bluuebunny/crossref_metadata_2025 huggingface dataset:
Leukocyte adhesion deficiencies
Authors: Hanna Suhair , Etzioni Amos
Published: January 2012

Leukocyte trafficking from the blood stream to tissues is essential for continuous surveillance of foreign antigens. This dynamic process, designated as the leukocyte adhesion cascade, involves distinct steps. In leukocyte adhesion deficiency (LAD) I the firm adhesion of leukocyte to the endothelium is defective, due to mutations in the beta 2 integrin gene. LAD II is caused by mutations in the fucose transporter specific to the Golgi apparatus, leading to the absence of Sialyl Lewis X—the fucosylated ligand for the selectins—thus affecting the rolling phase, the first phase of the cascade. In LAD III, a primary activation defect occurs in beta integrins 1, 2, and 3. Recently, the genetic basis for LAD III has been revealed to involve mutations in kindlin‐3, a newly recognized essential component of integrin activation—the second phase of the adhesion cascade. Until now, no human or animal models of defect in transmigration—the fourth and last phase of the cascade—has been described.
Early detection of risk factors for seclusion and restraint: a prospective study
Authors: Georgieva Irina , Vesselinov Roumen , Mulder Cornelis L.
Published: January 2012

Aim: The study aims to examine the predictive power of static and dynamic risk factors assessed at admission to an acute psychiatric ward and to develop a prediction model evaluating the risk of seclusion and restraint.

Methods: Over 20 months, data on demographic and clinical characteristics, psychosocial functioning, level of insight, uncooperativeness, and use of coercive measures were collected prospectively on 520 patients at admission. Logistic regression analysis was used to develop a prediction model. The magnitude of the predictive power of this model was estimated using receiver operating characteristic analysis.

Results: The prediction model contained one static predictor (involuntary commitment) and two dynamic predictors (psychological impairment and uncooperativeness), with a high predictive power (receiver operating characteristic area under the curve = 0.83). The final risk model classified 72% of the patients correctly, with a higher sensitivity rate (80%) than specificity rate (71%).

Conclusion: Early assessment of patients' psychological impairment and uncooperativeness can help clinicians to recognize patients at risk for coercive measures and approach them on time with preventive and less restrictive interventions. Although this simple, highly predictive model accurately predicts the risk of seclusion or restraint, further validation studies are needed before it can be adopted into routine clinical practice.
Heritability of corneal refraction and corneal astigmatism: a population‐based twin study among 66‐ to 79‐year‐old female twins
Authors: Pärssinen Olavi , Kauppinen Markku , Kaprio Jaakko , Koskenvuo Markku , Rantanen Taina
Published: January 2012

Purpose:  To examine the heritability of corneal refraction power (CR) and corneal astigmatism (AST) in older women.

Methods:  Corneal refraction and AST were measured by IOL master in 52 monozygotic (MZ) and 47 dizygotic (DZ) female twin pairs aged 66–79 years. The relative contribution of genetic and environmental factors to individual differences in CR was estimated by applying an independent pathway model to the twin data and AST by intraclass correlations (ICC).

Results:  For the right eye, mean CR was 44.58 dioptres (D) (standard deviation (SD) ±1.28) When comparing CR of the right and left eye between MZ and DZ, no significant difference was found. Mean AST was 0.77 D (SD ±0.44) with no differences observed either between the MZ and the DZ individuals, or between the left and the right eyes. ICCs between the sisters for CR were, for the right eye, 0.882 and 0.378 for MZ and DZ, respectively, and for the left eye 0.855 and 0.358. For AST of the right eye, the ICCs were 0.533 and 0.096 for the MZ and DZ pairs, respectively, and for the left eye, the MZ and DZ correlations were 0.396 and 0.299. Quantitative genetic modelling showed that 81% of the variance in CR could be explained by genetic factors, additive genetic factors explaining 62% (95% confidence interval [CI] 44% ‐86%) and dominant genetic effect 19% (95% CI 7–49%) of the variance in CR. Different models were constructed to explain the heredity of AST. None of these models gave meaningful results, although the ICC values for MZ were higher than those for DZ.

Conclusions:  Most of the variance in CR among older Finnish women could be explained by genetic factors.
The invention of an iliosacral screw fixation guide and its preliminary clinical application
Authors: Pan Wei‐bo , Liang Jun‐bo , Wang Bin , Chen Guo‐fu , Hong Hua‐xing , Li Qian‐yun , Chen Hai‐xiao
Published: January 2012

Objective:  To introduce an iliosacral screw fixation guide and evaluate its efficacy in fixation of sacroiliac joint fracture‐dislocations.

Methods:  Between January 2011 and May 2011, eight patients (five men, three women) with sacroiliac joint fracture‐dislocation underwent percutaneous iliosacral screw fixation with the assistance of this minimally invasive guide and under CT guidance. The patients, aged from 26 to 56 years (mean 32 years), had vertically unstable pelvic fractures. Before surgery, six patients who had displacement of >2 cm in their sacroiliac joints underwent skeletal traction on the femoral condyle. The inserted sites were marked out on the affected side of their buttocks after the best screw trajectory had been determined under CT control. The gear that controls the direction of the minimally invasive guide was adjusted according to the inserting angle determined by CT scans. A K‐wire was inserted into the sacroiliac joint along the pilot sleeve of the guide, and a hollow screw (diameter 7.3 mm) was implanted into the sacroiliac joint along the K‐wire.

