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The origins of the various elements in the human antibody repertoire have been and still are subject to considerable uncertainty. Uncertainty in respect of whether the various elements have always served a specific defense function or whether they were co-opted from other organismal roles to form a crude naïve repertoire that then became more complex as combinatorial mechanisms were added. Estimates of the current size of the human antibody naïve repertoire are also widely debated with numbers anywhere from 10 million members, based on experimentally derived numbers, to in excess of one thousand trillion members or more, based on the different sequences derived from theoretical combinatorial calculations. There are questions that are relevant at both ends of this number spectrum. At the lower bound it could be questioned whether this is an insufficient repertoire size to counter all the potential antigen-bearing pathogens. At the upper bound the question is rather simpler: How can any individual interrogate such an astronomical number of antibody-bearing B cells in a timeframe that is meaningful? This review evaluates the evolutionary aspects of the adaptive immune system, the calculations that lead to the large repertoire estimates, some of the experimental evidence pointing to a more restricted repertoire whose variation appears to derive from convergent ‘structure and specificity features’, and includes a theoretical model that seems to support it. Finally, a solution that may reconcile the size difference anomaly, which is still a hot subject of debate, is suggested.

The present study aimed to explore the existence of an asymmetrical bias in the imagination of pairs of objects of unequal size. We assumed that such pairs are conceptualized with the smaller object being placed on the left, creating an ascending size order from left to right. Such a bias could derive from a cognitive strategy known from the mental number line. Sixty-four participants were instructed to imagine stimulus-pairs that were staggered from those showing very prominent intra-pair size differences (e.g., elephant vs. mouse) to very low size differences (e.g., orange vs. apple). The results showed that the tendency to imagine the bigger object on the right side increases with the size difference of the two stimuli. Such a visual field bias was also present in stimulus-pairs including numbers so that the participants imagined smaller and larger numbers on the left and the right side of the visual fields, respectively. Taken together, our findings could imply that the left-to-right orientation observed in our object imagining task may share the same cognitive mechanism as the mental number line.

Pansharpening is a process of fusing the spatial detail of a high-resolution panchromatic (Pan) image and the spectral information of a low-resolution multispectral (MS) image to generate a high-resolution MS image. With the fast development of high-resolution satellites, pansharpening techniques are increasingly used worldwide. Even though pansharpening research has been done for decades and numerous techniques have been developed, research efforts are still continuing to further improve the techniques. The most common problems encountered by pansharpening algorithms are colour distortion and spatial artefacts. This article provides a review on recent advances in solving or reducing the problems of colour distortion and spatial artefacts. On the other hand, miss-registration and object size difference between Pan and MS images are also two common key problems in pansharpening applications. Very few publications have discussed these issues. Therefore, this article also addresses these two key problems and...

According to the theory of limiting similarity, two closely similar species that compete for resources can coexist when the ratio of the sizes of their trophic apparatus is approximately 1.3. In this study, we investigated how two similar tadpole forms coexist. We described the temporal distribution of the tadpoles of Hypsiboas faber and H. leptolineatus in ponds during the course of one year, detailing the respective age structures (Gosner stages and size). We also estimated total length ratios. The larger-sized species, H. faber, entered the ponds earlier in the year, which might give it some advantage in resource exploitation and favour the maintenance of the size difference between the species. The size difference may lead to a difference in microhabitat utilization and/or modify resource preferences, thus allowing the two species to coexist.

In 2009 Pertab, James, and Bigler published a critique of two prior meta-analyses by Binder, Rohling, and Larrabee (1997) and Frencham, Fox, and Maybery (2005) that showed small effect size difference at least 3 months post-injury in individuals who had sustained a mild traumatic brain injury (mTBI). The Binder et al. and Frencham et al. meta-analyses have been widely cited as showing no lasting effect of mTBI. In their critique Pertab et al. (2009) point out many limitations of these two prior meta-analyses, demonstrating that depending on how inclusion/exclusion criteria were defined different meta-analytic findings occur, some supporting the persistence of neuropsychological impairments beyond 3 months. Rohling et al. (2011) have now critiqued Pertab et al. (2009). Herein we respond to the Rolling et al. (2011) critique reaffirming the original findings of Pertab et al. (2009), providing additional details concerning the flaws in prior meta-analytic mTBI studies and the effects on neuropsychological performance.

