Strength of Gamma Rhythm Depends on Normalization

Neuronal assemblies often exhibit stimulus-induced rhythmic activity in the gamma range (30–80 Hz), whose magnitude depends on the attentional load. This has led to the suggestion that gamma rhythms form dynamic communication channels across cortical areas processing the features of behaviorally relevant stimuli. Recently, attention has been linked to a normalization mechanism, in which the response of a neuron is suppressed (normalized) by the overall activity of a large pool of neighboring neurons. In this model, attention increases the excitatory drive received by the neuron, which in turn also increases the strength of normalization, thereby changing the balance of excitation and inhibition. Recent studies have shown that gamma power also depends on such excitatory–inhibitory interactions. Could modulation in gamma power during an attention task be a reflection of the changes in the underlying excitation–inhibition interactions? By manipulating the normalization strength independent of attentional load in macaque monkeys, we show that gamma power increases with increasing normalization, even when the attentional load is fixed. Further, manipulations of attention that increase normalization increase gamma power, even when they decrease the firing rate. Thus, gamma rhythms could be a reflection of changes in the relative strengths of excitation and normalization rather than playing a functional role in communication or control

Mississippi State Axion Search: A Light Shining though a Wall ALP Search

The elegant solutions to the strong CP problem predict the existence of a particle called axion. Thus, the search for axion like particles (ALP) has been an ongoing endeavor. The possibility that these axion like particles couple to photons in presence of magnetic field gives rise to a technique of detecting these particles known as light shining through a wall (LSW). Mississippi State Axion Search (MASS) is an experiment employing the LSW technique in search for axion like particles. The apparatus consists of two radio frequency (RF) cavities, both under the influence of strong magnetic field and separated by a lead wall. While one of the cavities houses a strong RF generator, the other cavity houses the detector systems. The MASS apparatus looks for excesses in RF photons that tunnel through the wall as a signature of candidate axion-like particles. The concept behind the experiment as well as the projected sensitivities are presented here.Comment: Xth Patras Workshop on Axions, WIMPs and WISPs; 4 Pages, 5 figure

Effect of composting and soil type on dissipation of veterinary antibiotics in land-applied manures

The objective of this study was to determine the fate of commonly used veterinary antibiotics in their naturally excreted form when manure-based amendments are applied to soil. Beef cattle were administered sulfamethazine, tylosin, and chlortetracycline and dairy cows were treated with pirlimycin according to standard animal production practice. The resulting manure was composted for 42 days under static or turned conditions and applied at agronomic N rates to sandy, silt, and silty clay loam soils and compared with amendment with corresponding raw manures in sacrificial microcosms over a 120-day period. Antibiotic dissipation in the raw manure-amended soils followed bi-phasic first order kinetics. The first phase half-lives for sulfamethazine, tylosin, chlortetracycline, and pirlimycin ranged from 6.0 to 18 days, 2.7 to 3.7 days, 23 to 25 days, and 5.5 to 8.2 days, respectively. During the second phase, dissipation of sulfamethazine was negligible, while the half-lives for tylosin, chlortetracycline, and pirlimycin ranged from 41 to 44 days, 75 to 144 days, and 87 to 142 days, respectively. By contrast, antibiotic dissipation in the compost-amended soils followed single-phase first order kinetics with negligible dissipation of sulfamethazine and half-lives of tylosin and chlortetracycline ranging from 15 to 16 days and 49 to 104 days, respectively. Pirlimycin was below the detection limit in the compost-amended soils. After incubating 120-days, antibiotics in compost-amended soils (up to 3.1 ug/kg) were significantly lower than in the manure-amended soils (up to 19 ug/kg; p<0.0001), with no major effect of soil type on the dissipation. Risk assessment suggested that manure composting can reduce antibiotic resistance selection potential in manure-amended soils

