bluuebunny/crossref_metadata_2025 huggingface dataset:
Secure content delivery over device‐to‐device communications underlaying cellular networks
Authors: Zhang Aiqing , Wang Lei , Ye Xinrong , Zhou Liang
Published: June 2016

Abstracdt

Content delivery via device‐to‐device (D2D) communications is a promising technology for offloading the heavy traffic for future mobile communication networks. As security is a critical concern for the users, we focus on improving the secrecy capacity for content dissemination in D2D communications. In this work, we explore the inherent characteristics of wireless channels to prevent eavesdropping. Firstly, we propose a power control scheme to obtain the optimal transmission powers for the D2D links without violating secrecy requirement of cellular users. Then, we formulate the problem as a stochastic optimization problem, aiming at maximizing the secrecy capacity gain of D2D communications. By solving the expected value model for the stochastic optimization problem, the optimal D2D links are selected to realize maximal ergodic secrecy capacity gain. Specifically, a weighted conflict graph is formulated according to the protocol model. Thus, the optimization problem has been transformed to the maximum weighted independent set problem, which is solved by a greedy weighted minimum degree algorithm. Simulation results demonstrate that the content dissemination scheme with power control can bring high secrecy capacity gain to the network. Copyright © 2016 John Wiley & Sons, Ltd.
Semiconducting polymer nanoparticles as photoacoustic molecular imaging probes
Authors: Cui Liyang , Rao Jianghong
Published: June 2016

As an emerging class of optical nanomaterials, semiconducting polymer nanoparticles (SPNs) are highly photostable, optically active and versatile in chemistry; these properties make them attractive as molecular imaging agents to enable imaging of biological events and functionalities at multiple scales. More recently, a variety of SPNs have been found to exhibit high photoacoustic properties, and further empowered photoacoustic imaging for contrast enhanced in vivo molecular imaging. Target‐sensitive components can be incorporated in the SPNs to create activatable imaging probes to sense and monitor the target dynamics in living objects. Intrinsically biophotonic and biocompatible, SPNs can be further engineered for multimodal imaging and for real‐time imaging of drug delivery. WIREs Nanomed Nanobiotechnol 2017, 9:e1418. doi: 10.1002/wnan.1418

This article is categorized under:

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging
Usefulness of Canadian Public Health Insurance Administrative Databases to Assess Breast and Ovarian Cancer Screening Imaging Technologies for BRCA1/2 Mutation Carriers
Authors: Larouche Geneviève , Chiquette Jocelyne , Plante Marie , Pelletier Sylvie , Simard Jacques , Dorval Michel
Published: June 2016

Purpose

In Canada, recommendations for clinical management of hereditary breast and ovarian cancer among individuals carrying a deleterious BRCA1 or BRCA2 mutation have been available since 2007. Eight years later, very little is known about the uptake of screening and risk-reduction measures in this population. Because Canada's public health care system falls under provincial jurisdictions, using provincial health care administrative databases appears a valuable option to assess management of BRCA1/2 mutation carriers. The objective was to explore the usefulness of public health insurance administrative databases in British Columbia, Ontario, and Quebec to assess management after BRCA1/2 genetic testing.

Methods

Official public health insurance documents were considered potentially useful if they had specific procedure codes, and pertained to procedures performed in the public and private health care systems.

Results

All 3 administrative databases have specific procedures codes for mammography and breast ultrasounds. Only Quebec and Ontario have a specific procedure code for breast magnetic resonance imaging. It is impossible to assess, on an individual basis, the frequency of others screening exams, with the exception of CA-125 testing in British Columbia. Screenings done in private practice are excluded from the administrative databases unless covered by special agreements for reimbursement, such as all breast imaging exams in Ontario and mammograms in British Columbia and Quebec. There are no specific procedure codes for risk-reduction surgeries for breast and ovarian cancer.

Conclusion

Population-based assessment of breast and ovarian cancer risk management strategies other than mammographic screening, using only administrative data, is currently challenging in the 3 Canadian provinces studied.
Maternal obesity leads to increased proliferation and numbers of astrocytes in the developing fetal and neonatal mouse hypothalamus
Authors: Kim Dong Won , Glendining Kelly A. , Grattan David R. , Jasoni Christine L.
Published: June 2016

Maternal obesity during pregnancy is associated with chronic maternal, placental, and fetal inflammation; and it elevates the risk for offspring obesity. Changes in the development of the hypothalamus, a brain region that regulates body weight and energy balance, are emerging as important determinants of offspring risk, but such changes are only beginning to be defined. Here we focused on the hypothesis that the pathological exposure of developing hypothalamic astrocytes to cytokines would alter their development.

A maternal high‐fat diet (mHFD) mouse model was used to investigate changes in hypothalamic astrocytes in the fetus during late gestation and in early neonates by using immunochemistry, confocal microscopy, and qPCR.

The number of astrocytes and the proportion of proliferating astrocytes was significantly higher in the arcuate nucleus (ARC) and the supraoptic nucleus (SON) of the hypothalamus at both ages compared to control offspring from normal weight pregnancies. Supplemental to this we found that cultured fetal hypothalamic astrocytes proliferated significantly in response to IL6 (10 ng/ml), one of the cytokines significantly elevated in fetuses of obese dams, via the JAK/STAT3 signaling pathway.

