A Barren Landscape?

We consider the generation of a non-perturbative superpotential in F-theory compactifications with flux. We derive a necessary condition for the generation of such a superpotential in F-theory. For models with a single volume modulus, we show that the volume modulus is never stabilized by either abelian instantons or gaugino condensation. We then comment on how our analysis extends to a larger class of compactifications. From our results, it appears that among large volume string compactifications, metastable de Sitter vacua (should any exist) are non-generic.Comment: 14 pages, comments adde

“You can help people”: Adolescents’ Views on Engaging Young People in Longitudinal Research

We sought to discover adolescents’ thoughts about participation in longitudinal research and identify recruitment and retention strategies that were meaningful to them. We conducted seven focus groups with 10–15-year-olds in two large rural centers in New South Wales, Australia, and all focus groups were digitally recorded, transcribed, and analyzed. Adolescents discussed factors salient to their involvement in focus groups, as well as factors that may influence involvement in a longitudinal study. At the outset of the focus groups, adolescents had a positive view of “research,” but were reluctant to engage in research that involved biologic samples. Effective recruitment of adolescents requires an appreciation of motivators, and time and resources to extend potential participants’ understanding.Supported by Sydney Medical School Foundation

Seasonal and Interannual Variability of Phytoplankton Abundance and Community Composition on the Central Coast of California

Variations in the abundance and composition of phytoplankton greatly impact ecosystem structure and function. Within the California Current System (CCS), phytoplankton community structure is tightly coupled to seasonal variability in wind-driven coastal upwelling, a process that drives changes in coastal water temperatures and nutrient concentrations. Based on approximately a decade (2008-2018) of weekly phytoplankton measurements, this study provides the first characterization of the seasonal and interannual variability of phytoplankton abundance and composition in San Luis Obispo (SLO) Bay, an understudied region within the CCS. Overall, the seasonality of phytoplankton in SLO Bay mirrored that of the larger CCS; diatoms dominated the community during the spring upwelling season, whereas dinoflagellates dominated the community during the fall relaxation period. While we observed considerable interannual variability among phytoplankton taxa, of particular note was the absence of a fall dinoflagellate-dominated period from 2010 through 2013, followed by the return of the fall dinoflagellate-dominated period in 2014. This compositional shift coincided with a major phase shift of both the Pacific Decadal Oscillation (PDO) and North Pacific Gyre Oscillation (NPGO). In addition to exerting a strong influence on the seasonality of phytoplankton community succession and transition between diatom- and dinoflagellate-dominated periods, the state of both the PDO and NPGO also influenced the extent to which environmental conditions (temperature and upwelling winds) could predict community type. These results highlight the importance of long-term datasets and the consideration of large-scale climate patterns when assessing local ecosystem dynamics

Work-related psychological health and psychological type among lead elders within the Newfrontiers network of churches in the United Kingdom

Building on a series of recent studies concerned with assessing work-related psychological health and psychological type among various groups of church leaders, this study reports new data provided by 134 Lead Elders within the Newfrontiers network of churches in the United Kingdom who completed the Francis Psychological Type Scales (FPTS) together with the two scales of the Francis Burnout Inventory (FBI) concerned with emotional exhaustion and satisfaction in ministry. Compared with other groups of church leaders, Lead Elders within the Newfrontiers network of churches reported lower levels of emotional exhaustion and higher levels of satisfaction in ministry. Compared with other groups of church leaders, there was a higher proportion of extraverts among Lead Elders within the Newfrontiers network of churches. There was only a weak association between psychological type and burnout

Evolution of displacements and strains in sheared amorphous solids

The local deformation of two-dimensional Lennard-Jones glasses under imposed shear strain is studied via computer simulations. Both the mean squared displacement and mean squared strain rise linearly with the length of the strain interval $\Delta \gamma$ over which they are measured. However, the increase in displacement does not represent single-particle diffusion. There are long-range spatial correlations in displacement associated with slip lines with an amplitude of order the particle size. Strong dependence on system size is also observed. The probability distributions of displacement and strain are very different. For small $\Delta \gamma$ the distribution of displacement has a plateau followed by an exponential tail. The distribution becomes Gaussian as $\Delta \gamma$ increases to about .03. The strain distributions consist of sharp central peaks associated with elastic regions, and long exponential tails associated with plastic regions. The latter persist to the largest $\Delta \gamma$ studied.Comment: Submitted to J. Phys. Cond. Mat. special volume for PITP Conference on Mechanical Behavior of Glassy Materials. 16 Pages, 8 figure

