Experimental observation of moving intrinsic localized modes in germanium

Deep level transient spectroscopy shows that defects created by alpha irradiation of germanium are annealed by low energy plasma ions up to a depth of several thousand lattice units. The plasma ions have energies of 2-8eV and therefore can deliver energies of the order of a few eV to the germanium atoms. The most abundant defect is identified as the E-center, a complex of the dopant antimony and a vacancy with and annealing energy of 1.3eV as determined by our measurements. The inductively coupled plasma has a very low density and a very low flux of ions. This implies that the ion impacts are almost isolated both in time and at the surface of the semiconductor. We conclude that energy of the order of an eV is able to travel a large distance in germanium in a localized way and is delivered to the defects effectively. The most likely candidates are vibrational nonlinear wave packets known as intrinsic localized modes, which exist for a limited range of energies. This property is coherent with the fact that more energetic ions are less efficient at producing the annealing effect.Comment: 20 pages, 10 figure

Farmers’ spending on variable inputs tends to maximise crop yields, not profit

We estimate the marginal returns to spending on Crop Variable Inputs (CVI) (such as fertilizers and crop protection), to explore whether observed spending maximises physical or economic returns to farmers. Data are taken from the Farm Business Survey for 2004-2013, where gross margins and input spending are available, in over 10,300 crops of conventional winter wheat or oilseed rape in England and Wales. Marginal spending on CVIs generate financial returns significantly less than £1 per marginal pound spent. This suggests that expenditure on CVIs exceeds an economic optimum that would maximise profit. However marginal physical products (crop yields) are positive, but small and significantly different from zero. This suggests that, on average, farmers approximately maximise yields. These results hold across a wide range of alternative economic models and two crop species. Similar results have been reported in estimations for Indian grain production and for maize in China. In practice, farmers are making decisions on input use in advance of having information on a variety of factors, including future yield, product quality and price, making it difficult to optimise input levels according to expected profit. Farmers may be consistently optimistic, prefer to avoid risk, or deliberately seek to maximise yields. Some farmers may put on the standard recommended application irrespective of input or expected output price. It is also possible that advice may sometimes aim to maximise yield, influenced by an incentive to encourage greater sales. Excessive input use both reduces private profits and is a cause of environmental damage. There are thus potential private as well as social benefits to be gained from optimising levels of input use

Adaptive Resonance Theory (ART) for social media analytics

This chapter presents the ART-based clustering algorithms for social media analytics in detail. Sections 3.1 and 3.2 introduce Fuzzy ART and its clustering mechanisms, respectively, which provides a deep understanding of the base model that is used and extended for handling the social media clustering challenges. Important concepts such as vigilance region (VR) and its properties are explained and proven. Subsequently, Sects. 3.3-3.7 illustrate five types of ART adaptive resonance theory variants, each of which addresses the challenges in one social media analytical scenario, including automated parameter adaptation, user preference incorporation, short text clustering, heterogeneous data co-clustering and online streaming data indexing. The content of this chapter is several prior studies, including Probabilistic ART [15

Regulation of Anthrax Toxin-Specific Antibody Titers by Natural Killer T Cell-Derived IL-4 and IFNγ

Activation of Natural Killer-like T cells (NKT) with the CD1d ligand α-GC leads to enhanced production of anthrax toxin protective Ag (PA)-neutralizing Abs, yet the underlying mechanism for this adjuvant effect is not known. In the current study we examined the role of Th1 and Th2 type responses in NKT-mediated enhancement of antibody responses to PA. First, the contribution of IL-4 and IFNγ to the production of PA-specific toxin-neutralizing Abs was examined. By immunizing C57Bl/6 controls IL-4−/− mice and IFNγ−/− mice and performing passive serum transfer experiments, it was observed that sera containing PA-specific IgG1, IgG2b and IgG2c neutralized toxin in vitro and conferred protection in vivo. Sera containing IgG2b and IgG2c neutralized toxin in vitro but were not sufficient for protection in vivo. Sera containing IgG1 and IgG2b neutralized toxin in vitro and conferred protection in vivo. IgG1 therefore emerged as a good correlate of protection. Next, C57Bl/6 mice were immunized with PA alone or PA plus a Th2-skewing α-GC derivative known as OCH. Neutralizing PA-specific IgG1 responses were modestly enhanced by OCH in C57Bl/6 mice. Conversely, IgG2b and IgG2c were considerably enhanced in PA/OCH-immunized IL-4−/− mice but did not confer protection. Finally, bone marrow chimeras were generated such that NKT cells were unable to express IL-4 or IFNγ. NKT-derived IL-4 was required for OCH-enhanced primary IgG1 responses but not recall responses. NKT-derived IL-4 and IFNγ also influenced primary and recall IgG2b and IgG2c titers. These data suggest targeted skewing of the Th2 response by α-GC derivatives can be exploited to optimize anthrax vaccination

Cytotoxic and antibacterial activities of endophytic fungi isolated from plants at the National Park, Pahang, Malaysia

