Small-seeded Hakea species tolerate cotyledon loss better than large-seeded congeners
Journal ArticleSix Hakea species varying greatly in seed size were selected for cotyledon damage experiments. The
growth of seedlings with cotyledons partially or completely removed was monitored over 90 days. All
seedlings perished by the fifth week when both cotyledons were removed irrespective of seed size.
Partial removal of cotyledons caused a significant delay in the emergence of the first leaf, and reduction
in root and shoot growth of the large-seeded species. The growth of seedlings of small-seeded species
was less impacted by cotyledon damage. The rate of survival, root and shoot lengths and dry biomass
of the seedlings were determined after 90 days. When seedlings were treated with balanced nutrient
solutions following removal of the cotyledons, survival was 95–98%, but 0% when supplied with
nutrient solutions lacking N or P or with water only. The addition of a balanced nutrient solution failed
to restore complete growth of any species, but the rate of root elongation for the small-seeded species
was maintained. Cotyledons provide nutrients to support early growth of Hakea seedlings, but other
physiological roles for the cotyledons are also implicated. In conclusion, small-seeded Hakea species can
tolerate cotyledons loss better than large-seeded species.
Shhoob Mohamed imhmed Elahmir, Byron B. Lamont, Tianhua He, (01-2017), استراليا: Scientific Reports, 7 (1), 1-9
The Impact of Water and Some Salt Solutions on Some Properties of Hydrophilic Acrylamide Copolymeric Hydrogels
Journal ArticleAbstract-A series of polyelectrolyte hydrogels ranging from 92-98wt% were synthesized by copolymerization of acrylamide,
AAM with 2-acrylamido-2-methyl propane sulphonic acid, AMPS using 0.001g APS as initiator in the presence of 30wt% H2O
and 1.0wt% ethylene glycol dimethacrylate,EDMA as cross-linking agent. The final copolymers was obtained in the form of
glassy and transparent roads at room temperature, these roads were soaked in water for two days to remove unreacted
monomers. The swelling behavior of the hydrogels was studied in distilled water and salt solutions of 1.5 mol/l each of NaCl
and KCl. The Swelling in water shows decreasing values of q, LE, Ø1, EWC% and increasing polymer volume fraction, Ø2 by
increasing acrylamide, due to increasing hydrophobicity and decreasing the hydrophilicity. The swelling in salt solutions
shows a decreasing in the values of ESSNa%, WCNa%, SCNa%, ESSK%, WCK% and SCK% by increasing acrylamid
monomer in the feed due to increasing the hydrophobicity and decreasing the ionized ionic groups (SO3H). The increasing
values of ESSNa%, WCNa% and SCNa% compared with the values of ESSK%, WCK% and SCK% respectively, is due to
the higher charge density of sodium ion than that of potassium ion.
Shhoob Mohamed imhmed Elahmir, Abdurhman A.Abuabdalla Khalifa1, (01-2017), ابريطانيا: MAYFEB Journal of Materials Science, 1 (1), 7-16
A semantic-driven model for ranking digital learning objects based on diversity in the user comments
Conference paperThis paper presents a computational model for measuring diversity in terms of variety, balance and disparity. This model is informed by the Stirling’s framework for understanding diversity from social science and underpinned by semantic techniques from computer science. A case study in learning is used to illustrate the application of the model. It is driven by the desire to broaden learners’ perspectives in an increasingly diverse and inclusive society. For example, interpreting body language in a job interview may be influenced by the different background of observers. With the explosion of digital objects on social platforms, selecting the appropriate ones for learning can be challenging and time consuming. The case study uses over 2000 annotated comments from 51 YouTube videos on job interviews. Diversity indicators are produced based on the comments for each video, which in turn facilitate the ranking of the videos according to the degree of diversity in the comments for the selected domain.
Entisar Nassr Abdulati Abolkasim, (09-2016), Springer: Springer, 3-15
Improving a Bag of Words Approach for Skin Cancer Detection in Dermoscopic Images.
