To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
The overall incidence of spinal tuberculosis (TB) appears to be stable or declining in most European countries, but with an increasing proportion of cases in the foreign-born populations. We performed a retrospective observational study (1993–2014), including all cases of spinal TB diagnosed at a Barcelona hospital to assess the epidemiological changes. Fifty-four episodes (48·1% males, median age 52 years) of spinal TB were diagnosed. The percentage of foreign-born residents with spinal TB increased from 14% to 45·2% in the last 10 years (P = 0·017). Positive Mycobacterium tuberculosis testing in vertebral specimens was 88·2% (15/17) for GeneXpert MTB/RIF. Compared with natives, foreign-born patients were younger (P < 0·01) and required surgery more often (P = 0·003) because of higher percentages of paravertebral abscess (P = 0·038), cord compression (P = 0·05), and persistent neurological sequelae (P = 0·05). In our setting, one-third of spinal TB cases occurred in non-native residents. Compared with natives, foreign-born patients were younger and had greater severity of the disease. The GeneXpert MTB/RIF test may be of value for diagnosing spinal TB.
Over the last few decades the number of radiocarbon dates available for West Central Africa has increased substantially, even though it is still meagre compared with other areas of the continent. In order to contribute to a better understanding of the Iron Age of this area we present and analyze a total of 22 radiocarbon dates obtained from sites from the island of Corisco (Equatorial Guinea). By comparing them with those from Equatorial Guinea, southern Cameroon, and coastal Gabon and Congo we intend to clarify the picture of the West Central African Iron Age and propose a more accurate archaeological sequence.
Mesolithic hunter-gatherer settlements generally leave ephemeral archaeological traces and are notoriously difficult to detect. Nowhere is this more so than on the northern coast of Spain, despite a long tradition of Mesolithic research. In this project, evidence of Mesolithic activity together with the geomorphological and topographical suitability of particular locations were used to select areas for large-scale geophysical survey. The results demonstrate the potential of the new methodology: magnetometry survey at El Alloru revealed the very first Asturian open-air settlement site to be discovered.
The objective of this study was to estimate the relationship between serum vitamin D (VitD) status and tuberculosis (TB) infection conversion (TBIC), measured by the tuberculin skin test (TST) and an interferon-gamma release assay, the QuantiFERON-TB Gold In-Tube (QFT-GIT) test, in the contacts of pulmonary TB patients in Castellon (Spain) in a prospective cohort study from 2010 to 2012. Initially, the participants were negative to latent TB infection after a screening that included TST and QFT-GIT tests, and other examinations. A baseline determination of 25-hydroxyvitamin D [25(OH)D] was obtained by chemiluminescence immunoassay. After 8–10 weeks, participants were screened for a second time to determine TB infection conversion (TBIC). Poisson regression models were used in the statistical analysis. Of the 247 participants in the cohort, 198 (80·2%) were screened twice and 18 (9·1%) were TBIC cases. The means of VitD concentration in the TBIC cases and the non-cases were 20·7±11·9 and 27·2±11·4 ng/ml (P = 0·028), respectively. Adjusted for high exposure and TB sputum acid-fast bacilli (AFB)-positive index case, higher serum VitD concentration was associated with low incidence of TBIC (Ptrend = 0·005), and an increase of 1 ng/ml VitD concentration decreased the incidence of TBIC by 6% (relative risk 0·94, 95% confidence interval 0·90–0·99, P = 0·015). The results suggest that sufficient VitD level could be a protective factor of TBIC.
Patagonia in southern South America is among the few world regions where direct human impact is still limited but progressively increasing, mainly represented by tourism, farming, fishing and mining activities. The sanitary condition of Patagonian wildlife is unknown, in spite of being critical for the assessment of anthropogenic effects there. The aim of this study was the characterization of Salmonella enterica strains isolated from wild colonies of Magellanic penguins (Spheniscus magellanicus) located in Magdalena Island and Otway Sound, in Chilean Patagonia. Eight isolates of Salmonella were found, belonging to Agona and Enteritidis serotypes, with an infection rate of 0·38%. Resistance to ampicillin, cefotaxime, ceftiofur and tetracycline antimicrobials were detected, and some of these strains showed genotypic similarity with Salmonella strains isolated from humans and gulls, suggesting inter-species transmission cycles and strengthening the role of penguins as sanitary sentinels in the Patagonian ecosystem.
Previous geochronological and archaeological studies on the rock shelter Jarama VI suggested a late survival of Neanderthals in central Iberia and the presence of lithic assemblages of Early Upper Paleolithic affinity. New data on granulometry, mineralogical composition, geochemical fingerprints and micromorphology of the sequence corroborate the previous notion that the archaeological units JVI.2.1 to JVI.2.3 are slackwater deposits of superfloods, which did not experience significant post-depositional changes, whereas the artifact-rich units JVI.3 and JVI.1 mainly received sediment inputs by sheetwash and cave spall. New AMS radiocarbon measurements on three samples of cut-marked bone using the ultrafiltration technique yielded ages close to, or beyond, the limit of radiocarbon dating at ca. 50 14C ka BP, and hence suggest much higher antiquity than assumed previously. Furthermore, elevated temperature post-IR IRSL luminescence measurements on K feldspars yielded burial ages for subunits JVI.2.2 and JVI.2.3 between 50 and 60 ka. Finally, our reappraisal of the stone industry strongly suggests that the whole sequence is of Mousterian affinity. In conclusion, Jarama VI most probably does not document a late survival of Neanderthals nor an Early Upper Paleolithic occupation in central Iberia, but rather indicates an occupation breakdown after the Middle Paleolithic.
