Mycoplasma: A genus of gram-negative, mostly facultatively anaerobic bacteria in the family MYCOPLASMATACEAE. The cells are bounded by a PLASMA MEMBRANE and lack a true CELL WALL. Its organisms are pathogens found on the MUCOUS MEMBRANES of humans, ANIMALS, and BIRDS.Mycoplasma Infections: Infections with species of the genus MYCOPLASMA.Pneumonia: Infection of the lung often accompanied by inflammation.Pneumonia, Bacterial: Inflammation of the lung parenchyma that is caused by bacterial infections.Mycoplasma hominis: A common inhabitant of the vagina and cervix and a potential human pathogen, causing infections of the male and female reproductive tracts. It has also been associated with respiratory disease and pharyngitis. (From Dorland, 28th ed)Mycoplasma genitalium: A species of gram-negative bacteria originally isolated from urethral specimens of patients with non-gonoccocal URETHRITIS. In primates it exists in parasitic association with ciliated EPITHELIAL CELLS in the genital and respiratory tracts.Mycoplasma fermentans: A species of the genus MYCOPLASMA, originally isolated infrequently from the lower genital tract of humans, and possessing uncertain pathogenicity. The incognitus strain of M. fermentans has been identified in necrotizing lesions of multiple organs from AIDS and non-AIDS patients dying of an acute influenza-like disease.Mycoplasma mycoides: The etiological agent of contagious pleuropneumonia (PLEUROPNEUMONIA, CONTAGIOUS) of cattle and goats.Pneumonia, Viral: Inflammation of the lung parenchyma that is caused by a viral infection.Mycoplasma hyopneumoniae: A species of gram-negative bacteria that causes MYCOPLASMA PNEUMONIA OF SWINE. The organism damages the CILIA in the airways of the pig, and thus compromises one of the most effective mechanical barriers against invading pathogens. The resulting weakening of the IMMUNE SYSTEM can encourage secondary infections, leading to porcine respiratory disease complex.Pneumonia, Pneumococcal: A febrile disease caused by STREPTOCOCCUS PNEUMONIAE.Mycoplasma bovis: A species of gram-negative bacteria causing MASTITIS; ARTHRITIS; and RESPIRATORY TRACT DISEASES in CATTLE.Mycoplasma pulmonis: A species of gram-negative bacteria highly pathogenic to RATS and MICE. It is the primary cause of murine respiratory mycoplasmosis.Mycoplasma gallisepticum: A species of gram-negative bacteria causing chronic respiratory disease in POULTRY.Mycoplasma penetrans: A species of gram-negative, facultatively anaerobic bacteria. This organism shows remarkable pathobiologic properties: it adheres to cell surfaces, deeply penetrates into the cell, and strongly adsorbs human red blood cells and human CD4+ lymphocytes and monocytes. M. penetrans was first isolated from the urogenital tract of patients with AIDS and high frequencies of antibodies to it are seen in HIV-infected patients.Cryptogenic Organizing Pneumonia: An interstitial lung disease of unknown etiology, occurring between 21-80 years of age. It is characterized by a dramatic onset of a "pneumonia-like" illness with cough, fever, malaise, fatigue, and weight loss. Pathological features include prominent interstitial inflammation without collagen fibrosis, diffuse fibroblastic foci, and no microscopic honeycomb change. There is excessive proliferation of granulation tissue within small airways and alveolar ducts.Mycoplasma agalactiae: A species of gram-negative bacteria causing contagious agalactia of SHEEP and GOATS.Pneumonia, Pneumocystis: A pulmonary disease in humans occurring in immunodeficient or malnourished patients or infants, characterized by DYSPNEA, tachypnea, and HYPOXEMIA. Pneumocystis pneumonia is a frequently seen opportunistic infection in AIDS. It is caused by the fungus PNEUMOCYSTIS JIROVECII. The disease is also found in other MAMMALS where it is caused by related species of Pneumocystis.Mycoplasma synoviae: A species of gram-negative bacteria pathogenic to CHICKENS; TURKEYS, and guinea fowls. It causes disease in a wide variety of organs and tissues including JOINTS, tendon sheaths and the RESPIRATORY TRACT.Mycoplasma hyorhinis: A species of gram-negative bacteria and a common inhabitant of the NASAL CAVITY of both healthy and diseased PIGS. It is a common secondary invader in MYCOPLASMAL PNEUMONIA OF