bluuebunny/crossref_metadata_2025 huggingface dataset:
Geochemical Niches of Iron-Oxidizing Acidophiles in Acidic Coal Mine Drainage
Authors: Jones Daniel S. , Kohl Courtney , Grettenberger Christen , Larson Lance N. , Burgos William D. , Macalady Jennifer L.
Published: December 2014

A legacy of coal mining in the Appalachians has provided a unique opportunity to study the ecological niches of iron-oxidizing microorganisms. Mine-impacted, anoxic groundwater with high dissolved-metal concentrations emerges at springs and seeps associated with iron oxide mounds and deposits. These deposits are colonized by iron-oxidizing microorganisms that in some cases efficiently remove most of the dissolved iron at low pH, making subsequent treatment of the polluted stream water less expensive. We used full-cycle rRNA methods to describe the composition of sediment communities at two geochemically similar acidic discharges, Upper and Lower Red Eyes in Somerset County, PA, USA. The dominant microorganisms at both discharges were acidophilic
Gallionella
-like organisms, “
Ferrovum
” spp., and
Acidithiobacillus
spp.
Archaea
and
Leptospirillum
spp. accounted for less than 2% of cells. The distribution of microorganisms at the two sites could be best explained by a combination of iron(II) concentration and pH. Populations of the
Gallionella
-like organisms were restricted to locations with pH >3 and iron(II) concentration of >4 mM, while
Acidithiobacillus
spp. were restricted to pH <3 and iron(II) concentration of <4 mM.
Ferrovum
spp. were present at low levels in most samples but dominated sediment communities at pH <3 and iron(II) concentration of >4 mM. Our findings offer a predictive framework that could prove useful for describing the distribution of microorganisms in acid mine drainage, based on readily accessible geochemical parameters.
Bright Fluorescent Streptococcus pneumoniae for Live-Cell Imaging of Host-Pathogen Interactions
Authors: Kjos Morten , Aprianto Rieza , Fernandes Vitor E. , Andrew Peter W. , van Strijp Jos A. G. , Nijland Reindert , Veening Jan-Willem
Published: December 2014

Streptococcus pneumoniae
is a common nasopharyngeal resident in healthy people but, at the same time, one of the major causes of infectious diseases such as pneumonia, meningitis, and sepsis. The shift from commensal to pathogen and its interaction with host cells are poorly understood. One of the major limitations for research on pneumococcal-host interactions is the lack of suitable tools for live-cell imaging. To address this issue, we developed a generally applicable strategy to create genetically stable, highly fluorescent bacteria. Our strategy relies on fusing superfolder green fluorescent protein (GFP) or a far-red fluorescent protein (RFP) to the abundant histone-like protein HlpA. Due to efficient translation and limited cellular diffusion of these fusions, the cells are 25-fold brighter than those of the currently best available imaging
S. pneumoniae
strain. These novel bright pneumococcal strains are fully virulent, and the GFP reporter can be used for
in situ
imaging in mouse tissue. We used our reporter strains to study the effect of the polysaccharide capsule, a major pneumococcal virulence factor, on different stages of infection. By dual-color live-cell imaging experiments, we show that unencapsulated pneumococci adhere significantly better to human lung epithelial cells than encapsulated strains, in line with previous data obtained by classical approaches. We also confirm with live-cell imaging that the capsule protects pneumococci from neutrophil phagocytosis, demonstrating the versatility and usability of our reporters. The described imaging tools will pave the way for live-cell imaging of pneumococcal infection and help further understanding of the mechanisms of pneumococcal pathogenesis.
The Flagellar Set Fla2 in Rhodobacter sphaeroides Is Controlled by the CckA Pathway and Is Repressed by Organic Acids and the Expression of Fla1
Authors: Vega-Baray Benjamín , Domenzain Clelia , Rivera Anet , Alfaro-López Rocío , Gómez-César Elidet , Poggio Sebastián , Dreyfus Georges , Camarena Laura
Published: December 2014

Rhodobacter sphaeroides
has two different sets of flagellar genes. Under the growth conditions commonly used in the laboratory, the expression of the
fla1
set is constitutive, whereas the
fla2
genes are not expressed. Phylogenetic analyses have previously shown that the
fla1
genes were acquired by horizontal transfer from a gammaproteobacterium and that the
fla2
genes are endogenous genes of this alphaproteobacterium. In this work, we characterized a set of mutants that were selected for swimming using the Fla2 flagella in the absence of the Fla1 flagellum (Fla2
+
strains). We determined that these strains have a single missense mutation in the histidine kinase domain of CckA. The expression of these mutant alleles in a Fla1
−
strain allowed
fla2
-dependent motility without selection. Motility of the Fla2
+
strains is also dependent on ChpT and CtrA. The mutant versions of CckA showed an increased autophosphorylation activity
in vitro
. Interestingly, we found that
cckA
is transcriptionally repressed by the presence of organic acids, suggesting that the availability of carbon sources could be a part of the signal that turns on this flagellar set. Evidence is presented showing that reactivation of
fla1
gene expression in the Fla2
+
background strongly reduces the number of cells with Fla2 flagella.
Correlating Student Knowledge and Confidence Using a Graded Knowledge Survey to Assess Student Learning in a General Microbiology Classroom
Authors: Favazzo Lacey , Willford John D. , Watson Rachel M.
Published: December 2014

