bluuebunny/crossref_metadata_2025 huggingface dataset:
Does catch and release affect the mating system and individual reproductive success of wild Atlantic salmon (Salmo salar L.)?
Authors: Richard Antoine , Dionne Mélanie , Wang Jinliang , Bernatchez Louis
Published: November 2012

In this study, we documented the breeding system of a wild population of Atlantic salmon (Salmo salar L.) by genetically sampling every returning adult and assessed the determinants of individual fitness. We then quantified the impacts of catch and release (C&R) on mating and reproductive success. Both sexes showed high variance in individual reproductive success, and the estimated standardized variance was higher for males (2.86) than for females (0.73). We found a weak positive relationship between body size and fitness and observed that fitness was positively correlated with the number of mates, especially in males. Mature male parr sired 44% of the analysed offspring. The impact of C&R on the number of offspring was size dependent, as the reproductive success of larger fish was more impaired than smaller ones. Also, there was an interactive negative effect of water temperature and air exposure time on reproductive success of C&R salmon. This study improves our understanding of the complex reproductive biology of the Atlantic salmon and is the first to investigate the impact of C&R on reproductive success. Our study expands the management toolbox of appropriate C&R practices that promote conservation of salmon populations and limit negative impacts on mating and reproductive success.
A question of time: the land snailMurella muralis(Gastropoda:Pulmonata) reveals constraints on past ecological speciation
Authors: Fiorentino V. , Manganelli G. , Giusti F. , Tiedemann R. , Ketmaier V.
Published: November 2012

The lively debate about speciation currently focuses on the relative importance of factors driving population differentiation. While many studies are increasingly producing results on the importance of selection, little is known about the interaction between drift and selection. Moreover, there is still little knowledge on the spatial‐temporal scales at which speciation occurs, that is, arrangement of habitat patches, abruptness of habitat transitions, climate and habitat changes interacting with selective forces. To investigate these questions, we quantified variation on a fine geographical scale analysing morphological (shell) and genetic data sets coupled with environmental data in the land snailMurella muralis, endemic to theMediterranean island ofSicily. Analysis of a fragment of the mitochondrialDNAcytochrome oxidaseIgene (COI) and eight nuclear microsatellite loci showed that genetic variation is highly structured at a very fine spatial scale by local palaeogeographical events and historical population dynamics. Molecular clock estimates, calibrated here specifically forTyrrhenian land snails, provided a framework of palaeogeographical events responsible for the observed geographical variations and migration routes. Finally, we showed for the first time well‐documented lines of evidence of selection in the past, which explains divergence of land snail shell shapes. We suggest that time and palaeogeographical history acted as constraints in the progress along the ecological speciation continuum. Our study shows that testing for correlation among palaeogeography, morphology and genetic data on a fine geographical scale provides information fundamental for a detailed understanding of ecological speciation processes.
Glycoengineering of host mimicking type‐2 LacNAc polymers and Lewis X antigens on bacterial cell surfaces
Authors: Mally Manuela , Fontana Carolina , LeibundGut‐Landmann Salomé , Laacisse Lamia , Fan Yao‐Yun , Widmalm Göran , Aebi Markus
Published: November 2012

Bacterial carbohydrate structures play a central role in mediating a variety of host–pathogen interactions. Glycans can either elicit protective immune response or lead to escape of immune surveillance by mimicking host structures. Lipopolysaccharide (LPS), a major component on the surface of Gram‐negative bacteria, is composed of a lipid A‐core and the O‐antigen polysaccharide. Pathogens like Neisseria meningitidis expose a lipooligosaccharide (LOS), which outermost glycans mimick mammalian epitopes to avoid immune recognition. Lewis X (Galβ1–4(Fucα1–3)GlcNAc) antigens of Helicobacter pylori or of the helminth Schistosoma mansoni modulate the immune response by interacting with receptors on human dendritic cells. In a glycoengineering approach we generate human carbohydrate structures on the surface of recombinant Gram‐negative bacteria, such as Escherichia coli and Salmonella enterica sv. Typhimurium that lack O‐antigen. A ubiquitous building block in mammalian N‐linked protein glycans is Galβ1‐4GlcNAc, referred to as a type‐2 N‐acetyllactosamine, LacNAc, sequence. Strains displaying polymeric LacNAc were generated by introducing a combination of glycosyltransferases that act on modified lipid A‐cores, resulting in efficient expression of the carbohydrate epitope on bacterial cell surfaces. The poly‐LacNAc scaffold was used as an acceptor for fucosylation leading to polymers of Lewis X antigens. We analysed the distribution of the carbohydrate epitopes by FACS, microscopy and ELISA and confirmed engineered LOS containing LacNAc and Lewis X repeats by MALDI‐TOF and NMR analysis. Glycoengineered LOS induced pro‐inflammatory response in murine dendritic cells. These bacterial strains can thus serve as tools to analyse the role of defined carbohydrate structures in different biological processes.
Kinematic performance of fine motor control in attention‐deficit/hyperactivity disorder: The effects of comorbid developmental coordination disorder and core symptoms
Authors: Lee I‐Ching , Chen Yung‐Jung , Tsai Chin‐Liang
Published: November 2012

Background

The aims of this study were: (i) to determine whether differences exist in the fine motor fluency and flexibility of three groups (children with attention‐deficit/hyperactivity disorder [ADHD], children in whomADHDis comorbid with developmental coordination disorder [DCD] [denoted asADHD+DCD], and a typically developing control group); and (ii) to clarify whether the degree of severity of core symptoms affects performance.

