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We carried out new observations of two fields in the northern ring of M31 with XMM-Newton with two exposures of 100 ks each and obtained a complete list of X-ray sources down to a sensitivity limit of ~7 x 10^34 erg s^-1 (0.5 - 2.0 keV). The major objective of the observing programme was the study of the hot phase of the ISM in M31. The analysis of the diffuse emission and the study of the ISM is presented in a separate paper. We analysed the spectral properties of all detected sources using hardness ratios and spectra if the statistics were high enough. We also checked for variability. We cross-correlated the source list with the source catalogue of a new survey of the northern disc of M31 carried out with Chandra and Hubble (Panchromatic Hubble Andromeda Treasury, PHAT) as well as with other existing catalogues. We detected a total of 389 sources, including 43 foreground stars and candidates and 50 background sources. Based on the comparison to the Chandra/PHAT survey, we classify 24 hard X-ray sources as new candidates for X-ray binaries (XRBs). In total, we identified 34 XRBs and candidates and 18 supernova remnants (SNRs) and candidates. Three of the four brightest SNRs show emission mainly below 2 keV, consistent with shocked ISM. The spectra of two of them also require an additional component with a higher temperature. The SNR [SPH11] 1535 has a harder spectrum and might suggest that there is a pulsar-wind nebula inside the SNR. We find five new sources showing clear time variability. We also studied the spectral properties of the transient source SWIFT J004420.1+413702, which shows significant variation in flux over a period of seven months (June 2015 to January 2016) and associated change in absorption. Based on the likely optical counterpart detected in the Chandra/PHAT survey, the source is classified as a low-mass X-ray binary., Comment: Accepted for publication in A&A

The Andromeda Galaxy recurrent nova M31N 2008-12a had been observed in eruption ten times, including yearly eruptions from 2008-2014. With a measured recurrence period of $P_\mathrm{rec}=351\pm13$ days (we believe the true value to be half of this) and a white dwarf very close to the Chandrasekhar limit, M31N 2008-12a has become the leading pre-explosion supernova type Ia progenitor candidate. Following multi-wavelength follow-up observations of the 2013 and 2014 eruptions, we initiated a campaign to ensure early detection of the predicted 2015 eruption, which triggered ambitious ground and space-based follow-up programs. In this paper we present the 2015 detection; visible to near-infrared photometry and visible spectroscopy; and ultraviolet and X-ray observations from the Swift observatory. The LCOGT 2m (Hawaii) discovered the 2015 eruption, estimated to have commenced at Aug. $28.28\pm0.12$ UT. The 2013-2015 eruptions are remarkably similar at all wavelengths. New early spectroscopic observations reveal short-lived emission from material with velocities $\sim13000$ km s$^{-1}$, possibly collimated outflows. Photometric and spectroscopic observations of the eruption provide strong evidence supporting a red giant donor. An apparently stochastic variability during the early super-soft X-ray phase was comparable in amplitude and duration to past eruptions, but the 2013 and 2015 eruptions show evidence of a brief flux dip during this phase. The multi-eruption Swift/XRT spectra show tentative evidence of high-ionization emission lines above a high-temperature continuum. Following Henze et al. (2015a), the updated recurrence period based on all known eruptions is $P_\mathrm{rec}=174\pm10$ d, and we expect the next eruption of M31N 2008-12a to occur around mid-Sep. 2016., 46 pages, 19 figures, 14 tables, accepted for publication in ApJ (accepted version, minor changes made during the refereeing process)

