julilili42/papers huggingface dataset:
Helper Function of the Wolffian Ducts and Role of Androgens in the Development of the Vagina
2007-01-01

The development of a vagina as a separate outlet of the birth canal evolves at the transition of egg laying species to eutherian mammals. The derivation of the vagina from the Wolffian and Müllerian ducts and the contribution of the urogenital sinus are still open questions. Here experiments with the complete androgen receptor defect in the testicular feminisation (Tfm) mouse are reported which show that the vagina is formed by caudal migration of Wolffian and Müllerian ducts. The cranial ends of the Wolffian ducts successively regress while the Müllerian ducts fuse to form the vagina. Immunohistochemistry of the androgen receptor reveals that the caudal ends of the Wolffian ducts remain in the indifferent stage and therefore have been mistaken as sinuvaginal bulbs. The Wolffian ducts do not contribute to the vagina itself but have a helper function during downward movement of the vaginal bud in the female. In the male the caudal ends serve as androgen operated switch for the negative control of vaginal development. The results indicate that the rudimentary vagina in the complete androgen insensitivity syndrome (CAIS) corresponds to non obliterated caudal ends of the Müllerian ducts. Selective atresia of the vagina in the MRKH (Mayer-Rokitansky-Küster-Hauser) syndrome may be explained by the failure of Wolffian and Müllerian ducts to descend caudally.
Arterial Blood Pressure and Renal Sodium Excretion in Dopamine D3 Receptor Knockout Mice
2007-01-01

Alterations in the dopaminergic system may contribute to the development of hypertension. Recently, it has been reported that pentobarbital-anesthetized mice with deficient dopamine D(3) receptors showed renin-dependent elevation in blood pressure. In a series of experiments, we evaluated the contribution of the dopamine D(3) receptor to the renal sodium excretion and arterial blood pressure behavior in conscious as well as anesthetized dopamine D(3) receptor knockout (-/-) mice. The blood pressure measuring study was designed as a cross-over trial to investigate the influence of different sodium loads. The animals were fed a normal salt diet (0.6% NaCl, NS) for 1 week and afterwards a low (0.2% NaCl, LS) or a high salt diet (4.6% NaCl, HS) for 2 weeks. After the third week, the animals were switched to the corresponding protocol. Systolic blood pressure in conscious (-/-) mice measured by tail-cuff plethysmography was not different from that of wild-type (+/+) animals, irrespective of the time course or the salt diet. In another experiment, challenge of an acute sodium loading per gavage in conscious D(3) receptor (-/-) and (+/+) animals on HS or NS diet did not show significant differences in renal sodium excretion between the two genotypes. Additionally, animals were fed an NS diet for 1 week and an HS diet for another week. As expected, sodium excretion significantly increased after the change from the NS to the HS diet. A slightly lower urinary sodium excretion was observed when comparing D(3) receptor (-/-) mice to their corresponding (+/+) mice, both on an HS diet. Clearance experiments with anesthetized D(3) receptor (-/-) and (+/+) mice were performed to investigate the renal sodium excretion capacity, when exposed to a moderate volume expansion (VE). Urinary sodium excretion increased in response to the VE; however, no difference were observed between the two genotypes. Taking these results together, we conclude that in the present animal model renal dopamine D(3) receptors are not significantly involved in the regulation of blood pressure associated with a deficiency in renal sodium elimination.
Peer-to-Peer-Based Infrastructure Support for Massively Multiplayer Online Games
2007-01-01

