julilili42/papers huggingface dataset:
Experimental analysis of smelling Braitenberg vehicles
2003-01-01

This paper addresses the problem of localisation of a static odour source in an unstructured indoor environment by a mobile robot using electrochemical gas sensors. In particular, reactive localisation strategies based on the instantaneously measured spatial concentration gradient are considered. In contrast to previous works, the environment is not artificially ventilated to produce a strong constant airflow, and thus the distribution of the odour molecules is dominated by turbulence. An experimental set-up is presented that enables different strategies for odour source localisation to be compared directly in a precisely measured experiment. Two alternative strategies that utilise a direct sensor-motor coupling are then investigated and a detailed numerical analysis of the results is presented, including tests of statistical significance. Both tested strategies proved to be useful to accomplish the localisation task. As a possible solution to the problem of detecting that the odour source - which is usually not corresponding to the global concentration maximum - was found, one of the tested strategies exploits the fact that local concentration maxima occur more frequently near the odour source compared to distant regions
Hydraulic boundary conditions as a controlling factor in karst genesis: A numerical modeling study on artesian conduit development in gypsum
2003-01-01

A coupled continuum‐pipe flow model is employed to simulate the development of karst conduits in an artesian setting, where aggressive water flows upward from an insoluble aquifer into a gypsum unit. Speleogenetic processes and controlling parameters are identified first for single conduit development. It is demonstrated that transient flow from the conduit into the surrounding fissured system of the rock enhances solutional conduit enlargement. Moreover, single conduit development is found to be highly sensitive to variations in initial diameter and hydraulic gradient. Simulating the solutional enlargement of pipe networks reveals that these two factors determine the resulting conduit pattern. Structural preferences are found to be essential for horizontal conduit development, otherwise flow paths are solely enlarged in vertical direction following the hydraulic gradient. Hydraulic gradients that increase with time can limit the extension or completely inhibit the development of horizontal caves even if lateral conduit development was structurally preferred.
Vaginal Intercourse Frequency and Heart Rate Variability
2003-01-01

We examined the relationship between recalled and diary recorded frequency of penile-vaginal intercourse (FSI) and both resting heart rate variability (HRV; an index of cardiac autonomic control and parasympathetic tone associated with cardiovascular health outcomes) and resting diastolic blood pressure (DBP) in 120 healthy adults aged 19-38 (subjects scoring above the 87th percentile on the Lie scale of the Eysenck Personality Inventory were excluded from analyses). As in a previous smaller study, greater HRV was associated with greater FSI (but not masturbation or non-coital sex with a partner) and rated importance of intercourse. There were no sex differences in the HRV-FSI relationship, and the relationship was not explained by including measures of Extraversion, Neuroticism, Depression, Trait Anxiety, or partnership satisfaction. However, the previously obtained negative association of FSI with DBP was not replicated.
The millimeter wave spectrum of aGg′ ethylene glycol: The quest for higher precision
2003-01-01

The rotation-tunneling spectrum of the aGg′ lowest energy conformer of ethylene glycol (1,2-ethanediol) has been studied between 54 and 370 GHz employing conventional absorption spectroscopy. Almost 450 different transitions between and within the v = 0 and v = 1 tunneling substates have been recorded with an accuracy of mostly 10 to 20 kHz and with J and Ka quantum numbers up to 51 and 25, respectively. The current investigation was guided by fits and predictions based on a reduced axis system (RAS) Hamiltonian. Despite considerable Coriolis interaction between the two tunneling states, the new lines together with more than 100 transitions from a previous study could be fit within experimental uncertainties using a Hamiltonian with only 34 spectroscopic parameters. These are the rotational, quartic, and sextic centrifugal distortion constants, the energy difference with quadratic and quartic distortion corrections along with eleven terms describing the Coriolis interaction between the two states.
cAMP-mediated regulation of murine intestinal/pancreatic Na+/HCO 3 − cotransporter subtype pNBC1
2003-01-01

