1,434 research outputs found
Blockchain, Leadership And Management: Business AS Usual Or Radical Disruption?
The Internet provided the world with interconnection. However, it did not provide it with trust. Trust is lacking everywhere in our society and is the reason for the existence of powerful intermediaries aggregating power. Trust is what prevents the digital world to take over. This has consequences for organisations: they are inefficient because time, energy, money and passion are wasted on verifying everything happens as decided. Managers play the role of intermediaries in such case: they connect experts with each others and instruct them of what to do. As a result, in our expert society, people's engagement is low because no one is there to inspire and empower them. In other words, our society faces an unprecedented lack of leadership. Provided all those shortcomings, the study imagines the potential repercussions, especially in the context of management, of implementing a blockchain infrastructure in any type of organisation. Indeed, the blockchain technology seems to be able to remedy to those issues, for this distributed and immutable ledger provides security, decentralisation and transparency. In the context of a blockchain economy, the findings show that value creation will be rearranged, with experts directly collaborating with each others, and hierarchy being eliminated. This could, in turn, render managers obsolete, as a blockchain infrastructure will automate most of the tasks. As a result, only a strong, action-oriented, leadership would maintain the organisation together. This leadership-in-action would consist in igniting people to take action; coach members of the organisations so that their contribution makes sense in the greater context of life
Facial Pain Associated with CPAP Use: Intra-Sinusal Third Molar
Objective. This paper describes a patient with left hemifacial pain elicited by the use of a CPAP mask. Case Report. A 74-year-old man was referred with a history of pain in the left maxillary sinus related to the use of his CPAP interface, thereby prohibiting the use of the latter. Computed tomography revealed an intra-sinusal ectopic third molar in the left maxillary sinus floor corresponding to the painful area. After removal of the ectopic tooth under local anesthesia by a Caldwell-Luc approach, the patient was relieved of his symptoms. Conclusion. Although an ectopic tooth in the maxillary sinus is rare, this case points out the importance of actively looking for a regional problem if patients cannot tolerate the CPAP interface since this can lead to issues of incompliance and medical complications due to the untreated obstructive sleep apnoea syndrome
The [4+2]‐Cycloaddition of α‐Nitrosoalkenes with Thiochalcones as a Prototype of Periselective Hetero‐Diels–Alder Reactions—Experimental and Computational Studies
The [4+2]‐cycloadditions of α‐nitrosoalkenes with thiochalcones occur with high selectivity at the thioketone moiety of the dienophile providing styryl‐substituted 4H‐1,5,2‐oxathiazines in moderate to good yields. Of the eight conceivable hetero‐Diels–Alder adducts only this isomer was observed, thus a prototype of a highly periselective and regioselective cycloaddition has been identified. Analysis of crude product mixtures revealed that the α‐nitrosoalkene also adds competitively to the thioketone moiety of the thiochalcone dimer affording bis‐heterocyclic [4+2]‐cycloadducts. The experiments are supported by high‐level DFT calculations that were also extended to related hetero‐Diels–Alder reactions of other nitroso compounds and thioketones. These calculations reveal that the title cycloadditions are kinetically controlled processes confirming the role of thioketones as superdienophiles. The computational study was also applied to the experimentally studied thiochalcone dimerization, and showed that the 1,2‐dithiin and 2H‐thiopyran isomers are in equilibrium with the monomer. Again, the DFT calculations indicate kinetic control of this process
Long-term results of a multicenter SAKK trial on high-dose ifosfamide and doxorubicin in advanced or metastatic gynecologic sarcomas
Background: Dose intensive chemotherapy has not been tested prospectively for the treatment of gynecologic sarcomas. We investigated the antitumor activity and toxicity of high-dose ifosfamide and doxorubicin, in the context of a multidisciplinary strategy for the treatment of advanced and metastatic, not pretreated, gynecologic sarcomas. Patients and methods: Thirty-nine patients were enrolled onto a phase I-II multicenter trial of ifosfamide, 10 g/m2 as a continuous infusion over 5 days, plus doxorubicin intravenously, 25 mg/m2/day for 3 days with Mesna and granulocyte-colony-stimulating factor every 21 days. Salvage therapy was allowed after chemotherapy. Results: Among the 37 evaluable patients, the tumor was locally advanced (n = 