bluuebunny/crossref_metadata_2025 huggingface dataset:
The evolution of highly variable immunity genes across a passerine bird radiation
Authors: O'Connor E. A. , Strandh M. , Hasselquist D. , Nilsson J.‐Å. , Westerdahl H.
Published: January 2016

To survive, individuals must be able to recognize and eliminate pathogens. The genes of the major histocompatibility complex (MHC) play an essential role in this process in vertebrates as their diversity affects the repertoire of pathogens that can be recognized by the immune system. Emerging evidence suggests that birds within the parvorder Passerida possess an exceptionally high number of MHC genes. However, this has yet to be directly investigated using a consistent framework, and the question of how this MHC diversity has evolved has not been addressed. We used next‐generation sequencing to investigate how MHC class I gene copy number and sequence diversity varies across the Passerida radiation using twelve species chosen to represent the phylogenetic range of this group. Additionally, we performed phylogenetic analyses on this data to identify, for the first time, the evolutionary model that best describes how MHC class I gene diversity has evolved within Passerida. We found evidence of multiple MHC class I genes in every family tested, with an extremely broad range in gene copy number across Passerida. There was a strong phylogenetic signal in MHC gene copy number and diversity, and these traits appear to have evolved through a process of Brownian motion in the species studied, that is following the pattern of genetic drift or fluctuating selection, as opposed to towards a single optimal value or through evolutionary ‘bursts’. By characterizing MHC class I gene diversity across Passerida in a systematic framework, this study provides a first step towards understanding this huge variation.
Patterns of cryptic host specificity in duck lice based on molecular data
Authors: ESCALANTE G. C. , SWEET A. D. , MCCRACKEN K. G. , GUSTAFSSON D. R. , WILSON R. E. , JOHNSON K. P.
Published: January 2016

Documenting patterns of host specificity in parasites relies on the adequate definition of parasite species. In many cases, parasites have simplified morphology, making species delimitation based on traditional morphological characters difficult. Molecular data can help in assessing whether widespread parasites harbour cryptic species and, alternatively, in guiding further taxonomic revision in cases in which there is morphological variation. The duck louse genus Anaticola (Phthiraptera: Philopteridae), based on current taxonomy, contains both host‐specific and widespread species. Mitochondrial and nuclear DNA sequences of samples from this genus were used to document patterns of host specificity. The comparison of these patterns with morphological variations in Anaticola revealed a general correspondence between the groups identified by DNA sequences and morphology, respectively. These results suggest that a more thorough taxonomic review of this genus is needed. In general, the groups identified on the basis of molecular data were associated with particular groups of waterfowl (e.g. dabbling ducks, sea ducks, geese) or specific biogeographic regions (e.g. North America, South America, Australia, Eurasia).
Genome evolution of ferns: evidence for relative stasis of genome size across the fern phylogeny
Authors: Clark James , Hidalgo Oriane , Pellicer Jaume , Liu Hongmei , Marquardt Jeannine , Robert Yannis , Christenhusz Maarten , Zhang Shouzhou , Gibby Mary , Leitch Ilia J. , Schneider Harald
Published: January 2016

The genome evolution of ferns has been considered to be relatively static compared with angiosperms. In this study, we analyse genome size data and chromosome numbers in a phylogenetic framework to explore three hypotheses: the correlation of genome size and chromosome number, the origin of modern ferns from ancestors with high chromosome numbers, and the occurrence of several whole‐genome duplications during the evolution of ferns.

To achieve this, we generated new genome size data, increasing the percentage of fern species with genome sizes estimated to 2.8% of extant diversity, and ensuring a comprehensive phylogenetic coverage including at least three species from each fern order.

Genome size was correlated with chromosome number across all ferns despite some substantial variation in both traits. We observed a trend towards conservation of the amount of DNA per chromosome, although Osmundaceae and Psilotaceae have substantially larger chromosomes. Reconstruction of the ancestral genome traits suggested that the earliest ferns were already characterized by possessing high chromosome numbers and that the earliest divergences in ferns were correlated with substantial karyological changes.

Evidence for repeated whole‐genome duplications was found across the phylogeny. Fern genomes tend to evolve slowly, albeit genome rearrangements occur in some clades.
Successful ageing in lesbian, gay and bisexual older people: a concept analysis
Authors: Caceres Billy A. , Frank Mayu O.
Published: January 2016

Aims and objectives

The aim of this study was to report on an analysis of the concept of successful ageing in lesbian, gay and bisexual older people.

Background

Research indicates that lesbian, gay and bisexual older people experience significant health disparities. Yet there is a lack of understanding on what factors contribute to successful ageing in this population. Nursing has lagged behind other disciplines in investigating the health of lesbian, gay and bisexual older people.

Design

A concept analysis using Rodgers' evolutionary method.

Data sources

Twenty studies were retrieved by searching PubMed, CINAHL, PsycInfo, EMBASE, Cochrane Library and Scopus for English‐language peer‐reviewed studies published from January 2004 to March 2014.

Methods

The antecedents, attributes and consequences of the concept were identified through the Rodgers' method of concept analysis.

Results

Attributes included support from families of origin and/or families of choice, access to lesbian, gay, and bisexual‐friendly services and crisis competence. Self‐realisation of lesbian, gay and bisexual identity (coming out to oneself) and age >50 were identified as antecedents. Three consequences of successful ageing in lesbian, gay and bisexual older people were social engagement, optimism and resilience.

