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We present the discovery and characterization of six short-period, transiting giant planets from NASA's Transiting Exoplanet Survey Satellite (TESS) -- TOI-1811 (TIC 376524552), TOI-2025 (TIC 394050135), TOI-2145 (TIC 88992642), TOI-2152 (TIC 395393265), TOI-2154 (TIC 428787891), & TOI-2497 (TIC 97568467). All six planets orbit bright host stars (8.9, Comment: 20 Pages, 6 Figures, 8 Tables, Accepted by MNRAS

We report the Transiting Exoplanet Survey Satellite (TESS) discovery of a three-planet system around the bright Sun-like star HD~22946(V=8.3 mag),also known as TIC~100990000, located 63 parsecs away.The system was observed by TESS in Sectors 3, 4, 30 and 31 and two planet candidates, labelled TESS Objects of Interest (TOIs) 411.01 (planet $c$) and 411.02 (planet $b$), were identified on orbits of 9.57 and 4.04 days, respectively. In this work, we validate the two planets and recover an additional single transit-like signal in the light curve, which suggests the presence of a third transiting planet with a longer period of about 46 days.We assess the veracity of the TESS transit signals and use follow-up imaging and time series photometry to rule out false positive scenarios, including unresolved binary systems, nearby eclipsing binaries or background/foreground stars contaminating the light curves. Parallax measurements from Gaia EDR3, together with broad-band photometry and spectroscopic follow-up by TFOP allowed us to constrain the stellar parameters of TOI-411, including its radius of$1.157\pm0.025R_\odot$. Adopting this value, we determined the radii for the three exoplanet candidates and found that planet $b$ is a super-Earth, with a radius of $1.72\pm0.10R_\oplus$, while planet $c$ and $d$ are sub-Neptunian planets, with radii of$2.74\pm0.14R_\oplus$ and $3.23\pm0.19R_\oplus$ respectively. By using dynamical simulations, we assessed the stability of the system and evaluated the possibility of the presence of other undetected, non-transiting planets by investigating its dynamical packing. We find that the system is dynamically stable and potentially unpacked, with enough space to host at least one more planet between $c$ and $d$.(Abridged), 21 pages, 12 figures. Accepted for publication on A&A

We describe the target selection procedure by which stars are selected for 2-minute and 20-second observations by TESS. We first list the technical requirements of the TESS instrument and ground systems processing that limit the total number of target slots. We then describe algorithms used by the TESS Payload Operation Center (POC) to merge candidate targets requested by the various TESS mission elements (the Target Selection Working Group, TESS Asteroseismic Science Consortium, and Guest Investigator office). Lastly, we summarize the properties of the observed TESS targets over the two-year primary TESS mission. We find that the POC target selection algorithm results in 2.1 to 3.4 times as many observed targets as target slots allocated for each mission element. We also find that the sky distribution of observed targets is different from the sky distributions of candidate targets due to technical constraints that require a relatively even distribution of targets across the TESS fields of view. We caution researchers exploring statistical analyses of TESS planet-host stars that the population of observed targets cannot be characterized by any simple set of criteria applied to the properties of the input Candidate Target Lists., 15 pages, 6 figures, accepted for publication in PASP

