Top PDF The biological and mathematical basis of L systems

The biological and mathematical basis of L systems

The biological and mathematical basis of L systems

yield the languages be can to used families the demonstrated be will development formal and languages Chomsky from them understand terminal is aspects When a contain generated production[r]

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Mechanistic mathematical models for the design of synthetic biological systems : DNA recombination, recombinase based temporal logic gates and antibiotic production

Mechanistic mathematical models for the design of synthetic biological systems : DNA recombination, recombinase based temporal logic gates and antibiotic production

requirements. SSRs are classified as belonging to two groups, the tyrosine recombi- nases and the serine recombinases. The former have been shown to provide effective genetic switch mechanisms [Buchholz et al., 1996; Kilby et al., 1993; Rossant and Nagy, 1995] however, their functionality is often dependent upon cell-specific cofac- tors as in the case of λ integrase [Landy, 2015]. This is problematic in a similar vein to that of transcriptional systems with regards to the deployment of modules across multiple organisms. Tyrosine recombinase systems that are not dependent on host cofactors are bidirectional and are therefore incapable of highly efficient switching since there can be no guarantee that an induced transition to a desired DNA state would be effectively maintained without unwanted transitioning back to the original state [van Duyne, 2001]. In contrast, the serine recombinases do not require such cofactors and have been used effectively to perform highly efficient unidirectional gene assembly and modification [Colloms et al., 2014]. This has led to the construc- tion of a rewritable RAD module exhibiting passive information storage within a chromosome [Bonnet et al., 2012]. Switching the RAD module ‘on’ requires only the presence of integrase whereas the ‘off’ switch requires integrase in conjunction with a recombination directionality factor (RDF), also referred to as excisionase. The integration and excision events can take on several guises depending on the ini- tial composition of the genetic sequence and the relevant attachment sites. Specific recombination arrangements are directly influential upon the operational character- istics of a genetic toggle switch, such as the RAD module, and higher-order circuitry that utilises multiplexed switches.
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Biological Basis of Emotions: Brain Systems and Brain Development

Biological Basis of Emotions: Brain Systems and Brain Development

tage of activity-dependent stabilization of neuronal pathways is that there will not be an unnecessary expenditure of genes to code precisely for the large number of connections in the brain. Rather, repeated early environmental exposure will serve to guide the molding of an optimum cortical cytoarchitecture for the individual’s future needs. The molecular basis for the stabilization and retention of some pathways and vulnerability of others to be pruned or eliminated is an area of intense investigation. Recent studies have suggested that in the visual cortex of kittens, activity- dependent stabilization may involve activation of the N-methyl-d-aspartate subclass of glutamate recep- tors, associated perhaps with the expression of spe- cific neuronal proteins. 31,32
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A basis for a visual language for describing, archiving and analyzing functional models of complex biological systems

A basis for a visual language for describing, archiving and analyzing functional models of complex biological systems

As a starting point, consider the common metaphor of bio- logical systems as ‘circuits’. Indeed, viewing metabolic path- ways as electrical circuits is particularly apt as, in each case, a limited set of entity classes (metabolites versus resistors, capacitors and inductors) are represented by icons that are linked by lines (or arrows) representing interactions between iconified entities. The benefit of such pathway and circuit diagrams is, of course, that they help us infer and track how a change in a ‘state property’ (for example, metabolite concentration versus electrical voltage) of one icon acts via an ‘action property’ (metabolic flux rate versus electrical current) on the state properties of linked icons. The problem for biologists is that metabolite concentrations and flux rates, while absolutely fundamental to many biolog- ical systems, are not the only functional properties that need to be considered.
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Mathematical modelling of biological wastewater treatment of oxidation pond and constructed wetland systems

Mathematical modelling of biological wastewater treatment of oxidation pond and constructed wetland systems

I would also like to thank the Ministry of Higher Education Malaysia (MOHE) for the financial support through the research grant R.J130000.7809.4F637. Part of the research was undertaken while visiting the Mathematical Institute, University of Oxford, UK. I wish to thank the members of the institute for the pleasant mathematical atmosphere they offered. I would also gratefully acknowledge the help of Prof. Dr. Graham Sander on clarifying certain aspects of mathematical modeling of wetland system. This visit was supported by UTMLead, UTM and Graduate Employability Grants (STEM), UTM.
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Mathematical modeling of task managers for multiprocessor systems on the 
		basis of open loop queuing networks

