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The Guillain-Barré syndrome (GBS) has been previously associated with Zika virus infection. We analysed the data from all the patients with GBS diagnosis that were admitted to a referral hospital, in Tapachula City during the period from January 2013 to August 2016, comparing the incidence of GBS according to the temporality of the Zika outbreak in Southern Mexico. Additionally, we described the clinical and epidemiological characteristics of the GBS patients admitted before or after the Zika outbreak. We observed a sharp increase in the number of patients hospitalised due to GBS from the time the first confirmed Zika cases appeared in Mexico. Clinically we observed GBS cases before zika outbreak had more frequently history of respiratory/gastrointestinal symptoms and GBS during zika outbreak had significantly more frequently recent history of rash/conjunctivitis. Although we cannot affirm that the increased cases of GBS have a specific aetiologic association with Zika, our results suggest that this observed outbreak of in Tapachula, might have been associated to the emerging Zika epidemic, locally and suggests that rare complications associated with acute infections (such as GBS) might be useful in the surveillance systems for emerging infections.
The Desert Andes contain >4500 ice masses, but only a handful are currently being monitored. We present the mass changes of the small mountain glacier Agua Negra (1 km2) and of the rest of glaciers in the Jáchal river basin. Remote-sensing data show Agua Negra glacier lost 23% of its area during 1959–2019. Glaciological measurements during 2014–2021 indicate an average annual mass balance of −0.52 m w.e. a−1, with mean winter and summer balances of 0.80 and −1.33 m w.e. a−1, respectively. The Equilibrium Line Altitude (ELA) is estimated to be 5100 ± 100 m a.s.l., which corresponds to an Accumulation Area Ratio (AAR) of 0.28 ± 0.21. Geodetic data from SRTM X and Pléiades show a doubling of the loss rate from −0.32 ± 0.03 m w.e. a−1 in 2000–2013, to −0.66 ± 0.06 m w.e. a−1 in 2013–2019. Comparatively, the ice losses for the entire Jáchal river basin (25 500 km2) derived from ASTER show less negative values, −0.11 ± 16 m w.e. a−1 for 2000–2012 and −0.23 ± 14 m w.e. a−1 for 2012–2018. The regional warming trend since 1979 and a recent decline in snow accumulation are probably driving the observed glacier mass balance.
The COVID-19 pandemic struck Spain severely from the beginning. Prevention via information that fosters knowledge, reasonable concern, control, and personal care is the most effective means to slow down the pandemic. In this intervention field study, first, we assessed actual knowledge, concern, control, and care about the COVID-19 in 111 Spanish university teachers and students. Subsequently, we randomly assigned them to two groups. One group (n = 53) received uncertain information about prevention measures, whereas the other group (n = 58) received certain information. Analysis of covariance, using baseline measures as covariates, revealed that the group receiving the certain information reported an immediately increased perceived control and personal care about the pandemic. These findings suggest that measures that are known to be effective in COVID-19 prevention, if communicated with certainty (i.e., solid evidence), could influence people's attitudes, possibly through the schematic organisation of new information.
This paper analyzes the nonlinear relationship between the advertising investment and reputation of collective brand members in an experience goods industry, as well as the moderating role of their market share within the collective brand. The central assumption is that the quality reputation of collective brand members has a positive effect on their advertising investment until a reputation threshold is reached, after which the effect on advertising investment becomes negative. This change in the slope is explained by the information sets (firm reputation and collective reputation) used by consumers to reduce uncertainty, which leads to a weaker motivation for the firm to invest in advertising. In addition, scale economies of advertising mean that the market share of collective brand members negatively moderates the curvilinear relationship between quality reputation and advertising investment. The results for a sample of 176 companies in a Spanish experience goods industry (i.e., winemaking) between 2004 and 2014 show an inverted U-shaped relationship between the advertising investment and reputation of collective brand members. The results also show that market share negatively moderates this curvilinear relationship. (JEL Classifications: M31, M37, Q13)
Self-assembly, a process in which molecules, polymers, and particles are driven by local interactions to organize into patterns and functional structures, is being exploited in advancing silicon electronics and in emerging, unconventional electronics. Silicon electronics has relied on lithographic patterning of polymer resists at progressively smaller lengths to scale down device dimensions. Yet, this has become increasingly difficult and costly. Assembly of block copolymers and colloidal nanoparticles allows resolution enhancement and the definition of essential shapes to pattern circuits and memory devices. As we look to a future in which electronics are integrated at large numbers and in new forms for the Internet of Things and wearable and implantable technologies, we also explore a broader material set. Semiconductor nanoparticles and biomolecules are prized for their size-, shape-, and composition-dependent properties and for their solution-based assembly and integration into devices that are enabling unconventional manufacturing and new device functions.
