bluuebunny/crossref_metadata_2025 huggingface dataset:
Public Attitudes About Body-Worn Cameras in Police Work: A National Study of the Sources of Their Contextual Variability
Authors: Miethe Terance D. , Lieberman Joel D. , Heen Miliaikeala S. J. , Sousa William H.
Published: May 2019

Based on a large national sample of U.S. adults, the current study examines the nature and correlates of public support for body-worn cameras (BWCs) in various policing activities. Multivariate analyses were performed to assess the direct and moderating effects of individuals’ socioeconomic characteristics, general police attitudes and experiences, and specific beliefs about benefits of BWCs on the level of public support for this technology. Strong public support for BWC usage is found across different areas of police work. However, substantial contextual variability in this support is also evident when the analysis focused on the conjunctive influences of individuals’ level of confidence in social institutions, personal involvement in these institutions, and beliefs about police legitimacy and their effectiveness. These results are discussed in terms of their implications for future research on the sources of public receptivity, resistance, and change in these attitudes about BWCs over time.
Why Us?! How Members of Minority Groups React to Public Health Advertisements Featuring Their Own Group
Authors: El Hazzouri Mohammed , Hamilton Leah K.
Published: May 2019

This research investigates how members of minority groups respond to public health advertising that features models who belong to their own group. Results of three experiments show that ethnic minority individuals report lower intentions to take the advice solicited by widely distributed public health advertisements when the advertisements feature models who belong to their own ethnic group (as opposed to white models). This effect is driven by the fact that, for ethnic minorities, featuring one’s own ethnic group in public health advertising creates perceptions of being negatively stereotyped by the advertisers. This outcome is pronounced for those with average and high stigma consciousness. These effects were generalized in a fourth experiment in which participants with obesity reacted negatively to public health advertising featuring obese models. Public health advertising featuring minorities does not generate this backlash effect when the advertising appears in community-based publications mostly read by the featured group.
Positive Emotions During Infant Feeding and Breastfeeding Outcomes
Authors: Wouk Kathryn , Tucker Christine , Pence Brian W. , Meltzer-Brody Samantha , Zvara Bharathi , Grewen Karen , Stuebe Alison M.
Published: May 2019

Background:

Few studies have examined the role of maternal emotions in breastfeeding outcomes.

Research aim:

We aimed to determine the extent to which positive maternal emotions during human milk feeding at 2 months were associated with time to any and exclusive human milk feeding cessation and overall breastfeeding experience.

Methods:

A sample of 192 women intending to breastfeed for at least 2 months was followed from the third trimester until 12 months postpartum. Positive emotions during infant feeding at 2 months were measured using the modified Differential Emotions Scale. Cox proportional hazards regression was used to estimate adjusted hazard ratios (aHR) for time to any and exclusive human milk feeding cessation associated with a 1-point increase in positive emotions. Linear regression was used to estimate the association between positive emotions and maternal breastfeeding experience reported at 12 months.

Results:

Among those human milk feeding at 2 months, positive emotions during feeding were not associated with human milk feeding cessation by 12 months (aHR = 0.94, 95% CI [0.64, 1.31]). However, among women exclusively human milk feeding at 2 months, a 1-point increase in positive emotions was associated with a 35% lower hazard of introducing formula or solid foods by 6 months (aHR = 0.65, 95% CI [0.46, 0.92]). Positive emotions were associated with a significantly more favorable maternal report of breastfeeding experience at 12 months. Results were similar in sensitivity analyses using maternal feelings about breastfeeding in the first week as the exposure.

Conclusions:

A positive maternal emotional experience of feeding is associated with breastfeeding outcomes.
Examining the Impacts of Middle School Disciplinary Policies on Ninth-Grade Retention
Authors: Swanson Elise , H. Erickson Heidi , Ritter Gary W.
Published: May 2019

We estimate the relationship between exclusionary discipline given in eighth-grade and the probability of ninth-grade retention. We use a rich 7-year, student-level, panel data set from Arkansas. We use a novel approach by limiting our sample to students who switch schools between eighth and ninth grades. This movement gives each student a fresh start and removes the potential confound of a student’s reputation as a “problem student” that could influence teachers to be harsher on students who already have a disciplinary record. Further, we control for student infractions in eighth-grade, to focus on the relationship between the exclusionary consequence (rather than the precipitating behavior) and future academic success. We find that students who receive exclusionary discipline in eighth grade are more likely to be retained in ninth-grade compared with similar students whose infractions did not result in exclusionary discipline. Moreover, we find that the likelihood of ninth-grade retention increases with the number of days of exclusionary discipline. We, however, did not find any statistically significant subgroup differences.
A full-scale experimental investigation of passenger and freight train aerodynamics
Authors: Soper David , Baker Chris
Published: May 2019