Methods

ThePeabodyPictureVocabularyTest‐Revised, theBeery–BuktenicaDevelopmentTest ofVisual‐MotorIntegration and theMovementAssessmentBattery forChildren were used as prescreening tests. TheIntegratedVisual andAuditory+Plus test was utilized to assess subjects' attention. The redesigned fine motor tracking and pursuit tasks were administered to evaluate subjects' fine motor performance.

Results

No significant difference was found when comparing the performance of theChildren withADHDand the typically developing group. Significant differences existed between children in whomADHDis comorbid withDCDand typically developing children.

Conclusions

Children withADHDdemonstrated proper fine motor fluency and flexibility, and deficient performance occurred whenADHDwas comorbid with developmental coordination disorder. Children withADHDhad more difficulty implementing closed‐loop movements that required higher levels of cognitive processing than those of their typically developing peers. Also, deficits in fine motor control were more pronounced whenADHDwas combined with movement coordination problems. The severity of core symptoms had a greater effect on children with ADHD's fine motor flexibility than did fluency performance. In children with pureADHD, unsmooth movement performance was highly related to the severity of core symptoms.
High Strain Rate Pure Shear and Axial Compressive Response of Porcine Lung Tissue
Authors: Sanborn B. , Nie X. , Chen W. , Weerasooriya T.
Published: November 2012

In this study, both the dynamic shear (torsion) and axial compressive responses of porcine lung tissue were examined using modified Kolsky bar techniques. High-rate compression data were collected using a Kolsky bar with a hollow transmission bar on annular specimens at strain rates between 1000–3000 s−1. The radial deformation of the annular specimen was recorded on a modified single loading Kolsky bar using high-speed imaging capabilities. The collected images and analysis of boundary movement indicated inhomogeneous specimen deformation induced by radial inertia, which significantly altered the desired uniaxial stress state in such high-rate compression test techniques. A novel torsion experimental technique was developed to obtain the dynamic pure shear behavior of lung tissue at shear strain rates above 500 s−1 without inertia effects. The pure shear response was found to be two orders of magnitude weaker than the uniaxial compressive response when compared by equivalent stress–strain relations.
A Two-Scale Computational Model of pH-Sensitive Expansive Porous Media
Authors: Ponce F. Ranena V. , Murad Márcio A. , Lima Sidarta A.
Published: November 2012

We propose a new two-scale model to compute the swelling pressure in colloidal systems with microstructure sensitive to pH changes from an outer bulk fluid in thermodynamic equilibrium with the electrolyte solution in the nanopores. The model is based on establishing the microscopic pore scale governing equations for a biphasic porous medium composed of surface charged macromolecules saturated by the aqueous electrolyte solution containing four monovalent ions (Na+,Cl-,H+,OH-). Ion exchange reactions occur at the surface of the particles leading to a pH-dependent surface charge density, giving rise to a nonlinear Neumann condition for the Poisson–Boltzmann problem for the electric double layer potential. The homogenization procedure, based on formal matched asymptotic expansions, is applied to up-scale the pore-scale model to the macroscale. Modified forms of Terzaghi's effective stress principle and mass balance of the solid phase, including a disjoining stress tensor and electrochemical compressibility, are rigorously derived from the upscaling procedure. New constitutive laws are constructed for these quantities incorporating the pH-dependency. The two-scale model is discretized by the finite element method and applied to numerically simulate a free swelling experiment induced by chemical stimulation of the external bulk solution.
Bernoulli–Euler Dielectric Beam Model Based on Strain-Gradient Effect
Authors: Liang Xu , Hu Shuling , Shen Shengping
Published: November 2012

The theoretical investigation of the size dependent behavior of a Bernoulli–Euler dielectric nanobeam based on the strain gradient elasticity theory is presented in this paper. The variational principle is utilized to derive the governing equations and boundary conditions, in which the coupling between strain and electric field, strain gradient and electric field, and strain gradient and strain gradient are taken into account. Different from the classical beam theory, the size dependent behaviors of dielectric nanobeams can be described. The static bending problems of elastic, pure dielectric (nonpiezoelectric), and piezoelectric cantilever beams are solved to show the effects of the electric field-strain gradient coupling and the strain gradient elasticity. Comparisons between the classical beam theory and the strain gradient beam theory are given in this study. It is found that the beam deflection predicted by the strain gradient beam theory is smaller than that by the classical beam theory when the beam thickness is comparable to the internal length scale parameters and the external applied voltage obviously affects the deflection of the dielectric and piezoelectric nanobeam. The presented model is very useful for understanding the electromechanical coupling in nanoscale dielectric structures and is very helpful for designing devices based on cantilever beams.
Complete Genome Sequence of Klebsiella pneumoniae Phage JD001
Authors: Cui Zelin , Shen Wenbin , Wang Zheng , Zhang Haotian , Me Rao , Wang Yanchun , Zeng Lingbin , Zhu Yongzhang , Qin Jinhong , He Ping , Guo Xiaokui
Published: November 2012

Klebsiella pneumoniae
is a member of the family
Enterobacteriaceae
, opportunistic pathogens that are among the eight most prevalent infectious agents in hospitals. The emergence of multidrug-resistant strains of
K. pneumoniae
has became a public health problem globally. To develop an effective antimicrobial agent, we isolated a bacteriophage, named JD001, from seawater and sequenced its genome. Comparative genome analysis of phage JD001 with other
K. pneumoniae
bacteriophages revealed that phage JD001 has little similarity to previously published
K. pneumoniae
phages KP15, KP32, KP34, and phiKO2. Here we announce the complete genome sequence of JD001 and report major findings from the genomic analysis.
Complete Genome Sequencing of Four Geographically Diverse Strains of Batai Virus
Authors: Groseth Allison , Matsuno Keita , Dahlstrom Eric , Anzick Sarah L. , Porcella Stephen F. , Ebihara Hideki
Published: November 2012