Conference paperAbstract—With a rapidly increasing incidence of melanoma
skin cancer, there is a need for decision support systems to
detect it in its early stages, which would lead to better decisions
in treating it successfully. However, developing such systems is
still a challenging task for researchers. Several Computer Aided-
Diagnosis (CAD) systems have been proposed in the last two
decades to increase the accuracy of melanoma detection. Image
feature extraction is a critical step in differentiating between
melanoma and normal skin lesions. In this paper, we propose
to improve a bag-of-words approach by combining features
consisting of the color histogram and first order moments with the
Histogram of Oriented Gradients (HOG). Experimental results
show that the proposed technique significantly improves the
detection accuracy, with an average sensitivity of 91% and
specificity of 85%. The proposed system was validated on a
dataset of 200 medically annotated images (40 melanomas and
160 non-melanomas) obtained from the database of the Hospital
Pedro Hispano.
Naser Alfed, Fouad Khelifi, Ahmed Bouridane, (04-2016), Saint Julian's, Malta: IEEE. DOI: 10.1109/CoDIT38383.2016, 24-27
Mathematical reflection approach to instrumental variable estimation method for simple regression model
Journal ArticleThe measurement errors problem is endemic in many econometric studies, and one of the oldest known statistical problems. Instrumental variable (IV) method is one of the popular solutions adopted to deal with the mismeasured variables in statistical and econometric analyses. This paper proposes an efficient IV estimator to the parameters of the simple regression model where both variables are subject to measurement errors. The proposed IV is defined using simple mathematical transformation of the manifest independent variable (mismeasured variable). The proposed method is straightforward, and easy to implement. The theoretical superiority of the proposed estimator over the existing IV based estimators due to Wald (1940), Bartlett (1949), and Durbin (1954) is established by analytical comparison and geometric expositions. Simulation based numerical comparisons of the proposed estimator with four different existing estimators are also included.
Anwar A Mohamad Saqr, (01-2016), Pakistan Journal of Statistics: Pakistan Journal of Statistics, 32 (1), 37-48
Olive Pomace as an Abundant, Low-cost Adsorbent for Nitrate Removal from Aqueous Solution
Journal ArticleAbstract- Many methods have been applied in order to reduce nitrate concentration in aqueous solutions, among them
is the adsorption onto the surface of agricultural wastes. In this study, batch experiments were carried out to investigate
the adsorption of nitrate onto olive pomace (OP), a solid by-product of olive oil industry. To achieve this, six parameters
were studied by varying only one parameter at a time. These parameters were the effect of: pH, contact time,
temperature, adsorbent weight, agitation speed and nitrate concentration. The optimum pH was found to be 5, while the
optimum time was 75 minutes. Nitrate removal percentage was found to increase with increasing adsorbent weight or
temperature, with 92.5% of nitrate removed by using 2 g of OP and 48% of nitrate was removed at 60ºC. Generally,
agitation speed increased the nitrate removal percentage, while high initial concentration of nitrate was found to decrease
its removal percentage. These findings, combined with the low cost of OP and its abundance, suggest that OP is a
potential adsorbent for nitrate removal provided that the optimum conditions are applied. Applying this method for
nitrate removal will make drinking water safer to drink and wastewater safer to discharge.
Abdounasser Omar, (01-2016), 000: MAYFEB Journal of Environmental Science, 1 10-19
Pigment network-based skin cancer detection.
Conference paperAbstract— Diagnosing skin cancer in its early stages is a challenging task for dermatologists given the fact that the chance for a patient’s survival is higher and hence the process of analyzing skin images and making decisions should be time efficient. Therefore, diagnosing the disease using automated and computerized systems has nowadays become essential. This paper proposes an efficient system for skin cancer detection on dermoscopic images. It has been shown that the statistical characteristics of the pigment network, extracted from the dermoscopic image, could be used as efficient discriminating features for cancer detection. The proposed system has been assessed on a dataset of 200 dermoscopic images of the ‘Hospital Pedro Hispano’ [1] and the results of cross-validation have shown high detection accuracy.
