bluuebunny/crossref_metadata_2025 huggingface dataset:
Mixed-phenotype acute leukemia: current challenges in diagnosis and therapy
Authors: Wolach Ofir , Stone Richard M.
Published: January 2017

Purpose of review

Mixed-phenotype acute leukemia (MPAL) is a rare disease that poses many diagnostic and therapeutic challenges. Patients with MPAL are considered to have poor outcomes. The difficulties in classifying this leukemia, the lack of prospectively collected data concerning therapeutic outcomes, and rare incidence result in much uncertainty as to the best approach for patients with MPAL.

Recent findings

Recent studies demonstrated that most MPALs are associated with cytogenetic abnormalities; genetic sequencing studies disclose a high frequency of somatic mutations in genes encoding epigenetic regulators, tumor suppressors, and transcription factors. The limited available data suggest that higher remission rates are achieved with acute lymphoblastic leukemia-like induction regimens compared with acute myeloid leukemia-type approaches. Allogeneic transplantation in first remission may be associated with improved survival compared with consolidation chemotherapy.

Advances in understanding the genetic landscape of MPAL may allow a more biologically driven classification of this heterogeneous group of leukemias in the future that will lead to optimized therapies for individual patients. Most data that inform therapy are based on retrospective, uncontrolled studies; prospective trials that incorporate targeted approaches based on genetics and immunophenotype are needed.
Characterization, regulation, and targeting of erythroid progenitors in normal and disordered human erythropoiesis
Authors: Dulmovits Brian M. , Hom Jimmy , Narla Anupama , Mohandas Narla , Blanc Lionel
Published: January 2017

Purpose of review

The erythroid progenitors burst-forming unit-erythroid and colony-forming unit-erythroid have a critical role in erythropoiesis. These cells represent a heterogeneous and poorly characterized population with modifiable self-renewal, proliferation and differentiation capabilities. This review focuses on the current state of erythroid progenitor biology with regard to immunophenotypic identification and regulatory programs. In addition, we will discuss the therapeutic implications of using these erythroid progenitors as pharmacologic targets.

Recent findings

Erythroid progenitors are classically characterized by the appearance of morphologically defined colonies in semisolid cultures. However, these prior systems preclude a more thorough understanding of the composite nature of progenitor populations. Recent studies employing novel flow cytometric and cell-based assays have helped to redefine hematopoiesis, and suggest that erythroid progenitors may arise from different levels of the hematopoietic tree. Moreover, the identification of cell surface marker patterns in human burst-forming unit-erythroid and colony-forming unit-erythroid enhance our ability to perform downstream functional and molecular analyses at the population and single cell level. Advances in these techniques have already revealed novel subpopulations with increased self-renewing capacity, roles for erythroid progenitors in globin gene expression, and insights into pharmacologic mechanisms of glucocorticoids and pomalidomide.

Immunophenotypic and molecular characterization resolves the diversity of erythroid progenitors, and may ultimately lead to the ability to target these progenitors to ameliorate diseases of dyserythropoiesis.
The Association of Serum 25-Hydroxyvitamin D With Biomarkers of Hemolysis in Pediatric Patients With Sickle Cell Disease
Authors: Adegoke Samuel A. , Braga Josefina A.P. , Adekile Adekunle D. , Figueiredo Maria S.
Published: January 2017

Although vitamin D deficiency (VDD) has been linked to anemia among sickle cell disease (SCD), its relationship with hemolysis is unclear. Serum 25-hydroxyvitamin D and biomarkers of hemolysis (hemoglobin [Hb]/hematocrit, reticulocyte percentage, absolute reticulocyte, and lactate dehydrogenase [LDH] levels) in 36 hydroxyurea-naive SCD children were quantified. Correlations were significantly positive with Hb/hematocrit (r=0.40, P=0.017; r=0.45, P=0.006, respectively); inverse with reticulocyte percentage, absolute reticulocyte, and LDH (r=−0.44, P=0.008; r=−0.47, P=0.007; r=−0.45, P=0.007, respectively). In VDD groups, Hb was lower (P=0.014), reticulocyte counts and LDH were higher (P=0.047 and 0.003, respectively). Serum 25-hydroxyvitamin D correlated with biomarkers of hemolysis in SCD and VDD may play a role in SCD pathogenesis.
Determinants of health knowledge and health perceptions from the perspective of health-related education of patients with spinal cord injury: a systematic review
Authors: Tederko Piotr , Krasuski Tomasz , Krasuski Marek , Długołęcka Alicja , Tarnacka Beata
Published: January 2017

