970 research outputs found
Quiz Games as a model for Information Hiding
We present a general computation model inspired in the notion of information
hiding in software engineering. This model has the form of a game which we call
quiz game. It allows in a uniform way to prove exponential lower bounds for
several complexity problems of elimination theory.Comment: 46 pages, to appear in Journal of Complexit
Cadaveric and ultrasonographic validation of needling placement in the cervical multifidus muscle
Objective: The aim of this study was to determine if a needle is able to reach the cervical multifidus during the
application of dry needling or acupuncture.
Methods: Dry needling and ultrasound imaging of cervical multifidi was conducted on 5 patients (age: 32 ± 5 years)
with mechanical neck pain and on 2 fresh cadavers (age: 64 ± 1 years). Dry needling was done using a needle of 40 mm in
length inserted perpendicular to the skin about 1 cmlateral to the spinous process at C3-C4. The needlewas advanced from
a posterior to anterior direction into the cervical multifidus with a slight inferior-medial angle (approximately 10°) to reach
the vertebra lamina. For the cadaveric study, the multifidus was isolated by carefully resecting the superficial posterior
cervical muscles: trapezius, splenius, and semispinalis. For the ultrasonographic study, a convex transducer was placed
transversely over C3-C4 after the insertion of the needle into the muscle.
Results: The results of both the cadaveric and ultrasonic studies found that the needle does pierce the cervical
multifidus muscle during insertion and that the tip of the needle rests properly against the vertebral laminae, thereby
guarding the sensitive underlying spinal structures from damage.
Conclusion: This anatomical and ultrasound imaging study supports that dry needling of the cervical multifidus
could be conducted clinically. (J Manipulative Physiol Ther 2017;xx:0-6)pre-print800 K
Alta frecuencia de sintomatología depresiva en cuidadores de pacientes pediátricos en diálisis peritoneal y hemodiálisis en un hospital público de Lima.
Objective: To describe the frequency of depressive symptomatology in caregivers of pediatric patients on peritoneal dialysis and hemodialysis. Material and methods: Descriptive, cross-sectional study of 33 caregivers of pediatric patients with Chronic Kidney Disease, under treatment in the Hemodialysis and Peritoneal Dialysis Unit of the Cayetano Heredia Hospital in Lima (Peru). The participants completed the Patient Health Questionnaire (PHQ-9), which assessed their degree of depressive symptomatology. Results: A total of 54.54% of caregivers showed depressive symptomatology; 9.09% moderately severe, 18.18% moderate and 27.27% mild; only 3.03% reported intake of antidepressants. All caregivers with moderate and moderately severe depression reported some degree of difficulty in performing their tasks. Conclusions: A high frequency of depressive symptomatology in caregivers of pediatric patients on dialysis was found. The recognition of depression in primary caregivers is important, in order to carry out interventions aimed at maintaining their emotional well-being.Objetivo: El objetivo del estudio fue describir la frecuencia de sintomatología depresiva en cuidadores de pacientes pediátricos en diálisis peritoneal y hemodiálisis. Material y Métodos: Estudio descriptivo de corte transversal en el cual participaron 33 cuidadores de pacientes pediátricos con enfermedad renal crónica de la unidad de hemodiálisis y diálisis peritoneal del Hospital Cayetano Heredia en Lima (Perú). El nivel de sintomatología depresiva de los cuidadores fue evaluado mediante el Patient Health Questionnaire (PHQ-9). Resultados: Un total de 54,54% de cuidadores presentaron sintomatología depresiva; el 9,09% moderadamente severa, el 18,18% moderada y el 27,27% leve; solo el 3,03% reportó uso de antidepresivos. Todos los cuidadores con depresión moderada y moderadamente severa reportaron algún grado de dificultad para realizar sus labores. Conclusiones: Se evidenció una alta frecuencia de sintomatología depresiva en cuidadores de pacientes pediátricos en diálisis. El reconocimiento de la depresión en los cuidadores principales es importante a fin de conducir intervenciones dirigidas a la preservación de su bienestar emocional
MAGIC Observations of the Nearby Short Gamma-Ray Burst GRB 160821B