Objective—To assess whether the 90 minute corrected thrombolysis in myocardial infarction frame count (CTFC) in the infarct related artery predicts left ventricular function at 48 hours in patients with myocardial infarction treated with aspirin, streptokinase, and either heparin or Hirulog. Design and setting—Analysis of 251 patients with acute myocardial infarction enrolled in the international, multicentre Hirulog early reperfusion/occlusion (HERO-1) trial, who underwent both 90 minute coronary angiography and 48 hour left ventriculography. Main outcome variables—The CTFC was determined in the infarct related artery 90 minutes after starting intravenous streptokinase (1.5 × 106 U over 30 to 60 minutes), and compared with indices of left ventricular function assessed by contrast ventriculography at 48 hours. Results—A CTFC of ⩽ 27 frames (previously reported mean + 2 SD in coronary arteries of patients without acute infarction) occurred in 29% of infarct related arteries, and was associated with a lower infarct zone mean chord score (−2.06 v −2.54, p = 0.01), a lower fraction of chords > 2 SD below normal (37% v 51%, p = 0.005), and trends towards higher left ventricular ejection fractions (60.9% v 58.2%, p = 0.11) and lower end systolic volumes (50.1 ml v 55.9 ml, p = 0.23). A CTFC of ⩽ 40 at 90 minutes occurred in 50% of infarct related arteries, and was associated with a significantly lower mean chord score (−2.20 v −2.60, p = 0.02), a smaller fraction of chords > 2 SD below normal (41% v 52%, p = 0.025), a smaller end systolic volume (49.1 ml v 59.3 ml, p = 0.02), and a higher left ventricular ejection fraction (60.4% v 56.5%, p = 0.03). Conclusions—The 90 minute CTFC predicts left ventricular function at 48 hours following streptokinase. The CTFC associated with better ventricular function may be higher than values determined from a non-infarct population. Keywords: streptokinase; Hirulog; perfusion; ventricular function; frame count

Cerebrovascular accidents (CVA) as a complication of sickle cell disease occur most frequently in childhood. Life-long transfusion prevents recurrent stroke, but inevitably leads to iron overload. Although effective chelation exists, many patients are not compliant. Erythrocytapheresis, an automated method of red blood cell exchange, was evaluated as an alternative to control transfusion-related iron load. Eleven patients with sickle cell anemia and a history of stroke were converted from simple transfusion to pheresis. Total time on pheresis for the group averaged 19 months (range 4-36 months). No significant complications occurred with a mean pre-pheresis hemoglobin S (Hb S) level of 44%. Blood utilization increased by an average of 50%. The effect of pheresis on serum ferritin depended on the patient's pre-pheresis ferritin level and chelation regimen. Ferritin levels remained stable for chelated patients with ferritin levelsor = 5,000 ng/ml, but decreased in a chelated patient with a pre-pheresis ferritin level of 4,000 ng/ml. For non-chelated patients with significant pre-pheresis iron load, ferritin levels remained stable. No patient on chelation prior to pheresis was able to discontinue deferoxamine. However, one patient with pre-pheresis ferritin of 500 ng/ml maintained serum ferritin levels200 ng/ml for 36 months of pheresis without chelation. Pheresis is more expensive than simple transfusion unless the cost of chelation and organ damage from iron overload are considered. Erythrocytapheresis is a safe method of controlling Hb S levels and limiting or preventing iron load in chronically transfused sickle cell patients.

To compare a thromboxane antagonist (GR3219) with aspirin in patients with prolonged chest pain and ST segment depression to see if the frequency of attacks of chest pain was reduced.The trial was part of a study comparing GR3219 with aspirin, and streptokinase with placebo and comprised the GR3219/aspirin leg. Thirty one patients were randomly assigned to GR3219 80 mg twice daily and 28 to aspirin 300 mg daily. The patients were under the age of 76 and admitted to a coronary care unit within 6 hours of continuous chest pain. The ECG showed at least 1 mm of flat or down-going ST segment. The patients kept diaries of their pain over the subsequent 31 days.Seventy percent of patients developed further chest pain. There was no difference between the pattern of recurrent chest pain according to which drug was used.The hypothesis that specific thromboxane A blockade with GR3219 would be more efficacious than aspirin was not supported by these results.

The effect of filtration on water fluoride level was investigated in a study using commercially available filters. Testing was carried out in London (low fluoride), Braintree (optimum fluoride, naturally occurring) and Birmingham (optimum fluoride, artificially adjusted). It was found that none of the filters removed fluoride. In Birmingham, but not in either Braintree or London, there was a small, clinically insignificant increase in fluoride levels with filtration using two of the five filters. It is concluded that the water filtration systems tested will not affect the advantage offered by optimum water fluoride levels. Fluoride dietary supplements should not be prescribed for children living in optimal fluoride areas, irrespective of whether they use household filters.

