Using Bayesian variable selection methods to choose style factors in global stock return models

This paper applies Bayesian variable selection methods from the statistics literature to give guidance in the decision to include/omit factors in a global (linear factor) stock return model. Once one has accounted for country and sector, it is possible to see which style or styles best explains current asset returns. This study does not find compelling evidence for global styles as useful explanatory factors, once country and sector have been accounted for

No-till Forage Establishment in Alaska

We assessed the effectiveness of no-till forage establishment at six Alaska locations: Anchor Point, Sterling, Point MacKenzie, Palmer, Delta Junction, and Fairbanks. Directly seeding grass into established grass stands generally did not improve forage yields or quality. Seeding rate had little effect on establishment of newly seeded forages in no-till. Grass yields were depressed when companion crop yields were high, and they typically did not recover in subsequent years. Red clover established well, producing high yields of good quality forage under no-till at Point MacKenzie, but established poorly at Anchor Point and Delta Junction. These results indicated that no-till seeding of most forage crops into declining grass stands is not likely to be successful in Alaska with current available technology

A multimodal perspective on the composition of cortical oscillations.

An expanding corpus of research details the relationship between functional magnetic resonance imaging (fMRI) measures and neuronal network oscillations. Typically, integrated electroencephalography and fMRI, or parallel magnetoencephalography (MEG) and fMRI are used to draw inference about the consanguinity of BOLD and electrical measurements. However, there is a relative dearth of information about the relationship between E/MEG and the focal networks from which these signals emanate. Consequently, the genesis and composition of E/MEG oscillations requires further clarification. Here we aim to contribute to understanding through a series of parallel measurements of primary motor cortex (M1) oscillations, using human MEG and in vitro rodent local field potentials. We compare spontaneous activity in the ∼10 Hz mu and 15-30 Hz beta frequency ranges and compare MEG signals with independent and integrated layers III and V (LIII/LV) from in vitro recordings. We explore the mechanisms of oscillatory generation, using specific pharmacological modulation with the GABA-A alpha-1 subunit modulator zolpidem. Finally, to determine the contribution of cortico-cortical connectivity, we recorded in vitro M1, during an incision to sever lateral connections between M1 and S1 cortices. We demonstrate that frequency distribution of MEG signals appear have closer statistically similarity with signals from integrated rather than independent LIII/LV laminae. GABAergic modulation in both modalities elicited comparable changes in the power of the beta band. Finally, cortico-cortical connectivity in sensorimotor cortex (SMC) appears to directly influence the power of the mu rhythm in LIII. These findings suggest that the MEG signal is an amalgam of outputs from LIII and LV, that multiple frequencies can arise from the same cortical area and that in vitro and MEG M1 oscillations are driven by comparable mechanisms. Finally, cortico-cortical connectivity is reflected in the power of the SMC mu rhythm

Desynchronization of pathological low-frequency brain activity by the hypnotic drug zolpidem.

Reports of the beneficial effects of the hypnotic imidazopyridine, zolpidem, described in persistent vegetative state^1, 2^ have been replicated recently in brain-injured and cognitively impaired patients^3-7^. Previous single photon emission computed tomography (SPECT) studies have suggested that sub-sedative doses of zolpidem increased regional cerebral perfusion in affected areas^5, 8^, implying enhanced neuronal metabolic activity; which has led to speculation that zolpidem 'reawakens' functionally dormant cortex. However, a neuronal mechanism by which this hypnotic drug affords benefits to brain injured patients has yet to be demonstrated. Here, we report the action of sub-sedative doses of zolpidem on neuronal network oscillatory activity in human brain, measured using pharmaco-magnetoencephalography (pharmaco-MEG). Study participant JP suffered a stroke in 1996, causing major damage to the left hemisphere that impaired aspects of both motor and cognitive function. Pharmaco-MEG analyses revealed robust and persistent pathological theta (4-10Hz) and beta (15-30Hz) oscillations within the lesion penumbra and surrounding cortex. Administration of zolpidem (5mg) reduced the power of pathological theta and beta oscillations in all regions of the lesioned hemisphere. This desynchronizing effect correlated well with zolpidem uptake (occurring approximately 40 minutes after acute administration) and was coincident with marked improvements in cognitive and motor function. Control experiments revealed no effect of placebo, while a structurally unrelated hypnotic, zopiclone, administered at a comparable dose (3.5mg) elicited widespread increases in cortical oscillatory power in the beta (15-30Hz) band without functional improvement. These results suggest that in JP, specific motor and cognitive impairments are related to increased low-frequency oscillatory neuronal network activity. Zolpidem is unique amongst hypnotic drugs in its ability to desynchronize such pathological low-frequency activity, thereby restoring cognitive function

