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PubMed2004

IMRT optimization: variability of solutions and its radiobiological impact.

We aim at (1) defining and measuring a "complexity" index for the optimization process of an intensity modulated radiation therapy treatment plan (IMRT TP), (2) devising an efficient approximate optimization strategy, and (3) evaluating the impact of the complexity of the optimization process on the radiobiological quality of the treatment. In this work, for a prostate therapy case, the IMRT TP optimization problem has been formulated in terms of dose-volume constraints. The cost function has been minimized in order to achieve the optimal solution, by means of an iterative procedure, which is repeated for many initial modulation profiles, and for each of them the final optimal solution is recorded. To explore the complexity of the space of such solutions we have chosen to minimize the cost function with an algorithm that is unable to avoid local minima. The size of the (sub)optimal solutions distribution is taken as an indicator of the complexity of the optimization problem. The impact of the estimated complexity on the probability of success of the therapy is evaluated using radiobiological indicators (Poissonian TCP model [S. Webb and A. E. Nahum, Phys. Med. Biol. 38(6), 653-666 (1993)] and NTCP relative seriality model [Kallman et al., Int. J. Radiat. Biol. 62(2), 249-262 (1992)]). We find in the examined prostate case a nontrivial distribution of local minima, which has symmetry properties allowing a good estimate of near-optimal solutions with a moderate computational load. We finally demonstrate that reducing the a priori uncertainty in the optimal solution results in a significant improvement of the probability of success of the TP, based on TCP and NTCP estimates.

Algorithms↗
PubMed2001

A rate distortion optimal ECG coding algorithm.

Signal compression is an important problem encountered in many applications. Various techniques have been proposed over the years for addressing the problem. In this paper, we present a time domain algorithm based on the coding of line segments which are used to approximate the signal. These segments are fit in a way that is optimal in the rate distortion sense. Although the approach is applicable to any type of signal, we focus, in this paper, on the compression of electrocardiogram (ECG) signals. ECG signal compression has traditionally been tackled by heuristic approaches. However, it has been demonstrated [1] that exact optimization algorithms outperform these heuristic approaches by a wide margin with respect to reconstruction error. By formulating the compression problem as a graph theory problem, known optimization theory can be applied in order to yield optimal compression. In this paper, we present an algorithm that will guarantee the smallest possible distortion among all methods applying linear interpolation given an upper bound on the available number of bits. Using a varied signal test set, extensive coding experiments are presented. We compare the results from our coding method to traditional time domain ECG compression methods, as well as, to more recently developed frequency domain methods. Evaluation is based both on percentage root-mean-square difference (PRD) performance measure and visual inspection of the reconstructed signals. The results demonstrate that the exact optimization methods have superior performance compared to both traditional ECG compression methods and the frequency domain methods.

Algorithms↗
PubMed2003

Robust estimation of ultrasound pulses using outlier-resistant de-noising.

A different approach to the problem of estimation of the ultrasound pulse spectrum, which usually arises as a part of ultrasound image restoration algorithms, is presented. It is shown that this estimation problem can be reformulated in terms of a de-noising problem. In this formulation, the log-spectrum of a radio-frequency line (RF-line) is viewed as a noisy measurement of the signal that needs to be estimated, i.e., the ultrasound pulse log-spectrum. The log-spectrum of the tissue reflectivity function (i.e., tissue response) is considered as the noise to be rejected. The contribution of the paper is twofold. First, it provides statistical description of the reflectivity function log-spectrum for the case, when the samples of the reflectivity function are independent identically distributed (i.i.d.) Gaussian random variables. Moreover, it is shown that the problem of the pulse spectrum recovery is essentially a de-noising problem. Consequently, it is suggested to solve the problem within the framework of the de-noising by wavelet shrinkage. Second, a computationally efficient algorithm is proposed for the pulse-spectrum estimation, which can be viewed as a modified version of the classical Donoho's three-step de-noising procedure. This modification is necessary, because of specific properties of the noise to be rejected. It is shown, that whenever the samples of the reflectivity function can be assumed to be i.i.d. Gaussian random variables, the samples of its log-spectrum obey the Fisher-Tippet distribution. For this type of noise, straightforward implementation of the standard de-noising can cause serious estimation errors. In order to overcome this difficulty, an outlier-resistant de-noising is performed. The unique properties of this modified de-noising algorithm allow estimating the pulse spectrum adaptively to its properties, as they are continuously influenced by the frequency-dependent attenuation process. The performance of the proposed algorithm is examined in a series of computer-simulations. It is shown that this algorithm, developed on the assumption of the "Gaussian" reflectivity function, remains applicable for broader classes of distributions. The results obtained in a series of in vivo experiments reveal superior performance of the novel approach over some of alternative estimation techniques, e.g., cepstrum-based estimation.

