bluuebunny/crossref_metadata_2025 huggingface dataset:
Loss of PodJ in Agrobacterium tumefaciens Leads to Ectopic Polar Growth, Branching, and Reduced Cell Division
Authors: Anderson-Furgeson James C. , Zupan John R. , Grangeon Romain , Zambryski Patricia C.
Published: May 2016

Agrobacterium tumefaciens
is a rod-shaped Gram-negative bacterium that elongates by unipolar addition of new cell envelope material. Approaching cell division, the growth pole transitions to a nongrowing old pole, and the division site creates new growth poles in sibling cells. The
A. tumefaciens
homolog of the
Caulobacter crescentus
polar organizing protein PopZ localizes specifically to growth poles. In contrast, the
A. tumefaciens
homolog of the
C. crescentus
polar organelle development protein PodJ localizes to the old pole early in the cell cycle and accumulates at the growth pole as the cell cycle proceeds. FtsA and FtsZ also localize to the growth pole for most of the cell cycle prior to Z-ring formation. To further characterize the function of polar localizing proteins, we created a deletion of
A. tumefaciens
podJ
(

podJ
At

). Δ

podJ
At

cells display ectopic growth poles (branching), growth poles that fail to transition to an old pole, and elongated cells that fail to divide. In Δ

podJ
At

cells,
A. tumefaciens
PopZ-green fluorescent protein (PopZ
At
-GFP) persists at nontransitioning growth poles postdivision and also localizes to ectopic growth poles, as expected for a growth-pole-specific factor. Even though GFP-PodJ
At
does not localize to the midcell in the wild type, deletion of

podJ
At

impacts localization, stability, and function of Z-rings as assayed by localization of FtsA-GFP and FtsZ-GFP. Z-ring defects are further evidenced by minicell production. Together, these data indicate that PodJ
At
is a critical factor for polar growth and that Δ

podJ
At

cells display a cell division phenotype, likely because the growth pole cannot transition to an old pole.

IMPORTANCE
How rod-shaped prokaryotes develop and maintain shape is complicated by the fact that at least two distinct species-specific growth modes exist: uniform sidewall insertion of cell envelope material, characterized in model organisms such as
Escherichia coli
, and unipolar growth, which occurs in several alphaproteobacteria, including
Agrobacterium tumefaciens
. Essential components for unipolar growth are largely uncharacterized, and the mechanism constraining growth to one pole of a wild-type cell is unknown. Here, we report that the deletion of a polar development gene,

podJ
At

, results in cells exhibiting ectopic polar growth, including multiple growth poles and aberrant localization of cell division and polar growth-associated proteins. These data suggest that PodJ
At
is a critical factor in normal polar growth and impacts cell division in
A. tumefaciens
.
Alternative Translation Initiation of a Haloarchaeal Serine Protease Transcript Containing Two In-Frame Start Codons
Authors: Tang Wei , Wu Yufeng , Li Moran , Wang Jian , Mei Sha , Tang Bing , Tang Xiao-Feng
Published: May 2016

Recent studies have shown that haloarchaea employ leaderless and Shine-Dalgarno (SD)-less mechanisms for translation initiation of leaderless transcripts with a 5′ untranslated region (5′ UTR) of <10 nucleotides (nt) and leadered transcripts with a 5′ UTR of ≥10 nt, respectively. However, whether the two mechanisms can operate on the same naturally occurring haloarchaeal transcript carrying multiple potential start codons is unknown. In this study, the transcript of the
sptA
gene (encoding an extracellular serine protease of
Natrinema
sp. strain J7-2) was experimentally determined and found to contain two potential in-frame AUG codons (AUG
1
and AUG
2
) located 5 and 29 nt, respectively, downstream of the transcription start site. Mutational analysis revealed that both AUGs can function as the translation start codon for production of active SptA, although AUG
1
is more efficient than AUG
2
for translation initiation. Insertion of a stable stem-loop structure between the two AUGs completely abolished initiation at AUG
1
but did not affect initiation at AUG
2
, indicating that AUG
2
-initiated translation does not involve ribosome scanning from the 5′ end of the transcript. Furthermore, the efficiency of AUG
2
-initiated translation was not influenced by an upstream SD-like sequence. In addition, both AUG
1
and AUG
2
contribute to transcript stability, probably by recruiting ribosomes to protect the transcript against degradation. These data suggest that depending on which of two in-frame start codons is used, the
sptA
transcript can act as either a leaderless or a leadered transcript for SptA production in haloarchaea.

IMPORTANCE
In eukaryotes and bacteria, alternative translation start sites contribute to proteome complexity and can be used as a functional mechanism to increase translation efficiency. However, little is known about alternative translation initiation in archaea. Our results demonstrate that leaderless and SD-less mechanisms can be used for translation initiation of the
sptA
transcript from two in-frame start codons, raising the possibility that in haloarchaea, alternative translation initiation on one transcript functions to increase translation efficiency and/or contribute to proteome complexity.
Growth Inhibition by External Potassium of Escherichia coli Lacking PtsN (EIIA
Ntr
) Is Caused by Potassium Limitation Mediated by YcgO
Authors: Sharma Ravish , Shimada Tomohiro , Mishra Vinod K. , Upreti Suchitra , Sardesai Abhijit A.
Published: May 2016

