bluuebunny/crossref_metadata_2025 huggingface dataset:
Cost‐effectiveness of plant and animal biodiversity indicators in tropical forest and agroforest habitats
Authors: Kessler Michael , Abrahamczyk Stefan , Bos Merijn , Buchori Damayanti , Putra Dadang Dwi , Robbert Gradstein S. , Höhn Patrick , Kluge Jürgen , Orend Friederike , Pitopang Ramadhaniel , Saleh Shahabuddin , Schulze Christian H. , Sporn Simone G. , Steffan‐Dewenter Ingolf , Tjitrosoedirdjo Sri S. , Tscharntke Teja
Published: December 2010

1. Biodiversity data are needed for conservation and management of tropical habitats, but the high diversity of these ecosystems makes comprehensive surveys prohibitively expensive and indicator taxa reflecting the biodiversity patterns of other taxa are frequently used. Few studies have produced the necessary comprehensive data sets to assess the quality of the indicator groups, however, and only one previous study has considered the monetary costs involved in sampling them.

2. We surveyed four plant groups (herbs, liverworts, trees, lianas) and eight animal groups (ants, canopy and dung beetles, birds, butterflies, bees, wasps and the parasitoids of the latter two) in 15 plots of 50 × 50 m2 each, representing undisturbed rainforest and two types of cacao agroforest in Sulawesi, Indonesia. We calculated three biodiversity measures (α and β diversity; percentage of species indicative of habitat conditions), built simple and multiple regression models among species groups (single groups, combinations of 2–11 groups, averaged relative diversity of all 12 groups), and related these to three measures of survey cost (absolute costs and two approaches correcting for different sampling intensities).

3. Determination coefficients (R2 values) of diversity patterns between single study groups were generally low (<0·25), while the consideration of several study groups increased R2 values to up to 0·8 for combinations of four groups, and to almost 1·0 for combinations of 11 groups. Survey costs varied 10‐fold between study groups, but their cost‐effectiveness (indicator potential versus monetary cost) varied strongly depending on the biodiversity aspect taken into account (α or β diversity, single or multiple groups, etc.).

4. Synthesis and applications. We found that increasing the number of taxa resulted in best overall biodiversity indication. We thus propose that the most cost‐efficient approach to general tropical biodiversity inventories is to increase taxonomic coverage by selecting taxa with the lowest survey costs.
Chromosomal instability in enterohaemorrhagic Escherichia coli O157:H7: impact on adherence, tellurite resistance and colony phenotype
Authors: Bielaszewska Martina , Middendorf Barbara , Tarr Phillip I. , Zhang Wenlan , Prager Rita , Aldick Thomas , Dobrindt Ulrich , Karch Helge , Mellmann Alexander
Published: December 2010

Tellurite (Tel) resistant enterohaemorrhagic Escherichia coli (EHEC) O157:H7 is a global pathogen. In strain EDL933 Tel resistance (TelR) is encoded by duplicate ter cluster in O islands (OI) 43 and 48, which also harbour iha, encoding the adhesin and siderophore receptor Iha. We identified five EHEC O157:H7 strains that differentiate into large (L) colonies and small (S) colonies with high and low Tel minimal inhibitory concentrations (MICs) respectively. S colonies (Tel‐MICs ≤ 4 µg ml−1) sustained large internal deletions within the TelR OIs via homologous recombination between IS elements and lost ter and iha. Moreover, complete excision of the islands occurred by site‐specific recombination between flanking direct repeats. Complete excision of OI 43 and OI 48 occurred in 1.81 × 10−3 and 1.97 × 10−4 cells in culture, respectively; internal deletion of OI 48 was more frequent (9.7 × 10−1 cells). Under iron limitation that promotes iha transcription, iha‐negative derivatives adhered less well to human intestinal epithelial cells and grew slower than did their iha‐positive counterparts. Experiments utilizing iha deletion and complementation mutants identified Iha as the major factor responsible for these phenotypic differences. Spontaneous deletions affecting TelR OIs contribute to EHEC O157 genome plasticity and might impair virulence and/or fitness.
Tandem use of selenocysteine: adaptation of a selenoprotein glutaredoxin for reduction of selenoprotein methionine sulfoxide reductase
Authors: Kim Moon‐Jung , Lee Byung Cheon , Jeong Jaeho , Lee Kong‐Joo , Hwang Kwang Yeon , Gladyshev Vadim N. , Kim Hwa‐Young
Published: December 2010

Several engineered selenocysteine (Sec)‐containing glutaredoxins (Grxs) and their enzymatic properties have been reported, but natural selenoprotein Grxs have not been previously characterized. We expressed a bacterial selenoprotein Grx from Clostridium sp. (also known as Alkaliphilus oremlandii) OhILAs in Escherichia coli and characterized this selenoenzyme and its natural Cys homologues in Clostridium and E. coli. The selenoprotein Grx had a 200‐fold higher activity than its Sec‐to‐Cys mutant form, suggesting that Sec is essential for catalysis by this thiol‐disulfide oxidoreductase. Kinetic analysis also showed that the selenoprotein Grx had a 10‐fold lower Km than Cys homologues. Interestingly, this selenoenzyme efficiently reduced a Clostridium selenoprotein methionine sulfoxide reductase A (MsrA), suggesting that it is the natural reductant for the protein that is not reducible by thioredoxin, a common reductant for Cys‐containing MsrAs. We also found that the selenoprotein Grx could not efficiently reduce a Cys version of Clostridium MsrA, whereas natural Clostridium and E. coli Cys‐containing Grxs, which efficiently reduce Cys‐containing MsrAs, poorly acted on the selenoprotein MsrA. This specificity for MsrA reduction could explain why Sec is utilized in Clostridium Grx and more generally provides a novel example of the use of Sec in biological systems.
Minor histocompatibility antigens in Tunisians: Could platelet endothelial cell adhesion molecule 1 marker be one of them?
Authors: Sellami M. H. , Kaabi H. , Bibi A. , Sahli C. , Bani M. , Ben Ahmed A. , Massoud T. , Hmida S.
Published: December 2010

