Noncommutative Particles in Curved Spaces

We present a formulation in a curved background of noncommutative mechanics, where the object of noncommutativity $\theta^{\mu\nu}$ is considered as an independent quantity having a canonical conjugate momentum. We introduced a noncommutative first-order action in D=10 curved spacetime and the covariant equations of motions were computed. This model, invariant under diffeomorphism, generalizes recent relativistic results.Comment: 1+15 pages. Latex. New comments and results adde

The Meaning of Memory Safety

We give a rigorous characterization of what it means for a programming language to be memory safe, capturing the intuition that memory safety supports local reasoning about state. We formalize this principle in two ways. First, we show how a small memory-safe language validates a noninterference property: a program can neither affect nor be affected by unreachable parts of the state. Second, we extend separation logic, a proof system for heap-manipulating programs, with a memory-safe variant of its frame rule. The new rule is stronger because it applies even when parts of the program are buggy or malicious, but also weaker because it demands a stricter form of separation between parts of the program state. We also consider a number of pragmatically motivated variations on memory safety and the reasoning principles they support. As an application of our characterization, we evaluate the security of a previously proposed dynamic monitor for memory safety of heap-allocated data.Comment: POST'18 final versio

Behavioural responses in a congested sea: an observational study on a coastal nest-guarding fish

The deleterious effects of anthropogenic noise on animal communication are nowadays recognised, not only in urban environments but also in terrestrial habitats and along coasts and in open waters. Yet, the assessment of short- and long-term exposure consequences of anthropogenic noise in marine organisms remains challenging, especially in fish and invertebrates. Males of the Mediterranean damselfish Chromis chromis vocalise and perform visual displays (multimodal communication) to attract mates. The frequency-range of courtship vocalisations overlaps with low-frequency noise generated by maritime activities, resulting in a reduced detection distance among conspecifics. We quantified the number of courtship-related visual displays performed by males living in areas with different levels of maritime traffic. We also tried to manipulate ambient noise in the field to test male short-term response to increased noise levels. Males living in busier areas (near to a harbour) performed significantly more visual displays than those living in less congested areas. When exposed to artificially-increased ambient noise level (playback of boat noise), males did not adjust the number of visual displays accordingly. Yet, we note how assessing the actual effect of maritime traffic in marine populations in their natural environments is particularly difficult, as the effects of boat noise cannot be easily disentangled from a variety of other intrinsic or environmental factors, discussed in the paper. We thus present suggestions to obtain more robust analyses of variations of courtship behaviours in territorial fishes. We hope this will facilitate a further understanding of the potential long-term effects of anthropogenic noise, whose analyses should be prioritised in the context of environmental impact assessment, resource management and biodiversity conservation

Effects of the functional HOTAIR rs920778 and rs12826786 genetic variants in glioma susceptibility and patient prognosis

Abnormal expression of the long non-coding RNA HOX transcript antisense intergenic RNA (HOTAIR) is oncogenic in several human cancers, including gliomas. The HOTAIR single nucleotide polymorphisms (SNPs) rs920778 (C > T) and rs12826786 (C > T) present in the intronic enhancer and promoter regions of HOTAIR, respectively, are associated with expression, cancer susceptibility, and patient prognosis in some tumor types. However, the relevance of these HOTAIR SNPs has not been studied in glioma. Here, we report a case-control study comprising 177 Portuguese glioma patients and 199 cancer-free controls. All subjects were genotyped by PCR and restriction fragment length polymorphism (RFLP). No statistically significant differences were found in the genotype or allele distributions of either rs920778 or rs12826786 between glioma patients and controls, suggesting these SNPs are not associated with glioma risk. No significant associations were found between rs920778 variants and HOTAIR expression levels, while rs12826786 CT genotype was associated with increased intratumoral HOTAIR RNA levels when compared to TT genotype (p-value = 0.04). Univariate (Log-rank) and multivariate (Cox proportional) analyses showed both rs920778 CT and rs12826786 CT genotypes were significantly associated with longer overall survival of WHO grade III anaplastic oligodendroglioma patients. Our results suggest that HOTAIR SNPs rs920778 and rs12826786 do not play a significant role in glioma susceptibility, but may be important prognostic factors in anaplastic oligodendroglioma patients. Future studies are warranted to validate and expand these findings, and to further dissect the importance of these SNPs in glioma.info:eu-repo/semantics/publishedVersio