Multiplayer games played over the Internet have become very popular in the lastfew years. An interesting subcategory are the so-called massively multiplayeronline games (MMOGs) that allow thousands of player characters to share asingle game world. Such a world is usually run on a high-performance and high-availability server cluster. However, even with games that have been extensivelybeta-tested, downtimes of several hours because of hard- or software failures arenot uncommon. Downtimes, especially in the first few weeks after the release,can negatively affect the image of the game and the company that created it.Traditionally, a cluster of servers contains one virtual world of a MMOG.Such infrastructure is inflexible and error-prone. One would rather like to havea system that allows disconnecting a server at runtime while others take overits tasks. Server-based MMOGs can have performance problems if players areconcentrated in certain parts of the game world or some worlds are overpopu-lated. Thus, there is also a need for load balancing mechanisms. Peer-to-Peer(P2P) systems quite naturally support the use of load balancing.In this paper we use a structured P2P technology for the organization of theinfrastructure and thus for the reduction of downtimes in MMOGs. We splitthe game world in disjunctive rectangular zones and distribute them on differentnodes of the P2P network.Online games are an interesting challenge and chance for the future devel-opment of the P2P paradigm. A wide variety of aspects of only theoreticallysolved and especially yet completely unsolved problems are covered by this ap-plication. Security and trust problems appear as well as the need to preventcheating. The application is not as tolerant to faults as instant messaging or filesharing. Consistent data storage is a problem, decisions and transactions haveto be performed in a decentralized way. Moreover, the P2P network is not usedas pure lookup service, but more as a communication and application-specificsocial structure.The rest of this paper is organized as follows: First we discuss related work inSection 2 and give a brief introduction to P2P and MMOGs and their challengesin Section 3. Section 4 shows our approach to use structured P2P Systems forMMOGs and section 5 the evaluation with player traces from a real MMOG.Finally, Section 6 provides conclusions.
Basement Membrane Remodeling in Skeletal Muscles of Patients with Limb Ischemia Involves Regulation of Matrix Metalloproteinases and Tissue Inhibitor of Matrix Metalloproteinases
2007-01-01

&lt;i&gt;Background/Aim:&lt;/i&gt; Because the pericapillary basement membrane in skeletal muscles of patients with chronic critical limb ischemia (CLI) is thickened, we determined the expression patterns of genes involved in collagen metabolism, using samples from 9 CLI patients, 4 patients with acute limb ischemia and 4 healthy controls. &lt;i&gt;Methods:&lt;/i&gt; Gene array analysis, quantitative RT-PCR and semiquantitative grading of immunohistochemical reactivity were performed to determine mRNA/cDNA and protein concentrations. &lt;i&gt;Results:&lt;/i&gt; In CLI patients compared to controls, cDNA levels of matrix metalloproteinase (MMP)-9 and MMP-19 were higher, collagen type IV chains A1 and A2, tissue inhibitor of matrix metalloproteinase (TIMP)-1 and TIMP-2 were similar and MMP-2 were lower. On the protein level, MMP-2, MMP-9, MMP-19 and TIMP-1 were more abundantly expressed. In skeletal muscles from patients with acute limb ischemia, cDNA and protein levels of MMP-9, MMP-19, collagen type IV chains, TIMP-1 and TIMP-2 were high. MMP-2 was elevated at the protein but decreased on the cDNA level. &lt;i&gt;Conclusion:&lt;/i&gt; Expression of basement membrane components in skeletal muscles of CLI and acute limb ischemia patients is altered, possibly contributing to the pathogenesis of peripheral arterial disease.
Neural Control of Saccadic Eye Movements
2007-01-01

One of the major functions of the central nervous system is the generation of movement in response to sensory stimulation. The visual guidance of saccadic eye movement represents one form of sensory-to-motor transformation that has contributed significantly to our understanding of motor control and sensorimotor processing at large. The neural circuitry controlling saccadic eye movements is now understood at a level that is sufficient to link the specific roles of a number of saccade-related cortical and subcortical areas. In this chapter, we review the main subcortical areas for controlling saccades, concentrating mostly on the role of the posterior cerebellar vermis (PV), with the dorsal pontine nuclei and the nucleus reticularis tegmenti pontis as the major gateway to the PV and the fastigial nucleus as the link between the PV and the brainstem saccade generator. We argue that the PV is the key structure enabling saccadic learning and that this contribution is based on the control of saccade duration by a PV Purkinje cell population signal.
Topology measurements of metal nanoparticles with 1 nm accuracy by Confocal Interference Scattering Microscopy
2007-01-01

We present a novel scattering microscopy method to detect the orientation of individual silver nanorods and to measure their relative distances. Using confocal microscopy in combination with either the fundamental or higher order laser modes, scattering images of silver nanorods were recorded. The distance between two individual nanorods was measured with an accuracy in the order of 1 nm.We detected the orientation of isolated silver nanorods with a precision of 0.5 degree that corresponds to a rotational arch of about 1 nm. The results demonstrate the potential of the technique for the visualization of non-bleaching labels in biosciences.
A New Small-Incision Technique for Injector Implantation of Transsclerally Sutured Foldable Lenses
2007-01-01