Results:  All eight operations were successful on the first attempt. The operations lasted from 10 to 20 minutes (mean 14 minutes). Immediate CT scans confirmed that all the screws had been placed in the desired positions, none had penetrated the bones and the configuration of the sacroiliac joints had been satisfactorily restored and firmly fixed. No patient experienced numbness or radiating pain in the lower limbs during surgery. There were no postoperative vascular or neurological complications.

Conclusion:  The minimally invasive guide can eliminate discrepancies resulting from the surgeon's own sensory input when inserting screws under the guidance of CT, making percutaneous iliosacral screw fixation more accurate, safe and simple.
Clinical and safety profiles of bipolar transurethral vaporization of the prostate in saline: A preliminary report
Authors: Isotani S , Muto S , Yu J , Nagae M , China T , Koseki T , Kumamoto T , Tokiwa S , Yoshii T , Saito K , Yamaguchi R , Ide H , Horie S
Published: January 2012

Transurethral vaporization of the prostate in saline (TURisV) is an innovative endoscopic surgical modality for the treatment of benign prostatic hyperplasia (BPH) that vaporizes prostate tissue using a uniquely designed mushroom electrode. TURisV promises instant hemostatic tissue ablation under saline irrigation and offers clinical advantages for endoscopic BPH operations. From July 2008 to February 2009, TURisV was performed in 17 cases with clinically significant BPH. Median operation time was 127.0 min and median volume of vaporized prostate tissue was 41.1 g. Median International Prostate Symptom Score improved from 20 to 4 after 12 months. Median maximum flow rate increased from 5.3 mL/s to 13.8 mL/s after 12 months. Postoperative median residual urine improved from 48.0 mL to 7.0 mL after 12 months. No changes in hemoglobin or electrolyte levels were seen postoperatively. Our results suggest that TURisV is a safe and efficacious treatment for BPH.
Minimally invasive removal of a recurrent lumbar herniated nucleus pulposus by the small incised microendoscopic discectomy interlaminar approach
Authors: Koga S , Sairyo K , Shibuya I , Kanamori Y , Kosugi T , Matsumoto H , Kitagawa Y , Sumita T , Dezawa A
Published: January 2012

In this report, we introduce two cases of recurrent herniated nucleus pulposus (HNP) at L5‐S1 that were successfully removed using the small incised microendoscopic discectomy (sMED) technique, proposed by Dezawa and Sairyo in 2011. sMED was performed via the interlaminar approach with a percutaneous endoscope. The patients had previously underdone microendoscopic discectomy for HNP. For the recurrent HNP, the sMED interlaminar approach was selected because the HNP occurred at the level of L5‐S1; the percutaneous endoscopic transforaminal approach was not possible for anatomical reasons. To perform sMED via the interlaminar approach, we employed new, specially made devices to enable us to use this technique. In conclusion, sMED is the most minimally invasive approach available for HNP, and its limitations have been gradually eliminated with the introduction specially made devices. In the near future, percutaneous endoscopic surgery could be the gold standard for minimally invasive disc surgery.
Extrathoracic malignant peripheral nerve sheath tumor of the lateral chest wall locally recurred and metastasized to peritoneum: Report of a case
Authors: Gu Jundong , Zhao Hui , Xu Hongrui , Zhu Siwei , Li Li , Yao Hong , Wen Yanjun , Wang Xinzhuo , Wang Shuchuan , Chen Jun , Zhou Qinghua
Published: January 2012

Malignant peripheral nerve sheath tumors (MPNSTs) are rare, with an expected incidence of 0.0001% per year in the general population and 4.6% in patients with von Recklinghausen's disease. They are defined as any malignant tumors arising or differentiating from cells of the peripheral nerve sheath. MPNSTs can develop in various sites including the trunk and head/neck region. However, its onset on the chest wall is very rare. Here we report a case of MPNST growing outside the thorax on the chest wall. The patient developed a local recurrence twice, which caused multiple metastases to the lung and peritoneum.
The inhibition of the development of the spores of a spoilage mould by chemical preservatives
Authors: McCafferty Margaret , Parker Malcolm S
Published: January 2012

The swelling characteristics of developing spores from a variety of spoilage moulds have been examined using the Coulter Counter. P. spinulosum spores began swelling earliest and had the most rapid swelling rate. For these reasons these spores were the most suitable for rapid electronic sizing and were used to assess preservative efficiency. The preservatives examined were propylhydroxybenzoate, Phenonip (a mixture of esters of hydroxybenzoic acid and β-phenoxyethylalcohol, Nipa Laboratories Ltd.) and benzoic acid. The first two preservatives reduce the rate of swelling of germinating spores at its onset while benzoic acid increases the time before swelling begins. Suppression of spore swelling provides early indication of preservative potential and the type of swelling curve produced indicates the mechanism of fungistasis.
The distribution of chloroquine in man after fatal poisoning
Authors: Robinson Ann E , Coffer Arnold I , Camps Francis E
Published: January 2012

Detailed analysis of autopsy specimens from two fatal cases of chloroquine poisoning is reported. Post-mortem blood levels of 1.60 and 1.24 mg chloroquine/100 ml blood were found; results for liver blood, urine, stomach contents, liver, lungs and kidneys are given. The highest chloroquine concentration was in liver and the presence of a metabolite was demonstrated in the tissues.
Hilbert schemes of points on a locally planar curve and the Severi strata of its versal deformation
Authors: Shende Vivek
Published: January 2012

