118 research outputs found
Ricci cubic gravity in d dimensions, gravitons and SAdS/Lifshitz black holes
A special class of higher curvature theories of gravity, Ricci Cubic Gravity
(RCG), in general d dimensional space-time has been investigated in this paper.
We have used two different approaches, the linearized equations of motion and
auxiliary field formalism to study the massive and massless graviton
propagating modes of the AdS background. Using the auxiliary field formalism,
we have found the renormalized boundary stress tensor to compute the mass of
Schwarzschild AdS and Lifshitz black holes in RCG theory.Comment: 35 pages. Published versio
The Effects Of Photographic Presentation Modes On Semiotic Understanding Of Land Art Among Iranian Art Students
Land art consists of sculptures, carvings, and performances located at specific natural surroundings to deliver messages of love and concern for the environment. As they are ephemeral or located in inaccessible places they are documented for reference in the form of photographs taken by the artists or by people interested in the works.
Seni bumi terdiri dari arca, ukiran, dan persembahan yang dibuat di lokasi semulajadi tertentu untuk menyampaikan mesej cinta dan keperhatinan terhadap alam sekitar. Oleh kerana hasilan seni ini adalah bersifat sementara atau ditinggalkan di lokasi-lokasi yang sukar dilawati maka dokumentasi hasilan karya ini dibuat melalui gambar-gambar foto yang diambil oleh artis-artis berkenaan atau penggemar-penggemar seni tersebut
Trial-by-Trial Coding of Instructive Signals in the Cerebellum: Insights From Eyeblink Conditioning in Mice
The cerebellum is an area of the brain that plays a crucial role in the learning of motor skills. This process involves climbing fibers, which provide teaching signals to Purkinje cells in the cerebellar cortex when perturbations occur during a movement. However, controversy has arisen over climbing fibers contribution to cerebellar learning. This is because climbing-fiber signals are described as all-or-nothing : they fire a single burst of action potentials in response to all supra-threshold stimuli, regardless of their strength. On the contrary, motor learning is not all-or-nothing: the amount of learning is driven by the strength of perturbations. In this dissertation, I describe the experiments that I performed to unravel how climbing fibers may encode the strength of teaching signals. In Chapter 2, I present my behavioral studies in mice, which involved a simple cerebellar-dependent motor learning task, eyeblink conditioning. I show that mice take into account the strength of unexpected perturbations to adapt their movements trial-by-trial. In Chapter 3, I present a review of the previous literature and provide a hypothesis on how climbing fibers can encode the strength of teaching signals in a single trial. In Chapter 4, I present the findings of my in vivo two-photon calcium imaging experiments, which suggest climbing-fiber signals may not be all-or-nothing at the post-synaptic level. Finally, in Chapter 5 I describe the different mechanisms that we discovered for coding the intensity of teaching signals by Purkinje cells in the cerebellum of awake mice
ON THE STRECH CURVATURE OF HOMOGENEOUS FINSLER METRICS
In this paper, we prove that every homogeneous Finsler metric has relatively isotropic stretch curvature if and only if it is a Landsberg metric. It follows that every weakly Berwald homogeneous metric has relatively isotropic stretch curvature if and only if it is a Berwald metric. We show that a homogeneous metric of non-zero scalar flag curvature has relatively isotropic stretch curvature if and only if it is a Riemannian metric of constant sectional curvature. It turns out that a homogeneous (a,b)-metric with relatively isotropic stretch curvature is a Berwald metric. Also, it follows that ahomogeneous spherically symmetric metric with relatively isotropic stretch curvature reduces to a Riemannian metric. Finally, we prove that every homogeneous stretch-recurrent metric is a Landsberg metric
Changes in antioxidant enzymes activities and proline, total phenol and anthocyanine contents in Hyssopus officinalis L. plants under salt stress
The relationships between salt stress and antioxidant enzymes activities, proline, phenol and anthocyanine contents in Hyssopus officinalis L. plants in growth stage were investigated. The plants were subjected to five levels of saline irrigation water, 0.37 (tap water as control) with 2, 4, 6, 8 and 10 dSm−1 of saline water. After two months the uniform plants were harvested for experimental analysis. Antioxidant enzymes activities and proline, phenol and anthocyanine contents of the plants were examinated. Enhanced activities of peroxidase, catalase and superoxide dismutase were determined by increasing salinity that plays an important protective role in the ROS-scavenging process. Proline, phenol and anthocyanine contents increased significantly with increasing salinity. These results suggest that salinity tolerance of Hyssopus officinalis plants might be closely related with the increased capacity of antioxidative system to scavenge reactive oxygen species and with the accumulation of osmoprotectant proline, phenol and anthocyanine contents under salinity conditions
Evaluation of In-vitro Antimicrobial Activity of some Newly Synthe-sized2-amino-3-phenylsulfonyl-4-aryl-4H-benzo[h]chromens Derivatives
In this study, some chromens derivatives were synthesized as mentioned in our previous report.The synthesized compounds were evaluated for their antibacterial effect against three different bacterial species, using Disk Diffusion Agar test and microdilution broth (MIC) method against the S. aureus, E. coli, P. aeruginosabacterias according to the National Committee for Clinical Laboratory Standards (NCCLS) recommendations. The results indicated that 4-nitro compound has considerable antibacterial activity against S. aureusbacteria. Moreover, compound 3-chloro has antibacterial properties againstE. coli standard strain and none of 4H-Chromens derivatives have antibacterial effect on P. aeruginosa strains
Evaluation of the Effect of Intravenous Ondansetron versus Placebo before Anesthesia on Vomiting after Endoscopy and Colonoscopy Procedures
Background: Vomiting is a common complication after endoscopic procedures in children. Different medications could be administered to control vomiting after endoscopy. The goal of this study is to evaluate anti-emetic effects of ondansetron in children who undergo endoscopic procedures.Methods: In this clinical randomized trial, 198 children (103 female/95 male) were randomly assigned into one of the following two studied groups. Case group (G1): Fentanyl 1 µg/kg + propofol 2.5 mg/kg + ondansetron 0.15 mg/kg and control group (G2): Fentanyl 1 µg/kg + propofol 2.5 mg/kg + 2 cc normal saline.Results: The mean age was 6.3 ± 3.5 years (6.2 ± 3.6 years in G1 vs. 6.4 ± 3.5 years in G2). The most common cause of endoscopy procedure in both groups was hematochezia. Vomiting, recovery time, Paediatric Anesthesia Emergence Delirium (PAED), and Aldrete scores were compared. Rate of vomiting after recovery and Aldrete score were significantly different between the two groups.Conclusions:Ondansetron is effective in controlling vomiting after colonoscopy and upper gastrointestinal endoscopic procedures. Also, patients in intervention group experienced better recovery time
Study of Pluto's Atmosphere Based on 2020 Stellar Occultation Light Curve Results
On 6 Jun 2020, Pluto's stellar occultation was successfully observed at a
ground-based observatory and Pluto's atmospheric parameters were investigated.
