bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermodynamic efficiency limits of classical and bifacial multi-junction tandem solar cells: An analytical approach
Authors: Alam Muhammad Ashraful , Khan M. Ryyan
Published: October 2016

Bifacial tandem cells promise to reduce three fundamental losses (i.e., above-bandgap, below bandgap, and the uncollected light between panels) inherent in classical single junction photovoltaic (PV) systems. The successive filtering of light through the bandgap cascade and the requirement of current continuity make optimization of tandem cells difficult and accessible only to numerical solution through computer modeling. The challenge is even more complicated for bifacial design. In this paper, we use an elegantly simple analytical approach to show that the essential physics of optimization is intuitively obvious, and deeply insightful results can be obtained with a few lines of algebra. This powerful approach reproduces, as special cases, all of the known results of conventional and bifacial tandem cells and highlights the asymptotic efficiency gain of these technologies.
Extracting the temperature distribution on a phase-change memory cell during crystallization
Authors: Bakan Gokhan , Gerislioglu Burak , Dirisaglik Faruk , Jurado Zoila , Sullivan Lindsay , Dana Aykutlu , Lam Chung , Gokirmak Ali , Silva Helena
Published: October 2016

Phase-change memory (PCM) devices are enabled by amorphization- and crystallization-induced changes in the devices' electrical resistances. Amorphization is achieved by melting and quenching the active volume using short duration electrical pulses (∼ns). The crystallization (set) pulse duration, however, is much longer and depends on the cell temperature reached during the pulse. Hence, the temperature-dependent crystallization process of the phase-change materials at the device level has to be well characterized to achieve fast PCM operations. A main challenge is determining the cell temperature during crystallization. Here, we report extraction of the temperature distribution on a lateral PCM cell during a set pulse using measured voltage-current characteristics and thermal modelling. The effect of the thermal properties of materials on the extracted cell temperature is also studied, and a better cell design is proposed for more accurate temperature extraction. The demonstrated study provides promising results for characterization of the temperature-dependent crystallization process within a cell.
Linear quadratic optimal control of solar photovoltaic system: An experimental validation
Authors: MP Anbarasi , S Kanthalakshmi
Published: October 2016

This work reports on the development of Linear Quadratic Regulator (LQR) based maximum power point tracking method for standalone photovoltaic system. The advantages of the method are faster tracking ability, transfer of maximum deliverable power and its implementation with reduced complexity. The tracking performance of the proposed LQR method is compared with that of the conventional Perturb and Observe (P&O) method in MATLAB/Simulink environment for both constant and varying irradiation conditions. The improved performance of the LQR method in terms of tracking speed and tracking efficiency is confirmed through experimental results obtained using dSPACE controller.
Integration of parallel mechanosensory and visual pathways resolved through sensory conflict
Authors: Roth Eatai , Hall Robert W. , Daniel Thomas L. , Sponberg Simon
Published: October 2016

Significance

Animals rely on information drawn from a host of sensory systems to control their movement as they navigate in and interact with their environment. How the nervous system consolidates and processes these channels of information to govern locomotion is a challenging reverse engineering problem. To address this issue, we asked how a hawkmoth feeding from a moving flower combines visual and mechanical (force) cues to follow the flower motion. Using experimental and theoretical approaches, we discover that the brain performs a remarkably simple summation of information from visual and mechanosensory pathways. Moreover, we reveal that the moth could perform the behavior with either visual or mechanical information alone, and this redundancy provides a robust strategy for movement control.
Sulfur and lead isotopic evidence of relic Archean sediments in the Pitcairn mantle plume
Authors: Delavault Hélène , Chauvel Catherine , Thomassot Emilie , Devey Colin W. , Dazas Baptiste
Published: October 2016

Significance

The source material for mantle plume volcanism is generally agreed to show geochemical signatures of former oceanic lithosphere (crust and/or sediments) recycled into the mantle by subduction. The specific nature and ages of these materials remains, however, controversial. This study shows that the source of Pitcairn basalts contains Archean sediments (i.e. >2.45 Ga) that have remained chemically isolated in Earth´s mantle for billions of years.
Mixing of secondary organic aerosols versus relative humidity
Authors: Ye Qing , Robinson Ellis Shipley , Ding Xiang , Ye Penglin , Sullivan Ryan C. , Donahue Neil M.
Published: October 2016

Significance

Recent studies called into question whether diffusion in “glassy” atmospheric secondary organic aerosols (SOA) is fast enough for phase partitioning to equilibrate, as commonly assumed in models; however, most of those studies relied on rheological measurements or uptake of small molecules such as water and ammonia. Here, we conduct unique SOA mixing experiments using single-particle mass spectrometry to probe the diffusion of semivolatile organics into SOA derived from toluene and α-pinene at different relative humidities. Results show that, if the SOA systems are representative, equilibrium partitioning likely does have time to occur in the boundary layer. This work directly probes uptake of semivolatile organics by SOA particles over a wide humidity range.
Quantifying and sustaining biodiversity in tropical agricultural landscapes
Authors: Mendenhall Chase D. , Shields-Estrada Analisa , Krishnaswami Arjun J. , Daily Gretchen C.
Published: October 2016