Adult↗
PubMed1994

The confusion of tongues and psychic trauma.

'The confusion of tongues' characterised the polarised dimensions of the closing Ferenczi/Freud communication, and extended to problems of psychoanalytic formulation and publication. There were manifest and latent issues which remain of historic importance. Ferenczi was dying and assumed Freud was dying when he wrote this classic essay, so relevant to contemporary psychoanalytic thought and controversy. Denying and sometimes acknowledging his progressive, fatal illness, Ferenczi made enduring contributions to the understanding of child abuse and trauma while severely traumatised. Concepts of trauma and countertransference were amplified and expanded. Freud remained remarkably creative while physically declining with oral cancer; Ferenczi manifested progressive and regressive trends, fostering both sublimated innovation and wild analysis. Psychoanalysts tended to avoid, for half a century, confronting the problems of the ill, impaired, and dying analyst. The clarification of 'The confusion of tongues' continues in contemporary psychoanalytic discussion and debate. The paper presaged a widened interest in the analyst's analysing functions, unconscious communication, countertransference, and the interplay of reality and fantasy inside and outside the psychoanalytic situation.

Adult↗
PubMed1999

National health policies: sub-Saharan African case studies (1980-1990).

Four countries, Botswana, Cote d'Ivoire, Ghana and Zimbabwe, were chosen as cases to study the impact of national health policies on national health status in sub-Saharan Africa. Through a conceptual framework that covers health problem identification, policy formulation and implementation procedures, the study examined national translations of Primary Health Care (PHC) and Health for All by the Year 2000 (HFA/2000) strategies. A series of government measures, taken between 1980-1986 for health policy development and implementation in these countries, were treated as policy determinants of national health outcomes for the period ending 1990. The impact of these determinants on national health status was then analyzed through a comparative description and documentation of observable patterns and trends in infant mortality rates (IMR), under-5 mortality rates (U5MR) and life expectancy. Policy guidelines from PHC and HFA/2000 were used in conjunction with the respective per capita Gross National Products to categorize the four cases. Based on these guidelines, Botswana was ranked high, both in terms of policy development and the level of economic development, while Zimbabwe ranked high in terms of policy development but relatively low in economic terms. Cote d'Ivoire ranked high on economic development but low with regard to its policy framework. Ghana was at the other end of the spectrum, ranking low both in terms of its policy development and its economic performance. The comparative analysis revealed that Botswana and Zimbabwe performed better than Cote d'Ivoire and Ghana on the three outcome indicators. Despite Cote d'Ivoire's superior level of economic development, its health status fell behind that of Zimbabwe and even Ghana. The study concluded that policies formulated and implemented in accordance with key PHC principles could account for improvements in national health status. Since the end of the study period (1990), there have been significant political changes in the sub-Saharan African region as a whole and in some of the case countries in particular. Political leadership has changed in Ghana and Cote d'Ivoire with some course corrections in Ghana's health plans. Health sector financing in the region has become more dependent on external donors. The World Bank leads the external donor community in promoting policy-based lending. The complexity of a number of health problems has changed while the problems themselves remain the same as before. Essentially, building viable public health infrastructures to address basic public health needs must still be high on the agenda of action for most governments in the region. Thus, notwithstanding some course corrections and reasonable shifts in priorities, all the PHC principles are still applicable, indeed, much needed in the sub-Saharan African region. This study's findings, underscoring the fact that significant improvements in health are possible even where financial resources are limited, still hold true.

Africa South of the Sahara↗
PubMed2001

Predictive algorithms for neuromuscular control of human locomotion.

