bluuebunny/crossref_metadata_2025 huggingface dataset:
Post-traumatic basal ganglia haemorrhage in a child with primary central nervous system lymphoma
Authors: Jankowski Pawel P , Levy Michael L , Crawford John Ross
Published: August 2013

Primary central nervous system lymphoma (PCNSL) is a rare tumour of childhood with 15–20 cases reported yearly in North America. We present a case of a 13-year-old boy diagnosed with PCNSL who presented more than one-and-a-half years post-treatment with high dose cytosine arabinoside and methotrexate with a right-sided basal ganglia haemorrhage on MRI following a concussion while playing organised football against medical advice. There was no evidence of an underlying vascular malformation or recurrent disease by MRI, cerebrospinal fluid analysis or positron emission tomography computed tomography (PET-CT). However, 6 months post-injury he presented with asymptomatic disease recurrence of the frontal lobe. Our case reports an unusual MRI pattern of post-traumatic injury in a child previously treated for PCNSL that would support a recommendation for the avoidance of contact sports in this population.
Intracranial aneurysm arising from infundibular dilation
Authors: Pereira Benedito Jamilson Araujo , Holanda Vanessa Milanesi , de Holanda Carlos Vanderlei Medeiros , de Oliveira Jean Goncalves
Published: August 2013

Infundibular dilations (IDs) are funnel-shaped enlargements in the origin of intracranial arteries. Usually, IDs occur at the junction between posterior communicating artery (PcomA) and internal carotid artery (ICA). Progression from an ID of the PcomA to aneurysms has been described, but is unclear whether an ID is a preaneurysmal state or a normal anatomical variant. The authors describe a 55-year-old female patient presenting multiple intracranial aneurysms with a small one arising from an ID at the level of posterior communicating segment of ICA. To the best of our knowledge, after a criterious search in the English literature, it is the first description of such unusual combination. The preoperative neurosurgical planning is discussed as well as the importance of intraoperative findings to the best management of this unusual situation.
SACRAL syndrome
Authors: Yadav Devendra Kumar , Panda Shasanka Shekhar , Teckchandani Narinder , Bagga Deepak
Published: August 2013

Haemangiomas are the most common tumours of infancy and early childhood. They are usually present in the neonate in the first 2 weeks of life. Haemangioma usually involves the head and neck area but less commonly involves the lumbosacral and perineal areas. Involvement of lumbosacral, perineal and other areas with associated anomalies are very rare. We present a neonatal case with extensive superficial haemangioma from the perineum to the neck along with multiple congenital anomalies.
Unusual choroidal mass
Authors: Parchand Swapnil Madhukar , Sharma Kusum , Sharma Aman , Singh Ramandeep
Published: August 2013

We present a unique case of disseminated tuberculosis presenting initially in the eye solely as a choroidal mass without any inflammation, mimicking choroidal metastasis. A 19-year-old girl presented with a large choroidal mass lesion in the right eye. Systemic examination revealed axillary lymphadenopathy. A fundus fluorescein angiography, positron emission tomography scan, abdominal ultrasonography and raised biochemical markers such as serum CA-125 pointed towards the diagnosis of choroidal metastases with primary in the ovaries. Fine needle aspiration cytology of the adnexal mass and ascitic fluid revealed granulomatous inflammation with a negative acid-fast bacilli stain. A multiplex PCR of ascitic fluid for the sequence MPB64 and IS6110 was positive for tuberculosis. The final diagnosis of disseminated tuberculosis was made and the patient subsequently showed a good response to antitubercular therapy.
High prevalence of overuse injury among iron-distance triathletes
Authors: Andersen Christian A , Clarsen Ben , Johansen Tone V , Engebretsen Lars
Published: August 2013

Background

Triathlon is an increasingly popular sport at both the elite and the recreational level. However, there have been few high-quality studies of injuries and illnesses among triathletes.

Objective

To register overuse problems and acute injuries among iron-distance triathletes throughout a training season leading up to a major event.

Methods

A 26-week prospective cohort study was conducted including 174 participants of the 2011 Norseman Xtreme Triathlon. Data on overuse injuries located in the shoulder, lower back, thigh, knee and lower leg were collected every second week using the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. Illnesses, acute injuries and overuse problems affecting other anatomical areas were also recorded using standard injury surveillance methods.

Results

The average prevalence of overuse problems was 56% (95% CI 51 to 61) (490 cases). The average prevalence of substantial overuse problems was 20% (95% CI 18 to 21) (165 cases). The most prevalent sites of overuse problems were the knee (25%), lower leg (23%) and lower back (23%). The acute injury incidence was 0.97 injuries per 1000 h of training (36 cases) and 1.02 injuries per 1000 h of competition (5 cases). A majority of moderate and severe acute injuries were located at the knee, shoulder/clavicle and sternum/ribs. The predominant types of acute injuries were contusions, fractures and sprains. The incidence of illness was 5.3/1000 athlete-days (156 cases).