Conclusion

Successful ageing in lesbian, gay and bisexual older people is defined as a subjective and multifactorial concept that is characterised by support from families of origin/families of choice, access to lesbian, gay, and bisexual‐friendly services and the development of crisis competence skills which impact the ageing experience of LGB individuals.

Implications for practice

Successful ageing models can provide a roadmap for developing culturally competent interventions to address key healthcare issues present in this population. The nursing profession's multidisciplinary knowledge and competence in providing health promotion makes nurses well positioned to take a leading role in reducing disparities of lesbian, gay and bisexual older people.
Six minute walk test versus incremental shuttle walk test in cystic fibrosis
Authors: Saglam Melda , Vardar‐Yagli Naciye , Savci Sema , Inal‐Ince Deniz , Aribas Zeynep , Bosnak‐Guclu Meral , Arikan Hulya , Calik‐Kutukcu Ebru , Gunes‐Yalcin Ebru
Published: January 2016

Background

Although both self‐paced and externally paced field tests are widely used in cystic fibrosis (CF), it is still unclear whether they induce clinically relevant and similar cardiorespiratory responses. The aim of this study was therefore to compare the incremental shuttle walk test (ISWT) and 6 min walk test (6MWT), and to determine the factors influencing exercise capacity in CF.

Methods

Fifty clinically stable CF patients were included in the study. Pulmonary function, peripheral and respiratory muscle strength were assessed, anthropometric measurements were recorded, and 6MWT and ISWT carried out.

Results

The CF patients covered significantly more distance in the ISWT than 6MWT (P < 0.001). Heart rate response and dyspnea score at the end of the tests and during the recovery phase were significantly higher in the ISWT compared with the 6MWT (P < 0.05). The 6MWT and ISWT had similar moderate–strong correlations with age, height, weight, pulmonary function, respiratory and peripheral muscle strength (P < 0.05). Forty‐nine percent of the variance in 6MWT distance was explained by age and forced expiratory volume in 1 s (FEV1; R2 = 0.49, F(2–48) = 22.033, P < 0.001). The variables contributing to ISWT distance were FEV1, inspiratory muscle strength, and body mass index (R2 = 0.596, F(3–44) = 20.176, P < 0.001).

Conclusions

The ISWT is a better reflection of exercise tolerance in CF than 6MWT. ISWT is a preferable alternative assessment of exercise tolerance in terms of cardiorespiratory response.
Cross‐protective efficacy from a immunogen firstly identified in Leishmania infantum against tegumentary leishmaniasis
Authors: Martins V. T. , Lage D. P. , Duarte M. C. , Costa L. E. , Chávez‐Fumagalli M. A. , Roatt B. M. , Menezes‐Souza D. , Tavares C. A. P. , Coelho E. A. F.
Published: January 2016

Experimental vaccine candidates have been evaluated to prevent leishmaniasis, but no commercial vaccine has been proved to be effective against more than one parasite species. LiHyT is a Leishmania‐specific protein that was firstly identified as protective against Leishmania infantum. In this study, LiHyT was evaluated as a vaccine to against two Leishmania species causing tegumentary leishmaniasis (TL): Leishmania major and Leishmania braziliensis. BALB/c mice were immunized with rLiHyT plus saponin and lately challenged with promastigotes of the two parasite species. The immune response generated was evaluated before and 10 weeks after infection, as well as the parasite burden at this time after infection. The vaccination induced a Th1 response, which was characterized by the production of IFN‐γ, IL‐12 and GM‐CSF, as well as by high levels of IgG2a antibodies, after in vitro stimulation using both the protein and parasite extracts. After challenge, vaccinated mice showed significant reductions in their infected footpads, as well as in the parasite burden in the tissue and organs evaluated, when compared to the control groups. The anti‐Leishmania Th1 response was maintained after infection, being the IFN‐γ production based mainly on CD4+ T cells. We described one conserved Leishmania‐specific protein that could compose a pan‐Leishmania vaccine.
Explaining Normative Versus Nonnormative Action: The Role of Implicit Theories
Authors: Shuman Eric , Cohen‐Chen Smadar , Hirsch‐Hoefler Sivan , Halperin Eran
Published: January 2016

The current research investigates what motivates people to engage in normative versus nonnormative action. Prior research has shown that different emotions lead to different types of action. We argue that these differing emotions are determined by a more basic characteristic, namely, implicit theories about whether groups and the world in general can change. We hypothesized that incremental theories (beliefs that groups/the world can change) would predict normative action, and entity theories (beliefs that groups/the world cannot change) as well as group identification would predict nonnormative action. We conducted a pilot in the context of protests against a government plan to relocate Bedouin villages in Israel and a main study during the Israeli social protests of the middle class. Results revealed three distinct pathways to collective action. First, incremental theories about the world predicted hope, which predicted normative action. Second, incremental theories about groups and group identification predicted anger, which also predicted normative collective action. Lastly, entity theories about groups predicted nonnormative collective action through hatred, but only for participants who were highly identified with the group. In sum, people who believed in the possibility of change supported normative action, whereas those who believed change was not possible supported nonnormative action.
Necker cube copying may not be appropriate as an examination of dementia: reanalysis from the Tajiri Project
Authors: Oonuma Jiro , Kasai Mari , Meguro Mitsue , Akanuma Kyoko , Yamaguchi Satoshi , Meguro Kenichi
Published: January 2016

Background

The Necker cube is usually used for evaluating the visuoconstructional ability of patients with mild cognitive impairment (MCI) and dementia. However, the Necker cube is often considered a drawing with a visual illusionary perspective. The purpose of this study was to investigate whether Necker cube copying could detect participants with MCI due to dementia.