The absence of PtsN, the terminal phosphoacceptor of the phosphotransferase system comprising PtsP-PtsO-PtsN, in
Escherichia coli
confers a potassium-sensitive (K
s
) phenotype as the external K
+
concentration ([K
+
]
e
) is increased above 5 mM. A growth-inhibitory increase in intracellular K
+
content, resulting from hyperactivated Trk-mediated K
+
uptake, is thought to cause this K
s
. We provide evidence that the K
s
of the Δ
ptsN
mutant is associated with K
+
limitation. Accordingly, the moderate K
s
displayed by the Δ
ptsN
mutant was exacerbated in the absence of the Trk and Kup K
+
uptake transporters and was associated with reduced cellular K
+
content. Conversely, overproduction of multiple K
+
uptake proteins suppressed the K
s
. Expression of PtsN variants bearing the H73A, H73D, and H73E substitutions of the phosphorylation site histidine of PtsN complemented the K
s
. Absence of the predicted inner membrane protein YcgO (also called CvrA) suppressed the K
s
, which was correlated with elevated cellular K
+
content in the Δ
ptsN
mutant, but the Δ
ptsN
mutation did not alter YcgO levels. Heterologous overexpression of
ycgO
also led to K
s
that was associated with reduced cellular K
+
content, exacerbated by the absence of Trk and Kup and alleviated by overproduction of Kup. Our findings are compatible with a model that postulates that K
s
in the Δ
ptsN
mutant occurs due to K
+
limitation resulting from activation of K
+
efflux mediated by YcgO, which may be additionally stimulated by [K
+
]
e
, implicating a role for PtsN (possibly its dephosphorylated form) as an inhibitor of YcgO activity.

IMPORTANCE
This study examines the physiological link between the phosphotransferase system comprising PtsP-PtsO-PtsN and K
+
ion metabolism in
E. coli
. Studies on the physiological defect that renders an
E. coli
mutant lacking PtsN to be growth inhibited by external K
+
indicate that growth impairment results from cellular K
+
limitation that is mediated by YcgO, a predicted inner membrane protein. Additional observations suggest that dephospho-PtsN may inhibit and external K
+
may stimulate K
+
limitation mediated by YcgO. It is speculated that YcgO-mediated K
+
limitation may be an output of a response to certain stresses, which by modulating the phosphotransfer capacity of the PtsP-PtsO-PtsN phosphorelay leads to growth cessation and stress tolerance.
Earliest occurrence of Hydrocynus (Characiformes, Alestidae) from Eocene continental deposits of Méridja Hamada, northwestern Sahara, Algeria
Authors: Hammouda Sid-Ahmed , Murray Alison M. , Divay Julien D. , Mebrouk Fateh , Adaci Mohammed , Bensalah Mustapha
Published: May 2016

We here report the oldest remains (teeth) of the African tigerfish (Hydrocynus) from the Oued Méridja and Garet Dermchane sections, Hamada of Méridja deposits, in southwestern Algeria. The tigerfish, a large carnivorous fish today represented by several species in the freshwaters of Africa, was previously found in upper middle to upper Eocene deposits in Egypt and Libya. The remains described here are several million years older, being early to middle Eocene in age, and are associated with other fish elements including lungfish, polypterid, amiiform, possible cichlid, and Alestes and Brycinus material, along with several fish elements that cannot be associated with a specific taxon and some fragmentary amphibian bones. This represents the first detailed description of a freshwater fish assemblage from the Eocene of Algeria, although a short list of fish taxa from Eocene Algerian deposits was previously reported. Furthermore, these new Algerian fossils allow us to assess the hypothesized existence of an east–west or west–east hydrological connection between eastern and western parts of northern Africa. We suggest that the shared presence of tigerfish in the Eocene deposits of Algeria, Libya, and Egypt does not necessarily indicate a permanent (i.e., nonseasonal) connection east–west or west–east among these areas. Rather, the observed faunal similarities could have been the result of seasonal flooding that caused the dispersal of Hydrocynus and associated taxa across coastal flood plains.
Organic and inorganic contamination impacts on metabolic capacities in American and European yellow eels
Authors: Caron Antoine , Pannetier Pauline , Rosabal Maikel , Budzinski Hélène , Lauzent Mathilde , Labadie Pierre , Nasri Bouchra , Pierron Fabien , Baudrimont Magalie , Couture Patrice
Published: May 2016

American (Anguilla rostrata) and European (Anguilla anguilla) eel populations are declining since the 1980s, and contamination is thought to play a role. To determine the influence of organic (organochlorinated pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs)) and inorganic (Zn, As, Cd, Cu, Pb, Cr, Ni, Ag, Se, Hg) contaminants on wild yellow eels liver and muscle metabolic capacities, enzymatic assays were performed. In A. rostrata liver, G6PDH moderate negative correlations with Ag, Pb, and As suggest impacts on lipid metabolism, and correlations between Cd and age (positive) and between Cd and relative condition factor (Kn; negative) indicate impacts on older eels health. Anguilla anguilla liver proteins, pyruvate kinase (PK), and lactate dehydrogenase (LDH) were positively linked to Zn, Pb, and Cu, suggesting effects on glycolytic and anaerobic capacities. In A. anguilla muscle, absence of correlation between age and lipids plus strong positive correlations between age and OCPs, PBDEs, PCBs, and Hg suggest lipid storage impairment in older contaminated eels. Overall, our study indicates contamination impacts on both species’ metabolic capacities, but the broader range of contaminants found in A. anguilla brings greater impacts compared with A. rostrata.
Glycerol metabolism promotes biofilm formation byPseudomonas aeruginosa
Authors: Scoffield Jessica , Silo-Suh Laura
Published: May 2016

