Structure and dynamics of the supercluster of galaxies SC0028-0005

According to the standard cosmological scenario, superclusters are objects that have just passed the turn around point and are collapsing. The dynamics of very few superclusters have been analysed up to now. In this paper we study the supercluster SC0028-0005, at redshift 0.22, identify the most prominent groups and/or clusters that make up the supercluster, and investigate the dynamic state of this structure. For the membership identification, we have used photometric and spectroscopic data from SDSS-DR10, finding 6 main structures in a flat spatial distribution. We have also used a deep multi-band observation with MegaCam/CFHT to estimate de mass distribution through the weak-lensing effect. For the dynamical analysis, we have determined the relative distances along the line of sight within the supercluster using the Fundamental Plane of early-type galaxies. Finally, we have computed the peculiar velocities of each of the main structures. The 3D distribution suggests that SC0028-005 is indeed a collapsing supercluster, supporting the formation scenario of these structures. Using the spherical collapse model, we estimate that the mass within $r = 10$~Mpc should lie between 4 and $16 \times 10^{15} M_\odot$. The farthest detected members of the supercluster suggest that within $\sim 60$~Mpc the density contrast is $\delta \sim 3$ with respect to the critical density at $z=0.22$, implying a total mass of $\sim 4.6$--$16 \times 10^{17} M_\odot$, most of which in the form of low-mass galaxy groups or smaller substructures.Comment: 12 pages, 9 figures, Accepted for publication in MNRA

On the nonlinear hunting stability of a high-speed train bogie

The hunting phenomenon is an intrinsic swaying motion appearing in railway vehicles due to the vehicle’s forward speed and the wheel–rail contact forces. Hunting motion consists of wheelset and other vehicle’s components oscillations that arise above a certain vehicle’s speed known as critical or hunting speed. These oscillations are of unstable nature and represent a safety hazard as they could lead to the vehicle’s derailment. This article analyses the stability of a bogie nonlinear model for a Spanish high-speed train when this is travelling at speeds near the hunting speed. The vehicle’s stability is studied by means of root loci methods, and the value of the critical speed is found. In addition to this, the behaviour of the vehicle is studied in both stable and unstable regions and the existence of limit cycles is discussed in this work. Finally, a sensitivity analysis of the axle load and suspension parameters is performed. The results show that the axle load, the vertical stiffness of the primary suspension and the lateral damping of the secondary suspension have a significant influence on the value of the critical speed

Clinical study of cervicogenic headache

The cervicogenic headache was studied to get a deeper insight into the pathogenetic mechanisms, and clinical presentation forms. Material and Methods. Eleven female patients, ranging from 34 to 81 years-old, with cervicogenic headaches, were studied and correlated with NMR images of the cervical spine. Results. Intense neck pain irradiated to parietal, occipital, temporal regions, and shoulders were correlated with NMR images of the degenerated cervical spine. Also, lumbar spine pathology, osteoporosis, gallstones, and cholecystitis were found. The following associated neurological, neurobehavioral, and metabolic diseases comorbidities were observed, such as blood hypertension, diabetes, obesity, hypothyroidism, partial epilepsy, tremor, familial stress, memory, sleep disorders, and dizziness. Also, we found mixed cervicogenic headaches and migraines in 50% of cases studied. Conclusion. The headache and the associated images of cervical pathology have been clinically interpreted as cardinal signs of cervicogenic headache. A mixed cervicogenic mixed type was observed

Zinc depletion regulates the processing and secretion of IL-1β.

Sterile inflammation contributes to many common and serious human diseases. The pro-inflammatory cytokine interleukin-1β (IL-1β) drives sterile inflammatory responses and is thus a very attractive therapeutic target. Activation of IL-1β in sterile diseases commonly requires an intracellular multi-protein complex called the NLRP3 (NACHT, LRR, and PYD domains-containing protein 3) inflammasome. A number of disease-associated danger molecules are known to activate the NLRP3 inflammasome. We show here that depletion of zinc from macrophages, a paradigm for zinc deficiency, also activates the NLRP3 inflammasome and induces IL-1β secretion. Our data suggest that zinc depletion damages the integrity of lysosomes and that this event is important for NLRP3 activation. These data provide new mechanistic insight to how zinc deficiency contributes to inflammation and further unravel the mechanisms of NLRP3 inflammasome activation

Citicoline may prevent cognitive decline in patients with cerebrovascular disease

