bluuebunny/crossref_metadata_2025 huggingface dataset:
Recurrent compartment syndrome in a patient with clinical features of a connective tissue disorder
Authors: Barajas Brenda D. , Sun Angela , Rimoin David L. , Reinstein Eyal
Published: April 2013

Arterial complications are common in vascular type Ehlers–Danlos syndrome (EDS), accounting for 66% of first complications. Several cases in the literature have documented acute compartment syndrome (ACS) following vascular rupture in vascular type EDS. Other disorders of connective tissue have also demonstrated vascular fragility, leading to arterial aneurysm and rupture, but there have been no documented cases of ACS. Here, we report on a female patient with a history of recurrent compartment syndrome who exhibits some clinical findings seen in hypermobile and vascular EDS; however she does not meet clinical and molecular diagnostic criteria for either of them. We further review the literature on ACS in heritable connective tissue disorders and suggest that compartment syndrome may rarely complicate other heritable disorders of connective tissue. © 2013 Wiley Periodicals, Inc.
Expanded Prader–Willi syndrome due to chromosome 15q11.2–14 deletion: Report and a review of literature
Authors: Liu Anthony P.Y. , Tang Wing Fai , Lau Elizabeth T. , Chan Kelvin Y.K. , Kan Anita S.Y. , Wong Kar Yin , Tso Winnie W.Y. , Jalal Khair , Lee So Lun , Chau Christy S.K. , Chung Brian H.Y.
Published: April 2013

We report on a male infant with de novo unbalanced t(5;15) translocation resulting in a 17.23 Mb deletion within 15q11.2–q14 and a 25.12 kb deletion in 5pter. The 15q11.2–q14 deletion encompassed the 15q11.2–q13 Prader–Willi syndrome (PWS) critical region and the recently described 15q13.3 microdeletion syndrome region while the 5pter deletion contained no RefSeq genes. From our literature review, patients with similar deletions in chromosome 15q exhibit expanded phenotype of severe developmental delay, protracted feeding problem, absent speech, central visual impairment, congenital malformations and epilepsy in addition to those typical of PWS. The patient reported herein had previously unreported anomalies of mega cisterna magna, horseshoe kidney and the rare neonatal interstitial lung disease known as pulmonary interstitial glycogenosis. Precise breakpoint delineation by microarray is useful in patients with atypical PWS deletions to guide investigation and prognostication. © 2013 Wiley Periodicals, Inc.
Mass measurements of singly and highly charged radioactive ions at TITAN: A new QEC‐value measurement of 10C
Authors: Kwiatkowski Anna A. , Chaudhuri Ankur , Chowdhury Usman , Gallant Aaron T. , Macdonald Tegan D. , Schultz Bradley E. , Simon Martin C. , Dilling Jens
Published: April 2013

Superallowed β‐decay strengths or corrected values provide some of the most stringent limits for physics beyond the standard three‐quark model. For this reason, the ‐value 10C has been measured and found to be 3468.31(51) keV with the TITAN Penning trap mass spectrometer. The facility is unique in coupling such an online spectrometer to a charge breeder, permitting a mass measurement of another superallowed β‐emitter, 74Rb, in the 8+ charge state. An overview of the TITAN facility and recent highlights are presented alongside the new ‐value determination of 10C.
Interpreting the knowledge map of digital library research (1990–2010)
Authors: Nguyen Son Hoang , Chowdhury Gobinda
Published: April 2013

A knowledge map of digital library (DL) research shows the semantic organization ofDLresearch topics and also the evolution of the field. The research reported in this article aims to find the core topics and subtopics ofDLresearch in order to build a knowledge map of theDLdomain. The methodology is comprised of a four‐step research process, and two knowledge organization methods (classification and thesaurus building) were used. A knowledge map covering 21 core topics and 1,015 subtopics ofDLresearch was created and provides a systematic overview ofDLresearch during the last two decades (1990–2010). We argue that the map can work as a knowledge platform to guide, evaluate, and improve the activities ofDLresearch, education, and practices. Moreover, it can be transformed into aDLontology for various applications. The research methodology can be used to map any human knowledge domain; it is a novel and scientific method for producing comprehensive and systematic knowledge maps based on literary warrant.
Heterologous expression and biochemical characterization of an endo‐β‐1,4‐glucanase from Thermobifida fusca
Authors: Yan Peng'an , Su Lingqia , Chen Jian , Wu Jing
Published: April 2013

The endoglucanase Cel5A from Thermobifida fusca was cloned and expressed in Escherichia coli BL21(DE3). The carboxymethyl cellulase (CMCase) activity in shake flasks and 3‐L fermentation scale reached 46.8 and 656.6 IU/mL, respectively. The CMCase activity in 3‐L fermentation scale represented the highest yield of T. fusca Cel5A reported so far. Recombinant Cel5A was purified and characterized in detail. The optimum temperature of recombinant enzyme was 80 °C, and the half‐life of the enzyme was 132 H at 50 °C and 65 H at 60 °C. The activity of recombinant Cel5A was retained more than 90% over the range of pH 5.0–10.0 with maximal activity at pH 5.5. Using carboxymethyl cellulose as the substrate, the Km and Vmax values were 5.1 mg/mL and 48.7 IU/mg, respectively. The enzyme showed superstability in surfactants and was retained above 90% activity after treatment with sodium dodecyl sulfate, linear alkyl benzene sulfonate, fatty alcohol polyoxyethylene (9) ether, and polyoxyethylene (10) nonyl phenyl ether at 25 °C for 1 H, indicating that the enzyme could be a valuable component in detergents. The potential mechanism of this stability was investigated by analysis of the electrostatic potential of the surface of the enzyme.
UPLC‐ESI/MS determination of 17 active constituents in two categorized formulas of traditional Chinese medicine, Sanhuang Xiexin Tang and Fuzi Xiexin Tang: application in comparing the differences in decoctions and macerations
Authors: Zhang Qian , Wang Chang‐hong , Ma Yue‐ming , Zhu En‐yuan , Wang Zheng‐tao
Published: April 2013