Platelet endothelial cell adhesion molecule 1 (PECAM‐1/CD31) is one of the human minor histocompatibility antigens that are the main targets of alloreactive T‐cells after hematopoietic stem cells or solid organs transplantation. In order to investigate its polymorphism in Tunisians, three single nucleotide polymorphisms (SNPs) (rs668, rs12953 and rs1131012) were selected to perform an allele and haplotype analysis. Hundred‐and‐forty‐two healthy and unrelated subjects were enrolled in this survey. Genomic DNAs were extracted using salting out method. SNP genotyping assays were performed with home‐designed sequence‐specific primers polymerase chain reaction (SSP‐PCR). As a result, molecular analysis showed that PECAM‐1 is one of the most polymorphic markers in the Tunisian population because minor allele frequency was 0.3, and minimum haplotype frequency was 0.03. A low linkage disequilibrium (D′ = 0.45) between rs12953 and rs1131012 was noticed, although all other loci were in the Hardy–Weinberg equilibrium (minimum Pvalue = 0.07). The frequencies were close to those reported in African‐American and Caucasian groups.
Allelic and haplotypic HLA frequency distribution in Spanish hematopoietic patients. Implications for unrelated donor searching
Authors: Balas A. , García‐Sánchez F. , Vicario J. L.
Published: December 2010

Histocompatibility criteria for unrelated donor selection are based on high‐resolution definition of HLA genes. In spite of the expansion of the unrelated donor registries, HLA matching remains a problem for many patients because of the great diversity of HLA alleles and haplotypes. The availability of matched donors at an allelic level depends on the frequency of the patient's alleles and haplotypes. Therefore, data regarding HLA distribution for each population are needed in order to evaluate the donor searching approach and, may be, even the therapeutic strategy. In the present report, we have analyzed 253 haematological Spanish patients awaiting unrelated haematopoietic stem cell (HSC) donors. HLA allele and haplotype frequencies have been defined at high resolution for the first time in this population. Significant differences in HLA distribution have been reported when comparing two patient groups, one that received full‐match (10/10) unrelated donors and one that did not. Factors like rare alleles, presence of B*510101 (because of the association with multiple HLA‐C alleles), as well as infrequent B‐C and DRB1‐DQB1 associations, showed a negative value for finding a suitable donor, whereas the presence of one of the six‐gene haplotypes with a frequency ≥0.9% in our sample was a positive factor influencing donor searching. These differences will be useful in donor searching advising and in the use of different therapeutic strategies.
Posterior reversible encephalopathy syndrome after liver transplantation in children: A rare complication related to calcineurin inhibitor effects
Authors: Santos Maria M. , Tannuri Ana Cristina A. , Gibelli Nelson E. , Ayoub Ali A. , Maksoud‐Filho João G. , Andrade Wagner C. , Velhote Manoel C. P. , Silva Marcos M. , Pinho Maria L. , Miyatani Helena T. , Susuki Liza , Tannuri Uenis
Published: December 2010

Santos MM, Tannuri ACA, Gibelli NE, Ayoub AA, Maksoud‐Filho JG, Andrade WC, Velhote MCP, Silva MM, Pinho ML, Miyatani HT, Suzuki L, Tannuri U. Posterior reversible encephalopathy syndrome after liver transplantation in children: A rare complication related to calcineurin inhibitor effects. Pediatr Transplantation 2011: 15:157–160. © 2010 John Wiley & Sons A/S.

Abstract:  PRES is a neuroclinical and radiological syndrome that results from treatment with calcineurin inhibitor immunosuppressives. Severe hypertension is commonly present, but some patients may be normotensive. We report herein two children who received liver transplants, as treatment for biliary atresia in the first case and for Alagille’s syndrome in the second one. In the early postoperative, both patients presented hypertension and seizures. In both cases, the image findings suggested the diagnosis of PRES. The CT scan showed alterations in the posterior area of the brain, and brain MRI demonstrated parietal and occipital areas of high signal intensity. Both children were treated by switching the immunosuppressive regimen and controlling arterial blood pressure. They displayed full recuperation without any neurologic sequelae. Probably, the pathophysiology of PRES results from sparse sympathetic innervation of the vertebrobasilar circulation, which is responsible for supplying blood to the posterior areas of the brain. In conclusion, all liver‐transplanted children who present with neurological symptoms PRES should be considered in the differential diagnosis, although this is a rare complication. As treatment, we recommend rigorous control of arterial blood pressure and switching the immunosuppressive regimen.
Minimizing steroid use in pediatric kidney recipients
Authors: Grenda Ryszard
Published: December 2010

Grenda R. Minimizing steroid use in pediatric kidney recipients. Pediatr Transplantation 2011: 15:32–36. © 2010 John Wiley & Sons A/S.

Abstract:  Outcomes of pediatric kidney transplantation have improved significantly over the years, such that the majority of graft recipients survive to become adolescents and adults. In this article, the findings of some of the important trials that shaped the current therapeutic landscape of immunosuppression will be reviewed. As an evolving landscape, novel strategies are continuously being sought to address the significant challenges in pediatric transplantation. Among these challenges is the development of immunosuppressive strategies that not only minimize the risk of allograft rejection but also allow normal growth and developmental patterns in children. To that end, the growing clinical evidence that indicates that the use of steroid‐sparing regimens is effective will be reviewed. Finally, a brief description of the TWIST study will be provided. This large‐scale comparative study has been designed specifically to assess the effect of early steroid withdrawal on growth in pediatric renal transplant recipients. An overview of the preliminary analysis of the eagerly anticipated results of this landmark trial will also be provided.
Blood conservation and pain control in scoliosis corrective surgery: an online survey of UK practice
Authors: Bird Scott , McGill Neil
Published: December 2010

Background:  Discussion at local meetings led to the realization of the diversity in anaesthetic practice for pediatric and adolescent scoliosis surgery. This diversity was assessed using an online survey, the aim being to provoke discussion and highlight areas of future research.

