The race to securitize the Arctic in a post-Cold War scenario

The Arctic implies a planetary struggle to stop the rapid change of its ecosystem caused by global climate change, with the global impact it could generate in the future. as a consequence of this first ecological challenge, the Arctic scenario is becoming more interesting for key transnational actors to develop new business opportunities related to mining exploitation, energy reserves and logistics services, where the result will tend to prioritize business and safety on the ecology, reaffirming the meta-tragedy in the arctic region. Due to the complexity of the Arctic scenario, the preference for intergovernmental forums and the ambiguous interests and roles of its actors, the inadequate trinomial between a global ecological tragedy, an individual economic business and a collective security career will tend to subsist and increase its tragic effects about the environmentEl Ártico implica una lucha planetaria para detener el rápido cambio de su ecosistema causado por el cambio climático global, con el impacto global que podría generar en el futuro. Como consecuencia de este primer desafío ecológico, el escenario del Ártico se está volviendo más interesante para los actores transnacionales clave para desarrollar nuevas oportunidades de negocios relacionadas con la explotación minera, las reservas de energía y los servicios logísticos, donde el resultado tenderá a priorizar los negocios y la seguridad sobre la ecología, reafirmando la meta- tragedia en la región del Ártico. debido a la complejidad del escenario Ártico, la preferencia por foros intergubernamentales y los intereses y roles ambiguos de sus actores, el trinomio inadecuado entre una tragedia ecológica global, un negocio económico individual y una carrera de seguridad colectiva tenderán a subsistir e incrementar sus efectos trágicos sobre el medio ambient

Growth and development of the third permanent molar in Paranthropus robustus from Swartkrans, South Africa

Third permanent molars (M3s) are the last tooth to form but have not been used to estimate age at dental maturation in early fossil hominins because direct histological evidence for the timing of their growth has been lacking. We investigated an isolated maxillary M3 (SK 835) from the 1.5 to 1.8-million-year-old (Mya) site of Swartkrans, South Africa, attributed to Paranthropus robustus. Tissue proportions of this specimen were assessed using 3D X-ray micro-tomography. Thin ground sections were used to image daily growth increments in enamel and dentine. Transmitted light microscopy and synchrotron X-ray fluorescence imaging revealed fluctuations in Ca concentration that coincide with daily growth increments. We used regional daily secretion rates and Sr marker-lines to reconstruct tooth growth along the enamel/dentine and then cementum/dentine boundaries. Cumulative growth curves for increasing enamel thickness and tooth height and age-of-attainment estimates for fractional stages of tooth formation differed from those in modern humans. These now provide additional means for assessing late maturation in early hominins. M3 formation took ≥ 7 years in SK 835 and completion of the roots would have occurred between 11 and 14 years of age. Estimated age at dental maturation in this fossil hominin compares well with what is known for living great apes

Weathering of Viama?o granodiorite, south Brazil : Part 2-Initial porosity of un-weathered rock controls porosity development in the critical zone

The development of porosity during rock weathering is a key process controlling nutrients release, water holding capacity available for plants and water flow. Here we used X-ray Computed Tomography (XRCT) and 14C PolyMethylMethAcrylate (PMMA) autoradiography to show how cracks are created and enlarged during initial weathering stages (saprock and saprolite) of granodiorite in southern Brazil (Viama similar to o - RS). The physical evolution is characterized by imaging the pore network, using 14C-PMMA and XRCT methods. Combined with bulk porosity measurements, they highlight the increase in porosity with the degree of weathering (un-weathered rock phi = 1.66 %, saprolite phi = 11.7 %). This increase is related to the joint increase of the density of the cracks (unweathered rock D = 0.28 mm-1, saprolite D = 0.94 mm-1) and of the average opening of the microcracks (unweathered rock w = 2.4 mu m, saprolite w = 3.9 mu m) and macrocracks (un-weathered rock w = 176 mu m, saprolite w = 400 mu m). However, these average crack openings do not account for the variability of the openings that govern the flows, characterized here by specific distribution ranging from the submicrometre to the centimetre scale. The results highlight that the pore network of the un-weathered rock plays a key role in the initial stages or incipient weathering. The density and aperture and cracks increase following the subcritical cracking concept and new pores are formed by chemo-mechanical processes. The presence/absence of initial fractures in the regolith is certainly a key parameter controlling the weathering of different rock types (mafic vs felsic).Peer reviewe

Neuropathic complications after 157 procedures of continuous popliteal nerve block for hallux valgus surgery. A retrospective study

