Exponential Increase In Size Research Articles

On Limits to Flotation Cell Size

Mechanical cells have seen an exponential increase in size over the past 60 years. However, a possible size limitation due to carrying capacity constraints has been raised. Taking a Cu porphyry case, a cell sizing exercise is used to show that possible size limitation due to carrying capacity can be tested using available techniques. A range of conditions is explored that suggest a continued increase above the current maximum cell size, ca. 600 m3, does not seem warranted.

Case report: Persistent Herpes Simplex in an HIV patient with myositis and numerous eosinophils

The herpesviruses are DNA viruses that cause a variety of disease and infections in humans. The most common types of herpesviruses that affect humans include, herpes simplex 1 (HSV-1), herpes simplex 2, varicella zoster virus, Epstein-Barr virus, and cytomegalovirus. The oral findings and treatment of HSV-1 in immunocompetent patients are well documented. However, the presentation of oral HSV in immunocompromised patients can be challenging both diagnostically and therapeutically. We describe a 50-year-old male with a medical history of HIV, hepatitis C, diabetes, and hypertension who presented for evaluation of a necrotic ulcer of his right lateral and ven- tral tongue. A similar lesion had been biopsied approximately four months prior and diagnosed as herpes simplex virus infection. The area was re-biopsied given exponential increase in size of the lesion. Histopathologic exami- nation revealed ulcerated mucosa with numerous eosinophils. Scattered epithelial cells with VCE were identified, similar to the first biopsy in which immunohistochemical staining was positive for HSV. A diagnosis of ulceration with chronic mucositis, myositis and eosinophilia with evidence of persistent herpes simplex virus infection was rendered, with a comment suggesting that immunosuppression and myositis with eosinophils were likely contribut- ing to the nonhealing nature of the lesion. We herein explore the diverse presentation and management of HSV infection in immunocompromised patients.

Design and Analysis of Pattern Matching Algorithms Based on QuRAM Processing

The pattern matching problem remains in survival since past decades and becomes more sophisticated due to exponential increase in size of text databases. An effective deterministic classical algorithm is always expected to be at least $${\rm O}\left( N \right)$$ time. Quantum computations are enough capable of performing exponential operations in single step of execution, so the quantum algorithms are effective. In general, the quantum pattern matching solution is possible in $${\rm O}\left( {\sqrt N } \right)$$ time as its design is based on Grover’s quantum search algorithm. To our knowledge, quantum algorithms for single pattern matching are available with limitations, and no algorithm has designed for multiple pattern matching. The main objective is to design quantum algorithm for both single and multiple patterns on a processing architecture of quantum random access memory $$\left( {QuRAM} \right)$$ . This gives a significant advantage to process large text databases in an efficient manner. Our complexity analysis justifies that the quantum algorithmic solutions achieve computational speedup over classical methods. We summarize the emergence of quantum-based pattern matching algorithms to process biological applications. The simulation is additionally done to validate and analyze the performance of proposed quantum algorithms. Lastly, we justify that our algorithms outperform the classical and quantum solutions and they are competent for implementing over quantum computer.

Is There Safety in Numbers? Organizing as a Cooperative in the Freelance Economy

Freelance work is becoming increasingly ubiquitous and pervasive across multiple sectors of the economy. Freelancers are especially vulnerable to hazards of opportunism, and lack the protections traditional workers typically enjoy. In the current study, we enquire whether organizing as a cooperative can aid freelancers in overcoming the challenges they face. To address this question, we conduct a single in-depth case study. We selected Magnum Photos, an exclusive freelancer cooperative agency, founded in 1947 to further the interests of its members. We find that the agency adopted a novel organizational cooperative form we entitle entrepreneurial club, in which the members, who are carefully screened and selected, retain individual property and decision rights. This novel form served to mitigate agency problems, facilitate innovation, reduce transaction costs of exchange, and ultimately contributed to changing the established rules of the game in the field of photojournalism. Currently, Magnum is considered to be a flagship organization in the profession, although the exponential increase in size has led to recent organizational changes. Predicated on our analysis, we suggest that organizing as a cooperative along the above espoused parameters is more beneficial for freelancers than following an atomized approach.