The movement of a train creates a disturbance to the air through which it passes, known as a slipstream. Such disturbances are characterised by changes in pressure, notably around the vehicle nose/tail, and a highly turbulent boundary growth along the vehicle side with an increasing slipstream velocity magnitude. Although these characteristic features occur in some form for all trains, the flow development associated with various train types can often be very different. Variability in train type makes it difficult to accurately characterise the aerodynamic effects of each individual train. In this paper, a detailed set of tests are undertaken to assess the aerodynamic flow development created around various train types common to the UK railway network. A comparison of the analysed data from different passenger and freight trains was made. The variability of freight train results was larger in comparison to the passenger trains examined, because of the large flow separations around the bluff freight train. Although the speed was lower for freight trains, the slipstream velocity and pressure magnitudes were larger than those observed for passenger trains. Passenger trains could be divided aerodynamically into two main types: long distance passenger trains and commuter trains. Longer train lengths were shown to increase the boundary layer growth: an important feature for long distance passenger trains as it creates an increase in the slipstream velocity peak magnitude at the train tail. Boundary layer stabilisation is not observed as in previous studies. The coupling of two carriage sets together, creating a large V-shaped region at the centre of the train, led to a clear step slipstream velocity peak coinciding with the change in pressure at the coupling region. Cross-correlation of results from measuring positions within the characteristic turbulent length scale range appeared to show similar results to autocorrelation time scales for larger scale separation of turbulent structures from the bogie and inter-carriage regions.
Radiotherapy treatment of human inflammatory diseases and conditions: Optimal dose
Authors: Calabrese EJ , Dhawan G , Kapoor R , Kozumbo WJ
Published: May 2019

During the early part of the past century, hundreds of clinical studies involving more than 37,000 patients were conducted that showed radiotherapy (RT) to be a successful and safe alternative to drug therapy for the treatment of many diverse inflammatory conditions and diseases (e.g. tendonitis, bursitis, arthritis, and serious inflammatory lung conditions). Data from these studies were collected and analyzed with the intent of estimating an optimal dosing range for RT that would induce an efficacious treatment response. RT was reported to be frequently effective after only a single treatment, with a rapid (within 24 h) and often long-lasting (from months to years) relief from symptoms. Over a two-decade span from the 1920s to the 1940s, the therapeutic responses to a single RT treatment consistently improved as the dosing for multiple ailments decreased over time to between 30 roentgen (r) and 100 r. These findings are significant and in agreement with a number of contemporary reports from Germany where RT has been commonly and successfully employed in treating ailments with an inflammatory origin. A proposed mechanism by which RT mitigates inflammation and facilitates healing is via the polarization of macrophages to an anti-inflammatory or M2 phenotype.
Nosology and metaphor: How pornography viewers make sense of pornography addiction
Authors: Taylor Kris
Published: May 2019

Pornography addiction is increasingly a focus of both lay and expert attention, despite ongoing debate as to whether viewing pornography can be categorized as such. The present study takes a step back from such debates to ask fundamental questions about how pornography addiction is conceptualized between such lay and expert jurisdictions, and how the flow of information between these domains helps to create and sustain a pornography addiction diagnosis. Drawing upon philosopher Ian Hacking's theory of ‘making up people’, responses from a qualitative survey ( n = 213), and semi-structured interviews ( n = 30) are analysed, attending specifically to how pornography viewers themselves draw upon different ways of explaining how a pornography addiction works, and how the language of addiction is applied as either a literal or metaphorical explanation of behaviour. The results indicate, not only that addiction criteria are applied in surprisingly diverse ways, but also that pornography addiction's boundaries are elastic, its definitions transient, and its use dependent upon both metaphor and claims to neurological knowledge. It is suggested that if pornography addiction is being taken seriously, it is necessary to elaborate upon this relationship between metaphor and nosology.
Selected synchronous state of the vibration system driven by three homodromy eccentric rotors
Authors: Chen Xiaozhe , Li Lingxuan
Published: May 2019

In order to verify that the vibration system driven by multi-eccentric rotors has multiple synchronous states, a model of three eccentric rotors horizontal installation of plane motion is established to study the coupling dynamic characteristics. Based on the average method of modified small parameters, the frequency capture equation is constructed to obtain the conditions of synchronous motion and vibration synchronization transmission. According to the synchronous conditions, the stability state of achieving synchronous motion is converted into the solution of balance equation of the synchronous torque. There are multiple solutions to the torque equation because of the non-linear characteristics of the vibration system driven by multi-eccentric rotors. Then the stability condition is used to estimate which of the solutions is stable. After substituting the parameters of the experimental machine into the above method, the curves of the phase difference and its stability coefficients of three eccentric rotors system are obtained numerically. Two experiments show that the selected synchronous state depends on the initial condition and external disturbance, and if the vibration synchronization transmission conditions are satisfied, three eccentric rotors can not only achieve vibration synchronization transmission of one motor with switching off the power but also that of two motors with switching off the power.
Initial Clinical Results and In Vitro Testing of the New CGuard MicroNet-Covered “One-Size-Fits-All” Carotid Stent
Authors: Wissgott Christian , Brandt-Wunderlich Christoph , Kopetsch Christoph , Schmidt Wolfram , Andresen Reimer
Published: May 2019

