215 research outputs found
Australian Pentatomidae
p. 187-214, [1] leaf of plates : ill. ; 24 cm.Includes bibliographical references
Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole
<p>Abstract</p> <p>Background</p> <p>Elevated blood O<sub>2 </sub>affinity enhances survival at low O<sub>2 </sub>pressures, and is perhaps the best known and most broadly accepted evolutionary adjustment of terrestrial vertebrates to environmental hypoxia. This phenotype arises by increasing the intrinsic O<sub>2 </sub>affinity of the hemoglobin (Hb) molecule, by decreasing the intracellular concentration of allosteric effectors (e.g., 2,3-diphosphoglycerate; DPG), or by suppressing the sensitivity of Hb to these physiological cofactors.</p> <p>Results</p> <p>Here we report that strictly fossorial eastern moles (<it>Scalopus aquaticus</it>) have evolved a low O<sub>2 </sub>affinity, DPG-insensitive Hb - contrary to expectations for a mammalian species that is adapted to the chronic hypoxia and hypercapnia of subterranean burrow systems. Molecular modelling indicates that this functional shift is principally attributable to a single charge altering amino acid substitution in the ÎČ-type ÎŽ-globin chain (ÎŽ136GlyâGlu) of this species that perturbs electrostatic interactions between the dimer subunits via formation of an intra-chain salt-bridge with ÎŽ82Lys. However, this replacement also abolishes key binding sites for the red blood cell effectors Cl<sup>-</sup>, lactate and DPG (the latter of which is virtually absent from the red cells of this species) at ÎŽ82Lys, thereby markedly reducing competition for carbamate formation (CO<sub>2 </sub>binding) at the ÎŽ-chain N-termini.</p> <p>Conclusions</p> <p>We propose this Hb phenotype illustrates a novel mechanism for adaptively elevating the CO<sub>2 </sub>carrying capacity of eastern mole blood during burst tunnelling activities associated with subterranean habitation.</p
Molecular basis of a novel adaptation to hypoxic-hypercapnia in a strictly fossorial mole
Background: Elevated blood O2 affinity enhances survival at low O2 pressures, and is perhaps the best known and most broadly accepted evolutionary adjustment of terrestrial vertebrates to environmental hypoxia. This phenotype arises by increasing the intrinsic O2 affinity of the hemoglobin (Hb) molecule, by decreasing the intracellular concentration of allosteric effectors (e.g., 2,3-diphosphoglycerate; DPG), or by suppressing the sensitivity of Hb to these physiological cofactors.
Results: Here we report that strictly fossorial eastern moles (Scalopus aquaticus) have evolved a low O2 affinity, DPG-insensitive Hb - contrary to expectations for a mammalian species that is adapted to the chronic hypoxia and hypercapnia of subterranean burrow systems. Molecular modelling indicates that this functional shift is principally attributable to a single charge altering amino acid substitution in the ÎČ-type ÎŽ-globin chain (ÎŽ136GlyâGlu) of this species that perturbs electrostatic interactions between the dimer subunits via formation of an intra-chain salt-bridge with ÎŽ82Lys. However, this replacement also abolishes key binding sites for the red blood cell effectors Cl-, lactate and DPG (the latter of which is virtually absent from the red cells of this species) at ÎŽ82Lys, thereby markedly reducing competition for carbamate formation (CO2 binding) at the ÎŽ-chain N-termini.
Conclusions: We propose this Hb phenotype illustrates a novel mechanism for adaptively elevating the CO2 carrying capacity of eastern mole blood during burst tunnelling activities associated with subterranean habitation
The European Union funded NEOShield project: a global approach to near-Earth object impact threat mitigation
Although discussions are underway within the Action Team 14 of the United Nations COPUOS, there is currently no concerted international plan addressing the impact threat from near-Earth objects (NEOs) and how to organize, prepare and implement mitigation measures. We report on a new international project to address impact hazard mitigation issues, being the subject of a proposal submitted to the European Commission in response to the 2011 FP7 Call âPrevention of impacts from near-Earth objects on our planetâ. Our consortium consists of 13 research institutes, universities, and industrial partners from 6 countries and includes leading US and Russian space organizations. The primary aim of the project, NEOShield, is to investigate in detail the three most promising mitigation techniques: the kinetic impactor, blast deflection, and the gravity tractor, and devise feasible demonstration missions. Furthermore, we will investigate options for an international strategy for implementation when an actual impact threat arises.
