Reflex effects following selective stimulation of J receptors in the cat

1. Experiments carried out on anaesthetized cats showed that increasing blood flow, through the lobes of a lung, by 133% (S.E. 33%) generated an average of 0.75 impulses/sec (S.E. 0.3) in ten almost silent J receptors. Equivalent activity was produced by injecting 12-18 μg phenyl diguanide/kg into the right atrium. Such activity caused marked reflex effects, i.e. apnoea, rapid shallow breathing and reduction in the knee jerk. 2. The reflex effects of J receptors were studied after blocking the activity from cardiac receptors by intrapericardial injections of xylocaine. This was necessary because left atrial injections of phenyl diguanide produced reflex respiratory effects and inhibition of the knee jerk. 3. Hypoxia, but not hypercapnia, attenuated the reflex effects of J receptors, apnoea being abolished if the Pa,O2 fell below 35 mmHg. This was a central effect as it occurred in spite of increased activity of J receptors following phenyl diguanide, and effects of hypoxia persisted after cutting both carotid nerves. 4. The only invariable reflex effect of J receptors was a reduction in the total number and the average frequency of phrenic impulses in each breath. The changes in inspiratory time (ti) and expiratory time (te) following apnoea were variable although most frequently both were reduced. In about half the observations the first effect before the apnoea was a reduction in ti, in the other half it was a reduction in te. It was concluded that an input from J receptors inhibits inspiratory and expiratory mechanisms directly. 5. In some cats apnoea and rapid shallow breathing produced by J receptors continued after interrupting their activity by vagotomy and this did not diminish the reduction in ti or te; in other cats it did. The reduction in te was at times quite independent of changes in ti, i.e. pulmonary stretch receptor activity. 6. It was concluded that J receptors must be stimulated during moderate exercise to levels that produce marked respiratory reflex effects and inhibition of muscles

The influence of the sympathetic outflow on aortic chemoreceptors of the cat during hypoxia and hypercapnia

1. An attempt has been made to reconcile differing observations, made by different groups of investigators, on the responses of aortic chemoreceptors of cats during normoxia, hypoxia and hypercapnia. 2. In cats anaesthetized with sodium pentobarbitone it was observed that during hypoxic stimulation of twelve chemoreceptors, an intravenous injection of about 20 mg sodium pentobarbitone produced hypotension which was accompanied by an initial fall in chemoreceptor activity instead of the expected increase that invariably occurred in all the receptors when hypotension was produced mechanically by distending a balloon in the right atrium (twenty-six during normoxia, eleven during hypoxia and eight during hypercapnia). 3. In twelve receptors a reflex fall in blood pressure produced by injecting 8-25 μg veratridine (Bezold-Jarisch reflex) yielded results qualitatively similar to those following injection of sodium pentobarbitone. 4. In sixteen out of twenty-five chemoreceptors it was observed that ventilating the cat with 5.6-6.7 % CO2 produced either no or little increase in activity; in nine receptors there was a clear increase in activity, which fell initially or was abolished after injecting a single dose of 20 mg sodium pentobarbitone. 5. In all seven chemoreceptors tested in seven deeply anaesthetized cats it was found that a larger dose (about 50-60 mg) of sodium pentobarbitone had no direct depressant effect on aortic chemoreceptor activity. It followed that the initial depressant effect of the much smaller doses of sodium pentobarbitone observed during hypoxic and hypercapnic stimulation (see above) must be due to reduction in the sympathetic outflow to the aortic bodies. This conclusion was supported by the results following injections of veratridine. 6. By comparing the present results with those reported previously it was concluded that the variations in the responses of aortic chemoreceptors during hypoxia and hypercapnia reported by different investigators could be partly due to variations in the level of sympathetic activity prevailing under different experimental conditions

Factors affecting movement of excitatory substances from pulmonary capillaries to type J receptors of anaesthetized cats

1. Using phenyl diguanide (PDG) as an excitatory substance, the role of certain factors that could influence the movement of such substances across the pulmonary capillaries to the J receptors was studied in cats anaesthetized with sodium pentobarbitone. This was aided by using a new method for estimating continuously in vivo the concentration (C) of PDG in the blood of the pulmonary artery. 2. Reduction of pulmonary blood flow by partial occlusion of the inferior vena cava enhanced the responses of the J receptors to PDG significantly in twelve out of thirteen trials. These effects, which occurred at a time when pulmonary capillary pressure (PCP) had fallen, could be related to the increase in the estimated mean C of PDG over the first 3 s or to the C t (concentration × time) area to 50% of peak C. The responses bore no relation to peak C or rate of rise of C. 3. The responses of the receptors to PDG increased significantly after three out of eight injections of PDG while the PCP was raised by partial occlusion of the mitral orifice; reduced responses were recorded after two injections. These results, showing relatively much weaker stimulation by PDG in spite of the enhanced level of J receptor excitability produced by the raised PCP itself, suggest that movement of PDG out of the capillaries to the J receptors must be influenced primarily by forces governing diffusion, not filtration. 4. In addition to C of PDG there appear to be other factors that influence the responses of the receptors to PDG

