1,380 research outputs found
Measuring the Use of the Active and Assisted Living Prototype CARIMO for Home Care Service Users: Evaluation Framework and Results
To address the challenges of aging societies, various information and communication technology (ICT)-based systems for older people have been developed in recent years. Currently, the evaluation of these so-called active and assisted living (AAL) systems usually focuses on the analyses of usability and acceptance, while some also assess their impact. Little is known about
the actual take-up of these assistive technologies. This paper presents a framework for measuring the take-up by analyzing the actual usage of AAL systems. This evaluation framework covers detailed information regarding the entire process including usage data logging, data preparation, and usage data analysis. We applied the framework on the AAL prototype CARIMO for measuring
its take-up during an eight-month field trial in Austria and Italy. The framework was designed to guide systematic, comparable, and reproducible usage data evaluation in the AAL field; however, the general applicability of the framework has yet to be validated
Identification of Plk1 type II inhibitors by structure-based virtual screening
Protein kinases are targets for drug development. Dysregulation of kinase activity leads to various diseases, e.g. cancer, inflammation, diabetes. Human polo-like kinase 1 (Plk1), a serine/threonine kinase, is a cancer-relevant gene and a potential drug target which attracts increasing attention in the field of cancer therapy. Plk1 is a key player in mitosis and modulates entry into mitosis and the spindle checkpoint at the meta-/anaphase transition. Plk1 overexpression is observed in various human tumors, and it is a negative prognostic factor for cancer patients. The same catalytical mechanism and the same co-substrate (ATP) lead to the problem of inhibitor selectivity. A strategy to solve this problem is represented by targeting the inactive conformation of kinases. Kinases undergo conformational changes between active and inactive conformation and thus an additional hydrophobic pocket is created in the inactive conformation where the surrounding amino acids are less conserved. A "homology model" of the inactive conformation of Plk1 was constructed, as the crystal structure in its inactive conformation is unknown. A crystal structure of Aurora A kinase served as template structure. With this homology model a receptor-based pharmacophore search was performed using SYBYL7.3 software. The raw hits were filtered using physico-chemical properties. The resulting hits were docked using Gold3.2 software, and 13 candidates for biological testing were manually selected. Three compounds of the 13 tested exhibit anti-proliferative effects in HeLa cancer cells. The most potent inhibitor, SBE13, was further tested in various other cancer cell lines of different origins and displayed EC50 values between 12 microM and 39 microM. Cancer cells incubated with SBE13 showed induction of apoptosis, detected by PARP (Poly-Adenosyl-Ribose-Polymerase) cleavage, caspase 9 activation and DAPI staining of apoptotic nuclei
The spatial-temporal patterns of Asian summer monsoon precipitation in response to Holocene insolation change: a model-data synthesis
Highlights:
• Slice and transient simulations of Holocene climate change were performed.
• Spatial–temporal patterns of Holocene Asian summer precipitation are investigated.
• A tripole pattern of summer precipitation can be seen over monsoonal Asia.
• Insolation change is a key factor for Holocene Asian summer monsoon change.
• Internal feedbacks are important to Holocene Asian summer precipitation changes.
Abstract:
Paleoclimate proxy records of precipitation/effective moisture show spatial–temporal inhomogeneous over Asian monsoon and monsoon marginal regions during the Holocene. To investigate the spatial differences and diverging temporal evolution over monsoonal Asia and monsoon marginal regions, we conduct a series of numerical experiments with an atmosphere–ocean–sea ice coupled climate model, the Kiel Climate Model (KCM), for the period of Holocene from 9.5 ka BP to present (0 ka BP). The simulations include two time-slice equilibrium experiments for early Holocene (9.5 ka BP) and present-day (0 ka BP), respectively and one transient simulation (HT) using a scheme for model acceleration regarding to the Earth's orbitally driven insolation forcing for the whole period of Holocene (from 9.5 to 0 ka BP). The simulated summer precipitation in the equilibrium experiments