76 research outputs found
A study of the origin of an indigenous community in central Nigeria: interrogating Akpoto-Igala phenomenon
The Igala lives in a deciduous forest belt to the south and open savannah vegetation to the north. They occupy a triangular tract of land located at the confluence of rivers Niger and Benue. The Igala, like many other ethnic groups in Nigeria, holds several myths and traditions concerning their probable place of origin. Various attempts at tracing the origin of the people have elicited as many traditions as are scholars who attempted to unravel the origin of the people. This paper is therefore, an attempt to examine the various arguments on the origin and the place of Akpoto in the traditions of the people
Computing regularities in strings
Regularities in strings model many phenomena and thus form the subject of extensive mathematical studies . Perhaps the most conspicuous regularities in strings are those that manifest themselves in the form of repeated subpatterns. In this paper, we study several forms of regularities of strings, that is, repeats, multirepeats, repetitions and runs. We present their similarities and differences by discussing their forms and properties and we explore the existing computation algorithms. We also discuss several data structures useful for computing regularities
Faster algorithms for computing maximal multirepeats in multiple sequences
A repeat in a string is a substring that occurs more than once. A repeat is extendible if every occurrence of the repeat has an identical letter either on the left or on the right; otherwise, it is maximal. A multirepeat is a repeat that occurs at least mmin times (mmin greater than/equal to 2) in each of at least q greater than/equal to 1 strings in a given set of strings. In this paper, we describe a family of efficient algorithms based on suffix arrays to compute maximal multirepeats under various constraints. Our algorithms are faster, more flexible and much more space-efficient than algorithms recently proposed for this problem. The results extend recent work by two of the authors computing all maximal repeats in a single string
Early Diagnosis of Breast Cancer
Cancer of the breast is the commonest malignant disease in women. It is
a major public health problem worldwide. The cause is unknown, but
there are documented risk factors. Most of the patients are symptomatic
at the time of detection. A breast lump is by far the most common and
the only symptom in majority of patients. The diagnosis is made from
physical examination, imaging, cytology and biopsy
Effects of Intraframe Distortion on Measures of Cone Mosaic Geometry from Adaptive Optics Scanning Light Ophthalmoscopy
Purpose: To characterize the effects of intraframe distortion due to involuntary eye motion on measures of cone mosaic geometry derived from adaptive optics scanning light ophthalmoscope (AOSLO) images.
Methods: We acquired AOSLO image sequences from 20 subjects at 1.0, 2.0, and 5.08 temporal from fixation. An expert grader manually selected 10 minimally distorted reference frames from each 150-frame sequence for subsequent registration. Cone mosaic geometry was measured in all registered images (n ¼ 600) using multiple metrics, and the repeatability of these metrics was used to assess the impact of the distortions from each reference frame. In nine additional subjects, we compared AOSLO-derived measurements to those from adaptive optics (AO)-fundus images, which do not contain system-imposed intraframe distortions.
Results: We observed substantial variation across subjects in the repeatability of density (1.2%–8.7%), inter-cell distance (0.8%–4.6%), percentage of six-sided Voronoi cells (0.8%–10.6%), and Voronoi cell area regularity (VCAR) (1.2%–13.2%). The average of all metrics extracted from AOSLO images (with the exception of VCAR) was not significantly different than those derived from AO-fundus images, though there was variability between individual images.
Conclusions: Our data demonstrate that the intraframe distortion found in AOSLO images can affect the accuracy and repeatability of cone mosaic metrics. It may be possible to use multiple images from the same retinal area to approximate a ‘‘distortionless’’ image, though more work is needed to evaluate the feasibility of this approach.
