bluuebunny/crossref_metadata_2025 huggingface dataset:
Almost fixed-point-free automorphisms of prime order
Authors: Wehrfritz Bertram
Published: February 2011

Let ϕ be an automorphism of prime order p of the group G with C
G(ϕ) finite of order n. We prove the following. If G is soluble of finite rank, then G has a nilpotent characteristic subgroup of finite index and class bounded in terms of p only. If G is a group with finite Hirsch number h, then G has a soluble characteristic subgroup of finite index in G with derived length bounded in terms of p and n only and a soluble characteristic subgroup of finite index in G whose index and derived length are bounded in terms of p, n and h only. Here a group has finite Hirsch number if it is poly (cyclic or locally finite). This is a stronger notion than that used in [Wehrfritz B.A.F., Almost fixed-point-free automorphisms of order 2, Rend. Circ. Mat. Palermo (in press)], where the case p = 2 is discussed.
Bianchi type-II cosmological model: some remarks
Authors: Saha Bijan
Published: February 2011

Within the framework of a Bianchi type-II (BII) cosmological model the behavior of matter distribution has been considered. It is shown that the non-zero off-diagonal component of the Einstein tensor implies some severe restrictions on the choice of matter distribution. In particular, for a locally rotationally symmetric Bianchi type-II (LRS BII) space-time, it is proved that the matter distribution should be strictly isotropic if the corresponding matter field possesses only non-zero diagonal components of the energy-momentum tensor.
The Determinants of Interdistrict Open Enrollment Flows
Authors: Carlson Deven , Lavery Lesley , Witte John F.
Published: February 2011

Interdistrict open enrollment is the most widely used form of school choice in the United States. Through the theoretical lens of a utility maximization framework, this article analyzes the determinants of interdistrict open enrollment flows in Minnesota and Colorado. The authors’ empirical analysis employs an original data set that details open enrollment flows between all pairwise combinations of school districts within 100 miles of each other in these two states. These flows are merged with demographic and geographic data from the Common Core of Data and U.S. Census Bureau. The findings indicate that open enrollment flows are driven mainly by student achievement and structural characteristics of districts; distance plays a large constraining role. The results also suggest that most transfers take place between relatively high-achieving districts. The authors discuss the policy implications of these findings.
The Non-Cognitive Returns to Class Size
Authors: Dee Thomas S. , West Martin R.
Published: February 2011

The authors use nationally representative survey data and a research design that relies on contemporaneous within-student and within-teacher comparisons across two academic subjects to estimate how class size affects certain non-cognitive skills in middle school. Their results indicate that smaller eighth-grade classes are associated with improvements in several measures of school engagement, with effect sizes ranging from .05 to .09 and smaller effects persisting 2 years later. Patterns of selection on observed traits and falsification exercises suggest that these results accurately identify (or possibly understate) the causal effects of smaller classes. Given the estimated earnings impact of these non-cognitive skills, the implied internal rate of return from an eighth-grade class-size reduction is 4.6% overall, but 7.9% in urban schools.
Reading and Language Outcomes of a Multiyear Randomized Evaluation of Transitional Bilingual Education
Authors: Slavin Robert E. , Madden Nancy , Calderón Margarita , Chamberlain Anne , Hennessy Megan
Published: February 2011

This article reports the outcomes of a multiyear study comparing the English and Spanish language and reading performance of Spanish-dominant children randomly assigned, beginning in kindergarten, to transitional bilingual education (TBE) or structured English immersion (SEI) for periods of up to 5 years. On the Peabody Picture Vocabulary Test and its Spanish equivalent (Test de Vocabulario en Imagenes Peabody) and on the English and Spanish versions of three Woodcock Reading Scales, first graders in TBE performed significantly better in Spanish and worse in English than did their SEI counterparts. Differences diminished in second and third grades, and by fourth grade, when all students in TBE had transitioned to English-only instruction, there were no significant differences on English reading measures. These findings suggest that Spanish-dominant students learn to read in English equally well in TBE and SEI and that policy should therefore focus on the quality of instruction rather than on the language of instruction for English-language learners.
A Comparison of Imputation Methods for Bayesian Factor Analysis Models
Authors: Merkle Edgar C.
Published: February 2011