Pseudomonas aeruginosa causes persistent infections in the airways of cystic fibrosis (CF) patients. Airway sputum contains various host-derived nutrients that can be utilized by P. aeruginosa, including phosphotidylcholine, a major component of host cell membranes. Phosphotidylcholine can be degraded by P. aeruginosa to glycerol and fatty acids to increase the availability of glycerol in the CF lung. In this study, we explored the role that glycerol metabolism plays in biofilm formation by P. aeruginosa. We report that glycerol metabolism promotes biofilm formation by both a chronic CF isolate (FRD1) and a wound isolate (PAO1) of P. aeruginosa. Moreover, loss of the GlpR regulator, which represses the expression of genes involved in glycerol metabolism, enhances biofilm formation in FRD1 through the upregulation of Pel polysaccharide. Taken together, our results suggest that glycerol metabolism may be a key factor that contributes to P. aeruginosa persistence by promoting biofilm formation.
DNA barcode variability and host plant usage of fruit flies (Diptera: Tephritidae) in Thailand
Authors: Kunprom Chonticha , Pramual Pairot
Published: May 2016

The objectives of this study were to examine the genetic variation in fruit flies (Diptera: Tephritidae) in Thailand and to test the efficiency of the mitochondrial cytochrome c oxidase subunit I (COI) barcoding region for species-level identification. Twelve fruit fly species were collected from 24 host plant species of 13 families. The number of host plant species for each fruit fly species ranged between 1 and 11, with Bactrocera correcta found in the most diverse host plants. A total of 123 COI sequences were obtained from these fruit fly species. Sequences from the NCBI database were also included, for a total of 17 species analyzed. DNA barcoding identification analysis based on the best close match method revealed a good performance, with 94.4% of specimens correctly identified. However, many specimens (3.6%) had ambiguous identification, mostly due to intra- and interspecific overlap between members of the B. dorsalis complex. A phylogenetic tree based on the mitochondrial barcode sequences indicated that all species, except for the members of the B. dorsalis complex, were monophyletic with strong support. Our work supports recent calls for synonymization of these species. Divergent lineages were observed within B. correcta and B. tuberculata, and this suggested that these species need further taxonomic reexamination.
Computer simulations of rotating systems of few particles bound by gravitation
Authors: Hopstad Yngve , Myrheim Jan
Published: May 2016

The shapes of rotating drops of liquid bound by gravitation is a classical subject of study. Inspired by this classical theory, we have simulated numerically a related problem, the rotating rigid configurations of a finite number of point particles. Two particles at a distance [Formula: see text] have a long range attractive potential [Formula: see text] and a short range repulsive potential [Formula: see text] preventing collapse. We take the angular momentum to be conserved, but not the energy.This system has a variable density, unlike the classical liquid drops. When the number of particles is small, it is more rigid than a liquid drop, implying that many different stable equilibrium configurations may exist with the same angular momentum but different energies. When the number of particles becomes large, our system should resemble a self-gravitating polytropic gas.We present here the results of a preliminary study with only 3, 4, and 5 particles. The methods used could be applied to the study of rotating molecules.
More Flexible Curve Matching via the Partial Fréchet Similarity
Authors: Scheffer Christian
Published: May 2016

We study a modified version of the partial Fréchet similarity that is motivated by real world applications, e.g. the analysis of spectroscopic data in the context of astroinformatics and the analysis of birds’ migration trajectories. In those practical applications of curve matching it is often necessary to ignore outliers while dissimilarities regarding individual directions should be weighted by individual costs.

We enable both by computing the partial Fréchet similarity between polygonal curves w.r.t. a non-uniform metric. In particular, we measure distances by a function [Formula: see text] that is induced by a set of weighted vectors. We discuss the approximation quality of [Formula: see text] regarding any [Formula: see text] metric and present a polynomial time algorithm for computing an exact solution of the resulting modified partial Fréchet similarity.
Quasi-isometric maps between direct products of hyperbolic spaces
Authors: Bowditch Brian H.
Published: May 2016

We give conditions under which a quasi-isometric map between direct products of hyperbolic spaces splits as a direct product up to bounded distance and permutation of factors. This is a variation on a result due to Kapovich, Kleiner and Leeb.
Relative autocommutator subgroups of abelian groups
Authors: Naghshinehfard Mohammad
Published: May 2016

We compute the autocentral and autoderived series of a finite abelian group [Formula: see text] corresponding to several groups of automorphisms [Formula: see text]. As a result, we determine the autonilpotency and autosolvability of [Formula: see text] with respect to [Formula: see text].
Zero-divisor graphs for modules over integral domains
Authors: Safaeeyan S. , Momtahan E. , Baziar M.
Published: May 2016

The zero-divisor graphs of modules introduced and studied in [S. Safaeeyan, M. Baziar and E. Momtahan, A generalization of the zero-divisor graph for modules, J. Korean Math. Soc. 51(1) (2014) 87–98]. Basic results for zero-divisor graphs of [Formula: see text]-modules were obtained in [M. Baziar, E. Momtahan and S. Safaeeyan, Zero-divisor graph of abelian groups, J. Algebra Appl. 13(6) (2014) 13]. In this paper, zero-divisor graphs in the title are studied. Here, among other things, we generalize results stated in [M. Baziar, E. Momtahan and S. Safaeeyan, Zero-divisor graph of abelian groups, J. Algebra Appl. 13(6) (2014) 13]. Some results for modules over non-integral domains are also obtained.
CONTAGION IN HETEROGENEOUS FINANCIAL NETWORKS
Authors: GUAN YUANYING , POLLAK MICAH
Published: May 2016

