julilili42/papers huggingface dataset:
Amino acid transporters in plants.
2008-01-01

Plants require large amounts of nitrogen for optimal growth and development. Nitrogen is mainly acquired from the soil in inorganic form such as NO3- and NH4+. Inorganic nitrogen is partially assimilated in roots or translocated via the vasculature and is then reduced to organic nitrogen and assimilated into amino acids. Amino acids are translocated to the sink tissues via the phloem and xylem. The loading and unloading steps require amino acid transport proteins. During plant development, the nitrogen requirement for most organs changes drastically. In the earlier stages of development, growing leaves and roots are major sinks for carbon and nitrogen. At later stages, reproductive organs, such as seeds or tubers, become the major sinks. In the model plant Arabidopsis, but similarly in other plants, several amino acid transporters with specific expression patterns and transport activities have been molecularly identified and characterized in the past years. Related genes are found in the databases of genome projects of various plant species. The potential role of these transporters in the plant adaptation to meet the nitrogen requirements of different plant tissues and under varying environmental conditions is discussed and summarized here.
Synthesis of Covalently-Linked Phthalocyanine–Phthalocyanine and Porphyrin–Phthalocyanine Dimers
2008-01-01

The synthesis of the dimeric homonuclear phthalocyanines (Pc) 4a, 4b, 5a and 5b and the dimeric heteronuclear Pc 4c and 5c is reported. The reactions are carried out by coupling the monomeric Pc 1a and 1b each containing a phenolic OH group in one of its substituents with the bromoalkyl-substituted Pc 2a,b or 3a,b respectively. From the spectral data of 4a–c and 5a–c, it can be concluded that in dichloromethane and toluene as solvents, these binuclear Pc are equilibrating between cofacial and open conformations with the open form predominating. Changing the solvent polarity, e.g. by adding methanol, the equilibrium is shifted towards a cofacial conformation. Treatment of the Pc 2a,b and 3a,b with 5-(4′-oxyphenyl)-10,15,20-triphenylporphin (6) in a basic solution gives the porphyrins (P)-Pc dimers 7a,b and 8a,b respectively. In dichloromethane, the open conformation is preferred for the P-Pc dimers.
Occult hepatitis C virus infection is more common than hepatitis B infection in maintenance hemodialysis patients
2008-01-01

Patients of end stage renal disease on maintenance hemodialysis were enrolled to study the prevalence of occult and dual hepatitis B virus (HBV) and hepatitis C virus (HCV) infection and non-occult hepatitis B and C virus infection.One hundred and two patients were enrolled.Thirty patients had HCV infection, three of them were positive in anti-HCV.So, 27 (90%) of HCVpositive patients had occult HCV infection.Eleven (11%) patients had HBV infection.Five patients were positive in anti-HBc or HBV-DNA, but negative in HBsAg (occult HBV infection).Three (3%) patients had dual HBV and HCV infection.None of the patients showed changes in viral markers during the follow-up of 8 mo on average (1-12 mo).
Processes vs. User-Level Threads in Scsh
2008-01-01

The new version of scsh enables concurrent system programming with portable user-level threads. In scsh, threads behave like processes in many ways. Each thread receives its own set of process resources. Like Unix processes, forked threads can inherit resources from the parent thread. To store these resources scsh uses preserved thread fluids, a special kind of fluid variables. The paper gives a detailed description of an efficient implementation for thread-local process resources. Scsh also provides an interface to the fork system calls which avoids common pitfalls which arise with a userlevel thread system. Scsh contains a binding for fork that forks “only the current thread.” 1
Deformation partitioning within a sinistral transpression zone along the southwestern margin of the Tauern Window (eastern Alps)
2008-01-01