Imputation methods are popular for the handling of missing data in psychology. The methods generally consist of predicting missing data based on observed data, yielding a complete data set that is amiable to standard statistical analyses. In the context of Bayesian factor analysis, this article compares imputation under an unrestricted multivariate normal model (Multiple Imputation [MI]) to imputation under the statistical model of interest (Data Augmentation [DA]). The former method is popular in applied research, but the latter method is more straightforward from a Bayesian perspective. Simulations demonstrate that DA yields less-biased parameter estimates for moderate sample sizes and high missingness proportions. MI, however, yields less-biased parameter estimates for large sample sizes with misspecified models. The incorporation of auxiliary variables in DA is also addressed, and BUGS code is provided.
Extraventricular corpus callosotomy
Authors: Joseph Jacob R. , Viswanathan Ashwin , Yoshor Daniel
Published: February 2011

Corpus callosotomy offers useful palliation for selected patients with medically intractable seizures, particularly those with uncontrolled and disabling drop attacks. Here the authors present their technique for performing a corpus callosotomy that allows for complete sectioning of the callosum while avoiding entry into the lateral ventricles. The anatomical basis for the technique is the presence of a definable cleft just ventral to the corpus callosum in the midline, formed by the fusion of the two laminae of the septum pellucidum. This small cleft is typically present even in the absence of a cavum septum pellucidum on MR imaging. The authors have found that dividing the body of the corpus callosum by exploiting the cleft of the septum pellucidum in the absolute midline is a simple and expeditious way to perform a callosotomy without entering the lateral ventricles.
Fluoroscopically guided epidural blood patch with subsequent spinal CT scans in the treatment of spontaneous cerebrospinal fluid hypovolemia
Authors: Watanabe Keisuke , Hashizume Keiji , Kawaguchi Masahiko , Fujiwara Aki , Sasaoka Noriyuki , Furuya Hitoshi
Published: February 2011

Object

Recent evidence has indicated that the efficacy of the epidural blood patch (EBP) in the treatment of spontaneous CSF hypovolemia (SCH) is still limited. Therefore, further improvement of the EBP technique is an important clinical challenge. The authors describe a series of cases of SCH treated with fluoroscopically guided placement of an EBP and followed up with subsequent spinal CT scans.

Methods

Thirteen patients with SCH that was proven on CT myelography studies underwent epidural puncture under fluoroscopic guidance and received an injection of a mixture of contrast medium and autologous blood. Contrast medium was injected to cover the area of CSF leakage during EBP guided by fluoroscopy, and the spread of the blood was subsequently evaluated using spinal CT scanning. If the amount of blood injected was insufficient to cover the leakage area, a second EBP was performed at a later date.

Results

At the first EBP procedure, a mixture with a mean volume of 9.4 ml (range 3–20 ml) was injected, and subsequent spinal CT scans revealed contrast enhancement in the desired epidural space in 12 of 13 patients. In 2 patients, a second EBP was required because of insufficient coverage of the leakage area or delayed recurrence of headache. In all patients, a complete recovery from orthostatic headache was obtained after the last EBP.

Conclusions

The results indicated that fluoroscopically guided EBP and subsequent spinal CT scans may provide a highly effective therapy in patients with SCH proven on CT myelography studies.
Combined endovascular embolization and stereotactic radiosurgery in the treatment of large arteriovenous malformations
Authors: Blackburn Spiros L. , Ashley William W. , Rich Keith M. , Simpson Joseph R. , Drzymala Robert E. , Ray Wilson Z. , Moran Christopher J. , Cross DeWitte T. , Chicoine Michael R. , Dacey Ralph G. , Derdeyn Colin P. , Zipfel Gregory J.
Published: February 2011

Object

Large cerebral arteriovenous malformations (AVMs) are often not amenable to direct resection or stereotactic radiosurgery (SRS) treatment. An alternative treatment strategy is staged endovascular embolization followed by SRS (Embo/SRS). The object of this study was to examine the experience at Washington University in St. Louis with Embo/SRS for large AVMs and review the results in earlier case series.

Methods

Twenty-one cases involving patients with large AVMs treated with Embo/SRS between 1994 and 2006 were retrospectively evaluated. The AVM size (before and after embolization), procedural complications, radiological outcome, and neurological outcome were examined. Radiological success was defined as AVM obliteration as demonstrated by catheter angiography, CT angiography, or MR angiography. Radiological failure was defined as residual AVM as demonstrated by catheter angiography, CT angiography, or MR angiography performed at least 3 years after SRS.

