27 research outputs found

    Tools and Termites: Implications for the Foraging Behavior of the Swartkrans Hominids.

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    Termites have recently become a subject of interest for paleoanthropologists. In 2001, Backwell and d’Errico reported evidence of termite foraging by the Swartkrans hominids as seen in the wear patterns on bone tools from the site. This conclusion has been credited by some to be a plausible explanation for unexpected carbon isotope signatures present in South African hominid teeth that suggest the diet was different from that of extant non-human great apes, consisting of a significant amount of resources not from woody plants. Grass-eating termites such as the genus Trinervitermes are one potential resource that could contribute to the carbon signature. However, not all termites forage for grass, and in fact, Macrotermes, the termites most widely consumed by chimpanzees and by many present-day human populations, almost exclusively forage on the remains of woody plants and therefore would not contribute to the signature. This dissertation focuses on how the bone tools were being used in order to address which termites were being consumed and their nutritional role in the hominid diet. One possibility is that they were used in a manner similar to “perforating,” a complex action utilized by the chimpanzees of the Goualougo Triangle, Republic of Congo, to use a stick to reopen the exit/entry holes created by termites on their mounds. After analyzing observations of this action, the task was recreated with experimental bone tools and the wear patterns compared to those on the ends of the Swartkrans bone tools. Digging into Trinervitermes mounds was also investigated. The wear pattern analyses were inconclusive, and the best support for which termites would have been consumed comes from behavioral and ethnographic data. Termites of the genus Macrotermes may be the most likely resource for Plio-Pleistocene hominids since they are highly selected by both chimpanzees and humans. These termites would not contribute to the surprising carbon isotope signature, but if both the soldiers and alates were being consumed, they would provide a reliable source of protein and fat, which are valuable for larger brained hominids navigating the South African savanna.Ph.D.AnthropologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/89755/1/lesnikju_1.pd

    Taxonomic Features and Comparison of the Gut Microbiome from Two Edible Fungus-Farming Termites (Macrotermes falciger, M. natalensis) Harvested in the Vhembe District of Limpopo, South Africa

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    Background Termites are an important food resource for many human populations around the world, and are a good supply of nutrients. The fungus-farming ‘higher’ termite members of Macrotermitinae are also consumed by modern great apes and are implicated as critical dietary resources for early hominins. While the chemical nutritional composition of edible termites is well known, their microbiomes are unexplored in the context of human health. Here we sequenced the V4 region of the 16S rRNA gene of gut microbiota extracted from the whole intestinal tract of two Macrotermes sp. soldiers collected from the Limpopo region of South Africa. Results Major and minor soldier subcastes of M. falciger exhibit consistent differences in taxonomic representation, and are variable in microbial presence and abundance patterns when compared to another edible but less preferred species, M. natalensis. Subcaste differences include alternate patterns in sulfate-reducing bacteria and methanogenic Euryarchaeota abundance, and differences in abundance between Alistipes and Ruminococcaceae. M. falciger minor soldiers and M. natalensissoldiers have similar microbial profiles, likely from close proximity to the termite worker castes, particularly during foraging and fungus garden cultivation. Compared with previously published termite and cockroach gut microbiome data, the taxonomic representation was generally split between termites that directly digest lignocellulose and humic substrates and those that consume a more distilled form of nutrition as with the omnivorous cockroaches and fungus-farming termites. Lastly, to determine if edible termites may point to a shared reservoir for rare bacterial taxa found in the gut microbiome of humans, we focused on the genus Treponema. The majority of Treponemasequences from edible termite gut microbiota most closely relate to species recovered from other termites or from environmental samples, except for one novel OTU strain, which clustered separately with Treponema found in hunter-gatherer human groups. Conclusions Macrotermes consumed by humans display special gut microbial arrangements that are atypical for a lignocellulose digesting invertebrate, but are instead suited to the simplified nutrition in the fungus-farmer diet. Our work brings to light the particular termite microbiome features that should be explored further as avenues in human health, agricultural sustainability, and evolutionary research

    Bi-allelic <i>NIT1 </i>variants cause a brain small vessel disease characterized by movement disorders, massively dilated perivascular spaces, and intracerebral hemorrhage

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    Purpose: To describe a recessively inherited cerebral small vessel disease, caused by loss-of-function variants in Nitrilase1 (NIT1). Methods:We performed exome sequencing, brain magnetic resonance imaging, neuropathology, electron microscopy, western blotting, and transcriptomic and metabolic analyses in 7 NIT1-small vessel disease patients from 5 unrelated pedigrees. Results: The first identified patients were 3 siblings, compound heterozygous for the NIT1 c.727C&gt;T; (p.Arg243Trp) variant and the NIT1 c.198_199del; p.(Ala68∗) variant. The 4 additional patients were single cases from 4 unrelated pedigrees and were all homozygous for the NIT1 c.727C&gt;T; p.(Arg243Trp) variant. Patients presented in mid-adulthood with movement disorders. All patients had striking abnormalities on brain magnetic resonance imaging, with numerous and massively dilated basal ganglia perivascular spaces. Three patients had non-lobar intracerebral hemorrhage between age 45 and 60, which was fatal in 2 cases. Western blotting on patient fibroblasts showed absence of NIT1 protein, and metabolic analysis in urine confirmed loss of NIT1 enzymatic function. Brain autopsy revealed large electron-dense deposits in the vessel walls of small and medium sized cerebral arteries. Conclusion: NIT1-small vessel disease is a novel, autosomal recessively inherited cerebral small vessel disease characterized by a triad of movement disorders, massively dilated basal ganglia perivascular spaces, and intracerebral hemorrhage.</p

    Bi-allelic <i>NIT1 </i>variants cause a brain small vessel disease characterized by movement disorders, massively dilated perivascular spaces, and intracerebral hemorrhage