A rapid and sensitive UPLC‐ESI/MS method was established and validated to determine 17 active constituents (aconitine, hypaconitine, mesaconitine, benzoylaconine, benzoylhypaconine, benzoylmesaconine, berberine, palmatine, jatrorrhizine, coptisine, baicalein, wogonin, baicalin, wogonoside, emodin, aloe‐emodin and rhein) in Sanhuang Xiexin Tang (SXT) and Fuzi Xiexin Tang (FXT), which are two classic compound recipes from Xiexin Tang categorized formulas in traditional Chinese medicien. The separation was performed on a UPLC BEH C18 column gradient eluted using acetonitrile and 0.1% formic acid as mobile phase. ESI/MS was operated in positive ([M + H]+) in selected ion recording mode for analysis of alkaloids and flavones, while in negative ([M − H]−) selected ion recording mode for anthraquinones. All of the 17 constituents exhibited good linearity in a relatively wide concentration ranges with the lowest limits of detection of 0.38 ng/mL. All of the relative standard deviation values of intra‐ and inter‐precisions and stabilities of 17 constituents were within 5%. The method was successfully applied to determine 17 active constituents in decoctions and macerations of SXT and FXT. The results indicated that different preparative methods resulted in significant diversity in concentrations of the 17 analytes. Herb–herb interaction appeared between aconitum alkaloids in Aconiti Lateralis Radix Preparata and another three herbs. Copyright © 2013 John Wiley & Sons, Ltd.
Angiographic characteristics of femoropopliteal in‐stent restenosis: Association with long‐term outcomes after endovascular intervention
Authors: Armstrong Ehrin J. , Singh Satinder , Singh Gagan D. , Yeo Khung‐Keong , Ludder Shaan , Westin Gregory , Anderson David , Dawson David L. , Pevec William C. , Laird John R.
Published: April 2013

Objectives

The purpose of this study was to identify the relationship between angiographic patterns of restenosis and outcomes after endovascular treatment of femoro‐popliteal in‐stent restenosis (FP‐ISR).

Background

ISR is a frequent clinical problem after femoro‐popliteal stenting.

Methods

This was a single center study of all endovascular interventions for FP‐ISR from 2006 to 2012. Class I ISR was defined as focal lesions ≤50 mm; Class II ISR as lesions > 50 mm; and Class III ISR as stent chronic total occlusion. Recurrent ISR was defined as peak systolic velocity ratio > 2.4 by duplex ultrasound.

Results

Among 75 cases of FP‐ISR, 28 (37%) were Class I, 22 (29%) were Class II, and 25 (33%) were Class III. The mean lesion length was 26 mm for Class I, 135 mm for Class II, and 178 mm for Class III ISR. Patients with Class III ISR more frequently had ISR extending into both the superficial femoral and popliteal artery (48% vs. 18%, P = 0.005). Balloon angioplasty was used most frequently to treat Class I ISR, while adjunctive atherectomy and/or stenting was used for almost all cases of Class III ISR. During 2‐year follow‐up, rates of repeat restenosis were 39% for Class I, 67% for Class II, and 72% for Class III ISR (P = 0.04). Rates of stent occlusion were 8% for Class I, 11% for Class II, and 52% for Class III ISR (P = 0.009). Class III ISR was associated with significantly increased risk of recurrent ISR (HR 2.4, 95% CI 1.1–5.6) and recurrent occlusion (HR 5.8, 95% CI 1.8–19.0) compared to other types of ISR.

Conclusion

Angiographic patterns of FP‐ISR are important determinants of subsequent outcomes. Repeat restenosis and occlusion remain common despite currently available technologies.© 2013 Wiley Periodicals, Inc.
Imaging systems and urine specimens
Authors: Antic Tatjana
Published: April 2013

The application of standard cytologic examination of the urine specimen can now be augmented by using ThinPrep technology and other automatic screening devices. The technical and preparation adjustments required for these new technologies notwithstanding, the potential for shorter screening times and the possibility of greater diagnostic accuracy may provide great diagnostic promise for this very common specimen. Cancer (Cancer Cytopathol) 2013;121:407‐9. © 2013 American Cancer Society.
Growth and defect studies of CdTe particles
Authors: Nepijko S. A. , Fedchenko O. , Chernov S. V. , Schönhense G.
Published: April 2013

The paper reports the epitaxial growth of cadmium telluride (CdTe) particles by thermal deposition on cleaved planes of (001)NaCl and (001)KBr. Using high resolution transmission electron microscopy and electron diffraction it was shown that CdTe particles could have different orientation and phase (cubic or hexagonal) depending on the substrate temperature. Their most common defects are twins and stacking faults.
Structural relationships between single atom type crystal structures and intermetallic compound structures, as illustrated by Laves‐ and Hume‐Rothery phases
Authors: Ruhnow M.
Published: April 2013