Results

The maximum diameter of all AVMs in this series was > 3 cm (mean 4.2 cm); 12 (57%) were Spetzler-Martin Grade IV or V. Clinical follow-up was available in 20 of 21 cases; radiological follow-up was available in 19 of 21 cases (mean duration of follow-up 3.6 years). Forty-three embolization procedures were performed; 8 embolization-related complications occurred, leading to transient neurological deficits in 5 patients (24%), minor permanent neurological deficits in 3 patients (14%), and major permanent neurological deficits in none (0%). Twenty-one SRS procedures were performed; 1 radiation-induced complication occurred (5%), leading to a permanent minor neurological deficit. Of the 20 patients with clinical follow-up, none experienced cerebral hemorrhage. In the 19 patients with radiological follow-up, AVM obliteration was confirmed by catheter angiography in 13, MR angiography in 2, and CT angiography in 1. Residual nidus was found in 3 patients. In patients with follow-up catheter angiography, the AVM obliteration rate was 81% (13 of 16 cases).

Conclusions

Staged endovascular embolization followed by SRS provides an effective means of treating large AVMs not amenable to standard surgical or SRS treatment. The outcomes and complication rates reported in this series compare favorably to the results of other reported therapeutic strategies for this very challenging patient population.
Spinal cord concussion in a professional ice hockey player
Authors: Winder Mark J. , Brett Kelly , Hurlbert R. John
Published: February 2011

Spinal cord concussion (SCC) is an uncommon injury resulting in transient quadriplegia. The pathophysiology of SCC has been related to underlying spinal canal stenosis in many cases, yet is not always identified. The authors present the case of a professional ice hockey player, without evidence of canal compromise, who sustained an SCC during a regulation game after being struck by a puck in the upper cervical spine. The unusual mechanism of injury is discussed along with a comprehensive review of the literature.
Hepatoprotective Effect of Cynodon dactylon on CCI4 Induced Experimental Mice
Authors: Prabha DC , Annapoorani S
Published: February 2011

Context: Medicinal plants having diverse pharmacological properties including cytotoxic and cancer chemopreventive effects can be developed as novel drugs for cancer chemoprevention. One of the best approaches in search for anticancer agents from plant resources is the selection of plants based ethnomedical leads and testing the selected plants efficacy and safety in light of modern science.Objectives: The present study aims in assessing the hepatoprotective activity of protein fraction of Cynodon dactylon on CCl4 induced mice.Materials and Methods: Fresh leaves were homogenized with phosphate buffered saline (PBS) at 4°C to obtain 20 % homogenate. The supernatant obtained was used for the ammonium sulphate fractionation. Hepatoprotective role was evaluated in the liver of mice administered with and without protein fraction. Paraffin oil and PBS serves as the vehicle control for Silymarin and protein fraction respectively. Silymarin was used as the standard antioxidant. CCl4 acts as a hepatotoxin. The activity of enzymic antioxidants Catalase (CAT), Superoxide dismutase (SOD) and Peroxidase (Px) were determined in the liver homogenate of the control and experimental mice. The levels of these antioxidants were also assessed in the liver homogenate of the control and experimental mice.Results: The protein fraction of Cynodon dactylon had significant hepatoprotective potential by enhancing the activities of enzymic antioxidants, increasing the levels of non enzymic antioxidants, marker enzymes and antilipid peroxidative role by decreasing the lipid peroxide levels. These effects were found to be more significant than that of silymarin, the standard antioxidant and the CCl4 the hepatotoxin. Administration of Cynodon dactylon plus CCl4 significantly decreases the levels of liver marker enzymes, hepatic enzymic and non enzymic antioxidants. The observed increased levels of lipid peroxides and decreased levels of enzymic and non enzymic antioxidants are the indications of liver damage due to high oxidative stress in CCl4 induced mice when compared to the respective vehicle controls.Conclusion: The findings of the present study revealed that the Cynodon dactylon had the potent hepatoprotective activity due to its antioxidant property against CCl4 induced liver damage in mice. Key words: Protein fraction; Cynodon dactylon; enzymic antioxidants; lipid peroxides; marker enzymes; CCl4.DOI: 10.3329/jbs.v17i0.7096J. bio-sci. 17: 27-34, 2009
Influence of Growth Regulators on Root and Shoot Characters of Onion
Authors: Ud-Deen MM , Kabir G
Published: February 2011

