Causal connectivity from right DLPFC to IPL in schizophrenia patients:a pilot study

Abnormal function and connectivity of the fronto-parietal network (FPN) have been documented in patients with schizophrenia, but studies are correlational. We applied repetitive transcranial magnetic stimulation (rTMS) to the dorso-lateral prefrontal cortex (DLPFC) and observed causal connectivity to the inferior parietal lobe (IPL). We hypothesized that patients with schizophrenia would have lower activation and slower reaction in the IPL following DLPFC stimulation. Thirteen patients with schizophrenia (SZ) and fourteen healthy controls subjects (HC) underwent rTMS at 10 Hz to the right DLPFC. Simultaneously, we measured brain activation in the IPL, represented as oxygenized hemoglobin (HbO) levels, using functional near-infrared spectroscopy (fNIRS). rTMS consisted of 20 trains of impulses at 10 Hz for 3 seconds, and 60 seconds waiting time. Using NIRSLab software, GLM was applied to estimate both hemodynamic response function (HRF) and its derivative. Following TMS to the DLPFC, SZ showed a smaller decrease in HbO levels in the bilateral IPL than HC (p = 0.05). Timecourse analysis revealed an immediate decrease in parietal HbO levels in HC, but not in SZ. This difference was significant (at a threshold level of p ≤ 0.05, with Bonferroni correction) for several time segments and channels in both rights and left IPL. Our findings suggest abnormal fronto-temporal connectivity in patients with schizophrenia, beyond a mere decrease or slowing of information processing. This is in line with the hypothesis of reduced fronto-parietal inhibition in schizophrenia

Callaway Measurement Device

The purpose of this document is to illustrate the Callaway Measurement Device senior project from start to finish. The challenge given to the team was to update and improve a gauge used by Callaway employees to measure the loft, lie, and face angle of their full spectrum of golf clubs. Once the team understood how the pre-existing gauge operates, the team conducted background research into other technologies that could improve the gauge. The team decided to digitalize the device amongst other tweaks to reduce error. Because the CAD files were not available for the pre-existing device, the team began reverse engineering the device. The team iterated through design choices for each subsystem of the device and decided to alter the clamping and lie system for ease of manufacturability and effectiveness while mimicking the loft and face angle subsystems. Based on these design choices in early prototyping, the team created a CAD design. Once the CAD was polished and the material was selected, the team and sponsors decided to switch to 3D-printed parts to save on material and manufacturing costs. This altered the design into more of a concept prototype. During manufacturing, the team iterated through many design tweaks by reprinting 3D parts, altering the code and encoder types of the digital assembly, machining some metal parts, and assembling various components and subsystems. During testing, the team found that as expected, the device did not reach the accuracy goal. However, this is believed to be a result of the flexibility and non-uniformity of the 3D-printed parts. Because the resolution and precision of the device surpassed the goals, the team believes that if their device was made from sturdier material such as metal in a future iteration it would improve upon the pre-existing device and surpass the goals given to the team by Callaway Golf

Neural Field Models: A mathematical overview and unifying framework

Rhythmic electrical activity in the brain emerges from regular non-trivial interactions between millions of neurons. Neurons are intricate cellular structures that transmit excitatory (or inhibitory) signals to other neurons, often non-locally, depending on the graded input from other neurons. Often this requires extensive detail to model mathematically, which poses several issues in modelling large systems beyond clusters of neurons, such as the whole brain. Approaching large populations of neurons with interconnected constituent single-neuron models results in an accumulation of exponentially many complexities, rendering a realistic simulation that does not permit mathematical tractability and obfuscates the primary interactions required for emergent electrodynamical patterns in brain rhythms. A statistical mechanics approach with non-local interactions may circumvent these issues while maintaining mathematically tractability. Neural field theory is a population-level approach to modelling large sections of neural tissue based on these principles. Herein we provide a review of key stages of the history and development of neural field theory and contemporary uses of this branch of mathematical neuroscience. We elucidate a mathematical framework in which neural field models can be derived, highlighting the many significant inherited assumptions that exist in the current literature, so that their validity may be considered in light of further developments in both mathematical and experimental neuroscience.Comment: 55 pages, 10 figures, 2 table

Similar EEG Activity Patterns During Experimentally-Induced Auditory Illusions and Veridical Perceptions

