bluuebunny/crossref_metadata_2025 huggingface dataset:
Foliar uptake of fog water and transport belowground alleviates drought effects in the cloud forest tree species, Drimys brasiliensis (Winteraceae)
Authors: Eller Cleiton B. , Lima Aline L. , Oliveira Rafael S.
Published: March 2013

Foliar water uptake (FWU) is a common water acquisition mechanism for plants inhabiting temperate fog‐affected ecosystems, but the prevalence and consequences of this process for the water and carbon balance of tropical cloud forest species are unknown.

We performed a series of experiments under field and glasshouse conditions using a combination of methods (sap flow, fluorescent apoplastic tracers and stable isotopes) to trace fog water movement from foliage to belowground components of Drimys brasiliensis. In addition, we measured leaf water potential, leaf gas exchange, leaf water repellency and growth of plants under contrasting soil water availabilities and fog exposure in glasshouse experiments to evaluate FWU effects on the water and carbon balance of D. brasiliensis saplings.

Fog water diffused directly through leaf cuticles and contributed up to 42% of total foliar water content. FWU caused reversals in sap flow in stems and roots of up to 26% of daily maximum transpiration. Fog water transported through the xylem reached belowground pools and enhanced leaf water potential, photosynthesis, stomatal conductance and growth relative to plants sheltered from fog.

Foliar uptake of fog water is an important water acquisition mechanism that can mitigate the deleterious effects of soil water deficits for D. brasiliensis.
Protozoa enhance foraging efficiency of arbuscular mycorrhizal fungi for mineral nitrogen from organic matter in soil to the benefit of host plants
Authors: Koller Robert , Rodriguez Alia , Robin Christophe , Scheu Stefan , Bonkowski Michael
Published: March 2013

Dead organic matter (OM) is a major source of nitrogen (N) for plants. The majority of plants support N uptake by symbiosis with arbuscular mycorrhizal (AM) fungi. Mineralization of N is regulated by microfauna, in particular, protozoa grazing on bacteria. We hypothesized that AM fungi and protozoa interactively facilitate plant N nutrition from OM.

In soil systems consisting of an OM patch and a root compartment, plant N uptake and consequences for plant carbon (C) allocation were investigated using stable isotopes.

Protozoa mobilized N by consuming bacteria, and the mobilized N was translocated via AM fungi to the host plant. The presence of protozoa in both the OM and root compartment stimulated photosynthesis and the translocation of C from the host plant via AM fungi into the OM patch. This stimulated microbial activity in the OM patch, plant N uptake from OM and doubled plant growth.

The results indicate that protozoa increase plant growth by both mobilization of N from OM and by protozoa–root interactions, resulting in increased C allocation to roots and into the rhizosphere, thereby increasing plant nutrient exploitation. Hence, mycorrhizal plants need to interact with protozoa to fully exploit N resources from OM.
Class III PI3K Vps34: essential roles in autophagy, endocytosis, and heart and liver function
Authors: Jaber Nadia , Zong Wei‐Xing
Published: March 2013

Mammalian phosphatidylinositol (PI) 3‐kinases are a family of proteins that share the ability to phosphorylate phosphoinositides at the 3 position of the inositol ring. By doing so, these kinases produce phospholipid molecules that are involved in various cell signaling pathways, such as insulin signaling and endocytosis. The pathways regulated by PI3‐kinases are crucial for maintaining cellular homeostasis and thus must be tightly regulated. Irregular PI3‐kinase activity is observed in numerous human pathological conditions, such as diabetes, cancer, and inflammation. One family member, Vps34, is of particular interest because it is the only PI3‐kinase identified in yeast and it has been evolutionarily conserved through mammals. Vps34 plays an essential role in the cellular process of autophagy, a process linked to human health and disease. Understanding the precise role of mammalian Vps34 will likely be integral to drug development for various diseases.
Achieving cancer cell death with PI3K/mTOR‐targeted therapies
Authors: Yea Sung Su , Fruman David A.
Published: March 2013

Inhibitors of the PI3K/mTOR signaling network are under development as novel cancer therapies. However, these compounds do not cause robust cytotoxic responses in tumor cells unless combined with other agents. Rational combinations with other targeted therapies will likely be necessary to achieve the potential of PI3K/mTOR inhibitors in oncology.
Phosphoinositide 3‐kinase gamma in T cell biology and disease therapy
Authors: Fung‐Leung Wai‐Ping
Published: March 2013

Phosphoinositide 3‐kinase gamma (PI3Kγ) kinase activity is important for its signaling functions in T cell development, activation, differentiation, and trafficking. Protection of PI3Kγ knockout mice from disease in multiple autoimmune models suggests that targeting PI3Kγ alone, or in combination with PI3Kδ, could be a promising approach to disease therapy.
Phosphoinositide 3‐kinase and INPP4B in human breast cancer
Authors: Bertucci Micka C. , Mitchell Christina A.
Published: March 2013

The PI3K/Akt signaling pathway is frequently increased in many human cancers, including breast cancer. Recent studies have identified INPP4B, which inhibits PI3K signaling, as an emerging tumor suppressor in breast cancer. This short review discusses these issues and the possibility that INPP4B is an important regulator in many cancers.
Inhibition of phosphoinositide 3‐kinase γ attenuates inflammation, obesity, and cardiovascular risk factors
Authors: Wymann Matthias P. , Solinas Giovanni
Published: March 2013