Gamma oscillatory amplitude encodes stimulus intensity in primary somatosensory cortex

Gamma oscillations have previously been linked to pain perception and it has been hypothesised that they may have a potential role in encoding pain intensity. Stimulus response experiments have reported an increase in activity in the primary somatosensory cortex (SI) with increasing stimulus intensity, but the specific role of oscillatory dynamics in this change in activation remains unclear. In this study, Magnetoencephalography (MEG) was used to investigate the changes in cortical oscillations during 4 different intensities of a train of electrical stimuli to the right index finger, ranging from low sensation to strong pain. In those participants showing changes in evoked oscillatory gamma in SI during stimulation, the strength of the gamma power was found to increase with increasing stimulus intensity at both pain and sub-pain thresholds. These results suggest that evoked gamma oscillations in SI are not specific to pain but may have a role in encoding somatosensory stimulus intensity. © 2013 Rossiter, Worthen, Witton, Hall and Furlong

Riots and Political Protest: Notes from the Post-Political Present

The years 2008 to 2013 saw a new generation of political protestors take to the streets. Riots disrupted many Western cities and new protest movements emerged, keen to address a bleak context of economic collapse and austerity politics. In this groundbreaking new study, Winlow, Hall, Briggs and Treadwell push past the unworldly optimism of the liberal left to offer an illuminating account of the enclosure and vacuity of contemporary politics. Focusing on the English riots of 2011, the ongoing crisis in Greece, the Indignados, 15M and Podemos in Spain, the Occupy movement in New York and London and the English Defence League in northern England, this book uses original empirical data to inform a strident theoretical critique of our post-political present. It asks: what are these protest groups fighting for, and what are the chances of success? Written by leading criminological theorists and researchers, this book makes a major contribution to contemporary debates on social order, politics and cultural capitalism. It illuminates the epochal problems we face today. Riots and Political Protest is essential reading for academics and students engaged in the study of political sociology, criminological theory, political theory, sociological theory and the sociology of deviance.No data (2015)UE

The Prehistoric Sites at Choke Canyon Reservoir, Southern Texas: Results of Phase II Archaeological Investigations

Reported in this volume are the results of archaeological investigations at 72 prehistoric sites located in the basin of Choke Canyon Reservoir on the Frio River in Live Oak and McMullen Counties, southern Texas. The sites investigated in this study will be affected in one way or another by a lake formed after construction of Choke Canyon Dam, a project of the United States Bureau of Reclamation CUSBR). The research was sponsored by the USBR as the second and final phase of a two-stage program of archaeological investigations designed to mitigate damage or destruction of cultural resources resulting from dam construction and subsequent long-term inundation of a large area of the Frio River valley. Methods used to study Choke Canyon\u27s prehistoric sites during the Phase II investigation were various types of subsurface excavations, documentation of surface features and characteristics, and collection of artifacts from site surfaces. The people who inhabited the Choke Canyon region in prehistoric times, representing an approximate span of 10,000 years, existed as mobile hunter/gatherer bands. They subsisted by tapping virtually every conceivable source of edible natural food. A full spectrum of animals, from lowly field mice and lizards up to bison and deer, was exploited by various techniques of hunting, trapping, and catching. Large land snails and mussels were sources of meat food that Choke Canyon\u27s prehistoric people could easily gather. Gar, drum, and turtles were taken from local creeks, sloughs, and the river, perhaps using spears, nets, or weirs. Analysis of vertebrate faunal remains, results of which are presented herein, rather conclusively demonstrates that Late Prehistoric people exploited big game species more commonly than did their Archaic period predecessors. Floral products must also have comprised a substantial portion of the foods consumed by Choke Canyon\u27s prehistoric inhabitants. Direct evidence of plant food utilization is nonexistent on the sites. However, the very common occurrence of sandstone manes and metates implies heavy reliance on seeds, nuts, or beans. Also, the tremendous amount of burned rock that accumulated in Archaic components at many sites, often found as very carefully constructed hearth features, suggests that baking or roasting activities were extremely common. Roots, tubers, stalks, and other edible plant parts may have been what was being prepared in these facilities. Diagnostic artifacts recovered from prehistoric sites at Choke Canyon during the various phases of archaeological investigation clearly indicate that the general vicinity witnessed aboriginal activity from Paleo-Indian times up through the early Historic period. Evidence of Paleo-Indian people is limited to surface finds along the valley margin and on high, ancient terrace formations down in the river valley. No in situ subsurface Paleo-Indian components have yet been isolated at Choke Canyon. Where previously the earliest subsurface component known at Choke Canyon dated to the Middle Archaic period (ca. 3400 B.C. to 2400 B.C.), the Phase II excavations led to discovery of an Early Archaic component dating to the period from 5000 B.C. xi to 4000 B.C. While recognizable Paleo-Indian, Early Archaic, and Middle Archaic components are relatively scarce, the Late Archaic and Late Prehistoric periods are amply represented in the prehistoric sites at Choke Canyon. Phase II investigations also produced the first clear indication of an aboriginal component containing evidence of contact with Anglo-Europeans in early historic times. The bulk of cultural, paleobotanical, and vertebrate faunal data representing the prehistory of Choke Canyon indicates that floral and faunal communities and the general climatic regime remained essentially unchanged from at least 4000 B.C. up to the period in historic times when certain livestock and land management practices led to a drastic expansion of brush communities and severe erosion of formerly stable land surfaces