Knowledge surveys are a type of confidence survey in which students rate their confidence in their ability to answer questions rather than answering the questions. These surveys have been discussed as a tool to evaluate student in-class or curriculum-wide learning. However, disagreement exists as to whether confidence is actually an accurate measure of knowledge. With the concomitant goals of assessing content-based learning objectives and addressing this disagreement, we present herein a pretest/posttest knowledge survey study that demonstrates a significant difference correctness on graded test questions at different levels of reported confidence in a multi-semester timeframe. Questions were organized into Bloom’s taxonomy, allowing for the data collected to further provide statistical analyses on strengths and deficits in various levels of Bloom’s reasoning with regard to mean correctness. Collectively, students showed increasing confidence and correctness in all levels of thought but struggled with synthesis-level questions. However, when students were only asked to rate confidence and not answer the accompanying test questions, they reported significantly higher confidence than the control group which was asked to do both. This indicates that when students do not attempt to answer questions, they have significantly greater confidence in their ability to answer those questions. Additionally, when students rate only confidence without answering the question, resolution across Bloom’s levels of reasoning is lost. Based upon our findings, knowledge surveys can be an effective tool for assessment of both breadth and depth of knowledge, but may require students to answer questions in addition to rating confidence to provide the most accurate data.
Build-a-Polypeptide: A Hands-On Worksheet to Enhance Student Learning in an Introductory Biology Course
Authors: Hall Kristi , Dunitz Jackson , Shields Patricia
Published: December 2014

Many introductory biology students have a weak (or nonexistent) chemistry background. Due to this apparent knowledge gap, many students struggle to understand the process of polypeptide formation via dehydration synthesis as well as the interactions between individual polypeptide chains. This inability to reason about how individual amino acids interact with one another prevents students from making the cognitive leap from primary to secondary structure. In turn, students do not fully understand how even higher levels of organizations (i.e., tertiary and quaternary interactions) form the final three-dimensional configurations of proteins. We designed Build-a-Polypeptide in an attempt to help fill the part of the knowledge gap. In this activity, students physically represent the process of polypeptide synthesis and R group interactions using a paper model. Essentially, this is a simple cut and paste project that allows students to build a beginner's (i.e., highly truncated and simplified) model of protein folding. Previous research has shown that physical modeling can aid student understanding of complex topics (1,2). With that in mind, we developed this interactive activity to improve student understanding of protein synthesis and structure formation. This activity requires no laboratory equipment and can be completed within one (50 minute) class. Our worksheets were designed for use in introductory college-level biology courses, but could easily be adapted for high school or AP biology classes.
Integrating Ethics into Case Study Assignments
Authors: Marshall Pamela A.
Published: December 2014

I teach an upper-level writing course, Genes, Race, Gender, and Society, designed for Life Science majors, in which I utilize a case study to expose students to ethical ways of thinking. Students first work through the topical case study and then are challenged to rethink their responses through the lenses of ethics, taking into account different ethical frameworks. Students then develop their own case study, integrating ethical components. I want to expose my students to this way of thinking because I see technology being driven by the Jurassic Park phenomenon, “Your scientists were so preoccupied with whether or not they could, they didn’t stop to think if they should,” and want future physicians grounded in a sense of how their actions relate to the greater good.
Utilizing the Committee on Publication Ethics (COPE) Resources to Teach Ethical Writing Skills to Undergraduates in STEM CoursesReview of:	Committee on Publication Ethics (COPE) resources http://publicationethics.org/
Authors: Rediske Andrea Pratt
Published: December 2014

Review of:
Committee on Publication Ethics (COPE)
resources
http://publicationethics.org/
Storytelling as an Active Learning Tool to Engage Students in a Genetics Classroom
Authors: Moitra Karobi
Published: December 2014

Storytelling is an ancient art that originated long before the written word. Storytelling interspersed with traditional lectures has been used as a teaching tool in an Introductory Genetics course. Students have eagerly responded to the storytelling pedagogy, suggesting that it can be leveraged to help students grasp complicated theories, engage students, and help improve student retention in STEM fields.
Critical Issues in the Teaching of Responsible Writing
Authors: Roig Miguel
Published: December 2014

In this paper I identify some of the more common, problematic writing practices (e.g., plagiarism, selective reporting of literature, and/or results, ‘spin’) found in traditional journal articles, along with associated variables, and suggest ways to correct them. The primary aim of the discussion is to emphasize the cultivation of transparency, excellence in scholarship, and a ‘best practices’ approach to disseminating the results of our research.
Topics in Bioethics: A Development of Student Perspectives
Authors: Johnson Keith A.
Published: December 2014

