Top PDF Evolution at shifting range margins

Evolution at shifting range margins

Evolution at shifting range margins

Surprisingly it was found that this effect persists when the mutation rate between morphs tends to zero (Elliott and Cornell, 2012). The reason behind this is unclear because the invasion speed is determined by what happens at low density, and in this limit the number of individuals of the minority morph tends to zero. The question therefore arises as to whether anomalous speeds occur as an artefact of the model, or if they are still present in more complex models where there is the possibility that at low density only one morph can be present at the invasion front. In this chapter a stochastic version of the model will be developed in the hope that it will shed some light on the answer to this question. The use of deterministic and stochastic models for predicting the rate of spread of species has highlighted some important differences. In density independent models demographic stochasticity does not generally slow invasions (Kot et al., 2004). This was also found by Mollison (1991), who showed that linear stochastic models often give the same result as deterministic models, and that speeds predicted using these provide an upper bound for the more realistic nonlinear stochastic case. Incorporating demographic stochasticity into density dependent models has provided further insight into whether stochasticity affects invasion speeds (Clark et al., 2001; Lewis, 2000; Lewis and Pacala, 2000; Snyder, 2003). These models reach varying conclusions with Snyder (2003) finding that the addition of demographic stochasticity results in marginally slower invasions, and Clark et al. (2001) finding that adding stochasticity can turn accelerating invasions into constant speed invasions. Kot et al. (2004) also demonstrated that in contrast to the density independent case, the combined effect of stochasticity and density dependence can slow invasions. Travis et al. (2011) have also highlighted the importance of using both deterministic and stochastic modelling approaches when predicting invasion speeds. They found that although both models produced similar trends, their analytical model predicted significantly higher speeds than their stochastic IBM (Travis et al., 2011). They found that the greater the amount of stochasticity incorporated into the model, through increasing the number of age classes, the greater the difference in the speed predicted by the two models. Their results revealed that looking at both stochastic and deterministic models can help to more accurately predict the speed at which a species expands its range.
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Inter-annual variability influences the eco-evolutionary dynamics of range-shifting

Inter-annual variability influences the eco-evolutionary dynamics of range-shifting

increases. This is consistent with previous results that higher rates of climate change drive the evolution of higher rates of dispersal (Boeye et al., 2013). In all scenarios, at the end of climate change, the emigration probability is much lower at the trailing edge of the range compared to the front and environmental noise typically increases selection for higher emigration rates. However, at the front there is an interesting switch and now, rather than temporal environmental variability increasing dispersal, it is in fact disrupting its evolution. The environmental gradient results in poorer conditions (lower K) at the range front compared with the core, these patches are therefore more susceptible to extinction in bad years. Under temporal variability there is no longer a smooth advance of suitable environmental space, instead populations will expand somewhat only to be knocked back following a run of poorer years, this effect being more pronounced under positively autocorrelated variability. The most dispersive individuals assorted into the furthest advanced patches in a period of better conditions will be those prone to extinction when a sequence of poorer years occurs. This effectively disrupts the spatial sorting and natural selection processes, reducing the evolved dispersal at the front. Once climate change has ended, the dispersiveness of individuals evolves back to levels similar to those prior to climate change. Although our choice of landscape should not quantitatively change the results, we highlight that it may influence the underlying evolutionary processes after climate change. For example, with narrower climate windows the dispersiveness of the whole population will increase rapidly as all individuals are forced to track a narrower area of habitat and thus less dispersive genotypes will be lost. After climate change the decrease in dispersiveness back to levels similar to those prior to climate change therefore requires the evolution of lower dispersive genotypes to replace those lost in the range shifting process. However with increasingly wider climate windows and invasion scenarios, where individuals are initialised at one end of the landscape and allowed to expand across empty space, habitat at the rear of the range is less likely to disappear. Thus less dispersive genotypes at the rear of the range are unlikely to be lost and once climate change has ceased the return to lower average dispersal will not rely solely on new mutations but can be achieved by the spread of existing genotypes.
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Biophysics, environmental stochasticity, and the evolution of thermal safety margins in intertidal limpets