Basolateral Na + -HCO[Formula: see text] cotransport is essential for intestinal anion secretion, and indirect evidence suggests that it may be stimulated by a rise of intracellular cAMP. We therefore investigated the expression, activity, and regulation by cAMP of the Na + -HCO[Formula: see text] cotransporter isoforms NBC1 and NBCn1 in isolated murine colonic crypts. Na + -HCO[Formula: see text] transport rates were measured fluorometrically in BCECF-loaded crypts, and mRNA expression levels and localization were determined by semiquantitative PCR and in situ hybridization. Acid-activated Na + -HCO[Formula: see text]cotransport rates were 5.07 ± 0.7 mM/min and increased by 62% after forskolin stimulation. NBC1 mRNA was more abundant in colonic crypts than in surface cells, and crypts expressed far more NBC1 than NBCn1. To investigate whether the cAMP-induced Na + -HCO[Formula: see text] cotransport activation was secondary to secretion-associated changes in HCO[Formula: see text] or cell volume, we measured potential forskolin-induced changes in intracellular pH and assessed Na + -HCO[Formula: see text]transport activity in CFTR −/− crypts (in which no forskolin-induced cell shrinkage occurs). We found 30% reduced Na + -HCO[Formula: see text] transport rates in CFTR −/− compared with CFTR +/+ crypts but similar Na + -HCO[Formula: see text] cotransport activation by forskolin. These studies establish the existence of an intracellular HCO[Formula: see text] concentration- and cell volume-independent activation of colonic NBC by an increase in intracellular cAMP.
Fatal Parvovirus B19 Myocarditis in an 8-Year-Old Boy
2003-01-01

Abstract A report is given on an 8-year-old boy who suddenly and unexpected died. Autopsy findings point to acute heart failure. Microscopic examination of the heart showed increased interstitial and perivasal fibrosis and myocarditis with macrophage infiltration. Polymerase chain reaction (PCR) analysis for parvovirus B19 was positive in heart samples and in the spleen. Immunostaining for parvoviral surface antigens was negative. Although the virus does not appear to have infected the cardiomyocytes, we speculate that myocarditis arose from immunological cross-reaction to epitopes shared between the virus and the myocardium.
Myocardial damage in falciparum malaria detectable by cardiac troponin T is rare
2003-01-01

Summary objectives To estimate the prevalence of myocardial damage in falciparum malaria by serum concentration of cardiac troponin T. methods Retrospective study of stored sera and patient files; assessment of acute myocardial damage by serum concentration or activity of cardiac troponin T, creatine kinase, creatine kinase MB and myoglobin and by routine electrocardiography. results A total of 161 patients with falciparum malaria were included in the study; troponin T was elevated in one case (0.6%), no CK‐MB elevations were found, myoglobin was elevated in 10 of 161 patients (6.2%), all of whom were elderly and had concomitant elevated serum concentration levels of cystatin C; ECG abnormalities were seen in 23 patients. conclusion Assessed by troponin T, myocardial damage in falciparum malaria is rare.
On the simulation of complex universes in the case of applying the german microcensus
2003-01-01

The aim of the DACSEIS project is to deliver recommendations on the use of variance estimators under complex survey designs in the presence of nonresponse. Since mathematical comparisons on the efficiency of variance estimation methods in this field are generally unavailable or lead to irrelevant results, adequate simulation studies have to be carried out that are based on realistic data sets. To be able to carry out a simulation study in the frame of complex designs one has to draw samples from a universe respecting for the true sampling design. However, in many cases, no data or only outdated data are available for the universe which leads to the need of adequately generating a micro data set from the sample. Within this paper, a procedure of generating the universe for the German microcensus, which is a 1% sample of the population living in Germany, will be presented. The procedure allows for an adequate consideration of the individual information on a limited data set and can therefore be used as a basis for the simulations on variance estimation methods on the German microcensus data.
Regulation of Channels by the Serum and Glucocorticoid-Inducible Kinase - Implications for Transport, Excitability and Cell Proliferation
2003-01-01