Glaciers and the periglacial environment in Argentina have been protected by the Law since 2010. This legislation required the development of the first National Glacier Inventory (NGI), which was officially presented in May 2018 and based on satellite images spanning between 2004 and 2016. Here, we present the methods and results of the NGI, summarize the glaciers’ morphological and spatial characteristics, and compare our results to previous regional and global inventories. The NGI reveals an impressive variety of ice masses including rock glaciers, permanent snowfields, mountain and valley glaciers with varying amounts of debris-cover and large outlet glaciers. The Argentinean Andes contain 16 078 ice masses covering an area of 5769 km2 between 200 and 6900 m a.s.l. Comparison of the combined national inventories of Argentina and Chile (~30 000 glaciers and 28 400 km2) with the Randolph Glacier Inventory 6.0 for the Southern Andes (~16 000 glaciers and 29 400 km2), shows that there are large differences in extent and number of glaciers in some sub-regions. The NGI represents an improvement for a better understanding of Argentina's freshwater reservoirs and provides detailed information for the preservation and study of ice masses along 4000 km of the Southern Andes.
Glacier ice thickness is crucial to quantifying water resources in mountain regions, and is an essential input for ice-flow models. Using a surface velocity inversion method, we combine ice thickness measurements with detailed surface elevation and velocity data, and derive ice thickness and volume estimates for the Monte Tronador glaciers, North Patagonian Andes. We test the dependence of the inversion model on surface slope by resampling glacier slopes using variable smoothing filter sizes of 16–720 m. While total glacier volumes do not differ considerably, ice thickness estimates show higher variability depending on filter size. Smaller (larger) smoothing scales give thinner (thicker) ice and higher (lower) noise in ice thickness distribution. A filter size of 300 m, equivalent to four times the mean ice thickness, produces a noise-free thickness distribution with an accuracy of 35 m. We estimate the volume of the Monte Tronador glaciers at 4.8 ± 2 km3 with a mean ice thickness of 75 m. Comparison of our results with earlier regional and global assessments shows that the quality of glacier inventories is a significant source of discrepancy. We show that including surface slope as an input parameter increases the accuracy of ice thickness distribution estimates.
Heat-assisted magnetic recording (HAMR) is being developed as the next-generation magnetic recording technology. High anisotropy granular media such as FePt-C have been demonstrated as HAMR media for ∼2 Tbpsi (terabits per in2) recording density. In order for this technology to reach its full potential of 4–5 Tbpsi, more progress and innovations are needed for the key requirements for HAMR media, including microstructure, design, magnetic distribution, and thermal design. Beyond granular media, heated-dot magnetic recording (HDMR) is planned to extend areal density toward 10 Tbpsi. HDMR combines similar advanced recording layer materials with advanced patterning techniques to fabricate <10-nm rectangular dot media.
The present investigation focused on evaluating the effects of different amounts of precipitates on tension and hardness properties of a Ti–6Al–4V alloy, for this, two sets of samples with bimodal and equiaxed microstructures were obtained by heat treatment process. After this, the samples were aged at 545 °C for holding times of 100 and 200 h. Observation of the aged samples in the scanning electron microscope revealed fine α2 (Ti3Al) particles precipitating in the α matrix of the alloy. Uni-axial tension tests and Vickers microhardness measurements were conducted on the unaged and aged samples. Experimental results show that ultimate strength and hardness of bimodal and equiaxed microstructures are significantly affected by the heat treatment applied to produce such microstructures. Also, it was found that the precipitation of α2 particles drastically reduced the plastic response of the Ti–6Al–4V alloy.
To determine the effects of lipid-based nutrient supplements (LNS) on children’s Hb, linear growth and development, compared with supplementation with micronutrient powder (MNP).
The study was a two-arm parallel-group randomized controlled trial, where participants received either LNS or MNP for daily consumption during 6 months. Supplements were delivered by staff at government-run health centres. Hb, anthropometric, motor development, language development and problem-solving indicators were measured by trained research assistants when children were 12 months of age.
The study was conducted in five rural districts in the Province of Ambo in the Department of Huánuco, Peru.
We enrolled 6-month-old children (n 422) at nineteen health centres.
Children who received LNS had a higher mean Hb concentration and lower odds of anaemia than those who received MNP. No significant differences in height-for-age, weight-for-height or weight-for-age Z-score, or stunting and underweight prevalence, were observed. Provision of LNS was associated with a higher pre-verbal language (gestures) score, but such effect lost significance after adjustment for covariates. Children in the LNS group had higher problem-solving task scores and increased odds of achieving this cognitive task than children in the MNP group. No significant differences were observed on receptive language or gross motor development.
