Development of the Finnish Height Conversion Surface FIN2005N00

With the new Finnish height system, N2000, came the need for a new national height conversion surface, with which ellipsoidal EUREF-FIN heights, as measured with GPS in Finland, can be transformed into N2000 heights, as measured by levelling. The conversion surface was calculated by fitting a correction surface to the Nordic NKG2004-geoid model using 50 EUVN-DA-points, for which both levelled and GPS-determined heights were available. Polynomial surfaces with varying degrees were fitted to the data, as well as least-squares collocation surfaces using varying parameter values The surfaces were analysed using cross-validation. Collocation surfaces performed better than the polynomial surfaces, resulting in smoother surfaces and better fit statistics. Best results were obtained using a correlation length of 200 km and 2 cm noise level in the least-squares collocation. The resulting surface was added to the NKG2004 geoid model to form the new height conversion surface for Finland: FIN2005N00. The standard deviation of the cross-validation residuals indicates that with the new surface heights can be converted with an accuracy better than 2 cm

Thromboembolic and neurologic sequelae of discontinuation of an antihyperlipidemic drug during ongoing warfarin therapy

Warfarin and antihyperlipidemics are commonly co-prescribed. Some antihyperlipidemics may inhibit warfarin deactivation via the hepatic cytochrome P450 system. Therefore, antihyperlipidemic discontinuation has been hypothesized to result in underanticoagulation, as warfarin metabolism is no longer inhibited. We quantified the risk of venous thromboembolism (VTE) and ischemic stroke (IS) due to statin and fibrate discontinuation in warfarin users, in which warfarin was initially dose-titrated during ongoing antihyperlipidemic therapy. Using 1999-2011 United States Medicaid claims among 69 million beneficiaries, we conducted a set of bidirectional self-controlled case series studies-one for each antihyperlipidemic. Outcomes were hospital admissions for VTE/IS. The risk segment was a maximum of 90 days immediately following antihyperlipidemic discontinuation, the exposure of interest. Time-varying confounders were included in conditional Poisson models. We identified 629 study eligible-persons with at least one outcome. Adjusted incidence rate ratios (IRRs) for all antihyperlipidemics studied were consistent with the null, and ranged from 0.21 (0.02, 2.82) for rosuvastatin to 2.16 (0.06, 75.0) for gemfibrozil. Despite using an underlying dataset of millions of persons, we had little precision in estimating IRRs for VTE/IS among warfarin-treated persons discontinuing individual antihyperlipidemics. Further research should investigate whether discontinuation of gemfibrozil in warfarin users results in serious underanticoagulation