Exposing students to current biotechnological and medical issues is eye-opening for many students in a way that is not always achieved through lecture-based learning. Lecture or investigative teaching styles provide a tremendous knowledge base for the students, but sometimes these teaching styles do not allow the student to fully develop, especially personal attitudes to issues in bioethics. Through online videos, Hollywood movies, guided readings and classroom discussions, students in this course are informed of some bioethical topics, encouraged to learn about other topics, and use this gained knowledge to develop personal positions regarding the value and/or risk of the issues. This course has been well-received by previous students as a favorite in terms of both topics covered and style.
(The Ethics of) Teaching Science and Ethics: A Collaborative Proposal
Authors: Kabasenche William P.
Published: December 2014

I offer a normative argument for a collaborative approach to teaching ethical issues in the sciences. Teaching science ethics requires expertise in at least two knowledge domains—the relevant science(s) and philosophical ethics. Accomplishing the aims of ethics education, while ensuring that science ethics discussions remain grounded in the best empirical science, can generally best be done through collaboration between a scientist and an ethicist. Ethics as a discipline is in danger of being misrepresented or distorted if presented by someone who lacks appropriate disciplinary training and experience. While there are exceptions, I take philosophy to be the most appropriate disciplinary domain in which to gain training in ethics teaching. Science students, who must be prepared to engage with many science ethics issues, are poorly served if their education includes a misrepresentation of ethics or specific issues. Students are less well prepared to engage specific issues in science ethics if they lack an appreciation of the resources the discipline of ethics provides. My collaborative proposal looks at a variety of ways scientists and ethicists might collaborate in the classroom to foster good science ethics education.
The Interrelationship between Research Integrity, Conflict of Interest, and the Research Environment
Authors: Grinnell Frederick
Published: December 2014

Quite distinct regulatory measures have been established to try to deal with research misconduct and conflict of interest. To decrease research misconduct, the emphasis has been on education aimed at promoting an understanding of and commitment to research integrity. To decrease the impact of conflict of interest, the emphasis has been on management of the research environment. In this essay I discuss the idea that research misconduct and its close relative “questionable research practices” should be framed in the context of conflict of interest. If we take seriously the implication of conflict of interest regulations that even a $5,000 financial interest might bias the design, conduct, or reporting of research, then how much more risk of bias will be in play when what is at stake is ongoing funding of short-term research grants on which a researcher’s salary and job depend? Education is important and necessary to promote research integrity but by itself will not be sufficient. Placing problems of research misconduct and questionable research practices in the context of conflict of interest makes it clear that we also will need to develop new approaches to manage the structure of the research environment. One example of such a management strategy would be for NIH to phase in a limit on the overall percentage of a faculty member’s salary permitted to be supported with NIH grant funds, complementing the already existing upper dollar limit that can be used for faculty salaries.
Cross-Cultural Considerations in U.S. Research Ethics Education
Authors: Heitman Elizabeth
Published: December 2014

Demand among graduate and postdoctoral trainees for international research experience brings together students and investigators from increasingly diverse cultural backgrounds around the world. Educators in research ethics and scientific integrity need to address the cultural aspects of both science and ethics to help all trainees learn ethical practices for effective collaboration with a diverse array of partners. NIH and NSF’s mandates for instruction in the responsible conduct of research do not specifically address the needs of international trainees or U.S. trainees who undertake research projects abroad. Nonetheless, research ethics educators’ typical focus on policy and professional standards can offer trainees and faculty investigators helpful insights into differing ethical values and priorities in research. Examination of linguistic differences can also reveal important conceptual frameworks that shape ethical practice. New resources for teaching research integrity in cross-cultural settings can be a valuable addition to the development of shared understanding of the goals of scientific research.
Authorship Guidelines and Actual Practice: Are They Harmonized in Different Research Systems?
Authors: Vasconcelos Sonia , Vasgird Daniel , Ichikawa Iekuni , Plemmons Dena
Published: December 2014

Changing patterns in collaborative research networks reflect a new geography of science that is increasingly shaped by interactions between established and emerging scientific powers, whose cultural and political diversity are now reflected in perhaps never before thought of interactions. The various partners in these international collaborations are likely to produce research results that should gradually lead to stronger diversity in research output, including an increase in international co-authorship. When it comes to multinational co-authored publications, among sensitive questions that may complicate these relationships is the way different research systems deal with research integrity. It is well worth examining how to accommodate different cultural traditions and normative assumptions embedded in academic practices for collaborative research networks. Given the increasingly international and interdisciplinary nature of science and engineering, any guidelines for authorship practices in international collaborations must be clear about the variations that exist across disciplines and cultures, variations which will have an impact on accepted practices and expectations for collaboration. Collaborative endeavors in research will succeed only if a broader understanding of potential obstacles to these collaborations is reached.
How Journals and Institutions Can Work Together to Promote Responsible Conduct
Authors: Mah Eric C.
Published: December 2014

