Deficient Problems Research Articles

Investigating Meteorological Drought in the Northern Region of Nigeria and its Linkage with Climatic Drivers

Drought is a dearth of water, and a recurrence in all regions, but severe in the semi-arid and arid areas with adverse climatic conditions. There have been quite several studies in the country, but fewer in comparison to flood studies, which is in part due to drought nature as a hazard in the region. Drought creeping presence, the prevalence in arid northern Nigeria, and the water deficient problems have spawned the need for this research. The study aims to investigate drought events and drivers using the Standardised Precipitation Index and Standardised Precipitation Evapotranspiration Index for assessing drought historicity, principal component analysis to ascertain the spatiotemporal distribution of rainfall and meteorological drought, in addition to wavelet analysis to determine the relationship with climatic drivers in the region. The region is around latitude 6° N and 14° N and between longitude 2° E and 15° E within the Savanna region of Nigeria covering an area of 729, 815 square kilometers. For analyses, gridded rainfall data was collected from 1951-2021 and processed with a 4-step homogeneity test to track the decline in rainfall and the advent of drought in the region. These analyses showed that drought episodes are a recurring climatic theme in the region, and it was severe in the 1970s, 1980s and continued into the 21st century. Also, principal component analysis and K-means clustering techniques proved that coherence and variation between the regions are a function of the spatial distance between them. Further examination proved that rainfall transits between humid to arid regions, declining in events and intensity as it moves northward of the area. Drought relationship with climatic indices outlines the Tropical South Atlantic as a principal factor with a leading signal of 4-12 months, in the influence of weather conditions, which creates a window in drought management through monitoring.

Understanding the Role of Oxidative Stress, Neuroinflammation and Abnormal Myelination in Excessive Aggression Associated with Depression: Recent Input from Mechanistic Studies.

Aggression and deficient cognitive control problems are widespread in psychiatric disorders, including major depressive disorder (MDD). These abnormalities are known to contribute significantly to the accompanying functional impairment and the global burden of disease. Progress in the development of targeted treatments of excessive aggression and accompanying symptoms has been limited, and there exists a major unmet need to develop more efficacious treatments for depressed patients. Due to the complex nature and the clinical heterogeneity of MDD and the lack of precise knowledge regarding its pathophysiology, effective management is challenging. Nonetheless, the aetiology and pathophysiology of MDD has been the subject of extensive research and there is a vast body of the latest literature that points to new mechanisms for this disorder. Here, we overview the key mechanisms, which include neuroinflammation, oxidative stress, insulin receptor signalling and abnormal myelination. We discuss the hypotheses that have been proposed to unify these processes, as many of these pathways are integrated for the neurobiology of MDD. We also describe the current translational approaches in modelling depression, including the recent advances in stress models of MDD, and emerging novel therapies, including novel approaches to management of excessive aggression, such as anti-diabetic drugs, antioxidant treatment and herbal compositions.

Preconditioners for rank deficient least squares problems

In this paper we present a method for computing sparse preconditioners for iteratively solving rank deficient least squares problems (LS) by the LSMR method. The main idea of the method proposed is to update an incomplete factorization computed for a regularized problem to recover the solution of the original one. The numerical experiments for a wide set of matrices arising from different science and engineering applications show that the preconditioner proposed, in most cases, can be successfully applied to accelerate the convergence of the iterative Krylov subspace method.

A note on the optimal parameters of USSOR method for solving linear least squares problems

For solving rank deficient linear least squares problems, unsymmetric successive overrelaxation (USSOR) type methods are investigated by some researchers recently. In this note, we continue to study the USSOR method for solving rank deficient linear least squares problems and obtain the optimal iteration parameters and the corresponding optimal convergence factors. Numerical experiments are given to examine the feasibility and effectiveness of the USSOR method with optimal parameters.