Biophysics, environmental stochasticity, and the evolution of thermal safety margins in intertidal limpets

Given time-series for each environmental factor that influences body temperature, this environmental ensemble can then be ‘played’ through the L.  gigantea heat-budget model to provide a hypothetical time-series of body temperature of any length desired. For example, Denny and colleagues (Denny et al., 2009) used 1000- year records to ask how long a limpet would have to wait (on average) between experiencing days in which, by chance, its body temperature approached or exceeded lethal limits. These random stressful events were predicted to occur at intervals of 1.6 to 8.1years, depending on the definition of ‘stress’ (for details, see Denny et al., 2009). Miller and colleagues (Miller et al., 2009) coupled predictions of this sort with measurements of the location of L.  gigantea in the field to suggest that these rare, random stressful events might control the vertical range of L.gigantea. The environmental bootstrap can thus provide the sort of detailed, long- term time-series required to explore the effect of fluctuating body temperature on the spatial distribution of an important component species in an intertidal community. Here, we use the same approach to explore the evolution of thermal tolerance.
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Evolution of density-dependent movement during experimental range expansions

Evolution of density-dependent movement during experimental range expansions

The importance of an evolutionary and eco-evolutionary perspective for understanding the dynamics of species ranges becomes evident when considering the main drivers of range dynamics: dispersal and reproduction. These life-history traits not only have a genetic basis (Bonte & Dahirel, 2017; Saastamoinen et al., submitted) and can be subject to evolutionary change, but ample theoretical evidence suggests that the evolution of dispersal and reproduction may also have important effects on the dynamics of species ranges (e.g. reviewed in Kubisch et al., 2014). For instance, dispersal during range expansions is predicted to evolve to higher rates at range margins, a phenomenon called ‘spatial selection’ (Phillips et al., 2010). Spatial selection relies on a simple ecological filter effect: if there is variation in dispersal ability, fast individuals will automatically be spreading more towards the range margin and colonize previously empty patches (see also Haag et al., 2005). As a consequence, populations at the range margin have a higher proportion of more dispersive individuals that will mate with each other. In combination with fitness advantages due to low intraspecific competition at the range margin, this spatial assortment can lead to the evolution of increased dispersal and movement abilities. These evolutionary changes have important consequences for (macro)ecological patterns: range expansions and biological invasions are predicted to proceed faster if dispersal evolves (Perkins et al., 2013). Theoretical predictions regarding the evolution of reproduction have also been made, especially in the context of life-history trade-offs between dispersal, reproduction and competitive ability (Burton et al., 2010; Fronhofer & Altermatt, 2015; Fronhofer et al., 2017). Since dispersal is costly (Bonte et al., 2012), models generally assume that either reproduction or competitive ability have to decrease if dispersal increases.
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The evolution of snow bedforms in the Colorado Front Range and the processes that shape them

The evolution of snow bedforms in the Colorado Front Range and the processes that shape them

Finally, as described above, the erosion rate of solid mate- rials is proportional to the energy of the impacting particles minus a threshold energy (Anderson, 1986). In Fig. 7b, we showed an example of differential erosion on two layers of snow steps. As these steps were subject to the same fluxes of wind and snow, we assume that the older, non-eroding layer had a higher erosion threshold. Based on our current observations, however, we do not expect snow step erosion rates to be determined by the average properties of the snow pack. Figure 9c shows five snow steps moving at different ve- locities, despite being mere meters apart. Those snow steps decelerated over time. We infer from this that snow step ero- sion rates are a function of the age of the step but that this age differs from step to step across the shifting landscapes of bedform-covered snow.
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Professions at the margins