Conclusions

Overuse problems constitute the majority of injury cases among iron-distance triathletes, and are far more common than acute injuries and illnesses. The most prevalent sites of injury in the present study were the knee, lower leg, lower back and shoulder. Future injury prevention studies in iron-distance triathletes should focus on these areas.
Use of selective serotonin reuptake inhibitors and lifestyle among women of childbearing age: a Danish cross-sectional survey
Authors: Laugesen Kristina , Telén Andersen Ane Birgitte , Nørgaard Mette , Nielsen Rikke Beck , Thomsen Reimar Wernich , Larsen Finn Breinholt , Sørensen Henrik Toft
Published: August 2013

Objective

To examine the use of selective serotonin reuptake inhibitors (SSRIs) among Danish women of childbearing age according to lifestyle factors.

Design

Cross-sectional survey.

Setting

The Central Denmark Region.

Participants

4234 women (71.5% of the invited women) aged 25–44 years who participated in a public health survey in 2006.

Outcome measures

Prevalence and prevalence ratios (PRs) of current and former SSRI use among women characterised by selected lifestyle factors. We obtained information on SSRI use through linkage to the Aarhus University Prescription Database covering all pharmacies in the region.

Results

Of the 4234 women in the study, 161 (3.8%) were current SSRI users, 60 (1.4%) were recent users, 223 (5.3%) were former users and 3790 (89.5%) were never users. Current use of SSRIs was more prevalent in obese women than in non-obese women (PR 1.5, 95% CI 1.0 to 2.3), in current smokers compared with non-current smokers (PR 1.6, 95% CI 1.1 to 2.2), in women who drank more than seven alcoholic drinks weekly compared with women who drank seven or fewer drinks weekly (PR 1.8, 95% CI 1.2 to 2.8) and in women with an unhealthy diet compared with women with a healthy diet (PR 1.7, 95% CI 1.2 to 2.6). Prevalence of former use of SSRIs was similarly increased except in those with an unhealthy diet (PR 1.1, 95% CI 0.8 to 1.7). SSRI use did not differ according to participation in regular physical activity.

Conclusions

Women with an unhealthy lifestyle were about 1.5-fold more likely to be current or former users of SSRIs than those with a healthy lifestyle. These findings may be useful for quantitative assessment of the contribution of lifestyle factors to uncontrolled confounding in studies of SSRI use in pregnancy.
Concomitant chronic pulmonary diseases and their association with hospital outcomes in patients with anaphylaxis and other allergic conditions: a cohort study
Authors: Mulla Zuber D , Simons F Estelle R
Published: August 2013

Objectives

To determine if chronic pulmonary diseases adversely impact selected outcomes in hospitalised patients who have various allergic conditions including anaphylaxis.

Design

A population-based cohort study.

Participants

A statewide hospital inpatient discharge database from Texas, USA, covering the years 2004–2007 was analysed. Patients with anaphylaxis and other allergic conditions were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification codes. Within each group of patients (the overall group with various selected allergic conditions and the subgroup with anaphylaxis), the exposure variables were 11 chronic pulmonary diseases including asthma, chronic obstructive pulmonary disease (COPD) and cystic fibrosis.

Primary outcome measures

Admission to an intensive care unit, a prolonged (>3 days) hospital stay, receipt of mechanical ventilation and death in hospital. Logistic regression was used to calculate adjusted OR and 95% CI for these four outcomes.

Results

30 390 patients with allergic conditions were identified, of whom 2410 had anaphylaxis. The following results pertain to the subcohort of patients with anaphylaxis. Median age was 50 years (range 0–95 years) and 1470 (61%) were female. The hospital mortality was 2.7%. Although asthma was not associated with hospital mortality (OR=1.27, 95% CI 0.55 to 2.90), asthmatics had more than twice the odds of non-asthmatics of receiving mechanical ventilation (OR=2.45, 95% CI 1.81 to 3.33). Chronic bronchitis, COPD, emphysema and interstitial lung diseases (ILDs) were also associated with an increased risk of requiring mechanical ventilation. Chronic bronchitis and COPD were associated with a prolonged length of stay: OR=2.69 (95% CI 1.45 to 4.98) and OR=1.86 (95% CI 1.30 to 2.66), respectively. ILD was the only chronic pulmonary disease associated with an elevated risk of hospital mortality: OR=8.71 (95% CI 1.48 to 51.20).

Conclusions

In this unique analysis of a large database, we found that asthma, COPD and other chronic pulmonary diseases increased the risk of adverse outcomes among hospitalised patients with anaphylaxis.
A system-wide approach to explaining variation in potentially avoidable emergency admissions: national ecological study
Authors: O'Cathain Alicia , Knowles Emma , Maheswaran Ravi , Pearson Tim , Turner Janette , Hirst Enid , Goodacre Steve , Nicholl Jon
Published: August 2013

Background

Some emergency admissions can be avoided if acute exacerbations of health problems are managed by the range of health services providing emergency and urgent care.

Aim

To identify system-wide factors explaining variation in age sex adjusted admission rates for conditions rich in avoidable admissions.

Design

National ecological study.

Setting

152 emergency and urgent care systems in England.

Methods

Hospital Episode Statistics data on emergency admissions were used to calculate an age sex adjusted admission rate for conditions rich in avoidable admissions for each emergency and urgent care system in England for 2008–2011.