Context: The growth behaviour and yield of any crop plants are governed by their genetic potential, climatic conditions and the supply of nutrients. Specific control of these processes can be done by the application of plant bioregulators of natural or synthetic origin.Objectives: The aim of the present investigation was to study the effect of different plant growth regulators on root and shoot emergence, and root and shoot length of onion.Materials and Methods: Onion. var "Taherpuri" was used as plant material and four growth regulators namely GA3, Uniconazol, CCC and 2,3,6-TBA along with water as control with different concentration viz. 100, 150, 200, 250 and 300 ppm were used as treatment. Onion bulbs were placed on vials containing different doses of growth regulators. Data recorded on root and shoot emergence and their lengths after different days of setting the experiment.Results: Higher concentrations of uniconazole necessitated maximum days for root and shoot emergence whereas GA3 required minimum days. Root length decreased gradually with increasing the concentrations of all the growth regulators at different days of emergence. Higher concentrations of GA3 produced longest shoot whereas same concentrations of uniconazole produced the shortest than the lower ones at different days of emergence. The highly significant and negative correlation was found between days to root emergence and shoot length and between days to shoot emergence and shoot length but highly significant and positive correlation was found between root length and shoot length.  Conclusion: GA3 required minimum days to root and shoot emergence and promote the vegetative growth of onion whereas uniconazole and CCC are retards and 2,3,6-TBA shows a little retarding effect.Key words: Growth regulators; Root and shoot characters; OnionDOI: 10.3329/jbs.v17i0.7101J. bio-sci. 17: 51-55, 2009
Ovicidal Activity of Essential Oils against Red Flour Beetle, Tribolium castaneum (Coleoptera: Tenebrionidae)
Authors: Mondal Mina , Khalequzzaman M
Published: February 2011

Context: The essential oils are being tried as potential candidates for pest and disease management. Several essential oils of botanical origin have been reported for their repellant, toxic and developmental inhibitory activities. The ovicidal effect of essential oil is probably the major factor in the suppression of the development of adults from treated eggs.Objectives: To investigate the ovicidal effect of vapours of five essential oils viz., cardamom (Elletaria cardamomum L.), cinnamon (Cinnamomum zeylanicum Blume), clove (Sygium aromaticum L. Merrill. et. Perry), Eucalyptus spp. and neem (Azadirectica indica A. juss) against the eggs of red flour beetle, Tribolium castaneum (Herbst).Materials and Methods: Ten eggs (24 h old) of T. castaneum were placed in each petridish with wheat flour as food medium and without flour medium and then the petridish were kept inside 650 ml jars with screwed lids. Aliquots of 0.5 ml of each dose of essential oils were applied on filter paper attached to the lower side of the lids. The exposure periods were 24, 48, 72 and 96 h, respectively. After treatment periods, petridishes were taken out of the jars and the final mortality counts were made after 11 days. Mortality data were subjected to probit analysis. Results: The oils had high-fumigant activity against eggs and toxicity progressively increased with increase in exposure time and concentration. At the highest concentration of 5.769 mg/l air and exposure period of 24 h, cinnamon oil achieved 100% mortality in flour and without flour media. The vapours of essential oils from cardamom and clove resulted in 100% mortality of the eggs. Neem oil achieved mortalities as high as 51.66 and 50% mortality at the highest concentration and exposure period in with-flour and without flour medium respectively. At a concentration of 5.769 mg/ l air cardamom oil, the LT90 values were 50.80 and 62.78 h for with-flour and without flour medium respectively.Conclusion: The essential oils of cinnamon and clove, proved to be promising as control agents against stored-product insects, especially T. castaneum.Key words: Essential oil; Fumigant toxicity; Ovicidal activity; Tribolium castaneumDOI: 10.3329/jbs.v17i0.7102J. bio-sci. 17: 57-62, 2009
Isolation and Characterization of Chromate Resistant and Reducing Bacteria from Tannery Effluent of Chittagong, Bangladesh
Authors: Fakruddin M , Mazumder Reaz Mohammad , Tania Towhida Khanom , Islam Saiful , Nipa Meher Nigad , Iqbal Asif , Bhuiyan Habibur R
Published: February 2011

Context: Waste water containing Chromium (Cr6+) is by far the most important environmental challenge being faced. Objectives: The present study was planned on the isolation and characterization of chromate resistant and reducing bacterial strains in order to use them for detoxification of chromate.Materials and Methods: Water samples were collected to isolate microorganisms from tannery effluent of Baluchara, Chittagong and inoculated into Luria-Bertani medium with added Cr6+ as K2Cr2O7. The organisms have been identified and studied for Cr6+ reduction-ability in growth dependent manner.Results: A total of 35 isolates have been selected as potential organism belonging to the species of Moraxella (14.3%), Bacillus (11.43%), Streptococcus (25.72%), Staphylococcus (5.7%), Salmonella (12.3%), E. coli (13.3%), Enterobacter (11.3%), Hafnia alvei (2.45%) and Alcaligenes (3.5%). The selected isolates were able to tolerate at least 500 mg/l of Cr6+. The total Cr6+ concentration of the effluent sample analysed was found to be about 23.73 mg/l as determined by Atomic Absorption Spectrophotometry. Two of the isolates reduced 38% and 32% of Cr6+ added to the medium. Another 7 isolates showed Cr6+; reducing capability ranging from 18 to 22%.Conclusion: As the isolates have turned out to successfully reduce Cr6+ in this study, these can be used for the development of bioremediation process. Key words: Enzymatic reduction; Bioremediation; Chromium; Ecotoxicity; Tannery.DOI: 10.3329/jbs.v17i0.7104J. bio-sci. 17: 71-76, 2009
Isolation of a 29.5 kb Plasmid conferring Multiple Drug Resistance in Pseudomonas aeruginosa
Authors: Begum Shahanara , Ahmed Iftikhar , Alam Faisal , Samsuzzaman M , Hassan Parvez , Absar Nurul , Haq Jalaluddin Ashraful
Published: February 2011

