991 research outputs found
Expansão potencial da cultura do sorgo granífero no Brasil considerando o zoneamento de risco climático.
Semiclassical approach to black hole absorption of electromagnetic radiation emitted by a rotating charge
We consider an electric charge, minimally coupled to the Maxwell field,
rotating around a Schwarzschild black hole. We investigate how much of the
radiation emitted from the swirling charge is absorbed by the black hole and
show that most of the photons escape to infinity. For this purpose we use the
Gupta-Bleuler quantization of the electromagnetic field in the modified Feynman
gauge developed in the context of quantum field theory in Schwarzschild
spacetime. We obtain that the two photon polarizations contribute quite
differently to the emitted power. In addition, we discuss the accurateness of
the results obtained in a full general relativistic approach in comparison with
the ones obtained when the electric charge is assumed to be orbiting a massive
object due to a Newtonian force.Comment: 8 pages (revtex), 8 figure
Verifying Quantitative Reliability of Programs That Execute on Unreliable Hardware
Emerging high-performance architectures are anticipated to contain unreliable components that may exhibit soft errors, which silently corrupt the results of computations. Full detection and recovery from soft errors is challenging, expensive, and, for some applications, unnecessary. For example, approximate computing applications (such as multimedia processing, machine learning, and big data analytics) can often naturally tolerate soft errors. In this paper we present Rely, a programming language that enables developers to reason about the quantitative reliability of an application -- namely, the probability that it produces the correct result when executed on unreliable hardware. Rely allows developers to specify the reliability requirements for each value that a function produces. We present a static quantitative reliability analysis that verifies quantitative requirements on the reliability of an application, enabling a developer to perform sound and verified reliability engineering. The analysis takes a Rely program with a reliability specification and a hardware specification, that characterizes the reliability of the underlying hardware components, and verifies that the program satisfies its reliability specification when executed on the underlying unreliable hardware platform. We demonstrate the application of quantitative reliability analysis on six computations implemented in Rely.This research was supported in part by the National Science Foundation (Grants CCF-0905244, CCF-1036241, CCF-1138967, CCF-1138967, and IIS-0835652), the United States Department of Energy (Grant DE-SC0008923), and DARPA (Grants FA8650-11-C-7192, FA8750-12-2-0110)
Characterising the Performance of XOR Games and the Shannon Capacity of Graphs
In this paper we give a set of necessary and sufficient conditions such that
quantum players of a two-party {\sc xor} game cannot perform any better than
classical players. With any such game, we associate a graph and examine its
zero-error communication capacity. This allows us to specify a broad new class
of graphs for which the Shannon capacity can be calculated. The conditions also
enable the parametrisation of new families of games which have no quantum
advantage, for arbitrary input probability distributions up to certain
symmetries. In the future, these might be used in information-theoretic studies
on reproducing the set of quantum non-local correlations.Comment: 5 pages. Clarified proof of theorem 1, typos correcte
Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli
Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts. Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins. Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets
Current and Future Prospects of Nitro-compounds as Drugs for Trypanosomiasis and Leishmaniasis
Interest in nitroheterocyclic drugs for the treatment of infectious diseases has undergone a resurgence in recent years. Here we review the current status of monocyclic and bicyclic nitroheterocyclic compounds as existing or potential new treatments for visceral leishmaniasis, Chagas' disease and human African trypanosomiasis. Both monocyclic (nifurtimox, benznidazole and fexinidazole) and bicyclic (pretomanid (PA-824) and delamanid (OPC-67683)) nitro-compounds are prodrugs, requiring enzymatic activation to exert their parasite toxicity. Current understanding of the nitroreductases involved in activation and possible mechanisms by which parasites develop resistance is discussed along with a description of the pharmacokinetic / pharmacodynamic behaviour and chemical structure-activity relationships of drugs and experimental compounds.</p
Novelty, emotions and intention to be physically active in physical education students
