A bizonytalanságnak és a vevőkör nagyságának együttes hatása az árakra (Investigating how the number of policies effect the optimum insurance premium)

Ebben a cikkben azzal foglalkozom, hogy a kockázat és a vevőkör nagysága együttesen hogyan hat a termék árára. Kétféle piacot hasonlítok össze: egy biztosítási piacot, és egy termékpiacot. A kétféle piac között az a legfontosabb különbség, hogy termékpiac esetében az eladó számára csak ott jelentkezik kockázat, hogy el tudja-e adni a terméket, míg biztosítási piac esetében az eladó a termék értékesítése után is szembesül kockázattal. A cikk során megmutatom, hogy a vevőkör növekedésének ellentétes hatása lehet a termék árára termék- illetve biztosítási piacok esetében. / === / An economic approach for modeling the insurance markets. The study focuses on the monopolistic market, where one insurance company sells a product with predetermined benefits for the customers. An outline of the company and the insureds' behavior with utility functions is given. The study investigates the problem of policy pricing in relation to the number of clients the company acquires. Analytic tools will be used to further clarify the points.

New contributions to the native and alien flora in riparian habitats of the Cantabrian watershed (Northern Spain)

As a result of a floristic survey carried out in riparian habitats of northern Spain, new chorological data are provided for 9 alien and 6 native plant species. Some species are reported for the first time at regional scale, such as Carex strigosa, Helianthus x laetiflorus and Persicaria pensylvanica in Cantabria. Also noteworthy is the finding of naturalised populations of the North American grass Muhlenbergia schreberi at the Urumea river basin, which represents the second reference for the Iberian Peninsula.

Utemiljön som undervisningsverktyg inom matematiken : En studie om fyra lärares uppfattningar och användning av utomhusmatematik i årskurs 1-3

Syftet med denna studie var att undersöka hur lärares uppfattningar om utomhusmatematik som undervisningsmetod är i årskurserna 1-3 samt i vilken utsträckning de använder detta. De frågeställningarna som var bärande i studien var hur användandet av utomhusmatematik ser ut, vilka för- och nackdelar informanterna ser med utomhusmatematik, om något kunskapsområde inom matematiken lämpar sig bättre eller sämre vid användning av undervisningsformen samt om det är någon av de matematiska förmågorna eleverna lättare kan utveckla med detta. Metoden som tillämpades var kvalitativa semistrukturerade intervjuer med fyra lärare vilka har arbetat olika länge samt arbetar i delvis olika årskurser och på olika skolor. Resultatet visade att användande av utomhusmatematik inte är allt för stort men intresset för undervisningsformen är desto större. En bidragande orsak till att det inte används är storleken på klasserna idag. En fördel som informanterna ser med undervisningsformen är att eleverna får arbeta konkret, praktiskt, röra på sig samt att de får frisk luft. Med hjälp av utomhusmatematiken anser informanterna att både kunskapsområdena inom matematiken och de matematiska förmågorna går att utveckla med utomhusmatematik.

The Accuracy and Reliability of Traditional Surface Flow Type Mapping: Is It Time for A New Method of Characterising Physical River Habitat?

Surface flow types (SFT) are advocated as ecologically relevant hydraulic units, often mapped visually from the bankside to characterise rapidly the physical habitat of rivers. SFT mapping is simple, non-invasive and cost-efficient. However, it is also qualitative, subjective and plagued by difficulties in recording accurately the spatial extent of SFT units. Quantitative validation of the underlying physical habitat parameters is often lacking, and does not consistently differentiate between SFTs. Here, we investigate explicitly the accuracy, reliability and statistical separability of traditionally mapped SFTs as indicators of physical habitat, using independent, hydraulic and topographic data collected during three surveys of a c. 50m reach of the River Arrow, Warwickshire, England. We also explore the potential of a novel remote sensing approach, comprising a small unmanned aerial system (sUAS) and Structure-from-Motion photogrammetry (SfM), as an alternative method of physical habitat characterisation. Our key findings indicate that SFT mapping accuracy is highly variable, with overall mapping accuracy not exceeding 74%. Results from analysis of similarity (ANOSIM) tests found that strong differences did not exist between all SFT pairs. This leads us to question the suitability of SFTs for characterising physical habitat for river science and management applications. In contrast, the sUAS-SfM approach provided high resolution, spatially continuous, spatially explicit, quantitative measurements of water depth and point cloud roughness at the microscale (spatial scales ≤1m). Such data are acquired rapidly, inexpensively, and provide new opportunities for examining the heterogeneity of physical habitat over a range of spatial and temporal scales. Whilst continued refinement of the sUAS-SfM approach is required, we propose that this method offers an opportunity to move away from broad, mesoscale classifications of physical habitat (spatial scales 10-100m), and towards continuous, quantitative measurements of the continuum of hydraulic and geomorphic conditions which actually exists at the microscale.

