bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serial Founder Effects During Range Expansion: A Spatial Analog of Genetic Drift
Authors: Slatkin Montgomery , Excoffier Laurent 
Published: February 2012

Abstract
Range expansions cause a series of founder events. We show that, in a one-dimensional habitat, these founder events are the spatial analog of genetic drift in a randomly mating population. The spatial series of allele frequencies created by successive founder events is equivalent to the time series of allele frequencies in a population of effective size ke, the effective number of founders. We derive an expression for ke in a discrete-population model that allows for local population growth and migration among established populations. If there is selection, the net effect is determined approximately by the product of the selection coefficients and the number of generations between successive founding events. We use the model of a single population to compute analytically several quantities for an allele present in the source population: (i) the probability that it survives the series of colonization events, (ii) the probability that it reaches a specified threshold frequency in the last population, and (iii) the mean and variance of the frequencies in each population. We show that the analytic theory provides a good approximation to simulation results. A consequence of our approximation is that the average heterozygosity of neutral alleles decreases by a factor of 1 – 1/(2ke) in each new population. Therefore, the population genetic consequences of surfing can be predicted approximately by the effective number of founders and the effective selection coefficients, even in the presence of migration among populations. We also show that our analytic results are applicable to a model of range expansion in a continuously distributed population.
Homologous Recombination via Synthesis-Dependent Strand Annealing in Yeast Requires the Irc20 and Srs2 DNA Helicases
Authors: Miura Tohru , Yamana Yoshimasa , Usui Takehiko , Ogawa Hiroaki I , Yamamoto Masa-Toshi , Kusano Kohji 
Published: February 2012

Abstract
Synthesis-dependent strand-annealing (SDSA)-mediated homologous recombination replaces the sequence around a DNA double-strand break (DSB) with a copy of a homologous DNA template, while maintaining the original configuration of the flanking regions. In somatic cells at the 4n stage, Holliday-junction-mediated homologous recombination and nonhomologous end joining (NHEJ) cause crossovers (CO) between homologous chromosomes and deletions, respectively, resulting in loss of heterozygosity (LOH) upon cell division. However, the SDSA pathway prevents DSB-induced LOH. We developed a novel yeast DSB-repair assay with two discontinuous templates, set on different chromosomes, to determine the genetic requirements for somatic SDSA and precise end joining. At first we used our in vivo assay to verify that the Srs2 helicase promotes SDSA and prevents imprecise end joining. Genetic analyses indicated that a new DNA/RNA helicase gene, IRC20, is in the SDSA pathway involving SRS2. An irc20 knockout inhibited both SDSA and CO and suppressed the srs2 knockout-induced crossover enhancement, the mre11 knockout-induced inhibition of SDSA, CO, and NHEJ, and the mre11-induced hypersensitivities to DNA scissions. We propose that Irc20 and Mre11 functionally interact in the early steps of DSB repair and that Srs2 acts on the D-loops to lead to SDSA and to prevent crossoverv.
Preparation and Rheocasting of Semi-solid Aluminum-alloy Slurry with Indirect Ultrasonic Vibration Process
Authors: Wu Shusen , Lü Shulin , An Ping , Zhu Zeming 
Published: February 2012

ABSTRACTDirect ultrasonic vibration (DUV) method by dipping the horn into the melt can be used to make semi-solid metal slurry, but application of this process is embarrassed because of the erosion problem of titanium-alloy horn by aluminum melt. In order to avoid this problem, a slurry-making process with indirect ultrasonic vibration (IUV), in which the horn is vibrated under the outside of the metallic cup containing alloy melt, has been developed in this research. Semisolid slurry of A356 Al alloy was prepared by this process, and the effects of IUV treatment time on the morphology of the primary α-Al phase and mechanical properties of rheo-diecasting samples were studied. The results indicate that excellent semisolid slurry of A356 Al alloy could be obtained within 50s by applying IUV near its liquidus temperature, and the average diameter and shape coefficient of the primary α-Al particles were 75μm and 0.62, respectively. IUV treatment time had a significant effect on the mechanical properties of the rheo-diecasting samples, and samples treated by IUV for 50s had the maximum tensile strength and elongation. The maximum as-cast tensile strength and elongation were 244MPa and 7.5% respectively, which were increased by 10% and 75% respectively compared to conventional molten-melt die-casting samples. In addition, the mechanism of preparing semisolid slurry of A356 Al alloy by IUV is discussed.
Characterization of multimetallic nanomaterial obtained from cyanidation solutions.
Authors: Soria-Aguilar M. , Carrillo-Pedroza F. , García-Cerda L.A. , Sanchez-Castillo M. , Dávalos-Sánchez A. , Puente-Siller D. 
Published: February 2012