Appropriate health knowledge (HK) and health perceptions (HP) of patients with spinal cord injury (SCI) are linked to health-related behaviors, compliance, the involvement of caregivers and efficacy of prophylaxis, and management of secondary conditions. The significance of factors determining the efficacy of educational interventions in patients with SCI is underestimated. This systematic literature review aims at identification of determinants of HK and HP among patients with SCI. We identified 16 papers with quantitative HK and HP measurements conclusive in the identification of HK and HP determinants in individuals with SCI. Better HK and HP correlated with health condition-related variables (traumatic SCI, history of secondary conditions, except depression), body functions and structures (tetraplegia, incomplete deficit), activities (independence in daily living activities, ability of locomotion on a wheelchair, inability to walk), social and vocational participation, environmental factors (access to a computer with Internet connection, living in a big city, being married, healthcare recently received), and personal factors (younger age among adults, living with SCI for a longer time, younger age at SCI onset, higher educational level, internal locus of control). Limitations encountered included high nonresponse rates among the patients enrolled, and use of heterogeneous and nonvalidated tools. The results of these studies do not cover the entire scope of possible interactions and exclusively apply univariate correlations. The paucity and methodological limitations of studies conclusive in the identification of HK and HP determinants in SCI patients and the development of new approaches to information and education warrant more high-quality research on the basis of multivariate analyses.
Symptom Presentation and Prescription of Sleep Medications for Veterans With Posttraumatic Stress Disorder
Authors: Greenbaum Mark A. , Neylan Thomas C. , Rosen Craig S.
Published: January 2017

This study tested whether sleep medications prescribed to veterans diagnosed with posttraumatic stress disorder (PTSD) are being targeted to patients who report more severe insomnia or nightmares. Secondary analysis of survey and pharmacy data was conducted in samples of veterans from two periods: from 2006 to 2008 and from 2009 to 2013. Logistic regression tested associations between self-reported insomnia and nightmare severity, and being prescribed trazodone, prazosin, zolpidem, and benzodiazepines, controlling for PTSD severity and other covariates. In both samples, insomnia severity independently predicted trazodone receipt, and nightmare severity independently predicted prazosin receipt. In the later study, insomnia severity predicted receipt of zolpidem. Veterans in the later sample were more likely to receive trazodone, prazosin, and non-benzodiazepine hypnotics, and less likely to receive benzodiazepines than those in the earlier sample. Further research is needed to evaluate and optimize pharmacological and psychosocial treatments for sleep problems among veterans with PTSD.
Comparison of cobas 4800, m2000, Viper XTR, and Infinity 80 Automated Instruments When Processing Urine Specimens for the Diagnosis of Chlamydia trachomatis and Neisseria gonorrhoeae
Authors: Chernesky Max A. , Jang Dan , Gilchrist Jodi , Smieja Marek , Arias Manuel , Hatchette Todd , Poirier Andre , Mayne Donna , Ratnam Sam
Published: January 2017

Objectives

North American and European advisory groups recommend testing for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) with nucleic acid amplification tests. Testing is often performed on automated instruments. The objectives of this study were to process urines for the diagnosis of CT and NG and to examine workflow procedures and outcomes.

Methods

While processing 1, 24, 48, 96, and 192 urine specimens on 3 batch-mode systems which use 96-well plates: cobas 4800, m2000, and Viper XTR and the random access cartridge testing GeneXpert Infinity 80, we measured assay performance, hands-on time for processing and maintenance, reagents and plastics consumption, time required to obtain results, and testing accuracy.

Results

The Infinity 80 required the least hands-on time for single specimens and smaller batches, whereas the Viper XTR and m2000 required the most hands-on time for all batch sizes. Cumulative daily, weekly, and monthly maintenance was highest for the Viper XTR and lowest for Infinity 80. All batch-mode instruments consumed large amounts of disposables. Time to results was shortest for the Infinity 80, and the Viper XTR provided the shortest time for the batch-mode instruments. All systems showed similar diagnostic accuracy.

Conclusions

Because detection performances were similar, issues of hands-on time, maintenance, time to results, and consumables are important operational factors for the diagnosis and treatment of CT/NG infections.
The Missing Record of Mental Status in Written Sign-Outs
Authors: Croix Michael , Miller Donna , Whittle Jeff , Singh Siddhartha , Schapira Marilyn M. , Carnahan Jennifer , Kuester Jessica , Kallio Christa , Framberg Susan , Fletcher Kathlyn E.
Published: January 2017

Objective

The aim of the study was to determine how frequently mental status and mental status changes are documented in the written patient summary (“sign-out”) provided to covering physicians.

Patients and Methods

This was a retrospective cohort study of general medical patients hospitalized between March 16, 2009, and March 15, 2010, conducted at 2 teaching hospitals. Participants included patients with mental status change adverse events (MSAEs) and their providers. Chart review was performed to identify patients with MSAEs and details about these events. Sign-outs were reviewed for documentation of mental status. Main outcome measures were (1) proportion of patients with MSAEs who had mental status ever recorded in sign-out entries and (2) the proportion of patients with MSAEs whose change in mental status was recorded in the sign-out.

Results

Sixty-eight patients had MSAEs and were included in the sample. Fifty percent of MSAEs were attributed to medications; 75% of these events were first detected by nurses. Only 25% of patients with MSAEs had their change in mental status recorded in sign-outs.

Conclusions

Recording mental status in written sign-outs is uncommon. Particularly concerning is that patients with MSAEs identified by chart review seldom had sign-outs that reflected those events. Interventions should be designed to increase the recording of this information in sign-outs.
Median Lingual Lymph Nodes: Prevalence on Imaging and Potential Implications for Oral Cavity Cancer Staging
Authors: Tomblinson Courtney M. , Nagel Thomas H. , Hu Leland S. , Zarka Matthew A. , Hoxworth Joseph M.
Published: January 2017

Objective

This study sought to estimate the prevalence of median lingual lymph node (MLLN) metastases from oral cavity squamous cell carcinoma (OCSCC) and determine the frequency with which MLLNs can be identified with magnetic resonance imaging (MRI) in control subjects.

