Comparison of Transmitter Nonlinearity Impairments in externally modulated Sigma-Delta-over Fiber vs Analog Radio-over-Fiber links

Sigma-Delta-over-Fiber and Analog-Radio-over-Fiber are compared in terms of non-linearity impairments in a transmitter with external optical modulation. The results show that Sigma-Delta-over-Fiber is more robust towards nonlinear characteristics in the modulator

Kan etterretningsprosessen redusere usikkerhet i kriser?

Master's thesis in Risk management and societal safetyOrganisasjoner av en viss størrelse rammes med jevne mellomrom av kriser og alvorlige hendelser som krever spesiell håndtering. Slike typer hendelser krever ofte at beslutninger må tas med et begrenset kunnskapsgrunnlag, under tidspress og med store verdier på spill. Følgelig skaper dette usikkerhet i organisasjonene som omfattes av hendelsen, personene som håndterer hendelsen og lederne som må fatte beslutninger. Anerkjente forskere på feltet som Rosenthal (2001), Engen et al. (2016) og Boin (2009) beskriver hvordan krisehåndtering er synonymt med usikkerhet, men det er i liten grad fremmet konkrete forslag til hvordan denne usikkerheten kan reduseres. Å heve nivået på håndtering og beslutninger som tas i kriser kan potensielt bidra til å redde liv og store verdier. Formålet med denne studien har derfor vært å undersøke om og i hvilken grad prinsipper, metode og prosess fra fagfeltet etterretning kan benyttes av private organisasjoner under kriser for å redusere usikkerhet og ta bedre beslutninger. Studien ønsker å bidra med kunnskap til organisasjoner som vil arbeide mer strukturert og analytisk med å produsere og formidle beslutningsstøtte under kriser. For å besvare studiens problemstilling er det benyttet et eksplorativt forskningsdesign og en kvalitativ metode. Det teoretiske perspektivet har vært krisehåndtering og etterretning, og hvor de to kan komplementere hverandre. Studiet er gjennomført i form av en casestudie der semistrukturerte intervjuer, dokumentanalyse og aktiv observasjon danner det primære grunnlaget for empirien. Det ble gjennomført intervjuer med totalt seks fagspesialister innen etterretning og krisehåndtering, hvorav to fra Oslo Politidistrikt og fire fra DNB. Det ble også gjennomført intervjuer med totalt fire ledere med erfaring fra kriseledelse i de samme organisasjonene. Det ble intervjuet to ledere i hver organisasjon. I tillegg til intervjuer er det gjennomført aktiv observasjon av krisehåndtering i begge organisasjoner, samt en dokumentgjennomgang av relevante dokumenter i de to organisasjonene. Data fra alle kildene ble så analysert og sett mot hverandre. Funnene i studien bekrefter langt på vei det som beskrives i teorien om hvordan kriser skaper usikkerhet og at det å ta gode beslutninger i kriser er svært krevende. Funnene viser likevel at det er store forskjeller på hvordan de to organisasjonene håndterer kriser, og hvordan de henter inn, håndterer og analyserer informasjon for å skape et godt beslutningsgrunnlag. OPD benytter en egen spesialisert gruppe for informasjonshåndtering og analyse under alvorlige hendelser og kriser, mens DNB på sin side ikke har en slik funksjon. Erfaringer fra OPD tilsier at denne funksjonen bygget med utgangspunkt i prinsipper fra etterretningsprosessen har bidratt til bedre situasjonsforståelse og ro i organisasjonen under kriser. Selv om bruken av hypoteser står sentralt for begge organisasjonenes krisehåndtering, avslører funnene at DNBs tilnærming med bruk av en verstefallshypotese tilfører krisehåndteringen mindre verdi enn Politiets tilnærming med konsekvent bruk av flere hypoteser. Denne studien anbefaler at organisasjoner som i form av deres størrelse eller samfunnsfunksjon kan sammenlignes med DNB, ser til etterretning som metodikk og en prosess som kan løfte deres hypotesegenerering, informasjonshåndtering og analyse under kriser. Dette vil føre til bedre beslutningsstøtte for beslutningstagere under kriser og redusere usikkerhet