Batai virus (BATV) is a widely distributed but poorly studied member of the
Orthobunyavirus
genus in the family
Bunyaviridae
and is of particular interest as a known participant in natural reassortment events. Both research and surveillance efforts on this and other related viruses have been hampered by the lack of available full-length sequence data covering all three genomic segments. Here, we report the complete genome sequence of four BATV strains (MM2222, Chittoor/IG-20217, UgMP-6830, and MS50) isolated from various geographical locations. Based on these data, we have determined that strain MS50 is in fact unrelated to BATV and likely represents as a novel genotype in the genus
Orthobunyavirus
.
Complete Genome Sequencing of Mosquito and Human Isolates of Ngari Virus
Authors: Groseth Allison , Weisend Carla , Ebihara Hideki
Published: November 2012

Ngari virus (NRIV) is a recently described, naturally occurring reassortant between two other orthobunyaviruses, Bunyamwera virus (BUNV) and Batai virus (BATV). Intriguingly, this reassortment was associated with the acquisition of heightened virulence, although the molecular basis for this is not understood. Here we report the first complete genome sequences of Ngari virus. We include five isolates from various geographical locations, as well as samples isolated from both mosquitos and human cases. Based on an analysis of these sequence data, NRIVs are clearly genetically distinct from all known BUNV and BATV strains but are very closely related to one another regardless of their source.
Complete Genome Sequence of Serratia plymuthica Bacteriophage ϕMAM1
Authors: Matilla Miguel A. , Salmond George P. C.
Published: November 2012

A virulent bacteriophage (ϕMAM1) that infects
Serratia plymuthica
was isolated from the natural environment and characterized. Genomic sequence analysis revealed a circular double-stranded DNA sequence of 157,834 bp, encoding 198 proteins and 3 tRNAs. The ϕMAM1 genome shows high homology to previously reported ViI-like enterobacterial bacteriophage genomes.
Complete Genome Sequence of an Infectious Bronchitis Virus Chimera between Cocirculating Heterotypic Strains
Authors: He Kun , Li Meng , Wei Ping , Mo Mei-lan , Wei Tian-chao , Li Kang-ran
Published: November 2012

To date, multiple serotypes and genotypes of infectious bronchitis virus (IBV) have been isolated and identified. In order to provide more information on the viral evolution of IBVs, a new virulent strain named GX-NN09032, isolated from Guangxi, China, in 2009, was sequenced, and phylogenetic and recombination analyses were conducted. Furthermore, potential recombination events associated with GX-NN09032 were found in four IBV strains, including GX-YL5, DY07, CK/CH/SD09/005, TC07-2. The present study suggested that GX-NN09032 might contribute to the emergence of modern IBV variants through recombination.
Complete Genome Sequence of Wide-Host-Range Staphylococcus aureus Phage JD007
Authors: Cui Zelin , Song Zhen , Wang Yanchun , Zeng Lingbin , Shen Wenbin , Wang Zheng , Li Qingtian , He Ping , Qin Jinhong , Guo Xiaokui
Published: November 2012

Methicillin-resistant
Staphylococcus aureus
-related infections have become a serious problem worldwide. Bacteriophage therapy is an alternative approach against this threat.
S. aureus
phage JD007, which belongs to the
Myoviridae
family according to transmission electron microscopic imaging, could lyse nearly 30% of the
S. aureus
strains from Ruijin Hospital, Shanghai, China, and was isolated from chicken feces in Shanghai, China. The complete genome showed that JD007 is a linear, double-stranded DNA phage 141,836 bp in length with a GC content of 30.4% encoding 217 open reading frames. A BLAST search of the JD007 genome revealed that it was very similar to that of phage GH15.
Complete Genome Sequence of Porcine Reproductive and Respiratory Syndrome Virus Strain ZCYZ Isolated from Hybrid Wild Boars
Authors: Wu Jiaqiang , Liu Shaoning , Du Yijun , Gao Yingchun , Wang Guisheng , Wang Jinbao
Published: November 2012

A serologic investigation of porcine reproductive and respiratory syndrome virus (PRRSV) in hybrid wild boar herds was conducted during 2008–2009. PRRSV isolates with novel genetic markers were recovered. Experimental infection of pigs indicated that hybrid wild boars are involved in the epidemiology of PRRSV.
Uncommon presentation of a common cancer papillary thyroid cancer in paediatric population
Authors: Lodha Sambhav , Bhatt Chhaya
Published: November 2012

Carcinoma of thyroid gland is rare in the paediatric age group before the age of 15 years. A 12-year-old girl presented with a swelling in the midline of neck, with no exposure of radiation in the past. On ultrasonography and fine needle aspiration cytology, the findings were suggestive of papillary carcinoma of thyroid. The case is being reported on account of its rarity.
A delayed diagnosis of a retained guidewire during central venous catheterisation: a case report and review of the literature
Authors: Gunduz Yasemin , Vatan Mehmet Bulent , Osken Altug , Cakar Mehmet Akif
Published: November 2012

