bluuebunny/crossref_metadata_2025 huggingface dataset:
In VitroandIn VivoFlavor Release from Intact and Fresh‐Cut Apple in Relation with Genetic, Textural, and Physicochemical Parameters
Authors: J.L. Ting Valentina , Soukoulis Christos , Silcock Patrick , Cappellin Luca , Romano Andrea , Aprea Eugenio , Bremer Phil J. , Märk Tilmann D. , Gasperi Flavia , Biasioli Franco
Published: October 2012

Abstract: Flavor release from 6 commercial apple cultivars (Fuji, Granny Smith, Golden Delicious, Jonagold, Morgen Dallago, and Red Delicious) under static conditions (intact or fresh‐cut samples) and during consumption of fresh‐cut samples (nosespace) was determined by proton transfer reaction mass spectrometry. Textural (firmness, fracturability, flesh elasticity, and rupture) and physicochemical (pH, acidity, and water content) properties of the apples were also measured. Static headspace analysis of intact fruits revealed Fuji and Granny Smith apples had the lowest concentration for all measured flavor compounds (esters, aldehydes, alcohols, and terpenes), whereas Red Delicious apples had the highest. Fresh‐cut samples generally showed a significant increase in total volatile compounds with acetaldehyde being most abundant. However, compared to intact fruits, cut Golden and Red Delicious apples had a lower intensity for ester related peaks. Five parameters were extracted from the nosespace data of peaks related to esters (m/z43, 61), acetaldehyde (m/z45), and ethanol (m/z47): 2 associated with mastication (duration of mastication–tcon; time required for first swallowing event–tswal), and 3 related with in‐nose volatile compound concentration (area under the curve–AUC; maximum intensity–Imax; time for achievingImax–tmax). Three different behaviors were identified in the nosespace data: a) firm samples with low AUC andtswalvalues (Granny Smith, Fuji), b) mealy samples with high AUC,Imax,tswalvalues, and lowtcon(Morgen Dallago, Golden Delicious), and c) firm samples with high AUC andImaxvalues (Red Delicious). Strengths and limitations of the methodology are discussed.

Practical Application: Volatile compounds play a fundamental role in the perceived quality of food. Using apple cultivars, this research showed thatin vivoproton transfer reaction mass spectrometry (PTR‐MS) could be used to determine the relationship between the release of volatile flavor compounds and the physicochemical parameters of a real food matrix. This finding suggests thatin vivoPTR‐MS coupled with traditional physicochemical measurements could be used to yield information on flavor release from a wide range of food matrices and help in the development of strategies to enhance food flavor and quality.
Treebase: an R package for discovery, access and manipulation of online phylogenies
Authors: Boettiger Carl , Temple Lang Duncan
Published: October 2012

The TreeBASE portal is an important and rapidly growing repository of phylogenetic data. The R statistical environment has also become a primary tool for applied phylogenetic analyses across a range of questions, from comparative evolution to community ecology to conservation planning.

We have developed treebase, an open‐source software package (freely available from http://cran.r-project.org/web/packages/treebase) for the R programming environment, providing simplified, programmatic and interactive access to phylogenetic data in the TreeBASE repository.

We illustrate how this package creates a bridge between the TreeBASE repository and the rapidly growing collection of R packages for phylogenetics that can reduce barriers to discovery and integration across phylogenetic research.

We show how the treebase package can be used to facilitate replication of previous studies and testing of methods and hypotheses across a large sample of phylogenies, which may help make such important reproducibility practices more common.
A Quality Improvement Project to Decrease the Length of Stay on a Psychiatric Adolescent Partial Hospital Program
Authors: Memel Brenda
Published: October 2012

Problem

Clinicians are challenged to treat adolescents with life‐threatening behaviors while accessing fewer mental health resources with increased utilization management pressures.

Methods

Dialectical behavior therapy (DBT) skills training groups were implemented as a quality improvement project to decrease the length of stay on an adolescent psychiatric partial hospital program by reducing potential life‐threatening behaviors.

Findings

The average length of stay decreased nearly 5 days during the project. Potential life‐threatening urges seemed to increase from pretreatment findings while life‐threatening actions appeared to decrease.

Conclusions

While the findings were inconclusive regarding the actual effect on life‐threatening urges and behaviors, dialectical behavior therapy skills training groups may have positive outcomes on an adolescent psychiatric partial hospital program.
School‐Wide Staff and Faculty Training in Suicide Risk Awareness: Successes and Challenges
Authors: Walsh Elaine , Hooven Carole , Kronick Barbara
Published: October 2012

Problem

Rates of youth suicide and suicidal behavior remain high despite prevention efforts. Training high school personnel as gatekeepers is an important strategy.

Methods

Training was implemented in a school district's five comprehensive high schools. Surveys were conducted before and after training sessions, which targeted all adults working at the high school. Two hundred thirty‐seven individuals completed the pretest and/or posttest.

Findings

Participants reported gains in knowledge, confidence, and feelings of competence in recognizing, approaching, and connecting distressed youth to school‐based resources. Training was well received.