ABSTRACTThe cyanide is the main process for the extraction of gold from its ores. This process produces rich cyanide solutions containing gold and silver, and waste cyanide solutions with different metal compounds such as copper, zinc and iron. These elements or compounds can be extracted in the form of high-value compounds as nanoparticles. This work presents some result of the remove and recovery of metallic values from waste cyanide solutions to obtain novel metallic nanoparticles. These materials were obtaining by modified sol-gel method from an industrial cyanide waste solution previously treated by advanced oxidation. This work reports the characterization from the nanoparticles by DRX and SEM-EDX. The results indicate that multimetallic nanoparticles can be obtained from cyanidation effluents.
Empirical Model to Estimate Mn2+ Precipitation Rate from a Leaching Solution Using SO2/O2 as Oxidizing Agent
Authors: Bello-Teodoro S. , Pérez-Garibay R. 
Published: February 2012

ABSTRACTA method, based in leaching with SO2, to process low grade pyrolusite minerals has shown good results at laboratory scale. After the separation of the solid impurities, the dissolved manganese is subsequently precipitated using the SO2/O2 gas mixture as oxidising agent. In this research it was obtained a mathematical model to estimate the oxidative precipitation process, as a function of temperature, pH and SO2 gas flow rate. It was found that pH and temperature have the main influence in the reaction rate. An optimal SO2 concentration in the mixture must be used to avoid generation of reductive conditions. It was observed a most efficient reaction with a low gas flow rate injection. The predicted reaction rates presents a good concordance with the experimental results (R2=0.97), showing a worthy potential for practical uses.
Strategies of Materials Industry to Changes of Metallic Mineral Resources and Environment of the Earth
Authors: Wu Yu 
Published: February 2012

ABSTRACTWith the impending depletion of mineral resources and a worsening environment, the need to enhance energy efficiency and reduce emission of CO2 gas has become a serious global issue. This paper discusses the current condition of metallic ore resources, then lays emphasis on the counter measure of metallic materials processing. The principal metallic materials are iron and aluminum, and in the scrap of these materials there contains metallic resources and deposited huge energy. Through the recycling of the scrap metal, we can reduce the energy consumption on the extraction of these materials and decrease the emission of CO2 gas. The energy consumed in manufacturing products by using reclaimed raw aluminum is only 4.9% of that using new raw materials, and as for iron and steel, the data is 40.7%. In the manufacturing of metal components, while the impurity element content is rigorously restricted in the plastic forming method, the casting method has a much larger permissible range. Thus, remelting and casting is a more appropriate method in the recycling of metallic materials.
Phase II Study of Sequential Gemcitabine Followed by Docetaxel for Recurrent Ewing Sarcoma, Osteosarcoma, or Unresectable or Locally Recurrent Chondrosarcoma: Results of Sarcoma Alliance for Research Through Collaboration Study 003
Authors: Fox Elizabeth , Patel Shreyaskumar , Wathen J. Kyle , Schuetze Scott , Chawla Sant , Harmon David , Reinke Denise , Chugh Rashmi , Benjamin Robert S. , Helman Lee J. 
Published: February 2012

Abstract

Background.
Gemcitabine and docetaxel have a broad spectrum of clinical activity in patients with carcinoma. The Sarcoma Alliance for Research Through Collaboration conducted a phase II trial of gemcitabine in combination with docetaxel in children and adults with recurrent Ewing sarcoma (EWS), osteosarcoma (OS), or unresectable or recurrent chondrosarcoma. The primary objective was to determine the objective response rate using Response Evaluation Criteria in Solid Tumors (RECIST).

Methods.
Gemcitabine (675 mg/m2 i.v. over 90 minutes on days 1 and 8) was administered in combination with docetaxel (75 mg/m2 i.v. over 1 hour on day 8) every 21 days. All patients received filgrastim or pegfilgrastim. A Bayesian formulation was used to determine the probability of achieving the target response rate for each subtype—0.35 for EWS and OS or 0.20 for chondrosarcoma. If the probability of achieving the target response rate was &lt;0.05, the combination was considered inactive. Toxicity was graded according to Common Terminology Criteria for Adverse Events (CTCAE), version 3.0.