Little has been published on how institutions and journals can work together in an increasingly visible arena of research misconduct. The investigatory process can be challenged with the scientific community's need or want to know about allegations and findings of misconduct. This article explores how journals and institutions have different perspectives and possible ways institutions and journals can cooperate.
From the Editor-in-Chief: A Look at 2014
Authors: Elliott Samantha L.
Published: December 2014

This letter from the Editor-in-Chief details the changes
JMBE
has made in 2014 and looks forward to upcoming journal initiatives.
MRI findings in soccer players with long-standing adductor-related groin pain and asymptomatic controls
Authors: Branci Sonia , Thorborg Kristian , Bech Birthe Højlund , Boesen Mikael , Nielsen Michael Bachmann , Hölmich Per
Published: December 2014

Background

Soccer players are commonly affected by long-standing adductor-related groin pain (ARGP), but the clinical significance of MRI findings in these athletes is largely unknown. Our aims were (1) to evaluate whether MRI findings are associated with long-standing ARGP in soccer players, (2) to assess MRI findings in asymptomatic soccer players and non-soccer playing controls.

Methods

This cross-sectional study included 28 male soccer players with long-standing ARGP, 17 male asymptomatic soccer players and 20 male asymptomatic non-soccer playing athletes of matching age and athletic exposure. Participants underwent identical standardised and reliable clinical examination, and MRI scans (3 T) of the pelvis performed by a blinded observer. Images were consensus rated by three blinded radiologists according to a standardised MRI evaluation protocol. The associations between clinical adductor-related findings and pathological MRI findings were investigated with χ2statistics and OR.

Results

Central disc protrusion (p=0.027) and higher grades of pubic bone marrow oedema (BMO; p=0.027) were significantly more present in symptomatic players than asymptomatic players. However, up to 71% of asymptomatic soccer players displayed different positive MRI findings, and asymptomatic soccer players had significantly higher odds (OR ranging from 6.3 to 13.3) for BMO, adductor tendinopathy and degenerative changes than non-soccer players.

Conclusions

ARGP in soccer players was associated with central disc protrusion and higher grades of pubic BMO. Moreover, positive MRI findings were significantly more frequent in soccer players compared with non-soccer players irrespective of symptoms, suggesting that these MRI changes may be associated with soccer play itself rather than clinical symptoms.
Will a quadruple multiplexed point-of-care screening strategy for HIV-related co-infections be feasible and impact detection of new co-infections in at-risk populations? Results from cross-sectional studies
Authors: Pai Nitika Pant , Dhurat Rachita , Potter Martin , Behlim Tarannum , Landry Geneviève , Vadnais Caroline , Rodrigues Camilla , Joseph Lawrence , Shetty Anjali
Published: December 2014

Objectives

Multiplexed point-of-care (POC) devices can rapidly screen for HIV-related co-infections (eg, hepatitis C (HCV), hepatitis B (HBV), syphilis) in one patient visit, but global evidence for this approach remains limited. This study aimed to evaluate a multiplex POC testing strategy to expedite screening for HIV-related co-infections in at-risk populations.

Methods

A multiplex strategy was developed with two subsequent versions of an investigational device Miriad. It was evaluated in two non-comparable settings and populations in two countries for feasibility of conduct, detection of new infections, preference and accuracy. Version 1 was evaluated in 375 sexually transmitted disease clinic attendees in Mumbai, India; version 2 was evaluated in 119 injection drug users in Montreal, Canada.

Results

Feasibility (completion rate) of the multiplex strategy was high (86.1% Mumbai; 92.4% Montreal). A total of 170 new infections were detected in Mumbai (56 HIV, 75 HBV, 37 syphilis, 2 HCV) versus 2 in Montreal. Preference was 60% in Mumbai and 97% in Montreal. Miriad version 1 specificities were high: HIV 99.7% (98.3% to 100%), HBV 99.3% (97.6% to 99.9%), HCV 99.7% (98.5% to 99.9%), syphilis 85.2% (80.9% to 88.8%); sensitivities were as follows: HIV 100% (94.8% to 100%), HBV 13.3% (6.6% to 23.2%), HCV 50% (1.3% to 98.7%), syphilis 86.1% (70.5% to 95.3%). With version 2, specificities improved: HIV 100% (97.2% to 100%), HBV 100% (97.3% to 100%), HCV 85.3% (73.8% to 93.0%), syphilis 98.1% (93.3% to 99.8%); sensitivities were: HIV 100% (47.3% to 100%), HCV 80.4% (66.1% to 90.6%), syphilis 100% (22.4% to 100%).

Conclusions

A quad multiplex POC strategy for HIV and co-infections was feasible to operationalise and preferred by patients in both settings. Many new infections were identified in Mumbai and accuracy improved with version 2 of the assay. Such a strategy will help expedite screening for co-infections, particularly where baseline screening is low. These findings are valuable to practitioners, researchers, policymakers and funders involved in initiatives for all four diseases with implications for scale-up.
Denial of abortion in legal settings
Authors: Gerdts Caitlin , DePiñeres Teresa , Hajri Selma , Harries Jane , Hossain Altaf , Puri Mahesh , Vohra Divya , Foster Diana Greene
Published: December 2014

Background

Factors such as poverty, stigma, lack of knowledge about the legal status of abortion, and geographical distance from a provider may prevent women from accessing safe abortion services, even where abortion is legal. Data on the consequences of abortion denial outside of the US, however, are scarce.