Conclusion

Training is acceptable and appropriate for school personnel. Increasing the number of school personnel who participate in the training is challenging.
The lethal and sublethal effects of three pesticides on the striped lynx spider (Oxyopes salticus Hentz)
Authors: Hanna C. , Hanna C.
Published: October 2012

The striped lynx spider, Oxyopes salticus Hentz, is found in high abundances in agricultural fields where it forages on many agricultural pests. Pesticides are applied to these fields and can therefore impact these natural pest predators. Researchers have examined the effects of a number of pesticides on this spider and other pest predators, but many of these studies only examine how these pesticides affect mortality. More recently, researchers have begun to examine the sublethal effects of these chemicals. We examined both the lethal and sublethal effects of three common pesticides with the active ingredients bifenthrin, carbaryl and malathion. We found that only malathion significantly reduced the post‐exposure lifespan of these spiders; however, each pesticide had sublethal effects on behaviour. Exposure to malathion reduced jumping, likely an important foraging and escape behaviour. Spiders exposed to bifenthrin spent increased time grooming, which can reduce the time spent performing other important behaviours. Finally, spiders that were exposed to carbaryl surprisingly increased their prey capture rate. We show here that pesticides can not only directly affect the lifespan of the striped lynx spider but that each pesticide can cause different sublethal effects that likely impact the survival and ecology of these important pest predators.
Chemical Characterization and Antibacterial Activity of Two Aromatic Herbs (Santolina chamaecyparissus and Sideritis angustifolia) Widely Used in the Folk Medicine
Authors: Ruiz‐Navajas Yolanda , Viuda‐Martos Manuel , Perez‐Alvarez Jose Angel , Sendra Esther , Fernández‐López Juana
Published: October 2012

The aim of this work was characterize the essentials oils (EOs) obtained from Santolina chamaecyparissus and Sideritis angustifolia determining (1) its chemical composition and (2) its effectiveness on the growth of some bacteria related to food spoilage, such as Listeria innocua, Serratia marcescens, Pseudomonas fragi, Pseudomonas fluorescens, Aeromonas hydrophila, Shewanella putrefaciens, Alcaligenes faecalis, Achromobacter denitrificans, Enterobacter amnigenus, Enterobacter gergoviae and Leuconostoc carnosum. The EOs were chemically analyzed and identified by gas chromatography and gas chromatography/mass spectrometry, while the agar disc diffusion method was used to determine their antibacterial activities. The concentration effect was also determined. In S. chamaecyparissus, the major constituents were artemisia ketone (27.19%), dihydroaromadendrene (18.21%) and β‐phellandrene (7.49%), while in S. angustifolia EO, the major constituent is α‐pinene (12.71%). Another important compound was β‐phellandrene (11.97%). The agar disc diffusion method indicated that S. chamaecyparissus EO showed the highest antibacterial activity against the L. innocua and A. hydrophila, with inhibition zones of 12.70 and 16.50 mm, respectively. S. angustifolia EO showed the highest antibacterial activity against A. faecalis, S. marcescens and A. denitrificans. S. chamaecyparissus and S. angustifolia EOs can be used as antibacterial agents.

Practical Applications

The research on plant‐based natural bioactive compounds to control the foodborne and spoilage pathogens has attained special interest in the recent years. The use of essential oils of Santolina chamaecyparissus and Sideritis angustifolia as antibacterial agents will be suitable for applications on the food industry as natural preservatives or flavoring to control foodborne pathogens. Another important reason for their suitability is their natural origin, which consumers find comforting.
Mass spectrometric analysis of gingival crevicular fluid biomarkers can predict periodontal disease progression
Authors: Ngo L. H. , Darby I. B. , Veith P. D. , Locke A. G. , Reynolds E. C.
Published: October 2012

Background and Objective

Gingival crevicular fluid has been suggested as a possible source of biomarkers for periodontal disease progression. This paper describes a technique for the analysis of gingival crevicular fluid from individual sites using mass spectrometry. It explores the novel use of mass spectrometry to examine the relationship between the relative amounts of proteins and peptides in gingival crevicular fluid and their relationship with clinical indices and periodontal attachment loss in periodontal maintenance patients. The aim of this paper was to assess whether the mass spectrometric analysis of gingival crevicular fluid may allow for the site‐specific prediction of periodontal disease progression.

Material and Methods

Forty‐one periodontal maintenance subjects were followed over 12 mo, with clinical measurements taken at baseline and every 3 mo thereafter. Gingival crevicular fluid was collected from subjects at each visit and was analysed using matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectrometry. Samples were classified based upon pocket depth, modified gingival index (MGI), plaque index and attachment loss, and were analysed within these groups. A genetic algorithm was used to create a model based on pattern analysis to predict sites undergoing attachment loss.

Results

Three hundred and eighty‐five gingival crevicular fluid samples were analysed. Twenty‐five sites under observation in 14 patients exhibited attachment loss of > 2 mm over the 12‐mo period. The clinical indices pocket depth, MGI, plaque levels and bleeding on probing served as poor discriminators of gingival crevicular fluid mass spectra. Models generated from the gingival crevicular fluid mass spectra could predict attachment loss at a site with a high specificity (97% recognition capability and 67% cross‐validation).

Conclusions

Gingival crevicular fluid mass spectra could be used to predict sites with attachment loss. The use of algorithm‐generated models based on gingival crevicular fluid mass spectra may provide utility in the diagnosis of periodontal disease.
Early on‐treatment change in liver stiffness predicts development of liver‐related events in chronic hepatitis B patients receiving antiviral therapy
Authors: Kim Beom K. , Oh Hyun J. , Park Jun Y. , Kim Do Y. , Ahn Sang H. , Han Kwang H. , Park Yehyun , J. Yoo Eun , Park Young N. , Kim Seung U.
Published: October 2012

Backgrounds/Aims

Monitoring fibrosis is mandatory for detailed prognostification in patients with chronic liver disease. We developed optimized cut‐offs for liver stiffness (LS) values, based on the histological subclassification of cirrhosis, and investigated whether early on‐treatment changes in LS values can predict long‐term prognosis in patients with hepatitis B virus (HBV)‐related advanced liver fibrosis receiving antiviral therapy.