Results

There were 3 273 395 relevant admissions in 2008–2011, accounting for 22% of all emergency admissions. The mean age sex adjusted admission rate was 2258 per year per 100 000 population, with a 3.4-fold variation between systems (1268 and 4359). Factors beyond the control of health services explained the majority of variation: unemployment rates explained 72%, with urban/rural status explaining further variation (R2=75%). Factors related to emergency departments, hospitals, emergency ambulance services and general practice explained further variation (R2=85%): the attendance rate at emergency departments, percentage of emergency department attendances converted to admissions, percentage of emergency admissions staying less than a day, percentage of emergency ambulance calls not transported to hospital and perceived access to general practice within 48 h.

Conclusions

Interventions to reduce avoidable admissions should be targeted at deprived communities. Better use of emergency departments, ambulance services and primary care could further reduce avoidable emergency admissions.
Risk factors for unplanned pregnancy among young women in Tanzania
Authors: Calvert Clara , Baisley Kathy , Doyle Aoife M , Maganja Kaballa , Changalucha John , Watson-Jones Deborah , Hayes Richard J , Ross David A
Published: August 2013

Background

With effective contraceptives available, unplanned pregnancies are preventable and educational interventions have been cited as a promising platform to increase contraceptive use through improving knowledge. However, results from trials of educational interventions have been disappointing. In order to effectively target future interventions, this study aimed to identify risk factors for unplanned pregnancy among young women in Mwanza, Tanzania.

Methods

Data were analysed from the MEMA kwa Vijiana Trial Long-term Evaluation Survey, a cross-sectional study of 13 814 young adults aged 15–30 years in Mwanza, Tanzania. Potential risk factors for unplanned pregnancy were grouped under three headings: socio-demographic, knowledge of and attitude towards sexual health, and sexual behaviour and contraceptive use. Conditional logistic regression was used to identify predictors of reported unplanned pregnancy among all sexually active women.

Results

Increasing age, lower educational level, not being currently married, knowing where to access condoms, increasing number of sexual partners and younger reported age at sexual debut were associated with unplanned pregnancy.

Discussion

A number of demographic and sexual behaviour risk factors for pregnancy are identified which will help guide future intervention programmes aiming to reduce unplanned pregnancies. This study suggests effective measures to prevent unplanned pregnancies should focus on encouraging girls to stay in school.
French military general practitioner: ultrasound practice
Authors: Maurin Olga , De Regloix S , Lefort H , Delort G , Domanski L , Tourtier J-P , Palmier B
Published: August 2013

Objectives

Ultrasound has been used in the field and in emergency departments for more than two decades. In a military setting, its use has grown rapidly as it has gained widespread acceptance among emergency physicians and as the range of diagnostic and triage applications has continued to expand. Technological changes have enabled ultrasound devices to become accessible to general practitioners (GP), and it could be of particular interest for military GPs in isolated environments. We have investigated both the training of French military GPs in the area of ultrasonography and the use of ultrasound devices, in daily practice and abroad, in isolated military settings.

Methods

In 2011, a questionnaire was sent to all 147 in-the-field GPs of the French southeast regional military health service. The questionnaire evaluated the training of military GPs in ultrasonography, the use of ultrasound in France in daily practice, and during military operations in isolated environments abroad during 2010.

Results

The response rate was 52%. On the one hand, half the responding GPs had been specially trained in ultrasound, mainly (97%) in military institutes. On the other hand, only a quarter of doctors used ultrasound in daily practice. Among those GPs performing ultrasound examinations in France, 75% used it in 2010 during isolated operations abroad. Ultrasound examinations performed in such an austere environment were retrospectively declared useful to guide clinical reasoning (41% of examinations carried out), diagnosis (21%) and decision making as regards evacuation (11%).

Conclusions

The challenge for the future is to make ultrasound courses mandatory for all military GPs going on overseas operations, to develop daily practice, and to investigate effective triage systems, combining both ultrasound imagery and physical examination.
Know Pain Know Gain: proposing a treatment approach for phantom limb pain
Authors: Le Feuvre Peter , Aldington D
Published: August 2013

Phantom limb pain affects between 50 and 80% of amputees. With an increasing number of battle casualties having had an amputation after combat trauma, it is inevitable that both primary and secondary care clinicians will come into contact with a patient with phantom limb pain (PLP). It is widely acknowledged that its complex aetiology means that this condition is often poorly understood and difficult to manage. A growing pathophysiological understanding is shedding new light on the mechanisms which underlie PLP. Knowledge of these mechanisms will inform treatment and enable clinicians to plan and implement solutions which make a difference to those individuals with this condition. This paper seeks to outline current research into this condition and proposes an approach to treatment. This approach has been formulated from an amalgamation of clinical experience working with battle casualties at the Defence Medical Rehabilitation Centre, Headley Court.
Human placenta as an ex vivo vascular model for neurointerventional research
Authors: Kwok John Ching Kwong , Huang Wei , Leung Wing-Cheong , Chan Siu-Ki , Chan Kwong-Yau , Leung Kar-Ming , Chu Alberto Chi Ho , Lam Alexander Kar Ngai
Published: August 2013

Background

Human placenta is a convenient resource for biomedical research, and has not yet been used for neurointerventional surgery research.

Objective

Our objective was to explore the feasibility of using human placenta to test various endovascular interventions and for training.