Thus, maternal obesity during pregnancy stimulated the proliferation and thereby increased numbers of astrocytes in the fetal as well as early neonatal hypothalamus, which may be driven, during fetal life, by IL6.
Low digestive hemorrhage caused by a vascular malformation in a patient with Crohn's disease: case report and literature review
Authors: Santos Carlos Henrique Marques dos , Stefanello José Valério Librelotto , Carvalho Yuri Maciel , Senefonte Flávio Renato de Almeida
Published: June 2016

The authors report the case of a 19-year-old male patient with Crohn's disease treated with infliximab and azathioprine, with sustained clinical remission; in the course of the evolution, this patient showed a vascular malformation in his rectum, with daily massive bleeding, in need of several blood transfusions and finally with an indication for surgical treatment. Data from the literature on the association of the injury at issue and CD, as well as the drugs used by the patient, are evaluated. The literature lacks information linking this malformation with CD or with the drugs used.
Augmentation enterocystoplasty without reimplantation for patients with neurogenic bladder and vesicoureteral reflux
Authors: Zhang Han‐Chao , Yang Jin , Ye Xin , Hu Hai‐Feng
Published: June 2016

The objective of this study was to assess the clinical outcome of vesicoureteral reflux (VUR) after augmentation cystoplasty alone in patients with a hypocompliant neurogenic bladder. Between January 2009 and December 2014, 29 patients with a hypocompliant bladder associated with VUR confirmed by videourodynamics (VUD) preoperatively were recruited in this study. All patients had undergone bladder augmentation with a generous detubularized segment of bowel at our institution. No effort had been made to correct the existing reflux. Preoperative assessment included urinalysis, kidney function tests, ultrasonography, and videourodynamic evaluation. All patients had various degrees of VUR. The status of VUR and bladder function were studied by VUD. The mean follow‐up period was 2.2 years (range 0.5–5.5 years). The VUD manifested a significant improvement of bladder capacity, diminution of intravesical pressure, and resolution of reflux after bladder augmentation. After the surgery, 24/29 (83%) no longer had reflux, 3/29 (10%) showed improvement in reflux, and 2/29 (7%) demonstrated no change in reflux. In addition, 16/21 (76%) patients had reflux Grades I‐III; 100% patients with reflux Grades IV and V had complete cessation of reflux. Only one patient had symptomatic urinary infection after the surgery. Augmentation enterocystoplasty without ureteral reimplantation is thus effective and adequate for patients with high‐pressure and hypocompliant neurogenic bladder. Therefore, ureteral reimplantation is not necessary when augmentation enterocystoplasty is recommended for patients with high‐pressure, low‐compliant bladder and VUR.
Insulin‐like growth factor‐1 receptor regulates repair of ultraviolet B‐induced DNA damage in human keratinocytes in vivo
Authors: Loesch Mathew M. , Collier Ann E. , Southern David H. , Ward Rachel E. , Tholpady Sunil S. , Lewis Davina A. , Travers Jeffrey B. , Spandau Dan F.
Published: June 2016

The activation status of the insulin‐like growth factor‐1 receptor (IGF‐1R) regulates the cellular response of keratinocytes to ultraviolet B (UVB) exposure, both in vitro and in vivo. Geriatric skin is deficient in IGF‐1 expression resulting in an aberrant IGF‐1R‐dependent UVB response which contributes to the development of aging‐associated squamous cell carcinoma. Furthermore, our lab and others have reported that geriatric keratinocytes repair UVB‐induced DNA damage less efficiently than young adult keratinocytes. Here, we show that IGF‐1R activation influences DNA damage repair in UVB‐irradiated keratinocytes. Specifically, in the absence of IGF‐1R activation, the rate of DNA damage repair following UVB‐irradiation was significantly slowed (using immortalized human keratinocytes) or inhibited (using primary human keratinocytes). Furthermore, inhibition of IGF‐1R activity in human skin, using either ex vivo explant cultures or in vivo xenograft models, suppressed DNA damage repair. Primary keratinocytes with an inactivated IGF‐1R also exhibited lower steady‐state levels of nucleotide excision repair mRNAs. These results suggest that deficient UVB‐induced DNA repair in geriatric keratinocytes is due in part to silenced IGF‐1R activation in geriatric skin and provide a mechanism for how the IGF‐1 pathway plays a role in the initiation of squamous cell carcinoma in geriatric patients.
Window of Opportunity for New Disease Surveillance: Developing Keyword Lists for Monitoring Mental Health and Injury Through Syndromic Surveillance
Authors: Lauper Ursula , Chen Jian-Hua , Lin Shao
Published: June 2016

Studies have documented the impact that hurricanes have on mental health and injury rates before, during, and after the event. Since timely tracking of these disease patterns is crucial to disaster planning, response, and recovery, syndromic surveillance keyword filters were developed by the New York State Department of Health to study the short- and long-term impacts of Hurricane Sandy. Emergency department syndromic surveillance is recognized as a valuable tool for informing public health activities during and immediately following a disaster. Data typically consist of daily visit reports from hospital emergency departments (EDs) of basic patient data and free-text chief complaints. To develop keyword lists, comparisons were made with existing CDC categories and then integrated with lists from the New York City and New Jersey health departments in a collaborative effort. Two comprehensive lists were developed, each containing multiple subcategories and over 100 keywords for both mental health and injury. The data classifiers using these keywords were used to assess impacts of Sandy on mental health and injuries in New York State. The lists will be validated by comparing the ED chief complaint keyword with the final ICD diagnosis code. (Disaster Med Public Health Preparedness. 2017;11:173–178)
Marine and anthropogenic controls on the estuary of the Suriname River over the past 50 years
Authors: Gersie K. , Augustinus P.G.E.F. , Van Balen R.T.
Published: June 2016

