27,448 research outputs found
Information complexity of the AND function in the two-Party, and multiparty settings
In a recent breakthrough paper [M. Braverman, A. Garg, D. Pankratov, and O.
Weinstein, From information to exact communication, STOC'13] Braverman et al.
developed a local characterization for the zero-error information complexity in
the two party model, and used it to compute the exact internal and external
information complexity of the 2-bit AND function, which was then applied to
determine the exact asymptotic of randomized communication complexity of the
set disjointness problem.
In this article, we extend their results on AND function to the multi-party
number-in-hand model by proving that the generalization of their protocol has
optimal internal and external information cost for certain distributions. Our
proof has new components, and in particular it fixes some minor gaps in the
proof of Braverman et al
Visual Responses in Mice Lacking Critical Components of All Known Retinal Phototransduction Cascades
The mammalian visual system relies upon light detection by outer-retinal rod/cone photoreceptors and melanopsin-expressing retinal ganglion cells. Gnat1(-/-); Cnga3(-/-); Opn4(-/-) mice lack critical elements of each of these photoreceptive mechanisms via targeted disruption of genes encoding rod alpha transducin (Gnat1); the cone-specific alpha 3 cyclic nucleotide gated channel subunit (Cnga3); and melanopsin (Opn4). Although assumed blind, we show here that these mice retain sufficiently widespread retinal photoreception to drive a reproducible flash electroretinogram (ERG). The threshold sensitivity of this ERG is similar to that of cone-based responses, however it is lost under light adapted conditions. Its spectral efficiency is consistent with that of rod opsin, but not cone opsins or melanopsin, indicating that it originates with light absorption by the rod pigment. The TKO light response survives intravitreal injection of U73122 (a phospholipase C antagonist), but is inhibited by a missense mutation of cone alpha transducin (Gnat2(cpfl3)), suggesting Gnat2-dependence. Visual responses in TKO mice extend beyond the retina to encompass the lateral margins of the lateral geniculate nucleus and components of the visual cortex. Our data thus suggest that a Gnat1-independent phototransduction mechanism downstream of rod opsin can support relatively widespread responses in the mammalian visual system. This anomalous rod opsin-based vision should be considered in experiments relying upon Gnat1 knockout to silence rod phototransduction
Explicit Solution of the Time Domain Volume Integral Equation Using a Stable Predictor-Corrector Scheme
An explicit marching-on-in-time (MOT) scheme for solving the time domain volume integral equation is presented. The proposed method achieves its stability by employing, at each time step, a corrector scheme, which updates/corrects fields computed by the explicit predictor scheme. The proposedmethod is computationally more efficient when compared to the existing filtering techniques used for the stabilization of explicit MOT schemes. Numerical results presented in this paper demonstrate that the proposed method maintains its stability even when applied to the analysis of electromagnetic wave interactions with electrically large structures meshed using approximately half a million discretization elements
Twenty years conservation and monitoring of re-introduced mountain gazelle in the Ibex Reserve, Saudi Arabia
Historically, the mountain gazelle (Gazella gazella) occurred across most of the Arabian Peninsula into northern Syria and Turkey. Early explorers and scientists reported that the mountain gazelle is closely associated with Acacia spp. trees. The current range includes southern Turkey, Jordan, Israel, Iran (Farur Island), Oman, United Arab Emirates, Yemen and Saudi Arabia. The IUCN Red List currently ranks this species as ‘Vulnerable’ (A2ad). Mountain gazelle numbers have decreased dramatically throughout their range, particularly in Saudi Arabia. The only protected areas in Saudi Arabia with natural populations of mountain gazelle are Al Khunfah, Harrat al Harrah, and Farasan Islands. A few scattered populations occur outside of protected areas in the western Asir Mountains, Hejaz Mountains, and possibly on the Tihama coastal plain. There are only two reports of mountain gazelle occurring historically in the central mountains of Saudi Arabia. Both reports are for mountain gazelle in the Jebel Tuwaiq, which is where the Ibex Reserve is situated. In an effort to re-establish the locally extinct population in the Tuwaiq Mountains (Ibex Reserve), the Saudi Wildlife Authority (SWA) initiated a mountain gazelle re-introduction program in 1990 (Dunham et al., 1993). The released gazelles came from the King Khalid Wildlife Research Centre (KKWRC), Saudi Arabia
Polypogon monspeliensis waste biomass: A potential biosorbent for Cd (II)
Polypogon monspeliensis a globally available natural waste material was used for uptake of Cd (II) from aqueous solutions in this study. The results clearly demonstrate the effect of important experimental parameters on the biosorption process in batch experiments. The evaluated pH, biosorbent dose, size and initial metal concentration for Cd (II) uptake by P. monspeliensis waste biomass were 6, 0.05 g, 0.10 mm and 100 mg/L respectively. The Cd (II) sorption process by P. monspeliensis waste biomass was described well by pseudo second order kinetic model and Langumir sorption isotherm model. Metal equilibrium was reached in 120 min. A further increase in incubation time had no significant effect on the biosorption of the metal. FTIR spectroscopic results pointed out the involvement of hydroxyl and amine groups in the Cd (II) sorption by P. monspeliensis waste biomass
