Flux of Atmospheric Neutrinos

Atmospheric neutrinos produced by cosmic-ray interactions in the atmosphere are of interest for several reasons. As a beam for studies of neutrino oscillations they cover a range of parameter space hitherto unexplored by accelerator neutrino beams. The atmospheric neutrinos also constitute an important background and calibration beam for neutrino astronomy and for the search for proton decay and other rare processes. Here we review the literature on calculations of atmospheric neutrinos over the full range of energy, but with particular attention to the aspects important for neutrino oscillations. Our goal is to assess how well the properties of atmospheric neutrinos are known at present.Comment: 68 pages, 26 figures. With permission from the Annual Review of Nuclear & Particle Science. Final version of this material is scheduled to appear in the Annual Review of Nuclear & Particle Science Vol. 52, to be published in December 2002 by Annual Reviews (http://annualreviews.org

Near-unity quantum yields from chloride treated CdTe colloidal quantum dots

Colloidal quantum dots (CQDs) are promising materials for novel light sources and solar energy conversion. However, trap states associated with the CQD surface can produce non‐radiative charge recombination that significantly reduces device performance. Here a facile post‐synthetic treatment of CdTe CQDs is demonstrated that uses chloride ions to achieve near‐complete suppression of surface trapping, resulting in an increase of photoluminescence (PL) quantum yield (QY) from ca. 5% to up to 97.2 ± 2.5%. The effect of the treatment is characterised by absorption and PL spectroscopy, PL decay, scanning transmission electron microscopy, X‐ray diffraction and X‐ray photoelectron spectroscopy. This process also dramatically improves the air‐stability of the CQDs: before treatment the PL is largely quenched after 1 hour of air‐exposure, whilst the treated samples showed a PL QY of nearly 50% after more than 12 hours

Mass and half-life measurements of neutron-deficient iodine isotopes

Neutron-deficient iodine isotopes, 116I and 114I, were produced at relativistic energies by in-flight fragmentation at the Fragment Separator (FRS) at GSI. The FRS Ion Catcher was used to thermalize the ions and to perform highly accurate mass measurements with a Multiple-Reflection Time-of-Flight Mass-Spectrometer (MR-TOF-MS). The masses of both isotopes were measured directly for the first time. The half-life of the 114I was measured by storing the ions in an RF quadrupole for different storage times and counting the remaining nuclei with the MR-TOF-MS. The measured half-life was used to assign the ground state to the measured 114I ions. Predictions on the possible α-decay branch for 114I are presented based on the reduced uncertainties obtained for the Qα-value. Systematic studies of the mass surface were performed with the newly obtained masses, showing better agreement with the expected trend in this mass region.peerReviewe

PageRank without hyperlinks: Reranking with PubMed related article networks for biomedical text retrieval

Graph analysis algorithms such as PageRank and HITS have been successful in Web environments because they are able to extract important inter-document relationships from manually-created hyperlinks. We consider the application of these algorithms to related document networks comprised of automatically-generated content-similarity links. Specifically, this work tackles the problem of document retrieval in the biomedical domain, in the context of the PubMed search engine. A series of reranking experiments demonstrate that incorporating evidence extracted from link structure yields significant improvements in terms of standard ranked retrieval metrics. These results extend the applicability of link analysis algorithms to different environments

Flower Bats (Glossophaga soricina) and Fruit Bats (Carollia perspicillata) Rely on Spatial Cues over Shapes and Scents When Relocating Food

Natural selection can shape specific cognitive abilities and the extent to which a given species relies on various cues when learning associations between stimuli and rewards. Because the flower bat Glossophaga soricina feeds primarily on nectar, and the locations of nectar-producing flowers remain constant, G. soricina might be predisposed to learn to associate food with locations. Indeed, G. soricina has been observed to rely far more heavily on spatial cues than on shape cues when relocating food, and to learn poorly when shape alone provides a reliable cue to the presence of food.Here we determined whether G. soricina would learn to use scent cues as indicators of the presence of food when such cues were also available. Nectar-producing plants fed upon by G. soricina often produce distinct, intense odors. We therefore expected G. soricina to relocate food sources using scent cues, particularly the flower-produced compound, dimethyl disulfide, which is attractive even to G. soricina with no previous experience of it. We also compared the learning of associations between cues and food sources by G. soricina with that of a related fruit-eating bat, Carollia perspicillata. We found that (1) G. soricina did not learn to associate scent cues, including dimethyl disulfide, with feeding sites when the previously rewarded spatial cues were also available, and (2) both the fruit-eating C. perspicillata and the flower-feeding G. soricina were significantly more reliant on spatial cues than associated sensory cues for relocating food.These findings, taken together with past results, provide evidence of a powerful, experience-independent predilection of both species to rely on spatial cues when attempting to relocate food

Comparison of phylogenetic trees through alignment of embedded evolutionary distances

<p>Abstract</p> <p>Background</p> <p>The understanding of evolutionary relationships is a fundamental aspect of modern biology, with the phylogenetic tree being a primary tool for describing these associations. However, comparison of trees for the purpose of assessing similarity and the quantification of various biological processes remains a significant challenge.</p> <p>Results</p> <p>We describe a novel approach for the comparison of phylogenetic distance information based on the alignment of representative high-dimensional embeddings (xCEED: Comparison of Embedded Evolutionary Distances). The xCEED methodology, which utilizes multidimensional scaling and Procrustes-related superimposition approaches, provides the ability to measure the global similarity between trees as well as incongruities between them. We demonstrate the application of this approach to the prediction of coevolving protein interactions and demonstrate its improved performance over the mirrortree, tol-mirrortree, phylogenetic vector projection, and partial correlation approaches. Furthermore, we show its applicability to both the detection of horizontal gene transfer events as well as its potential use in the prediction of interaction specificity between a pair of multigene families.</p> <p>Conclusions</p> <p>These approaches provide additional tools for the study of phylogenetic trees and associated evolutionary processes. Source code is available at <url>http://gomezlab.bme.unc.edu/tools</url>.</p