In comparison to the single atom type crystal structures, which are relatively simple and are concentrated in four types of structure (Cu, W, Mg, diamond), the crystal structures of intermetallic phases are manifold and often very complicated. At first sight there is no obvious connection between these types of crystal structures, however, a transition mechanism must exist for the solid‐state transition from the simple single atom type crystal structures to the intermetallic phase structures. Such a mechanism would show the inner connection between the structures. In this work the topic is dealt with from a crystallographic point of view. The transition between the structures can be described by the three steps (1) substitution of atoms, (2) systematically ejection of particular atoms from the emerging intermediate structure and (3) spatial relaxation especially of the atoms around the newly formed interstices. This general structural phase transition path will be discussed for two of the intermetallic classes, the Laves phases and the Hume‐Rothery phases. A suitable way of showing this is by making a comparison between the coordination polyhedra (atomic environments) of the single atom type crystal structures and those of the derived intermetallic crystal structures.
Morphometric evaluation and nonclassical criteria for the diagnosis of HPV infection and cytological atypia in cervical samples
Authors: Sana Dandara Emery Morais , Mayrink de Miranda Priscila , Pitol Bruna Caroline Vieira , Moran Mariana Soares , Silva Nayara Nascimento Toledo , Guerreiro da Silva Ismael Dali Cotrim , de Cássia Stocco Rita , Beçak Willy , Lima Angélica Alves , Carneiro Cláudia Martins
Published: April 2013

Herein, we evaluated cervical samples from normal tissue or HPV‐infected tissue, to determine if the relative nuclear/cytoplasmic ratio (NA/CA) and the presence of nonclassical cytological criteria are a novel cytological criterion for the diagnosis of HPV. Significantly, larger NA/CA ratios were found for the HPV−ATYPIA+ and HPV+ATYPIA+ groups compared with HPV−ATYPIA− group, regardless of collection method. For the samples collected with a spatula, only three samples from the HPV−ATIPIA− group showed four or more nonclassical parameters (i.e., were positive), while a larger number of the samples in the HPV−ATYPIA+, HPV+ATYPIA−, and HPV+ATYPIA+ groups were positive (13, 4, and 13 samples, respectively). Among those collected with a brush, no sample showed four or more nonclassical criteria in the HPV−ATYPIA− group, while a number of samples were positive in the HPV−ATYPIA+, HPV+ATYPIA−, and HPV+ATYPIA+ groups (4, 3, and 4 samples, respectively). HPV infection was associated with significant morphometrical changes; no increase in the NA/CA ratio was found in the HPV+ATYPIA‐ samples, compared with the HPV−ATIPIA− samples collected with either a spatula or a brush. In conclusion, by including nonclassical cytological criteria into the patient diagnosis, we were able to reduce the number of false negative and false positive HPV diagnoses made using conventional cytology alone. Diagn. Cytopathol. 2013;41:785–792. © 2013 Wiley Periodicals, Inc.
Batch and dynamics modeling of the biosorption of Cr(VI) from aqueous solutions by solid biomass waste from the biodiesel production
Authors: Shanmugaprakash Muthusamy , Sivakumar Venkatachalam , Manimaran Manickavelu , Aravind Jeyaseelan
Published: April 2013

Pongamia oil cake (POC), a bio‐residual waste is obtained during the production of biodiesel as a byproduct. This is used as biosorbent to evaluate the removal of chromium (VI) ions from an aqueous synthetic solution. The effects of various process parameters such as pH, contact time, initial chromium ions concentration and adsorbent dosage have been investigated. The FT‐IR and SEM analysis of the adsorbents was done in the native‐ and Cr(VI)‐loaded state, to explore the position of the functional groups available for binding of chromium ions and the structural morphology of the studied adsorbents respectively. Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm were used to study the adsorption mechanism, and it was found that the equilibrium data was better represented by the Freundlich isotherm. The maximal removal of hexavalent chromium ion was found to be at a pH of 2.0 within 2 h. The sorption kinetic follows the pseudo second order kinetic model. The Cr(VI) ions bound to the biosorbent could be effectively removed, using dilute H2SO4 (0.05 mM). The ability of POC to adsorb Cr(VI) ions in packed column was also investigated through the column studies. Bed Depth Service Time model and the Thomas model were used to analyze the experimental data and evaluate the model parameters. POC was shown to be a promising adsorbent for removal of Cr(VI) ions from aqueous solutions. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 342–352, 2014
Multiple pilomatricomas with somatic CTNNB1 mutations in children with constitutive mismatch repair deficiency
Authors: Chmara Magdalena , Wernstedt Annekatrin , Wasag Bartosz , Peeters Hilde , Renard Marleen , Beert Eline , Brems Hilde , Giner Tina , Bieber Imke , Hamm Henning , Sciot Raf , Wimmer Katharina , Legius Eric
Published: April 2013

Constitutional mismatch repair deficiency (CMMR‐D) due to biallelic germline mutations in one of four mismatch repair genes causes a childhood cancer syndrome characterized by a broad tumor spectrum including hematological malignancies, and brain and Lynch syndrome‐associated tumors. Herein, we report three children who had in addition to CMMR‐D‐associated malignancies multiple pilomatricomas. These are benign skin tumors of hair matrical differentiation frequently associated with somatic activating mutations in the ß‐catenin gene CTNNB1. In two of the children, the diagnosis of CMMR‐D was confirmed by the identification of biallelic germline PMS2 mutations. In the third individual, we only found a heterozygous germline PMS2 mutation. In all nine pilomatricomas with basophilic cells, we detected CTNNB1 mutations. Our findings indicate that CTNNB1 is a target for mutations when mismatch repair is impaired due to biallelic PMS2 mutations. An elevated number of activating CTNNB1 alterations in hair matrix cells may explain the development of multiple pilomatricomas in CMMR‐D patients. Of note, two of the children presented with multiple pilomatricomas and other nonmalignant features of CMMR‐D before they developed malignancies. To offer surveillance programs to CMMR‐D patients, it may be justified to suspect CMMR‐D syndrome in individuals fulfilling multiple nonmalignant features of CMMR‐D (including multiple pilomatricomas) and offer molecular testing in combination with interdisciplinary counseling. © 2013 Wiley Periodicals, Inc.
Frequent PLAG1 gene rearrangements in skin and soft tissue myoepithelioma with ductal differentiation
Authors: Antonescu Cristina R. , Zhang Lei , Shao Sung Yun , Mosquera Juan‐Miguel , Weinreb Ilan , Katabi Nora , Fletcher Christopher D. M.
Published: April 2013

