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Rewilding and Invasion
Published in Kezia Barker, Robert A. Francis, Routledge Handbook of Biosecurity and Invasive Species, 2021
Timothy Hodgetts, Jamie Lorimer
Indeed, the call for stakeholder engagement within rewilding is more than an empty gesture. Certain articulations of the rewilding approach have been much critiqued in some quarters for their neocolonial tendencies, such as imposing large-scale landscape planning regimes from above or promoting the removal of human communities from newly designated wild areas (Jørgensen, 2015). The echoes of ‘fortress conservation’ are real and of concern (Brockington, 2002), as are the sometimes reified ideas of wilderness as a place without people (Cronon, 1996) that have been given renewed vigour through some rewilding narratives (Jørgensen, 2015). Furthermore, analysing carnivore (re)introductions from the standpoint of political ecology illuminates how the costs of such schemes may hit the poorest, marginalised communities (such as upland livestock farmers or rural dwellers newly exposed to large carnivores), with the benefits mostly accruing to wealthy elites (urban-living tourists). Given these concerns, rewilding schemes should only proceed with the genuine support of local communities (Sandom and Wynne-Jones, 2018).
Changing Circumstances and Diets
Published in Christopher Cumo, Ancestral Diets and Nutrition, 2020
Heterotrophs may be classified by what they eat, with the range of foods determining degree of specialization. Herbivores eat only plants. This category includes specialists like the panda (Ailuropoda melanoleuca), which derives almost all its nourishment from bamboo (species in subfamily Bambusoideae) leaves, stems, and shoots. Such narrowness poses risks because the staple’s endangerment causes hunger and starvation. Eradication of that food triggers extinction. At the other end of the spectrum are herbivores that eat many species. Elephants (Elephas maximus and Loxodonta africana), for example, consume several plants’ bark, branches, roots, leaves, and fruits. Herbivores feed carnivores. Lions (Panthera leo), for example, target the African savanna’s herbivores. Not necessarily restricted to herbivores, carnivores may also eat other carnivores and omnivores. Carnivory is not unique to animals because the Venus flytrap (Dionaea muscipula) and allied plants consume insects. Such organisms are both autotroph and heterotroph.
Toxoplasma gondii
Published in Peter D. Walzer, Robert M. Genta, Parasitic Infections in the Compromised Host, 2020
The tissue cyst is associated with transmission because it persists in tissues of chronically infected animals, which may be ingested by carnivores, including humans. Undercooked meat has been implicated as the source of several common-source outbreaks of toxoplasmosis (21-23). In various surveys, as much as 25% of the mutton and pork in butcher shops contains Toxoplasma (24). However, it is rare for beef to contain Toxoplasma except for those occasions on which it is contaminated with pork (22,23). After ingestion, the cyst wall is disrupted by peptic or tryptic digestion, which liberates viable T. gondii bradyzoites. The bradyzoites resist peptic and tryptic digestion and survive several hours after exposure to these digestive enzymes and are capable of invading the host through the digestive tract. The cyst may also be important in the transmission of infection in organ transplantation (28-30). It has been demonstrated that heart transplant patients who are seronegative for Toxoplasma antibody and receive a heart from a seropositive donor have a high incidence of developing disseminated toxoplasmosis. This mode of transmission has also been demonstrated in other organ transplant recipients (75).
Cellulolytic bacteria in the large intestine of mammals
Published in Gut Microbes, 2022
Alicia Froidurot, Véronique Julliand
CAZymes have also been investigated directly via the sequencing of the intestinal microbiota genome. A greater number of total CAZymes was found in the bovine rumen, between 3,828 and 27,755 CAZymes according to previous studies, vs. 11,038 from the adult elephant gut, which is another large herbivorous mammal. In the Tiberian pig feces, which are omnivorous mammals, 13,000 carbohydrate-degrading genes were identified.79 Among carnivorous animals, only 372 and 440 CAZymes were detected in the Iberian lynx and giant panda feces, respectively, even if the latter is a carnivore that feeds on bamboo. Unexpectedly, 84 GH families were detected from Asian elephant microbiota.103 This high diversity of GH families was surprising compared with that known in the cow, another herbivorous mammal, in which 35–60 GHs were detected in the bovine rumen.104,105 In the fecal samples of giant pandas, 44 GH were found,106 whereas 42 GHs were identified in the Iberian lynx fresh fecal samples, a carnivore.107
Enriched metabolites that potentially promote age-associated diseases in subjects with an elderly-type gut microbiota
Published in Gut Microbes, 2021
Shin Yoshimoto, Eri Mitsuyama, Keisuke Yoshida, Toshitaka Odamaki, Jin-zhong Xiao
This study suggests that age-related changes in the gut microbiota in healthy individuals, especially in the elderly, cause or exacerbate systemic age-related diseases through specific metabolites. At the same time, it has also been shown that chronic inflammation-related diseases could be prevented by suppressing age-related changes in gut microbiota composition in the elderly. For example, it has been clarified that the abundances of TMA-producing bacteria were decreased in herbivores compared with carnivores and omnivores.26 However, since there are some limitations in this study, we consider these result as preliminary and need further detailed analysis. One is the small sample size. In this study, we analyzed the gut microbiota profile of 453 healthy Japanese subjects and found only about 40 elderly subjects classified as age-mismatched gut microbiota composition clusters (cluster 3 and 4). In the next analysis, it will be necessary to confirm the results using more samples. At the same time, it is necessary to acquire the subject’s dietary habits, clinical characteristics, medicine information, etc., to show the objectivity of healthy subjects. Contrary to this study, it is also need to investigate the fecal metabolites of adult subjects with aged-gut microbiota composition. In the future, it will also be necessary to evaluate the relationship of the elderly-type metabolites identified in this study with inflammaging, CVD, and colon cancer progression using aged mice or various disease model mice.
Effects of temperature on feeding and digestive processes in fish
Published in Temperature, 2020
Helene Volkoff, Ivar Rønnestad
Digestion consists of a series of complex series of processes with the overall aim to maximize absorption of dietary nutrients (Figure 5). After ingestion, food is mainly degraded by digestive enzymes and to some extent mechanically by muscular movements of the GIT. Among fish species, different feeding habits (e.g. herbivore, omnivore, carnivore) result in different GIT morphologies. Carnivores usually have short and straight intestines, most often with the presence of a true stomach and pyloric ceca (finger-like appendages in the proximal intestine, which increase the overall intestinal absorptive surface area) whereas herbivores tend to have longer intestines without ceca and sometimes no true stomach [83]. Agastric fish may possess an intestinal bulb or an enlargement in the anterior intestine that might somewhat increase retention time [84]. A number of gastrointestinal factors (hormones, neurotransmitters) act locally to regulate digestive processes [85]. Temperature affects the secretory activity of digestive juices (by its effect on food ingestion), GIT motility, the activity of digestive enzymes, and digestion and absorption rates [86].