Professions at the margins

While some occupational groups have succeeded in achieving high levels of social recognition, others have found themselves languishing at the margins and striving to legitimize their work as professionals. Examples of such marginalization include the way that medical doctors have attained a prestigious professional status, whereas radiologists, nurses and midwives have struggled to acquire the same kind of social and economic rewards from their work (Freidson, 2007; Scott, 2008). Similarly, airline pilots have managed to secure for themselves an esteemed professional image – which continues today even though most of the actual flying is fully automated – whereas cabin personnel and air traffic controllers have found it difficult to gain respect for their work, although they are also responsible for a great deal of the safety in the air (Ashcraft, 2005; 2007; Hopkins, 1998). We tend to agree with commentators who suggest that the study of professions at the margins may offer considerable insight into issues around occupational development, regulation and closure. As McKenna notes (2007: 208), ‘the specific reasons behind the institutional failures of these potential professions are far more instructive than the subsequent explanations of institutional success’. This is because the progress of thriving professions, such as medicine or piloting, can be misleading because the process of professionalization for these occupational groups seems inevitable and unproblematic. Examining professions at the margins, by contrast, serves to illuminate the kinds of institutional power struggles, social inequalities, and race- and gender-based exclusions that lie at the heart of the system of professions.
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Exports Margins in Austria’s Export Growth

Exports Margins in Austria’s Export Growth

Abstract: Recent empirical research in international trade emphasizes the role of the extensive and intensive margin as determinants of countries’ trade patterns. Considering the case of Austria, the present paper uses detailed bilateral export data with 215 partner countries over the period 1998-2011, differentiated by product categories where we distinguish between total goods, final goods and intermediate goods, in order to calculate the contribution of the extensive and intensive margins to Austria’s export performance. Intensive margin are further decomposed into price and quantity margins in order to evaluate the role of to changes in price (quality) and changes in quantity. Unlike previous studies that have mainly used a single approach for the decomposition of exports into its margins, the present paper uses three alternative methods: i) the count method, ii) the decomposition method of export shares proposed by Hummels and Klenow (2005), and iii) the decomposition method of export growth rates by Bingzhan (2011). Results show that the intensive margin is key driver of Austria’s export growth across each product category. Additionally, the results indicate that the growth in the intensive margin of Austria’s exports is mainly explained by quantity growth.
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Advantages of a non-linear frequency compression algorithm in noise

Advantages of a non-linear frequency compression algorithm in noise

reported to sound unnatural. People with bilaterally sym- metrical hearing losses may have quite different auditory experiences compared to people with bilaterally asym- metrical hearing losses. Furthermore, hearing losses higher than 70 dB may produce qualitatively different effects compared to losses lower than these, based on the fact that more severe hearing losses usually involve different structures within the cochlea. Additionally, many hearing impaired people have a reduced dynamic range. The compression of selected high-frequency signals into a narrower frequency range, where the listener has better residual hearing, could have enabled more effective use of the additional audible speech information, although fre- quency compression may introduce artefacts in intelligi- bility and therefore may sound unnatural. Thus, these are encouraging results for those hearing impairments affect- ing high frequencies.
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Mass composition of cosmic rays with energies from [1017.2]eV to [1020]eV using surface and fluorescence detectors of the Pierre Auger Observatory

Mass composition of cosmic rays with energies from [1017.2]eV to [1020]eV using surface and fluorescence detectors of the Pierre Auger Observatory

Compared to a lighter primary, a heavier primary with mass A will therefore interact earlier in the atmosphere and produce a much wider shower front (due to more scattering centers). In order to infer the mass of a primary particle, we must select observational parameters (observ- ables) detected by the SD or FD, which are sensitive to the mass composition of primaries. A range of observables has been identified in [1], including the depth of shower maximum X max from the FD, and lateral distribution function, risetime t 1/2 , number of particles at the