LNS between 6 and 12 months of age increased Hb concentration, reduced anaemia and improved cognitive development in children, but showed no effects on anthropometric indicators, motor or language development.
The susceptibility to glyphosate and genetic diversity based on intersimple sequence repeat markers were characterized for 17 tropical sprangletop populations collected from two separate regions mainly in Persian lime groves in Veracruz, Mexico. The whole-plant dose response together with shikimic acid assays indicated different levels of glyphosate resistance in those populations. Genetic diversity values (h) estimated using POPGENE ranged from 0.119 to 0.198 and 0.117 to 0.214 within susceptible and resistant populations, respectively. The average genetic diversity (HS) within the susceptible populations was 0.157, and the total genetic diversity (HT) was 0.218. The HS of the resistant populations was 0.144, and the HT was 0.186. The analysis of molecular variance based on the response to glyphosate indicated that most of the genetic variation was found within groups of susceptible and resistant populations (90% of the genetic variation), whereas 10% or less was among groups. The high level of genetic diversity between glyphosate-resistant tropical sprangletop populations from distant and adjacent locations is likely due to both short- and long-distance seed dispersal and independent evolutionary events in tropical sprangletop populations among Persian lime groves in Veracruz.
The lack of paleoecological records from the montane Atlantic Rainforest of coastal Brazil, a hotspot of biological diversity, has been a major obstacle to our understanding of the vegetational changes since the last glacial cycle. We present carbon isotope and pollen records to assess the impact of the glaciation on the native vegetation of the Serra do Mar rainforest in São Paulo, Brazil. From ca. 28,000 to ∼ 22,000 14C yr BP, a subtropical forest with conifer trees is indicative of cool and humid conditions. In agreement carbon isotopic data on soil organic matter suggest the presence of C3 plants and perhaps C4 plants from ∼ 28,000 to ∼ 19,000 14C yr BP. The significant increase in the sedimentation rate and algal spores from ∼ 19,450 to ∼ 19,000 14C yr BP indicates increasing humidity, associated to an erosion process between ∼ 19,000 and ∼ 15,600 14C yr BP. From ∼ 15,600 14C yr BP to present there is a substantial increase in arboreal elements and herbs, indicating more humid and warmer climate. From ∼ 19,000 to ∼ 1000 14C yr BP, δ13C values indicated the predominance of C3 plants. These results are in agreement with studies in speleothems of caves, which suggest humid conditions during the last glacial maximum.
In the present work nanostructures of manganese dioxide have been synthesized and characterized as potential catalysts for Li-air batteries. The R-MnO2 nanourchin-shaped catalyst was synthesized by mild hydrothermal conditions under autogeneous pressure. X-ray powder diffraction (XRD) was used to confirm the formation of single R-MnO2. The microstructure of the obtained nanostructures was investigated by scanning and transmission electron microscopy (SEM and TEM) showing the presence of acicular manganese oxide aggregates (5-10 nm wide) which tend to form spherical clusters, taking on an urchin-shaped form of roughly 6 microns diameter. The cyclability analyses reveal an enhanced performance and efficiency for the batteries with higher amounts of catalyst. This catalyst is thought to promote alternative reaction pathways in the Li2CO3 decomposition which attenuate the instability of the electrolyte and/or carbon electrode during the discharge resulting in an improved cyclability.
In Amazonian fisheries, the silver arowana, Osteoglossum
bicirrhosum (Cuvier 1829) is heavily exploited for human
consumption as an adult, and for the aquarium trade as a small juvenile
(yolk sac juvenile mainly). The periodicity of annuli formation
on otoliths and growth variability of the silver arowana were studied in
different river river-basins of the Peruvian Amazon between 2006
and 2009. Transverse stained sections of 606 individual otoliths
were analysed from four different river-basins, the Amazonas, Ucayali,
Napo and Putumayo, of which 554 could be interpreted. These belonged
to 274 females ranging from 15 to 91 cm (standard length) and 280
males ranging from 30 to 91 cm. In addition, yolk sac juveniles
of known age were collected to improve growth modelling. Monthly
proportions of stained otolith edges validated the formation of
a single annulus per year in two different river-basins with lagged
hydrological cycles: the Amazonas-Ucayali and the Putumayo. Stained
growth mark counts resulted in a longevity estimate of at least
16 years for the silver arowana in the Peruvian Amazon. This fish
grew quickly during the first two years, and asymptotic growth was
reached after four to five years, except in the Putumayo where it
was reached slightly earlier. Results showed no significant growth
dimorphism between sexes within basins, but indicated significant
growth differences among river basins. Silver arowanas measured,
on average, between 38 and 40 cm at the end of their first year.