Purpose: To evaluate a MicroNet-covered stent designed for the carotid artery with the new ability to adjust to different vessel diameters. Materials and Methods: Thirty consecutive patients (mean age 72.1±7.7 years; 26 men) with symptomatic stenosis (86.3%±6.4%) of the internal carotid artery were treated with the new self-adjusting nitinol stent, which has a self-expanding, open-cell design covered by an outer conformable layer (MicroNet). The only stent used was the “One-Size-Fits-All” CGuard stent with lengths of 30 or 40 mm. In bench testing, the chronic outward force of the One-Size-Fits-All stent was determined with a segmented head radial force test device. The stent was deployed directly into the test device at a diameter of 5.0 mm, and the chronic outward force was measured up to 10.0 mm, the maximum expansion of the stent. Results: The stent was successfully implanted in all 30 patients without periprocedural complications, including no neurological events within 30 days. The chronic outward force normalized by stent length demonstrated a near-equivalent radial force outcome: The stent displayed only a minor difference between the minimal radial force at 9.0 mm (0.195 N/mm) and the maximal radial force at 5.5 mm (0.330 N/mm). Conclusion: The new self-adjusting, MicroNet-covered stent has high conformability combined with an almost equivalent radial force at expansion diameters ranging from 5.5 to 9.0 mm. The first clinical results demonstrate that the new One-Size-Fits-All stent can be safely implanted in internal carotid arteries with reference diameters within this range.
Evaluation and a Proposed Revision of the CAMM Among Underrepresented Elementary School Children
Authors: Mezo Peter G. , Herc Hannah C. , Pritchard Kelsey J. , Bullock Wesley A.
Published: May 2019

The Child and Adolescent Mindfulness Measure (CAMM) is a frequently used measure of mindfulness in school settings. This study evaluates the psychometric properties and internal consistency of the CAMM in a predominantly African American, low socioeconomic status (SES) school sample drawn from students in kindergarten through fourth grade. In addition, a revised version of the CAMM (the CAMM-R) was developed and evaluated in the same sample. Results are generally supportive of the internal consistency and item-level characteristics of both the CAMM and the CAMM-R. These results are discussed in terms of implications for understanding the reliability and validity of the CAMM and CAMM-R among underrepresented students, as well as students within a younger sample.
A feasible study for the working mechanism and parameter optimization of the agitator
Authors: Jing Jun , Liu Weiji , Zhou Yunlai
Published: May 2019

The challenges such as large frictional drag, difficult weight-on-bit transmission, and low rate of penetration are frequently met in modern directional drilling, especially in horizontal well drilling. This study presented a nonlinear dynamic simulation model of horizontal well considering the random interaction between drill string and wellbore as well as bit and rock. In this study, the dynamic characteristics of the bottom hole assembly during drilling with and without agitator as well as the working mechanism and optimization parameters of the agitator were simulated and compared. The field application of the agitator is also simulated for the design and working parameter optimization. The results show that using agitator can improve the weight-on-bit transmission efficiency and reduce the frictional drag, tropsh-pressure, and occurrence probability of drill string buckling. The optimal installation position of the ∅172 mm agitator obtained in this study is [200, 300] m away from the bit, the optimum frequency range is [3, 17] Hz, and the optimal impact load is 100 kN.
The high-speed rotorcraft unmanned aerial vehicle path planning based on the biogeography-based optimization algorithm
Authors: Song Jia , Zhao Mingfei , Yang Erfu , Lin Jiaming
Published: May 2019

A three-dimensional path planning method based on the biogeography-based optimization algorithm is presented for high-speed rotorcraft unmanned aerial vehicle which has a maximum speed of 20 m/s. In this study, a novel exponential artificial potential field is used to prevent saturation, for its peculiarity of smoothness and boundness. Several parameters, which can make a large influence to the result of path planning, are picked out and used to improve the process of planning. Biogeography-based optimization algorithm is first used to optimize the parameters of artificial potential fields, for its best performance in stability and speed. The algorithm has good stability and fast operation speed, which can realize the global path planning of multi-rotor aircraft well, verified by the simulation results.
Chemical Constituents From the Flowers of Aloe arborescens
Authors: Kurizaki Ayumi , Watanabe Takashi , Devkota Hari Prasad
Published: May 2019

(3 R)-3,4-Dihydro-6,8-dihydroxy-3-(2'-acetyl-3'- O-β-d-glucopyranosyl-5'-hydroxyphenyl)methyl-2(1 H)-benzopyran-1-one (feralolide-3’- O-β- d -glucopyranoside, 1), feralolide (2), aloe-emodin (3), feroxidin (4), and chlorogenic acid (5) were isolated from the 70% EtOH extract of flowers of Aloe arborescens. Structures of these compounds were elucidated on the basis of physical and spectral data. Absolute structure of 1 was determined on the basis of circular dichroism spectra for the first time.
The Influence of Stress on Depression and Substance Use Problems Among Young Male Same-Sex Couples: Relationship Functioning as an Underlying Mechanism
Authors: Feinstein Brian A. , McConnell Elizabeth , Dyar Christina , Mustanski Brian , Newcomb Michael E.
Published: May 2019