Mathematical modeling of task managers for multiprocessor systems on the basis of open loop queuing networks

can be set in any CPU. In this article tasks setting according to a CPU is selected with equal probability to assess approximately the situation of mathematical modeling (analytical and simulation) of a real process, to avoid a system usage, when all tasks try to get a room in one or more of the CPUs, and some CPUs are idle. A queue is formed with a limited number of places (queue failures), so when it becomes full, a part of requests will be denied in service that corresponds to the actual mode of operation of a computer system, when a downloaded application remains on the hard disk until the tasks queue ready to service is busy in the processor node [1, 7]. The intensity of the tasks flow in this case will be equal to
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Ventilation systems failure prediction on the basis of the stochastic 
		branching processes mathematical model

Ventilation systems failure prediction on the basis of the stochastic branching processes mathematical model

A. Markov processes (not branching) are the basis of the existing procedures of predicting an additional system resource after maintenance. The limitation of their use consists in the fact that they do not take into account the background state of the parameters of assembly units before maintenance (process without “memory”).

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Biological and mathematical modeling of melanocyte development

Biological and mathematical modeling of melanocyte development

To investigate bcat, wild-type and bcat* melanoblast proliferation in developing skin, we developed a mathematical model to estimate the doubling time of dermal and epidermal melanoblasts. In the truncal region, founder melanoblasts are determined from the neural crest around E8.5-E9.5 and can be easily detected from E10.5 in a Dct::lacZ background. In both compartments, dermal and epidermal melanoblasts can theoretically undergo proliferation, apoptosis, loss-of-differentiation or/and transdifferentiation. Moreover, melanoblasts cross the basement membrane from the dermis to the epidermis but there is no evidence of a reverse flow of melanoblasts from epidermis to dermis in normal conditions. We showed that melanoblasts do not die, do not transdifferentiate and do not lose their differentiation. On the basis of these findings, we constructed a simplified model of melanoblast proliferation as depicted in Fig. 6A,B and detailed in the Appendix in the Fig. 4. b-Catenin activity affects melanoblast production. (A)  Macroscopic observations of the trunk region of bcat, wild-type and bcat* E14.5 embryos. Note that melanoblasts are less abundant in both b-catenin mutants than in wild type, and in bcat than in bcat*. Scale bar: 100  mm. (B)  The number of X-gal-positive cells in bcat, wild type and bcat* from E10.5 to E15.5 was determined by eye on both sides of embryos in the trunk region. The mean X-gal-positive cell number is shown by the white line in the colored boxes and is given above them; the non-atypical minimum and maximum are shown for each day of development by the vertical bars. Melanoblast doubling times (t) were determined (as in Fig. 1) and indicated for each type of mutant and wild-type mice.
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The Improvement of Quality of Pasta on the Basis of the Vegetable Raw Materials

The Improvement of Quality of Pasta on the Basis of the Vegetable Raw Materials

On the basis of results of researches of influence of corn and ñhickpea flour on rheological properties of dough and quality of ready pasta optimum dosages of cornmeal of 10% are established, chickpea flour of 12,5% to the mass of wheat flour of the first grade, the further increase in dosages of corn and chickpea flour leads to deterioration of technological properties of pasta. It is established that use of ion ozonated water at preparation of dough promotes improvement of rheological properties of dough and quality of pasta; it is defined that from the point of view of improvement of quality of pasta by an optimum dosage of corn and ñhickpea flour 20%, concentration of ozone of 2 mg/l and ions of 1000 pieces/cm3 in ion ozonated water are being. Use of flour from grain and bean crops expediently for enrichment of pasta valuable food components – proteins, irreplaceable amino acids, vitamins and mineral substances. (Iskakova et al, 2011;)
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The Basics of General, Organic, and Biological Chemistry

The Basics of General, Organic, and Biological Chemistry

 Proper chemical formulas for ionic compounds balance the total positive charge with. the total negative charge[r]

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Generalized Mathematical Model for Biological Growths

Generalized Mathematical Model for Biological Growths

In this paper, we present a generalization of the commonly used growth models. We introduce Koya-Goshu biological growth model, as a more general solution of the rate-state ordinary differential equation. It is shown that the commonly used growth models such as Brody, Von Bertalanffy, Richards, Weibull, Monomolecular, Mitscherlich, Gompertz, Lo- gistic, and generalized Logistic functions are its special cases. We have constructed growth and relative growth func- tions as solutions of the rate-state equation. The generalized growth function is the most flexible so that it can be useful in model selection problems. It is also capable of generating new useful models that have never been used so far. The function incorporates two parameters with one influencing growth pattern and the other influencing asymptotic behav- iors. The relationships among these growth models are studies in details and provided in a flow chart.
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Nonlocal Navier-Stokes problem with a small parameter