Decision-makers increasingly seek scientific guidance on investing in nature, but biodiversity remains difficult to estimate across diverse landscapes. Here, we develop empirically based models for quantifying biodiversity across space. We focus on agricultural lands in the tropical forest biome, wherein lies the greatest potential to conserve or lose biodiversity. We explore two questions, drawing from empirical research oriented toward pioneering policies in Costa Rica. First, can remotely sensed tree cover serve as a reliable basis for improved estimation of biodiversity, from plots to regions? Second, how does tropical biodiversity change across the land-use gradient from native forest to deforested cropland and pasture? We report on understory plants, nonflying mammals, bats, birds, reptiles, and amphibians. Using data from 67,737 observations of 908 species, we test how tree cover influences biodiversity across space. First, we find that fine-scale mapping of tree cover predicts biodiversity within a taxon-specific radius (of 30–70 m) about a point in the landscape. Second, nearly 50% of the tree cover in our study region is embedded in countryside forest elements, small (typically 0.05–100 ha) clusters or strips of trees on private property. Third, most species use multiple habitat types, including crop fields and pastures (to which 15% of species are restricted), although some taxa depend on forest (57% of species are restricted to forest elements). Our findings are supported by comparisons of 90 studies across Latin America. They provide a basis for a planning tool that guides investments in tropical forest biodiversity similar to those for securing ecosystem services.
Partitioning direct and indirect effects reveals the response of water-limited ecosystems to elevated CO2
Authors: Fatichi Simone , Leuzinger Sebastian , Paschalis Athanasios , Langley J. Adam , Donnellan Barraclough Alicia , Hovenden Mark J.
Published: October 2016

Significance

Elevated levels of atmospheric carbon dioxide affect plants directly by stimulating photosynthesis and reducing stomatal aperture. These direct effects trigger several more subtle, indirect effects via changes in soil moisture and plant structure. While such effects have been acknowledged, they have never been assessed quantitatively, partly due to the fact they are inseparable in field experiments. Here we show that the indirect effects of elevated CO2explain, on average, 28% of the total plant productivity response, and are almost equal to the size of direct effects on evapotranspiration. This finding has major implications for our mechanistic understanding of plant response to elevated CO2, forcing us to revisit the interpretation of experimental results as well as simulations of future productivity.
Urban point sources of nutrients were the leading cause for the historical spread of hypoxia across European lakes
Authors: Jenny Jean-Philippe , Normandeau Alexandre , Francus Pierre , Taranu Zofia Ecaterina , Gregory-Eaves Irene , Lapointe François , Jautzy Josue , Ojala Antti E. K. , Dorioz Jean-Marcel , Schimmelmann Arndt , Zolitschka Bernd
Published: October 2016

Significance

Using a compilation of data arising from over 1,500 European watersheds, we have identified the relative role of different drivers in initiating hypolimnetic hypoxia, a critical indicator of lake health. In particular, our regional synthesis of laminated lake sediments indicated a significant acceleration in the spread of lacustrine hypoxia in the 1900s, which occurred well before the general use of commercial fertilizers in the mid-20th century and the onset of supraregional climate warming in the 1970s. The spread of hypoxia was best explained by urban expansion and the associated intensification of anthropogenic point sources of phosphorus, whereby changes in lifestyle increased the discharge of nutrients from treated and raw sewage, and ultimately led to enhanced lacustrine biological productivity.
Geometry-induced capillary emptying
Authors: Rascón Carlos , Parry Andrew O. , Aarts Dirk G. A. L.
Published: October 2016

Significance

We present a precise mathematical criterion that determines whether the liquid in a capillary of arbitrary cross-section will remain in it or will flow out when the capillary is at a horizontal position. The rich phenomenology found can be used to construct very sensitive microfluidics devices.
Increased risk of dementia in the aftermath of the 2011 Great East Japan Earthquake and Tsunami
Authors: Hikichi Hiroyuki , Aida Jun , Kondo Katsunori , Tsuboya Toru , Matsuyama Yusuke , Subramanian S. V. , Kawachi Ichiro
Published: October 2016

Significance

Recovery after major disaster poses potential risks of dementia for the elderly population. However, no previous studies have examined exposure to natural disaster and changes in risk factors as predictors of deterioration in cognitive function. We prospectively examined whether housing damage and loss of relatives or friends were associated with cognitive decline in the aftermath of the 2011 Great East Japan Earthquake and Tsunami. In this study, which included 3,566 survivors who are 65 y old or older, the severity of housing damage was significantly associated with cognitive decline after controlling changes of covariates and risk factors during the follow-up period. The cognitive decline should be listed as a health risk of older survivors in the aftermath of natural disasters.
Adaptive integration of habits into depth-limited planning defines a habitual-goal–directed spectrum
Authors: Keramati Mehdi , Smittenaar Peter , Dolan Raymond J. , Dayan Peter
Published: October 2016