Deconvolved conventional beamforming for a planar array and Cramer Rao bound

It is well known that the beam power output of conventional (delay and sum) beamforming (CBF) can be expressed as the convolution of the source distribution and the response of the beamformer to the point source. Consequently, the original source distribution can be recovered by deconvolution, yielding not only improved direction of arrival (DOA) estimation in terms of a narrower beam width and suppressed side lobes but also higher array gain than CBF (the deconvolution gain) as demonstrated by Yang for a uniformly spaced line array (ULA) [T. C. Yang, 10.1109/ JOE. 2017. 2680818]. In addition, the method is insensitive to signal mismatch and snapshot deficient problems in comparison with other high resolution methods such as minimum variance distortionless response (MVDR). In this paper, we extend the Richardson-Lucy algorithm for deconvolution to a planar array where the signal can be coming in any direction. Simulation analysis as well as experimental data will be presented to study the beam width and array gain as a function of number of receivers, the frequency of the incoming signals including narrow and broad band signals, and the ability to reject interference. We also calculate the Cramer-Rao bound to compare with the experimental result.

Assesment of changes in the sagittal pharyngeal airway dimensions post twin-block therapy using polar planimeter

Background and Aim: An inordinate percentage of orthodontic patients present with Class II mandibular deficient problems. Mandibular deficiency is one of the major risk factors for developing obstructive sleep apnea (OSA). If functional appliance therapy for mandibular development also increases the pharyngeal airway dimensions the risk for developing OSA in these patients will be minimized. The aim of the present study is to evaluate the changes in the sagittal pharyngeal airway dimensions (SPAD) after twin-block functional appliance therapy in adolescent patients with mandibular retrognathism, utilizing linear, and area measurements. Materials and Methods: A total of 14 patients with an age range of 12–14 years, both the genders having skeletal Class II malocclusion with a deficient mandible were selected and twin-block functional therapy was initiated. Lateral cephalograms were taken at the start of functional jaw orthopedic treatment (time point T1) and at its completion (time point T2) after 4–5 months. Specific areas and distances were measured and analyzed. Results: The area measures increased significantly while the linear measurements showed a non significant increase. The oropharynx (P = 0.008) area displayed the most significant increase followed by nasopharynx (P = 0.014) and laryngopharynx (P = 0.028). Conclusion: Functional appliance therapy utilizing twin-block appliance in Class II malocclusion patients with retrognathic mandible was efficient in increasing the SPAD.

On the Matrix Square Root via Geometric Optimization

This paper is triggered by the preprint [P. Jain, C. Jin, S.M. Kakade, and P. Netrapalli. Computing matrix squareroot via non convex local search. Preprint, arXiv:1507.05854, 2015.], which analyzes gradient-descent for computing the square root of a positive definite matrix. Contrary to claims of Jain et al., the author’s experiments reveal that Newton-like methods compute matrix square roots rapidly and reliably, even for highly ill-conditioned matrices and without requiring com-mutativity. The author observes that gradient-descent converges very slowly primarily due to tiny step-sizes and ill-conditioning. The paper derives an alternative first-order method based on geodesic convexity; this method admits a transparent convergence analysis (< 1 page), attains linear rate, and displays reliable convergence even for rank deficient problems. Though superior to gradient-descent, ultimately this method is also outperformed by a well-known scaled Newton method. Nevertheless, the primary value of the paper is conceptual: it shows that for deriving gradient based methods for the matrix square root, the manifold geometric view of positive definite matrices can be much more advantageous than the Euclidean view.

Chemical species tomography of turbulent flows: Discrete ill-posed and rank deficient problems and the use of prior information

Due to the inherent ill-posed nature of chemical species tomography (CST) problems, additional information based on the presumed species distribution must be introduced into the reconstruction procedure. The role that this prior information plays in tomographic reconstruction differs depending on whether the CST problem is discrete ill-posed or rank-deficient. The former case arises mainly in laboratory studies involving small scale problems with high degrees of optical access and often a stationary flow field, while the later occurs when the number and arrangement of measurements are limited by the size and/or the optical access afforded by the containing geometry. This paper elucidates the difference between these two types of CST problems, and reviews various ways that prior information can be used to enhance reconstruction accuracy of CST experiments on turbulent flows.

Menopausal Symptoms and Its Correlates: A Study on Tribe and Caste Population of East India.