Humans have played an important role in fluvial systems because of the impact of their land-use activities, frequently leading to degradation of environmental conditions. Rivers, which are the primary agents in sediment transport, have thus been subject to changes in sediment fluxes. The Suriname River has been affected by anthropogenic activities since colonial times, and has experienced strong discharge and sediment-load changes since the construction of the Afobaka Dam in 1964. The river's estuary sediments largely consist of fine-grained sediments, originating, ultimately, from the Amazon River and transported by the strong tidal current. The influence of this tidal current is diminished at the head of the estuary, allowing the river flow to become dominant. Also remarkable is the interaction of the Suriname River and the westward-migrating mudbanks which is evident in the changing magnitude and volume of Braamspunt, a mudcape located at the mouth of the estuary. The regulated discharge of the river results in a change of the river's morphology, resulting, among other things, in the growth of river bars.
Tectonic evolution and stress pattern of South Wagad Fault at the Kachchh Rift Basin in western India
Authors: KOTHYARI G. C. , DUMKA R. K. , SINGH A. P. , CHAUHAN G. , THAKKAR M. G. , BISWAS S. K.
Published: June 2016

We describe a study of the E–W-trending South Wagad Fault (SWF) complex at the eastern part of the Kachchh Rift Basin (KRB) in Western India. This basin was filled during Late Cretaceous time, and is presently undergoing tectonic inversion. During the late stage of the inversion cycle, all the principal rift faults were reactivated as transpressional strike-slip faults. The SWF complex shows wrench geometry of an anastomosing en échelon fault, where contractional and extensional segments and offsets alternate along the Principal Deformation Zone (PDZ). Geometric analysis of different segments of the SWF shows that several conjugate faults, which are a combination of R synthetic and R’ antithetic, propagate at a short distance along the PDZ and interact, generating significant fault slip partitioning. Surface morphology of the fault zone revealed three deformation zones: a 500 m to 1 km wide single fault zone; a 5–6 km wide double fault zone; and a c. 500 m wide diffuse fault zone. The single fault zone is represented by a higher stress accumulation which is located close to the epicentre of the 2001 Bhuj earthquake of Mw 7.7. The double fault zone represents moderate stress at releasing bends bounded by two fault branches. The diffuse fault zone represents a low-stress zone where several fault branches join together. Our findings are well corroborated with the available geological and seismological data.
Parasites as bioindicators of environmental degradation in Latin America: A meta-analysis
Authors: Vidal-Martínez V.M. , Wunderlich A.C.
Published: June 2016

Unregulated economic growth in Latin America has resulted in environmental degradation, including the release of toxic compounds into the environment. One strategy to understand and prevent the outcomes of this harmful environmental degradation is the use of bioindicators. These are free-living or parasite species that respond to habitat alterations with changes in their numbers, physiology or chemical composition. The aim of this review was to determine whether there is evidence of a significant parasite response to environmental damage in Latin America. We collected 26 papers published between 2003 and 2015 and conducted a meta-analysis to test the null hypothesis that there is no significant overall effect of environmental insults on parasites. The meta-analysis showed a low but still significant negative mean overall effect (Hedges’ g = −0.221; 95% CI: −0.241 to −0.200;P< 0.0001). However, the magnitudes and directions of the significant effects varied widely. These results suggest that different groups of parasites have distinct responses to various environmental insults and that the groups should be separately analysed after the accumulation of a sufficient number of studies. For future studies on this topic in Latin America, we suggest: (1) using field and experimental approaches to determine the response of parasites to environmental degradation; (2) using an interdisciplinary approach, including different types of biomarkers in both parasites and individual hosts to generate long-term datasets in polluted and reference areas; (3) conducting studies on parasites as accumulation bioindicators.
Gender and laterality in semicircular canal dehiscence syndrome
Authors: Karimnejad K , Czerny M S , Lookabaugh S , Lee D J , Mikulec A A
Published: June 2016

Objective:

To determine if there is gender or laterality predilection in patients with semicircular canal dehiscence syndrome.

Methods:

A multi-institutional chart review was performed to identify patients diagnosed with semicircular canal dehiscence between 2000 and 2015. A systematic literature search was conducted using PubMed to further identify patients with semicircular canal dehiscence. Age, gender and laterality data were collected. Statistical analysis was performed to evaluate for gender or laterality preponderance.

Results:

A total of 682 patients with semicircular canal dehiscence were identified by literature and chart review. Mean age of diagnosis was 49.75 years (standard deviation = 15.33). Semicircular canal dehiscence was associated with a statistically significant female predominance (chi-square = 7.185,p= 0.007); the female-to-male ratio was 1.2 to 1. Left-sided semicircular canal dehiscence was most common, followed by right-sided then bilateral (chi-square = 23.457,p< 0.001).