Methods:  Of the 24 centers practicing pediatric and adolescent scoliosis surgery, 21 completed questionnaires, a response rate of 88%.

Results:  Blood conservation; the area of greatest clinical variability was seen in dosing regimes for Tranexamic acid. Thromboprophylaxis; both mechanical and pharmacological regimes showed wide range in both application and timing. Pain control; eight different types of postoperative pain relief were utilized across the centres, some in isolation but many in combination.

Conclusions:  The results from our survey show wide variation nationally and hopefully will provoke discussion and ultimately national multi‐centred research to define best practice.
Slaying the ‘Westmonster’ in the Caribbean? Constitutional Reform in St Vincent and the Grenadines
Authors: Bishop Matthew Louis
Published: December 2010

The model of governance bequeathed by Britain to the Caribbean has long been praised for ensuring that vibrant democratic practice has generally prevailed since the era of decolonisation. Yet it has also become increasingly clear that the Westminster system of politics, as it is applied to the region's tiny polities, has come to exhibit serious deficiencies and is in need of reform. The current government of St Vincent and the Grenadines has recently made a serious attempt to address the issue, engaging in an expansive process of public consultation and constitutional reform which was ultimately rejected by the populace in a referendum held in November 2009. This article seeks to analyse both the form and content of the constitutional reform process, situating it within broader debates about the Westminster Model itself.
One‐bath union dyeing of a modified wool/acrylic blend with acid and reactive dyes
Authors: El‐Shishtawy Reda M , El‐Zawahry Manal M , Ahmed Nahed S E
Published: December 2010

Pretreated wool/acrylic fibre was obtained by a facile amidoximation process. Fibre characterisation (nitrogen content, tensile strength, shrinkage, infrared spectra and X‐ray diffraction) proved the success of the pretreatment. Union dyeing of wool/acrylic fabrics with acid and reactive dyes, namely CI Acid Red 40, CI Acid Blue 25, CI Reactive Red 194 and CI Reactive Blue 25, was obtained using a one‐bath dyeing process. Different factors that may affect the dyeability of the blend fibre, such as dyebath pH, liquor ratio, temperature, time and dye concentration, were evaluated with respect to the dye exhaustion, fixation, colour strength, levelling and fastness properties. Excellent to good fastness was obtained for all samples, irrespective of the dye used. The result of the investigation offers a new viable method for union dyeing of wool/acrylic fibres in a one‐dyebath process.
I Listen, Therefore I Am: An Asian American Approach to Post‐Materialist Living
Authors: McDaniel Jay
Published: December 2010

Abstract:  Consumerism is a cultural atmosphere that permeates societies when they are saturated with market‐driven values at the expense of social values. It prioritizes personal needs over the common good and reduces even religion to a “brand” that people wear like an emblem. It simultaneously approaches the world itself as a resource to be managed, forgetful of the fact that all living beings are songs and stories worth hearing. As Christianity becomes a post‐western religion, opportunities emerge for Christians to develop cross‐cultural poetics that are conducive to post‐materialist ways of living in the world. Poetics are not theologies, but rather outlooks on life or, perhaps more appropriately, ways of listening to the voices of people and other living beings. The purpose of this essay is to propose one such Asian American theology that can be a commitment to deep listening: that is, to dwelling musically in the world. This manner of dwelling can recognize that even the heart of the universe—even God—is a listening presence at the heart of the universe.
From Consumerism to Stewardship: The Troublesome Ambiguities of an Attractive Option1
Authors: Santmire H. Paul
Published: December 2010

Abstract:  Problems with consumerism may lead Christians to project the idea of responsible stewardship as an alternative. But this would be highly problematic. Although a part of many American Christians’ experience, and apparently bolstered by the authority of Jesus himself, the construct resists normative theological definition. It is too closely allied in our culture with “the spirit of capitalism” and tends to re‐enforce secular understandings of private property. The construct stewardship, therefore, should be used sparingly, if at all, in church circles.
In Forty Years, What has Changed … or Not?
Authors: Bloomquist Karen L.
Published: December 2010

Abstract:  Drawing on the background of her own experiences over the past forty years, the author reflects on the marginalization, tokenism, and mainstreaming of women in ministry and feminist theology that has occurred during this time. She calls for greater sensitivity to the realities women globally still face today, and for more interactive, trans‐contextual, and transformational engagement with these realities.
IMAGING DIAGNOSIS—MAGNETIC RESONANCE IMAGING PULSATILITY ARTIFACT IN THE CANINE CERVICAL SPINE
Authors: SEILER GABRIELA S. , ROBERTSON IAN D. , MUKUNDAN SRINIVASAN , THRALL DONALD E.
Published: December 2010

Pulsatile venous flow in the internal vertebral venous plexus of the cervical spine can lead to vertical, linear T2‐hyperintensities in the spinal cord at the cranial aspect of C3 and C4 in transverse T2‐weighted images in large breed dogs that are not accompanied by ghosting. The artifact is more conspicuous in pre‐ and postcontrast transverse T1‐weighted images and is accompanied by ghosting in that sequence, typical of a pulsatility artifact. A flow‐related artifact was confirmed as the cause for this appearance by noting its absence after either exchange of phase and frequency encoding direction or by flow compensation. Care should be exercised to avoid misdiagnosing this pulsatility artifact seen in transverse T2‐weighted images of the midcervical spine in large dogs as an intramedullary lesion when T1‐images or phase‐swap images are not available to confirm its artifactual origin.
CONTRAST‐ENHANCED PORTAL MAGNETIC RESONANCE ANGIOGRAPHY IN DOGS WITH SUSPECTED CONGENITAL PORTAL VASCULAR ANOMALIES
Authors: MAI WILFRIED , WEISSE CHICK
Published: December 2010