Significance

Solving complex tasks often requires estimates of the future consequences of current actions. Estimates could be learned from past experience, but they then risk being out of date, or they could be calculated by a form of planning into the future, a process that is computationally taxing. We show that humans integrate learned estimates into their planning calculations, saving mental effort and time. We also show that increasing time pressure leads to reliance on learned estimates after fewer steps of planning. We suggest a normative rationale for this effect using a computational model. Our results provide a perspective on how the brain combines different decision processes collaboratively to exploit their comparative computational advantages.
FoxO6 affects Plxna4-mediated neuronal migration during mouse cortical development
Authors: Paap Ricardo H. , Oosterbroek Saskia , Wagemans Cindy M. R. J. , von Oerthel Lars , Schellevis Raymond D. , Vastenhouw-van der Linden Annemarie J. A. , Groot Koerkamp Marian J. A. , Hoekman Marco F. M. , Smidt Marten P.
Published: October 2016

Significance

The molecular basis of radial migration of cortical neurons is a well-studied process showing prominent roles for axon guidance, cell adhesion, cell polarity, and cytoskeleton remodeling. Remarkably, knowledge about transcriptional control of such processes is scarce. In this study, we show that the forkhead transcription factor FoxO6 influences
Plexin A4
(
Plxna4
) expression, a key component of the Semaphorin signaling pathway, known for its role in axonal guidance and cortical migration.
FoxO6
knockdown animals show a hampered migration of embryonic day 14.5-born neurons, which can be rescued by recombinant
Plxna4
expression constructs. Altogether, our data provide insights into the molecular mechanisms whereby transcriptional programs influence cortical development.
Roles for small noncoding RNAs in silencing of retrotransposons in the mammalian brain
Authors: Nandi Sayan , Chandramohan Dhruva , Fioriti Luana , Melnick Ari M. , Hébert Jean M. , Mason Christopher E. , Rajasethupathy Priyamvada , Kandel Eric R.
Published: October 2016

Significance

Piwi-interacting RNAs (piRNAs), a class of small noncoding RNAs whose primary function in mammals is silencing germline-resident retrotransposons, are also expressed in the
Aplysia
brain, where they play roles in memory storage. Transposons constitute a bulk of the genome and, when activated, can cause genomic instability and variability by integrating into various gene loci, including those in the mammalian brain, where they can modulate stress response and adaptive behavior and contribute to brain pathology. We show that small RNAs with conserved piRNA-like features are present in the mouse brain. In addition, we describe another class of small noncoding RNAs with features of endogenous siRNAs, which along with putative piRNAs could play critical roles by silencing brain-expressed retrotransposons contributing to mammalian behavior.
Archaea catalyze iron-dependent anaerobic oxidation of methane
Authors: Ettwig Katharina F. , Zhu Baoli , Speth Daan , Keltjens Jan T. , Jetten Mike S. M. , Kartal Boran
Published: October 2016

Significance

Carbon and nitrogen cycles have been altered dramatically by human activities. Methane-producing (methanogenic) and methane-consuming (methanotrophic) microorganisms control the emission of methane, one of the most potent greenhouse gases, to the atmosphere. Earlier studies identified methanotrophic microorganisms that use methane as an electron donor and oxygen, sulfate, nitrite, and nitrate as electron acceptors. Previous research showed that methanotrophy coupled to the reduction of oxidized metals could be important in the environment. In the current paper, we identified archaea of the order
Methanosarcinales
, related to “
Candidatus
Methanoperedens nitroreducens,” which couple the reduction of environmentally relevant particulate forms of iron and manganese to methane oxidation, filling one of the remaining lacunas in anaerobic methane oxidation.
Structural flexibility at a major conserved antibody target on hepatitis C virus E2 antigen
Authors: Kong Leopold , Lee David E. , Kadam Rameshwar U. , Liu Tong , Giang Erick , Nieusma Travis , Garces Fernando , Tzarum Netanel , Woods Virgil L. , Ward Andrew B. , Li Sheng , Wilson Ian A. , Law Mansun
Published: October 2016

Significance

Hepatitis C virus is an important human pathogen, and its E2 envelope glycoprotein is the major target of neutralizing antibodies (NAbs) and, hence, a promising vaccine candidate. Many broadly NAbs (bNAbs) to E2 recognize the conserved receptor-binding site, but immunization with soluble E2 antigen rarely elicits a potent bNAb response. Here, we show that soluble E2 is highly stable except for the receptor-binding site and variable loops. Thus, despite high sequence conservation, structural flexibility at the receptor-binding site may distract the immune system from eliciting bNAbs that recognize the conformation required for its function on virions. Stabilization of the E2 CD81 receptor-binding site (CD81bs) by structure-based design may improve its performance as a vaccine candidate.
Universality in human cortical folding in health and disease
Authors: Wang Yujiang , Necus Joe , Kaiser Marcus , Mota Bruno
Published: October 2016

Significance

Despite of the enormous diversity in size and function of the mammalian cerebral cortex, it has been shown that the cortices of different species fold according to a simple universal law. In this study, we investigate if this law also applies to variation within a single species—our own. Specifically, we examine how the law is affected by sex, age, or the presence of Alzheimer’s disease. By investigating and quantifying what remains invariant and what changes in each case, we shed some light on the underlying mechanisms through which the cortex changes in health and disease and argue that morphological complexity could emerge from a few simple rules.
The heterocyst regulatory protein HetP and its homologs modulate heterocyst commitment in
Anabaena
sp. strain PCC 7120
Authors: Videau Patrick , Rivers Orion S. , Hurd Kathryn , Ushijima Blake , Oshiro Reid T. , Ende Rachel J. , O’Hanlon Samantha M. , Cozy Loralyn M.
Published: October 2016

