Orientation cues and mechanisms used during avian navigation: A review

The navigational systems of different animal species are by a wide margin less notable as compared to birds. Humans have been interested in how migratory birds discover their way more than thousands of miles for quite a long time. This review summarizes the cues and compass mechanisms applied in orientation and navigation by non-migrants, diurnal and nocturnal migrants. The magnetic compass, landmarks, olfactory, and memory of spatial cues en route were utilized in homing and migration. The equivalent is valid for the sun compass despite the fact that its job during migration might be undeniably less significant than commonly presumed. Stellar compass and celestial rotation, as a result of their nighttime accessibility, appear to influence the direction of nighttime migrants during the course of migration. The celestial cues go through notable changes because of the latitude shift during bird migration. Sunset cues alter their location with seasons and latitudes. The recognizable stars lose height and lastly vanish underneath the horizon, whereas new stars show up. These new ones must be calibrated. As celestial rotation not imparting a reference, it is not unexpected that the magnetic compass turns into the main cue that controls the directional importance of stars and sunset cues. Field studies have revealed that, in certain species, a considerable extent of individuals get back to similar breeding, overwintering, and stopover areas in progressive years. This review proposes that migratory birds have advanced uncommon cognitive capacities that empower them to achieve these accomplishments.     

Real-Time Demonstration of Concurrent Upstream and Inter-ONU Communications in Hybrid OFDM DFMA PONs

This paper presents the first real-time experimental demonstration of concurrent upstream and inter-ONU communications in a hybrid OFDM DFMA PON, enabled by a simple low-cost alteration to the remote node. Real-time FPGA-based DSP, incorporating a 128-pt FFT and a joint sideband processing technique, is used to demultiplex different sub-wavelength channels at the ONU and OLT receivers. The simple modification in the remote node removes the need for direct user-to-user data to pass via the OLT and core network thus providing ultra-low latency inter-ONU connectivity to support a variety of newly emerging latency sensitive 5G services. The presented PON is validated with two subwavelength bands, each capable of carrying one of two possible orthogonal channels ( I or Q ). The dynamic channel and subcarrier allocation allows flexible allocation of PON capacity between upstream and inter-ONU links for dynamic on-demand capacity allocation and also performance optimisation according to the different length dependent link characteristics. Moreover, the backscattering effect associated with upstream signals is shown to have negligible effect on the BER performance of the inter-ONU communications

Robotic intraoperative tracheal repair during retrosternal malignant goiter excision: an anesthetic challenge

Thyroidectomy is the treatment of choice for large retrosternal goiters. These tumors often are large enough to require thoracotomy. Robotic surgery can help in avoiding thoracotomy and its associated post operative complications. Rarely, such tumors and their surgery can be complicated by tracheal tears. Such tears, especially those near the carina are difficult to repair and often require open thoracotomy. We described such a case where we avoided open thoracotomy and instead performed a minimally invasive robotic repair of tracheal tear. The maintenance of ventilation during this robotic repair was critical. A combination of several airway devices was used to allow the complex surgical repair to be executed without affecting ventilation

Ball valving laryngeal masses: a difficult “ball” in the anaesthetists’ court

Dynamic airway obstruction (also called ball-valve effect) is a serious condition often seen in glottic lesions. This is an anesthetic challenge as total airway obstruction can occur after the induction of general anesthesia. We present a case of a middle aged female who had a large laryngeal mass which was showing ball-valve effect. The patient had refused for tracheostomy despite it being the safest procedure in the circumstances. We then performed videolaryngoscopy and managed to intubate the patient with the help of some improvisation. The patient underwent a succesful and uneventful surgery

Magnetic Compass Orientation in a Palaearctic–Indian Night Migrant, the Red-Headed Bunting

Red-headed Buntings (Emberiza bruniceps) perform long-distance migrations within their southerly overwintering grounds and breeding areas in the northern hemisphere. Long-distance migration demands essential orientation mechanisms. The earth’s magnetic field, celestial cues, and memorization of geographical cues en route provide birds with compass knowledge during migration. Birds were tested during spring migration for orientation under natural clear skies, simulated overcast skies at natural day length and temperature, simulated overcast at 22 °C and 38 °C temperatures, and in the deflected (−120°) magnetic field. Under clear skies, the Red-headed Buntings were oriented NNW (north–northwest); simulated overcast testing resulted in a northerly mean direction at local temperatures as well as at 22 °C and 38 °C. The Buntings reacted strongly in favor of the rotated magnetic field under the simulated overcast sky, demonstrating the use of a magnetic compass for migrating in a specific direction

Development of Levan capped silver nanoparticles based product and its effect on wound healing