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    Purpose: To describe a recessively inherited cerebral small vessel disease, caused by loss-of-function variants in Nitrilase1 (NIT1). Methods:We performed exome sequencing, brain magnetic resonance imaging, neuropathology, electron microscopy, western blotting, and transcriptomic and metabolic analyses in 7 NIT1-small vessel disease patients from 5 unrelated pedigrees. Results: The first identified patients were 3 siblings, compound heterozygous for the NIT1 c.727C&gt;T; (p.Arg243Trp) variant and the NIT1 c.198_199del; p.(Ala68∗) variant. The 4 additional patients were single cases from 4 unrelated pedigrees and were all homozygous for the NIT1 c.727C&gt;T; p.(Arg243Trp) variant. Patients presented in mid-adulthood with movement disorders. All patients had striking abnormalities on brain magnetic resonance imaging, with numerous and massively dilated basal ganglia perivascular spaces. Three patients had non-lobar intracerebral hemorrhage between age 45 and 60, which was fatal in 2 cases. Western blotting on patient fibroblasts showed absence of NIT1 protein, and metabolic analysis in urine confirmed loss of NIT1 enzymatic function. Brain autopsy revealed large electron-dense deposits in the vessel walls of small and medium sized cerebral arteries. Conclusion: NIT1-small vessel disease is a novel, autosomal recessively inherited cerebral small vessel disease characterized by a triad of movement disorders, massively dilated basal ganglia perivascular spaces, and intracerebral hemorrhage.</p

    Translational models for vascular cognitive impairment: a review including larger species.

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    BACKGROUND: Disease models are useful for prospective studies of pathology, identification of molecular and cellular mechanisms, pre-clinical testing of interventions, and validation of clinical biomarkers. Here, we review animal models relevant to vascular cognitive impairment (VCI). A synopsis of each model was initially presented by expert practitioners. Synopses were refined by the authors, and subsequently by the scientific committee of a recent conference (International Conference on Vascular Dementia 2015). Only peer-reviewed sources were cited. METHODS: We included models that mimic VCI-related brain lesions (white matter hypoperfusion injury, focal ischaemia, cerebral amyloid angiopathy) or reproduce VCI risk factors (old age, hypertension, hyperhomocysteinemia, high-salt/high-fat diet) or reproduce genetic causes of VCI (CADASIL-causing Notch3 mutations). CONCLUSIONS: We concluded that (1) translational models may reflect a VCI-relevant pathological process, while not fully replicating a human disease spectrum; (2) rodent models of VCI are limited by paucity of white matter; and (3) further translational models, and improved cognitive testing instruments, are required

    The Interdigital Brace and Other Grips for Termite Nest Perforation by Chimpanzees of the Goualougo Triangle, Republic of Congo

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    Studies of chimpanzee termite foraging enlighten our understanding of early hominin tool use not only by modeling the cognitive ability of our ancestors but also by emphasizing the possible role of social insects in the hominin diet. The chimpanzees of the Goualougo Triangle are known to have one of the largest and most complex tool repertoires reported for wild chimpanzees. One tool set habitually used by this population includes a perforating tool to penetrate the hard outer crust of elevated termite nests before fishing for termite prey with an herbaceous stem. Here, we report the variation present in the grips used on the perforating tool. Our analysis of video recordings of chimpanzee visitation to termite nests over a 3‐year period shows that these chimpanzees use a variety of grips to navigate the challenges encountered in opening a termite nest. For situations in which the soil is most hardened, perforating requires force and a power grip is often used. When the soil in the passageway is loose, precision grips are suitable for the task. One of the preferred grips reported here is an interdigital brace, which has previously been described in studies of how some people hold a pencil. In this study, for the first time, the interdigital brace has been thoroughly described for chimpanzees. The various strategies and grips used during perforation emphasize the importance of termites as a nutritional resource that should be considered more strongly as a food used by early hominins. Am J Phys Anthropol 157:252–259, 2015. © 2015 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111769/1/ajpa22706.pd

    Association of Cholesterol Efflux Capacity With Clinical Features of Metabolic Syndrome: Relevance to Atherosclerosis

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    International audienceBackground: The contribution of high‐density lipoprotein to cardiovascular benefit is closely linked to its role in the cellular cholesterol efflux process; however, various clinical and biochemical variables are known to modulate the overall cholesterol efflux process. The aim of this study was to evaluate the extent to which clinical and biological anomalies associated with the establishment of the metabolic syndrome modulate cholesterol efflux capacity and contribute to development of atherosclerosis.Methods and Results: This study involved patients (n=1202) displaying atherogenic dyslipidemia in primary prevention who were referred to our prevention center. Among these patients, 25% presented at least 3 criteria of the metabolic syndrome, as defined by the National Cholesterol Education Program Adult Treatment Panel III. We measured the capacity of 40‐fold diluted serum to mediate cholesterol efflux from cholesterol‐loaded human THP‐1 macrophages. Cholesterol efflux capacity was reduced progressively by 4% to 11% (P<0.0001) as a function of the increasing number of coexisting criteria for the metabolic syndrome from 1 to 5. This observation was primarily related to reductions in scavenger receptor class B member 1 and ATP binding cassette subfamily G member 1–dependent efflux. Multivariate analyses indicate that serum efflux capacity was significantly associated with established metabolic syndrome (odds ratio 0.45; 95% CI 0.28–0.72; P=0.009) independent of age, low‐density lipoprotein cholesterol, status with regard to lipid‐lowering therapy, smoking status, and alcohol consumption.Conclusions: Our study revealed that individual criteria of metabolic syndrome are closely related synergistically to cholesterol efflux capacity. In addition, established metabolic syndrome and cholesterol efflux capacity were independently associated with clinical features of atherosclerosis
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