Let C be a locally planar curve. Its versal deformation admits a stratification by the genera of the fibres. The strata are singular; we show that their multiplicities at the central point are determined by the Euler numbers of the Hilbert schemes of points on C. These Euler numbers have made two prior appearances. First, in certain simple cases, they control the contribution of C to the Pandharipande–Thomas curve counting invariants of three-folds. In this context, our result identifies the strata multiplicities as the local contributions to the Gopakumar–Vafa BPS invariants. Second, when C is smooth away from a unique singular point, a conjecture of Oblomkov and the present author identifies the Euler numbers of the Hilbert schemes with the ‘U(∞)’ invariant of the link of the singularity. We make contact with combinatorial ideas of Jaeger, and suggest an approach to the conjecture.
Evaluating the physiological significance of respiratory sinus arrhythmia: looking beyond ventilation–perfusion efficiency
Authors: Ben‐Tal A. , Shamailov S. S. , Paton J. F. R.
Published: January 2012

Key points 

Respiratory sinus arrhythmia (RSA) is the variation of heart rate with breathing: heart rate increases during inspiration and decreases during expiration.

RSA is seen in many species including humans where it is strongest in the young and fit. The loss of RSA has been linked with cardiac mortality; however, the function of RSA is presently unknown.

One hypothesis proposed previously is that RSA allows for more efficient gas exchange between the lungs and the blood.

Our theoretical study does not support this hypothesis. Instead, a new hypothesis is proposed and tested using computational tools – that RSA helps the heart do less work while maintaining healthy levels of blood gases.

Of course, this new hypothesis needs to be further tested both experimentally and by using more sophisticated mathematical models, but if correct, it could explain why inducing RSA artificially in patients with cardiovascular disease improves their health.
An Experimental Investigation of State-Variable Modal Decomposition for Modal Analysis
Authors: Farooq Umar , Feeny Brian F.
Published: January 2012

This work presents the experimental evaluation of the state-variable modal decomposition method for a modal parameter estimation of multidegree-of-freedom and continuous vibration systems. Using output response ensembles only, the generalized eigenvalue problem is formed to estimate eigenfrequencies and modal vectors for a lightly damped linear clamped-free experimental beam. The estimated frequencies and modal vectors are compared against the theoretical system frequencies and modal vectors. Satisfactory results are obtained for estimating both system frequencies and modal vectors for the first five modes. To validate the actual modes from the spurious ones, modal coordinates are employed, which, together with frequency and vector estimates, substantiate the true modes. This paper also addresses the error associated with estimation when the number of sensors is less than the active/dominant modes of the system shown via a numerical example.
Effect of Melting on Mixed Convection Heat and Mass Transfer in a Non-Newtonian Fluid Saturated Non-Darcy Porous Medium
Authors: Kairi R. R. , Murthy P. V. S. N.
Published: January 2012

In this paper, we investigate the influence of melting on mixed convection heat and mass transfer from vertical flat plate in a non-Newtonian fluid-saturated non-Darcy porous medium including the prominent Soret effect. The wall and the ambient medium are maintained at constant but different levels of temperature and concentration such that the heat and mass transfer occurs from the wall to the medium. The Ostwald–de Waele power law model is used to characterize the non-Newtonian fluid behavior. A similarity solution for the transformed governing equations is obtained. The numerical computation is carried out for various values of the nondimensional physical parameters. The variation of temperature, concentration, and heat and mass transfer coefficients with the power law index, mixed convection parameter, inertia parameter, melting parameter, Soret number, buoyancy ratio, and Lewis number is discussed for a wide range of values of these parameters.
Numerical Investigation of a Centrifugal Compressor With Holed Casing Treatment
Authors: Xu Wei , Wang Tong , Gu Chuangang , Ding Liang
Published: January 2012

The holed casing treatment is a new type of casing treatment that has self-adaptability for a centrifugal compressor with unshrouded impeller. It was demonstrated experimentally and numerically that both the stall margin and the choked margin of the compressor were able to be expanded by the treatment. Numerical results indicate that there is reinjected flow in the holes when the compressor works at low flow rate conditions, and bypass flow at high flow rate conditions. The key principles for choosing the diameter and the radial position of the hole are presented in this paper. The hole’s diameter is an important parameter for the holed casing treatment. Five numerical cases with different diameters (1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm and 3.0 mm) were carried out to compare the results. The reinjected flow enters into the impeller passage periodically and it tends to increase when the hole diameter gets larger. In the case of 2.5 mm, both the stall margin increment and the efficiency of the compressor were the highest among the five cases. Unsteady simulations suggest that the reinjected flow is not only periodic in time but also periodic in circumferential direction. This is the reason why only 2% of the flow amounts would get 20% of the working range expansion.
Active Damping of Nonlinear Vibrations of Functionally Graded Laminated Composite Plates using Vertically/Obliquely Reinforced 1-3 Piezoelectric Composite
Authors: Panda Satyajit , Ray M. C.
Published: January 2012

