1,470 research outputs found
Population, sexual and reproductive health, rights and sustainable development: forging a common agenda.
This article suggests that sexual and reproductive health and rights activists seeking to influence the post-2015 international development paradigm must work with sustainable development advocates concerned with a range of issues, including climate change, environmental issues, and food and water security, and that a way of building bridges with these communities is to demonstrate how sexual and reproductive health and rights are relevant for these issues. An understanding of population dynamics, including urbanization and migration, as well as population growth, can help to clarify these links. This article therefore suggests that whether or not sexual and reproductive health and rights activists can overcome resistance to discussing "population", become more knowledgeable about other sustainable development issues, and work with others in those fields to advance the global sustainable development agenda are crucial questions for the coming months. The article also contends that it is possible to care about population dynamics (including ageing and problems faced by countries with a high proportion of young people) and care about human rights at the same time. It expresses concern that, if sexual and reproductive health and rights advocates do not participate in the population dynamics discourse, the field will be left free for those for whom respecting and protecting rights may be less of a priority
The G-O Rule and Waldmeier Effect in the Variations of the Numbers of Large and Small Sunspot Groups
We have analysed the combined Greenwich and Solar Optical Observing Network
(SOON) sunspot group data during the period of 1874-2011 and determined
variations in the annual numbers (counts) of the small, large and big sunspot
groups (these classifications are made on the basis of the maximum areas of the
sunspot groups). We found that the amplitude of an even-numbered cycle of the
number of large groups is smaller than that of its immediately following
odd-numbered cycle. This is consistent with the well known Gnevyshev and Ohl
rule or G-O rule of solar cycles, generally described by using the Zurich
sunspot number (Rz). During cycles 12-21 the G-O rule holds good for the
variation in the number of small groups also, but it is violated by cycle pair
(22, 23) as in the case of Rz. This behaviour of the variations in the small
groups is largely responsible for the anomalous behaviour of Rz in cycle pair
(22, 23). It is also found that the amplitude of an odd-numbered cycle of the
number of small groups is larger than that of its immediately following
even-numbered cycle. This can be called as `reverse G-O rule'. In the case of
the number of the big groups, both cycle pairs (12, 13) and (22, 23) violated
the G-O rule. In many cycles the positions of the peaks of the small, large,
and big groups are different and considerably differ with respect to the
corresponding positions of the Rz peaks. In the case of cycle 23, the
corresponding cycles of the small and large groups are largely symmetric/less
asymmetric (Waldmeier effect is weak/absent) with their maxima taking place two
years later than that of Rz. The corresponding cycle of the big groups is more
asymmetric (strong Waldmeier effect) with its maximum epoch taking place at the
same time as that of Rz.Comment: 13 pages, 5 figures, 1 table, accepted by Solar Physic
Dose-dependent activation of gene expression is achieved using CRISPR and small molecules that recruit endogenous chromatin machinery
Gene expression can be activated or suppressed using CRISPR--Cas9 systems. However, tools that enable dose-dependent activation of gene expression without the use of exogenous transcription regulatory proteins are lacking. Here we describe chemical epigenetic modifiers (CEMs) designed to activate the expression of target genes by recruiting components of the endogenous chromatin-activating machinery, eliminating the need for exogenous transcriptional activators. The system has two parts: catalytically inactive Cas9 (dCas9) in complex with FK506-binding protein (FKBP) and a CEM consisting of FK506 linked to a molecule that interacts with cellular epigenetic machinery. We show that CEMs upregulate gene expression at target endogenous loci up to 20-fold or more depending on the gene. We also demonstrate dose-dependent control of transcriptional activation, function across multiple diverse genes, reversibility of CEM activity and specificity of our best-in-class CEM across the genome.Activation of gene expression with chemical epigenetic modifier
