1,740 research outputs found
When Less is More: Evolutionary Origins of the Affect Heuristic
The human mind is built for approximations. When considering the value of a large aggregate of different items, for example, we typically do not summate the many individual values. Instead, we appear to form an immediate impression of the likeability of the option based on the average quality of the full collection, which is easier to evaluate and remember. While useful in many situations, this affect heuristic can lead to apparently irrational decision-making. For example, studies have shown that people are willing to pay more for a small set of high-quality goods than for the same set of high-quality goods with lower-quality items added [e.g. 1]. We explored whether this kind of choice behavior could be seen in other primates. In two experiments, one in the laboratory and one in the field, using two different sets of food items, we found that rhesus monkeys preferred a highly-valued food item alone to the identical item paired with a food of positive but lower value. This finding provides experimental evidence that, under certain conditions, macaque monkeys follow an affect heuristic that can cause them to prefer less food. Conservation of this affect heuristic could account for similar āirrationalā biases in humans, and may reflect a more general complexity reduction strategy in which averages, prototypes, or stereotypes represent a set or group
children: differentiation using diffusion-weighted magnetic resonance imaging
Purpose
To evaluate differences in magnetic resonance imaging (MRI) appearance between infantile hemangiomas and rhabdomyosarcomas of the orbit in pediatric patients using diffusion-weighted imaging.
Methods
A multicenter retrospective review of MRIs of pediatric patients with infantile hemangiomas and rhabdomyosarcomas of the orbit was performed. MRI examinations from a total of 21 patients with infantile hemangiomas and 12 patients with rhabdomyosarcomas of the orbit were independently reviewed by two subspecialty board-certified neuroradiologists masked to the diagnosis. A freehand region of interest was placed in the mass to obtain the mean apparent diffusion coefficient (ADC) value of the mass as well as within the medulla to obtain a ratio of the ADC mass to the medulla. A t test was used to compare mean ADC and ADC ratios between the two groups. Receiver operating characteristic analysis was performed to determine ADC value and ADC ratio thresholds for differentiation of infantile hemangioma and rhabdomyosarcoma.
Results
There was a statistically significant difference in the mean ADC value of infantile hemangiomas compared to rhabdomyosarcomas (1527 Ć 10ā6 mm2/s vs 782 Ć 10ā6 mm2/s; P = 0.0001) and the ADC ratio of the lesion to the medulla (1.77 vs 0.92; P = 0.0001). An ADC threshold of <1159 Ć 10ā6 mm2/sec and an ADC ratio of <1.38 differentiated rhabdomyosarcoma from infantile hemangioma (sensitivity 100% and 100%; specificity 100% and 100%) with area under the curve of 1.0 and 1.0, respectively.
Conclusions
In conjunction with conventional MRI sequences, ADC values obtained from diffusion-weighted MRI are useful to differentiate orbital infantile hemangiomas from rhabdomyosarcomas in pediatric patients
Using 18O/2H, 3H/3He, 85Kr and CFCs to determine mean residence times and water origin in the Grazer and Leibnitzer Feld groundwater bodies (Austria)
Two groundwater bodies, Grazer Feld and Leibnitzer Feld, with surface areas of 166 and 103 km2 respectively are characterised for the first time by measuring the combination of Ī“18O/Ī“2H, 3H/3He, 85Kr, CFC-11, CFC-12 and hydrochemistry in 34 monitoring wells in 2009/2010. The timescales of groundwater recharge have been characterised by 131 Ī“18O measurements of well and surface water sampled on a seasonal basis. Most monitoring wells show a seasonal variation or indicate variable contributions of the main river Mur (0ā30%, max. 70%) and/or other rivers having their recharge areas in higher altitudes. Combined Ī“18O/Ī“2H-measurements indicate that 65ā75% of groundwater recharge in the unusual wet year of 2009 was from precipitation in the summer based on values from the Graz meteorological station. Monitoring wells downstream of gravel pit lakes show a clear evaporation trend.
