The who and the what of usage of two cancer online communities

The explosion of use of Internet-based communication for health requires attention to the ways survivors of specific diseases and those close to them participate in using resources. This research focuses on two cancer groups – breast and prostate – and how they use WebMD asynchronous bulletin boards. Four hundred and eighty two messages were coded for communicator (survivors, spouses, others) and content of messages. Most common communicators were survivors, but the two groups differed in percentages of communicator. Of four main categories of content – medical/treatment, intimacy/sexuality, emotional expression, and support – most common were support and medical/treatment. The groups differed significantly on those four categories, with breast cancer more support-dominated and prostate more medical/treatment-dominated and more intimacy/sexuality messages. There were no group differences in emotional-toned vs. social support seeking vs. providing support, or positive vs. negative emotions expressed. Generally, there was considerable commonality, and the differences found primarily supported gender-specific notions of communication and need.     

“Collapsible” lightweight aggregate concrete. Part II: characterization under static and dynamic loadings

In this work a granular cementitious composite has been developed, tailoring its performance to a low compressive strength and high deformation and energy dissipation capacity, which can be required to the material when employed in post-installed screeds for protection of structures and infrastructures against accidental actions such as impact and blast. The required level of performance can be achieved by uniform grain size distribution, paste content as low as minimum theoretical void ratio and low paste strength: it is believed that the synergy between the aforementioned three requirements can allow for energy dissipation capacity after paste cracking due to both rearrangement of grain meso-structure and, in case, grain crushing. After the mix design concept and optimization of the material composition, illustrated in the first part of this companion paper study, the mechanical performance of the composite under static and impact compressive loadings has been thoroughly characterized, as affected by mix-design variables, such as paste volume fraction, water to cement ratio and aggregate size. The reliability will thus be thoroughly checked, of the employed material concept, and the influence will also be investigated, if any, of specimen shape, size and boundary conditions.     

150km optical fibre transmission network experiment with 2Gbit/s throughput

Optical time-division multiplexing is considered for synchronous gigabit/s long-distance ransmission networks. Experimental results are presented for a 150 km fibre network of 2 Gbit/s capacity. The problem of differential fibre propagation delay variations is addressed with signal processing developed for the implementation of closed-loop feedback control.     

Influence of microcracking and homogeneity on the mechanical behaviour of (Al2O3 + ZrO2) ceramics

Quantitative methods for estimations of microcrack density and dispersion homogeneity give evidence of microcrack generation on macrofracture as the dominating mechanism responsible for toughening. The efficiency of energy dissipation at one microcrack density is higher in zirconia-toughened alumina than in pure Al₂O₃ ceramics. Deterioration of dispersion homogeneity results in the promotion of subcritical crack growth and low strength due to large flaw sizes at instability.     

Pessimistic cost-sensitive active learning of decision trees for profit maximizing targeting campaigns

In business applications such as direct marketing, decision-makers are required to choose the action which best maximizes a utility function. Cost-sensitive learning methods can help them achieve this goal. In this paper, we introduce Pessimistic Active Learning (PAL). PAL employs a novel pessimistic measure, which relies on confidence intervals and is used to balance the exploration/exploitation trade-off. In order to acquire an initial sample of labeled data, PAL applies orthogonal arrays of fractional factorial design. PAL was tested on ten datasets using a decision tree inducer. A comparison of these results to those of other methods indicates PAL’s superiority.     

