For in vivo neural recording, local field potential (LFP) is often corrupted by spatially correlated artifacts, especially in awake/behaving subjects. A method named adaptive common average reference (ACAR) based on the concept of adaptive noise canceling (ANC) that utilizes the correlative features of common noise sources and implements with common average referencing (CAR), was proposed for removing the spatially correlated artifacts. Moreover, a correlation analysis was devised to automatically select appropriate channels before generating the CAR reference. The performance was evaluated in both synthesized data and real data from the hippocampus of pigeons, and the results were compared with the standard CAR and several previously proposed artifacts removal methods. Comparative testing results suggest that the ACAR performs better than the available algorithms, especially in a low SNR. In addition, feasibility of this method was provided theoretically. The proposed method would be an important pre-processing step for in vivo LFP processing.
Artifacts ; Columbidae ; Hippocampus ; Methods ; Noise

Control at beyond-visual ranges is of great significance to animal-robots with wide range motion capability. For pigeon-robots, such control can be done by the way of onboard preprogram, but not constitute a closed-loop yet. This study designed a new control system for pigeon-robots, which integrated the function of trajectory monitoring to that of brain stimulation. It achieved the closed-loop control in turning or circling by estimating pigeons' flight state instantaneously and the corresponding logical regulation. The stimulation targets located at the formation reticularis medialis mesencephali (FRM) in the left and right brain, for the purposes of left- and right-turn control, respectively. The stimulus was characterized by the waveform mimicking the nerve cell membrane potential, and was activated intermittently. The wearable control unit weighted 11.8 g totally. The results showed a 90% success rate by the closed-loop control in pigeon-robots. It was convenient to obtain the wing shape during flight maneuver, by equipping a pigeon-robot with a vivo camera. It was also feasible to regulate the evolution of pigeon flocks by the pigeon-robots at different hierarchical level. All of these lay the groundwork for the application of pigeon-robots in scientific researches.
Animals ; Columbidae/physiology* ; Robotics/methods* ; Cerebral Cortex

To explore the feasibility of applying magnetic stimulation technology to the movement control of animal robots, the influence of coil radius, number of turns and other factors on the intensity, depth and focus of magnetic stimulation was simulated and analyzed for robot pigeons. The coil design scheme was proposed. The coil was placed on the head and one of the legs of the pigeon, and the leg electromyography (EMG) was recorded when magnetic stimulation was performed. Results showed that the EMG was significantly strengthened during magnetic stimulation. With the reduction of the output frequency of the magnetic stimulation system, the output current was increased and the EMG was enhanced accordingly. Compared with the brain magnetic stimulation, sciatic nerve stimulation produced a more significant EMG enhancement response. This indicated that the magnetic stimulation system could effectively modulate the functions of brain and peripheral nerves by driving the coil. This study provides theoretical and experimental guidance for the subsequent optimization and improvement of practical coils, and lays a preliminary theoretical and experimental foundation for the implementation of magnetic stimulation motion control of animal robots.
Animals ; Columbidae ; Robotics ; Motion ; Brain ; Magnetic Phenomena

Twenty nine samples of pigeon droppings (n = 12) and soil contaminated with avian excreta (n = 19), collected from different sites in Busan, were examined for isolation and characterization of Cryptococcus neoformans. Of these samples, 5 strains of C. neoformans were recovered from pigeon droppings (5/12 : 41.7%). All isolates were belonged to C. neoformans var. grubii (serotype A). The extracellular enzyme activities of the strains by using the API-ZYM system showed two different enzymatic patterns. The genetic variability among C. neoformans isolates was analyzed by random amplified polymorphic DNA (RAPD) using three 10-mer primers. Two different RAPD patterns, which clearly distinguished the isolates, were identified. Analysis of RAPD patterns provided a good characterization of environmental strains of C. neoformans serotype A as a heterogeneous group and were in good agreement with enzymatic profiles.
Busan* ; Columbidae ; Cryptococcus neoformans* ; Cryptococcus* ; DNA ; Soil

The morphologic differences hetween a mucoid and pasty type of Cryptococcus neoformans derived from pigeon drops were investigated using an eIectron microscope. The following results were obtained: No essential differences in ultramicroscopic structures were noted hetween the mucoid and pasty type of C. neoformans, but the capsule is thicker in the mucoid type than the pasty one and the intracytoplasmic structures were seen more clearly in the mucoid type. These differences seem to he related to chemical components and the difficulty of penetration of fixing solution through thick capsules. There were no differences between C. neoformans derived from pigeon drops and those from pathogenic strains which were reported by others. Therefore, C. neoformans derived form pigeon drops can infect humans.
Capsules ; Columbidae* ; Cryptococcus neoformans* ; Cryptococcus* ; Humans