This paper deals with a study on the active constrained layer damping (ACLD) of geometrically nonlinear vibrations of functionally graded (FG) laminated composite plates. The constraining layer of the ACLD treatment is considered to be made of the vertically/obliquely reinforced 1-3 piezoelectric composites (PZCs). The substrate FG laminated composite plate is composed of generally orthotropic FG layers. The generally orthotropic FG layer is a fiber reinforced composite layer in which the fibers are longitudinally aligned in the plane parallel to the top and bottom surfaces of the layer and their orientation angle is assumed to vary in the thickness direction according to a simple power-law in order to make it as a graded layer only in the thickness direction. The constrained viscoelastic layer of the ACLD treatment is modeled by implementing the Golla-Hughes-McTavish (GHM) method. Based on the first order shear deformation theory, the finite element (FE) model is developed to model the open-loop and closed-loop nonlinear dynamics of the overall FG laminated composite plates integrated with a patch of such ACLD treatment. The analysis suggests the potential use of the ACLD treatment with its constraining layer made of the vertically/obliquely reinforced 1-3 PZC material for active control of geometrically nonlinear vibrations of FG laminated composite plates. The effect of piezoelectric fiber orientation in the active 1-3 PZC constraining layer on the damping characteristics of the overall FG laminated composite plates is also investigated.
Spanwise Heat Transport in Turbulent Channel Flow With Prandtl Numbers Ranging From 0.025 to 5.0
Authors: Matsubara Koji , Sakurai Atsushi , Miura Takahiro , Kawabata Takuya
Published: January 2012

The near-wall turbulent heat transport of the three orthogonal directions was directly solved for the Prandtl numbers ranging from 0.025 to 5.0 to validate the algebraic models of the turbulent heat flux. Two kinds of thermal situations were considered in the low Reynolds number turbulent flow: (a) the case with a uniform heat flux in the spanwise direction (UHF) and (b) the case with the mean spanwise temperature gradient (STG). Among the turbulent heat flux models tested, the model of Rogers preferably predicted over the treated range of the Prandtl numbers, but it failed to reproduce the low Prandtl number effects very accurately. This paper revealed that the coefficient of the Rotta model can be modified to include the low Prandtl number effects by means of the correlation between the exact coefficient suggested by DNS and the Prandtl number.
Biaxial Tensile Testing and Constitutive Modeling of Human Supraspinatus Tendon
Authors: Szczesny Spencer E. , Peloquin John M. , Cortes Daniel H. , Kadlowec Jennifer A. , Soslowsky Louis J. , Elliott Dawn M.
Published: January 2012

The heterogeneous composition and mechanical properties of the supraspinatus tendon offer an opportunity for studying the structure-function relationships of fibrous musculoskeletal connective tissues. Previous uniaxial testing has demonstrated a correlation between the collagen fiber angle distribution and tendon mechanics in response to tensile loading both parallel and transverse to the tendon longitudinal axis. However, the planar mechanics of the supraspinatus tendon may be more appropriately characterized through biaxial tensile testing, which avoids the limitation of nonphysiologic traction-free boundary conditions present during uniaxial testing. Combined with a structural constitutive model, biaxial testing can help identify the specific structural mechanisms underlying the tendon’s two-dimensional mechanical behavior. Therefore, the objective of this study was to evaluate the contribution of collagen fiber organization to the planar tensile mechanics of the human supraspinatus tendon by fitting biaxial tensile data with a structural constitutive model that incorporates a sample-specific angular distribution of nonlinear fibers. Regional samples were tested under several biaxial boundary conditions while simultaneously measuring the collagen fiber orientations via polarized light imaging. The histograms of fiber angles were fit with a von Mises probability distribution and input into a hyperelastic constitutive model incorporating the contributions of the uncrimped fibers. Samples with a wide fiber angle distribution produced greater transverse stresses than more highly aligned samples. The structural model fit the longitudinal stresses well (median R2 ≥ 0.96) and was validated by successfully predicting the stress response to a mechanical protocol not used for parameter estimation. The transverse stresses were fit less well with greater errors observed for less aligned samples. Sensitivity analyses and relatively affine fiber kinematics suggest that these errors are not due to inaccuracies in measuring the collagen fiber organization. More likely, additional strain energy terms representing fiber-fiber interactions are necessary to provide a closer approximation of the transverse stresses. Nevertheless, this approach demonstrated that the longitudinal tensile mechanics of the supraspinatus tendon are primarily dependent on the moduli, crimp, and angular distribution of its collagen fibers. These results add to the existing knowledge of structure-function relationships in fibrous musculoskeletal tissue, which is valuable for understanding the etiology of degenerative disease, developing effective tissue engineering design strategies, and predicting outcomes of tissue repair.
Broadband acoustic concentrator with multilayered alternative homogeneous materials
Authors: Wang Yu-ran , Zhang Hui , Zhang Shu-yi , Fan Li , Sun Hong-xiang
Published: January 2012

A two-dimensional cylindrical acoustic concentrator is designed with multilayered alternative homogeneous materials, which can focus acoustic field and enhance acoustic energy in a given area. The frequency response analysis of the acoustic concentrator demonstrates that the acoustic energy can be concentrated within the device over a wide frequency band. Meanwhile, there are contradictory relations between the acoustic concentrating performances in the inner region and the scattering properties in the outer region of these concentrators. When the contradictory relations satisfy compromise balance, the concentration ratio can reach at least 70%.
A selective array activation method for the generation of a focused source considering listening position
Authors: Song Min-Ho , Choi Jung-Woo , Kim Yang-Hann
Published: January 2012