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Professions at the margins

Professions at the margins

Let me start from the obvious and what may strike many as somewhat odd – the book’s title. To juxtapose ‘machine’ and ‘imagination’ may seem peculiar at first, one concept so close and the other so distant from the world of industrial production. And yet of course it should not be so, as the combination signals a call for us to begin producing alternatives ourselves. Shukaitis excellently discusses the evolution of the use of the two terms together, from Peter Lamborn Wilson (1996), then to Deleuze and Guattari (1977), all the way back to Castoriadis (1975). And this is just a prelude. In the relatively limited space of the book’s 255 pages Shukaitis manages to delve into debates on everyday life; on the eternal problem of insurrections and revolutions left incomplete, or even recuperated by the forces of capital (how apt in the case of the Egyptian Revolution, or the Greek Uprising); on the perceived existence, in revolutionary circles, of an autonomous, pure quality of society that only requires the veil removed from the false totality of the present to make itself present in return (‘to understand revolution as revelation’, [53]); on the role of outer space and extraterrestrial voyage in shaping radical imagination; on affective composition, self-management, the politics of minor composition (creating social movement from within intense, everyday relations); on the question of organisation within the social antagonist movement (‘the labor of imagination’ [119]); on affective relations and their relationship in creating communities of resistance; all before devoting a chapter to precarity struggles and, finally, a chapter confronting recuperation of radical politics – both as a threat, but even more as a reminder for us to continually recompose our political theory and our praxis. Clearly a review of all the ideas discussed in the book would be perforce incomplete, confined by this text’s allowed length. What I want to do instead is to take a handful of these ideas and use them as a starting point for a discussion not only about the book’s potential legacies but also the legacies of the antagonist movement as a whole – and even more so, its potential amidst the current crisis of capital.
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Positioning error and expanding margins of planning target volume with kilovoltage cone beam computed tomography for prostate cancer radiotherapy

Positioning error and expanding margins of planning target volume with kilovoltage cone beam computed tomography for prostate cancer radiotherapy

Radiotherapy is one of the radical treatments for prostate cancer. In recent years, with the development of intensity-modulated radiation therapy, the dose and effect of radiotherapy for prostate cancer have been further improved. Accurate radiotherapy technology requires the reduction of the influence of positioning errors. However, positioning error remains as one of the obstacles in further improving the accuracy of treatment. External error size is an important factor of clinical target volume (CTV)- to-planning target volume (PTV) margins (M PTV ) in radiotherapy. At present, M PTV is usually 10 mm in the absence of corrective measures. 1
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Late Holocene landscape evolution in the Dazzler Range: new evidence

Late Holocene landscape evolution in the Dazzler Range: new evidence

Saxons Creek drains a low ridge at the southern end of the Dazzler Range, and discharges ultimately into the southeastern arm of Port Sorell via Franklin Rivulet. Its catchment is slightly larger, lower and less steep than that of Branchs Creek, with which it shares a drainage divide ranging from 520 m to 215 m altitude. As at Branchs Creek and Massey Creek, channel straightening associated with land development for agriculture has increased the erosive capacity of the flow relative to that through the original, unmodified channel, and facilitated pronounced gullying (Kiernan 1999).
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Optimizing the delivery of contraceptives in low- and middle-income countries through task shifting: a systematic review of effectiveness and safety

Optimizing the delivery of contraceptives in low- and middle-income countries through task shifting: a systematic review of effectiveness and safety

Studies assessing the safety and effectiveness of task shifting in contraceptive provision, and particularly of IUD insertion and tubal ligation, have been conducted since the 1960s [33-38]. Most have concluded that task shifting in contraceptive delivery is safe and effective. Other reviews, such as Malarcher et al. [13], have em- phasized the safety and effectiveness of injectable con- traceptives being delivered by LHWs. But a more recent review of the use of LHWs to provide injectable contra- ceptives concluded that it is uncertain whether the use of LHWs improves contraceptive uptake or is able to maintain patient safety and satisfaction. The review sug- gests, however, that where access to professional health workers is limited and where LHW programmes already exist, consideration should be given to training LHWs to administer injections with a safe injection device [17]. In their commentary on contraceptive studies, Janowitz et al. [8] suggest that task shifting is safe and effective for different contraceptive methods and types of health workers. Our review findings are consistent with the
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Two new species of Nototelmatoscopus (Jozifekia), with records of three other species from Thailand (Diptera: Psychodidae)

Two new species of Nototelmatoscopus (Jozifekia), with records of three other species from Thailand (Diptera: Psychodidae)