Context: Worldwide emergence of plasmid mediated multi drug resistant bacterial strain is a growing concern, especially in hospital infections caused by Pseudomonas aeruginosa. Relation of plasmid and drug resistance in clinical isolates of P. aeruginosa by curing and transformation experiments is scanty.Objectives: To isolate, purify and characterize plasmid DNA harbored in a selected Pseudomonas aeruginosa strain encoding multiple drug resistance and to perform transformation of the isolated plasmid into a sensitive strain of Escherichia coli LE 392 to judge transformation potential of the donor P. aeruginosa strain. Materials and Methods: Plasmid DNA was isolated from a multidrug-resistant (MDR) strain of P. aeruginosa obtained from swab of a hospitalized burn patient by mini-scale method. DNA was purified, quantitatively estimated and electrophoresed on 0.8% agarose gel. Transformation was done as per Cohen and co-workers using plasmid DNA isolated from MDR P. aeruginosa strain as the donor and the E. coli LE 392 strain. The presence of plasmid in transformants checked through electrophoresis and the transformants was also tested for each drug resistance already recorded for the donor strain by disc diffusion method and again confirmed by spreading its culture on the selected antibiotic plate of different concentrations. Results: A single plasmid of nearly 29.5 kb mass was isolated from MDR P. aeruginosa strain from clinical swab. This plasmid was transferred into sensitive and plasmid lacking recipient E. coli LE 392. Subsequent experiments on the transformed strain revealed that it acquired MDR and harbored a 29.5 kb plasmid which resembled to that of the donor strain proving that it encodes transferable MDR.Conclusion: The MDR P. aeruginosa strain contained a transferable plasmid conferring resistance to ampicillin, chloramphenicol, cotrimoxazole, tetracycline and ciprofloxacin. Key words: Pseudomonas aeruginosa; Multidrug–resistance; plasmid isolation; transformation. DOI: 10.3329/jbs.v17i0.7113J. bio-sci. 17: 95-100, 2009
Racial Variation in Serum Lipid and Lipoprotein Levels in Type 2 Diabetic Subjects of Bangladesh
Authors: Hoque Mohammad Razuanul , Kabir Md Golam , Sikdar Dwaipayan
Published: February 2011

Context: Racial and sex differences are documented globally regarding patterns of serum lipids among diabetic patients. Differences of lipid profile of normal and diabetic subjects of the different ethnic groups of Bangladesh may differ.Objectives: To find out if there were any differences in the serum lipid and lipoprotein levels in the type 2 diabetic patients of two different races namely, Bangalee and Chakma of Bangladesh. Materials and Methods: Study population consisted of 76 (Chakma / Bangalee: 35 / 41) patients aged between 40-60 years with type 2 diabetes mellitus who were on follow-up at the Rangamati Diabetes Hospital, Chittagong Hill Tract, Bangladesh and forty (Chakma / Bangalee: 20 / 20) non-diabetic subjects of same age were randomly selected as control. Biochemical parameters analyzed include - Serum total cholesterol and triglyceride (TG), serum high-density lipoprotein (HDL), low-density lipoprotein (LDL) cholesterol and atherogenic index.Results:  Dyslipidemia was found in the diabetic patients of both races and the patients had higher serum TG), atherogenic index and lower serum HDL than their normal counterpart. The Bangalee patients were found to have higher TG and lower atherogenic index compared with the Chakma patients although no racial differences found regarding total, HDL and LDL cholesterol. Also no differences were found between the lipid profiles of normal control subjects of these two races. Conclusion: Present study confirms that racial differences exist in serum lipid abnormalities between Chakma and Bangalee subjects with type 2 diabetes.Key words: Diabetes Type 2; Triglyceride; Lipoprotein; Total cholesterol; Bangalee; Chakma.DOI: 10.3329/jbs.v17i0.7116J. bio-sci. 17: 113-116, 2009
Molecular Screen of Trichoderma Isolates
Authors: Ali Amna , Bajwa Rukhsana , Mehmood Nasir , Jabeen Rasheda
Published: February 2011