Methods

Between 2005 and 2008, 103 patients with F3 or F4 fibrosis on liver biopsy were enrolled prospectively. Cirrhosis was subclassified into three groups (F4A, F4B and F4C) according to Laennec system. The primary end‐point was occurrence of liver‐related event (LRE), including decompensation, hepatocellular carcinoma and liver‐related death.

Results

Suggested LS cut‐offs for predicting F4B‐FC (vs. F3‐F4A) and F4C (vs. F3‐F4B) were 11.6 and 18.2 kPa respectively. As proportions of patients with LRE occurrence increased according to histological subclassifications stage F3‐4A vs. F4B‐4C (7.4% vs. 17.1%) and stage F3‐4B vs. F4C (13.8% vs. 18.8%), they also increased according to LS cut‐off value of 11.6 kPa (5.9% vs. 23.1%) and 18.2 kPa (9.8% vs. 33.3%) respectively (all P < 0.05). Similarly, according to stratified LS values (<11.6, 11.6–18.2 and ≥18.2 kPa), overall incidence of LREs and each constituent event increased significantly (all P < 0.05). In addition, the observed changes in LS values between baseline and 6 months of follow‐up showed significant correlations with LRE development.

Conclusions

Stratified LS values based on Laennec system and dynamic changes in LS values on follow‐up may be helpful in assessing risk of LREs in subjects with HBV‐related advanced liver fibrosis receiving antiviral therapy.
Building capacity in palliative care for personal support workers in long‐term care through experiential learning
Authors: Kaasalainen Sharon , Brazil Kevin , Kelley Mary L.
Published: October 2012

Background

Providing palliative care in long‐term care (LTC) homes is an area of growing importance. As a result, attention is being given to exploring effective palliative care learning strategies for personal support workers (PSWs) who provide the most hands‐on care to LTC residents.

Aim

The purpose of this intervention was to explore hospice visits as an experiential learning strategy to increase the capacity of PSWs in palliative care, specifically related to their new learning, and how they anticipated this experience changed their practices in LTC.

Design

This study utilised a qualitative descriptive design.

Methods

Eleven PSWs from four Ontario LTC homes were sent to their local hospice to shadow staff for one to two days. After the visit, PSWs completed a questionnaire with open‐ended questions based on critical reflection. Data were analysed using thematic content analysis.

Results

PSWs commented on the extent of resident‐focused care at the hospice and how palliative care interventions were tailored to meet the needs of residents. PSWs were surprised with the lack of routine at the hospice but felt that hospice staff prioritised their time effectively in order to meet family and client care needs. Some PSWs were pleased to see how well integrated the PSW role is on the community hospice team without any hierarchical relationships. Finally, PSWs felt that other LTC staff would benefit from palliative care education and becoming more comfortable with talking about death and dying with other staff, residents and family members.

Conclusion

This study highlighted the benefits of PSWs attending a hospice as an experiential learning strategy. Future work is needed to evaluate this strategy using more rigorous designs as a way to build capacity within PSWs to provide optimal palliative care for LTC residents and their family members.

Implications for practice

PSWs need to be recognised as important members within the interdisciplinary team. PSWs who shadow staff at hospices view this experience as a positive strategy to meet their learning needs related to palliative care.
Educational Inequalities and Cardiovascular Risk Factors. A Cross‐Sectional Population‐Based Study in Southern Spain
Authors: Morales‐Asencio José Miguel , Mancera‐Romero José , Bernal‐Lopez Rosa , Martos‐Cerezuela Ildefonso , Baca‐Osorio Antonio J. , Moyano‐Paris Maria Teresa , Montiel‐Murillo Juana , Juncosa Flores Perez , Perez Rosa Sanchez , Tinahones Francisco J. , Gomez‐Huelgas Ricardo
Published: October 2012

Objectives

To determine the prevalence and distribution of modifiable cardiovascular risk factors focused on educational level differences, in an adult population in Southern Spain.

Design and Sample

Cross‐sectional population‐based study. Random sample from the adult population assigned to a Primary Health Care Centre in Málaga (Southern Spain), which attends 38,625 inhabitants.

Measures

Level of education, physical activity, blood pressure, waist perimeter, body mass index, lipid profile, fasting plasma glucose, among others, were assessed.

Results

Final sample included 2,270 subjects with a mean age of 43.65 (SD: 16.65), 49.74% male and 50.26% female. 57.6% had none or only primary studies. Overweight was present in 55.8%, smokers were 27.6% and sedentary people 51.9%. Once adjusted by sex and age, all modifiable factors were lower in people with higher education. The highest risks were sedentarism (OR 1.95; 95% CI: 1.16–3.29) and hypertension (OR: 2.07 95% CI: 1.49–2.80) for those with lower education.

