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1.
ArXiv ; 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38947919

ABSTRACT

Continual learning (CL) refers to an agent's capability to learn from a continuous stream of data and transfer knowledge without forgetting old information. One crucial aspect of CL is forward transfer, i.e., improved and faster learning on a new task by leveraging information from prior knowledge. While this ability comes naturally to biological brains, it poses a significant challenge for artificial intelligence (AI). Here, we suggest that environmental enrichment (EE) can be used as a biological model for studying forward transfer, inspiring human-like AI development. EE refers to animal studies that enhance cognitive, social, motor, and sensory stimulation and is a model for what, in humans, is referred to as 'cognitive reserve'. Enriched animals show significant improvement in learning speed and performance on new tasks, typically exhibiting forward transfer. We explore anatomical, molecular, and neuronal changes post-EE and discuss how artificial neural networks (ANNs) can be used to predict neural computation changes after enriched experiences. Finally, we provide a synergistic way of combining neuroscience and AI research that paves the path toward developing AI capable of rapid and efficient new task learning.

2.
Proc Natl Acad Sci U S A ; 119(27): e2115229119, 2022 07 05.
Article in English | MEDLINE | ID: mdl-35759669

ABSTRACT

Understanding how the brain learns throughout a lifetime remains a long-standing challenge. In artificial neural networks (ANNs), incorporating novel information too rapidly results in catastrophic interference, i.e., abrupt loss of previously acquired knowledge. Complementary Learning Systems Theory (CLST) suggests that new memories can be gradually integrated into the neocortex by interleaving new memories with existing knowledge. This approach, however, has been assumed to require interleaving all existing knowledge every time something new is learned, which is implausible because it is time-consuming and requires a large amount of data. We show that deep, nonlinear ANNs can learn new information by interleaving only a subset of old items that share substantial representational similarity with the new information. By using such similarity-weighted interleaved learning (SWIL), ANNs can learn new information rapidly with a similar accuracy level and minimal interference, while using a much smaller number of old items presented per epoch (fast and data-efficient). SWIL is shown to work with various standard classification datasets (Fashion-MNIST, CIFAR10, and CIFAR100), deep neural network architectures, and in sequential learning frameworks. We show that data efficiency and speedup in learning new items are increased roughly proportionally to the number of nonoverlapping classes stored in the network, which implies an enormous possible speedup in human brains, which encode a high number of separate categories. Finally, we propose a theoretical model of how SWIL might be implemented in the brain.


Subject(s)
Learning , Neocortex , Neural Networks, Computer , Humans , Models, Neurological , Neocortex/physiology , Systems Theory
3.
Neuron ; 110(9): 1441-1442, 2022 05 04.
Article in English | MEDLINE | ID: mdl-35512636

ABSTRACT

In this issue of Neuron, Widloski and Foster (2022) show that, in a complex maze with changing barrier configurations, rat hippocampal neurons maintain their location-specific firing but learn to generate activity sequences representing possible routes to rewards, that respect the locations of barriers, and to rapidly adapt to barrier reconfiguration.


Subject(s)
Hippocampus , Neurons , Action Potentials/physiology , Animals , Cognition , Hippocampus/physiology , Maze Learning/physiology , Neurons/physiology , Rats , Reward
4.
J Neurophysiol ; 120(5): 2383-2395, 2018 11 01.
Article in English | MEDLINE | ID: mdl-30044689

ABSTRACT

Most studies of neural correlates of spatial navigation are restricted to small arenas (≤1 m2) because of the limits imposed by the recording cables. New wireless recording systems have a larger recording range. However, these neuronal recording systems lack the ability to track animals in large area, constraining the size of the arena. We developed and benchmarked an open-source, scalable multicamera tracking system based on low-cost hardware. This "Picamera system" was used in combination with a wireless recording system for characterizing neural correlates of space in environments of sizes up to 16.5 m2. The Picamera system showed substantially better temporal accuracy than a popular commercial system. An explicit comparison of one camera from the Picamera system with a camera from the commercial system showed improved accuracy in estimating spatial firing characteristics and head direction tuning of neurons. This improved temporal accuracy is crucial for accurately aligning videos from multiple cameras in large spaces and characterizing spatially modulated cells in a large environment. NEW & NOTEWORTHY Studies of neural correlates of space are limited to biologically unrealistically small spaces by neural recording and position tracking hardware. We developed a camera system capable of tracking animals in large spaces at a high temporal accuracy. Together with the new wireless recording systems, this system facilitates the study of neural correlates of space at biologically relevant scale. This increased temporal accuracy of tracking also improves the estimates of spatiotemporal correlates of neural activity.