Conclusion:

Semicircular canal dehiscence syndrome is most commonly left-sided and exhibits a female predominance. This may be secondary to morphological cerebral hemisphere asymmetries in both sexes and a predilection of women to seek more medical care than men.
A prospective study of pre-trauma risk factors for post-traumatic stress disorder and depression
Authors: Wild J. , Smith K. V. , Thompson E. , Béar F. , Lommen M. J. J. , Ehlers A.
Published: June 2016

Background

It is unclear which potentially modifiable risk factors best predict post-trauma psychiatric disorders. We aimed to identify pre-trauma risk factors for post-traumatic stress disorder (PTSD) or major depression (MD) that could be targeted with resilience interventions.

Method

Newly recruited paramedics (n = 453) were assessed for history of mental disorders with structured clinical interviews within the first week of their paramedic training and completed self-report measures to assess hypothesized predictors. Participants were assessed every 4 months for 2 years to identify any episodes of PTSD and MD; 386 paramedics (85.2%) participated in the follow-up interviews.

Results

In all, 32 participants (8.3%) developed an episode of PTSD and 41 (10.6%) an episode of MD during follow-up. In all but nine cases (2.3%), episodes had remitted by the next assessment 4 months later. At 2 years, those with episodes of PTSD or MD during follow-up reported more days off work, poorer sleep, poorer quality of life, greater burn-out; and greater weight-gain for those with PTSD. In line with theories of PTSD and depression, analyses controlling for psychiatric and trauma history identified several pre-trauma predictors (cognitive styles, coping styles and psychological traits). Logistic regressions showed that rumination about memories of stressful events at the start of training uniquely predicted an episode of PTSD. Perceived resilience uniquely predicted an episode of MD.

Conclusions

Participants at risk of developing episodes of PTSD or depression could be identified within the first week of paramedic training. Cognitive predictors of episodes of PTSD and MD are promising targets for resilience interventions.
The molecular choreography of protein synthesis: translational control, regulation, and pathways
Authors: Chen Jin , Choi Junhong , O'Leary Seán E. , Prabhakar Arjun , Petrov Alexey , Grosely Rosslyn , Puglisi Elisabetta Viani , Puglisi Joseph D.
Published: June 2016

Translation of proteins by the ribosome regulates gene expression, with recent results underscoring the importance of translational control. Misregulation of translation underlies many diseases, including cancer and many genetic diseases. Decades of biochemical and structural studies have delineated many of the mechanistic details in prokaryotic translation, and sketched the outlines of eukaryotic translation. However, translation may not proceed linearly through a single mechanistic pathway, but likely involves multiple pathways and branchpoints. The stochastic nature of biological processes would allow different pathways to occur during translation that are biased by the interaction of the ribosome with other translation factors, with many of the steps kinetically controlled. These multiple pathways and branchpoints are potential regulatory nexus, allowing gene expression to be tuned at the translational level. As research focus shifts toward eukaryotic translation, certain themes will be echoed from studies on prokaryotic translation. This review provides a general overview of the dynamic data related to prokaryotic and eukaryotic translation, in particular recent findings with single-molecule methods, complemented by biochemical, kinetic, and structural findings. We will underscore the importance of viewing the process through the viewpoints of regulation, translational control, and heterogeneous pathways.
Bridging the gap betweenin vitroandin vivoRNA folding
Authors: Leamy Kathleen A. , Assmann Sarah M. , Mathews David H. , Bevilacqua Philip C.
Published: June 2016

Deciphering the folding pathways and predicting the structures of complex three-dimensional biomolecules is central to elucidating biological function. RNA is single-stranded, which gives it the freedom to fold into complex secondary and tertiary structures. These structures endow RNA with the ability to perform complex chemistries and functions ranging from enzymatic activity to gene regulation. Given that RNA is involved in many essential cellular processes, it is critical to understand how it folds and functionsin vivo. Within the last few years, methods have been developed to probe RNA structuresin vivoand genome-wide. These studies reveal that RNA often adopts very different structuresin vivoandin vitro, and provide profound insights into RNA biology. Nonetheless, bothin vitroandin vivoapproaches have limitations: studies in the complex and uncontrolled cellular environment make it difficult to obtain insight into RNA folding pathways and thermodynamics, and studiesin vitrooften lack direct cellular relevance, leaving a gap in our knowledge of RNA foldingin vivo. This gap is being bridged by biophysical and mechanistic studies of RNA structure and function under conditions that mimic the cellular environment. To date, most artificial cytoplasms have used various polymers as molecular crowding agents and a series of small molecules as cosolutes. Studies under suchin vivo-likeconditions are yielding fresh insights, such as cooperative folding of functional RNAs and increased activity of ribozymes. These observations are accounted for in part by molecular crowding effects and interactions with other molecules. In this review, we report milestones in RNA foldingin vitroandin vivoand discuss ongoing experimental and computational efforts to bridge the gap between these two conditions in order to understand how RNA folds in the cell.
Colistin-resistant Escherichia coli clinical isolate harbouring the mcr-1 gene in Ecuador
Authors: ORTEGA-PAREDES D. , BARBA P. , ZURITA J.
Published: June 2016