Central venous catheterisation allows delivery of medications, intravenous fluids, parenteral nutrition, haemodialysis and monitoring of haemodynamic variables. Various complications may occur during and after the procedure. However, the complete guidewire retention has rarely been reported. In this report, we have presented a complete guidewire retention as a result of inadvertent catheter insertion. After 17 months of the first operation performed upon the diagnosis of Fournier's gangrene, the patient was admitted to the cardiology polyclinic with a recurrent chest pain. Echocardiography showed a wire-shaped foreign body within the right part of the heart, and a fluoroscopic examination showed a guidewire reaching from the superior vena cava to the right external iliac vein. In retrospect, the wire was already visible on the postoperative chest x-rays and CT taken while the patient was still in intensive care unit, but its presence was overlooked at that time. The guidewire was retrieved completely during a surgery.
Teleoncology: a tool for supporting cancer care
Authors: Penzo Chiara , Pietersma Anne
Published: November 2012

Telemedicine offers a range of options for accessing remote specialist oncology support to help provide high quality cancer care for pets. Chiara Penzo and Anne Pietersma discuss the theoretical and practical aspects of teleoncology, including cost analysis and legal‐ethical issues. They also discuss the current and future role of teleoncology tools in enhancing multidisciplinary teamwork and partnership.
State-Granted Practice Authority: Do Nurse Practitioners Vote with Their Feet?
Authors: Perry John J.
Published: November 2012

Nurse practitioners have become an increasingly important part of the US medical workforce as they have gained greater practice authority through state-level regulatory changes. This study investigates one labor market impact of this large change in nurse practitioner regulation. Using data from the National Sample Survey of Registered Nurses and a dataset of state-level nurse practitioner prescribing authority, a multivariate estimation is performed analysing the impact of greater practice authority on the probability of a nurse practitioner moving from a state. The empirical results indicate that nurse practitioners in states that grant expanded practice are less likely to move from the state than nurse practitioners in states that have not granted expanded practice authority. The estimated effect is robust and is statistically and economically meaningful. This finding is in concert with and strengthens the wider literature which finds states that grant expanded practice authority to nurse practitioners tend to have larger nurse practitioner populations.
Functional Dyspepsia: Subtypes, Risk Factors, and Overlap with Irritable Bowel Syndrome in a Population of African Patients
Authors: Nwokediuko Sylvester Chuks , Ijoma Uchenna , Obienu Olive
Published: November 2012

Background. Functional dyspepsia is the prototype functional gastrointestinal disorder. This study was designed to determine its prevalence, subtypes, and risk factors associated with the subtypes.Method. Patients with upper gastrointestinal symptoms who presented for endoscopy were administered a questionnaire containing the functional dyspepsia and irritable bowel syndrome modules of the Rome III diagnostic criteria.Results. Of 192 patients who had functional dyspepsia, epigastric pain syndrome, postprandial distress syndrome, and combination of the two subtypes accounted for 79.2%, 62.5%, and 50%, respectively. Multivariate analysis of the risk factors showed that independent predictors of postprandial distress syndrome were alcohol and irritable bowel syndrome while irritable bowel syndrome was independent predictor of epigastric pain syndrome. Alcohol, smoking, and use of nonsteroidal anti-inflammatory drugs were independent predictors of cooccurrence of postprandial distress syndrome and epigastric pain syndrome.Conclusion. Functional dyspepsia accounts for 62.5% of dyspepsia in a population of black African patients. Regarding symptomatology, epigastric pain syndrome, postprandial distress syndrome, and combination of the two subtypes account for 79.2%, 62.5%, and 50%, respectively. Risk factors for functional dyspepsia are irritable bowel syndrome, alcohol, smoking, and use of nonsteroidal anti-inflammatory drugs.
Synthesis and Antimicrobial Activity of Carboxylate Phosphabetaines Derivatives with Alkyl Chains of Various Lengths
Authors: Galkina Irina V. , Bakhtiyarova Yuliya V. , Shulaeva Marina P. , Pozdeev Oskar K. , Egorova Svetlana N. , Cherkasov Rafael A. , Galkin Vladimir I.
Published: November 2012

The purpose of the present study was to investigate the antibacterial activity of fifteen novel nanosized alkyl esters of carboxylate phosphabetaine: β‐(carboxyalkyl)ethyltriphenylphosphonium bromides 4–8, β‐(carboxyalkyl)‐β‐methylethyltriphenylphosphonium bromides 9–13, and β‐(carboxyalkyl)‐α‐methylethyltriphenylphosphonium bromides 14–18. The in vitro microbiological activity of the synthesized phosphonium bromides against gram‐positive and gram‐negative bacteria and the yeast Candida albicans was determined in comparison to standard agents. Microbiological results indicate that the synthesized phosphonium salts 4–18 possess a broad spectrum of activity against the tested microorganisms. Every newly synthesized compound was characterized by elemental analyses, IR, 1H NMR, and 31P NMR spectral studies.
Intonation Adapts to Lexical Tone: The Case of Kammu
Authors: Karlsson Anastasia , House David , Svantesson Jan-Olof
Published: November 2012

In this paper, we investigate how lexical tones interact with intonation, using data from the Austroasiatic language Kammu, one of few languages with two dialects whose only major phonological difference is the presence or absence of lexical tones. Northern (and Western) Kammu have developed tones in connection with the merger of voiceless and voiced initial consonants, while the non-tonal Eastern dialect kept the segmental opposition with no tones. We found the following prosodic hierarchy: (1) lexical tones, (2) phrase-final boundary tone, (3) focus marking. The results strongly suggest that the intonational systems of the two Kammu dialects are basically identical, and that the main differences between the dialects are adaptations of intonation patterns to the lexical tones when the identities of the tones are jeopardized.
On Handling Ephemeral Resource Constraints in Evolutionary Search
Authors: Allmendinger Richard , Knowles Joshua
Published: November 2012