A Multi-Keyword Ranked Search Scheme Over Encrypted Based on Hierarchical Clustering Index

Abstract A Secure and Dynamic Multi-keyword Ranked Search Scheme over Encrypted Cloud Data Due to the increasing popularity of cloud computing, more and more data owners are motivated to outsource their data to cloud servers for great convenience and reduced cost in data management. In this project, present a secure multi-keyword ranked search scheme over encrypted cloud data, which simultaneously supports dynamic update operations like deletion and insertion of documents. Specifically, the vector space model and the widely-used TFIDF model are combined in the index construction and query generation. The proposed hierarchical approach clusters the documents based on the minimum relevance threshold, and then partitions the resulting clusters into sub-clusters until the constraint on the maximum size of cluster is reached. In the search phase, this approach can reach a linear computational complexity against an exponential size increase of document collection. In order to verify the authenticity of search results, a structure called minimum hash sub-tree is designed in this paper. Due to the use of our special tree-based index structure, the proposed scheme can achieve sub-linear search time and deal with the deletion and insertion of documents flexibly. Extensive experiments are conducted to demonstrate the efficiency of the proposed scheme.

Ontogeny of Trimerocephalus lelievrei (Trilobita, Phacopida), a representative of the Late Devonian phacopine paedomorphocline; a morphometric approach

A detailed morphometric approach based on size and on outline analyses has been used on an exceptionally well-preserved assemblage of silicified trilobite exuvia, recovered from a Late Devonian limestone from southeastern Morocco. The material comprises a series of late larval to postlarval growth stages belonging to a single phacopine species, Trimerocephalus lelievrei Cronier and Feist, 1997. Plurimodality of size distribution has allowed us to discriminate postlarval instars. Distinct dimensional classes of isolated parts are obtained using the intertooth distances on the posterior pygidial margin and the internotch distances in the cephalic vincular furrow, which are functionally linked during trilobite enrollment. Morphometric analysis of development permitted demonstration of progressive shape change in agreement with ontogenetic ordination and a comparison of the timing of size and shape changes. The main shape changes appear to occur early in development, and once the adult morphology is obtained, size increases significantly. The growth rate during ontogeny is estimated by analogy with extant deep-sea crustaceans. Exponential size increase resulting from constant duration of intermolt periods may be regarded as a life history strategy to compete in a nutrient-impoverished offshore environment. The particular phacopine mode of molting, which involves the opening of the neck joint after ankylosis of the facial sutures, occurred in Trimerocephalus lelievrei between the first two postlarval instars, later than in its ancestor. Trimerocephalus lelievrei occupies an intermediate position within the phacopine paedomorphocline as indicated by the delayed onset of ankylosis.

An Efficient Privacy-Preserving Ranked Keyword Search Method

Cloud data owners prefer to outsource documents in an encrypted form for the purpose of privacy preserving. Therefore it is essential to develop efficient and reliable ciphertext search techniques. One challenge is that the relationship between documents will be normally concealed in the process of encryption, which will lead to significant search accuracy performance degradation. Also the volume of data in data centers has experienced a dramatic growth. This will make it even more challenging to design ciphertext search schemes that can provide efficient and reliable online information retrieval on large volume of encrypted data. In this paper, a hierarchical clustering method is proposed to support more search semantics and also to meet the demand for fast ciphertext search within a big data environment. The proposed hierarchical approach clusters the documents based on the minimum relevance threshold, and then partitions the resulting clusters into sub-clusters until the constraint on the maximum size of cluster is reached. In the search phase, this approach can reach a linear computational complexity against an exponential size increase of document collection. In order to verify the authenticity of search results, a structure called minimum hash sub-tree is designed in this paper. Experiments have been conducted using the collection set built from the IEEE Xplore. The results show that with a sharp increase of documents in the dataset the search time of the proposed method increases linearly whereas the search time of the traditional method increases exponentially. Furthermore, the proposed method has an advantage over the traditional method in the rank privacy and relevance of retrieved documents.

Size lower bounds for quantum automata

We compare the descriptional power of quantum finite automata with control language (qfcs) and deterministic finite automata (dfas). By suitably adapting Rabin's technique, we show how to convert any given qfc to an equivalent dfa, incurring in an at most exponential size increase. This enables us to state a lower bound on the size of qfcs, which is logarithmic in the size of equivalent minimal dfas. In turn, this result yields analogous size lower bounds for several models of quantum finite automata in the literature.