Conclusions

There is a clear inverse gradient of cardiovascular risk factors and educational level in the study population. Public health and community nurses should develop strong interventions for this challenge and extend their influence to public policies focused on educational inequalities and health.
3D Residual Stress Field in Arteries: Novel Inverse Method Based on Optical Full‐field Measurements
Authors: Badel P. , Genovese K. , Avril S.
Published: October 2012

Abstract:  Arterial tissue consists of multiple structurally important constituents that have individual material properties and associated stress‐free configurations that evolve over time. This gives rise to residual stresses contributing to the homoeostatic state of stress in vivo as well as adaptations to perturbed loads, disease or injury. The existence of residual stresses in an intact but load‐free excised arterial segment suggests compressive and tensile stresses, respectively, in the inner and outer walls. Accordingly, an artery ring springs open into a sector after a radial cut. The measurement of the opening angle is commonly used to deduce the residual stresses, which are the stresses required to close back the ring. The opening angle method provides an average estimate of circumferential residual stresses but it gives no information on local distributions through the thickness and along the axial direction. To address this lack, a new method is proposed in this article to derive maps of residual stresses using an approach based on the contour method. A piece of freshly excised tissue is carefully cut into the specimen, and the local distribution of residual strains and stresses is determined from whole‐body digital image correlation measurements using an inverse approach based on a finite element model.
Selective recruitment of mRNAs and miRNAs to polyribosomes in response to rhizobia infection in Medicago truncatula
Authors: Reynoso Mauricio Alberto , Blanco Flavio Antonio , Bailey‐Serres Julia , Crespi Martín , Zanetti María Eugenia
Published: October 2012

Translation of mRNAs is a key regulatory step that contributes to the coordination and modulation of eukaryotic gene expression during development or adaptation to the environment. mRNA stability or translatability can be regulated by the action of small regulatory RNAs (sRNAs), which control diverse biological processes. Under low nitrogen conditions, leguminous plants associate with soil bacteria and develop a new organ specialized in nitrogen fixation: the nodule. To gain insight into the translational regulation of mRNAs during nodule formation, the association of mRNAs and sRNAs to polysomes was characterized in roots of the model legume Medicago truncatula during the symbiotic interaction with Sinorhizobium meliloti. Quantitative comparison of steady‐state and polysomal mRNAs for 15 genes involved in nodulation identified a group of transcripts with slight or no change in total cellular abundance that were significantly upregulated at the level of association with polysomes in response to rhizobia. This group included mRNAs encoding receptors like kinases required either for nodule organogenesis, bacterial infection or both, and transcripts encoding GRAS and NF‐Y transcription factors (TFs). Quantitative analysis of sRNAs in total and polysomal RNA samples revealed that mature microRNAs (miRNAs) were associated with the translational machinery, notably, miR169 and miR172, which target the NF‐YA/HAP2 and AP2 TFs, respectively. Upon inoculation, levels of miR169 pronouncedly decreased in polysomal complexes, concomitant with the increased accumulation of the NF‐YA/HAP2 protein. These results indicate that both mRNAs and miRNAs are subject to differential recruitment to polysomes, and expose the importance of selective mRNA translation during root nodule symbiosis.
An AM‐induced, MYB‐family gene of Lotus japonicus (LjMAMI) affects root growth in an AM‐independent manner
Authors: Volpe Veronica , Dell'Aglio Elisa , Giovannetti Marco , Ruberti Cristina , Costa Alex , Genre Andrea , Guether Mike , Bonfante Paola
Published: October 2012

The interaction between legumes and arbuscular mycorrhizal (AM) fungi is vital to the development of sustainable plant production systems. Here, we focus on a putative MYB‐like (LjMAMI) transcription factor (TF) previously reported to be highly upregulated in Lotus japonicus mycorrhizal roots. Phylogenetic analyses revealed that the protein is related to a group of TFs involved in phosphate (Pi) starvation responses, the expression of which is independent of the Pi level, such as PHR1. GUS transformed plants and quantitative reverse transcription PCR revealed strong gene induction in arbusculated cells, as well as the presence of LjMAMI transcripts in lateral root primordia and root meristems, even in the absence of the fungus, and independently of Pi concentration. In agreement with its putative identification as a TF, an eGFP‐LjMAMI chimera was localized to the nuclei of plant protoplasts, whereas in transgenic Lotus roots expressing the eGFP‐LjMAMI fusion protein under the control of the native promoter, the protein was located in the nuclei of the arbusculated cells. Further expression analyses revealed a correlation between LjMAMI and LjPT4, a marker gene for mycorrhizal function. To elucidate the role of the LjMAMI gene in the mycorrhizal process, RNAi and overexpressing root lines were generated. All the lines retained their symbiotic capacity; however, RNAi root lines and composite plants showed an important reduction in root elongation and branching in the absence of the symbiont. The results support the involvement of the AM‐responsive LjMAMI in non‐symbiotic functions: i.e. root growth.
CT-Compatible Medical Drilling Stylet
Authors: Walsh Conor J. , Meskers Arjan J. H. , Slocum Alexander H. , Gupta Rajiv
Published: October 2012

This paper describes the design of a compact, lightweight CT-compatible, drill-press that is designed to be used in either a hand-held or stand-alone mode to assist with percutaneous bone based interventions. Previous medical drilling tools that have been developed have a metal structure and typically have one actuator for advancing the drill (feed) and another for rotating it (speed). After defining the device functional requirements and specifications, a deterministic design process was followed to generate several design concepts that were then evaluated based on their ability to satisfy the functional requirements. A final concept that uses a custom screw-spline to achieve helical motion of a shaft that is attached to a standard orthopedic drill was selected for prototyping. The design uses a single actuator to drive both the screw and spline nuts through two different gear ratios, resulting in a fixed ratio between the feed and speed. Apart from the motor which is placed away from the central drill axis, the device is largely made from plastic materials. A custom experimental setup was developed that enabled drilling into bone inside a CT scanner to be examined. Results showed that the device was successfully able to penetrate thick cortical bone and that its structure did not appreciably distort the medical images.
Measurement Versus Predictions of Rotordynamic Coefficients of a Hole-Pattern Gas Seal With Negative Preswirl
Authors: Brown Philip D. , Childs Dara W.
Published: October 2012