Present study aimed to compare the incidence of menopausal problems and concomitants between tribe and caste population. This cross section study was conducted in five villages of West Bengal, a state in the eastern part of India. This study was conducted between two different ethnic groups—one of the “Particularly Vulnerable Tribal Groups (PTG)” of India named as “Lodha” and the other was a Bengali speaking caste population. A total number of 313 participants were finally recruited for this study. Study participants were married, had at least one child, had no major gynaecological problems, and had stopped menstrual bleeding spontaneously for at least 1 year. Additionally, data on sociodemographic status and menstrual and reproductive history were collected using a pretested questionnaire/schedule. Bivariate analyses (chi square test) revealed that significantly more number of caste participants suffered from urinary problems than their tribe counterpart. The reverse trend has been noticed for the frequency of vaginal problems. Multivariate analyses (binary logistic regression) show that sociodemographic variables and menstrual and reproductive history of the present study participants seem to be the concomitants of menopausal symptoms. Tribe and caste study population significantly differed with respect to the estrogen deficient menopausal problems and the concomitants to these problems.

Development for generating electric power shoes having a vibrating sheet generator assembly

It is often seen an object move or vibrate repeatedly. Some phenomenons are useful, but another is unavailable motion. The unavailable motion makes a lot of energy dissipation. In order to utilize the energy unavailable motion makes, the research will use the energy to generate electric power for solving the deficient personal energy sources problems. In general, the generator coil sweeps the magnetic field line to generate the electric power these days. The revolving spindle will abrasion and the energy will loss. Therefore, the generating efficiency of electric power will decrease [1-4]. The research utilizes a structure of sheet generator to generate electric power. The present research relates to a method for manufacturing a sheet generator having a flat coil assembly, and more particularly to a method comprising the steps of placing a flat coil into an injecting mold; forming a locating section to secure the flat coil; and assembling the sheet generator. The relative motion between coil and magnet will generate electric power in accordance with the Fleming’s right-hand rule. In order to assess the efficiency of generating electric power, the research will design an experimental device to simulate the sheet generator. First, two plastic diaphragms be used to laminate the coil. Then, place the laminate diaphragm on the inverted U-shape structure of experimental device. Because the inverted U-shape structure and magnet move relatively, so the electric power will be produce by cutting magnetic field line. The server motor drives the cam to press the inverted U-shape structure. When the motor rotational speed is 120 r.p.m. (2Hz), then the voltage of generating electric power can obtain exceeds respectively 1.5V, 2.0V and 2.5V without assembling the bridge circuit at the coil of 1 layer, 2 layers and 3 layers, as shown in Table ​Table1.1. Actually, the voltages of generating electric power shoes exceed respectively 1V and 2V without assembling the bridge circuit under the human walking motion and running motion, as shown in Figure ​Figure1.1. The basic goal of the research has achieved. And the design parameters can easily provide the industry of electric power shoes. The industry of storage energy will be developed and established. Table 1 The table of relationship between number of coil layers and voltage Figure 1 Testers wore shoes for generating voltage measurements

Radioactive body burden measurements in (131)iodine therapy for differentiated thyroid cancer: effect of recombinant thyroid stimulating hormone in whole body (131)iodine clearance.

