Simultaneous effect of spatial variability of ground motion due to site conditions and SSI on the seismic response of multi-span viaducts

This work focuses on the effects of the spatial variability of the seismic motion due to site effects on the seismic response of multi-span viaducts on pile foundations. A methodology is proposed to include the effects of both soil-structure interaction and non-synchronous seismic actions in the nonlinear response of bridges. Then, some results of nonlinear dynamic analyses performed on a multi-span bridge founded on soft soil are presented. The deposit is characterized by an inclined layout of the bedrock and the seismic input is represented by a set of suitably selected real accelerograms. Comparisons with results obtained considering synchronous seismic motions demonstrate the influence of site effects on the response of long bridges

Seismic Response of Bridges Accounting for Soil-Structure Interaction effects and the Non-Synchronous Ground Motion due to 1D and 2D site analysis.

This work focuses on the effects of soil-structure interaction and the spatial variability of seismic motion due to site effects on the seismic response of a multi-span viaduct on pile foundations. In particular, site effects induced in a soft clay deposit by an inclined bedrock layout are evaluated through different models, characterised by an increasing level of accuracy, which allows determining the free-field motion that is adopted to perform soilstructure interaction analyses in the frame of the substructure approach. The seismic input is represented at the outcropping bedrock by a set of suitably selected and scaled real accelerograms. After a brief presentation of the adopted numerical procedure, analyses results are presented focusing on both site and structural response. Amplifications effects obtained from simplified linear equivalent 1D and nonlinear 2D site response models are compared, discussing the applicability of the simplified approach. Structural responses, obtained by considering the non-synchronous motion resulting from the local stratigraphic conditions, in conjunction with soil-structure interaction effects, are shown in terms of piers displacement and ductility demands. Furthermore, the role of soil structure interaction is clarified comparing results with those obtained from fixed base bridge models, proving that its contribution is more significant if the simplified model for site response is adopted

Dark halo baryons not in ancient halo white dwarfs

Having ruled out the possibility that stellar objects are the main contributor of the dark matter embedding galaxies, microlensing experiments cannot exclude the hypothesis that a significant fraction of the Milky Way dark halo might be made of MACHOs with masses in the range 0.5-0.8 \msun. Ancient white dwarfs are generally considered the most plausible candidates for such MACHOs. We report the results of a search for such white dwarfs in a proper motion survey covering a 0.16 sqd field at three epochs at high galactic latitude, and 0.938 sqd at two epochs at intermediate galactic latitude (VIRMOS survey), using the CFH telescope. Both surveys are complete to I = 23, with detection efficiency fading to 0 at I = 24.2. Proper motion data are suitable to separate unambiguously halo white dwarfs identified by belonging to a non rotating system. No candidates were found within the colour-magnitude-proper motion volume where such objects can be safely discriminated from any standard population as well as from possible artefacts. In the same volume, we estimate the maximum white dwarf halo fraction compatible with this observation at different significance levels if the halo is at least 14 gigayears old and under different ad hoc initial mass functions. Our data alone rules out a halo fraction greater than 14% at 95% confidence level. Combined with two previous investigations exploring comparable volumes pushes the limit below 4 % (95% confidence level) or below 1.3% (64% confidence), this implies that if baryonic dark matter is present in galaxy halos, it is not, or it is only marginally in the form of faint hydrogen white dwarfs.Comment: accepted in Astronomy and Astrophysics (19-05-2004

Implementation of access and benefit-sharing measures has consequences for classical biological control of weeds