Contrast‐enhanced multiphase magnetic resonance angiography (CE‐MRA) was used in 17 dogs with a suspected congenital portal vascular anomaly. Portal vascular anomalies were identified in 16 of the 17 dogs. Eleven had a single intrahepatic portocaval shunt (two central divisional, three right divisional, and six left divisional), one dog had a double intrahepatic portocaval shunt, one dog had a hepatic arteriovenous malformation, one dog had a complex intrahepatic porto‐caval shunt. Two dogs had an extrahepatic portosystemic shunt and no shunt was identified in one dog. Total imaging time was <10 min and image quality was good to excellent in all dogs. Portal CE‐MRA is a feasible, fast and non invasive technique to diagnose portal vascular anomalies in dogs, with a large field‐of‐view and good anatomic depiction of the abnormal vessels. Based on these results, CE‐MRA is an efficient imaging technique for the diagnosis of portal vascular anomalies in dogs.
Fractal geometry of angular momentum evolution in near-Keplerian systems
Authors: Gürkan M. Atakan
Published: December 2010

In this Letter, we propose a method to study the nature of resonant relaxation in near-Keplerian systems. Our technique is based on measuring the fractal dimension of the angular momentum trails and we use it to analyse the outcome of N-body simulations. With our method, we can reliably determine the time-scale for resonant relaxation, as well as the rate of change of angular momentum in this regime. We find that growth of angular momentum is more rapid than random walk, but slower than linear growth. We also determine the presence of long-term correlations arising from the bounds on angular momentum growth. We develop a toy model that reproduces all essential properties of angular momentum evolution.
MEASUREMENTS OF NORMAL AND COLLATERAL CORONARY BLOOD FLOW BY CLOSE‐ARTERIAL AND INTRAMYOCARDIAL INJECTION OF KRYPTON85 AND XENON133
Authors: LINDER ERLAND
Published: December 2010

A recent method for measuring collateral blood flow in the myocardium of dogs was based on an analysis of the composite clearance of Krypton85 administered close‐arterially (Johansson, Linder and Seeman 1964, 1966). This method has been critically analysed and various sources of possible errors in the estimations are discussed.

Comparisons between paired measurements by this technique and results obtained by recordings of the wash‐out rate of intramuscularly injected Xenon133 depots, in the well‐perfused and ischemic myocardial areas respectively, strongly suggest that the method is fairly accurate and reliable, despite the fact that it has obvious theoretical limitations.

The results also reveal that the collateral flow to the ischemic area is not entirely uniform. Within a narrow border zone there is a steep reduction of blood flow, with a more gradual diminution towards central parts of the ischemic zone. This regional heterogeneity in collateral flow could not for several reasons, be analysed in exact detail from the composite curve alone, but was revealed by recordings of clearance of strictly localized, intramuscular tracer injections.

Peak flow during reactive hyperemia could also be fairly satisfactorily measured, provided certain precautions were taken. The results suggest that it is, in addition, possible to make a fair estimation of the mass of the ischemic tissue from the composite curve.

The method may prove to be useful in experimental studies designed to investigate different means for improving collateral blood supply to an ischemic myocardial area.
Unusual clinical presentations of new‐onset herpetic eye disease after ocular surgery
Authors: Jhanji Vishal , Ferdinands Mervyn , Sheorey Harsha , Sharma Namrata , Jardine Darren , Vajpayee Rasik B.
Published: December 2010

Purpose:  To report five cases of new‐onset herpetic eye disease with unusual presentation after ocular surgery.

Methods:  Herpetic eye disease was suspected in five cases, three after cataract surgery and two after lamellar corneal transplantation surgery. Of these, four cases presented within 2–6 weeks of surgery. The clinical presentation was in the form of an epithelial defect, suspected epithelial down growth, graft oedema with unexplained anterior chamber inflammation and graft–host interface infection. A swab for viral detection with real‐time polymerase chain reaction was performed in all the described cases.

Results:  Herpes simplex disease was detected in all cases. All cases responded to the antiherpetic medications.

Conclusions:  Our study shows that new‐onset herpetic eye disease may occur after cataract surgery and lamellar corneal transplantation, and a high index of suspicion may be necessary for the diagnosis in such cases.
Unifying the Intellectual Virtues
Authors: LEPOCK CHRISTOPHER
Published: December 2010

The intellectual virtues include two seemingly quite different types of traits: reliable faculties on the one hand and inquiry‐regulating traits of intellectual character like conscientiousness and openmindedness on the other. Extant virtue theories do not appear to have provided a single account that adequately covers both types of virtue. In this paper, I examine the different ways in which a trait or disposition can contribute to our cognitive goal of acquiring significant true beliefs. I propose that the two types of virtues can be understood as contributing in different ways to our cognitive goal, and develop a general framework for understanding their value.
The oxygen isotope composition of Almahata Sitta
Authors: RUMBLE Douglas , ZOLENSKY Michael E. , FRIEDRICH Jon M. , JENNISKENS Peter , SHADDAD Muawia H.
Published: December 2010