THE ECOLOGY OF INTERORGANIZATIONAL INFORMATION SHARING

Increasingly, companies use interorganizational information systems to support business process partnerships, such as automatic replenishment systems and other supply chain initiatives, invoicing and payments, and insurance claims processing. Inter-firm networking in turn can increase the visibility of information generated and used by business partners. These business partners may experience intended and unintended impacts from the changes in the partnering relationship, in effect altering the ecology of the organization. Yet IT researchers rarely study an organization’s ecology, focusing instead on impacts upon internal processes. Our goal in this paper is to propose a definition of interorganizational information ecology, to provide IT researchers with a lens through which interorganizational information sharing should be studied. We begin by reviewing principles of ecology from the natural and social sciences and then discuss the emergence of principles of organizational ecology and information ecology within the management literature. We then argue that advances in information technology have been a primary enabler for companies’ focus on interorganizational business processes and that field research on IT-enabled business partnerships must include the impacts upon each partner and the information shared among them. An example from health care demonstrates the usefulness of the concept, and we conclude with suggestions for field-based research on the ecology of interorganizational information sharing

Evolution since z = 0.5 of the Morphology-Density relation for Clusters of Galaxies

Using traditional morphological classifications of galaxies in 10 intermediate-redshift (z~0.5) clusters observed with WFPC-2 on the Hubble Space Telescope, we derive relations between morphology and local galaxy density similar to that found by Dressler for low-redshift clusters. Taken collectively, the `morphology-density' relationship, M-D, for these more distant, presumably younger clusters is qualitatively similar to that found for the local sample, but a detailed comparison shows two substantial differences: (1) For the clusters in our sample, the M-D relation is strong in centrally concentrated ``regular'' clusters, those with a strong correlation of radius and surface density, but nearly absent for clusters that are less concentrated and irregular, in contrast to the situation for low redshift clusters where a strong relation has been found for both. (2) In every cluster the fraction of elliptical galaxies is as large or larger than in low-redshift clusters, but the S0 fraction is 2-3 times smaller, with a proportional increase of the spiral fraction. Straightforward, though probably not unique, interpretations of these observations are (1) morphological segregation proceeds hierarchically, affecting richer, denser groups of galaxies earlier, and (2) the formation of elliptical galaxies predates the formation of rich clusters, and occurs instead in the loose-group phase or even earlier, but S0's are generated in large numbers only after cluster virialization.Comment: 35 pages, 19 figures, uses psfig. Accepted for publication in Ap

Initial experience of dedicated breast PET imaging of ER+ breast cancers using [F-18]fluoroestradiol.

Dedicated breast positron emission tomography (dbPET) is an emerging technology with high sensitivity and spatial resolution that enables detection of sub-centimeter lesions and depiction of intratumoral heterogeneity. In this study, we report our initial experience with dbPET using [F-18]fluoroestradiol (FES) in assessing ER+ primary breast cancers. Six patients with &gt;90% ER+ and HER2- breast cancers were imaged with dbPET and breast MRI. Two patients had ILC, three had IDC, and one had an unknown primary tumor. One ILC patient was treated with letrozole, and another patient with IDC was treated with neoadjuvant chemotherapy without endocrine treatment. In this small cohort, we observed FES uptake in ER+ primary breast tumors with specificity to ER demonstrated in a case with tamoxifen blockade. FES uptake in ILC had a diffused pattern compared to the distinct circumscribed pattern in IDC. In evaluating treatment response, the reduction of SUVmax was observed with residual disease in an ILC patient treated with letrozole, and an IDC patient treated with chemotherapy. Future study is critical to understand the change in FES SUVmax after endocrine therapy and to consider other tracer uptake metrics with SUVmax to describe ER-rich breast cancer. Limitations include variations of FES uptake in different ER+ breast cancer diseases and exclusion of posterior tissues and axillary regions. However, FES-dbPET has a high potential for clinical utility, especially in measuring response to neoadjuvant endocrine treatment. Further development to improve the field of view and studies with a larger cohort of ER+ breast cancer patients are warranted

Discovery of Two Very Wide Binaries with Ultracool Companions and a New Brown Dwarf at the L/T Transition

