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In this work we tested the suitability of thermistor strings as automatic tools for the continuous measurement of glacier ice ablation. Experimental data collected in summer 2017 over an Italian glacier provided ice ablation readings with accuracy similar to manual measurements with ablation stakes and other automatic systems, like the draw-wire method and the Bøggild ablatometer. Thermistor strings have potential for future applications in remote glacier monitoring, thanks to their flexibility, simple construction, and robustness.
Environmental factors during perinatal life can lead to changes in the mammary gland, making it susceptible to cancer in adulthood. Breastfeeding has a special importance since it takes place at a critical period of growth and development of the newborn. We aimed to analyze if an appropriate lactation protects the offspring against mammary carcinogenesis during adult life and explore the mechanisms involved in the protective effect. One-day-old Sprague-Dawley female rats were randomly distributed in litters of three (L3), eight (L8) or 12 (L12) pups per dam, to induce a differential consumption of breast milk. At 55 days of age, the animals were treated with a single dose of dimethylbenzanthracene to study tumor latency, incidence and progression. Histological, immunohistochemical and Western blot studies were performed. We observed lower incidence and higher latency in L3 compared to the other groups. The mitotic index and expression of proliferating cell nuclear antigen (PCNA) was significantly augmented in tumors of L12 rats compared to L3 and L8, while the apoptotic index was augmented in tumors of L3 v. L12. Cleaved caspase 8 was significantly higher in tumors from L3 compared to L12. Tumors developed in L3 have a greater number of apoptotic bodies and a greater expression of caspase 8. These results demonstrate that the animals that maintained a higher intake of maternal milk (L3) presented lower incidence and greater tumor latency. Lower consumption of breast milk (L12) would increase tumor mitosis and the expression of PCNA, explaining the higher tumor incidence observed in this group.
Ortles mountain (3905 m a.s.l.), South Tyrol, Italy, is the highest mountain of the Eastern European Alps, and its upper glacier, Alto dell’Ortles, presents a unique opportunity to obtain the first paleoenvironmental record from an ice core in this area. To study the suitability of this glacier as a drilling site, in 2009 we performed the first preliminary study of its glaciological characteristics at ˜3830 m a.s.l. The maximum thickness is ˜75 m, and lamination of the exposed ice layers is excellent down to bedrock. Firn and ice lenses were observed in a 10 m shallow core, and the firn/ice transition was below ˜24m. The seasonal chemical signal is clearly preserved only within the uppermost 2008 and 2009 snow/firn. A simple mass-balance model, the incipient ‘smoothing’ of the chemical record, and the observed ice lenses provide evidence that melting, infiltration and refreezing cycles occurred within the firn layers formed before 2008. Nevertheless, the mass balance of the upper part of Alto dell’Ortles was positive (˜800mma_1) during the last few years. We suggest that an environmental history is likely to be well preserved only within the ice layers formed before ˜1980, when summer air temperature was ˜2°C colder than today in this area. Clearly the continued warming trend predicted to occur over the next few decades, and the consequent increase in frequency and/or intensity of infiltration processes, will endanger the preservation of the glacial archive conserved in the deep ice layers of Ortles mountain.
Two lacustrine sediment sequences, La Olla 1 and Laguna del Sauce Grande, on the southern coast of Buenos Aires Province, Argentina, were investigated for carbon reservoir effects, which may influence age-depth chronologies. Fruits of the submerged macrophyte Ruppia cf. maritima from the La Olla 1 sequence, and gastropod shells of Heleobia parchappii from the Laguna del Sauce Grande core, were radiocarbon dated. In addition, terrestrial plant remains and shells of living specimens were dated to assess the presence and magnitude of a reservoir effect. A reservoir age of about 800 14C yr is estimated for the aquatic plant samples of La Olla 1 for the early Holocene. The reservoir effect is attributed to the in wash of 14C-deficient bicarbonate from the surrounding sand dunes. The decay of marine organisms and salt spray are likely the main sources of 14C-deficient carbon. The magnitude of the reservoir effect is consistent with marine reservoir offsets reported for the region. The 14C measurements on shells of living and fossil specimens of Heleobia parchappii indicate the absence of a reservoir effect at Laguna del Sauce Grande, which may be due to the large size and shallow nature of the lake. This study shows how the reservoir ages of 2 close-by lakes in very similar geological settings can be largely different. These results have significant implications for the interpretation of 14C dates from lacustrine deposits in the region.