Test results are presented for the rotordynamic coefficients of a hole-pattern annular gas seal at supply pressures to 84 bar and running speeds to 20200 rpm. The principal test variable of interest was negative preswirl. Preswirl signifies the circumferential fluid flow entering a seal and negative preswirl indicates a fluid swirl in a direction opposite to rotor rotation. The influences of the pressure ratio and rotor speed were also investigated. The measured results produce direct and cross-coupled stiffness and damping coefficients that are a function of the excitation frequency Ω. Changes in the pressure ratio had only small effects on most rotordynamic coefficients. Cross-coupled stiffness showed slightly different profiles through the midrange of Ω values. Increasing rotor speed significantly increased the cross-coupled stiffness and cross-coupled damping. At 10,200 RPM, high negative inlet preswirl produced negative cross-coupled stiffness over an excitation frequency range of 200–250 Hz. Negative preswirl did not affect the direct stiffness and damping coefficients. Effective damping combines the stabilizing effect of direct damping and the destabilizing effect of cross-coupled stiffness. The crossover frequency is the precession frequency where effective damping transitions from a negative value to a positive value with increasing frequency. At 20,200 rpm with a pressure ratio of 50%, the peak effective damping was increased by 50%, and the crossover frequency was reduced by 50% for high-negative preswirl versus zero preswirl. Hence, reverse swirl can greatly enhance the stabilizing capacity of a hole-pattern balance-piston or division-wall seals for compressors. A two-control-volume model that uses the ideal gas law at constant temperature was used to predict rotordynamic coefficients. The model predicted direct rotordynamic coefficients well, however, substantially under-predicted cross-coupled rotordynamic coefficients, especially at high negative preswirls.
Modeling of Flange Joints for the Nonlinear Dynamic Analysis of Gas Turbine Engine Casings
Authors: Schwingshackl C. W. , Petrov E. P.
Published: October 2012

The finite element analysis of individual components of aircraft engine casings provides high accuracy and a good agreement with the measured response data. However, when these components are assembled, the accuracy of such predictions can significantly deteriorate since models describing stiffness and friction properties of joints are linearized. A full nonlinear analysis of the casing flanges is required to fully include the influence of the bolted joints, model the flexibility in the contact interface, and consider the nonlinear behavior of the contact due to partial slip and separation. In this paper different nonlinear models of casings are investigated with an available nonlinear analysis tool: A parametric study of the contact interface meshes is conducted to identify a satisfying analysis approach. The dynamic flange behavior is analyzed in detail, including effects of the bolt and normal load distribution. A comparison of the introduced nonlinear modeling with more traditional rigid or linear-elastic flange joint models is carried out to evaluate the effect of the nonlinear approach. The study demonstrates the nonlinear nature of a casing flange joint and highlights the need to include them in the analysis. The detailed modeling of the contact interaction of joints gives an insight in the nonlinear contact behavior of flanges of aircraft engine casings, and the predictive capabilities for the nonlinear analysis of gas turbine engines.
An Analytical Theory for Radial Crack Propagation: Application to Spherical Indentation
Authors: Seagraves Andrew N. , Radovitzky Raúl A.
Published: October 2012

A simple analytical theory is proposed for estimating the number of radial cracks which will propagate in brittle materials subjected to axisymmetric transverse surface loads. First, an expression is obtained for the stress intensity factor of a traction-free star-shaped crack in an infinite elastic membrane subjected to axisymmetric transverse loads. Combining this relation with the critical stress intensity factor criterion for fracture, an implicit expression is obtained which defines the number of cracks as a function of the applied loading, initial flaw size, and fracture toughness. Based on the form of this expression, we argue that if the initial flaw size is sufficiently small compared to the length scale associated with the loading, then the number of cracks can be determined approximately in closed-form from the analysis of a traction-free star-shaped crack in a thin body subjected to uniform equibiaxial in-plane tension. In an attempt to validate the theory, comparisons are made with spherical micro-indentation experiments of silicon carbide (Wereszczak and Johanns, 2008, “Spherical Indentation of SiC,” Advances in Ceramic Armor II, Wiley, NY, Chap. 4) and good agreement is obtained for the number of radial cracks as a function of indentation load.
Design and Cadaveric Validation of a Novel Device to Quantify Knee Stability During Total Knee Arthroplasty
Authors: Siston Robert A. , Maack Thomas L. , Hutter Erin E. , Beal Matthew D. , Chaudhari Ajit M. W.
Published: October 2012

