bluuebunny/crossref_metadata_2025_split huggingface dataset:
Incentive motivation in pet dogs – preference for constant vs varied food rewards
Authors: Bremhorst Annika , Bütler Sarah , Würbel Hanno , Riemer Stefanie 
Published: June 2018

AbstractRecently, there has been a move towards positive reinforcement using food rewards in animal training. By definition, rewards function as reinforcers if they increase or maintain the frequency of behaviour that they follow. However, in operant conditioning tasks animals frequently show systematic changes in performance – in particular a reduction in responding over time. One suggested strategy to avoid such performance decrements is to provide a variety of food rewards, rather than the same food reward in all trials. The enhancement of appetitive behaviour and consumption by reward variation is referred to as ‘variety effect’. We investigated whether dogs preferred a variable or a constant food reward in a concurrent two-choice test. Of 16 dogs, six subjects showed a significant preference for the varied food reward and six for the constant food reward, while four dogs exhibited no significant preference for either option. At the group level, there was a significant effect of block: preference for the varied food reward increased across six blocks of ten trials each. Thus, although some individuals may prefer a single, favourite food reward in the short term, introducing variation in reward types may maintain dogs’ motivation in operant tasks over a longer time period.
Maternal Vitamin D Prevents Abnormal Dopaminergic Development and Function in a Mouse Model of Prenatal Immune Activation
Authors: Luan Wei , Hammond Luke Alexander , Vuillermot Stephanie , Meyer Urs , Eyles Darryl Walter 
Published: June 2018

AbstractDysfunction in dopamine (DA) systems is a prominent feature in schizophrenia patients and may result from the abnormal development of mesencephalic (mes)DA systems. Maternal immune activation (MIA) and developmental vitamin D (DVD)-deficiency both induce schizophrenia-relevant dopaminergic abnormalities in adult offspring. In this study, we investigated whether maternal administration of the vitamin D hormone (1,25OHD, VITD) could prevent MIA-induced abnormalities in DA-related behaviors and mesDA development. We administrated the viral mimetic polyriboinosinic-polyribocytidylic (poly (I:C)) simultaneously with 1,25OHD and/or their vehicles, to pregnant mouse dams at gestational day 9. Maternal treatment with VITD prevented MIA-induced hypersensitivity to acute DA stimulation induced by amphetamine, whereas it failed to block prepulse inhibition deficiency in MIA-exposed offspring. MIA and VITD both reduced fetal mesDA progenitor (Lmx1a + Sox2+) cells, while VITD treatment increased the number of mature (Nurr1 + TH+) mesDA neurons. Single-cell quantification of protein expression showed that VITD treatment increased the expression of Lmx1a, Nurr1 and TH in individual mesDA cells and restored normal mesDA positioning. Our data demonstrate that VITD prevents abnormal dopaminergic phenotypes in MIA offspring possibly via its early neuroprotective actions on fetal mesDA neurons. Maternal supplementation with the dietary form of vitamin D, cholecalciferol may become a valuable strategy for the prevention of MIA-induced neurodevelopmental abnormalities.
Cancer risk by the subtype of alopecia
Authors: Lee Ji Hyun , Song Yumee , Do Han Kyung , Park Young Min , Lee Jun Young , Park Yong-Gyu , Lee Young Bok 
Published: June 2018

AbstractThe cancer risk in patients with alopecia areata (AA) or alopecia totalis (AT)/alopecia universalis (AU) remains unknown. In this study, national statistical data were used to study the association between these forms of alopecia and the risk of cancer. We enrolled 668,604 patients who were treated for alopecia from 2007 to 2014, and age- and sex-matched control subjects. AA and AT/AU patients had slightly higher overall cancer risks (hazard ratio (HR), 1.043; 95% confidence interval (CI), 1.022–1.065 and HR, 1.07; 95% CI, 1.013–1.129, respectively) than controls, after adjusting for confounding factors. The risks of oral cavity, esophagus, liver, biliary tract, pancreas, larynx, lung, kidney, breast, cervix, ovary, uterus, testis, nerve, and skin cancers; and lymphoma, multiple myeloma, and leukemia, were not increased in alopecia patients. In AA or AT/AU patients, the only increased risk was that of thyroid cancer. In AA patients alone, the risks of bladder and prostate cancers were increased. Thus, the cancer risks varied by the alopecia subtype. Careful monitoring is needed to explore if the actual risks of thyroid, bladder, and prostate cancers are increased in alopecia patients.
Ramsey interferometry with trapped motional quantum states
Authors: Hu Dong , Niu Linxiao , Jin Shengjie , Chen Xuzong , Dong Guangjiong , Schmiedmayer Jörg , Zhou Xiaoji 
Published: June 2018