Silver nanoparticles (AgNPs) are extensively investigated for their potential physical, chemical, and biological properties. Silver nanoparticles (AgNPs) have several applications in diagnosis, therapy (wound healing, cancer), electronic devices, water treatment, etc. The present study used the cost-effective and ecologically approachable technique to synthesize levan-capped silver nanoparticles of about 22 nm. These silver nanoparticles were subsequently introduced into a gel to create a silver release system with bacteria inhibition activity. The study also aimed to evaluate synthesized Levan-based silver nanoparticles loaded gel for its wound healing property in the excision rat model. Compared to commercial products, levan-based AgNPs were used for in-vitro antimicrobial activities on E. Coli and Staphylococcus aureus and in-vivo wound healing properties.The wound healing property was assessed by area and time of wound closure in rats. In the excision wound model, Levan-based AgNPs exhibited a reduction in wound area that was more as compared to standard and control. In this study, the nanoparticles of silver were spherical and homogeneous in size, which showed bactericidal effects for E. coli and B. subtilis. Levan acts as a coating and reducing agent for silver nanoparticles and acts as an anti-inflammatory agent in the healing process. Carbopol was used for topical formulations such as hydrogel due to high viscosity at low concentration and low toxicity profile. This polymer is anionic that needs to be neutralized with triethanolamine to become jellified, and it has good bio-adhesive properties required for gel formulation. The present challenge of silver nanoparticles (AgNPs) is to maximize their benefits and minimize their toxic effects on humans and the environment. For future perspective, its synthesis, release into the atmosphere, and scaling up production must be considered

Utility of volume, conductivity and scatter parameters for early diagnosis of neonatal sepsis

Introduction: Neonatal sepsis comprises a major problem in India. Early detection of neonatal sepsis is challenging as clinical signs are subjective and the gold standard, a positive culture, requires 1–3 days. Volume conductivity scatter (VCS) data were obtained simultaneously with the differential count without additional cost or sample requirement. The present study was undertaken in a tertiary care teaching hospital with the aim of evaluating VCS data and other laboratory parameters for diagnosis of neonatal sepsis. Materials And Methods: Peripheral blood samples of 500 consecutive neonates were analyzed over a period of 2 years for complete blood count (CBC) with band cells, eosinophils, C-reactive protein (CRP), and culture. VCS parameters were obtained simultaneously from Beckman coulter analyzers for neonates aged 0–28 days with suspected sepsis. Controls: Gestation-matched healthy controls with no clinical or laboratory suspicion of infection. The study population was divided into following groups: proven sepsis, clinical sepsis, and no sepsis. A cutoff value of 0.3615 based on CRP, mean neutrophil volume (MNV), and volume distribution width (VDW) was taken to indicate the presence or absence of sepsis; based on the previously published work by Celik et al. Results: A total of 500 consecutive samples of neonates admitted in neonatal Intensive Care Unit of Bharati Hospital were analyzed. All the three groups were analyzedd with respect to CBC values, peripheral blood smear, VCS parameters, CRP values and blood cultures which gave a sensitivity of 76%, specificity of 88%, positive predictive value 77%, and negative predictive value 87%. Conclusions: We analyzed the utility of VCS parameters along with CRP for early diagnosis of neonatal sepsis. The study results indicate that the factor based on MNV, VDW, and CRP with cutoff of 0.3615 is a useful indicator of neonatal sepsis without incurring additional cost, with high specificity (88%), and high negative predictive value (87%)

Evaluation, comparison of different solvent extraction, cell disruption methods and hydrothermal liquefaction of Oedogonium macroalgae for biofuel production

Cell disruption and lipid extraction methods for macroalgae are not well reported. Therefore, we compared various lipid extraction methods and extraction efficiency of various solvents to improve lipid yields from Oedogonium fresh water macroalgae. Lipid extraction was done by 2 methods viz., modified Bligh and Dyer method and soxhlet extraction using either single solvents or mixtures. In soxhlet extraction method five solvents were used (1) Hexane commonly used solvent for lipid extractions, (2) chloroform: methanol (2:1), (3) Chloroform: hexane (1:1), (4) Chloroform: hexane (1:2), (5) Dichloromethane + methanol (2:1). To improve lipid extraction yields, various cell disruption methods were also compared during the present study. Impurities of chlorophyll and protein were also detected in the extracted lipids. Hydrothermal liquefaction of algal biomass with TiO2 was also conducted at 300 °C. HTL was more effective by which 23.3 wt% of bio-crude oil was obtained. Keywords: Oedogonium, Macroalgae, Cell disruption, Lipid, Biodiesel, HT