Alpha-interferon (alpha-IFN) therapy is an effective agent in early chronic phase (ECP) chronic myeloid leukemia (CML), achieving hematologic control in the majority and major cytogenetic response (MCR) (reduction in Ph' +ve metaphases to35%) in a substantial minority. Currently no pretreatment markers exist to ascertain likelihood of meaningful response. The site of breakpoint in M-bcr and relationship to prognosis is controversial. Studies have been hampered by variation in definition of breakpoint and difference in treatment protocols. In this study of ECP CML patients, Southern analysis and reverse transcription polymerase chain reaction (RT-PCR) were used to determine breakpoint location. Patients received alpha-IFN (9 x 10(6) units/day) and dose-adjusted hydroxyurea (HU) to maintain granulocyte count between 1.0-2.0 x 10(9)/l for 6 months or more. Twelve of 31 patients entered on the study achieved a MCR. The Sokal index did not predict for cytogenetic response to alpha-IFN. Eight of 11 patients with 5' breakpoint achieved MCR compared to only four of 20 patients with 3' breakpoint (P = 0.007). These results suggest site of M-bcr rearrangement may be predictive of response to alpha-IFN therapy. If verified by further study, this may allow more appropriate use of alpha-IFN with respect to other modalities such as allogeneic transplant.

Participation of NICU staff in special education teacher training is discussed as a method for improving follow-up care of high-risk infants and for helping agencies comply with Public Law 99-457, which mandates services for disabled preschoolers and encourages intervention for infants and toddlers. Through a collaborative training program involving a medical center and a university, education students spent 15 to 20 hours in the NICU. Nurses gained a greater understanding of community-based early intervention programs and available providers and made referrals with more confidence. Student teachers witnessed the medical conditions and treatments experienced by NICU patients, gaining an understanding of the types of medical histories their future clients would have. The collaborating hospital developed working relationships with agencies that provide follow-up care to NICU graduates. The article discusses medical and educational models of care, implications and benefits of incorporating developmental care into NICU practice, effects of the law on early intervention programs, and features of the model collaborative program.

Clinical and lifestyle parameters were assessed in 145 patients who were randomised in a double blind study comparing streptokinase or placebo given within four hours of the onset of ischaemic chest pain. Sixty-six percent of patients were in paid employment at the time of their infarct and 79% returned to paid employment. Patients who received streptokinase returned to work 17 days earlier (p less than 0.05) and returned to sport and leisure activities 33 days earlier (p less than 0.05) than those who received placebo. Those who had received streptokinase also tended to leave hospital earlier (0.8 days, p = 0.07). There were no differences in angioplasty or coronary surgery rates or the incidence of reinfarction in the first year (8%). Total community costs were reduced in the patients who received thrombolytic therapy. These findings have important implications in the benefit:cost analysis of thrombolytic therapy.

We present new optical images of the supernova remnant (SNR) W44 in the H-alpha and [S II] lines covering the entire source for the first time. We also report on improved radio image of W44 at 1442.5 MHz, obtained after the reprocessing of existing VLA data. A spectral index a of -0.4 was derived for the whole source, without indication of significant spectral variations between 0.3 and 1.4 GHz across the remnant. Accurate multiwavelength comparisons were made based on existing observations of W44 in the different spectral regimes. We find excellent correlation between optical and radio emission along the northwest border of the remnant, suggesting that the optical radiation is originating through radiative cooling of the shocked gas immediately behind the shock front. Some diffuse optical emission is also observed towards the interior of W44, with no clear radio counterpart. We confirm that over most of the source, the bright X-ray emission corresponds with regions of low radio brightness. At the northern border of the remnant, diffuse X-ray emission exactly overlaps the radio and optical radiation. From the study of the immediate environs of W44 we conclude that the remnant is interacting with molecular clouds along the eastern border. Such a scenario is compatible with the filamentary structure of W44, the excitation of OH masers and the apparent lack of optical emission along the eastern border. To the north, an extended atomic cloud surrounds the remnant, although the interaction is not evident in this case.

Since their introduction as laboratory devices about five years ago, negative electron affinity (NEA) electron emitters have found many applications for low-light-level detection. Over forty types of photomultiplier tubes with NEA materials are now available for detection of light from the ultraviolet to the near infrared. These devices provide useful photosensitivity to 1.1 micrometers. The detectors which are currently available will be reviewed, and the prospects for the near future will be discussed. A general summary of the contribution of NEA materials to low-light-level detection will be included.

Homo‐ and heteroepitaxial layers of GaAs were examined by transmission electron microscopy. The epitaxial layers contained four types of defects. These were intrinsic stacking faults, extrinsic faulted loops, dislocations, and precipitates. It is shown that, of these defects, the ones most responsible for limiting the minority‐carrier diffusion length are stacking faults.