In this paper, we use the financial network contagion model of Gai P. and Kapadia S. [Contagion in financial networks, Proc. R. Soc. A 466 (2010) 2401–2423] to investigatethe interaction of several types of heterogeneity found in real world banking systems. The first source of heterogeneity originates in the distribution of assets across banks in the financial system. The second source is in how individual banks then distribute these assets among their neighbors. We characterize how these two sources of heterogeneity interact to affect the probability and extent of financial contagions in three network structures. We find that greater heterogeneity has a stabilizing effect for networks that are sparsely connected and a destabilizing effect for networks that are highly interconnected. Finally, we consider multiple sequential shocks and find that when banks redistribute assets following an initial mild contagion it increases the stability, on average, of the system to subsequent shocks originating at weakened banks.
Stable recovery of sparse signals with coherent tight frames via lp-analysis approach
Authors: Liu Dekai , Li Song
Published: May 2016

In this paper, we consider to recover a signal which is sparse in terms of a tight frame from undersampled measurements via [Formula: see text]-minimization problem for [Formula: see text]. In [Compressed sensing with coherent tight frames via [Formula: see text]-minimization for [Formula: see text], Inverse Probl. Imaging 8 (2014) 761–777], Li and Lin proved that when [Formula: see text] there exists a [Formula: see text], depending on [Formula: see text] such that for any [Formula: see text], each solution of the [Formula: see text]-minimization problem can approximate the true signal well. The constant [Formula: see text] is referred to as the [Formula: see text]-RIP constant of order [Formula: see text] which was first introduced by Candès et al. in [Compressed sensing with coherent and redundant dictionaries, Appl. Comput. Harmon. Anal. 31 (2011) 59–73]. The main aim of this paper is to give the closed-form expression of [Formula: see text]. We show that for every [Formula: see text]-RIP constant [Formula: see text], if [Formula: see text] where [Formula: see text] then the [Formula: see text]-minimization problem can reconstruct the true signal approximately well. Our main results also hold for the complex case, i.e. the measurement matrix, the tight frame and the signal are all in the complex domain. It should be noted that the[Formula: see text]-RIP condition is independent of the coherence of the tight frame (see [Compressed sensing with coherent and redundant dictionaries, Appl. Comput. Harmon. Anal. 31 (2011) 59–73]). In particular, when the tight frame reduces to an identity matrix or an orthonormal matrix, the conclusions in our paper coincide with the results appeared in [Stable recovery of sparse signals via [Formula: see text]-minimization, Appl. Comput. Harmon. Anal. 38 (2015) 161–176].
Quick draw of the original handwriting base on quadratic Bezier curve
Authors: Zhou Shengan , Gao Dongfa , Zhou Dehua
Published: May 2016

According to the use of normal mouse as an input device to achieve the quick draw of the original handwriting, this paper proposed a quick draw Method of original handwriting based on quadratic Bezier curve. Firstly, the method obtained moving speed and the direction information of the mouse and the information helped to obtain the periphery polygon vertex of the original handwriting drawing. Then Corresponding vertices of a polygon was used to structure the Bezier curve on both sides of the original handwriting to generate the peripheral curve polygon of the original handwriting. Finally, it was input by filling the curve polygon to simulate the user’s handwriting. The experimental results show that the algorithm interacts smoothly and has good simulation effect. Compared with other original handwriting drawing methods with the help of the related electronic input devices, this method only needs the normal mouse instead of stylus and multi touch device to achieve the smooth drawing of original handwriting. Therefore it has wide application value.
A differential geometry model for the perceived colors space
Authors: Provenzi Edoardo
Published: May 2016

The space of perceived colors, before acquiring an industrial interest, has received a systematic theoretical attention from philosophers, physicists and mathematicians. The research about this topic is still active nowadays. In this paper, it will be presented a critical overview of a model based on differential geometry proposed by H. L. Resnikoff in 1974. It will be shown that, while some fundamental and elegant ideas behind this model can be still used as a guiding principle, some other parts of the model must be updated to comply with the modern findings about color perception.
A gauge theory of gravity in curved phase-spaces
Authors: Castro Carlos
Published: May 2016

After a cursory introduction of the basic ideas behind Born’s Reciprocal Relativity theory, the geometry of the cotangent bundle of spacetime is studied via the introduction of nonlinear connections associated with certain nonholonomic modifications of Riemann–Cartan gravity within the context of Finsler geometry. A novel gauge theory of gravity in the [Formula: see text] cotangent bundle [Formula: see text] of spacetime is explicitly constructed and based on the gauge group [Formula: see text] which acts on the tangent space to the cotangent bundle [Formula: see text] at each point [Formula: see text]. Several gravitational actions involving curvature and torsion tensors and associated with the geometry of curved phase-spaces are presented. We conclude with a brief discussion of the field equations, the geometrization of matter, quantum field theory (QFT) in accelerated frames, T-duality, double field theory, and generalized geometry.
The W2-curvature tensor on warped product manifolds and applications
Authors: Shenawy Sameh , Ünal Bülent
Published: May 2016