Stress experienced by either partner in a couple can have a negative impact on each partner’s health, but most dyadic research on stress and health has focused on different-sex couples. We examined relationship functioning as a mechanism underlying the longitudinal actor and partner effects of stress on depression and substance use problems among 109 young male same-sex couples. There were significant indirect actor effects of internalized stigma and microaggressions on depression and alcohol use problems through negative relationship interactions. Participants who reported higher levels of internalized stigma and microaggressions reported increases in negative relationship interactions, which in turn was associated with reporting greater depression and alcohol use problems. In contrast, none of the indirect partner effects were significant. Findings implicate negative relationship interactions as a mechanism linking minority stress to health but raise questions about the influence of partner stress on individual health among young male same-sex couples.
C-Peptide Suppression During Insulin Infusion in the Extremely Preterm Infant Is Associated With Insulin Sensitivity
Authors: Hellström William , Hansen-Pupp Ingrid , Hellgren Gunnel , Engström Eva , Stigson Lennart , Sävman Karin , Ley David , Löfqvist Chatarina
Published: May 2019

Context

Little is known about the individual response of glucose-regulating factors to administration of exogenous insulin infusion in extremely preterm infants.

Objective

To evaluate longitudinal serum concentrations of insulin, C-peptide, and plasma glucose levels in a high-frequency sampling regimen in extremely preterm infants treated with insulin because of hyperglycemia.

Design

Prospective longitudinal cohort study.

Setting

Two university hospitals in Sweden between December 2015 and September 2016.

Patients and Intervention

Serum samples were obtained from nine extremely preterm infants, gestational age between 22 (+3) and 26 (+5) weeks (+ days), with hyperglycemia (plasma-glucose >10 mmol/L) at the start of insulin infusion, at 12, 24, and every 24 hours thereafter during ongoing infusion, and 12, 24, and 72 hours after the end of insulin infusion.

Main outcome measures

Longitudinal serum concentrations of insulin and C-peptide and plasma glucose levels.

Results

During insulin infusion, the serum C-peptide concentrations decreased compared with at start of infusion (P = 0.036), and then increased after ending the infusion. Individual insulin sensitivity based on the nonfasting plasma glucose/insulin ratio at the start of insulin infusion correlated with the initial decrease in serum ΔC-peptide[after 12h] (P = 0.007) and the degree of lasting decrease in serum ΔC-peptide[after end of infusion] (P = 0.015).

Conclusion

Exogenous insulin infusion suppressed the C-peptide concentration to individually different degrees. In addition, the effect of insulin infusion on β cells may be linked to individual insulin sensitivity, where a low insulin sensitivity resulted in a more pronounced decrease in C-peptide during insulin infusion.
Impaired Fasting Glucose and Chronic Kidney Disease, Albuminuria, or Worsening Kidney Function: A Secondary Analysis of SPRINT
Authors: Bigotte Vieira Miguel , Neves João Sérgio , Leitão Lia , Baptista Rute Baeta , Magriço Rita , Viegas Dias Catarina , Oliveira Ana , Carvalho Davide , Mc Causland Finnian R
Published: May 2019

Purpose

Diabetes mellitus is a risk factor for the development and progression of chronic kidney disease (CKD). However, the association of prediabetes with adverse kidney outcomes is uncertain.

Methods

We performed a secondary analysis of the Systolic Blood Pressure Intervention Trial (SPRINT), including 9361 participants without diabetes at baseline. We categorized participants according to fasting glucose level as having impaired fasting glucose [≥100 mg/dL (≥5.6 mmol/L)] or normoglycemia [<100 mg/dL (<5.6 mmol/L)]. Unadjusted and adjusted proportional hazards models were fitted to estimate the association of impaired fasting glucose (vs normoglycemia) with a composite outcome of worsening kidney function [≥30% decrease in estimated glomerular filtration rate (eGFR) to <60 mL/min/1.73 m2 in participants without baseline CKD; ≥50% decrease in eGFR or need for long-term dialysis/kidney transplantation in participants with CKD] or incident albuminuria (doubling of urinary albumin/creatinine ratio from <10 mg/g to >10 mg/g). These outcomes were also evaluated separately and according to CKD status at baseline.

Results

Participants’ mean age was 67.9 ± 9.4 years, 35.5% were female, and 31.4% were black. The median follow-up was 3.3 years, and 41.8% had impaired fasting glucose. Impaired fasting glucose was not associated with higher rates of the composite outcome [hazard ratio (HR): 0.97; 95% CI: 0.8 to 1.16], worsening kidney function (HR: 1.02; 95% CI: 0.75 to 1.37), or albuminuria (HR: 0.98; 95% CI: 0.78 to 1.23). Similarly, there was no association of impaired fasting glucose with outcomes according to baseline CKD status.