Clinico-microbiological analysis of bactibilia isolates in patients of cholecystectomy

Background: The current study determined microbial flora in bile aspirates from patients undergoing cholecystectomy along with antibiotic susceptibility pattern and resistance mechanism viz. extended spectrum β-lactamase (ESBL).Methods: The study included 110 such patients which were divided in three groups as: Group A that included acute cholecystitis with or without cholelithiasis, Group B included chronic cholecystitis with or without cholelithiasis and Group C included other hepatobiliary ailments requiring cholecystectomy viz. gallbladder carcinoma, acute emphysematous gall bladder and mucocele gall bladder. The bile was subjected to complete microbiological and histopathological examination. Antimicrobial susceptibility of the isolates was performed as per CLSI guidelines.Results: Bacteria were recovered from 07 samples (20%) in Group A, 17 (48.57%) in Group B and 11 (31.43%) in Group C. The polymicrobial infection was seen in 04 (11.43%) patients. The most common organisms isolated were Escherichia coli 15 (38.46%), Klebsiella pneumoniae and Pseudomonas aeruginosa 8 (20.51% each). The majority of Enterobacteriaceae isolates were susceptible to piperacillin-tazobactam and carbapenems. The ESBL production was observed in 17 (43.58%) isolates.Conclusions: Therefore, antimicrobial susceptibility of potential causative organisms, presence of resistant strains in bile, the severity of the cholecystitis, and the local susceptibility pattern must be taken into consideration while prescribing antibiotics. A protocol regarding the management of such cases should be formulated based on observations of similar studies.

Sensory origin of lobeline-induced sensations: a correlative study in man and cat

1. Intravenous injections of lobeline HCl into twenty-six normal young male human volunteers produced sensations of choking, pressure or fumes in the throat and upper chest at a mean threshold dose of 12 μg kg-1. 2. Reflex changes in breathing pattern usually appeared just before the sensations. Increasing the dose of lobeline increased the intensity of the sensations gradually until a dry cough appeared at a mean threshold dose of 24.3 μg kg-1. At these doses there was a mean difference of 0.3 s in the latencies for sensation and respiratory reflex; in four subjects there was no difference at all. 3. In cats anaesthetized with 35 μg kg-1 sodium pentobarbitone, injecting 25-67 μg kg-1 lobeline into the right atrium sensitized thirteen out of seventeen rapidly adapting receptors (RARs). In three out of four cats lobeline had no excitatory effect on the RARs in the absence of normal activity (i.e. when it was injected while artificial respiration was suspended), but on restarting the respiration the activity increased greatly. After injecting lobeline, the activity increased during inflation or deflation or in both phases of the respiratory cycle. It also increased greatly during deflation produced by suction of air from the lungs after lobeline. Such presumed increased activity in the RARs of man produced by forced expiration to residual volume at the time lobeline-induced sensations were expected did not enhance the sensations in any subject. 4. In all the subjects tested, forced expiration alone, which should stimulate RARs, never produced a dry cough or sensations similar to those produced by lobeline.5. The results suggest that since the reflex respiratory effects of lobeline are due to J receptors, the sensations and cough can also be attributed to them, since both events occur at about the same time, and also because the RARs, and the slowly adapting receptors (SARs), do not seem to play a primary role in producing or potentiating the sensations

Applicability of carboxydotrophic bacterial carbon monoxide dehydrogenase (CODH) in carbon sequestration and bioenergy generation

381-384This review presents applicability of carboxydotrophic bacterial carbon monoxide dehydrogenase (CODH) in carbon sequestration and bioenergy generation. CODH catalyzes reversible conversion of CO2 to CO. These bacteria use CO and CO2 as source of energy and carbon for growth, and therefore, play a vital role in maintaining very low CO level in the environment. The enzyme finds application in detection and mitigation of CO levels, and also to produce bioenergy from CO2

Improving Sentiment Analysis in Social Media by Handling Lengthened Words

Machines are continually being channelized in the current era of automation to deliver accurate interpretations of what people communicate on social media. The human species is today engulfed in the concept of what and how people believe, and the decisions made as a result are mostly dependent on the sway of the masses on social media platforms. The usage of internet as well as social media is booming day by day. Today, this ocean of data can be used for the fruitful purposes. Analysis of social media sentiment textual posts can supply knowledge and information that can be used in citizen opinion polling, business intelligence, social contexts, and Internet of Things (IOT)-mood triggered devices. In this manuscript, the main focus is the sentiment analysis based on Emotional Recognition (ER). The proposed system highlights the process of gaining actual sentiment or mood of a person. The key idea to this system is posed by the fact that if smile and laughter can be two different categories of being happy, then why not happpyyyyyy and happy. A novel lexicon based system is proposed that considers the lengthened word as it is, instead of being omitted or normalized. The aggregated intensified senti-scores of lengthened words are calculated using framed lexicon rules. After that, these senti-scores of lengthened words are used to calculate the level of sentiment of the person. The dataset used in this paper is the informal chats happened among different friend groups over Facebook, Tweets and personal chat. The performance of proposed system is compared with traditional systems that ignore lengthened words and proposed system outperform tradition systems by achieving 81% to 96% F-measure rate for all datasets