Subject(s)
Locomotion , Spatial Navigation , Video Recording/instrumentation , Animals , Costs and Cost Analysis , Male , Rats , Rats, Long-Evans , Sensitivity and Specificity , Video Recording/economics , Video Recording/standards
5.
Lung India ; 34(1): 88-91, 2017.
Article in English | MEDLINE | ID: mdl-28144070

ABSTRACT

Congenital cystic adenomatoid malformations (CCAMs) are rare congenital, nonhereditary developmental anomalies of the lung with unknown etiology. CCAM is predominantly a disorder of infancy with the majority of the cases being diagnosed within the first 2 years of life. When CCAM presents in adults, it represents a diagnostic dilemma and requires careful evaluation. We here report a case of large solitary congenital pulmonary cystic adenomatoid malformation with infection and hemorrhage, which was diagnosed as encysted hydropneumothorax on computerized tomography scans but turned out to be infected pulmonary cystic adenomatoid malformation after surgical excision.

6.
Article in English | MEDLINE | ID: mdl-28213139

ABSTRACT

As part of a study of pyrrole hydrazone, we have investigated quantum chemical calculations, molecular geometry, relative energy, vibrational properties and antimycobacterial/antimicrobial activity of pyrrole-2-carboxaldehyde isonicotinyl hydrazone (PCINH), by applying the density functional theory (DFT) and Hartree Fock (HF). Good reproduction of experimental values is obtained and with small percentage error in majority of the cases in comparison to theoretical result (DFT). The experimental FT-IR and Raman wavenumbers were compared with the respective theoretical values obtained from DFT calculations and found to agree well. In crystal structure studies the hydrated PCINH (syn-syn conformer) shows different conformation than from anhydrous form (syn-anti conformer). The rotational barrier between syn-syn and syn-anti conformers of PCINH is 12.7kcal/mol in the gas phase. In this work, use of FT-IR, FT-Raman, 1H NMR, 13C NMR and UV-Vis spectroscopies has been made for full characterization of PCINH. A detailed interpretation of the vibrational spectrum was carried out with the aid of normal coordinate analysis using single scaling factor. Our results support the hydrogen bonding pattern proposed by reported crystalline structure. The calculated nature of electronic transitions within molecule found to be π→π*. The electronic descriptors study indicates that PCINH can be used as robust synthon for synthesis of new heterocyclic compounds. The first static hyperpolarizability (ß0) of PCINH is calculated as 33.89×10-30esu, (gas phase); 68.79×10-30 (CHCl3), esu; 76.76×10-30esu (CH2Cl2), 85.16×10-30esu (DMSO). The solvent induced effects on the first static hyperpolarizability were studied and found to increase as dielectric constants of the solvents increases. Investigated molecule shows better NLO value than Para nitroaniline (PNA). The compound PCINH shows good antifungal and antibacterial activity against Aspergillus niger and gram-positive bacteria Bacillus subtilis, respectively. The compound also shows good antituberculosis activity against Mycobacterium tuberculosis H37Rv using the microplate alamar blue assay (MABA).


Subject(s)
Anti-Infective Agents/pharmacology , Hydrazines/pharmacology , Magnetic Resonance Spectroscopy , Mycobacterium/drug effects , Pyrroles/pharmacology , Quantum Theory , Spectrum Analysis, Raman , Anisotropy , Antitubercular Agents/pharmacology , Calorimetry, Differential Scanning , Microbial Sensitivity Tests , Molecular Conformation , Spectrophotometry, Ultraviolet , Spectroscopy, Fourier Transform Infrared , Static Electricity , Thermodynamics , Vibration
7.
Article in English | MEDLINE | ID: mdl-27980539