Magnetostriction, elasticity, and D03 phase stability in Fe–Ga and Fe–Ga–Ge alloys
The contrast between the saturation tetragonal magnetostriction, λγ,2 = (3/2)λ100, of Fe1−xGax and Fe1−yGey, at compositions where both alloys exhibit D03 cubic symmetry (second peak region), was investigated. This region corresponds to x = 28 at. % Ga and y = 18 at. % Ge or, in terms of e/a = 2 x + 3 y + 1, to an e/a value of ∼1.55 for each of the alloys. Single crystal, slow-cooled, ternary Fe1−x−y GaxGey alloys with e/a ∼1.55 and gradually increasing y/x were investigated experimentally (magnetostriction, elasticity, powder XRD) and theoretically (density functional calculations). It was found that a small amount of Ge (y = 1.3) replacing Ga in the Fe–Ga alloy has a profound effect on the measured λγ,2. As y increases, the drop in λγ,2 is considerable, reaching negative values at y/x = 0.47. The two shear elastic constants c′ = (c11− c12)/2 and c44 measured for four compositions with 0.06 ≤ y/x ≤ 0.45 at 7 K range from 16 to 21 GPa and from 133 to 138 GPa, respectively. Large temperature dependence was observed for c′ but not for c44, a trend seen in other high-solute Fe alloys. The XRD analysis shows that the metastable D03 structure, observed previously in slow-cooled Fe–Ga at e/a = 1.55, is replaced with two phases, fcc L12 and hexagonal D019, at just 1.6 at. % Ge. The two are the stablephases of the assessed Fe–Ga phase diagram at x ∼ 28. Notably, at y = 7.8, only the D03phase (the equilibrium phase of Fe–Ge at e/a = 1.54) was found in the ternary alloy. The theory also shows that the D03 instability is removed for compositions with y ≥ 3.9, when D03 becomes the structure’s ground-state phase. Thus, the high, positive λγ,2 value for Fe–Ga at x = 28 could be the result of the high sensitivity of its metastable D03 structure
Revolutionary Concepts of Radiation Shielding for Human Exploration of Space
This Technical Memorandum covers revolutionary ideas for space radiation shielding that would mitigate mission costs while limiting human exposure, as studied in a workshop held at Marshall Space Flight Center at the request of NASA Headquarters. None of the revolutionary new ideas examined for the .rst time in this workshop showed clear promise. The workshop attendees felt that some previously examined concepts were de.nitely useful and should be pursued. The workshop attendees also concluded that several of the new concepts warranted further investigation to clarify their value
Designing Efficient Taxi Pickup Operations at Airports
This paper provides a practical procedure for designing efficient taxi pickup operations at airports. How to do this effectively is an open question. Solutions are not available, and practices vary. They reflect different approaches to and lack of research on the subject. The solutions are often unsatisfactory. At many airports, passengers routinely suffer long waits outdoors, exposed to the elements, after a tiring journey. Such disagreeable experiences are avoidable. Designing efficient taxi pickup operations at airports is problematic. The peculiarities of the process preclude easy solutions. First, the process involves queuing, so system performance is a nonlinear function of the loads. Second, it features unstable transient situations, since travelers typically arrive in bulk over short periods. Third, traffic is significantly differentiated and consists of a wide variety of groups implying different service characteristics. Standard results from queuing theory thus do not have a useful application to this problem. The design process uses simulation that is based on detailed observation of local practices. It involves four steps: (a) detailed local measurements of the arrival of both travelers and taxis, and the service rates provided by taxis in different queuing positions; (b) creation and validation of a simulation model sufficiently detailed to account for these realities; (c) exploration of design alternatives to estimate the characteristics of the service they would provide; and (d) selection of a preferred design that properly balances efforts to minimize average and extreme wait times. The paper demonstrates the procedure through application to Lisbon International Airport, Portugal.SIMUL8 Corporatio
Actinobacterial Diversity in Volcanic Caves and Associated Geomicrobiological Interactions