Introduction: Neuroprotective drugs such as citicoline could improve cognitive performance and quality of life. We studied the effect of citicoline treatment and its association with Vascular Risk Factors (VRF) and APOE on cognition in patients with Subjective Cognitive Complaints (SCC) and Mild Cognitive Impairment (MCI). Methods: This is an observational and prospective study with citicoline during 12 months follow-up. Eighty-one subjects who met criteria for SCC/MCI, aged 50–75 years with VRF were included and prescribed citicoline 1g/day. Subjects with previous cognitive impairment and any other central nervous system affection were excluded. Wilcoxon Signed Ranks test and paired samples t-test were used to analyze the change in neuropsychological performance. Results: Mean age of the sample was 68.2 (SD 6.8) years and 26 (32.09%) were females. Fifteen subjects (24.6%) were APOE-ε4 carriers, fifty-six (76.7%) had hypertension, fifty-eight (79.5%) had dyslipidemia, twenty-one (28.8%) had diabetes mellitus and twenty-six (35.6%) had cardiopathy. Thirty-two (43.8%) subjects were diagnosed as SCC and forty-one (56.16%) as MCI. During the follow-up, Tweny-six patients (81.25%) in the group of SCC remained stable, six subjects (18.8%) converted to MCI. Twelve patients (29.9%) with MCI reverted to SCC and twenty-nine patients (70.7%) remained stable. At follow-up, SCC subjects had an improvement in the global language domain (p=0.03), naming (p<0.001), attention (p=0.01) and visuospatial abilities (p<0.01). MCI group showed an improvement in the screening test (p=0.03), delayed memory (p<0.01), global cognition (p=0.04) and in cognitive flexibility (p=0.03). Presence of APOE-ε4 had no impact on the above findings. Discussion: SCC subjects showed an improvement in language and attention domains, while those with MCI performed better after 12 months in total scores of MoCA and RBANS domains, some converting back to SCC. This supports the idea that citicoline may prevent cognitive decline in patients with cognitive deficits

Validation of a computer-adaptive test to evaluate generic health-related quality of life

<p>Abstract</p> <p>Background</p> <p>Health Related Quality of Life (HRQoL) is a relevant variable in the evaluation of health outcomes. Questionnaires based on Classical Test Theory typically require a large number of items to evaluate HRQoL. Computer Adaptive Testing (CAT) can be used to reduce tests length while maintaining and, in some cases, improving accuracy. This study aimed at validating a CAT based on Item Response Theory (IRT) for evaluation of generic HRQoL: the CAT-Health instrument.</p> <p>Methods</p> <p>Cross-sectional study of subjects aged over 18 attending Primary Care Centres for any reason. CAT-Health was administered along with the SF-12 Health Survey. Age, gender and a checklist of chronic conditions were also collected. CAT-Health was evaluated considering: 1) feasibility: completion time and test length; 2) content range coverage, Item Exposure Rate (IER) and test precision; and 3) construct validity: differences in the CAT-Health scores according to clinical variables and correlations between both questionnaires.</p> <p>Results</p> <p>396 subjects answered CAT-Health and SF-12, 67.2% females, mean age (SD) 48.6 (17.7) years. 36.9% did not report any chronic condition. Median completion time for CAT-Health was 81 seconds (IQ range = 59-118) and it increased with age (p < 0.001). The median number of items administered was 8 (IQ range = 6-10). Neither ceiling nor floor effects were found for the score. None of the items in the pool had an IER of 100% and it was over 5% for 27.1% of the items. Test Information Function (TIF) peaked between levels -1 and 0 of HRQoL. Statistically significant differences were observed in the CAT-Health scores according to the number and type of conditions.</p> <p>Conclusions</p> <p>Although domain-specific CATs exist for various areas of HRQoL, CAT-Health is one of the first IRT-based CATs designed to evaluate generic HRQoL and it has proven feasible, valid and efficient, when administered to a broad sample of individuals attending primary care settings.</p

Kinematic Self-Similarity

Self-similarity in general relativity is briefly reviewed and the differences between self-similarity of the first kind and generalized self-similarity are discussed. The covariant notion of a kinematic self-similarity in the context of relativistic fluid mechanics is defined. Various mathematical and physical properties of spacetimes admitting a kinematic self-similarity are discussed. The governing equations for perfect fluid cosmological models are introduced and a set of integrability conditions for the existence of a proper kinematic self-similarity in these models is derived. Exact solutions of the irrotational perfect fluid Einstein field equations admitting a kinematic self-similarity are then sought in a number of special cases, and it is found that; (1) in the geodesic case the 3-spaces orthogonal to the fluid velocity vector are necessarily Ricci-flat and (ii) in the further specialisation to dust the differential equation governing the expansion can be completely integrated and the asymptotic properties of these solutions can be determined, (iii) the solutions in the case of zero-expansion consist of a class of shear-free and static models and a class of stiff perfect fluid (and non-static) models, and (iv) solutions in which the kinematic self-similar vector is parallel to the fluid velocity vector are necessarily Friedmann-Robertson-Walker (FRW) models.Comment: 29 pages, AmsTe

An experimental protocol for mimicking pathomechanisms of traumatic brain injury in mice

Traumatic brain injury (TBI) is a result of an outside force causing immediate mechanical disruption of brain tissue and delayed pathogenic events. In order to examine injury processes associated with TBI, a number of rodent models to induce brain trauma have been described. However, none of these models covers the entire spectrum of events that might occur in TBI. Here we provide a thorough methodological description of a straightforward closed head weight drop mouse model to assess brain injuries close to the clinical conditions of human TBI