We report the discovery of an ultrahot Jupiter with an extremely short orbital period of $0.67247414\,\pm\,0.00000028$ days ($\sim$16 hr). The $1.347 \pm 0.047$ $R_{\rm Jup}$ planet, initially identified by the Transiting Exoplanet Survey Satellite (TESS) mission, orbits TOI-2109 (TIC 392476080): a $T_{\rm eff} \sim 6500$ K F-type star with a mass of $1.447 \pm 0.077$ $M_{\rm Sun}$, a radius of $1.698 \pm 0.060$ $R_{\rm Sun}$, and a rotational velocity of $v\sin i_* = 81.9 \pm 1.7$ km s$^{-1}$. The planetary nature of TOI-2109b was confirmed through radial velocity measurements, which yielded a planet mass of $5.02 \pm 0.75$ $M_{\rm Jup}$. Analysis of the Doppler shadow in spectroscopic transit observations indicates a well-aligned system, with a sky-projected obliquity of $\lambda = 1\overset{\circ}{.}7 \pm 1\overset{\circ}{.}7$. From the TESS full-orbit light curve, we measured a secondary eclipse depth of $731 \pm 46$ ppm, as well as phase-curve variations from the planet's longitudinal brightness modulation and ellipsoidal distortion of the host star. Combining the TESS-band occultation measurement with a $K_s$-band secondary eclipse depth ($2012 \pm 80$ ppm) derived from ground-based observations, we find that the dayside emission of TOI-2109b is consistent with a brightness temperature of $3631 \pm 69$ K, making it the second hottest exoplanet hitherto discovered. By virtue of its extreme irradiation and strong planet-star gravitational interaction, TOI-2109b is an exceptionally promising target for intensive follow-up studies using current and near-future telescope facilities to probe for orbital decay, detect tidally driven atmospheric escape, and assess the impacts of H$_2$ dissociation and recombination on the global heat transport., Comment: 30 pages, 17 figures, published in AJ

We report the discovery of two transiting brown dwarfs (BDs), TOI-811b and TOI-852b, from NASA's Transiting Exoplanet Survey Satellite mission. These two transiting BDs have similar masses, but very different radii and ages. Their host stars have similar masses, effective temperatures, and metallicities. The younger and larger transiting BD is TOI-811b at a mass of $M_b = 55.3 \pm 3.2{\rm M_J}$ and radius of $R_b = 1.35 \pm 0.09{\rm R_J}$ and it orbits its host star in a period of $P = 25.16551 \pm 0.00004$ days. Its age of $93^{+61}_{-29}$ Myr, which we derive from an application of gyrochronology to its host star, is why this BD's radius is relatively large, not heating from its host star since this BD orbits at a longer orbital period than most known transiting BDs. This constraint on the youth of TOI-811b allows us to test substellar mass-radius isochrones where the radius of BDs changes rapidly with age. TOI-852b is a much older (4.0 Gyr from stellar isochrone models of the host star) and smaller transiting BD at a mass of $M_b = 53.7 \pm 1.3{\rm M_J}$, a radius of $R_b = 0.75 \pm 0.03{\rm R_J}$, and an orbital period of $P = 4.94561 \pm 0.00008$ days. TOI-852b joins the likes of other old transiting BDs that trace out the oldest substellar mass-radius isochrones where contraction of the BD's radius asymptotically slows. Both host stars have a mass of $M_\star = 1.32{\rm M_\odot}\pm0.05$ and differ in their radii, $T_{\rm eff}$, and [Fe/H] with TOI-811 having $R_\star=1.27\pm0.09{\rm R_\odot}$, $T_{\rm eff} = 6107 \pm 77$K, and $\rm [Fe/H] = +0.40 \pm 0.09$ and TOI-852 having $R_\star=1.71\pm0.04{\rm R_\odot}$, $T_{\rm eff} = 5768 \pm 84$K, and $\rm [Fe/H] = +0.33 \pm 0.09$. We take this opportunity to examine how TOI-811b and TOI-852b serve as test points for young and old substellar isochrones, respectively., 20 pages, 12 figures, 7 tables, submitted to AJ

We present 2,241 exoplanet candidates identified with data from the Transiting Exoplanet Survey Satellite (TESS) during its two-year prime mission. We list these candidates in the TESS Objects of Interest (TOI) Catalog, which includes both new planet candidates found by TESS and previously-known planets recovered by TESS observations. We describe the process used to identify TOIs and investigate the characteristics of the new planet candidates, and discuss some notable TESS planet discoveries. The TOI Catalog includes an unprecedented number of small planet candidates around nearby bright stars, which are well-suited for detailed follow-up observations. The TESS data products for the Prime Mission (Sectors 1-26), including the TOI Catalog, light curves, full-frame images, and target pixel files, are publicly available on the Mikulski Archive for Space Telescopes., Comment: 39 pages, 16 figures. The Prime Mission TOI Catalog is included in the ancillary data as a CSV. For the most up-to-date catalog, refer to https://tess.mit.edu/toi-releases/