We consider optimization problems where the set of solutions available for evaluation at any given time t during optimization is some subset of the feasible space. This model is appropriate to describe many closed-loop optimization settings (i.e., where physical processes or experiments are used to evaluate solutions) where, due to resource limitations, it may be impossible to evaluate particular solutions at particular times (despite the solutions being part of the feasible space). We call the constraints determining which solutions are non-evaluable ephemeral resource constraints (ERCs). In this paper, we investigate two specific types of ERC: one encodes periodic resource availabilities, the other models commitment constraints that make the evaluable part of the space a function of earlier evaluations conducted. In an experimental study, both types of constraint are seen to impact the performance of an evolutionary algorithm significantly. To deal with the effects of the ERCs, we propose and test five different constraint-handling policies (adapted from those used to handle standard constraints), using a number of different test functions including a fitness landscape from a real closed-loop problem. We show that knowing information about the type of resource constraint in advance may be sufficient to select an effective policy for dealing with it, even when advance knowledge of the fitness landscape is limited.
Dysregulated adipokines in the pathogenesis of type 2 diabetes and vascular disease
Authors: Brown James E
Published: November 2012

Obesity is commonly associated with type 2 diabetes and vascular disease. Changes in body composition in the obese state lead to a dysregulation of secretion of adipocyte-secreted hormones known as adipokines. Adipokines such as leptin and adiponectin are known to be involved in many physiological and pathological processes. Current knowledge suggests that adipokines provide potential therapeutic targets against type 2 diabetes and vascular disease.
Proteomic profiling of Rhizobium tropiciPRF 81: identification of conserved and specific responses to heat stress
Authors: Gomes Douglas Fabiano , Batista Jesiane Stefânia da Silva , Schiavon Aline Luiza , Andrade Diva Souza , Hungria Mariangela
Published: November 2012

Background

Rhizobium tropici strain PRF 81 (= SEMIA 4080) has been used in commercial inoculants for application to common-bean crops in Brazil since 1998, due to its high efficiency in fixing nitrogen, competitiveness against indigenous rhizobial populations and capacity to adapt to stressful tropical conditions, representing a key alternative to application of N-fertilizers. The objective of our study was to obtain an overview of adaptive responses to heat stress of strain PRF 81, by analyzing differentially expressed proteins when the bacterium is grown at 28°C and 35°C.

Results

Two-dimensional gel electrophoresis (2DE) revealed up-regulation of fifty-nine spots that were identified by MALDI-TOF/TOF-TOF. Differentially expressed proteins were associated with the functional COG categories of metabolism, cellular processes and signaling, information storage and processing. Among the up-regulated proteins, we found some related to conserved heat responses, such as molecular chaperones DnaK and GroEL, and other related proteins, such as translation factors EF-Tu, EF-G, EF-Ts and IF2. Interestingly, several oxidative stress-responsive proteins were also up-regulated, and these results reveal the diversity of adaptation mechanisms presented by this thermotolerant strain, suggesting a cross-talk between heat and oxidative stresses.

Conclusions

Our data provide valuable protein-expression information relevant to the ongoing genome sequencing of strain PRF 81, and contributes to our still-poor knowledge of the molecular determinants of the thermotolerance exhibited by R. tropici species.
Study of the betulin enriched birch bark extracts effects on human carcinoma cells and ear inflammation
Authors: Dehelean Cristina A , Şoica Codruţa , Ledeţi Ionuţ , Aluaş Mihaela , Zupko Istvan , Gǎluşcan Atena , Cinta-Pinzaru Simona , Munteanu Melania
Published: November 2012

Background

Pentacyclic triterpenes, mainly betulin and betulinic acid, are valuable anticancer agents found in the bark of birch tree. This study evaluates birch bark extracts for the active principles composition.

Results

New improved extraction methods were applied on the bark of Betula pendula in order to reach the maximum content in active principles. Extracts were analyzed by HPLC-MS, Raman, SERS and 13C NMR spectroscopy which revealed a very high yield of betulin (over 90%). Growth inhibiting effects were measured in vitro on four malignant human cell lines: A431 (skin epidermoid carcinoma), A2780 (ovarian carcinoma), HeLa (cervix adenocarcinoma) and MCF7 (breast adenocarcinoma), by means of MTT assay. All of the prepared bark extracts exerted a pronounced antiproliferative effect against human cancer cell lines. In vivo studies involved the anti-inflammatory effect of birch extracts on TPA-induced model of inflammation in mice.

Conclusions

The research revealed the efficacy of the extraction procedures as well as the antiproliferative and anti-inflammatory effects of birch extracts.
5-year experience with varicose vein laser surgery
Authors: Bihari Imre , Ayoub George , Bihari András
Published: November 2012