The purpose of this paper is to study the [Formula: see text]-curvature tensor on (singly) warped product manifolds as well as on generalized Robertson–Walker and standard static space-times. Some different expressions of the [Formula: see text]-curvature tensor on a warped product manifold in terms of its relation with [Formula: see text]-curvature tensor on the base and fiber manifolds are obtained. Furthermore, we investigate [Formula: see text]-curvature flat warped product manifolds. Many interesting results describing the geometry of the base and fiber manifolds of a [Formula: see text]-curvature flat warped product manifold are derived. Finally, we study the [Formula: see text]-curvature tensor on generalized Robertson–Walker and standard static space-times; we explore the geometry of the fiber of these warped product space-time models that are [Formula: see text]-curvature flat.
Some remarks on topological phases and topological insulators
Authors: Asorey Manuel
Published: May 2016

The remarkable properties of topological phases and topological insulators are analyzed in very simple quantum mechanical models. A characteristic effect of magnetic fields on quantum systems is the appearance of degenerate ground states. The level of degeneracy of the corresponding quantum phases depends on the strength of the magnetic field and the topology of the configuration space. In topological insulators, in absence of magnetic fields, the essential ingredients are time reversal symmetry, the existence of edge states and a non-trivial topological structure of the Jacobian space (Brillouin zone). In both cases the main features are encoded by topological indices. In topological phases induced by magnetic fields, the index is a topological invariant that depends on the Chern class of the magnetic fields and the topology of the space. In topological insulators the topological index is given by the number of edge levels crossing the Fermi surface that remains invariant under time reversal invariant perturbations. The robustness of the corresponding effects under perturbations follows from the topological nature of both phenomena.
Dupuytren's Contracture. The Safety and Efficacy of Collagenase Treatment
Authors: Odinsson Adalsteinn , Brenne Lars Erik , Lurie Tone Bøyesen , Finsen Vilhjalmur
Published: May 2016

Background: Our main goal was to see if treatment with collagenase injection is safe and effective and to assess patient satisfaction with this new treatment.

Methods: We prospectively followed 77 consecutive patients, treated for contracture in 91 fingers and 142 joints that received total of 109 collagenase injections. The patients were reviewed on the first and second day and at 4 and 12 months. A contracture reduced to five degrees or less at 12 months after the last injection, was considered to be a successful outcome.

Results: A mean of 1.2 injections were used per patient and 0.8 injections per joint. There was a significant improvement in mean passive extension deficit. Out of the 142 joints treated, 84 (59%) met our criterion for a successful outcome; 56 (80%) out of 70 MCP joints and 28 (39%) out of 72 PIP joints. There were also significant improvements in both hand function and pain. No serious adverse events were observed. The mean patient satisfaction with the treatment at the 12-month follow up was a VAS score of 78 (0 = none; 100 = complete) and only 11% stated that they would not have consented to the treatment if they had known the outcome in advance.

Conclusions: Treatment of Dupuytren's disease with collagenase injection is both safe and effective. It is now our primary treatment for Dupuytren's disease.
Recovery of Wrist Function after Volar Locking Plate Fixation for Distal Radius Fractures
Authors: Takeuchi Naohide , Hotokezaka Shunsuke , Okada Takamitsu , Yuge Hidehiko , Mae Takao , Iwamoto Yukihide
Published: May 2016

Background: The purpose of our present study was to examine the recovery of the postoperative wrist function, and to compare the range of motion among each direction ofthe wrist joint during the same time periods after surgery for distal radius fractures.

Methods: Twenty patients treated with a volar locking plate were evaluated. The active range of motion and grip strength were assessed at four weeks, six weeks, three months, six months and one year after surgery.

Results: The ratio of the range of motion in pronation and supination recovered significantly earlier than for any other directions within six months after surgery (p = 0.0205), however, the ratio of the range of motion among the six directions was not significantly different at one year after surgery (p = 0.0823). The recovery of the range of motion in flexion was 96.8% compared with the contralateral wrist at one year after surgery, and it was not significantly lower than that in extension, radial deviation or ulnar deviation (97.8%, 93.5%, 94.4%, respectively). The grip strength of dominant hand recovered from 50% after four weeks to 66% after six weeks, 83% after three months, 91% after six months and 106% at the examination performed after one year compared with the uninjured non-dominant hand. The grip strength of non-dominant hand recovered from 52% after four weeks to 59% after six weeks, 79% after three months, 84% after six months and 94% at the examination performed after one year compared with the uninjured dominant hand. The mean DASH score was 5.3.

Conclusions: The range of motion in flexion can achieve similar improvement to that in the other directions by obtaining the appropriate postoperative parameters. The optimal postoperative radiographic parameters were thus identified to be essential for successfully obtaining a recovery of the wrist function for unstable distal radius fractures.
Computer Aided Assessment in Microsurgical Training
Authors: Lahiri Amitabha , Sebastin Sandeep Jacob , Yusoff Siti Khadijah , Sze Chong Alphonsus Khin
Published: May 2016

Background: Acquiring competence in microsurgical suturing is a basic requirement for any trainee aspiring to perform clinical microsurgery. New methods and simulation platform continue to evolve, but the assessment of the quality of microsurgical suturing is largely subjective. We present the concept of computer aided assessment of standardised microsurgical task, using a novel training platform. The platform comprises of a simulator (hardware) that provides the trainee standardised microsurgical tasks, which are then evaluated using a customised software.

Methods: A cohort of trainees attending a five day microsurgery training course was selected. The trainees performed three standardised exercises on the platform, on the first third and the fifth day of the course. All the exercises were subjected to computer aided assessment.

