julilili42/papers huggingface dataset:
EVOLUTION OF SULFIDE MINERALIZATION IN FERROCARBONATITE, SWARTBOOISDRIF, NORTHWESTERN NAMIBIA: CONSTRAINTS FROM MINERAL COMPOSITIONS AND SULFUR ISOTOPES
2006-08-01

The Mesoproterozoic (ca. 1140–1120 Ma) ferrocarbonatite dykes of Swartbooisdrif, northwestern Namibia, transect the anorthositic rocks of the Kunene Intrusive Complex. The ferrocarbonatite is mainly composed of ankerite and magnetite, and is highly contaminated by fragmented and fenitized wallrock anorthosite (albite, biotite and sodalite), with Fe–Cu–Ni sulfides (assemblage: pyrite, chalcopyrite, millerite, polydymite, fletcherite) being widespread minor components. In order to constrain the compositional evolution and to reconstruct the T–f(O2) conditions during progressive crystallization and subsolidus re-equilibration of the ferrocarbonatites, a detailed study of the mineral chemistry and sulfur isotope signatures of the sulfide mineralization has been carried out. Owing to the finely intergrown nature of the sulfide assemblages, sulfur isotope analysis has been performed using an in situ laser-microprobe technique. The δ34S values of early carbonatite-hosted pyrite range from 3.8 to 5.1‰. Similar δ34S values were obtained for metasomatically formed pyrite from the fenitized anorthosites (+3.3 to +3.4‰). Distinctly lower, negative δ34S values have been determined for pyrite (−2.4 to −2.1‰) and chalcopyrite (−3.3 to 0.0‰) in late sulfide–oxide veins, with the lowest values obtained for sulfides from samples that contain additional secondary barite. This overall isotopic trend is interpreted in terms of changing proportions of oxidized and reduced sulfur species in the carbonatite-derived fluids, and is supported by calculations of phase equilibria in the system Cu–Fe–S–O–H and modeling of isotopic mass-balance. During the early stage of mineralization, the oxygen fugacity was presumably low, with reduced sulfur species (H2S, HS−) dominant in the fluids, promoting the precipitation of pyrite and the metasomatic formation of nearly pure, SO4-free sodalite. A subsequent increase in f(O2) led to a systematic increase in the ∑SO4/∑H2S ratio of the fluid. This resulted in a depletion of 34S in the residual reduced sulfur, which is manifested by the negative δ34S values of the late sulfide mineralization.
Cartilage Defects: Epidemiology and Natural History
2006-08-01

In contrast to earlier reports, recent studies clearly document that articular cartilage defects occur rather often but remain unnoticed in many cases. Depending on the lesion size, primary articular cartilage defects eventually increase the risk of osteoarthritis (OA) significantly. OA develops locally and is associated with biomechanical aetiology: in most cases excessive load onto cartilage and aging are among the main factors contributing to OA. This type of OA is sometimes referred to as primary OA. Friction and wear particles, injury, systemic diseases or dysplasia may cause OA prematurely and individuals develop a so-called secondary OA. Evaluation of prevalence and incidence of primary versus secondary OA is difficult, as onset and development of cartilage degradation remain obscure in many cases for a long time. However, published data of latest research suggest significant frequencies of secondary OA, especially in the knee, as a consequence of primary cartilage defects and other injuries of the joint. Therefore, improved techniques of diagnosis are urgently needed in order to inform patients or even treat cartilage defects at early stages before degenerative processes destroy articular cartilage and joint function completely.
Influence of Small‐Scale Heterogeneities on Contaminant Transport in Fractured Crystalline Rock
2006-08-01

Abstract We present a sequence of purely advective transport models that demonstrate the influence of small‐scale geometric inhomogeneities on contaminant transport in fractured crystalline rock. Special weight is placed on the role of statistically generated variable fracture apertures. The fracture network geometry and the aperture distribution are based on information from an in situ radionuclide retardation experiment performed at Grimsel test site (Swiss Alps). The obtained breakthrough curves are fitted with the advection dispersion equation and continuous‐time random walks (CTRW). CTRW is found to provide superior fits to the late‐arrival tailing and is also found to show a good correlation with the velocity distributions obtained from the hydraulic models. The impact of small‐scale heterogeneities, both in fracture geometry and aperture, on transport is shown to be considerable.
SPATIAL, SEASONAL AND INTRAPOPULATIONAL VARIATION IN THE DIET OF PSEUDIS CARDOSOI (ANURA: HYLIDAE) FROM THE ARAUCÁRIA PLATEAU OF RIO GRANDE DO SUL, BRAZIL
2006-08-01