Hallucinations and illusions are two instances of perceptual experiences illustrating how perception might diverge from external sensory stimulations and be generated or altered based on internal brain states. The occurrence of these phenomena is not constrained to patient populations. Similar experiences can be elicited in healthy subjects by means of suitable experimental procedures. Studying the neural mechanisms underlying these experiences not only has the potential to expand our understanding of the brain's perceptual machinery but also of how it might get impaired. In the current study, we employed an auditory signal detection task to induce auditory illusions by presenting speech snippets at near detection threshold intensity embedded in noise. We investigated the neural correlates of auditory false perceptions by examining the EEG activity preceding the responses in speech absent (false alarm, FA) trials and comparing them to speech present (hit) trials. The results of the comparison of event-related potentials (ERPs) in the activation period vs. baseline revealed the presence of an early negativity (EN) and a late positivity (LP) similar in both hits and FAs, which were absent in misses, correct rejections (CR) and control button presses (BPs). We postulate that the EN and the LP might represent the auditory awareness negativity (AAN) and centro-parietal positivity (CPP) or P300, respectively. The event-related spectral perturbations (ERSPs) exhibited a common power enhancement in low frequencies

Abnormal connectivity between attentional, language and auditory networks in schizophrenia

Brain circuits involved in language processing have been suggested to be compromised in patients with schizophrenia. This does not only include regions subserving language production and perception, but also auditory processing and attention. We investigated resting state network connectivity of auditory, language and attention networks of patients with schizophrenia and hypothesized that patients would show reduced connectivity. Patients with schizophrenia (n=45) and healthy controls (n=30) underwent a resting state fMRI scan. Independent components analysis was used to identify networks of the auditory cortex, left inferior frontal language regions and the anterior cingulate region, associated with attention. The time courses of the components where correlated with each other, the correlations were transformed by a Fisher's Z transformation, and compared between groups. In patients with schizophrenia, we observed decreased connectivity between the auditory and language networks. Conversely, patients showed increased connectivity between the attention and language network compared to controls. There was no relationship with severity of symptoms such as auditory hallucinations. The decreased connectivity between auditory and language processing areas observed in schizophrenia patients is consistent with earlier research and may underlie language processing difficulties. Altered anterior cingulate connectivity in patients may be a correlate of habitual suppression of unintended speech, or of excessive attention to internally generated speech. This altered connectivity pattern appears to be present independent of symptom severity, and may be suggestive of a trait, rather than a state characteristic. (C) 2011 Elsevier B.V. All rights reserved

Envelope structure of deeply embedded young stellar objects in the Serpens Molecular Cloud

Aperture synthesis and single-dish (sub) millimeter molecular lines and continuum observations reveal in great detail the envelope structure of deeply embedded young stellar objects (SMM1, SMM2, SMM3, SMM4) in the densely star-forming Serpens Molecular Cloud. Resolved millimeter continuum emission constrains the density structure to a radial power law with index -2.0 +/- 0.5, and envelope masses of 8.7, 3.0, and 5.3 M_sol for SMM1, SMM3, and SMM4. The core SMM2 does not seem to have a central condensation and may not have formed a star yet. The molecular line observations can be described by the same envelope model, if an additional, small amount of warm (100 K) material is included. This probably corresponds to the inner few hundred AU of the envelope were the temperature is high. In the interferometer beam, the molecular lines reveal the inner regions of the envelopes, as well as interaction of the outflow with the surrounding envelope. Bright HCO+ and HCN emission outlines the cavities, while SiO and SO trace the direct impact of the outflow on ambient gas. Taken together, these observations provide a first comprehensive view of the physical and chemical structure of the envelopes of deeply embedded young stellar objects in a clustered environment on scales between 1000 and 10,000 AU.Comment: 46 pages, incl. 12 postscript figures, uses ApJ latex and psfig macro

Clinical features and long-term follow-up of 70 cases of canine idiopathic eosinophilic lung disease.

BACKGROUND: Canine idiopathic eosinophilic lung disease (ELD) is sparsely documented in the literature. METHODS: Clinical presentation and outcome of dogs diagnosed with ELD (eosinophilic bronchitis or eosinophilic bronchopneumonia) were reviewed. Subgroups were made based on chronicity of clinical signs and findings of thoracic imaging: NCI (no changes in thoracic imaging), BRON (bronchial/peribronchial pattern), INT (bronchointerstitial/interstitial/alveolar). RESULTS: Seventy cases were included. There were more young to adult, crossbreed and female dogs. Compared with the other two groups NCI dogs showed lower bronchoalveolar lavage fluid eosinophilic pleocytosis and absence of circulating eosinophilia, bronchiectasis or death due to respiratory disease. All dogs responded clinically to corticosteroids. Median treatment duration was four months. Remission (no clinical signs after treatment discontinuation for >one month) and long-term remission (>six months) was achieved in 60 per cent, and 51 per cent of patients, respectively. Relapse occurred in 26 per cent of cases after remission but was rare (3 per cent) after long-term remission. The one-year, two-year and four-year survival to death due to respiratory disease was 98 per cent, 97 per cent and 91 per cent, respectively. CONCLUSION: Prognosis and initial clinical response for ELD was generally good although achievement of long-term remission was only seen in 51 per cent of dogs. Different outcomes based on chronicity of signs, corticosteroid dose, thoracic imaging abnormalities and other clinical variables were not appreciated