A focused source can provide an auditory illusion of a virtual source placed between the loudspeaker array and the listener. When a focused source is generated by time-reversed acoustic focusing solution, its use as a virtual source is limited due to artifacts caused by convergent waves traveling towards the focusing point. This paper proposes an array activation method to reduce the artifacts for a selected listening point inside an array of arbitrary shape. Results show that energy of convergent waves can be reduced up to 60 dB for a large region including the selected listening point.
Ultrafast Viscous Permeation of Organic Solvents Through Diamond-Like Carbon Nanosheets
Authors: Karan Santanu , Samitsu Sadaki , Peng Xinsheng , Kurashima Keiji , Ichinose Izumi
Published: January 2012

Porous Membranes

Thin semi-permeable membranes are commonly used as chemical barriers or for filtration purposes. While the size of the pores will influence which molecules are able to pass, other factors—including the surface chemistry of the pore walls, electrostatic interactions, and differences in solubility—can also affect the diffusion rates. There is also a trade-off between the thickness of the membrane regarding strength and permeation rates (see the Perspective by

Paul

).

Karan
et al.

(p.
444
) fabricated membranes from amorphous carbon, which showed excellent strength and could be used for filtrations involving organic solvents.

Nair
et al.

(p.
442
) observed unusual behavior in graphene-based membranes which were able to prevent the diffusion of many small-molecule gases, including helium, but showed almost barrier-free movement of water.
The Molecular Diversity of Adaptive Convergence
Authors: Tenaillon Olivier , Rodríguez-Verdugo Alejandra , Gaut Rebecca L. , McDonald Pamela , Bennett Albert F. , Long Anthony D. , Gaut Brandon S.
Published: January 2012

Natural Selection Caught in the Act

Understanding how new functions evolve has been of long-standing interest. However, the number of mutations needed to evolve a key innovation is rarely known, or whether other sets of mutations would also suffice, whether the intermediate steps are driven by natural selection, or how contingent the outcome is on steps along the way.

Meyer
et al.

(p.
428
; see the Perspective by

Thompson

) answer these questions for a case in which phage lambda evolved the ability to infect its host
Escherichia coli
through a novel receptor. This shift required four mutations, which accumulated under natural selection in concert with coevolution of the host. However, when

Tenaillon
et al.

(p.
457
) exposed 115 lines of
E. coli
to high temperature and sequenced them, adaptation occurred through many different genetic paths, showing parallelism at the level of genes and interacting protein complexes, but only rarely at the nucleotide level. Thus, epistasis—nonadditive genetic interaction—is likely to play an important part in the process of adaptation to this environment.
Crystal Structure of the Human K2P TRAAK, a Lipid- and Mechano-Sensitive K
+
Ion Channel
Authors: Brohawn Stephen G. , del Mármol Josefina , MacKinnon Roderick
Published: January 2012

Potassium Permeation

Two–pore domain potassium (K2P) channels conduct K
+
ions across the plasma membrane of eukaryotic cells. They help to maintain the cellular resting potential and their modulation can tune cellular excitability (see the Perspective by

Poulsen and Nissen

).
Miller and Long
(p.
432
) describe a high-resolution crystal structure of the human K2P channel K2P1 (TWIK-1) and

Brohawn
et al.

(p.
436
) present a high-resolution structure of the lipid and mechanosensitive human channel TRAAK. In both structures an extracellular domain constricts the channel entrance so that K
+
ions reach the selectivity filter through side portals. Openings in the transmembrane region expose the central cavity to the lipid bilayer and a helix is kinked so that its C-terminal part lies in the cytosol-membrane interface. The structural features explain K2P conductance and gating and give insight into how the channels are regulated by diverse stimuli.
Repeatability and Contingency in the Evolution of a Key Innovation in Phage Lambda
Authors: Meyer Justin R. , Dobias Devin T. , Weitz Joshua S. , Barrick Jeffrey E. , Quick Ryan T. , Lenski Richard E.
Published: January 2012

Natural Selection Caught in the Act

Understanding how new functions evolve has been of long-standing interest. However, the number of mutations needed to evolve a key innovation is rarely known, or whether other sets of mutations would also suffice, whether the intermediate steps are driven by natural selection, or how contingent the outcome is on steps along the way.

Meyer
et al.

(p.
428
; see the Perspective by

Thompson

) answer these questions for a case in which phage lambda evolved the ability to infect its host
Escherichia coli
through a novel receptor. This shift required four mutations, which accumulated under natural selection in concert with coevolution of the host. However, when

Tenaillon
et al.

(p.
457
) exposed 115 lines of
E. coli
to high temperature and sequenced them, adaptation occurred through many different genetic paths, showing parallelism at the level of genes and interacting protein complexes, but only rarely at the nucleotide level. Thus, epistasis—nonadditive genetic interaction—is likely to play an important part in the process of adaptation to this environment.
The Risk of Prion Zoonoses
Authors: Collinge John
Published: January 2012

Transmission of prions between species through both lymphoid and neural tissues has implications for public health and risk management.
A Virtual National Laboratory for Reengineering Clinical Translational Science
Authors: Dilts David M. , Rosenblum Daniel , Trochim William M.
Published: January 2012

The CTSA Consortium has developed a national test bed that can be used for evaluating approaches aimed at reducing wasted efforts and speeding clinical trial completion.
When Fat Gets on Your Nerves
Authors: Mashour George A.
Published: January 2012