Methods

Pathology reports were used to identify patients with surgically treated OCSCC who underwent preoperative positron emission tomography–computed tomography to define the prevalence of MLLN metastases. As a control group, 500 consecutive face-neck MRIs from noncancer patients were reviewed for structures consistent with MLLNs.

Results

In the study group, 1 (0.95%) of 105 OCSCC cases demonstrated a single MLLN metastasis from a lateral tongue tumor (T4aN2c). The MLLN exceeded 1 cm in all planes and was abnormal in morphology. The frequency of suspected MLLNs in controls was 1.0%, with a maximum measurement of 0.9 cm.

Conclusions

Median lingual lymph nodes are infrequently identified with MRI in controls, concordant with the low prevalence of metastases from OCSCC to this inconstant nodal group.
Comparison of Model-Based Iterative Reconstruction, Adaptive Statistical Iterative Reconstruction, and Filtered Back Projection for Detecting Hepatic Metastases on Submillisievert Low-Dose Computed Tomography
Authors: Son Jung Hee , Kim Seung Ho , Yoon Jung-Hee , Lee Yedaun , Lim Yun-Jung , Kim Seon-Jeong
Published: January 2017

Objective

The aim of the study was to compare the diagnostic performance of model-based iterative reconstruction (MBIR), adaptive statistical iterative reconstruction (ASIR), and filtered back projection (FBP) on submillisievert low-dose computed tomography (LDCT) for detecting hepatic metastases.

Methods

Thirty-eight patients having hepatic metastases underwent abdomen CT. Computed tomography protocol consisted of routine standard-dose portal venous phase scan (120 kVp) and 90-second delayed low-dose scan (80 kVp). The LDCT images were reconstructed with FBP, ASIR, and MBIR, respectively. Two readers recorded the number of hepatic metastases on each image set.

Results

A total of 105 metastatic lesions were analyzed. For reader 1, sensitivity for detecting metastases was stationary between FBP (49%) and ASIR (52%, P = 0.0697); however, sensitivity increased in MBIR (66%, P = 0.0035). For reader 2, it was stationary for all the following sets: FBP (65%), ASIR (68%), and MBIR (67%, P > 0.05).

Conclusions

The MBIR and ASIR showed a limited sensitivity for detecting hepatic metastases in submillisievert LDCT.
Evaluating the Impact of Intraoperative Surgical Team Handoffs on Patient Outcomes
Authors: Giugale Lauren E. , Sears Sarah , Lavelle Erin S. , Carter-Brooks Charelle M. , Bonidie Michael , Shepherd Jonathan P.
Published: January 2017

Objective

The aim of the study was to assess the impact of intraoperative personnel handoffs on clinical outcomes in patients undergoing minimally invasive sacrocolpopexy (SCP).

Methods

We retrospectively reviewed SCPs performed at an academic center between 2009 and 2014. We analyzed the number of staff handoffs, defined as any instance a scrub technician (tech) or circulating nurse handed off responsibility for a break or shift change. Outcomes included operative (OR) time and composite variables for major complications (conversion to an open procedure, bladder injury, bowel injury, blood transfusion, infection, ileus, bowel obstruction, readmission, or mesh complication) and prolapse recurrence (prolapse at or beyond the hymen or retreatment). Postoperative complications were defined as being within 6 weeks of surgery. Mesh complications and prolapse recurrence were recorded for the entire 68-month study period.

Results

Of 814 patients, 97.4% were white, 85.3% postmenopausal, mean (SD) age 59.7 (8.8) years, and mean (SD) body mass index 27.5 (4.5) kg/m2. Most had stage 3 prolapse (n = 563, 69.9%). There were 478 (58.7%) laparoscopic and 336 (41.3%) robotic SCPs. The median scrub tech and nurse handoff per case was 1.0 (interquartile range [IQR], 0.0–1.0) and 1.0 (IQR, 1.0–2.0), respectively. Mean (SD) OR time was 204.8 (69.0) minutes. One hundred twenty-nine patients (15.8%) had a major complication and 45 (7.5%) experienced prolapse recurrence over a median follow-up interval of 41.0 weeks (IQR, 12.0–101.0). On multivariable linear regression, each tech and nurse handoff was associated with an increased OR time of 13.6 (P < 0.001) and 9.4 minutes (P < 0.001), respectively. Thus, the median of 1 tech and 1 nurse handoff per case will increase OR time by 23.0 minutes (11.2%). On multivariable logistic regression, staff handoffs were not associated with major complications or prolapse recurrence.

Conclusions

Intraoperative scrub technician and circulating nurse handoffs increased OR time for minimally invasive SCP procedures.
Impact of Case Order on Laparoscopic Sacrocolpopexy: Do Surgeons Need a Warm-Up?
Authors: Lavelle Erin Seifert , Turner Lindsay C. , Shepherd Jonathan P.
Published: January 2017

Objectives

Warm-up is defined as a preparatory activity or procedure. Using case order as a surrogate for surgeon warm-up, first cases were compared with second or later cases for intraoperative complications, operative time, and length of stay (LOS) among women undergoing laparoscopic sacrocolpopexy.