We present the discovery and spectroscopic follow-up of a nearby late-type L dwarf (2M0614+3950), and two extremely wide very-low-mass binary systems (2M0525-7425AB and 2M1348-1344AB), resulting from our search for common proper motion pairs containing ultracool components in the Two Micron All Sky Survey (2MASS) and the Wide-field Infrared Survey Explorer (WISE) catalogs. The near-infrared spectrum of 2M0614+3950 indicates a spectral type L$9 \pm 1$ object residing at a distance of $26.0 \pm 1.8$ pc. The optical spectrum of 2M0525-7425A reveals an M$3.0 \pm 0.5$ dwarf primary, accompanied by a secondary previously classified as L2. The system has an angular separation of $\sim 44"$, equivalent to $\sim 2000$AU at distance of $46.0 \pm 3.0$ pc. Using optical and infrared spectra, respectively, we classify the components of 2M1348-1344AB as M$4.5 \pm 0.5$ and T$5.5 \pm 1$. The angular separation of $\sim 68"$ is equivalent to $\sim 1400$AU at a distance of $20.7 \pm 1.4$ pc. 2M1348-1344AB is one of only six very wide (separation $>$ 1000 AU) systems containing late T dwarfs known to date.Comment: Astronomical Journal, 2012, in pres

A Randomized Trial Evaluating a Parent Based Intervention to Reduce College Drinking

This study evaluated the effectiveness of a parent based intervention (PBI) in reducing drinking among first year college students (N = 443). Students were assigned to one of three conditions: PBI, PBI plus booster brochures (PBI-B), and an assessment only control group (CNT). At a 4-month post-intervention follow-up, results indicated students in the PBI-B group reported significantly less drinking to intoxication and peak drinking relative to the PBI group and CNT group. No significant differences were found between the PBI group and CNT group. Results provide further support for PBIs to reduce college student drinking and suggest that a booster brochure increases the effectiveness of PBIs

Conformational Changes in Pediocin AcH upon Vesicle Binding and Approximation of the Membrane-Bound Structure in Detergent Micelles

Pediocin AcH is a 44-residue antimicrobial peptide with bactericidal potency against Gram-positive bacteria such as Listeria. It belongs to a family of bacteriocins that, when membrane-associated, is predicted to contain β-sheet and α-helical regions. All bacteriocins in this family have a conserved N-terminal disulfide bond. An additional C-terminal disulfide bond in pediocin AcH is thought to confer enhanced potency and broader specificity range against sensitive bacteria. The C-terminal disulfide bond may also affect the conformation of the C-terminus. The secondary structures of pediocin AcH in aqueous solution and vesicles from susceptible cells, as well as the ability of trifluoroethanol (TFE) and detergent systems to induce secondary structures like those induced in vesicles, were studied by circular dichroism (CD) spectroscopy. Like related peptides, pediocin AcH was highly unordered in aqueous solution, 56%. However, it also contained 20% β-strand and 15% β-turn structures. Upon complete binding to vesicles, 32% α-helical structure formed, the unordered structure decreased to 32%, and the β-strand and β-turn structures remained largely unchanged. Thus, a βα domain structure formed in vesicles. The helical structure likely forces the C-terminal tail to loop back on the helix so that the C24−C44 disulfide bond can form. Detergent micelles were superior to TFE in their ability to induce secondary structural fractions in pediocin AcH comparable to those observed in vesicles. This demonstrates the importance of a hydrocarbon−water interface to pediocin AcH structure induction and suggests that it is preferable to use detergent micelles as solvents in NMR studies of pediocin AcH structure

Infrared-Faint Radio Sources: A New Population of High-redshift Radio Galaxies

We present a sample of 1317 Infrared-Faint Radio Sources (IFRSs) that, for the first time, are reliably detected in the infrared, generated by cross-correlating the Wide-Field Infrared Survey Explorer (WISE) all-sky survey with major radio surveys. Our IFRSs are brighter in both radio and infrared than the first generation IFRSs that were undetected in the infrared by the Spitzer Space Telescope. We present the first spectroscopic redshifts of IFRSs, and find that all but one of the IFRSs with spectroscopy has z > 2. We also report the first X-ray counterparts of IFRSs, and present an analysis of radio spectra and polarization, and show that they include Gigahertz-Peaked Spectrum, Compact Steep Spectrum, and Ultra-Steep Spectrum sources. These results, together with their WISE infrared colours and radio morphologies, imply that our sample of IFRSs represents a population of radio-loud Active Galactic Nuclei at z > 2. We conclude that our sample consists of lower-redshift counterparts of the extreme first generation IFRSs, suggesting that the fainter IFRSs are at even higher redshift.Comment: 23 pages, 17 figures. Submitted to MNRA