Significance

Terminal commitment of differentiating cells is fundamental to multicellular life but remains the least characterized phase of development. Using
Anabaena
, a multicellular cyanobacterium that irreversibly commits 10% of cells to specialized nitrogen-fixing heterocysts, we report the identification of four genes that regulate commitment timing and efficacy in a cyanobacterium, including two that delay commitment: a unique finding across developmental model systems. Through protein–protein interactions, cell type-specific and -nonspecific expression patterns, and epistatic relationships, we present evidence that these four genes function together in a hierarchy to control correct timing of the commitment decision. This work illustrates the importance of
Anabaena
as a model system for studying the genetic underpinnings controlling the process of cellular differentiation.
Probing the free energy landscapes of ALS disease mutants of SOD1 by NMR spectroscopy
Authors: Sekhar Ashok , Rumfeldt Jessica A. O. , Broom Helen R. , Doyle Colleen M. , Sobering Ryan E. , Meiering Elizabeth M. , Kay Lewis E.
Published: October 2016

Significance

A series of amyotrophic lateral sclerosis disease-causing mutants of superoxide dismutase have been studied using NMR experiments probing sparsely populated, transiently formed protein conformers. Focusing on the most immature enzyme form, which is monomeric, metal-free, and lacking a stabilizing disulfide bond, we show that the ground states for the wild-type and disease mutant proteins are similar, with an intact eight-stranded β-barrel structure resembling the structure of the mature enzyme. In contrast, conformationally excited states can be affected by mutation, both in terms of the number and types of structures accessible to the mutant. These excited states can play roles in both maturation and aggregation processes and, in the latter case, can provide a variety of possible pathways for aberrant interactions.
Expression of multiplecbb3cytochromecoxidase isoforms by combinations of multiple isosubunits inPseudomonas aeruginosa
Authors: Hirai Takehiro , Osamura Tatsuya , Ishii Masaharu , Arai Hiroyuki
Published: October 2016

Significance

Thecbb3cytochromecoxidase has high affinity for oxygen and is typically used for respiration in many pathogenic bacteria in hypoxic environments. Here we show that the opportunistic human pathogenPseudomonas aeruginosahas a capability to produce 16 differentcbb3isoforms by combinations of multiple isosubunits. Utilization of multiple isoforms with different properties contributes to the robustness of the bacterium under hypoxic growth conditions and might have practical implications for resistance to antibiotics and formations of biofilms and persister cells. Our findings indicate that the mechanism for the production of the isoforms could be possible therapeutic targets for treating chronicP. aeruginosainfection.
Optimal immunization cocktails can promote induction of broadly neutralizing Abs against highly mutable pathogens
Authors: Shaffer J. Scott , Moore Penny L. , Kardar Mehran , Chakraborty Arup K.
Published: October 2016

Significance

The design of vaccination strategies that generate potent Abs directed against diverse strains of highly mutable pathogens, like HIV and malaria, will significantly impact global health. Such Abs are called broadly neutralizing Abs (bnAbs). Abs are produced by a Darwinian evolutionary process called affinity maturation. Induction of bnAbs will likely require vaccination with diverse mutant antigens. How affinity maturation occurs in the presence of multiple diverse antigens is not well-understood, thus hindering rational design of immunization strategies. We study this issue using computer simulations and statistical mechanical theory. Our results provide guides for the rational design of optimal vaccination strategies, and they reveal mechanistic principles at a crossroad of immunology and evolutionary biology.
Targeted molecular-genetic imaging and ligand-directed therapy in aggressive variant prostate cancer
Authors: Ferrara Fortunato , Staquicini Daniela I. , Driessen Wouter H. P. , D’Angelo Sara , Dobroff Andrey S. , Barry Marc , Lomo Lesley C. , Staquicini Fernanda I. , Cardó-Vila Marina , Soghomonyan Suren , Alauddin Mian M. , Flores Leo G. , Arap Marco A. , Lauer Richard C. , Mathew Paul , Efstathiou Eleni , Aparicio Ana M. , Troncoso Patricia , Navone Nora M. , Logothetis Christopher J. , Marchiò Serena , Gelovani Juri G. , Sidman Richard L. , Pasqualini Renata , Arap Wadih
Published: October 2016

Significance

Aggressive variant prostate cancer (AVPC) is a clinically defined tumor with neuroendocrine or small-cell differentiation, visceral metastases, low prostate-specific antigen, androgen receptor insensitivity, and poor/brief responses to androgen-deprivation or platinum-based chemotherapy. AVPC incidence has markedly increased, yielding an unmet diagnostic/therapeutic need. Here we adapted a patient-derived xenograft model and tumor samples to demonstrate ligand-directed theranostics of AVPC in vivo. We engineered human
Herpes simplex
virus thymidine kinase type-1 as a noninvasive imaging reporter/suicide transgene into adeno-associated virus/phage (AAVP) particles displaying motif ligands to cell surface-associated glucose-regulated protein 78kD (GRP78), toward a clinic-ready system. Although individual components of the AAVP system have been extensively investigated, this study is evidence of successful application in relevant preclinical models of untreatable and hard to diagnose aggressive tumor variants.
Control of embryonic stem cell self-renewal and differentiation via coordinated alternative splicing and translation of YY2
Authors: Tahmasebi Soroush , Jafarnejad Seyed Mehdi , Tam Ingrid S. , Gonatopoulos-Pournatzis Thomas , Matta-Camacho Edna , Tsukumo Yoshinori , Yanagiya Akiko , Li Wencheng , Atlasi Yaser , Caron Maxime , Braunschweig Ulrich , Pearl Dana , Khoutorsky Arkady , Gkogkas Christos G. , Nadon Robert , Bourque Guillaume , Yang Xiang-Jiao , Tian Bin , Stunnenberg Hendrik G. , Yamanaka Yojiro , Blencowe Benjamin J. , Giguère Vincent , Sonenberg Nahum
Published: October 2016