Dynamic thoracohumeral kinematics are dependent upon the etiology of the shoulder injury

[EN] Obtaining kinematic patterns that depend on the shoulder injury may be important when planning rehabilitation. The main goal of this study is to explore whether the kinematic patterns of continuous and repetitive shoulder elevation motions are different according to the type of shoulder injury in question, specifically tendinopathy or rotator cuff tear, and to analyze the influence of the load handled during its assessment. For this purpose, 19 individuals with tendinopathy and 9 with rotator cuff tear performed a repetitive scaption movement that was assessed with stereophotogrammetry. Furthermore, static range of motion (ROM) and isometric strength were evaluated with a goniometer and a dynamometer, respectively. Dynamic measurements of maximum elevation (Emax), variablility of the maximum angle (VMA), maximum angular velocity (Velmax), and time to maximum velocity (tmaxvel) were found to be significantly different between the tendinopathy group (TG) and the rotator cuff tear group (RTCG). No differences were found in the ROM assessed with goniometry and the isometric strength. The effect of increasing the load placed in the hand during the scaption movement led to significant differences in Emax, VMA, tmaxvel and repeatability. Therefore, only the dynamic variables showed sufficient capability of detecting differences in functional performance associated with structural shoulder injury. The differences observed in the kinematic variables between patients with tendinopathy and rotator cuff tear seem to be related to alterations in thoracohumeral rhythm and neuromuscular control. Kinematic analysis may contribute to a better understanding of the functional impact of shoulder injuries, which would help in the assessment and treatment of shoulder pain.This work was funded by the Spanish Government, Secretaria de Estado de Investigacion, Desarrollo e Innovacion, and co-financed by EU FEDER funds (Grant DPI2013-44227-R). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Lopez Pascual, J.; Page Del Pozo, AF.; Serra Añó, P. (2017). Dynamic thoracohumeral kinematics are dependent upon the etiology of the shoulder injury. PLoS ONE. 12(8). https://doi.org/10.1371/journal.pone.0183954S12

Comparison between BCNU and procarbazine chemotherapy for treatment of gliomas

We compared sequential single-agent BCNU and procarbazine (PCB) chemotherapy in 31 patients with gliomas [grade IV (10), grade III (15), grade II (6)]. Patients had failed surgical biopsy ± resection and radiation therapy. All patients were treated initially with BCNU 150-300mg/m 2 by intra-arterial or intravenous route every 6 weeks. After CT evidence of tumor progression, all patients received PCB 150mg/m 2 /day for 28 days every 8 weeks. Patient responses to BCNU were CR (0), PR (7), SD (12), progression (12), and to PCB CR (2), PR (9), SD (6), and progression (14). Kaplan-Meier estimates of median time to failure for all patients were shorter for BCNU, 5.0 months (range 1.5–20), than for PCB, 6.0 months (range 2–50+). There was a statistically significant difference (Mantel-Cox test, p=0.02) in the distribution of time to disease progression between the two drugs, especially for grade III tumors (p= 0.02). The cumulative proportion of patients without disease progression at 6 months was 26% while on BCNU, compared to 48% while on PCB; at 12 months the cumulative proportions were 3% for BCNU compared to 35% for PCB. Although there was no formal washout period between administration of the two drugs, no carryover effect was evident. These data provide further evidence that PCB has significant activity against malignant glioma and may, in fact, be more effective than BCNU.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45377/1/11060_2005_Article_BF01050072.pd

Chimpanzee and Human Y Chromosomes Are Remarkably Divergent in Structure and Gene Content

LetterThe human Y chromosome began to evolve from an autosome hundreds of millions of years ago, acquiring a sex-determining function and undergoing a series of inversions that suppressed crossing over with the X chromosome[1, 2]. Little is known about the recent evolution of the Y chromosome because only the human Y chromosome has been fully sequenced. Prevailing theories hold that Y chromosomes evolve by gene loss, the pace of which slows over time, eventually leading to a paucity of genes, and stasis [3, 4]. These theories have been buttressed by partial sequence data from newly emergent plant and animal Y chromosomes [5, 6, 7, 8], but they have not been tested in older, highly evolved Y chromosomes such as that of humans. Here we finished sequencing of the male-specific region of the Y chromosome (MSY) in our closest living relative, the chimpanzee, achieving levels of accuracy and completion previously reached for the human MSY. By comparing the MSYs of the two species we show that they differ radically in sequence structure and gene content, indicating rapid evolution during the past 6 million years. The chimpanzee MSY contains twice as many massive palindromes as the human MSY, yet it has lost large fractions of the MSY protein-coding genes and gene families present in the last common ancestor. We suggest that the extraordinary divergence of the chimpanzee and human MSYs was driven by four synergistic factors: the prominent role of the MSY in sperm production, ‘genetic hitchhiking’ effects in the absence of meiotic crossing over, frequent ectopic recombination within the MSY, and species differences in mating behaviour. Although genetic decay may be the principal dynamic in the evolution of newly emergent Y chromosomes, wholesale renovation is the paramount theme in the continuing evolution of chimpanzee, human and perhaps other older MSYs.National Institutes of Health (U.S.)Howard Hughes Medical Institut