Abstract This study is concerned with a newly recognized structure at the southwestern border of the Tauern Window and the neighbouring Austroalpine basement rocks, the Lappach Structure. Structural and isotopic investigations show that this structure is the result of sinistral transpression and backthrusting along the Austroalpine–Penninic contact. Deformation partitioning and differential exhumation of crustal wedges is documented by a succession of ductile and brittle deformation stages. Two stages are distinguished: (1) up-doming of Penninic units and associated advective heat transfer caused a strong temperature variation with the highest temperatures in central portions of the Tauern Window. Coeval transpression with distributed sinistral shear formed high-temperature, partly annealed fabrics in central portions and lower-temperature fabrics with strong crystallographic preferred orientation of quartz along the Tauern Window margin. Southward decrease of temperatures was matched by increases in stress and deformation intensity. (2) Progressive cooling was accompanied by shear localization, deformation partitioning and fluid infiltration. Overall sinistral shear resolved in a discrete strike slip–fault and south vergent folds with associated thrusts defining a backthrust zone along the southern Tauern margin. Southwards extrusion disturbed previously established palaeo-isogrades and juxtaposed rocks from greater depths against lower-grade metamorphic units. Fluids penetrated faults, reduced shear strength and contributed to shear localization.
Speaker-oriented Adverbs of the German -wise Sort
2008-01-01

Bonami and Godard (to appear) suggest that the oddness of such sentences as (1b) is due to the clash between the “main assertion”: ¬have(v, ts) and the “ancillary commitment”: have(v, ts) → fortunate(have(v, ts)). However, even when preceding adverbs are not negative, e. g. immer ‘always’, with which the clash should not arise as the “main assertion” is positive, the sentences remain bad. Compare:
Crystal Structure of 4-Hydroxy-3-[(2-oxo-2H-chromen-3-yl)-(3,4,5-trimethoxyphenyl)methyl]chromen-2-one
2008-01-01

The title compound, 4-hydroxy-3-[(2-oxo-2H-chromen-3-yl)-(3,4,5-trimethoxyphenyl)methyl]chromen-2-one, C28H22NO9, as a dimer C56H44O18 Mr = 1004.91, crystallizes in the monoclinic system, space group C2/c with cell constants: a = 3599.8(4)pm, b = 900.7(1)pm, c = 1460.7(2)pm, β = 98.02(1)°, V = 4.690(1)nm3, Z = 4. The 4-hydroxycoumarins are intra-molecularly hydrogen bonded between hydroxyls and carbonyls.
Unusual presentation of central nervous system metastases: mechanisms of spread and radiological findings
2008-01-01

Brain metastases are a well-known complication of systemic cancer, occurring in 20–40% of the patients suffering from cancer1. In adults, the lungs represent the most common source of brain metastases comprising 36–64% of the cases1. The cerebral hemispheres, cerebellum, brainstem1, pituitary (sellar region)2-4, cerebellopontine angle (CPA)/ internal auditory canal (IAC)2,5, and leptomeningeal metastases (LM)1,2,6,7 are potential locations of dissemination [...] Unusual presentation of central nervous system metastases: mechanisms of spread and radiological findings
Effect of Adenosine on Membrane Potential and Ca<sup>2+</sup> in Juxtaglomerular Cells
2008-01-01

&lt;i&gt;Background:&lt;/i&gt;Renin is mainly secreted from the juxtaglomerular cells (JGC) in the kidney situated in the afferent arteriole close to the vessel pole. Angiotensin II (ANG II) and adenosine inhibit renin secretion and synergistically constrict the afferent arteriole. ANG II depolarises JGC and increases the cytoplasmic free Ca&lt;sup&gt;2+&lt;/sup&gt; concentration [Ca&lt;sup&gt;2+&lt;/sup&gt;]&lt;sub&gt;i&lt;/sub&gt;. The responses of JGC to adenosine are less known. &lt;i&gt;Methods:&lt;/i&gt;Effects of adenosine on membrane potential and [Ca&lt;sup&gt;2+&lt;/sup&gt;]&lt;sub&gt;i&lt;/sub&gt; were studied in afferent arterioles from NaCl-depleted rats and mice. &lt;i&gt;Result:&lt;/i&gt;Stimulation of A&lt;sub&gt;1&lt;/sub&gt; adenosine receptors (A&lt;sub&gt;1&lt;/sub&gt;AR) by adenosine (10 μ&lt;i&gt;M&lt;/i&gt;) or cyclohexyladenosine (1 μ&lt;i&gt;M&lt;/i&gt;) increased the spiking frequency of JGC, slightly depolarised the cells and, in ≤50% of the cases, increased [Ca&lt;sup&gt;2+&lt;/sup&gt;]&lt;sub&gt;i&lt;/sub&gt;. These effects were much smaller than those of ANG II (3 n&lt;i&gt;M&lt;/i&gt;). Simultaneous application of cyclohexyladenosine and ANG II gave only additive effects on [Ca&lt;sup&gt;2+&lt;/sup&gt;]&lt;sub&gt;i&lt;/sub&gt;; in addition, responses to ANG II in JGC from A&lt;sub&gt;1&lt;/sub&gt;AR knockout mice were similar to those from control mice. &lt;i&gt;Conclusion:&lt;/i&gt; The small changes in membrane potential and [Ca&lt;sup&gt;2+&lt;/sup&gt;]&lt;sub&gt;i&lt;/sub&gt; in response to A&lt;sub&gt;1&lt;/sub&gt;AR stimulation as compared to those of ANG II may suggest that these 2 tissue hormones use different signal transduction mechanisms to affect JGC function, including the inhibition of renin release.
Construction of hyperboloidal black hole initial data
2008-01-01