The Convention on Biological Diversity and the Nagoya Protocol establish that genetic resources shall be accessed only upon the existence of prior informed consent of the country that provides those resources and that benefits arising from their utilization shall be shared. Pursuant to both agreements several countries have adopted regulations on access and benefit-sharing. These regulations have created a challenging obstacle to classical biological control of weeds. This paper reviews the experiences of Argentina, Brazil, South Africa, the USA, Canada and CABI in implementing access and benefit-sharing regulations and the implications these measures have on the effective and efficient access, exchange and utilization of biological control agents. We conclude that policy makers should be made aware of the key role biological control plays for agriculture and the environment and they are encouraged to develop tailored access and benefit-sharing legal frameworks that facilitate biological control research and implementation.Fil: Silvestri, Luciana Carla. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Sosa, Alejandro Joaquín. Fundación para el Estudio de Especies Invasivas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mc Kay, Fernando. Fundación para el Estudio de Especies Invasivas; ArgentinaFil: Diniz Vitorino, Marcelo. Universidade Regional de Blumenau; BrasilFil: Hill, Martin. Rhodes University.; SudáfricaFil: Zachariades, Costas. University of KwaZulu-Natal; SudáfricaFil: Hight, Stephen. No especifíca;Fil: Weyl, Philip. No especifíca;Fil: Smith, David. No especifíca;Fil: Djeddour, Djamila. No especifíca;Fil: Mason, Peter G.. No especifíca

Geographical inequalities in lung cancer management and survival in South East England: evidence of variation in access to oncology services?

This study aimed to determine whether the management and survival of patients with lung cancer varied among 26 health authorities in South East England. The Thames Cancer Registry identified patients diagnosed with lung cancer (ICD-10 codes C33-C34) between 1995 and 1999. After excluding death certificate only patients, 32,818 (81%) patients were analysed. The proportions of patients receiving active treatment varied among health authorities between 5 and 17% for non-investigative surgery, 4 and 17% for any chemotherapy, 8 and 30% for any radiotherapy and 15 and 42% for any active treatment. One-year patient survival ranged from 11 to 34%. There was evidence of health authority level variation even after adjusting for case mix. Patients whose first hospital attendance was at a radiotherapy centre were more likely to receive active treatment (OR 1.72, 95% CI 1.21-2.46), chemotherapy (1.38, 1.06-1.79) or radiotherapy (1.86, 1.28-2.71). There was some evidence that patients whose first hospital attendance was at a radiotherapy centre survived longer. This study shows there is geographical inequality in the treatment given to lung cancer patients and patient survival in South East England. There was some evidence to suggest that these inequalities might be explained by variations in access to oncology services. Future studies should investigate the pathways and barriers to specialist care in this condition

Implementation of access and benefit-sharing measures has consequences for classical biological control of weeds:

The Convention on Biological Diversity and the Nagoya Protocol establish that genetic resources shall be accessed only upon the existence of prior informed consent of the country that provides those resources and that benefits arising from their utilization shall be shared. Pursuant to both agreements several countries have adopted regulations on access and benefit-sharing. These regulations have created a challenging obstacle to classical biological control of weeds. This paper reviews the experiences of Argentina, Brazil, South Africa, the USA, Canada and CABI in implementing access and benefit-sharing regulations and the implications these measures have on the effective and efficient access, exchange and utilization of biological control agents

Early Divergent Host Responses in SHIVsf162P3 and SIVmac251 Infected Macaques Correlate with Control of Viremia

We previously showed intravaginal inoculation with SHIVsf162p3 results in transient viremia followed by undetectable viremia in most macaques, and some displayed subsequent immunity to superinfection with pathogenic SIVmac251. Here we compare early T cell activation, proliferation, and plasma cytokine/chemokine responses in macaques intravaginally infected with either SHIVsf162p3 or SIVmac251 to determine whether distinct differences in host responses may be associated with early viral containment. The data show SIVmac251 infection results in significantly higher levels of T cell activation, proliferation, and a mixed cytokine/chemokine “storm” in plasma in primary infection, whereas infection with SHIVsf162p3 resulted in significantly lower levels of T cell activation, proliferation, and better preservation of memory CD4+ T cells in early infection which immediately preceded control of viremia. These results support the hypothesis that early systemic immune activation, T cell proliferation, and a more prominent and broader array of cytokine/chemokine responses facilitate SIV replication, and may play a key role in persistence of infection, and the progression to AIDS. In contrast, immune unresponsiveness may be associated with eventual clearance of virus, a concept that may have key significance for therapy and vaccine design

Relationship of circulating hyaluronic Acid levels to disease control in asthma and asthmatic pregnancy.