16 páginas.-- 8 figuras.-- 2 tablas.-- 66 referencias.-- Material suplementario http://dx.doi.org/10.3389/fmicb.2015.01342Volcanic caves are filled with colorful microbial mats on the walls and ceilings. These volcanic caves are found worldwide, and studies are finding vast bacteria diversity within these caves. One group of bacteria that can be abundant in volcanic caves, as well as other caves, is Actinobacteria. As Actinobacteria are valued for their ability to produce a variety of secondary metabolites, rare and novel Actinobacteria are being sought in underexplored environments. The abundance of novel Actinobacteria in volcanic caves makes this environment an excellent location to study these bacteria. Scanning electron microscopy (SEM) from several volcanic caves worldwide revealed diversity in the morphologies present. Spores, coccoid, and filamentous cells, many with hair-like or knobby extensions, were some of the microbial structures observed within the microbial mat samples. In addition, the SEM study pointed out that these features figure prominently in both constructive and destructive mineral processes. To further investigate this diversity, we conducted both Sanger sequencing and 454 pyrosequencing of the Actinobacteria in volcanic caves from four locations, two islands in the Azores, Portugal, and Hawai'i and New Mexico, USA. This comparison represents one of the largest sequencing efforts of Actinobacteria in volcanic caves to date. The diversity was shown to be dominated by Actinomycetales, but also included several newly described orders, such as Euzebyales, and Gaiellales. Sixty-two percent of the clones from the four locations shared less than 97% similarity to known sequences, and nearly 71% of the clones were singletons, supporting the commonly held belief that volcanic caves are an untapped resource for novel and rare Actinobacteria. The amplicon libraries depicted a wider view of the microbial diversity in Azorean volcanic caves revealing three additional orders, Rubrobacterales, Solirubrobacterales, and Coriobacteriales. Studies of microbial ecology in volcanic caves are still very limited. To rectify this deficiency, the results from our study help fill in the gaps in our knowledge of actinobacterial diversity and their potential roles in the volcanic cave ecosystems.The authors acknowledge the Spanish Ministry of Economy and Competitiveness (project CGL2013-41674-P) and FEDER Funds for financial support. AM acknowledges the support from the Marie Curie Intra-European Fellowship of the European Commission's 7th Framework Programme (PIEF-GA-2012-328689). CR was funded by the Regional Fund for Science and Technology and Pro-Emprego program of the Regional Government of the Azores, Portugal [M3.1.7/F/013/2011, M3.1.7/F/030/2011]. Her work was partly supported by National funds from the Foundation for Science and Technology of the Portuguese Government, [Understanding Underground Biodiversity: Studies in Azorean Lava Tubes (reference PTDC/AMB/70801/2006]. The authors would like to thank the TRU Innovation in Research Grant, TRU UREAP Fund, Western Economic Diversification Canada Fund, Kent Watson (assisted with the Helmcken Falls Cave sample collection), Derrick Horne (UBC BioImaging Facility for the SEM work). We acknowledged the Canadian Ministry of Forests, Lands, and Natural Resource Operations for Park Use Permit#102172. This work was also supported by the Cave Conservancy of the Virginias, the Graduate Research Allocation Committee at UNM Biology, UNM Biology Grove Scholarship, the Student Research Allocation Committee at UNM, the National Speleological Society, the New Mexico Space Grant Consortium, the New Mexico Alliance for Minority Participation Program, the New Mexico Geological Society, and Kenneth Ingham Consulting. We acknowledge support from the UNM Molecular Biology Facility, which is supported by NIH grant number P20GM103452. The authors also wish to thank Fernando Pereira, Ana Rita Varela, Pedro Correia, Berta Borges, and Guida Pires for help during field and lab work in the Azores. The authors gratefully acknowledge the photographic contributions of Kenneth Ingham and Pedro Cardoso and Michael Spilde (SEM images). The authors would like to thank Dr. Steven Van Wagoner (TRU) and Drs. Julian Davies and Vivian Miao (UBC) for their invaluable comments in manuscript preparation. We gratefully acknowledge the help and collecting permits granted by the staff of El Malpais National Monument and Hawai'i Volcanoes National Park (USA).Peer reviewe
Evolution of active and polar photospheric magnetic fields during the rise of Cycle 24 compared to previous cycles
The evolution of the photospheric magnetic field during the declining phase
and minimum of Cycle 23 and the recent rise of Cycle 24 are compared with the
behavior during previous cycles. We used longitudinal full-disk magnetograms
from the NSO's three magnetographs at Kitt Peak, the Synoptic Optical Long-term
Investigations of the Sun (SOLIS) Vector Spectro-Magnetograph (VSM), the