We present the detection of 1,617 new transiting planet candidates, identified in the Transiting Exoplanet Survey Satellite (TESS) full-frame images (FFIs) observed during the Primary Mission (Sectors 1 - 26). These candidates were initially detected by the Quick-Look Pipeline (QLP), which extracts FFI lightcurves for and searches all stars brighter than TESS magnitude T = 13.5 mag in each sector. However, QLP heavily relies on manual inspection for the identification of planet candidates, limiting vetting efforts to planet-hosting stars brighter than T = 10.5 mag and leaving millions of potential transit signals un-vetted. We describe an independent vetting pipeline applied to QLP transit search results, incorporating both automated vetting tests and manual inspection to identify promising planet candidates around these fainter stars. The new candidates discovered by this ongoing project will allow TESS to significantly improve the statistical power of demographics studies of giant, close-in exoplanets., 8 pages, 3 figures; submitted to AAS journals

We report the detection of a Saturn-size exoplanet orbiting HD 332231 (TOI 1456) in light curves from the Transiting Exoplanet Survey Satellite (TESS). HD 332231, an F8 dwarf star with a V-band magnitude of 8.56, was observed by TESS in Sectors 14 and 15. We detect a single-transit event in the Sector 15 presearch data conditioning (PDC) light curve. We obtain spectroscopic follow-up observations of HD 332231 with the Automated Planet Finder, Keck I, and SONG telescopes. The orbital period we infer from the radial velocity (RV) observations leads to the discovery of another transit in Sector 14 that was masked by PDC due to scattered light contamination. A joint analysis of the transit and RV data confirms the planetary nature of HD 332231 b, a Saturn-size ($0.867^{+0.027}_{-0.025} \; R_{\rm J}$), sub-Saturn-mass ($0.244\pm0.021 \; M_{\rm J}$) exoplanet on a 18.71 day circular orbit. The low surface gravity of HD 332231 b and the relatively low stellar flux it receives make it a compelling target for transmission spectroscopy. Also, the stellar obliquity is likely measurable via the Rossiter-McLaughlin effect, an exciting prospect given the 0.14 au orbital separation of HD 332231 b. The spectroscopic observations do not provide substantial evidence for any additional planets in the HD 332231 system, but continued RV monitoring is needed to further characterize this system. We also predict that the frequency and duration of masked data in the PDC light curves for TESS Sectors 14-16 could hide transits of some exoplanets with orbital periods between 10.5 and 17.5 days., Comment: 17 pages, 9 figures, 4 tables. Published in the Astronomical Journal

We have identified a quadruple system with two close eclipsing binaries in TESS data. The object is unresolved in Gaia and appears as a single source at parallax 1.08~$\pm$0.01 mas. Both binaries have observable primary and secondary eclipses and were monitored throughout TESS Cycle 1 (sectors 1-13), falling within the TESS Continuous Viewing Zone. In one eclipsing binary (P = 5.488 d), the smaller star is completely occluded by the larger star during the secondary eclipse; in the other (P = 5.674 d) both eclipses are grazing. Using these data, spectroscopy, speckle photometry, SED analysis and evolutionary stellar tracks, we have constrained the masses and radii of the four stars in the two eclipsing binaries. The Li I EW indicates an age of 10-50 Myr and, with an outer period of $858^{+7}_{-5}$ days, our analysis indicates this is one of the most compact young 2+2 quadruple systems known., Comment: Submitted to AJ