Suomen geoidimallit ja niiden käyttäminen korkeuden muunnoksissa

Geoidimallien käyttö on viime vuosina lisääntynyt huomattavasti. Kansallisen geoidimallin, tai oikeammin muunnospinnan avulla voidaan GPS:llä mitatut ellipsoidiset korkeudet muuntaa vaaituiksi korkeuksiksi kansallisessa korkeusjärjestelmässä. Tiedotteessa esitellään Suomen alueen geoidimallit ja niiden käyttö. Suomen alueella merkittävimmät globaaliset geoidimallit ovat OSU91A, EGM96 ja GGM02. Alueelliset geoidimallit ovat eurooppalainen EGG97-malli ja Pohjoismaisen geodeettisen komission geoidityöryhmän laskemat mallit NKG89, NKG96 ja NKG2004. Suomen alueen vanhat geoidimallit ovat astrogeodeettinen Bomford 1970 ja painovoimahavaintoihin perustuva FIN95-malli. Nykyisin Suomessa käytössä olevat geoidimallit ovat FIN2000 ja FIN2005N00. FIN2000-malli on muunnospinta jolla EUREF-FIN-koordinaatistossa GPS:llä mitatut ellipsoidiset korkeudet voidaan muuntaa N60-korkeusjärjestelmän mukaisiksi vaaituskorkeuksiksi. FIN2000-malli on laskettu sovittamalla korjauspinta NKG96-geoidimalliin 156 GPS/vaaituspisteiden avulla. Mallin tarkkuus on 3 cm ja suurimmat muunnosvirheet voivat olla 9 cm. FIN2005N00 on uusin valtakunnallinen malli. Tällä muunnospinnalla EUREF-FINkoordinaatistossa GPS:llä mitatut ellipsoidiset korkeudet voidaan muuntaa N2000-korkeusjärjestelmän mukaisiksi vaaituskorkeuksiksi. Mallin pohjana on NKG2004-geoidimalli, johon on laskettu korjauspinta 50 EUVN-DA (European Vertical Reference Network – Densification Act) GPS/vaaituspisteiden avulla. Mallin tarkkuus on 2 cm ja suurimmat muunnosvirheet voivat olla 6 cm. FIN2000- ja FIN2005N00-mallit ovat saatavissa hila-muotoisina EUREF-FIN-koordinaateissa. Hilasta voidaan laskea halutulle pisteelle geoidikorkeus bi-lineaarisella interpolointimenetelmällä. Alueellisilla GPS/vaaituspisteillä voidaan määrittää kansallisesta mallista paikallinen muunnospinta maantieteellisissä EUREF-FIN koordinaateissa tai haluttaessa tasokoordinaateissa.Over the years the use of geoid models has increased considerably. Using a national geoid model, or better said a transformation surface, ellipsoidal heights, as measured by GPS, can be transformed into heights in the national height system, as measured by levelling. This publication gives an overview of the geoid models available for Finland and their use. Global geoid models of importance for Finland are OSU91, EGM96, and GGM02. Important regional models are the European model EGG97 and the Nordic models NKG98, NKG96, and NKG2004 calculated by the working group on geoid determination of the Nordic Geodetic Commission. Old Finnish models are the astro-geodetic geoid model Bomford 1970 and the FIN95 model, which is based on gravity observations. At present, two geoid models are used in Finland: FIN2000 and FIN2005N00. The FIN2000 model is a transformation surface with which ellipsoidal coordinates, measured with GPS in the EUREF-FIN reference frame, can be transformed into leveled coordinates in the N60 height system. The FIN200 model was calculated by fitting a correction surface to the NKG96 model using data of 156 GPS/levelling points. The accuracy of the model is 3 cm and the biggest transformation errors can be 9 cm. The newest model for Finland is FIN2005N00. With this transformation surface ellipsoidal heights, measured with GPS in the EUREF-FIN reference frame, can be transformed into leveled heihts in the N2000 height system. The model is based on the NKG2004 geoid model to which a correction surface was fitted using the data of the 50 EUVN-DA (European Vertical Reference Network – Densification Act) GPS/levelling points. The accuracy of the model is 2 cm and largest transformation errors can be 6 cm. The FIN2000 and FIN2005N00 models are available in grid-formats in EUREF-FIN coordinates. Geoid heights for points can be calculated from the grids using bi-linear interpolation. When local GPS/levelling data is available a local transformation surface can be determined from a national model. This can be done either in EUREF-FIN coordinates or optionally in projected coordinates

Telling the truth from lie in individual subjects with fast event-related fMRI

Deception is a clinically important behavior with poorly understood neurobiological correlates. Published functional MRI (fMRI) data on the brain activity during deception indicates that, on a multisubject group level, lie is distinguished from truth by increased prefrontal and parietal activity. These findings are theoretically important; however, their applied value will be determined by the accuracy of the discrimination between single deceptive and truthful responses in individual subjects. This study presents the first quantitative estimate of the accuracy of fMRI in conjunction with a formal forced-choice paradigm in detecting deception in individual subjects. We used a paradigm balancing the salience of the target cues to elicit deceptive and truthful responses and determined the accuracy of this model in the classification of single lie and truth events. The relative salience of the task cues affected the net activation associated with lie in the superior medial and inferolateral prefrontal cortices. Lie was discriminated from truth on a single-event level with an accuracy of 78%, while the predictive ability expressed as the area under the curve (AUC) of the receiver operator characteristic curve (ROC) was 85%. Our findings confirm that fMRI, in conjunction with a carefully controlled query procedure, could be used to detect deception in individual subjects. Salience of the task cues is a potential confounding factor in the fMRI pattern attributed to deception in forced choice deception paradigms

