639 research outputs found
Characterization of Prejunctional Muscarinic Receptors: Effects on the Release of VIP and Functional Responses and Receptor Expression in the Ovine Submandibular Gland
In the in vivo experiments on anaesthetized sheep, it was presently examined whether
muscarinic receptor antagonists with diverse selectivity affect the release of VIP in response to electrical stimulation of the parasympathetic chorda tympanic nerve differently, and if the changes in the release could be associated to altered secretory and vasodilator responses. The location of the muscarinic receptor subtypes was examined also. In the experiments, blood
was collected out of the submandibular venous drainage before and during electrical stimulation of chorda tympani nerve in the absence and presence either of pirenzepine or methoctramine. While metchoctramine increased the output of protein, pirenzepine inhibited flow of saliva and increased protein output, vasodilatation, and VIP output. In morphological examinations, the inhibitory muscarinic M4 receptor occurred interacinarily in the gland. It is concluded that prejunctional muscarinic receptors, most likely of the M4 subtype, exert inhibitory modulation of the parasympathetic release of VIP in the ovine submandibular gland
South Atlantic opening: A plume-induced breakup?
Upwelling hot mantle plumes are thought to disintegrate continental lithosphere and are considered to be drivers of active continental breakup. The formation of the Walvis Ridge during the opening of the South Atlantic is related to a putative plume-induced breakup. We investigated the crustal structure of the Walvis Ridge (southeast Atlantic Ocean) at its intersection with the continental margin and searched for anomalies related to the possible plume head. The overall structure we identify suggests that no broad plume head existed during opening of the South Atlantic and anomalous mantle melting occurred only locally. We therefore question the importance of a plume head as a driver of continental breakup and further speculate that the hotspot was present before the rifting, leaving a track of kimberlites in the African craton
Allele diversity of the H-ras-1 variable number of tandem repeats in Norwegian lung cancer patients
We have examined restriction fragment length polymorphisms of the H-ras-1 gene in germ-line DNA from 214 lung cancer patients and 309 unaffected controls. When DNA samples were digested with MspI/HpaII, Southern blot analysis revealed at least 22 different alleles, grouped according to their frequencies as common, intermediate, and rare. The frequency of rare alleles in lung cancer patients (16/428) is significantly different (p = 0.002) from that in the control group (5/618). Individuals with rare alleles were found to be at 4.7-fold greater risk of lung cancer than those with no rare alleles.publishedVersio
Crustal Structure Around the Tristan da Cunha Hotspot Derived from Ambient Noise
According to classical plume theory, the Tristan da Cunha hotspot is thought to have played a major role in the rifting of the South Atlantic margins and the creation of the aseismic Walvis Ridge during and after the breakup of the South Atlantic. Between February 2012 and January 2013 a network of 24 broadband ocean-bottom seismometers was in operation around the volcanic archipelago of Tristan da Cunha. Ambient noise data from the OBS and a seismic station on Nightingale Island were used to constrain the crustal and uppermost structure around the island. From the vertical and hydrophone recordings of more than 300 days we could reconstruct the ambient noise Green's functions by cross-correlation. The dispersion curves of Rayleigh/Scholte waves could be derived from the cross-correlations in the period range from 2 to 32 seconds. Group velocity maps were determined for each individual period using travel time tomography. These group velocity maps were converted to depth by dispersion curve inversion to construct a 3D S-wave velocity model of the crust and uppermost mantle in the region. This model shows a strong velocity anomaly beneath the Tristan da Cunha archipelago. The influence of the water depth on the inversion is discussed
On the socio-technical potential for onshore wind in Europe : a response to Enevoldsen et al. (2019), Energy Policy, 132, 1092-1100
Acknoweldgements: S.W. and J.S. received funding from the European Research Council (ERC) under the European Unionâs Horizon 2020 research and innovation programme (reFUEL, grant agreement No. 758149). J.L. and T.T. received funding from the European Research Council (ERC) under the European Unionâs Horizon 2020 research and innovation programme (grant agreement no. 715132).Peer reviewedPostprin
Anthracycline-Induced Cardiotoxicity: Cardiac Monitoring by Continuous Wave-Doppler Ultrasound Cardiac Output Monitoring and Correlation to Echocardiography
Background: Anthracyclines are agents with a well-known cardiotoxicity. The study sought to evaluate the hemodynamic response to an anthracycline using real-time continuous-wave (CW)-Doppler ultrasound cardiac output monitoring (USCOM) and echocardiography in combination with serum biomarkers. Methods: 50 patients (26 male, 24 female, median age 59 years) suffering from various types of cancer received an anthracycline-based regimen. Patients' responses were measured at different time points (T0 prior to infusion, T1 6 h post infusion, T2 after 1 day, T3 after 7 days, and T4 after 3 months) with CW-Doppler ultrasound (T0-T4) and echocardiography (T1, T4) for hemodynamic parameters such as stroke volume (SV; SVUSCOM ml) and ejection fraction (EF; EFechocardiography%) and with NT-pro-BNP and hs-Troponin T (T0-T4). Results: During the 3-month observation period, the relative decrease in the EF determined by echocardiography was -2.1% (Delta T0-T4, T0 71 +/- 7.8%, T4 69.5 +/- 7%, p = 0.04), whereas the decrease in SV observed using CW-Doppler was -6.5% (Delta T0-T4, T0 54 +/- 19.2 ml, T4 50.5 +/- 20.6 ml, p = 0.14). The kinetics for serum biomarkers were inversely correlated. Conclusions: Combining real-time CW-Doppler USCOM and serum biomarkers is feasible for monitoring the immediate and chronic hemodynamic changes during an anthracycline-based regimen; the results obtained were comparable to those from echocardiography
Shallow lithological structure across the Dead Sea Transform derived from geophysical experiments
The curse of the uncultured fungus
The international DNA sequence databases abound in fungal sequences not annotated beyond the kingdom level, typically bearing names such as âuncultured fungusâ. These sequences beget low-resolution mycological results and invite further deposition of similarly poorly annotated entries. What do these sequences represent? This study uses a 767,918-sequence corpus of public full-length fungal ITS sequences to estimate what proportion of the 95,055 âuncultured fungusâ sequences that represent truly unidentifiable fungal taxa â and what proportion of them that would have been straightforward to annotate to some more meaningful taxonomic level at the time of sequence deposition. Our results suggest that more than 70% of these sequences would have been trivial to identify to at least the order/family level at the time of sequence deposition, hinting that factors other than poor availability of relevant reference sequences explain the low-resolution names. We speculate that researchersâ perceived lack of time and lack of insight into the ramifications of this problem are the main explanations for the low-resolution names. We were surprised to find that more than a fifth of these sequences seem to have been deposited by mycologists rather than researchers unfamiliar with the consequences of poorly annotated fungal sequences in molecular repositories. The proportion of these needlessly poorly annotated sequences does not decline over time, suggesting that this problem must not be left unchecked
Ab initio alpha-alpha scattering
Processes involving alpha particles and alpha-like nuclei comprise a major
part of stellar nucleosynthesis and hypothesized mechanisms for thermonuclear
supernovae. In an effort towards understanding alpha processes from first
principles, we describe in this letter the first ab initio calculation of
alpha-alpha scattering. We use lattice effective field theory to describe the
low-energy interactions of nucleons and apply a technique called the adiabatic
projection method to reduce the eight-body system to an effective two-cluster
system. We find good agreement between lattice results and experimental phase
shifts for S-wave and D-wave scattering. The computational scaling with
particle number suggests that alpha processes involving heavier nuclei are also
within reach in the near future.Comment: 6 pages, 6 figure
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