Using large-scale neural models to interpret connectivity measures of cortico-cortical dynamics at millisecond temporal resolution

Over the last two decades numerous functional imaging studies have shown that higher order cognitive functions are crucially dependent on the formation of distributed, large-scale neuronal assemblies (neurocognitive networks), often for very short durations. This has fueled the development of a vast number of functional connectivity measures that attempt to capture the spatiotemporal evolution of neurocognitive networks. Unfortunately, interpreting the neural basis of goal directed behavior using connectivity measures on neuroimaging data are highly dependent on the assumptions underlying the development of the measure, the nature of the task, and the modality of the neuroimaging technique that was used. This paper has two main purposes. The first is to provide an overview of some of the different measures of functional/effective connectivity that deal with high temporal resolution neuroimaging data. We will include some results that come from a recent approach that we have developed to identify the formation and extinction of task-specific, large-scale neuronal assemblies from electrophysiological recordings at a ms-by-ms temporal resolution. The second purpose of this paper is to indicate how to partially validate the interpretations drawn from this (or any other) connectivity technique by using simulated data from large-scale, neurobiologically realistic models. Specifically, we applied our recently developed method to realistic simulations of MEG data during a delayed match-to-sample (DMS) task condition and a passive viewing of stimuli condition using a large-scale neural model of the ventral visual processing pathway. Simulated MEG data using simple head models were generated from sources placed in V1, V4, IT, and prefrontal cortex (PFC) for the passive viewing condition. The results show how closely the conclusions obtained from the functional connectivity method match with what actually occurred at the neuronal network level

Migrating Ingested Foreign Body of the Upper Aerodigestive Tract with Resultant Septic Shock : Case report and literature review

Complications due to foreign body ingestion are rare; however, if present, these can cause significant morbidity to the patient. An overlooked ingested foreign body could present as an emergency and may prove fatal. We present a case of an accidentally ingested foreign body with delayed presentation, which migrated to the neck and produced a cervical abscess presenting as septic shock. The patient required prompt stabilisation followed by surgical intervention. The patient’s vital signs returned to normal on the second post-operative day, and he was discharged the following day

Incidence of Anaerobic Bacteria in 118 Patients with Deep-space Head and Neck Infections from the People’s University Hospital of Maxillofacial Surgery, Bhopal, India

susceptibility to antibacterial agents of anaerobic strains in 118 patients with head and neck abscesses (31) and cellulitis (87). Materials and methods: In total, 118 pus specimens from 118 consecutive patients with abscesses (31 cases) and cellulitis (87) of the head and neck were evaluated from 2006 to the end of 2011. The patients were admitted to the University Hospital of Maxillofacial Surgery, Bhopal, India, and comprised 76 men and 42 women: Four children, 103 adults and 11 elderly people. Results: Anaerobic bacteria (174 strains within 18 genera) were found in 88 (74.6%) of the 118 specimens. Anaerobes only were present in 23 (19.5%) specimens, aerobic/facultative bacteria only in 20 (16.9%) and mixed aerobic/anaerobic flora in 65 (55.1%). No growth was detected in 10 (8.5%) specimens. Two or more anaerobes per specimen were found in 56 (63.6%) of the specimens yielding anaerobes. The incidence of isolation of anaerobes from patients with identified odontogenic sources of infection was 82.2% (60 of 73 cases) and that in patients with other sources of infection was 71.4% (15 of 21, p > 0.20).  Conclusion: The start of empirical treatment could influence the frequency or rate of isolation of Fusobacterium species. The involvement of the Bacteroides fragilis group in some head and neck infections should be considered.&nbsp

Geriatric Endodontic

Developments in medicine have resulted in an increase in the life span of people, thereby leading to an increase in the number of geriatric patients. Adverse oral health has been identified as a risk factor for several systemic disorders/diseases. Therefore, dental care should be integrated into overall health management of all geriatric patients. Increased numbers of such patients in dentistry has resulted in the preferred use of alternatives like endodontics rather than extractions to improve the longevity of the natural dentition. Special knowledge, skills and attitude are necessary for the management of the geriatric patients. This review discusses the unique challenges faced by the endodontist in carrying out root canal treatment in such individuals

Effective Connectivity Modeling for fMRI: Six Issues and Possible Solutions Using Linear Dynamic Systems

Analysis of directionally specific or causal interactions between regions in functional magnetic resonance imaging (fMRI) data has proliferated. Here we identify six issues with existing effective connectivity methods that need to be addressed. The issues are discussed within the framework of linear dynamic systems for fMRI (LDSf). The first concerns the use of deterministic models to identify inter-regional effective connectivity. We show that deterministic dynamics are incapable of identifying the trial-to-trial variability typically investigated as the marker of connectivity while stochastic models can capture this variability. The second concerns the simplistic (constant) connectivity modeled by most methods. Connectivity parameters of the LDSf model can vary at the same timescale as the input data. Further, extending LDSf to mixtures of multiple models provides more robust connectivity variation. The third concerns the correct identification of the network itself including the number and anatomical origin of the network nodes. Augmentation of the LDSf state space can identify additional nodes of a network. The fourth concerns the locus of the signal used as a “node” in a network. A novel extension LDSf incorporating sparse canonical correlations can select most relevant voxels from an anatomically defined region based on connectivity. The fifth concerns connection interpretation. Individual parameter differences have received most attention. We present alternative network descriptors of connectivity changes which consider the whole network. The sixth concerns the temporal resolution of fMRI data relative to the timescale of the inter-regional interactions in the brain. LDSf includes an “instantaneous” connection term to capture connectivity occurring at timescales faster than the data resolution. The LDS framework can also be extended to statistically combine fMRI and EEG data. The LDSf framework is a promising foundation for effective connectivity analysis