Significance

Embryonic stem cells (ESCs) maintain a low translation rate; therefore control of mRNA translation is critical for preserving their stemness. We identified a hitherto unstudied transcription factor, Yin-yang 2 (YY2), which is translationaly regulated and controls self-renewal and differentiation of mouse ESCs (mESCs). Although YY2 is essential for mESC self-renewal, increased YY2 expression directs differentiation of mESCs toward cardiovascular lineages. Examination of the
Yy2
5′-UTR revealed a multilayer regulatory mechanism through which YY2 expression is dictated by the combined actions of the splicing regulator, Polypyrimidine tract-binding protein 1 (PTBP1), and the translation inhibitors, Eukaryotic initiation factor 4E-binding proteins (4E-BPs). YY2 directly controls the expression of several pluripotency and development-related genes. This study describes a synchronized network of alternative splicing and mRNA translation in controlling self-renewal and differentiation.
Global-local processing impacts academic risk taking
Authors: Tan Elvis W. S. , Lim Stephen Wee Hun , Manalo Emmanuel
Published: October 2016

Research has shown that academic risk taking—the selection of school tasks with varying difficulty levels—affords important implications for educational outcomes. In two experiments, we explored the role of cognitive processes—specifically, global versus local processing styles—in students’ academic risk-taking tendencies. Participants first read a short passage, which provided the context for their subsequent academic risk-taking decisions. Following which, participants undertook the Navon's task and attended to either global letters or local letters only, i.e., were either globally or locally primed. The effects of priming on academic risk taking were then assessed using a perception-based measure (Experiment 1) and a task-based measure (Experiment 2). Experiment 1 provided preliminary evidence, which Experiment 2 confirmed, that globally focused individuals took more academic risk than did locally focused individuals after controlling for participants’ need for cognition (how much they enjoy effortful cognitive activities). Additionally, the inclusion of and comparisons with a control group in Experiment 2 revealed that locally focused participants drove the observed effects. The theory of predictive and reactive control systems (PARCS) provides a cogent account of our findings. Future directions and practical applications in education are discussed.
The perils of the transfer of power in the Kingdom of Saudi Arabia
Authors: Aarts Paul , Roelants Carolien
Published: October 2016

The Saudi leadership feels threatened, first of all by Shi’ite Iran, but also by the extremist Islamic State (IS), the Muslim Brotherhood and even liberal intellectuals. Low oil prices cause growing deficits, while youth unemployment remains huge. Is the House of Saud on the verge of collapse? This paper first addresses the recent succession, as a result of which new King Salman’s young son, Muhammad bin Salman, accumulated unparalleled power. It asks whether his ambitious plans to modernize the Saudi economy can save the kingdom or if his fast rise will unleash a power struggle. This paper also looks at the war in Yemen which Muhammad bin Salman started and that might deepen the already problematic state of the Saudi economy. Finally, it explores a number of scenarios from muddling through to total implosion.
Decision rules for quota setting to support spatial management in a lobster (Jasus edwardsii) fishery
Authors: McGarvey Richard , Linnane Adrian , Matthews Janet M. , Jones Annabel
Published: October 2016

The Northern Zone rock lobster fishery in South Australia is extensive, covering ca. 207 000 km2. Managed under transferable quotas, the majority of the annual total allowable commercial catch (TACC) is taken on eastern inshore grounds, targeting the smaller redder lobsters favoured by Chinese buyers. The confined nature of fishing under the TACC system has led to concerns of localized spatial depletion and suggested a need for spatial management. A regional partition of the TACC was proposed. Formal prescriptive decision-rule tables for setting regional TACCs annually were constructed based on target exploitation rates. A target exploitation rate of 20% historically produced zero average yearly change in biomass and, in previous bioeconomic projection modelling, achieved near-optimal net economic return. Using an age-based fishery assessment model that fits to catch totals by both weight and number landed, conditioning on fishing effort and mean weights-at-age, we estimated harvestable biomass for three regions. The management response was to establish inner and outer subzones where separate TACC decision rules are now adopted. Basing the harvest strategy on a target exploitation rate underlies a simple direct method for constructing decision-rule tables for setting TACC using the indicator of previous year’s catch per unit effort (cpue). In the normal cpue range, a constant target exploitation rate is applied. At lower levels of stock abundance, below a designated upper limit reference point of cpue, the exploitation rates used to assign TACCs are set to decline linearly from the normal target level, reaching zero at a designated lower-limit reference cpue point below which the fishery is closed. At higher levels of cpue, stakeholders agreed to a TACC cap, under which exploitation rate decreases if biomass rises. This case study applies where formal harvest strategy decision rules for quota-based lobster fisheries are considered at finer spatial scales.
Polynomial matrix equivalences: system transformations and structural invariants
Authors: Vologiannidis S , Antoniou E N , Karampetakis N P , Vardulakis A I G
Published: October 2016