Does Epileptiform Activity Represent a Failure of Neuromodulation to Control Central Pattern Generator-Like Neocortical Behavior?

Rhythmic motor patterns in invertebrates are often driven by specialized "central pattern generators" (CPGs), containing small numbers of neurons, which are likely to be "identifiable" in one individual compared with another. The dynamics of any particular CPG lies under the control of modulatory substances, amines, or peptides, entering the CPG from outside it, or released by internal constituent neurons; consequently, a particular CPG can generate a given rhythm at different frequencies and amplitudes, and perhaps even generate a repertoire of distinctive patterns. The mechanisms exploited by neuromodulators in this respect are manifold: Intrinsic conductances (e.g., calcium, potassium channels), conductance state of postsynaptic receptors, degree of plasticity, and magnitude and kinetics of transmitter release can all be affected. The CPG concept has been generalized to vertebrate motor pattern generating circuits (e.g., for locomotion), which may contain large numbers of neurons - a construct that is sensible, if there is enough redundancy: that is, the large number of neurons consists of only a small number of classes, and the cells within any one class act stereotypically. Here we suggest that CPG and modulator ideas may also help to understand cortical oscillations, normal ones, and particularly transition to epileptiform pathology. Furthermore, in the case illustrated, the mechanism of the transition appears to be an exaggerated form of a normal modulatory action used to influence sensory processing

Designing antibiotic cycling strategies by determining and understanding local adaptive landscapes

The evolution of antibiotic resistance among bacteria threatens our continued ability to treat infectious diseases. The need for sustainable strategies to cure bacterial infections has never been greater. So far, all attempts to restore susceptibility after resistance has arisen have been unsuccessful, including restrictions on prescribing [1] and antibiotic cycling [2,3]. Part of the problem may be that those efforts have implemented different classes of unrelated antibiotics, and relied on removal of resistance by random loss of resistance genes from bacterial populations (drift). Here, we show that alternating structurally similar antibiotics can restore susceptibility to antibiotics after resistance has evolved. We found that the resistance phenotypes conferred by variant alleles of the resistance gene encoding the TEM {\beta}-lactamase (blaTEM) varied greatly among 15 different {\beta}-lactam antibiotics. We captured those differences by characterizing complete adaptive landscapes for the resistance alleles blaTEM-50 and blaTEM-85, each of which differs from its ancestor blaTEM-1 by four mutations. We identified pathways through those landscapes where selection for increased resistance moved in a repeating cycle among a limited set of alleles as antibiotics were alternated. Our results showed that susceptibility to antibiotics can be sustainably renewed by cycling structurally similar antibiotics. We anticipate that these results may provide a conceptual framework for managing antibiotic resistance. This approach may also guide sustainable cycling of the drugs used to treat malaria and HIV