A RADIOLOGICAL PROFILE OF FUNGAL SINUSITIS

  Objectives: To create a radiological profile of fungal sinusitis and determine the radiological differences between fungal and nonfungal sinusitis based on the presence of hyperattenuation, bony erosion, neo-osteogenesis, air-fluid level, and extrasinus extension.Methods: This is a retrospective, single-blind, case-control study involving the analysis of 119 computed tomography (CT) scans of the paranasal sinuses. Based on the histopathology, they were divided into cases comprising fungal sinusitis and controls of nonfungal sinusitis. Benign and malignant tumors and previously operated cases of fungal sinusitis were excluded from the study. The principal investigators were blinded to the diagnosis. The comparison parameters were hyperattenuation, the presence of air-fluid level, bone erosion, neo-osteogenesis, and extrasinus extension. Data was analyzed by Chi-square and Fischer exact t-test using SPSS 14.0 software and a p < 0.05 was considered significant.Results: Our study showed the presence of hyperattenuation, neo-osteogenesis, bone erosion, air-fluid level, extrasinus extension in 75.2%, 48.3%, 25.9%, 36.2%, and 6.9% of the cases and 13.1%, 16.4%, 6.6%, 9.8%, and 0 controls, respectively. All the parameters were statistically significant in cases when compared to controls.Conclusion: Hyperattenuation, neo-osteogenesis, air-fluid level, bone erosion, and extrasinus extension are the parameters on CT imaging that will help routinely assess and differentiate fungal sinusitis from nonfungal sinusitis with considerable accuracy, although, there is an overlap with malignancy when the parameter of bone erosion is considered as a differential diagnosis of chronic invasive fungal sinusitis. It reiterates the fact that history, clinical examination, and laboratory evaluation hold an important role in provisional diagnosis

Sinus Bradyarrhythmia in Accidental Kodo Millet (Paspalum scrobiculatum) Poisoning – A Case Report

Introduction: The Kodo Millet crop is known by different names in different regions such as Varagu, Harka and Arikelu. It is predominantly grown in India and commonly consumed. When infected by certain fungus species, the compound cyclopiazonic acid causes the crop to be toxic to humans. Case Report: The following article discusses a case of Kodo Millet poisoning, which is presented with episodes of vomiting, sweating, giddiness and dysphagia. Upon examination, Sinus bradycardia and hypotension were the major findings. The electrocardiograph (ECG) showed sinus brady arrhythmia, which is rarely presented in Kodo Millet poisoning. The emergency physician team treated the patient symptomatically and he was discharged after 24 hours as the symptoms and the ECG findings were reverted. Discussion: Kodo Millet poisoning often occurs due to accidental consumption of infected crops. Its occurrence is rare and the treatment involves only supportive care and monitoring. However, it is important to rule it out as a possible differential diagnosis in similar cases due to other causes.  Conclusion: Sinus bradyarrhythmia is a rare condition associated with Kodo Millet poisoning. Emergency physicians should be aware of this toxicity to rule out all other possible differential diagnoses and to provide patients with early treatment

Curriculum Innovation in Vietnam: A Study on Teachers’ Attitudes using the Dimensions of ACB (Affective, Cognitive and Behavioral) Model

This study examines teachers’ attitudes towards curriculum innovation in Vietnam. The paper attempts to contribute to understanding teachers’ attitudes and responses towards curriculum innovation by identifying that in terms of competencies, several affective, cognitive, and behavioral abilities of teachers may affect the overall attitudes towards curriculum innovation, which has extensive ramifications for the success of an educational project. To understand the attitude of teachers, a mixed-method explanatory sequential design approach is used. The authors collected quantitative data and then designed a qualitative open-ended plan to build upon the quantitative research. ANOVA was performed to test the statistical significance and correlations were established. Data gathered from interviews were analysed using thematic analysis. This study shows that the overall attitudes of teachers and educators towards curriculum innovation in Vietnam are favourable. However, both quantitative and qualitative analysis show there are certain challenges about such innovation. No teacher had either a broad view of curriculum innovation or awareness of the interrelationship between the three dimensions of attitude and the implementation of the curriculum although aspects of each dimension were mentioned by individual teachers

Malaria Parasite clag3 Genes Determine Channel-Mediated Nutrient Uptake by Infected Red Blood Cells

SummaryDevelopment of malaria parasites within vertebrate erythrocytes requires nutrient uptake at the host cell membrane. The plasmodial surface anion channel (PSAC) mediates this transport and is an antimalarial target, but its molecular basis is unknown. We report a parasite gene family responsible for PSAC activity. We used high-throughput screening for nutrient uptake inhibitors to identify a compound highly specific for channels from the Dd2 line of the human pathogen P. falciparum. Inheritance of this compound's affinity in a Dd2 × HB3 genetic cross maps to a single parasite locus on chromosome 3. DNA transfection and in vitro selections indicate that PSAC-inhibitor interactions are encoded by two clag3 genes previously assumed to function in cytoadherence. These genes are conserved in plasmodia, exhibit expression switching, and encode an integral protein on the host membrane, as predicted by functional studies. This protein increases host cell permeability to diverse solutes.PaperFlic