4,153 research outputs found

    Quantum walk-based search and centrality

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    We study the discrete-time quantum walk-based search for a marked vertex on a graph. By considering various structures in which not all vertices are equivalent, we investigate the relationship between the successful search probability and the position of the marked vertex, in particular its centrality. We find that the maximum value of the search probability does not necessarily increase as the marked vertex becomes more central and we investigate an interesting relationship between the frequency of the successful search probability and the centrality of the marked vertex.Comment: 29 pages, 17 figure

    Analysis of Microstrip Patch Antennas for Dielectric Measurement

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    The microstrip patch antenna has been employed by Shimin [1] to measure the dielectric constant of thin slab materials. Although the applicability of the method in [1] is not restricted by the size of the material under test, the etching of the patch and the introduction of the ground plane on the material cannot be practical in many cases. A more practical approach based on the microstrip antenna is reported in [2] for the measurement of the dielectric constant of snow. The technique employs the antenna as an applicator. The antenna is brought to the close proximity or in contact with the surface of the material in order to cause interaction between the antenna’s near field and the object. The result is a change in the input impedance and the resonant frequency of the antenna. Similar to short antenna applicators [3], a patch antenna applicator can take measurements under resonant and off resonant conditions. However, at resonance, achieving accurate measurements are straight-forward. The technique can be applied to solids as well as to liquids with small or large losses. It can also be used in the thickness measurement of layered materials

    Long-term Follow Up of Van Nes Rotationplasty for Proximal Focal Femoral Deficiency

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    Proximal focal femoral deficiency (PFFD) is a congenital anomaly that presents challenges for orthopaedic and prosthetic management. The Van Nes rotationplasty is one treatment in which the extremity is surgically rotated to utilize the ankle and foot as a functional knee joint in a prosthesis. The purpose of this study is to determine the long-term functional and quality of life (QOL) outcomes for individuals who have undergone rotationplasty surgery for congenital PFFD compared to age and gender matched controls

    Long-term Follow up of Van Nes Rotationplasty for Congenital Proximal Focal Femoral Deficiency [Proceedings]

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    INTRODUCTIONProximal focal femoral deficiency (PFFD) is a congenital anomaly that presents challenges for orthopaedic and prosthetic management. The Van Nes rotationplasty is one treatment in which the extremity is surgically rotated to utilize the ankle and foot as a functional knee joint in a prosthesis. The purpose of this study is to determine the long-term functional and quality of life (QOL) outcomes for individuals who have undergone rotationplasty surgery for congenital PFFD compared to age and gender matched controls. METHODSThis prospective study had 12 prosthetic participants (PFFD Group: 8 M, 4F, age range 16-57 years) average 31.6±13.5 years and 12 control participants (Control Group: 8M, 4F) with an average age 32.6±14.1 years. Participants completed the following outcome questionnaires: SF-36, Revised-Faces Pain Scale, Harris Hip Score, Oswestry back pain score; and underwent lower extremity range of motion (ROM), hand held dynamometry, gait analysis, computerized dynamic posturography and Timed ‘Up& Go’ (TUG) testing. The PFFD Group also completed the Prosthetic Evaluation Questionnaire© (PEQ). The Wilcoxon Signed rank test was used to statistically compare each PFFD Group participant to the matched Control Group participant with values statistically significant at p\u3c 0.0123. RESULTSParticipants had rotationplasty performed at an average age of 6.5±3.9 years with follow up testing done 25.1±11.2 years later. All adult subjects were working full time in a variety of manual and office/desk jobs. No significant issues were seen for body image. Pain: The PFFD and Control Groups both reported similar low back pain with 6.8±9.7% and 7.0±13.0% disability respectively on the Oswestry back pain questionnaire. On the day of testing, only one PFFD participant reported mild low back pain on the Revised- Faces Pain Scale. The average Harris Hip Score for the PFFD Group was 92.7±9.2 out of 100, indicating excellent outcome. Two participants reported pain on their non-prosthetic hip. ROM: The PFFD Group showed significantly decreased hip flexion and ankle dorsiflexion, and increased ankle plantarflexion strength on the prosthetic side compared to the Control Group. The PFFD Group had significantly greater ankle abduction strength on their non-prosthetic side compared to the Control Group. Strength: The PFFD Group demonstrated significantly weaker hip flexion, hip abduction and ankle plantarflexion on the prosthetic side compared to the Control Group. TUG: The PFFD Group scored an average of 8.5±1.6 seconds on the TUG, demonstrating a low fall risk. The Control Group scored significantly lower with an average of 6.5 ±1.0 seconds. SF-36: There were no significant differences between the groups in overall health and well-being. PEQ©: The PFFD Group scored lower in areas of satisfaction, appearance, and sounds of the prosthesis. However, participants reported that others perceived them well and they did not see themselves as a social burden. Gait Analysis: Temporal-spatial gait parameters for the PFFD Group demonstrated significant decrease in cadence, stride time, opposite foot off, single support and walking speed compared to Control Group. Posturography: The PFFD Group showed significant decrease in symmetry in stance, as well as a decrease in end point and maximum excursion in limits of stability testing compared to the Control Group. DISCUSSION AND CONCLUSIONOverall, long-term follow up of teens and adults who underwent Van Nes rotationplasty showed that they maintained a high level of function, participation and QOL. They did present with significant differences in temporal spatial and posturography parameters compared to the Control Group