A new protoperidiniacean dinoflagellate cyst species recorded from the Lower Pliocene Serripes Zone of the Tjornes beds in northern Iceland is formally described and its palaeoecological preferences are evaluated. Selenopemphix islandensis sp. nov. is a thin-walled cyst with strong polar compression and a reniform outline in apical view. The wide cingular margins are dorsally ornamented with processes of varying morphology and ventrally with large fan-shaped processes. A distinct size difference between the dorsal and ventral cingular processes is a major diagnostic characteristic of this species. A differential diagnosis for Selenopemphix islandensis sp. nov. is presented. Within the Tjornes section, Selenopemphix islandensis sp. nov. is restricted to the uppermost Serripes Zone of the Tjornes beds. The base of this zone corresponds to the invasion of cold-water molluscs of Pacific affinity through the Bering Strait into the northern Atlantic. The sudden appearance of Selenopemphix islandensis sp. nov. f...

Densities and viscosities for the system, water (W) + 1,2-dimethoxyethane (DME), have been determined for the entire range of composition at temperatures, ranging from 303.15 to 323.15 K. Density, viscosity, enthalpy, entropy and free energy of activation for viscous flow have been plotted against the mole fraction of DME. Excess molar volume, , excess viscosity, η E, and excess free energy of activation, ΔG ≠E, have also been plotted against the mole fraction of DME. Most of these properties have been fitted to appropriate polynomial equations. Results have been explained in terms of such factors as, size difference of component molecules, hydrophilic effect, hydrophobic hydration and dipole–dipole interaction.

The Meadow viper, Vipera ursinii (Bonaparte, 1835) is the most threatened Italian snake species. The apparent frequency of observations and local distribution were investigated al a few central Apennine massifs. The most abundant populations appeared to be those inhabiting the Gran Sasso massif, particularly the Campo Imperatore valley. On the other hand, the most vulnerable populations appeared to be those inhabiting the Duchessa Mountains and the Majella Massif. The viper populations are affected by negative factors which may have a longitudinal effect (i.e. that may affect the viper populations during the whole cycle of annual activity) or a punctual effect (i.e. that may affect the viper populations during some specific phases of the annual activity cycle). Mean body sizes were similar in all areas, but the few specimens captured on Vettore Massif were significantly smaller than those captured in all other areas. This is probably due simply to the small sample size, rather than to true size difference...

Molecular dynamics simulation results for the compressibility factor of size asymmetric nonadditive hard spheres are reported. Three recently proposed mixture models and the van der Waals one-fluid theory are tested against the simulation data. It is found that the van der Waals theory is totally inadequate for mixtures with large non-additivity or size difference at high densities. The recent models are satisfactory in general. The one model that satisfies exact consistency relationships is the most accurate.

We study the nature of intermediate range order (IRO) in a 2:1 model liquid binary mixture as the range of the potentials is changed from short to long range. The calculations were carried out within the Mean Spherical Approximation, and the study focuses on the Bhatia-Thornton partial structure factors. We find evidence of IRO when there is size difference between the atoms in the mixture. However, at the level of description of this work, there appears no way of distinguishing between the IRO in a compound forming or an ionic system.

A theoretical model based on the grand partition function has been developed to investigate the role of size effects on surface tension and surface segregation of liquid binary alloys. The necessary relation, which connects the surface composition with surface tension through order potential, surface coordination and volume ratio, is obtained. This has been applied to liquid Na-Cs alloys. Likewise bulk properties, surface segregation and surface tension of Na-Cs liquid alloys are also affected appreciably by the size difference and are anomalous around C Na = 0.8.