The nuclear magnetic resonance in bismuth metal powder has been observed from 9 to 19 Mc/sec at 4.2\ifmmode^\circ\else\textdegree\fi{}K. The isotropic and anisotropic Knight shifts and the quadrupole coupling constant have been determined as (-1.25\ifmmode\pm\else\textpm\fi{}.30)%, (-0.3\ifmmode\pm\else\textpm\fi{}0.3)%, and 2.10\ifmmode\pm\else\textpm\fi{}.05 Mc/sec, respectively. The intrinsic linewidth was found to be 130\ifmmode\pm\else\textpm\fi{}20 kc/sec. A technique is developed to take into consideration the broadening of the observed lines due to the combined effects of the magnetic dipolar broadening and the width due to the quadrupolar splitting of each line.

Ga1−xInxAs alloys in the composition range 0≤x≥0.52 and band‐gap (Eg) range of 1.38 to 0.74 eV were activated with Cs and O2. Samples of different carrier concentrations were investigated. For band gaps down to about 0.8 eV, the photothreshold was equal to the band gap. The longest wavelength threshold determined was 1.58 μm. To the best of our knowledge, this represents the longest wavelength response yet achieved for photoemission into vacuum from a III‐V compound. The surface escape probability, B, was derived from the quantum yield data for each sample. The B‐vs‐Eg data were analyzed according to a surface escape model which includes the effects of (i) a finite‐width initial energy distribution of photoexcited carriers, (ii) the bent‐band region and (iii) various types of surface potential barriers. Surface escape probability data pertaining to a single doping density could be explained by a model that includes only a work‐function barrier or simple step potential. However, in order to explain the dat...

Auger electrons resulting from across-the-gap recombination are believed to have been identified by their velocity distribution which does not depend on the energy of the exciting photons.

The introduction of electron emitters utilizing negative electron affinity has greatly improved the performance of many conventional light-sensing devices. The unique properties of such emitters have also made possible devices which were heretofore not feasible. Since their arrival as laboratory curiosities about five years ago, these emitters have had a large impact in the area of low-light-level detection, particularly scintillation counting. Recent advances in materials technology and surface activation processes have brought negative electron affinity photocathodes to the market place for use as detectors for both the Nd and GaAs lasers. In both cases, the detectors are more than an order of magntiude more sensitive to the laser light than previous photocathodes, and the dark currents (thermionic emission from the cathodes which can be limiting in low-light-level use) are several orders of magnitude less. Several other applications of negative electron affinity are presently under development which may further affect photocathodes, photomultipliers, imaging devices, and even the time-honored thermionic cathode. The operating principles of this type of electron emitter, the present state of the art and its effect on device performance, and the possible developments in the near future are discussed.

The five nuclear quadrupole resonances of ${\mathrm{Sb}}^{121}$ and ${\mathrm{Sb}}^{123}$ have been measured at 4.2\ifmmode^\circ\else\textdegree\fi{}K giving the quadrupole couplings $eqQ=76.867\ifmmode\pm\else\textpm\fi{}0.001 \mathrm{and} 97.999\ifmmode\pm\else\textpm\fi{}0.001$ Mc/sec, respectively. The temperature dependence of the interaction has been measured from 2 to 480\ifmmode^\circ\else\textdegree\fi{}K. Both isotopes have the same temperature dependence of $(\frac{1}{\ensuremath{\nu}})(\frac{d\ensuremath{\nu}}{\mathrm{dT}})\ensuremath{\approx}2.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$\ifmmode^\circ\else\textdegree\fi{}${\mathrm{K}}^{\ensuremath{-}1}$. The ionic field gradient provides about 10% of this measured quadrupole coupling.

The secondary-emission process, which is fundamental to photomultipliers used in scintillation counters, can be considered to consist of three physical processes: (1) excitation of secondary electrons, (2) transport of these electrons through the solid, and (3) transport through the vacuum-solid interface. Based upon these processes, a model can be derived which explains the shape and magnitude of the secondary-emission yield curves as well as the velocity distribution of the emitted electrons. Furthermore, such a model can be useful in the search for better secondary emitters. The application of certain solid-state concepts such as band bending to the preparation and processing of appropriate semiconductors has led to enormous improvement in the transport and escape of secondary electrons and has made possible the development of a new type of secondary emitter with a maximum yield which is an order of magnitude or more greater than the yields of the best previously described materials. These secondary-electron emitters may be useful in producing multipliers with fewer stages, better statistics, and higher speeds than those presently available.