11), with concomitant distant metastases (n = 5) or with distant metastases only (n = 21). After a median of three (range 1-7) chemotherapy cycles, six patients experienced a complete response and 12 a partial response for an overall response rate of 49% (95% CI 32% to 66%). The response rate was higher in poorly differentiated tumors (62%) compared with moderately well differentiated ones (18%), but was not different according to histology subtypes. Eleven patients had salvage therapy, either immediately following chemotherapy (n = 7) or at time of progression (n = 4). With a median follow-up time of 5 years, the median overall survival was 30.5 months. Hematological toxicity was as expected neutropenia, thrombopenia and anemia ≥grade 3 at 50%, 34% and 33% of cycles respectively. No toxic death occurred. Conclusions: High-dose ifosfamide plus doxorubicin is an active regimen for all subtypes of gynecological sarcomas. Its toxicity was manageable in a multicentric setting. The prolonged survival might be due to the multidisciplinary strategy that was possible in one-third of the patient
Axonemal Lumen Dominates Cytosolic Protein Diffusion inside the Primary Cilium
Transport of membrane and cytosolic proteins in primary cilia is thought to depend on intraflagellar transport (IFT) and diffusion. However, the relative contribution and spatial routes of each transport mechanism are largely unknown. Although challenging to decipher, the details of these routes are essential for our understanding of protein transport in primary cilia, a critically affected process in many genetic diseases. By using a high-speed virtual 3D super-resolution microscopy, we have mapped the 3D spatial locations of transport routes for various cytosolic proteins in the 250-nm-wide shaft of live primary cilia with a spatiotemporal resolution of 2 ms and <16 nm. Our data reveal two spatially distinguishable transport routes for cytosolic proteins: an IFT-dependent path along the axoneme, and a passive-diffusion route in the axonemal lumen that escaped previous studies. While all cytosolic proteins tested primarily utilize the IFT path in the anterograde direction, differences are observed in the retrograde direction where IFT20 only utilizes IFT, and approximately half of KIF17 and one third of α–tubulin utilizes diffusion besides IFT
State space modelling and data analysis exercises in LISA Pathfinder
LISA Pathfinder is a mission planned by the European Space Agency to test the
key technologies that will allow the detection of gravitational waves in space.
The instrument on-board, the LISA Technology package, will undergo an
exhaustive campaign of calibrations and noise characterisation campaigns in
order to fully describe the noise model. Data analysis plays an important role
in the mission and for that reason the data analysis team has been developing a
toolbox which contains all the functionalities required during operations. In
this contribution we give an overview of recent activities, focusing on the
improvements in the modelling of the instrument and in the data analysis
campaigns performed both with real and simulated data.Comment: Plenary talk presented at the 9th International LISA Symposium, 21-25
May 2012, Pari
Beyond the required LISA free-fall performance: new LISA pathfinder results down to 20 μHz
In the months since the publication of the first results, the noise performance of LISA Pathfinder has improved because of reduced Brownian noise due to the continued decrease in pressure around the test masses, from a better correction of noninertial effects, and from a better calibration of the electrostatic force actuation. In addition, the availability of numerous long noise measurement runs, during which no perturbation is purposely applied to the test masses, has allowed the measurement of noise with good statistics down to 20 μHz. The Letter presents the measured differential acceleration noise figure, which is at (1.74±0.05) fm s^{-2}/sqrt[Hz] above 2 mHz and (6±1)×10 fm s^{-2}/sqrt[Hz] at 20 μHz, and discusses the physical sources for the measured noise. This performance provides an experimental benchmark demonstrating the ability to realize the low-frequency science potential of the LISA mission, recently selected by the European Space Agency
The LISA pathfinder mission
ISA Pathfinder (LPF), the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology validation mission for future spaceborne gravitational wave detectors, such as the proposed eLISA mission. LISA Pathfinder, and its scientific payload - the LISA Technology Package - will test, in flight, the critical technologies required for low frequency gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control and an ultra-precise micro-Newton propulsion system. LISA Pathfinder is due to be launched in mid-2015, with first results on the performance of the system being available 6 months thereafter.