Colistin resistance mediated by the mcr-1 gene has been reported worldwide, but to date not from the Andean region, South America. We report the first clinical isolate of Escherichia coli harbouring the mcr-1 gene in Ecuador. The strain was isolated from peritoneal fluid from a 14-year-old male with acute appendicitis, and subjected to molecular analysis. The minimum inhibitory concentration of colistin for the strain was 8 mg/ml and it was susceptible to carbapenems but resistant to tigecycline. The strain harboured mcr-1 and blaCTX-M-55 genes and was of sequence type 609. The recognition of an apparently commensal strain of E. coli harbouring mcr-1 serves as an alert to the presence in the region of this recently described resistance mechanism to one of the last line of drugs available for the treatment of multi-resistant Gram-negative infections.
SIX NEW SPECIES OF SYZYGIUM (MYRTACEAE) FROM SUMATRA
Authors: Widodo P. , Chikmawati T.
Published: June 2016

Six new species of Syzygium Gaertn. from Sumatra are described and illustrated. Three are newly described, namely Syzygium abatakum Widodo, S. bengkulense Widodo and S. ketambense Widodo. The descriptions of the other three species, namely Syzygium angustovatum Widodo & Chikmawati, S. comosum Widodo and S. longipetiolatum Widodo are republished to validate their names. The conservation status of each species is proposed, following IUCN guidelines.
Choosing Wisely
Authors: FLECK LEONARD M.
Published: June 2016

The American College of Physicians in its ethics manual endorsed the idea that physicians ought to improve their ability to provide care to their patients more parsimoniously. This elicited a critical backlash; critics essentially claimed that what was being endorsed was a renamed form of rationing. In a recent article, Tilburt and Cassel argued that parsimonious care and rationing are ethically distinct practices. In this essay I critically assess that claim. I argue that in practice there is considerable overlap between what they term parsimonious care and what they define as rationing. The same is true of the Choosing Wisely campaign endorsed by the American Board of Internal Medicine. In both cases, if the goal is to control healthcare costs by reducing the use of marginally beneficial care that is not cost effective, then a public conversation about the justness of specific choices is essential.
An Ethical Analysis of Performance-Based Supplementary Payment in Turkey’s Healthcare System
Authors: KADIOGLU FUNDA GULAY
Published: June 2016

In 2003 Turkey introduced the Health Transition Program to develop easily accessible, high-quality, and effective healthcare services for the population. This program, like other health reforms, has three primary goals: to improve health status, to enhance financial protection, and to ensure patients’ satisfaction. Although there is considerable literature on the anticipated positive results of such health reforms, little evidence exists on their current effectiveness. One of the main initiatives of this health reform is a performance-based supplementary payment system, an additional payment healthcare professionals receive each month in addition to their regular salaries. This system may cause some ethical problems. Physicians have an ethical duty to provide high-quality care to each patient; however, pay-for-performance and other programs that create strong incentives for high-quality care set up a potential conflict between this duty and the competing interest of complying with a performance measure.
An Ethical Analysis of Assisted Reproduction Providers’ Websites in Pakistan
Authors: IRSHAD AYESHA , WERNER-FELMAYER GABRIELE
Published: June 2016

Assisted reproductive technologies (ARTs) and reproductive genetic technologies (RGTs) are intertwined and coevolving. These technologies are increasingly used to fulfill socially and culturally framed requests, for example, “family balancing,” or to enable postmenopausal women or homosexual couples to have genetically linked children. The areas of ART and RGT are replete with ethical issues, because different social practices and legal regulations, as well as economic inequalities within and among countries, create vulnerable groups and, therefore, the potential for exploitation. This article provides an overview of the ART and RGT landscape in Pakistan and analyzes the available online content addressing Pakistani citizens and international clients. We explored the topic in view of socioeconomic challenges in Pakistan, particularly deeply rooted poverty, lack of education, gender discrimination, and absence of regulation. As online information given by ART and RGT providers is readily available and could easily raise false hopes, make use of discriminatory statements with regard to women, and promote gender selection to meet sociocultural expectations, it should be subjected to quality control.
Commentary: Clarifying Medical Decisionmaking—Who, How, and Why?
Authors: Gibb Tyler S. , Redinger Michael J.
Published: June 2016

In its simplest interpretation, this is a case about goals of care and appropriate code status. At the outset, we must confess that we found this case to be extremely interesting—not for the novelty of the issues or its ethical complexity but because it is truly a case of the ordinary. Too often when teaching or discussing clinical ethics cases, we are distracted by the exotic and the unusual and ignore the mundane cases that every practicing clinical ethicist must be able to competently manage.1,2,3
Commentary: Surrogate Decisionmaking and Communication
Authors: Mukherjee Debjani
Published: June 2016

Mr. Hope’s family’s expectations and his staff’s concerns raise important issues about surrogate decisionmaking, communication regarding prognosis, and staff angst. Unfortunately, Mr. Hope himself is unable to reliably understand and communicate his preferences, especially for complex medical decisions, so the ethics consultant is left to negotiate the disagreement between his family and his healthcare providers, who presumably both believe they are acting in his best interest.
Relationships between sucretolerance and salinotolerance in bacteria from hypersaline environments and their implications for the exploration of Mars and the icy worlds
Authors: Fredsgaard Casper , Moore Donald B. , Al Soudi Amer F. , Crisler James D. , Chen Fei , Clark Benton C. , Schneegurt Mark A.
Published: June 2016