Results.
Fifty-three eligible patients were enrolled in the three subtype groups—OS (n = 14), EWS (n = 14), and chondrosarcoma (n = 25). Toxicities included neutropenia, thrombocytopenia, fatigue, dyspnea, bronchospasm, edema, neuropathy, and liver function abnormalities. Dose modification for toxicity was required for eight patients during cycle 1 and 16 patients in subsequent cycles. Seven patients withdrew from therapy as a result of toxicity. No complete responses were observed. Partial responses were observed in OS (n = 1), EWS (n = 2), and chondrosarcoma (n = 2) patients.

Conclusion.
Gemcitabine in combination with docetaxel was associated with a probability of reaching the target 35% response rate of &lt;5% in OS patients and 5.6% in EWS patients; the probability of reaching a 20% response rate in chondrosarcoma patients was 14%.
First-Line Cetuximab Plus Capecitabine in Elderly Patients with Advanced Colorectal Cancer: Clinical Outcome and Subgroup Analysis According toKRASStatus from a Spanish TTD Group Study
Authors: Sastre Javier , Grávalos Cristina , Rivera Fernando , Massuti Bartomeu , Valladares-Ayerbes Manuel , Marcuello Eugenio , Manzano José L. , Benavides Manuel , Hidalgo Manuel , Díaz-Rubio Eduardo , Aranda Enrique 
Published: February 2012

AbstractSingle-agent cetuximab is safe and active in elderly patients with advanced colorectal cancer (CRC). A cetuximab–capecitabine combination has not previously been tested in elderly patients with advanced CRC.Material and Methods.Sixty-six patients with advanced CRC were treated with cetuximab as a 400 mg/m2 i.v. infusion followed by 250 mg/m2 i.v. weekly plus capecitabine at a dose of 1,250 mg/m2 every 12 hours. After the inclusion of 27 patients, the protocol was amended for safety reasons, reducing the dose of capecitabine to 1,000 mg/m2 every 12 hours. Thirty-nine additional patients were treated with the reduced dose of capecitabine.Results.The overall response rate was 31.8%. KRAS status was determined in 58 patients (88%). Fourteen of 29 patients with wild-type KRAS tumors responded (48.3%; 95% confidence interval [CI], 29.4%–67.5%), compared with six of 29 patients with mutant KRAS tumors (20.7%; 95% CI, 8.0%–39.7%). The median progression-free survival (PFS) interval was 7.1 months. The median PFS interval for patients whose tumors were wild-type KRAS was significantly longer than for those with mutant KRAS tumors (8.4 months versus 6.0 months; p = .024). The high incidence of severe paronychia (29.6%) declined (7.7%) after capecitabine dose adjustment.Conclusions.Cetuximab plus capecitabine at a dose of 1,000 mg/m2 every 12 hours may be an alternative to more aggressive regimens in elderly patients with advanced wild-type KRAS CRC.
Autophagy favors Brucella melitensis survival in infected macrophages
Authors: Guo Fei , Zhang Hui , Chen Chuangfu , Hu Shengwei , Wang Yuanzhi , Qiao Jun , Ren Yan , Zhang Ke , Wang Yong , Du Guoqing 
Published: February 2012

AbstractThis study investigated the role of autophagy in the survival of the invasive bacterium Brucella melitensis strain 16M in murine macrophages. Here, Brucella melitensis 16M was found to trigger autophagosome formation, enhance autophagy flux and increase the expression level of the autophagy marker protein LC3-II. When autophagy was pharmacologically inhibited by 3-methyladenine (3-MA), Brucella replication efficiency was significantly decreased (p < 0.05). These results suggest that autophagy favors Brucella melitensis 16M survival in murine macrophages.
New records of parasitic copepods (Crustacea, Copepoda) from marine fishes in the Argentinean Sea
Authors: Paula Cantatore , Elizabeth Braicovich , Julia Alarcos , Laura Lanfranchi , Alejandra Rossin , Gustavo Vales , Tomás Timi 
Published: February 2012