Results: Trainees demonstrated a learning curve over the five day period through the evaluation system, with initial increase in performance followed by a plateau. Eighty four percent of the trainees were able to achieve acceptable scores. Sixteen percent of the trainees were unable to perform a suturing of acceptable quality at the end of the training (fifth day).

Conclusions: The mean scores correlated with the level of difficulty of the exercise. We conclude that computer aided assessment can provide an objective view of the quality of suturing as well as skill maintenance in for trainees.
An Anechoic Space at the Carpal Tunnel Inlet is a Consistent Ultrasonographic Entity which Accommodates Tendon Displacement during Finger Flexion
Authors: Lee Bing Howe , Goh Chin Hock , Lahiri Amitabha
Published: May 2016

Background: We consistently observed the presence of anechoic spaces on standard ultrasonographic imaging of the carpal tunnel inlet in normal subjects. These spaces change in size during finger flexion and have not been characterized in a large sample of normal individuals. Ultrasonographic quantification of these spaces may indicate the available space in the region of the carpal tunnel, which allows the normal motion of tendons and the median nerve.

Methods: Transverse ultrasonographic images of the carpal tunnel inlet from 33 asymptomatic volunteers were obtained at Position A (fingers in extension) and B (fingers in flexion). Cross-sectional area (CSA), perimeter and position of anechoic space relative to median nerve were recorded.

Results: Analysis showed a 75.4% prevalence rate of a single anechoic space. Two discrete patterns were observed. 89.1% had a decrease in CSA and perimeter of anechoic space from Position A to B while 10.9% exhibited an increase. Mean position of the anechoic space is ulnar (7.49 ± 3.57 mm) and dorsal (2.18 ± 1.28 mm) to the median nerve.

Conclusions: A consistent anechoic space at the carpal tunnel inlet is seen in 75.4% of normal hands and can be quantified (cross sectional area 11.75 ± 7.36 mm2). It allows for the accommodation of flexor tendons during finger flexion.
The “Trigger” Thumb Locked in Extension – An Unusual Presentation of a Common Paediatric Condition
Authors: Johnstone Bruce R. , Currie L. J. , Ek Edmund W. , Wilks Daniel J. , McCombe David B. , Coombs Christopher J.
Published: May 2016

Background: We report a variant of paediatric trigger thumb which is locked in extension rather than flexion.

Methods: Eleven children with 14 trigger thumbs (three bilateral) locked in extension were reviewed retrospectively over a 12-year period. The number of flexed trigger thumbs encountered over this period was established from the operating room database.

Results: All children were treated with release of the A1 pulley. Nine children achieved a full range of motion at the interphalangeal joint. One child with bilateral extended trigger thumbs required bilateral dorsal capsulotomy and another child developed temporary mild triggering in flexion.

Conclusions: Approximately 1% of trigger thumbs treated operatively at this institution presented as the extended variant. Trigger thumb locked in extension should be considered in a child presenting with inability to flex the thumb.
Novel Suture Anchor Technique with Continuous Locking Stitch for Collateral Ligament Repair
Authors: Tokunaga Susumu , Abe Yoshihiro
Published: May 2016

Collateral ligaments are difficult to repair due to large amount of fraying in detached ligaments and attenuated stumps that may not provide enough strength after the repair. Although strong locking sutures are used to repair the ligament with proper tension, these damages can cause pull-out failure or relaxation of the repaired ligaments even from undersized load that may extend postoperative splinting or casting time. Furthermore, current suture techniques can repair varus or valgus instability of the elbow and radial or ulnar instability of the fingers, but these techniques do not offer rotatory stability of these areas. We have developed a novel suture anchor technique that has overcome this problem of current suture techniques, and this can be used to correct rotatory instability in the elbow and fingers. We used this procedure in seven cases with injury of collateral ligament in the elbow and eight cases with detached collateral ligaments of finger joint. No patient experienced rerupture or any kind of residual instability. We believe that the proposed method can produce much stronger repair and may shorten the postoperative immobilization period.
Technical Tip for Proximal Release During Open Carpal Tunnel Release Using a Subcutaneous Pocket
Authors: Nikkhah Dariush , Sadr Amir H. , Akhavani Mohammed Ali
Published: May 2016

Technical steps to avoid incomplete proximal release of the carpal tunnel are described. Local anaesthesia is infiltrated as a subcutaneous bleb over the distal wrist crease and extending 2–3 cm over the forearm fascia. Tumescence of local anaesthesia into the subcutaneous plane helps create a pocket between the forearm fascia and subcutaneous tissues. Intraoperatively a subcutaneous pocket is made above the transverse carpal ligament and antebrachial fascia with blunt dissection. A retractor is placed under the pocket, which facilitates optimal visualization to allow reliable complete proximal release of compression.The authors have found that this technique is reproducible and reliable across their collective experience.
Intramuscular Hemangioma of the Pronator Quadratus Muscle of Forearm
Authors: Jeong Euicheol , Kim Hyo Seong
Published: May 2016

Intramuscular hemangioma is a rare type that has been reported in less than 0.8% of all hemangiomas. In particular, there are few reports of intramuscular hemangioma in the upper extremity. Authors describe the experience of complete excision of the hemangioma of the pronator quadratus muscle of the forearm with good functional recovery.
Fibro-Osseous Pseudotumor of the Hand
Authors: Kontogeorgakos Vasileios A. , Papachristou Dionysios J. , Varitimidis Sokratis
Published: May 2016