The most extremely osmotolerant microbial isolates are fungi from high-sugar environments that tolerate the lowest water activity (0.61) for growth yet reported. Studies of osmotolerant bacteria have focused on halotolerance rather than sucretolerance (ability to grow in high sugar concentrations). A collection of salinotolerant (≥10% NaCl or ≥50% MgSO4) bacterial isolates from the Great Salt Plains of Oklahoma and Hot Lake in Washington were screened for sucretolerance in medium supplemented with ≥50% fructose, glucose or sucrose. Tolerances significantly differed between solutes, even though water activities for saline media (0.92 and 0.85 for 10 and 20% NaCl Salt Plains media, respectively) were comparable or lower than water activities for high-sugar media (0.93 and 0.90 for 50 and 70% sucrose artificial nectar media, respectively). These specific solute effects were differentially expressed among individual isolates. Extrapolating the results of earlier food science studies with yeasts at high sugar concentrations to bacteria in salty environments with low water activity should be done with caution. Furthermore, the discussion of habitable Special Regions on Mars and the icy worlds should reflect an understanding of specific solute effects.
Reflecting on one's own death: The existential questions that nurses face during end-of-life care
Authors: Karlsson Margareta , Kasén Anne , Wärnå-Furu Carola
Published: June 2016

Objective:

When registered nurses care for patients at the end of life, they are often confronted with different issues related to suffering, dying, and death whether working in hospital or community care. Serious existential questions that challenge nurses’ identities as human beings can arise as a result of these situations. The aim of our study was to describe and gain a deeper understanding of nurses’ existential questions when caring for dying patients.

Method:

Focus-group interviews with registered nurses who shared similar experiences and backgrounds about experiences in end-of-life care were employed to gain a deeper understanding about this sensitive subject. Focus-group interviews were performed in hospice care, in community care, and in a palliative care unit in western Sweden. A qualitative hermeneutic approach was employed to interpret the data.

Results:

Nurses’ existential questions balanced between responsibility and guilt in relation to their patients, between fear and courage in relation to being professional caregivers and fellow human beings, and between hope and despair in relation to the other's and their own death.

Significance of results:

Nurses in end-of-life care experience various emotions from patients related to things physical, spatial, and temporal. When nurses encounter these emotions as expressing a patient's suffering, they lead to challenges of balancing between different feelings in relation to patients, as both professional caregivers and fellow human beings. Nurses can experience growth both professionally and as human beings when caring for patients at the end of life.
A 4-Minute Video Improves Parents’ Instruction Delivery to Young Children: A Multiple-Baseline Investigation
Authors: Riley Andrew R. , Boshkoff Emily A. , Neisius Abby , Freeman Kurt A.
Published: June 2016

Researchers have noted the potential of very brief technology-based multimedia interventions to disseminate positive parenting practices in pediatric primary care. Such interventions are well-accepted and reported as useful, but no study has objectively assessed their effects on target parenting behaviors. To determine the effects of a 4-min video intervention on effective instruction delivery, a multiphase multiple-baseline across participants design was used to sequentially expose parent–child dyads ( N = 3) to the following conditions: Baseline, Video Intervention, Video Intervention + Self-Feedback, Video Intervention + Self-Feedback + Researcher-Feedback. Parent-child dyads were directly observed and parent behavior was coded for effective instruction delivery. Each dyad showed improvement in effective instruction delivery in response to the intervention. For 2/3 dyads, feedback phases resulted in additive gains. The results demonstrate that in addition to being well-accepted and perceived as useful, ultra-brief multimedia interventions hold potential to alter specific parenting behaviors.
Stimulus-responsive light-harvesting complexes based on the pillararene-induced co-assembly of β-carotene and chlorophyll
Authors: Sun Yan , Guo Fang , Zuo Tongfei , Hua Jingjing , Diao Guowang
Published: June 2016

The locations and arrangements of carotenoids at the subcellular level are responsible for their designated functions, which reinforces the necessity of developing methods for constructing carotenoid-based suprastructures beyond the molecular level. Because carotenoids lack the binding sites necessary for controlled interactions, functional structures based on carotenoids are not easily obtained. Here, we show that carotene-based suprastructures were formed via the induction of pillararene through a phase-transfer-mediated host–guest interaction. More importantly, similar to the main component in natural photosynthesis, complexes could be synthesized after chlorophyll was introduced into the carotene-based suprastructure assembly process. Remarkably, compared with molecular carotene or chlorophyll, this synthesized suprastructure exhibits some photocatalytic activity when exposed to light, which can be exploited for photocatalytic reaction studies of energy capture and solar conversion in living organisms.
Mechanisms of increased Trichodesmium fitness under iron and phosphorus co-limitation in the present and future ocean
Authors: Walworth Nathan G. , Fu Fei-Xue , Webb Eric A. , Saito Mak A. , Moran Dawn , Mcllvin Matthew R. , Lee Michael D. , Hutchins David A.
Published: June 2016