We report the discovery of two short-period massive giant planets from NASA's Transiting Exoplanet Survey Satellite (TESS). Both systems, TOI-558 (TIC 207110080) and TOI-559 (TIC 209459275), were identified from the 30-minute cadence Full Frame Images and confirmed using ground-based photometric and spectroscopic follow-up observations from TESS's Follow-up Observing Program Working Group. We find that TOI-558 b, which transits an F-dwarf ($M_{*}=1.349^{+0.064}_{-0.065}\ M_{\odot}$, $R_{*}=1.496^{+0.042}_{-0.040}\ R_{\odot}$, $T_{eff}=6466^{+95}_{-93}\ K$, age $1.79^{+0.91}_{-0.73}\ Gyr$) with an orbital period of 14.574 days, has a mass of $3.61\pm0.15\ M_{\rm J}$, a radius of $1.086^{+0.041}_{-0.038}\ R_{\rm J}$, and an eccentric (e=$0.300^{+0.022}_{-0.020}$) orbit. TOI-559 b transits a G-dwarf ($M_{*}=1.026\pm0.057\ M_{\odot}$, $R_{*}=1.233^{+0.028}_{-0.026}\ R_{\odot}$, $T_{eff}=5925^{+85}_{-76}\ K$, age $6.8^{+2.5}_{-2.0}\ Gyr$) in an eccentric (e=$0.151\pm0.011$) 6.984-day orbit with a mass of $6.01^{+0.24}_{-0.23}\ M_{\rm J}$ and a radius of $1.091^{+0.028}_{-0.025}\ R_{\rm J}$. Our spectroscopic follow-up also reveals a long-term radial velocity trend for TOI-559, indicating a long-period companion. The statistically significant orbital eccentricity measured for each system suggests that these planets migrated to their current location through dynamical interactions. Interestingly, both planets are also massive ($>3\ M_{\rm J}$), adding to the population of massive giant planets identified by TESS. Prompted by these new detections of high-mass planets, we analyzed the known mass distribution of hot and warm Jupiters but find no significant evidence for multiple populations. TESS should provide a near magnitude-limited sample of transiting hot Jupiters, allowing for future detailed population studies., 18 pages, 7 figures, 5 tables, accepted to The Astronomical Journal

The plastic behaviour of a bituminous coal was determined under conditions pertinent to modern high-temperature coal conversion processes, using a specially developed fast-response plastometer. The instrument determines the torque required for constant rotation of a thin disc embedded within a thin layer of coal heated between two parallel metal plates. Heating rates, final temperatures and sample residence times at final temperature can be separately selected and controlled over the ranges 40–800 K s −1 , 600–1250 K and 0–40 s, respectively. The instrument is enclosed in a vessel designed for hydrogen or inert gas pressures up to 10 MPa. Typical results are illustrated and compared with predictions of a preliminary mathematical model of the kinetics of coal plasticity. The observed kinetics are also discussed with reference to solvent extraction data on the residues of coal samples that have undergone the same temperature-time histories as those employed in the plastometer. The effect of external gas pressure on plasticity is also briefly discussed.

We present a case of Ga-PSMA PET/CT imaging of PSMA expression in neurofibromas in a patient with neurofibromatosis type 1 (or von Recklinghausen disease). PSMA uptake has previously been demonstrated in schwannomas both with PET and histological staining. The presented images confirm that PSMA expression in cutaneous neurofibromas can be well imaged with PET, with uptake mostly at relatively low levels. Interestingly, some lesions demonstrated significantly higher PSMA expression, although the clinical significance of these differences remains to be determined. The images raise the possibility of a potential role for Ga-PSMA PET/CT in neurofibromatosis type 1 monitoring.