Uncontrolled asthma is a risk factor for pregnancy-related complications. Hyaluronic acid (HA), a potential peripheral blood marker of tissue fibrosis in various diseases, promotes eosinophil survival and plays a role in asthmatic airway inflammation as well as in physiological processes necessary to maintain normal pregnancy; however the level of circulating HA in asthma and asthmatic pregnancy is unknown. We investigated HA levels in asthmatic patients (N = 52; asthmatic pregnant (AP) N = 16; asthmatic non-pregnant (ANP) N = 36) and tested their relationship to asthma control. Serum HA level was lower in AP than in ANP patients (27 [24.7-31.55] vs. 37.4 [30.1-66.55] ng/mL, p = 0.006); the difference attenuated to a trend after its adjustment for patients' age (p = 0.056). HA levels and airway resistance were positively (r = 0.467, p = 0.004), HA levels and Asthma Control Test (ACT) total score inversely (r = -0.437, p = 0.01) associated in ANP patients; these relationships remained significant even after their adjustments for age. The potential value of HA in the determination of asthma control was analyzed using ROC analysis which revealed that HA values discriminate patients with ACT total score >/=20 (controlled patients) and <20 (uncontrolled patients) with a 0.826 efficacy (AUC, 95% CI: 0.69-0.97, p = 0.001) when 37.4 ng/mL is used as cut-off value in ANP group, and with 0.78 efficacy (AUC, 95% CI: 0.65-0.92, p = 0.0009) in the whole asthmatic cohort. In conclusion circulating HA might be a marker of asthma control, as it correlates with airway resistance and has good sensitivity in the detection of impaired asthma control. Decrease of HA level in pregnancy may be the consequence of pregnancy induced immune tolerance

SIVagm Infection in Wild African Green Monkeys from South Africa: Epidemiology, Natural History, and Evolutionary Considerations

Pathogenesis studies of SIV infection have not been performed to date in wild monkeys due to difficulty in collecting and storing samples on site and the lack of analytical reagents covering the extensive SIV diversity. We performed a large scale study of molecular epidemiology and natural history of SIVagm infection in 225 free-ranging AGMs from multiple locations in South Africa. SIV prevalence (established by sequencing pol, env, and gag) varied dramatically between infant/juvenile (7%) and adult animals (68%) (p<0.0001), and between adult females (78%) and males (57%). Phylogenetic analyses revealed an extensive genetic diversity, including frequent recombination events. Some AGMs harbored epidemiologically linked viruses. Viruses infecting AGMs in the Free State, which are separated from those on the coastal side by the Drakensberg Mountains, formed a separate cluster in the phylogenetic trees; this observation supports a long standing presence of SIV in AGMs, at least from the time of their speciation to their Plio-Pleistocene migration. Specific primers/probes were synthesized based on the pol sequence data and viral loads (VLs) were quantified. VLs were of 104-106 RNA copies/ml, in the range of those observed in experimentally-infected monkeys, validating the experimental approaches in natural hosts. VLs were significantly higher (107-108 RNA copies/ml) in 10 AGMs diagnosed as acutely infected based on SIV seronegativity (Fiebig II), which suggests a very active transmission of SIVagm in the wild. Neither cytokine levels (as biomarkers of immune activation) nor sCD14 levels (a biomarker of microbial translocation) were different between SIV-infected and SIV-uninfected monkeys. This complex algorithm combining sequencing and phylogeny, VL quantification, serology, and testing of surrogate markers of microbial translocation and immune activation permits a systematic investigation of the epidemiology, viral diversity and natural history of SIV infection in wild African natural hosts. © 2013 Ma et al