AbstractRamsey interferometers using internal electronic or nuclear states find wide applications in science and engineering. We develop a matter wave Ramsey interferometer for trapped motional quantum states exploiting the s- and d-bands of an optical lattice and study it both experimentally and theoretically, identifying the different de-phasing and de-coherence mechanisms. Implementing a band echo technique, employing repeated π-pulses we suppress the de-phasing evolution and significantly increase the coherence time of the trapped state interferometer by one order of magnitude. Thermal fluctuations are the main mechanism for the remaining decay of the contrast. Our demonstration of an echo-Ramsey interferometer with trapped quantum states in an optical lattice has potential application in the study of quantum many-body lattice dynamics, and motional qubits manipulation.
High-J CO emission spatial distribution and excitation in the Orion Bar
Authors: Parikka A. , Habart E. , Bernard-Salas J. , Köhler M. , Abergel A. 
Published: June 2018

Context. With Herschel, we can for the first time observe a wealth of high-J CO lines in the interstellar medium with a high angular resolution. These lines are specifically useful for tracing the warm and dense gas and are therefore very appropriate for a study of strongly irradiated dense photodissocation regions (PDRs).
Aims. We characterize the morphology of CO J = 19–18 emission and study the high-J CO excitation in a highly UV-irradiated prototypical PDR, the Orion Bar.
Methods. We used fully sampled maps of CO J = 19–18 emission with the Photoconductor Array Camera and Spectrometer (PACS) on board the Herschel Space Observatory over an area of ~110′′ × 110′′ with an angular resolution of 9′′. We studied the morphology of this high-J CO line in the Orion Bar and in the region in front and behind the Bar, and compared it with lower-J lines of CO from J = 5–4 to J = 13–12 and 13CO from J = 5–4 to J = 11–10 emission observed with the Herschel Spectral and Photometric Imaging Receiver (SPIRE). In addition, we compared the high-J CO to polycyclic aromatic hydrocarbon (PAH) emission and vibrationally excited H2. We used the CO and 13CO observations and the RADEX model to derive the physical conditions in the warm molecular gas layers.
Results. The CO J = 19–18 line is detected unambiguously everywhere in the observed region, in the Bar, and in front and behind of it. In the Bar, the most striking features are several knots of enhanced emission that probably result from column and/or volume density enhancements. The corresponding structures are most likely even smaller than what PACS is able to resolve. The high-J CO line mostly arises from the warm edge of the Orion Bar PDR, while the lower-J lines arise from a colder region farther inside the molecular cloud. Even if it is slightly shifted farther into the PDR, the high-J CO emission peaks are very close to the H/H2 dissociation front, as traced by the peaks of H2 vibrational emission. Our results also suggest that the high-J CO emitting gas is mainly excited by photoelectric heating. The CO J = 19–18/J = 12–11 line intensity ratio peaks in front of the CO J = 19–18 emission between the dissociation and ionization fronts, where the PAH emission also peak. A warm or hot molecular gas could thus be present in the atomic region where the intense UV radiation is mostly unshielded. In agreement with recent ALMA detections, low column densities of hot molecular gas seem to exist between the ionization and dissociation fronts. As found in other studies, the best fit with RADEX modeling for beam-averaged physical conditions is for a density of 106 cm−3 and a high thermal pressure (P∕k = nH × T) of ~1–2 × 108 K cm−3.
Conclusions. The high-J CO emission is concentrated close to the dissociation front in the Orion Bar. Hot CO may also lie in the atomic PDR between the ionization and dissociation fronts, which is consistent with the dynamical and photoevaporation effects.
The Gaia-ESO Survey: the origin and evolution of s-process elements
Authors: Magrini L. , Spina L. , Randich S. , Friel E. , Kordopatis G. , Worley C. , Pancino E. , Bragaglia A. , Donati P. , Tautvaišienė G. , Bagdonas V. , Delgado-Mena E. , Adibekyan V. , Sousa S. G. , Jiménez-Esteban F. M. , Sanna N. , Roccatagliata V. , Bonito R. , Sbordone L. , Duffau S. , Gilmore G. , Feltzing S. , Jeffries R. D. , Vallenari A. , Alfaro E. J. , Bensby T. , Francois P. , Koposov S. , Korn A. J. , Recio-Blanco A. , Smiljanic R. , Bayo A. , Carraro G. , Casey A. R. , Costado M. T. , Damiani F. , Franciosini E. , Frasca A. , Hourihane A. , Jofré P. , de Laverny P. , Lewis J. , Masseron T. , Monaco L. , Morbidelli L. , Prisinzano L. , Sacco G. , Zaggia S. 
Published: June 2018

