Evidence for a very slow X-ray pulsar in 2S0114+650 from RXTE All-Sky Monitor Observations

Rossi X-ray Timing Explorer (RXTE) All-Sky Monitor (ASM) observations of the X-ray binary 2S0114+650 show modulations at periods close to both the optically derived orbital period (11.591 days) and proposed pulse period (~ 2.7 hr). The pulse period shows frequency and intensity variability during the more than 2 years of ASM observations analyzed. The pulse properties are consistent with this arising from accretion onto a rotating neutron star and this would be the slowest such period known. The shape of the orbital light curve shows modulation over the course of the entire orbit and a comparison is made with the orbital light curve of Vela X-1. However, the expected phase of eclipse, based on an extrapolation of the optical ephemeris, does not correspond with the observed orbital minimum. The orbital period derived from the ASM light curve is also slightly longer than the optical period.Comment: To be published in the Astrophysical Journal, 1999, volume 511. 9 figure

4U2206+54 - an Unusual High Mass X-ray Binary with a 9.6 Day Orbital Period but No Strong Pulsations

Rossi X-ray Timing Explorer All-Sky Monitor observations of the X-ray source 4U2206+54, previously proposed to be a Be star system, show the X-ray flux to be modulated with a period of approximately 9.6 days. If the modulation is due to orbital variability then this would be one of the shortest orbital periods known for a Be star X-ray source. However, the X-ray luminosity is relatively modest whereas a high luminosity would be predicted if the system contains a neutron star accreting from the denser inner regions of a Be star envelope. Although a 392s pulse period was previously reported from EXOSAT observations, a reexamination of the EXOSAT light curves does not show this or any other periodicity. An analysis of archival RXTE Proportional Counter Array observations also fails to show any X-ray pulsations. We consider possible models that may explain the properties of this source including a neutron star with accretion halted at the magnetosphere and an accreting white dwarf.Comment: Accepted for publication in the Astrophysical Journa

Unique phase recovery for nonperiodic objects

It is well known that the loss of phase information at detection means that a diffraction pattern may be consistent with a multitude of physically different structures. This Letter shows that it is possible to perform unique structural determination in the absence of a priori information using x-ray fields with phase curvature. We argue that significant phase curvature is already available using modern x-ray optics and we demonstrate an algorithm that allows the phase to be recovered uniquely and reliably. DOI: 10.1103/PhysRevLett.91.203902 PACS numbers: 42.30.Rx, 41.50.+h, 61.10.Nz, 87.10.+e Since the discovery of the laws describing the diffraction of x rays by crystals, x-ray diffraction has played a pivotal role in developing an understanding of the physics of materials and is a central technique of modern structural biology. The development of very high-brightness x-ray sources, such as third-generation synchrotron sources, enables diffraction data to be acquired from ever-smaller samples. The loss of phase information at measurement may be compensated by introducing additional information via, for example, atomicity assumptions in direct methods The diffraction imaging work of Miao et al. [5], following on from the ideas of Sayre and colleagues Recent work has shown that noninterferometric phase recovery is possible in real space for x rays [10], along with other forms of waves Suppose a coherent x-ray wave, inc r r; z, wherer r is a two-dimensional vector, strikes a finite sample and produces a diffracted wave diff . The sample is assumed to be sufficiently small so that the diffracted field is detected in the far field and its diffracting properties are contained in its 3D scattering potential, Vr r; z. In the far field, diff r r; z ! diff r , where r is the distance of the observation point from the detector point, x ; y ; 1 ÿ 2 x ÿ 2 y q is the unit vector in the direction of propagation, and we define x ; y . As a very small sample will only diffract x rays weakly, we adopt the Born approximation so that the diffracted wave is described by diff r inc r f r ; where where k 0 2=, and is the wavelength. In the P H Y S I C A

Partnerships to Address School Safety through a Student Support Lens

School safety is a primary concern of school leaders, employees, parents, and a variety of community stakeholders. Attempts to mitigate and prevent school safety concerns often focus on strategies around school climate assessment, emergency communication, school safety plan development, and school resource officer employment (U.S. DHS et al., 2018). Involvement of key stakeholders, such as school social workers, school counselors, and school-based mental health professionals is emphasized in creating and assessing school safety in a wholistic manner. This article provides an overview of a Trainings to Increase School Safety grant program that was implemented with public school stakeholders through partnerships between a university and five public school districts in the Southeastern North Carolina region

RXTE Observations of the Be star X-ray Transient X0726-260 (4U0728-25) - Orbital and Pulse Periods

Rossi X-ray Timing Explorer (RXTE) All Sky Monitor observations of the transient Be star X-ray source X0726-260 suggest a 34.5 day period. This is apparently confirmed by a serendipitous RXTE Proportional Counter Array (PCA) slew detection of the source on 1997 May 5, near the time of a predicted flux maximum. A subsequent 5000 second pointed observation of X0726-260 with the RXTE PCA detector was carried out on 1997 June 7, when X0726-260 was predicted to be bright again, and this revealed pulsations at a period of 103.2 seconds. If the 34.5 day period is orbital, then the pulse period is surprisingly long compared to that predicted by the correlation between orbital period and spin period observed for other Be/neutron star systems. A possible similarity with GROJ2058+42 is briefly discussed.Comment: 7 pages LateX, 7 figures. To be published in Astrophysical Journal Letter