Methods

We retrospectively analyzed the database of the 1998 prevalence study that was part of the Tajiri Project (n = 599). Pencil drawings of the Necker cube on A4‐sized white paper by non‐demented people (Clinical Dementia Rating (CDR) 0 and 0.5, n = 256) were classified into two patterns: non‐three‐dimension (3‐D) and 3‐D. Two neuropsychologists assessed Necker cube copying according to the criteria of the classification. After the classification, the database of the 2003 incidence study was used according to the subjects’ conversion to dementia.

Results

In the prevalence study, among those who made a non‐3‐D drawing of the Necker cube, there were significantly fewer people in the CDR 0 group than in the CDR 0.5 and CDR 1+ groups; similarly, there were significantly fewer people in the CDR 0.5 group than in the CDR 1 + group (χ2 = 32.6, P < 0.001; post‐hoc tests using χ2 tests, CDR 0 > CDR 0.5 > CDR 1+, P < 0.001). In the incidence study, among those who made a non‐3‐D drawing of the Necker cube, there were significantly fewer people in the non‐converter group than in the converter group (χ2 = 19.9, P < 0.001). However, there was no significant difference between the non‐converter group (n = 21) and the converter group (n = 21) when age, sex, educational levels, and Mini‐Mental State Examination scores were controlled (χ2 = 0.0, P = 1.000).

Conclusions

Our results suggested that Necker cube copying may evaluate visual illusion as well as visuoconstructional ability. The Necker cube may not be an appropriate test to detect participants with MCI due to dementia.
Heterogeneity of patients receiving artificial nutrition in Japanese psychiatric hospitals: a cross‐sectional study
Authors: Hirao Akihiko , Abe Keiichi , Takayama Keiko , Kondo Keiko , Yokota Osamu , Sato Yoshiki , Norikiyo Taizo , Sato Soichiro , Nakashima Tadao , Hayashi Hideki , Nakata Kenji , Asaba Hiroyuki , Tanaka Kazuyoshi , Tanaka Ritsuho , Morisada Yumi , Itakura Hisakazu , Honda Hajime , Okabe Nobuyuki , Oshima Etsuko , Terada Seishi ,   Middle Western Japan‐Dementia Study (mid‐Dem study)
Published: January 2016

Aim

Artificial nutrition, including tube feeding, continues to be given to dementia patients in numerous geriatric facilities in Japan. However, the clinical characteristics of patients receiving artificial nutrition have not been fully investigated. Therefore, we tried to evaluate the clinical features of those patients in this study.

Methods

Various clinical characteristics of all inpatients at 18 of 20 psychiatric hospitals in Okayama Prefecture, Japan, with a percutaneous endoscopic gastrostomy tube, nasogastric tube, or total parenteral nutrition were evaluated.

Results

Two hundred twenty‐one patients (5.4% of all inpatients) had been receiving artificial nutrition for more than 1 month, and 187 (130 women, 57 men; 84.6% of 221 patients) were fully investigated. The mean age was 78.3 years old, and the mean duration of artificial nutrition was 29.8 months. Eighty‐four patients (44.7% of 187 patients) were receiving artificial nutrition for more than 2 years. Patients with Alzheimer's disease (n = 78) formed the biggest group, schizophrenia (n = 37) the second, and vascular dementia (n = 26) the third.

Conclusion

About one‐fifth of the subjects receiving artificial nutrition were in a vegetative state. More than a few patients with mental disorders, including schizophrenia, also received long‐term artificial nutrition. We should pay more attention to chronic dysphasia syndrome in mental disorders.
Health‐related quality of life as a predictor of recurrent falling in Parkinson's disease: 1‐year follow‐up study
Authors: Gazibara Tatjana , Kisic‐Tepavcevic Darija , Svetel Marina , Tomic Aleksandra , Stankovic Iva , Kostic Vladimir S. , Pekmezovic Tatjana
Published: January 2016

Objective

The aim of this study was to assess whether various domains related to health‐related quality of life could be predictive of recurrent falls among persons with Parkinson's disease (PD) during a 1‐year follow‐up study.

Methods

A total of 120 consecutive persons with PD who had denied falling in past 6 months were recruited at regular check‐ups at the Department of Movement Disorders, Neurology Clinic, Clinical Center of Serbia in Belgrade, from 15 August 2011 to 15 December 2012. At baseline, study participants were clinically assessed. Health‐related quality of life was evaluated with the generic 36‐item Short Form Health Survey. Participants were prospectively followed for 1 year, and occurrence of falls was registered.