The paper introduces the LISA Pathfinder mission, followed by an explanation of the physical principles of measurement concept and associated hardware. We then provide a detailed discussion of the LISA Technology Package, including both the inertial sensor and interferometric readout. As we approach the launch of the LISA Pathfinder, the focus of the development is shifting towards the science operations and data analysis - this is described in the final section of the paper
Kinetics of active surface-mediated diffusion in spherically symmetric domains
We present an exact calculation of the mean first-passage time to a target on
the surface of a 2D or 3D spherical domain, for a molecule alternating phases
of surface diffusion on the domain boundary and phases of bulk diffusion. We
generalize the results of [J. Stat. Phys. {\bf 142}, 657 (2011)] and consider a
biased diffusion in a general annulus with an arbitrary number of regularly
spaced targets on a partially reflecting surface. The presented approach is
based on an integral equation which can be solved analytically. Numerically
validated approximation schemes, which provide more tractable expressions of
the mean first-passage time are also proposed. In the framework of this minimal
model of surface-mediated reactions, we show analytically that the mean
reaction time can be minimized as a function of the desorption rate from the
surface.Comment: Published online in J. Stat. Phy
What comes first? The dynamics of cerebral oxygenation and blood flow in response to changes in arterial pressure and intracranial pressure after head injury
Background Brain tissue partial oxygen pressure (PbtO2) and near-infrared spectroscopy (NIRS) are novel methods to evaluate cerebral oxygenation. We studied the response patterns of PbtO2, NIRS, and cerebral blood flow velocity (CBFV) to changes in arterial pressure (AP) and intracranial pressure (ICP). Methods Digital recordings of multimodal brain monitoring from 42 head-injured patients were retrospectively analysed. Response latencies and patterns of PbtO2, NIRS-derived parameters [tissue oxygenation index (TOI) and total haemoglobin index (THI)], and CBFV reactions to fluctuations of AP and ICP were studied. Results One hundred and twenty-one events were identified. In reaction to alterations of AP, ICP reacted first [4.3 s; inter-quartile range (IQR) −4.9 to 22.0 s, followed by NIRS-derived parameters and CBFV (10.9 s; IQR: −5.9 to 39.6 s, 12.1 s; IQR: −3.0 to 49.1 s, 14.7 s; IQR: −8.8 to 52.3 s for THI, CBFV, and TOI, respectively), with PbtO2 reacting last (39.6 s; IQR: 16.4 to 66.0 s). The differences in reaction time between NIRS parameters and PbtO2 were significant (P<0.001). Similarly when reactions to ICP changes were analysed, NIRS parameters preceded PbtO2 (7.1 s; IQR: −8.8 to 195.0 s, 18.1 s; IQR: −20.6 to 80.7 s, 22.9 s; IQR: 11.0 to 53.0 s for THI, TOI, and PbtO2, respectively). Two main patterns of responses to AP changes were identified. With preserved cerebrovascular reactivity, TOI and PbtO2 followed the direction of AP. With impaired cerebrovascular reactivity, TOI and PbtO2 decreased while AP and ICP increased. In 77% of events, the direction of TOI changes was concordant with PbtO2. Conclusions NIRS and transcranial Doppler signals reacted first to AP and ICP changes. The reaction of PbtO2 is delayed. The results imply that the analysed modalities monitor different stages of cerebral oxygenatio
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