We check the feasibility of the Thin-Sandwich formulation of the constraints for the construction of hyperboloidal initial data, and present a first numerical check (boundary treatment) of the method with Schwarzschild data.
Almost periodicity of stochastic operators on $\\ell^1(\\mathbb{N})$
2008-01-01

We characterize from a functional analytic point of view almost periodicity of operators on given by infinite column-stochastic matrices. Some of the equivalent properties occur, under the name of Foster's condition, in the theory of stochastic processes. The results are applied to flows in infinite networks.
Miocene emplacement and rapid cooling of the Pohorije pluton at the Alpine-Pannonian-Dinaridic junction, Slovenia
2008-01-01

New laser ablation-inductive coupled plasma-mass spectrometry U-Pb analyses on oscillatory-zoned zircon imply Early Miocene crystallization (18.64±0.11 Ma) of the Pohorje pluton at the southeastern margin of the Eastern Alps (northern Slovenia). Inherited zircon cores indicate two crustal sources: a late Variscan magmatic population (∼270–290 Ma), and an early Neoproterozoic one (850–900 Ma) with juvenile Hf isotope composition close to that of depleted mantle. Initial ∈Hf of Miocene zircon points to an additional, more juvenile source component of the Miocene magma, which could be either a juvenile Phanerozoic crust or the Miocene mantle. The new U-Pb isotope age of the Pohorje pluton seriously questions its attribution to the Oligocene age 'Periadriatic" intrusions. The new data imply a temporal coincidence with 19–15 Ma magmatism in the Pannonian Basin system, more specifically in the Styrian Basin. K-Ar mineral- and whole rock ages from the pluton itself and cogenetic shallow intrusive dacitic rocks (∼18–16 Ma), as well as zircon fission track data (17.7–15.6 Ma) gave late Early to early Middle Miocene ages, indicating rapid cooling of the pluton within about 3 Million years. Medium-grade Austroalpine metamorphics north and south of the pluton were reheated and subsequently cooled together. Outcrop-and micro scale structures record deformation of the Pohorje pluton and few related mafic and dacitic dykes under greenschist facies conditions. Part of the solidstate fabrics indicate E-W oriented stretching and vertical thinning, while steeply dipping foliation and NW-SE trending lineation are also present. The E-W oriented lineation is parallel to the direction of subsequent brittle extension, which resulted in normal faulting and tilting of the earlier ductile fabric at around the Early/Middle Miocene boundary; normal faulting was combined with strike-slip faulting. Renewed N-S compression may be related to late Miocene to Quaternary dextral faulting in the area. The documented syn-cooling extensional structures and part of the strike-slip faults can be interpreted as being related to lateral extrusion of the Eastern Alps and/or to back-arc rifting in the Pannonian Basin.
A Landscape of Logics for Finite Unordered Unranked Trees
2008-01-01

In this paper, we draw a landscape of the expressive power of diverse logics over finite unordered unranked trees. A tree is unordered iff for each node there is no order on its children. A tree is unranked iff for each node the number of its children is independent of its label. We compare here the expressive power of logics from three non-disjoint areas: logics related to automata theory, logics from descriptive complexity theory, and secondorder logics. Several of these logics form natural hierarchies of expressive power. We will show several separation results in these hierarchies thus showing that the hierarchies are mostly proper. We also present that the automata logics are incomparable to the logics from descriptive complexity theory.
The Double Dynamic Martin Screw (DMS)
2008-01-01

The scope and importance of hip fractures is almost incomprehensible. With a world wide incidence of close to 2 million cases per year, these fractures pose a daunting challenge to our ability to affe
Apatite fission track and (U-Th)/He thermochronology of the Rochovce granite (Slovakia) — implications for the thermal evolution of the Western Carpathian-Pannonian region
2008-01-01

