A case of natural queen succession in a captive colony of naked mole-rats, Heterocephalus glaber

Naked mole-rats occur in large colonies where usually a single queen monopolizes reproduction. Queen succession occurs from within usually as a result of aggressive encounters with subordinate females that queue for reproductive succession following colony instability, which inevitably results in death of either the queen or the challenging conspecific. We monitored a queen succession following the death of the breeding male in a colony of the naked mole-rat, Heterocephalus glaber, prior to, during as well as after replacement of the original breeding female. The response of the pituitary luteotrophs was investigated in the non-reproductive females during this period of instability by the administration of endogenous gonadotrophin releasing hormone (GnRH) and evaluating the subsequent luteinising hormone (LH) response in the blood. Larger and older non-breeding females engaged in aggressive encounters that culminated in death. The new breeding successor which arose from within the colony was a large female who continued to procreate. The six non-breeding females that were killed during reproductive takeover were larger and older females which exhibited elevated basal circulating LH concentrations as well as increased pituitary sensitivity as measured by the amount of releasable LH to an exogenous GnRH challenge. By contrast, non-breeding females that survived the succession were smaller and younger animals with reduced basal and GnRH challenged LH concentrations. Likewise, five non-breeding males which were heavier and older than those non-breeding males which survived were killed. These animals did not, however, show elevated basal or exogenous GnRH challenged LH concentrations when compared to the surviving males. The non-breeding animals of both sexes which survived the reproductive takeover event represented individuals which posed a minimal threat to the new successor and hence promoted the continuation of the marked reproductive skew that is prevalent in this highly inbred colonial subterranean hystricomorph.The authors thank R.P. Millar, Department of Chemical Pathology, University of Cape Town, for donating the mammalian GnRH. We also thank the National Institute of Biological Standards and Control, Hertfordshire, England, for the LH pituitary preparation (2nd International Standard 1988, code 80/552). The work was supported by research grants from the then Foundation for Research Development (to N.C.B. and J.U.M.J.), the University of Pretoria (to N.C.B.) and the University of Cape Town (to J.U.M.J). This study was approved by the Animal Ethics Committee of the University of Cape Townhttp://africanzoology.journals.ac.za/am2013ab201

A Case of Natural Queen Succession in a Captive Colony of Naked Mole-Rats,Heterocephalus glaber

16 p.Objetivos: Identificar las características demográficas y patológicas de los pacientes con estenosis laríngea y describir los desenlaces del manejo endoscópico según sus características, elección de técnica quirúrgica y uso de fármacos adyuvantes. Metodología: Cohorte de pacientes con diagnóstico de estenosis laríngea recibiendo manejo quirúrgico endoscópico en el Hospital Infantil Universitario Infantil San José entre el 2010 y 2014. Seguimiento durante 1 año evaluando desenlaces de éxito (mejoría sintomática, retiro de traqueostomía, no requerimiento de cirugía abierta). Resultados: Incluye 38 casos con seguimiento de 47 meses (RIQ 24-62). El 75,7% de pacientes fueron niños, con mediana de edad de 7 meses (RIQ 4-36). Todos tenían compromiso subglótico y 92.7% fueron adquiridas por intubación endotraqueal. Un 71,4% fueron manejados con dilatadores rígidos, asociado a Mitomicina C en el 82%. Se requirió una mediana de 1 dilatación (RIQ 1-2), obteniendo mejoría sintomática en el 74,1%. El 24,3% de los pacientes fueron adultos, con mediana de edad de 32 años (RIQ 30-52). Un 70% fueron manejados con técnicas combinadas (dilatador neumático, microdebridador y radiofrecuencia), asociado a Mitomicina C en el 90%. Se requirió una mediana de 1,5 dilataciones (RIQ 1-2) obteniendo mejoría sintomática en el 100%. Conclusiones: El manejo endoscópico de las estenosis laríngeas en pacientes pediátricos y adultos presenta desenlaces exitosos con menor morbilidad y estancia hospitalaria, inclusive en pacientes con estenosis severas

case of natural queen succession in a captive colony of naked mole-rats, Heterocephalus glaber

Naked mole-rats occur in large colonies where usually a single queen monopolizes reproduction. Queen succession occurs from within usually as a result of aggressive encounters with subordinate females that queue for reproductive succession following colony instability, which inevitably results in death of either the queen or the challenging conspecific. We monitored a queen succession following the death of the breeding male in a colony of the naked mole-rat, Heterocephalus glaber, prior to, during as well as after replacement of the original breeding female. The response of the pituitary luteotrophs was investigated in the non-reproductive females during this period of instability by the administration of endogenous gonadotrophin releasing hormone (GnRH) and evaluating the subsequent luteinising hormone (LH) response in the blood. Larger and older non-breeding females engaged in aggressive encounters that culminated in death. The new breeding successor which arose from within the colony was a large female who continued to procreate. The six  non-breeding females that were killed during reproductive takeover were larger and older females which exhibited elevated basal circulating LH concentrations as well as increased pituitary sensitivity as measured by the amount of releasable LH to an exogenous GnRH challenge. By contrast, non-breeding females that survived the succession were smaller and younger animals with reduced basal and GnRH challenged LH concentrations. Likewise, five non-breeding males which were heavier and older than those non-breeding males which survived were killed. These animals did not, however, show elevated basal or exogenous GnRH challenged LH  concentrations when compared to the surviving males. The non-breeding animals of both sexes which survived the reproductive takeover event represented individuals which posed a minimal threat to the new successor and hence promoted the continuation of the marked reproductive skew that is prevalent in this highly inbred colonial subterranean hystricomorph.Key words: naked mole-rat, Heterocephalus glaber, luteinizing hormone, queen, reproductive replacement, succession