Chromosome numbers of 1 N=24 were determined for three species of Gracilaria (G. flabelliforme P. Crouan et H. Grouan ex Schramm et Maze, G. mammillaris Montagne and G. tikvahiae McLachlan) and 1 N=32 for two species of Gracilariopsis (G. lemaneiformis (Bory) Dawson, Acleto et Folvik and G. tenuifrons (Bird et Oliveira) Fredericq et Hommersand). Karyotypes for these species exhibit a characteristic size difference between largest and smallest chromosomes. Polyvalents were a common feature of meiotic nuclei. Microspectrophotometry with the DNA-localising fluorochrome DAPI was used to quantify nuclear genome sizes. A 2 C genome size of 0·37–0·40 pg was determined for five species of Gracilaria (G. chilensis Bird, McLachlan et Oliveira, G. flabelliforme, G. mammillaris, G. pacifica Abbott, G. tikvahiae) and 0·33 pg for an isolate of G. verrucosa (Hudson) Papenfuss from Pas de Calais, France. Species of Hydropuntia (H. cornea (J. Agardh) Wynne and H. dentata (J. Agardh) Wynne) and Gracilariopsis (G. lemaneifo...

The nature ol the agonistic interactions between males, competing for females or space, are compared with those between females in the spider Lycosa tarentula fasciiventris. Sex differences are found in the behavioural repertoire, the duration and the outcome of the contests. Interactions between males are shorter, less intense and less variable than those between females. The duration of male agonistic interactions does not decrease as size difference increases. Prior access to the female terrarium consistently predicts the outcome of male agonistic interactions, but size difference does not. Sex differences are interpreted in relation to the optimization of the cost-benefit balance by individuals during interactions.

The components of behavioral interactions between pairs of dogs were observed during exercise periods in public open spaces. Most of the interactions were nonaggressive and ended without interference from either of the owners. Even in the 13% of interactions that were ended by owners, there was little evidence to suggest that either dog's behavior had triggered the intervention. The dog that started the interaction was most likely to finish it, particularly when there was a size difference between the two dogs. The majority of the behavioral components observed during such interactions could be categorized into a small number of fixed action patterns in predictable sequences. This suggests that domestic dogs, despite selective breeding, have retained inherited social behavior patterns. After an initial approach phase, the majority of the interactions appeared to consist of olfactory inspections, particularly of the head and anal regions. Female dogs concentrated on the head area, and male dogs the...

The biometrics of breeding Purple Sandpipers from southern and northern Norway and Svalbard were described from fresh material There was a slight size difference for the birds in the two areas of Norway, and the Svalbard birds were significantly larger than the Norwegian birds. Previously collected data sets were compared with the current measurements.

The Oceans: Their Hidden Treasures involves students in hands-on activities in both geography and science. Maps are used to identify the locations of oceans and their bordering countries. They also provide information to help students create original ocean floor maps and three-dimension structures of ocean topography. The dynamics of wave motion are investigated and the creation of a wave bottle allow students to study the movement of waves. The use of graphs encourages students to focus on the ratio of ocean to landmass and the size difference of the oceans. This lesson will increase the students' knowledge and awareness of the oceans and ocean phenomena.

Geographic variation in the Zebra Finch Taeniopygia guttata was examined by comparing live wild-caught and captive T. g. guttata from the Lesser Sunda Islands in Indonesia and T. g. castanotis from the Australian mainland and confirmed by museum skin measurements of guttata and castanotis. (1) T. g. castanotis is significantly larger than T. g. guttata, as measured by wing length, weight and bill length. (2) castanotis have redder, darker, brighter bills than T. g. guttata. (3) T. g. castanotis males have larger breast- bands than T. g. guttata males, even when the size difference is taken into account, with strongly pronounced black bar- ring on the throat and upper breast which are absent from T. g. guttata males on Lombok, Sumbawa, Flores and Timor. (4) T. g. castanotis produce lower frequency distance calls and the males differ from T. g. guttata males in having a noise part to this call. (5) The songs of captive T. g. castanotis males are lower in frequency and their song phrases are shorter, with fewer elements per phrase, than captive T. g. guttata males from Timor. In contrast to the differences between T. g. castanotis and T. g. guttata, little geographic variation was found within T. g. guttata on the four islands studied, although there was a cline of decreasing size in bill depth from west (Lombok) to east (Timor). The status of the two forms, T. g. guttata and T. g. castanotis, is discussed.

