Deformation of canonical morphisms and the moduli of surfaces of general type

In this article we study the deformation of finite maps and show how to use this deformation theory to construct varieties with given invariants in a projective space. Among other things, we prove a criterion that determines when a finite map can be deformed to a one--to--one map. We use this criterion to construct new simple canonical surfaces with different $c_1^2$ and $\chi$. Our general results enable us to describe some new components of the moduli of surfaces of general type. We also find infinitely many moduli spaces $\mathcal M_{(x',0,y)}$ having one component whose general point corresponds to a canonically embedded surface and another component whose general point corresponds to a surface whose canonical map is a degree 2 morphism.Comment: 32 pages. Final version with some simplifications and clarifications in the exposition. To appear in Invent. Math. (the final publication is available at springerlink.com

Quantum cryptography using balanced homodyne detection

We report an experimental quantum key distribution that utilizes balanced homodyne detection, instead of photon counting, to detect weak pulses of coherent light. Although our scheme inherently has a finite error rate, it allows high-efficiency detection and quantum state measurement of the transmitted light using only conventional devices at room temperature. When the average photon number was 0.1, an error rate of 0.08 and "effective" quantum efficiency of 0.76 were obtained.Comment: Errors in the sentence citing ref.[20] are correcte

Complementary and alternative medicine use among women at increased genetic risk of breast and ovarian cancer

<p>Abstract</p> <p>Background</p> <p>Complementary and alternative medicine (CAM) use is well documented among breast cancer patients and survivors, but little evidence is available to describe rates and patterns of use among women at increased genetic risk of breast cancer.</p> <p>Methods</p> <p>A pre-visit telephone interview was conducted to ascertain CAM use among the <it>BRCA </it>mutation carriers enrolled in a high-risk breast cancer screening study. Participants were asked to report on their use of thirteen therapies within the year prior to enrollment into the study. Logistic regression was used to evaluate the association between various factors and CAM use in this population.</p> <p>Results</p> <p>Among the 164 <it>BRCA1 </it>or <it>BRCA2 </it>mutation-positive (<it>BRCA</it>+) women in this analysis, 78% reported CAM use, with prayer and lifestyle diet being the two most commonly reported modalities. Many subjects used multiple CAM therapies, with 34% reporting use of three or more modalities. The most commonly used modalities were mind-body therapies and biologically-based practices, 61.6% and 51.8%, respectively. High-risk women were more likely to use CAM if they were older, more educated, more worried about ovarian cancer risk, or had a previous cancer diagnosis.</p> <p>Conclusion</p> <p>This study suggests that the prevalence of CAM use is high among <it>BRCA </it>mutation carriers, with frequency of use comparable to that of breast cancer patients and survivors. Given the high prevalence of CAM use in our subjects, especially biologically-based therapies including herbal supplements, whose safety and efficacy in relation to cancer risk are unknown, our study suggests that future research is necessary to clarify these risks, and that it is important for providers to inquire about and to discuss the pros and cons of CAM use with their <it>BRCA+ </it>patients.</p

Subendocardial contractile impairment in chronic ischemic myocardium: assessment by strain analysis of 3T tagged CMR

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to quantify myocardial strain on the subendocardial and epicardial layers of the left ventricle (LV) using tagged cardiovascular magnetic resonance (CMR) and to investigate the transmural degree of contractile impairment in the chronic ischemic myocardium.</p> <p>Methods</p> <p>3T tagged CMR was performed at rest in 12 patients with severe coronary artery disease who had been scheduled for coronary artery bypass grafting. Circumferential strain (C-strain) at end-systole on subendocardial and epicardial layers was measured using the short-axis tagged images of the LV and available software (Intag; Osirix). The myocardial segment was divided into stenotic and non-stenotic segments by invasive coronary angiography, and ischemic and non-ischemic segments by stress myocardial perfusion scintigraphy. The difference in C-strain between the two groups was analyzed using the Mann-Whitney U-test. The diagnostic capability of C-strain was analyzed using receiver operating characteristics analysis.</p> <p>Results</p> <p>The absolute subendocardial C-strain was significantly lower for stenotic (-7.5 ± 12.6%) than non-stenotic segment (-18.8 ± 10.2%, p < 0.0001). There was no difference in epicardial C-strain between the two groups. Use of cutoff thresholds for subendocardial C-strain differentiated stenotic segments from non-stenotic segments with a sensitivity of 77%, a specificity of 70%, and areas under the curve (AUC) of 0.76. The absolute subendocardial C-strain was significantly lower for ischemic (-6.7 ± 13.1%) than non-ischemic segments (-21.6 ± 7.0%, p < 0.0001). The absolute epicardial C-strain was also significantly lower for ischemic (-5.1 ± 7.8%) than non-ischemic segments (-9.6 ± 9.1%, p < 0.05). Use of cutoff thresholds for subendocardial C-strain differentiated ischemic segments from non-ischemic segments with sensitivities of 86%, specificities of 84%, and AUC of 0.86.</p> <p>Conclusions</p> <p>Analysis of tagged CMR can non-invasively demonstrate predominant impairment of subendocardial strain in the chronic ischemic myocardium at rest.</p

First experimental determination of the radiative-decay probability of the 31− state in ¹²C for estimating the triple alpha reaction rate in high temperature environments