Phosphoinositide 3‐kinase γ (PI3Kγ) plays a central role in inflammation, allergy, cardiovascular, and metabolic disease. Obesity is accompanied by chronic, low‐grade inflammation. As PI3Kγ plays a major role in leukocyte recruitment, targeting of PI3Kγ has been considered to be a strategy for attenuating progression of obesity to insulin resistance and type 2 diabetes. Indeed, PI3Kγ null mice are protected from high fat diet–induced obesity, metabolic inflammation, fatty liver, and insulin resistance. The lean phenotype of the PI3Kγ‐null mice has been linked to increased thermogenesis and energy expenditure. Surprisingly, the increase in fat mass and metabolic aberrations were not linked to PI3Kγ activity in the hematopoietic compartment. Thermogenesis and oxygen consumption are modulated by PI3Kγ lipid kinase–dependent and –independent signaling mechanisms. PI3Kγ signaling controls metabolic and inflammatory stress, and may provide an entry point for therapeutic strategies in metabolic disease, inflammation, and cardiovascular disease.
Targeting phosphoinositide 3‐kinase δ for the treatment of respiratory diseases
Authors: Sriskantharajah Srividya , Hamblin Nicole , Worsley Sally , Calver Andrew R. , Hessel Edith M. , Amour Augustin
Published: March 2013

Asthma and chronic obstructive pulmonary disease (COPD) are characterized in their pathogenesis by chronic inflammation in the airways. Phosphoinositide 3‐kinase δ (PI3Kδ), a lipid kinase expressed predominantly in leukocytes, is thought to hold much promise as a therapeutic target for such inflammatory conditions. Of particular interest for the treatment of severe respiratory disease is the observation that inhibition of PI3Kδ may restore steroid effectiveness under conditions of oxidative stress. PI3Kδ inhibition may also prevent recruitment of inflammatory cells, including T lymphocytes and neutrophils, as well as the release of proinflammatory mediators, such as cytokines, chemokines, reactive oxygen species, and proteolytic enzymes. In addition, targeting the PI3Kδ pathway could reduce the incidence of pathogen‐induced exacerbations by improving macrophage‐mediated bacterial clearance. In this review, we discuss the potential and highlight the unknowns of targeting PI3Kδ for the treatment of respiratory disease, focusing on recent developments in the role of the PI3Kδ pathway in inflammatory cell types believed to be critical to the pathogenesis of COPD.
Role of PI3K/Akt and mTOR complexes in Th17 cell differentiation
Authors: Nagai Shigenori , Kurebayashi Yutaka , Koyasu Shigeo
Published: March 2013

Interleukin (IL)‐17–producing helper T (Th17) cells serve as a Th subset involved in epithelial cell– and neutrophil‐mediated immune responses against extracellular microbes and in the development of various autoimmune diseases. The differentiation of Th17 cells is controlled by a number of intracellular signaling cascades and a complex network of transcription factors. Recently, it has been shown that PI3K, Akt, and mammalian target of rapamycin (mTOR) complexes, such as mTORC1 and mTORC2, also positively regulate Th17 differentiation both in vivo and in vitro via multiple mechanisms; here, we review the current knowledge regarding the mechanisms through which these molecules enhance Th17 differentiation.
Interventions designed to limit gestational weight gain: a systematic review of theory and meta‐analysis of intervention components
Authors: Hill B. , Skouteris H. , Fuller‐Tyszkiewicz M.
Published: March 2013

Limiting gestational weight gain (GWG) to recommended levels is important to optimize health outcomes for mother and baby. Surprisingly, a recent review revealed that theory‐based interventions to limit GWG were less effective than interventions that did not report a theory‐base; however, strict criteria were used to identify theory‐informed studies. We extended this review and others by systematically evaluating the theories of behaviour change informing GWG interventions using a generalized health psychology perspective, and meta‐analysing behaviour change techniques reported in the interventions. Interventions designed to limit GWG were searched for using health, nursing and psychology databases. Papers reporting an underpinning theory were identified and the CALO‐RE taxonomy was used to determine individual behaviour change techniques. Nineteen studies were identified for inclusion. Eight studies were informed by a behaviour change theory; six reported favourable effects on GWG. Overall, studies based on theory were as effective as non–theory‐based studies at limiting GWG. Furthermore, the provision of information, motivational interviewing, behavioural self‐monitoring and providing rewards contingent on successful behaviour appear to be key strategies when intervening in GWG. Combining these behaviour change techniques with dietary interventions may be most effective. Future research should focus on determining the exact combination of behaviour change techniques, or which underpinning theories, are most useful for limiting GWG.
Pneumoperitoneum for neonatal laparoscopy: how safe is it?
Authors: Olsen Melanie , Avery Nicole , Khurana Sanjeev , Laing Rob
Published: March 2013

We present the case of a 3 day old term neonate who experienced a cardiopulmonary arrest during creation of pneumoperitoneum for laparoscopic repair of duodenal atresia. The arrest was thought likely to have occurred as a result of a gas embolism. We discuss the features of the neonatal circulation which may predispose neonates to embolic phenomena during laparoscopic procedures, and the potential benefit of priming the insufflation apparatus with carbon dioxide. The possibility of gas embolism should be considered when contemplating laparoscopic surgery in this patient group.
Evaluation of distal radial artery cross‐sectional internal diameter in pediatric patients using ultrasound
Authors: Varga Eliane Q.S. , Candiotti Keith A. , Saltzman Bruce , Gayer Steven , Giquel Jadelis , Castillo‐Pedraza Catalina , Sanchez Grace , Halliday Norman
Published: March 2013

