phages, bacterial viruses that cause the disintegration (lysis) of bacteria and other microorganisms. Bacteriophages reproduce in cells, lyse them, and enter other—generally young—growing cells. Transmissible lysis of bacteria (anthrax bacilli) was first observed in 1898 by the Russian microbiologist N. F. Gamaleia. In 1915 the English scientist F. Twort described the same phenomenon in suppurative staphylococci. In 1917 the French scientist F. d’Hérelle called the lytic agent passing through bacterial filters a “bacteriophage.”
Structure and chemical composition. The particles of many bacteriophages consist of a round, hexagonal, or rod-shaped head 45–140 nanometers (nm) in diameter and a process 100–200 nm thick (see Figure 1). Other bacteriophages do not have a process; some are round, others threadlike, 8 x 800 nm in size. The head contains mostly deoxyribonucleic acid (DNA; the length of a strand greatly exceeds that of the head and attains 60–70 microns, and the strand is tightly coiled within the head) or ribonucleic acid (RNA) and a small amount (about 3 percent) of protein and some other substances. The process has the shape of a hollow tube surrounded by a sheath containing contractile proteins similar to muscular proteins. The sheath in some bacteriophages can contract, revealing part of the shaft. At the end of the process in many bacteriophages there is a basal plate with several spinelike or other projections. Long delicate strands proceed from the plate to help attach the phage to the bacteria (see Figure 1). The membranes of the head and process consist of proteins. The total amount of proteins is 50–60 percent of a phage particle; the nucleic acids account for 40–50 percent. Every bacteriophage has specific antigenic properties differing from the antigens of the host bacterium and other phages. There are antigens common to several phages (especially those containing RNA).
Occurrence. Bacteriophages exist for most bacteria, including pathogenic and saprophytic, and also for actinomycetes (actinophages) and blue-green algae. They are found in the intestines of man and animals, in plants, soil, bodies of water, sewage, manure, and so on. Bacteriophages of soil microorganisms influence the course of the microbiological processes at work in the soil (denitrification, ammonification, nitrogen fixation).
Reproduction. The bacteriophage attaches itself to a bacterial cell by its process and dissolves the cell wall by releasing an enzyme. The contents of the head then pass through the canaliculus of the process into the cell, where the phage’s nucleic acid halts the synthesis of bacterial proteins, DNA, and RNA; then the synthesis of phage nucleic acid and then of phage proteins begins. Some of these proteins are enzymes; others form the membrane of the mature phage particle. Smaller, spherical phages enter bacteria without the participation of the process. If a bacterial cell is infected simultaneously with phage particles differing from one another in a number of properties, then among the offspring—in addition to particles similar to the parents—there will be particles in which these properties occur in a new combination. This is due to the fact that phage reproduction is characterized by recombination—the exchange of fragments of strains of nucleic acid, which is the carrier of hereditary information. Particles of large phages destroy the bacteria in leaving them, whereas the particles of small and threadlike phages leave living bacteria. Some bacteriophages are highly specific and capable of lysing the cells of only one particular species of microorganism (monophages), and others can lyse the cells of various species (polyphages).
Bacteriophages are of two types: virulent bacteriophages cause the lysis of cells and formation of new particles; mild (symbiotic) bacteriophages are adsorbed by the cell and penetrate it but do not cause lysis—they remain in the cells in a latent, noninfectious form (prophage). Cultures containing latent phage are called lysogenic. Lysogenesis is transmitted to the offspring of bacteria. A lysogenic culture may contain two, three, or more phages; it is generally resistant to the phages present. (Only a few cells are lysed and liberate mature phages.) By exposing a lysogenic culture to ultraviolet or X rays, hydrogen peroxide, and some other substances, it is possible to increase substantially the number of cells liberating phages (so-called bacteriophage induction). Lysogenesis is widespread among all species of bacteria and actinomycetes. In a number of cases many properties of a lysogenic culture (toxicity, bacterial mobility, and so on) depend on the presence therein of certain prophages. Many mutations of bacteriophages have been described. These are associated with change in their lytic activity, structure of the particles and colonies, resistance to unfavorable factors, and other properties. Bacteriophages play a major role in microbial variability and evolution. There are various mechanisms by which they act on the cells. They can markedly alter the nitrogen-fixing ability of Azotobacter, the toxicity and antigenic properties of pathogenic bacteria, and so on.
Practical significance. Some phages (alone or combined with antibiotics) have been used to prevent (phagopro-phylaxis) and treat (phagotherapy) a number of bacterial infections of man (dysentery, typhoid, cholera, plague, staphylococcal and anaerobic infections, and others) and animals. However, antibiotics and other chemotherapeutic agents proved to be more efficacious than phages, and their use for therapeutic purposes has narrowed. Bacteriophages are successfully used to determine the species of bacteria and actinomycetes. They may harm the production of antibiotics, amino acids, milk products, bacterial fertilizers, and other aspects of microbiological synthesis. They are important in theoretical studies on genetics and molecular biology.
Bacteriophages offer a unique tool to gently fine-tune the gut microbiota by specifically targeting problem-causing bacteria.
Bacteriophages were isolated from wastewater of a medium (P) and a small (S) scale poultry processing plants (Table 1) in Pichincha-Ecuador.