&lt;P&gt; A new, minimally invasive technique for clear cornea implantation of one-piece acrylic posterior chamber lenses for transscleral suture fixation in aphakic eyes without capsular support is described. Based on the techniques of modern small-incision cataract surgery, implantation was performed through a self-sealing, 2.75-mm temporal clear cornea incision using the injector technique. This was possible by modifying the insertion of the lens into the cartridge and introducing a new suturing technique of the lens. Suturing of the leading haptic end was performed while the lens was still securely stored inside the cartridge. The trailing haptic was tied after implantation. By using a self-sealing tunnel incision and injector technique, significant fluid egress and consecutive transient hypotony may be minimized throughout the procedure and early visual rehabilitation achieved. [&lt;CITE&gt;Ophthalmic Surg Lasers Imaging&lt;/CITE&gt; 2007;38:76-80.] &lt;/P&gt; &lt;H4&gt;AUTHORS&lt;/H4&gt; &lt;P&gt;From the Department of Ophthalmology I, University of Tubingen, Tubingen, Germany. &lt;/P&gt; &lt;P&gt;Accepted for publication June 26, 2006. &lt;/P&gt; &lt;P&gt;Presented in part at the 18th Annual Meeting of the “Deutschsprachige Gesellschaft für Intraokularlinsen-Implantation und refraktive Chirurgie” (DGII), Heidelberg, Germany, February 28, 2004, and at the 102nd Annual Meeting of the “Deutsche Ophthalmologische Gesellschaft” (DOG), Berlin, Germany, September 23-26, 2004. &lt;/P&gt; &lt;P&gt;Address correspondence to Peter Szurman, MD, Department of Ophthalmology I, University of Tubingen, Schleichstr. 12, 72076 Tubingen, Germany. &lt;/P&gt;
Inhibition of adhesion molecule expression on human venous endothelial cells by non‐viral siRNA transfection
2007-01-01

Abstract Objective: Expression of adhesion molecule receptors on venous endothelial cells crucially influences the fate of venous grafts by mediating leukocyte‐endothelium interactions. These interactions include adhesion of leuko‐cytes to the endothelium, followed by transendothelial migration, leading to neointimal hyperplasia (NIH) and finally graft occlusion. Therefore, inhibition of adhesion molecule expression may be a promising strategy to improve the quality of venous grafts.We tested the efficiency of non‐viral transfection of human venous endothe‐lial cells (HVEC) with short interfering RNA (siRNA) to specifically down‐regulate adhesion molecule expression. Methods: Primary cultures of HVEC were examined for expression of the adhesion molecules ICAM1, VCAM1 and E‐selectin (SELE) after non viral siRNA transfection. Adhesion molecule expression was measured by flow cytom‐etry, real‐time polymerase chain reaction and immunoblotting after stimulation with TNF‐α, an inflammatory cytokine. Results: Non‐transfected cells showed a strong increase of adhesion molecule expression following cytokine stimulation ( P &lt; 0.01). Upon transfection with specific siRNAs a sixfold decrease in ICAM1 ( P &lt; 0.001) and SELE expression and cell positivity ( P &lt; 0.05) and a twofold decrease in VCAM1 expression and cell positiv‐ity ( P &lt; 0.01) Pcould be observed. SiRNA‐mediated gene suppression of adhesion molecules was also reflected by corresponding decreases in adhesion protein and transcript levels. Conclusions: The expression of adhesion molecules on HVECs can be effectively inhibited by specific siRNAs using a safe, non‐viral transfection approach. This is a promising tool to pre‐condition venous bypass grafts in order to interfere with endothelium‐leukocyte interactions and to prohibit neointima thickening or ath‐erosclerosis, which are regarded to be the most important causes of venous graft failure.
Neutral delay equations from and for population dynamics
2007-01-01

For a certain class of neutral differential equations it is shown that these equations can serve as population models in the sense that they can be interpreted as special cases or caricatures of the standard Gurtin-MacCamy model for a population structured by age with birth and death rate depending on the total adult population. The delayed logistic equation does not belong to this class but the blowfly equation does. These neutral delay equations can be written as forward systems of an ordinary differential equation and a shift map. There are several quite distinct ways to perform the transformation to a system, either following a method of Hale or following more closely the renewal process. Similarly to the delayed logistic equation, the neutral equation (and the blowfly equation as a special case) exhibit periodic solutions, although only for a restricted range of parameters.
Placement of Intraventricular Catheters Using Flexible Electromagnetic Navigation and a Dynamic Reference Frame: A New Technique
2007-01-01