Conclusions

Impaired fasting glucose at baseline was not associated with the development of worsening kidney function or albuminuria in participants of SPRINT.
Necropolitics, Postmortem/Transmortem Politics, and Transfeminisms in the Sexual Economies of Death
Authors: Valencia Sayak , Zhuravleva Olga Arnaiz
Published: May 2019

This article proposes two specific interventions, utilizing a critical transfeminist positioning to critique a transexclusionary perspective in writing and research on the crucial problem of necropolitics and the murder of women in Mexican society: (1) the term postmortem/transmortem politics, to reflect on the forms that imagination and political practice developed inside a Mexican trans community to deal with the necropolitics that murders trans and cis women on an everyday basis with complete impunity—in this sense, the process of mobilization, here called postmortem/transmortem, builds bridges of transfeminist alliance since it reactivates and embodies struggles against femicide and transfemicide from communities of care and vulnerability; and (2) the goals of the transfeminist movement as a source of feminist repolitization and greater inclusivity for the subject of feminisms, considering those subjects left outside or energetically moved away from the neoliberal reconversion of the critical devices of the white heterosexual and institutional feminisms that we know today as gender politics or “women's politics,” managed and operated by the state.
Physical and functional cell-matrix uncoupling in a developing tissue under tension
Authors: Proag Amsha , Monier Bruno , Suzanne Magali
Published: May 2019

Tissue mechanics play a crucial role in organ development. They rely on the properties of cells and the extracellular matrix (ECM), but the relative physical contribution of cells and ECM to morphogenesis is poorly understood. Here, we analyzed the behavior of the peripodial epithelium (PE) of the Drosophila leg disc in the light of the dynamics of its cellular and ECM components. The PE undergoes successive changes during leg development, including elongation, opening and removal to free the leg. During elongation, we found that the ECM and cell layer are progressively uncoupled. Concomitantly, the tension, mainly borne by the ECM at first, builds up in the cell monolayer. Then, each layer of the peripodial epithelium is removed by an independent mechanism: while the ECM layer withdraws following local proteolysis, cellular monolayer withdrawal is independent of ECM degradation and driven by myosin-II-dependent contraction. These results reveal a surprising physical and functional cell-matrix uncoupling in a monolayer epithelium under tension during development.
Lin28-mediated promotion of protein synthesis is critical for neural progenitor cell maintenance and brain development in mice
Authors: Herrlinger Stephanie , Shao Qiang , Yang Mei , Chang Qing , Liu Yang , Pan Xiaohan , Yin Hang , Xie Li-Wei , Chen Jian-Fu
Published: May 2019

Neural progenitor cells (NPCs) undergo rapid proliferation during neurulation. This rapid growth generates a high demand for mRNA translation in a timing-dependent manner, but its underlying mechanism remains poorly understood. Lin28 is an RNA-binding protein with two paralogs, Lin28a and Lin28b, in mammals. Mice with Lin28b deletion exhibit no developmental defects, whereas we previously reported that Lin28a deletion led to microcephaly. Here we found that Lin28a/b double knockout (dKO) mice displayed neural tube defects (NTDs) coupled with reduced proliferation and precocious differentiation of NPCs. Using ribosomal protein 24 hypomorphic mice (Rpl24Bst/+) as a genetic tool to dampen global protein synthesis, we found that Lin28a−/−;Rpl24Bst/+ compound mutants exhibited NTDs resembling those seen in Lin28a/b dKO mice. Increased NPC numbers and brain sizes in Lin28a-overexpressing mice were rescued by Rpl24Bst/+ heterozygosity. Mechanistically, polysome profiling revealed reduced translation of genes involved in the regulation of cell cycle, ribosome biogenesis, and translation in dKO mutants. Ribosome biogenesis was reduced in dKO and increased in Lin28a-overexpressing NPCs. Therefore, Lin28-mediated promotion of protein synthesis is essential for NPC maintenance and early brain development.
DnaJB6 is a RanGTP-regulated protein required for microtubule organization during mitosis
Authors: Rosas-Salvans Miquel , Scrofani Jacopo , Modol Aitor , Vernos Isabelle
Published: May 2019

Bipolar spindle organization is essential for the faithful segregation of chromosomes during cell division. This organization relies on the collective activities of motor proteins. The minus-end-directed dynein motor complex generates spindle inward forces and plays a major role in spindle pole focusing. The dynactin complex regulates many dynein functions, increasing its processivity and force production. Here, we show that DnaJB6 is a novel RanGTP-regulated protein. It interacts with the dynactin subunit p150Glued (also known as DCTN1) in a RanGTP-dependent manner specifically in M-phase, and promotes spindle pole focusing and dynein force generation. Our data suggest a novel mechanism by which RanGTP regulates dynein activity during M-phase.
Proximity-dependent biotinylation mediated by TurboID to identify protein–protein interaction networks in yeast
Authors: Larochelle Marc , Bergeron Danny , Arcand Bruno , Bachand François
Published: May 2019

The use of proximity-dependent biotinylation assays coupled to mass spectrometry (PDB-MS) has changed the field of protein–protein interaction studies. However, despite the recurrent and successful use of BioID-based protein–protein interactions screening in mammalian cells, the implementation of PDB-MS in yeast has not been effective. Here, we report a simple and rapid approach in yeast to effectively screen for proximal and interacting proteins in their natural cellular environment by using TurboID, a recently described version of the BirA biotin ligase. Using the protein arginine methyltransferase Rmt3 and the RNA exosome subunits, Rrp6 and Dis3, the application of PDB-MS in yeast by using TurboID was able to recover protein–protein interactions previously identified using other biochemical approaches and provided new complementary information for a given protein bait. The development of a rapid and effective PDB assay that can systematically analyze protein–protein interactions in living yeast cells opens the way for large-scale proteomics studies in this powerful model organism.
Tibialis anterior tendinous tissue plays a key role in energy absorption during human walking
Authors: Maharaj Jayishni N. , Cresswell Andrew G. , Lichtwark Glen A.
Published: May 2019