A subset of cutaneous and superficial soft tissue myoepithelial (ME) tumors displays a distinct ductal component and closely resembles mixed tumors/pleomorphic adenomas of salivary gland. As PLAG1 and HMGA2 rearrangements are the most common genetic events in pleomorphic adenomas, we sought to investigate if these abnormalities are also present in the skin/soft tissue ME lesions. In contrast, half of the deep‐seated soft tissue ME tumors lacking ductal differentiation are known to be genetically unrelated, showing EWSR1 rearrangements. FISH analysis to detect PLAG1 and HMGA2 abnormalities was performed in 35 ME tumors, nine skin and 26 soft tissue, lacking EWSR1 and FUS rearrangements. For the PLAG1‐rearranged tumors, FISH and RACE were performed to identify potential fusion partners, including CTNNB1 (beta‐catenin) on 3p21 and LIFR (leukemia inhibitory factor receptor) on 5p13. Recurrent PLAG1 rearrangement by FISH was detected in 13 (37%) lesions, including three (33%) in the skin and 10 (38%) in the soft tissue. All were classified as benign and all except one showed abundant tubulo‐ductal differentiation (comprising 12/24 [50%] of all tumors with ductal structures). A LIFR‐PLAG1 fusion was detected by RACE and then confirmed by FISH in one soft tissue ME tumor with tubular formation. No CTNNB1 or LIFR abnormalities were detected in any of the remaining PLAG1‐rearranged tumors. No structural HMGA2 abnormalities were detected in any of the 22 ME lesions tested. A subset of cutaneous and soft tissue ME tumors appears genetically linked to their salivary gland counterparts, displaying frequent PLAG1 gene rearrangements and occasionally LIFR‐PLAG1 fusion. © 2013 Wiley Periodicals, Inc.
Identification of the transcription factor HOXB4 as a novel target of miR‐23a
Authors: Koller Karin , Das Suman , Leuschner Ivo , Korbelius Melanie , Hoefler Gerald , Guertl Barbara
Published: April 2013

The transcription factor HOXB4 not only plays a role during nephrogenesis, but displays also oncogenic characteristics in different malignant neoplasms. An in‐silico analysis revealed HOXB4 as a new target of microRNA‐23a (miR‐23a). Nephroblastomas are malignant embryonal renal neoplasms of childhood resembling developing kidney morphologically and genetically. In our study we verified HOXB4 as a target of miR‐23a and furthermore examined the expression of HOXB4 and miR‐23a in nephroblastomas. We investigated binding of miR‐23a to the 3'UTR of HOXB4 by a luciferase assay. Effects on protein levels of HOXB4 were analysed in Western blot experiments. Expression of HOXB4 in nephroblastomas was assessed by quantitative REALtime PCR (qRT PCR) and immunohistochemistry. The luciferase reporter assay showed a statistically significant downregulation of activity by 72,5% demonstrating direct binding of miR‐23a to the 3'UTR of HOXB4. In addition, miR‐23a reduced the protein expression of HOXB4 statistically significantly by 65.1%. All 21 nephroblastomas investigated had statistically significantly decreased expression levels of miR‐23a. A high level of HOXB4 mRNA was found in five out of 33 nephroblastomas including mixed, blastema‐type and stroma‐type tumors. Protein expression of HOXB4 was stronger in 15 out of 27 nephroblastomas of all subtypes in a semiquantitative comparison to normal kidney parenchyma. Our study demonstrates for the first time the regulation of HOXB4 by miR‐23a. In comparison to mature kidney, nephroblastomas had low levels of miR‐23a, and in a majority of them a stronger protein expression in comparison to mature kidney was found. © 2013 Wiley Periodicals, Inc.
Prevalence of unwanted pregnancy in Iran: a systematic review and meta‐analysis
Authors: Moosazadeh Mahmood , Nekoei‐moghadam Mahmood , Emrani Zahra , Amiresmaili Mohammadreza
Published: April 2013

Introduction

Different studies show that a considerable number of pregnancies are unwanted and can have side effects on mothers'‚ children's and finally society's health. Accordingly, this meta‐analysis study has been carried out to estimate a relatively accurate level of unwanted pregnancies in Iran.

Methods

Present studies and published documents were retrieved from Persian and English electronic databases. To increase sensitivity and to select more studies, the reference list of the published studies was checked. After studying the titles and texts of documents, repeated and irrelevant ones were excluded. Data was analyzed using STATA V.11.

Results

Forty‐nine qualified papers were selected with a 43 061 sample size. The meta‐analysis of unwanted pregnancy prevalence in Iran equals 30.6% (CI = 28.1–33.1). Also‚ according to the present meta‐analysis‚ the most common contraceptive methods used by couples prior to unwanted pregnancies are as follows: pills 27.1%‚ withdrawal 38.6%‚ IUD 11.4%‚ injection contraceptives 2.8%‚ vasectomy 0.28% and no method 24.5%.