Starting from a sketch of the s-process concept formulated 50 years ago, the nuclear physics data for s-process calculations are briefly reviewed with emphasis on the status of neutron capture cross sections and beta decay rates. Accurate and comprehensive experimental data are mandatory as direct input for s-process calculations as well as for improving the complementary information from nuclear theory. The current challenges of the field are discussed in the light of new or optimized methods and state-of-the-art facilities, indicating the potential for accurate measurements and the possibility to study cross sections of radioactive isotopes. These opportunities will be considerably enriched by the enormous improvements provided by new facilities.
In this work, we investigate the influence of surface roughness on the kinetics of Li+ during the insertion process in the well-known electrochromic material WO3. Thin films 500 Å thick have been grown by rf-sputtering and annealed in therange of 25-350ºC. Grazing angle X-ray reflectometry shows that the film roughnessincreases considerably with thermal treatment. These measurements are correlated with chemical diffusion investigations obtained by electrochemical titration in Li/WO3 cells.
Hevolution spectra were measured for hydrogenated Amorphous silicon (a-Si:H) films of varying thickness. A low temperature evolution peak at about 380 °C was determined to arise from a surface monolayer. The bulk limited main peak of the evolution spectrum arises from a very narrow range of binding energies (<0.2 eV). The evolution spectra of a-Si:H, hydrogenated polycrystalline Si, and c-Si containing platelet structures are virtually identical in both size and temperature of the various peaks. Less than 5% of the H is released in an evolution peak occurring at about 800 °C, a peak possibly due to H bound at isolated dangling bonds.
An efficient technique for determining the small-signal equivalent-circuit model of a Metal collector-up Heterojunction Bipolar Transistor (C-up MHBT) is presented. The technique employs analytically derived expressions for direct calculation of HBT T-Model equivalent circuit element values in terms of the measured S-parameters. This approach avoids errors due to uncertainty in fitting to large, over determined equivalent circuits and does not require the use of test structures and extra measurement steps to evaluate parasitics. Physically realistic results are demonstrated under various biasing conditions for the n-p-n InP/InGaAs HBT with metallic collector up structure. The agreement between the measured and model-produced data is excellent over the large frequency range and for several polarizations conditions for devices.
CASPER (Concordia Atmospheric SPectroscopy of Emitted Radiation)
is a spectrometer proposed for installation at Dome C, devoted to
measurements of atmospheric emission in the spectral region
between 180 μm and 3 mm (3–55 cm-1). This
instrument will be able to perform continuous spectral sampling at
different altitudes at angular scales of ~1°. From the
recorded data it is possible to extract atmospheric transmittance
within 1% in the whole wide operating band, together with water
vapour content and O2 and O3 concentrations. CASPER will
allow us to characterize the site for future FIR/mm telescopes.
Atmospheric data recorded by CASPER will allow for correction of
astrophysical and cosmological observations without the need for
telescope-specific procedures and further loss of observation time
with more precision in the observations themselves. Calibration of
ground-based telescopes on known sky sources is strongly affected
by atmospheric absorption. CASPER has this as its primary goal.
The spectrometer is based on a Martin-Puplett interferometer. Two
data sampling solutions will be performed: phase modulation &
fast scan strategy. Sky radiation is collected towards the
interferometer by an optical setup that allows the field of view,
to explore the full 0° ÷ 90° range of elevation angles. With
a low spurious polarization instrument, monitoring of polarized
atmospheric contribution will be possible.
Not long after the arrival of the Mendicant orders in New Spain, a view emerged among the friars that the subjection of the Mexican Indians to Spanish law might not be a goal as practical and desirable as the Crown expected, at least not for the immediate future. Franciscans, in particular, thought that the transfer and application of long-established legal principles to the Mexican Indians, such as the customary distinction of jurisdictions, could ultimately hurt rather than facilitate their full conversion to Christianity. For them, the administration of justice was but a natural extension of the enterprise of evangelization, a point that they made repeatedly in letters and reports throughout the sixteenth century.1 In part, their opposition to seeing the new converts subject to secular law stemmed from a general dissatisfaction with the state of legal affairs in the Peninsula, where an alarming increase in lawsuits and legal costs leading to the further consolidation of a class of letrados appeared to threaten the fabric of social life.