Methods

This is a retrospective study of laparoscopic sacrocolpopexies performed from 2009 through 2014 at a large academic center. Any surgery preceding laparoscopic sacrocolpopexy was considered a surrogate for surgeon warm-up. Logistic and linear regression analyses were used to identify predictors of complications, operative time, and LOS.

Results

Of 480 procedures, 192 (40%) were first cases and 288 (60%) were second or later. Baseline characteristics were similar between groups. Intraoperative complication rate was not different between groups (6.3% vs 3.1%, P = 0.50) even after controlling for risk factors. Operative times were comparable on initial analysis (231.2 ± 55.2 vs 225.9 ± 51.2 minutes, P = 0.28l), but a small difference was detected after adjusting for confounding factors (body mass index, menopausal status, surgeon experience, intraoperative complications, and concomitant hysterectomy or midurethral sling; adjusted β = 8.44 minutes, P = 0.037). Length of stay was longer for first case patients (1.44 ± 0.67 vs 1.24 ± 0.50 days, P < 0.001) even after adjusting for age, medical comorbidities, operative time, conversion to laparotomy, ileus/bowel obstruction, and postoperative urinary retention (adjusted β = 0.183 days, P = 0.001) as well as after accounting for delayed start time of second or later cases.

Conclusions

Laparoscopic sacrocolpopexy performed first case of the day without preoperative surgeon warm-up conferred no significant increase in intraoperative complications. Second or later cases were associated with small decreases in operative time and in LOS.
Leveraging genome-wide datasets to quantify the functional role of the anti-Shine–Dalgarno sequence in regulating translation efficiency
Authors: Hockenberry Adam J. , Pah Adam R. , Jewett Michael C. , Amaral Luís A. N.
Published: January 2017

Studies dating back to the 1970s established that sequence complementarity between the anti-Shine–Dalgarno (aSD) sequence on prokaryotic ribosomes and the 5′ untranslated region of mRNAs helps to facilitate translation initiation. The optimal location of aSD sequence binding relative to the start codon, the full extents of the aSD sequence and the functional form of the relationship between aSD sequence complementarity and translation efficiency have not been fully resolved. Here, we investigate these relationships by leveraging the sequence diversity of endogenous genes and recently available genome-wide estimates of translation efficiency. We show that—after accounting for predicted mRNA structure—aSD sequence complementarity increases the translation of endogenous mRNAs by roughly 50%. Further, we observe that this relationship is nonlinear, with translation efficiency maximized for mRNAs with intermediate levels of aSD sequence complementarity. The mechanistic insights that we observe are highly robust: we find nearly identical results in multiple datasets spanning three distantly related bacteria. Further, we verify our main conclusions by re-analysing a controlled experimental dataset.
Flexibility of habitat use in novel environments: insights from a translocation experiment with lesser black-backed gulls
Authors: van Toor Mariëlle L. , Arriero Elena , Holland Richard A. , Huttunen Markku J. , Juvaste Risto , Müller Inge , Thorup Kasper , Wikelski Martin , Safi Kamran
Published: January 2017

Being faced with unknown environments is a concomitant challenge of species' range expansions. Strategies to cope with this challenge include the adaptation to local conditions and a flexibility in resource exploitation. The gulls of theLarus argentatus-fuscus-cachinnansgroup form a system in which ecological flexibility might have enabled them to expand their range considerably, and to colonize urban environments. However, on a population level both flexibility and local adaptation lead to signatures of differential habitat use in different environments, and these processes are not easily distinguished. Using the lesser black-backed gull (Larus fuscus) as a system, we put both flexibility and local adaptation to a test. We compare habitat use between two spatially separated populations, and use a translocation experiment during which individuals were released into novel environment. The experiment revealed that on a population-level flexibility best explains the differences in habitat use between the two populations. We think that our results suggest that the range expansion and huge success of this species complex could be a result of its broad ecological niche and flexibility in the exploitation of resources. However, this also advises caution when using species distribution models to extrapolate habitat use across space.
A full lifespan model of vertebrate lens growth
Authors: Šikić Hrvoje , Shi Yanrong , Lubura Snježana , Bassnett Steven
Published: January 2017

The mathematical determinants of vertebrate organ growth have yet to be elucidated fully. Here, we utilized empirical measurements and a dynamic branching process-based model to examine the growth of a simple organ system, the mouse lens, from E14.5 until the end of life. Our stochastic model used difference equations to model immigration and emigration between zones of the lens epithelium and included some deterministic elements, such as cellular footprint area. We found that the epithelial cell cycle was shortened significantly in the embryo, facilitating the rapid growth that marks early lens development. As development progressed, epithelial cell division becomes non-uniform and four zones, each with a characteristic proliferation rate, could be discerned. Adjustment of two model parameters, proliferation rate and rate of change in cellular footprint area, was sufficient to specify all growth trajectories. Modelling suggested that the direction of cellular migration across zonal boundaries was sensitive to footprint area, a phenomenon that may isolate specific cell populations. Model runs consisted of more than 1000 iterations, in each of which the stochastic behaviour of thousands of cells was followed. Nevertheless, sequential runs were almost superimposable. This remarkable degree of precision was attributed, in part, to the presence of non-mitotic flanking regions, which constituted a path by which epithelial cells could escape the growth process. Spatial modelling suggested that clonal clusters of about 50 cells are produced during migration and that transit times lengthen significantly at later stages, findings with implications for the formation of certain types of cataract.
Symmetry, topology and the maximum number of mutually pairwise-touching infinite cylinders: configuration classification
Authors: Pikhitsa Peter V. , Pikhitsa Stanislaw
Published: January 2017