In this study, we measure the radial artery internal diameter (RAID) in children up to 4 years of age before and after the induction of anesthesia. A B‐mode portable color Doppler ultrasound was used to measure the RAID. Three sets of measurements were taken for each child before and after the induction of anesthesia and with the wrist in the neutral and dorsiflexed positions. The reliability of the mean value of the RAID in the three sets in 24 patients was established. There were discrepancies between the RAID and the proposed catheter size in some individuals, which may not only render placement difficult but also have potential for arterial injury. There are good reasons to measure the RAID in small children prior to insertion of an intra‐arterial catheter.
Phenylephrine as a simulated intravascular epidural test dose in pediatrics: a pilot study
Authors: Pancaro Carlo , Nasr Viviane G. , Paulus Jessica K. , Bonney Iwona , Flores Alejandro F. , Galper Jonas B. , Ahmed Iqbal
Published: March 2013

Background

A test dose is used to detect intravascular injection during neuraxial block in pediatrics. Accidental intravascular epidural local anesthetic injection might be unrecognized in anesthetized children leading to potential life‐threatening complications. In children, sevoflurane anesthesia blunts the hemodynamic response when intravascular cathecolamines are administered. No studies have explored the hemodynamics and the criteria for a positive test dose result following phenylephrine in sevoflurane anesthetized children.

Methods

Healthy children undergoing minor procedures were randomly assigned to receive intravenous placebo, or 5 μg∙kg−1 phenylephrine (n = 11/group) during sevoflurane anesthesia. Hemodynamic response was assessed using electrocardiography, pulse oxymetry and non‐invasive blood pressure monitoring for 5 min following drug administration in anesthetized patients.

Results

All patients receiving phenylephrine showed a decreased heart rate (HR) but not all of them met the positive criterion for test dose response. Overall, at 1 min, patients receiving phenylephrine showed a 25% decrease in HR from the baseline while an increase in blood pressure was noticed in 54% of patients receiving phenylephrine.

Discussion

Phenylephrine might be a future indicator of positive intravascular test dose. Further investigation is needed to find out the phenylephrine dose that elicits a reliable hemodynamic response and whether phenylephrine needs to be dose age‐adjusted in order to appreciate relevant hemodynamic changes in children receiving neuraxial blocks undergoing general anesthesia.
Genome‐wide promoter methylation analysis identifies epigenetic silencing of MAPK13 in primary cutaneous melanoma
Authors: Gao Linda , Smit Marjon A. , van den Oord Joost J. , Goeman Jelle J. , Verdegaal Els M. E. , van der Burg Sjoerd H. , Stas Marguerite , Beck Samuel , Gruis Nelleke A. , Tensen Cornelis P. , Willemze Rein , Peeper Daniel S. , van Doorn Remco
Published: March 2013

The involvement of epigenetic alterations in the pathogenesis of melanoma is increasingly recognized. Here, we performed genome‐wide DNA methylation analysis of primary cutaneous melanoma and benign melanocytic nevus interrogating 14 495 genes using BeadChip technology. This genome‐wide view of promoter methylation in primary cutaneous melanoma revealed an array of recurrent DNA methylation alterations with potential diagnostic applications. Among 106 frequently hypermethylated genes, there were many novel methylation targets and tumor suppressor genes. Highly recurrent methylation of the HOXA9, MAPK13, CDH11, PLEKHG6, PPP1R3C, and CLDN11 genes was established. Promoter methylation of MAPK13, encoding p38δ, was present in 67% of primary and 85% of metastatic melanomas. Restoration of MAPK13 expression in melanoma cells exhibiting epigenetic silencing of this gene reduced proliferation, indicative of tumor suppressive functions. This study demonstrates that DNA methylation alterations are widespread in melanoma and suggests that epigenetic silencing of MAPK13 contributes to melanoma progression.
Congenital Ulcer of the Buttock
Authors: Torrelo Antonio , Soriano María Isabel , Hernández‐Martín Angela , Colmenero Isabel
Published: March 2013

We present the case of a congenital, deep ulcer of the buttock in an otherwise healthy newborn girl. Histopathology excluded any specific cause of ulceration. The ulcer healed spontaneously at 4 weeks of age, leaving a scar. Because the patient also had symmetrical pits on her knees and because the ulcer was located in an area typically affected by dimples, we interpret this unique manifestation as a congenital defect in the spectrum of congenital dimples.
Merkel Cell Polyomavirus Detection in a Patient with Familial Epidermodysplasia Verruciformis
Authors: Kwon Eun‐Kyung M. , Halvorson Christian R. , Rady Peter , Tyring Stephen , Nguyen Harrison P. , Kao Grace F. , Gaspari Anthony A.
Published: March 2013

We report a case of Merkel cell polyomavirus detection in the skin of a patient with epidermodysplasia verruciformis (EDV) and a family history remarkable for an unusual inheritance pattern for EDV.
Photoinactivation of Bacteria Attached to Glass and Acrylic Surfaces by 405 nm Light: Potential Application for Biofilm Decontamination
Authors: McKenzie Karen , Maclean Michelle , Timoshkin Igor V. , Endarko Endarko , MacGregor Scott J. , Anderson John G.
Published: March 2013

