Saliva Droplets Research Articles

Galapagos Mockingbird Pecks at Sea Lion Mouth

The mockingbirds of the Galipagos Islands (Nesomimnus spp.) are well-known for their opportunistic feeding habits. Hood Island Mockingbirds (N. macdonaldi), in particular, use a wide variety of sources for food and water. Presumably, the extreme aridity and barrenness of their home island have precipitated such habits as egg-eating, blood-drinking, and predation on Tropidurus lizards and nestling sea-birds. Bowman and Carter (Living Bird 10:24:3-270, 1971) tabulated feeding habits of Galipagos mockingbirds. While at Punta Suarez on Hood Island, 26 July 1973, I witnessed a behavior not recorded in their paper or elsewhere in the literature. A N. macdonaldi foraged along a sandy beach littered with sleeping sea lions (Zalophus californianus). This mockingbird spent several minutes hopping from one sea lion to another, pecking at their teeth (fig. 1). The bird appeared to obtain and swallow bits of moist food and/or droplets of saliva. The sea lions continued to sleep, showing no reaction to the mockingbird's pecks. Lack of water, a conspicuous feature of Hood Island, has fostered several unusual methods of feeding in the island's mockingbirds; pecking at sea lions' mouths seems to be an addition to this

Coronavirus Pandemic: Emergence, Transmission, Preventive Measures and Management

Coronavirus is found in animals and, rarely, can be transmitted from animals to humans and then spread person to person. An occurrence of the coronavirus infection (COVID-19) in China is causing global concern. It came from a seafood and meat market in Wuhan, China, in December 2019. It has since spread to many countries around the world including India. World Health Organization (WHO) declared novel coronavirus eruption a “pandemic” on March 11th, 2020. Patients infected with the COVID-19 virus will experience mild to moderate respiratory illness. Older people and those with underlying medical problems like cardiovascular disease, diabetes, chronic respiratory disease, and cancer are more likely to develop serious illness. Prevent spread of infection by washing hands or using an alcohol based rub frequently and not touching face. This virus transmits primarily through droplets of saliva or discharge from the nose when adiseased person coughs or sneezes, so it’s important to cover face by mask and coughing into a flexed elbow at public places. Currently there are no specific vaccines or treatments for COVID-19. In this review, we summarize recent information about the emergence, tansmission, preventive measures and therapeutic options available now.
 

Preliminary observations on a skin-piercing blood-sucking moth (Calyptra eustrigata (Hmps.) (Lep., Noctuidae)) in Malaya

In the course of entomological investigations in Malaya between 1965 and 1967, it was found that Calyptra eustrigata (Hmps.) (Noctuidae) frequently pierces the skin of mammals to feed on blood, and in this respect differs from those Noctuids that marely imbibe blood from an open wound. Other species of Calyptra are known as fruit-piercing moths, and C. minuticornis (Gn.) which was taken in Cambodia on one occasion at the eye of a buffalo, is also one of the eye-frequenting moths, which imbibe lachrymal secretions of Ungulata, Proboscidea and occasionally of man. C. eustrigata has been observed imbibing blood after piercing the skin of buffalo, Sambar deer, Malayan tapir and nilgai antelope. Caged adults in the laboratory were observed piercing the skin of human fingers offered to them; and imbibition of blood continued for up to and hour. The proboscis, which ends in a sclerotised and strongly barbed point, can penetrate about six millimetres below the surface. The two halves of the proboscis work like two paralled saws moving alternately. While feeding is in progress, droplets of saliva exude at the base of the probiscis and run down the outside. Often some blood is regurgitated, then reabsorbed. The puncture causes itching, which can last for up to an hour, and local hardening of the tissue, which can persist for five weeks. By reason of its mode of feeding, C. eustrigata would appear to be a potential vector of disease, as the saliva and regurgitated fluids might transmit pathogenic agents.

Gluconeogenesis in the Oriental Hornet Vespa Orientalis F

Adults and larvae of the Oriental Hornet (Vespa orientalis F.) have been fed on C14—labeled protein, derived from Chlorella, in order to determine to what extent such protein may be converted into carbohydrates. Only larvae were found capable of converting the labeled protein. Products of this conversion were the sugars glucose, fructose and sucrose, and also tri— and tetrasaccharides as yet unidentified. It is suggested that this ability of the larvae to carry out gluconeogenesis and the subsequent transfer of the formed sugars to the adults (in saliva droplets) may play an important part in the adult—larva interrelations of various insect societies.

Relation between the Airborne Diameters of Respiratory Droplets and the Diameter of the Stains left after Recovery

SEVERAL workers have investigated the numbers and sizes of droplets expelled during expiratory manoeuvres such as coughing or sneezing. When droplets are recovered by settling, by impaction or by some form of air sampler, it is necessary to calculate the airborne diameter of the original droplet from the diameter of the stain left after recovery. Duguid1 repeated the experiments of Strauss2 in which large droplets of saliva (1–3 mm in diameter) were measured with a micrometer eyepiece, first while they hung from fine glass capillaries and then again after they had fallen, flattened and evaporated on a slide. When a glass slide was used, the diameters of the original droplets were about half those of the stain marks. Buckland and Tyrrell3, using glass slides, calculated the airborne diameter of droplets as 1/2.5 of the diameter of the stain marks left after impaction. May4 described the use of glass slides coated with magnesium oxide in estimating the airborne diameter of droplets; droplets landing on this surface will penetrate the magnesium oxide crust like stones falling into snow, and the diameter of the entry-hole is related to the airborne diameter of the droplet. He investigated this relationship for droplets with airborne diameters ranging from 20µ to 250µ, determining the airborne diameter by an “absolute method” which involved trapping the droplet in oil, and measuring it microscopically5. He concluded that the airborne diameter averaged 0.858 times the magnesium oxide entry-hole diameter, and that this relationship was independent of the speed of impaction and, within the range investigated, of the diameter of the droplet involved.