Results

The median age of subjects was 60.0 years, with a median disease duration of 4.0 years. Of 120 persons with PD, 42 (35%) experienced falls during the 12‐month study period, including 23 (19.2%) who fell repeatedly. After adjustment for gender, age, PD duration, levodopa dosage, Hoehn and Yahr stage, Unified Parkinson's Disease Rating Scale I–IV, Hamilton Depression Rating Scale, and Hamilton Anxiety Rating Scales, we identified the 36‐item Short Form Health Survey domains of role physical (P = 0.033) and vitality (P = 0.019) as being associated with recurrent falls of persons with PD within the 1‐year follow‐up period.

Conclusion

Baseline 36‐item Short Form Health Survey scores regarding both the physical and mental components of overall health may be related to recurrent falling among persons with PD. These HRQoL domains could be considered as potential markers for persons with PD who are prone to recurrent falls.
Exploration of the importance of geriatric frailty on health‐related quality of life
Authors: Lee I‐Chen , Chiu Yu‐Hsien , Lee Chun‐Ying
Published: January 2016

Aim

The ageing of the population is a demographic trend globally. Promoting the health of elderly persons has become a crucial priority. However, knowledge about the relationship between frailty and quality of life (QoL) remains limited. This research aimed to investigate the association between elderly frailty and QoL, and to identify whether frailty or current health status more significantly affects the QoL of elderly persons.

Methods

This research began in 2012, and by the end of the study in April 2013, 375 samples had been collected. Structured questionnaires and the face‐to‐face questionnaire interviews were used. Multiple linear regression, t‐test, and one‐way anova were administered.

Results

Elderly individuals who were hospitalized performed worse in the physical health QoL domain, whereas those who regularly attended outpatient follow‐ups performed worse in the mental health QoL domain. QoL was only partially affected in both groups. All QoL domains were affected in elderly individuals with symptoms of frailty. Age, marital status, and financial status significantly affect health‐related QoL.

Conclusion

Geriatric frailty significantly affects general QoL. Early screening of frailty‐related conditions among the elderly can prompt early and proper intervention for this population.
Bayesian Two-Stage Dose Finding for Cytostatic Agents Via Model Adaptation
Authors: Xu Jiajing , Yin Guosheng , Ohlssen David , Bretz Frank
Published: January 2016

In phase I clinical trials with cytostatic agents, the typical objective is to identify the optimal biological dose, which should be tolerable as well as achieving the highest effectiveness. Towards this goal, we consider binary toxicity and efficacy end points simultaneously and develop a two-stage Bayesian adaptive design. Stage 1 searches for the maximum tolerated dose by using a beta–binomial model in conjunction with a probit model, for which decision making is based on the model that fits the toxicity data better. Stage 2 identifies the optimal biological dose while still controlling the level of toxicity. We enumerate all the possibilities that each of the admissible doses may deliver the highest effectiveness so that the dose–efficacy curve is allowed to be increasing, decreasing or concave. We conduct simulation studies to examine the ability of the proposed method to pinpoint both the maximum tolerated dose and the optimal biological dose and demonstrate the design’s satisfactory performance with the BKM120 and cetuximab phase I clinical trials.
Spatiotemporal Model Fusion: Multiscale Modelling of Civil Unrest
Authors: Hoegh Andrew , Ferreira Marco A. R. , Leman Scotland
Published: January 2016

Civil unrest is a complicated, multifaceted social phenomenon that is difficult to forecast. Relevant data for predicting future protests consist of a massive set of heterogeneous sources of data, primarily from social media. Using a modular approach to extract pertinent information from disparate sources of data, we develop a spatiotemporal multiscale framework to fuse predictions from algorithms mining social media. This novel multiscale spatiotemporal model is developed to satisfy four essential requirements: be scalable to handle massive spatiotemporal data sets, incorporate hierarchical predictions, accommodate predictions of differing quality and uncertainty, and be flexible, allowing revisions to existing algorithms and the addition of new algorithms. The paper details the challenges that are posed by these four requirements and outlines the benefits of our novel multiscale spatiotemporal model relative to existing methods. In particular, our multiscale approach coupled with an efficient sequential Monte Carlo framework enables scalable rapid computation of richly specified Bayesian hierarchical models for spatiotemporal data.
Update on the End‐Stage Renal Disease Quality Incentive Program
Authors: Wanchoo Rimda , Hazzan Azzour D. , Fishbane Steven
Published: January 2016

The End‐Stage Renal Disease Quality Incentive Program continues to evolve and expand. In this article, we will review the program's structure and critically assess the clinical metrics in place. In addition, we will discuss upcoming program changes to help prepare dialysis facilities and nephrologists to meet new proposed metrics.
A Patient‐Centered Approach to Hemodialysis Vascular Access in the Era of Fistula First
Authors: Kalloo Sean , Blake Peter G. , Wish Jay
Published: January 2016