An unusually long-lasting community-acquired outbreak of Legionnaires’ disease (LD) occurred in the inhabitants of a town in northern Italy from 2005 to 2008. Overall, 43 cases were diagnosed including five deaths. Hundreds of water samples were collected for Legionella isolation but only two clinical samples were obtained. Clinical strains were ST23 as were environmental isolates detected in most Legionella-positive patients' homes and those from a public fountain. Although no Legionella was found in the municipal water mains, a continuous chlorination was applied in 2008. This action resulted in a halving of cases, although incidence remained tenfold higher than the Italian average incidence until the end of 2013, when it dropped to the expected rate. Retrospective analyses of prevalent wind direction suggested that a hidden cooling tower could have been the main cause of this uncommon outbreak, highlighting the importance of implementation of cooling tower registers in supporting LD investigations.
We present the synthesis and characterization of nanocrystalline II-VI semiconductors of mixed composition (CdSe/ZnSe, CdS) grown in fatty acid Langmuir-Schaefer multi-layer templates. The controlled production of i) homogeneous nanocrystalline CdxZn1−xSe alloys and ii) heterogeneous mixtures of different pure composition II-VI semiconductors such as CdSe and ZnSe provides, in addition to the size control, the parameter of the chemical composition for the fine tuning of the electronic properties. The samples are characterized bty optical and quasi-resonance micro-Raman spectroscopy.
The bombardment of ions and electrons at the substrate has been studied by
varying the magnetic field distribution and the grid-target distance in a
triode magnetron sputtering system. The substrate temperature was correlated
with the substrate current density and with the type of species bombarding
the substrate. The results indicate a possibility to modify and control the
bombardment at the substrate surface from predominantly electronic to
predominantly ionic, which increases the substrate temperature from 383 K to
473 K, respectively.
Cylindrical hollow cathode magnetron sputtering (HCMS) system was used to
deposit crystalline titanium dioxide thin films on p-Si (100) substrates.
For a fixed pressure of 0.6 Pa total gas flow rate of 20 sccm and power of
55 W, the influence of the oxygen percentage in the Ar+O2 gas mixture on
the structural and surface properties of the films was studied by
profilometry, XRD and AFM. The substrates were placed inside the hollow
cathode at different positions along its symmetrical axis. Numerical
simulations of cathode ion collection probability (CICP) were done in order
to compare calculated data with the deposition process characteristics. The
results indicate that the deposition rate and the surface roughness
gradually decrease with the distance from the bottom of the cathode, due to
the decrease of the CICP. The increase of the oxygen percentage in the gas
discharge influences directly the deposition rate and decrease the surface
roughness. The XRD analyses show that all the films are crystalline with
predominant anatase (101) and rutile (110) orientations.
This study evaluated the influence of cognitive reserve on
neuropsychological test performance in 198 patients infected with the
hepatitis C virus. IQ scores, educational level, and occupational rating
were combined to calculate a Cognitive Reserve Score (CRS) for each
patient. Similar to studies of infection with the human immunodeficiency
virus, there was a significantly increased risk of impairment in
neuropsychological test performance in individuals with lower CRSs. It is
important to account for CRS when assessing cognitive findings in
large-scale clinical trials. (JINS, 2007, 13,
687–692.)Financial relationships of
the authors with Hoffmann-La Roche, Inc., are as follows: K.L. Lindsay is
a consultant and receives research support; A.S.F. Lok is a consultant and
receives grant support; and R.J. Fontana is on the speaker's bureau.
Authors with no financial relationships related to this project are as
follows: L.A. Bieliauskas, C. Back-Madruga, E.C. Wright, and Z.
We study the stochastic folding kinetics of RNA
sequences into secondary structures with a new algorithm
based on the formation, dissociation, and the shifting
of individual base pairs. We discuss folding mechanisms
and the correlation between the barrier structure of the
conformational landscape and the folding kinetics for a
number of examples based on artificial and natural sequences,
including the influence of base modification in tRNAs.
Normal and tangential resistance coefficients are calculated for a rigid slender body close to a planar no-slip boundary or midway between and close to two such boundaries. The important length scale is found to be the separation distance from the boundaries, and the forces per unit length acting on the slender body are approximately constant along most of its length. Owing to the presence of the walls, the ratio of the normal and tangential resistance coefficients can be greater than 2, its maximum limiting value in the infinite-fluid case. Applications to the movements of flagellated micro-organisms are discussed.
A definition of historic sites archaeology as it applies in the New World is offered, and a five-fold classification of historic sites is proposed (protohistoric, contact, postcontact, frontier, and nonaboriginal). The usefulness of the concept of historic sites archaeology is discussed.
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