We report the discovery and validation of four extrasolar planets hosted by the nearby, bright, Sun-like (G3V) star HD~108236 using data from the Transiting Exoplanet Survey Satellite (TESS). We present transit photometry, reconnaissance and precise Doppler spectroscopy as well as high-resolution imaging, to validate the planetary nature of the objects transiting HD~108236, also known as the TESS Object of Interest (TOI) 1233. The innermost planet is a possibly-rocky super-Earth with a period of $3.79523_{-0.00044}^{+0.00047}$ days and has a radius of $1.586\pm0.098$ $R_\oplus$. The outer planets are sub-Neptunes, with potential gaseous envelopes, having radii of $2.068_{-0.091}^{+0.10}$ $R_\oplus$, $2.72\pm0.11$ $R_\oplus$, and $3.12_{-0.12}^{+0.13}$ $R_\oplus$ and periods of $6.20370_{-0.00052}^{+0.00064}$ days, $14.17555_{-0.0011}^{+0.00099}$ days, and $19.5917_{-0.0020}^{+0.0022}$ days, respectively. With V and K$_{\rm s}$ magnitudes of 9.2 and 7.6, respectively, the bright host star makes the transiting planets favorable targets for mass measurements and, potentially, for atmospheric characterization via transmission spectroscopy. HD~108236 is the brightest Sun-like star in the visual (V) band known to host four or more transiting exoplanets. The discovered planets span a broad range of planetary radii and equilibrium temperatures, and share a common history of insolation from a Sun-like star ($R_\star = 0.888 \pm 0.017$ R$_\odot$, $T_{\rm eff} = 5730 \pm 50$ K), making HD 108236 an exciting, opportune cosmic laboratory for testing models of planet formation and evolution., accepted for publication in The Astronomical Journal

Background 99mTechnetium-HDP (HDP) bone scans differentiate transthyretin (ATTR) cardiac amyloid from other infiltrative myocardial diseases. These scans are not quantitative and are assessed by comparing myocardial uptake to bone. This study examined whether quantitative HDP SPECT/CT can discriminate individuals with cardiac ATTR from the population without this disease. Methods HDP thoracic xSPECT/CT QUANT (xQUANT) was performed in 29 patients: ATTR cardiac amyloid (n = 6); AL cardiac amyloid (n = 1); other infiltrative myocardial disease (n = 4); no known infiltrative cardiac disease (n = 18). SUVmax measured within volumes of interest for whole heart, ascending aorta blood pool, and specific bones. HDP myocardial uptake calculated as whole heart minus blood pool. Results The cardiac ATTR group had greater HDP myocardial uptake than those with no known infiltrative disease (p = 0.002). AL and other myocardial diseases had uptake indistinguishable from the group with no known infiltrative cardiac disease. The SUVmaxima were sufficiently similar between individuals without cardiac ATTR that a 99% reference interval for HDP uptake could be calculated, providing an upper limit cut point of SUVmax 1.2. Individuals with cardiac ATTR had SUVmax well above this cut point. Conclusion Quantitative SPECT/CT can measure HDP myocardial uptake in individuals with normal hearts and those with cardiac ATTR without recourse to comparison with bone. It enables calculation of a reference interval for HDP myocardial uptake in the population without ATTR cardiac amyloid. Using this reference interval single individuals with cardiac ATTR can be accurately discriminated from the non-affected population. This technique uses a NIST traceable calibration source, potentially allowing development of multicentre clinical decision limits. Its role in disease management warrants further assessment.

Gallium-68 (Ga-68) labelled prostate-specific membrane antigen (PSMA) imaging by positron emission tomography (PET) has emerged as a promising tool for staging of prostate cancer and restaging of disease in recurrence or biochemical failure after definitive treatment of prostate cancer. Ga-68 PSMA PET produces high target-to-background images of prostate cancer and its metastases which are reflective of the significant overexpression of PSMA in these cells and greatly facilitates tumour detection. However, relatively little is known about the PSMA expression of benign neoplasms and non-prostate epithelial malignancies. This is a case report of PSMA uptake in an adrenal adenoma incidentally discovered on PET performed for restaging of biochemically suspected prostate cancer recurrence. With the increasing use of PSMA PET in the management of prostate cancer - and the not infrequent occurrence of adrenal adenomas - the appearance of low- to moderate-grade PSMA uptake in adrenal adenomas should be one with which reporting clinicians are familiar.