Practice recommendation for the detection and diagnosis of patients with alzheimer’s disease dementia at Buenos Aires City

La Enfermedad de Alzheimer es la causa más frecuente de trastornos cognitivos y demencia en adultos mayores, y es considerada una nueva epidemia. Por sus diferentes manifestaciones cognitivas, conductuales y funcionales, la detección, diagnóstico y tratamiento de los pacientes con Demencia debida a Enfermedad de Alzheimer puede representar un desafío. En las presentes recomendaciones se dan pautas de manejo con niveles de recomendación basados en la mejor evidencia científica disponible. Asimismo, se presentan indicaciones y sugerencias de estudio, o derivación a un nivel superior de asistencia según la complejidad de cada caso. De este modo, se brinda un conjunto de recomendaciones prácticas de apoyo para la toma de decisiones por parte de los profesionales de la salud en cada nivel sanitario, desde la asistencia primaria hasta los médicos especialistas. Mediante un enfoque operativo y dinámico, estas Recomendaciones proponen un enfoque global basado en la evidencia para los pacientes, familiares y agentes de Salud involucrados en esta patología, de enorme relevancia a nivel social.Alzheimer’s disease is the most frequent cause of cognitive disorders and dementia in older adults and is considered a new epidemic. Due to its different cognitive, behavioral and functional manifestations, the detection, and diagnosis of patients with Alzheimer’s Disease Dementia can represent a challenge. In this Clinical Practice Recommendation, management are given with levels based on the best scientific evidence available. Likewise, indications for study, or referral to a higher level of sanitary assistance are presented, according to the complexity of each clinical case. In this way, a set of practical recommendations of support is provided for decision making by health professionals at each sanitary level, from primary care to medical specialists. Through an operational and dynamic approach, this recommendations proposes a global strategy based on evidence for patients, family members and health agents involved in this pathology, of great social relevance.Fil: Demey, Ignacio. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Hospital Británico de Buenos Aires; ArgentinaFil: Ollari, Juan A.. Hospital Británico de Buenos Aires; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital Municipal "José Tiburcio Borda"; ArgentinaFil: Rojas, Galeno. Hospital Británico de Buenos Aires; Argentina. Fundación Favaloro; Argentina. Ministerio de Salud. Administración Nacional de Medicamentos, Alimentos y Tecnología Médica; ArgentinaFil: Bagnati, Pablo. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Sarasola, Diego. No especifíca;Fil: Román, Fabián. Gobierno de la Ciudad Autonoma de Buenos Aires. Ministerio de Salud. Subsecretaria de Atencion Hospitalaria.; Argentina. Universidad de la Costa.; ColombiaFil: Tarulla, Adriana. Gobierno de la Ciudad Autonoma de Buenos Aires. Ministerio de Salud. Subsecretaria de Atencion Hospitalaria.; Argentina. Universidad de la Costa.; ColombiaFil: Blake, Andre. Gobierno de la Ciudad Autonoma de Buenos Aires. Ministerio de Salud. Subsecretaria de Atencion Hospitalaria.; ArgentinaFil: Sevlever, Gustavo. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; ArgentinaFil: Caridi, Aldo. Gobierno de la Ciudad Autonoma de Buenos Aires. Ministerio de Salud. Subsecretaria de Atencion Hospitalaria.; ArgentinaFil: Allegri, Ricardo Francisco. Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia; Argentina. Gobierno de la Ciudad Autonoma de Buenos Aires. Ministerio de Salud. Subsecretaria de Atencion Hospitalaria.; Argentina. Universidad de la Costa.; Colombia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

The detection of Class I methanol masers towards regions of low-mass star formation

Six young bipolar outflows in regions of low-to-intermediate-mass star formation were observed in the 7_0-6_1A+, 8_0-7_1A+, and 5_{-1}-4_0E methanol lines at 44, 95, and 84 GHz, respectively. Narrow features were detected towards NGC 1333IRAS4A, HH 25MMS, and L1157 B1. Flux densities of the detected lines are no higher than 11 Jy, which is much lower than the flux densities of strong maser lines in regions of high-mass star formation. Analysis shows that most likely the narrow features are masers.Comment: 12 pages, 6 figures, to be published in Astronomy Report