Fibro-osseous pseudotumor of digits (FOPD) is an uncommon histological diagnosis. Clinical and imaging findings may resemble high-grade sarcoma or infection. We describe a patient with progressive pain and swelling at the dorsal surface of the first web space. MRI and CT imaging revealed an intramuscular heterogenous soft tissue mass defined by a mineralized peripheral ring. Core needle biopsy diagnosed FOPD. Eight months later a matured ossified nodule that was quite smaller than the initial soft tissue mass was excised. The patient is symptom free without local recurrence at 1 year follow up. Soft tissue masses of the hand pose a challenging diagnostic and therapeutic issue. An in depth interpretation of clinical, imaging and histology findings is important to avoid erroneous diagnosis and treatment.
Game Theory Framework for MAC Parameter Optimization in Energy-Delay Constrained Sensor Networks
Authors: Doudou Messaoud , Barcelo-Ordinas Jose M. , Djenouri Djamel , Garcia-Vidal Jorge , Bouabdallah Abdelmadjid , Badache Nadjib
Published: May 2016

Optimizing energy consumption and end-to-end (e2e) packet delay in energy-constrained, delay-sensitive wireless sensor networks is a conflicting multiobjective optimization problem. We investigate the problem from a game theory perspective, where the two optimization objectives are considered as game players. The cost model of each player is mapped through a generalized optimization framework onto protocol-specific MAC parameters. From the optimization framework, a game is first defined by the Nash bargaining solution (NBS) to assure energy consumption and e2e delay balancing. Secondy, the Kalai-Smorodinsky bargaining solution (KSBS) is used to find an equal proportion of gain between players. Both methods offer a bargaining solution to the duty-cycle MAC protocol under different axioms. As a result, given the two performance requirements (i.e., the maximum latency tolerated by the application and the initial energy budget of nodes), the proposed framework allows to set tunable system parameters to reach a fair equilibrium point that dually minimizes the system latency and energy consumption. For illustration, this formulation is applied to six state-of-the-art wireless sensor network (WSN) MAC protocols: B-MAC, X-MAC, RI-MAC, SMAC, DMAC, and LMAC. The article shows the effectiveness and scalability of such a framework in optimizing protocol parameters that achieve a fair energy-delay performance trade-off under the application requirements.
Plasma amino acid and metabolite signatures tracking diabetes progression in the UCD-T2DM rat model
Authors: Piccolo Brian D. , Graham James L. , Stanhope Kimber L. , Fiehn Oliver , Havel Peter J. , Adams Sean H.
Published: May 2016

Elevations of plasma concentrations of branched-chain amino acids (BCAAs) are observed in human insulin resistance and type 2 diabetes mellitus (T2DM); however, there has been some controversy with respect to the passive or causative nature of the BCAA phenotype. Using untargeted metabolomics, plasma BCAA and other metabolites were assessed in lean control Sprague-Dawley rats (LC) and temporally during diabetes development in the UCD-T2DM rat model, i.e., prediabetic (PD) and 2 wk (D2W), 3 mo (D3M), and 6 mo (D6M) post-onset of diabetes. Plasma leucine, isoleucine, and valine concentrations were elevated only in D6M rats compared with D2W rats (by 28, 29, and 30%, respectively). This was in contrast to decreased plasma concentrations of several other amino acids in D3M and/or D6M relative to LC rats (Ala, Arg, Glu, Gln, Met, Ser, Thr, and Trp). BCAAs were positively correlated with fasting glucose and negatively correlated with plasma insulin, total body weight, total adipose tissue weight, and gastrocnemius muscle weight in the D3M and D6M groups. Multivariate analysis revealed that D3M and D6M UCD-T2DM rats had lower concentrations of amino acids, amino acid derivatives, 1,5-anhydroglucitol, and conduritol-β-opoxide and higher concentrations of uronic acids, pantothenic acids, aconitate, benzoic acid, lactate, and monopalmitin-2-glyceride relative to PD and D2W UCD-T2DM rats. The UCD-T2DM rat does not display elevated plasma BCAA concentrations until 6 mo post-onset of diabetes. With the acknowledgement that this is a rodent model of T2DM, the results indicate that elevated plasma BCAA concentrations are not necessary or sufficient to elicit an insulin resistance or T2DM onset.
TXNIP regulates myocardial fatty acid oxidation via miR-33a signaling
Authors: Chen Junqin , Young Martin E. , Chatham John C. , Crossman David K. , Dell'Italia Louis J. , Shalev Anath
Published: May 2016

Myocardial fatty acid β-oxidation is critical for the maintenance of energy homeostasis and contractile function in the heart, but its regulation is still not fully understood. While thioredoxin-interacting protein (TXNIP) has recently been implicated in cardiac metabolism and mitochondrial function, its effects on β-oxidation have remained unexplored. Using a new cardiomyocyte-specific TXNIP knockout mouse and working heart perfusion studies, as well as loss- and gain-of-function experiments in rat H9C2 and human AC16 cardiomyocytes, we discovered that TXNIP deficiency promotes myocardial β-oxidation via signaling through a specific microRNA, miR-33a. TXNIP deficiency leads to increased binding of nuclear factor Y (NFYA) to the sterol regulatory element binding protein 2 (SREBP2) promoter, resulting in transcriptional inhibition of SREBP2 and its intronic miR-33a. This allows for increased translation of the miR-33a target genes and β-oxidation-promoting enzymes, carnitine octanoyl transferase (CROT), carnitine palmitoyl transferase 1 (CPT1), hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase/enoyl-CoA hydratase-β (HADHB), and AMPKα and is associated with an increase in phospho-AMPKα and phosphorylation/inactivation of acetyl-CoA-carboxylase. Thus, we have identified a novel TXNIP-NFYA-SREBP2/miR-33a-AMPKα/CROT/CPT1/HADHB pathway that is conserved in mouse, rat, and human cardiomyocytes and regulates myocardial β-oxidation.
What we need to know about the effect of lithium on the kidney
Authors: Gong Rujun , Wang Pei , Dworkin Lance
Published: May 2016

