376 research outputs found
Kasvupaikkojen puuntuotoskyvyn ja puuston kasvun alueellinen vaihtelu Pohjanmaan rannikolta sisämaahan.
TutkimusartikkeliTutkimuksessa tarkasteltiin kangasmaiden valtapituusboniteetin ja puuston vuotuisen tilavuuskasvun länsi–itä-suuntaista vaihtelua Suomessa. Aineisto oli peräisin valtakunnan metsien inventoinneista vuosilta 1971–75, 1977–83 ja 1987–92. Pituusboniteettia käytettiin kangasmaiden puuntuotoskyvyn mittarina. Mitattuja tilavuuskasvuja verrattiin kasvumalleilla ennustettuihin arvoihin mallien yleisen paikkansapitävyyden toteamiseksi ja poikkeavien kasvualueiden erottamiseksi. §§ Kangasmaiden valtapituusboniteetin alueelliset erot olivat suuret. Erityisen selvä raja oli Pohjanmaan ja muun Etelä-Suomen välillä. Kasvupaikan luokittelutunnukset, kuten kasvupaikkatyyppi, kivisyys ja soistuneisuus selittivät valtapituusboniteettia varsin hyvin. Lisäksi lämpösumma ja korkeus merenpinnasta nostivat selitysastetta huomattavasti. Korkeusasemalla voitiin selittää länsi–itä-suunnassa havaittua vaihtelua. Keskimääräinen valtapituusboniteetti ei varsinaisesti laske Pohjanmaan rannikolle mentäessä. Tämä johtuu lämpösumman kohoamisesta ja viljavien kasvupaikkojen yleistymisestä, jotka kumoavat rannikon läheisyyden puuntuotoskykyä alentavat vaikutukset. §§ Kasvuennusteiden taso mitattuun kasvuun verrattuna vaihteli eri mallien mukaan. Kaikista malleista löytyi kuitenkin sama piirre: jos mallit kalibroidaan Etelä-Suomen sisäosien metsiköiden mukaan, saadaan Pohjanmaan metsälautakunnan männiköille 17–22 %:n ja kuusikoille 23–29 %:n yliarvioita. Kasvun taso vaihteli metsälautakuntien sisällä ja männiköiden ja kuusikoiden huonokasvuisimpien alueiden ulottuvuudet poikkesivat toisistaan. Syyt alhaisempaan kasvun tasoon voivat olla tiivis maaperä männyllä sekä viljava, mutta kivinen maaperä kuusella. Yhteydet ilmastoon on syytä tutkia tarkemmin. §§ Tilavuuskasvun tasokertoimia esitettiin eri malleille metsälautakunnittaisina arvoina, kahdella teemakartalla sekä graafisesti korkeuden funktiona. Näitä kertoimia voidaan käyttää kasvuennusteiden korjaamiseksi. Pohjanmaan alaville seuduille tulisi kuitenkin laatia uudet kasvumallit
Doppler Spread in Reverberation Chamber Predicted From Measurements During Step-Wise Stationary Stirring
We propose a simple method to accurately predict Doppler spread in a reverberation chamber (RC) by using frequency domain S-parameters measured with a vector network analyzer (VNA) at many fixed stirrer positions (step-wise stationary mode). Thus, the measurements are done under repeatable stationary conditions, so no Doppler shift is present during the actual measurements. Still, this letter shows that the measured S-parameters in step-wise stationary mode can be used to determine Doppler spread appearing during continuous movement of the stirrers. This can be done by computation for any stirrer speed by assuming that the fixed stirrer position steps are the time steps of a continuous movement of the stirrers, and by adding a virtual stirrer speed between the positions corresponding to the desired continuous movement of the stirrers. The computed Doppler spreads are validated over a large frequency band by measuring the time-varying S-parameters for a given stirrer speed
Hyvin suunniteltu on puoliksi tehty? Pohjoismaiden puolitiehen jääneet mielenterveyspalvelujen uudistukset
Convulsive Seizures as Presenting Symptom of Metronidazole-Induced Encephalopathy:A Case Report
Introduction: Encephalopathy and convulsive seizures are rare manifestations of metronidazole toxicity. The incidence is unknown, but the condition has most frequently been reported in patients in their fifth to sixth decades. Usually, this condition is regarded as reversible, but permanent deficits and even death have been reported. Case Report: A 66-year-old female patient undergoing metronidazole treatment for pleural empyema was admitted to our institution after her second episode of seizure. Over the course of 1 week after admittance, the patient developed several convulsive seizures along with progressive cerebellar dysfunction and cognitive impairment. MRI revealed bilateral, symmetrical hyperintense signal changes in the pons and dentate nuclei. EEG, ECG, lumbar puncture, and blood samples were normal. The patient improved already 2–3 days after discontinuation of metronidazole and was discharged fully recovered after 17 days. Follow-up clinical assessment and MRI were unremarkable. Conclusion: Metronidazole-induced encephalopathy is a rare condition, and due to a general lack of awareness the diagnosis is often delayed. This condition should be considered in metronidazole-treated patients presenting with unprovoked seizures, myoclonus, cerebellar signs, and encephalopathy. Characteristic MRI lesions may support the clinical suspicion