The serum and glucocorticoid-inducible kinase SGK1 stimulates the Na+ channels ENaC and SCN5A, the K+ channels ROMK1, Kv1.3, and KCNE1/KCNQ1, the cation conductance induced by 4F2/LAT1 and the chloride conductance induced by CFTR. The isoforms SGK2 and SGK3 have similarly been shown to regulate ENaC, SCN5A, Kv1.3 and KCNE1/KCNQ1. The kinases regulate channel abundance in the plasma membrane in part by inhibition of the ubiquitin ligase Nedd4-2 and in part by interaction with trafficking molecules such as the Na+/H+ exchanger regulating factor NHERF2. An in vivo role of SGK1 mediated ENaC channel regulation in renal salt excretion and blood pressure control is documented by the impaired ability of SGK1 knockout mice to adequately reduce renal Na+ output and maintain blood pressure during dietary salt restriction and by enhanced blood pressure in individuals carrying certain polymorphisms in the SGK1 gene. The in vivo physiological significance of SGK dependent regulation of the other channels remains to be shown even though circumstantial evidence points to involvement in the regulation of epithelial transport, cell volume, cell proliferation, cardiac action potential and neuroexcitability. There is little doubt that further channels will be identified which are modulated by the SGKs and that further in vivo physiological functions will be defined where channel regulation by the SGKs plays a critical role.
Splatting Illuminated Ellipsoids with Depth Correction
2003-01-01

Ellipsoids are important primitives used in visualization and modeling, where often a larger number of ellipsoids have to be displayed in real-time. The standard approach of tessellating each ellipsoid into a smooth polygonal mesh leads to unacceptable polygon counts that dramatically increase the rendering time. In this paper a method is proposed to splat ellipsoids perspectively correct. The splatted ellipsoids are illuminated with the accuracy of floating point precision by exploiting the fragment shader facility of current graphics accelerators. It is also shown how to correct the depth value of the fragment position such that overlapping ellipsoids are displayed correctly.
Blunted Apoptosis of Erythrocytes from Taurine Transporter Deficient Mice
2003-01-01

In nucleated cells cellular taurine is released prior to DNA fragmentation and the breakdown of phosphatidylserine asymmetry within the plasma membrane. Similar to what is seen in nucleated cells, phosphatidylserine asymmetry is also abolished in erythrocytes exposed to osmotic shock or oxidative stress. The present study has been performed to explore the sensitivity of erythrocytes from a taurine transporter knockout mouse (taut-/-) against osmotic shock and oxidative stress. Erythrocyte cell volume was estimated from forward scatter and breakdown of phosphatidylserine asymmetry was identified by determination of annexin binding using FACS analysis. Erythrocytes from taut-/- mice were compared to erythrocytes from wild type littermates (taut+/+). Plasma concentration and erythrocyte content of taurine was significantly lower in taut-/- than in taut+/+ mice, but the intraerythrocyte taurine concentration did not exceed the plasma concentration. Hyperosmotic shock (exposure to 700 mOsm) and oxidative stress (exposure to 0.1 mM tert-butyl-hydroperoxide) significantly decreased the cell volume and increased the number of annexin binding sites of erythrocytes from both, taut-/- and taut+/+ mice. However, decrease of cell volume and increase of annexin binding was significantly blunted in erythrocytes from taut-/- mice as compared to their taut+/+ littermates. Stimulation of erythropoiesis by prior hemorrhage did not abrogate the difference between taut+/+ and taut-/- erythrocytes. The present observations point to a decreased sensitivity of mature erythrocytes from taut-/- mice to osmotic shock and oxidative stress, rendering them more resistant to apoptosis.
Gas distribution in unventilated indoor environments inspected by a mobile robot
2003-01-01

Gas source localisation with robots is usually performed in environments with a strong, unidirectional airflow created by artificial ventilation. This tends to create a strong, well defined analyte plume and enables upwind searching. By contrast, this paper presents experiments conducted in unventilated rooms. Here, the measured concentrations also indicate an analyte plume with, however, different properties concerning its shape, width, concentration profile and stability over time. In the results presented in this paper, two very different mobile robotic systems for odour sensing were investigated in different environments, and the similarities as well as differences in the analyte gas distributions measured are discussed.
On the interpretation of age–intensity profiles and dispersion patterns in parasitological surveys
2003-01-01