Omega-3 fatty acids are protective against peripheral nerve injury.
Two Novel Class I Integron Arrays Containing IMP-18 Metallo-β-Lactamase Gene in Pseudomonas aeruginosa Clinical Isolates from Puerto Rico
Authors: Martínez T. , Vazquez G. J. , Aquino E. E. , Goering R. V. , Robledo I. E.
Published: January 2012

During a β-lactam resistance surveillance study, 12 IMP-18-positive
Pseudomonas aeruginosa
isolates belonging to 9 different pulsed-field gel electrophoresis groups were identified. In nine isolates, a class I integron with a novel gene array was identified that contained
bla
IMP-18
and
bla
OXA-224
, while in two isolates the class I integron contained
bla
IMP-18
and
bla
OXA-2
but in a new arrangement. Our findings show the dissemination of two novel class I integrons in
P. aeruginosa
from different regions of Puerto Rico.
Protective Immunity against Tularemia Provided by an Adenovirus-Vectored Vaccine Expressing Tul4 of Francisella tularensis
Authors: Kaur Ravinder , Chen Shan , Arévalo Maria T. , Xu Qingfu , Chen Yanping , Zeng Mingtao
Published: January 2012

Francisella tularensis, a category A bioterrorism agent, is a highly infectious organism that is passed on via skin contact and inhalation routes. A live attenuated vaccine strain (LVS) has been developed, but it has not been licensed for public use by the FDA due to safety concerns. Thus, there exists a need for a safer and improved vaccine. In this study, we have constructed a replication-incompetent adenovirus, Ad/opt-Tul4, carrying a codon-optimized gene for expression of a membrane protein, Tul4, ofF. tularensisLVS. Its ability to protect against lethal challenge and its immunogenicity were evaluated in a murine model. An intramuscular injection of a single dose (1 × 107PFU) of Ad/opt-Tul4 elicited a robust Tul4-specific antibody response. Assays suggest a Th1-driven response. A single dose elicited 20% protection against challenge with 100 × 50% lethal dose (LD50)F. tularensisLVS; two additional booster shots resulted in 60% protection. In comparison, three doses of 5 μg recombinant Tul4 protein did not elicit significant protection against challenge. Therefore, the Ad/opt-Tul4 vaccine was more effective than the protein vaccine, and protection was dose dependent. Compared to LVS, the protection rate is lower, but an adenovirus-vectored vaccine may be more attractive due to its enhanced safety profile and mucosal route of delivery. Furthermore, simple genetic modification of the vaccine may potentially produce antibodies protective against a fully virulent strain ofF. tularensis. Our data support the development and further research of an adenovirus-vectored vaccine against Tul4 ofF. tularensisLVS.
Detection of Established Virulence Genes and Plasmids To Differentiate Borrelia burgdorferi Strains
Authors: Chan Kamfai , Casjens Sherwood , Parveen Nikhat
Published: January 2012

Borrelia burgdorferi
sensu stricto is the major causative agent of Lyme disease in the United States, while
B. garinii
and
B. afzelii
are more prevalent in Europe. The highly complex genome of
B. burgdorferi
is comprised of a linear chromosome and a large number of variably sized linear and circular plasmids. Many plasmids of this spirochete are unstable during its culture
in vitro
. Given that many of the
B. burgdorferi
virulence factors identified to date are plasmid encoded, spirochetal plasmid content determination is essential for genetic analysis of Lyme pathogenesis. Although PCR-based assays facilitate plasmid profiling of sequenced
B. burgdorferi
strains, a rapid genetic content determination strategy for nonsequenced strains has not yet been described. In this study, we combined pulsed-field gel electrophoresis (PFGE) and Southern hybridization for detection of genes encoding known virulence factors,
r
ibosomal RNA gene
s
pacer restriction fragment length polymorphism
t
ypes (RSTs),
ospC
group determination, and sequencing of the variable
dbpA
and
ospC
genes. We show that two strains isolated from the same tick and both originally named N40 are in fact very distinct. Furthermore, we failed to detect
bbk32
, which encodes a fibronectin-binding adhesin, in one “N40” strain. Thus, two distinct strains that show different plasmid profiles, as determined by PFGE and PCR, were isolated from the same tick and vary in their
ospC
and
dbpA
sequences. However, both belong to group RST3B.
Dual Priming Oligonucleotides for Broad-Range Amplification of the Bacterial 16S rRNA Gene Directly from Human Clinical Specimens
Authors: Kommedal Øyvind , Simmon Keith , Karaca Dilek , Langeland Nina , Wiker Harald G.
Published: January 2012

Broad-range amplification and sequencing of the bacterial 16S rRNA gene directly from clinical specimens are offered as a diagnostic service in many laboratories. One major pitfall is primer cross-reactivity with human DNA which will result in mixed chromatograms. Mixed chromatograms will complicate subsequent sequence analysis and impede identification. In SYBR green real-time PCR assays, it can also affect crossing threshold values and consequently the status of a specimen as positive or negative. We evaluated two conventional primer pairs in common use and a new primer pair based on the dual priming oligonucleotide (DPO) principle. Cross-reactivity was observed when both conventional primer pairs were used, resulting in interpretation difficulties. No cross-reactivity was observed using the DPOs even in specimens with a high ratio of human to bacterial DNA. In addition to reducing cross-reactivity, the DPO principle also offers a high degree of flexibility in the design of primers and should be considered for any PCR assay intended for detection and identification of pathogens directly from human clinical specimens.
Vaccinia Mature Virus Fusion Regulator A26 Protein Binds to A16 and G9 Proteins of the Viral Entry Fusion Complex and Dissociates from Mature Virions at Low pH
Authors: Chang Shu-Jung , Shih Ao-Chun , Tang Yin-Liang , Chang Wen
Published: January 2012