Влияние ширины реза на осевую проекцию силы резания

В статье обосновывается влияние ширины реза на проекцию составляющей силы резания на ось вращения геохода. Рассмотрена актуальность исследования. Для постановки цели и задач исследования определена проекция составляющей силы резания на ось вращения геохода. На основании проведенного исследования построена зависимость осевой проекции силы резанию ножевого исполнительного органа геохода (Р0.СВ) от расстояния х на которое отдалена точка от оси вращения

Forty-three years of absolute gravity observations of the Fennoscandian postglacial rebound in Finland

Postglacial rebound in Fennoscandia causes striking trends in gravity measurements of the area. We present time series of absolute gravity data collected between 1976 and 2019 on 12 stations in Finland with different types of instruments. First, we determine the trends at each station and analyse the effect of the instrument types. We estimate, for example, an offset of 6.8 μgal for the JILAg-5 instrument with respect to the FG5-type instruments. Applying the offsets in the trend analysis strengthens the trends being in good agreement with the NKG2016LU_gdot model of gravity change. Trends of seven stations were found robust and were used to analyse the stabilization of the trends in time and to determine the relationship between gravity change rates and land uplift rates as measured with global navigation satellite systems (GNSS) as well as from the NKG2016LU_abs land uplift model. Trends calculated from combined and offset-corrected measurements of JILAg-5- and FG5-type instruments stabilized in 15 to 20 years and at some stations even faster. The trends of FG5-type instrument data alone stabilized generally within 10 years. The ratio between gravity change rates and vertical rates from different data sets yields values between − 0.206 ± 0.017 and − 0.227 ± 0.024 µGal/mm and axis intercept values between 0.248 ± 0.089 and 0.335 ± 0.136 µGal/yr. These values are larger than previous estimates for Fennoscandia

Severe hypoglycemia in users of sulfonylurea antidiabetic agents and antihyperlipidemics

Drug-drug interactions causing severe hypoglycemia due to antidiabetic drugs is a major clinical and public health problem. We assessed whether sulfonylurea use with a statin or fibrate was associated with severe hypoglycemia. We conducted cohort studies of users of glyburide, glipizide, and glimepiride plus a statin or fibrate within a Medicaid population. The outcome was a validated, diagnosis-based algorithm for severe hypoglycemia. Among 592,872 persons newly exposed to a sulfonylurea+antihyperlipidemic, the incidence of severe hypoglycemia was 5.8/100 person-years. Adjusted hazard ratios (HRs) for sulfonylurea+statins were consistent with no association. Most overall HRs for sulfonylurea+fibrate were elevated, with sulfonylurea-specific adjusted HRs as large as 1.50 (95% confidence interval (CI): 1.24-1.81) for glyburide+gemfibrozil, 1.37 (95% CI: 1.11-1.69) for glipizide+gemfibrozil, and 1.63 (95% CI: 1.29-2.06) for glimepiride+fenofibrate. Concomitant therapy with a sulfonylurea and fibrate is associated with an often delayed increased rate of severe hypoglycemia

Comparative risk of severe hypoglycemia among concomitant users of thiazolidinedione antidiabetic agents and antihyperlipidemics

We conducted high-dimensional propensity score-adjusted cohort studies to examine whether thiazolidinedione use with a statin or fibrate was associated with an increased risk of severe hypoglycemia. We found that concomitant therapy with a thiazolidinedione+fibrate was associated with a generally delayed increased risk of severe hypoglycemia