AbstractIncreasing knowledge of the biodiversity of parasitic copepods in the Argentinean Sea will provide a baseline against which changes in the distribution of marine biota can be detected. We provide new information on the distribution of 13 known species of parasitic copepods gathered from 11 species of marine fishes from Argentinean Sea, including 7 new host records and 9 new locality records. These species are: Bomolochus globiceps (Vervoort et Ramírez, 1968) and Nothobomolochus cresseyi Timi et Sardella, 1997 (Bomolochidae Sumpf, 1871); Brasilochondria riograndensis Thatcher et Pereira, 2004 (Chondracanthidae Milne Edwards, 1840); Taeniacanthus lagocephali Pearse, 1952 (Taeniacanthidae Wilson, 1911); Caligus rogercresseyi Boxshall et Bravo, 2000 and Metacaligus uruguayensis (Thomsen, 1949) (Caligidae Burmeister, 1835); Hatschekia conifera Yamaguti, 1939 (Hatschekiidae Kabata, 1979); Clavellotis pagri (Krøyer, 1863), Clavella adunca (Strøm, 1762), Clavella bowmani Kabata, 1963 and Parabrachiella amphipacifica Ho, 1982 (Lernaeopodidae Milne Edwards, 1840), and Lernanthropus leidyi Wilson, 1922 and Lernanthropus caudatus Wilson, 1922 (Lernanthropidae Kabata, 1979). A list of host species lacking parasitic copepods, for which large samples were investigated by the authors, is also provided in order to compare in future surveys.
Chewing lice (Phthiraptera) from wild birds in Senegal, with descriptions of three new species of the genera Brueelia and Philopteroides
Authors: Najer Tomáš , Sychra Oldřich , Literák Ivan , Procházka Petr , Čapek Miroslav , Koubek Petr 
Published: February 2012

AbstractA total of 170 wild birds from Senegal, belonging to 48 species and 9 orders, were searched for lice in 2005 and 2007. Chewing lice were found on 58 birds of 18 species and 5 orders (Columbiformes, Cuculiformes, Coraciiformes, Galliformes and Passeriformes). Twenty-two species of chewing lice of 13 genera were determined. Other nine samples of chewing lice that represent a new host-parasite association were determined at generic level only, because only one sex or nymph of these lice were found. Our records represent the first louse records from passerines Camaroptera brachyura (Cisticolidae), Chalcomitra senegalensis (Nectariniidae), Corvinella corvina (Laniidae), Laniarius barbarus (Malaconotidae), Prinia erythroptera (Cisticolidae) and Turdus pelios (Turdidae). Descriptions and illustrations are given for Brueelia chalcomitrae Najer et Sychra sp. nov. ex Chalcomitra senegalensis (Nectariniidae), Brueelia priniae Najer et Sychra sp. nov. ex Prinia subflava (Cisticolidae), and Philopteroides terpsiphoni Najer et Sychra sp. nov. ex Terpsiphone viridis (Monarchidae).
Seroprevalence of Toxoplasma gondii and Neospora caninum in dogs from Korea
Authors: Nguyen Thuy , Choe Se-Eun , Byun Jae-Won , Koh Hong-Bum , Lee Hee-Soo , Kang Seung-Won 
Published: February 2012

AbstractToxoplasma gondii and Neospora caninum are closely related protozoan parasites, they share many common hosts, and can cause neurological diseases in dogs. Dogs can have close contacts with humans and livestock and therefore they can act as reservoirs of these parasites. The aim of this study was to survey the seroprevalence of antibodies against T. gondii and N. caninum and their co-infection rate in dogs in Korea. In total, sera from 553 domestic dogs were collected from different breeds, sexes, and ages of dogs from nine provinces across the country of Korea during 2006 and 2007. The presence of antibodies against T. gondii and N. caninum was analyzed using the latex agglutination test (LAT) with a cut-off value of 1:32, and the indirect fluorescent antibody test (IFAT) using a serum titer of 1:100. In the total dog population, 71 (12.8%) dogs were positive for anti-T. gondii antibodies and only 20 (3.6%) were positive for anti-N. caninum antibodies. Relatively higher seropositive frequencies of antibodies against T. gondii (20.1%) and N. caninum (4.9%) were detected in the dog population from the Gyeonggi. A higher proportion of animals seropositive for anti-T. gondii antibodies was found in stray dog populations as compared to household dog populations: 18.5% (59/319) vs 5.1% (12/234), respectively. The Chi-square tests revealed significant differences in the seropositive frequencies of antibodies against T. gondii between stray and household dogs in the total population (p<0.0001), and in dogs from the Gyeonggi (p<0.01). No significant differences were observed for the presence of antibodies against T. gondii or N. caninum when compared across the sex or age (p>0.05). The first serological survey on antibodies against both T. gondii and N. caninum parasites across the entire country showed that co-infection was not common in these canine populations with a seropositive level of 0.72%. The significantly higher positive frequency of T. gondii antibodies in stray dogs in both, Gyeonggi and in the total dog populations suggests that further investigation on the seroprevalence of parasites should focus on stray dogs.
Staged resection of large vestibular schwannomas
Authors: Raslan Ahmed M. , Liu James K. , McMenomey Sean O. , Delashaw Johnny B. 
Published: February 2012