Protocols in the management of differentiated thyroid cancer, recommend adequate thyroid stimulating hormone (TSH) stimulation for radioactive 131I administrations, both for imaging and subsequent ablations. Commonly followed method is to achieve this by endogenous TSH stimulation by withdrawal of thyroxine. Numerous studies worldwide have reported comparable results with recombinant human thyroid stimulating hormone (rhTSH) intervention as conventional thyroxine hormone withdrawal. Radiation safety applications call for the need to understand radioactive 131I (RA131I) clearance pattern to estimate whole body doses when this new methodology is used in our institution. A study of radiation body burden estimation was undertaken in two groups of patients treated with RA131I; (a) one group of patients having thyroxine medication suspended for 5 weeks prior to therapy and (b) in the other group retaining thyroxine support with two rhTSH injections prior to therapy with RA131I. Sequential exposure rates at 1 m in the air were measured in these patients using a digital auto-ranging beta gamma survey instrument calibrated for measurement of exposure rates. The mean measured exposure rates at 1 m in μSv/h immediately after administration and at 24 h intervals until 3 days are used for calculating of effective ½ time of clearance of administered activity in both groups of patients, 81 patients in conventionally treated group (stop thyroxine) and 22 patients with rhTSH administration. The 131I activities ranged from 2.6 to 7.9 GBq. The mean administered 131I activities were 4.24 ± 0.95 GBq (n = 81) in “stop hormone” group and 5.11 ± 1.40 GBq (n = 22) in rhTSH group. The fall of radioactive body burden showed two clearance patterns within observed 72 h. Calculated T½eff values were 16.45 h (stop hormone group) 12.35 h (rhTSH group) for elapsed period of 48 h. Beyond 48 h post administration, clearance of RA131I takes place with T½eff> 20 h in both groups. Neck and stomach exposure rate measurements showed reduced uptakes in the neck for rhTSH patients compared with “stop thyroxine” group and results are comparable with other studies. Whole body clearance is faster for patients with rhTSH injection, resulting in less whole body absorbed doses, and dose to blood. These patients clear circulatory radioactivity faster, enabling them to be discharged sooner, thus reduce costs of the hospitalization. Reduction in background whole body count rate may improve the residual thyroid images in whole body scan. rhTSH provides TSH stimulation without withdrawal of thyroid hormone and hence can help patients to take up therapy without hormone deficient problems in the withdrawn period prior to RA131I therapy. This also will help in reducing the restriction time periods for patients to mix up with the general population and children.

Clinical and Experimental Immunomodulation

Clinical and Experimental Immunomodulation

Ears and airways in children with down's syndrome

Keynote speaker at BAPA special interest session at RCPCH annual conference.Down's syndrome is the most common human chromosomal defect encountered in paediatrics. It occurs in one in 600 to 800...

Analysis Of The Academic Studıes’ Results In Environmental Education In Turkey About Global Warming And Greenhouse Effect

This study aimed to analyze the articles and proceedings on global warming and greenhouse effect published in environmental education area in Turkey. Docu- ment analysis was used in data collection procedure within the frame of qualitative research; however, content analysis technique was used in the analysis of texts. Examined texts showed that the students in all education levels from elementary to higher education, and even the teachers had concept errors and deficient knowledge problems related to the issue of global warming and greenhouse effect. Therefore, the designation of the researches that will be conducted in environmental education area from now on in the direction of solutions for these problems which can appear in learning would be beneficial.

Deconstructing ‘Aspiration’: UK Policy Debates and European Policy Trends

Strategies of ‘employability’ and ‘activation’ are increasingly favoured in the European Union policy context. These strategies are aimed at fostering inclusion by stressing the responsibility of the individual to participate in education and employment. Similar tendencies can be observed in the United Kingdom (UK) over the last decade, among them a debate on raising young people's aspirations. The article reports first findings from a research project on the construction of ‘aspiration’ in and through policy debates in the United Kingdom. Drawing on Michel Foucault's concepts of Archaeology and Genealogy, policy documents were analysed for the discursive strategies they employ. The analysis suggests that the debate on ‘aspiration’ constructs young people from disadvantaged backgrounds as deficient, conflates economic and social equality discourses and individualises structural problems. These discursive strategies mirror tendencies that can be observed in strategies of activation and employability in the United Kingdom and the European Union. Focusing on ‘aspiration’ can be regarded as a way to prepare young people for the responsibility to actively pursue labour market participation at an even earlier stage.

Preconditioner based on the Sherman–Morrison formula for regularized least squares problems

We propose a sparse approximate inverse preconditioner based on the Sherman–Morrison formula for Tikhonov regularized least square problems. Theoretical analysis shows that, the factorization method can take the advantage of the symmetric property of the coefficient matrix and be implemented cheaply. Combined with dropping rules, the incomplete factorization leads to a preconditioner for Krylov iterative methods to solve regularized least squares problems. Numerical experiments show that our preconditioner is competitive compared to existing methods, especially for ill-conditioned and rank deficient least squares problems.