A boronānitrate differentiation plot shows more frequent boron-rich water in the more urbanised Grazer Feld and more frequent nitrate-rich water in the more agricultural used Leibnitzer Feld indicating that a some of the nitrate load in the Grazer Feld comes from urban sewer water. Several lumped parameter models based on tritium input data from Graz and monthly data from the river Mur (Spielfeld) since 1977 yield a Mean Residence Time (MRT) for the Mur-water itself between 3 and 4 years in this area. Data from Ī“18O, 3H/3He measurements at the Wagna lysimeter station supports the conclusion that 90% of the groundwaters in the Grazer Feld and 73% in the Leibnitzer Feld have MRTs of 20 m) with relative thicker unsaturated zones. The young MRT of groundwater from two monitoring wells in the Leibnitzer Feld was confirmed by 85Kr-measurements. Most CFC-11 and CFC-12 concentrations in the groundwater exceed the equilibration concentrations of modern concentrations in water and are therefore unsuitable for dating purposes. An enrichment factor up to 100 compared to atmospheric equilibrium concentrations and the obvious correlation of CFC-12 with SO4, Na, Cl and B in the ground waters of the Grazer Feld suggest that waste water in contact with CFC-containing material above and below ground is the source for the contamination. The dominance of very young groundwater (<5 years) indicates a recent origin of the contamination by nitrate and many other components observed in parts of the groundwater bodies. Rapid measures to reduce those sources are needed to mitigate against further deterioration of these waters
Herpes Simplex Virus 1 and Chlamydophila (Chlamydia) pneumoniae promote Ab 1-42 amyloid processing in murine astrocytes linking an infectious process to Alzheimer\u27s disease
Background: Several studies have suggested an infectious etiology for Alzheimer\u27s disease (AD). Previously, our laboratory identified Chlamydia pneumoniae (Cpn) from autopsied sporadic AD brains, as well as developed a BALB/c mouse model that demonstrated infection-induced amyloid plaques similar to those found in AD. Hypothesis: We propose that an additional pathogen such as herpes simplex virus type 1 (HSV1), also may be a contributing factor in toin the pathology seen in AD. HSV1, in addition to Cpn, may be triggering the abnormal cleavage of the beta amyloid precursor protein (bAPP) into Ab1-42 , thereby contributing to amyloid plaque formation. Our current study examines amyloid processing following infection of primary and C8-DIA murine astrocytes with Cpn and HSV1. Materials and Methods: Immunocytochemistry and western analysis was used to analyze the outcome of infection by these two pathogens. Results: Cpn infection resulted in an increase in cytoplasmic labeling of Ab 1-42 relative to uninfected cells, while increased nuclear labeling of Ab 1-42 was observed following HSV1 infection. Co-infections with Cpn and HSV1 resulted in amyloid labeling resembling that of HSV1 infection alone, though Ab 1-42 labeling appeared decreased specifically in Cpn-infected cells of the co-infected monolayers. Conclusions: These data suggest that infection of astrocytic cells by HSV1 and (Cpn) alter the processing of bAPP, thereby producing Ab1-42. Therefore, these studies, inaddition to the previous research reported by our laboratory, support an emerging linkage of the infectious processs to the neuropathology characteristic of Alzheimer\u27s disease.https://digitalcommons.pcom.edu/posters/1008/thumbnail.jp
Graphene-based photovoltaic cells for near-field thermal energy conversion
Thermophotovoltaic devices are energy-conversion systems generating an
electric current from the thermal photons radiated by a hot body. In far field,
the efficiency of these systems is limited by the thermodynamic
Schockley-Queisser limit corresponding to the case where the source is a black
body. On the other hand, in near field, the heat flux which can be transferred
to a photovoltaic cell can be several orders of magnitude larger because of the
contribution of evanescent photons. This is particularly true when the source
supports surface polaritons. Unfortunately, in the infrared where these systems
operate, the mismatch between the surface-mode frequency and the semiconductor
gap reduces drastically the potential of this technology. Here we show that
graphene-based hybrid photovoltaic cells can significantly enhance the
generated power paving the way to a promising technology for an intensive
production of electricity from waste heat.Comment: 5 pages, 4 figure
Skyrmions and edge spin excitations in quantum Hall droplets
We present an analysis of spin-textures in Quantum Hall droplets, for filling
factors . Analytical wavefunctions with well defined quantum
numbers are given for the low-lying states of the system which result to be
either bulk skyrmions or edge spin excitations. We compute dispersion relations
and study how skyrmions become ground states of the Quantum Hall droplet at
. A Hartree-Fock approximation is recovered and discussed for
those spin textures.Comment: RevTeX, four postscript figures appende
Improved understanding of dynamic water and mass budgets of highāalpine karst systems obtained from studying a wellādefined catchment area
Large areas of Europe, especially in the Alps, are covered by carbonate rocks and in many alpine regions, karst springs are important sources for drinking water supply. Because of their high variability and heterogeneity, the understanding of the hydrogeological functioning of karst aquifers is of particular importance for their protection and utilisation. Climate change and heavy rainfall events are major challenges in managing alpine karst aquifers which possess an enormous potential for future drinking water supply. In this study, we present research from a highāalpine karst system in the UNESCO Biosphere Reserve GroĆes Walsertal in Austria, which has a clearly defined catchment and is drained by only one spring system. Results show that (a) the investigated system is a highly dynamic karst aquifer with distinct reactions to rainfall events in discharge and electrical conductivity; (b) the estimated transient atmospheric CO2 sink is about 270āt/a; (c) the calculated carbonate rock denudation rate is between 23 and 47āmm/1000a and (d) the rainfallādischarge behaviour and the internal flow dynamics can be successfully simulated using the modelling package KarstMod. The modelling results indicate the relevance of matrix storage in determining the discharge behaviour of the spring, particularly during lowāflow periods. This research and the consequent results can contribute and initiate a better understanding and management of alpine karst aquifers considering climate change with more heavy rainfall events and also longer dry periods.The investigated karst system contributes to the transient atmospheric CO2 sink with about 270āt/a.