Abstract– Eleven fragments of the meteorite Almahata Sitta (AHS) have been analyzed for oxygen isotopes. The fragments were separately collected as individual stones from the meteorite’s linear strewn field in the Nubian Desert. Each of the fragments represents a sample of a different and distinct portion of asteroid 2008 TC3. Ten of the fragments span the same range of values of δ18O, δ17O, and Δ17O, and follow the same trend along the carbonaceous chondrite anhydrous minerals (CCAM) line as monomict and polymict members of the ureilite family of meteorites. The oxygen isotope composition of fragment #25 is consistent with its resemblance petrographically to an H5 ordinary chondrite. Our results demonstrate that a single small asteroidal parent body, asteroid 2008 TC3, only 4 m in length, encompassed the entire range of variation in oxygen isotope compositions measured for monomict and polymict ureilites.
Polycyclic aromatic hydrocarbons in asteroid 2008 TC3: Dispersion of organic compounds inside asteroids
Authors: SABBAH Hassan , MORROW Amy L. , JENNISKENS Peter , SHADDAD Muawia H. , ZARE Richard N.
Published: December 2010

Abstract– Ureilites are carbon‐bearing ultramafic rocks characterized by partial melt depletion and a violent disruption resulting in graphitic carbon and diamonds. Among the predominantly polymict ureilite meteorites collected from the impact of asteroid 2008 TC3 on October 7, 2008—the first time an asteroid was spotted in space and subsequently recovered in the form of meteorites—were many fresh‐looking chondrites. Four were classified as EH6 (#16), H5 (sample #25), EL6 (#41), and L4 (#A100) chondrites. All are called “Almahata Sitta,” named after the nearby inhabited outpost of Station 6. Six hundred meteorites were collected, which show a wide range of densities, textures, reflection properties, and elemental compositions. In this study, we employ laser desorption laser ionization mass spectrometry to analyze the polycyclic aromatic hydrocarbon (PAH) contents of six meteorites from 2008 TC3 that are ureilites (sample #1, #4, #7, #15, #27, and #47) and three anomalous fragments (sample #25, #16, and #41). Numerous organic compounds were detected with a PAH signature that has not been observed in the carbonaceous chondrites previously studied by our experimental apparatus. Specifically, the Almahata Sitta spectra lack the diversity of alkylation series of parent PAHs commonly observed in Murchison and other carbonaceous chondrites. Spatial mappings of aromatic species across the surface of a fragment of sample #4 are presented including detection of what appears to be the aromatic amino acid tyrosine. Potential sources of terrestrial organic contamination are discussed and ruled out as a source of our observations. Meteorites #25 and #16 are found to have the same distribution of PAHs as the Almahata Sitta meteorites. Other chondrites have much different organic fingerprints. We conclude that both an H5 and E chondrite were included in asteroid 2008 TC3 as foreign clasts and that organic compounds contained in ureilites can spread into other parts of an asteroid.
The chromium isotopic composition of Almahata Sitta
Authors: QIN Liping , RUMBLE Douglas , ALEXANDER Conel M. O’D. , CARLSON Richard W. , JENNISKENS Peter , SHADDAD Muawia H.
Published: December 2010

Abstract– Nine ureilitic fragments of the anomalous polymict ureilite Almahata Sitta have been analyzed for their Cr isotopic compositions. All the samples, including both nonmagnetic and magnetic portions, show essentially the same ε54Cr deficit (−0.77 ± 0.10), relative to the terrestrial Cr standard. This contrasts with the variable positive 54Cr anomalies observed for carbonaceous chondrites, but agrees with the values measured for eucrites, diogenites, and mesosiderites (Trinquier et al. 2007). This implies that, contrary to previous suggestions based on O isotopes, ureilites were not derived from any known carbonaceous chondrite parent body. Instead, the Almahata Sitta parent body may have accreted in a nebular region/environment similar to that of the howardite, eucrite, and diogenite (HED) parent body. In addition, the lack of variation in ε54Cr combined with variable O isotopic compositions in the meteorite fragments suggests that whatever process(es) caused the O isotopic heterogeneity of the solar system was probably not responsible for heterogeneity in ε54Cr. The samples show resolvable variations in ε53Cr (0.15–0.41) that are correlated with Mn/Cr ratios, suggesting that live 53Mn was present at the time of formation of Almahata Sitta. The isochron yields an initial 53Mn/55Mn value of 3.1 (±1.1) × 10−6, corresponding to an age of 4563.6 ± (2.2) Ma when related to U‐Pb and Mn‐Cr data for the D’Orbigny angrite. This age is consistent with the Mn‐Cr and Al‐Mg ages of two other polymict ureilites (Goodrich et al. 2010). Magmatic activity on the ureilites’ parent body seems to have postdated the formation of refractory inclusions by approximately 4–5 Ma.
Inhomogeneity of asteroid 2008 TC3 (Almahata Sitta meteorites) revealed through magnetic susceptibility measurements
Authors: KOHOUT Tomáš , JENNISKENS Peter , SHADDAD Muawia H. , HALODA Jakub
Published: December 2010

Abstract– Magnetic susceptibility measurements were performed on freshly fallen Almahata Sitta meteorites. Most recovered samples are polymict ureilites. Those found in the first 4 months since impact, before the meteorites were exposed to rain, have a magnetic susceptibility in the narrow range of 4.92 ± 0.08 log 10−9 Am2 kg−1 close to the range of other ureilite falls 4.95 ± 0.14 log 10−9 Am2 kg−1 reported by Rochette et al. (2009). The Almahata Sitta samples collected 1 yr after the fall have similar values (4.90 ± 0.06 log 10−9 Am2 kg−1), revealing that the effect of 1 yr of terrestrial weathering was not severe. However, our reported values are higher than derived from polymict (brecciated) ureilites 4.38 ± 0.47 log 10−9 Am2 kg−1 (Rochette et al. 2009) containing both falls and finds, confirming that these are significantly weathered. Additionally, other fresh‐looking meteorites of nonureilitic compositions were collected in the Almahata Sitta strewn field. Magnetic susceptibility measurements proved to be a convenient nondestructive method for identifying nonureilitic meteorites among those collected in the Almahata Sitta strewn field, even among fully crusted. Three such meteorites, no. 16, 25, and 41, were analyzed and their composition determined as EH6, H5, and EL6, respectively (Zolensky et al. 2010). A high scatter of magnetic susceptibility values among small (<5 g) samples revealed high inhomogeneity within the 2008 TC3 material at scales below 1–2 cm.
Doppler weather radar as a meteorite recovery tool
Authors: FRIES Marc , FRIES Jeffrey
Published: December 2010