Lithium has been a valuable treatment for bipolar affective disorders for decades. Clinical use of lithium, however, has been problematic due to its narrow therapeutic index and concerns for its toxicity in various organ systems. Renal side effects associated with lithium include polyuria, nephrogenic diabetes insipidus, proteinuria, distal renal tubular acidosis, and reduction in glomerular filtration rate. Histologically, chronic lithium nephrotoxicity is characterized by interstitial nephritis with microcyst formation and occasional focal segmental glomerulosclerosis. Nevertheless, this type of toxicity is uncommon, with the strongest risk factors being high serum levels of lithium and longer time on lithium therapy. In contrast, in experimental models of acute kidney injury and glomerular disease, lithium has antiproteinuric, kidney protective, and reparative effects. This paradox may be partially explained by lower lithium doses and short duration of therapy. While long-term exposure to higher psychiatric doses of lithium may be nephrotoxic, short-term low dose of lithium may be beneficial and ameliorate kidney and podocyte injury. Mechanistically, lithium targets glycogen synthase kinase-3β, a ubiquitously expressed serine/threonine protein kinase implicated in the processes of tissue injury, repair, and regeneration in multiple organ systems, including the kidney. Future studies are warranted to discover the exact “kidney-protective dose” of lithium and test the effects of low-dose lithium on acute and chronic kidney disease in humans.
Exercise-induced albuminuria is related to metabolic syndrome
Authors: Greenberg Sharon , Shenhar-Tsarfaty Shani , Rogowski Ori , Shapira Itzhak , Zeltser David , Weinstein Talia , Lahav Dror , Vered Jaffa , Tovia-Brodie Oholi , Arbel Yaron , Berliner Shlomo , Milwidsky Assi
Published: May 2016

Microalbuminuria (MA) is a known marker for endothelial dysfunction and future cardiovascular events. Exercise-induced albuminuria (EiA) may precede the appearance of MA. Associations between EiA and metabolic syndrome (MS) have not been assessed so far. Our aim was to investigate this association in a large sample of apparently healthy individuals with no baseline albuminuria. This was a cross-sectional study of 2,027 adults with no overt cardiovascular diseases who took part in a health survey program and had no baseline MA. Diagnosis of MS was based on harmonized criteria. All patients underwent an exercise test (Bruce protocol), and urinary albumin was measured before and after the examination. Urinary albumin-to-creatinine ratio (ACR) values before and after exercise were 0.40 (0.21–0.89) and 1.06 (0.43–2.69) mg/g for median (interquartile range) respectively. A total of 394 (20%) subjects had EiA; ACR rose from normal rest values (0.79 mg/g) to 52.28 mg/g after exercise ( P < 0.001); this effect was not shown for the rest of the study population. EiA was related to higher prevalence of MS (13.8% vs. 27.1%, P < 0.001), higher metabolic equivalents ( P < 0.001), higher baseline blood pressure ( P < 0.001), and higher levels of fasting plasma glucose, triglycerides, and body mass index ( P < 0.001). Multivariate binary logistic regression model showed that subjects with MS were 98% more likely to have EiA (95% confidence interval: 1.13–3.46, P = 0.016). In conclusion, EiA in the absence of baseline MA is independently related to MS.
Granule cell excitability regulates gamma and beta oscillations in a model of the olfactory bulb dendrodendritic microcircuit
Authors: Osinski Bolesław L. , Kay Leslie M.
Published: May 2016

Odors evoke gamma (40–100 Hz) and beta (20–30 Hz) oscillations in the local field potential (LFP) of the mammalian olfactory bulb (OB). Gamma (and possibly beta) oscillations arise from interactions in the dendrodendritic microcircuit between excitatory mitral cells (MCs) and inhibitory granule cells (GCs). When cortical descending inputs to the OB are blocked, beta oscillations are extinguished whereas gamma oscillations become larger. Much of this centrifugal input targets inhibitory interneurons in the GC layer and regulates the excitability of GCs, which suggests a causal link between the emergence of beta oscillations and GC excitability. We investigate the effect that GC excitability has on network oscillations in a computational model of the MC-GC dendrodendritic network with Ca2+-dependent graded inhibition. Results from our model suggest that when GC excitability is low, the graded inhibitory current mediated by NMDA channels and voltage-dependent Ca2+channels (VDCCs) is also low, allowing MC populations to fire in the gamma frequency range. When GC excitability is increased, the activation of NMDA receptors and other VDCCs is also increased, allowing the slow decay time constants of these channels to sustain beta-frequency oscillations. Our model argues that Ca2+flow through VDCCs alone could sustain beta oscillations and that the switch between gamma and beta oscillations can be triggered by an increase in the excitability state of a subpopulation of GCs.