Design

18 placentas soon after delivery were prepared for six pilot studies. (1) Study on anatomical similarity to human cerebral vessel. (2) Simulation of stent assisted coiling and flow diversion on an aneurysm model. (3) Simulation of intra-arterial thrombolysis. (4) Simulation of embolization of arteriovenous malformation with glues. (5) Simulation of mechanical thrombolysis and comparison of different devices. (6) Vascular model for training of neurointerventionalists.

Results

When the chorionic plate vessels were compared with the cerebral cortical vessels, similarities were found in vascular branch patterns, histological cross sections, and angiographic appearances. Due to the semitransparency of its vessel wall, performance of flow diverter and stent assisted coiling of an aneurysm could be visualized under direct microscopic observation. Similarly, timing of clot lysis and glue polymerization could be estimated. Endothelial change after thrombectomy could be assessed by histological methods. From these pilot studies, the placenta model could be adopted to simulate various clinical situations. It is also ideal for interventional radiology training.

Conclusions

It is feasible to adopt the human placenta as an ex vivo vascular model in neurointerventional surgery research due to the fact that its vessels resemble the brain vasculature.
Combined usage of stable isotopes and GPS-based telemetry to understand the feeding ecology of an omnivorous bird, the Ring-billed Gull (Larus delawarensis)
Authors: Caron-Beaudoin É. , Gentes M.-L. , Patenaude-Monette M. , Hélie J.-F. , Giroux J.-F. , Verreault J.
Published: August 2013

The aim of the present study was to investigate the feeding ecology of an omnivorous bird, the Ring-billed Gull (Larus delawarensis Ord, 1815), breeding in a highly urbanized and heterogeneous landscape (Montréal area, Quebec, Canada). We used gastrointestinal (G.I.) tract content analysis, GPS-based tracking information, and stable isotope profiles of carbon (δ13C) and nitrogen (δ15N) in selected tissues and major food items. Based on GPS tracking data (1–3 days), Ring-billed Gulls were categorized according to their use of three main foraging habitats: agricultural, St. Lawrence River, and anthropogenic (comprising urban areas, landfills, and wastewater treatment plant basins). Ring-billed Gulls that foraged predominantly in anthropogenic habitats exhibited significantly lower δ15N in blood cells and higher total C to N ratios (C:N) in liver. These lower δ15N and higher C:N ratios were characteristic of profiles determined in food items consumed by Ring-billed Gulls at these urbanized sites (e.g., processed foods). The strong positive correlations between δ13C and δ15N in Ring-billed Gull tissues (plasma, blood cells, and liver) that differed in isotopic turnover times, as well as the strong positive correlations in both δ13C and δ15N between tissue pairs, indicated that Ring-billed Gulls exhibited conserved dietary habits throughout the nesting period. This study demonstrates that combining conventional dietary examination, tissue stable isotope analysis, and fine-scale GPS tracking information may improve our understanding of the large intrapopulation variations in foraging behaviour (and isotopic profiles) commonly observed in omnivorous birds.
Genome size increases in recently diverged hornwort clades
Authors: Bainard Jillian D. , Villarreal Juan Carlos
Published: August 2013

As our knowledge of plant genome size estimates continues to grow, one group has continually been neglected: the hornworts. Hornworts (Anthocerotophyta) have been traditionally grouped with liverworts and mosses because they share a haploid dominant life cycle; however, recent molecular studies place hornworts as the sister lineage to extant tracheophytes. Given the scarcity of information regarding the DNA content of hornworts, our objective was to estimate the 1C-value for a range of hornwort species within a phylogenetic context. Using flow cytometry, we estimated genome size for 36 samples representing 24 species. This accounts for roughly 10% of known hornwort species. Haploid genome sizes (1C-value) ranged from 160 Mbp or 0.16 pg (Leiosporoceros dussii) to 719 Mbp or 0.73 pg (Nothoceros endiviifolius). The average 1C-value was 261 ± 104 Mbp (0.27 ± 0.11 pg). Ancestral reconstruction of genome size on a hornwort phylogeny suggests a small ancestral genome size and revealed increases in genome size in the most recently divergent clades. Much more work is needed to understand DNA content variation in this phylogenetically important group, but this work has significantly increased our knowledge of genome size variation in hornworts.
BECKNER LOGARITHMIC UNCERTAINTY PRINCIPLE FOR THE RIEMANN–LIOUVILLE OPERATOR
Authors: AMRI BESMA , RACHDI LAKHDAR T.
Published: August 2013

First, we establish the Stein–Weiss inequality for the B-Riesz potential generated by the Riemann–Liouville operator. Next, we prove the Pitt's and Beckner logarithmic inequalities related to the connected Fourier transform.
Brief history for the search and discovery of the Higgs particle – A personal perspective
Authors: Wu Sau Lan
Published: August 2013