Attachment of bacteria to surfaces and subsequent biofilm formation remains a major cause of cross‐contamination capable of inducing both food‐related illness and nosocomial infections. Resistance to many current disinfection technologies means facilitating their removal is often difficult. The aim of this study was to investigate the efficacy of 405 nm light for inactivation of bacterial attached as biofilms to glass and acrylic. Escherichia coli biofilms (103–108 CFU mL−1) were generated on glass and acrylic surfaces and exposed for increasing times to 405 nm light (5–60 min) at ca 140 mW cm−2. Successful inactivation of biofilms has been demonstrated, with results highlighting complete/near‐complete inactivation (up to 5 log10 reduction on acrylic and 7 log10 on glass). Results also highlight that inactivation of bacterial biofilms could be achieved whether the biofilm was on the upper “directly exposed” surface or “indirectly exposed” underside surface. Statistically significant inactivation was also shown with a range of other microorganisms associated with biofilm formation (Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes). Results from this study have demonstrated significant inactivation of bacteria ranging from monolayers to densely populated biofilms using 405 nm light, highlighting that with further development this technology may have potential applications for biofilm decontamination in food and clinical settings.
When Precaution Creates Misunderstandings: The Unintended Effects of Precautionary Information on Perceived Risks, the EMF Case
Authors: Wiedemann Peter M. , Schuetz Holger , Boerner Franziska , Clauberg Martin , Croft Rodney , Shukla Rajesh , Kikkawa Toshiko , Kemp Ray , Gutteling Jan M. , de Villiers Barney , da Silva Medeiros Flavia N. , Barnett Julie
Published: March 2013

In the past decade, growing public concern about novel technologies with uncertain potential long‐term impacts on the environment and human health has moved risk policies toward a more precautionary approach. Focusing on mobile telephony, the effects of precautionary information on risk perception were analyzed. A pooled multinational experimental study based on a 5 × 2 × 2 factorial design was conducted in nine countries. The first factor refers to whether or not information on different types of precautionary measures was present, the second factor to the framing of the precautionary information, and the third factor to the order in which cell phones and base stations were rated by the study participants. The data analysis on the country level indicates different effects. The main hypothesis that informing about precautionary measures results in increased risk perceptions found only partial support in the data. The effects are weaker, both in terms of the effect size and the frequency of significant effects, across the various precautionary information formats used in the experiment. Nevertheless, our findings do not support the assumption that informing people about implemented precautionary measures will decrease public concerns.
A Bayes Linear Bayes Method for Estimation of Correlated Event Rates
Authors: Quigley John , Wilson Kevin J. , Walls Lesley , Bedford Tim
Published: March 2013

Typically, full Bayesian estimation of correlated event rates can be computationally challenging since estimators are intractable. When estimation of event rates represents one activity within a larger modeling process, there is an incentive to develop more efficient inference than provided by a full Bayesian model. We develop a new subjective inference method for correlated event rates based on a Bayes linear Bayes model under the assumption that events are generated from a homogeneous Poisson process. To reduce the elicitation burden we introduce homogenization factors to the model and, as an alternative to a subjective prior, an empirical method using the method of moments is developed. Inference under the new method is compared against estimates obtained under a full Bayesian model, which takes a multivariate gamma prior, where the predictive and posterior distributions are derived in terms of well‐known functions. The mathematical properties of both models are presented. A simulation study shows that the Bayes linear Bayes inference method and the full Bayesian model provide equally reliable estimates. An illustrative example, motivated by a problem of estimating correlated event rates across different users in a simple supply chain, shows how ignoring the correlation leads to biased estimation of event rates.
Stretch‐shortening cycle muscle power in women and men aged 18–81 years: Influence of age and gender
Authors: Edwén C. E. , Thorlund J. B. , Magnusson S. P. , Slinde F. , Svantesson U. , Hulthén L. , Aagaard P.
Published: March 2013

This study explored the age‐related deterioration in stretch‐shortening cycle (SSC) muscle power and concurrent force–velocity properties in women and men across the adult life span.

A total of 315 participants (women: n = 188; men: n = 127) aged 18–81 years performed maximal countermovement jumps on an instrumented force plate.

Maximal SSC leg extension power expressed per kg body mass (Ppeak) was greater in men than in women across the adult age span (P < 0.001); however, this gender difference was progressively reduced with increasing age, because men showed an ∼50% faster rate of decline in SSC power than women (P < 0.001). Velocity at peak power (VPpeak) was greater in men than in women (P < 0.001) but declined at a greater rate in men than in women (P = 0.002). Vertical ground reaction force at peak power (FPpeak) was higher in men than in women in younger adults only (P < 0.001) and the age‐related decline was steeper in men than in women (P < 0.001).

Men demonstrated a steeper rate of decline in Ppeak than women with progressive aging. This novel finding emerged as a result of greater age‐related losses in men for both force and velocity. Consequently, maximal SSC power production was observed to converge between genders when approaching old age.
The relationship between the Young's modulus of the stratum corneum and age: a pilot study
Authors: Hara Yusuke , Masuda Yuji , Hirao Tetsuji , Yoshikawa Nobuhiro
Published: March 2013

Background/purpose

The mechanical properties of the stratum corneum play an important role in protecting the body from external physical stimuli and excessive sensitivity. However, it is difficult to analyze these mechanical properties in vivo. To resolve this problem, we carried out a numerical analysis to calculate the Young's modulus of the stratum corneum. We then investigated the relationship between the Young's modulus of the stratum corneum and age.