Spectromagnetograph and the 512-Channel Magnetograph instruments, and
longitudinal full-disk magnetograms from the Mt. Wilson 150-foot tower. We
analyzed 37 years of observations from these two observatories that have been
observing daily, weather permitting, since 1974, offering an opportunity to
study the evolving relationship between the active region and polar fields in
some detail over several solar cycles. It is found that the annual averages of
a proxy for the active region poloidal magnetic field strength, the magnetic
field strength of the high-latitude poleward streams, and the time derivative
of the polar field strength are all well correlated in each hemisphere. These
results are based on statistically significant cyclical patterns in the active
region fields and are consistent with the Babcock-Leighton phenomenological
model for the solar activity cycle. There was more hemispheric asymmetry in the
activity level, as measured by total and maximum active region flux, during
late Cycle 23 (after around 2004), when the southern hemisphere was more
active, and Cycle 24 up to the present, when the northern hemisphere has been
more active, than at any other time since 1974. The active region net proxy
poloidal fields effectively disappeared in both hemispheres around 2004, and
the polar fields did not become significantly stronger after this time. We see
evidence that the process of Cycle 24 field reversal has begun at both poles.Comment: Accepted for publication in Solar Physic
A Bayesian Analysis of the Correlations Among Sunspot Cycles
Sunspot numbers form a comprehensive, long-duration proxy of solar activity
and have been used numerous times to empirically investigate the properties of
the solar cycle. A number of correlations have been discovered over the 24
cycles for which observational records are available. Here we carry out a
sophisticated statistical analysis of the sunspot record that reaffirms these
correlations, and sets up an empirical predictive framework for future cycles.
An advantage of our approach is that it allows for rigorous assessment of both
the statistical significance of various cycle features and the uncertainty
associated with predictions. We summarize the data into three sequential
relations that estimate the amplitude, duration, and time of rise to maximum
for any cycle, given the values from the previous cycle. We find that there is
no indication of a persistence in predictive power beyond one cycle, and
conclude that the dynamo does not retain memory beyond one cycle. Based on
sunspot records up to October 2011, we obtain, for Cycle 24, an estimated
maximum smoothed monthly sunspot number of 97 +- 15, to occur in
January--February 2014 +- 6 months.Comment: Accepted for publication in Solar Physic
A point mutation in cpsE renders Streptococcus pneumoniae nonencapsulated and enhances its growth, adherence and competence.
BACKGROUND: The polysaccharide capsule is a major virulence factor of the important human pathogen Streptococcus pneumoniae. However, S. pneumoniae strains lacking capsule do occur.
RESULTS: Here, we report a nasopharyngeal isolate of Streptococcus pneumoniae composed of a mixture of two phenotypes; one encapsulated (serotype 18C) and the other nonencapsulated, determined by serotyping, electron microscopy and fluorescence isothiocyanate dextran exclusion assay.By whole genome sequencing, we demonstrated that the phenotypes differ by a single nucleotide base pair in capsular gene cpsE (C to G change at gene position 1135) predicted to result in amino acid change from arginine to glycine at position 379, located in the cytoplasmic, enzymatically active, region of this transmembrane protein. This SNP is responsible for loss of capsule production as the phenotype is transferred with the capsule operon. The nonencapsulated variant is superior in growth in vitro and is also 117-fold more adherent to and more invasive into Detroit 562 human epithelial cells than the encapsulated variant.Expression of six competence pathway genes and one competence-associated gene was 11 to 34-fold higher in the nonencapsulated variant than the encapsulated and transformation frequency was 3.7-fold greater.
CONCLUSIONS: We identified a new single point mutation in capsule gene cpsE of a clinical S. pneumoniae serotype 18C isolate sufficient to cause loss of capsule expression resulting in the co-existence of the encapsulated and nonencapsulated phenotype. The mutation caused phenotypic changes in growth, adherence to epithelial cells and transformability. Mutation in capsule gene cpsE may be a way for S. pneumoniae to lose its capsule and increase its colonization potential
- …