Utilitarian Collective Choice and Voting

In his seminal Social Choice and Individual Values, Kenneth Arrow stated that his theory applies to voting. Many voting theorists have been convinced that, on account of Arrow’s theorem, all voting methods must be seriously flawed. Arrow’s theory is strictly ordinal, the cardinal aggregation of preferences being explicitly rejected. In this paper I point out that all voting methods are cardinal and therefore outside the reach of Arrow’s result. Parallel to Arrow’s ordinal approach, there evolved a consistent cardinal theory of collective choice. This theory, most prominently associated with the work of Harsanyi, continued the older utilitarian tradition in a more formal style. The purpose of this paper is to show that various derivations of utilitarian SWFs can also be used to derive utilitarian voting (UV). By this I mean a voting rule that allows the voter to score each alternative in accordance with a given scale. UV-k indicates a scale with k distinct values. The general theory leaves k to be determined on pragmatic grounds. A (1,0) scale gives approval voting. I prefer the scale (1,0,-1) and refer to the resulting voting rule as evaluative voting. A conclusion of the paper is that the defects of conventional voting methods result not from Arrow’s theorem, but rather from restrictions imposed on voters’ expression of their preferences. The analysis is extended to strategic voting, utilizing a novel set of assumptions regarding voter behavior

A segmented and clawed male foreleg in a newly described genus and species of eumaeine butterfly (Lepidoptera: Lycaenidae)

Grishinata Robbins and Busby, new genus (Lepidoptera: Lycaenidae: Eumaeini), possesses a five-segmented foretarsus with a clawed pretarsus, a trait that differentiates it from all eumaeine genera except Theclopsis Godman and Salvin. Grishinata penny Busby, Hall, and Robbins, new species, differs from all species of Theclopsis (and most Eumaeini) in lacking male secondary sexual organs on the wings or in the abdomen. It is recorded from the eastern slope of the Andes in Ecuador and Peru. We cannot place Grishinata penny in an existing Eumaeini genus based upon its wing pattern, male foreleg structure, lack of male second­ary sexual organs, and male genitalic morphology. We propose names for the genus and species to document its leg morphology and to provide a name for a genome sequencing project, which will allow us to place the genus in the eumaeine Linnaean hierarchy. There are two morphological types of male forelegs in the lepidopteran butterfly family Lycaenidae, each of which is functionally and structurally different from male forelegs in other diurnal butterfly families. The first male foreleg type is superficially similar to that of Nymphalidae and Riodinidae in that the tarsus is unsegmented, lacks a pretarsus, and is not used to groom the antennae (Robbins 1988, 1990). It differs functionally from these families in that it is used for walking. It differs morphologically in that it possesses tarsal alpha and beta trichoid sensilla (terminology from Chun and Schoonhoven 1973), which are lacking in Nymphalidae and Riodinidae with few exceptions (Robbins 1988). This male foreleg type occurs in more than 98% of lycaenid species (Mattoni and Fiedler 1991). The second lycaenid male foreleg type is superficially similar to that of Hesperiidae, Papilionidae, and Pieridae in that the foretarsus is segmented with a clawed pretarsus. It differs functionally from these families in that it is not used to groom the antennae (Jander 1966; Robbins 1990). It differs morphologically in that it lacks the tibial epiphysis of Hesperiidae and Papilionidae or the vestigial remnant of an epiphysis that occurs in some Pieridae (Robbins 1990). Within Eumaeini, this male foreleg type is restricted to some species of Theclopsis Godman and Salvin, 1887 (Godman and Salvin 1887; Robbins 2004). We discovered a species (Fig. 1) belonging to the Eumaeini with a male foreleg that has a clawed pretarsus and a five-segmented tarsus (Fig. 2), but the male genitalia, secondary sexual characters, and wing pattern (Fig. 1, 3) are dissimilar from those of Theclopsis. The males lack secondary sexual organs on the wings or in the abdomen (Fig. 1, 3), which is highly unusual in Eumaeini (Valencia-Montoya et al. 2021). The male genitalia (Fig. 3) lack structures that would be useful in determining its closest phylogenetic relatives. More generally, we find no clear-cut morphological evidence to place this species in an available eumaeine genus. The purpose of this paper is to propose new generic and specific names for this newly discovered taxon. One reason is that we need a name to document its unusual leg morphology. Another is that we are currently sequencing its genome for a phylogenetic project. Phylogenetic analysis of the sequence data will allow us to place the genus in the eumaeine Linnaean hierarchy. We predict that it will show, in accord with the findings of Mattoni and Fiedler (1991), that its male foreleg with a clawed pretarsus and five-segmented tarsus evolved from a tarsus that was fused without a pretarsus