Distributed Massive MIMO via all-Digital Radio Over Fiber

A crucial challenge in the implementation of distributed massive multiple-input multiple-output (MIMO) architectures is to provide phase coherence while, at the same time, limit the complexity of the remote-radio heads (RRHs), which is important for cost-efficient scalability. To address this challenge, we present in this paper a phase-coherent distributed MIMO architecture, based on off-the-shelf, low-cost components. In the proposed architecture, up- and down-conversion are carried out at the central unit (CU). The RRHs are connected to the CU by means of optical fibers carrying oversampled radio-frequency (RF) 1-bit signals. In the downlink, the 1-bit signal is generated via sigma-delta modulation. At the RRH, the RF signal is recovered from the 1-bit signal through a bandpass filter and a power amplifier, and then fed to an antenna. In the uplink, the 1-bit signal is generated by a comparator whose inputs are the low-noise-amplified received RF signal and a suitably designed dither signal. The performance of the proposed architecture is evaluated with satisfactory results both via simulation and measurements from a testbed

Weight changes and mobility in the early phase after hip fracture in community-dwelling older persons

Purpose Hip fractures in older persons are associated with reduced mobility and loss of independence. Few studies address the nutritional status and mobility in the early phase after hip fracture. The objective of the present study was, therefore, to investigate weight changes and their effect on mobility during the first two months following hip fracture in community-dwelling older persons without dementia. Methods Patients (> 60 years) admitted for a first hip fracture were recruited from two tertiary referral hospitals in Bergen, Norway. The patients' weights and dietary intakes were determined in the hospital and at home after two months. Mobility was assessed based on the New Mobility Score (NMS) (scale 0–9, with values > 5 regarded as sufficient mobility). Results We included 64 patients (median age 80 years, 48 women, 16 men) with information on weight collected in the hospital. Follow-up measurements were available for 32 patients, corresponding to an attrition rate of 50%. The patients had a median weight loss of 1.8 kg (IQR = − 3.7, 0 kg). Most of them had reduced mobility at two months after the surgery [median NMS = 5 (IQR = 3–6)]. Both age and the weight change after surgery were predictors of the NMS at follow-up. Conclusion Bodyweight loss was observed in three out of four patients in the early phase after hip fracture and was associated with decreased mobility measured by the NMS. The results should be interpreted with caution as half of the patients dropped out of the study and did not participate in the follow-up visit.publishedVersio

Monitoring of Myocardial Involvement in Early Arrhythmogenic Right Ventricular Cardiomyopathy Across the Age Spectrum

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is characterized by fibrofatty replacement of primarily the right ventricular myocardium, a substrate for life-threatening ventricular arrhythmias (VAs). Repeated cardiac imaging of at-risk relatives is important for early disease detection. However, it is not known whether screening should be age-tailored. OBJECTIVES: The goal of this study was to assess the need for age-tailoring of follow-up protocols in early ARVC by evaluating myocardial disease progression in different age groups. METHODS: We divided patients with early-stage ARVC and genotype-positive relatives without overt structural disease and VA at first evaluation into 3 groups: age 50 years without overt ARVC phenotype at first evaluation. Unlike recommended by current guidelines, our study suggests that follow-up of ARVC patients and relatives should not stop at older age

The added value of abnormal regional myocardial function for risk prediction in arrhythmogenic right ventricular cardiomyopathy