L134N is a cold, starless cloud, very high above the galactic plane,
close to us and well delineated in continuum dust emission maps. This
cloud is considered to be representative of oxygen rich dark clouds
(with the presence of SO, SO2, NO, ...). It is thus a good
reference together with TMC-1 to test astrochemical models. Thanks to
ISO, SCUBA and near IR wide field cameras, the detailed study of the
dust has become possible in such cold and dark clouds. In parallel,
progress in radiotelescope receiver sensitivity now allows to map weak
lines on large surfaces. We have thus started a project to study both
dust and a few gaseous key species (CO, CS, SO and N2H+) to
address several questions. We want to assess the quantity of dust and
gas all over the cloud, study possible C18O and/or C17O
depletion towards dense cores, evaluate the structure of the gas, the
abundance of CS and SO to possibly estimate the chemical age of the
cloud (time dependent models show that the CS/SO ratio diminishes with
time) and evaluate the rare isotope abundances, especially 17O
and 34S in a first step. To constrain the molecular abundances
with the highest possible confidence, we have observed several
transitions for each species and each isotopomer. Though we have
observed far less species than Dickens et al. , we
have done it on a larger area, including thus the strongest C18O
peak and two other peaks, with a better signal-to-noise ratio. Most of
the data are already acquired. We present here preliminary results.
A preliminary purification has been carried out by continuous elution electrophoresis of a 49.5 kDa protease of crude extracts from Dicrocoelium dendriticum eggs. The enzyme showed a high capacity to degrade the collagen derivative azocoll at acidic pH. Although it is necessary to carry out further experiments to confirm any physiological role, this protease could be implicated in penetration mechanisms.
A 24-kDa collagenase was localized in the Gymnorhynchus gigas plerocercoid immunohistochemically by peroxidase complex staining using polyclonal antibodies from NMRI mouse sera immunized with purified enzyme. Immunoreactivity was determined at different parts of the body (scolex, vesicle and caudal region) and mainly localized in microtriches and parenchymal tissues of the scolex and vesicle. These results, along with the absence of the enzyme in the plerocercoid excretion–secretion products, suggest that the 24-kDa collagenase is produced by parenchymal cells in the anterior region and transported to the outer regions of the worm It is possible that the enzyme plays an important role in degrading parasite tissues during the moulting process.
We show that if R is a ring such that each minimal left ideal is essential in a (direct) summand of RR, then the dual of each simple right R-module is simple if and only if R is semiperfect with Soc(RR)=Soc(RR) and Soc(Re) is simple and essential for every local idempotent e of R. We also show that R is left CS and right Kasch if and only if R is a semiperfect left continuous ring with Soc(RR)⊆eRR. As a particular case of both results we obtain that R is a ring such that every (essential) closure of a minimal left ideal is summand (R is then said to be left strongly min-CS) and the dual of each simple right R-module is simple if and only if R is a semiperfect left continuous ring with Soc(RR)=Soc(RR)⊆eRR. Moreover, in this case R is also left Kasch, Soc(eR)≠0 for every local idempotent e of R, and R admits a (Nakayama) permutation of a basic set of primitive idempotents. As a consequence of this result we characterise left PF rings in terms of simple modules over the 2×2 matrix ring by showing that R is left PF if and only if M2(R) is a left strongly min-CS ring such that the dual of every simple right module is simple.
Proteolytic activities of soluble and insoluble fractions of the free-living soil nematode Caenorhabditis elegans were measured across a range of substrates, temperatures and pH conditions. Several protease inhibitors were also tested under these conditions. Results of these studies indicate that proteolytic activity is present in cytosolic (CF) and non-cytosolic (NCF) fractions of C. elegans extracts at every condition of pH, temperature and buffer assayed. On the other hand, the use of different protease inhibitors demonstrated the existence of exo and endoproteases types in CF as well as NCF. Moreover our results show that the use of two protease inhibitor mixed types proposed by several authors are not enough to avoid this lytic activity when homogenates of this nematode are employed in biochemical assays.
Earlier analysis of the Italian population showed patterns of genetic
differentiation that were
interpreted as being the result of population settlements going back to
pre-Roman times. DNA
disease mutations may be a powerful tool in further testing this hypothesis
since the analysis of
diseased individuals can detect variants too rare to be resolved in normal
individuals. We present
data on the relative frequencies of 60 cystic fibrosis (CF) mutations in
Italy and the geographical
distribution of the 12 most frequent CF mutations screened in 3492 CF
chromosomes originating in
13 Italian regions. The 12 most frequent mutations characterize about 73%
of the Italian CF
chromosomes. The most common mutation, ΔF508, has an average frequency
51%, followed by
N1303K and G542X, both with average frequencies around 5%. Multivariate
analyses show that the
relative frequencies of CF mutations are heterogeneous among Italian regions,
and that this
heterogeneity is weakly correlated with the geographical pattern of non-DNA
markers. The northern regions are well differentiated from the central-southern
regions and within
the former group the western and eastern regions are remarkably distinct.
Moreover, Sardinia shows
the presence of mutation T338I, which seems absent in any other European
CF chromosome. The
north-western regions of Italy, characterized by the mutation 1717-1G→A,
under Celtic influence, while the north-east regions, characterized by
mutations R1162X, 2183AA→G and
7115G→A, were under the influence of the Venetic culture.