Introduction: The incidence of varicose veins in the lower limb is relatively frequent in Europe including Hungary. Aim: Authors report their 5-year experience in varicose vein laser surgery focusing with regards to recurrence and complication rates. Patients and methods: Surgery was performed on 647 lower limbs in 546 patients with an age between 17 and 80 years. They were overweight in 4.6 % of cases. The diameter of treated saphenous veins was between 4 and 31 mm. Indications for surgery were recurrence in 9.1% of cases and crural ulcer in 4.0% of cases. Laser fibre was introduced into the varicose saphenous stems and then 980 nm, later 1470 nm wavelength laser was delivered while the fibre was step-by-step pulled-out. Following the learning period laser energy was raised from a mean of 28 J/cm to 164 J/cm because of high recurrence rate. Results: During the learning period the recurrence rate was 13.8% while it was 1.9% thereafter. Pulmonary embolism occurred in two cases, which could have been avoidable. Further minor complications were also noted. Conclusions: Varicose vein laser surgery can be recommended because the recurrence rate is very low, major complications can be avoided and minor complications are temporary. Orv. Hetil., 2012, 153, 1863–1869.
Relative Tolerance of Perennial Ryegrass (Lolium perenne) and Tall Fescue (Festuca arundinacea) to Flucarbazone
Authors: McCullough Patrick E. , Yu Jialin , Brosnan James T. , Breeden Gregory K.
Published: November 2012

Flucarbazone controls certain grassy weeds in wheat and may have potential for controlling perennial ryegrass in tall fescue turf. The objective of these experiments was to investigate perennial ryegrass and tall fescue tolerance to flucarbazone at two application timings. In field experiments, flucarbazone applications in May were more injurious to both species than in February and March. Single applications of flucarbazone from 30 to 60 g ai ha−1in May injured both species 35 to 50% and sequential treatments increased injury approximately twofold. Two applications of flucarbazone at 60 g ha−1in May injured both grasses > 90%, similar to sequential applications of trifloxysulfuron at 29 g ai ha−1. In growth chamber experiments, injury from flucarbazone on both grasses increased as temperature increased from 10 to 30 C. Flucarbazone reduced total shoot biomass of both grasses at all temperatures after 4 wk. Overall, perennial ryegrass and tall fescue are tolerant to flucarbazone at moderate temperatures (10 to 20 C). However, injury increased substantially under warmer conditions (30 C), suggesting flucarbazone could control perennial ryegrass and tall fescue during late spring and early summer.
Relationship between Temperature and Heat Duration on Large Crabgrass (Digitaria sanguinalis), Virginia Buttonweed (Diodia virginiana), and Cock's-Comb Kyllinga (Kyllinga squamulata) Seed Mortality
Authors: Hoyle Jared A. , McElroy J. Scott
Published: November 2012

Thermal heat has been utilized for nonselective weed control methods. These methods are highly variable in application and efficacy. One effective weed–seed-control determining factor is achieving the thermal death point of targeted weed seeds. The thermal death point varies by weed species, temperature, and exposure time. Our objective was to determine the thermal death point of large crabgrass, cock's-comb kyllinga, and Virginia buttonweed at short thermal exposure periods. Studies conducted utilized 5 and 20 s exposure periods for incremental range, 60 to 250 C temperatures. Sigmoid regression curves were used to predict weed seed mortality by temperature and exposure time. A significant interaction between exposure period and temperature occurred for each weed species. Weed species increased in susceptibility to 20 s thermal heat as follows: Virginia buttonweed < cock's-comb kyllinga < large crabgrass. Increasing thermal exposure time from 5 to 20 s reduced thermal temperature by 21 C to achieve 50% mortality for large crabgrass and by 10 C for cock's-comb kyllinga. Virginia buttonweed achieved 50% mortality at 99 C for 5 and 20 s exposure periods. These data indicate that at least 50% weed seed mortality can be achieved at 99 and 103 C for 20 and 5 s exposure periods, respectively, for these weed species.
Duration of Flumioxazin-Based Weed Control in Container-Grown Nursery Crops
Authors: Wehtje Glenn , Gilliam Charles H. , Marble Stephen C.
Published: November 2012

Flumioxazin is used in nursery production and landscape maintenance industries. In these situations, weed control provided by flumioxazin often lasts longer than that reported in soil. Our objective was to quantify flumioxazin longevity under conditions found in nursery production. Pots were filled with 6 : 1 (v/v) pine bark : sand mixture. This nonsoil media is typical of what is used for nursery crop production. Pots were treated with flumioxazin at either 0.28 or 0.42 kg ai ha−1, and subsequently sown with either hairy bittercress (two winter experiments) or spotted spurge (two summer experiments) at weekly intervals. Weed seed germination, emergence, and seedling establishment in the treated pots was compared with nontreated control and used as a proxy for herbicide activity. Flumioxazin provided approximately 7 wk of complete (100%) hairy bittercress control regardless of rate. However, a rate effect was evident in only one of the two experiments conducted with hairy bittercress. In both experiments with hairy bittercress, marginal and highly variable activity was still evident at 18 wk after treatment. Flumioxazin at 0.28 and 0.42 kg ha−1provided 2- and 4-wk complete spotted spurge control, respectively. No spotted spurge control was evident after about 8 wk. Subjecting this less-variable data to nonlinear regression revealed that the time required for 50% reduction in flumioxazin activity was approximately 5.5 and 6.6 wk for the two rates, respectively. A column leaching study revealed that flumioxazin activity remained localized near the surface (0 to 4 cm). Therefore the dissipation observed was likely the result of in situ degradation and not displacement. The high organic matter content of the nonsoil media contributes to the observed persistence of flumioxazin activity.
Crop Response and Control of Common Purslane (Portulaca oleraceae) and Prostrate Pigweed (Amaranthus blitoides) in Green Onion with Oxyfluorfen
Authors: Doohan Doug , Felix Joel
Published: November 2012