Acciari, A. V., et al.The coincident detection of GW170817 in gravitational waves and electromagnetic radiation spanning the radio to MeV gamma-ray bands provided the first direct evidence that short gamma-ray bursts (GRBs) can originate from binary neutron star (BNS) mergers. On the other hand, the properties of short GRBs in high-energy gamma-rays are still poorly constrained, with only ∼20 events detected in the GeV band, and none in the TeV band. GRB 160821B is one of the nearest short GRBs known at z = 0.162. Recent analyses of the multiwavelength observational data of its afterglow emission revealed an optical-infrared kilonova component, characteristic of heavy-element nucleosynthesis in a BNS merger. Aiming to better clarify the nature of short GRBs, this burst was automatically followed up with the MAGIC telescopes, starting from 24 s after the burst trigger. Evidence of a gamma-ray signal is found above ∼0.5 TeV at a significance of ∼ 3σ during observations that lasted until 4 hr after the burst. Assuming that the observed excess events correspond to gamma-ray emission from GRB 160821B, in conjunction with data at other wavelengths, we investigate its origin in the framework of GRB afterglow models. The simplest interpretation with one-zone models of synchrotron-self-Compton emission from the external forward shock has difficulty accounting for the putative TeV flux. Alternative scenarios are discussed where the TeV emission can be relatively enhanced. The role of future GeV-TeV observations of short GRBs in advancing our understanding of BNS mergers and related topics is briefly addressed.We would like to thank the Instituto de Astrofísica de Canarias
for the excellent working conditions at the Observatorio del
Roque de los Muchachos in La Palma. The financial support of
the German BMBF and MPG; the Italian INFN and INAF; the
Swiss National Fund SNF; the ERDF under the Spanish
MINECO (FPA2017-87859-P, FPA2017-85668-P, FPA2017-
82729-C6-2-R, FPA2017-82729-C6-6-R, FPA2017-82729-C6-5-
R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2017-
87055-C2-2-P, FPA2017-90566-REDC); the Indian Department
of Atomic Energy; the Japanese ICRR, the University of Tokyo,
JSPS, and MEXT; the Bulgarian Ministry of Education and
Science, National RI Roadmap Project DO1-268/16.12.2019 and
the Academy of Finland grant No. 320045 is gratefully
acknowledged. This work was also supported by the Spanish
Centro de Excelencia “Severo Ochoa” SEV-2016-0588, SEV2015-0548 and SEV-2012-0234, the Unidad de Excelencia
“María de Maeztu” MDM-2014-0369 and the “la Caixa”
Foundation (fellowship LCF/BQ/PI18/11630012), by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the
University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the
Polish National Research Centre grant UMO-2016/22/M/ST9/
00382 and by the Brazilian MCTIC, CNPq and FAPERJ. K.N. is
thankful for the support by Marie Skłodowska-Curie actions (H2020-MSCA-COFUND-2014, Project P-Sphere GA 665919),
and JSPS KAKENHI grant No. JP20KK0067 from MEXT,
Japan. L.N. acknowledges funding from the European Union’s
Horizon 2020 research and innovation program under the Marie
Skłodowska-Curie grant agreement No. 664931. S.I. is supported
by JSPS KAKENHI grant No. JP17K05460 from MEXT, Japan,
and the RIKEN iTHEMS program
Multiwavelength variability and correlation studies of Mrk 421 during historically low X-ray and γ-ray activity in 2015-2016
Acciari, V. A., et al. (MAGIC Collaboration)We report a characterization of the multiband flux variability and correlations of the nearby (z = 0.031) blazar Markarian 421 (Mrk 421) using data from Metsähovi, Swift, Fermi-LAT, MAGIC, FACT, and other collaborations and instruments from 2014 November till 2016 June. Mrk 421 did not show any prominent flaring activity, but exhibited periods of historically low activity above 1 TeV (F>1 TeV 0.1 TeV) γ-rays, which, despite the low activity, show a significant positive correlation with no time lag. The HRkeV and HRTeV show the harder-when-brighter trend observed in many blazars, but the trend flattens at the highest fluxes, which suggests a change in the processes dominating the blazar variability. Enlarging our data set with data from years 2007 to 2014, we measured a positive correlation between the optical and the GeV emission over a range of about 60 d centred at time lag zero, and a positive