549 research outputs found

    Phenotypic and genotypic analysis of benzimidazole resistance in reciprocal genetic crosses of Haemonchus contortus

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    Haemonchus contortus is arguably one of the most economically important and ubiquitous parasites of livestock globally and commonly involved in cases of anthelmintic resistance. Here, we performed reciprocal genetic crosses using susceptible (MHco3(ISE)) and multiple anthelmintic resistant (MHco18(UGA2004)) H. contortus isolates. Resultant admixed populations were designated MHco3/18 or MHco18/3, where the lead isolate reflects the origin of the females. Three independent filial generations were generated for each cross, which were subjected to bioassays, molecular approaches and population genetic analyses to investigate the phenotypic and genotypic inheritance of benzimidazole (BZ) resistance at each stage. A panel of microsatellite markers confirmed the success of the genetic cross as markers from both parents were seen in the F(1) crosses. Egg hatch tests revealed a stark difference between the two F(1) crosses with ED(50) estimates for MHco18/3 being 9 times greater than those for MHco3/18. Resistance factors based on ED(50) estimates ranged from 6 to 57 fold in the filial progeny compared to MHco3(ISE) parents. Molecular analysis of the F167Y and F200Y SNP markers associated with BZ resistance were analysed by pyrosequencing and MiSeq deep amplicon sequencing, which showed that MHco3/18.F(1) and MHco18/3.F(1) both had similar frequencies of the F200Y resistant allele (45.3% and 44.3%, respectively), whereas for F167Y, MHco18/3.F(1) had a two-fold greater frequency of the resistant-allele compared to MHco3/18.F(1) (18.2% and 8.8%, respectively). Comparison between pyrosequencing and MiSeq amplicon sequencing revealed that the allele frequencies derived from both methods were concordant at codon 200 (r(c) = 0.97), but were less comparable for codon 167 (r(c) = 0.55). The use of controlled reciprocal genetic crosses have revealed a potential difference in BZ resistance phenotype dependent on whether the resistant allele is paternally or maternally inherited. These findings provide new insight and prompt further investigation into the inheritance of BZ resistance in H. contortus

    New records of Rhodothemis rufa (Rambur, 1842) and Lamelligomphus biforceps (Selys 1878) (Odonata: Anisoptera) from Pakistan with redescription of L. biforceps (Selys 1878)

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    Abstract The current status and distribution of the dragonflies (Anisoptera) of Pakistan were studied during [2005][2006][2007][2008][2009]. Two dragonfly species were identified for the first time from Pakistan. Among these, Rhodothemis rufa is a red, medium-sized dragonfly. Lamelligomphus biforceps is also reported for the first time from Pakistan and redescribed owing to having minor taxonomic differences from that of Fraser's description. Some notes on the color, literature records and geographical distributions are summarized

    Draft Genome Report of Bacillus altitudinis SORB11, Isolated from the Indian Sector of the Southern Ocean

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    Here, we present the draft genome sequence of Bacillus altitudinis SORB11, which is tolerant to UV radiation. The strain was isolated from the Indian sector of the Southern Ocean at a depth of 3.8 km. The genome sequence information reported here for B. altitudinis SORB11 gives the basis of its UV resistance mechanism and provides data for further comparative studies with other bacteria resistant to UV radiation

    Embryonic stem cells in scaffold-free three-dimensional cell culture: osteogenic differentiation and bone generation

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    Extracorporeal formation of mineralized bone-like tissue is still an unsolved challenge in tissue engineering. Embryonic stem cells may open up new therapeutic options for the future and should be an interesting model for the analysis of fetal organogenesis. Here we describe a technique for culturing embryonic stem cells (ESCs) in the absence of artificial scaffolds which generated mineralized miromasses. Embryonic stem cells were harvested and osteogenic differentiation was stimulated by the addition of dexamethasone, ascorbic acid, and ß-glycerolphosphate (DAG). After three days of cultivation microspheres were formed. These spherical three-dimensional cell units showed a peripheral zone consisting of densely packed cell layers surrounded by minerals that were embedded in the extracellular matrix. Alizarine red staining confirmed evidence of mineralization after 10 days of DAG stimulation in the stimulated but not in the control group. Transmission electron microscopy demonstrated scorching crystallites and collagenous fibrils as early indication of bone formation. These extracellular structures resembled hydroxyl apatite-like crystals as demonstrated by distinct diffraction patterns using electron diffraction analysis. The micromass culture technique is an appropriate model to form three-dimensional bone-like micro-units without the need for an underlying scaffold. Further studies will have to show whether the technique is applicable also to pluripotent stem cells of different origin

    Not Managing Expectations: A Grounded Theory of Intimate Partner Violence From the Perspective of Pakistani People

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    Intimate partner violence (IPV) is a major social and public health problem affecting people from different cultures and societies. Much research has been undertaken to understand the phenomenon, its determinants, and its consequences in numerous countries. However, there is a paucity of research on IPV in many areas of the world including Pakistan. The present study aimed to develop a theory of the meaning and process of IPV from the perspective of Pakistani men and women living in and outside Pakistan
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