The thermal evolution of the only known Alpine (Cretaceous) granite in the Western Carpathians (Rochovce granite) is studied by low-temperature thermochronological methods. Our apatite fission track and apatite (U-Th)/He ages range from 17.5±1.1 to 12.9±0.9 Ma, and 12.9±1.8 to 11.3±0.8 Ma, respectively. The data thus show that the Rochovce granite records a thermal event in the Middle to early Late Miocene, which was likely related to mantle upwelling, volcanic activity, and increased heat flow. During the thermal maximum between ∼17 and 8 Ma, the granite was heated to temperatures ≳60°C. Increase of cooling rates at ∼12 Ma recorded by the apatic fission track and (U-Th)/He data is primarily related to the cessation of the heating event and relaxation of the isotherms associated with the termination of the Neogene volcanic activity. This contradicts the accepted concept, which stipulates that the internal parts of the Western Carpathians were not thermally affected during the Cenozoic period. The Miocene thermal event was not restricted to the investigated part of the Western Carpathians, but had regional character and affected several basement are as in the Western Carpathians, the Pannonian basin and the margin of the Eastern Alps.
Firm Productivity and the Foreign-Market Entry Decision
2008-01-01

We use Japanese firm-level data to examine how a firm?s productivity affects its choice of foreign-market entry strategy. We study a sequence of decisions, starting with the choice between exporting and foreign direct investment (FDI). In the case of FDI, the firm faces two options: greenfield investment or merger and acquisition (M&amp;A). If it selects greenfield investment, it has two ownership choices: whole ownership or a joint venture. Controlling for industry- and country-specific characteristics, we find that the more productive a firm is, the more likely it is to choose FDI rather than exporting, greenfield investment rather than M&amp;A, and whole ownership rather than a joint venture. We also find that the assumed sequence of decisions fits the data better than alternative specifications.
Pricing American options with Mellin transforms
2008-01-01

Mellin transforms in option pricing theory were introduced by Panini and Srivastav (2004). In this contribution, we generalize their results to European power options. We derive Black-Scholes-Merton-like valuation formulas for European power put options using Mellin transforms. Thereafter, we restrict our attention to plain vanilla options on dividend-paying stocks and derive the integral equations to determine the free boundary and the price of American put options using Mellin transforms. We recover a result found by Kim (1990) regarding the optimal exercise price of American put options at expiry and prove the equivalence of integral representations herein, the representation derived by Kim (1990), Jacka (1991), and by Carr et al. (1992). Finally, we extend the results obtained in Panini and Srivastav (2005) and show how the Mellin transform approach can be used to derive the valuation formula for perpetual American put options on dividend-paying stocks.
The Impact of Thin-Capitalization Rules on External Debt Usage – A Propensity Score Matching Approach
2008-01-01

This paper analyzes how multinational enterprises respond to a restriction on interest deductions incurred for internal borrowing. The emphasis of the study is on a firm’s response with respect to external borrowing. The empirical investigation applies propensity score matching techniques and exploits the 2001 reform of the German thin-capitalization rule to solve endogeneity problems. The results suggest that restrictions on internal debt are associated with expansions in external debt finance, indicating a substitutional relationship. Since multinational enterprises can use internal debt to shift profits from high- to low-tax countries, this finding implies that policies aimed at securing corporate tax revenue possibly fail and should be subject to careful scrutiny by policymakers. JEL Code: G32, H25.
International price discovery in the presence of market microstructure effects
2008-01-01

This paper addresses and resolves the problems caused by microstructure effects when measuring the relative importance of home and U.S. market in the price discovery process of internationally cross listed stocks. In order to avoid large bounds for information shares, previous studies applying the Cholesky decomposition within the Hasbrouck (1995) framework had to rely on high frequency data. However, this entails a potential bias of estimated information shares induced by microstructure effects. We propose a modified approach that relies on distributional assumptions and yields unique and unbiased information shares. Our results indicate that the role of the U.S. market in the price discovery process of Canadian interlisted stocks has been severely underestimated to date. Moreover, we find that rather than stock specific factors, market design determines information shares.
Mating Behaviour of the Sperm Trading Sea Slug Chelidonura hirundinina: Repeated Sex Role Alternation Balances Reciprocity
2008-01-01