correlation between the optical/GeV and the radio emission over a range of about 60 d centred at a time lag of 43+9-6 d. This observation is consistent with the radio-bright zone being located about 0.2 parsec downstream from the optical/GeV emission regions of the jet. The flux distributions are better described with a lognormal function in most of the energy bands probed, indicating that the variability in Mrk 421 is likely produced by a multiplicative process.The financial support of the German BMBF and MPG; the Italian INFN and INAF; the Swiss National Fund SNF; the ERDF under the Spanish MINECO (FPA2017-87859-P, FPA2017-85668-P, FPA2017-82729-C6-2-R, FPA2017-82729-C6-6-R, FPA2017-82729-C6-5-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2017-87055-C2-2-P, FPA2017-90566-REDC); the Indian Department of Atomic Energy; the Japanese ICRR, the University of Tokyo, JSPS, and MEXT; the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-268/16.12.2019 and the Academy of Finland grant nr. 320045 is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia ‘Severo Ochoa’ SEV-2016-0588 and SEV-2015-0548, the Unidad de Excelencia ‘María de Maeztu’ MDM-2014-0369 and the ‘la Caixa’ Foundation (fellowship LCF/BQ/PI18/11630012), by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre grant UMO-2016/22/M/ST9/00382 and by the Brazilian MCTIC, CNPq, and FAPERJ
Reversible Dimerization/Polymerization of a Janus Diradical Producing Labile CC Bonds and Giant Chromism
En esta comunicación se presenta el estudio espectroscópico y téorico de la dimerización/oligomerización reversible de un birradical derivado de naftoditiofeno el cual en su forma monomérica presenta una intenso color azul mientras que al agregar se muestra incoloro, siendo éstas formas intercambiables gracias a la aplicación de estímulos débiles como presión o temperatura.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Intrinsically determined cell death of developing cortical interneurons
Cortical inhibitory circuits are formed by GABAergic interneurons, a cell population that originates far from the cerebral cortex in the embryonic ventral forebrain. Given their distant developmental origins, it is intriguing how the number of cortical interneurons is ultimately determined. One possibility, suggested by the neurotrophic hypothesis1-5, is that cortical interneurons are overproduced, and then following their migration into cortex, excess interneurons are eliminated through a competition for extrinsically derived trophic signals. Here we have characterized the developmental cell death of mouse cortical interneurons in vivo, in vitro, and following transplantation. We found that 40% of developing cortical interneurons were eliminated through Bax- (Bcl-2 associated X-) dependent apoptosis during postnatal life. When cultured in vitro or transplanted into the cortex, interneuron precursors died at a cellular age similar to that at which endogenous interneurons died during normal development. Remarkably, over transplant sizes that varied 200-fold, a constant fraction of the transplanted population underwent cell death. The death of transplanted neurons was not affected by the cell-autonomous disruption of TrkB (tropomyosin kinase receptor B), the main neurotrophin receptor expressed by central nervous system (CNS) neurons6-8. Transplantation expanded the cortical interneuron population by up to 35%, but the frequency of inhibitory synaptic events did not scale with the number of transplanted interneurons. Together, our findings indicate that interneuron cell death is intrinsically determined, either cell-autonomously, or through a population-autonomous competition for survival signals derived from other interneurons
A Non-Invasive method of quantifying pancreatic volume in mice using micro-MRI