The present article is a survey on linear multivariable systems equivalences. We attempt a review of the most significant forms of system equivalence having as a starting point matrix transformations preserving certain aspects of their spectral structure. From a system theoretic point of view, the need for a variety of forms of polynomial matrix equivalences, arises from the fact that different types of spectral invariants give rise to different types of dynamics of the underlying linear system. A historical perspective of the key results and their contributors is also given.
An Interprofessional Curriculum on Antimicrobial Stewardship Improves Knowledge and Attitudes Toward Appropriate Antimicrobial Use and Collaboration
Authors: MacDougall Conan , Schwartz Brian S. , Kim Lisa , Nanamori Mari , Shekarchian Sharmin , Chin-Hong Peter V.
Published: October 2016

Background

Inappropriate antimicrobial use can threaten patient safety and is the focus of collaborative physician and pharmacist antimicrobial stewardship teams. However, antimicrobial stewardship is not comprehensively taught in medical or pharmacy school curricula. Addressing this deficiency can teach an important concept as well as model interprofessional healthcare.

Methods

We created an antimicrobial stewardship curriculum consisting of an online learning module and workshop session that combined medical and pharmacy students, with faculty from both professions. Learners worked through interactive, branched-logic clinical cases relating to appropriate antimicrobial use. We surveyed participants before and after the curriculum using validated questions to assess knowledge and attitudes regarding antimicrobial stewardship and interprofessional collaboration. Results were analyzed using paired χ2 and t tests and mixed-effects logistic regression.

Results

Analysis was performed with the 745 students (425 medical students, 320 pharmacy students) who completed both pre- and postcurriculum surveys over 3 years. After completing the curriculum, significantly more students perceived that they were able to describe the role of each profession in appropriate antimicrobial use (34% vs 82%, P < .001), communicate in a manner that engaged the interprofessional team (75% vs 94%, P < .001), and describe collaborative approaches to appropriate antimicrobial use (49% vs 92%, P < .001). Student favorability ratings were high for the online learning module (85%) and small group workshop (93%).

Conclusions

A curriculum on antimicrobial stewardship consisting of independent learning and an interprofessional workshop significantly increased knowledge and attitudes towards collaborative antimicrobial stewardship among preclinical medical and pharmacy students.
Technical tip: distal locking of a tibial nail in the presence of a preexisting distal tibial plate
Authors: Arnaout Firas , Paliobeis Christos
Published: October 2016

Tibial refracture is a common problem among active individuals, with a second surgery presenting several challenges and difficulties. Previously implanted metalwork can cause obstruction of distal locking of the intramedullary tibial nails due to radiographic overlap. Full removal of a distal tibial plate is associated with significant surgical morbidity and wound complications as well as increased operative time and X-ray exposure. We report a simple method to overcome the above problem by removing only some tibial plate screws percutaneously, leaving the plate itself in situ and using some of the plate holes for distal locking of the tibial nail.
Longitudinal changes in menopausal symptoms comparing women randomized to low-dose oral conjugated estrogens or transdermal estradiol plus micronized progesterone versus placebo: the Kronos Early Estrogen Prevention Study
Authors: Santoro Nanette , Allshouse Amanda , Neal-Perry Genevieve , Pal Lubna , Lobo Rogerio A. , Naftolin Frederick , Black Dennis M. , Brinton Eliot A. , Budoff Matthew J. , Cedars Marcelle I. , Dowling N. Maritza , Dunn Mary , Gleason Carey E. , Hodis Howard N. , Isaac Barbara , Magnani Maureen , Manson JoAnn E. , Miller Virginia M. , Taylor Hugh S. , Wharton Whitney , Wolff Erin , Zepeda Viola , Harman S. Mitchell
Published: October 2016

Objective:

The objective of the present study was to compare the efficacy of two forms of menopausal hormone therapy in alleviating vasomotor symptoms, insomnia, and irritability in early postmenopausal women during 4 years.

Methods:

A total of 727 women, aged 42 to 58, within 3 years of their final menstrual period, were randomized to receive oral conjugated estrogens (o-CEE) 0.45 mg (n = 230) or transdermal estradiol (t-E2) 50 μg (n = 225; both with micronized progesterone 200 mg for 12 d each mo), or placebos (PBOs; n = 275). Menopausal symptoms were recorded at screening and at 6, 12, 24, 36, and 48 months postrandomization. Differences in proportions of women with symptoms at baseline and at each follow-up time point were compared by treatment arm using exact χ2 tests in an intent-to-treat analysis. Differences in treatment effect by race/ethnicity and body mass index were tested using generalized linear mixed effects modeling.