Nitrogen fixation by cyanobacteria supplies critical bioavailable nitrogen to marine ecosystems worldwide; however, field and lab data have demonstrated it to be limited by iron, phosphorus and/or CO2. To address unknown future interactions among these factors, we grew the nitrogen-fixing cyanobacterium Trichodesmium for 1 year under Fe/P co-limitation following 7 years of both low and high CO2 selection. Fe/P co-limited cell lines demonstrated a complex cellular response including increased growth rates, broad proteome restructuring and cell size reductions relative to steady-state growth limited by either Fe or P alone. Fe/P co-limitation increased abundance of a protein containing a conserved domain previously implicated in cell size regulation, suggesting a similar role in Trichodesmium. Increased CO2 further induced nutrient-limited proteome shifts in widespread core metabolisms. Our results thus suggest that N2-fixing microbes may be significantly impacted by interactions between elevated CO2 and nutrient limitation, with broad implications for global biogeochemical cycles in the future ocean.
Mechanical perturbations trigger endothelial nitric oxide synthase activity in human red blood cells
Authors: Nagarajan Shunmugan , Raj Rajendran Kadarkarai , Saravanakumar Venkatesan , Balaguru Uma Maheswari , Behera Jyotirmaya , Rajendran Vinoth Kumar , Shathya Yogarajan , Ali B. Mohammed Jaffar , Sumantran Venil , Chatterjee Suvro
Published: June 2016

Nitric oxide (NO), a vascular signaling molecule, is primarily produced by endothelial NO synthase. Recently, a functional endothelial NO synthase (eNOS) was described in red blood cells (RBC). The RBC-eNOS contributes to the intravascular NO pool and regulates physiological functions. However the regulatory mechanisms and clinical implications of RBC-eNOS are unknown. The present study investigated regulation and functions of RBC-eNOS under mechanical stimulation. This study shows that mechanical stimuli perturb RBC membrane, which triggers a signaling cascade to activate the eNOS. Extracellular NO level, estimated by the 4-Amino-5-Methylamino-2′, 7′-Difluorofluorescein Diacetate probe, was significantly increased under mechanical stimuli. Immunostaining and western blot studies confirmed that the mechanical stimuli phosphorylate the serine 1177 moiety of RBC-eNOS and activates the enzyme. The NO produced by activation of RBC-eNOS in vortexed RBCs promoted important endothelial functions such as migration and vascular sprouting. We also show that mechanical perturbation facilitates nitrosylation of RBC proteins via eNOS activation. The results of the study confirm that mechanical perturbations sensitize RBC-eNOS to produce NO, which ultimately defines physiological boundaries of RBC structure and functions. Therefore, we propose that mild physical perturbations before, after, or during storage can improve viability of RBCs in blood banks.
The Lombard effect in male ultrasonic frogs: Regulating antiphonal signal frequency and amplitude in noise
Authors: Shen Jun-Xian , Xu Zhi-Min
Published: June 2016

Acoustic communication in noisy environments presents a significant challenge for vocal animals because noise can interfere with animal acoustic signals by decreasing signal-to-noise ratios and masking signals. Birds and mammals increase call intensity or frequency as noise levels increase, but it is unclear to what extend this behavior is shared by frogs. Concave-eared torrent frogs (Odorrana tormota) have evolved the capacity to produce various calls containing ultrasonic harmonics and to communicate beside noisy streams. However, it is largely unclear how frogs regulate vocalization in response to increasing noise levels. We exposed male frogs to various levels of noise with playback of conspecific female courtship calls and recorded antiphonal signals and spontaneous short calls. Males were capable of rapidly adjusting fundamental frequency and amplitude of antiphonal signals as noise levels increased. The increment in fundamental frequency and amplitude was approximately 0.5 kHz and 3 dB with every 10 dB increase in noise level, indicating the presence of noise-dependent signal characteristics. Males showed the noise-tolerant adaption in response to female calls in noise level from 40 to 90 dB SPL. The results suggest that the noise-dependent signal characteristics in O. tormota have evolved as a strategy to cope with varying torrent noise.
The new and recurrent FLT3 juxtamembrane deletion mutation shows a dominant negative effect on the wild-type FLT3 receptor
Authors: Sandhöfer Nadine , Bauer Julia , Reiter Katrin , Dufour Annika , Rothenberg Maja , Konstandin Nikola P. , Zellmeier Evelyn , Tizazu Belay , Greif Philipp A. , Metzeler Klaus H. , Hiddemann Wolfgang , Polzer Harald , Spiekermann Karsten
Published: June 2016

In acute myeloid leukemia (AML), the Fms-like tyrosine kinase 3 (FLT3) is one of the most frequently mutated genes. Recently, a new and recurrent juxtamembrane deletion mutation (p.Q569Vfs*2) resulting in a truncated receptor was identified. The mutated receptor is expressed on the cell surface and still binds its ligand but loses the ability to activate ERK signaling. FLT3 p.Q569fs-expressing Ba/F3 cells show no proliferation after ligand stimulation. Furthermore, coexpressed with the FLT3 wild-type (WT) receptor, the truncated receptor suppresses stimulation and activation of the WT receptor. Thus, FLT3 p.Q569Vfs*2, to our knowledge, is the first FLT3 mutation with a dominant negative effect on the WT receptor.
Histone modifications and p53 binding poise the p21 promoter for activation in human embryonic stem cells
Authors: Itahana Yoko , Zhang Jinqiu , Göke Jonathan , Vardy Leah A. , Han Rachel , Iwamoto Kozue , Cukuroglu Engin , Robson Paul , Pouladi Mahmoud A. , Colman Alan , Itahana Koji
Published: June 2016