The NEOShield project was formally accepted by the European Commission on 17 November 2011 and funded with a total of 5.8 million Euros for a period of 3.5 years. The kick-off meeting took place at the DLR Institute of Planetary Research, Berlin, in January 2012. In this paper we present a brief overview of the planned scope of the project
Tiger beetles of Lower California
28 p. : ill., maps ; 24 cm.Includes bibliographical references (p. 27-28)
Mutations in STK11 gene in Czech Peutz-Jeghers patients
<p>Abstract</p> <p>Background</p> <p>Peutz-Jeghers syndrome (PJS) is an autosomal dominant hereditary disease characterized by mucocutaneous pigmentation and gastrointestinal hamartomatous polyposis. The germline mutations in the serine/threonine kinase 11 (<it>STK11</it>) gene have been shown to be associated with the disease. Individuals with PJS are at increased risk for development of various neoplasms. The aim of the present study was to characterize the genotype and phenotype of Czech patients with PJS.</p> <p>Methods</p> <p>We examined genomic DNA of 8 individuals from five Czech families by sequencing analysis of <it>STK11 </it>gene, covering its promotor region, the entire coding region and the splice-site boundaries, and by multiplex ligation-dependent probe amplification (MLPA) assay designed for the identification of large exonic deletions or duplications of <it>STK11 </it>gene.</p> <p>Results</p> <p>We found pathogenic mutations in <it>STK11 </it>gene in two families fulfilling the diagnostic criteria of PJS and in one of three sporadic cases not complying with the criteria. The patient with the frameshift mutation in <it>STK11 </it>gene developed aggressive gastric cancer. No other studied proband has developed a carcinoma so far.</p> <p>Conclusion</p> <p>Our results showed that a germline mutation of <it>STK11 </it>gene can be found not only in probands fulfilling the PJS diagnostic criteria, but also in some sporadic cases not complying with the criteria. Moreover, we observed a new case of aggressive gastric cancer in a young patient with a frameshift mutation of <it>STK11 </it>gene.</p
Com o diabo no corpo: os terrĂveis papagaios do Brasil colĂŽnia
Desde a Antiguidade, papagaios, periquitos e afins (Psittacidae) fascinaram os europeus por seu vivo colorido e uma notĂĄvel capacidade de interação com seres humanos. A descoberta do Novo Mundo nada faria alĂ©m de acrescentar novos elementos ao trĂĄfico de animais exĂłticos hĂĄ muito estabelecido pelos europeus com a Ăfrica e o Oriente. Sem possuir grandes mamĂferos, a AmĂ©rica tropical participaria desse comĂ©rcio com o que tinha de mais atrativo, essencialmente felinos, primatas e aves - em particular os papagaios, os quais eram embarcados em bom nĂșmero. Contudo, a julgar pelos documentos do Brasil colĂŽnia, esses volĂĄteis podiam inspirar muito pouca simpatia, pois nenhum outro animal - exceto as formigas - foi tantas vezes mencionado como praga para a agricultura. AlĂ©m disso, alguns psitĂĄcidas mostravam-se tĂŁo loquazes que inspiravam a sĂ©ria desconfiança de serem animais demonĂacos ou possessos, pois sĂł trĂȘs classes de entidades - anjos, homens e demĂŽnios - possuĂam o dom da palavra. Nos dias de hoje, vĂĄrios representantes dos Psittacidae ainda constituem uma ameaça para a agricultura, enquanto os indivĂduos muito faladores continuam despertando a suspeita de estarem possuĂdos pelo demĂŽnio. Transcendendo a mera curiosidade, essa crença exemplifica o quĂŁo intrincadas podem ser as relaçÔes do homem com o chamado âmundo naturalâ, revelando um universo mais amplo e multifacetado do que se poderia supor a princĂpio. Nesse sentido, a existĂȘncia de aves capazes de falar torna essa relação ainda mais complexa e evidencia que as dificuldades de estabelecer o limite entre o animal e o humano se estendem alĂ©m dos primatas e envolvem as mais inusitadas espĂ©cies zoolĂłgicas.Since ancient times, parrots and their allies (Psittacidae) have fascinated Europeans by their striking colors and notable ability to interact with human beings. The discovery of the New World added new species to the international exotic animal trade, which for many centuries had brought beasts to Europe from Africa and the Orient. Lacking large mammals, tropical America participated in this trade with its most appealing species, essentially felines, primates and birds - especially parrots - which were shipped in large numbers. It should be noted, however, that at times these birds were not well liked. In fact, according to documents from colonial Brazil, only the ants rank higher than parrots as the animals most often mentioned as agricultural pests. On the other hand, some of these birds were so chatty that people suspected them to be demonic or possessed animals, since only three classes of beings - angels, men and demons - have the ability to speak. Nowadays, several Psittacidae still constitute a threat to agriculture, and the suspicion that extremely talkative birds were demon possessed has also survived. More than a joke or a mere curiosity, this belief exemplifies how intricate manâs relationships with the ânatural worldâ may be. In this sense, the existence of birds that are able to speak adds a further twist to these relationships, demonstrating that the problem of establishing a boundary between the animal and the human does not only involve primates, but also includes some unusual zoological species
A global approach to near-Earth object impact threat mitigation
There is currently no concerted international plan addressing the impact threat and how to organize, prepare and implement mitigation measures. We report on a new international project to address impact hazard mitigation issues, being the subject of a proposal to the European Commission in response to the 2011 FP7 Call âPrevention of impacts from near-Earth objects on our planetâ. Our consortium consists of 13 research institutes, universities, and industrial partners and includes leading US and Russian space organizations. The primary aim of the project, NEOShield, is to investigate in detail the three most promising mitigation techniques: the kinetic impactor, blast deflection, and the gravity tractor, and devise feasible demonstration missions. Furthermore, we will investigate options for an international strategy for implementation when an actual impact threat arises.
The European Commissionâs funding contribution for the successful project in this Call will be a maximum of 4 million Euro. Final confirmation of funding is preceded by a phase of negotiation between the Consortium and the European
Commission. At the time of writing the proposal assessment exercise has been completed and the NEOShield proposal has far exceeded all thresholds for acceptance into the negotiation phase. We anticipate a project duration of some 3.5 years with a kick-off meeting at the end of 2011. In this paper we present a brief overview of the planned scope of the project
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