    Acute Renal Failure Following the Saharan Horned Viper (Cerastes cerastes) Bite

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    Introduction: The Saharan horned viper (Cerastes cerastes) is a common snake in the sandy and rocky regions in the south of Morocco. Although nearly all snakes with medical relevance can induce acute renal failure (ARF), it’s unusual except with bites by some viper species. ARFhas very rarely been reported following Cerastes cerastes bite.Case Report: A 55-year-old Moroccan man was bitten on his right hand by a Saharan horned viper, Cerastes cerastes. He presented 24 hours later in a state of confusion, agitation and hypotension with marked swelling of his right hand. Investigations revealed evidence of disseminated intravascular coagulation (DIC) and rhabdomyolysis. The appropriate antivenom wasnot available. Despite adequate hydration, he developed acute renal failure necessitating prolonged hemodialysis. He subsequently improved and was discharged from the hospital after four weeks with normal renal function.Conclusion: Although uncommon, the bite of Cerastes cerastes can result in ARF due to DIC and rhabdomyolysis. The appropriate antivenom should be made available in areas where this snake is prevalent

    Long-term Follow up of Van Nes Rotationplasty for Congenital Proximal Focal Femoral Deficiency

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    Van Nes rotationplasty may be used for patients with congenital proximal focal femoral deficiency (PFFD). The lower limb is rotated to use the ankle and foot as a functional knee joint within a prosthesis. A small series of cases was investigated to determine the long-term outcome. At a mean of 21.5 years (11 to 45) after their rotationplasty, a total of 12 prosthetic patients completed the Short-Form (SF)-36, Faces Pain Scale-Revised, Harris hip score, Oswestry back pain score and Prosthetic Evaluation Questionnaires, as did 12 age- and gender-matched normal control participants. A physical examination and gait analysis, computerised dynamic posturography (CDP), and timed ‘Up & Go’ testing was also completed. Wilcoxon Signed rank test was used to compare each PFFD patient with a matched control participant with false discovery rate of 5%. There were no differences between the groups in overall health and well-being on the SF-36. Significant differences were seen in gait parameters in the PFFD group. Using CDP, the PFFD group had reduced symmetry in stance, and reduced end point and maximum excursions. Patients who had undergone Van Nes rotationplasty had a high level of function and quality of life at long-term follow-up, but presented with significant differences in gait and posture compared with the control group

    Impact of direct seeding on soil water retention in semi-arid area (region highlands of western Algeria)