Radiation Hardness Studies in a CCD with High-Speed Column Parallel Readout

Charge Coupled Devices (CCDs) have been successfully used in several high energy physics experiments over the past two decades. Their high spatial resolution and thin sensitive layers make them an excellent tool for studying short-lived particles. The Linear Collider Flavour Identification (LCFI) collaboration is developing Column-Parallel CCDs (CPCCDs) for the vertex detector of the International Linear Collider (ILC). The CPCCDs can be read out many times faster than standard CCDs, significantly increasing their operating speed. The results of detailed simulations of the charge transfer inefficiency (CTI) of a prototype CPCCD are reported and studies of the influence of gate voltage on the CTI described. The effects of bulk radiation damage on the CTI of a CPCCD are studied by simulating the effects of two electron trap levels, 0.17 and 0.44 eV, at different concentrations and operating temperatures. The dependence of the CTI on different occupancy levels (percentage of hit pixels) and readout frequencies is also studied. The optimal operating temperature for the CPCCD, where the effects of the charge trapping are at a minimum, is found to be about 230 K for the range of readout speeds proposed for the ILC. The results of the full simulation have been compared with a simple analytic model.Comment: 3 pages, 6 figures; presented at IEEE'07, ALCPG'07, ICATPP'0

Unfamiliar faces engaged in non-rigid motion are processed holistically

Paper presented at the Australasian Experimental Psychology Conference 2015, 8-11 April 2015, Sydney, Australia

Coastal upwelling seasonality and variability of temperature and chlorophyll in a small coastal embayment

While the seasonality of wind-driven coastal upwelling in eastern boundary upwelling systems has long been established, many studies describe two distinct seasons (upwelling and non-upwelling), a generalized framework that does not capture details relevant to marine ecosystems. In this contribution, we present a more detailed description of the annual cycle and upwelling seasonality for an understudied location along the central California coast. Using both the mean monthly upwelling favorable wind stress and the monthly standard deviation, we define the following seasons (contiguous months) and a transitional period (non-contiguous months): “Winter Storms” season (Dec-Jan-Feb), “Upwelling Transition” period (Mar and Jun), “Peak Upwelling” season (Apr-May), “Upwelling Relaxation” season (Jul-Aug-Sep), and “Winter Transition” season (Oct-Nov). In order to describe the oceanic response to this upwelling wind seasonality, we take advantage of nearly a decade of full water-column measurements of temperature and chlorophyll made using an automated profiling system at the end of the California Polytechnic State University Pier in San Luis Obispo Bay, a small (~ 2 km wide near study site) and shallow (~ 10 m average bay depth) coastal embayment. Variability and average-year patterns are described inside the bay during the various upwelling seasons. Moreover, the role of the local coastline orientation and topography on bay dynamics is also assessed using long-term measurements collected outside of the bay. The formation of a seasonally variable upwelling shadow system and potential nearshore retention zone is discussed. The observations presented provide a framework on which to study interannual changes to the average-year seasonal cycle, assess the contribution of higher-frequency features to nearshore variability, and better predict dynamically and ecologically important events