Ultra-luminous X-ray sources as super-critical propellers

We study the evolution of newborn neutron stars in high-mass X-ray binaries interacting with a wind-fed super-Eddington disk. The inner disk is regularized to a radiation-dominated quasi-spherical configuration for which we calculate the inner radius of the disk, the total luminosity of the system and the torque acting on the neutron star accordingly, following the evolution of the system through the ejector and early propeller stages. We find that the systems with $B \gtrsim 10^{13}$ G pass through a short ($\sim 20\,{\rm yr}$) ejector stage appearing as supernova impostors followed by a propeller stage lasting $\sim 10^3\,{\rm yr}$. In the super-critical propeller stage the system is still bright ($L\sim 10^{40}\,{\rm erg\, s^{-1}}$) due to the spindown power and therefore appears as an ultra-luminous X-ray source (ULX). The system evolves into pulsating ULX (PULX) when the neutron star spins down to a period ($P\sim 1$ s) allowing for accretion onto its surface to commence. Systems with lower magnetic fields, $B \sim 10^{11}$ G, pass through a long ($10^5\,{\rm yr}$) super-critical propeller stage with luminosities similar to those of the ultra-luminous super-soft sources (ULS), $L \lesssim 10^{40}\,{\rm erg\, s^{-1}}$. The equilibrium periods of these systems in the accretion stage is about $10\,{\rm ms}$, which is much smaller than the typical period range of PULX observed to date. Such systems could have a larger population, but their pulsations would be elusive due to the smaller size of the magnetosphere. Our results suggest that the ULS and some nonpulsating ULX are rapidly spinning and highly magnetized young neutron stars at the super-critical propeller stage.Comment: ApJ in press. 9 pages, 4 figure

The anomalous x-ray pulsar 4U 0142+61: a neutron star with a gaseous fallback disk

The recent detection of the anomalous X-ray pulsar (AXP) 4U 0142+61 in the mid infrared with the Spitzer Observatory (Wang, Chakrabarty & Kaplan 2006) constitutes the first instance for a disk around an AXP. We show, by analyzing earlier optical and near IR data together with the recent data, that the overall broad band data can be reproduced by a single irradiated and viscously heated disk model

A natural limit on the observable periods of anomalous x-ray pulsars and soft gamma-ray repeaters

We investigate the dependence of the evolution of neutron stars with fallback disks on the strength of the magnetic dipole field of the star. Using the same model as employed by Ertan et al. (2009), we obtain model curves for different dipole fields showing that the neutron stars with magnetic dipole fields greater than ∼ 1013 G on the surface of the star are not likely to become anomalous X‐ray pulsars (AXPs) and soft gamma‐ray repeaters (SGRs). Other sources with conventional dipole fields evolve into the AXP phase if their disk can penetrate the light cylinder. The upper limits to the observed periods of AXP and SGRs could be understood if the disk becomes inactive below a low temperature around 100 K. We summarize our present and earlier results indicated by the evolutionary model curves of these sources with an emphasis on the importance of the minimum disk temperature and the X‐ray irradiation in the long‐term evolution of AXPs and SGRs with fallback disks

On fallback disks and magnetars

The discovery of a disk around the anomalous X-ray pulsar 4U 0142+61, has rekindled the interest in fallback disks around magnetars. We briefly review the assumptions of fallback disk models and magnetar models. Earlier data in optical and near IR bands combined with new Spitzer data in the mid-IR range are compatible with a gas disk. Higher multipole fields with magnetar strengths together with a dipole field of 1012-1013 G on the neutron star surface are compatible with the presence of a disk around the neutron star. The possible presence and properties of a fallback disk after the supernova explosion is a likely initial condition to complement the initial rotation period and initial dipole field in determining the evolutionary paths and different types of isolated neutron stars

Thin Disk Models of Anomalous X-ray Pulsars

We discuss the options of the fall-back disk model of Anomalous X-Ray Pulsars (AXPs). We argue that the power-law index of the mass inflow rate during the propeller stage can be lower than those employed in earlier models. We take into account the effect of the super-critical mass inflow at the earliest stages on the inner radius of the disk and argue that the system starts as a propeller. Our results show that, assuming a fraction of the mass inflow is accreted onto the neutron star, the fall-back disk scenario can produce AXPs for acceptable parameters.Comment: 6 pages, 2 figures, Proc. of the II BeppoSAX Meeting: "The Restless High-Energy Universe" (Amsterdam, May 5-8, 2003), E.P.J. van den Heuvel, J.J.M. in 't Zand, and R.A.M.J. Wijers Ed

Uma análise epidemiológica das infecções urinárias por Candida spp. em unidade de terapia intensiva

