A mitochondrial-like targeting signal on the hydrogenosomal malic enzyme from the anaerobic fungus Neocallimastix frontalis:Support for the hypothesis that hydrogenosomes are modified mitochondria

The hydrogenosomal malic enzyme (ME) was purified from the anaerobic fungus Neocallimastix frontalis. Using reverse genetics, the corresponding cDNA was isolated and characterized. The deduced amino acid sequence of the ME showed high similarity to ME from metazoa, plants and protists. Putative functional domains for malate and NAD(+)/NADP(+) binding were identified. Phylogenetic analysis of the deduced amino acid sequence of the new ME suggests that it is homologous to reference bacterial and eukaryotic ME. Most interestingly, the cDNA codes for a protein which contains a 27-amino-acid N-terminus which is not present on the purified mature protein. This presequence shares features with known mitochondrial targeting signals, including an enrichment in Ala, Leu, Ser, and Arg, and the presence of an Arg at position -2 relative to amino acid 1 of the mature protein. This is the first report of a mitochondrial-like targeting signal on a hydrogenosomal enzyme from an anaerobic fungus and provides support for the hypothesis that hydrogenosomes in Neocallimastix frontalis might be modified mitochondria

Silicon Nanowire as Virus Sensor in a Total Analysis System

AbstractSilicon nanowires are very promising candidates for the sensitive detection of viruses or even early detection of cancer. Due to their small dimensions the attachment of even one particle on their surface leads to detectable changes in their conductivity. In this paper we describe the development (fabrication and testing) of a silicon nanowire biosensor equipped with microfludic channels and automatized data aquisition for the detection of antibodies against a small virus (Aleutian Disease Virus) causing plasmacytosis on mink and ferrets

Effects of patch quality and network structure on patch occupancy dynamics of a yellow-bellied marmot metapopulation

1. The presence/absence of a species at a particular site is the simplest form of data that can be collected during ecological field studies. We used 13 years (1990-2002) of survey data to parameterize a stochastic patch occupancy model for a metapopulation of the yellow-bellied marmot in Colorado, and investigated the significance of particular patches and the influence of site quality, network characteristics and regional stochasticity on the metapopulation persistence. 2. Persistence of the yellow-bellied marmot metapopulation was strongly dependent on the high quality colony sites, and persistence probability was highly sensitive to small changes in the quality of these sites. 3. A relatively small number of colony sites was ultimately responsible for the regional persistence. However, lower quality satellite sites also made a significant contribution to long-term metapopulation persistence, especially when regional stochasticity was high. 4. The northern network of the marmot metapopulation was more stable compared to the southern network, and the persistence of the southern network depended heavily on the northern network. 5. Although complex models of metapopulation dynamics may provide a more accurate description of metapopulation dynamics, such models are data-intensive. Our study, one of the very few applications of stochastic patch occupancy models to a mammalian species, suggests that stochastic patch occupancy models can provide important insights into metapopulation dynamics using data that are easy to collect

Effect of predation risk on the presence and persistence of yellow-bellied marmot (Marmota flaviventris) colonies

Habitat selection may have population level consequences and ultimately may influence a population's local persistence or extinction. We capitalized on a long-term study (1962-2004) of yellow-bellied marmots Marmota flaviventris in and around the Rocky Mountain Biological Laboratory, Gothic, Colorado, USA, and compared habitat characteristics associated with food availability and predation risk to explain variation in persistence of marmots at 27 sites, and their absence at 22 additional, randomly selected sites. We classified sites as persistent, intermittent or null based on whether there was a history of extinction; intermittent sites periodically went extinct and null sites never had marmots. Logistic regression analyses revealed that environmental variables associated with visibility and safety, rather than food, correctly classified sites as persistent or non-persistent as well as persistent or intermittent. Discriminant function analysis that included the null sites revealed that the same visibility-related characteristics predicted where marmots were found. These results highlight the importance of variation in safety among sites in predicting long-term population persistence, as well as a species' distribution

Cannabinoids to Improve Health-Related Quality of Life in Patients with Neurological or Oncological Disease: A Meta-Analysis.

Background: Cannabinoids have been suggested to alleviate frequently experienced symptoms of reduced mental well-being such as anxiety and depression. Mental well-being is an important subdomain of health-related quality of life (HRQoL). Reducing symptoms and maintaining HRQoL are particularly important in malignant primary brain tumor patients, as treatment options are often noncurative and prognosis remains poor. These patients frequently report unprescribed cannabinoid use, presumably for symptom relieve. As studies on brain tumor patients specifically are lacking, we performed a meta-analysis of the current evidence on cannabinoid efficacy on HRQoL and mental well-being in oncological and neurological patients. Methods: We performed a systematic PubMed, PsychINFO, Embase, and Web of Science search according to PRISMA guidelines on August 2 and 3, 2021. We included randomized controlled trials (RCTs) that assessed the effects of tetrahydrocannabinol (THC) or cannabidiol (CBD) on general HRQoL and mental well-being. Pooled effect sizes were calculated using Hedges g. Risk of bias of included studies was assessed using Cochrane's Risk of Bias tool. Results: We included 17 studies: 4 in oncology and 13 in central nervous system (CNS) disease. Meta-analysis showed no effect of cannabinoids on general HRQoL (g=-0.02 confidence interval [95% CI -0.11 to 0.06]; p=0.57) or mental well-being (g=-0.02 [95% CI -0.16 to 0.13]; p=0.81). Conclusions: RCTs in patients with cancer or CNS disease showed no effect of cannabinoids on HRQoL or mental well-being. However, studies were clinically heterogeneous and since many glioma patients currently frequently use cannabinoids, future studies are necessary to evaluate its value in this specific population