Context. Several works have found an increase of the abundances of the s-process neutron-capture elements in the youngest Galactic stellar populations. These trends provide important constraints on stellar and Galactic evolution and they need to be confirmed with large and statistically significant samples of stars spanning wide age and distance intervals.
Aims. We aim to trace the abundance patterns and the time evolution of five s-process elements – two belonging to the first peak, Y and Zr, and three belonging to the second peak, Ba, La, and Ce – using the Gaia-ESO IDR5 results for open clusters and disc stars.
Methods. From the UVES spectra of cluster member stars, we determined the average composition of clusters with ages >0.1 Gyr. We derived statistical ages and distances of field stars, and we separated them into thin and thick disc populations. We studied the time-evolution and dependence on metallicity of abundance ratios using open clusters and field stars whose parameters and abundances were derived in a homogeneous way.
Results. Using our large and homogeneous sample of open clusters, thin and thick disc stars, spanning an age range larger than 10 Gyr, we confirm an increase towards young ages of s-process abundances in the solar neighbourhood. These trends are well defined for open clusters and stars located nearby the solar position and they may be explained by a late enrichment due to significant contribution to the production of these elements from long-living low-mass stars. At the same time, we find a strong dependence of the s-process abundance ratios on the Galactocentric distance and on the metallicity of the clusters and field stars.
Conclusions. Our results, derived from the largest and most homogeneous sample of s-process abundances in the literature, confirm the growth with decreasing stellar ages of the s-process abundances in both field and open cluster stars. At the same time, taking advantage of the abundances of open clusters located in a wide Galactocentric range, these results offer a new perspective on the dependence of the s-process evolution on the metallicity and star formation history, pointing to different behaviours at various Galactocentric distances.
The evolutionary nature of RV Tauri stars in the SMC and LMC
Authors: Manick Rajeev , Van Winckel Hans , Kamath Devika , Sekaran Sanjay , Kolenberg Katrien 
Published: June 2018

Context. Based on their stellar parameters and the presence of a mid-IR excess due to circumstellar dust, RV Tauri stars have been classified as post-AGB stars. Our recent studies, however, reveal diverse spectral energy distributions (SEDs) among RV Tauri stars, suggesting they may occupy other evolutionary channels as well.
Aims. The aim of this paper is to present the diverse SED characteristics of RV Tauri stars and investigate their evolutionary nature as a function of their SEDs.
Methods. We carried out a systematic study of RV Tauri stars in the SMC and LMC because of their known distances and hence luminosities. Their SEDs were classified into three groups: dusty (disc-type), non-dusty (non-IR), and uncertain. A period-luminosity-colour (PLC) relation was calibrated. The luminosities from the PLC were complemented with those found using their SEDs and the stars were placed on a Hertzsprung-Russell diagram (HRD). I-band time series were used to search for period changes via (O−C) analyses to identify period changes.
Results. The four main results from this study are: (1) RV Tauri stars with a clear IR excess have disc-type SEDs, which indicates that the dust is trapped in a stable disc. Given the strong link between disc-type SEDs and binarity in the Galaxy, we postulate that these are binaries as well. These cover a range of luminosities and we argue that the more luminous binaries are post-AGB stars while the lower luminosity binaries are likely post-red giant branch (post-RGB) stars. (2) Two of these objects have variable mean brightness with periods of 916 and 850 days, respectively, caused by variable extinction during orbital motion. (3) Non-dusty RV Tauri stars and objects with an uncertain SED evolve such that the circumstellar dust has dispersed. If they are single stars, they are post-AGB objects of low initial mass (<1.25 M⊙), while if they are binaries, the low-luminosity portion of the sample are likely post-RGB stars. (4) We find that RV Tauri stars with dust are on average more luminous than the rest of the sample.
Factor V from Human Plasma
Authors: Surgenor Douglas M. , Wilson Nancy A. , Henry Anne S. 
Published: June 2018