Length-at-age differences among river basins increased with age
to reach over 14 cm (and >3 kg) after 7 years between the faster
and slower growing populations (Amazonas and Putumayo, respectively).
The growth differences observed emphasize the need for further investigation
on the population structure of this species as, although these differences
might merely be phenotypic responses to contrasted environmental
conditions, they could alternatively reflect the existence of several
populations with distinct genetic and life history characteristics.
The consequences of such differences would be very important for
the management and conservation of this fragile and extensively
A novel biopolymer derived from diallyl sucrose (A2S) and dithiotreitol (DTT) was prepared by means of Thiol-Ene Photopolymerization. A2S was prepared by alkylating the sucrose with allyl bromide, using water as solvent. After purification by column chromatography, a fraction (F2A2S) with 94% diallyl sucrose (A2S), 4 % of triallyl sucrose (A3S) and 2 % of monoallyl sucrose (A1S) was obtained. This fraction was subsequently photopolymerized with Dithiothreitol (DTT) which is a difunctional thiol. Kinetics of photopolymerization were determined by means of Real-Time Infrared spectroscopy. It was found that the photocurable formulation with DTT and F2A2S, polymerized rapidly in the presence and absence of a photoinitiator, at low intensities of UV light. After bulk polymerization, a flexible material with high elastic modulus and a Tg of 30 °C was obtained. Besides, the polymer displayed moderate water absorbance properties as a result of the presence of multiple hydroxyl groups. This property was pH dependent with maximum absorbance at pH=14. The polymer degraded rapidly under acidic conditions
We present a fully adaptive multiresolution scheme for spatially
one-dimensional quasilinear strongly degenerate parabolic equations
with zero-flux and periodic boundary conditions. The numerical scheme
is based on a finite volume discretization using the Engquist-Osher
numerical flux and explicit time stepping. An adaptive multiresolution
scheme based on cell averages is then used to speed up the CPU time and
the memory requirements of the underlying finite volume scheme, whose
first-order version is known to converge to an entropy solution of the
problem. A particular feature of the method is the storage of the
multiresolution representation of the solution in a graded tree, whose
leaves are the non-uniform finite volumes on which the numerical divergence
is eventually evaluated. Moreover using the L1 contraction of the discrete
time evolution operator we derive the optimal choice of the threshold in the
adaptive multiresolution method. Numerical examples illustrate the
computational efficiency together with the convergence properties.
The hypothesis that the unsaponifiable fraction of olive oil dramatically influences hepatic gene expression was tested in mice. Two olive oils, obtained from the same olive cultivar but by different technological procedures, were characterized to show that they differed mainly in terms of the composition/quantity of this unsaponifiable fraction. Using DNA microarrays, hepatic gene expression was analysed in apoE-deficient mice fed one of two isoenergetic, isonitrogenous diets containing either 10 % (w/w) olive oil or unsaponifiable fraction-enriched olive oil. To provide an initial screening of potential candidate genes involved in a differential response, only genes with remarkably modified expression (signal log2 ratio >3 or < − 3) were further considered. The eleven genes fulfilling these prerequisites were confirmed by quantitative RT–PCR, and then analysed in apoE-deficient mice with a C57BL/6J genetic background. Orosomucoid and serum amyloid A2 were upregulated (to variable extents depending on the genetic background) in the absence of hepatic steatosis and inflammation. Fabp5 and Mt2 were also strongly upregulated. Several proteases were highly suppressed by the unsaponifiable-enriched olive diet, independent of the genetic background. The findings indicate that change in the expression of these genes is a good marker of the intake of the unsaponifiable fraction of olive oil. The results highlight the important biological effects of the unsaponifiable fraction of olive oil. The term ‘monounsaturated fatty acid-enriched oil’ no longer appears appropriate for describing all the oils to which it is currently applied since it does not adequately reflect that they have different biological effects.
Pentacene thin films were grown in ultra high vacuum on amorphous SiO2 and on a high dielectric constant material, crystalline BaTiO3. During pentacene deposition, substrates were held at three different temperatures (-650, 250 and 750 C). In general, three different morphologies were identified: a first closed interfacial layer, a thin film mode composed of faceted grains with single molecule step height, and a volume mode with features substantially higher than those of the thin film mode. Analysis was carried out by atomic force microscopy and in some cases by synchrotron X-ray diffraction.
An ectopic functioning pituitary in the sphenoid is an extremely rare occurrence, and even rarer is pituitary adenoma causing symptoms of Nelson's syndrome. A case is presented of a young female diagnosed and treated in our clinic. The only functioning hypophyseal tissue was detected inside the sphenoid, as the pituitary gland had been radiated because of Cushing's syndrome 10 years before and imaging studies revealed an empty sella.