The present paper describes how age–intensity profiles of macroparasite burdens are affected by processes underlying the distribution of the parasite numbers in host populations. In a comparative way, we consider the following 6 processes: (i) age-dependent exposure, (ii) parasite-induced host mortality, (iii) heterogeneity within the host population, (iv) clumped infection, (v) density-dependent parasite mortality and (vi) density-dependent parasite establishment. For each of these processes, we show typical patterns in the age–intensity profile and provide, if possible, explicit and simple solutions for the age-dependent mean parasite burden and the corresponding dispersion patterns. Emphasis is given to density-dependent parasite establishment and to age–intensity profiles resulting from the superposition of different processes. By means of 2 examples we show that the interpretation of observed patterns can be ambiguous if more than 1 process takes place. These findings underline that age–intensity profiles should be interpreted on the basis of available a priori knowledge about the processes assumed to be involved. For purposes of testing different hypotheses, a simulation program is provided with which discrepancies between model prediction and data can be explored.
Role of Peroxisome Proliferator-Activated Receptor g and Its Ligands in the Control of Immune Responses
2003-01-01

To ensure that efficient immune responses against dangerous antigens are raised while tolerance to self molecules is preserved, the immune system tightly regulates activation and survival of its cellular compartments through mechanisms only partially characterized. In this context, recent evidence indicates a role in immunity of the nuclear receptor PPAR-gamma, which is upregulated in activated lymphocytes and in dendritic cells. Preliminary in vitro studies indicate that PPAR-gamma activation profoundly alters the immune properties of these cells, usually leading to the inhibition of immune responses. Naturally occurring PPAR-gamma ligands include the cyclopentenone prostaglandins of the J series, which are present in bone marrow, thymus, and secondary lymphatic tissues. The levels of these metabolites are increased in inflamed tissues, where they exert strong anti-inflammatory effects leading to resolution of inflammation and wound healing. Cyclopentenone prostaglandins activate both PPAR-gamma-dependent and PPAR-gamma-independent pathways, possess intrinsic proapoptotic potential and are direct inhibitors of NF-kappaB signaling. The relevance of these effects in vivo still awaits proper evaluation in humans. Some of the newly described regulatory pathways might eventually be exploited in the treatment of immune diseases by means of PPAR-gamma ligands, such as thiazolidinediones or prostaglandins.
Flip the Tip: An Automated, High Quality, Cost-Effective Patch Clamp Screen
2003-01-01

The race for creating an automated patch clamp has begun. Here, we present a novel technology to produce true gigaseals and whole cell preparations at a high rate. Suspended cells are flushed toward the tip of glass micropipettes. Seal, whole-cell break-in, and pipette/liquid handling are fully automated. Extremely stable seals and access resistance guarantee high recording quality. Data obtained from different cell types sealed inside pipettes show long-term stability, voltage clamp and seal quality, as well as block by compounds in the pM range. A flexible array of independent electrode positions minimizes consumables consumption at maximal throughput. Pulled micropipettes guarantee a proven gigaseal substrate with ultra clean and smooth surface at low cost.
Three-dimensional GPR analysis of various Quaternary gravel-bed braided river deposits (southwestern Germany)
2003-01-01

Abstract Closely spaced (1 m) ground penetrating radar (GPR) profiles were used for a three-dimensional characterization and comparison of glaciofluvial gravel-bed deposits in palaeodischarge zones of the Würmian Rhine glacier (southwestern Germany). Previous sedimentological outcrop investigations revealed three regionally reoccurring architectural styles of gravel bodies. For each of these styles a three-dimensional GPR dataset has been acquired in active gravel pits in order to calibrate the radar profiles with outcrop walls and to analyse, in three dimensions, the depositional elements and their stacking pattern in the subsurface. The GPR data were interpreted by mapping reflection terminations in order to delineate genetically related units. In particular, radar facies types and radar sequence boundaries were used to define and map depositional elements. Both accretionary and cut-and-fill depositional elements could be identified. Accretionary elements are characterized by horizontally to low-angle inclined (1–3°) and moderately continuous reflections (5–30 m) terminating on flat sequence boundaries; they represent the deposits of gravel sheets and traction carpets. In contrast, cut-and-fill elements are characterized by low to steeply inclined (3–25°), often discontinuous reflections terminating on concave to trough-shaped lower truncation boundaries; these are interpreted as scour-pool fills and small dissection elements (e.g. chutes and lobes). The three basic architectural styles of gravel bodies can be distinguished on the basis of the size and proportion of cut-and-fill elements mapped within the radar images. One type of gravel body is composed of an amalgamation of large cut-and-fill elements whereas the other two types are dominated by accretionary elements and differ by the proportion of smaller cut-and-fill elements. The results show that GPR is an adequate technique to illuminate the sedimentary architecture of the various types of gravel bodies. GPR data allow detailed three-dimensional reconstruction of depositional elements and their stacking pattern in the subsurface.
Intracellular pH Activates Membrane-Bound Na<sup>+</sup>/H<sup>+</sup> Exchanger and Vacuolar H<sup>+</sup>-ATPase in Human Embryonic Kidney (HEK) Cells
2003-01-01