Nonlocal Navier-Stokes problem with a small parameter

Note that the existence of weak or strong solutions and regularity properties of classical Navier-Stokes problems were extensively studied, e.g., in [–, , –]. There is extensive literature on the solvability of the initial value problem for the Navier-Stokes equation ( see, e.g., [] for further papers cited there ). Hopf [] proved the existence of a global weak solution of (.) using the Faedo-Galerkin approximation and an energy inequality. Another approach to problem (.) is to use semigroup theory. Kato and Fujita [, , ] and Sobolevskii [] transformed equation (.) into an evolution equation in the Hilbert space L  . They proved the existence of a unique global strong solution for any square- summable initial velocity when n = . On the other hand, when n =  they proved the existence of a unique local strong solution if the initial velocity has some regularity. Other contributions in this field have also assumed some regularity of the initial velocity cor- responding to the Stokes problem; see, for example, Solonnikov [] and Heywood []. Afterward, Giga and Sohr [] improved this result in two directions. First, they general- ized the result of Solonnikov for spaces with different exponents in space and time, and the estimate obtained was global in time. Here, first at all, we consider the nonlocal (bound- ary value problem) BVP for the following differential operator equation (DOE) with small parameters:
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<p>The Use of Measurement Systems to Support Patient Self-Management of Long-Term Conditions: An Overview of Opportunities and Challenges</p>

<p>The Use of Measurement Systems to Support Patient Self-Management of Long-Term Conditions: An Overview of Opportunities and Challenges</p>

Recently, there has been a paradigm shift in health care, from an illness-focused approached, to a person- centred approach; within this paradigm, one important aim is to achieve better quality of life for individuals with long-term conditions. As well as commissioning ser- vices and providing care, policy makers are encouraging patients to take an active role in managing their health. The person-centred approach advocates patient self- management, which refers to any action taken by people to recognise, treat and manage their own health or chronic conditions, either independently or in conjunction with the healthcare system. 4 In this context, self-management of chronic illness involves patients recognising their health needs and performing health promotion activities, activat- ing healthcare resources, obtaining support, as well as ongoing processing and adjustment to living with a chronic illness. 5,6 Related to self-management, taking ownership of one ’ s health is crucial to achieving positive outcomes and better quality of life. 7 However, self- management is not straight forward and can be challenging for many patients. It is therefore important to develop methods to support and empower patients to self-manage. Patient reported outcome measures (PROMs) and their implementation within measurement systems constitute one promising approach to supporting patient self-management of long-term conditions. PROMs are standardized instru- ments for collecting patients ’ perceptions of and views about their health. 8,9 PROMs can capture valuable informa- tion on the outcomes that are meaningful to patients, includ- ing symptoms, functioning, and emotional wellbeing 10 as well as capturing patients ’ broader perspectives on their health; they often use continuous measures that permit nuance and subjectivity. 11 They can be used by clinicians to inform clinical care, extending clinical knowledge beyond test results (which can be poorly correlated with clinical status and quality-of-life) 12 and encouraging clini- cians to attend to issues that are important to patients such as treatment burden and function. 13 Measurement systems are an innovative digital method to gather and report PROMs throughout a patient ’ s course of care, conveying patient-reported information to healthcare professionals and
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The Design and Optimization of Automated Storage and Retrieval Systems