&lt;i&gt;Background:&lt;/i&gt; Catheterization of narrow ventricles may prove difficult resulting in misplacement or inefficient trials with potential damage to brain tissue. &lt;i&gt;Material and Methods:&lt;/i&gt; The application of a new module for navigated ventricular catheterization using flexible electromagnetic navigation and a dynamic reference frame is presented. &lt;i&gt;Results:&lt;/i&gt; Navigated catheter placement was successful and accurate in a pilot study. Electromagnetic interferences had to be taken into consideration. &lt;i&gt;Conclusion:&lt;/i&gt; Flexible electromagnetic navigation with a dynamic reference frame is a useful tool for catheter placement as it reduces the risk of misplacement or repeated catheterization trials.
Weakly and almost weakly stable C<SUB align=right>0-semigroups
2007-01-01

In this paper we survey results concerning the asymptotic properties of C0-semigroups on Banach spaces with respect to the weak operator topology. The property "no eigenvalues of the generator on the imaginary axis" is equivalent to weak stability for most time values; a phenomenon called 'almost weak stability'. Further, sufficient conditions actually implying weak stability are also given. By several examples we explain weak and almost weak stability and illustrate the fundamental difference between them. Many historical and bibliographical remarks position the material in the literature. We conclude the paper with some open questions and comments.
Effects of Cervical Headgear on Overbite against the Background of Existing Growth Patterns
2007-01-01

Abstract Objective: To test the questions “Does cervical headgear treatment necessarily lead to a reduction of overbite?” and “Are there differences in treatment results due to different growth patterns or the initial overbite?” Materials and Methods: Initial and intermediary casts of 247 patients who had been treated exclusively with headgear were analyzed for changes in the occlusal relationship of the first molars and overbite. Orthodontic treatment consisted of the application of cervical headgear with nonangulated external arms applied at a force of 3.5–4.0 N. Only patients showing dental changes of occlusal relationship ≥4 mm during at least a 6-month treatment duration were selected. Growth patterns were identified by the y-axis values measured on lateral cephalograms obtained at study entry. Six groups were formed on the basis of these growth patterns. Results: Headgear treatment induced bite deepening in patients with vertical growth patterns and bite opening in patients with horizontal growth patterns. Further subdivision based on initial overbite revealed bite deepening in patients with small initial overbite and bite opening in patients with large initial overbite. These differences were statistically significant (P &amp;lt; .05). Only minor changes were observed in patients with an initial overbite of 3–4 mm. Conclusions: Overbite reductions were not dependent on the growth pattern. Orthodontists should expect bite opening in deep-bite situations and bite deepening in open-bite situations. However, initial overbite situations of 3–4 mm should not be expected to change in a significant way.
Coverage Driven Verification applied to Embedded Software
2007-01-01

The verification of complex systems, like embedded real time systems as well as SoCs, can not only be considered on hardware module level anymore. The amount of software has increased over the last years and, therefore, the verification of embedded software has got a fundamental importance. One of the main problems in embedded software verification is to stress and cover variables and functions in the embedded software that is already running on microprocessor models, during the design phase. In this paper we present a novel approach to verify embedded software running on a microprocessor model, based on a coverage driven verification technique. We have combined a new application called generic software adapter with a SystemC PowerPC microprocessor model in order to cover difficult corner case scenarios in embedded software. This approach avoids setting several parameters and registers during the initialization when no microprocessor model is used. The embedded software is a case study from the automotive industry which is responsible for controlling read and write requests to a non-volatile memory
Configuration
2007-01-01

Over the years, a whole sector of AI dealing with configuration problems has emerged, and since 1996, an annual configuration workshop has been held in affiliation with a major AI conference. This installment of Trends & Controversies presents essays from the configuration workshop held in August 2006 as part of ECAI in Riva del Garda, Italy.
Effect of Anandamide on Erythrocyte Survival
2007-01-01