Methods

We used a Cutometer® and a Dermal Torque Meter® for measuring skin mechanical parameters, and optical coherence tomography and an ultrasonic imaging system for measuring skin thickness. Based on these non‐invasive results, liner elastic analysis was performed by the finite element method, and the Young's moduli of the stratum corneum and the dermis were calculated by solving an inverse problem. Using these techniques, we analyzed the correlation between the Young's modulus of the stratum corneum for the cheeks of seventy‐eight Japanese women aged from 20 to 68 years.

Results

In the group study, the mean Young's moduli of the stratum corneum and dermis were calculated 1.993 MPa and 0.066 MPa, respectively. While carrying out individual analyses, there was a weak relationship between the Young's modulus of the stratum corneum and age (r = 0.337).

Conclusion

We calculated the Young's modulus of the stratum corneum in vivo, with commercially available systems, and found that it is a weak correlation with age in this group of subjects. Future developments of our method would be beneficial in the characterization of facial skin aging and the validation of cosmetic and medical applications.
Intra‐ and inter‐rater reliability of digital image analysis for skin color measurement
Authors: Sommers Marilyn , Beacham Barbara , Baker Rachel , Fargo Jamison
Published: March 2013

Background

We determined the intra‐ and inter‐rater reliability of data from digital image color analysis between an expert and novice analyst.

Methods

Following training, the expert and novice independently analyzed 210 randomly ordered images. Both analysts used Adobe® Photoshop lasso or color sampler tools based on the type of image file. After color correction with Pictocolor® in camera software, they recorded L*a*b* (L*=light/dark; a*=red/green; b*=yellow/blue) color values for all skin sites. We computed intra‐rater and inter‐rater agreement within anatomical region, color value (L*, a*, b*), and technique (lasso, color sampler) using a series of one‐way intra‐class correlation coefficients (ICCs).

Results

Results of ICCs for intra‐rater agreement showed high levels of internal consistency reliability within each rater for the lasso technique (ICC ≥ 0.99) and somewhat lower, yet acceptable, level of agreement for the color sampler technique (ICC = 0.91 for expert, ICC = 0.81 for novice). Skin L*, skin b*, and labia L* values reached the highest level of agreement (ICC ≥ 0.92) and skin a*, labia b*, and vaginal wall b* were the lowest (ICC ≥ 0.64).

Conclusion

Data from novice analysts can achieve high levels of agreement with data from expert analysts with training and the use of a detailed, standard protocol.
The effect of rainfall on spatio‐temporal variability in cropping systems and duration of crop cover in the Northern Ethiopian Highlands
Authors: Frankl A. , Jacob M. , Haile M. , Poesen J. , Deckers J. , Nyssen J.
Published: March 2013

In the Northern Ethiopian Highlands, ca. 33% of the land is cropland, which is mainly cultivated by smallholders who based on indigenous knowledge plan their cropping system on the basis of spatio‐temporal variability in rainfall. To understand the relationships between rainfall variability and cropping systems, a field campaign was undertaken in the rainy season of 2009 when 118 farmers were interviewed at different locations with different environmental characteristics. Five cropping systems were identified, each having a distinct cropping season length and crop association. Cropping systems with shorter cropping seasons were generally on the valleysides, whereas longer cycles occurred in the valley bottoms. The length of cropping season also increased from north–northeast to south–southwest. Crop associations within cropping systems also varied with altitude. Cropping systems changed in response to variation in annual rainfall. This resulted in shifts of cropping systems at catchment and regional scales, with cropping systems having longer cropping seasons where there was greater annual precipitation. The results were scaled up to the whole region by modelling the spatial distribution of cropping systems at a 8 × 8 km² resolution over the period 1996–2009. The results indicate that indigenous knowledge is important when assessing the impact of climatic variability on agricultural production and that large inter‐annual variability in the duration of crop cover in Northern Ethiopia might be an important, although generally overlooked, explanatory factor for explaining previous land degradation cycles.
How mechanical stress controls microtubule behavior and morphogenesis in plants: history, experiments and revisited theories
Authors: Landrein Benoît , Hamant Olivier
Published: March 2013

Microtubules have a key role in plant morphogenesis, as they control the oriented deposition of cellulose in the cell wall, and thus growth anisotropy. The idea that mechanical stress could be one of the main determinants behind the orientation of microtubules in plant cells emerged very soon after their discovery. The cause of mechanical stress in plant cells is turgor pressure, which can build up to 1 MPa and is restrained by cell wall stiffness. On the tissue scale, this can lead to regional patterns of tension, in particular in the epidermis of aerial organs, which resist the stress generated by cells in internal tissues. Here we summarize more than 50 years of work on the contribution of mechanical stress in guiding microtubule behavior, and the resulting impact on growth anisotropy and growth heterogeneity. We propose a conceptual model on microtubule dynamics and their ability to self‐organize in bundles parallel to the direction of maximal stress, as well as a synthetic representation of the putative mechanotransducers at play.
The evolution and diversification of plant microtubule‐associated proteins
Authors: Gardiner John
Published: March 2013