ABSTRACT

BACKGROUND: Aspergillus is a ubiquitous fungus responsible for allergic as well as saprophytic and invasive manifestations depending on host's immune status. The following case report demonstrates progression of allergic manifestations of Aspergillus to its invasive form in an individual with decreasing immunity. This can lead to uncertainties in diagnosis and management. CASE PRESENTATION: A 28-year-old male, non smoker, known case of ABPA (allergic bronchopulmonary aspergillosis) was admitted with complaints of cough for 1 month, associated with recurrent episodes of hemoptysis for last 5 days. CT Thorax revealed homogenous dense round opacity in right upper lobe which replaced previous fibrocalcific bronchiectatic lesion with cavity and aspergilloma, bulging across the major fissure with fibrotic strands extending to periphery in all directions. Post-pneumonectomy microscopic examination revealed Aspergillus hyphae invading blood vessels. CONCLUSION: There is a need for close clinical and radiologic follow up of patients with Aspergillus and our patient demonstrated overlap of complete spectrum of Aspergillus disease with march from one end to the other end.

8.
J Clin Diagn Res ; 9(8): TD03-4, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26436015

ABSTRACT

Echinococcus commonly affects the liver and the lung, but several organs can be affected by this disease. The isolated primary diaphragmatic hydatid cyst, not associated with liver or lung, is very rare. We report a case of hydatid cyst in a 55-year-old male, located in the abdominal side of the left hemidiaphragm which mimicked a hypovascular diaphragmatic tumour and exophytic splenic cyst. In our case the diagnosis was confirmed only with histopathological examination done after surgical excision of the cyst. The aim of this work lies in the fact that knowledge of this clinical entity especially in endemic areas as in India will enable radiologists to guide the clinicians in proper diagnosis and adequate pre-operative planning.

9.
Respirol Case Rep ; 3(4): 155-8, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26740885

ABSTRACT

Uncontrolled diabetes is a known immunosuppressive state. It predisposes individuals to bacterial and fungal infections. The present case report demonstrates sequential infections by Klebsiella followed by tuberculosis and later development of mucormycosis in a poorly controlled diabetic patient. Timing of diagnosis is of essence because of high mortality seen with such pulmonary infections. High index of suspicion needs to be maintained as the same individual may harbor multiple infections as highlighted in this case.

10.
Indian J Chest Dis Allied Sci ; 56(4): 255-7, 2014.
Article in English | MEDLINE | ID: mdl-25962201

ABSTRACT

Thymic carcinoids are rare mediastinal tumours. These are aggressive tumours that often present late and have poor prognosis. Primary surgical treatment is recommended even in metastatic tumours since the role of adjuvant therapy is not well established. We present a case of metastatic thymic carcinoid managed with surgical excision.


Subject(s)
Carcinoid Tumor , Thoracotomy/methods , Thymectomy/methods , Thymus Neoplasms , Adult , Carcinoid Tumor/pathology , Carcinoid Tumor/surgery , Humans , Male , Positron-Emission Tomography , Preoperative Care , Thymus Gland/pathology , Thymus Gland/surgery , Thymus Neoplasms/pathology , Thymus Neoplasms/surgery , Tomography, X-Ray Computed , Treatment Outcome
11.
Surg Laparosc Endosc Percutan Tech ; 13(1): 48-50, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12598760

ABSTRACT

The occurrence of arterial pseudoaneurysms after laparoscopic cholecystectomy in the right hepatic artery, common hepatic artery, and cystic artery has been well documented. We describe a case of pseudoaneurysm of the common iliac artery presenting after laparoscopic stapled mesh rectopexy. As the benefits of minimal access surgery are extended to more and more procedures, surgeons should recognize the possibility of such a complication.


Subject(s)
Aneurysm, False/etiology , Iliac Aneurysm/etiology , Laparoscopy/adverse effects , Rectal Prolapse/surgery , Rectum/surgery , Surgical Mesh/adverse effects , Surgical Stapling/adverse effects , Aneurysm, False/diagnosis , Aneurysm, False/surgery , Humans , Iliac Aneurysm/diagnosis , Iliac Aneurysm/surgery , Male , Middle Aged
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