Nonclinical model for assessing gastric effects of bisphosphonates

Mechanisms by which ketones potentiate manganese-bilirubin (Mn-BR)-induced cholestasis are unknown. The purpose of the present study was to investigate the effect of methyl isobutyl ketone (MiBK), a widely used ketonic solvent, at the level of the bile canalicular membrane (BCM) and to verify if altered membrane lipid dynamics could be involved in MiBK-potentiated Mn-BR cholestasis. Male Sprague-Dawley rats were exposed 4 hr/day for 3 days to MiBK vapors (200 or 600 ppm). Eighteen hours after the last exposure, manganese (Mn, 4.5 mg/kg) was given i.v. followed 15 min later by bilirubin (BR, 25 mg/kg). Rats were killed 30 min after BR; liver cell plasma membranes (bile canalicular and sinusoidal), microsomes, mitochondria, and cytosol were isolated by differential centrifugation. Lipids were extracted and cholesterol was measured in each fraction. After Mn-BR and MiBK exposure (600 ppm), results indicated a marked increase in BCM cholesterol content compared to rats exposed to air only. This increase was greater than that due to Mn-BR or MiBK given alone. Also, results indicated that cholesterol increased in a dose-related fashion in BCM after MiBK exposure, whereas PM cholesterol remained unaltered. To identify the source of the increased BCM cholesterol and to permit distinction between de novo cholesterol synthesis and subcellular shifts, the hepatic lipid pool was labeled in vivo with [3H]-cholesterol and [2-14C]-mevalonic acid, a cholesterol synthesis precursor. Results showed that after 600 ppm MiBK exposure, 14C-labeled cholesterol was greater than 3H-labeled cholesterol, indicating that the contribution of de novo cholesterol synthesis to the total cholesterol content of the various isolated hepatocellular fractions was more important than the contribution of intracellular pools. Therefore, increased BCM cholesterol content and enhanced accumulation of newly synthesized cholesterol appear to be involved in MiBK potentiation of Mn-BR-induced cholestasis.     

Solubility Limits of La and Y in Aluminum Oxynitride at 1870°C

The solubility limits of important dopants (La and Y) in aluminum oxynitride (AlON) were measured using wavelength-dispersive spectroscopy (WDS) mounted on a scanning electron microscope, from samples quickly cooled from 1870°C. To provide saturated AlON, samples were prepared with dopant concentrations well above the solubility limit, which was confirmed by the appearance of secondary phases using X-ray diffraction, backscattered electron micrographs, and WDS. Measurements were conducted on polished samples without thermal or chemical etching. The results indicate solubility limits of 498±82 and 1775±128 ppm for La and Y in AlON at 1870°C, respectively. The solubility limit of Mg in AlON at 1870°C was found to be >4000 ppm. The relation between solubility limit and cation size is briefly discussed.     

Determination of the oxidizing ability of HTSC materials containing two elements with a variable degree of oxidation

The presence of mixed valence states of elements is supposed to be a common characteristic feature of the high-T _c superconductors, based on copper oxides. Methods have been suggested for the determination of Cu(III) in the Y-Ba-Cu-O ceramics and separate determination of two oxidants: Bi(V) and Cu(III), Tl(III) and Cu(III) in the corresponding materials. Compounds of Bi(V) oxidize in the ions of Mn(II) to MnO ₄ ⁻ in the acidic medium. Active oxygen, bound to Cu(III) is isolated, not oxidizing Mn(II). MnO ₄ ⁻ is titrated then with a solution of Fe(II) sulphate. For the determination of Tl(III) the sample is dissolved in the acid, Cu(III) is reduced to Cu(II) and Tl(III) is titrated with the hydroquinone solution. The compounds of Bi(V), Tl(III) and Cu(III), having high oxidation-reduction potentials can oxidize the complex Co(II)-EDTA to Co(III)-EDTA. The colour intensity of the latter is proportional to the content of Cu(III) or to the sum of Bi(V) and Cu(III) or Tl(III) and Cu(III). The content of Cu(III) in Bi- and Tl-containing materials is determined by the difference.     

Decomposition of Fe5C2 catalyst particles in carbon nanofibers during TEM observation

The effect of an electron beam on nanoparticles of two Fe carbide catalysts inside a carbon nanofiber was investigated in a transmission electron microscope. Electron beam exposure does not result in significant changes for cementite (θ-Fe₃C). However, for Hägg carbide nanoparticles (χ-Fe₅C₂), explosive decay is observed after exposure for 5–10 s. This produces small particles of cementite and γ-Fe, each covered with a multilayer carbon shell, and significantly modifies the carbon-fiber structure. It is considered that the decomposition of Hägg carbide is mostly due to the damage induced by high-energy electron collisions with the crystal lattice, accompanied by the heating of the particle and by mechanical stress provided by the carbon layers of the nanofiber.