Discussion and conclusion

The results of meta‐analysis showed that about one‐third of pregnancies in Iran are unwanted and a high percent of them are among women who had used contraceptives. Therefore‚ it is necessary to adopt more appropriate policies on the following: education, proper pregnancy age, using contraceptive methods, men's role in family planning programs and quality promotion in family planning services. Copyright © 2013 John Wiley & Sons, Ltd.
Evaluation of genetic variants in microRNA biosynthesis genes and risk of breast cancer in Chinese women
Authors: Jiang Yue , Chen Jiaping , Wu Jiangping , Hu Zhibin , Qin Zhenzhen , Liu Xiao'an , Guan Xiaoxiang , Wang Yanru , Han Jing , Jiang Tao , Jin Guangfu , Zhang Mingfeng , Ma Hongxia , Wang Shui , Shen Hongbing
Published: April 2013

MicroRNAs (miRNA) are a class of small, noncoding RNA molecules involved in a diversity of cellular functions. Single nucleotide polymorphisms (SNPs) in miRNA biosynthesis genes may affect the biogenesis of miRNAs and consequently affect the miRNAs regulation. In this study, we systematically selected 24 functional SNPs located in eight key biosynthesis genes of miRNA (DROSHA, DGCR8, RAN, DICER, AGO2, GEMIN3, GEMIN4 and HIWI) and investigated the association between these SNPs and the risk of breast cancer in a Chinese population. All 24 SNPs were firstly genotyped in stage 1 (878 cases and 900 controls) and three promising SNPs (DROSHA rs2291109, RAN rs7301722 and DGCR8 rs417309) were selected for further validation in stage 2 (914 cases and 967 controls). We found that only one SNP (rs417309) located in the 3′‐UTR of DGCR8 was consistently associated with an increased breast cancer risk in two stages with a combined odds ratio (OR) of 1.50 [95% confidence interval (CI) = 1.16–1.93]. Based on the bioinformatics prediction, rs417309 is located at the binding sites of miR‐106b and miR‐579 in the 3′‐UTR of DGCR8. To evaluate whether rs417309 variant affects the binding capacity of miRNAs, we cotransfected luciferase reporter plasmids of DGCR8 3′‐UTR and miR‐106b/miR‐579 in three cell lines. Luciferase activity assay showed a higher expression level with rs417309 A allele compared with G allele in MCF‐7 cell lines (p = 3.31 × 10–7, 9.29 × 10–7 for miR‐106b and miR‐579, respectively). Our findings suggested that DGCR8 rs417309 G > A might affect breast cancer risk through the interruption of miRNA binding.
Regulation of Muscle Hydration Upon Hypo‐ or Hyper‐Osmotic Shocks: Differences Related to Invasion of the Freshwater Habitat by Decapod Crustaceans
Authors: FREIRE CAROLINA A. , SOUZA‐BASTOS LUCIANA R. , AMADO ENELISE M. , PRODOCIMO VIVIANE , SOUZA MARTA M.
Published: April 2013

Decapod crustaceans have independently invaded freshwater habitats from the sea/estuaries. Tissue hydration mechanisms are necessary for the initial stages of habitat transitions but can be expected to diminish, as the capacity for extracellular homeostasis increases in hololimnetic species. Six decapod species have been compared concerning the maintenance of muscle hydration in vitro:Hepatus pudibundus(marine);Palaemon pandaliformis(estuarine resident),Macrobrachium acanthurus(freshwater diadromous), and the three hololimneticMacrobrachium potiuna,Dilocarcinus pagei, andAegla parana. The effects of inhibitors of potassium channels (barium chloride) and NKCC (furosemide) were evaluated under isosmotic, and respectively hypo‐ (50% below iso) or hyper‐ (50% above iso) conditions. There was high muscle hydration control inH. pudibunduswith a possible role of NKCC in isosmotic conditions. Shrimps consistently showed small deviations in muscle hydration under anisosmotic conditions;P. pandaliformishas shown evidence of the presence of NKCC;M. potiunawas the species less affected by both inhibitors, under iso‐ or anisosmotic conditions. In the two hololimnetic crab species, both independent long‐time inhabitants of freshwater, while the capacity to deal with hyper‐osmotic shock is decreased, the capacity to deal with hyposmotic shock is retained, possibly because of hemolymph dilution during molting in fresh water.D. pageiapparently depends on potassium channels for volume recovery after swelling, whereasA. paranashows some dependence on NKCC to minimize volume loss in hyper‐osmotic conditions. Although no molecular screening techniques have been tried here, data point to distinct cell/tissue transport mechanisms acting upon hydration/volume challenges in decapods of different habitats and lineages.J. Exp. Zool. 319A:297–309, 2013. © 2013© 2013 Wiley Periodicals, Inc.
Reactive transport at stressed grain contact and creep compaction of quartz sand
Authors: He Wenwu , Sparks David , Hajash Andrew
Published: April 2013

A kinetic model is developed to investigate intergranular pressure solution. This model couples stress‐induced dissolution at grain contacts, diffusion through grain boundaries, and precipitation in pore spaces. The rate‐controlling processes are evaluated according to the dimensionless concentrations at grain contacts and in the pore fluid. Constrained by the experimental results of creep compaction of quartz sands, calculations suggest that the equilibrium concentration at stressed grain contacts (ceqb) does not exceed 1 order of magnitude higher than the hydrostatic equilibrium concentration (ceq) at the initial stages of creep compaction. However,ceqbdecays rapidly with increasing compaction and becomes close toceqafter several percent strain. The diffusivity at grain contacts is 1–2 orders of magnitude lower than the diffusivity in pore fluid. The rate‐controlling process is related to grain size and strain. An increase in grain size shifts the systems toward the diffusion‐controlled regime, while an increase in strain shifts the systems from dissolution‐controlled regime toward either diffusion‐controlled regime (larger grains) or precipitation‐controlled regime (smaller grains). Intergranular pressure solution appears to be very sensitive to pore‐fluid chemistry. Even a slight supersaturation in the pore fluid could prevent the diffusion along grain contacts. This may explain why the strength of intergranular pressure solution varies widely in natural sandstones.
High‐pressure elasticity of serpentine and seismic properties of the hydrated mantle wedge
Authors: Bezacier L. , Reynard B. , Cardon H. , Montagnac G. , Bass J. D.
Published: April 2013