Cognitive Load And Self-determination Theories Applied To E-learning: Impact On Students' Participation And Academic Performance
Emergency clerkships expose students to a stressful environment that require multiple tasks, which may have a direct impact on cognitive load and motivation for learning. To address this challenge, Cognitive Load Theory and Self Determination Theory provided the conceptual frameworks to the development of a Moodle-based online Emergency Medicine course, inspired by real clinical cases. Methods Three consecutive classes (2013-2015) of sixth-year medical students (n = 304) participated in the course, during a curricular and essentially practical emergency rotation. "Virtual Rounds" provided weekly virtual patients in narrative format and meaningful schemata to chief complaints, in order to simulate real rounds at Emergency Unit. Additional activities such as Extreme Decisions, Emergency Quiz and Electrocardiographic challenge offered different views of emergency care. Authors assessed student's participation and its correlation with their academic performance. A survey evaluated students' opinions. Students graduating in 2015 answered an online questionnaire to investigate cognitive load and motivation. Results Each student produced 1965 pageviews and spent 72 hours logged on. Although Clinical Emergency rotation has two months long, students accessed the online course during an average of 5.3 months. Virtual Rounds was the most accessed activity, and there was positive correlations between the number of hours logged on the platform and final grades on Emergency Medicine. Over 90% of students felt an improvement in their clinical reasoning and considered themselves better prepared for rendering Emergency care. Considering a Likert scale from 1 (minimum load) to 7 (maximum load), the scores for total cognitive load were 4.79 +/- 2.2 for Virtual Rounds and 5.56 +/- 1.96 for real medical rounds(p<0,01). Conclusions A real-world inspired online course, based on cognitive and motivational conceptual frameworks, seems to be a strong tool to engage students in learning. It may support them to manage the cognitive challenges involved in clinical care and increase theirmotivation for learning.1
Physiological effects of diet mixing on consumer fitness: a meta-analysis
The degree of dietary generalism among consumers has important consequences for population, community, and ecosystem processes, yet the effects on consumer fitness of mixing food types have not been examined comprehensively. We conducted a meta-analysis of 161 peer-reviewed studies reporting 493 experimental manipulations of prey diversity to test whether diet mixing enhances consumer fitness based on the intrinsic nutritional quality of foods and consumer physiology. Averaged across studies, mixed diets conferred significantly higher fitness than the average of single-species diets, but not the best single prey species. More than half of individual experiments, however, showed maximal growth and reproduction on mixed diets, consistent with the predicted benefits of a balanced diet. Mixed diets including chemically defended prey were no better than the average prey type, opposing the prediction that a diverse diet dilutes toxins. Finally, mixed-model analysis showed that the effect of diet mixing was stronger for herbivores than for higher trophic levels. The generally weak evidence for the nutritional benefits of diet mixing in these primarily laboratory experiments suggests that diet generalism is not strongly favored by the inherent physiological benefits of mixing food types, but is more likely driven by ecological and environmental influences on consumer foraging
The phytochemical, antibacterial and antioxidant activity of five medicinal plants against the wound infecting bacteria
Leaf extracts of Senna italica, Ricinus communis, Lantana camara, Lippia javanica and Ziziphus mucronata were screened for biological activity against bacteria which infect wounds. The leaves were extracted using different solvents of varying polarity (hexane, dichloromethane, acetone and methanol). Phytochemical analyses of the extracts were performed using thin layer chromatography (TLC). The extracts were loaded on TLC plates and developed in three solvent systems that is benzene/ethanol /ammonium solution (BEA), chloroform/ethyl acetate/formic acid (CEF) and ethyl acetate/methanol /water (EMW). Antibacterial activity of the plants was evaluated using micro-dilution and bioautography methods. The test organisms used were Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Enterococcus faecalis. Acetone extracts were chosen for antioxidant activity. Methanol was the best extractant, followed by acetone and dichloromethane (DCM). In the phytochemical analysis, more compounds were observed on BEA, followed by EMW and CEF plates. Lantana camara had no activity against any of the bacteria used. P. aeruginosa was the most resistant bacterium with only two plants active against it. E. faecalis and E. coli were sensitive to the extracts. More antibacterial compounds were observed on BEA plates against all the test bacteria in bioautographic method. The Rf values calculated from bioautography indicated that the selected plants have different active compounds. The most active compounds were from S. italica and Z. mucronata. BEA and EMW plates had good antioxidant activity. No antioxidant activity was observed on the CEF plate. Most extracts were active against wound pathogens; their application on the wound area may prevent infection. Further studies are required to identify the active compounds in the plant extracts which showed significant anti-bacterial activities.Key words: Thin layer chromatography (TLC), plant extract, bacteria
- …