The primary vascular access options for the hemodialysis population are arteriovenous fistulas (AVF), arteriovenous grafts, and cuffed central venous catheters (CVC). AVFs are associated with the most favorable outcomes with respect to complications, interventions required to maintain functionality and patency, and overall cost. These population‐based outcomes, in conjunction with the efforts of the Fistula First Breakthrough Initiative, have propelled the prevalence of AVFs in the US hemodialysis population. While this endeavor remains steadfast in assuring the continued dominance of this policy for AVF preference, it fails to take into account a subset of the dialysis population who will fail to see the benefits of an AVF. This subset of patients may include the elderly, those with poor vasculature anatomy, those with slowly progressive CKD who are more likely to die than progress to ESRD, and those with an overall poor long‐term prognosis and shortened life expectancy. Thus, in an effort to avoid numerous unnecessary surgical and interventional procedures with minimal to no gains in clinical outcomes, an individualized patient approach must be adopted. The Centers for Medicare and Medicaid Services–instituted quality incentive program is designed to reward high AVF prevalence while also penalizing high CVC prevalence. The current model is devoid of case‐based adjustment, thus penalties are disbursed to dialysis providers in accordance with a “one‐size‐fits‐all” fistula only approach. The most suitable access for a patient remains the one that takes into account the characteristics unique to the individual patient with a primary focus on patient comfort, satisfaction, quality of life, and clinical outcomes.
Family Mathematics Nights: An Opportunity to Improve Preservice Teachers' Understanding of Parents' Roles and Expectations
Authors: Bofferding Laura , Kastberg Signe , Hoffman Andrew
Published: January 2016

Providing preservice teachers with opportunities to engage with parents and begin to see them as collaborators in their children's education is a persistent challenge in mathematics methods courses and teacher preparation programs more broadly. We describe the use of family mathematics nights as a model for engaging parents and preservice teachers. These events helped preservice teachers feel more comfortable in working with parents, while also giving them a friendly space for learning more about parents, the ways they work with their children, and activities they do with their children. Incorporating surveys about parents' needs and suggestions for preservice teachers allowed us to use the results as a catalyst for fostering discussions around parent engagement later in the methods course.
Creating a Model of Acceptance: Preservice Teachers Interact With Non‐English‐Speaking Latino Parents Using Culturally Relevant Mathematics and Science Activities at Family Learning Events
Authors: Ramirez Olga , McCollough Cherie A. , Diaz Zulmaris
Published: January 2016

The following describes a culturally relevant mathematics and science content program implemented by preservice teachers (PSTs) at Family Math/Science Learning Events (FM/SLEs) conducted through two different university programs in south Texas. These experiences are required course activities designed to inform PSTs of the importance of interacting with Latino families' culture and language in after school settings. Data were collected from elementary PSTs attending FMLEs and include interactions recorded during the FMLE and interviews with Latino non‐English‐speaking parents after the event. Anecdotal data were also included from parents' interviews collected during culturally relevant Family Science Learning Events. Researchers investigated the following questions: (1) what did Latino parents and PSTs report learning from the FMLE and, (2) how do perceptions toward Latino parents change when PSTs are given the opportunity to interact with and interview Latino parents? Results show that PSTs perceptions of Latino parents can be changed through these events. Implications for teacher preparation programs include providing PSTs with opportunities for participation in FM/SLEs that incorporate planning and teaching culturally relevant math and science activities. The following model of acceptance requires PSTs to identify and reconstruct misconceptions and perceptions of parents, especially non‐English‐speaking Latino parents.
Taking Science Home: Connecting Schools and Families Through Science Activity Packs for Young Children
Authors: Reinhart Meredith , Bloomquist Debra , Strickler‐Eppard Lacey , Czerniak Charlene M. , Gilbert Amanda , Kaderavek Joan , Molitor Scott C.
Published: January 2016

A Framework forK‐12 Science Education indicates that introducing young children to scientific and engineering practices, core disciplinary ideas, and crosscutting concepts during the early years is essential for the development of conceptual understanding in science. Unfortunately, science is infrequently included in preschool and primary classrooms, and parents are sometimes uncomfortable engaging their children in science. This article describes the development and initial evaluation of “family science activity packs” as an intervention to fill this void. The study examined four research questions focused on families' use of the packs, parental questions, children's inquiry behaviors, and the nature of parent and children's reactions to the packs. Questionnaires sent to families regarding the packs and videos of families completing the activities were analyzed using descriptive statistics and qualitative methods. Findings suggest that take‐home activity packs have the potential to teach science in a motivating manner and spur further interest in science. However, parent questioning and wait‐time impacted the quality of students' responses. A discussion of how family science activities potentially result in high‐quality discourse is presented, and implications and suggestions for further research and pack development are reviewed.

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The CLAVATA signaling pathway mediating stem cell fate in shoot meristems requires Ca2+ as a secondary cytosolic messenger
Authors: Chou Hsuan , Zhu Yingfang , Ma Yi , Berkowitz Gerald A.
Published: January 2016