The triple alpha reaction is one of the most important reactions in the nuclear astrophysics. However, its reaction rate in high temperature environments at T₉>2 was still uncertain. One of the major origins of the uncertainty was that the radiative-decay probability of the 3⁻₁ state in ¹²C was unknown. In the present work, we have determined the radiative-decay probability of the 3⁻₁ state to be 1.3[+1.2][-1.1] × 10⁻⁶ by measuring the ¹H(¹²C, ¹²Cp) reaction for the first time, and derived the triple alpha reaction rate in high temperature environments from the measured radiative-decay probability. The present result suggests that the 3⁻₁ state noticeably enhances the triple alpha reaction rate although the contribution from the 3⁻₁ state had been assumed to be small

A genomic biomarker signature can predict skin sensitizers using a cell-based in vitro alternative to animal tests

<p>Abstract</p> <p>Background</p> <p>Allergic contact dermatitis is an inflammatory skin disease that affects a significant proportion of the population. This disease is caused by an adverse immune response towards chemical haptens, and leads to a substantial economic burden for society. Current test of sensitizing chemicals rely on animal experimentation. New legislations on the registration and use of chemicals within pharmaceutical and cosmetic industries have stimulated significant research efforts to develop alternative, human cell-based assays for the prediction of sensitization. The aim is to replace animal experiments with in vitro tests displaying a higher predictive power.</p> <p>Results</p> <p>We have developed a novel cell-based assay for the prediction of sensitizing chemicals. By analyzing the transcriptome of the human cell line MUTZ-3 after 24 h stimulation, using 20 different sensitizing chemicals, 20 non-sensitizing chemicals and vehicle controls, we have identified a biomarker signature of 200 genes with potent discriminatory ability. Using a Support Vector Machine for supervised classification, the prediction performance of the assay revealed an area under the ROC curve of 0.98. In addition, categorizing the chemicals according to the LLNA assay, this gene signature could also predict sensitizing potency. The identified markers are involved in biological pathways with immunological relevant functions, which can shed light on the process of human sensitization.</p> <p>Conclusions</p> <p>A gene signature predicting sensitization, using a human cell line in vitro, has been identified. This simple and robust cell-based assay has the potential to completely replace or drastically reduce the utilization of test systems based on experimental animals. Being based on human biology, the assay is proposed to be more accurate for predicting sensitization in humans, than the traditional animal-based tests.</p

Potential health risks of complementary alternative medicines in cancer patients

Many cancer patients use complementary alternative medicines (CAMs) but may not be aware of the potential risks. There are no studies quantifying such risks, but there is some evidence of patient risk from case reports in the literature. A cross-sectional survey of patients attending the outpatient department at a specialist cancer centre was carried out to establish a pattern of herbal remedy or supplement use and to identify potential adverse side effects or drug interactions with conventional medicines. If potential risks were identified, a health warning was issued by a pharmacist. A total of 318 patients participated in the study. Of these, 164 (51.6%) took CAMs, and 133 different combinations were recorded. Of these, 10.4% only took herbal remedies, 42.1% only supplements and 47.6% a combination of both. In all, 18 (11.0%) reported supplements in higher than recommended doses. Health warnings were issued to 20 (12.2%) patients. Most warnings concerned echinacea in patients with lymphoma. Further warnings were issued for cod liver/fish oil, evening primrose oil, gingko, garlic, ginseng, kava kava and beta-carotene. In conclusion, medical practitioners need to be able to identify the potential risks of CAMs. Equally, patients should be encouraged to disclose their use. Also, more research is needed to quantify the actual health risks

The Role of the Frank–Starling Law in the Transduction of Cellular Work to Whole Organ Pump Function: A Computational Modeling Analysis

We have developed a multi-scale biophysical electromechanics model of the rat left ventricle at room temperature. This model has been applied to investigate the relative roles of cellular scale length dependent regulators of tension generation on the transduction of work from the cell to whole organ pump function. Specifically, the role of the length dependent Ca2+ sensitivity of tension (Ca50), filament overlap tension dependence, velocity dependence of tension, and tension dependent binding of Ca2+ to Troponin C on metrics of efficient transduction of work and stress and strain homogeneity were predicted by performing simulations in the absence of each of these feedback mechanisms. The length dependent Ca50 and the filament overlap, which make up the Frank-Starling Law, were found to be the two dominant regulators of the efficient transduction of work. Analyzing the fiber velocity field in the absence of the Frank-Starling mechanisms showed that the decreased efficiency in the transduction of work in the absence of filament overlap effects was caused by increased post systolic shortening, whereas the decreased efficiency in the absence of length dependent Ca50 was caused by an inversion in the regional distribution of strain

Distinct Roles of ComK1 and ComK2 in Gene Regulation in Bacillus cereus

The B. subtilis transcriptional factor ComK regulates a set of genes coding for DNA uptake from the environment and for its integration into the genome. In previous work we showed that Bacillus cereus expressing the B. subtilis ComK protein is able to take up DNA and integrate it into its own genome. To extend our knowledge on the effect of B. subtilis ComK overexpression in B. cereus we first determined which genes are significantly altered. Transcriptome analysis showed that only part of the competence gene cluster is significantly upregulated. Two ComK homologues can be identified in B. cereus that differ in their respective homologies to other ComK proteins. ComK1 is most similar, while ComK2 lacks the C-terminal region previously shown to be important for transcription activation by B. subtilis ComK. comK1 and comK2 overexpression and deletion studies using transcriptomics techniques showed that ComK1 enhances and ComK2 decreases expression of the comG operon, when B. subtilis ComK was overexpressed simultaneously