Carbonate denudation rates vary between 23 and 47āmm/1000a.
Rainfallādischarge modelling results indicate the importance of matrix storage particularly during lowāflow periods.
imageBundesministerium fĆ¼r Bildung und Forschung
http://dx.doi.org/10.13039/501100002347FP7 People: MarieāCurie Actions
http://dx.doi.org/10.13039/10001126
Soybean Straw, Corn Stover and Sunflower Stalk as Possible Substrates for Biogas Production in Croatia: A Review
Biomass availability is one of the key factors for biogas production in the future. The current status and possibilities for utilizing harvest residues (soybean straw, corn stover and sunflower stalk) in Croatia for biogas production is given. In the last few decades, different pretreatment methods have been developed for the degradation of different lignocellulosic biomass, but many of them are environmentally unfriendly and sometimes very expensive. More research and development is necessary in order to find both
economically and environmentally friendly pretreatment methods. This paper provides a review on the mechanical, physical, and biological methods used for different lignocellulose material pretreatment. Harvest residues are usually left in the field, but with the improvement of the pretreatment process along with soil protection, they could be used for the production of huge amounts of energy in the future.
This work is licensed under a Creative Commons Attribution 4.0 International License
INTERACTION OF THE DRY MATTER ON CONTENTS OF BIOGAS PRODUCED FROM PIG MANURE
KoriÅ”tenje svinjske gnojovke kao biomase za proizvodnju bioplina jedan je od naÄina za uÄinkovitu uporabu otpada uz minimalan utjecaj na okoliÅ”. Prednost bioplina i biomase u odnosu na fosilna goriva je neusporedivo manje emisije Å”tetnih plinova i otpadnih tvari. OptereÄenje atmosfere ugljik dioksidom (CO2) pri koriÅ”tenju biomase je zanemarivo, jer je koliÄina emitiranog CO2 prilikom izgaranja jednaka koliÄini apsorbiranog CO2 tijekom rasta biljaka. Materijal istraživanja je svinjska gnojovka sa farme u okolici Osijeka gdje su svinje držane na reÅ”etkastom podu a u istraživanju koristila se standardna metoda i kvantitativni postupak. Na uzorku se ispitivao postotak suhe tvari (ST) i njegova ovisnost o koliÄini nastalog bioplina razliÄitog sastava. KoliÄina (ST) je niska i teoretski se kreÄe se od 0,5 do 10 %. Ona je varijabilna i ovisi o pasmini, hranidbi, uvjetima držanja, tehnologiji, izgnojavanju itd. Uzorak sa niskom koliÄinom (ST) sadržavao je veliku koliÄinu pepela te je njegov postotak iznosio viÅ”e od 50 %. VeÄina uzoraka s najveÄim postotkom suhe tvari imala je visoki postotak (iznad 70 %) hlapljive organanske tvari (OT). Udio duÅ”ika (N) i CO2 viÅ”i je u bioplinu proizvedenom iz svinjske gnojovke s veÄim udjelom ST. KoliÄina N obrnuto je proporcionalna koliÄini metana (CH4) /r=-0,948; p<0,001/. Dokazana je visoko pozitivna korelacija izmeÄu koncentracije ST i koliÄine bioplina (r = 0,947, p<0,001). KoliÄina bioplina ovisi o sadržaju ST s posebnim naglaskom na visoki postotak OT. Koncentracija CH4 najveÄa je kod skupine s najnižom
proizvodnjom bioplina. Å to je veÄi sadržaj suhe OT i udio masti u supstratu, veÄi je i postotak CH4.Taking advantage of pig manure as biomass for production of biogas, is one of the ways of efficient use of waste with minimum interaction with the environment. Biogas and biomass oposite on fossil fuels has less emission of harmfull gasses and wastage rate. Emissions of carbon dioxide (CO2) in biomass, as a fuels, become from burning out is almost equal with amoung of apsorpted CO2 during growth of plants. Material from investigation was pig manure from a farm near Osijek, where all the pigs were kept on latticed floor. Methods of investigation were quantitative procedure with standard methods. On pig manure was investigated percent of dry matter (DM) and her correlation on amount of biogas with different composition. Amount of (DM) is low and teoreticaly between 0,5- 10 %. Results are variable and depends on rase, nutrition, handeling conditions, technology... The sample with low (DM) had high amount of ash > 50 % mineral part and high amount of (DM) had > 70 % dry organic matter (DOM). Higher amount of (DM) represents nutritive base for microorganisms with growing faster and produce more methane (CH4). High amount of (DM) gave high percentage of nitrogen N and CO2. Amount of N was in inverse proportion to the amount of CH4 (r=-0,948; p<0,001). Highly positive correlation was determined between (DM) on special accent on (DOM) and biogas amount (r = 0,947, p<0,001). Methane concentration was the highest in the group with the lowest biogas production. Higher content the (DOM) and the share of has positive correlation with fat in pig manure and gave high percentage of CH4
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