A multiwavlength study of PSR B0628-28: The first overluminous rotation-powered pulsar?

The ROSAT source RX J0630.8-2834 was suggested by positional coincidence to be the X-ray counterpart of the old field pulsar PSR B0628-28. This association, however, was regarded to be unlikely based on the computed energetics of the putative X-ray counterpart. In this paper we report on multiwavelength observations of PSR B0628-28 made with the ESO/NTT observatory in La Silla, the Jodrell Bank radio observatory and XMM-Newton. Although the optical observations do not detect any counterpart of RX J0630.8-2834 down to a limiting magnitude of V=26.1 mag and B=26.3 mag, XMM-Newton observations finally confirmed it to be the pulsar's X-ray counterpart by detecting X-ray pulses with the radio pulsar's spin-period. The X-ray pulse profile is characterized by a single broad peak with a second smaller peak leading the main pulse component by ~144 degree. The fraction of pulsed photons is (38 +- 7)% with no strong energy dependence in the XMM-Newton bandpass. The pulsar's X-ray spectrum is well described by a single component power law with photon index 2.63^{+0.23}_{-0.15}, indicating that the pulsar's X radiation is dominated by non-thermal emission processes. A low level contribution of thermal emission from residual cooling or from heated polar caps, cannot be excluded. The pulsar's spin-down to X-ray energy conversion efficiency is obtained to be ~16% for the radio dispersion measure inferred pulsar distance. If confirmed, PSR B0628-28 would be the first X-ray overluminous rotation-powered pulsar identified among all ~1400 radio pulsars known today.Comment: Accepted for publication in ApJ. Find a paper copy with higher resolution images at ftp://ftp.xray.mpe.mpg.de/people/web/astro-ph-0505488_rev2.pd

Divergent modulation of nociception by glutamatergic and GABAergic neuronal subpopulations in the periaqueductal gray

The ventrolateral periaqueductal gray (vlPAG) constitutes a major descending pain modulatory system and is a crucial site for opioid-induced analgesia. A number of previous studies have demonstrated that glutamate and GABA play critical opposing roles in nociceptive processing in the vlPAG. It has been suggested that glutamatergic neurotransmission exerts antinociceptive effects, whereas GABAergic neurotransmission exert pronociceptive effects on pain transmission, through descending pathways. The inability to exclusively manipulate subpopulations of neurons in the PAG has prevented direct testing of this hypothesis. Here, we demonstrate the different contributions of genetically defined glutamatergic and GABAergic vlPAG neurons in nociceptive processing by employing cell type-specific chemogenetic approaches in mice. Global chemogenetic manipulation of vlPAG neuronal activity suggests that vlPAG neural circuits exert tonic suppression of nociception, consistent with previous pharmacological and electrophysiological studies. However, selective modulation of GABAergic or glutamatergic neurons demonstrates an inverse regulation of nociceptive behaviors by these cell populations. Selective chemogenetic activation of glutamatergic neurons, or inhibition of GABAergic neurons, in vlPAG suppresses nociception. In contrast, inhibition of glutamatergic neurons, or activation of GABAergic neurons, in vlPAG facilitates nociception. Our findings provide direct experimental support for a model in which excitatory and inhibitory neurons in the PAG bidirectionally modulate nociception

Impact of random outliers in auto-segmented targets on radiotherapy treatment plans for glioblastoma.