Weed management in green onion continues to be a challenge for vegetable growers in Ohio. Field experiments were conducted from 2005 to 2009 to evaluate oxyfluorfen efficacy on common purslane and prostrate pigweed and green onion tolerance when applied POST at 0, 30, 70, 105, and 290 g ai ha−1 approximately 3 wk after planting. No crop injury was observed from any of the herbicide rates, except in 2009 when 209 g ha−1 oxyfluorfen resulted in 10% injury at 7 d after treatment. The transient injury did not reduce green onion yield. Green onion yield ranged from 1.8 to 2.2 kg plot−1 in 2006 and 1.3 to 1.5 kg plot−1 in 2009. In 2007 yield increased linearly from 1.9 to 3.0 kg plot−1 with oxyfluorfen rates of 0 to 105 g ha−1. Common purslane control increased as the rate of oxyfluorfen increased. Application of oxyfluorfen at 70 to 105 g ha−1 provided the best control of common purslane, ranging from 61 to 95% across the years. Similar control results were observed for prostrate pigweed. Prostrate pigweed control with 70 to 105 g ha−1 ranged from 40 to 93% from 2005 to 2009. These results suggest that green onion tolerates oxyfluorfen rates of 70 to 105 g ha−1, and these rates provide common purslane and prostrate pigweed control that growers would find acceptable. Registration of the water-based formulation of oxyfluorfen would provide growers an opportunity to control weeds and reduce the need for hand labor.
Italian Ryegrass (Lolium perenne) Control and Winter Wheat Response to POST Herbicides
Authors: Grey Timothy L. , Cutts George S. , Sosnoskie Lynn , Culpepper A. Stanley
Published: November 2012

Field studies were conducted to evaluate Italian ryegrass control and winter wheat tolerance to applications of diclofop, mesosulfuron plus methylated seed oil (MSO) alone or with 30% urea ammonium nitrate (UAN), mesosulfuron plus thifensulfuron plus tribenuron plus MSO, mesosulfuron plus MCPA plus MSO, or flufenacet plus metribuzin. Treatments were applied to wheat PRE, two- to three-leaf wheat (2–3 LF) at Feekes stage 1.0 or to one- to two-tiller wheat (TILL) at Feekes stage 3.0, depending on label recommendations. Studies were conducted in Williamson, GA, and Plains, GA, from autumn 2003 to spring 2005. Italian ryegrass control was variable, depending on location and year. Maximum and most-consistent Italian ryegrass control (> 90%) occurred with mesosulfuron plus MSO and UAN. Without UAN, control of Italian ryegrass with mesosulfuron varied from 44 to 97%. That variability was partially attributed to unfavorable environmental conditions associated with cold night time temperatures at or below 0 C, following applications. Wheat injury observed in response to herbicide treatments was minimal (< 15%) and transient; wheat recovered with no differences in yield.
Evaluation of Mowing Height and Fertilizer Application Rate on Quality and Weed Abundance of Five Home Lawn Grasses
Authors: DeBels Brad T. , Griffith Shane E. , Kreuser William C. , Melby Eric S. , Soldat Douglas J.
Published: November 2012

Evaluation of turfgrass performance at low nitrogen fertility levels is important because many home lawns are fertilized below common recommendations. The objective of this study was to evaluate visible quality and weed susceptibility of common and alternative cool season grasses under multiple management regimes in Wisconsin. A split-split plot completely randomized block design was used to evaluate ‘Kingfisher' Kentucky bluegrass (Kentucky bluegrass), ‘Kenblue' Kentucky bluegrass, ‘Victory II' chewings fescue, ‘Grande II' tall fescue, and ‘Jiffe II' perennial ryegrass. Each species was mowed at 3.5, 6.0, or 8.5 cm, and fertilized with 0, 98, or 196 kg ha−1yr−1of nitrogen. Visible quality and weed cover were evaluated four times annually for 3 yr. Tall fescue had the greatest turf quality across all treatments. Kingfisher Kentucky bluegrass, an improved variety, responded most dramatically to nitrogen fertilization, with quality rating improved from 5.1 to 7.1 when annual nitrogen applications totaled 196 kg ha−1compared to the nonfertilized control. Kenblue Kentucky bluegrass, a common variety, had the greatest weed cover at all mowing heights and fertilizer rates. Assessment of common dandelion flowers by digital image analysis revealed that improved and common Kentucky bluegrass had greater common dandelion cover than fine or tall fescue when herbicides were withheld for 2.5 yr. Background soil fertility was found to have a significant impact on visible quality and weed cover. In an area with eroded, low-fertility soil, improved Kentucky bluegrass required 196 kg N ha−1yr−1to maintain high quality and limit weed invasion. These results suggest that tall fescue is best suited to low and high input conditions, while improved varieties of Kentucky bluegrass performed acceptably only under high inputs.
Effects of Shoot Clipping–Soil Disturbance Frequency and Tuber Size on Aboveground and Belowground Growth of Purple and Yellow Nutsedge (Cyperus rotundusandCyperus esculentus)
Authors: Bangarwa Sanjeev K. , Norsworthy Jason K. , Gbur Edward E.
Published: November 2012