SWINE.Pneumonia, Staphylococcal: Pneumonia caused by infections with bacteria of the genus STAPHYLOCOCCUS, usually with STAPHYLOCOCCUS AUREUS.Pneumonia, Ventilator-Associated: Serious INFLAMMATION of the LUNG in patients who required the use of PULMONARY VENTILATOR. It is usually caused by cross bacterial infections in hospitals (NOSOCOMIAL INFECTIONS).Acholeplasma: A genus of gram-negative organisms including saprophytic and parasitic or pathogenic species.Pneumonia, Aspiration: A type of lung inflammation resulting from the aspiration of food, liquid, or gastric contents into the upper RESPIRATORY TRACT.Community-Acquired Infections: Any infection acquired in the community, that is, contrasted with those acquired in a health care facility (CROSS INFECTION). An infection would be classified as community-acquired if the patient had not recently been in a health care facility or been in contact with someone who had been recently in a health care facility.Mycoplasma arthritidis: A species of gram-negative bacteria causing purulent POLYARTHRITIS in RATS.Pneumonia, Mycoplasma: Interstitial pneumonia caused by extensive infection of the lungs (LUNG) and BRONCHI, particularly the lower lobes of the lungs, by MYCOPLASMA PNEUMONIAE in humans. In SHEEP, it is caused by MYCOPLASMA OVIPNEUMONIAE. In CATTLE, it may be caused by MYCOPLASMA DISPAR.Acholeplasma laidlawii: An organism originally isolated from sewage, manure, humus, and soil, but recently found as a parasite in mammals and birds.Ureaplasma: A genus of gram-negative, nonmotile bacteria which are common parasitic inhabitants of the urogenital tracts of humans, cattle, dogs, and monkeys.Pleuropneumonia, Contagious: A pleuropneumonia of cattle and goats caused by species of MYCOPLASMA.Pneumonia, Lipid: Pneumonia due to aspiration or inhalation of various oily or fatty substances.Mycoplasma capricolum: A genus in the family ENTOMOPLASMATACEAE, order Entomoplasmatales. It is pathogenic to GOATS, causing caprine pleuropneumonia (PLEUROPNEUMONIA, CONTAGIOUS).Mycoplasma salivarium: A species of gram-negative bacteria strongly implicated in oral infection, PERIODONTAL DISEASES, eye and ear disorders, and SEPTIC ARTHRITIS.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Mycoplasma conjunctivae: A species of gram-negative bacteria causing CONJUNCTIVITIS and KERATOCONJUNCTIVITIS in SHEEP and GOATS.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Ureaplasma urealyticum: A species of gram-negative bacteria found in the human genitourinary tract (UROGENITAL SYSTEM), oropharynx, and anal canal. Serovars 1, 3, 6, and 14 have been reclassed into a separate species UREAPLASMA parvum.Lung Diseases, Interstitial: A diverse group of lung diseases that affect the lung parenchyma. They are characterized by an initial inflammation of PULMONARY ALVEOLI that extends to the interstitium and beyond leading to diffuse PULMONARY FIBROSIS. Interstitial lung diseases are classified by their etiology (known or unknown causes), and radiological-pathological features.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.Mycoplasma ovipneumoniae: A species of gram-negative bacteria originally isolated from the LUNGS; TRACHEA; and NASAL CAVITY of SHEEP. It causes chronic interstitial pneumonia (PNEUMONIA, MYCOPLASMA) in both SHEEP and GOATS.Mycoplasma iowae: A species of gram-negative bacteria causing lesions to AIR SACS and HOCK joints in TURKEYS.Tenericutes: A phylum of gram-negative bacteria consisting of cells bounded by a plasma membrane. Its organisms differ from other bacteria in that they are devoid of cell walls. This phylum was formerly the class Mollicutes. Mollicutes is now the sole class in the phylum Tenericutes.Ureaplasma Infections: Infections with bacteria of the genus UREAPLASMA.Bronchopneumonia: Inflammation of the lung parenchyma that is associated with BRONCHITIS, usually involving lobular areas from TERMINAL BRONCHIOLES to the PULMONARY ALVEOLI. The affected areas become filled with exudate that forms consolidated patches.Idiopathic Interstitial Pneumonias: A group of interstitial lung diseases with no known etiology. There are several entities with varying patterns of inflammation and fibrosis. They are classified by their distinct clinical-radiological-pathological features and prognosis. They include