AIMS To save time and have more consistent contours, fully automatic segmentation of targets and organs at risk (OAR) is a valuable asset in radiotherapy. Though current deep learning (DL) based models are on par with manual contouring, they are not perfect and typical errors, as false positives, occur frequently and unpredictably. While it is possible to solve this for OARs, it is far from straightforward for target structures. In order to tackle this problem, in this study, we analyzed the occurrence and the possible dose effects of automated delineation outliers. METHODS First, a set of controlled experiments on synthetically generated outliers on the CT of a glioblastoma (GBM) patient was performed. We analyzed the dosimetric impact on outliers with different location, shape, absolute size and relative size to the main target, resulting in 61 simulated scenarios. Second, multiple segmentation models where trained on a U-Net network based on 80 training sets consisting of GBM cases with annotated gross tumor volume (GTV) and edema structures. On 20 test cases, 5 different trained models and a majority voting method were used to predict the GTV and edema. The amount of outliers on the predictions were determined, as well as their size and distance from the actual target. RESULTS We found that plans containing outliers result in an increased dose to healthy brain tissue. The extent of the dose effect is dependent on the relative size, location and the distance to the main targets and involved OARs. Generally, the larger the absolute outlier volume and the distance to the target the higher the potential dose effect. For 120 predicted GTV and edema structures, we found 1887 outliers. After construction of the planning treatment volume (PTV), 137 outliers remained with a mean distance to the target of 38.5 ± 5.0 mm and a mean size of 1010.8 ± 95.6 mm3. We also found that majority voting of DL results is capable to reduce outliers. CONCLUSIONS This study shows that there is a severe risk of false positive outliers in current DL predictions of target structures. Additionally, these errors will have an evident detrimental impact on the dose and therefore could affect treatment outcome

Pumping Iron - How Do Race and Gender Affect the Risk of Anemia in a Cohort of Predominantly Hispanic Heart Failure (HF) Patients Seen in a Community Hospital in the Rio Grande Valley (RGV)?

Introduction Anemia in patients with heart failure (HF) is common. Data reported shows a variable prevalence ranging from 10-40%. Additionally, it has also been demonstrated that it is associated with poor outcomes. Multiple risk factors have been shown to contribute to the presence of anemia in HF patients (1). We were interested in determining the risk factors for anemia in HF patients in our population in the lower Rio Grande Valley. Methods We performed a retrospective chart review of patients admitted with a diagnosis of HF (Heart Failure with Preserved Ejection Fraction HFpEF, Heart Failure with Reduced Ejection Fraction HFrEF or combined) during the year 2017 to our community hospital. Patients’ charts were reviewed for multimorbidities, laboratory data, and anemia treatments. Outcomes were assessed as readmissions and death within 1 year from index admission. Definitions were used according to preestablished guidelines. Statistical analysis was done using Minitab software and univariate and multivariate logistic regression analysis. Results A total of 320 patients were evaluated. The average age was 71 14, 121 (38%) were female, 229 (72%) were Hispanics, and average BMI was 31 7. 118 (37%) patients had HFrEF and 102 (32%) had HFpEF. 218 (68%) had coronary artery disease, 280 (88%) hypertension, 188 (59%) diabetes mellitus, 149 (47%) chronic kidney disease, and 102 (32%) atrial fibrillation. Of 320 patients that were evaluated, 185 (58%) had anemia with a mean hemoglobin level of 10 1 mg/dl. The major risk factors for anemia in our patient population were Hispanic race with an odds ratio (OR) of 1.8 (CI 1.01-2.3) p-value 0.03, HFpEF with an OR 1.6 (CI 1.2-2.6) p-value 0.04, female gender OR 2.3 (1.42-3.74) p-value 0.0007, and CKD with an OR 2.6 (CI 1.6-3.0) p-value 0.001 - all adjusted to age. Obesity and its different classifications was not a risk factor for anemia. Mortality and readmission rates were higher in patients with anemia (5.4% vs 2.9% and 34% vs 31%, respectively). Conclusions We found that women were more likely to have anemia than men, confirming previous observations (2). Additionally, Hispanics were more likely than non-Hispanics to have anemia, which has been suggested in previous studies (3). This probably accounts for the high prevalence of anemia in our patient population. We had anticipated that obesity would be a risk factor, but thorough analysis of the data could not detect any increase in anemia no matter the degree of obesity. We believe that further studies are warranted to evaluate this subset of HF patients since they are at higher risk of worse outcomes and to determine whether treating the anemia reduces negative outcomes such as death and readmission

Perturbed CD8+ T cell TIGIT/CD226/PVR axis despite early initiation of antiretroviral treatment in HIV infected individuals.