Purple and yellow nutsedges are two of the world's worst weeds, reproducing asexually by rhizomes that can develop into new shoots or tubers. These tubers are the storage organs for carbohydrate reserves that are replenished by growing shoots and exhausted by new shoot, root plus rhizome, and basal bulb production. Based on the biology of both species, we hypothesized that the regenerative potential of purple and yellow nutsedge would decrease, with increasing shoot clipping–soil disturbance (SCSD) frequency and decreasing tuber size. To test this hypothesis, greenhouse experiments were conducted in pots to determine the effect of SCSD frequency and tuber size on aboveground and belowground growth of purple and yellow nutsedges. Five viable tubers of two tuber category sizes (small, 0.40 ± 0.05; and large, 0.80 ± 0.05 g of tuber fresh weight) were subjected to four SCSD frequencies (weekly, biweekly, monthly, and none) for 12 wk. SCSD was performed by clipping the emerged nutsedge shoots followed by manually disturbing the soil. SCSD at biweekly or weekly intervals reduced purple nutsedge proliferation, regardless of initial tuber size. However, monthly SCSD did not suppress purple nutsedge as effectively as weekly or biweekly SCSD, and less proliferation occurred with small tubers than with large tubers. In contrast, yellow nutsedge proliferation was equally reduced with monthly or more-frequent SCSD, regardless of initial tuber size. Even weekly soil disturbance for 12 wk failed to eradicate all small or large tubers in either species. Thus, yellow nutsedge is managed more easily than purple nutsedge with less-frequent tillage or cultivation. However, tillage or cultivation alone during a 12-wk period will not likely eradicate either nutsedge species from infested soil.
Asynchronous food‐web pathways could buffer the response of Serengeti predators to El Niño Southern Oscillation
Authors: Sinclair A. R. E. , Metzger Kristine L. , Fryxell John M. , Packer Craig , Byrom Andrea E. , Craft Meggan E. , Hampson Katie , Lembo Tiziana , Durant Sarah M. , Forrester Guy J. , Bukombe John , Mchetto John , Dempewolf Jan , Hilborn Ray , Cleaveland Sarah , Nkwabi Ally , Mosser Anna , Mduma Simon A. R.
Published: November 2012

Understanding how entire ecosystems maintain stability in the face of climatic and human disturbance is one of the most fundamental challenges in ecology. Theory suggests that a crucial factor determining the degree of ecosystem stability is simply the degree of synchrony with which different species in ecological food webs respond to environmental stochasticity. Ecosystems in which all food‐web pathways are affected similarly by external disturbance should amplify variability in top carnivore abundance over time due to population interactions, whereas ecosystems in which a large fraction of pathways are nonresponsive or even inversely responsive to external disturbance will have more constant levels of abundance at upper trophic levels. To test the mechanism underlying this hypothesis, we used over half a century of demographic data for multiple species in the Serengeti (Tanzania) ecosystem to measure the degree of synchrony to variation imposed by an external environmental driver, the El Niño Southern Oscillation (ENSO). ENSO effects were mediated largely via changes in dry‐season vs. wet‐season rainfall and consequent changes in vegetation availability, propagating via bottom‐up effects to higher levels of the Serengeti food web to influence herbivores, predators and parasites. Some species in the Serengeti food web responded to the influence of ENSO in opposite ways, whereas other species were insensitive to variation in ENSO. Although far from conclusive, our results suggest that a diffuse mixture of herbivore responses could help buffer top carnivores, such as Serengeti lions, from variability in climate. Future global climate changes that favor some pathways over others, however, could alter the effectiveness of such processes in the future.
Convergent Flow in Unsaturated Fractured Chalk
Authors: Keim Dawn M. , West L. Jared , Odling Noelle E.
Published: November 2012

The Cretaceous Chalk in Northern Europe and other similar fractured rock aquifers frequently have very thick unsaturated (vadose) zones which control both their hydraulic response to rainfall and the extent to which pollutants are delayed or attenuated before reaching groundwater. Understanding their hydraulic responses is a prerequisite for prediction of future trends in groundwater recharge and quality. Accurate characterization of these responses remain elusive because of difficulties in both obtaining in situ measurements and in devising appropriate conceptual models of flow processes in unsaturated fractured rock. In this study we addressed both issues by simultaneously monitoring soil water dynamics through continuously logged matric potential and moisture content and measuring discharge into a subsurface tunnel at up to 45 m depth within the unsaturated zone of Cretaceous Chalk in northern England. Winter drainage fluxes from the base of the soil zone were estimated using the HYDRUS code for one‐dimensional variably saturated media. Comparison of soil zone drainage representing the hydraulic input into the Chalk unsaturated zone with tunnel discharge provides insights into the flow dynamics of the unsaturated zone. The relative magnitudes of the soil drainage and deeper unsaturated zone discharge show that flow pathways converge resulting in increased flow focusing with depth in the unsaturated zone. The observed short lag times between the soil surface and the inflow sites in the subsurface tunnel suggest that contaminants from the surface could rapidly reach the water table through thick unsaturated zones within the Chalk.
FEM-DEM Modeling for Out-of-plane Loaded Masonry Panels: A Limit Analysis Approach
Authors: Reccia Emanuele , Cazzani Antonio , Cecchi Antonella
Published: November 2012

In this work the performances of the Discrete Element Method (DEM) applied to kinematic limit analyses of the out-of-plane behavior of masonry wall panels (with different textures) are investigated.

A discrete model of masonry is proposed, which assumes that rigid blocks are connected by a mortar interface: this is ap-propriate for historical masonry, where mortar is much more deformable than blocks and joints thickness is negligible. Therefore blocks can be modeled as rigid bodies connected by zero thickness Mohr-Coulomb-type interfaces.

The applied method is known as FEM/DEM, which combines finite and discrete element models.

A comparison with well-known and meaningful examples presented by Giuffrè has been carried out in order to validate this method for studying the behavior of masonry. For this purpose, 2D DEM models reproducing walls sections have been considered: they reproduce masonry walls with different staggered blocks, in particular stack bond and running bond patterns, subjected to lateral loads.