We provide a complete classification of possible configurations of mutually pairwise-touching infinite cylinders in Euclidian three-dimensional space. It turns out that there is a maximum number of such cylinders possible in three dimensions independently of the shape of the cylinder cross-sections. We give the explanation of the uniqueness of the non-trivial configuration of seven equal mutually touching round infinite cylinders found earlier. Some results obtained for the chirality matrix, which is equivalent to the Seidel adjacency matrix, may be found useful for the theory of graphs.
Why do students quit school? Implications from a dynamical modelling study
Authors: Amdouni Bechir , Paredes Marlio , Kribs Christopher , Mubayi Anuj
Published: January 2017

In 2012, more than three million students dropped out from high school. At this pace, we will have more than 30 million Americans without a high school degree by 2022 and relatively high dropout rates among Hispanic and African American students. We have developed and analysed a data-driven mathematical model that includes multiple interacting mechanisms and estimates of parameters using data from a specifically designed survey applied to a certain group of students of a high school in Chicago to understand the dynamics of dropouts. Our analysis suggests students' academic achievement is directly related to the level of parental involvement more than any other factors in our study. However, if the negative peer influence (leading to lower academic grades) increases beyond a critical value, the effect of parental involvement on the dynamics of dropouts becomes negligible.
Learning partial differential equations via data discovery and sparse optimization
Authors: Schaeffer Hayden
Published: January 2017

We investigate the problem of learning an evolution equation directly from some given data. This work develops a learning algorithm to identify the terms in the underlying partial differential equations and to approximate the coefficients of the terms only using data. The algorithm uses sparse optimization in order to perform feature selection and parameter estimation. The features are data driven in the sense that they are constructed using nonlinear algebraic equations on the spatial derivatives of the data. Several numerical experiments show the proposed method's robustness to data noise and size, its ability to capture the true features of the data, and its capability of performing additional analytics. Examples include shock equations, pattern formation, fluid flow and turbulence, and oscillatory convection.
On compression and damage evolution in two thermoplastics
Authors: Bourne N. K. , Garcea S. C. , Eastwood D. S. , Parry S. , Rau C. , Withers P. J. , McDonald S. A. , Brown E. N.
Published: January 2017

The well-known Taylor cylinder impact test, which follows the impact of a flat-ended cylindrical rod onto a rigid stationary anvil, is conducted over a range of impact speeds for two polymers, polytetrafluoroethylene (PTFE) and polyetheretherketone (PEEK). In previous work, experiments and a model were developed to capture the deformation behaviour of the cylinder after impact. These works showed a region in which spatial and temporal variation of both longitudinal and radial deformation provided evidence of changes in phase within the material. In this further series of experiments, this region is imaged in a range of impacted targets at the Diamond synchrotron. Further techniques were fielded to resolve compressed regions within the recovered polymer cylinders that showed a fracture zone in the impact region. The combination of macroscopic high-speed photography and three-dimensional X-ray imaging has identified the development of failure with these polymers and shown that there is no abrupt transition in behaviours but rather a continuous range of responses to competing operating mechanisms. The behaviours noted in PEEK in these polymers show critical gaps in understanding of polymer high strain-rate response.
The theory on ‘gravity-driven horizontal locomotion’ is flawed; a commentary on ‘Gravity-driven horizontal locomotion: theory and experiment’ by Kanstad & Kononoff (2015)
Authors: ‘Knoek’ van Soest A. J. , Kistemaker D. A. , Bobbert M. F. , Lemaire K. K.
Published: January 2017

In a recent paper, Kanstad & Kononoff (
Proc. R. Soc. A
471
, 20150287. (
doi:10.1098/rspa.2015.0287
)) presented a theoretical analysis of the mechanical energetics of a particular style of human walking and running. According to their analysis, the force of gravity provides energy when this style of horizontal walking/running is adopted. Furthermore, Kanstad & Kononoff suggested that uphill walking at zero energy cost is possible when the suggested style of walking is adopted. In this commentary, we argue that these claims violate the basic laws of thermodynamics, and are based on erroneous application of the basic laws of classical mechanics.
Observation-based correction of dynamical models using thermostats
Authors: Myerscough Keith W. , Frank Jason , Leimkuhler Benedict
Published: January 2017

Models used in simulation may give accurate short-term trajectories but distort long-term (statistical) properties. In this work, we augment a given approximate model with a control law (a ‘thermostat’) that gently perturbs the dynamical system to target a thermodynamic state consistent with a set of prescribed (possibly evolving) observations. As proof of concept, we provide an example involving a point vortex fluid model on the sphere, for which we show convergence of equilibrium quantities (in the stationary case) and the ability of the thermostat to dynamically track a transient state.
Topological origin and not purely antisymmetric wave functions of many-body states in the lowest Landau level
Authors: Łydżba P. , Jacak J.
Published: January 2017