A mobile ionic species fixes thick‐phase holograms in Fe‐doped LiNbO3 crystals at temperatures between 100 and 200 °C. Results are given which show that Si ions are mobile at 200 °C in these crystals.

While there are several commercial businesses selling photovoltaic power supplies, the applications are all in places where conventional electric power is unavailable. The present interest in solar cell electricity for widespread terrestrial use has led to an intense activity exploring the opportunities for significant cost reduction. In this paper obstacles to cost reduction will be identified and the programs addressing techniques for overcoming those obstacles will be presented.

We have activated epitaxial layers of vapor‐deposited Ga1−xInxAs alloys in the bandgap range 0.96–1.18 eV with Cs and O2. The Cs–O was determined to be ∼1 monolayer thick. For each sample the photothreshold energy was approximately equal to the bandgap energy. A long‐wavelength limit of approximately 1.3 μm was determined for valence‐band emission. There was no evidence of an internal barrier which might have decreased this limit. Spectral yield data were analyzed to give a surface escape probability versus bandgap plot.

Electron emission into vacuum has been observed from a forward‐biased Cs‐ and O‐treated GaAs p‐n junction. The device was operated at room temperature with dc bias voltage. The effective efficiency of the device (emission current divided by internal diode current eligible for emission) was 0.05%, while the over‐all efficiency of the device (emission current divided by total diode current) was 10−6. The low over‐all efficiency is explained in terms of sample geometry and surface activation.

In this double-blind trial, the anticaries effectiveness of a test toothpaste formulated for young children with 550 ppm F was compared with that of a positive control toothpaste containing 1055 ppm fluoride. More than 3000 2-year-old children were enrolled in the study and after 3 years of toothpaste use, 2177 (72 per cent) were examined. From a clinical and radiographic assessment, more than half the children were found to be caries free and only 32 (1.5 per cent) had evidence of rampant caries. There appeared to be little or no difference between children who had used test or control pastes, either in caries or in plaque levels. On the basis of this clinical trial the experimental toothpaste with 550 ppm fluoride would appear to have a similar anticaries efficacy to that of the control toothpaste. Differences were seen in relation to sex of the child and to social class. Girls had lower levels of plaque than boys but more carious teeth. Children from families in higher social classes had fewer carious teeth and lower levels of plaque.

Optical data storage systems employing large varieties of different recording materials have been investigated in great detail over the last few years. In this paper, we present a review of most of the known classes of optical recording media and describe a procedure for identifying materials with potential interest for specific applications. To provide a context for demonstrating this point, we pick as an example an optical disc recording and playback system. We feel the most useful application of this type of analysis is to help eliminate those materials from consideration which are unlikely to meet system requirements.

Suite 6105 Doctor’s Office Tower 2200 Children’s Way Nashville, TN 37232-9780 Phone: 615.343.4673 Fax: 615.322.0370 / www.vanderbiltchildren’s.com Cleft Lip and Palate What are Cleft Lip and Cleft Palate? In the early weeks of fetal development, parts of the lip or palate (the roof of the mouth) usually fuse together. In some cases, however, this fusion does not occur and a cleft or separation occurs in the tissue, as seen in the diagrams below.

A new photomultiplier is described in which the recently reported GaP(Cs) material is used for the first dynode to obtain high secondary emission gain. Gain factors of 20 to 40 have been measured resulting in greatly improved performance of the new photomultiplier at very low light levels.

Internal photoemission quantum yield curves using a water electrolyte Schottky contact have been shown to be identical to vacuum photoemission activation yield curve shapes near threshold for negative electron affinity semiconductors GaAs, Ga0.81In0.19As, and GaAs/Ga0.52In0.48P/GaP. Reflection and semitransparent cathode Schottky yield curves can be generated on the bench in a matter of minutes.

The Cs content of GaAs(Cs) and GaAs(Cs–O) photocathodes was determined by direct chemical analysis. The surface films were found to be of monolayer dimension. From this result, it is concluded that the effect of these films on electron emission is probably not associated with the bulk properties of cesium oxide.

A new photocathode having high quantum yield for visible and ultraviolet radiation is reported. The cathode consists of a cesium‐activated strongly p‐type doped GaAs1−xPx alloy.