The adaptive augmented GMRES method for solving ill-posed problems

The GMRES method is an iterative method that provides better solutions when dealing with large linear systems of equations with a non-symmetric coefficient matrix. The GMRES method generates a Krylov subspace for the solution, and the augmented GMRES method allows augmentation of the Krylov subspaces by a user supplied subspace which represents certain known features of the desired solution. The augmented GMRES method performs well with suitable augmentation, but performs poorly with unsuitable augmentation. The adaptive augmented GMRES method automatically selects a suitable subspace from a set of candidates supplied by the user. This study shows that this method maintains the performance level of augmented GMRES and lightens the burden it puts on its users. Numerical experiments compare robustness as well as the efficiency of various heuristic strategies. References M. L. Baart. The use of auto-correlation for pseudo-rank determination in noisy ill-conditioned linear least-squares problems. IMA Journal of Numerical Analysis, 2:241--247, 1982. doi:10.1093/imanum/2.2.241 J. Baglama and L. Reichel. Augmented GMRES-type method. Numerical Linear Algebra with Applications, 14:337--350, 2007. doi:10.1002/nla.518 D. Calvetti, B. Lewis, and L. Reichel. GMRES-type methods for inconsistent systems. Linear Algebra and its Applications, 316:157--169, 2000. doi:10.1016/S0024-3795(00)00064-1 D. Calvetti, B. Lewis, and L. Reichel. On the choice of subspace for iterative methods for linear discrete ill-posed problems. Int. J. Appl. Math. Comput. Sci, 11:1069--1092, 2001. http://www.math.kent.edu/ reichel/publications/subspaceselect.pdf G. H. Golub and C. F. Van Loan. Matrix Computations. Johns Hopkins University Press, 2nd edition, 1989. P. C. Hansen. Regularization tools: A matlab package for analysis and solution of discrete ill-posed problems. Numerical Algorithms, 6:1--35, 1994. doi:10.1007/BF02149761 P. C. Hansen. Rank Deficient and Discrete Ill-Posed Problems. SIAM, Philadelphia, 1998. Y. Saad. and M. H. Schultz. GMRES: A generalized minimal residual method for solving nonsymmetric linear systems. SIAM J. Sci. Stat. Comput., 7:856--869, 1986. http://www.stanford.edu/class/cme324/saad-schultz.pdf

AOR iterative methods for rank deficient least squares problems

In this paper we study the semiconvergence of accelerated overrelaxation (AOR) iterative methods for the least squares solution of minimal norm of rank deficient linear systems. Necessary and sufficient conditions for the semiconvergence of the AOR and JOR iterative methods are given. The optimum parameters and the associated convergence factor are derived.

Analysis of the Medical Imaging Services at Three Hospitals of the Mexican National Health System

We present a study on the quality of operation and the characteristics of the medical imaging equipment in three specialty hospitals of the Mexican Health System. Six month residencies were carried out in order to better understand the problems and internal functioning of the three imaging departments. The kinds of equipment, the types of equipment failures and the internal operation of these services were analyzed. The results allow us to identify four factors that are linked to faults in the quality of the health care delivered to patients. The first factor is equipment obsolescence; the second is related to deficient preventive maintenance procedures and problems associated the supervising of external service providers. The third factor is derived from the equipment's (over) workload, which is indirectly tied to the age of the imaging modalities and the fourth factor is misuse of the equipment. The solutions to these problems include the modernization of the equipment and a better supervision by the clinical engineering department of all the processes involving the medical imaging services in each hospital. In addition to this, a special effort of the continuing education of personnel associated with medical imaging at all levels should be carried out.

Exploiting ICT potential in service firms in transition economies

Service industries are the most intensive users of information-communication technology (ICT) and some developed countries have already displayed noticeable productivity gains due to ICT use in services. The pattern of intensive use of ICT in services tends to be replicated in transition economies, however the evidence of ICT impacts on growth and productivity is lacking at the aggregate and industry level owing to deficient data and methodological problems. To overcome some of the problems in estimating the effects of ICT use we pursue firm-level analysis and apply production function approach to estimate the impact of ICT on the performance of service firms in Slovenia. The results suggest that service firms are more intensive ICT users than manufacturing firms and that ICT use significantly influences the productivity of service firms. The positive impact of ICT use on productivity applies to all service firms irrespective of their size. The links are stronger for service firms with above average ICT use. Due to the absence of data on complementary expenditures for training and organisational change related to ICT adoption the results might overemphasise the effects of ICT investment.