In this paper, we recall the topological approach to quantum Hall effects. We note that, in the presence of a magnetic field, trajectories representing elements of the system’s braid group are of cyclotron orbit type. In two-dimensional spaces, this leads to the restriction of the full braid group,
π
1
(
Ω
)—loopless generators (exchanges of
M

N

coordinates or classical particles) are unenforceable. As a result, the identification of a possible Hall-like state comes down to the identification of a possible subgroup of
π
1
(
Ω
). The latter follows from the connection between the one-dimensional unitary representation of the system’s braid group and particle statistics (unavoidable for any correlated state). In this work, we implement the topological approach to derive the lowest Landau-level pyramid of fillings. We point out that it contains all mysterious odd-denominator filling factors—like

4
11

,

4
13

or

6
17

—not trivial to explain within the standard picture. We also introduce, explicitly, cyclotron subgroup generators for all derived fractions. Preliminary results on wave functions, supported by several Monte Carlo calculations, are presented. It is worth emphasizing that not all proposed many-body functions are purely antisymmetric—they, however, transform in agreement with the scalar representations of the system’s braid group. The latter is enforced by standard quantization methods.
Diets derived from maize monoculture cause maternal infanticides in the endangered European hamster due to a vitamin B3 deficiency
Authors: Tissier Mathilde L. , Handrich Yves , Dallongeville Odeline , Robin Jean-Patrice , Habold Caroline
Published: January 2017

From 1735 to 1940, maize-based diets led to the death of hundreds of thousands of people from pellagra, a complex disease caused by tryptophan and vitamin B3 deficiencies. The current cereal monoculture trend restricts farmland animals to similarly monotonous diets. However, few studies have distinguished the effects of crop nutritional properties on the reproduction of these species from those of other detrimental factors such as pesticide toxicity or agricultural ploughing. This study shows that maize-based diets cause high rates of maternal infanticides in the European hamster, a farmland species on the verge of extinction in Western Europe. Vitamin B3 supplementation is shown to effectively restore reproductive success in maize-fed females. This study pinpoints how nutritional deficiencies caused by maize monoculture could affect farmland animal reproduction and hence their fitness.
Lowland biotic attrition revisited: body size and variation among climate change ‘winners’ and ‘losers’
Authors: Brodie Jedediah F. , Strimas-Mackey Matthew , Mohd-Azlan Jayasilan , Granados Alys , Bernard Henry , Giordano Anthony J. , Helmy Olga E.
Published: January 2017

The responses of lowland tropical communities to climate change will critically influence global biodiversity but remain poorly understood. If species in these systems are unable to tolerate warming, the communities—currently the most diverse on Earth—may become depauperate (‘biotic attrition’). In response to temperature changes, animals can adjust their distribution in space or their activity in time, but these two components of the niche are seldom considered together. We assessed the spatio-temporal niches of rainforest mammal species in Borneo across gradients in elevation and temperature. Most species are not predicted to experience changes in spatio-temporal niche availability, even under pessimistic warming scenarios. Responses to temperature are not predictable by phylogeny but do appear to be trait-based, being much more variable in smaller-bodied taxa. General circulation models and weather station data suggest unprecedentedly high midday temperatures later in the century; predicted responses to this warming among small-bodied species range from 9% losses to 6% gains in spatio-temporal niche availability, while larger species have close to 0% predicted change. Body mass may therefore be a key ecological trait influencing the identity of climate change winners and losers. Mammal species composition will probably change in some areas as temperatures rise, but full-scale biotic attrition this century appears unlikely.
Conditional fetal and infant killing by male baboons
Authors: Zipple Matthew N. , Grady Jackson H. , Gordon Jacob B. , Chow Lydia D. , Archie Elizabeth A. , Altmann Jeanne , Alberts Susan C.
Published: January 2017

Sexually selected feticide—the death of infants
in utero
as a result of male behaviour—has only rarely been described or analysed, although it is presumed to be favoured by the same selective pressures that favour sexually selected infanticide. To test this hypothesis, we measured the frequency of feticide and infanticide by male baboons of the Amboseli basin in Kenya, and examined which characteristics of a male and his environment made him more likely to commit feticide and/or infanticide. We found a dramatic increase in fetal and infant death rates, but no increase in death rates of 1- to 2-year-old individuals, following the immigration of males who stood to benefit from feticide and infanticide. Specifically, fetal and infant death rates were highest following immigrations in which: (i) the immigrant male rapidly attained high rank, (ii) that male remained consistently resident in the group for at least three months, (iii) food availability and social group range overlap was relatively low and (iv) relatively many pregnant females and/or dependent infants were present. Together, these results provide strong evidence for the existence of both sexually selected feticide and infanticide in our population, and they indicate that feticide and infanticide are conditional male behavioural strategies employed under particular circumstances.
Spatial point pattern analysis of prehospital naloxone administrations
Authors: Ryan Christopher
Published: January 2017

Objectives

The increasing problem in the United States with opioid dependence and overdose, often fatal, is well-recognized. As naloxone has only one clinical use—the treatment of opioid overdose—its administration by EMS personnel can serve as a surveillance indicator for opioid overdose. This study uses specific locations of EMS calls, and methods of point pattern analysis, to detect overall spatial clustering among EMS naloxone administrations compared to EMS calls in general.