In 1964, a new particle was proposed by several groups to answer the question of where the masses of elementary particles come from; this particle is usually referred to as the Higgs particle or the Higgs boson. In July 2012, this Higgs particle was finally found experimentally, a feat accomplished by the ATLAS Collaboration and the CMS Collaboration using the Large Hadron Collider at CERN. It is the purpose of this review to give my personal perspective on a brief history of the experimental search for this particle since the '80s and finally its discovery in 2012. Besides the early searches, those at the LEP collider at CERN, the Tevatron Collider at Fermilab, and the Large Hadron Collider at CERN are described in some detail. This experimental discovery of the Higgs boson is often considered to be the most important advance in particle physics in the last half a century, and some of the possible implications are briefly discussed. This review is partially based on a talk presented by the author at the conference "Higgs Quo Vadis," Aspen Center for Physics, Aspen, CO, USA, March 10–15, 2013.
ARTIFICIAL SEISMIC SHADOW ZONE BY ACOUSTIC METAMATERIALS
Authors: KIM SANG-HOON , DAS MUKUNDA P.
Published: August 2013

We developed a new method of earthquake-proof engineering to create an artificial seismic shadow zone using acoustic metamaterials. By designing huge empty boxes with a few side-holes corresponding to the resonance frequencies of seismic waves and burying them around the buildings that we want to protect, the velocity of the seismic wave becomes imaginary. The meta-barrier composed of many meta-boxes attenuates the seismic waves, which reduces the amplitude of the wave exponentially by dissipating the seismic energy. This is a mechanical method of converting the seismic energy into sound and heat. We estimated the sound level generated from a seismic wave. This method of area protection differs from the point protection of conventional seismic design, including the traditional cloaking method. The artificial seismic shadow zone is tested by computer simulation and compared with a normal barrier.
CRYSTALLOGRAPHIC, FERROELECTRIC AND ELECTRONIC PROPERTIES OF THE Sr2ZrTiO6 DOUBLE PEROVSKITE
Authors: LANDÍNEZ TÉLLEZ D. A. , CARRERO BERMÚDEZ L. A. , DELUQUE TORO C. E. , CARDONA R. , ROA-ROJAS J.
Published: August 2013

In this paper, we report structural analysis, ferroelectric behavior and electronic structure of Sr 2 ZrTiO 6 double perovskite. Samples were produced by the solid state reaction recipe. Crystallographic analysis was performed by Rietveld refinement of experimental X-ray diffraction patterns. Results show that this material crystallizes in a tetragonal perovskite structure which corresponds to the space group I4/m. The curve of polarization as a function of applied voltage evidences a ferroelectric character with saturation polarization on the application of voltages up to 1800 V. Calculations of density of states and band structure for this manganite-like material were carried out by means of the density functional theory implemented into the Wien2k code. Results of total and partial density of states reveal the insulator character of this material with an energy gap of 2.66 eV.
Practical linear-time
O
(1)-workspace suffix sorting for constant alphabets
Authors: Nong Ge
Published: August 2013

This article presents an
O
(
n
)-time algorithm called SACA-K for sorting the suffixes of an input string
T
[0,
n
-1] over an alphabet
A
[0,
K
-1]. The problem of sorting the suffixes of
T
is also known as constructing the suffix array (SA) for
T
. The theoretical memory usage of SACA-K is
n
log
K
+
n
log
n
+
K
log
n
bits. Moreover, we also have a practical implementation for SACA-K that uses
n
bytes + (
n
+ 256) words and is suitable for strings over any alphabet up to full ASCII, where a word is log
n
bits. In our experiment, SACA-K outperforms SA-IS that was previously the most time- and space-efficient linear-time SA construction algorithm (SACA). SACA-K is around 33% faster and uses a smaller deterministic workspace of
K
words, where the workspace is the space needed beyond the input string and the output SA. Given
K
=
O
(1), SACA-K runs in linear time and
O
(1) workspace. To the best of our knowledge, such a result is the first reported in the literature with a practical source code publicly available.
Cooperative augmentation of mobile smart objects with projected displays
Authors: Molyneaux David , Gellersen Hans , Finney Joe
Published: August 2013

Sensors, processors, and radios can be integrated invisibly into objects to make them smart and sensitive to user interaction, but feedback is often limited to beeps, blinks, or buzzes. We propose to redress this input-output imbalance by augmentation of smart objects with projected displays, that—unlike physical displays—allow seamless integration with the natural appearance of an object. In this article, we investigate how, in a ubiquitous computing world, smart objects can acquire and control a projection. We consider that projectors and cameras are ubiquitous in the environment, and we develop a novel conception and system that enables smart objects to spontaneously associate with projector-camera systems for cooperative augmentation. Projector-camera systems are conceived as generic, supporting standard computer vision methods for different appearance cues, and smart objects provide a model of their appearance for method selection at runtime, as well as sensor observations to constrain the visual detection process. Cooperative detection results in accurate location and pose of the object, which is then tracked for visual augmentation in response to display requests by the smart object. In this article, we define the conceptual framework underlying our approach; report on computer vision experiments that give original insight into natural appearance-based detection of everyday objects; show how object sensing can be used to increase speed and robustness of visual detection; describe and evaluate a fully implemented system; and describe two smart object applications to illustrate the system's cooperative augmentation process and the embodied interactions it enables with smart objects.
Introduction to the special section on eye gaze and conversation
Authors: André Elisabeth , Chai Joyce
Published: August 2013

This editorial introduction first explains the origin of this special section. It then outlines how each of the two articles included sheds light on possibilities for conversational dialog systems to use eye gaze as a signal that reflects aspects of participation in the dialog: degree of engagement and turn taking behavior, respectively.
Gaze and turn-taking behavior in casual conversational interactions
Authors: Jokinen Kristiina , Furukawa Hirohisa , Nishida Masafumi , Yamamoto Seiichi
Published: August 2013