Succinctness of the Complement and Intersection of Regular Expressions

We study the succinctness of the complement and intersection of regular expressions. In particular, we show that when constructing a regular expression defining the complement of a given regular expression, a double exponential size increase cannot be avoided. Similarly, when constructing a regular expression defining the intersection of a fixed and an arbitrary number of regular expressions, an exponential and double exponential size increase, respectively, cannot be avoided. All mentioned lower bounds improve the existing ones by one exponential and are tight in the sense that the target expression can be constructed in the corresponding time class, that is, exponential or double exponential time. As a by-product, we generalize a theorem by Ehrenfeucht and Zeiger stating that there is a class of DFAs which are exponentially more succinct than regular expressions, to a fixed alphabet. When the given regular expressions are one-unambiguous, as for instance required by the XML Schema specification, the complement can be computed in polynomial time whereas the bounds concerning intersection continue to hold. For the subclass of single-occurrence regular expressions, we prove a tight exponential lower bound for intersection.

Succinctness of regular expressions with interleaving, intersection and counting

In this paper, we study the succinctness of regular expressions (REs) extended with interleaving, intersection and counting operators. We show that in a translation from REs with interleaving to standard regular expressions a double exponential size increase cannot be avoided. We also consider the complexity of translations to finite automata. We give a tight exponential lower bound on the translation of REs with intersection to NFAs, and, for each of the three classes of REs, we show that in a translation to a DFA a double exponential size increase cannot be avoided. Together with known results, this gives a complete picture of the complexity of translating REs extended with interleaving, intersection or counting into (standard) regular expressions, NFAs, and DFAs.

Theoretical models of hyperbranched polymers

We have investigated linear, starbranched and hyperbranched X n H m polymers and determined the number of atoms, rotors, internal coordinates, valence and HOMO molecular orbitals as well as molecular mass for each generation and valency. We use the semi-empirical MNDO model to obtain full geometry optimization for increasingly larger clusters for each generation in order to obtain total relative energies. We then generate analytical functions, which correlate the total relative energies with the generation, for each valency, for the hyperbranched polymers. We have also generated analytic functions, which correlate total relative energies, experimental van der Waals coefficients and standard enthalpy of combustion with the number of carbon atoms in each chain of the linear alkanes. These results are used to predict the enthalpy of combustion for higher generations of alkanes in good agreement with experiment. Due to the exponential increase in size with generation of the hyperbranched polymers alternative analytical models may be of interest to theoretical chemists working in this line of research.

EARLY VS. ASYMPTOTIC GROWTH RESPONSES OF HERBACEOUS PLANTS TO ELEVATED CO2

Although many studies have examined the effects of elevated carbon dioxide on plant growth, the dynamics of growth involve at least two parameters, namely, an early rate of exponential size increase and an asymptotic size reached late in plant ontogeny. The common practice of quantifying CO2 responses as a single ratio thus obscures two qualitatively distinct kinds of effects. The present experiment examines effects of elevated CO2 on both early and asymptotic growth parameters in eight C3 herbaceous plant species (Abutilon theophrasti, Cassia obtusifolia, Plantago major, Rumex crispus, Taraxacum officinale, Dactylis glomerata, Lolium multiflorum, and Panicum dichotomoflo- rum). Plants were grown for 118-172 d in a factorial design of CO2 (350 and 700 FIL/L) and plant density (individually grown vs. high-density monocultures) under edaphic con- ditions approximating those of coastal areas in Massachusetts. For Abutilon theophrasti, intraspecific patterns of plant response were also assessed using eight genotypes randomly sampled from a natural population and propagated as inbred lines. The species and genotypes examined generally showed enhanced early relative growth rates (RGR) under elevated C02; however, such early growth responses did not necessarily correspond to increases in asymptotic size. As a result, interspecific and genetic correlations between early RGR enhancements and asymptotic size enhancements were weak. Effects of elevated CO2 also varied systematically among the size metrics examined. The maximum leaf area attained by individually grown plants was generally reduced under elevated C02; however, most species showed positive effects of CO2 on vegetative mass at final harvest. Final biomass responses were greatest in species showing large enhancements in root growth. In addition, CO2 responses of plants grown in dense monocultures differed from plants grown individually, showing reduced responses for both early RGR and final biomass. Average reproductive responses to elevated CO2 were positive for individually grown plants, but negative for dense monocultures. It has previously been suggested that differences in species' growth rates may be the best single predictor of plant growth responses to CO2. Here we found that RGR (at ambient C02) appeared to limit potential early growth responses among species, but that there was no such relationship between RGR and asymptotic size responses. We suggest that the latter may be determined in part by the degree to which large carbon sinks are formed late in plant ontogeny. The overall pattern of early and asymptotic growth responses to elevated CO2 varied widely both among and within species, and we found little evidence for the existence of discrete functional types. We argue that both early and asymptotic responses are of fundamental interest from a modeling and a physiological perspective. Both types of growth response should be incorporated in all efforts to understand and predict responses of terrestrial vegetation to rising CO2 and other aspects of global change.