Abstract– We report the use of Doppler weather radar as a tool for locating meteorites, both at the time of a fall and from archived radar data. This asset is especially useful for meteorite recovery as it can provide information on the whereabouts of falling meteorites in “dark flight” portion of their descent where information on their flight paths cannot be discerned from more traditional meteorite location techniques such as eyewitness accounts. Weather radar data can provide information from detection in three distinct regimes: (A) direct detection of the rapidly moving, optically bright fireball by distant radars, (B) detection of falling debris to include hand‐sample sized rocks, and (C) detection of dust produced by detonation events that can occur tens of minutes and many kilometers laterally removed from the actual fireball locality. We present examples of each, as well as comparisons against man‐made debris from a re‐entering Soyuz rocket and the Stardust Sample Return Capsule. The use of Doppler weather radar as a supplement to traditional meteorite recovery methods holds the promise of improving both the speed and total number of meteorite recoveries, thereby increasing the number of freshly fallen meteorites for scientific study.
The recovery of asteroid 2008 TC3
Authors: SHADDAD Muawia H. , JENNISKENS Peter , NUMAN Diyaa , KUDODA Ayman M. , ELSIR Saadia , RIYAD Ihab F. , ALI Awad Elkareem , ALAMEEN Mohammed , ALAMEEN Nada M. , EID Omer , OSMAN Ahmed T. , AbuBAKER Mohamed I. , YOUSIF Mohamed , CHESLEY Steven R. , CHODAS Paul W. , ALBERS Jim , EDWARDS Wayne N. , BROWN Peter G. , KUIPER Jacob , FRIEDRICH Jon M.
Published: December 2010

Abstract– On October 7, 2008, asteroid 2008 TC3 impacted Earth and fragmented at 37 km altitude above the Nubian Desert in northern Sudan. The area surrounding the asteroid’s approach path was searched, resulting in the first recovery of meteorites from an asteroid observed in space. This was also the first recovery of remains from a fragile “cometary” PE = IIIa/b type fireball. In subsequent searches, over 600 mostly small 0.2–379 g meteorites (named “Almahata Sitta”) with a total mass 10.7 kg were recovered from a 30 × 7 km area. Meteorites fell along the track at 1.3 kg km−1, nearly independent of mass between 1 and 400 g, with a total fallen mass of 39 ± 6 kg. The strewn field was shifted nearly 1.8 km south from the calculated approach path. The influence of winds on the distribution of the meteorites, and on the motion of the dust train, is investigated. The majority of meteorites are ureilites with densities around 2.8 g cm−3, some of an anomalous (porous, high in carbon) polymict ureilite variety with densities as low as 1.5 g cm−3. In addition, an estimated 20–30% (in mass) of recovered meteorites were ordinary, enstatite, and carbonaceous chondrites. Their fresh look and matching distribution of fragments in the strewn field imply that they were part of 2008 TC3. For that reason, they are all referred to as “Almahata Sitta.” No ureilite meteorites were found that still held foreign clasts, suggesting that the asteroid’s clasts were only loosely bound.
IP
7
Akts as an Inhibitor
Authors: Foley John F.
Published: December 2010

Insulin signaling stimulates the generation of the inositol pyrophosphate IP
7
, which inhibits the activation of Akt, thus attenuating insulin signaling.
Muscle Building
Authors: Hurtley Stella M.
Published: December 2010

An alternative signaling mechanism for nucleating unbranched actin filaments is required for skeletal muscle maturation.
Aspasing Out Metacaspases and Caspases: Proteases of Many Trades
Authors: Bozhkov Peter V. , Smertenko Andrei P. , Zhivotovsky Boris
Published: December 2010

The substrates of the metacaspase type of proteases are beginning to be identified.
INTERSECTINg Pathways in Cell Biology
Authors: O’Bryan John P.
Published: December 2010

The intersectin family of scaffolding proteins link signaling and endocytic pathways.
In Vitro
Activity and Single-Step Mutational Analysis of Rifamycin SV Tested against Enteropathogens Associated with Traveler's Diarrhea and
Clostridium difficile
Authors: Farrell David J. , Putnam Shannon D. , Biedenbach Douglas J. , Moro Luigi , Bozzella Roberta , Celasco Giuseppe , Jones Ronald N.
Published: December 2010