Context: In the last few decades an ample array of molecular techniques has been introduced to obtain new disposition for the classification of Trichoderma species. Today the concern of scientists is either in the direction of gene targeting or ribotyping, the newest fingerprinting tool for genomic DNA that contain all or part of the genes coding for 18S rRNA in eukaryotes.Objectives: To take advantage of advanced molecular techniques for phylogenetic analysis of indigenous isolates of Trichoderma to comprehend our knowledge of this genus by supplementing the phenotypic identification.Materials and Methods:  Genomic DNA of twenty four isolates of Trichoderma species (T. harzianum, T. hamatum, T. koningii and T. pseudokoningii) were extracted by CTAB method and indicated band of ~15Kb on 0.8% agarose gel. Quality of DNA was determined by obtaining absorbance ratio (260/280) in the range of 1.7-1.9. Restriction fragment length polymorphism (RFLP) analyses were performed by using two restriction endonulease enzymes i.e., BamHI and HindIII. The BamHI represented results in the range of 500bp-750bp. 18S rRNA gene targeting was further carried out through optimization in ribotyping analysis.Results: The DNA bands of 24 isolates of Trichoderma species were compared with marker DNA bands and indicated the presence of genomic DNA intact band of ~15Kb. The ratio of absorbance 260/280nm (1.8-1.9 for pure DNA preparations) provided an estimate of the purity of the DNA RFLP analysis, along with the negative control of twenty four different isolates of Trichoderma species subjected to restriction using BamHI enzyme. The rRNA gene amplified band was observed at 600bp in the case of T. hamatum isolate (S. cumini stem bark, FCBP accession number 769) while in remaining isolates bands were in slightly smeared form. Furthermore, rRNA gene amplification conditions were optimized by altering different Tm and MgCl2 concentrations. Conclusion: The genomic DNA can serve as long term storage of information. Therefore advance molecular techniques can be used to study the variability in the genome of organism. RFLP are the initial steps for screening the genome of any organism.Key words: Trichoderma; DNA; RFLP; restriction endonuleases; 18S rRNA.DOI: 10.3329/jbs.v17i0.7117J. bio-sci. 17: 117-122, 2009
Effect of pH on in vitro Pollen Germination of Fourteen Cultivated and Wild Species of Cucurbit
Authors: Zaman M Rashed
Published: February 2011

Context: The pH of the in vitro germination medium is the important factor controlling pollen germination and pollen tube development in different plant speciesObjectives: The aim of the present study was to assess the effect of pH levels of germination medium on the germinability 14 species of cucurbit.Materials and Methods: In vitro pollen germination of 14 cucurbit species was examined at five different levels of pH using Brewbaker and Kwack's medium. The pH of the medium was adjusted to 7.0, 7.5, 8.0, 8.5 and 9.0 by using a digital pH meter with the help of 0.1 N HCl and 0.1 N NaOH. In vitro pollen germination was tested using sitting drop culture technique. Five sitting drop cultures of pollen grains of five different pH for each species were raised on five different microslides. Then the slides were placed in a humidity chamber and incubated at 22 ± 2 °C for 1 to 2 hrs. All the cultures were fixed by adding a drop of a 1-2% acetocarmine before start scoring and the germinated and non-germinated pollen grains were scored using a microscope.Results: The pollen germination rate was higher in increased pH level in most of the cucurbit species studied and at 9.0 pH the maximum germination was observed in pumpkin (98%), snake gourd (98%), ridge gourd (96%), pointed gourd (89%), cucumber (98%), bitter gourd (96%), sweet gourd (98%) and sponge gourd (93%). The highest percentage of germination was observed in bottle gourd (98%) cucumber short (96%), watermelon (98%), muskmelon (97%) and ivy gourd (87%) at 8.5 pH level. The only cucurbit species wax gourd showed highest germination (97%) at the lower pH level of 7.5. Analysis of variance for the 14 cucurbits at five different pH levels showed that the differences between the germination rates of pollen grains of 14 cucurbit species at different pH level were highly significant (F=12.49, P<0.001, at 13/52 df). Conclusion: In most of the investigated cucurbit species pH level 8.5 to 9.0 was found optimum for the highest number of in vitro pollen germination, while wax gourd responded maximum pollen germination at pH 7.5.Key words: cucurbit; pollen; germination; pH.DOI: 10.3329/jbs.v17i0.7120J. bio-sci. 17: 129-133, 2009
Isolation and Identification of Bacteria from the Workers of Live Bird Markets at Mymensingh, Bangladesh
Authors: Sarker S , Talukder S , Chowdhury EH , Das PM
Published: February 2011