The elastic tendinous tissues of distal lower limb muscles can improve the economy of walking and running, amplify the power generated by a muscle as well as absorb energy. This paper explores the behaviour of the tibialis anterior (TA) muscle and its tendinous tissue during gait, as it absorbs energy during contact and controls foot position during swing. Simultaneous measurements of ultrasound, surface electromyography and 3-dimensional motion capture with musculoskeletal modelling from twelve healthy participants were recorded as they walked at preferred and fast walking speeds. We quantified the length changes and velocities of the TA muscle-tendon unit and its fascicles across the stride at each speed. Fascicle length changes and velocities were relatively consistent across speeds, although the magnitude of fascicle length change differed between the deep and superficial regions. At contact, when the TA is actively generating force, the fascicles remained relatively isometric as the MTU actively lengthened, presumably stretching the TA tendinous tissue and absorbing energy. This potentially protects the muscle fibres from damage during weight acceptance and allows energy to be returned to the system later in the stride. During early swing the fascicles and MTU both actively shortened to dorsiflex the foot, clearing the toes from the ground; although, at the fast walking velocity the majority of the shortening occurred through tendinous tissue recoil, highlighting its role in accelerating ankle dorsi-flexion to power rapid foot clearance in swing.
Resource profitability, but not caffeine, affects individual and collective foraging in the stingless beePlebeia droryana
Authors: Peng Tianfei , Segers Francisca H. I. D. , Nascimento Fabio , Grüter Christoph
Published: May 2019

Plants and pollinators form beneficial relationships with plants offering resources and, in return, they get pollinated. Some plants, however, add compounds to nectar to manipulate pollinators. Caffeine is a secondary plant metabolite found in some nectars that affects foraging in pollinators. In honeybees, caffeine increases foraging and recruitment to mediocre food sources, which might benefit the plant, but potentially harms the colonies. For the largest group of social bees, the stingless bees, the effect of caffeine on foraging behavior has not been tested yet, despite their importance for tropical ecosystems. More generally, recruitment and foraging dynamics are not well understood in most species. We examined whether caffeine affects the foraging behaviour of the stingless bee Plebeia droryana, which frequently visits plants that produce caffeinated nectar and pollen. We trained bees to food sources containing field-realistic concentrations of sugar and caffeine. Caffeine did not cause P. droryana to increase foraging frequency and persistency. We observed P. droryana recruiting to food sources, however, this behaviour was also not affected by caffeine. Instead we found that higher sugar concentrations caused bees to increase foraging effort. Thus, unlike in other pollinators, foraging behaviour in this stingless bee is not affected by caffeine. As the Brazilian P. droryana population that we tested has been exposed to coffee over evolutionary time periods, our results raise the possibility that it may have evolved a tolerance towards this central nervous system stimulant. Alternatively, stingless bees may show physiological responses to caffeine that differ from other bee groups.
UV-light perception is modulated by the odour element of an olfactory-visual compound in restrained honeybees
Authors: Becker Mira C. , Rössler Wolfgang , Strube-Bloss Martin Fritz
Published: May 2019

Honeybees use visual and olfactory cues to detect flowers during foraging trips. Hence, the reward association of a nectar source is a multimodal construct which has at least two major components – olfactory and visual cues. How both sensory modalities are integrated to form a common reward association and whether and how they may interfere, is an open question. The present study used stimulation with UV, blue and green light to evoke distinct photoreceptor activities in the compound eye and two odour components (Geraniol, Citronellol). To test if a compound of both modalities is perceived as the sum of its elements (elemental processing) or as a unique cue (configural processing) we combined monochromatic light with single odour components in positive (PP) and negative patterning (NP) experiments. During PP, the compound of two modalities was rewarded, whereas the single elements were not. For NP, stimuli comprising a single modality were rewarded, whereas the olfactory-visual compound was not. Furthermore, we compared the differentiation abilities between two light stimuli with and without being part of an olfactory-visual compound. Interestingly, the behavioural performances revealed a prominent case of configural processing, but only in those cases when UV light was an element of an olfactory-visual compound. Instead, learning with green- and blue-containing compounds rather supports elemental processing theory.
Septate junction in the distal ileac plexus of larval lepidopteranTrichoplusia ni: alterations in paracellular permeability during ion transport reversal
Authors: Kolosov Dennis , Jonusaite Sima , Donini Andrew , Kelly Scott P. , O'Donnell Michael J.
Published: May 2019