Vaccinia mature virus enters cells through either endocytosis or plasma membrane fusion, depending on virus strain and cell type. Our previous results showed that vaccinia virus mature virions containing viral A26 protein enter HeLa cells preferentially through endocytosis, whereas mature virions lacking A26 protein enter through plasma membrane fusion, leading us to propose that A26 acts as an acid-sensitive fusion suppressor for mature virus (S. J. Chang, Y. X. Chang, R. Izmailyan R, Y. L. Tang, and W. Chang, J. Virol. 84:8422–8432, 2010). In the present study, we investigated the fusion suppression mechanism of A26 protein. We found that A26 protein was coimmunoprecipitated with multiple components of the viral entry-fusion complex (EFC) in infected HeLa cells. Transient expression of viral EFC components in HeLa cells revealed that vaccinia virus A26 protein interacted directly with A16 and G9 but not with G3, L5 and H2 proteins of the EFC components. Consistently, a glutathione
S
-transferase (GST)-A26 fusion protein, but not GST, pulled down A16 and G9 proteins individually
in vitro
. Together, our results supported the idea that A26 protein binds to A16 and G9 protein at neutral pH contributing to suppression of vaccinia virus-triggered membrane fusion from without. Since vaccinia virus extracellular envelope proteins A56/K2 were recently shown to bind to the A16/G9 subcomplex to suppress virus-induced fusion from within, our results also highlight an evolutionary convergence in which vaccinia viral fusion suppressor proteins regulate membrane fusion by targeting the A16 and G9 components of the viral EFC complex. Finally, we provide evidence that acid (pH 4.7) treatment induced A26 protein and A26-A27 protein complexes of 70 kDa and 90 kDa to dissociate from mature virions, suggesting that the structure of A26 protein is acid sensitive.
Discovery of Seven Novel Mammalian and Avian Coronaviruses in the Genus Deltacoronavirus Supports Bat Coronaviruses as the Gene Source of Alphacoronavirus and Betacoronavirus and Avian Coronaviruses as the Gene Source of Gammacoronavirus and Deltacoronavirus
Authors: Woo Patrick C. Y. , Lau Susanna K. P. , Lam Carol S. F. , Lau Candy C. Y. , Tsang Alan K. L. , Lau John H. N. , Bai Ru , Teng Jade L. L. , Tsang Chris C. C. , Wang Ming , Zheng Bo-Jian , Chan Kwok-Hung , Yuen Kwok-Yung
Published: January 2012

Recently, we reported the discovery of three novel coronaviruses, bulbul coronavirus HKU11, thrush coronavirus HKU12, and munia coronavirus HKU13, which were identified as representatives of a novel genus,
Deltacoronavirus
, in the subfamily
Coronavirinae
. In this territory-wide molecular epidemiology study involving 3,137 mammals and 3,298 birds, we discovered seven additional novel deltacoronaviruses in pigs and birds, which we named porcine coronavirus HKU15, white-eye coronavirus HKU16, sparrow coronavirus HKU17, magpie robin coronavirus HKU18, night heron coronavirus HKU19, wigeon coronavirus HKU20, and common moorhen coronavirus HKU21. Complete genome sequencing and comparative genome analysis showed that the avian and mammalian deltacoronaviruses have similar genome characteristics and structures. They all have relatively small genomes (25.421 to 26.674 kb), the smallest among all coronaviruses. They all have a single papain-like protease domain in the nsp3 gene; an accessory gene, NS6 open reading frame (ORF), located between the M and N genes; and a variable number of accessory genes (up to four) downstream of the N gene. Moreover, they all have the same putative transcription regulatory sequence of ACACCA. Molecular clock analysis showed that the most recent common ancestor of all coronaviruses was estimated at approximately 8100 BC, and those of
Alphacoronavirus
,
Betacoronavirus
,
Gammacoronavirus
, and
Deltacoronavirus
were at approximately 2400 BC, 3300 BC, 2800 BC, and 3000 BC, respectively. From our studies, it appears that bats and birds, the warm blooded flying vertebrates, are ideal hosts for the coronavirus gene source, bats for
Alphacoronavirus
and
Betacoronavirus
and birds for
Gammacoronavirus
and
Deltacoronavirus
, to fuel coronavirus evolution and dissemination.
Polarographic and voltammetric determination of genotoxic nitro derivatives of quinoline using mercury electrodes
Authors: Vyskočil Vlastimil , Jiránek Ivan , Daňhel Aleš , Zima Jiří , Barek Jiří , Wang Joseph , Pecková Karolina
Published: January 2012