The success of total knee arthroplasty depends, in part, on the ability of the surgeon to properly manage the soft tissues surrounding the joint, but an objective definition as to what constitutes acceptable postoperative joint stability does not exist. Such a definition may not exist due to lack of suitable instrumentation, as joint stability is currently assessed by visual inspection while the surgeon manipulates the joint. Having the ability to accurately and precisely measure knee stability at the time of surgery represents a key requirement in the process of objectively defining acceptable joint stability. Therefore, we created a novel sterilizable device to allow surgeons to measure varus-valgus, internal-external, or anterior-posterior stability of the knee during a total knee arthroplasty. The device can be quickly adjusted between 0 deg and 90 deg of knee flexion. The device interfaces with a custom surgical navigation system, which records the resultant rotations or translations of the knee while the surgeon applies known loads to a patient’s limb with a handle instrumented with a load cell. We validated the performance of the device by having volunteers use it to apply loads to a mechanical linkage that simulated a knee joint; we then compared the joint moments calculated by our stability device against those recorded by a load cell in the simulated knee joint. Validation of the device showed low mean errors (less than 0.21 ± 1.38 Nm and 0.98 ± 3.93 N) and low RMS errors (less than 1.5 Nm and 5 N). Preliminary studies from total knee arthroplasties performed on ten cadaveric specimens also demonstrate the utility of our new device. Eventually, the use of this device may help determine how intra-operative knee stability relates to postoperative function and could lead to an objective definition of knee stability and more efficacious surgical techniques.
On the Importance of Work-Conjugacy and Objective Stress Rates in Finite Deformation Incremental Finite Element Analysis
Authors: Ji Wooseok , Waas Anthony M. , Bazant Zdenek P.
Published: October 2012

This paper is concerned with two issues that arise in the finite element analysis of 3D solids. The first issue examines the objectivity of various stress rates that are adopted in incremental analysis of solids. In doing so, it is revealed that large errors are incurred by an improper choice of stress rate. An example problem is presented to show the implications of the choice of stress rate. The second issue addresses the need to maintain work-conjugacy in formulating and solving bifurcation buckling problems of 3D elastic solids. Four popular commercial codes are used to obtain buckling loads of an axially compressed thick sandwich panel, and it is shown that large errors in buckling load predictions are incurred as a result of violating the requirement of work-conjugacy. Remedies to fix the errors in the numerical solution strategy are given.
I “Saw” Newton's Three Laws
Authors: Shaw Mike
Published: October 2012

Would you like to build an inexpensive, highly visible, quickly assembled device that dramatically illustrates Newton's three laws of motion? This model incorporates sturdiness, high-profile visibility, and a student interest component that is sure to capture and hold their attention.
Providing the Essential Questions of the Course to Students
Authors: Vondracek Mark
Published: October 2012

Teachers often look for examples of review materials to provide students so they may be able to quickly check their understanding of key ideas and concepts leading into quizzes or tests. Over the years, I have done this same search and have modified what students receive based on their feedback, and have finally found a template that seems to satisfy students' needs.
English sentence recognition in speech-shaped noise and multi-talker babble for English-, Chinese-, and Korean-native listeners
Authors: Jin Su-Hyun , Liu Chang
Published: October 2012

This study aimed to investigate English sentence recognition in quiet and two types of maskers, multi-talker babble (MTB) and long-term speech-shaped noise (LTSSN), with varied signal-to-noise ratios, for English-, Chinese-, and Korean-native listeners. Results showed that first, sentence recognition for non-native listeners was affected more by background noise than that for native listeners; second, the masking effects of LTSSN were similar between Chinese and Korean listeners, but the masking effects of MTB were greater for Chinese than for Korean listeners, suggesting possible interaction effects between the non-native listener's native language and speech-like competing noise in sentence recognition.
Hybrid phononic crystals for broad-band frequency noise control by sound blocking and localization
Authors: Yoo Sungmin , Kim Yoon Jae , Kim Yoon Young
Published: October 2012

A bandgap cannot be enlarged sufficiently enough to suppress a broad-band noise only with a single type of finite-length phononic crystals. Here, a hybrid phononic crystal consisting of a bi-prism and an inverted bi-prism is proposed for noise control in a broad band; a stop band is formed in a central frequency range while positive-positive and positive-negative refractions occur in lower and higher frequency ranges to concentrate acoustic energy in a central localized zone. Thereby, the remaining zone becomes little affected by the noise. Analysis and numerical simulations are given for the justification of the proposed configuration.
Photomechanical Responses in
Drosophila
Photoreceptors
Authors: Hardie Roger C. , Franze Kristian
Published: October 2012

Feeling the Light

There has been a link missing in our understanding of the biochemical signaling mechanism initiated when photons are absorbed by rhodopsin in the photoreceptor cells of
Drosophila
eyes. Photoisomerization of rhodopsin activates a heterotrimeric guanine nucleotide—binding protein which leads to activation of phospholipase C. But how phospholipase C activates the transient receptor potential (TRP) or the transient receptor potential–like (TRPL) ion channels that produce the rest of the cellular response has been unclear.
Hardie and Franze
(p.
260
; see the Perspective by

Liman

) propose that there is a physical mechanism at work. Atomic force microscopy revealed light-induced contractions of photoreceptor cells. Consistent with a physical coupling mechanism, manipulations of the membrane altered responses of the photoreceptor cells to light. Thus, physical changes in the membrane appear to couple phospholipase C activity to the opening of mechanosensitive TRP and TRPL channels.
To Endow Trust
Liars and Outliers
Enabling the Trust That Society Needs to Thrive

by Bruce Schneier

Wiley, Indianapolis, IN, 2012. 382 pp. $24.95, C$27.95. ISBN 9781118143308.
Authors: Herrmann Benedikt
Published: October 2012