The Malpighian tubules (MTs) and hindgut together act as the functional kidney in insects. MTs of caterpillars are notably complex and consist of several regions that display prominent differences in ion transport. The distal ileac plexus (DIP) is a region of Malpighian tubule that is of particular interest because it switches from ion secretion to ion reabsorption in larvae fed on ion-rich diets. The pathways of solute transport in the DIP are not well understood, but one potential route is the paracellular pathway between epithelial cells. This pathway is regulated by the septate junctions (SJs) in invertebrates, and in this study, we found regional and cellular heterogeneity in expression of several integral SJ proteins. DIP of larvae fed ion-rich diets demonstrated a reduction in paracellular permeability, coupled with alterations in both SJ morphology and the abundance of its molecular components. Similarly, treatment in vitro with helicokinin (HK), an antidiuretic hormone identified by previous studies, altered mRNA abundance of many SJ proteins and reduced paracellular permeability. HK was also shown to target a secondary cell-specific SJ protein Tsp2A. Taken together, our data suggest that dietary ion loading, known to cause ion transport reversal in the DIP of larval T. ni, leads to alterations in the paracellular permeability, SJ morphology and its molecular component abundance. The results suggest that HK is an important endocrine factor that co-regulates ion transport, water transport and paracellular permeability in MTs of larval lepidopterans. We propose that co-regulation of all three components of the MT function in larval lepidopterans allows for safe toggling between ion secretion and reabsorption in the DIP in response to variations in dietary ion availability.
Effects of Virtual Reality training on medical students’ learning motivation and competency
Authors: Sattar Mian Usman , Palaniappan Sellappan , Lokman Asiah , Hassan Atif , Shah Nauman , Riaz Zurabia
Published: May 2019

Objectives: To determine the need of contemporary immersive approaches (Virtual Reality) in teaching and training at medical sector. The main objective of this study was to explore the effects of text, video and immersive technologies learning methodologies for participants’ learning in public and private medical colleges and universities of Pakistan.

Methods: In this quantitative research 87 medical students of 4th year from three public and five private medical colleges and universities participated. A laparoscopy operation was selected in consultation with senior medical consultants for this experiment. The experimental material was arranged in virtual reality, video and text based learning. At completion of each of which, participants completed a questionnaire about learning motivation and learning competency through the different mediums.

Results: Statistical t-test was selected for the analysis of this study. By comparing the mean values of virtual reality, video, and text based learning methodologies in medical academics; result of virtual reality is at top of others. All performed model are statistically significant (P=0.000) and results can be applied at all population.

Conclusion: Through this research, we contribute to medical students learning methodologies. In medical studies, both theoretical and practical expertise has a vital role, while repetition of hands-on practice can improve young doctors’ professional competency. Virtual reality was found best for medical students in both learning motivation and learning competency. Medical students and educationist may select virtual reality as new learning methodology for curriculum learning.

doi: https://doi.org/10.12669/pjms.35.3.44

How to cite this:Sattar MU, Palaniappan S, Lokman A, Hassan A, Shah N, Riaz Z. Effects of Virtual Reality training on medical students’ learning motivation and competency. Pak J Med Sci. 2019;35(3):852-857. doi: https://doi.org/10.12669/pjms.35.3.44

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Rationalizable Implementation of Correspondences
Authors: Kunimoto Takashi , Serrano Roberto
Published: May 2019

A new condition, which we call uniform monotonicity, is shown to be necessary and almost sufficient for rationalizable implementation of correspondences. Uniform monotonicity is much weaker than Maskin monotonicity and reduces to it in the case of functions. Maskin monotonicity, the key condition for Nash implementation, had also been shown to be necessary for rationalizable implementation of social choice functions. Our conclusion is that the conditions for rationalizable implementation are not only starkly different from but also, much weaker than those for Nash implementation when we consider social choice correspondences. Thus, dropping rational expectations significantly expands the class of rules that can be decentralized by communication-based economic institutions.
Solving Zero-Sum Games Using Best-Response Oracles with Applications to Search Games
Authors: Hellerstein Lisa , Lidbetter Thomas , Pirutinsky Daniel
Published: May 2019

How to Choose Between Exponentially Many Strategies

In “Solving Zero-Sum Games Using Best-Response Oracles with Applications to Search Games,” L. Hellerstein, T. Lidbetter, and D. Pirutinsky consider zero-sum games between a minimizer and a maximizer, where the number of pure strategies of the minimizer is exponential in the number of pure strategies of the maximizer. Such games are frequent in the search-games literature. Solving them with standard algorithms typically takes exponential time. The authors show how to compute (approximate) solutions in polynomial time, provided that there is a polynomial time (approximate) algorithm solving the best-response problem: given a mixed (randomized) strategy of the maximizer, what is a best response of the minimizer? The paper presents both a learning approach using weight updates and an approach of solely theoretical interest based on the ellipsoid algorithm. The learning approach performs well experimentally compared with approaches in the literature. The results are applied to obtain new algorithms for solving specific search games.
Editorial
Authors: Soares Adriana Benevides , Tsallis Alexandra Cleopatre , Mendes Deise Maria Fernandes , Moraes Marcia , Barros Rita Maria Manso de
Published: May 2019

Adriana Benevides Soares, Alexandra Cleopatre Tsallis, Deise Maria Fernandes Mendes, Marcia Moraes, Rita Maria Manso de Barros
Seguindo as políticas de ação afirmativa no ensino superior pelas redes tecnossociais
Authors: Gonzales Zuleika Köhler , Guareschi Neuza Maria de Fátima
Published: May 2019