Our current debate over vaccinations, and the difficulty in convincing parents to agree to vaccinate their children, suggests that it would be equally difficult to get the general public to support the use of bacteriophages to cure disease.
Isolation, characterization and therapeutic potential assessment of bacteriophages virulent to Staphylococcus aureus associated with goat mastitis, Iranian.
In the past 15 years, articles and books about the effect of bacteriophages on biofilm have been published internationally, but no specific information is currently available for Romania.
In order to use bacteriophages, scientists have needed to find out how precisely the viruses destroy cell walls.
The Stx-2A bacteriophages were highly similar in morphologic features, restriction endonuclease profiles, chromosomal integration sites, and superinfection immunity (2,3) and showed <65% similarity to Stx phages from non-O104 strains.
It is very important to note that bacteriophages have served as a vital tool for understanding molecular biology besides serving as potential treatment agent to combat bacterial infection.
A set of consecutive binary digits representing data in coded form, in which the significance of each bit is determined by its position in the sequence and its relation to the other bits.
An ordered sequence of bits. This is very similar to a bit pattern except that the term "string" suggests an arbitrary length sequence as opposed to a pre-determined length "pattern".
Figure 3(a) elaborated the typical matching rule in which detectors are generated through a process of negative selection with bit string comprises of parent, average estimate and hop count.
This bit string challenge looks for missing information, and is not a computational horsepower comparison between classical and quantum computers.
The bit string is set up out of a set of selected local patch comparisons to describe the structure of the central patch.
But, on the other hand, the probability for a bit at a given position l in a random bit string to be 1 is 0.
When encrypting two plain texts, this takes advantage of the characteristics of polynomial multiplication, reordering the bit string of one in ascending order, the other in descending order, and then converting both to polynomials, which makes it possible for inner products of encrypted bit strings to be calculated as a batch.
A representation is not necessarily a contiguous bit string, but may consist of separate blocks of memory that could be just anywhere in the address space.
Each bee in the population represents a bit string of length equal to the number of the box types of the given CL problem.
Hence, one encrypts and randomizes the bit string by a bitwise exclusive or with a key string, and then embeds it by performing a bitwise exclusive or with the lowermost bit of selected pixel values.
A frequency domain manipulation based approach towards steganographic embedding in digital images for covert communication
Given a fixed-length binary code for the state space of a planning problem, BDDs can be used to represent the characteristic function of a set of states (which evaluates to true for a given bit string, that is, state, if and only if it is a member of this set).
Once the message is received, the receiver recreates the hash bit string by applying the hashing algorithm to the message.
Essentially, these tools generate the configuration bit string, given such inputs as a logic diagram or a high-level functional description.
This may sound impossible--how can you check that a bit string is a satisfying assignment without reading every bit in it?
(rāt`əl), carnivore, Mellivora capensis, of the forest and brush country of Africa, the Middle East, and India; it is a member of the badger and skunk family. Related to the wolverine and martens, as shown by the resemblance in teeth, the honey badger resembles in fossorial form and perhaps in its fierce disposition the true badgers. The honey badger has short legs and stout claws and is a strong burrower and a good climber. About 2 ft (61 cm) long excluding the tail, it has a coat that is black on the lower half of the body and pale gray above. The honey badger resembles its distant relative the skunk in coloration and in the possession of an anal scent gland. It is nocturnal, feeds on rodents, reptiles, and insects, and has a thick loose coat that protects it against snake bites and insect stings. The honey badger collaborates with the honeyguidehoneyguide,
small plainly colored Old World bird of the family Indicatoridae, known for its habit of leading man and some lower animals (notably the honey badger) to the nests of wild bees. Honeyguides are native to Africa, the Himalayas, and the East Indies.
..... Click the link for more information. , or indicator bird, in obtaining honey, a favorite food. The bird searches for a bee colony, and when one is found, the honey badger rips it open. The bird and the honey badger then share the honey. Honey badgers travel singly or in pairs. The young, usually two, are born in burrows. Honey badgers are classified in the phylum ChordataChordata
Also since honey badgers have that air of nonchalance about them, they are often seen preying on animals that are bigger in stature and more lethal than they are in real life -&nbsp;evidence being the several videos of honey badgers hunting,&nbsp;available on social media.
The rare Ruffle's fox, jackals, bland fords, a great number of gazelles, sheep, honey badger, Indian-crested porcupine, Ethiopian hedgehog, Brandt's hedgehog, and long-eared hedgehog, and 18 species of rats and gerbils, eagle owl known to be the largest in the region, and the Arabian red fox, which is the biggest of the species in the Arabian Peninsula, are among the nocturnal animals visitors can discover for themselves.
But what if Tyrann Mathieu - Honey Badger - had not awakened LSU from an upset daze against Georgia with a punt return for a touchdown, and then set up another TD with a fumble recovery?
He may be crazy as a hungry honey badger, and should have been fired years ago for his repeated alleged abuses of women, but what he's not is an anti-Semite.
The species included hog deer, marsh crocodile, otter, caracal, pangolin, fishing cat, Indian civet, honey badger, desert cat, monitor lizard, black and grey partridges, and waterfowls.
However, the ratel or honey badger Mellivora capensis was only first formally recorded in the UAE in 2005, near Ruwais, and there remains the possibility that this large, but shy, canid may be present in the far west of the UAE.