Synthesizing anthropology and biogeography, Harcourt discusses how geography has affected our anatomy, physiology, cultures, and population densities.
Downsizing the Deep Biosphere
Authors: Hinrichs Kai-Uwe , Inagaki Fumio
Published: October 2012

A recent study provides new constraints on the size and distribution of microbial biomass beneath the ocean floor, but key factors remain uncertain.
Putting the Squeeze on Phototransduction
Authors: Liman Emily R.
Published: October 2012

Changes in the physical properties of the lipid bilayer stimulate the opening of ion channels during fly phototransduction.
Reprogrammed Cells Earn Biologists Top Honor
Authors: Vogel Gretchen , Normile Dennis
Published: October 2012

Work upending the assumption that a cell's differentiation and maturation could not be reversed netted John Gurdon and Shinya Yamanaka this year's Nobel Prize in physiology or medicine.
Oh, Baby: Fight Brews Over U.S. Import of Beluga Whales
Authors: Underwood Emily
Published: October 2012

The Georgia Aquarium's controversial request to import 18 wild beluga whales captured in the Sea of Okhotsk for display and breeding is expected to get its first formal airing on 12 October.
NIH Funding Shifts With Disease Lobbying, Study Suggests
Authors: Kaiser Jocelyn
Published: October 2012

The growing power and influence of disease lobbying groups over the past 2 decades have dramatically reshaped the priorities of the U.S. National Institutes of Health, according to a new analysis.
Tumors Vent Their Spleen
Authors: Nahrendorf Matthias
Published: October 2012

The spleen may contribute to immune tolerance to tumors.
Nontoxigenic Vibrio parahaemolyticus Strains Causing Acute Gastroenteritis
Authors: Ottaviani Donatella , Leoni Francesca , Serra Roberto , Serracca Laura , Decastelli Lucia , Rocchegiani Elena , Masini Laura , Canonico Cristina , Talevi Giulia , Carraturo Antonio
Published: October 2012

We investigated the virulence properties of four
Vibrio parahaemolyticus
strains causing acute gastroenteritis following consumption of indigenous mussels in Italy. The isolated strains were cytotoxic and adhesive but, surprisingly, lacked
tdh
,
trh
, and type three secretion system 2 (T3SS2) genes. We emphasize that nontoxigenic
V. parahaemolyticus
can induce acute gastroenteritis, highlighting the need for more investigation of the pathogenicity of this microorganism.
Phylogenetic Analysis of Non-O157 Shiga Toxin-Producing Escherichia coli Strains by Whole-Genome Sequencing
Authors: Ju Wenting , Cao Guojie , Rump Lydia , Strain Errol , Luo Yan , Timme Ruth , Allard Marc , Zhao Shaohua , Brown Eric , Meng Jianghong
Published: October 2012

Non-O157 Shiga toxin-producing
Escherichia coli
(STEC) strains are emerging food-borne pathogens causing life-threatening diseases and food-borne outbreaks. A better understanding of their evolution provides a framework for developing tools to control food safety. We obtained 15 genomes of non-O157 STEC strains, including O26, O111, and O103 strains. Phylogenetic trees revealed a close relationship between O26:H11 and O111:H11 and a scattered distribution of O111. We hypothesize that STEC serotypes with the same H antigens might share common ancestors.
Peroxiredoxin II Regulates Effector and Secondary Memory CD8+T Cell Responses
Authors: Michalek Ryan D. , Crump Katie E. , Weant Ashley E. , Hiltbold Elizabeth M. , Juneau Daniel G. , Moon Eun-Yi , Yu Dae-Yeul , Poole Leslie B. , Grayson Jason M.
Published: October 2012

Reactive oxygen intermediates (ROI) generated in response to receptor stimulation play an important role in cellular responses. However, the effect of increased H2O2on an antigen-specific CD8+T cell response was unknown. Following T cell receptor (TCR) stimulation, the expression and oxidation of peroxiredoxin II (PrdxII), a critical antioxidant enzyme, increased in CD8+T cells. Deletion of PrdxII increased ROI, S phase entry, division, and death duringin vitrodivision. During primary acute viral and bacterial infection, the number of effector CD8+T cells in PrdxII-deficient mice was increased, while the number of memory cells were similar to those of the wild-type cells. Adoptive transfer of P14 TCR transgenic cells demonstrated that the increased expansion of effector cells was T cell autonomous. After rechallenge, effector CD8+T cells in mutant animals were more skewed to memory phenotype than cells from wild-type mice, resulting in a larger secondary memory CD8+T cell pool. During chronic viral infection, increased antigen-specific CD8+T cells accumulated in the spleens of PrdxII mutant mice, causing mortality. These results demonstrate that PrdxII controls effector CD8+T cell expansion, secondary memory generation, and immunopathology.
Efficiency of Bridging-Sheet Recruitment Explains HIV-1 R5 Envelope Glycoprotein Sensitivity to Soluble CD4 and Macrophage Tropism
Authors: O'Connell Olivia , Repik Alexander , Reeves Jacqueline D. , Gonzalez-Perez Maria Paz , Quitadamo Briana , Anton Elizabeth D. , Duenas-Decamp Maria , Peters Paul , Lin Rongheng , Zolla-Pazner Susan , Corti Davide , Wallace Aaron , Wang Shixia , Kong Xiang-Peng , Lu Shan , Clapham Paul R.
Published: October 2012

