence of 23% in the general population. The long-term prognosis is poor, with only one third of people pain-free 1 year after diagnosis. The biomedical model of pain in relation to persistent PFP has recently been called into question. It has been suggested that interventions for chronic musculoskeletal conditions should consider alternative mechanisms of action, beyond muscles and joints. Modern treatment therapies should consider desensitising strategies, with exercises that target movements and activities patients find fearful and painful. High-quality research on exercise prescription in relation to pain mechanisms, not directed at specific tissue pathology, and dose response clearly warrants further investigation. Our primary aim is to establish the feasibility and acceptability of conducting a definitive RCT which will evaluate the clinical and cost-effectiveness of a loaded self-managed exercise programme for people with patellofemoral pain.
Method: This is a single-centred, multiphase, sequential, mixed-methods trial that will evaluate the feasibility of running a definitive large-scale randomised controlled trial of a loaded self-managed exercise programme versus usual physiotherapy. Initially, 8–10 participants with a minimum 3-month history of PFP will be recruited from an NHS physiotherapy waiting list and interviewed. Participants will be invited to discuss perceived barriers and facilitators to exercise engagement, and the meaning and impact of PFP. Then, 60 participants will be recruited in the same manner for the main phase of the feasibility trial. A web-based service will randomise patients to a loaded self-managed exercise programme or usual physiotherapy. The loaded self-managed exercise programme is aimed at addressing lower limb knee and hip weakness and is positioned within a framework of reducing fear/avoidance with an emphasis on self-management. Baseline assessment will include demographic data, average pain within the last week (VAS), fear avoidance behaviours, catastrophising, self-efficacy, sport and leisure activity participation, and general quality of life. Follow-up will be 3 and 6 months. The analysis will focus on descriptive statistics and confidence intervals. The qualitative components will follow a thematic analysis approach.
Discussion: This study will evaluate the feasibility of running a definitive large-scale trial on patients with patellofemoral pain, within the NHS in the UK. We will identify strengths and weaknesses of the proposed protocol and the utility and characteristics of the outcome measures. The results from this study will inform the design of a multicentre trial
Perceived quality of physiotherapist-led orthopaedic triage compared with standard practice in primary care: a randomised controlled trial
Implementation outcome instruments for use in physical healthcare settings: a systematic review
BACKGROUND: Implementation research aims to facilitate the timely and routine implementation and sustainment of evidence-based interventions and services. A glaring gap in this endeavour is the capability of researchers, healthcare practitioners and managers to quantitatively evaluate implementation efforts using psychometrically sound instruments. To encourage and support the use of precise and accurate implementation outcome measures, this systematic review aimed to identify and appraise studies that assess the measurement properties of quantitative implementation outcome instruments used in physical healthcare settings. METHOD: The following data sources were searched from inception to March 2019, with no language restrictions: MEDLINE, EMBASE, PsycINFO, HMIC, CINAHL and the Cochrane library. Studies that evaluated the measurement properties of implementation outcome instruments in physical healthcare settings were eligible for inclusion. Proctor et al.'s taxonomy of implementation outcomes was used to guide the inclusion of implementation outcomes: acceptability, appropriateness, feasibility, adoption, penetration, implementation cost and sustainability. Methodological quality of the included studies was assessed using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist. Psychometric quality of the included instruments was assessed using the Contemporary Psychometrics checklist (ConPsy). Usability was determined by number of items per instrument. RESULTS: Fifty-eight publications reporting on the measurement properties of 55 implementation outcome instruments (65 scales) were identified. The majority of instruments assessed acceptability (n = 33), followed by appropriateness (n = 7), adoption (n = 4), feasibility (n = 4), penetration (n = 4) and sustainability (n = 3) of evidence-based practice. The methodological quality of individual scales was low, with few studies rated as 'excellent' for reliability (6/62) and validity (7/63), and both studies that assessed responsiveness rated as 'poor' (2/2). The psychometric quality of the scales was also low, with 12/65 scales scoring 7 or more out of 22, indicating greater psychometric strength. Six scales (6/65) rated as 'excellent' for usability. CONCLUSION: Investigators assessing implementation outcomes quantitatively should select instruments based on their methodological and psychometric quality to promote consistent and comparable implementation evaluations. Rather than developing ad hoc instruments, we encourage further psychometric testing of instruments with promising methodological and psychometric evidence. SYSTEMATIC REVIEW REGISTRATION: PROSPERO 2017 CRD42017065348
- …