The problem of quantifying muscular activity of the human body can be formulated as an optimal control problem. The current methods used with large-scale biomechanical systems are non-derivative techniques. These methods are costly, as they require numerous integrations of the equations of motion. Additionally, the convergence is slow, making them impractical for use with large systems. We apply an efficient numerical algorithm to the biomechanical optimal control problem. Using direct collocation with a trapezoidal discretization, the equations of motion are converted into a set of algebraic constraint equations. An augmented Lagrangian formulation is used for the optimization problem to handle both equality and inequality constraints. The resulting min-max problem is solved with a generalized Newton method. In contrast to the prevalent optimal control implementations, we calculate analytical first- and second-derivative information and obtain local quadratic convergence. To demonstrate the efficacy of the method, we solve a steady-state pedaling problem with 7 segments and 18 independent muscle groups. The computed muscle activations compare well with experimental EMG data. The computational effort is significantly reduced and solution times are a fraction of those of the non-derivative techniques.

Algorithms↗
PubMed1996

Pharmaceutical care applied to the hospice setting: a cancer pain model.

A review of the concept of pharmaceutical care applied to the hospice setting with emphasis on the management of cancer pain. Traditionally pharmacists involved in hospice care have acted in a distributive function and as an information resource. The advantages of having a hospice pharmacist practicing pharmaceutical care are many and include enhanced patient quality of care through monitoring patient outcomes, establishing drug therapy protocols, enhanced patient compliance through patient education, better pain and symptom control, and staff education. Monitoring therapeutic outcomes starts with chart reviews to collect all relevant information and attending patient care conferences to obtain information concerning the patient's condition. Once this is done, a patient-specific drug-related problem list is formulated, and from this list, desired therapeutic outcomes and alternatives are established to monitor therapy and to insure the drug is producing the desired effect. Pharmaceutical care fits well with the concept of hospice care, which has as its primary purpose maintaining the quality of life in the terminal patient. There is no portion of caring for the terminally ill patient that is more important than the management of pain. As a result of implementing the concept of pharmaceutical care in the hospice setting for cancer patients, pain can be managed in an effective and compassionate way. By monitoring treatments and eliminating medication-induced problems, the pharmacist becomes a valuable member of the health care team in the management of terminally ill patients. This in turn increases the quality of care as well as the quality of life for the hospice patient.

Hospice Care↗
PubMed2005

Oral formulation of a novel antiviral agent, PG301029, in a mixture of gelucire 44/14 and DMA (2:1, wt/wt).

To develop an oral formulation for PG301029, a novel potent agent for the treatment of Hepatitis C virus infection, that not only has very low aqueous solubility but also degrades rapidly in water. The solubility of PG301029 was determined in water, various aqueous media, and several neat organic solvents. The stability of PG301029 was monitored at room temperature in buffers for 4 days, and in several neat organic solvents for up to 8 mo. Drug concentrations were measured by high-performance liquid chromatography (HPLC). Based on solubility and stability data, Gelucire 44/14 and DMA (N,N-dimethylacetamide) at a weight ratio of 2 to 1 were chosen as the formulation vehicle. After the vehicle was prepared, it was maintained in liquid form at approximately 40 degrees C until the PG301029 was dissolved. The final formulation product was a semisolid at room temperature. The bioavailability of the formulation was tested on 4 female BALB/c mice. PG301029 is insoluble in all tested aqueous media, while its solubility is promising in DMA. This compound is unstable in aqueous media and some organic solvents; however, it is stable in DMA. This proposed formulation is able to hold up to 10 mg/mL of drug and is stable at 4 degrees C. The shelf life for this formulation stored at 4degreesC is extrapolated to be greater than 4 years. This formulation dramatically increases the bioavailability of PG301029. This nonaqueous formulation solves the stability, solubility, and bioavailability problems for PG301029. This semisolid formulation can easily be incorporated into soft elastic capsules.

Acetamides↗
PubMed2001

Constrained optimization of L-lysine production based on metabolic flux using a mathematical programming method.

Constrained optimization for microbial fermentation was studied. For optimization, we used not the maximum principle but a nonlinear programming method because of the need to consider many metabolic reactions. In the case of L-lysine fermentation, the optimization problem in L-lysine production was formulated as a nonlinear programming problem. In general, the state equations based on material balances are represented as differential equations, but such equations which are dependent on time can not be applied to a nonlinear programming problem. Therefore, the state equations were made discrete in a time base, and a new single vector which is not dependent on time was substituted. From these formulae, the objective function and the constraints using nonlinear programming problem were defined as the amount of L-lysine produced, and as a metabolic reaction model and empirical equations, respectively. Computer program was developed to solve this constrained nonlinear programming problem. The applied algorithm of the computer programming was a sequential quadratic programming method (SQP method). When the constrained nonlinear programming problem is solved using the SQP method, the maximum amount of L-lysine produced and the optimal feeding rate of L-threonine could be calculated. From the calculated results, it was clear that introduction of the equality and inequality constraints was easy. L-Lysine at a concentration up to 75.3 g/l could be produced when the fermentation was carried out under optimal conditions.