Plant evolution is marked by major advances in structural characteristics that facilitated the highly successful colonization of dry land. Underlying these advances is the evolution of genes encoding specialized proteins that form novel microtubular arrays of the cytoskeleton. This review investigates the evolution of plant families of microtubule‐associated proteins (MAPs) through the recently sequenced genomes of Arabidopsis thaliana, Oryza sativa, Selaginella moellendorffii, Physcomitrella patens, Volvox carteri and Chlamydomonas reinhardtii. The families of MAPs examined are AIR9, CLASP, CRIPT, MAP18, MOR1, TON, EB1, AtMAP70, SPR2, SPR1, WVD2 and MAP65 families (abbreviations are defined in the footnote to Table 1). Conjectures are made regarding the evolution of MAPs in plants in relation to the evolution of multicellularity, oriented cell division and vasculature. Angiosperms in particular have high numbers of proteins that are involved in promotion of helical growth or its suppression, and novel plant microtubular structures may have acted as a catalyst for the development of novel plant MAPs. Comparisons of plant MAP gene families with those of animals show that animals may have more flexibility in the structure of their microtubule cytoskeletons than plants, but with both plants and animals possessing many MAP splice variants.
Response evaluation criteria for solid tumours in dogs (v1.0): a Veterinary Cooperative Oncology Group (VCOG) consensus document
Authors: Nguyen S. M. , Thamm D. H. , Vail D. M. , London C. A.
Published: March 2013

In veterinary medical oncology, there is currently no standardized protocol for assessing response to therapy in solid tumours. The lack of such a formalized guideline makes it challenging to critically compare outcome measures across various treatment protocols. The Veterinary Cooperative Oncology Group (VCOG) membership consensus document presented here is based on the recommendations of a subcommittee of American College of Veterinary Internal Medicine (ACVIM) board‐certified veterinary oncologists. This consensus paper has used the human response evaluation criteria in solid tumours (RECIST v1.1) as a framework to establish standard procedures for response assessment in canine solid tumours that is meant to be easy to use, repeatable and applicable across a variety of clinical trial structures in veterinary oncology. It is hoped that this new canine RECIST (cRECIST v1.0) will be adopted within the veterinary oncology community and thereby facilitate the comparison of current and future treatment protocols used for companion animals with cancer.
Implementing the Supportive Supervision Intervention for Registered Nurses in a Long‐Term Care Home: A Feasibility Study
Authors: McGilton Katherine S. , Profetto‐McGrath Joanne , Robinson Angela
Published: March 2013

Background

This pilot study was conducted in response to the call in 2009 by the International Association of Gerontology and Geriatrics to focus on effective leadership structures in nursing homes and to develop leadership capacity. Few researchers have evaluated interventions aimed at enhancing the leadership ability of registered nurses in long‐term care.

Aim

The aim of the pilot study was to test the feasibility of a three‐part supportive supervisory intervention to improve supervisory skills of registered nurses in long‐term care.

Methods

A repeated measures group design was used. Quantitative data were collected from healthcare aides, licensed practical nurses (i.e., supervised staff), and registered nurses (i.e., supervisors). Focus groups with care managers and supervisors examined perceptions of the intervention.

Results

There were nonsignificant changes in both the registered nurse supervisors’ job satisfaction and the supervised staff's perception of their supervisors’ support. Supervised staff scores indicated an increase in the use of research utilization but did not reflect an increase in job satisfaction. Focus group discussions revealed that the supervisors and care managers perceived the workshop to be valuable; however, the weekly self‐reflection, coaching, and mentoring components of the intervention were rare and inconsistent.

Conclusions

While the primary outcomes were not influenced by the Supportive Supervision Intervention, further effort is required to understand how best to enhance the supportive supervisory skills of RNs. Examples of how to improve the possibility of a successful intervention are advanced.

Implications

Effective supervisory skills among registered nurses are crucial for improving the quality of care in long‐term care homes. Registered nurses are receptive to interventions that will enhance their roles as supervisors.
Multistable Behaviors of Compliant Sarrus Mechanisms
Authors: Chen Guimin , Zhang Shouyin , Li Geng
Published: March 2013

Multistable mechanisms providing spatial motion could be useful in numerous applications; this paper explores the multistable behavior of the overconstrained spatial Sarrus mechanisms with compliant joints (CSMs). The mechanism analysis is simplified by considering it as two submechanisms. The kinetostatics of CSMs have been formulated based on the pseudorigid-body method for compliant members at any combination of joints. The kinetostatic results show that a CSM is capable of exhibiting bistability, tristability, and quadristability. The type of behavior is found to depend on the initial (as-fabricated) position and the relative limit positions of the two submechanisms. Possible applications of multistable CSMs include deployable structures, static balancing of human/robot bodies, and weight compensators.
Assessing Position Error Due to Clearances and Deformations of Links in Parallel Manipulators
Authors: Aginaga Jokin , Altuzarra Oscar , Macho Erik , Iriarte Xabier
Published: March 2013

Two of the main sources of position error in parallel manipulators are clearances at joints and elastic deformations of the links. The former are usually necessary in order to produce a smooth movement between the pin and the hub of a joint. The latter are unavoidable and they tend to be greater in manipulators designed for pick-and-place tasks due to the need of light links. It can be stated that the end-effector pose error depends on the mechanism configuration, the applied external wrenches, the nature and magnitude of clearances, and the rigidity of the mechanical components. This paper proposes a procedure to calculate position error in parallel manipulators due to both clearances and elastic deformations. Although the procedure is applicable to any planar or spatial parallel manipulator, a planar 5R mechanism is used as an illustrative example in order to make it easier to understand.
Comment on “Nuclear Genomic Sequences Reveal that Polar Bears Are an Old and Distinct Bear Lineage”
Authors: Nakagome Shigeki , Mano Shuhei , Hasegawa Masami
Published: March 2013