SummaryBackgroundContinuous peripheral nerve block (CPNB), in particular at the popliteal fossa, is widely used in orthopedic surgery, allowing good postoperative analgesia. Possible neuropathic complications, however, remain poorly known.ObjectiveTo review the characteristics of peripheral neuropathy (PN) after sciatic CPNB at the popliteal fossa, estimating prevalence, severity, evolution and possible risk factors, especially those relating to the procedure.MethodsRetrospective study of PN associated with popliteal fossa CPNB for hallux valgus surgery, between November 1st, 2005 and November 1st, 2009. All procedures were analyzed (type of anesthesia, approach, nerve location technique, number of procedures by operator) with, for each case of PN, analysis of clinical and electromyographic data.ResultsOne hundred and fifty seven sciatic CPNBs were performed (92% women; mean age, 55 years). The approach was lateral (n=62), posterior (n=74) or unknown (n=21). Ultrasound guidance was combined to neurostimulation for 69 patients (44%). Three women (prevalence=1.91%), aged 19, 24 and 65 years respectively, developed associated common superficial peroneal and sural nerve injury (2), axonal on electromyography, with motor (n=1) and/or sensory (n=3) residual dysfunction.DiscussionThe higher prevalence found in the present study than in the literature (0 to 0.5%) raises questions of methodological bias or technical problems. The common peroneal and sural nerves seem to be exposed, unlike the tibial. Several mechanisms can be suggested: anesthetic neurotoxicity, direct mechanical lesion, or tourniquet-related ischemia and conduction block. Further studies are necessary to determine the ideal anesthetic procedure.ConclusionPatients should be informed of the potential risk, however rare, even during mild surgery. The best possible technique should be implemented, with reinforced surveillance.Level of evidenceLevel IV retrospective study

A new candidate mutation, G1629R, in a patient with type 2A von Willebrand's disease: basic mechanisms and clinical implications

Type 2A von Willebrand's disease (VWD) refers to disease variants with decreased platelet-dependent function of von Willebrand factor (VWF) associated with the absence of high molecular weight (HMW) multimers. The candidate G1629R mutation, identified in an Italian patient with type 2A VWD, was expressed to confirm the relationship between phenotype and genotype. Plasma samples from the patient were studied after DDAVP or FVIII/VWF concentrate injections. Furthermore, an expression vector carrying the G1629R mutation was constructed by site-directed mutagenesis and transiently expressed in Cos-7 cells. The characteristics of the corresponding recombinant protein were analyzed. After 1-deamino-8-D-argine vasopressin (DDAVP) infusion, factor VIII and VWF activities increased and HMW VWF multimers were transiently observed in the patient's plasma. VWF activity increased only after administration of a dual FVIII/VWF concentrate. ADAMTS-13 activity did not change significantly before or after the therapies. Secretion, in culture medium, of the corresponding mutated protein (R1629-rVWF) was slightly decreased and this rVWF contained intermediate and HMW multimers. Furthermore, binding of R1629-rVWF to platelet GPIb was moderately reduced compared to that of the wild-type rVWF. Based on the DDAVP and in vitro expression results, we classified the G1629R mutation in group 2 type 2A mutations. Our findings could explain why DDAVP may only be partially effective and suggest that FVIII/VWF concentrates should be used in cases of prolonged mucosal bleeding and major surgery when functional VWF is required

Методическая работа в дошкольной образовательной организации как условие развития профессионально-педагогической культуры педагогов

Тема работы актуальна. В ВКР представлена методическая работа с педагогами ДОУ, по формирования профессионально-педагогической культуры. Работа имеет практическую значимост

Force-Velocity Measurements of a Few Growing Actin Filaments

The authors propose a new mechanism for actin-based force generation based on results using chains of actin-grafted magnetic colloids

Comparative Expression Profiling of Leishmania: Modulation in Gene Expression between Species and in Different Host Genetic Backgrounds

The single-celled parasite Leishmania, transmitted by sand flies in more than 88 tropical and sub-tropical countries globally, infects man and other mammals, causing a spectrum of diseases called the leishmaniases. Over 12 million people are currently infected worldwide with 2 million new cases reported each year. The type of leishmaniasis that develops in the mammalian host is dependent on the species of infecting parasite and the immune response to infection (that can be influenced by host genetic variation). Our research is focused on identifying parasite factors that contribute to pathogenicity in the host and understanding how these might differ between parasite species that give rise to the different clinical forms of leishmaniasis. Molecules of this type might lead to new therapeutic tools in the longer term. In this paper, we report a comparative analysis of gene expression profiles in three Leishmania species that give rise to different types of disease, focusing on the intracellular stages that reside in mammalian macrophages. Our results show that there are only a small number of differences between these parasite species, with host genetics playing only a minor role in influencing the parasites' response to their intracellular habitat. These small changes may be significant, however, in determining the clinical outcome of infection