Abstract The diet of Pseudis cardosoi was studied in the Araucaria forest and adjacent grassland ecosystems of southern Brazilian highlands by stomach content analysis of 119 individuals. Frogs were collected in ponds surrounded by different grassland habitats. Besides diet composition, diet diversity and volume were explored. Stomach contents were compared among samples from different habitats and collection times. Male, female, and juvenile diets were also compared. A total of 29 prey categories were identified. The most frequent items in the diet of P. cardosoi were: Diptera (15.4%), Coleoptera (14.2%), Hymenoptera (14.3%), plant remains (12.5%), Hemiptera (5.5%), Odonata naiad (2.9%), Isoptera (2.4%), and Araneae (2.3%). There were no significant differences in diet composition among areas. Significant differences in diet composition among males, females, and juveniles were detected, whereas diet diversity and diet volume did not differ significantly among these groups. Diet diversity was higher during spring and summer (January, February and October) and lower in winter (June and July). Certain items showed frequency peaks along the year, suggesting that the diet of P. cardosoi could vary in response to prey temporal dynamics.
Three distinct regions of deletion on 13q in squamous cell carcinoma of the larynx
2006-08-01

Genetic etiology of squamous cell carcinoma of the larynx (SCCL) is very complex, with both molecular and chromosomal alterations involved. The target genes have not yet been clearly identified. Therefore, our study focused on searching for regions that potentially harbor genes related to SCCL. After comparative genomic hybridization (CGH) analysis of a set of 52 SCCL we specified 13q21-q32 and 13q34 as the most frequently deleted regions. In order to precisely map the critical region of deletion, we studied these areas by using 15 microsatellite markers. In our material a significantly high frequency of loss of heterozygosity (LOH) (test for a difference in two proportions, p<0.001) was observed for the following markers: D13S1320 (13q21.1), D13S800 (13q21.3), D13S1818 (13q32.1), D13S770 (13q32.3) and D13S285 (13q34). Three hot spots of LOH were found: 13q21.1-q22.1 (D13S1320-D13S1824-D13S800-SHGC30014- WI-16413-D13S1186), 13q.31.1-13q32.3 (D13S317-D13S1818-D13S770), 13q34 (D13S285). Among these areas, 13q31.1-q32.3 was identified as new hot spot of deletion in SCCLs.
Perception of Elliptic Biological Motion
2006-08-01

We tested the ability of the mature visual system for discrimination between types of elliptic biological motion on the basis of event kinematics. Healthy adult volunteers were presented with point-light displays depicting elliptic motion when only a single dot, a moving point-light arm, or a whole point-light human figure was visible. The displays were created in accordance with the two-thirds power kinematic law ( natural motion), whereas the control displays violated this principle ( unnatural motion). On each trial, participants judged whether the display represented natural or unnatural motion. The findings indicate that adults are highly sensitive to violation of the two-thirds power kinematic law. Notably, participants can easily discriminate between natural and unnatural motions without recognising the stimuli, which suggests that people implicitly use kinematic information. Most intriguing, event recognition seems to diminish the capacity to judge whether event kinematics is unnatural. We discuss possible ways for a cross-talk between perception and production of biological movement, and the brain mechanisms involved in biological motion processing.
Creating and probing long‐range order in atomic clouds
2006-08-01

Abstract Ultracold atoms interacting with the optical modes of a high‐ Q optical ring cavity can synchronize their motion. The collective behavior makes the system interesting for quantum computing applications. This paper is devoted to the study of the collective coupling. We report on the first observation of a collective dynamics and on the realization of a laser, the gain mechanism of which is based on collective atomic recoil. We show that, if the atoms are subject to a friction force, starting from an unordered distribution they spontaneously form a moving density grating. Furthermore, we demonstrate that a 1D atomic density grating can be probed via Bragg scattering. By heterodyning the Bragg‐reflected light with a reference beam, we obtain detailed information on phase shifts induced by the Bragg scattering process.
Aquaporin Water and Solute Channels from Malaria Parasites and Other Pathogenic Protozoa
2006-08-01