Study Design

A cross-sectional study of incident locations of EMS responses in a three-county EMS region in the United States.

Methods

Repeated random samples from the spatial distribution of all EMS calls were used, in a Monte Carlo simulation, to represent the background inhomogeneity of the population. Observed F, G, and inhomogeneous K and L functions from the spatial distribution of naloxone-involved calls were compared to their null sampling distributions obtained from the Monte Carlo simulation.

Results

Cases of naloxone administration demonstrated spatial clustering in the range of 0 to 5000 meters, and particularly around 2500 meters, beyond what could be attributable to the spatial heterogeneity of all EMS calls.

Conclusions

Efforts to understand the fundamental nature of opioid overdose as a spatial point process could yield innovative public health interventions to control the epidemic.
Early transcriptome analysis of the brown streak virus–cassava pathosystem provides molecular insights into virus susceptibility and resistance
Authors: Anjanappa Ravi B. , Mehta Devang , Okoniewski Michal J. , Szabelska Alicja , Gruissem Wilhelm , Vanderschuren Hervé
Published: January 2017

Cassava brown streak viruses (CBSVs) are responsible for significant cassava yield losses in eastern sub–Saharan Africa. In the present work, we inoculated CBSV–susceptible and –resistant cassava varieties with a mixed infection of CBSVs using top-cleft grafting. Virus titres in grafted scions were monitored in a time course experiment in both varieties. We performed RNA-seq of the two cassava varieties at the earliest time-point of full infection in the susceptible scions. Genes encoding proteins in RNA silencing and salicylic acid pathways were regulated in the susceptible cassava variety but transcriptional changes were limited in the resistant variety. After infection, genes related to callose deposition at plasmodesmata were regulated and callose deposition was significantly reduced in the susceptible cassava variety. We also show that β–1,3–glucanase enzymatic activity is differentially regulated in the susceptible and resistant varieties. The differences in transcriptional responses to CBSV infection indicate that resistance involves callose deposition at plasmodesmata but does not trigger typical anti-viral defence responses. A meta-analysis of the current RNA-seq dataset and selected, previously reported, host–potyvirus and virus-cassava RNA-seq datasets revealed comparable host responses across pathosystems only at similar time points after infection or infection of a common host.

HIGHLIGHT

Our results suggest that resistance to CBSV in cassava involves callose deposition at the plasmodesmata and our meta-analysis of multiple virus-crop RNA-seq studies suggests that conserved responses across different host-virus systems are limited and depend greatly on time after infection.
Untangling intelligence, psychopathy, antisocial personality disorder, & conduct problems: A meta-analytic review
Authors: de Ribera Olga Sánchez , Kavish Nicholas , Katz Ian M. , Boutwell Brian B.
Published: January 2017

Substantial research has investigated the association between intelligence and psychopathic traits. The findings to date have been inconsistent and have not always considered the multi-dimensional nature of psychopathic traits. Moreover, there has been a tendency to confuse psychopathy with other closely related, clinically significant disorders. The current study represents a meta-analysis conducted to evaluate the direction and magnitude of the association of intelligence with global psychopathy, as well as its factors and facets, and related disorders (Antisocial Personality Disorder, Conduct Disorder, and Oppositional Defiant Disorder). Our analyses revealed a small, significant, negative relationship between intelligence and total psychopathy (r= -.07,p= .001). Analysis of factors and facets found differential associations, including both significant positive (e.g., interpersonal facet) and negative (e.g., affective facet) associations, further affirming that psychopathy is a multi-dimensional construct. Additionally, intelligence was negatively associated with Antisocial Personality Disorder (r= -.13,p= .001) and Conduct Disorder (r= -.11,p= .001), but positively with Oppositional Defiant Disorder (r= .06,p= .001). There was significant heterogeneity across studies for most effects, but the results of moderator analyses were inconsistent. Finally, bias analyses did not find significant evidence for publication bias or outsized effects of outliers.
Internal modifications in the CENP-A nucleosome modulate centromeric dynamics
Authors: Bui Minh , Pitman Mary , Nuccio Arthur , Roque Serene , Donlin-Asp Paul Gregory , Nita-Lazar Aleksandra , Papoian Garegin A. , Dalal Yamini
Published: January 2017

Post-translational modifications (PTMs) of core histones have studied for over 2 decades, and are correlated with changes in transcriptional status, chromatin fiber folding, and nucleosome dynamics. However, within the centromere-specific histone H3 variant CENP-A, few modifications have been reported, and their functions remain largely unexplored. In this multidisciplinary report, we utilizein silicocomputational andin vivoapproaches to dissect lysine 124 of human CENP-A, which was previously reported to be acetylated in advance of replication. Computational modeling demonstrates that acetylation of K124 causes tightening of the histone core, and hinders accessibility to its C-terminus, which in turn diminishes CENP-C binding. Additionally, CENP-A K124ac/H4 K79ac containing nucleosomes are prone to DNA sliding.In vivoexperiments using an acetyl or unacetylatable mimic (CENP-A K124Q and K124A respectively) reveal alterations in CENP-C levels, and a modest increase in mitotic errors. Furthermore, mutation of K124 results in alterations in centromeric replication timing, with the permanently acetylated form replicating centromeres early, and the unacetylable form replicating centromeres late. Purification of native CENP-A proteins followed by mass spectrometry analysis reveal that while CENP-A K124 is acetylated at G1/S, it switches to monomethylation during early and mid-S phase. Finally, we provide evidence that the HAT p300 is involved in this cycle. Taken together, our data suggest that cyclical modifications within the CENP-A nucleosome can influence the binding of key kinetochore proteins, the integrity of mitosis and centromeric replication. These data support the emerging paradigm that core modifications in histone variant nucleosomes transduce defined changes to key biological processes.
Evolutionary capacitance emerges spontaneously during adaptation to environmental changes
Authors: Nelson Paul G , Masel Joanna
Published: January 2017