Naser Alfed, Fouad Khelifi, Ahmed Bouridane, (08-2015), Milan, Italy: IEEE (EMBC), 7214-7217
Seed Size, Fecundity and Postfire Regeneration Strategy Are Interdependent in Hakea
Journal ArticleSeed size is a key functional trait that affects plant fitness at the seedling stage and may
vary greatly with species fruit size, growth form and fecundity. Using structural equation
modelling (SEM) and correlated trait evolution analysis, we investigated the interaction network
between seed size and fecundity, postfire regeneration strategy, fruit size, plant height
and serotiny (on-plant seed storage) among 82 species of the woody shrub genus, Hakea,
with a wide spectrum of seed sizes (2–500 mg). Seed size is negatively correlated with fecundity,
while fire-killed species (nonsprouters) produce more seeds than resprouters
though they are of similar size. Seed size is unrelated to plant height and level of serotiny
while it scales allometrically with fruit size. A strong phylogenetic signal in seed size revealed
phylogenetic constraints on seed size variation in Hakea. Our analyses suggest a
causal relationship between seed size, fecundity and postfire regeneration strategy in
Hakea. These results demonstrate that fruit size, fecundity and evolutionary history have
had most control over seed size variation among Hakea species.
Shhoob Mohamed imhmed Elahmir, (06-2015), UNITED STATES: journal.pone, 1 (1371), 1-12
Survival to extinction in a slowly varying harvested logistic population model
Journal ArticleThis work considers a harvested logistic population for which birth rate, carrying capacity and harvesting rate all vary slowly with time. Asymptotic results from earlier work, obtained using a multiscaling technique, are combined to construct approximate expressions for the evolving population for the situation where the population initially survives to a slowly varying limiting state, but then, due to increasing harvesting, is reduced to extinction in finite time. These results are shown to give very good agreement with those obtained from numerical computation.
Majda A. Idlango, (11-2013), Applied Mathematics Letters: ELSEVIER, 26 (11), 1035-1040
Cyclic AMP effectors in African trypanosomes revealed by genome-scale RNA Interference library screening for resistance to the phosphodiesterase inhibitor Cpd A
Journal ArticleOne of the most promising new targets for trypanocidal drugs to emerge in recent years is the cyclic AMP (cAMP) phosphodiesterase (PDE) activity encoded by TbrPDEB1 and TbrPDEB2. These genes were genetically confirmed as essential, and a highaffinity inhibitor, CpdA, displays potent antitrypanosomal activity. To identify effectors of the elevated cAMP levels resulting from CpdA action and, consequently, potential sites for adaptations giving resistance to PDE inhibitors, resistance to the drug was induced. Selection of mutagenized trypanosomes resulted in resistance to CpdA as well as cross-resistance to membranepermeable cAMP analogues but not to currently used trypanocidal drugs. Resistance was not due to changes in cAMP levels or in PDEB genes. A second approach, a genome-wide RNA interference (RNAi) library screen, returned four genes giving resistance to CpdA upon knockdown. Validation by independent RNAi strategies confirmed resistance to CpdA and suggested a role for the identified cAMP Response Proteins (CARPs) in cAMP action. CARP1 is unique to kinetoplastid parasites and has predicted cyclic nucleotide binding-like domains, and RNAi repression resulted in >100-fold resistance. CARP2 and CARP4 are hypothetical conserved proteins associated with the eukaryotic flagellar proteome or with flagellar function, with an orthologue of CARP4 implicated in human disease. CARP3 is a hypothetical protein, unique to Trypanosoma. CARP1 to CARP4 likely represent components of a novel cAMP signaling pathway in the parasite. As cAMP metabolism is validated as a drug target in Trypanosoma brucei, cAMP effectors highly divergent from the mammalian host, such as CARP1, lend themselves to further pharmacological development
Juma Ahmed Mohamed Ali, (10-2013), United States of America: Antimicrobial agents and chemotherapy, 10 (57), 4882-4893