CLAVATA1 (CLV1) is a receptor protein expressed in the shoot apical meristem (SAM) that translates perception of a non‐cell‐autonomous CLAVATA3 (CLV3) peptide signal into altered stem cell fate. CLV3 reduces expression of WUSCHEL (WUS) and FANTASTIC FOUR 2 (FAF2) in the SAM. Expression of WUS and FAF2 leads to maintenance of undifferentiated stem cells in the SAM. CLV3 binding to CLV1 inhibits expression of these genes and controls stem cell fate in the SAM through an unidentified signaling pathway. Cytosolic Ca2+ elevations, cyclic nucleotide (cGMP)‐activated Ca2+ channels, and cGMP have been linked to signaling downstream of receptors similar to CLV1. Hence, we hypothesized that cytosolic Ca2+ elevation mediates the CLV3 ligand/CLV1 receptor signaling that controls meristem stem cell fate. CLV3 application to Arabidopsis seedlings results in elevation of cytosolic Ca2+ and cGMP. CLV3 control of WUS was prevented in a genotype lacking a functional cGMP‐activated Ca2+ channel. In wild‐type plants, CLV3 inhibition of WUS and FAF2 expression was impaired by treatment with either a Ca2+ channel blocker or a guanylyl cyclase inhibitor. When CLV3‐dependent repression of WUS is blocked, altered control of stem cell fate leads to an increase in SAM size; we observed a larger SAM size in seedlings treated with the Ca2+ channel blocker. These results suggest that the CLV3 ligand/CLV1 receptor system initiates a signaling cascade that elevates cytosolic Ca2+, and that this cytosolic secondary messenger is involved in the signal transduction cascade linking CLV3/CLV1 to control of gene expression and stem cell fate in the SAM.
Calnuc Function in Endosomal Sorting of Lysosomal Receptors
Authors: Larkin Heidi , Costantino Santiago , Seaman Matthew N. J. , Lavoie Christine
Published: January 2016

Calnuc is a ubiquitous Ca2+‐binding protein present on the trans‐Golgi network (TGN) and endosomes. However, the precise role of Calnuc in these organelles is poorly characterized. We previously highlighted the role of Calnuc in the transport of LRP9, a new member of a low‐density lipoprotein (LDL) receptor subfamily that cycles between the TGN and endosomes. The objective of this study was to explore the role of Calnuc in the endocytic sorting of mannose‐6‐phosphate receptor (MPR) and Sortilin, two well‐characterized lysosomal receptors that transit between the TGN and endosomes. Using biochemical and microscopy assays, we showed that Calnuc depletion [by small interfering RNA (siRNA)] causes the misdelivery to and degradation in lysosomes of cationic‐independent mannose‐6‐phosphate receptor (CI‐MPR) and Sortilin due to a defect in the endosomal recruitment of retromers, which are key components of the endosome‐to‐Golgi retrieval machinery. Indeed, we demonstrated that Calnuc depletion impairs the activation and membrane association of Rab7, a small G protein required for the endosomal recruitment of retromers. Overall, our data indicate a novel role for Calnuc in the endosome‐to‐TGN retrograde transport of lysosomal receptors through the regulation of Rab7 activity and the recruitment of retromers to endosomes.
Comparison of 2 electrophoretic methods and a wet‐chemistry method in the analysis of canine lipoproteins
Authors: Behling‐Kelly Erica
Published: January 2016

Background

The evaluation of lipoprotein metabolism in small animal medicine is hindered by the lack of a gold standard method and paucity of validation data to support the use of automated chemistry methods available in the typical veterinary clinical pathology laboratory. The physical and chemical differences between canine and human lipoproteins draw into question whether the transference of some of these human methodologies for the study of canine lipoproteins is valid. Validation of methodology must go hand in hand with exploratory studies into the diagnostic or prognostic utility of measuring specific lipoproteins in veterinary medicine.

Objective

The goal of this study was to compare one commercially available wet‐chemistry method to manual and automated lipoprotein electrophoresis in the analysis of canine lipoproteins.

Methods

Canine lipoproteins from 50 dogs were prospectively analyzed by 2 electrophoretic methods, one automated and one manual method, and one wet‐chemistry method.

Results

Electrophoretic methods identified a higher proportion of low‐density lipoproteins than the wet‐chemistry method. Automated electrophoresis occasionally failed to identify very low‐density lipoproteins.

Conclusions

Wet‐chemistry methods designed for evaluation of human lipoproteins are insensitive to canine low‐density lipoproteins and may not be applicable to the study of canine lipoproteins. Automated electrophoretic methods will likely require significant modifications if they are to be used in the analysis of canine lipoproteins. Studies aimed at determining the impact of a disease state on lipoproteins should thoroughly investigate the selected methodology prior to the onset of the study.
Retrospective evaluation of concurrent intra‐abdominal injuries in dogs with traumatic pelvic fractures: 83 cases (2008–2013)
Authors: Hoffberg Jamie E. , Koenigshof Amy M. , Guiot Laurent P.
Published: January 2016

Objective

To report the occurrence of intra‐abdominal injury (IA) in dogs with pelvic fractures due to blunt trauma, to evaluate for association between characterization of pelvic fractures and the presence of IA, and to evaluate for association between IA and other specific clinical conditions.

Design

Retrospective case series (2008–2013).

Setting

University teaching hospital.

Animals

Eighty‐three client‐owned dogs with pelvic fractures due to blunt trauma.

Interventions

None.

Measurements and Main Results

Pelvic injuries included pubic fractures (90.4%), ischial fractures (80.7%), sacroiliac luxations (57.8%), iliac fractures (43.4%), acetabular fractures (30.1%), and sacral fractures (13.3%). Thirty‐one dogs (37%) had IA, which included hemoabdomen (27 dogs), uroabdomen (3), and septic abdomen (3); 2 dogs had 2 types of IA. Dogs with sacral fractures were significantly more likely to have IA than dogs without sacral fractures (P = 0.0162). Characterization of pelvic fractures included the direction of compression, presence of a weight‐bearing bone fracture, and degree of pelvic narrowing, none of which had an association with IA (P > 0.05). Dogs were more likely to have IA if they had cardiac dysrhythmia (P = 0.0002) or hematuria (P = 0.0001), and were more likely to have a hemoabdomen if they had cardiac dysrhythmia (P = 0.0005). Dogs with hematochezia were more likely to have a septic abdomen (P = 0.0123). Dogs were more likely to receive a transfusion if they had AI (P = 0.033) or hemoabdomen specifically (P = 0.0033). Overall survival to discharge was 89%, which was significantly greater than survival in dogs with pelvic injury that also had septic abdomen (33%; P = 0.0299).