Gallium-68 ((68) Ga)-labelled somatostatin analogue imaging by positron emission tomography (PET) is increasingly replacing single photon (such as (111) In-labelled octreotide) imaging in the detection and staging of carcinoid and other neuroendocrine tumours. Among other tissues, pituitary uptake of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-octreotate (DOTA-TATE) and other somatostatin analogues is physiological. DOTA-TATE also accumulates in meningiomas, which have a high density of somatostatin receptor expression. The combination of pituitary and skull base meningioma uptake results in a characteristic 'double hot spot' appearance, which indicates the presence of a meningioma. This is a case of a middle-aged woman who underwent (68) Ga-DOTA-TATE PET for confirmation and staging of clinically suspected carcinoid tumour, in whom a skull base meningioma was incidentally discovered. With the increasing use of PET in the management of neuroendocrine tumours - and the not infrequent occurrence of meningiomas - the appearance of meningiomas on somatostatin analogue imaging should be one with which reporting clinicians are familiar.

We report on a case of biopsy-proven and MRI-staged rectal carcinoma with avid prostate-specific membrane antigen (prostate-specific membrane antigen) uptake on Ga PET/CT as part of the workup for synchronous prostate cancer. This case adds to the growing number of observational reports on the presence of significant nonprostatic prostate-specific membrane antigen activity in malignant tumors and highlights the need for careful interpretation of unsuspected sites.

We present a unified approach for atomistic modeling of torsion and bending of nanowires that is free from artificial end effects. Torsional and bending periodic boundary conditions (t-PBC and b-PBC) are formulated by generalizing the conventional periodic boundary conditions (PBC) to cylindrical coordinates. The approach is simpler than the more general objective molecular dynamics formulation because we focus on the special cases of torsion and bending. A simple implementation of these boundary conditions is presented and correctly conserves linear and angular momenta. We also derive the virial expressions for the average torque and bending moment under these boundary conditions that are analogous to the virial expression for the average stress in PBC. The method is demonstrated by molecular dynamics simulation of Si nanowires under torsion and bending, which exhibit several modes of failure depending on their diameters.

The adoption of multiple time step integrators can provide substantial computational savings for mechanical systems with multiple time scales. However, the scope of these savings may be limited by the range of allowable time step choices. In this paper we analyze the linear stability of the fully asynchronous methods termed AVI, for asynchronous variational integrators. We perform a detailed analysis for the case of a one-dimensional particle moving under the action of a soft and a stiff quadratic potential, integrated with two time steps in rational ratios. In this case, we provide sufficient conditions for the stability of the method. These generalize to the fully asynchronous AVI case the results obtained for synchronous multiple time stepping schemes, such as r-RESPA, which show resonances when the larger time step is a multiple of the effective half-period of the stiff potential. Additionally, we numerically investigate the appearance of instabilities. Based on the experimental observations, we conjecture the existence of a dense set of unstable time steps when arbitrary rational ratios of time steps are considered. In this way, unstable schemes for arbitrarily small time steps can be obtained. However, the vast majority of these instabilities are extremely weak and do not present an obstacle to the use of these integrators. We then applied these results to analyze the stability of multiple time step integrators in the more complex mechanical systems arising in molecular dynamics and solid dynamics. We explained why strong resonances are ubiquitously found in the former, while rarely encountered in the latter. Finally, in this paper we introduce a formulation of AVI that highlights the symplectic nature of the algorithm, complementing those introduced earlier by other authors.

In this paper we provide an overview of model-based approaches to audio processing, with an emphasis on restoration and interpretable analysis. Application areas include denoising/declicking and correction of nonlinear distortions such as clipping and poor quantisation. We highlight the potential benefits arising from a carefully constructed model-based approach to audio problems, in which any prior knowledge about the generative mechanism for the data can be incorporated quantitatively into the restoration framework. We propose that model-based methods are the principal means by which high level inferences about an audio signal can be achieved in future work.