In recent years, the importance of students’ emotions in Physical Education classes has been highlighted. Novelty has also recently been proposed as a candidate for basic psychological need. To date, no study has specifically focused on analysing the relationships between these two constructs, which is the main objective of this paper. For this purpose, a structural equation model was tested with 799 Physical Education students with a mean age of 13.16 years (SD = 1.17). The results showed that students’ perception of their teachers’ novelty support strategies predicted the satisfaction of this need (ß = .81; p < .01). In turn, novelty satisfaction positively predicted positive emotions and negatively predicted negative emotions, with the explained variances of enjoyment (52%), pride (41%), and boredom (37%) standing out. Finally, the emotions enjoyment (ß = .45; p < .01) and hopelessness (ß = -.16; p < .01) predicted intention to be physically active in the future. These results show the importance of novelty in making PE a positive emotional experience and its effect on the creation of healthy habits
Dynamics of notch pathway expression during mouse testis post-natal development and along the spermatogenic cycle
Articles in International JournalsThe transcription and expression patterns of Notch pathway components (Notch 1–3, Delta1 and 4, Jagged1) and effectors
(Hes1, Hes2, Hes5 and Nrarp) were evaluated (through RT-PCR and IHC) in the mouse testis at key moments of post-natal
development, and along the adult spermatogenic cycle. Notch pathway components and effectors are transcribed in the
testis and expressed in germ, Sertoli and Leydig cells, and each Notch component shows a specific cell-type and timewindow
expression pattern. This expression at key testis developmental events prompt for a role of Notch signaling in prepubertal
spermatogonia quiescence, onset of spermatogenesis, and regulation of the spermatogenic cycle
Relax "Vitality in Practice" (VIP) project and design of an RCT to reduce the need for recovery in office employees
<p>Abstract</p> <p>Background</p> <p>There is strong evidence to suggest that multiple work-related health problems are preceded by a higher need for recovery. Physical activity and relaxation are helpful in decreasing the need for recovery. This article aims to describe (1) the development and (2) the design of the evaluation of a daily physical activity and relaxation intervention to reduce the need for recovery in office employees.</p> <p>Methods/Design</p> <p>The study population will consist of employees of a Dutch financial service provider. The intervention was systematically developed, based on parts of the Intervention Mapping (IM) protocol. Assessment of employees needs was done by combining results of face-to-face interviews, a questionnaire and focus group interviews. A set of theoretical methods and practical strategies were selected which resulted in an intervention program consisting of Group Motivational Interviewing (GMI) supported by a social media platform, and environmental modifications. The Be Active & Relax program will be evaluated in a modified 2 X 2 factorial design. The environmental modifications will be pre-stratified and GMI will be randomised on department level. The program will be evaluated, using 4 arms: (1) GMI and environmental modifications; (2) environmental modifications; (3) GMI; (4) no intervention (control group). Questionnaire data on the primary outcome (need for recovery) and secondary outcomes (daily physical activity, sedentary behaviour, relaxation/detachment, work- and health-related factors) will be gathered at baseline (T0), at 6 months (T1), and at 12 months (T2) follow-up. In addition, an economic and a process evaluation will be performed.</p> <p>Discussion</p> <p>Reducing the need for recovery is hypothesized to be beneficial for employees, employers and society. It is assumed that there will be a reduction in need for recovery after 6 months and 12 months in the intervention group, compared to the control group. Results are expected in 2013.</p> <p>Trial registration</p> <p>Netherlands Trial Register (NTR): NTR2553</p
Agronomic potential of Hermetia illucens frass in the cultivation of ryegrass in distinct soils
Publisher Copyright: © I. Rehan et al., 2024.Cropping systems are strongly dependent on mineral fertilisers, which are effective in achieving high crop productivities. However, these chemical inputs end up compromising soil quality in the long-term. Frass from black soldier fly (BSF) larvae is a novel organic fertiliser that is rich in organic matter and advocated as a material that can sustain crop productivity while increasing soil quality. This study aimed at evaluating distinct fertilisation regimes in the cultivation of ryegrass (Lolium multiflorum Lam. or annual ryegrass) in soils of different types (sandy, loamy and clay) and fertility levels. In a 7-month pot experiment conducted in a glass greenhouse, plants were cultivated with exclusive mineral (MT) or organic (OT) fertilisation, in addition to combinations between both (mineral and organic, MOTs) in different proportions (25:50; 50:50 and 75:25), considering a 140 kg per hectare N demand. Crop yield was favoured by the combination of organic and mineral fertilisers in all soils, which also had its fertility increased, especially regarding organic matter build-up and nutrient accumulation. In addition, the presence of frass in the sandy soil stimulated microbial activity, which was measured by the enzyme dehydrogenase. Frass derived from BSF larvae can be considered an adequate organic fertiliser in the cultivation of ryegrass in distinct soil types, when applied in partial (25% to 75%) replacement of mineral fertilisers, enabling high crop productivity and nutritional quality of the crop, while increasing soil fertility.publishersversioninpres
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