shows a tripole pattern over monsoonal Asia as depicted by the first modes of empirical orthogonal function (EOF1) of H0K and H9K. The transient simulation HT exhibits a wave train pattern in the summer precipitation across the Asian monsoon region associated with a gradually decreased trend in the strength of Asian summer monsoon, as a result of the response of Asian summer monsoon system to the Holocene orbitally-forced insolation change. Both the synthesis of multi-proxy records and model experiments confirm the regional dissimilarity of the Holocene optimum precipitation/effective moisture over the East Asian summer monsoon region, monsoon marginal region, and the westerly-dominated areas, suggesting the complex response of the regional climate systems to Holocene insolation change in association with the internal feedbacks within climate system, such as the air-sea interactions associated with the El Nino/Southern Oscillation (ENSO) and shift of the Intertropical Convergence Zone (ITCZ) in the evolution of Asian summer monsoon during the Holocene
Disentangling seasonal signals in Holocene climate trends by satellite-model-proxy integration
Past sea surface temperatures (SSTs) are routinely estimated from organic and inorganic remains of fossil phytoplankton or zooplankton organisms, recovered
from sea floor sediments. Potential seasonal biases of paleo proxies were intensely studied in the past, however, even for the two most commonly used paleo proxies for SST, UK0 37 and Mg/Ca ratios, a clear global picture does
not yet exist. In the present study we combine Holocene SST trends derived from UK0 37 and Mg/Ca ratios with results from idealized climate model simulations forced by changes in the orbital conguration, which represents the major climate driver over the last 10 kyrs. Such changes cause a spatio-temporal redistribution of incoming solar radiation resulting in a modulation of amplitude and phasing of the seasonal cycle. Considering that the climate signal
recorded by a plankton-based paleo proxy may be aected by the seasonal productivity cycle of the respective organism, we use the modern relationship between SST and marine net primary production (NPP), both obtained from satellite observations, to calculate a seasonality index (SI) as an
independent constraint to link modeled SST trends with proxy data. Although the climate model systematically underestimates Holocene SST trends, we find that seasonal productivity peaks of the phytoplankton-based UK0 37 result
in a preferential registering of the warm (cold) season in high (low) latitudes, as it was expected from the SI distribution. The overall smoother trends from the zooplankton-derived Mg/Ca-SSTs suggest a more integrated signal over longer time averages, which may also carry a seasonal bias, but the spatial pattern is less clear. Based on our ndings, careful multi-proxy approaches can actually go beyond the reconstruction of average climate trends, specifically allowing to resolve the evolution of seasonality
Effects of eustatic sea-level change, ocean dynamics, and nutrient utilization on atmospheric pCO2 and seawater composition over the last 130 000 years: a model study
We have developed and employed an Earth system
model to explore the forcings of atmospheric pCO2 change
and the chemical and isotopic evolution of seawater over the
last glacial cycle. Concentrations of dissolved phosphorus
(DP), reactive nitrogen, molecular oxygen, dissolved inorganic
carbon (DIC), total alkalinity (TA), 13C-DIC, and 14CDIC
were calculated for 24 ocean boxes. The bi-directional
water fluxes between these model boxes were derived from a
3-D circulation field of the modern ocean (Opa 8.2, NEMO)
and tuned such that tracer distributions calculated by the box
model were consistent with observational data from the modern
ocean. To model the last 130 kyr, we employed records
of past changes in sea-level, ocean circulation, and dust deposition.
According to the model, about half of the glacial
pCO2 drawdown may be attributed to marine regressions.
The glacial sea-level low-stands implied steepened ocean
margins, a reduced burial of particulate organic carbon, phosphorus,
and neritic carbonate at the margin seafloor, a decline
in benthic denitrification, and enhanced weathering of
emerged shelf sediments. In turn, low-stands led to a distinct
rise in the standing stocks of DIC, TA, and nutrients in the
global ocean, promoted the glacial sequestration of atmospheric
CO2 in the ocean, and added 13C- and 14C-depleted
DIC to the ocean as recorded in benthic foraminifera signals.