Results:

Moderate to severe hot flashes (from 44% at baseline to 28.3% for PBO, 7.4% for t-E2, and 4.2% for o-CEE) and night sweats (from 35% at baseline to 19% for PBO, 5.3% for t-E2, and 4.7% for o-CEE) were reduced significantly by 6 months in women randomized to either active hormone compared with PBO (P < 0.001 for both symptoms), with no significant differences between the active treatment arms. Insomnia and irritability decreased from baseline to 6 months postrandomization in all groups. There was an intermittent reduction in insomnia in both active treatment arms versus PBO, with o-CEE being more effective than PBO at 36 and 48 months (P = 0.002 and 0.05) and t-E2 being more effective than PBO at 48 months (P = 0.004). Neither hormone treatment significantly affected irritability compared with PBO. Symptom relief for active treatment versus PBO was not significantly modified by body mass index or race/ethnicity.

Conclusions:

Recently postmenopausal women had similar and substantial reductions in hot flashes and night sweats with lower-than-conventional doses of oral or transdermal estrogen. These reductions were sustained during 4 years. Insomnia was intermittently reduced compared with PBO for both hormone regimens.
Collagenopathies—Implications for Abdominal Wall Reconstruction: A Systematic Review
Authors: Harrison Bridget , Sanniec Kyle , Janis Jeffrey E.
Published: October 2016

Background:

The etiology of hernia formation is strongly debated and includes mechanical strain, prior surgical intervention, abnormal embryologic development, and increased intraabdominal pressure. Although the most common inciting cause in ventral hernias is previous abdominal surgery, many other factors contribute. We explore this etiology through an examination of the current literature and existing evidence on patients with collagen vascular diseases, such as Ehlers–Danlos syndrome.

Methods:

A systematic review of the published literature was performed of all available Spanish and English language PubMed and Cochrane articles containing the key words “collagenopathies,” “collagenopathy,” “Ehlers-Danlos,” “ventral hernia,” and “hernia.”

Results:

Three hundred fifty-two articles were identified in the preliminary search. After review, 61 articles were included in the final review.

Conclusions:

Multiple authors suggest a qualitative or quantitative defect in collagen formation as a common factor in hernia formation. High-level clinical data clearly linking collagenopathies and hernia formation are lacking. However, a trend in pathologic studies suggests a link between abnormal collagen production and/or processing that is likely associated with hernia development.
Integra-based Reconstruction of Large Scalp Wounds: A Case Report and Systematic Review of the Literature
Authors: Johnson Maxwell B. , Wong Alex K.
Published: October 2016

Background:

Large complex scalp wounds that have traditionally required free vascularized tissue transfer have been successfully reconstructed with skin substitutes such as Integra. Although there are multiple reports of Integra-based reconstructions of scalp wounds, there has not been a comprehensive assessment of this body of literature that critically examines this method. Our goal was to conduct a systematic review to determine the effectiveness of Integra-based reconstructions of scalp wounds, with emphasis on large defects.

Methods:

A comprehensive systematic review was completed using key search terms, including Integra, dermal regeneration template, bovine collagen, skin substitute, forehead, and scalp. Selected articles reported characteristics of patients and their reconstructions. The primary outcome measures were wound complications and percent graft take.

Results:

Thirty-four articles were included in this systematic review. Wound sizes ranged from 5.7 to 610 cm2, with 35.3% of articles reporting a mean defect size >100 cm2. Thirty-two articles reported mean percent take of skin graft ≥90%. Sixteen articles reported a minor complication. There were no major complications associated with the reconstructions.

Conclusions:

There is a substantial evidence base for the use of Integra to reconstruct scalp wounds. To date, the dermal regeneration template is generally reserved for salvage procedures or when the patient cannot tolerate free tissue transfer. Based on the findings of this systematic review and the authors’ clinical experience, Integra can be used to achieve predictable results in large complex scalp defects.
Aesthetic Surgery in Patients with Lung Cancer: A Paradigm Shift
Authors: Hidalgo David A. , Baranski Jan , Sinno Sammy
Published: October 2016

Background:

Lung cancer is the most common cancer worldwide and the leading cause of cancer death. With the development of targeted therapy against causative driver mutations, some patients have experienced dramatic responses that have converted their disease into a chronic, stable form. Shifting concerns away from survival and back to quality-of-life issues has led some of these patients to seek aesthetic surgery.

Methods:

Three patient examples are presented to illustrate current lung cancer treatment modalities, disease responses, and subsequent experiences with aesthetic surgical procedures. Two patients presented for blepharoplasty and the third for revisional breast augmentation surgery.

Results:

Two patients were treated for lung cancer with targeted therapy and a third with more traditional chemotherapy before undergoing aesthetic surgery. All 3 patients experienced a normal recovery from surgery without any untoward results. Two remain free of disease and one has chronic stable disease. All have returned to normal, active lives.