Journal Article↗
PubMed2006

Intensity correction of fluorescent confocal laser scanning microscope images by mean-weight filtering.

This paper addresses the problem of intensity correction of fluorescent confocal laser scanning microscope images. Confocal laser scanning microscope images are frequently used in medicine for obtaining 3D information about specimen structures by imaging a set of 2D cross sections and performing 3D volume reconstruction afterwards. However, 2D images acquired from fluorescent confocal laser scanning microscope images demonstrate significant intensity heterogeneity, for example, due to photo-bleaching and fluorescent attenuation in depth. We developed an intensity heterogeneity correction technique that (a) adjusts the intensity heterogeneity of 2D images, (b) preserves fine structural details and (c) enhances image contrast, by performing spatially adaptive mean-weight filtering. Our solution is obtained by formulating an optimization problem, followed by filter design and automated selection of filtering parameters. The proposed filtering method is experimentally compared with several existing techniques by using four quality metrics: contrast, intensity heterogeneity (entropy) in a low frequency domain, intensity distortion in a high frequency domain and saturation. Based on our experiments and the four quality metrics, the developed mean-weight filtering outperforms other intensity correction methods by at least a factor of 1.5 when applied to fluorescent confocal laser scanning microscope images.

Biometry↗
PubMed2005

Microlinguistic deficits in the narrative discourse of adults with traumatic brain injury.

BACKGROUND: Recent studies of microlinguistic impairments in the narrative discourse of adults with traumatic brain injury (TBI) have applied syntactic analyses, with some noting no deficits and others specific problems with sentence formulation. An alternative approach to examining the microlinguistic dysfunction in the discourse of individuals with TBI is through the use of propositional analysis. The advantage of propositional analysis is that it enables one to assess semantic complexity of utterances apart from sentence structure and grammaticality. AIMS: The present study applied propositional analysis to the story narratives of participants with TBI and participants with no brain injury (NBI). Specifically, the mean number of propositions within a sentence was tallied, in other words the participants' ability to insert multiple ideas into single surface sentences. It was hypothesized that the participants with TBI would produce fewer propositions per sentence because of organizational problems than the participants with NBI, regardless of level of education. METHODS AND PROCEDURES: Two story narratives (retelling and generation) previously elicited from the two participant groups (TBI (n = 53) and NBI (n = 42)) were analysed. For each language sample, the number of propositions was tallied and divided by the number of T-units. The resulting number, the propositional complexity index (PCI), was the average number of predicates per sentence. OUTCOMES AND RESULTS: Results indicated that the group with TBI produced significantly fewer propositions per T-unit. CONCLUSIONS: The present findings are in harmony with the notion that the participants with TBI studied presented with impairments of both micro- and macrolinguistic processes involved with the organization of semantic information in discourse. Clinical implications are discussed.

Adolescent↗
PubMed1978

Experience with a Fourier method for determining the extracellular potential fields of excitable cells with cylindrical geometry.