Eye gaze is an important means for controlling interaction and coordinating the participants' turns smoothly. We have studied how eye gaze correlates with spoken interaction and especially focused on the combined effect of the speech signal and gazing to predict turn taking possibilities. It is well known that mutual gaze is important in the coordination of turn taking in two-party dialogs, and in this article, we investigate whether this fact also holds for three-party conversations. In group interactions, it may be that different features are used for managing turn taking than in two-party dialogs. We collected casual conversational data and used an eye tracker to systematically observe a participant's gaze in the interactions. By studying the combined effect of speech and gaze on turn taking, we aimed to answer our main questions: How well can eye gaze help in predicting turn taking? What is the role of eye gaze when the speaker holds the turn? Is the role of eye gaze as important in three-party dialogs as in two-party dialogue? We used Support Vector Machines (SVMs) to classify turn taking events with respect to speech and gaze features, so as to estimate how well the features signal a change of the speaker or a continuation of the same speaker. The results confirm the earlier hypothesis that eye gaze significantly helps in predicting the partner's turn taking activity, and we also get supporting evidence for our hypothesis that the speaker is a prominent coordinator of the interaction space. Such a turn taking model could be used in interactive applications to improve the system's conversational performance.
Fast in-place binning of laser range-scanned point sets
Authors: Merry Bruce , Gain James , Marais Patrick
Published: August 2013

Laser range scanning is commonly used in cultural heritage to create digital models of real-world artefacts. A large scanning campaign can produce billions of point samples—too many to be manipulated in memory on most computers. It is thus necessary to spatially partition the data so that it can be processed in bins or slices. We introduce a novel compression mechanism that exploits spatial coherence in the data to allow the bins to be computed with only 1.01 bytes of I/O traffic for each byte of input, compared to 2 or more for previous schemes. Additionally, the bins are loaded from the original files for processing rather than from a sorted copy, thus minimizing disk space requirements. We demonstrate that our method yields performance improvements in a typical point-processing task, while also using little memory and guaranteeing an upper bound on the number of samples held in-core.
"Political polarization of web search queries and hashtags" by Ingmar Weber, with Martin Vesely as coordinator
Authors: Weber Ingmar
Published: August 2013

What can user-generated online data tell us about political issues and partisan politics? How polarized is a web search query such as "climategate 2.0" and can we quantify the leaning of the hashtag #climatechange?

We summarize recent work that studies U.S. politics using web search logs and Twitter data from the angle of political left-vs.-right polarization. With a simple yet effective methodology we discover a number of interesting findings. For example, we show a tendency for web search queries with a right leaning to surface more results with a negative sentiment, and we give a description of political hashtag hijacking where one political camp tries to \jam the frequency" of the other one.

We end with a discussion of challenges and opportunities in the area of data-driven political science that might be of interest to researchers looking to apply knowledge management in an interdisciplinary setting.
About the Institute of Information Systems at Hof University, Germany
Authors: Atzenbeck Claus
Published: August 2013

The Institute of Information Systems (iisys) is a young and upcoming research institute at Hof University, Germany, with a broad focus on information systems. Four scientific teams perform top level research in national and international projects. Additionally, associated experts add specific expertise of various application domains. Some of its researchers have a strong background in hypertext related topics.

For more information about iisys and its projects, please visit www.iisys.de.
Upcoming SIGWEB supported conferences
Authors: Samuel Hamman
Published: August 2013

The Special Interest Group on Hypertext and the Web, SIGWEB was created in 1989 to support the community participating in the annual ACM Hypertext Conference. Now in its third decade, SIGWEB has grown considerably and now sponsors five annual conferences of different sizes and covering a wide range of topics. SIGWEB supports several specialized conferences, short courses, and workshops, as well as the Annual Hypertext Conference. SIGWEB sponsored conferences focus on timely topics in applied and computational hypertext and Web disciplines and provide a place for members and the entire applied Hypermedia and Web community to exchange ideas and to meet with and expand their network of colleagues. In this article, we provide a brief overview of SIGWEB sponsored conferences, in addition to events that are in cooperation with SIGWEB.
More Encryption Is Not the Solution
Authors: Kamp Poul-Henning
Published: August 2013

The recent exposure of the dragnet-style surveillance of Internet traffic has provoked a number of responses that are variations of the general formula, "More encryption is the solution." This is not the case. In fact, more encryption will probably only make the privacy crisis worse than it already is.
The daily deals marketplace
Authors: Byers John W. , Mitzenmacher Michael , Zervas Georgios
Published: August 2013

The emergence of the daily deals online marketplace has been an e-commerce phenomenon that has engendered remarkable stories of rapid growth, exemplified by firms such as Groupon and Living Social. At the same time, critics have accumulated considerable evidence, largely anecdotal in nature, of incipient failure of this marketplace. Our recent empirical work has attempted to reconcile these divergent viewpoints through quantitative evaluation, in an effort to understand the sustainability and long-term outlook of the daily deals business model. Our methods draw from a rich tradition in marketing and econometrics to study the interplay between promotional offers, word-of-mouth engagement, and consumer satisfaction. Leveraging datasets we collected encompassing tens of thousands of daily deals offers and millions of Yelp reviews, we have quantified the significant extent to which daily deals users express dissatisfaction with today's offers, and elaborated the root causes underlying this behavior. We discuss the broader implications of our methodology and the managerial implications that follow from our root cause analysis, both for daily deals merchants and daily deals services, that could lead to a viable marketplace and improved consumer satisfaction.
Editor's introduction
Authors: Procaccia Ariel D.
Published: August 2013