The wide frequency band ECG (WFB-ECG) was recorded in 33 (anesthetized) normal pigeons by the microprocessor ECG system (made in Nanjing University) with a wide-frequency response (0-1000 Hz), a high-speed sweep (up to 1401 mm/s) and a high sensitivity (up to 28 mm/mV). The recording methods for limb leads in the pigeon were the same as those in man, except that the needle electrodes (made by No.5 needles) were subcutaneously inserted in the bases of the wings and in the legs. We studied the features of time domain and power spectrum of pigeons WFB-ECG. It presents P, R, S and T waves, but no Q wave, basically similar to the results from Aves described by Sturkie. But there are still many characters that were not be recorded on the conventional ECG: (1) the main QRS complex is inverted and forms the type of rS or rSr , no Q wave in leads II, III, aVF, and the S-T segment is absent, which is different from that of humans. The T wave is upright in leads II, III, and aVF (except one), in agreement with that of man. But in lead aVR, the main QRS complex is upright and forms the type of Rs, and the T wave is inverted without any exception. There is a large notch on the upstroke of S wave without any exception. The amplitude of the notch is 0.413+/-0.133 mV and the duration is 9.733+/-1.291 ms in lead II. (2) The ratio of duration of P wave to P-R segment is about 0.8, lower than that of humans (1.0-1.6), but higher than that of mice (0.4). (3) The low frequency signals (0-80 Hz) are prominent. The relative power content of high frequency range of QRS in lead II is: 100-1000 Hz: (10.181+/-7.443)%; 80-300 Hz: (15.418+/-10.579)%. (4)The QRS vector loop in the frontal plane lies between -90 degrees and -180 degrees. The electrical axis of QRS complex averages -118 +/-10 (ranges from -96 degrees to -136 degrees). The reason that position of vector loop and the direction of main wave of QRS in the pigeon are different from human s and rodent s is probably that the Purkinje fibers cross the whole ventricular wall and terminate in the subepicardium in Aves including pigeons . After the impulses coming from the sinoatrial node reach the ventricular muscles, the subepicardium is depolarized before the endocardium. However in human s and rodent s, the Purkinje fibres only reach one-forth to one-second of the whole thickness from the endocardium to the epicardium, the subendocardium is depolarized before the subepicardium.
Animals ; Columbidae ; physiology ; Electrocardiography ; Female ; Heart ; physiology ; Male

Three hundred and sixty five samples of avian droppings, collected from parks and zoo, were investigated for the occurrence of Cryptococcus neoformans in Korea. Thirteen samples were positive for C. neoformans. All isolates were obtained from withered pigeon droppings. Identification and serotyping of isolates were determined by means of serological test and polymerase chain reaction (PCR) fingerprinting. All isolates belonged to C. neoformans var. grubbi (serotype A).
Columbidae* ; Cryptococcus neoformans* ; Cryptococcus* ; Dermatoglyphics ; Korea* ; Polymerase Chain Reaction ; Serologic Tests ; Serotyping

West Nile virus (WNV) is a mosquito-borne zoonotic pathogen that has spread throughout Europe and the United States. Recently, WNV spread to East and Southeast Asia, and great efforts have been made in South Korea to prevent the spread of WNV from neighboring countries. In this study, we diagnosed the first case of WNV in pigeons (Columba livia domestica) residing in cities using a competitive enzyme-linked immunosorbent assay and confirmed it with nested reverse transcription polymerase chain reaction analysis and sequencing. This is the first report to provide convincing evidence that WNV is present within South Korea.
Asia, Southeastern ; Columbidae* ; Enzyme-Linked Immunosorbent Assay ; Europe ; Korea* ; Polymerase Chain Reaction ; Reverse Transcription ; United States ; West Nile virus*

Cryptococcus neoformans is a ubiquitous fungus found worldwide, particularly in soil contaminated by pigeon droppings. Pulmonary cryptococcosis occurs rarely in immunocompetent individuals. The risk of cryptococcal infection increases with the degree of immunal compromise, in human immunodeficiency virus infection especially. Pulmonary cryptococcosis is most frequently encountered as asymptomatic single or multiple pulmonary nodules found by routine chest x-ray examination. The diagnosis is most often made in these situations by the histology of the resected lesion. Acute progressive pneumonia may occur, with symptoms of cough, sputum production, fever, and weakness. The clinical picture is not pathognomonic. The yeasts are stained well by any of the special stains for fungi. Treatment is now indicated for all cases given a diagnosis of cryptococcosis, even if the diagnosis has been made by resecton of a solitary, asymptomatic pulmonary nodule.
Coloring Agents ; Columbidae ; Cough ; Cryptococcosis* ; Cryptococcus neoformans ; Diagnosis ; Fever ; Fungi ; HIV ; Multiple Pulmonary Nodules ; Pneumonia ; Soil ; Sputum ; Thorax ; Yeasts

Avian trichomoniasis caused by Trichomonas gallinae is a serious protozoan disease worldwide. The domestic pigeon (Columba livia domestica) is the main host for T. gallinae and plays an important role in the spread of the disease. Based on the internal transcribed spacers of nuclear ribosomal DNA of this parasite, a pair of primers (TgF2/TgR2) was designed and used to develop a PCR assay for the diagnosis of T. gallinae infection in domestic pigeons. This approach allowed the identification of T. gallinae, and no amplicons were produced when using DNA from other common avian pathogens. The minimum amount of DNA detectable by the specific PCR assay developed in this study was 15 pg. Clinical samples from Guangzhou, China, were examined using this PCR assay and a standard microscopy method, and their molecular characteristics were determined by phylogenetic analysis. All of the T. gallinae-positive samples detected by microscopic examination were also detected as positive by the PCR assay. Most of the samples identified as negative by microscopic examination were detected as T. gallinae positive by the PCR assay and were confirmed by sequencing. The positive samples of T. gallinae collected from Guangzhou, China, were identified as T. gallinae genotype B by sequencing and phylogenetic analyses, providing relevant data for studying the ecology and population genetic structures of trichomonads and for the prevention and control of the diseases they cause.
China* ; Columbidae* ; Diagnosis ; DNA ; DNA, Ribosomal ; Ecology ; Genetic Structures ; Genotype ; Methods ; Microscopy ; Parasites ; Polymerase Chain Reaction* ; Trichomonas*