IDIOPATHIC PULMONARY FIBROSIS; CRYPTOGENIC ORGANIZING PNEUMONIA; and others.Mycoplasmatales: An order of highly pleomorphic, gram-negative bacteria including both pathogenic and saprophytic species.Bacterial Proteins: Proteins found in any species of bacterium.Streptococcus pneumoniae: A gram-positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Goats: Any of numerous agile, hollow-horned RUMINANTS of the genus Capra, in the family Bovidae, closely related to the SHEEP.Bronchoalveolar Lavage Fluid: Washing liquid obtained from irrigation of the lung, including the BRONCHI and the PULMONARY ALVEOLI. It is generally used to assess biochemical, inflammatory, or infection status of the lung.Adhesins, Bacterial: Cell-surface components or appendages of bacteria that facilitate adhesion (BACTERIAL ADHESION) to other cells or to inanimate surfaces. Most fimbriae (FIMBRIAE, BACTERIAL) of gram-negative bacteria function as adhesins, but in many cases it is a minor subunit protein at the tip of the fimbriae that is the actual adhesin. In gram-positive bacteria, a protein or polysaccharide surface layer serves as the specific adhesin. What is sometimes called polymeric adhesin (BIOFILMS) is distinct from protein adhesin.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.Cattle Diseases: Diseases of domestic cattle of the genus Bos. It includes diseases of cows, yaks, and zebus.Legionnaires' Disease: An acute, sometimes fatal, pneumonia-like bacterial infection characterized by high fever, malaise, muscle aches, respiratory disorders and headache. It is named for an outbreak at the 1976 Philadelphia convention of the American Legion.Murine pneumonia virus: A species of the genus PNEUMOVIRUS causing pneumonia in mice.Complement Fixation Tests: Serologic tests based on inactivation of complement by the antigen-antibody complex (stage 1). Binding of free complement can be visualized by addition of a second antigen-antibody system such as red cells and appropriate red cell antibody (hemolysin) requiring complement for its completion (stage 2). Failure of the red cells to lyse indicates that a specific antigen-antibody reaction has taken place in stage 1. If red cells lyse, free complement is present indicating no antigen-antibody reaction occurred in stage 1.Pneumocystis jirovecii: A species of PNEUMOCYSTIS infecting humans and causing PNEUMOCYSTIS PNEUMONIA. It also occasionally causes extrapulmonary disease in immunocompromised patients. Its former name was Pneumocystis carinii f. sp. hominis.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Respiratory Tract Infections: Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.Pneumocystis: A genus of ascomycetous FUNGI, family Pneumocystidaceae, order Pneumocystidales. It includes various host-specific species causing PNEUMOCYSTIS PNEUMONIA in humans and other MAMMALS.Spiroplasma: A genus of gram-negative, helical bacteria, in the family SPIROPLASMATACEAE, order Entomoplasmatales, causing disease in PLANTS. It has been isolated from TICKS; INSECTS; and PLANTS.Radiography, Thoracic: X-ray visualization of the chest and organs of the thoracic cavity. It is not restricted to visualization of the lungs.Arthritis, Infectious: Arthritis caused by BACTERIA; RICKETTSIA; MYCOPLASMA; VIRUSES; FUNGI; or PARASITES.Chlamydophila pneumoniae: A species of CHLAMYDOPHILA that causes acute respiratory infection, especially atypical pneumonia, in humans, horses, and koalas.Macrolides: A group of often glycosylated macrocyclic compounds formed by chain extension of multiple PROPIONATES cyclized into a large (typically 12, 14, or 16)-membered lactone. Macrolides belong to the POLYKETIDES class of natural products, and many members exhibit ANTIBIOTIC properties.Cat Diseases: Diseases of the domestic cat (Felis catus or F. domesticus). This term does not include diseases of the so-called big cats such as CHEETAHS; LIONS; tigers, cougars, panthers, leopards, and other Felidae for which the heading CARNIVORA is used.Mycoplasma pneumoniae: Short filamentous organism of the genus Mycoplasma, which binds firmly to the cells of the respiratory epithelium. It is one of the etiologic agents of non-viral primary atypical pneumonia in man.Anti-Infective Agents: Substances that prevent infectious agents or organisms from