J.W. McConnell (1877–1963) was one of the most successful Canadian businessmen of his time, and possibly the richest man in Canada for much of his life. A promoter of stocks early in his career, he soon became a major industrialist and investor. He was president of St. Lawrence Sugar Refineries Limited for almost fifty years and publisher of the Montreal Daily Star and other newspapers for almost twenty-five. Among the companies of which he was a major shareholder were the International Nickel Company of Canada, Brazilian Traction, Montreal Tramways, Montreal Light, Heat and Power, Ogilvie Flour Mills, Canada Steamship Lines, and Borden. His reputation spread to Wall Street and the City of London, not only for his business acumen but also for his great generosity to medical and educational causes. He was one of the principal founders of the Montreal Neurological Institute. From 1909 to 1927, he was one of the most effective fundraisers in the country, for the YMCA, the war effort through Victory Loans, and the hospitals of Montreal. And for the remainder of his life he was the most generous contributor to good causes in Montreal if not in Canada as a whole.With Lord Strathcona and Sir William Macdonald, he became one of the three greatest benefactors of McGill. After the death of Sir Edward Beatty, the Chancellor of the university, in 1943, McConnell was a natural candidate to succeed him. The board of governors, who were responsible for choosing a new Chancellor, were nearly all businessmen like him, and his assumption of the post would have been indeed in the tradition of James Ferrier, Strathcona, Macdonald and Beatty. But McConnell did not become Chancellor, and this is the story of why he did not. In abbreviated form, this was published in chapter 17 of the author’s biography of McConnell in 2008. This article however presents considerably more detail.ResuméJ.W. McConnell (1877–1963) fut un des hommes d’affaires les plus prospères de son époque, et possiblement un des hommes les plus riches du Canada pour la plus grande partie de sa vie. Promoteur d’actions au début de sa carrière, il devint rapidement un industriel et un investisseur d’importance. Il fut président de la compagnie St. Lawrence Sugar Refineries Limited pendant presque cinquante ans, et éditeur du Montreal Daily Star et de divers autres journaux pendant presque vingt-cinq ans. Il fut un actionnaire important de plusieurs compagnies, notamment International Nickel Company of Canada, Brazilian Traction, Montreal Tramways, Montreal Light, Heat and Power, Ogilvie Flour Mills, Canada Steamship Lines, et Borden. Sa réputation se progagea jusqu’à Wall Street et Londres, non seulement pour sa perspicacité en affaires mais aussi pour sa grande générosité envers les bonnes causes dans les domaines de la medecine et de l’éducation. Il fut un des fondateurs principaux de l’Institut neurologique de Montréal. De 1909 à 1927, il fut un collecteur de fonds les plus efficaces au Canada, au profit de l’organisme YMCA, de l’effort de guerre par le biais du programme des Prêts de la victoire, et des hôpitaux montréalais. Il demeura pour le reste de sa vie un fort généreux contributeur aux bonnes causes à Montréal, sinon au Canada tout entierAvec Lord Strathcona et Sir William Macdonald, il devint une des trois plus grands bienfaiteurs de l’Université McGill. Après la mort de Sir Edward Beatty, le chancelier de l’Université, en 1942, McConnell fut un candidat tout désigné pour lui succéder. Les membres du Conseil des gouverneurs, qui avaient la responsabilité de choisir un nouveau chancelier, étaient presque tous des hommes d’affaire comme lui, et il aurait été dans la tradition de James Ferrier, Strathcona, Macdonald et Beatty que McConnell accède à ce poste. Toutefois, McConnell ne devint pas chancelier, et ceci est l’histoire qui raconte pourquoi il ne l’est pas devenu. Elle a été publiée sous la forme du chapitre 17 de la biographie de McConnell. Cet article, toutefois, présente considérablement plus de détails.