Recent changes in high power optical fibers

In the past years we have witnessed remarkable advances in optical fiber laser and amplifier technologies. Optical fiber lasers of output powers beyond a kilowatt or multi-kilowatt with high beam quality have already been demonstrated and started to be deployed in industries. This rapid progress has been stimulated by the exceptional power-handling capability of optical fibers as gain media as well as the availability of powerful diode lasers for use as pumps. The progress was first made at around 1.1 microns with Yb-doping, next around 1.6 microns with Er-doping, and most recently at wavelengths around 2 microns with Tm-doping. Optical fiber lasers have numerous attractions over the more conventional "bulk" lasers in terms of energy-efficiency, power-scalability, thermal-management, flexibility and controllability in spatial/spectral/temporal domains, compactness, cost-effectiveness, and more. Indeed, this optical fiber photonic circuitry combined with pump-diode technology provides a unique high-gain environment for robust designs, which are also all-solid state, compact, reliable, and reproducible. Here we review the recent advances in high power optical fibers with a particular focus on rare-earth-doped optical fibers in conventional double-clad, large-core designs as well as in novel microstructured designs for more refined performances. We also review some passive-type optical fibers particularly devised for high-power operations, e.g. double-clad passive-core fibers for Raman conversion, single-clad fibers and microstructured fibers for four-wave mixing, photonic bandgap fibers for beam delivery. We discuss their fundamental aspects and future prospects, also presenting our up-to-date experimental results based on various high power optical fibers developed at the ORC

Novel fibre technology for high-power lasers

We review and discuss the recent advances in high-power fibre lasers with a particular focus on novel fibre technology, which includes conventional double-clad, large-core fibres for continuous-wave generation, doubleclad passive-core fibres for Raman conversion, microstructured fibres for four-wave mixing, all-solid photonic bandgap fibres for waveguide filtering, etc

Neuromuscular disease genetics in under-represented populations: increasing data diversity

Neuromuscular diseases (NMDs) affect similar to 15 million people globally. In high income settings DNA-based diagnosis has transformed care pathways and led to gene-specific therapies. However, most affected families are in low-to-middle income countries (LMICs) with limited access to DNA-based diagnosis. Most (86%) published genetic data is derived from European ancestry. This marked genetic data inequality hampers understanding of genetic diversity and hinders accurate genetic diagnosis in all income settings. We developed a cloud-based transcontinental partnership to build diverse, deeply-phenotyped and genetically characterized cohorts to improve genetic architecture knowledge, and potentially advance diagnosis and clinical management.We connected 18 centres in Brazil, India, South Africa, Turkey, Zambia, Netherlands and the UK. We co-developed a cloud-based data solution and trained 17 international neurology fellows in clinical genomic data interpretation. Single gene and whole exome data were analysed via a bespoke bioinformatics pipeline and reviewed alongside clinical and phenotypic data in global webinars to inform genetic outcome decisions.We recruited 6001 participants in the first 43 months. Initial genetic analyses 'solved' or 'possibly solved' similar to 56% probands overall. In-depth genetic data review of the four commonest clinical categories (limb girdle muscular dystrophy, inherited peripheral neuropathies, congenital myopathy/muscular dystrophies and Duchenne/Becker muscular dystrophy) delivered a similar to 59% 'solved' and similar to 13% 'possibly solved' outcome. Almost 29% of disease causing variants were novel, increasing diverse pathogenic variant knowledge. Unsolved participants represent a new discovery cohort. The dataset provides a large resource from under-represented populations for genetic and translational research.In conclusion, we established a remote transcontinental partnership to assess genetic architecture of NMDs across diverse populations. It supported DNA-based diagnosis, potentially enabling genetic counselling, care pathways and eligibility for gene-specific trials. Similar virtual partnerships could be adopted by other areas of global genomic neurological practice to reduce genetic data inequality and benefit patients globally.Wilson et al. present the findings of an international partnership established to study genetic causes of neuromuscular diseases in under-represented diverse populations from 12 low-middle income sites. A genetic cause was identified in similar to 55% of cases and similar to 30% of variants were novel, improving understanding of neuromuscular disease genetics.Functional Genomics of Muscle, Nerve and Brain Disorder