Patterns of livestock depredation and cost‐effectiveness of fortified livestock enclosures in northern Tanzania

Human–carnivore conflicts and retaliatory killings contribute to carnivore populations' declines around the world. Strategies to mitigate conflicts have been developed, but their efficacy is rarely assessed in a randomized case–control design. Further, the economic costs prevent the adoption and wide use of conflict mitigation strategies by pastoralists in rural Africa. We examined carnivore (African lion [Panthera leo], leopard [Panthera pardus], spotted hyena [Crocuta crocuta], jackal [Canis mesomelas], and cheetah [Acinonyx jubatus]) raids on fortified (n = 45, total 631 monthly visits) and unfortified (traditional, n = 45, total 521 monthly visits) livestock enclosures (“bomas”) in northern Tanzania. The study aimed to (a) assess the extent of retaliatory killings of major carnivore species due to livestock depredation, (b) describe the spatiotemporal characteristics of carnivore raids on livestock enclosures, (c) analyze whether spatial covariates influenced livestock depredation risk in livestock enclosures, and (d) examine the cost‐effectiveness of livestock enclosure fortification. Results suggest that (a) majority of boma raids by carnivores were caused by spotted hyenas (nearly 90% of all raids), but retaliatory killings mainly targeted lions, (b) carnivore raid attempts were rare at individual households (0.081 raid attempts/month in fortified enclosures and 0.102 raid attempts/month in unfortified enclosures), and (c) spotted hyena raid attempts increased in the wet season compared with the dry season, and owners of fortified bomas reported less hyena raid attempts than owners of unfortified bomas. Landscape and habitat variables tested, did not strongly drive the spatial patterns of spotted hyena raids in livestock bomas. Carnivore raids varied randomly both spatially (village to village) and temporally (year to year). The cost‐benefit analysis suggest that investing in boma fortification yielded positive net present values after two to three years. Thus, enclosure fortification is a cost‐effective strategy to promote coexistence of carnivores and humans.     

Correction to: Genetic characterization of Addison’s disease in Bearded Collies

Diversity of the CRISPR locus of Mycobacterium tuberculosis complex has been studied since 1997 for molecular epidemiology purposes. By targeting solely the 43 spacers present in the two first sequenced genomes (H37Rv and BCG), it gave a biased idea of CRISPR diversity and ignored diversity in the neighbouring cas-genes. We set up tailored pipelines to explore the diversity of CRISPR-cas locus in Short Reads. We analyzed data from a representative set of 198 clinical isolates as evidenced by well-characterized SNPs. We found a relatively low diversity in terms of spacers: we recovered only the 68 spacers that had been described in 2000. We found no partial or global inversions in the sequences, letting always the Direct Variant Repeats (DVR) in the same order. In contrast, we found an unexpected diversity in the form of: SNPs in spacers and in Direct Repeats, duplications of various length, and insertions at various locations of the IS6110 insertion sequence, as well as blocks of DVR deletions. The diversity was in part specific to lineages. When reconstructing evolutionary steps of the locus, we found no evidence for SNP reversal. DVR deletions were linked to recombination between IS6110 insertions or between Direct Repeats. This work definitively shows that CRISPR locus of M. tuberculosis did not evolve by classical CRISPR adaptation (incorporation of new spacers) since the last most recent common ancestor of virulent lineages. The evolutionary mechanisms that we discovered could be involved in bacterial adaptation but in a way that remains to be identified.     

Association of neuregulin 1 with schizophrenia confirmed in a Scottish population

Recently, we identified neuregulin 1 (NRG1) as a susceptibility gene for schizophrenia in the Icelandic population, by a combined linkage and association approach. Here, we report the first study evaluating the relevance of NRG1 to schizophrenia in a population outside Iceland. Markers representing a core at-risk haplotype found in Icelanders at the 5' end of the NRG1 gene were genotyped in 609 unrelated Scottish patients and 618 unrelated Scottish control individuals. This haplotype consisted of five SNP markers and two microsatellites, which all appear to be in strong linkage disequilibrium. For the Scottish patients and control subjects, haplotype frequencies were estimated by maximum likelihood, using the expectation-maximization algorithm. The frequency of the seven-marker haplotype among the Scottish patients was significantly greater than that among the control subjects (10.2% vs. 5.9%, P=.00031). The estimated risk ratio was 1.8, which is in keeping with our report of unrelated Icelandic patients (2.1). Three of the seven markers in the haplotype gave single-point P values ranging from .000064 to .0021 for the allele contributing to the at-risk haplotype. This direct replication of haplotype association in a second population further implicates NRG1 as a factor that contributes to the etiology of schizophrenia.     