Conclusions

IA is common in dogs with pelvic fractures, especially those with sacral fractures. Pelvic fracture characterization had no bearing on the presence of IA.
Dynamic Balancing of Parallel Manipulators Through Reconfiguration
Authors: Zhang Dan , Wei Bin
Published: January 2016

When parallel manipulators move, due to the fact that the center of mass (CoM) of the system is not fixed and its angular momentum is not constant, vibration is usually produced in the system, which greatly affects the accuracy performance. Dynamic balance can be achieved by using counterweights and counter-rotations, but the whole system will become heavier and have more inertia. Here we try to achieve dynamic balance not by using counterweights or damping, but through designing naturally dynamic balanced mechanisms to achieve the goal. This can be done, for example, by the reconfiguration method that we proposed. After designing a dynamic balanced leg, legs are combined to synthesize parallel mechanisms. Finally spatial dynamic balanced grasper mechanism is proposed.
EEG Stochastic Nonlinear Oscillator Models for Alzheimer’s Disease
Authors: Ghorbanian Parham , Ramakrishnan Subramanian , Ashrafiuon Hashem
Published: January 2016

In this article, we derive unique stochastic nonlinear coupled oscillator models of EEG signals from an Alzheimer’s Disease (AD) study. EEG signals recorded during resting eyes-open (EO) and eyes-closed (EC) conditions in a pilot study with AD patients and age-matched healthy control subjects (CTL) are employed. An optimization scheme is then utilized to match the output of the stochastic Duffing - van der Pol double oscillator network with EEG signals recorded during each condition for AD and CTL subjects. The selected decision variable are the model parameters and noise intensity. While, the selected signal characteristics are power spectral densities in major brain frequency bands and Shannon and sample entropies to match the signal information content and complexity. It is shown that statistically significant unique models represent the EC and EO conditions for both CTL and AD subjects. Moreover, the inclusion of sample entropy in the optimization process significantly enhances the stochastic nonlinear oscillator model performance. The study suggests that EEG signals recorded under different brain states as well as those belonging to a brain disorder such as Alzheimer’s disease can be uniquely represented by stochastic nonlinear oscillators paving the way for identification of new discriminants.
Design and Analysis of a Scale-Sized Electromechanical Actuator for Unsteady Condition Monitoring Applications
Authors: Kolodziej Jason R. , Craig William S.
Published: January 2016

Growing interest in using Electromechanical Actuators to replace current hydraulic actuation methods on aircraft control surfaces has driven significant research in the area of prognostics and health management. Non-stationary speeds and loads in the course of controlling an aircraft surface make fault identification in EMAs difficult. This work presents a time-frequency analysis of EMA thrust bearing vibration signals using wavelet transforms. A lab sized EMA system is designed and fabricated to allow for quick and repeatable component replacement. Indentation faults from moderate and heavy loads are seeded in the thrust bearings and are then tested to generate data. An artificial neural network achieves 95% classification accuracy in a two class scenario using healthy and moderately spalled thrust bearings.
A Learning-Based Framework for Robot Peg-Hole-Insertion
Authors: Tang Te , Lin Hsien-Chung , Tomizuka Masayoshi
Published: January 2016

Peg-hole-insertion is a common operation in industry production, but autonomous execution by robots has been a big challenge for many years. Current robot programming for this kind of contact problem requires tremendous effort, which needs delicate trajectory and force tuning. However, human may accomplish this task with much less time and fewer trials. It will be a great benefit if robots can learn the human skill and apply it autonomously. This paper introduces a framework for teaching robot peg-hole-insertion from human demonstration. A Dimension Reduction and Recovery method is proposed to simplify control policy learning. The Gaussian Mixture Regression is utilized to imitate human skill and a Dual Stage Force Control strategy is designed for autonomous execution by robots. The effectiveness of the teaching framework is demonstrated by a series of experiments.
Continuous-Time Feedback Control With Finite-Time Boundedness and H∞ Performance Criteria
Authors: Hostettler Jacob D. , Wang Xin
Published: January 2016

For advanced control applications, research into the use of linear matrix inequalities has yielded a notable amount of work in the area of nonlinear systems. Linear Matrix Inequalities can be formed through the application of desired performance criteria to a general system. By proper selection of a Lyapunov energy function, sufficient conditions to satisfy the performance objectives can be realized. The performance criteria, typically chosen for the application, define the objectives associated with the control. This work presents a control method for discrete-time systems with finite-time boundedness and H∞ performance criteria. The design of the controller corresponds to a system existing with bounded model uncertainties, and in the presence of L2 type external disturbances. Through the use of a linear state feedback control, sufficient conditions which guarantee the finite-time stability and H∞ performance objectives are achieved via the solution of a Linear Matrix Inequality. MATLAB application and simulation is carried out using the field oriented control of a permanent magnet synchronous generator in order to effectively demonstrate the effectiveness of this control strategy in the wind energy conversion system application.
The Advantages of Velocity Control for Reactive Robot Motion
Authors: Zelenak Andy , Peterson Clinton , Thompson Jack , Pryor Mitch
Published: January 2016