<p>Abstract</p> <p>Background</p> <p>Endophytes, microorganisms which reside in plant tissues, have potential in producing novel metabolites for exploitation in medicine. Cytotoxic and antibacterial activities of a total of 300 endophytic fungi were investigated.</p> <p>Methods</p> <p>Endophytic fungi were isolated from various parts of 43 plants from the National Park Pahang, Malaysia. Extracts from solid state culture were tested for cytotoxicity against a number of cancer cell lines using the MTT assay. Antibacterial activity was determined using the disc diffusion method.</p> <p>Results</p> <p>A total of 300 endophytes were isolated from various parts of plants from the National Park, Pahang. 3.3% of extracts showed potent (IC₅₀< 0.01 μg/ml) cytotoxic activity against the murine leukemic P388 cell line and 1.7% against a human chronic myeloid leukemic cell line K562. <it>Sporothrix </it>sp. (KK29FL1) isolated from <it>Costus speciosus </it>showed strong cytotoxicity against colorectal carcinoma (HCT116) and human breast adenocarcinoma (MCF7) cell lines with IC₅₀values of 0.05 μg/ml and 0.02 μg/ml, respectively. Antibacterial activity was demonstrated for 8% of the extracts.</p> <p>Conclusion</p> <p>Results indicate the potential for production of bioactive agents from endophytes of the tropical rainforest flora.</p

Oral hygiene improvement: a pragmatic approach based upon risk and motivation levels

Good oral hygiene has always been the cornerstone of public and private dental health promotion. However, this has often been based upon incorrect assumptions. The public is not always willing and does not always need to change its oral health behavior to the same extent as that expected by the dental profession. The present commentary emphasizes the need to modify oral hygiene instruction according to specific risk and motivation levels. Dentistry needs to be flexible in accepting new evidence-based modalities of oral health promotion. Dentists, dental hygienists and the entire health care team need to accept that the traditional methods of oral health education are not always effective

A Revised Design for Microarray Experiments to Account for Experimental Noise and Uncertainty of Probe Response

Background Although microarrays are analysis tools in biomedical research, they are known to yield noisy output that usually requires experimental confirmation. To tackle this problem, many studies have developed rules for optimizing probe design and devised complex statistical tools to analyze the output. However, less emphasis has been placed on systematically identifying the noise component as part of the experimental procedure. One source of noise is the variance in probe binding, which can be assessed by replicating array probes. The second source is poor probe performance, which can be assessed by calibrating the array based on a dilution series of target molecules. Using model experiments for copy number variation and gene expression measurements, we investigate here a revised design for microarray experiments that addresses both of these sources of variance. Results Two custom arrays were used to evaluate the revised design: one based on 25 mer probes from an Affymetrix design and the other based on 60 mer probes from an Agilent design. To assess experimental variance in probe binding, all probes were replicated ten times. To assess probe performance, the probes were calibrated using a dilution series of target molecules and the signal response was fitted to an adsorption model. We found that significant variance of the signal could be controlled by averaging across probes and removing probes that are nonresponsive or poorly responsive in the calibration experiment. Taking this into account, one can obtain a more reliable signal with the added option of obtaining absolute rather than relative measurements. Conclusion The assessment of technical variance within the experiments, combined with the calibration of probes allows to remove poorly responding probes and yields more reliable signals for the remaining ones. Once an array is properly calibrated, absolute quantification of signals becomes straight forward, alleviating the need for normalization and reference hybridizations

Prevalence of Coxielle Burnetii anbitodies in Danish Dairy herds

<p>Abstract</p> <p>During recent years in Denmark higher rates of antibodies to <it>Coxiella burnetii </it>have been detected in animals and humans than previously reported. A study based on bulk tank milk samples from 100 randomly selected dairy herds was performed to estimate the prevalence and geographical distribution of antibody positive dairy herds. Using the CHEKIT Q-Fever Antibody ELISA Test Kit (IDEXX), the study demonstrated a prevalence of 59% antibody positive herds, 11% antibody intermediate herds and 30% antibody negative herds based on the instructions provided by the manufacturer. The geographical distribution does not indicate a relationship between the regional density of dairy farms and the prevalence of antibody positive dairy farms. The result supports the hypothesis of an increase in the prevalence of positive dairy herds compared to previous years.</p

Transforming growth factor-beta and mutant p53 conspire to induce metastasis by antagonizing p63: a (ternary) complex affair

How and when a tumor acquires metastatic properties remain largely unknown. Recent work has uncovered an intricate new mechanism through which transforming growth factor-beta (TGFβ) acts in concert with oncogenic Ras to antagonize p63-metastasis protective function. p63 inhibition requires the combined action of Ras-activated mutant p53 and TGFβ-induced Smads. Mechanistically, it involves the formation of a p63-Smads-mutant p53 ternary complex. Remarkably, just two of the key downstream targets of p63 turn out to be sufficient as a prognostic tool for breast cancer metastasis. Moreover, the molecular mechanism of this inhibition points to novel therapeutic possibilities