We found a new method of optical resolution based on the crystal size difference of the D- and L-crystals. In the crystallization from DL-Asn aqueous solution, enantio-differentiating additive (L-Cys) reduced only the L-crystals. The large D-crystals and the small L-crystals can be separated very easily, by sieving, for instance.

The agonistic acts and distances separating interacting individuals when acts occurred were recorded for specimens of the hermit crab Pagurus pollicaris. Individuals were observed in groups of six under several conditions (during a snail predation, with food in the aquarium, and nothing in the aquarium except the crabs before and after the crabs had access to empty gastropod shells). The pattern of agonistic interactions within the groups showed a high degree of order, but the lack of changes in behavior over time indicated these crabs have an aggressive order rather than a dominance hierarchy. The distances separating crabs when acts were executed were significantly affected by (1) the act being executed, (2) the act executed previously by the other crab, (3) the size of the acting crab, (4) the relative size difference of the two interactants, (5) the individual crabs’ identities, and (6) the condition of observation. The individual crab effects on distance were present when crab size was controlled and...

An a priori model has been developed for the prediction of particle segregation in a fluidized bed of particles of same density. The model predicts the phase equilibrium of any two-component system by taking into account the Uml of both components and the minimum concentration of fines for minimum bed viscosity. An extension of the model to a multi-component system leads to an algorithm which allows the prediction of the quantity and the concentration profiles of particles in both phases of a segregated fluidized bed. The algorithm requires only the initial concentration profile or the mixture and the physical properties of each component and the fluidizing gas. A good agreement between the predicted and the previously measured concentration profiles of both a two-size and a wide size mixture shows the adequacy of the model.

Map lettering on the body of a map is often used to indicate a hierarchy among like geographic phenomena. In a series of experiments, maps were presented to a group of 150 college students who were asked to answer whether specified pairs of place names were the same size or different. Pairs of lettering sizes between .041 and .131 in. in a simple black on white context are distinguishable if they differ by 2 to 2½ point sizes or .020 in. in height of capital letter. Conflicting infonnation in the form of background screens and interrupted lines does not substantially affect reader judgments except when the size difference between words is small. Cutting a box around a word improves discrimination.

The simple theory of resistivity originally applied to pure liquid metals (Ziman 1961, Bradley et al. 1962) is formally extended to liquid alloys. In dilute solutions, size difference between solute and solvent ions can be allowed for, approximately, by a modification of the pseudo-potential of the solute, in a manner reminiscent of the modification of solute valency suggested by Harrison and Blatt (1957) in dealing with the resistance of solid alloys. The theory explains qualitatively a number of interesting features of the behaviour of liquid binary alloys, e.g. the failure of liquid solutions in polyvalent metals to obey the familiar rules of Nordheim and Linde. Some speculations on the anomalous behaviour of mercury amalgams are included. A bibliography of experimental results for both resistivity and density in liquid alloys is collected in Appendix II.

A study of the fine structure of Oocystis apiculata W. West has been made. The internal cytology has been described and, where appropriate, comparisons have been made with the externally similar alga, Glaucocystis. Particular attention has been paid to the structure and composition of the wall; the microfibrils immediately external to the plasmalemma are shown to be highly oriented; they are also shown by freeze-etching to close in to a ‘pole’. A brief discussion on the size difference in microfibrils as determined by shadowing and staining is also made.