Duplicate Bug Report Detection and Classification System Based on Deep Learning Technique

Duplicate bug report detection is a process of finding a duplicate bug report in the bug tracking system. This process is essential to avoid unnecessary work and rediscovery. In typical bug tracking systems, more than thousands of duplicate bug reports are reported every day. In turn, human cost, effort and time are increased. This makes it an important problem in the software management process. The solution is to automate the duplicate bug report detection system for reducing the manual effort, thus the productivity of triager's and developer's is increased. It also speeds up the process of software management as a result software maintenance cost is also reduced. However, existing systems are not quite accurate yet, in spite of these systems used various machine learning approaches. In this work, an automatic bug report detection and classification model is proposed using deep learning technique. The proposed system has three modules i.e. Preprocessing, Deep Learning Model and Duplicate Bug report Detection and Classification. Further, the proposed model used Convolutional Neural Network based deep learning model to extract relevant feature. These relevant features are used to determine the similar features of bug reports. Hence, the bug reports similarity is computers through these similar features. The performance of the proposed system is evaluated on six publicly available datasets using six performance metrics. It is noticed that the proposed system outperforms the existing systems by achieving an accuracy rate in the range of 85% to 99 % and recall@k rate in between 79%-94%. Moreover, the effectiveness of the proposed system is also measured on the cross training datasets of same and different domain. The proposed system achieves a good high accuracy rate for same domain data sets and low accuracy rate for different domain datasets

How does lobeline injected intravenously produce a cough?

In order to examine, whether the lobeline-induced cough is a true reflex or a voluntary effort to get rid of its irritating sensations in the upper respiratory tract, we systematically studied the cough response to lobeline, of subjects who were unable to make conscious discriminations i.e. were either comatose (n = 4) or anaesthetized (n = 5). 8 µg/kg lobeline injected into the right atrium of one and 29 µg/kg intravenously (i.v.) into another evenly and spontaneously breathing comatose subject produced a cough after 4 s and 12 s, respectively. Cough was repeatable and showed a dose response relationship i.e., its latency decreasing and its duration/intensity increasing with the dose. In a third subject, capable only of weak spontaneous respiration, a relatively high dose injected into the right atrium (44 µg/kg) generated a pronounced cough-like respiratory movement superimposed on the artificial ventilation and also during the apnoea after disconnecting the pump. No respiratory response was evoked in a fourth subject who had no evidence of brainstem reflexes. In five normals, cough was elicited with a mean dose of 35 ± 5 µg/kg i.v. (latency 14 ± 2 s; duration 10 ± 3 s). After thiopental anaesthesia, injecting 41 ± 7 µg/kg produced a cough within 13 ± 2 s that lasted for 12 ± 2 s. It may be noted that neither the later dose nor the latency or duration of cough that it produced were significantly different from the pre anaesthesia values (P > 0.05). These two sets of results show unequivocally that the lobeline-induced cough is evoked reflexely; its magnitude in the conscious state could vary by subjective influences. We discuss the likelihood of its origin from juxtapulmonary capillary receptors

A Novel Deep-Learning-Based Bug Severity Classification Technique Using Convolutional Neural Networks and Random Forest with Boosting

The accurate severity classification of a bug report is an important aspect of bug fixing. The bug reports are submitted into the bug tracking system with high speed, and owing to this, bug repository size has been increasing at an enormous rate. This increased bug repository size introduces biases in the bug triage process. Therefore, it is necessary to classify the severity of a bug report to balance the bug triaging process. Previously, many machine learning models were proposed for automation of bug severity classification. The accuracy of these models is not up to the mark because they do not extract the important feature patterns for learning the classifier. This paper proposes a novel deep learning model for multiclass severity classification called Bug Severity classification to address these challenges by using a Convolutional Neural Network and Random forest with Boosting (BCR). This model directly learns the latent and highly representative features. Initially, the natural language techniques preprocess the bug report text, and then n-gram is used to extract the features. Further, the Convolutional Neural Network extracts the important feature patterns of respective severity classes. Lastly, the random forest with boosting classifies the multiple bug severity classes. The average accuracy of the proposed model is 96.34% on multiclass severity of five open source projects. The average F-measures of the proposed BCR and the existing approach were 96.43% and 84.24%, respectively, on binary class severity classification. The results prove that the proposed BCR approach enhances the performance of bug severity classification over the state-of-the-art techniques