The other half of the glacial drop in pCO2 was linked
to inferred shoaling of Atlantic meridional overturning circulation
and more efficient utilization of nutrients in the Southern
Ocean. The diminished ventilation of deep water in the
glacial Atlantic and Southern Ocean led to significant 14C
depletions with respect to the atmosphere. According to our
model, the deglacial rapid and stepwise rise in atmospheric
pCO2 was induced by upwelling both in the Southern Ocean
and subarctic North Pacific and promoted by a drop in nutrient
utilization in the Southern Ocean. The deglacial sea-level
rise led to a gradual decline in nutrient, DIC, and TA stocks,
a slow change due to the large size and extended residence
times of dissolved chemical species in the ocean. Thus, the
rapid deglacial rise in pCO2 can be explained by fast changes
in ocean dynamics and nutrient utilization whereas the gradual
pCO2 rise over the Holocene may be linked to the slow
drop in nutrient and TA stocks that continued to promote an
ongoing CO2 transfer from the ocean into the atmosphere
Role of the cellular environment in interstitial stem cell proliferation in Hydra
The role of the cellular environment on hydra stem cell proliferation and differentiation was investigated by introduction of interstitial cells into host tissue of defined cellular composition. In epithelial tissue lacking all non-epithelial cells the interstitial cell population did not grow but differentiated into nerve cells and nematocytes. In host tissue with progressively increased numbers of nerve cells growth of the interstitial cell population was positively correlated to the nerve cell density. In agreement with previous observations (Bode et al. 1976), growth of the interstitial cell population was also found to be negatively correlated to the level of interstitial cells present. The strong correlation between the growth of the interstitial cell population and the presence of interstitial cells and nerve cells implies that interstitial cell proliferation is controlled by a feedback signal from interstitial cells and their derivatives. Our results suggest that the cellular environment of interstitial cells provides cues which are instrumental in stem cell decision making
Beträchtlicher Forschungsbedarf bei der Evaluierung arbeitsmarktpolitischer Maßnahmen: Das Beispiel der Mitnahmeeffekte bei Strukturanpassungsmaßnahmen für ostdeutsche Wirtschaftsunternehmen
Obwohl beträchtliche Mittel in die aktive Arbeitsmarktpolitik fließen, fehlt es bislang an einer systematischen Evaluierung der arbeitsmarktpolitischen Instrumente. Dies liegt primär an der Unzugänglichkeit geeigneter Daten. Am Beispiel der Mitnahmeeffekte bei Strukturanpassungsmaßnahmen für ostdeutsche Wirtschaftsunternehmen werden exemplarisch die Probleme aufgezeigt, die aus der prekären Datenlage entstehen.
An object-based classification approach for mapping "migrant housing" in the mega-urban area of the Pearl River Delta (China)
Urban areas develop on formal and informal levels. Informal development is often highly dynamic, leading to a lag of spatial information about urban structure types. In this work, an object-based remote sensing approach will be presented to map the migrant housing urban structure type in the Pearl River Delta, China. SPOT5 data were utilized for the classification (auxiliary data, particularly up-to-date cadastral data, were not available). A hierarchically structured classification process was used to create (spectral) independence from single satellite scenes and to arrive at a transferrable classification process. Using the presented classification approach, an overall classification accuracy of migrant housing of 68.0% is attained
Climate and marine biogeochemistry during the Holocene from transient model simulations
Climate and marine biogeochemistry changes over the Holocene are investigated based on transient global climate and biogeochemistry model simulations over the last 9500 years. The simulations are forced by accelerated and non-accelerated orbital parameters, respectively, and atmospheric PCO2, CH4, and N2O. The analysis focusses on key climatic parameters of relevance to the marine biogeochemistry, and on the physical and biogeochemical processes that drive atmosphere-ocean carbon fluxes and changes in the oxygen minimum zones (OMZs). The simulated global mean ocean temperature is characterized by a mid-Holocene cooling and a late Holocene warming, a common feature among Holocene climate simulations which, however, contradicts a proxy-derived mid-Holocene climate optimum. As the most significant result, and only in the non-accelerated simulation, we find a substantial increase in volume of the OMZ in the eastern equatorial Pacific (EEP) continuing into the late Holocene. The concurrent increase in apparent oxygen utilization (AOU) and age of the water mass within the EEP OMZ can be attributed to a weakening of the deep northward inflow into the Pacific. This results in a large-scale mid-to-late Holocene increase in AOU in most of the Pacific and hence the source regions of the EEP OMZ waters. The simulated expansion of the EEP OMZ raises the question of whether the deoxygenation that has been observed over the last 5 decades could be a - perhaps accelerated - continuation of an orbitally driven decline in oxygen. Changes in global mean biological production and export of detritus remain of the order of 10 %, with generally lower values in the mid-Holocene. The simulated atmosphere-ocean CO2 flux would result in atmospheric pCO2 changes of similar magnitudes to those observed for the Holocene, but with different timing. More technically, as the increase in EEP OMZ volume can only be simulated with the non-accelerated model simulation, non-accelerated model simulations are required for an analysis of the marine biogeochemistry in the Holocene. Notably, the long control experiment also displays similar magnitude variability to the transient experiment for some parameters. This indicates that also long control runs are required when investigating Holocene climate and marine biogeochemistry, and that some of the Holocene variations could be attributed to internal variability of the atmosphere-ocean system
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