Country calling codes or country dial-in codes are telephone number prefixes for reaching telephone subscribers in the networks of the member countries or regions of the International Telecommunication Union (ITU). The codes are defined by the ...
2 天前 · A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (literally without tail in Ancient Greek).The oldest fossil "proto-frog" appeared in the early Triassic of ...
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Lactobacilli are homofermentative, i.e. hexoses are metabolised by Glycolysis to lactate as major end product, or heterofermentative, i.e. hexoses are metabolised by the Phosphoketolase pathway to lactate, CO2 and acetate or ethanol as major end products. Most lactobacilli are aerotolerant and some species respire if heme and menaquinone are present in the growth medium. Aerotolerance of lactobacilli is manganese-dependent and has been explored (and explained) in Lactiplantibacillus plantarum (previously Lactobacillus plantarum). Lactobacilli generally do not require ironfor growth. The Lactobacillaceae are the only family of the Lactic acid bacteria that includes homofermentative and heterofermentative organisms; in the Lactobacillaceae, homofermentative or heterofermentative metabolism is shared by all strains of a genus. Lactobacillus species are all homofermentative, do not express pyruvate formate lyase, and most species do not ferment pentoses. In L. crispatus, pentose metabol...
The genomes of lactobacilli are highly variable, ranging in size from 1.2 to 4.9 Mb (megabases). Accordingly, the number of protein-coding genes ranges from 1,267 to about 4,758 genes (in Fructilactobacillus sanfranciscensis and Lentilactobacillus parakefiri, respectively). Even within a single species there can be substantial variation. For instance, strains of L. crispatus have genome sizes ranging from 1.83 to 2.7 Mb, or 1,839 to 2,688 open reading frames. Lactobacillus contains a wealth of compound microsatellites in the coding region of the genome, which are imperfect and have variant motifs.Many lactobacilli also contain multiple plasmids. A recent study has revealed that plasmids encode the genes which are required for adaptation of lactobacilli to the given environment.
The genus Lactobacillus currently contains 44 species which are adapted to vertebrate hosts or to insects. In recent years, other members of the genus Lactobacillus (formerly known as the Leuconostoc branch of Lactobacillus) have been reclassified into the genera Atopobium, Carnobacterium, Weissella, Oenococcus, and Leuconostoc. The Pediococcus species P. dextrinicus has been reclassified as a Lapidilactobacillus dextrinicus and most lactobacilli were assigned to Paralactobacillus or one of the 23 novel genera of the Lactobacillaceae. Two websites inform on the assignment of species to the novel genera or species (http://www.lactobacillus.uantwerpen.be/; http://www.lactobacillus.ualberta.ca/).
The female genital tract is one of the principal colonisation sites for human microbiota, and there is interest in the relationship between the composition of these bacteria and human health, with a domination by a single species being correlated with general welfare and good outcomes in pregnancy. In around 70% of women, a Lactobacillusspecies is dominant, although that has been found to vary between American women of European origin and those of African origin, the latter group tending to h...
Interactions with other pathogens
Lactobacilli produce hydrogen peroxide which inhibits the growth and virulence of the fungal pathogen Candida albicans in vitro and in vivo. In vitro studies have also shown that lactobacilli reduce the pathogenicity of C. albicans through the production of organic acids and certain metabolites. Both the presence of metabolites, such as sodium butyrate, and the decrease in environmental pH caused by the organic acids reduce the growth of hyphae in C. albicans, which reduces its pathogenicity....
Fermentive bacteria like LAB produce hydrogen peroxide to protect themselves from oxygen toxicity. The accumulation of hydrogen peroxide in growth media, and its antagonistic effects on Staphylococcus aureus and Pseudomonas, have been demonstrated by researchers. LAB cultures have been used as starter cultures to create fermented foods since the beginning of the 20th century. Elie Metchnikoffwon a nobel price in 1908 for his work on LAB. Lactobacilli administered in combination with other pro...