The high proliferation rate of embryonic stem cells (ESCs) is thought to arise partly from very low expression of p21. However, how p21 is suppressed in ESCs has been unclear. We found that p53 binds to the p21 promoter in human ESCs (hESCs) as efficiently as in differentiated human mesenchymal stem cells, however it does not promote p21 transcription in hESCs. We observed an enrichment for both the repressive histone H3K27me3 and activating histone H3K4me3 chromatin marks at the p21 locus in hESCs, suggesting it is a suppressed, bivalent domain which overrides activation by p53. Reducing H3K27me3 methylation in hESCs rescued p21 expression, and ectopic expression of p21 in hESCs triggered their differentiation. Further, we uncovered a subset of bivalent promoters bound by p53 in hESCs that are similarly induced upon differentiation in a p53-dependent manner, whereas p53 promotes the transcription of other target genes which do not show an enrichment of H3K27me3 in ESCs. Our studies reveal a unique epigenetic strategy used by ESCs to poise undesired p53 target genes, thus balancing the maintenance of pluripotency in the undifferentiated state with a robust response to differentiation signals, while utilizing p53 activity to maintain genomic stability and homeostasis in ESCs.
Costs of life - Dynamics of the protein inventory of Staphylococcus aureus during anaerobiosis
Authors: Zühlke Daniela , Dörries Kirsten , Bernhardt Jörg , Maaß Sandra , Muntel Jan , Liebscher Volkmar , Pané-Farré Jan , Riedel Katharina , Lalk Michael , Völker Uwe , Engelmann Susanne , Becher Dörte , Fuchs Stephan , Hecker Michael
Published: June 2016

Absolute protein quantification was applied to follow the dynamics of the cytoplasmic proteome of Staphylococcus aureus in response to long-term oxygen starvation. For 1,168 proteins, the majority of all expressed proteins, molecule numbers per cell have been determined to monitor the cellular investments in single branches of bacterial life for the first time. In the presence of glucose the anaerobic protein pattern is characterized by increased amounts of glycolytic and fermentative enzymes such as Eno, GapA1, Ldh1, and PflB. Interestingly, the ferritin-like protein FtnA belongs to the most abundant proteins during anaerobic growth. Depletion of glucose finally leads to an accumulation of different enzymes such as ArcB1, ArcB2, and ArcC2 involved in arginine deiminase pathway. Concentrations of 29 exo- and 78 endometabolites were comparatively assessed and have been integrated to the metabolic networks. Here we provide an almost complete picture on the response to oxygen starvation, from signal transduction pathways to gene expression pattern, from metabolic reorganization after oxygen depletion to beginning cell death and lysis after glucose exhaustion. This experimental approach can be considered as a proof of principle how to combine cell physiology with quantitative proteomics for a new dimension in understanding simple life processes as an entity.
The role of environmental constraints in walking: Effects of steering and sharp turns on gait dynamics
Authors: Dotov Dobromir G. , Bardy Benoît G. , Dalla Bella Simone
Published: June 2016

Stride durations in gait exhibit long-range correlation (LRC) which tends to disappear with certain movement disorders. The loss of LRC has been hypothesized to result from a reduction of functional degrees of freedom of the neuromuscular apparatus. A consequence of this theory is that environmental constraints such as the ones induced during constant steering may also reduce LRC. Furthermore, obstacles may perturb control of the gait cycle and also reduce LRC. To test these predictions, seven healthy participants walked freely overground in three conditions: unconstrained, constrained (constant steering), and perturbed (frequent 90° turns). Both steering and sharp turning reduced LRC with the latter having a stronger effect. Competing theories explain LRC in gait by positing fractal CPGs or a biomechanical process of kinetic energy reuse. Mediation analysis showed that the effect of the experimental manipulation in the current experiment depends partly on a reduction in walking speed. This supports the biomechanical theory. We also found that the local Hurst exponent did not reflect the frequent changes of heading direction. This suggests that the recovery from the sharp turn perturbation, a kind of relaxation time, takes longer than the four to seven meters between successive turns in the present study.
Tribo-biological deposits on the articulating surfaces of metal-on-polyethylene total hip implants retrieved from patients
Authors: Cui Zhiwei , Tian Yi-Xing , Yue Wen , Yang Lei , Li Qunyang
Published: June 2016

Artificial total hip arthroplasty (THA) is one of the most effective orthopaedic surgeries that has been used for decades. However, wear of the articulating surfaces is one of the key failure causes limiting the lifetime of total hip implant. In this paper, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were employed to explore the composition and formation mechanism of the tribo-layer on the articulating surfaces of metal-on-polyethylene (MoPE) implants retrieved from patients. Results showed that, in contrast to conventional understanding, the attached tribo-layer contained not only denatured proteins but also a fraction of polymer particles. The formation of the tribo-layer was believed to relate to lubrication regime, which was supposed to be largely affected by the nature of the ultra-high-molecule-weight-polyethylene (UHMWPE). Wear and formation of tribo-layer could be minimized in elasto-hydrodynamic lubrication (EHL) regime when the UHMWPE was less stiff and have a morphology containing micro-pits; whereas the wear was more severe and tribo-layer formed in boundary lubrication. Our results and analyses suggest that enhancing interface lubrication may be more effective on reducing wear than increasing the hardness of material. This finding may shed light on the design strategy of artificial hip joints.