Terminalia (Figs 9–12) with hypandrium present, hyaline, truncate with margins thicker; gonocoxite trapezoid with outer margins longest, inner margins medially with bulbous ex- pansion; parameres trapezoid with margins sclerotized; gonocoxal condyles elongate and curved with small round medial sclerite; gonostyle slender, tubular, bent towards mesal side; distally with pair of sensilla; aedeagus with basiphallus narrow in dorsal view with origin of distiphallus expanded into a circular aperture, basal shape not discernable; distiphallus comprised of two elongate triangular lobes forming the margins of a membranous spatula, around 1.5 times as long as basiphallus; epandrium more than twice as broad as long, central aperture not discernable, distal corners with row of elongate setae and thickly sclerotized margins; surstyli (Fig. 11) about 1.5 times length of epandrium, subcylindrical with apex slightly pointed; inner margins with clearly defi ned ‘cercal area’ on mesal side reaching two thirds of total surstylus length; 16 tenacula present in irregular apicodorsal patch; apices of tenacula split (Fig. 12), longest tenaculum half-length of surstylus; proctiger with hypoproct tongue-shaped, epiproct oval, broader than long; both microsetose; hypoproct reaching one- -half the length of surstylus.
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Sine-modulated wavelength-independent full-range complex spectral optical coherence tomography with an ultra-broadband light source

Sine-modulated wavelength-independent full-range complex spectral optical coherence tomography with an ultra-broadband light source

To resolve the problem, one can measure the phase of the spectral interferometer signal. An inverse Fourier transform of the complex data directly provides the true object structure, eliminating any mirror terms. To achieve the full-range complex spectral domain optical coherence tomography (FRCSD-OCT), several meth- ods have been proposed. The first approach is to con- struct complex interference fringes by a phase-shifting method. The phase information required to reconstruct such a signal from intensity measurements is obtained from recording two to five spectra collected for a con- stant penetrating beam, but with the reference mirror being shifted by various fractions of wavelength of the light used. 8–10 In practice, such a result is difficult to achieve. Most of the methods require shifting the refer- ence mirror by a precise fraction of the wavelength. If a relatively broadband light source is used, this leads to so-called polychromatic error 11 since the condition is only fulfilled for one wavelength. Most of the light sources used in the above researches were generally superluminescent diode (SLD) with a central wave- length of ;820 nm and a bandwidth of ;20 nm. The light sources have narrow bandwidth, and therefore, the polychromatic error caused is relatively small. However, if a broadband light source is employed, the polychro- matic error will become obvious; also, the performance in the suppression of complex-conjugate artifacts will be deteriorated. Lippok et al. 12 used the Pancharatnam– Berry phase as a multifunctional tool for low-coherence interferometry. The geometric phase shift enables instantaneous retrieval of the quadrature components of the complex interferometric signal and allows for a complex-conjugate suppression of 40 dB for an optical bandwidth of 115 nm. Carrier-frequency-based tech- nique is another method to reconstruct the complex interference fringes; 13–15 a tilted reference mirror or a reflective grating was used to generate a spatial carrier- frequency into the two-dimensional (2D) spectral inter- ferogram registered in parallel FD-OCT. However, the
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Automatic height extraction from stereoscopic SAR imagery

Automatic height extraction from stereoscopic SAR imagery

7.1 case (A). The ninth value shows the multiplicative gain, which is the multiplicative scale factor between the coordinates of the two images, with an initial value of 1.0. The tenth is an integer field to denote the number of iterations used by G RU EN to search for the matched positions. This iteration value is the most important among all the other 8 output values, for it reveals the condition of the matching procedures, as illustrated in Fig. 7.1. In case (A), the iteration value is set to -1 which means that for this seed point, the matched patch has gone outside of the image boundary so that this point does not go into any matching process. This situation which can also be seen from observing the elements of the affine transformation as mentioned earlier. In case (B), the iteration value is set to -20 to imply that the points have not yet converged after 20 iterations, as a consequence of poor estimation of the initial values. If the iteration value is positive, the matching is going smoothly, as in case (C). Among the above three cases, case (A) should be given special attention because in the p\Tamidal matching employed in this project, this situation often occurs on the first tier of most matching points, where the image size is very small and the match patch radius for the seed points is more likely to be outside of the image boundary. The eleventh value gives the eigenvalue for the covariance matrix and as described in Chapter 4. It is the standard figure used to Judge the quality of the matching points. It is based on this value that G R U EN S grows other seed points. The twelfth value is an additive radiometric shift parameter with an initial value 0.0, and it is able to give an indication on the shifting quantity of the matched points between the left and right image.
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Evolution of the feline-subgroup parvoviruses and the control of canine host range in vivo.