A subset of the single‐crystal elastic moduli of natural antigorite has been measured using Brillouin scattering at high‐pressure up to 9 GPa. Aggregate properties and axial compressibilities are in good agreement with equation‐of‐state results from X‐ray diffraction. Stiffness along the c‐axis increases, becoming close to those within the silicate layer near 7 GPa. A slight discontinuity in the evolution of the elastic moduli near 7 GPa is associated with a phase transition. Raman spectroscopy shows that the transition does not occur in subducting slabs, except in the core of the coldest slabs where serpentine may be subducted to depths of about 200 km. Varying temperature and pressure has limited effects on the interpretation of seismic velocities, principally because of the limited depth range of serpentine stability (mostly above 100 km depth), and also due to the compensating effects of pressure and temperature that maintain velocity variations well within the uncertainties and statistical variability of seismological studies. Serpentinites are excellent candidates for explaining low velocities in the hydrated mantle wedge, inversion of the Moho, and thin anisotropic low‐velocity layers at the plate interface. Serpentinite layers provide an alternative explanation to fluid‐saturated oceanic crust for explaining these phenomena, and account for a transition to an aseismic, decoupled plate interface.
Understanding progressive‐arc‐ and strike‐slip‐related rotations in curve‐shaped orogenic belts: The case of the Olevano‐Antrodoco‐Sibillini thrust (Northern Apennines, Italy)
Authors: Turtù Antonio , Satolli Sara , Maniscalco Rosanna , Calamita Fernando , Speranza Fabio
Published: April 2013

We report on a paleomagnetic study of the southern sector of the Olevano‐Antrodoco‐Sibillini (OAS) thrust front, which corresponds to the southern limb of the Northern Apennines (Italy) orogenic salient. A lively debate has developed regarding the oroclinal/progressive‐arc versus non‐rotational nature of the OAS, which has been alternatively interpreted as a dextral strike‐slip fault, dextral transpressive fault, or frontal to oblique ramp that reactivated pre‐existing Jurassic normal faults. Here, we document the paleomagnetism, integrated with biostratigraphic and structural data, of 52 new sites from both the OAS hanging wall and footwall. On the basis of 39 retained sites, we find a peculiar pattern of tectonic rotations along the OAS thrust that evidences four rotational domains. The thrust footwall is characterized by a southern domain that undergoes an approximately 30° counterclockwise rotation with respect to the stable foreland, and an approximately non‐rotated domain. The data from the hanging wall indicate the occurrence of a dextral strike‐slip component along the southern sector of the OAS thrust supported by a strong clockwise rotation close to the NE‐SW lateral ramp, which rapidly fades 1 km from the thrust front. A slight but significant CW rotation observed in the remaining sites from the hanging wall confirms the progressive nature of the OAS, and its structural position as the southern limb of the Northern Apennines salient. Our detailed paleomagnetic study is crucial in discriminating between progressive‐arc‐ and strike‐slip‐related components in the main curved orogenic front of the Northern Apennines.
Sensitivity of hypoxia predictions for the northern Gulf of Mexico to sediment oxygen consumption and model nesting
Authors: Fennel Katja , Hu Jiatang , Laurent Arnaud , Marta‐Almeida Martinho , Hetland Robert
Published: April 2013

Every summer, a large area (15,000 km2 on average) over the Texas–Louisiana shelf in the northern Gulf of Mexico turns hypoxic due to decay of organic matter that is primarily derived from nutrient inputs from the Mississippi/Atchafalaya River System. Interannual variability in the size of the hypoxic zone is large. The 2008 Action Plan put forth by the Mississippi River/Gulf of Mexico Watershed Nutrient Task Force, an alliance of multiple state and federal agencies and tribes, calls for a reduction of the size of the hypoxic zone through nutrient management in the watershed. Comprehensive models help build mechanistic understanding of the processes underlying hypoxia formation and variability and are thus indispensable tools for devising efficient nutrient reduction strategies and for building reasonable expectations as to what responses can be expected for a given nutrient reduction. Here we present such a model, evaluate its hypoxia simulations against monitoring observations, and assess the sensitivity of the hypoxia simulations to model resolution, variations in sediment oxygen consumption, and choice of physical horizontal boundary conditions. We find that hypoxia simulations on the shelf are very sensitive to the parameterization of sediment oxygen consumption, a result of the fact that hypoxic conditions are restricted to a relatively thin layer above the bottom over most of the shelf. We show that the strength of vertical stratification is an important predictor of dissolved oxygen concentration in bottom waters and that modification of physical horizontal boundary conditions can have a large effect on hypoxia simulations because it can affect stratification strength.
Variability in light absorption and scattering of phytoplankton in Patagonian waters: Role of community size structure and pigment composition
Authors: Ferreira Amabile , Stramski Dariusz , Garcia Carlos A. E. , Garcia Virginia M. T. , Ciotti Áurea M. , Mendes Carlos R. B.
Published: April 2013