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
On the relevance of Compton scattering for the soft X-ray spectra of hot DA white dwarfs
2006-08-01

We re-examine the effects of Compton scattering on the emergent spectra of\\nhot DA white dwarfs in the soft X-ray range. Earlier studies have implied that\\nsensitive X-ray observations at wavelengths \\\\AA might be capable\\nof probing the flux deficits predicted by the redistribution of\\nelectron-scattered X-ray photons toward longer wavelengths. We adopt two\\nindependent numerical approaches to the inclusion of Compton scattering in the\\ncomputation of pure hydrogen atmospheres in hydrostatic equilibrium. One\\nemploys the Kompaneets diffusion approximation formalism, while the other uses\\nthe cross-sections and redistribution functions of Guilbert. Models and\\nemergent spectra are computed for stellar parameters representative of HZ 43\\nand Sirius B, and for models with an effective temperature K. The differences between emergent spectra computed for Compton and\\nThomson scattering cases are completely negligible in the case of both HZ 43\\nand Sirius B models, and are also negligible for all practical purposes for\\nmodels with temperatures as high as K. Models of the\\nsoft X-ray flux from these stars are instead dominated by uncertainties in\\ntheir fundamental parameters.\\n
Simple, Inexpensive, and Precise Paraffin Tissue Microarrays Constructed With a Conventional Microcompound Table and a Drill Grinder
2006-08-01

In 1998, paraffin tissue microarrays (PTMAs) as paraffin blocks containing up to 1,000 cylindrical paraffin tissue core biopsy specimens (PTCBs) for high-throughput molecular profiling of tumor specimens were introduced. PTCBs can be constructed using a manual tissue puncher/arrayer (Beecher Instruments, Sun Prairie, WI; cost, at least 900). In our search for a less expensive alternative, we constructed PTMAs with up to 558 PTCBs by using a drill grinder, a drill stand, and a microcompound table (Proxxon, Niersdorf, Germany; cost, <$300).
Acute Musculoskeletal Infection: Comparison of Different Methods for Intraoperative Bacterial Identification
2006-08-01

PURPOSE OF THE STUDYVarious techniques are used for detection of pathogens in musculoskeletal infection.These methods differ with respect to reliability and ease of handling.A prospective study was performed to evaluate the efficacy of three intraoperative techniques. MATERIAL AND METHODSIn 20 cases (18 patients) with clinically confirmed acute musculoskeletal infections, intraoperative collected swab samples, tissue samples and fluid samples injected into standard blood culture vials were used for microbiological diagnosis.Identification of bacteria, time necessary for detection and ease of handling during surgery was evaluated. RESULTSIn 19 cases bacterial growth was demonstrated using either intraoperative swabs or blood culture technique (95% sensitivity),whereas 18 tissue biopsies were positive (90% sensitivity.27 bacterial species were isolated.In 18 instances for the swab technique, 14 instances for the tissue biopsy and 4 operations for the blood culture vials, ease of handling was rated as excellent. DISCUSSIONThe study demonstrated differences between the three tested methods with respect to ease of handling.With respect to the number of detected organisms and time for their detection there are no significant differences.These last findings are in contrast to of the results of other authors.The reason for this could be that during operative dissection an accurate and specific collection of specimens from the acute deep infected soft tissues and bones independent from the type of surgical procedure is possible.Therefore, even with the swab method a high amount of microorganisms can be recovered.Especially for intraarticular infections, fluid samples injected into standard blood vials is a practical method for the surgeon.In acute musculoskeletal infections other than joint infections, there is less benefit for the blood culture vials. CONCLUSIONIntraoperative swab technique yields valid results comparable to other techniques and is an accurate technique for detection of pathogens from acute musculoskeletal infections.
Two‐dimensional Bose‐Einstein condensates in a CO2‐laser optical lattice
2006-08-01