Evolution of the feline-subgroup parvoviruses and the control of canine host range in vivo.

Canine host range in vivo. Both the recombinant (vBI410) and site-directed mutant (vBI319) viruses derived from FPV replicated in dogs to titers similar to those seen for CPV (Fig. 7). Replication in the ileum and mesenteric lymph nodes is a characteristic of CPV host range in dogs (61), and both recom- binant viruses replicated to high titers in those tissues. Virus- infected cells were also observed after immunoperoxidase staining in the intestine (Fig. 8) and other tissues (not shown). Viral DNA was demonstrated by dot blot Southern hybridiza- tion analysis, and viral DNAs from the tissues isolated by PCR amplification were cloned and sequenced, confirming that the correct mutations were present in the virus replicating in each dog (results not shown).
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Seasonal sea surface temperatures of the North Pacific

Seasonal sea surface temperatures of the North Pacific

Maps of the North Pacific sea surface above 20˚N (Figures 2 and 3), showing regions where the highest and lowest monthly mean temperatures occur, in the long term average, have never been drawn before, to the best of my knowledge. There are no a priori expectations for what such maps may turn out to look like. Also a recent map of the mean seasonal range of surface temperature has been produced below (Figure 1) to compare with a

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The impact of adding community-based distribution of oral contraceptives and condoms to a cluster randomized primary health care intervention in rural Tanzania

The impact of adding community-based distribution of oral contraceptives and condoms to a cluster randomized primary health care intervention in rural Tanzania

gender inclusion are not new: Three decades ago, Easter- lin and colleagues posited a framework that specified the importance of mitigating social and spousal constraints to fertility regulation (40, 41). Gender sensitive program- ming remains important in ensuring a comprehensive approach to social acceptance of family planning utilization (42). Yet, while social access to family plan- ning services is important, social, demographic, and be- havioral research in Tanzania and elsewhere has consistently demonstrated the importance of maximizing the range of contraceptive options alongside increased access to care (43, 44). Expanding method options con- tributes to the goal of improving the quality of care (45, 46), reproductive rights, and social acceptability of contraception (47).
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Research Highlights on the Evolution of Precambrian Crust of Peninsular India: Constraints from Rece

Research Highlights on the Evolution of Precambrian Crust of Peninsular India: Constraints from Rece

high precision age determination of mafic rocks at CSIR-NGRI (Kumar et al., 2014). Combined with Paleomagnetic and geochemical data, the new baddeleyite age data have contributed to the resolution of emplacement ages of mafic dykes from Dharwar, Bastar, Bundelkhand and Singhbhum cratons. For instance, the identification of giant radial dyke swarm emplaced at ~ 2367 Ma and ~2082 Ma with implications for Paleoproterozoic continental reconstructions and basin evolution (Kumar et al., 2012, 2015; Shankar et al., 2014). Several other researchers have provided new ages, geochemical and paleomagnetic data on the multiple generations of the mafic dyke swarms (e.g., Dash et al., 2013), Proterozoic gabbro-anorthosite plutons (e.g., Kaur et al., 2013; Dharma Rao et al., 2012; Koizumi et al., 2014; Raith et al., 2014), alkaline complexes, kimberlites and lamproites (e.g., Chalapathi Rao et al., 2014; Santosh et al., 2014; Karmalkar et al., 2014; Hippe et al., 2016; He et al., 2015) and a host of granitoid plutons and felsic volcanism (e.g., Ashwal et al., 2013; Dharma Rao et al., 2012, 2013; Meert et al., 2013; Ravikant et al., 2014) from the different tectonic provinces of peninsular India.
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