Intense phytoplankton blooms were observed along the Patagonian shelf‐break with satellite ocean color data, but few in situ optical observations were made in that region. We examine the variability of phytoplankton absorption and particulate scattering coefficients during such blooms on the basis of field data. The chlorophyll‐aconcentration, [Chla], ranged from 0.1 to 22.3 mg m−3in surface waters. The size fractionation of [Chla] showed that 80% of samples were dominated by nanophytoplankton (N‐group) and 20% by microphytoplankton (M‐group). Chlorophyll‐specific phytoplankton absorption coefficients at 440 and 676 nm,a*ph(440) anda*ph(676), and particulate scattering coefficient at 660 nm,b*p(660), ranged from 0.018 to 0.173, 0.009 to 0.046, and 0.031 to 2.37 m2(mg Chla)−1, respectively. Botha*ph(440) anda*ph(676) were statistically higher for the N‐group than M‐group and also considerably higher than expected from global trends as a function of [Chla]. This result suggests that size of phytoplankton cells in Patagonian waters tends to be smaller than in other regions at similar [Chla]. The phytoplankton cell size parameter,Sf, derived from phytoplankton absorption spectra, proved to be useful for interpreting the variability in the data around the general inverse dependence ofa*ph(440),a*ph(676), andb*p(660) on [Chla].Sfalso showed a pattern along the increasing trend ofa*ph(440) anda*ph(676) as a function of the ratios of some accessory pigments to [Chla]. Our results suggest that the variability in phytoplankton absorption and scattering coefficients in Patagonian waters is caused primarily by changes in the dominant phytoplankton cell size accompanied by covariation in the concentrations of accessory pigments.
Climatology of surface chlorophyll a, autumn‐winter and spring blooms in the southwest Pacific Ocean
Authors: Chiswell Stephen M. , Bradford‐Grieve Janet , Hadfield Mark G. , Kennan Sean C.
Published: April 2013

Ocean color data from the 13 year Sea‐viewing Wide Field‐of‐view Sensor mission are used to examine the distribution of surface chlorophyll a in the southwest Pacific Ocean. The mean surface chlorophyll field is similar to that found by previous workers, with elevated levels in the Subtropical Front and around the subantarctic islands that have an associated shelf. The annual cycle in surface chlorophyll shows a ubiquitous summer bloom in subantarctic water, with autumn, winter, and spring blooms variously in subtropical water and across the Subtropical Front. The autumn blooms progress equatorward with time at the same rate as wind stress. This supports the idea that the autumn bloom develops in response to increased wind stress, with a likely mechanism for the bloom being mixing to the surface of the deep chlorophyll maximum, and/or increased production due to entrainment of nutrients. The spring bloom progresses poleward with time. It starts after the mixed layer reaches its deepest, and its timing appears to be linked to the reduction in wind stress in spring. Under the assumption that all tracers are well mixed to the seasonal thermocline in autumn and winter, we conclude that vertically integrated chlorophyll increases at all latitudes in subtropical water during autumn and winter. Unfortunately, carbon‐to‐chlorophyll ratios are not known well enough to determine whether the same is true for vertically integrated carbon biomass. Individual spring blooms show significant spatial structure and are different from year to year. This leads to low spatial coherence for the temporal variability in surface chlorophyll.
Clarifying the link between surface salinity and freshwater fluxes on monthly to interannual time scales
Authors: Vinogradova Nadya T. , Ponte Rui M.
Published: April 2013

Freshwater fluxes (
) between the ocean and the atmosphere and land, comprised of evaporation, precipitation and terrestrial runoff, are an essential component of the Earth's climate system. However, direct observations of
and its components are sparse and available estimates have substantial uncertainties. In this study we investigate if measurements of sea‐surface salinity (
) can provide an alternative indirect method for estimating
. We examine the relationship between
,
and oceanic fluxes from surface advection and mixing processes, on time scales from months to years, using a consistent estimate of the ocean/atmosphere state obtained from model/data synthesis produced by the ECCO (Estimating Circulation and Climate of the Ocean) consortium. ECCO salinity averaged over the mixed layer is used as an estimate of
. Budget analysis shows that variability in
tendencies can be attributed to both
and oceanic fluxes, demonstrating the importance of the ocean's role in evolution of
, for both local and global mean fields. Regression analysis of the 13 year long ECCO fields shows that there are only a few regions (e.g., subtropical gyres) where
can be used as a proxy for
using linear models, and only at monthly to annual time scales. Results are similar over a range of spatial scales from ∼100 to 2000 km. Findings are discussed in the context of the general sensitivities of
to atmospheric and oceanic processes and the potential of satellite salinity measurements to constrain estimates of
.
Lateral diffusivity from tracer release experiments in the tropical North Atlantic thermocline
Authors: Banyte Donata , Visbeck Martin , Tanhua Toste , Fischer Tim , Krahmann Gerd , Karstensen Johannes
Published: April 2013

Lateral diffusivity is computed from a tracer release experiment in the northeastern tropical Atlantic thermocline. The uncertainties of the estimates are inferred from a synthetic particle release using a high‐resolution ocean circulation model. The main method employed to compute zonal and meridional components of lateral diffusivity is the growth of the second moment of a cloud of tracer. The application of an areal comparison method for estimating tracer‐based diffusivity in the field experiments is also discussed. The best estimate of meridional eddy diffusivity in the Guinea Upwelling region at about 300 m depth is estimated to be
m2 s−1. The zonal component of lateral diffusivity is estimated to be
m2 s−1, while areal comparison method yields areal equivalent zonal diffusivity component of
m2 s−1. In comparison to Ky, Kx is about twice larger, resulting from the tracer patch stretching by zonal jets. Employed conceptual jet model indicates that zonal jet velocities of about
m s−1 are required to explain the enhancement of the zonal eddy diffusivity component. Finally, different sampling strategies are tested on synthetic tracer release experiments. They indicate that the best sampling strategy is a sparse regular sampling grid covering most of the tracer patch.
LRO observations of morphology and surface roughness of volcanic cones and lobate lava flows in the Marius Hills
Authors: Lawrence Samuel J. , Stopar Julie D. , Hawke B. Ray , Greenhagen Benjamin T. , Cahill Joshua T. S. , Bandfield Joshua L. , Jolliff Bradley L. , Denevi Brett W. , Robinson Mark S. , Glotch Timothy D. , Bussey D. Benjamin J. , Spudis Paul D. , Giguere Thomas A. , Garry W. Brent
Published: April 2013