Abstract We report on experiments with all‐optically produced Bose‐Einstein condensates in a mesoscopic optical lattice. By retroreflecting the radiation of a CO 2 ‐laser operating near 10.6 μm, a lattice with spacing between sites of λ /2 ≃ 5.3 μm is realized, for which atom tunneling is negligible. Once cooled to quantum degeneracy by direct evaporative cooling in the lattice, the properties of the trapped microclouds can be studied with far field interference experiments. The microscopic atom clouds are shown to be in the two‐dimensional regime for small atom filling. The realized system has extremely long coherence times, and holds fascinating prospects for both quantum logic and the study of novel collective phenomena.
Acute musculoskeletal infection: comparison of different methods for intraoperative bacterial identification.
2006-08-01

Intraoperative swab technique yields valid results comparable to other techniques and is an accurate technique for detection of pathogens from acute musculoskeletal infections. Key words: implant, infections, bacteriological techniques, comparative study.
Reconstructive urology
2006-08-01

Purpose: We present our short-term results of abdominal transpubic perineal urethroplasty for complex posterior urethral disruption.Materials and Methods: From January 2000 to March 2005, 21 patients with complex posterior urethral disruption underwent abdominal transpubic perineal urethroplasty.Complex disruption was defined as stricture gap exceeding 3 cm or associated perineal fistulas, rectourethral fistulas, periurethral cavities, false passages, an open bladder neck or previous failed repair.Preoperative voiding cystourethrogram with retrograde urethrogram and cystourethroscopy were done to evaluate the stricture and bladder neck.Followup consisted of symptomatic assessment and voiding cystourethrogram.Results: There were 11 adults and 10 prepubescent boys with an average age of 26 years (range 6 to 62).Mean followup +/-SD was 28 months (range 9 to 40).Mean stricture length was 5.2 +/-1.4 cm.Of the 21 patients 12 had previously undergone failed urethroplasty.The mean period between original trauma/failed repair and definitive repair was 10.2 +/-4.3 months.Urethroplasty was achieved through the subpubic route in 16 patients, while 5 required supracrural rerouting.In 20 of 21 patients (95%) postoperative cystourethrography showed a wide, patent anastomosis.Postoperative incontinence developed in 2 of 21 patients (9.5%).Seven of the 21 patients (33%) were impotent after the primary injury, while 3 of 14 (21.4%) had impotence postoperatively.There were no complications related to pubic resection, bowel herniation or periurethral cavity recurrence.Conclusions: Combined abdominal transpubic perineal urethroplasty is a safe procedure in children and adults.It allows wide exposure to create a tension-free urethral anastomosis without significantly affecting continence or potency.Complications of pubic resection are now rarely seen.
Caspase-3-dependent Activation of Calcium-independent Phospholipase A2 Enhances Cell Migration in Non-apoptotic Ovarian Cancer Cells
2006-08-02

Calcium-independent phospholipase A(2) (iPLA(2)) plays a pivotal role in phospholipid remodeling and many other biological processes, including inflammation and cancer development. iPLA(2) can be activated by caspase-3 via a proteolytic process in apoptotic cells. In this study we identify novel signaling and functional loops of iPLA(2) activation leading to migration of non-apoptotic human ovarian cancer cells. The extracellular matrix protein, laminin-10/11, but not collagen I, induces integrin- and caspase-3-dependent cleavage and activation of overexpressed and endogenous iPLA(2). The truncated iPLA(2) (amino acids 514-806) generates lysophosphatidic acid and arachidonic acid. Arachidonic acid is important for enhancing cell migration toward laminin-10/11. Lysophosphatidic acid activates Akt that in turn acts in a feedback loop to block the cleavage of poly-(ADP-ribose) polymerase and DNA fragmentation factor as well as prevent apoptosis. By using pharmacological inhibitors, blocking antibodies, and genetic approaches (such as point mutations, dominant negative forms of genes, and siRNAs against specific targets), we show that beta(1), but not beta(4), integrin is involved in iPLA(2) activation and cell migration to laminin-10/11. The role of caspase-3 in iPLA(2) activation and cell migration are supported by several lines of evidence. 1) Point mutation of Asp(513) (a cleavage site of caspase-3 in iPLA(2)) to Ala blocks laminin-10/11-induced cleavage and activation of overexpressed iPLA(2), whereas mutation of Asp(733) to Ala has no such effect, 2) treatment of inhibitors or a small interfering RNA against caspase-3 results in decreased cell migration toward laminin-10/11, and 3) selective caspase-3 inhibitor blocks cleavage of endogenous iPLA(2) induced by laminin-10/11. Importantly, small interfering RNA-mediated down-regulation of endogenous iPLA(2) expression in ovarian carcinoma HEY cells results in decreased migration toward laminin, suggesting that our findings are pathophysiologically important.
4-[5-(4-Fluorophenyl)-3-isopropylisoxazol-4-yl]pyridine
2006-08-02