Rifamycin SV is a broad-spectrum, poorly absorbed antimicrobial agent that, when coupled with MMX technology, is being targeted for the oral treatment of traveler's diarrhea (TD) and
Clostridium difficile
-associated disease (CDAD). Rifamycin SV was tested for activity against 911 TD-associated enteropathogens and 30
C. difficile
isolates collected from several global surveillance studies. Rifamycin SV demonstrated similar antimicrobial activity levels against the
Enterobacteriaceae
, with MIC
50
values ranging from 32 to 128 μg/ml for all but one strain (an enterotoxigenic
Escherichia coli
at >512 μg/ml). For non-
Enterobacteriaceae
strains, MIC
50
values ranged from 2 to 8 μg/ml, with the exception of
Campylobacter
spp., for which all strains had MIC values of >512 μg/ml. Rifamycin SV also demonstrated excellent activity (MIC
50
of ≤0.03 μg/ml) against most
C. difficile
strains (including one hypervirulent NAP1 strain), and this activity was even superior to the potency observed for vancomycin, metronidazole, and rifaximin. In mutational passaging studies, rifamycin SV induced stable resistance and showed a mutation frequency in
E. coli
similar to that of rifampin. This study presents the potency of rifamycin SV for enteropathogens commonly recovered from patients with TD and CDAD. Additional
in vitro
and
in vivo
studies appear necessary to determine the utility of rifamycin SV as an oral agent for the prevention and treatment of TD and CDAD.
Interspecies Dissemination of the
bla
Gene Encoding PER-1 Extended-Spectrum β-Lactamase
Authors: Bae Il Kwon , Jang Sook Jin , Kim Juwon , Jeong Seok Hoon , Cho Byungkyu , Lee Kyungwon
Published: December 2010

PER-1 extended-spectrum β-lactamase-producing Gram-negative bacilli are resistant to oxyimino-cephalosporins. However, the
bla
PER-1
gene has never been reported in
Klebsiella pneumoniae
. Here, we studied interspecies dissemination of the
bla
PER-1
gene by horizontal transfer of Tn
1213
among
Acinetobacter baumannii
,
Pseudomonas aeruginosa
, and
K. pneumoniae.
In a
K. pneumoniae
clinical isolate, the
bla
PER-1
gene was located on a 150-kbp incompatibility group A/C plasmid.
The Tea Catechin Epigallocatechin Gallate Suppresses Cariogenic Virulence Factors of
Streptococcus mutans
Authors: Xu Xin , Zhou Xue D. , Wu Christine D.
Published: December 2010

Streptococcus mutans
, the primary etiologic agent of dental caries, possesses a series of virulence factors associated with its cariogenicity. Alternatives to traditional antimicrobial treatment, agents selectively inhibiting the virulence factors without necessarily suppressing the resident oral species, are promising. The anticariogenic properties of tea have been suggested in experimental animals and humans. Tea polyphenols, especially epigallocatechin gallate (EGCg), have been shown to inhibit the growth and glucosyltransferases activity of
S. mutans
. However, their effects on biofilm and cariogenic virulence factors of oral streptococci other than glucosyltransferases have not been well documented. In this study, we investigated the biological effect of EGCg on the virulence factors of
S. mutans
associated with its acidogenicity and acidurity. The antimicrobial effects of EGCg on
S. mutans
biofilm grown in chemically defined medium were also examined. EGCg inhibited growth of
S. mutans
planktonic cells at an MIC of 31.25 μg/ml and a minimal bactericidal concentration (MBC) of 62.5 μg/ml. EGCg also inhibited
S. mutans
biofilm formation at 15.6 μg/ml (minimum concentration that showed at least 90% inhibition of biofilm formation) and reduced viability of the preformed biofilm at 625 μg/ml (sessile MIC
80
). EGCg at sub-MIC levels inhibited acidogenicity and acidurity of
S. mutans
cells. Analysis of the data obtained from real-time PCR showed that EGCg significantly suppressed the
ldh
,
eno
,
atpD
, and
aguD
genes of
S. mutans
UA159. Inhibition of the enzymatic activity of F
1
F
o
-ATPase and lactate dehydrogenase was also noted (50% inhibitory concentration between 15.6 and 31.25 μg/ml). These findings suggest that EGCg is a natural anticariogenic agent in that it exhibits antimicrobial activity against
S. mutans
and suppresses the specific virulence factors associated with its cariogenicity.
A Two-Component Regulatory System Interconnects Resistance to Polymyxins, Aminoglycosides, Fluoroquinolones, and β-Lactams inPseudomonas aeruginosa
Authors: Muller Cédric , Plésiat Patrick , Jeannot Katy
Published: December 2010

Constitutive overexpression of the active efflux system MexXY/OprM is a major cause of resistance to aminoglycosides, fluoroquinolones, and cefepime in clinical strains ofPseudomonas aeruginosa. Upregulation of this pump often results from mutations occurring inmexZ, the local repressor gene of themexXYoperon. In this study, analysis of MexXY-overproducing mutants selectedin vitrofrom reference strain PAO1Bes on amikacin (at a concentration 1.5-fold higher than the MIC) led to identification of a new class of mutants harboring an intactmexZgene and exhibiting increased resistance to colistin and imipenem in addition to aminoglycosides, fluoroquinolones, and cefepime. Reverse transcription-quantitative PCR (RT-qPCR) experiments on a selected clone named PAOW2 demonstrated thatmexXYoverexpression was independent ofmexZand the PA5471 gene, which is required for drug-dependent induction ofmexXY. Furthermore, the transcript levels of theoprDgene, which encodes the carbapenem-selective porin OprD, were found to be reduced drastically in PAOW2. Whole-genome sequencing revealed a single mutation resulting in an M59I substitution in the ParR protein, the response regulator of the ParRS two-component regulatory system (with ParS being the sensor kinase), which is required for adaptive resistance ofP. aeruginosato polycationic peptides such as colistin. The multidrug resistance phenotype was suppressed in PAOW2 by deletion of theparSandparRSgenes and conferred to PAO1Bes by chromosomal insertion of the mutatedparRSlocus from PAOW2. As shown by transcriptomic analysis, only a very small number of genes were expressed differentially between PAOW2 and PAO1Bes, including the lipopolysaccharide (LPS) modification operonarnBCADTEF-ugd, responsible for resistance to polycationic agents. Exposure of wild-type PAO1Bes to different polycationic peptides, including colistin, was shown to result in increasedmexYand repressedoprDexpression via ParRS, independent of PA5471. In agreement with these results, colistin antagonized activity of the MexXY/OprM substrates in PAO1Bes but not in a ΔparRSderivative. Finally, screening of clinical strains exhibiting the PAOW2 resistance phenotype allowed the identification of additional alterations in ParRS. Collectively, our data indicate that ParRS may promote either induced or constitutive multidrug resistance to four different classes of antibiotics through the activation of three distinct mechanisms (efflux, porin loss, and LPS modification).
Thrombopoietin Contributes to Neuronal Damage in Experimental Bacterial Meningitis
Authors: Hoffmann Olaf , Rung Olga , Im Ae-Rie , Freyer Dorette , Zhang Juan , Held Josephin , Stenzel Werner , Dame Christof
Published: December 2010