Context: Identification of bacteria from the workers of live bird markets is important factor for zoonotic aspects and for implementing appropriate control strategies.Objectives: To determine the occurrence of bacteria especially Salmonella sp. and Escherichia coli from the workers of live bird markets.Materials and Methods: A total of 40 samples were collected from hand washes (n=20) and nasal swabs (n=20) of the associated workers in urban and suburban live bird markets. Bacteria were isolated in different media, and identification was performed based on the staining, cultural and some biochemical tests. For Salmonella sp., DNA was extracted using a DNA isolation kit and rfbs gene was amplified by using commercial PCR kit.Results: The bacteria such as Salmonella sp. and E. coli were detected in the samples by several microbial tests. The prevalence of Salmonella sp. was 40% and 30%, and E. coli was 70% and 40% in the hand washes and nasal swabs respectively of the workers of urban and periurban live bird markets.Conclusion: The results obtained in this study suggest that the appropriate precautions should be taken during and subsequent to the handling of live birds to minimize the risk of zoonotic diseases.Key words: Salmonella; Escherichia coli; live bird markets; isolation and identificationDOI: 10.3329/jbs.v17i0.7121J. bio-sci. 17: 135-138, 2009
In Vitro Regeneration of Brinjal (Solanum melongena L.) Using Stem and Leaf Explants
Authors: Ray BP , Hassan L , Sarker SK
Published: February 2011

DOI: 10.3329/jbs.v17i0.7126J. bio-sci. 17: 155-158, 2009
Involvement of COUP-TFs in Cancer Progression
Authors: Boudot Antoine , Le Dily François , Pakdel Farzad
Published: February 2011

The orphan receptors COUP-TFI and COUP-TFII are members of the nuclear receptor superfamily that play distinct and critical roles in vertebrate organogenesis, as demonstrated by loss-of-function COUP-TFI and/or COUP-TFII mutant mice. Although COUP-TFs are expressed in a wide range of tissues in adults, little is known about their functions at later stages of development or in organism homeostasis. COUP-TFs are expressed in cancer cell lines of various origins and increasing studies suggest they play roles in cell fate determination and, potentially, in cancer progression. Nevertheless, the exact roles of COUP-TFs in these processes remain unclear and even controversial. In this review, we report both in vitro and in vivo data describing known and suspected actions of COUP-TFs that suggest that these factors are involved in modification of the phenotype of cancer cells, notably of epithelial origin.
Size Effects on the Entropy Production in Oscillatory Flow between Parallel Plates
Authors: Vazquez Federico , Olivares-Robles Miguel Angel , Medina Sac
Published: February 2011

The heat transfer problem of a zero-mean oscillatory flow of a Maxwell fluid between infinite parallel plates with boundary conditions of the third kind is considered. The local and global time-averaged entropy production are computed, and the consequences of convective cooling of the plates are also assessed. It is found that the global entropy production is a minimum for certain suitable combination of the physical parameters and a discrete set of values of the separation between the parallel plates. The transferred heat at the plates also shows minima in the same discrete set of values of the plates separation.
Do I Really Want to Know? A Cognitive Dissonance-Based Explanation of Other-Regarding Behavior
Authors: Matthey Astrid , Regner Tobias
Published: February 2011

We investigate to what extent genuine social preferences can explain observed other-regarding behavior. In a dictator game variant subjects can choose whether to learn about the consequences of their choice for the receiver. We find that a majority of subjects showing other-regarding behavior when the payoffs of the receiver are known, choose to ignore these consequences if possible. This behavior is inconsistent with preferences about outcomes. Other-regarding behavior may also be explained by avoiding cognitive dissonance as in Konow (2000). Our experiment’s choice data is in line with this approach. In addition, we successfully relate individual behavior to proxies for cognitive dissonance.
Neutral and Non-Neutral Evolution of Duplicated Genes with Gene Conversion
Authors: Fawcett Jeffrey  A. , Innan Hideki
Published: February 2011