Translational Relevance: Even in subjects with good fixation, images from AOSLOs contain intraframe distortions due to eye motion during scanning. The existence of these artifacts emphasizes the need for caution when interpreting results derived from scanning instruments
MEH-PPV film thickness influenced fluorescent quenching of tip-coated plastic optical fiber sensors
The performance of plastic optical fiber sensors in detecting nitro aromatic explosives 1,4-dinitrobenzene (DNB) have been investigated by fluorescence spectroscopy and analyzed by using fluorescence quenching technique. The plastic optical fiber utilized is 90 degrees cut tip and dip-coated with conjugated polymer MEH-PPV poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] thin films for detection conjugants. The thicknesses of the MEH-PPV coating were varied to improvise the sensitivity whilst slowly reducing the fluorescence intensity. It was shown that fluorescence intensity from thinner film decreased by (82% in 40 s) in the presence of DNB signifying an improvement of 28% reduction with time 13 s less than that of the thicker film
Faster algorithms for computing maximal multirepeats in multiple sequences
A repeat in a string is a substring that occurs more than once. A repeat is extendible if every occurrence of the repeat has an identical letter either on the left or on the right; otherwise, it is maximal. A multirepeat is a repeat that occurs at least mmin times (mmin _ 2) in each of at least q (greater than or equal to) 1 strings in a given set of strings. In this paper, we describe a family of efficient algorithms based on suffix arrays to compute maximal multirepeats under various constraints. Our algorithms are faster, more flexible and much more space-efficient than algorithms recently proposed for this problem. The results extend recent work by two of the authors computing all maximal repeats in a single string
How to perform better intervention to prevent and control diabetic retinopathy among patients with type 2 diabetes
This meta-analysis of randomized controlled trials (RCTs) aims to investigate how to perform better interventions targeting modifiable risk factors of diabetic retinopathy (DR) to
prevent and control DR in patients with type 2 diabetes by comparing different intervention
types and follow-up intervals. Literature published before June 1st, 2019 were searched on
Pubmed, Embase and ScienceDirect. RCTs targeting modifiable risk factors of DR (including
blood glucose, blood pressure, lipid, dietary, physical activity and smoking) were selected
by two reviewers and double checked for accuracy. Random effects models were estimated
to calculate pooled Odds Ratios (OR). Twenty-two RCTs (n = 22,511) were included. In general, interventions targeting modifiable risk factor of DR reduced the risk of developing DR
(I
2 = 26.7%; OR = 0.60; 95% CI 0.45 to 0.79) and DR worsening (I
2 = 0.0%; OR = 0.62; 95% CI 0.47
to 0.80; P < 0.001). Multifactorial interventions had better effect on reducing the risk of
development and progression of DR in comparison with other interventions, while only
blood-pressure-control interventions showed significant effect on slowing down DR worsening. Additionally, interventions with follow-up >5 years had better effect on reduction of
DR development, and interventions with follow-up >2 years had better effect on reducing
the risk of DR worsenin
Manufacturing of Functionally Graded Porous Products by Selective Laser Sintering
This research article published by Scientific.Net, 2009Selective laser sintering (SLS) is a rapid prototyping technique which is used to manufacture plastic and metal models. The porosity of the final product obtained by SLS can be controlled by changing the energy density level used during the manufacturing process. The energy density level is itself dependent upon manufacturing parameters such as laser power, hatching distance and scanning speed. Through mechanical characterization techniques, it is possible to quantitatively relate the energy density levels to particular strength values. The present study is directed towards manufacturing functionally graded polyamide products by changing the energy density level in a predetermined manner. The mechanical properties of the functionally graded components are characterized by means of tensile testing. Both homogeneous and functionally graded specimens are produced and tested in order to examine the influence of the energy density level on the mechanical response and on the ultimate tensile and rupture strengths. Selective laser sintering is shown to possess the potential to produce functionally graded porous specimens with controlled variations in physical and mechanical properties
Ovarian Pregnancy Presenting as Ovarian Tumour: Report of 2 Cases
We present 2 cases of ovarian masses diagnosed as tumours but turned
out to be pregnancy. Ovarian pregnancy, a form of ectopic gestation has
a distinct pathology though it can be a source of diagnostic difficulty
clinically and intraoperatively. A total of 71 ectopic pregnancies were
seen in the department from January 2001 to December 2005, of these
only two were ovarian ectopics. Both patients were nulliparous and
presented with lower abdominal pains, abdominal masses and menstrual
irregularity. They both had laparotomy and total right
salpingo-oophorectomy. Grossly, the ovaries were enlarged, grey tan and
globular. Focal ruptures in the wall of the ovaries showed protruding
fetal parts. Microscopy showed chorionic villi within and in continuity
with ovarian stroma and corpus luteum. They were both diagnosed ovarian
ectopics. A good knowledge and understanding of the gross pathology,
combination of imaging studies and high index of suspicion should help
in making an intra-operative diagnosis.Nous pr\ue9sentons deux cas de masse ovariennes diagnostiques
cliniquement comme des tumeurs mais apr\ue8s histologiquement ce sont
r\ue9v\ue8les \ueatre des grossesses ectopiques. Les grossesses
ovariennes, une forme de grossesse ectopique as une pathologie
distincte est es difficilement diagnostiqu\ue9e cliniquement. Un
total de 71 grossesses ectopiques a \ue9t\ue9 vues au
D\ue9partement de Pathologie entre Janvier 2001 et D\ue9cembre
2005. Deux grossesses \ue9taient des grossesses ovariennes. Les deux
patientes \ue9taient nullipares et ce sont pr\ue9sent\ue9es avec
des douleurs au bas ventre, des tumeurs abdominales et des
menstruations irr\ue9guli\ue8res. Les deux ont eu une exploration
abdominale suivie d'une salpingoovarectomie. Anatomiquement, les
ovaires \ue9taient, gris, globulaire, et hypertrophier. Des ruptures
de la paroi ovaire montrait des protrusions d'\ue9l\ue9ments
foetal. Histologiquement les ovaires ont r\ue9v\ue9l\ue9s les
villosit\ue9s chorioniques dans et en continuit\ue9 avec le stroma
ovarien et le corpus luteum. Les deux ovaires ont \ue9taient
diagnostiqu\ue9s comme grossesse ovarienne. Une bonne connaissance et
un bon entendement de l'anatomie-pathologie, une combinaison de
l'imagerie et un fort taux de suspicion aide a faire un diagnostique
clinique
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