Issue 12.1 of SIGecom Exchanges includes a letter from the program chairs of EC'13, a survey, and six research letters. The purpose of the first letter is to update the community about some of the decisions and discussions surrounding EC'13. The previous Exchanges issue---11.2---included a letter from the SIG chair David Parkes, and going forward the plan is to alternate between these two types of updates, publishing a letter from the SIG chair in each December issue and a letter from the EC chairs in each June issue.
Notes from the EC'13 program chairs
Authors: McAfee R. Preston , Tardos Éva
Published: August 2013

This note describes our experience as 2013 ACM Electronic Commerce (EC) program chairs and summarizes a survey we ran after the program was complete.
Planning and learning in security games
Authors: Delle Fave Francesco M. , Qian Yundi , Jiang Albert X. , Brown Matthew , Tambe Milind
Published: August 2013

We present two new critical domains where security games are applied to generate randomized patrol schedules. For each setting, we present the current research that we have produced. We then propose two new challenges to build accurate schedules that can be deployed effectively in the real world. The first is a planning challenge. Current schedules cannot handle interruptions. Thus, more expressive models, that allow for reasoning over stochastic actions, are needed. The second is a learning challenge. In several security domains, data can be used to extract information about both the environment and the attacker. This information can then be used to improve the defender's strategies.
Quantitative changes in focal adhesion kinase and its inhibitor, FRNK, drive load-dependent expression of costamere components
Authors: Klossner Stephan , Li Ruowei , Ruoss Severin , Durieux Anne-Cécile , Flück Martin
Published: August 2013

Costameres are mechanosensory sites of focal adhesion in the sarcolemma that reinforce the muscle-fiber composite and provide an anchor for myofibrillogenesis. We hypothesized that elevated content of the integrin-associated regulator of costamere turnover in culture, focal adhesion kinase (FAK), drives changes in costamere component content in antigravity muscle in a load-dependent way in correspondence with altered muscle weight. The content of FAK in soleus muscle being phosphorylated at autoregulatory tyrosine 397 (FAK-pY397) was increased after 20 s of stretch. FAK-pY397 content remained elevated after 24 h of stretch-overload due to upregulated FAK content. Overexpression of FAK in soleus muscle fibers by means of gene electrotransfer increased the β1-integrin (+56%) and meta-vinculin (+88%) content. α7-Integrin ( P = 0.46) and γ-vinculin ( P = 0.18) content was not altered after FAK overexpression. Co-overexpression of the FAK inhibitor FAK-related nonkinase (FRNK) reduced FAK-pY397 content by 33% and increased the percentage of fast-type fibers that arose in connection with hybrid fibers with gene transfer. Transplantation experiments confirmed the association of FRNK expression with slow-to-fast fiber transformation. Seven days of unloading blunted the elevation of FAK-pY397, β1-integrin, and meta-vinculin content with FAK overexpression, and this was reversed by 1 day of reloading. The results highlight that the expression of components for costameric attachment sites of myofibrils is under load- and fiber type-related control via FAK and its inhibitor FRNK.
Exercise training increases the expression and nuclear localization of mRNA destabilizing proteins in skeletal muscle
Authors: Matravadia Sarthak , Martino Vanessa B. , Sinclair Daniel , Mutch David M. , Holloway Graham P.
Published: August 2013

While a paucity of information exists regarding posttranscriptional mechanisms influencing mitochondrial biogenesis, in resting muscle the stability of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) mRNA has been linked to mitochondrial content. Therefore, in the current study we have examined whether exercise promotes mRNA accumulation through the induction of proteins affiliated with mRNA stabilization (human antigen R, HuR) or conversely by decreasing the expression of mRNA destabilizing proteins [AU-rich binding factor (AUF1) and CUG binding protein (CUG-BP1)]. A single bout of exercise increased ( P < 0.05) the mRNA content of the transcriptional coactivator PGC-1α ∼3.5-fold without affecting mRNA content for HuR, CUG-BP1, or AUF1. One week of treadmill exercise training did not alter markers of mitochondrial content, the mRNA stabilizing protein HuR, or the mRNA destabilizing protein AUF1. In contrast, the mRNA destabilizing protein CUG-BP1 increased ∼40%. Four weeks of treadmill training increased the content of subunits of the electron transport chain ∼50%, suggesting induction of mitochondrial biogenesis. Expression levels for HuR and CUG-BP1 were not altered with chronic training; however, AUF1 expression was increased posttraining. Specifically, training increased ( P < 0.05) total muscle expression of two of four AUF1 isoforms ∼50% (AUF1p37, AUF1p40). Interestingly, these two isoforms were not detected in isolated nuclei; however, a large band representing the other two isoforms (AUF1p42, AUF1p45) was present in nuclei and increased ∼35% following chronic training. Altogether the current data provides evidence that mitochondrial biogenesis occurs in the presence of increased CUG-BP1 and AUF1, suggesting that reductions in known mRNA destabilizing proteins likely does not contribute to exercise-induced mitochondrial biogenesis.
Self-tuning of inhibition by endocannabinoids shapes spike-time precision in CA1 pyramidal neurons
Authors: Dubruc Franck , Dupret David , Caillard Olivier
Published: August 2013