The Design and Optimization of Automated Storage and Retrieval Systems

both systems. It can be seen that at low throughput capacities of the warehouse (<< Pf) it is reasonable to apply the multi-aisle ASRS, since the investment in the warehouse is much smaller than in the case of the single-aisle ASRS. In this case the difference in costs (840·10³ € - Pf = 60 TUL/h) is more significant in comparison with the single-aisle ASRS. With the rising of the Pf of the warehouse, the costs increase and also the appropriateness of applying the multi-aisle ASRS decreases. If the required throughput capacity is above Pf = 140 TUL/h, the application of the multi- aisle ASRS becomes rather questionable, since the SR machines are already overloaded (h = 94%) and the differences in costs are quite small. It can be seen that the investment within Pf = 160 TUL/h is larger for the value of 151·10³ € in comparison with the single- aisle ASRS, since 5 SR machines must be used in the ASRS. Additionally, in the above-mentioned Pf the application and the problem of the management and control of 5 SR machines at 7 picking aisles is rather questionable. The analysis has been carried out for the case of (i) random storage strategy and (ii) random retrieval strategy, without the introduction of the class- based storage. With the application of improved strategies, the efficiency of the multi-aisle ASRS would be much higher. It can be concluded that for the required >> Pf, with the application of the classical random strategy, we should generally apply the single-aisle ASRS. The opposite holds true for relatively << Pf, where especially the multi-aisle ASRS should be applied. A higher efficiency of the multi- aisle ASRS can be achieved by applying the most effective storage strategies and introducing a class- based ABC storage system.
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The Biological Basis of Sexual Behaviour in Amphibia  IV

The Biological Basis of Sexual Behaviour in Amphibia IV

THE INFLUENCE OF THE INJECTION OF ANTERIOR PITUITARY EXTRACTS ON THE MATING REFLEX OF HYPOPHYSECTOMIZED AND OF GONADECTOMIZED SOUTH AFRICAN CLAWED TOADS, AND IN ANIMALS WITH GONADAL HYPO[r]

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Animal agriculture and the importance of agnostic governance of biotechnology

Animal agriculture and the importance of agnostic governance of biotechnology

Human population growth and rising income levels in developing countries are increasing demand for animal pro- tein. One of the key enablers of the associated increase in global animal protein production has been biotechnology, defined as, “any technological application that uses biological systems, living organisms or derivatives thereof to make or modify products or processes for specific use.” Biotechnologies have directly benefitted the three core scientific disciplines of animal science—genetics, nutrition, and health. Significant potential remains to use biotechnologies to improve animal health. Globally, more than 20 % of animal protein is lost as a result of disease. A number of diseases have been targeted by using recombinant DNA (rDNA) techniques in the breeding process to develop disease- resistant food animals, although no such animals have yet been approved anywhere in the world. Part of the reason for this is that “modern” biotechnologies involving the use of rDNA are subject to a unique set of governance and regulatory requirements under the Cartagena Protocol on Biosafety and other national regulatory frameworks. The Protocol defines “modern biotechnology” as the application of in vitro nucleic acid techniques, including recombinant deoxyribonucleic acid (DNA) and direct injection of nucleic acid into cells or organelles, or fusion of cells beyond the taxonomic family, that overcome natural physiological reproductive or recombination barriers and that are not tech- niques used in traditional breeding and selection. In considering the impact of this modern biotechnology trigger for additional governance and regulatory oversight, a case study is presented of the various biotechnological approaches that might be employed to address the important tropical disease problem of African trypanosomiasis. Some
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Case studies in mathematical modelling for biological conservation

Case studies in mathematical modelling for biological conservation

The number of chicks coming into the population in this time interval h is taken care of by imposing the initial condition ml t, 0 = bn2t where b is the annual productivity rate per adul[r]

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A biological basis for the Tasmanian freshwater eel fishery

A biological basis for the Tasmanian freshwater eel fishery

ii A fyke net or eel trap shall not be set within 20 metres of ·any other fyke net or eel trap; iiA The licensee shall be present when a fyke net or eel trap to which the licence relates[r]

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Optical imaging probes for biomolecules: an introductory perspective

Optical imaging probes for biomolecules: an introductory perspective

Research into the molecular basis of the five senses has revealed the exquisite sensitivity of these biological systems: a rod cell within the eye can detect a single photon, olefactory receptors (which, interestingly, can only detect molecules with

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The Pharmacognostic Profile and Biological Potential of Traditional Medicinal Shrub Hibiscus hiritus L.

The Pharmacognostic Profile and Biological Potential of Traditional Medicinal Shrub Hibiscus hiritus L.

The biological potential of medicinal plants has been recognized since time immemorial. Even today, most population in many developing countries like India and China depend on herbal remedies to cure infectious diseases as an alternative to allopathy. Screening of bioactive natural compounds hence has been of great interest by researchers. Morphoanatomical studies and pharmacological evaluation have been proved as essential tools in routine quality control of new medicinal plants. Choice of these herbal screening tools has been adding valuable scientific information to establish rational relationship between chemical, biological and therapeutical activities of traditional plants [1] . Moreover, ethnomedical data of herbs not
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