The denarius of L. Vinicius (RRC 436). The complexities of political relations just before the beginning of the Second Civil War.

L. Vinicius issue a coin series in the late fifties of the first century BC, shortly before the outbreak of war between Julio Caesar (cos. I 59 BC) and the Senate, led by Cn. Pompey Magnus (cos. I 70 BC), that tries, by its iconography, seek harmony bet-ween the two leaders.

Tiempo de alumbramiento con drenaje y sin drenaje de sangre del cordón umbilical en pacientes anémicas y no anémicas en el Hospital Vicente Corral Moscoso, Cuenca-Ecuador 2007

Con un diseño experimental se realizó un estudio clínico, controlado, aleatorizado La muestra incluyó 200 pacientes, el grupo experimental comprendió 100 pacientes en las que se drenó la sangre de cordón umbilical 50 anémicas y 50 no anémicas, y el grupo de control con pinzamiento del cordón lo integraron 100 pacientes, 50 anémicas y 50 no anémicas. Resultados: al comparar la duración del tercer período del parto del grupo con drenaje se obtuvo una media de 4,6 ñ 1,4 min y en el grupo con pinzamiento 9,07 ñ 2,5 min. La diferencia fue significativa (P = 0,0001).Cuando se comparó la duración del tercer período del parto de 1 a 5 min vs 6 a 10 min, la mayoría de las pacientes del grupo con drenaje, estuvo entre 1 a 5 min, con un RR 0.239 (IC 95: 0.188 - 0.358), RRA 70.1, RRR 76.1, NNT 1.426, en las anémicas, y un RR 0.250 (IC 95: 0.179 - 0.383), RRA 66.1, RRR 75, NNT 1.513 en las no anémicas. El volumen de drenaje en el grupo de estudio, tuvo una media de 60.3 ñ 19.5 ml en las anémicas y 56.9 ñ 18 ml en las no anémicas (P = 0.369). La hemorragia del tercer período del parto del grupo con drenaje tuvo una media de 197.6 ñ 36 ml vs el grupo con pinzamiento 277.4 ñ 49 ml con un valor (P = 0,0001) lo cual es estadísticamente significativo a favor del drenaje. Cuando se comparó la hemorragia del tercer período del parto de menor que 250 ml vs 250 a 500 ml la mayoría de las pacientes del grupo con drenaje, estuvo en menor que 250 ml, con un RR 0.070 (IC 95: 0.025 - 0.168), RRA 80, RRR 93, NNT 1.25, en las anémicas, y un RR 0.074 (IC 95: 0.020 - 0.246), RRA 50, RRR 92.6, NNT 2 en las no anémicas. Conclusiones. La maniobra del drenaje de sangre del cordón umbilical reduce el tiempo y la hemorragia del tercer período del parto en pacientes con anemia leve y no anémicas sin producir efectos deletéreos

Performance of a vertical slot fish pass for the sea lamprey Petromyzon marinus L. and habitat recolonization.

In 2011, a vertical-slot fish pass was built at the Coimbra Açude-Ponte dam (Mondego River, Portugal), approximately 45 km upstream from the river mouth. The performance of this infrastructure for sea lamprey passage was evaluated between 2011 and 2015 using several complementary methodologies, namely radio telemetry [conventional and electromyogram (EMG)], passive integrated transponder (PIT) telemetry and electrofishing surveys. During the study period, the electrofishing revealed a 29-fold increase in the abundance of larval sea lamprey upstream of the fish pass. Of the 20 radio-tagged individuals released downstream from the dam, 33% managed to find and successfully surpass the obstacle in less than 2 weeks, reaching the spawning areas located in the upstream stretch of the main river and in one important tributary. Fish pass efficiency was assessed with a PIT antenna installed in the last upstream pool and revealed a 31% efficiency, with differences between and within migratory seasons. Time of day and river flow significantly influenced the attraction efficiency of the fish pass, with lampreys negotiating it mainly during the night period and when discharge was below 50m3 s_1. Sea lampreys tagged with EMG transmitters took 3 h to negotiate the fish pass, during which high muscular effort was only registered during passage, or passage attempts, of the vertical slots. The use of complementary methodologies provided a comprehensive passage evaluation for sea lamprey, a species for which there is a considerable paucity of valuable data concerning behavioural, physiological and environmental influences on obstacle negotiation.