The endocannabinoid anandamide (Arachidonylethanolamide, AEA) is known to induce apoptosis in a wide variety of nucleated cells. The present study explored whether anandamide induces suicidal death of erythrocytes or eryptosis, which is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine exposure at the erythrocyte surface. Eryptotic cells are phagocytosed and thus cleared from circulating blood. Triggers of eryptosis include increase of cytosolic Ca2+ activity, formation of PGE(2), oxidative stress and excessive cell shrinkage. Erythrocyte Ca2+ activity was estimated from Fluo3 fluorescence, phosphatidylserine exposure from annexin V binding, and erythrocyte volume from forward scatter in FACS analysis. Exposure of erythrocytes to anandamide (= 2.5 microM) increased cytosolic Ca2+ activity, enhanced the percentage of annexin V binding erythrocytes and decreased erythrocyte forward scatter, effects significantly blunted in the presence of cycloxygenase inhibitors acetylsalicylic acid (50 microM) or ibuprofen (100 microM) and in the nominal absence of extracellular Ca2+. Anandamide further enhanced the stimulating effects of hypertonic (addition of 550 mM sucrose) or isotonic (isosmotic replacement of Cl- with gluconate) cell shrinkage on annexin V binding. The present observations demonstrate that anandamide increases cytosolic Ca2+ activity, thus leading to cell shrinkage and cell membrane scrambling of mature erythrocytes.
Stimulation of Eryptosis by Anti-A IgG Antibodies
2007-01-01

Anti-A IgG antibodies have previously been shown to stimulate Ca2+ entry into red blood cells. Increased cytosolic free Ca2+ concentration is known to trigger eryptosis, i.e. suicidal erythrocyte death, characterized by exposure of phosphatidylserine at the erythrocyte surface. As macrophages are equipped with phosphatidylserine receptors, they bind, engulf and degrade phosphatidylserine exposing cells. The present experiments have been performed to explore whether anti-A IgGs trigger phosphatidylserine exposure of erythrocytes. Phosphatidylserine exposure was estimated from annexin-V binding as determined in FACS analysis. Exposure to anti-A IgGs (0.5 μg/ml) indeed significantly increased annexin-V binding in erythrocytes with blood group A, but not in erythrocytes with blood group 0. According to Fluo3 fluorescence, anti-A IgGs increased cytosolic Ca2+ concentration. Whole cell patch clamp recordings revealed the activation of a Ca2+-permeable cation channel following treatment with anti-A-IgGs. Annexin-V binding following anti-A IgG exposure was blunted by Ca2+ removal while anti-A IgG-stimulated cation channel activity was not dependent on extracellular Ca2+. Osmotic shock (exposure of erythrocytes to 850 mOsm) increased annexin binding, an effect further enhanced by exposure to anti-A IgGs. In conclusion, anti-A IgGs activate erythrocyte cation channels leading to Ca2+ entry and subsequent erythrocyte cell membrane scrambling. The effect most likely contributes to the elimination of erythrocytes following an immune reaction against the A antigen.
Comparison of Potent Kv1.5 Potassium Channel Inhibitors Reveals the Molecular Basis for Blocking Kinetics and Binding Mode
2007-01-01

In this study, we analysed the inhibitory potency, blocking characteristics and putative binding sites of three structurally distinct Kv1.5 channel inhibitors on cloned human Kv1.5 channels. Obtained IC(50) values for S9947, MSD-D and ICAGEN-4 were 0.7 microM, 0.5 microM, and 1.6 microM, respectively. The Hill-coefficients were close to 1 for S9947 and approximately 2 for MSD-D and ICAGEN-4. All three compounds inhibited Kv1.5 channels preferentially in the open state, with Kv1.5 block displaying positive frequency dependence, but no clear voltage and potassium dependence. In contrast to slow on- and off-rates of apparent binding of MSD-D and ICAGEN-4, S9947 had fast on- and off-rates resulting in faster adaptation to changes in pulse frequency. Utilizing Alanine-scanning and in silico modeling we suggest binding of the compounds to the central cavity with crucial residues Ile508 and Val512 in the S6-segment. Residue Thr480 located at the base of the selectivity filter is important for ICAGEN-4 and S9947 inhibition, but less so for MSD-D binding. Our docking models suggest that the innermost potassium ion in the selectivity filter may form a tertiary complex with oxygens of S9947 and ICAGEN-4 and residue Thr480. This binding component is absent in the MSD-D block. As S9947 and ICAGEN-4 show faster block with proceeding channel openings, formation of this tertiary complex may increasingly stabilise binding of S9947 and ICAGEN-4, thereby explaining open channel block kinetics of these compounds.