HIV-specific CD8+ T cells demonstrate an exhausted phenotype associated with increased expression of inhibitory receptors, decreased functional capacity, and a skewed transcriptional profile, which are only partially restored by antiretroviral treatment (ART). Expression levels of the inhibitory receptor, T cell immunoglobulin and ITIM domain (TIGIT), the co-stimulatory receptor CD226 and their ligand PVR are altered in viral infections and cancer. However, the extent to which the TIGIT/CD226/PVR-axis is affected by HIV-infection has not been characterized. Here, we report that TIGIT expression increased over time despite early initiation of ART. HIV-specific CD8+ T cells were almost exclusively TIGIT+, had an inverse expression of the transcription factors T-bet and Eomes and co-expressed PD-1, CD160 and 2B4. HIV-specific TIGIThi cells were negatively correlated with polyfunctionality and displayed a diminished expression of CD226. Furthermore, expression of PVR was increased on CD4+ T cells, especially T follicular helper (Tfh) cells, in HIV-infected lymph nodes. These results depict a skewing of the TIGIT/CD226 axis from CD226 co-stimulation towards TIGIT-mediated inhibition of CD8+ T cells, despite early ART. These findings highlight the importance of the TIGIT/CD226/PVR axis as an immune checkpoint barrier that could hinder future "cure" strategies requiring potent HIV-specific CD8+ T cells

An important role for CD4 + T cells in adaptive immunity to Toxoplasma gondii in mice lacking the transcription factor Batf3

Immunity t

Surfacing rates, swim speeds, and patterns of movement of Antarctic blue whales

During three surveys in the austral summers of 2013, 2015, 2019, data on Antarctic blue whale blow rates, dive times, swim speeds, and broadscale movements were collected using video photogrammetric tracking and intra-voyage photo-identification. A total of 24.4 hours of video observations were suitable for blow interval or movement analysis. Similar to other blue whale populations, Antarctic blue whale dive behaviour comprised a sequence of short dives followed by a long dive with a mean dive time for short dives of 17.6 s, and a mean long dive time of 189.3 s. Two separate methods were used to estimate the average blow rate for Antarctic blue whales, giving estimates of 59.7 and 63.2 blows per hour. The overall mean swim speed over the course of all suitable video track segments was 1.59 ms-1, but there were significant differences between years in the mean of the overall movement rate for each track; average movement rates were lower in 2015 compared to 2013 and 2019 (0.90 ms-1, 1.84 and 1.55 ms-1 respectively), with higher rates of turning in 2015. In 2019, there was faster overall movement through the study area in a consistent direction. The total number of photo-identified blue whales re-sighted intra-season in 2013 was nine (out of 50 identified individuals); in 2015 it was seven (out of 46); in 2019 two (out of 25). Whales remained for several days with little overall movement within the 2015 study area, whereas they were moving through the study area in 2019, which would explain the low number of intra-season resights. The predominant heading in 2019 was towards the area of Antarctic blue whale concentrations at the entrance to the Ross Sea observed in previous years. The photo-identification data also show a high proportion of resighted whales with coherent movements. This suggests that Antarctic blue whales might travel together, at least over periods of several days or sometimes up to a month. The differences between behaviours in 2015 and 2019 in particular may be related to differences in the characteristics of krill swarms between the study areas

A Feasibility Study on Disasters and Disaster Risk Reduction Factors Awareness of LSPU Students

This study determined the students' degree of awareness at Laguna State Polytechnic University (LSPU) Sta. Cruz, Laguna in terms of disaster risk reduction and its significance, which was the basis of the LSPU DRRM Center construct. This employed a descriptive- correlational study and used a purposive sampling technique. The results revealed that the respondents had experienced various types of disasters. They are slightly aware, at least, of risk reduction factors anchoring on political commitment, while they are no less than slightly aware of the particulars related to risk reduction measures. Moreover, the results of χ² Tests of Independence revealed that the awareness of Disaster Risk Reduction Factors depends on the individual's exposure to a single or a combination of natural disasters. On the contrary, the extent of awareness of those factors does not depend on the respondent's exposure or experience with global viral diseases and man-made disasters