Lactobacilli comprise most food fermenting lactic acid bacteria and are used as starter cultures in industry for controlled fermentation in the production of wine, yogurt, cheese, sauerkraut, pickles, beer, cider, kimchi, cocoa, kefir, and other fermented foods, as well as animal feeds and the bokashi soil amendment. Lactobacillus species are dominant in yoghurt, cheese, and sourdough fermentations.The antibacterial and antifungal activity of lactobacilli relies on production of bacteriocins and low molecular weight compounds that inhibits these microorganisms. Sourdough bread is made either spontaneously, by taking advantage of the bacteria naturally present in flour, or by using a "starter culture", which is a symbiotic culture of yeast and lactic acid bacteria growing in a water and flour medium.The bacteria metabolize sugars into lactic acid, which lowers the pH of their environment, creating a signature "sourness" associated with yogurt, sauerkraut, etc. In many traditional pic...
2 天前 · This article provides a general overview and documents the status of locations affected by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus which causes coronavirus disease 2019 (COVID-19) and is responsible for the ...
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These medium-sized caprids are 115 to 165 cm (45 to 65 in) long along the head-and-body, with a tail of 10 to 20 cm (3.9 to 7.9 in). They stand 69 to 91 cm (27 to 36 in) high at the shoulder. Body mass can range from 35 to 75 kg (77 to 165 lb). Males are slightly larger than females. Dense coat is slate grey in colour, sometimes with a bluish sheen. The underparts and backs of the legs are white, while the chest and fronts of the legs are black. Separating the grey back and white belly is a charcoal-colored stripe. The ears are small, and the bridge of the nose is dark. The horns are found in both sexes and are ridged on the upper surface. In males, they grow upwards, then turn sideways and curve backward, looking somewhat like an upside-down mustache. They may grow to a length of 80 cm (31 in). In females, the horns are much shorter and straighter, growing up to 20 cm (7.9 in) long.Chinese blue sheep, Pseudois nayaur szechuanensisHimalayan blue sheep, P. n. nayaurHelan Shan blue sheep, P. n.ssp.
Bharal are active throughout the day, alternating between feeding and resting on the grassy mountain slopes. Due to their excellent camouflage and the absence of cover in their environment, bharal remain motionless when approached. Once they have been noticed, however, they scamper up to the precipitous cliffs, where they once again freeze, using camouflage to blend into the rock face. Population densities in Nepal were found to be 0.9–2.7 animals per km2, increasing to a maximum of 10 animals in the winter, as herds congregate in valleys.Bharal are mainly grazers, but during times of scarcity of grass, they switch to browsers, eating herbs and shrubs. A high degree of diet overlap between livestock (especially donkeys) and bharal, together with density-dependent forage limitation, results in resource competition and a decline in bharal density. Where they overlap, they are the favored prey of snow leopards, Himalayan wolves, and leopards, with a few lambs falling prey to foxes or e...
The bharal is categorised as Least Concern by the International Union for Conservation of Nature. The population faces threats - poaching for meat and competition with livestock. Poaching, however, is uncommon due to the unsuitable conditions of its habitat. Similarly, livestock do not generally frequent the mountainous regions where bharal occur; even if they do coexist, no notable detrimental effect on the bharal has been observed.
Many Buddhist monasteries protect the bharal found around them, but lately, issues of crop damage caused by bharal have started to arise in areas such as the Spiti Valley.Namgail, T., Fox, J.L. & Bhatnagar, Y.V. (2004). Habitat segregation between sympatric Tibetan argali Ovis ammon hodgsoni and blue sheep Pseudois nayaur in the Indian Trans-Himalaya. Journal of Zoo...Namgail, T., van Wieren, S.E., Mishra, C. & Prins, H.H.T. (2010). Multi-spatial co-distribution of the endangered Ladakh urial and blue sheep in the arid Trans-Himalayan Mountains. Journal of Arid...Namgail, T., Mishra, C., de Jong, C. B., van Wieren, S.E. & Prins, H.H.T. (2009). Effects of herbivore species richness on blue sheep niche dynamics and distribution in the Indian Trans-Himalaya. D...Namgail, T. (2001). Habitat Selection and Ecological Separation Between Sympatric Tibetan Argali Blue Sheep in Northern India. University of Tromso, Norway.