Background and objectives: The finding of Candida species in urine is an usual finding and is called candiduria. There is an increase in the frequency of urinary tract infections (UTI) caused by Candida especially in critically ill patients. This study aimed to determine the epidemiological, clinical, and mycological characteristics of Candida urinary infections in intensive care unit (ICU) and antifungal susceptibilities. Methods: Urine cultures of 394 ICU patients with clinical suspicion of UTI were evaluated. After 24-48 hours of incubation, colonies appeared to grow as yeast, were morphologically examined by Gram staining. Candida strains that grew 104 ≥ CFU/mL in urine cultures were accepted as candiduria. The susceptibilities of the Candida strains to amphotericin B, itraconazole, fluconazole, voriconazole, flucytosine, and caspofungin were investigated with broth microdilution method. Results: The distribution of the isolated 100 urinary Candida strains were as, 54 Candida albicans, 34 C. glabrata, 7 C. tropicalis, 2 C. kefyr, 2 C. lusitaniae, and 1 as C. parapsilosis. Among 100 Candida species isolated in our study susceptibility rates of amphotericin B, flucytosine, caspofungin, fluconazole, itraconazole, and voriconazole were 100%, 100%, 91%, 23%, 13%, 25.8%, respectively. Conclusion: Accurate identification of Candida spp., as well as the investigating the antifungal susceptibility, will be beneficial in terms of the effectiveness of the treatment and the prevention of resistance development.El hallazgo de especies de Candida en la orina es un hallazgo habitual y se denomina candiduria. Hay un aumento en la frecuencia de infecciones del tracto urinario (ITU) causadas por Candida, especialmente en pacientes críticamente enfermos. Este estudio tuvo como objetivo determinar las características epidemiológicas, clínicas y micológicas de las infecciones urinarias por Candida en la unidad de cuidados intensivos (UCI) y la susceptibilidad antifúngica. Métodos: Se evaluaron urocultivos de 394 pacientes de UCI con sospecha clínica de ITU. Después de 24-48 horas de incubación, las colonias parecían crecer como levadura, se examinaron morfológicamente mediante tinción de Gram. Las cepas de Candida que crecieron 104 ≥ UFC / ml en urocultivos se aceptaron como candiduria. Las susceptibilidades de las cepas de Candida a la anfotericina B, itraconazol, fluconazol, voriconazol, flucitosina y caspofungina se investigaron con el método de microdilución en caldo. Resultados: La distribución de las cepas 100 urinarias aisladas de Candida fue de, 54 C. albicans, 34 C. glabrata, 7 C. tropicalis, 2 C. kefyr, 2 C. lusitaniae y 1 como C. parapsilosis. Entre las 100 especies de Candida aisladas en nuestro estudio, las tasas de susceptibilidad de anfotericina B, flucitosina, caspofungina, fluconazol, itraconazol y voriconazol fueron 100%, 100%, 91%, 23%, 13%, 25,8%, respectivamente. Conclusión: La identificación precisa de Candida spp., así como la investigación de la susceptibilidad antifúngica, será beneficiosa en términos de la eficacia del tratamiento y la prevención del desarrollo de resistencias.O achado de espécies de Candida na urina é um achado comum e é chamado de candidúria. Há um aumento na frequência de infecções do trato urinário (ITU) causadas por Candida, principalmente em pacientes críticos. Este estudo teve como objetivo determinar as características epidemiológicas, clínicas e micológicas das infecções urinárias por Candida em unidade de terapia intensiva (UTI) e a susceptibilidade aos antifúngicos. Métodos: Foram avaliadas culturas de urina de 394 pacientes de UTI com suspeita clínica de ITU. Após 24-48 horas de incubação, as colônias pareceram crescer como leveduras, foram morfologicamente examinadas por coloração de Gram. As cepas de Candida que cresceram ≥104 UFC/mL em culturas de urina foram aceitas como candidúria. As suscetibilidades das cepas de Candida à anfotericina B, itraconazol, fluconazol, voriconazol, flucitosina e caspofungina foram investigadas com o método de microdiluição em caldo. Resultados: A distribuição das cepas 100 isoladas de Candida urinária foi de 54 Candida albicans, 34 C. glabrata, 7 C. tropicalis, 2 C. kefyr, 2 C. lusitaniae e 1 como C. parapsilosis. Entre 100 espécies de Candida isoladas em nosso estudo, as taxas de susceptibilidade de anfotericina B, flucitosina, caspofungina, fluconazol, itraconazol e voriconazol foram de 100%, 100%, 91%, 23%, 13%, 25,8%, respectivamente. Conclusão: A identificação precisa de Candida spp., bem como a investigação da susceptibilidade aos antifúngicos, será benéfica em termos de eficácia do tratamento e prevenção do desenvolvimento de resistência

ATTITUDES OF PREHOSPITAL EMERGENCY HEALTH CARE WORKERS TOWARDS SPINAL CORD IMMOBILIZATION IN PATIENTS WITH MULTIPLE TRAUMA

INTRODUCTION: To evaluate the attitudes of prehospital emergency health care workers towards spinal cord immobilization in trauma patients. MATERIAL AND METHODS: This is a descriptive study, and its participants were 407 pre-hospital emergency healthcare workers working in a province in the west of the country between April 2022 and October 2022. The data were collected online with a questionnaire consisting of twenty-four questions. Statistical significance was defined as a p-value of 0.05 for all analyses. RESULTS: 73% of the participants that they decided to perform routine spinal cord immobilization in all trauma patients regardless of the clinical findings. 85% of the participants said they generally preferred the backboard for spinal cord immobilization of trauma-injured people. CONCLUSIONS: The study showed that prehospital emergency health care workers stated that they routinely perform spinal cord immobilization in every traumatized patient, despite knowing the indication for spinal cord immobilization of trauma patients