In the hippocampus, activity-dependent changes of synaptic transmission and spike-timing coordination are thought to mediate information processing for the purpose of memory formation. Here, we investigated the self-tuning of intrinsic excitability and spiking reliability by CA1 hippocampal pyramidal cells via changes of their GABAergic inhibitory inputs and endocannabinoid (eCB) signaling. Firing patterns of CA1 place cells, when replayed in vitro, induced an eCB-dependent transient reduction of spontaneous GABAergic activity, sharing the main features of depolarization-induced suppression of inhibition (DSI), and conditioned a transient improvement of spike-time precision during consecutive burst discharges. When evaluating the consequences of DSI on excitatory postsynaptic potential (EPSP)-spike coupling, we found that transient reductions of uncorrelated (spontaneous) or correlated (feedforward) inhibition improved EPSP-spike coupling probability. The relationship between EPSP-spike-timing reliability and inhibition was, however, more complex: transient reduction of correlated (feedforward) inhibition disrupted or improved spike-timing reliability according to the initial spike-coupling probability. Thus eCB-mediated tuning of pyramidal cell spike-time precision is governed not only by the initial level of global inhibition, but also by the ratio between spontaneous and feedforward GABAergic activities. These results reveal that eCB-mediated self-tuning of spike timing by the discharge of pyramidal cells can constitute an important contribution to place-cell assemblies and memory formation in the hippocampus.
Frequency response of vestibular reflexes in neck, back, and lower limb muscles
Authors: Forbes Patrick A. , Dakin Christopher J. , Vardy Alistair N. , Happee Riender , Siegmund Gunter P. , Schouten Alfred C. , Blouin Jean-Sébastien
Published: August 2013

Vestibular pathways form short-latency disynaptic connections with neck motoneurons, whereas they form longer-latency disynaptic and polysynaptic connections with lower limb motoneurons. We quantified frequency responses of vestibular reflexes in neck, back, and lower limb muscles to explain between-muscle differences. Two hypotheses were evaluated: 1) that muscle-specific motor-unit properties influence the bandwidth of vestibular reflexes; and 2) that frequency responses of vestibular reflexes differ between neck, back, and lower limb muscles because of neural filtering. Subjects were exposed to electrical vestibular stimuli over bandwidths of 0–25 and 0–75 Hz while recording activity in sternocleidomastoid, splenius capitis, erector spinae, soleus, and medial gastrocnemius muscles. Coherence between stimulus and muscle activity revealed markedly larger vestibular reflex bandwidths in neck muscles (0–70 Hz) than back (0–15 Hz) or lower limb muscles (0–20 Hz). In addition, vestibular reflexes in back and lower limb muscles undergo low-pass filtering compared with neck-muscle responses, which span a broader dynamic range. These results suggest that the wider bandwidth of head-neck biomechanics requires a vestibular influence on neck-muscle activation across a larger dynamic range than lower limb muscles. A computational model of vestibular afferents and a motoneuron pool indicates that motor-unit properties are not primary contributors to the bandwidth filtering of vestibular reflexes in different muscles. Instead, our experimental findings suggest that pathway-dependent neural filtering, not captured in our model, contributes to these muscle-specific responses. Furthermore, gain-phase discontinuities in the neck-muscle vestibular reflexes provide evidence of destructive interaction between different reflex components, likely via indirect vestibular-motor pathways.
Rectification of EMG in low force contractions improves detection of motor unit coherence in the beta-frequency band
Authors: Ward Nicholas J. , Farmer Simon F. , Berthouze Luc , Halliday David M.
Published: August 2013

Rectification of surface EMG before spectral analysis is a well-established preprocessing method used in the detection of motor unit firing patterns. A number of recent studies have called into question the need for rectification before spectral analysis, pointing out that there is no supporting experimental evidence to justify rectification. We present an analysis of 190 records from 13 subjects consisting of simultaneous recordings of paired single motor units and surface EMG from the extensor digitorum longus muscle during middle finger extension against gravity (unloaded condition) and against gravity plus inertial loading (loaded condition). We directly examine the hypothesis that rectified surface EMG is a better predictor of the frequency components of motor unit synchronization than the unrectified (or raw) EMG in the beta-frequency band (15–32 Hz). We use multivariate analysis and estimate the partial coherence between the paired single units using both rectified and unrectified surface EMG as a predictor. We use a residual partial correlation measure to quantify the difference between raw and rectified EMG as predictor and analyze unloaded and loaded conditions separately. The residual correlation for the unloaded condition is 22% with raw EMG and 3.5% with rectified EMG and for the loaded condition it is 5.2% with raw EMG and 1.4% with rectified EMG. We interpret these results as strong supporting experimental evidence in favor of using the preprocessing step of surface EMG rectification before spectral analysis.