At the hardware level, servo drives are traditionally controlled in the position or velocity domain. Frequently, roboticists do not recognize the significance of selecting one control domain over the other. This paper argues that velocity control is the clear choice for reactive trajectory modification and online motion planning. Velocity control provides smoother motion, is more suitable for low control frequencies, more robust to control signal variation, and it reduces collision forces more effectively. The primary advantage of position control is inherent safety with regards to signal delays. To support these points, this paper presents mathematical, graphical and experimental evidence. New experimental results explore the robustness of velocity control with regards to low-frequency control signals and signal delay. The experiment is based on a cooperative manipulation task performed with stiff industrial manipulators. Position and velocity control are also directly compared using a one-DOF linear actuator force control task using total work performed as a performance metric.
Road Roughness Preview With Drive History
Authors: Liu Nanjun , Alleyne Andrew , Elwart Shane , Pilutti Tom
Published: January 2016

This study has proposed a method of improving vehicle ride quality capitalizing on repetitive driving. When the vehicle is driving over the same road features repetitively, a drive-history map is created, and an optimal suspension profile is generated for that road feature. When it is detected that the vehicle is travelling over the same road feature again, the optimized suspension profile is applied to correct any disturbance preemptively to optimize passengers’ experiences. The algorithm is implemented on a full-car model using Carsim, and simulation results are obtained to identify any improvements.
A Discrete-Time Integral Sliding Model Predictive Control for Obstacle Avoidance of Ground Vehicles
Authors: Liao Yi-Wen , Hedrick J. Karl
Published: January 2016

In this paper, a robust control architecture is proposed for lane-keeping and obstacle avoidance of autonomous ground vehicles. A two-level hierarchical controller is used to separate the planning and tracking problems. At the higher-level, we solve a nonlinear model predictive control (MPC) problem with an oversimplified point-mass model. The desired trajectories are generated and fed into the lower-level controller, where a force-input nonlinear bicycle model is considered to set up the tracking control law. Moreover, at each time step, a linearized bicycle model is derived and implemented to reduce the real-time computational complexity. Based on the above profile, a discrete-time integral sliding MPC (DISMPC) technique is used to improve the system robustness. By introducing an additional sliding control term into the feedback control law, the system trajectories can be maintained within a quasi-sliding band. In this case, it becomes necessary to take into account the system dynamics induced by the sliding control. Namely, the state and the input constraints of the MPC problem at each level need to be tightened. This helps to guarantee the feasibility of the original constrained problem in the presence of disturbances. Simulations have been carried out to verify the effectiveness of the proposed controller. The results show that the controller is able to simultaneously achieve lane-keeping and obstacle avoidance with uncertain friction coefficients.
A Model Predictive Framework for Thermal Management of Aircraft
Authors: Deppen Timothy O. , Hey Joel E. , Alleyne Andrew G. , Fisher Timothy S.
Published: January 2016

The challenge of managing heat dissipation and enforcing operational constraints on temperature within a high-performance tactical aircraft is considered. For these systems, power density of the electrical equipment and the associated thermal loads are quickly outpacing the means of conventional thermal management systems (TMS) to provide on-demand cooling and in order to prevent thermal run away. The next generation of tactical aircraft is projected to include an order of magnitude greater thermal and electrical power magnitudes, and the time scale over which thermal loads will change is expected to shrink. To meet this rapidly evolving challenge, designing a TMS for the “worst case” scenario based on a steady-state thermal analysis will be infeasible. Rather, a holistic systems perspective is needed with new control methodologies that capture and even exploit the transient thermal behavior. To this end, a model predictive control strategy is presented that utilizes preview of upcoming loads and disturbances to prevent violation of temperature constraints. A simulation case study demonstrates that the predictive thermal controller can dramatically reduce constraint violations while reducing the work required by the TMS when compared to a cascaded PI feedback controller.
Characterization of Damping and Beating Effects Within the Aggregate Power Demand of Heterogeneous Thermostatically Controlled Loads
Authors: Docimo Donald J. , Fathy Hosam K.
Published: January 2016

This paper presents an analysis of the damping and beating effects within the aggregate power demand of heterogeneous thermostatically controlled loads (TCLs). Demand response using TCLs is an appealing method to enable higher levels of penetration of intermittent renewable resources into the electric grid. Previous literature covers the benefits of TCL population heterogeneity for control purposes, but the focus is solely on the damping observed in these systems. This work is, to the best of the authors’ knowledge, the first to characterize the combined damping and beating response of power demand versus the level of TCL population parameter heterogeneity. The forced aggregate dynamics of TCLs have been shown to be bilinear when set point temperature adjustment is used as a control input. This motivates the paper’s use of free response dynamics, which are linear, to characterize both the damping and beating phenomena. A stochastic parameter distribution is applied to the homogeneous power demand solution, furnishing an analytic expression for aggregate power demand. The resulting analysis shows that increasing parameter heterogeneity increases damping and shortens the beat period.