In the title compound, C17H15FN2O, the exocyclic bond angles at the C atoms of the isoxazole ring bearing the pyridyl and 4-fluorophenyl substituents are 129.66 (17) and 134.58 (16)°, respectively. The structure was determined in a study of the molecular geometry of isoxazole derivatives with biological activity as MAPK inhibitors.
A Functional dlt Operon, Encoding Proteins Required for Incorporation of d -Alanine in Teichoic Acids in Gram-Positive Bacteria, Confers Resistance to Cationic Antimicrobial Peptides in Streptococcus pneumoniae
2006-08-03

ABSTRACT Streptococcus pneumoniae is one of the few species within the group of low-G +C gram-positive bacteria reported to contain no d -alanine in teichoic acids, although the dltABCD operon encoding proteins responsible for d -alanylation is present in the genomes of two S. pneumoniae strains, the laboratory strain R6 and the clinical isolate TIGR4. The annotation of dltA in R6 predicts a protein, d -alanine- d -alanyl carrier protein ligase (Dcl), that is shorter at the amino terminus than all other Dcl proteins. Translation of dltA could also start upstream of the annotated TTG start codon at a GTG, resulting in the premature termination of dltA translation at a stop codon. Applying a novel integrative translation probe plasmid with Escherichia coli ′ lacZ as a reporter, we could demonstrate that dltA translation starts at the upstream GTG. Consequently, S. pneumoniae R6 is a dltA mutant, whereas S. pneumoniae D39, the parental strain of R6, and Rx, another derivative of D39, contained intact dltA genes. Repair of the stop codon in dltA of R6 and insertional inactivation of dltA in D39 and Rx yielded pairs of dltA -deficient and dltA -proficient strains. Subsequent phenotypic analysis showed that dltA inactivation resulted in enhanced sensitivity to the cationic antimicrobial peptides nisin and gallidermin, a phenotype fully consistent with those of dltA mutants of other gram-positive bacteria. In addition, mild alkaline hydrolysis of heat-inactivated whole cells released d -alanine from dltA -proficient strains, but not from dltA mutants. The results of our study suggest that, as in many other low-G+C gram-positive bacteria, teichoic acids of S. pneumoniae contain d -alanine residues in order to protect this human pathogen against the actions of cationic antimicrobial peptides.
Ammonia permeability of the aquaglyceroporins from Plasmodium falciparum, Toxoplasma gondii and Trypansoma brucei
2006-08-03

Summary Plasmodium falciparum uses amino acids from haemoglobin degradation mainly for protein biosynthesis. Glutamine, however, is mostly oxidized to 2‐oxoglutarate to restore NAD(P)H + H + . In this process two molecules of ammonia are released. We determined an ammonia production of 9 mmol h −1 per litre of infected red blood cells in the early trophozoite stage. External application of ammonia yielded a cytotoxic IC 50 concentration of 2.8 mM. As plasmodia cannot metabolize ammonia it must be exported. Yet, no biochemical or genomic evidences exist that plasmodia possess classical ammonium transporters. We expressed the P. falciparum aquaglyceroporin (PfAQP) in Xenopus laevis oocytes and examined whether it may serve as an exit pathway for ammonia. We show that injected oocytes: (i) acidify the medium due to ammonia uptake, (ii) take up [ 14 C]methylamine and [ 14 C]formamide, (iii) swell in solution with formamide and acetamide and (iv) display an ammonia‐induced NH 4 + ‐dependent clamp current. Further, a yeast strain lacking the endogenous aquaglyceroporin (Fps1) is rescued by expression of PfAQP which provides for the efflux of toxic methylamine. Ammonia permeability was similarly established for the aquaglyceroporins from Toxoplasma gondii and Trypanosoma brucei . Apparently, these aquaglyceroporins are important for the release of ammonia derived from amino acid breakdown.