Aims A risk calculator for individualized prediction of first-time sustained ventricular arrhythmia (VA) in arrhythmogenic right ventricular cardiomyopathy (ARVC) patients has recently been developed and validated (www.ARVCrisk.com). This study aimed to investigate whether regional functional abnormalities, measured by echocardiographic deformation imaging, can provide additional prognostic value. Methods From two referral centres, 150 consecutive patients with a definite ARVC diagnosis, no prior sustained VA, and an echo- and results cardiogram suitable for deformation analysis were included (aged 41 ± 17 years, 50% female). During a median follow-up of 6.3 (interquartile range 3.1–9.8) years, 37 (25%) experienced a first-time sustained VA. All tested left and right ventricular (LV and RV) deformation parameters were univariate predictors for first-time VA. While LV function did not add predictive value in multivariate analysis, two RV deformation parameters did; RV free wall longitudinal strain and regional RV deformation patterns remained independent predictors after adjusting for the calculator-predicted risk [hazard ratio 1.07 (95% CI 1.02–1.11); P = 0.004 and 4.45 (95% CI 1.07–18.57); P = 0.040, respectively] and improved its discriminative value (from C-statistic 0.78 to 0.82 in both; Akaike information criterion change > 2). Importantly, all patients who experienced VA within 5 years from the echocardiographic assessment had abnormal regional RV deformation patterns at baseline. Conclusions This study showed that regional functional abnormalities measured by echocardiographic deformation imaging can further refine personalized arrhythmic risk prediction when added to the ARVC risk calculator. The excellent negative predictive value of normal RV deformation could support clinicians considering the timing of implantable cardioverter defibrillator implantation in patients with intermediate arrhythmic risk

Comparison of veterinary drugs and veterinary homeopathy: part 1

For many years after its invention around 1796, homeopathy was widely used in people and later in animals. Over the intervening period (1796-2016) pharmacology emerged as a science from Materia Medica (medicinal materials) to become the mainstay of veterinary therapeutics. There remains today a much smaller, but significant, use of homeopathy by veterinary surgeons. Homeopathic products are sometimes administered when conventional drug therapies have not succeeded, but are also used as alternatives to scientifically based therapies and licensed products. The principles underlying the veterinary use of drug-based and homeopathic products are polar opposites; this provides the basis for comparison between them. This two-part review compares and contrasts the two treatment forms in respect of history, constituents, methods of preparation, known or postulated mechanisms underlying responses, the legal basis for use and scientific credibility in the 21st century. Part 1 begins with a consideration of why therapeutic products actually work or appear to do so

High sensitivity (1)H-NMR spectroscopy of homeopathic remedies made in water

BACKGROUND: The efficacy of homeopathy is controversial. Homeopathic remedies are made via iterated shaking and dilution, in ethanol or in water, from a starting substance. Remedies of potency 12 C or higher are ultra-dilute (UD), i.e. contain zero molecules of the starting material. Various hypotheses have been advanced to explain how a UD remedy might be different from unprepared solvent. One such hypothesis posits that a remedy contains stable clusters, i.e. localized regions where one or more hydrogen bonds remain fixed on a long time scale. High sensitivity proton nuclear magnetic resonance spectroscopy has not previously been used to look for evidence of differences between UD remedies and controls. METHODS: Homeopathic remedies made in water were studied via high sensitivity proton nuclear magnetic resonance spectroscopy. A total of 57 remedy samples representing six starting materials and spanning a variety of potencies from 6 C to 10 M were tested along with 46 controls. RESULTS: By presaturating on the water peak, signals could be reliably detected that represented H-containing species at concentrations as low as 5 μM. There were 35 positions where a discrete signal was seen in one or more of the 103 spectra, which should theoretically have been absent from the spectrum of pure water. Of these 35, fifteen were identified as machine-generated artifacts, eight were identified as trace levels of organic contaminants, and twelve were unexplained. Of the unexplained signals, six were seen in just one spectrum each. None of the artifacts or unexplained signals occurred more frequently in remedies than in controls, using a p < .05 cutoff. Some commercially prepared samples were found to contain traces of one or more of these small organic molecules: ethanol, acetate, formate, methanol, and acetone. CONCLUSION: No discrete signals suggesting a difference between remedies and controls were seen, via high sensitivity (1)H-NMR spectroscopy. The results failed to support a hypothesis that remedies made in water contain long-lived non-dynamic alterations of the H-bonding pattern of the solvent