HIV-1 R5 viruses vary extensively in their capacity to infect macrophages. R5 viruses that confer efficient infection of macrophages are able to exploit low levels of CD4 for infection and predominate in brain tissue, where macrophages are a major target for infection. HIV-1 R5 founder viruses that are transmitted were reported to be non-macrophage-tropic. Here, we investigated the sensitivities of macrophage-tropic and non-macrophage-tropic R5 envelopes to neutralizing antibodies. We observed striking differences in the sensitivities of Env+pseudovirions to soluble CD4 (sCD4) and to neutralizing monoclonal antibodies (MAbs) that target the CD4 binding site. Macrophage-tropic R5 Envs were sensitive to sCD4, while non-macrophage-tropic Envs were significantly more resistant. In contrast, all Envs were sensitive to VRC01 regardless of tropism, while MAb b12 conferred an intermediate neutralization pattern where all the macrophage-tropic and about half of the non-macrophage-tropic Envs were sensitive. CD4, b12, and VRC01 share binding specificities on the outer domain of gp120. However, these antibodies differ in their ability to induce conformational changes on the trimeric envelope and in specificity for residues on the V1V2 loop stem and β20-21 junction that are targets for CD4 in recruiting the bridging sheet. These distinct specificities of CD4, b12, and VRC01 likely explain the observed differences in Env sensitivity to inhibition by these reagents and provide an insight into the envelope mechanisms that control macrophage tropism. We present a model where the efficiency of bridging-sheet recruitment by CD4 is a major determinant of HIV-1 R5 envelope sensitivity to soluble CD4 and macrophage tropism.
Inhibitory Potential of Subpopulations of CD8+T Cells in HIV-1-Infected Elite Suppressors
Authors: Buckheit Robert W. , Salgado Maria , Silciano Robert F. , Blankson Joel N.
Published: October 2012

Elite controllers or suppressors (ES) are HIV-1-infected individuals who suppress viral replication to clinically undetectable levels without antiretroviral therapy. Understanding the mechanisms by which ES control viral replication may prove informative for the design of a therapeutic vaccine. Qualitative differences in the CD8+T cell response have been implicated in control. Therefore, we isolated CD8+T cells from ES and characterized the ability of sorted memory and activation subpopulations to control viral replication at various effector-to-target cell ratios using a novel modification of a CD8+T cell suppression assay. The effector memory and terminal effector subpopulations of memory CD8+T cells had the highest inhibitory potential over the course of a 3-dayin vitroinfection. Interestingly, after 5 days of infection, central memory CD8+T cells were also very effective at suppressing viral replication. No significant correlation between the suppression of viral replication and the number of HIV-1-specific CD8+T cells was observed. HLA-DR−CD38+CD8+T cells possessed the lowest inhibitory potential of the activation subpopulations. Taken together, our data suggest that there are key differences in the magnitude and kinetics of the suppression of HIV-1 replication by different CD8+T cell subsets. These data should guide the development of an effective, cellular therapeutic vaccine that has the potential to elicit similar CD8+T cell responses.
Idiopathic facial swelling secondary to sickle cell anaemia
Authors: Moghe Swapnil , Pillai Ajay , Guru Kanishka Navin , Nair Preeti P
Published: October 2012

Sickle cell disease is a common inherited autosomal disease that is characterised by abnormally shaped (sickle-shaped) red blood cells (RBCs). It can involve virtually any organ system. The clinical manifestations of sickle cell disease vary and are classified as vaso-occlusion, chronic anaemia and infection. The imaging appearances of central nervous system and musculoskeletal involvement by sickle cell disease have been well documented; however, involvement of the head and neck region is often unreported, although it is not uncommon. In the head and neck, sickle cell disease can involve the inner ears, orbits, paranasal sinuses, bones, lymph nodes and vessels. This paper describes a case of idiopathic facial swelling associated with sickle cell disease in a young patient.
Sporadic exophytic hepatic angiomyolipoma
Authors: Costa Sílvia , Tente David , Costa Alexandre , Maciel Jorge
Published: October 2012

Angiomyolipomas are rare mesenchymal tumours consisting of smooth muscle, blood vessels and adipocytes in variable proportions. These tumours are more usually seen in kidneys (incidence 0.3–3%), and the extrarenal location is rare. Since its initial description by Ishak in 1976, only about 200 cases of hepatic angiomyolipomas have been reported. We describe the case of a 59-year-old woman, without tuberous sclerosis, with a 6 cm tumour in hepatic segments II and III, gallbladder with parietal calcification and lithiasis. She was proposed to bisegmentectomy (II and III) and cholecystectomy, which were performed without complications. The pathological examination confirmed the diagnosis of hepatic angiomyolipoma (positive for HMB45 and focally positive for HHF35) and chronic cholecystitis. Although typically benign, the emergence of cases with malignant behaviour—recurrence or distant metastasis—led to a change in attitude towards these lesions, from clinical surveillance to surgical excision, with few exceptions.
AXELROD MODEL WITH EXTENDED CONSERVATIVENESS
Authors: DYBIEC BARTŁOMIEJ
Published: October 2012

Similarity of opinions and memory about recent interactions are two main factors determining likelihood of social contacts. Here, we explore the Axelrod model with an extended conservativeness which incorporates not only similarity between individuals but also a preference to the last source of accepted information. The additional preference given to the last source of information increases the initial decay of the number of ideas in the system, changes the character of the phase transition between homogeneous and heterogeneous final states and could increase the number of stable regions (clusters) in the final state.