Robust Connectivity With Multiple Directional Antennas for Vehicular Communications
For critical vehicular communication services, such as traffic safety and traffic efficiency, it is advisable to design systems with robustness as the main criteria, possibly at the price of reduced peak performance and efficiency. We describe a simple, low-cost method for combining the output of L directional (i.e., not omnidirectional) antennas to the input of a single-port receiver with the aim to guarantee robustness, i.e., to minimize the probability that K consecutive packets arriving from the worst-case angle-of-arrival are decoded incorrectly. To minimize complexity, the combining network does not estimate or use channel state information. The combining network consists of L-1 analog phase shifters whose phases are affine functions of time. For a general LĹ‚e K and when the packet error probability decays exponentially with the received SNR, the optimum slopes of the affine functions can be computed by solving an optimization problem that depends on the antenna far-field functions. We provide analytical solutions for the special case of L=2 and 3 antennas, which turns out to be independent of the antenna far-field functions and placement on a vehicle. In an experimental setup consisting of two monopole antennas mounted on the roof of a Volvo XC90, the proposed combining method is shown to give significant performance gains, compared to using any one of the antennas
Virtual Drive Testing Over-The-Air for Vehicular Communications
Multiple-input multiple-output (MIMO) over-the-air (OTA) testing is a standardized procedure to evaluate the performance of MIMO-capable devices such as mobile phones and laptops. With the growth of the vehicle-to-everything (V2X) service, the need for vehicular communication testing is expected to increase significantly. The so-called multi-probe anechoic chamber (MPAC) setup is standardized for MIMO OTA testing. Typically, a test zone of 0.85 wavelength in diameter can be achieved with an 8-probe MPAC setup, which can encompass device-under-test (DUT) of small form factors. However, a test zone of this size may not be large enough to encompass DUTs such as cars. In this article, the sufficient number of OTA probes for the MPAC setup for car testing is investigated with respect to the emulation accuracy. Our investigation shows that the effective antenna distance of the DUT is more critical than its physical dimensions to determine the required number of OTA probes. In addition, throughput measurements are performed under the standard SCME UMa and UMi channel models with the 8-probe MPAC setup and the wireless cable setup, i.e. another standardized testing setup. The results show reasonably good agreement between the two setups for MIMO OTA testing with cars under the standard channel models
Health-related quality of life across all stages of autosomal dominant polycystic kidney disease
Background. A limited number of studies have assessed health related quality of life (HRQoL) in autosomal dominant polycystic kidney disease (ADPKD). Results to date have been conflicting and studies have generally focused on patients with later stages of the disease. This study aimed to assess HRQoL in ADPKD across all stages of the disease, from patients with early chronic kidney disease (CKD) to patients with end-stage renal disease. Methods. A study involving cross-sectional patient-reported outcomes and retrospective clinical data was undertaken April December 2014 in Denmark, Finland, Norway and Sweden. Patients were enrolled into four mutually exclusive stages of the disease: CKD stages 1-3; CKD stages 4-5; transplant recipients; and dialysis patients. Results. Overall HRQoL was generally highest in patients with CKD stages 1-3, followed by transplant recipients, patients with CKD stages 4-5 and patients on dialysis. Progressive disease predominately had an impact on physical health, whereas mental health showed less variation between stages of the disease. A substantial loss in quality of life was observed as patients progressed to CKD stages 4-5. Conclusions. Later stages of ADPKD are associated with reduced physical health. The value of early treatment interventions that can delay progression of the disease should be considered.Peer reviewe
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