Based on nuclear and mitochondrial DNA, Hailer
et al
. (Reports, 20 April 2012, p. 344) suggested early divergence of polar bears from a common ancestor with brown bears and subsequent introgression. Our population genetic analysis that traces each of the genealogies in the independent nuclear loci does not support the evolutionary model proposed by the authors.
Response to Comment on “Nuclear Genomic Sequences Reveal that Polar Bears Are an Old and Distinct Bear Lineage”
Authors: Hailer Frank , Kutschera Verena E. , Hallström Björn M. , Fain Steven R. , Leonard Jennifer A. , Arnason Ulfur , Janke Axel
Published: March 2013

Nakagome
et al
. reanalyzed some of our data and assert that we cannot refute the mitochondrial DNA–based scenario for polar bear evolution. Their single-locus test statistic is strongly affected by introgression and incomplete lineage sorting, whereas our multilocus approaches are better suited to recover the true species relationships. Indeed, our sister-lineage model receives high support in a Bayesian model comparison.
Roots and Associated Fungi Drive Long-Term Carbon Sequestration in Boreal Forest
Authors: Clemmensen K. E. , Bahr A. , Ovaskainen O. , Dahlberg A. , Ekblad A. , Wallander H. , Stenlid J. , Finlay R. D. , Wardle D. A. , Lindahl B. D.
Published: March 2013

Forest Fungi

Boreal forest is one of the world's major biomes, dominating the subarctic northern latitudes of Europe, Asia, and America. The soils of boreal forest function as a net sink in the global carbon cycle and, hitherto, it has been thought that organic matter in this sink primarily accumulates in the form of plant remains.

Clemmensen
et al.

(p.
1615
; see the Perspective by

Treseder and Holden

) now show that most of the stored carbon in boreal forested islands in Sweden is in fact derived from mycorrhizal mycelium rather than from plant litter. Biochemical and sequencing studies show that carbon sequestration is regulated by functional and phylogenetic shifts in the mycorrhizal fungal community. The results will need to be explicitly considered in models of the role of the boreal forest in the global carbon cycle.
Diagnostic Cancer Genome Sequencing and the Contribution of Germline Variants
Authors: Kilpivaara O. , Aaltonen L. A.
Published: March 2013

Whole-genome sequencing (WGS) is revolutionizing medical research and has the potential to serve as a powerful and cost-effective diagnostic tool in the management of cancer. We review the progress to date in the use of WGS to reveal how germline variants and mutations may be associated with cancer. We use colorectal cancer as an example of how the current level of knowledge can be translated into predictions of predisposition. We also address challenges in the clinical implementation of the variants in germline DNA identified through cancer genome sequencing. We call for the international development of standards to facilitate the clinical use of germline information arising from diagnostic cancer genome sequencing.
Neural Stem Cells, Excited
Authors: Hsieh Jenny , Schneider Jay W.
Published: March 2013

Electrical activity in the adult mammalian brain triggers neurogenesis.
Grappling with Cancer
Authors: Liu Edison T.
Published: March 2013

One of the greatest challenges in the study of cancer has been confronting the mindset that the disease is too complex to address effectively: too many tissue types, too many etiologies, too much genetic chaos. In the 1970s, the oncogene concept provided temporary relief from this angst, because it was thought that a limited number of genes (proto-oncogenes), when activated through mutations, might turn a normal cell into a cancerous one. But what briefly seemed tidy quickly became messy again with the discovery of other classes of genes that normally protect against cancer. Most recently, advanced genome sequencing technologies have revealed a surprising fact: Every tumor contains hundreds to thousands of mutations, most of which affect only a small percentage of the cancers in any tumor type (see the Review by B. Vogelstein
et al.
, p. 1546). In addition, the high degree of cancer cell heterogeneity in each tumor suggests that we are studying a moving target that can readily dodge treatments through continual mutation. And the genetic uniqueness of every cancer raises the question of whether standardized cancer treatment protocols can ever achieve broad efficacy.
Return of Unexpected DNA Results Urged
Authors: Couzin-Frankel Jennifer
Published: March 2013

The American College of Medical Genetics and Genomics recommends patients be told whether their genes put them at risk of serious disease in the future—even if they don't want that information now.
Universe's High-Def Baby Picture Confirms Standard Theory
Authors: Cho Adrian
Published: March 2013

Data confirm the standard model of how the universe was born and what it consists of—but larger questions remain unanswered.
Surprisingly Low Seroprevalence of Burkholderia pseudomallei in Exposed Healthy Adults in the Darwin Region of Tropical Australia Where Melioidosis Is Highly Endemic
Authors: James Gemma L. , Delaney Ben , Ward Linda , Freeman Kevin , Mayo Mark , Currie Bart J.
Published: March 2013

In the Darwin region of Australia where melioidosis is highly endemic, only 11/354 (3%) healthy residents were seropositive by indirect hemagglutination assay, despite extensive exposure toBurkholderia pseudomallei. None developed melioidosis, but some described a prior self-limiting illness. This seropositivity rate is much lower than that seen in northeast Thailand, where melioidosis is similarly highly endemic, potentially reflecting important differences between these two locations in the epidemiology of melioidosis.
Use of Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry To Resolve Complex Clinical Cases of Patients with Recurrent Bacteremias
Authors: Nori Priya , Ostrowsky Belinda , Dorokhova Olena , Gialanella Philip , Moy Morgan , Muggia Victoria , Grossberg Robert , Kornblum John , Lin Ying , Levi Michael H.
Published: March 2013