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    This investigation is falls within the framework of conservation agriculture. Indeed, twentyfive years after the first of zero tillage farming experiences, this new method was named crop conservation agriculture because it helps preserve soil nutrients, water absorption enhancing and infiltration and biodiversity by maintaining the natural equilibrium in the soil. The objective of this is study is to compare the impact of the tillage (conventional work and the direct sowing) on water properties of the soil, especially the water-holding capacity of the soil in semi-arid zone (case of Tiaret region). According to the results, the comparative analysis between the two types of tillage (direct drilling sowing and conventional tillage) shows that water parameters studied such as moisture equivalent (He), of holding capacity (Cr), wilting point (Pf) and AWR (UK) are higher in the useful reserve case of direct seeding than in the case of conventional labor.Keywords: Conservation agriculture, direct sowing, conventional labor, soil moisture, holding capacit

    Buprenorphine added on brief cognitive behavioral therapy for treatment of methamphetamine use disorder

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    Background: Methamphetamine (MA) use remains a major public health concern around the world. Recent findings suggest that buprenorphine may be helpful for cocaine use reduction. Moreover, animal studies described reduced dopamine peak effect following MA use, due to the administration of low dose buprenorphine. Objectives: This study examined the effectiveness of buprenorphine with brief cognitive behavioral therapy on MA use disorder. Methods: The study was conducted in an outpatient substance abuse treatment center in Qazvin, Iran. Nineteen MA users received buprenorphine for 24 weeks combined with brief cognitive behavioral therapy in an outpatient substance abuse treatment program, three times per week, as a before and after non - randomization study. Clinical outcomes included treatment retention, MA use, degree of MA dependency and craving, quality of life, cognitive abilities questionnaire, addiction severity and also adverse events. Data was analyzed by performing repeated measures analysis and the Friedman test for nonparametric variables. Results: Fifteen participants completed the study during six months and frequency of MA use was significantly decreased at 24 weeks (P < 0.001). There were also significant reductions in craving (P < 0.001), degree of MA dependence (P < 0.001), and improvements in quality of life, cognitive ability, and some subscales of addiction severity. Conclusions: The results of this preliminary clinical study demonstrated that buprenorphine could potentially attenuate MA craving and alternate rewarding effects of MA and had promising effects on cognitive impairment. Furthermore, buprenorphine can be considered as a harm reduction intervention in some communities, in which the people, as a result of cultural beliefs, do not accept a therapy, which only consists of counseling and no medications

    Reed-Muller codes for random erasures and errors

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    This paper studies the parameters for which Reed-Muller (RM) codes over GF(2)GF(2) can correct random erasures and random errors with high probability, and in particular when can they achieve capacity for these two classical channels. Necessarily, the paper also studies properties of evaluations of multi-variate GF(2)GF(2) polynomials on random sets of inputs. For erasures, we prove that RM codes achieve capacity both for very high rate and very low rate regimes. For errors, we prove that RM codes achieve capacity for very low rate regimes, and for very high rates, we show that they can uniquely decode at about square root of the number of errors at capacity. The proofs of these four results are based on different techniques, which we find interesting in their own right. In particular, we study the following questions about E(m,r)E(m,r), the matrix whose rows are truth tables of all monomials of degree r\leq r in mm variables. What is the most (resp. least) number of random columns in E(m,r)E(m,r) that define a submatrix having full column rank (resp. full row rank) with high probability? We obtain tight bounds for very small (resp. very large) degrees rr, which we use to show that RM codes achieve capacity for erasures in these regimes. Our decoding from random errors follows from the following novel reduction. For every linear code CC of sufficiently high rate we construct a new code CC', also of very high rate, such that for every subset SS of coordinates, if CC can recover from erasures in SS, then CC' can recover from errors in SS. Specializing this to RM codes and using our results for erasures imply our result on unique decoding of RM codes at high rate. Finally, two of our capacity achieving results require tight bounds on the weight distribution of RM codes. We obtain such bounds extending the recent \cite{KLP} bounds from constant degree to linear degree polynomials

    Null Branes in Curved Backgrounds

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    We consider null bosonic p-branes in curved space-times. Some exact solutions of the classical equations of motion and of the constraints for the null membrane in general stationary, axially symmetrical, four dimensional, gravity background are found.Comment: 19 pages, LaTeX, no figures. Extended version. To appear in Phys. Rev.
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