In this chapter, well-known solutions that utilize a Fourier transform method for determining the extracellular, volume-conductor potential distribution surrounding elongated excitable cells of cylindrical geometry are reformulated as a discrete Fourier transform (DFT) problem, which subsequently permits the volume-conductor problem to be viewed as an equivalent linear-filtering problem. This DFT formulation is fast and computationally efficient. In addition, it lends itself to the application of some rather well-known techniques in linear systems theory (e.g., the DFT for convolution and least mean-square (Wiener) filtering for optimal prediction of a signal in random noise). Two specific examples are employed to demonstrate the utility of this discrete Fourier method: (1) the single, isolated, active nerve fiber in an essentially infinite volume conductor and (2) the isolated, active nerve trunk in a similar type of extracellular medium. In each of these, our DFT method is employed to obtain both the classical "forward" and "inverse" potential solutions for each volume conductor problem. In the case where the single, active nerve fiber is the bioelectric source in the volume conductor, simulated action-potential data from an invertebrate giant axon is utilized, and potentials at various points in the extracellular medium are calculated. The calculated potential distributions in axial distance z, at various radial distances r, are consistent with well-known experimental fact. When the active nerve trunk acts as the bioelectric source, the DFT method provides calculated potential distributions that are fairly consistent with experimental data under a variety of experimental conditions. For example, in these experiments, a special, isolated frog spinal cord preparation is used that permits separate or combined stimulation of the motor and sensory nerve fiber components of the attached sciatic nerve trunk. By manipulating the stimulus intensity applied to the motor (ventral) or appropriate sensory (dorsal) roots of the spinal cord, a variety of multiphasic extracellular volume-conductor potentials can be recorded from the sciatic nerve. The excellent agreement of model-generated and experimental data, regardless of the complexity of surface potential waveform, tends to validate the modeling assumptions and offer encouragement that this computationally efficient DFT method may be usefully employed in volume-conductor problems where both the bioelectric source, and the surrounding volume conductor, are of a much more complicated nature.

Action Potentials↗
PubMed2001

A systems approach to the evaluation of natural resource management initiatives.

Adopting a new paradigm for natural resource and environmental policy that emphasises continuous change, adaptation and learning demands a new approach to evaluation to enable improvements in the way these initiatives contribute to sustainable resource use. Evaluation is fundamental to identifying change, supporting an adaptive approach that is flexible enough to meet the challenge of change, and enabling learning at individual, community, institutional and policy levels. Based on a consideration of changing approaches to natural resource management (NRM) policy and observations and experiences in the practical assessment of on-the-ground initiatives, the authors develop a set of principles for evaluation in NRM that: (a) addresses evaluation from a systems perspective, (b) links objective to consequence, (c) considers the fundamental assumptions and hypotheses that underpin core policy or program objectives, (d) is grounded in the natural resource, policy/institutional, economic, socio-cultural and technological contexts of implementation in practice, (e) establishes practical and valid evaluation criteria by which change can be monitored and assessed, (f) involves methodological pluralism including both quantitative and qualitative methods to ensure rigour and comprehensiveness in assessment, and (g) integrates different disciplinary perspectives (i.e. social, economic, environmental, policy and technological). The paper develops a systems-based evaluation framework that incorporates these principles and also recognises the multiple levels and nested nature of NRM policy, namely: problem characterisation, policy formulation and intent, program logic, and on-ground implementation. Finally, we demonstrate its utility through application to three contrasting Australian case studies: a community-based Integrated Catchment Management policy implementation; a resource information delivery system; and the development of a Decision Support System.

Australia↗
PubMedDate not supplied

Physical and chemical stability of etoposide phosphate solutions.

OBJECTIVE: To evaluate the physical and chemical stability of etoposide phosphate solutions over 7 days at 32 degrees C and 31 days at 4 degrees C and 23 degrees C: (1) at etoposide concentrations of 0.1 and 10 mg/mL as phosphate in 0.9% sodium chloride injection and 5% dextrose injection and (2) at etoposide concentrations of 10 and 20 mg/mL as phosphate in bacteriostatic water for injection packaged in plastic syringes. DESIGN: Test samples of etoposide phosphate were prepared in polyvinyl chloride (PVC) bags of the two infusion solutions at etoposide concentrations of 0.1 and 10 mg/mL as phosphate. Additional test samples were prepared in bacteriostatic water for injection containing benzyl alcohol 0.9% at etoposide concentrations of 10 and 20 mg/mL as phosphate and were packaged in 5 mL plastic syringes. Evaluations for physical and chemical stability were performed initially; after 1 and 7 days of storage at 32 degrees C; and after 1, 7, 14, and 31 days of storage at 4 degrees C and 23 degrees C. Physical stability was assessed using visual observation in normal light and using a high-intensity monodirectional light beam. Turbidity and particle content were measured electronically. Chemical stability of the drug was evaluated by using a stability-indicating high-performance liquid chromatographic (HPLC) analytic technique. RESULTS: All samples were physically stable throughout the study. Little or no change in particulate burden and haze level were found. In the intravenous infusion solutions, little or no loss of etoposide phosphate occurred in any of the samples throughout the study period. The 10 and 20 mg/mL samples in bacteriostatic water for injection repackaged in syringes were also stable throughout the study, exhibiting a maximum of 6% or 7% loss after 31 days of storage at 23 degrees C and less than 4% in 31 days at 4 degrees C. CONCLUSION: Etoposide phosphate prepared as intravenous admixtures of etoposide 0.1 and 10 mg/mL as phosphate in 5% dextrose injection and 0.9% sodium chloride injection in PVC bags and as etoposide 10 and 20 mg/mL as phosphate in bacteriostatic water for injection packaged in plastic syringes is physically and chemically stable for at least 7 days at 32 degrees C and 31 days at 4 degrees C and 23 degrees C. This new water-soluble phosphate-ester of etoposide formulation solves the precipitation problems associated with the old organic solvent and surfactant-based formulation.