Methods

In this article we present data from studies among women seeking legal abortion services in four countries (Colombia, Nepal, South Africa and Tunisia) to assess sociodemographic characteristics of legal abortion seekers, as well as the frequency and reasons that women are denied abortion care.

Results

The proportion of women denied abortion services and the reasons for which they were denied varied widely by country. In Colombia, 2% of women surveyed did not receive the abortions they were seeking; in South Africa, 45% of women did not receive abortions on the day they were seeking abortion services. In both Tunisia and Nepal, 26% of women were denied their wanted abortions.

Conclusions

The denial of legal abortion services may have serious consequences for women's health and wellbeing. Additional evidence on the risk factors for presenting later in pregnancy, predictors of seeking unsafe illegal abortion, and the health consequences of illegal abortion and childbirth after an unwanted pregnancy is needed. Such data would assist the development of programmes and policies aimed at increasing access to and utilisation of safe abortion services where abortion is legal, and harm reduction models for women who are unable to access legal abortion services.
Evaluation of the natural perinatal transmission of bovine leukaemia virus
Authors: Mekata Hirohisa , Sekiguchi Satoshi , Konnai Satoru , Kirino Yumi , Honkawa Kazuyuki , Nonaka Nariaki , Horii Yoichiro , Norimine Junzo
Published: December 2014

The perinatal transmission of bovine leukaemia virus (BLV) plays a critical role in the spread and persistence of BLV infection in cattle herds. The purpose of this study was to examine the frequency of perinatal infections in an area in Japan and investigate some risk factors associated with infection. Altogether, 129 calves born to BLV‐infected cows in a herd in Japan were tested for infection immediately after birth and again at one month of age using nested PCR. Twenty‐four calves (18.6 per cent) were infected with BLV, of which 14 (10.8 per cent) and 10 (7.7 per cent) calves were infected via the transplacental and the birth canal routes, respectively. Maternal viral loads, breed, the presence or absence of assistance during parturition and the number of births per dam were evaluated to investigate risk factors associated with infection. Maternal viral load was significantly correlated with the frequency of perinatal infection, and more than 40 per cent of newborn calves born to dams with high viral loads were infected with BLV. The results of this study could contribute towards developing effective eradication programmes by providing necessary data for replacement of breeding cow in the field.
Linking cardiorespiratory fitness classification criteria to early subclinical atherosclerosis in children
Authors: Melo Xavier , Santa-Clara Helena , Santos Diana A. , Pimenta Nuno M. , Minderico Cláudia S. , Fernhall Bo , Sardinha Luís B.
Published: December 2014

It is unclear if cardiorespiratory fitness (CRF) can be used as a screening tool for premature changes in carotid intima-media thickness (cIMT) in paediatric populations. The purpose of this cross-sectional study was 3-fold: (i) to determine if CRF can be used to screen increased cIMT; (ii) to determine an optimal CRF cut-off to predict increased cIMT; and (iii) to evaluate its ability to predict increased cIMT among children in comparison with existent CRF cut-offs. cIMT was assessed with high-resolution ultrasonography and CRF was determined using a maximal cycle test. Receiver operating characteristic analyses were conducted in boys (n = 211) and girls (n = 202) aged 11–12 years to define the optimal sex-specific CRF cut-off to classify increased cIMT (≥75th percentile). Logistic regression was used to examine the association between the CRF cut-offs with the risk of having an increased cIMT. The optimal CRF cut-offs to predict increased cIMT were 45.81 and 34.46 mL·kg−1·min−1 for boys and girls, respectively. The odds-ratios for having increased cIMT among children who were unfit was up to 2.8 times the odds among those who were fit (95% confidence interval: 1.40–5.53). Considering current CRF cut-offs, only those suggested by Adegboye et al. 2011. (Br. J. Sports Med. 45(9): 722–728) and Boddy et al. 2012 (PLoS One, 7(9): e45755) were significant in predicting increased cIMT. In conclusion, CRF cut-offs (boys: ≤ 45.8; girls: ≤ 34.5 mL·kg−1·min−1) are associated with thickening of the arterial wall in 11- to 12-year-old children. Low CRF is an important cardiovascular risk factor in children and our data highlight the importance of obtaining an adequate CRF.
Temporal transferability of LiDAR-based imputation of forest inventory attributes
Authors: Fekety Patrick A. , Falkowski Michael J. , Hudak Andrew T.
Published: December 2014