Matrix-assisted laser desorption–ionization time of flight mass spectrometry (MALDI-TOF MS) is a rapid and accurate method of identifying microorganisms. Throughout Europe, it is already in routine use but has not yet been widely implemented in the United States, pending FDA approval. Here, we describe two medically complex patients at a large tertiary-care academic medical center with recurring bacteremias caused by distinct but related species. Bacterial identifications were initially obtained using the Vitek-2 system with the GPI card forEnterococcusand the API system for staphylococci. Initial results misled clinicians as to the source and proper management of these patients. Retrospective investigation with MALDI-TOF MS clarified the diagnosis by identifying a single microorganism as the pathogen in each case. To our knowledge, this is one of the first reports in the United States demonstrating the use of MALDI-TOF MS to facilitate the clinical diagnosis in patients with recurrent bacteremias of unclear source.
A Novel PCR Assay for Quantification of HIV-1 RNA
Authors: Shan Liang , Rabi S. Alireza , Laird Gregory M. , Eisele Evelyn E. , Zhang Hao , Margolick Joseph B. , Siliciano Robert F.
Published: March 2013

Current assays for quantification of HIV-1 virions rely on real-time reverse transcriptase (RT)-PCR detection of conserved regions of HIV-1 RNA and can be limited by detection of contaminating viral or plasmid DNA. We developed a novel RT-PCR assay using a reverse primer that hybridizes with the poly(A) tail of HIV-1 mRNAs, anchored by conserved viral nucleotides at the most distal region of the transcript. This assay can detect and quantify HIV-1 RNA with high specificity and sensitivity.
The Transcriptome of the Baculovirus Autographa californica Multiple Nucleopolyhedrovirus in Trichoplusia ni Cells
Authors: Chen Yun-Ru , Zhong Silin , Fei Zhangjun , Hashimoto Yoshifumi , Xiang Jenny Z. , Zhang Shiying , Blissard Gary W.
Published: March 2013

Baculoviruses are important insect pathogens that have been developed as protein expression vectors in insect cells and as transduction vectors for mammalian cells. They have large double-stranded DNA genomes containing approximately 156 tightly spaced genes, and they present significant challenges for transcriptome analysis. In this study, we report the first comprehensive analysis of AcMNPV transcription over the course of infection inTrichoplusia nicells, by a combination of strand-specific RNA sequencing (RNA-Seq) and deep sequencing of 5′ capped transcription start sites and 3′ polyadenylation sites. We identified four clusters of genes associated with distinctive patterns of mRNA accumulation through the AcMNPV infection cycle. A total of 218 transcription start sites (TSS) and 120 polyadenylation sites (PAS) were mapped. Only 29 TSS were associated with a canonical TATA box, and 14 initiated within or near the previously identified CAGT initiator motif. The majority of viral transcripts (126) initiated within the baculovirus late promoter motif (TAAG), and late transcripts initiated precisely at the second position of the motif. Analysis of 3′ ends showed that 92 (77%) of the 3′ PAS were located within 30 nucleotides (nt) downstream of a consensus termination signal (AAUAAA or AUUAAA). A conserved U-rich region was found approximately 2 to 10 nt downstream of the PAS for 58 transcripts. Twelve splicing events and an unexpectedly large number of antisense RNAs were identified, revealing new details of possible regulatory mechanisms controlling AcMNPV gene expression. Combined, these data provide an emerging global picture of the organization and regulation of AcMNPV transcription through the infection cycle.
Regulation of Hepatitis B Virus Infection by Rab5, Rab7, and the Endolysosomal Compartment
Authors: Macovei Alina , Petrareanu Catalina , Lazar Catalin , Florian Paula , Branza-Nichita Norica
Published: March 2013

Despite important progress toward deciphering human hepatitis B virus (HBV) entry into host cells, many aspects of the early steps of the life cycle remained completely obscure. Following endocytosis, HBV must travel through the complex network of the endocytic pathway to reach the cell nucleus and initiate replication. In addition to guiding the viral particles to the replication site, the endosomal vesicles may play a crucial role in infection, providing the appropriate environment for virus uncoating and nucleocapsid release. In this work, we investigated the trafficking of HBV particles internalized in permissive cells. Expression of key Rab proteins, involved in specific pathways leading to different intracellular locations, was modulated in HepaRG cells, using a stable and inducible short hairpin RNA (shRNA) expression system. The trafficking properties of the newly developed cells were demonstrated by confocal microscopy and flow cytometry using specific markers. The results showed that HBV infection strongly depends on Rab5 and Rab7 expression, indicating that HBV transport from early to mature endosomes is required for a step in the viral life cycle. This may involve reduction of disulfide bond-linked envelope proteins, as alteration of the redox potential of the endocytic pathway resulted in inhibition of infection. Subcellular fractionation of HBV-infected cells showed that viral particles are further transported to lysosomes. Intriguingly, infection was not dependent on the lysosomal activity, suggesting that trafficking to this compartment is a “dead-end” route. Together, these data add to our understanding of the HBV-host cell interactions controlling the early stages of infection.