In experimental models of pancreatic growth and recovery, changes in pancreatic size are assessed by euthanizing a large cohort of animals at varying time points and measuring organ mass. However, to ascertain this information in clinical practice, patients with pancreatic disorders routinely undergo non-invasive cross-sectional imaging of the pancreas using magnetic resonance imaging (MRI) or computed tomography (CT). The aim of the current study was to develop a thinsliced, optimized sequence protocol using a high field MRI to accurately calculate pancreatic volumes in the most common experimental animal, the mouse. Using a 7 Telsa Bruker micro-MRI system, we performed abdominal imaging in whole-fixed mice in three standard planes: axial, sagittal, and coronal. The contour of the pancreas was traced using Vitrea software and then transformed into a 3-dimensional (3D) reconstruction, from which volumetric measurements were calculated. Images were optimized using heart perfusion-fixation, T1 sequence analysis, and 0.2 to 0.4 mm thick slices. As proof of principle, increases in pancreatic volume among mice of different ages correlated tightly with increasing body weight. In summary, this is the first study to measure pancreatic volumes in mice, using a high field 7 Tesla micro-MRI and a thin-sliced, optimized sequence protocol. We anticipate that micro-MRI will improve the ability to non-invasively quantify changes in pancreatic size and will dramatically reduce the number of animals required to serially assess pancreatic growth and recovery.© 2014 Paredes et al
p21 as a Transcriptional Co-Repressor of S-Phase and Mitotic Control Genes
It has been previously described that p21 functions not only as a CDK inhibitor but also as a transcriptional co-repressor in some systems. To investigate the roles of p21 in transcriptional control, we studied the gene expression changes in two human cell systems. Using a human leukemia cell line (K562) with inducible p21 expression and human primary keratinocytes with adenoviral-mediated p21 expression, we carried out microarray-based gene expression profiling. We found that p21 rapidly and strongly repressed the mRNA levels of a number of genes involved in cell cycle and mitosis. One of the most strongly down-regulated genes was CCNE2 (cyclin E2 gene). Mutational analysis in K562 cells showed that the N-terminal region of p21 is required for repression of gene expression of CCNE2 and other genes. Chromatin immunoprecipitation assays indicated that p21 was bound to human CCNE2 and other p21-repressed genes gene in the vicinity of the transcription start site. Moreover, p21 repressed human CCNE2 promoter-luciferase constructs in K562 cells. Bioinformatic analysis revealed that the CDE motif is present in most of the promoters of the p21-regulated genes. Altogether, the results suggest that p21 exerts a repressive effect on a relevant number of genes controlling S phase and mitosis. Thus, p21 activity as inhibitor of cell cycle progression would be mediated not only by the inhibition of CDKs but also by the transcriptional down-regulation of key genes
123I-MIBG cardiac uptake and smell identification in parkinsonian patients with LRRK2 mutations
Reduced uptake of 123I- metaiodobenzylguanidine (MIBG) on cardiac gammagraphy and impaired odor identification are markers of neurodegenerative diseases with Lewy bodies (LB) as a pathological hallmark, such as idiopathic Parkinson’s disease (IPD). LRRK2 patients present with a clinical syndrome indistinguishable from IPD, but LB have not been found in some cases. Patients with such mutations could behave differently than patients with IPD with respect to MIBG cardiac uptake and olfaction. We studied 14 LRRK2 patients, 14 IPD patients matched by age, gender, disease duration and severity, and 13 age and gender matched control subjects. Olfaction was analyzed through the University of Pennsylvania Smell Identification Test (UPSIT). MIBG cardiac uptake was evaluated through the H/M ratio. The late H/M was 1.44 ± 0.31 for LRRK2 patients, 1.19 ± 0.15 for PD patients, and 1.67 ± 0.16 for control subjects. LRRK2 patients presented lower but not statistically significant MIBG cardiac uptake than controls (p = 0.08) and significant higher uptake than PD patients (p = 0.04). UPSIT mean scores were 21.5 ± 7.3 for LRRK2 patients, 18.7 ± 6.2 for IPD patients and 29.7 ± 5.7 for control subjects. UPSIT score was lower in both LRRK2 and PD than in controls. In LRRK2 patients a positive correlation was found between myocardial MIBG uptake and UPSIT scores, (R = 0.801, p < 0.001). In LRRK2 patients, MIBG cardiac uptake was less impaired than in PD; a positive correlation between MIBG cardiac uptake and UPSIT scores was observed. As MIBG cardiac reduced uptake and impaired odor identification are markers of LB pathology, this findings may represent neuropathological heterogeneity among LRRK2 patients
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