The Arabidopsis thaliana cysteine-rich receptor-like kinases CRK6 and CRK7 protect against apoplastic oxidative stress

Receptor-like kinases are important regulators of many different processes in plants. Despite their large number only a few have been functionally characterized. One of the largest subgroups of receptor-like kinases in Arabidopsis is the cysteine-rich receptor like kinases (CRKs). High sequence similarity among the CRKs has been suggested as major cause for functional redundancy. The genomic localization of CRK genes in back-to-back repeats has made their characterization through mutant analysis unpractical. Expression profiling has linked the CRKs with reactive oxygen species, important signaling molecules in plants. Here we have investigated the role of two CRKs, CRK6 and CRK7, and analyzed their role in extracellular ROS signaling. CRK6 and CRK7 are active protein kinases with differential preference for divalent cations. Our results suggest that CRK7 is involved in mediating the responses to extracellular but not chloroplastic ROS production.     

Antisense oligonucleotides containing modified bases inhibit in vitro translation of Leishmania amazonensis mRNAs by invading the mini-exon hairpin

Complementary oligodeoxynucleotides (ODNs) that contain 2-aminoadenine and 2-thiothymine interact weakly with each other but form stable hybrids with unmodified complements. These selectively binding complementary (SBC) agents can invade duplex DNA and hybridize to each strand (Kutyavin, I. V., Rhinehart, R. L., Lukhtanov, E. A., Gorn, V. V., Meyer, R. B., and Gamper, H. B. (1996) Biochemistry 35, 11170-11176). Antisense ODNs with similar properties should be less encumbered by RNA secondary structure. Here we show that SBC ODNs strand invade a hairpin in the mini-exon RNA of Leishmania amazonensis and that the resulting heteroduplexes are substrates for Escherichia coli RNase H. SBC ODNs either with phosphodiester or phosphorothioate backbones form more stable hybrids with RNA than normal base (NB) ODNs. Optimal binding was observed when the entire hairpin sequence was targeted. Translation of L. amazonensis mRNA in a cell-free extract was more efficiently inhibited by SBC ODNs complementary to the mini-exon hairpin than by the corresponding NB ODNs. Nonspecific protein binding in the cell-free extract by phosphorothioate SBC ODNs rendered them ineffective as antisense agents in vitro. SBC phosphorothioate ODNs displayed a modest but significant improvement of leishmanicidal properties compared with NB phosphorothioate ODNs.     

The Larval Eye of Nannochoristid Scorpionflies (Insecta,Mecoptera)

Abstract The stemmata of last–instar Nannochoristalarvae are compound eyes composed of 10 or more ommatidia. Each ommatidium has four Semper cells, four distal and four proximal retinula cells which form a cruciform and layered rhabdom. The ommatidia are separated by epidermal cells (possibly rudimentary pigment cells). Corneal lenses are lacking. At the posterior edge, aberrant stemma units may be present which lack a dioptric apparatus and have a star–shaped rhabdom composed of at least six retinula cells. The stemmata of Nannochoristaappear to be derived from stemmata of the Panorpa-type (Mecoptera-Panorpidae). Differences between the stemmata of Nannochoristaand Panorpacan be explained as adaptations to aquatic life (flat cornea) or as regression. A compound larval eye is ascribed to the ground plan of the Mecoptera sensu latoand is considered a genuine plesiomorphy. The identical basic number (seven) of stemmata in the Neuropteroid/Coleoptera assemblage, Amphiesmenoptera and some Mecoptera (Bittacidae, Boreidae) is attributed to parallel evolution.