Este artigo tem como objetivo abordar a política de ação afirmativa para o ingresso no ensino superior, na Universidade Federal do Rio Grande do Sul, através da rede de associações que se faz em nome da igualdade e que se compõe por argumentos e controvérsias materializadas em diferentes formas. Para isso delineamos alguns procedimentos que formam o caminho de acesso à universidade através da reserva de vagas pelo quesito social e étnico racial. Consideramos esses procedimentos como redes que conectam tecnologias, resoluções legais, instituições e candidatos ao vestibular e, portanto, performadoras de realidades e versões de ensino superior. Para a discussão nos valemos dos estudos cosmopolíticos da ciência sobre as redes tecnossociais realizados por Latour, Stengers e Despret. Esperamos com este estudo, fomentar o debate de enfrentamento das desigualdades sociais pela via das ações afirmativas nas universidades, entendendo que é um debate que gera sempre controvérsias e está sempre agregando outros argumentos e ações.
O cuidado em saúde: A experiência dos trabalhadores de limpeza na unidade de oncologia pediátrica
Authors: Lima Maria Juliana Vieira , Cavalcante Cinthia Mendonça
Published: May 2019

O objetivo deste estudo é compreender a experiência de cuidado do trabalhador de limpeza no contato com usuários de um centro de tratamento do câncer infantil. Foi realizada pesquisa qualitativa, da qual participaram seis trabalhadores do serviço de limpeza. Foram realizadas entrevistas semiestruturadas, as quais foram pautadas na hermenêutica fenomenológica para método de análise das falas. Percebeu-se estabelecimento de vínculo entre os usuários e os trabalhadores de limpeza através de trocas afetivas significativas. Ademais, ao vincularem e ofertarem cuidado, os profissionais de limpeza tornavam-se figuras importantes no tratamento dos usuários, atuando como suporte para reestruturação do self nos momentos de crise e vulnerabilidade. Os trabalhadores, a partir do seu cuidado, sofrem quando uma criança falece ou piora, não havendo, entretanto, espaço para vivenciar esse sofrimento. A contribuição deste estudo aponta para a necessidade de perceber as relações existentes entre os profissionais de limpeza e os usuários, pautando-se nesse vínculo construído para o cuidado integral aos usuários.
Os Primórdios da Psicanálise e a insuficiência do descritivismo
Authors: Pontes Samira , Calazans Roberto
Published: May 2019

A problemática perpassada neste trabalho refere-se ao questionamento, a partir da Psicanálise, da insuficiência do postulado descritivista que orienta a nosografia psiquiátrica do Manual Diagnóstico e Estatísticos de Transtornos Mentais (DSM), no que tange ao estabelecimento de um diagnóstico diferencial. Buscamos, nos textos pré-psicanalíticos de Freud, demonstrar que em seu esforço inicial de sistematização teórica e clínica, o autor já apontava a insuficiência de uma nosografia sintomática meramente descritiva, uma vez que a descrição pura dos sinais e sintomas de uma patologia não permite uma articulação inteligível, entre aquilo que se apresenta como fenômeno clínico, e os aspectos estruturais. Apresentamos também as formulações iniciais sobre a psicose, evidenciando o esforço freudiano no sentido de uma sistematização de seu diagnóstico diferencial. Se é no âmago das distinções das estruturas clínicas que se opera um diagnóstico diferencial, o descritivismo inviabiliza sua articulação ao promover a descaracterização das diferenças estruturais.
Editorial
Authors: Soares Adriana Benevides , Mendes Deise Maria Fernandes , Valentim Renata Patrícia Forain de , Barros Rita Maria Manso de
Published: May 2019

Adriana Benevides Soares, Deise Maria Fernandes Mendes, Renata Patrícia Forain de Valentim, Rita Maria Manso de Barros
Síndrome de Burnout em agentes penitenciários: Uma revisão sistemática sob a perspectiva de gênero
Authors: Braun Ana Claudia
Published: May 2019

O presente estudo objetivou realizar uma revisão sistemática de artigos sobre a temática da Síndrome de Burnout em agentes penitenciários sob a ótica de gênero. No total, foram selecionados 8 artigos. A maioria dos artigos teve como país de publicação os Estados Unidos da América (EUA), entre os anos de 1994 e 2013, predominância de métodos quantitativos, amostra composta por homens e mulheres, contexto prisional masculino, feminino e misto, assim como a utilização do MBI para mensurar a Síndrome de Burnout. A totalidade de artigos teve como objetivo geral de investigar a Síndrome de Burnout e variáveis associadas em agentes penitenciários. Dentre as dimensões da síndrome de burnout, os resultados gerais não demonstram diferenças significativas, porém, apontam para associação positiva da exaustão emocional e desilusão pelo trabalho com tempo de serviço. A dimensão de despersonalização foi mais elevada em homens. As análises demonstram lacunas na produção científica de gênero na categoria de agentes específicos, uma vez que os artigos explorados trouxeram em seu escopo discussões escassas sobre a temática, considerando em sua maioria gênero exclusivamente como a diferença entre homens e mulheres nas amostras exploradas.