We used an atmospheric model of Pluto (DO15), assuming a spherical and
transparent pure N2 atmosphere. Using ray-tracing code the stellar occultation
light curve was satisfactorily fitted to this model. We found that Pluto's
atmospheric pressure at the reference radius of 1215 km is 6.72+_0.21 {\mu}bar.
Our estimated pressure shows a continuation of the increasing pressure studied
in 2016 consistent with a seasonal volatile transport model. We concluded that
the N2 condensation processes in the Sputnik Planitia glacier are increasing
due to the heating of the N2 ice in this basin. This study's result was shown
on the diagram of the annual evolution of atmospheric pressure.Comment: 4 figures, 2 table
Effectiveness of Acupressure on Reducing Blood Sugar and Glycosylated Hemoglobin Levels in Patients with Type 2 Diabetes: A Rapid Systematic Review and Meta-analysis
Background: Acupressure as one of the complementary and alternative medicine (CAM) has become very popular in the management of various diseases such as diabetes. Although the increasing use of acupuncture, there are limited systematic reviews and meta-analyses in this field.Aim: The present study was performed with aim to investigate the effectiveness of acupressure on the blood sugar parameters of patients with type 2 diabetes.Method: In this rapid systematic review and meta-analysis, the studies published globally between 2010 and 2022 were searched in the PubMed, Google Scholar, and Science Direct databases with the keywords of acupressure, diabetes, complementary medicine, blood sugar and glycosylated hemoglobin as separately and in combination. To analyze data, STATA software version 11 was used to analyze data, and the random effect model method was applied for meta-analysis of the studies.Results: Among the 411 articles found in the initial search, finally 8 articles were selected for this study. The results of the meta-analysis of studies showed that acupressure had a positive effect on blood sugar (95% CI = 0.816-1.553, P < 0.001, OR = 1.18) and fasting blood sugar (95% CI = 0.260 - 0.857, P˂0.001, OR = 0.559) in diabetic patients, while it had no effect on the level of glycosylated hemoglobin (95% CI = -0.139 - 0.389, P = 0.355, OR = 0.559).Implications for Practice: This study showed the positive effect of acupressure in reducing blood sugar and fasting blood sugar in patients with diabetes, however more studies are required to confirm the effect of acupressure on glycosylated hemoglobin
Dataset from "Farzaneh Najafi, Gamaleldin F Elsayed, Robin Cao, Eftychios Pnevmatikakis, Peter E. Latham, John P Cunningham, Anne K Churchland (bioRxiv, 2018); Excitatory and inhibitory subnetworks are equally selective during decision-making and emerge simultaneously during learning.”
This package contains data, in NWB (Neurodata Without Borders) format, from the 4 mice included in "Farzaneh Najafi, Gamaleldin F Elsayed, Robin Cao, Eftychios Pnevmatikakis, Peter E. Latham, John P Cunningham, Anne K Churchland (bioRxiv, 2018); Excitatory and inhibitory subnetworks are equally selective during decision-making and emerge simultaneously during learning.”
The "FN_dataSharing/nwb' folder contains NWB files for all recorded sessions for four mice discussed in the paper. Each NWB file represents the data and metadata associated with one recording session. In each NWB file, the metadata related to the session (mouse name, session date/time, lab/institution name, etc.) can be found under "general". Information related to ROI-segmentation such as ROI mask, ROI type (excitatory or inhibitory), poor or good quality, etc. can be found under "modules/Image-Segmentation/pln-seg". Trial information (e.g. start, end times, trial types, trial outcomes, etc.) can be found under "trials". Recorded trial-segmented neuronal responses aligned to different time event (e.g. stimulus start, animal choice, etc.) can be found under "modules/ Trial-based-Segmentation". A jupyter notebook presenting in detail how to work with NWB files is provided at https://github.com/ttngu207/najafi-2018-nwb/blob/master/notebooks/Najafi-2018_example.ipynb
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