Forest inventory and planning decisions are frequently informed by LiDAR data. Repeated LiDAR acquisitions offer an opportunity to update forest inventories and potentially improve forest inventory estimates through time. We leveraged repeated LiDAR and ground measures for a study area in northern Idaho, U.S.A., to predict (via imputation) — across both space and time — four forest inventory attributes: aboveground carbon (AGC), basal area (BA), stand density index (SDI), and total stem volume (Vol). Models were independently developed from 2003 and 2009 LiDAR datasets to spatially predict response variables at both times. Annual rates of change were calculated by comparing response variables between the two collections. Additionally, a pooled model was built by combining reference observations from both years to test if imputation can be performed across measurement dates. The R2 values for the pooled model were 0.87, 0.90, 0.89, and 0.87 for AGC, BA, SDI, and Vol, respectively. Mapping response variables at the landscape level demonstrates that the relationship between field data and LiDAR metrics holds true even though the data were collected in different years. Pooling data across time increases the number of reference observations available to resource managers and may ultimately improve inventory predictions.
Weak classification of finite groups
Authors: Lal Ramji , Singh Atul Kumar
Published: December 2014

The purpose of this paper is to study groups (G, ⋅) with prescribed properties on the associated right loops (G, ○n) where ○n is the binary operation on G given by a ○n b = b-nabn+1, n being a fixed integer. Let us call a group G1 to be weakly n-isomorphic to a group G2 if there is a bijective map ϕ : G1 → G2 such that ϕ(y-nxyn+1) = ϕ(y)-nϕ(x)ϕ(y)n+1, ∀ x, y ∈ G1. Indeed, we initiate a weak classification program of finite groups and obtain some basic motivating results in this direction.
A characterization of n-connected splitting matroids
Authors: Malavadkar P. P. , Shikare M. M. , Dhotre S. B.
Published: December 2014

The splitting operation on an n-connected binary matroid may not yield an n-connected binary matroid. In this paper, we characterize n-connected binary matroids which yield n-connected binary matroids by the generalized splitting operation.
Palaeoclimate and palaeoceanographic conditions in the westernmost Mediterranean over the last millennium: an integrated organic and inorganic approach
Authors: Nieto-Moreno V. , Martínez-Ruiz F. , Gallego-Torres D. , Giralt S. , García-Orellana J. , Masqué P. , Sinninghe Damsté J. S. , Ortega-Huertas M.
Published: December 2014

Previous studies have revealed the excellence of the westernmost Mediterranean records for reconstructing climate conditions over the last two millennia. In particular, inorganic and organic proxies have revealed a coherent signal of climate and oceanographic responses during this time. Here we compare and integrate both proxy records for reconstructing climate and oceanographic conditions with focus on the last millennium. The higher temperatures indicated by lipid-based proxies during the Medieval Climate Anomaly (MCA) are coincident with drier conditions indicated by inorganic proxies. In contrast, lower temperatures and humid conditions are indicated during the Little Ice Age (LIA). The industrial period was characterized by increasing humidity in comparison with the previous LIA. However, a progressive aridification occurred since the second half of the twentieth century, coexisting with a warming trend and higher contribution of C
3
grasses. Proxy records are also interpreted to show Atlantic water inflow at AD 1450 and 1950 and an intensification of the upwelling conditions coinciding with a prolonged positive North Atlantic Oscillation (NAO) phase in the intervals AD 1000–1450 and 1960–1990. Large-scale oceanic–atmospheric circulation patterns (the NAO and the Atlantic meridional circulation) and solar irradiance variations seem to have played the major key role during the last millennium, together with anthropogenic contributions in the more recent record.
Late Cenozoic intraplate volcanism in Changbai volcanic field, on the border of China and North Korea: insights into deep subduction of the Pacific slab and intraplate volcanism
Authors: Zhang Maoliang , Guo Zhengfu , Cheng Zhihui , Zhang Lihong , Liu Jiaqi
Published: December 2014

Late Cenozoic intraplate volcanism in the Changbai volcanic field straddles the border between China and North Korea, forming basic (alkali basalts and tholeiites) and intermediate–acidic (trachytes and peralkaline rhyolites) volcanic rocks with ages ranging from 19.9 Ma to the present. Major and trace elements and Sr–Nd–Pb isotopic compositions indicate that the basic magmas were formed by partial melting of the depleted mid-ocean ridge basalt-source mantle and contaminated by aqueous fluids with EM1-like isotopic signatures from the lower continental crust, whereas the intermediate–acidic magmas resulted from assimilation–fractional crystallization processes on the basic magmas. On the basis of petrological and geochemical studies, we propose that a magma underplating model could be used to explain the genesis of the Late Cenozoic intraplate volcanism. In this model, the mantle-derived basaltic magma was underplated at the base of the continental crust and contaminated by EM1-like aqueous fluids liberated from the lower crustal granulites. Geodynamic processes responsible for the magma underplating and subsequent eruption might be lithospheric extension and small-scale thermal upwelling, induced by episodic changes in convergence rates between the Eurasian and Pacific plates, indicating a genetic link between the intraplate volcanism and deep subduction of the Pacific slab.
Real-Time Bid Optimization for Group-Buying Ads
Authors: Balakrishnan Raju , Bhatt Rushi P.
Published: December 2014