Procedure cloning

Functional partitioning assigns the functions of a system's program-like specification among system components, such as standard-software and custom-hardware processors. We introduce a new transformation, called procedure cloning, that significantly improves functional partitioning results. The transformation creates a clone of a procedure for sole use by a particular procedure caller, so the clone can be assigned to the caller's processor, which in turn improves performance through reduced communication. Heuristics are used to prevent the exponential size increase that could occur if cloning were done indiscriminately. We introduce a variety of cloning heuristics, highlight experiments demonstrating the improvements obtained using cloning, and compare the various cloning heuristics.

Bacteria as modular organisms.

The body plan of modular organisms is based on an indeterminate structure composed of iterated units or modules arrayed at various levels of complexity (such as leaves, twigs, and branches). Examples of modular organisms include plants and many sessile benthic invertebrates. In contrast, the body of unitary organisms is a determinate structure consisting usually of a strictly defined number of parts (such as legs or wings) established only during embryogenesis. Mobile animals are examples. Unlike that of unitary creatures, the form of a modular organism derives from a characteristic pattern of branching or budding of modules, which may remain attached or become separated to live physiologically independent lives as parts of a clone. Modular organisms tend to be sessile or passively mobile and, as genetic individuals, have the capacity for exponential increase in size. They do not necessarily undergo systemic senescence, and do not segregate somatic from germ line cells. It is argued here that bacteria are essentially modular organisms where the bacterial cell, microcolony, and macrocolony are modules of different levels of complexity analogous to modules of macroorganisms. This interpretation provides a broad conceptual basis for understanding the natural history of bacteria, and may illuminate the evolutionary origins and developmental biology of modular creatures.

The flat clam controversy: Where did they come from? Where did they go?

Thin-shelled, weakly articulated, epifaunal byssate to free-living flat clams characterize Devonian-Cretaceous dark, organic-rich shale facies. Convergent evolution on the flat-clam morph occurs among several families of Bivalvia. Flat clams regularly occurred in dense populations, dominating low diversity, inequitable communities for which they were commonly the pioneer species and formed shell islands for the colonization of smaller, firm-substrate dependent invertebrates. The unique flat-clam dominated ecosystem, as well as the widespread environments to which they were adapted, disappeared at the end of the Cretaceous. Although locally, low-oxygen benthic muds exist through the Cenozoic to Recent, they do not support large populations of flat clams, whose ecological niche was never filled after the Cretaceous. Flat clams underwent an exponential increase in size and apparent growth rates through the mid- and Late Cretaceous, reaching over 3 m in diameter (Inoceramidae). Most of this increase in shell size also involved expansion of mantle tissue and probably gills, relative to the size of the visceral mass. This suggests specific adaptations to colonization of oxygen-poor benthic habitats with hydrogensulfide enriched substrates, which broadly characterized Paleozoic and Mesozoic epicontinental seas, during greenhouse intervals. Such conditions were particularly well-developed during Cretaceous Oceanic Anoxic Events, at which time flat clams thrived.Functional morphology, geochemistry, and facies associations suggest that many flat clams were chemosymbiotic and/or had greatly expanded oxygen-absorption surfaces. These adaptations allowed them to be opportunistic in chemically stressed benthic environments; growth rates also seem to be enhanced in these environments, a characteristic of living chemosymbiotic species. Many lines of evidence prove that flat clams lived in these environments and do not represent pseudoplanktic rain. A combination of factors seems to have been responsible for their disappearance near the end of the Cretaceous; i.e., mass extinction, loss of primary habitats, and major radiation among bottom-feeding bivalve predators.

A Structure-preserving Clause Form Translation

Most resolution theorem provers convert a theorem into clause form before attempting to find a proof. The conventional translation of a first-order formula into clause form often obscures the structure of the formula, and may increase the length of the formula by an exponential amount in the worst case. We present a non-standard clause form translation that preserves more of the structure of the formula than the conventional translation. This new translation also avoids the exponential increase in size which may occur with the standard translation. We show how this idea may be combined with the idea of replacing predicates by their definitions before converting to clause form. We give a method of lock resolution which is appropriate for the non-standard clause form translation, and which has yielded a spectacular reduction in search space and time for one example. These techniques should increase the attractiveness of resolution theorem provers for program verification applications, since the theorems that arise in program verification are often simple but tedious for humans to prove.