SummaryA method is described for the partial purification of a human plasma factor which accelerates the conversion of prothrombin to thrombin in the presence of tissue thromboplastin. This factor may be dried from the frozen state, and may be kept in stable dry form for long periods of time. The quantitative assay of this activity is done in a classical two-stage prothrombin system using tissue thromboplastin and calcium. From its properties, it is concluded that this activity corresponds to factor V, labile factor and plasma Ac-globulin.Chemical and kinetic studies reveal that human factor V is active in plasma and is destroyed by thrombin. Human serum has little or no factor V activity.These results thus fail to support the postulated activation of factor V during clotting. All of the kinetic data are consistent with an enzymatic role for factor V in the formation of tissue prothrombin activator (thromboplastin).
Studie über die Vakuolenbildungen der Thrombozyten und über ihre Funktion
Authors: Fonio A 
Published: June 2018

ZusammenfassungOptisch leere Vakuolenbildungen finden sich bei einem Teil der Thrombozyten, sei es im Begriffe, aus der Zelle auszutreten, sei es, dieser anliegend oder in das umgebende Plasma abgestoßen, zuweilen mit einem oder mehreren Granulis in lebhafter Brownscher Bewegung. Bei elektronenmikroskopischen Aufnahmen sind zumeist im Granulomeranteil der Thrombozyten kleinste Vakuolengebilde enthalten, die sich zu kleinen oblongen Tubuli auswachsen können, und leicht an Größe zunehmend auch im Hyalomeranteil sichtbar erscheinen.In der Dunkelfeldaufnahme isolierter und mehrfach ausgewaschener Granula liegen deren Konglomeraten Mikro- und Makrovakuolen auf, im Begriff abgestoißen zu werden.Bei mehrfachem Auswaschen der isolierten Granula wird der Auswaschlösung, wie Gerinnungskontrollen ergeben, ein gerinnungsbeschleunigender Faktor zugegeben, und wie Maupin nachwies, wirken isolierte Granula, zu plättchenfreiem Plasma zugesetzt, gerinnungsbeschleunigend, parallel zu ihrer Konzentration, und sie sichern die Prothrombinkoilsumption.Aus diesen Befunden läßt sich ableiten, däiß die Vakuolen, die intrazellulär im Granulomeranteil entstehen und sch1ießlich aus dem Thrombozyt abgestoßen werden, als Sekretionsprodukt der Granula aufzufassen sind. An das Plasma abgegeben löst sich die Valiuole auf und gibt den Plättchenfaktor 3 frei, der am Gerinnungsvorgang teilnimmt.
Hautnekrosen als Nebenwirkung der Therapie mit Antikoagulantien
Authors: Stefenelli N , Tulzer H , Wewalka F 
Published: June 2018

ZusammenfassungDrei Fälle werden mitgeteilt, in denen am 4. Tag einer Cumarin-Behandlung an umschriebenen Hautpartien bis zu zweihandflächengroße Areale mit petechialen Blutungen auftraten. In zwei Fällen entwickelten sich in diesen Bezirken Hautnekrosen. Das Krankheitsbild ordnet sich in eine Gruppe bisher beschriebener Hauterscheinungen nach Behandlung mit verschiedenen Cumarinabkömmlingen ein. Die histologische Untersuchung in einem Falle und Hautteste auf Marcumar ließen die Frage nach dem Entstehungsmechanismus weiter offen. Die Gefahr für den Patienten besteht einerseits in einer begleitenden Toxämie, andererseits — wie Fälle der Literatur zeigen — im Aufhören der Anti- koagulantienwirkung nach Absetzen des Medikamentes. Die Veränderungen heilen meist ohne Komplikation ab. Sie beschränken sich auf die Haut und führen nur an den Akren zur Gangrän tieferer Schichten.
Urokinase Excretion in Man: A Method of Determination and Consideration of its Significance
Authors: von Kaulla Kurt N. , Riggenbach Neil 
Published: June 2018

SummaryA simple method is described for the quantitative determination of urokinase, a plasminogen activator, in human urine. Plasminogen activation by urokinase and the measurement of the proteolytic activity of the formed plasmin are separated in two individual steps. The normal urokinase excretion values for males and females in various conditions are discussed. Examples of pathological excretion patterns are also given.
A Case of Hageman-Factor Deficiency and a Method to Purify the Factor
Authors: Haanen C , Hommes F , Benraad H , Morselt G 
Published: June 2018