spreading or kill infectious agents in order to prevent the spread of infection.Bacteriological Techniques: Techniques used in studying bacteria.Hemadsorption: A phenomenon manifested by an agent or substance adhering to or being adsorbed on the surface of a red blood cell, as tuberculin can be adsorbed on red blood cells under certain conditions. (Stedman, 25th ed)Cross Infection: Any infection which a patient contracts in a health-care institution.Urethritis: Inflammation involving the URETHRA. Similar to CYSTITIS, clinical symptoms range from vague discomfort to painful urination (DYSURIA), urethral discharge, or both.Goat Diseases: Diseases of the domestic or wild goat of the genus Capra.Bronchoalveolar Lavage: Washing out of the lungs with saline or mucolytic agents for diagnostic or therapeutic purposes. It is very useful in the diagnosis of diffuse pulmonary infiltrates in immunosuppressed patients.Bacterial Adhesion: Physicochemical property of fimbriated (FIMBRIAE, BACTERIAL) and non-fimbriated bacteria of attaching to cells, tissue, and nonbiological surfaces. It is a factor in bacterial colonization and pathogenicity.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Swine Diseases: Diseases of domestic swine and of the wild boar of the genus Sus.RNA, Ribosomal, 16S: Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.Pulmonary Eosinophilia: A condition characterized by infiltration of the lung with EOSINOPHILS due to inflammation or other disease processes. Major eosinophilic lung diseases are the eosinophilic pneumonias caused by infections, allergens, or toxic agents.Trimethoprim-Sulfamethoxazole Combination: This drug combination has proved to be an effective therapeutic agent with broad-spectrum antibacterial activity against both gram-positive and gram-negative organisms. It is effective in the treatment of many infections, including PNEUMOCYSTIS PNEUMONIA in AIDS.RNA, Bacterial: Ribonucleic acid in bacteria having regulatory and catalytic roles as well as involvement in protein synthesis.Hospitalization: The confinement of a patient in a hospital.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Genes, Bacterial: The functional hereditary units of BACTERIA.Sexually Transmitted Diseases, Bacterial: Bacterial diseases transmitted or propagated by sexual conduct.Trachea: The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.Pneumonia, Progressive Interstitial, of Sheep: Chronic respiratory disease caused by the VISNA-MAEDI VIRUS. It was formerly believed to be identical with jaagsiekte (PULMONARY ADENOMATOSIS, OVINE) but is now recognized as a separate entity.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Empyema: Presence of pus in a hollow organ or body cavity.Mycoplasma dispar: A species of gram-negative bacteria causing PNEUMONIA, MYCOPLASMA in calves. Mycoplasma dispar also possibly plays a synergistic role with other BACTERIA and VIRUSES to cause other RESPIRATORY TRACT DISEASES in calves.Sheep Diseases: Diseases of domestic and mountain sheep of the genus Ovis.Ventilators, Mechanical: Mechanical devices used to produce or assist pulmonary ventilation.Genome, Bacterial: The genetic complement of a BACTERIA as represented in its DNA.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Respiration, Artificial: Any method of artificial breathing that employs mechanical or non-mechanical means to force the air into and out of the lungs. Artificial respiration or ventilation is used in individuals who have stopped breathing or have RESPIRATORY INSUFFICIENCY to increase their intake of oxygen (O2) and excretion of carbon dioxide (CO2).Legionella: Gram-negative aerobic rods, isolated from surface water or thermally polluted lakes or streams. Member are pathogenic for man. Legionella pneumophila is the causative agent for LEGIONNAIRES' DISEASE.Mycoplasmatales Infections: Infections with bacteria of the order MYCOPLASMATALES.Keratoconjunctivitis, Infectious: Infectious diseases of cattle, sheep, and goats, characterized by blepharospasm, lacrimation, conjunctivitis, and varying degrees of corneal opacity and ulceration. In cattle the causative agent is MORAXELLA (MORAXELLA) BOVIS; in sheep, MYCOPLASMA; RICKETTSIA; CHLAMYDIA; or ACHOLEPLASMA; in goats, RICKETTSIA.Sputum: Material coughed up from the lungs and expectorated via the mouth. It contains MUCUS, cellular debris, and microorganisms. It may also contain blood or pus.Pleuropneumonia: Inflammation of the lung parenchyma that is associated with PLEURISY, inflammation of the PLEURA.Intensive Care Units: Hospital units providing continuous surveillance and care to acutely ill patients.