Antineoplastic Agents↗
PubMed1979

Microscopical image analysis: problems and approaches.

This article reviews some of the problems which have been encountered in the application of automatic image analysis to problems in biology. Some of the questions involved in the actual formulation of such a problem for this approach are considered as well as the difficulties in the analysis due to lack of specific constrast in the image and to its complexity. Various practical methods which have been successful in overcoming these problems are outlined, and the question of the desirability of an opto-manual or semi-automatic system as opposed to a fully automatic version is considered.

Computers↗
PubMed2006

Data mining in medical time series.

This article proposes a modular, computer-based methodology to describe and compare medical problems using data mining methods. The methodology focuses on a mathematical formulation of typical classification problems, systematic extraction of interpretable features from time series, and an evaluation adapted to problem-specific preferences and limitations (computational power, interpretability, etc.). The approach is applied to instrumented gait analysis and to the individual design of myoelectric controllers for hand prostheses.

Algorithms↗
PubMed1983

Assessment of hazards associated with pesticide container disposal and of rinsing procedures as a means of enabling disposal of pesticide containers in sanitary landfills.

To study problems associated with pesticide container disposal, a small vegetable production area in southwestern Ontario, the Thedford Marsh, was selected as the site for a model study. A container collection system was organized during the 1981 growing season, with collections being made from the ca. 50 growers on the marsh twice each month. In addition to the regular collection program a cleanup service for empty pesticide containers stored on farms or discarded on public lands also was initiated. More than 3600 containers were collected and disposed of at an authorized landfill site. Ca. 2/3 were herbicide containers, ca. 1/4 were insecticide containers, and 3% were fungicide containers. Unrinsed containers contained as much as 5 1/2% of the original contents with an average of 1%. Containers rinsed by the triple rinse method or using rinsing devices (E-Z Rinse, JET Rinse) generally contained less than 0.1% of the original content. Some formulations presented rinsing problems due to settling and caking. The results indicated that, while unacceptable quantities of pesticide residues remain in unrinsed containers, most rinsed pesticide containers will be acceptable for disposal at municipal sanitary landfill sites.

Accident Prevention↗
PubMed1994

Blood safety in developing countries.

This study, based on responses to a questionnaire, was undertaken to define problems in and formulate solutions for improving blood safety in developing countries as part of an effort to monitor the status of blood transfusion services globally. Despite improvements between 1988 and 1992, only 66% of developing countries (DGCs) and 46% of least developed countries (LDCs) screen all blood donations for antibodies to human immunodeficiency viruses; 72% DGCs and 35% LDCs test all donations for hepatitis B surface antigen and 71 and 48%, respectively, for syphilis. The antihuman globulin test is performed routinely in 62% DGCs and 23% LDCs, and inadequate quality assurance in all aspects of preparatory testing is a major weakness in many countries. The blood supply is usually insufficient: none of the LDCs and 9% of the DGCs collect 30 units or more per 1,000 of the population annually. Blood donor systems are totally voluntary and non-remunerated in 15% DGCs and 7% LDCs; 80% DGCs and 93% LDCs rely totally or partially on replacement donors and 25% of both groups on paid donations. The proportion of repeat donors is low (medians: 47% in DGCs, 20% in LDCs), and discard rates for collected blood are often high (up to 33%). Most of the blood collected is transfused as whole blood, and most DGCs and LDCs have inadequate supplies of plasma substitutes for management of acute haemorrhage. The reasons for these problems and suggested solutions are discussed.

AIDS Serodiagnosis↗