Conclusions:

Recent developments in lung cancer treatment are transforming this entity into a less formidable diagnosis for some patients, much like breast cancer and prostate cancer. Plastic surgeons should be aware of this paradigm shift. Successfully treated patients should be considered as reasonable candidates for aesthetic surgery, particularly when they have the full support of their oncologist. Beyond the typical psychological benefits that plastic surgery can produce, it also provides affirmation in this patient population of a return to normalcy, thereby imparting hope and optimism for the future.
Measures of Patient Activation and Social Support in a Peer-Led Support Network for Women With Cardiovascular Disease
Authors: Witt Dawn , Benson Gretchen , Campbell Susan , Sillah Arthur , Berra Kathy
Published: October 2016

PURPOSE:

Social support has been associated with beneficial effects on many disease states and overall health and well-being. However, there is limited research exploring the impact of peer-led support models among women living with coronary heart disease. This study describes the structure of peer-led support groups offered by WomenHeart (WH): The National Coalition for Women Living with Heart Disease, and assesses WH participants' quality of life and social, emotional, and physical health.

METHODS:

Participants were recruited from 50 WH groups. A 70-item online survey was administered, and the main analytic sample included 157 women. Multivariate logistic regression was used to examine the association between patient activation levels (lower activation levels: 1, 2 vs higher activation levels: 3, 4) and social support scores (range: lowest 8 to highest 34), adjusting for age.

RESULTS:

High levels of social support, patient activation, physical activity, and low levels of stress, anxiety, and depression were reported. Those who were at or above the median for the social support measures (indicating high levels of social support) had greater odds of high levels of patient activation (level 3 or 4) than individuals reporting low levels of social support (OR = 2.23; 95% CI, 1.04-4.76; P = .012).

CONCLUSIONS:

Women who regularly attended a support group by a trained peer leader were highly engaged in their health care and had low levels of stress, anxiety, and depression. These findings lend credibility to the value of the peer support model and could potentially be replicated in other disease states to enhance patient care.
TRAUMATIC PROLIFERATIVE VITREORETINOPATHY
Authors: Jin Ying , Chen Huijin , Xu Xiaojian , Hu Yuntao , Wang Changguan , Ma Zhizhong
Published: October 2016

Purpose:

To determine the phases of traumatic proliferative vitreoretinopathy after open globe injury by assessing cellular components, extracellular matrix constituents of proliferative vitreoretinopathy membranes, and intraretinal changes over time.

Methods:

Twenty-one epiretinal and/or subretinal membrane specimens were obtained from 21 patients with open globe injuries. The patients were divided into Groups A (≤28 days), B (29–120 days), and C (>120 days) according to the interval between injury and vitrectomy. The staining intensity and percentage of positive cells in membranes were compared among the groups, and proliferative indices for Ki-67 and proliferating cell nuclear antigen were assessed. Intraretinal changes were evaluated through histology and immunohistochemistry. Fundus photography was performed during vitrectomy.

Results:

The proliferating cell nuclear antigen proliferative index was significantly higher in Group B (P = 0.002) than in Group A, and lower in Group C (P < 0.001) than in Group B. α-smooth muscle actin expression increased from day 29 to 120 after injury. Meanwhile, intraretinal gliosis and fibrosis developed.

Conclusion:

Active proliferation and contraction in proliferative vitreoretinopathy membranes continue until 120 days after injury, and are accompanied by the initiation of intraretinal gliosis and fibrosis. These findings provide further insight into the optimal timing of vitrectomy after trauma.
Staphylococcus lugdunensis: The “Lyon Heart” Pathogen
Authors: Kline Jessica A. , Byrnes Timothy J. , Myers Joseph P.
Published: October 2016

Staphylococcus lugdunensis is a coagulase-negative Staphylococcus capable of causing infective endocarditis on native as well as prosthetic valves and implanted cardiac devices. It causes acute disease clinically indistinguishable from that caused by Staphylococcus aureus. Bacteremic infections with S. lugdunensis have a high incidence of associated infective endocarditis. Many S. lugdunensis isolates are exquisitely sensitive to penicillin G. Endocarditis caused by S. lugdunensis frequently requires surgical intervention and has a high mortality rate. Case 1: A 48-year-old woman with mitral valve prolapse, S. lugdunensis bacteremia and mitral valve endocarditis. She underwent emergent mitral valve replacement and completed treatment with intravenous nafcillin. Case 2: A 31-year-old woman with spontaneous S. lugdunensis bacteremia and tricuspid valve endocarditis. She was successfully treated medically with 6 weeks of intravenous nafcillin. Case 3: A 44-year-old man with S. lugdunensis endocarditis on congenital bicuspid aortic valve with severe aortic insufficiency. He underwent emergent aortic valve replacement and successfully completed 6 weeks of intravenous nafcillin. Case 4: A 37-year-old woman with spontaneous S. lugdunensis bacteremia and native aortic valve endocarditis. She was successfully treated medically with 6 weeks of intravenous vancomycin. Case 5: A 57-year-old woman with hemodialysis catheter-related S. lugdunensis bacteremia and native mitral valve endocarditis. She was successfully treated medically with 6 weeks of intravenous cefazolin. Staphylococcus lugdunensis is a unique coagulase-negative Staphylococcus first identified in Lyon, France, the modern name for the Roman city of Lugdunum, ergo the organism's name. Since its identification, S. lugdunensis has been described as a “Lion among coagulase-negative staphylococci” and as “a dangerous wolf in sheep's clothing” because of the tendency of clinicians to initially discount positive blood cultures with “coagulase-negative staphylococci” as probable skin contaminants and thereby delay appropriate antimicrobial therapy. We report 5 patients with S. lugdunensis endocarditis and review the adult literature for other reported cases.