All biological populations are to a greater or lesser degree evolvable, but the forces that shape evolvability, especially the evolution of evolvability as an adaptive response to a changing environment, have been a source of controversy. One source of enhanced evolvability is the benign status of “cryptic sequences” typically expressed at low levels due to molecular errors, but with the potential to be expressed more fully following mutational co-option. A genome enriched for benign cryptic sequences has a more benign mutational neighborhood, via the possibility of co-option, and thus enhanced evolvability. Whether selection for evolvability itself can be the cause of a more benign mutational neighborhood remains an open question. Here, we show that environmental change can cause the evolution of increased evolvability, despite our use of a strong-selection weak mutation regime that precludes, by design, the adaptive evolution of evolvability. Instead, enhanced evolvability arises as a byproduct of environmental change via a novel mechanism that we call “emergent evolutionary capacitance”. When the environment changes, increased molecular error rates evolve as a strategy to rapidly change phenotypes, with the side effect of purging deleterious cryptic sequences and enhancing the mutational neighborhood for future adaptation. The behavior is strikingly similar to that seen in a model system for capacitance, the yeast prion [PSI+].
When eye movements express memory for old and new scenes in the absence of awareness and independent of hippocampus
Authors: Smith Christine N. , Squire Larry R.
Published: January 2017

Eye movements can reflect memory. For example, participants make fewer fixations and sample fewer regions when viewing old versus new scenes (the repetition effect). It is unclear whether the repetition effect requires that participants have knowledge (awareness) of the old–new status of the scenes or if it can occur independent of knowledge about old–new status. It is also unclear whether the repetition effect is hippocampus-dependent or hippocampus-independent. A complication is that testing conscious memory for the scenes might interfere with the expression of unconscious (unaware), experience-dependent eye movements. In experiment 1, 75 volunteers freely viewed old and new scenes without knowledge that memory for the scenes would later be tested. Participants then made memory judgments and confidence judgments for each scene during a surprise recognition memory test. Participants exhibited the repetition effect regardless of the accuracy or confidence associated with their memory judgments (i.e., the repetition effect was independent of their awareness of the old–new status of each scene). In experiment 2, five memory-impaired patients with medial temporal lobe damage and six controls also viewed old and new scenes without expectation of memory testing. Both groups exhibited the repetition effect, even though the patients were impaired at recognizing which scenes were old and which were new. Thus, when participants viewed scenes without expectation of memory testing, eye movements associated with old and new scenes reflected unconscious, hippocampus-independent memory. These findings are consistent with the formulation that, when memory is expressed independent of awareness, memory is hippocampus-independent.
BDNF regains function in hippocampal long-term potentiation deficits caused by diencephalic damage
Authors: Vedder Lindsey C. , Savage Lisa M.
Published: January 2017

Thiamine deficiency (TD), commonly associated with chronic alcoholism, leads to diencephalic damage, hippocampal dysfunction, and spatial learning and memory deficits. We show a decrease in the magnitude of long-term potentiation (LTP) and paired-pulse facilitation (PPF) at CA3–CA1 synapses, independent of sex, following diencephalic damage induced by TD in rats. Thus, despite a lack of extensive hippocampal cell loss, diencephalic brain damage down-regulates plastic processes within the hippocampus, likely contributing to impaired hippocampal-dependent behaviors. However, both measures of hippocampal plasticity (LTP, PPF) were restored with brain-derived neurotrophic factor (BDNF), revealing an avenue for neural and behavioral recovery following diencephalic damage.
Corporate social responsibility and firms’ cost of equity: how does culture matter?
Authors: Matthiesen Marie-Louise , Salzmann Astrid Juliane
Published: January 2017

Purpose

The purpose of this paper is to examine the relationship between corporate social responsibility (CSR) and cost of equity in an international context assessing the moderating effect of culture on the relation between CSR and the cost of equity.

Design/methodology/approach

The authors use an international sample of 42 countries, and company-level data from 2002 to 2013, to address cross-country variations in the effects of CSR on cost of equity in different cultural contexts.

Findings

The authors first substantiate previous research and show that the more a company is engaged in CSR, the lower its cost of equity. The authors then find that the relationship between CSR and cost of equity is stronger in countries with lower levels of assertiveness and higher levels of humane orientation and institutional collectivism.

Practical implications

The study advances understanding of how national culture promotes socially and environmentally responsible behavior. The implementation of CSR strategies depends on cultural norms, so companies need to be sensitive to local demands and adjust their CSR approaches accordingly.

Originality/value

The paper highlights the need to study how culture influences the relationship between CSR and cost of equity.