Group-buying ads seeking a minimum number of customers before the deal expiry are increasingly used by daily-deal providers. Unlike traditional web ads, the advertiser’s profits for group-buying ads depend on the time to expiry and additional customers needed to satisfy the minimum group size. Since both these quantities are time-dependent, optimal bid amounts to maximize profits change with every impression. Consequently, traditional static bidding strategies are far from optimal. Instead, bid values need to be optimized in real-time to maximize expected bidder profits. This online optimization of deal profits is made possible by the advent of ad exchanges offering real-time (spot) bidding. To this end, we propose a real-time bidding strategy for group-buying deals based on the online optimization of bid values. We derive the expected bidder profit of deals as a function of the bid amounts and dynamically vary the bids to maximize profits. Furthermore, to satisfy time constraints of the online bidding, we present methods of minimizing computation timings. Subsequently, we derive the real-time ad selection, admissibility, and real-time bidding of the traditional ads as the special cases of the proposed method. We evaluate the proposed bidding, selection, and admission strategies on a multimillion click stream of 935 ads. The proposed real-time bidding, selection, and admissibility show significant profit increases over the existing strategies. Further experiments illustrate the robustness of the bidding and acceptable computation timings.
Mining Mobile User Preferences for Personalized Context-Aware Recommendation
Authors: Zhu Hengshu , Chen Enhong , Xiong Hui , Yu Kuifei , Cao Huanhuan , Tian Jilei
Published: December 2014

Recent advances in mobile devices and their sensing capabilities have enabled the collection of rich contextual information and mobile device usage records through the device logs. These context-rich logs open a venue for mining the personal preferences of mobile users under varying contexts and thus enabling the development of personalized context-aware recommendation and other related services, such as mobile online advertising. In this article, we illustrate how to extract personal context-aware preferences from the context-rich device logs, or
context logs
for short, and exploit these identified preferences for building personalized context-aware recommender systems. A critical challenge along this line is that the context log of each individual user may not contain sufficient data for mining his or her context-aware preferences. Therefore, we propose to first learn common context-aware preferences from the context logs of many users. Then, the preference of each user can be represented as a distribution of these common context-aware preferences. Specifically, we develop two approaches for mining common context-aware preferences based on two different assumptions, namely, context-independent and context-dependent assumptions, which can fit into different application scenarios. Finally, extensive experiments on a real-world dataset show that both approaches are effective and outperform baselines with respect to mining personal context-aware preferences for mobile users.
High-Speed Hardware Partition Generation
Authors: Butler Jon T. , Sasao Tsutomu
Published: December 2014

We demonstrate circuits that generate set and integer partitions on a set
S
of
n
objects at a rate of one per clock. Partitions are ways to group elements of a set together and have been extensively studied by researchers in algorithm design and theory. We offer two versions of a hardware set partition generator. In the first, partitions are produced in lexicographical order in response to successive clock pulses. In the second, an index input determines the set partition produced. Such circuits are useful in the hardware implementation of the optimum distribution of tasks to processors. We show circuits for integer partitions as well. Our circuits are combinational. For large
n
, they can have a large delay. However, one can easily pipeline them to produce one partition per clock period. We show (1) analytical and (2) experimental time/complexity results that quantify the efficiency of our designs. For example, our results show that a hardware set partition generator running on a 100MHz FPGA produces partitions at a rate that is approximately 10 times the rate of a software implementation on a processor running at 2.26GHz.
An Automated High-Level Saliency Predictor for Smart Game Balancing
Authors: Koulieris George Alex , Drettakis George , Cunningham Douglas , Mania Katerina
Published: December 2014

Successfully predicting visual attention can significantly improve many aspects of computer graphics: scene design, interactivity and rendering. Most previous attention models are mainly based on low-level image features, and fail to take into account high-level factors such as scene context, topology, or task. Low-level saliency has previously been combined with task maps, but only for predetermined tasks. Thus, the application of these methods to graphics (e.g., for selective rendering) has not achieved its full potential. In this article, we present the first automated high-level saliency predictor incorporating two hypotheses from perception and cognitive science that can be adapted to different tasks. The first states that a scene is comprised of objects expected to be found in a specific context as well objects out of context which are salient (scene schemata) while the other claims that viewer’s attention is captured by isolated objects (singletons). We propose a new model of attention by extending Eckstein’s Differential Weighting Model. We conducted a formal eye-tracking experiment which confirmed that object saliency guides attention to specific objects in a game scene and determined appropriate parameters for a model. We present a GPU-based system architecture that estimates the probabilities of objects to be attended in real- time. We embedded this tool in a game level editor to automatically adjust game level difficulty based on object saliency, offering a novel way to facilitate game design. We perform a study confirming that game level completion time depends on object topology as predicted by our system.
A
uto
P
lacer
Authors: Paiva João , Ruivo Pedro , Romano Paolo , Rodrigues Luís
Published: December 2014