Mammalian cells regulate their cytosolic pH through a variety of proton extruding and bicarbonate loading mechanisms. The human embryonic kidney cell line HEK 293 is thought to show some characteristics of proximal tubule cells. The present study was performed to investigate the activity of proton extruding mechanisms (i.e. Na(+)/H(+) exchange and/or V-H(+)-ATPases) and the influence of intracellular pH (pH(i)) on the activation of these transport processes. At resting pH(i) (7.4) and in the absence of bicarbonate, removal of extracellular Na(+) did not alter pH(i) Intracellular acidification (pH(i) approximately 6.2) after a NH(4)Cl prepulse (20 mM) followed by exposure to a Na(+) free bath solution led to a slow pH(i) recovery (with a delay of 5 min), which was inhibited by the specific vacuolar H(+)-ATPase inhibitor bafilomyocin. There was no Na(+)-dependent pH(i) recovery upon exposure to Na(+) after a short intracellular acidification (less than 5 min). However, when the intracellular acidification phase was extended, the activation of a Na(+)-dependent pH(i) recovery was seen. This Na(+)-dependent pH(i) recovery was inhibited by 30 microM EIPA but not by 2 microM EIPA or less, suggesting the involvement of NHE3. Western blot analysis confirmed the presence of NHE3 protein in HEK 293 cells. Disruption of the microtubular network by colchicine (20 microM) did not significantly inhibit the rate of Na(+)-independent or dependent pH(i) recovery indicating that activation of both H(+)-ATPase, and the NHE were not due to stimulated trafficking of the transport proteins or some activators to the membrane. We conclude that a) the plasma membrane of HEK293 cells contains both, NHE and H(+)-ATPase and b) both H(+) extrusion systems are inactive at neutral pH(i), c) a decrease of cytosolic pH to 6.5 activates both transport proteins in a slow, time-dependent manner.
Current and Potential Role of Thermoradiotherapy for Solid Tumours
2003-01-01

The disappointing results for inoperable, locally advanced or recurrent solid tumours of the uterine cervix, rectum, chest wall, liver and deep seated, high-risk sarcomas after conventional radiotherapy alone necessitate the search for improved treatments. A benefit from simultaneous radiochemotherapy with regard to local tumour control and survival has been shown for a rising number of tumour entities. Radiofrequency hyperthermia is established in only a few centres, and represents another option to intensify the effect of radio- and chemotherapy. Altogether 11 randomised phase III trials with more than 1,000 patients proved the combination of hyperthermia (40-42 degrees C for at least 1 h) and radiation therapy in reference to local tumour control. Two of these trials could demonstrate a survival benefit; e.g. in locally advanced cervical cancer, stage FIGO IIB-IVa, the 3-year survival was improved from 27 to 51% with the addition of hyperthermia. Frequently trial design (main endpoint local tumour control), a low number of patients or a short follow- up period are the reasons why most trials of thermoradiotherapy failed to demonstrate a survival benefit. Disadvantageous effects of hyperthermia like an increased rate of distant metastases as a result of hyperthermia-induced elevated perfusion can be largely ruled out. While at the moment the equivalence of thermoradiotherapy and radiochemotherapy is still under evaluation, future studies have to investigate the question whether hyperthermia can add benefits when used in combination with simultaneous radiochemotherapy. An ongoing investigation of hyperthermia in multimodal treatment strategies for locally advanced solid tumours is warranted. These trials will help to improve temperature monitoring and temperature distribution and define particular groups of patients who will profit from the addition of hyperthermia. The 'Interdisziplinäre Arbeitsgruppe Hyperthermie', a working group of the German Cancer Society, introduces clinical protocols, treatment devices, and provides information for patients at www.hyperthermie.org.