Electrochemical behavior of genotoxic nitro derivatives of quinoline, namely 5-nitroquinoline (5-NQ), 6-nitroquinoline (6-NQ) and 8-nitroquinoline (8-NQ), was investigated by DC tast polarography (DCTP) and differential pulse polarography (DPP), both at a classical dropping mercury electrode (DME), and by differential pulse voltammetry (DPV) and adsorptive stripping differential pulse voltammetry (AdSDPV), both at a miniaturized hanging mercury drop minielectrode (HMDmE), in buffered aqueous (for 5-NQ) or aqueous-methanolic (for 6-NQ and 8-NQ) solutions. Optimum conditions were found for the determination of 5-NQ, 6-NQ and 8-NQ by DCTP at DME (with limits of quantification, LQ ≈ 9 × 10–7, 3 × 10–7 and 2 × 10–6 mol l–1, respectively), by DPP at DME (LQ ≈ 1 × 10–8, 9 × 10–8 and 1 × 10–7 mol l–1, respectively), by DPV at HMDmE (LQ ≈ 2 × 10–8, 1 × 10–7 and 1 × 10–7 mol l–1, respectively), and by AdSDPV at HMDmE (LQ ≈ 1 × 10–8 mol l–1 for 8-NQ; an attempt at increasing the sensitivity using AdSDPV at HMDmE was not successful for 5-NQ and 6-NQ). Practical applicability of the developed methods was verified on the direct determination of the studied compounds in model samples of drinking and river water in submicromolar concentrations and on the determination in model samples of drinking and river water using preliminary separation and preconcentration by solid phase extraction (SPE) in nanomolar concentrations.
Use of CPT and other direct push methods for (hydro-) stratigraphic aquifer characterization — a field study
Authors: Vienken Thomas , Leven Carsten , Dietrich Peter
Published: January 2012

Every environmental site investigation aims at delineating near-surface (hydro-) stratigraphic units and their characterization. To determine the type and hydraulic properties of sedimentary deposits, direct push (DP) sensor probes and tools are promising methods and are therefore frequently applied to measure high-resolution vertical profiles of soil properties. Given the variety of these tools, the objective of this paper is to compare selected DP tools for the (hydro-) stratigraphic subsurface characterization in a heterogeneous unconsolidated sedimentary aquifer. An overview of current DP applications is given and selected DP tools were tested for reproducibility, as well as their ability to reflect soil variability and to estimate hydraulic conductivity, K. Although resolution differences exist, all of the applied methods captured the main aquifer structure. Correlations of the DP-based K estimates or proxies with DP slug tests (DPST) show that it is possible to describe the aquifer hydraulic structure on less than a metre scale by combining DPST data and continuous DP measurements. Although correlations are site-specific and appropriate DP tools must be chosen, DP is a reliable and efficient alternative for characterizing even strongly heterogeneous sites with complex sedimentary architectures.
OPTIMIZED PARTICLES FOR 3D TRACKING
Authors: CHEN HUIYING , LI YOUFU
Published: January 2012

3D visual tracking is useful for many applications. In this paper, we propose two different ways for different system configurations to optimize particle filter for enhancing 3D tracking performances. On the one hand, a new data fusion method is proposed to obtain the optimal importance density function for active vision systems. With this method, the importance density function in particle filter can be modified to represent posterior states by particle crowds in a better way. Thus, it makes the tracking system more robust to noise and outliers. On the other hand, we develop a method for reconfigurable vision systems to maximize the effective sampling size in particle filter, which consequentially helps to solve the degeneracy problem and minimize the tracking error. Simulation and experimental results verified the effectiveness of the proposed method.
MINIMAL GEODESIC FOLIATION ON T2 IN CASE OF VANISHING TOPOLOGICAL ENTROPY
Authors: GLASMACHERS EVA , KNIEPER GERHARD
Published: January 2012

On a Riemannian 2-torus (T2, g) we study the geodesic flow in the case of low complexity described by zero topological entropy. We show that this assumption implies a nearly integrable behavior. In our previous paper [12] we already obtained that the asymptotic direction and therefore also the rotation number exists for all geodesics. In this paper we show that for all r ∈ ℝ ∪ {∞} the universal cover ℝ2 is foliated by minimal geodesics of rotation number r. For irrational r ∈ ℝ all geodesics are minimal, for rational r ∈ ℝ ∪ {∞} all geodesics stay in strips between neighboring minimal axes. In such a strip the minimal geodesics are asymptotic to the neighboring minimal axes and generate two foliations.
ON CLOSED LEAVES OF FOLIATIONS, MULTISECTIONS AND STABLE COMMUTATOR LENGTHS
Authors: BOWDEN JONATHAN
Published: January 2012

We give examples of foliations that answer two questions posed by Mitsumatsu and Vogt about the genus minimizing properties of closed leaves of 2-dimensional foliations on 4-manifolds. By studying stable commutator lengths in certain stable mapping class groups, we also answer an asymptotic version of another question of theirs concerning bounds on self-intersection numbers of multisections in surface bundles.
INJECTABLE OXYGEN DELIVERY BASED ON PROTEIN-SHELLED MICROBUBBLES
Authors: SWANSON EDWARD J. , BORDEN MARK A.
Published: January 2012

Injectable oxygen delivery is an emerging technology that presents an opportunity for improved patient care in a number of medical disciplines. Here, we report on the fabrication and characterization of novel protein-encapsulated oxygen microbubbles (OMBs) designed for intravenous injection. The nanothick albumin encapsulation provided OMBs small enough for transcapillary passage: 99% of the microbubbles were less than 3-μm diameter and less than 1% of the oxygen was encapsulated in microbubbles greater than 8-μm diameter. The protein OMBs were remarkably stable, losing less than 40% of the encapsulated gas over 12 days. Upon injection into an oxygen-depleted saline solution, the protein OMBs rapidly equilibrated by releasing their oxygen core. These results indicate that protein microbubbles may serve as a suitable platform for direct injection of bioactive and therapeutic gases.