The volcanic domes, cones, sinuous rilles, and pyroclastic deposits of the Marius Hills region of the Moon (~13.4°N, 304.6°E) represent a significant episode of magmatic activity at or near the lunar surface that is still poorly understood. Comparisons between LROC NAC block populations, Mini‐RF data, and Diviner‐derived rock abundances confirm that blocky lava flows comprise the domes of the Marius Hills. 8 µm features measured by Diviner indicate that the domes are not rich in silica and are not significantly different than surrounding mare materials. LROC observations indicate that some of the dome‐building lava flows originated directly from volcanic cones. Many of the cones are C‐shaped, while others are irregularly shaped, and local topography and lava eruptions affect cone shape. In general, the cones are morphologically similar to terrestrial cinder and lava cones and are composed of varying amounts of cinder, spatter, and lava. Many of the cones are found in local groupings or alignments. The wide range of volcanic features, from broad low domes to steep cones, represents a range of variable eruption conditions. Complex morphologies and variable layering show that eruption conditions were variable over the plateau.
Coordinated spectral and XRD analyses of magnesite‐nontronite‐forsterite mixtures and implications for carbonates on Mars
Authors: Bishop Janice L. , Perry Kaysea A. , Darby Dyar M. , Bristow Thomas F. , Blake David F. , Brown Adrian J. , Peel Samantha E.
Published: April 2013

Mineral detection on Mars largely relies on laboratory data of minerals and mineral mixtures. The objective of this study is to provide reflectance spectra in the visible/near‐infrared (VNIR) and mid‐IR regions, X‐ray diffraction (XRD) data and Mössbauer spectra of a suite of carbonate, phyllosilicate and olivine mixtures in order to facilitate identification and characterization of these minerals on Mars. Remote sensing observations indicate that combinations of these minerals are present in ancient rocks on Mars around the Isidis Basin and in Gusev crater. Magnesite, nontronite, and forsterite size fractions <125 µm were selected for this study. Results of the VNIR reflectance analyses illustrate the complexity of VNIR spectra of mixtures. Analyses of the NIR band depths near 2.3, 2.5, 3.4, and 4 µm showed clear trends with carbonate abundance, although the data are not linear. Mixtures of magnesite and nontronite exhibited a band near 2.3 µm much closer to that observed for nontronite than that for magnesite. VNIR analyses of the mixtures indicated that a small amount of forsterite in any of the mixtures contributed a large increase in the broad ~1 µm band and, hence, the red slope characteristic of Fe2+‐bearing minerals. Mid‐IR mixture spectra were dominated by magnesite and forsterite, and nontronite was much more difficult to detect by mid‐IR spectra in the mixtures. This could be related to why phyllosilicates are detected in many locations on Mars using data collected by the Compact Reconnaissance Imaging Spectrometer for Mars, but not detected using data collected by the Thermal Emission Spectrometer. Mössbauer spectroscopy is well suited for analyses of Fe2+‐ and Fe3+‐bearing minerals, and modeling of the peak areas gave well‐correlated trends for nontronite and forsterite abundances where abundant Fe was present. XRD full‐pattern fitting analyses were performed on the magnesite‐forsterite series, giving results within 6 wt % of the actual values, with a mean difference between actual and calculated values of 2.4 wt %. This study provides important laboratory data for characterizing the spectral and XRD properties of mineral mixtures that will facilitate mineral identification on Mars. Carbonates, in particular, have been primarily observed at low abundances and in small outcrops, and they are frequently found mixed with other minerals. Through analyses of mineral mixtures using multiple data sets, this study seeks to provide ground truthing that will enable better coordination of carbonate detections in the dust and rocks of Mars.
Orbital eccentricity driven temperature variation at Mercury's poles
Authors: Siegler Matthew A. , Bills Bruce G. , Paige D.A.
Published: April 2013

Due to Mercury's extremely small obliquity, variations in orbital eccentricity are likely to have been the dominant cause of changes in polar temperatures on Mercury throughout the bulk of its history. In the last 10 Myr, the eccentricity has varied between 0.1 and 0.3. Over the past 100 Myr, eccentricity extremes of nearly zero to greater than 0.4 have likely been reached. We calculate the temperature in the near‐polar region (within 10° of the North Pole) as it varies in response to past eccentricities. These calculations show periods with dramatically different temperatures, diurnal amplitudes, and long period thermal cycles—all of which can have a dramatic effect on longitudinal variations in long‐term subsurface ice stability. Given forthcoming topographic data, thermal models including long‐term eccentricity can help constrain when past ice might have been delivered to Mercury.
A mechanism for bringing ice and brines to the near surface of Mars
Authors: Travis Bryan J. , Feldman William C. , Maurice Sylvestre
Published: April 2013

Recent discovery of transient ice deposits uncovered by five small craters between 40 and 55°N latitude, reinterpretation of MONS neutron data that indicate the wide‐spread presence of ice within 1 m of the surface at midlatitudes (down to 30°N) of Mars, and evidence of recent periglacial activity within 10°N of the equator, all suggest ice may be or recently was present at latitudes where it is not expected and at unexplained abundance. As ice may be unstable under present Mars climatic conditions, a mechanism may be needed to explain the presence of ice in the near surface at these latitudes. Water release history, chemical composition, and heat fluxes are variable over the surface of Mars, and there could be more than one mechanism responsible for near‐surface ice. The purpose of this study is to show that hydrothermal circulation of brines in the subsurface of Mars is a possible mechanism that can deposit ice and brine, close to, or even at, the surface of Mars. Furthermore, the action of brine convection can be related to some of the surface features associated with subsurface water during previous or even present epochs, such as polygonal ground and sorted stone circles.