Abstract In animals with separate sexes, male fitness usually increases with the number of matings, whereas female fitness more directly depends on the amount of accessible reproductive resources. In simultaneous hermaphrodites, such differences in fitness pay‐offs between male and female sexual function can result in a preference to copulate in one particular sex role, generating conflicts over mating roles if mates share the same preference. Sperm trading, i.e. the conditional exchange of sperm between mates as found in some hermaphrodites, is often considered a possible solution for the conflict over mating roles. Conditional sperm exchange has recently been demonstrated in Chelidonura hirundinina (Opisthobranchia, Aglajidae), but its functional causes remain obscure. Based on a detailed characterization of mating in this species, we here assess two potential benefits of sperm trading, the balancing of sperm exchange between partners, and the acquisition of information about the partner’s fecundity. We found that the number of sperm droplets exchanged between partners varied more between than within pairs, supporting the first hypothesis. Moreover, larger individuals donated more sperm droplets and are known to produce more eggs. As body size is tightly linked to fecundity, a sperm recipient may use the number of received sperm droplets as an honest signal of the female quality of the sperm donor. Our findings thus help to elucidate how sperm trading may contribute to optimizing the investment of costly sperm in response to partner quality.
Development of a transoral fundoplication device and related experimental research
2008-01-01

This paper describes a device and surgical techniques developed between 1999 and 2003 to enable an entirely transoral approach to fundoplication. The Endofundoplication System (EFS) system consisted of a multifunctional flexible tube for oral introduction (18 mm) as the key component, with a specially designed retroverted grasper that was used to grasp the lower esophageal sphincter (LES) area of the esophagus, for invaginating the LES into the stomach and folding the gastric wall onto the wall of the intraabdominal esophagus. The EFS system was finally studied in a consecutive series of animal experiments in the domestic pig (n = 10). In nine out of the ten cases the procedure could be successfully completed and the animals survived six weeks according to the study protocol. The clinical follow-up of the nine animals went without problems. The animals behaved normally the first day after the procedure and tolerated regular diet very well. No signs of pain or any abdominal pathology were found in the clinical follow-up. Follow-up by endoscopy and fluoroscopy showed a subsequent postoperative migration of fasteners within the tissue. After autopsy and macroscopic inspection of the gastroesophageal junction (GEJ), we found firm tissue indurations around the fasteners. This may indicate that the fastener as a foreign body leads to a sufficient amount of scar tissue formation to contribute to permanent fixation of the tissue layers. The basic advantage of the EFS technique was seen by our group in the fact that it comes closer to the shape and function of a classical fundoplication than any other techniques proposed at the time we did our development. The nipple valve created by the EFS technique is, however, geometrically not identical to any existing fundoplication technique and is not directly comparable to any such procedure.
Beyond Mean Field Description of the Gamow-Teller β[sup +] Decay of Proton-Rich Kr Isotopes
2008-01-01

We studied the influence of shape mixing on the Gamow‐Teller β+ decay of the nucleus 74Kr using the complex Excited Vampir variational approach for the description of the ground state of the parent nucleus and the 1+ states in the beta window in the daughter nucleus 74Br. Within the same approach the Gamow‐Teller strength distributions for the decay of the ground state and the lowest‐excited states in the nucleus 72Kr to the 1+ states in the nucleus 72Br are obtained using a rather large model space and realistic effective interaction. The shape coexistence and mixing are consistently described for both the 0+ and 2+ states in the even‐even parent nucleus and the 1+ states in the odd‐odd daughter nucleus. The theoretical results for the Gamow‐Teller strength distributions and the accumulated strengths are compared with the available data and predictions concerning the decay of the first excited 0+ and the yrast 2+ in the rp‐process waiting point nucleus 72Kr are presented.
Regional mobility in early adulthood: The impact of qualifications
2008-01-01

"This paper presents selected findings on the regional mobility of young adults in West Germany in the 1980s and 1990s on asseses the impact of formal qualification on the process of residental mobility. It draws upon recently collected data from the West German Life History Study (1964 and 1971 birth cohorts). These data allow to observe the mobility patterns of the cohort members over time and also to link this individual-level information with regional-level data. The analyses look at patterns and determinants of individual mobility with a focus on incidence and distance of residential mobility in the context of education, employment and family formation." (author's abstract)