Disks Surviving the Radiation Pressure of Radio Pulsars

The radiation pressure of a radio pulsar does not necessarily disrupt a surrounding disk. The position of the inner radius of a thin disk around a neutron star can be estimated by comparing the electromagnetic energy density generated by the neutron star with the kinetic energy density of the disk. Inside the light cylinder, the near zone electromagnetic field is essentially the dipole magnetic field, and the inner radius is the conventional Alfven radius. Far outside the light cylinder, in the radiation zone, $E=B$ and the electromagnetic energy density is $/c \propto 1/r^2$ where $S$ is the Poynting vector. Shvartsman (1970) argued that a stable equilibrium can not be found in the radiative zone because the electromagnetic energy density dominates over the kinetic energy density, with the relative strength of the electromagnetic stresses increasing with radius. In order to check whether this is true also near the light cylinder, we employ global electromagnetic field solutions for rotating oblique magnetic dipoles (Deutsch 1955). Near the light cylinder the electromagnetic energy density increases steeply enough with decreasing $r$ to balance the kinetic energy density at a stable equilibrium. The transition from the near zone to the radiation zone is broad. The radiation pressure of the pulsar can not disrupt the disk for values of the inner radius up to about twice the light cylinder radius if the rotation axis and the magnetic axis are orthogonal. This allowed range beyond the light cylinder extends much further for small inclination angles. We discuss implications of this result for accretion driven millisecond pulsars and young neutron stars with fallback disks.Comment: Accepted by Astrophysical Journal, final version with a minor correctio

The impact of risk on Public Administration and social structure

Piyasa temelli üretim şekli toplumların karşı karşıya olduğu riskleri çeşitlendirmiş, risklerin oluşma olasılıklarını ve büyüklüklerini arttırmıştır. Yerel, bölgesel ve küresel boyutta risklerin artması ise toplumların risk toplumuna dönüşmelerine neden olmuştur. Özellikle gelişmekte olan ülkelerde, toplumların en önemli kaygılarından birisi, karşı karşıya oldukları risklerin yönetimi olmuştur. Toplumların hayatta kalabilmelerinde karşı karşıya oldukları risklere karşı direnç gösterebilmeleri gerekli olmuş, devletlerinde uluslararası egemenliklerini koruyabilmelerinde riskleri başarı ile yönetebilmeleri gerekmiştir. Çeşitlenen ve büyüyen risklerin yönetimi için güçlü bir kamu yönetimi ile birlikte, sorun çözme kapasitesi olan ve risklere karşı dirençli bir toplum ön koşuldur. Ancak 20. yüzyılın son çeyreğinde kamu yönetimi işletmeciliğinin hakim paradigma olması ile birlikte, devlet küçülmüş, kamu kurumları uzmanlık alanlarına göre parçalanarak ayrışmıştır. Dolayısıyla kamu yönetiminde büyük sorunlara karşı çözüm geliştirme konusunda koordinasyon problemi ortaya çıkmıştır. Tüm bunlarla birlikte, toplumlar karşı karşıya oldukları sorunlar karşısında edilgen bir konuma gelmiş ve riskler karşısında direnç kaybetmişlerdir. Kamu yönetiminde paradigma arayışları ve sivil toplum alanındaki gelişmeler, devletlerin ve toplumların edilgen konumdan çıkıp, sorun çözme kapasitesinin geliştirilmesi üzerine yoğunlaşmıştır. Çalışmanın amacı, piyasacı üretim şeklinin oluşturduğu hasar ve güvenlik açıkları ile artan risklerle birlikte, kamu yönetiminde ve toplumsal yapıdaki değişimin değerlendirilmesidir. Çalışma, özellikle Temmuz 2016 sonrasında Türkiye’de yaşanan süreci ve kamu yönetimindeki değişimi anlamak adına önemli görülmektedir.The market-based production has diversified risks and also increased the likelihood and magnitude of risks faced by societies. Since local, regional, and global risks have rised, societies have become risk communities. Especially in developing countries, risk management is one of the biggest problems. Societies should be able to resist the risks they are facing in order to survive. And states need to be able to successfully manage their risks in order to protect their international sovereignty. A resilient society with problem-solving capacity and a strong public administration have become a precondition for managing diversified and mounting risks. But in the last quarter of the 20th century, together with the dominant paradigm of new public administration management, the state shrunk and the public institutions shrunk by fragmentation according to their areas of expertise. Thus, coordination problems emerged in search of solutions to the major problems of public administration. With all of this, societies have become passive in facing problems and they have lost their resistance to risks. The search for a paradigm in public administration has focused on enabling the states and societies to get rid of their passive positions and to develop their problem-solving capacities. The aim of this study is to assess the change in public administration and community structure, together with increased risk of damage and vulnerability of the market-based production. This study is particularly important for making sense of the change in the public administration of Turkey especially after July 2016