This article addresses the problem of self-tuning the data placement in replicated key-value stores. The goal is to automatically optimize replica placement in a way that leverages locality patterns in data accesses, such that internode communication is minimized. To do this efficiently is extremely challenging, as one needs not only to find lightweight and scalable ways to identify the right assignment of data replicas to nodes but also to preserve fast data lookup. The article introduces new techniques that address these challenges. The first challenge is addressed by optimizing, in a decentralized way, the placement of the objects generating the largest number of remote operations for each node. The second challenge is addressed by combining the usage of consistent hashing with a novel data structure, which provides efficient probabilistic data placement. These techniques have been integrated in a popular open-source key-value store. The performance results show that the throughput of the optimized system can be six times better than a baseline system employing the widely used static placement based on consistent hashing.
Screening for Dispersion Effects by Sequential Bifurcation
Authors: Ankenman Bruce E. , Cheng Russell C. H. , Lewis Susan M.
Published: December 2014

The mean of the output of interest obtained from a run of a computer simulation model of a system or process often depends on many factors; many times, however, only a few of these factors are important. Sequential bifurcation is a method that has been considered by several authors for identifying these important factors using as few runs of the simulation model as possible. In this article, we propose a new sequential bifurcation procedure whose steps use a key stopping rule that can be calculated explicitly, something not available in the best methods previously considered. Moreover, we show how this stopping rule can also be easily modified to efficiently identify those factors that are important in influencing the variability rather than the mean of the output. In empirical studies, the new method performs better than previously published fully sequential bifurcation methods in terms of achieving the prescribed Type I error. It also achieves higher power for detecting moderately large effects using fewer replications than earlier methods. To achieve this control for midrange effects, the new method sometimes requires more replications than other methods in the case where there are many very large effects.
Resilient Round Robin
Authors: Salmani Vahid , Chou Pai H.
Published: December 2014

We consider the goal of adaptively controlling access to medium in wireless sensor networks with minimal footprint and complexity. Lightweight protocols are desirable in general and inevitable in some real-world applications such as infant monitoring. We assume high-data-rate, resource-constrained wireless sensor nodes in a star network. We take a deterministic approach to contention resolution to achieve bounded latency on data transmissions while reducing the overhead. In addition to simplicity and small footprint, our approach requires fewer message exchanges compared to the state of the art. We then present a lightweight hybrid protocol that is seamlessly integrated with the proposed contention-resolution scheme, one better suited for delay-sensitive applications with real-time constraints by providing determinism. Another feature of the proposed protocol is that it requires carrier-sensing hardware only on the base station but not on the sensor nodes. The average probing complexity of our protocol in a highly dynamic network is
O
(
n
/log
n
) per round, and experimental results show the proposed scheme to be scalable and highly adaptive to the contention level.
Reinforcement Learning of Informed Initial Policies for Decentralized Planning
Authors: Kraemer Landon , Banerjee Bikramjit
Published: December 2014

Decentralized partially observable Markov decision processes (Dec-POMDPs) offer a formal model for planning in cooperative multiagent systems where agents operate with noisy sensors and actuators, as well as local information. Prevalent solution techniques are centralized and model based—limitations that we address by distributed reinforcement learning (RL). We particularly favor alternate learning, where agents alternately learn best responses to each other, which appears to outperform concurrent RL. However, alternate learning requires an initial policy. We propose two principled approaches to generating informed initial policies: a naive approach that lays the foundation for a more sophisticated approach. We empirically demonstrate that the refined approach produces near-optimal solutions in many challenging benchmark settings, staking a claim to being an efficient (and realistic) approximate solver in its own right. Furthermore, alternate best response learning seeded with such policies quickly learns high-quality policies as well.
What About an Unintelligent Singularity?
Authors: Denning Peter J.
Published: December 2014

For years we humans have worried about plagues, asteroids, earthquakes, eruptions, fires, floods, famines, wars, genocides, and other uncontrollable events that could wipe away our civilization. In the modern age, with so much depending on computing and communications, we have added computers to our list of potential threats. Could we perish from the increasing intelligence of computers? Denning thinks that is less of a threat than the apparently mundane march of automated bureaucracies. He also asserts that none of the possible negative outcomes is a forgone conclusion because humans teaming with machines are far more intelligent than either one alone.
Biometrics via Oculomotor Plant Characteristics: Impact of Parameters in Oculomotor Plant Model
Authors: Komogortsev Oleg , Holland Corey , Karpov Alex , Price Larry R.
Published: December 2014

This article proposes and evaluates a novel biometric approach utilizing the internal, nonvisible, anatomical structure of the human eye. The proposed method estimates the anatomical properties of the human oculomotor plant from the measurable properties of human eye movements, utilizing a two-dimensional linear homeomorphic model of the oculomotor plant. The derived properties are evaluated within a biometric framework to determine their efficacy in both verification and identification scenarios. The results suggest that the physical properties derived from the oculomotor plant model are capable of achieving 20.3% equal error rate and 65.7% rank-1 identification rate on high-resolution equipment involving 32 subjects, with biometric samples taken over four recording sessions; or 22.2% equal error rate and 12.6% rank-1 identification rate on low-resolution equipment involving 172 subjects, with biometric samples taken over two recording sessions.