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Fluoroquinolones: A group of QUINOLONES with at least one fluorine atom and a piperazinyl group.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Legionella pneumophila: A species of gram-negative, aerobic bacteria that is the causative agent of LEGIONNAIRES' DISEASE. It has been isolated from numerous environmental sites as well as from human lung tissue, respiratory secretions, and blood.Mycoplasma hyosynoviae: A species of gram-negative bacteria isolated from the SYNOVIAL FLUID; LYMPH NODES; and MUCOUS MEMBRANE secretions in diseased SWINE. It causes nonsuppurative ARTHRITIS.Microbial Sensitivity Tests: Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).RNA, Ribosomal, 23S: Constituent of 50S subunit of prokaryotic ribosomes containing about 3200 nucleotides. 23S rRNA is involved in the initiation of polypeptide synthesis.Nasopharynx: The top portion of the pharynx situated posterior to the nose and superior to the SOFT PALATE. The nasopharynx is the posterior extension of the nasal cavities and has a respiratory function.Pneumonia of Swine, Mycoplasmal: A chronic, clinically mild, infectious pneumonia of PIGS caused by MYCOPLASMA HYOPNEUMONIAE. Ninety percent of swine herds worldwide are infected with this economically costly disease that primarily affects animals aged two to six months old. The disease can be associated with porcine respiratory disease complex. PASTEURELLA MULTOCIDA is often found as a secondary infection.Chlamydial Pneumonia: Pneumonia caused by infections with the genus CHLAMYDIA; and CHLAMYDOPHILA, usually with CHLAMYDOPHILA PNEUMONIAE.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Acute Disease: Disease having a short and relatively severe course.Pseudomonas Infections: Infections with bacteria of the genus PSEUDOMONAS.Pneumococcal Vaccines: Vaccines or candidate vaccines used to prevent infections with STREPTOCOCCUS PNEUMONIAE.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Lung Abscess: Solitary or multiple collections of PUS within the lung parenchyma as a result of infection by bacteria, protozoa, or other agents.Antigenic Variation: Change in the surface ANTIGEN of a microorganism. There are two different types. One is a phenomenon, especially associated with INFLUENZA VIRUSES, where they undergo spontaneous variation both as slow antigenic drift and sudden emergence of new strains (antigenic shift). The second type is when certain PARASITES, especially trypanosomes, PLASMODIUM, and BORRELIA, survive the immune response of the host by changing the surface coat (antigen switching). (From Herbert et al., The Dictionary of Immunology, 4th ed)Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Mycoplasma bovigenitalium: A species of gram-negative bacteria pathogenic to CATTLE.AIDS-Related Opportunistic Infections: Opportunistic infections found in patients who test positive for human immunodeficiency virus (HIV). The most common include PNEUMOCYSTIS PNEUMONIA, Kaposi's sarcoma, cryptosporidiosis, herpes simplex, toxoplasmosis, cryptococcosis, and infections with Mycobacterium avium complex, Microsporidium, and Cytomegalovirus.Pasteurella Infections: Infections with bacteria of the genus PASTEURELLA.Pneumocystis carinii: The prototype species of PNEUMOCYSTIS infecting the laboratory rat, Rattus norvegicus (RATS). It was formerly called Pneumocystis carinii f. sp. carinii. Other species of Pneumocystis can also infect rats.Erythromycin: A bacteriostatic antibiotic macrolide produced by Streptomyces erythreus. Erythromycin A is considered its major active component. In sensitive organisms, it inhibits protein synthesis by binding to 50S ribosomal subunits. This binding process inhibits peptidyl transferase activity and interferes with translocation of amino acids during translation and assembly of proteins.Time Factors: Elements of limited time intervals, contributing to particular results or situations.