Towards a tensionless string field theory for the N=(2,0) CFT in d=6

We describe progress in using the field theory of tensionless strings to arrive at a Lagrangian for the six-dimensional $\mathcal N=(2,0)$ conformal theory. We construct the free part of the theory and propose an ansatz for the cubic vertex in light-cone superspace. By requiring closure of the $(2,0)$ supersymmetry algebra, we fix the cubic vertex up to two parameters.Comment: 46 pages, 2 figures. V2: references added; minor changes and improvement

Comparison of diurnal variations, gestational age and gender related differences in fetal heart rate (FHR) parameters between appropriate-for-gestational-age (AGA) and small-for-gestational-age (SGA) fetuses in the home environment

Objective To assess the influence of gender, time of the day and gestational age on fetal heart rate (FHR) parameters between appropriate-for-gestational-age (AGA) and small-for-gestational age (SGA) fetuses using a portable fetal ECG monitor employed in the home setting. Methods We analysed and compared the antenatal FHR data collected in the home setting on 61 healthy pregnant women with singleton pregnancies from 24 weeks gestation. Of the 61 women, 31 had SGA fetuses (estimated fetal weight below the tenth gestational centile) and 30 were pregnant with AGA fetuses. FHR recordings were collected for up to 20 h. Two 90 min intervals were deliberately chosen retrospectively with respect to signal recording quality, one during day-time and one at night-time for comparison. Results Overall, success rate of the fetal abdominal ECG in the AGA fetuses was 75.7% compared to 48.6% in the SGA group. Based on randomly selected episodes of heart rate traces where recording quality exceeded 80% we were able to show a marginal difference between day and night-time recordings in AGA vs. SGA fetuses beyond 32 weeks of gestation. A selection bias in terms of covering different representation periods of fetal behavioural states cannot be excluded. In contrast to previous studies, we neither controlled maternal diet and activity nor measured maternal blood hormone and heart rate as all mothers were monitored in the home environment. Conclusion Based on clinically unremarkable, but statistically significant differences in the FHR parameters between the AGA and SGA group we suggest that further studies with large sample size are required to assess the clinical value of antenatal fetal ECG monitoring

The African Cichlid Fish Astatotilapia burtoni Uses Acoustic Communication for Reproduction: Sound Production, Hearing, and Behavioral Significance

Sexual reproduction in all animals depends on effective communication between signalers and receivers. Many fish species, especially the African cichlids, are well known for their bright coloration and the importance of visual signaling during courtship and mate choice, but little is known about what role acoustic communication plays during mating and how it contributes to sexual selection in this phenotypically diverse group of vertebrates. Here we examined acoustic communication during reproduction in the social cichlid fish, Astatotilapia burtoni. We characterized the sounds and associated behaviors produced by dominant males during courtship, tested for differences in hearing ability associated with female reproductive state and male social status, and then tested the hypothesis that female mate preference is influenced by male sound production. We show that dominant males produce intentional courtship sounds in close proximity to females, and that sounds are spectrally similar to their hearing abilities. Females were 2–5-fold more sensitive to low frequency sounds in the spectral range of male courtship sounds when they were sexually-receptive compared to during the mouthbrooding parental phase. Hearing thresholds were also negatively correlated with circulating sex-steroid levels in females but positively correlated in males, suggesting a potential role for steroids in reproductive-state auditory plasticity. Behavioral experiments showed that receptive females preferred to affiliate with males that were associated with playback of courtship sounds compared to noise controls, indicating that acoustic information is likely important for female mate choice. These data show for the first time in a Tanganyikan cichlid that acoustic communication is important during reproduction as part of a multimodal signaling repertoire, and that perception of auditory information changes depending on the animal's internal physiological state. Our results highlight the importance of examining non-visual sensory modalities as potential substrates for sexual selection contributing to the incredible phenotypic diversity of African cichlid fishes