Gallium-68 ((68) Ga)-labelled somatostatin analogue imaging by positron emission tomography (PET) is increasingly replacing single photon (such as (111) In-labelled octreotide) imaging in the detection and staging of carcinoid and other neuroendocrine tumours. Among other tissues, pituitary uptake of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-octreotate (DOTA-TATE) and other somatostatin analogues is physiological. DOTA-TATE also accumulates in meningiomas, which have a high density of somatostatin receptor expression. The combination of pituitary and skull base meningioma uptake results in a characteristic 'double hot spot' appearance, which indicates the presence of a meningioma. This is a case of a middle-aged woman who underwent (68) Ga-DOTA-TATE PET for confirmation and staging of clinically suspected carcinoid tumour, in whom a skull base meningioma was incidentally discovered. With the increasing use of PET in the management of neuroendocrine tumours - and the not infrequent occurrence of meningiomas - the appearance of meningiomas on somatostatin analogue imaging should be one with which reporting clinicians are familiar.

A patient had thrombocytopenia 15 years after splenectomy for idiopathic thrombocytopenia. A liver-spleen scan was requested to identify possible splenic regrowth. Heat-denatured erythrocyte scintigraphy showed normal hepatic activity, with increased radiotracer activity in the splenic bed, possibly representing significant splenic regrowth. However, both computed tomographic and magnetic resonance images of the abdomen confirmed that the scintigraphic findings represented contiguous tissues arising from the left lobe of the liver, giving a liver-tail appearance with all imaging methods. There was no evidence of splenosis elsewhere. Pseudospleen appearance on labeled erythrocyte studies is a potential problem in patients after splenectomy.

Prevention of hemodialysis subclavian vein catheter infections by topical povidone-iodine. Subclavian catheter (SCC) related infections are a major cause of morbidity in hemodialysis patients, the vast majority due to staphylococci species Povidone-iodine (PI) has proven anti-staphylococcal activity. Therefore, a randomized controlled trial of topical PI ointment was undertaken to evaluate the impact of this prophylactic intervention on the incidence of SCC related infections in hemodialysis patients. The role of S. aureus nasal carrier state in the acquisition of infection was also evaluated. Patients requiring SCC for temporary hemodialysis access were randomized to receive the treatment (T; N = 63) or sterile gauze dressings alone (C; N = 66). Catheter duration ranged from 2 to 210 days in both groups, with a mean of 38.6 days in T and 36.2 days in C (NS). Exit site (ES) infections were significantly less in T (5%) versus C (18%) (P < 0.02); tip colonization (TC) was 17% in T versus 36% in C (P < 0.01), while the incidence of septicemia (S) was also significantly less in C (2%) versus C (17%; P < 0.01). S. aureus nasal carriers were at a threefold higher risk of SCC related septicemia (0.009/day) than noncarriers (0.003/day; P < 0.05). The beneficial effect of PI ointment was most evident in this high risk group of S. aureus carriers: ES = 0% T versus 24% C, TC = 12% T versus 42% C, S = 0% T versus 29% C, P < 0.05. There were no adverse effects of the treatment. The routine application of topical PI ointment to temporary hemodialysis catheter exit sites is effective in reducing SCC related infections.

We develop methods for Monte Carlo filtering and smoothing for estimating an unobserved state given a non-linearly distorted signal. Due to the lengthy nature of real signals, we suggest processing the data in blocks and a block-based smoother algorithm is developed for this purpose. In particular, we describe algorithms for de-quantisation and declipping in detail. Both algorithms are tested with real audio data which is either heavily quantised or clipped and the results are shown.

We describe methods for applying Monte Carlo filtering and smoothing for estimation of unobserved states in a nonlinear state-space model. By exploiting the statistical structure of the model, we develop a Rao-Blackwellized particle smoother. Due to the lengthy nature of real signals, we suggest processing the data in blocks, and a block-based smoother algorithm is developed for this purpose. All the algorithms suggested are tested with real speech and audio data, and the results are shown and compared with those generated using the generic particle smoother and the extended Kalman filter (EKF). It is found that the proposed Rao-Blackwellized particle smoother improves on the standard particle smoother and the extended Kalman smoother. In addition, the proposed Block-based smoother algorithm enhances the efficiency of the proposed Rao-Blackwellized smoother by significantly reducing the storage capacity required for the particle in, formation.