Thrombopoietin (Tpo), which primarily regulates megakaryopoiesis, and its receptor (c-Mpl) are expressed in the brain, where Tpo exhibits proapototic effects on neurons. In the present study, we investigated the implication ofTpoin experimental pneumococcal meningitis. Following intrathecal infection with the encapsulatedStreptococcus pneumoniaestrain D39, we observed upregulation ofTpomRNA expression at 12 h and 24 h in brain homogenates of wild-type C57BL/6 mice. c-MplmRNA expression was upregulated at 12 h and returned to baseline at 24 h. Compared to wild-type mice, mutants with homozygous Tpo receptor ablation (c-Mpl−/−) displayed reduced microglial activation and neuronal apoptosis in the dentate gyrus. Concentrations of bacteria in blood or cerebrospinal fluid (CSF), as well as CSF pleocytosis, were not significantly different between wild-type and c-Mpl−/−mice. In human postmortem brain, Tpo protein was colocalized to macrophages during encephalitis. In murine primary microglia and RAW264.7 macrophages, upregulation ofTpomRNA was induced by D39-conditioned medium but not by bacterial lipopeptide or by medium conditioned by pneumococcal mutants defective in hydrogen peroxide formation (ΔspxB) or pneumolysin (Δpln). We conclude that Tpo acts as a mediator of neuronal damage in bacterial meningitis.
Activation of Motility by Sensing Short-Chain Fatty Acids via Two Steps in a Flagellar Gene Regulatory Cascade in Enterohemorrhagic
Escherichia coli
Authors: Tobe Toru , Nakanishi Noriko , Sugimoto Nakaba
Published: December 2010

The regulated expression of virulence genes is critical for successful infection by an intestinal pathogen. Bacteria rely on sensing environmental signals to find preferable niches and reach the infectious state. Orally ingested enterohemorrhagic
Escherichia coli
(EHEC) travels through the gastrointestinal tract and encounters a variety of environmental factors, some of which act as triggering signals for the induction of virulence genes. Butyrate, one of the main short-chain fatty acids (SCFAs), is such a signal, enhancing the expression of genes for intimate attachment and type III secretion. We further explored the role of SCFAs and found a positive effect of SCFAs on flagellar expression. Although EHEC did not produce flagella when grown in Dulbecco's modified Eagle's medium (DMEM), a tissue culture medium that enhances virulence gene expression, the addition of SCFAs to the medium induced the production of flagella, and the EHEC bacteria became motile. Among SCFAs, butyrate simultaneously activates both virulence and flagellar genes. Flagella did not affect initial adherence, and they were not expressed in adherent bacteria during microcolony formation. SCFAs activated flagellar genes via two regulatory steps. Butyrate activated the
flhDC
regulatory genes through leucine-responsive regulatory protein (Lrp), which is also a regulator of virulence genes. However, butyrate, acetate, and propionate also activated downstream genes independently of
flhDC
activation. Consequently, when encountering increased concentrations of SCFAs, which are abundant in acetate, in the intestine, EHEC first activates flagellar production and motility, followed by genes involved in adherence and type III secretion, which leads to efficient adherence in a preferable niche.
Molecular Correlates of Experimental Cerebral Malaria Detectable in Whole Blood
Authors: Oakley Miranda S. , Anantharaman Vivek , Venancio Thiago M. , Zheng Hong , Mahajan Babita , Majam Victoria , McCutchan Thomas F. , Myers Timothy G. , Aravind L. , Kumar Sanjai
Published: December 2010

Cerebral malaria (CM) is a primary cause of deaths caused byPlasmodium falciparumin young children in sub-Saharan Africa. Laboratory tests based on early detection of host biomarkers in patient blood would help in the prognosis and differential diagnosis of CM. Using thePlasmodium bergheiANKA murine model of experimental cerebral malaria (ECM), we have identified over 300 putative diagnostic biomarkers of ECM in the circulation by comparing the whole-blood transcriptional profiles of resistant mice (BALB/c) to those of two susceptible strains (C57BL/6 and CBA/CaJ). Our results suggest that the transcriptional profile of whole blood captures the molecular and immunological events associated with the pathogenesis of disease. We find that during ECM, erythropoiesis is dysfunctional, thrombocytopenia is evident, and glycosylation of cell surface components may be modified. Furthermore, analysis of immunity-related genes suggests that slightly distinct mechanisms of immunopathogenesis may operate in susceptible C57BL/6 and CBA/CaJ mice. Furthermore, our data set has allowed us to create a molecular signature of ECM composed of a subset of circulatory markers. Complement component C1q, β-chain, nonspecific cytotoxic cell receptor protein 1, prostate stem cell antigen, DnaJC, member 15, glutathioneS-transferase omega-1, and thymidine kinase 1 were overexpressed in blood during the symptomatic phase of ECM, as measured by quantitative real-time PCR analysis. These studies provide the first host transcriptome database that is uniquely altered during the pathogenesis of ECM in blood. A subset of these mediators of ECM warrant validation inP. falciparum-infected young African children as diagnostic markers of CM.