Summary1. Description of a new case of Hageman factor deficiency. The patient’s plasma was used for a quantitative estimation of the Hageman factor in normal plasma.2. By means of adsorption on to glass and elution at pH 9.6 followed by salting out procedures, it was possible to obtain a concentrated HF preparation, free from any other known coagulation factors.3. There were strong indications for the assumption that the activation of HF does not take place by releasing any inhibitor. It could result from a dissociation by the glass surface of a less active protein into two or more active factors.4. The slight inhibition which HF deficient plasma exerts on the activation of normal plasma is possibly caused by the occupation of the glass surface by non-specific proteins from HF deficient plasma.5. In plasma HF is reversibly bound to other non-specific proteins in the ß and y globulin fraction.6. After the activation by a glass surface the HF is still active in siliconed glass-ware.
Studies on Paracoagulation. Role of Antithrombin VI
Authors: Kopeć Maria , Kowalski Edward , Stachurska Jolanta 
Published: June 2018

Summary1. Conditions in which paracoagulation occurs were studied.2. It could be shown, that instead of protamine sulphate and toluidine blue, lysozyme, cooling to 4° C and acidification to pH 5,3—6,1 induce paracoagulation.3. Paracoagulation could be obtained in the presence of antithrombin VI in purified systems consisting either of fibrinogen or fibrin monomer.4. It could be stated, that antithrombin VI inhibits the polymerization of fibrin monomer and probably interferes with the protease activity of thrombin.5. Paracoagulating factors overcome the inhibitory action of antithrombin VI.6. The significance of the above findings is discussed.
Isolation and Purification of a Coagulant from Snake Venom of the Species Bothrops jararaca and the Study of its Properties
Authors: Banerjee R , Devi A , Sarkar N 
Published: June 2018

Summary1. A material active in coagulating fibrinogen has been purified thirty-fold from crude venom of the species Bothrops jararaca. This material exhibits clotting and esterase activities, but no measurable proteolytic activity if measured by its ability to digest denatured hemoglobin.2. The clotting activity of the purified material (but not its esterase activity) is greatly enhanced by the addition of 2—3 μM of calcium ion; no other divalent metallic ion can duplicate the accelerating effect of Ca++ ion.3. The purified material is stable to dialysis, standing at room temperature for 18—20 hours, or heating at 50° C for 10 minutes; it loses both its clotting and esterase activities if heated at 70° C for 25 minutes or at 80° C for 10 minutes4. Although the powerful proteolytic enzyme inhibitors ovomucoid and soyabean trypsin inhibitor can block the clotting and esterase activities of thrombin, they are ineffective with respect to these properties of venom-coagulin. DFP, an inhibitor of far less specificity, can prevent the actions both of thrombin and of venom-coagulin5. An amount of heparin sufficient to block the clotting activity of thrombin is unable to prevent the action of venom-coagulin on fibrinogen; a much higher concentration of heparin is needed. In both cases the addition of 2—3 μM of Ca++ ion necessitates the introduction of considerably more heparin in order to block the actions of thrombin and venom-coagulin.6. While the antithrombin contained in serum can neutralize the clotting and esterase activities of thrombin, it has no effect on the actions of venom-coagulin.
Study on the Red Cells Sediment After Clotting of Polycythaemic Blood
Authors: Chaudhuri Sujata , Soulier J. P 
Published: June 2018

SummaryUsing normal blood citrated or native, artificial haematocrit levels were obtained in vitro by increasing the relative amount of red cells. Clotting and lytic factors were studied, clot retraction and red cells sediment were measured. Clot retraction was found inversely proportional to the haematocrit level. Red cells sediment and proaccelerin times increased in proportion to the haematocrit level. There was no change in fibrinogen level nor in lytic activity in connection with haematocrit.Thus high red cells sediment found in polycythaemia does not seem to be related to proteolysis but to the incapacity of the fibrin net to retain the excess of cells. The prolonged proaccelerin time is itself not the result of proteolysis but could be an adsorption of factor V on the red cell surface.
Haemostasis in Haemophilia in Relation to the Haemostatic Balance in the Normal Organism and the Effect of Pea Nuts
Authors: Astrup Tage , Brakman Pieter , Ollendorff Preben , Rasmussen jørgen 
Published: June 2018

SummaryThe problems of haemostasis in haemophiloid patients are considered on the basis of a dynamic equilibrium between fibrin formation and fibrin resolution. It is suggested that the observation by Boudreaux and Frampton of an orally acting haemostatic factor in pea nuts is a result of a delayed fibrin resolution, caused by an antifibrinolytic compound, and not of a restoration of the plasma thromboplastin system (the antihaemophilic factor). This assumption is supported by the results of some preliminary experiments. The haemophiloid disorders represent a deviation in the normal haemostatic balance. For this reason they acquire a broader significance in the study of the physiology and pathology of tissue repair processes than represented by the number of patients carrying these diseases. Some implications concerning the pathogenesis of arteriosclerotic lesions are suggested.