Alcoholism and recovery: A case study of a former professional footballer

What little we know about alcoholism amongst professional footballers comes largely from the media (often tabloid newspapers) and published autobiographies and biographies of high profile stars. The coverage often focuses on deviant behaviour when drunk, such as driving under the influence, marital infidelity, violence, and breaking team rules. There is little or no published research which seeks to understand better what it is like to suffer from alcoholism from the perspective of the player-addicts themselves. In this paper I present a case study of British footballer who had a brief professional career and is in recovery from alcoholism. His subjective experience of alcoholism provides valuable insights into the underlying triggers and/or causes of the illness; its destructive nature; the link between the individual’s addiction and his social circumstances (including football); and his recovery

Evaluation of dipstick analysis among elderly residents to detect bacteriuria: a cross-sectional study in 32 nursing homes

Background: Up to half the residents of nursing homes for the elderly have asymptomatic bacteriuria (ABU), which should not be treated with antibiotics. Thus, it is difficult to know if new symptoms in residents with bacteriuria are caused by urinary tract infection (UTI), or if bacteriuria only represents an ABU. This is especially difficult in the presence of non-urinary tract specific symptoms. The diagnostic uncertainty is likely to generate significant overtreatment with UTI antibiotics. Aim: The general aim was to clarify the association between symptoms, bacteriuria, dipstick urinalysis and urine Interleukin-6 (IL-6) among nursing home residents to improve the diagnostic procedure of a suspected lower UTI. Methods: In 2003 a study protocol including newly onset symptoms was completed, and single voided urine specimens collected for dipstick urinalysis and cultures from 651 residents of 32 participating Swedish nursing homes for the elderly. This data was used for a study of dipstick urinalysis (Paper I) and for a study of nonspecific symptoms and bacteriuria (Paper II). In 2012, similar data was collected for 421 elderly residents of 22 nursing homes, which also included an analysis of IL-6 in urine and urine specimens from another 59 residents with urinary catheters. The association between bacteriuria, IL-6 in urine, dipstick urinalysis and newly onset symptoms was analysed (Paper III). Antimicrobial resistance rates were described among residents of nursing homes in 2012 and compared with those from 2003 (Paper IV). Results: Paper I: The negative predictive value for predicting absence of bacteriuria was 88 (84-92)% when dipstick urinalysis for nitrite and leukocyte esterase were simultaneously negative. A positive dipstick or any combination thereof could not sufficiently predict bacteriuria. Papers II-III: New or increased nonspecific symptoms were common among elderly residents of nursing homes. Residents without nonspecific symptoms had positive urine cultures as often as those with nonspecific symptoms with a duration of up to one month. Paper III: Residents with positive urine cultures had higher concentrations of IL-6 in the urine. However, among residents with positive urine cultures there were no differences in IL-6 concentrations or dipstick findings between those with or without nonspecific symptoms. Paper IV: The average rates of antimicrobial resistance were low and did not increase between 2003 and 2012 in Escherichia coli (E. coli) urinary isolates among Swedish nursing home residents. Any antibiotic treatment during the last month and hospitalization during the last six months predicted higher resistance rates among E. coli. Conclusions: Nonspecific symptoms among elderly residents of nursing homes are unlikely to be caused by bacteria in the urine. Therefore, dipstick urinalysis, IL-6 in the urine and urine cultures are of little or no value in clarifying the aetiology of nonspecific symptoms. If there is a reason for testing for bacteriuria, dipstick urinalysis for nitrite and leukocyte esterase can rule out but cannot reliably rule in bacteriuria. Antimicrobial resistance in urinary pathogens among Swedish nursing home residents remained low. It is important to use antibiotics rationally to preserve the effectiveness of antibiotics

Discrimination Training with Multimodal Stimuli Changes Activity in the Mushroom Body of the Hawkmoth Manduca sexta

The mushroom bodies of the insect brain play an important role in olfactory processing, associative learning and memory. The mushroom bodies show odor-specific spatial patterns of activity and are also influenced by visual stimuli.Functional imaging was used to investigate changes in the in vivo responses of the mushroom body of the hawkmoth Manduca sexta during multimodal discrimination training. A visual and an odour stimulus were presented either together or individually. Initially, mushroom body activation patterns were identical to the odour stimulus and the multimodal stimulus. After training, however, the mushroom body response to the rewarded multimodal stimulus was significantly lower than the response to the unrewarded unimodal odour stimulus, indicating that the coding of the stimuli had changed as a result of training. The opposite pattern was seen when only the unimodal odour stimulus was rewarded. In this case, the mushroom body was more strongly activated by the multimodal stimuli after training. When no stimuli were rewarded, the mushroom body activity decreased for both the multimodal and unimodal odour stimuli. There was no measurable response to the unimodal visual stimulus in any of the experiments. These results can be explained using a connectionist model where the mushroom body is assumed to be excited by olfactory stimulus components, and suppressed by multimodal configurations.Discrimination training with multimodal stimuli consisting of visual and odour cues leads to stimulus specific changes in the in vivo responses of the mushroom body of the hawkmoth