Object
Staged resection of large vestibular schwannomas (VSs) has been proposed as a strategy to improve facial nerve outcomes and morbidity. The authors report their experience with 2-stage resections of large VSs and analyze the indications, facial nerve outcomes, surgical results, and complications. The authors compare these results with those of a similar cohort of patients who underwent a single-stage resection.

Methods
A retrospective review of all patients (age > 18 years) who underwent surgery from 2002 to 2010 for large (≥ 3 cm) VSs at the authors' institution with a minimum of 6 months follow-up was undertaken. A first-stage retrosigmoid approach (without meatal drilling) was performed to remove the cerebellopontine angle portion of the tumor and to decompress the brainstem. A decision to stage the operation was made intraoperatively if there was cerebellar or brainstem edema, excessive tumor adherence to the facial nerve or brainstem, a poorly stimulating facial nerve, or a thinned or splayed facial nerve. A second-stage translabyrinthine approach was performed at a later date to remove the remaining tumor. The single-stage resection consisted of a retrosigmoid approach with meatal drilling. Patient charts were evaluated for tumor size, extent of resection, tumor recurrence, House-Brackmann facial nerve function grade, and complications.

Results
Twenty-eight and 19 patients underwent 2- or single-stage resection of a large VS, respectively. The average tumor size was 3.9 cm (range 3.2–7 cm) in the 2-stage group and 3.9 cm (range 3.1–5 cm) in the single-stage group. The mean follow-up was 36 ± 19 months in the 2-stage group versus 24 ± 14 months in the single-stage group. Gross-total or near-total resection was achieved in 27 (96.4%) of 28 patients in the 2-stage group and 15 (79%) of 19 patients in the single-stage group (p < 0.01). Anatomical facial nerve preservation was achieved in all but 1 patient (94.7%), and there were no recurrences on follow-up imaging in the 2-stage group. Good facial nerve functional outcome (House-Brackmann Grades I and II) at last follow-up was achieved in 23 (82%) of 28 patients in the 2-stage group and 10 (53%) of 19 patients in the single-stage group (p < 0.01). Cerebrospinal fluid leak–related complications (intracranial hypotension, blood patch, and lumboperitoneal shunt for pseudomeningocele) were more common in the 2-stage group. There were no postoperative strokes, hemorrhages, or deaths in either group.

Conclusions
The authors' results suggest that staged resection of large VSs may potentially achieve better facial nerve outcomes. There does not appear to be added neurological morbidity with staged resections.
Intramedullary recurrence of germinoma in the spinal cord 15 years after complete remission of a pineal lesion
Authors: Hanakita Shunya , Takenobu Atumi , Kambe Atsushi , Watanabe Takashi , Shin Masahiro , Teraoka Akira 
Published: February 2012

The authors present a case of germinoma that was initially found in the pineal region and recurred 15 years later in the intramedullary cervical spinal cord after intensive chemo- and radiotherapy and diagnosis of complete remission.
This 28-year-old man initially presented with seizures. Hydrocephalus and a pineal tumor were found on radiological examination, and partial resection of the tumor was performed. Histological diagnosis showed a pure germinoma. Following surgery, the patient received a combination of chemo- and radiotherapy, and a complete remission was shown. However, after 15 years of follow-up, he presented with gait disturbances. Spinal MRI showed an intramedullary mass lesion in the cervical spinal cord. The cervical lesion was biopsied, and histological examination again revealed a pure germinoma.
With germinomas, the possibility of a drop metastasis from an intracranial lesion to the spinal cord must be considered during follow-up. However, in the present case, analysis of a CSF sample showed no abnormalities as in previously published cases. In recent years, multidisciplinary treatments have demonstrated good event-free survival rates in cases of pure germinomas, but long-term outcomes over the decades are not fully known. Continual follow-up of such cases is recommended even after complete remission has been achieved.