Gene conversion is one of the major mutational mechanisms involved in the DNA sequence evolution of duplicated genes. It contributes to create unique patters of DNA polymorphism within species and divergence between species. A typical pattern is so-called concerted evolution, in which the divergence between duplicates is maintained low for a long time because of frequent exchanges of DNA fragments. In addition, gene conversion affects the DNA evolution of duplicates in various ways especially when selection operates. Here, we review theoretical models to understand the evolution of duplicates in both neutral and non-neutral cases. We also explain how these theories contribute to interpreting real polymorphism and divergence data by using some intriguing examples.
Prevalence and Antimicrobial-Resistance of Pseudomonas aeruginosa in Swimming Pools and Hot Tubs
Authors: Lutz Jonathan  K. , Lee Jiyoung
Published: February 2011

Pseudomonas aeruginosa is an important opportunistic pathogen in recreational waters and the primary cause of hot tub folliculitis and otitis externa. The aim of this surveillance study was to determine the background prevalence and antimicrobial resistance profile of P. aeruginosa in swimming pools and hot tubs. A convenience sample of 108 samples was obtained from three hot tubs and eight indoor swimming pools. Water and swab samples were processed using membrane filtration, followed by confirmation with polymerase chain reaction. Twenty-three samples (21%) were positive for P. aeruginosa, and 23 isolates underwent susceptibility testing using the microdilution method. Resistance was noted to several antibiotic agents, including amikacin (intermediate), aztreonam, ceftriaxone, gentamicin, imipenem, meropenem (intermediate), ticarcillin/clavulanic acid, tobramycin (intermediate), and trimethoprim/sulfamethoxazole. The results of this surveillance study indicate that 96% of P. aeruginosa isolates tested from swimming pools and hot tubs were multidrug resistant. These results may have important implications for cystic fibrosis patients and other immune-suppressed individuals, for whom infection with multidrug-resistant P. aeruginosa would have greater impact. Our results underlie the importance of rigorous facility maintenance, and provide prevalence data on the occurrence of antimicrobial resistant strains of this important recreational water-associated and nosocomial pathogen.
Characterization and Emulsification Properties of Rhamnolipid and Sophorolipid Biosurfactants and Their Applications
Authors: Nguyen Thu  T. , Sabatini David  A.
Published: February 2011

Due to their non-toxic nature, biodegradability and production from renewable resources, research has shown an increasing interest in the use of biosurfactants in a wide variety of applications. This paper reviews the characterization of rhamnolipid and sophorolipid biosurfactants based on their hydrophilicity/hydrophobicity and their ability to form microemulsions with a range of oils without additives. The use of the biosurfactants in applications such as detergency and vegetable oil extraction for biodiesel application is also discussed. Rhamnolipid was found to be a hydrophilic surfactant while sophorolipid was found to be very hydrophobic. Therefore, rhamnolipid and sophorolipid biosurfactants in mixtures showed robust performance in these applications.
Metallo-β-Lactamases and Aptamer-Based Inhibition
Authors: Schlesinger Sara R. , Lahousse Mieke J. , Foster Taylor O. , Kim Sung-Kun
Published: February 2011

An evolution of antibiotic-resistant bacteria has resulted in the need for new antibiotics. β-Lactam based drugs are the most predominantly prescribed antibiotics to combat bacterial infections; however, production of β-lactamases, which catalyze the hydrolysis of the β-lactam bond of this class of antibiotics, by pathogenic bacteria such as Bacillus cereus, are rendering them useless. Some inhibitors of β-lactamases have been found, but there are no inhibitors against a class of β-lactamases known as metallo-β-lactamases, and it has been reported that the number of bacteria that produce metallo-β-lactamases is on the rise. Finding inhibitors of metallo-β-lactamases is thus an urgent necessity. One way to approach the problem is by employing the combinatorial method SELEX. The SELEX method is significant in discovering and producing new classes of inhibitors, as well as providing insight into the development of these inhibitors and paves the way for future aptamer applications that further novel drug discovery.
Lymphoscintigraphy in breast cancer patients after neoadjuvant chemotherapy
Authors: Reitsamer R. , Holzmannhofer J. , Rendl G. , Pirich C. , Kronberger C. , Rettenbacher L. , Dalus K.
Published: February 2011

The aim of this study was to evaluate the diagnostic value of lymphatic mapping by lymphoscintigraphy in breast cancer patients undergoing neoadjuvant chemotherapy (NCTX). We assessed the association between clinicopathological factors and nonvisualized sentinel nodes during preoperative lymphoscintigraphy. As secondary aims, we analyzed whether post NCTX axillary ultrasonography and fluorine-18 fluorodeoxyglucose positron emission tomography and computed tomography (F18-FDG-PET/CT) might be useful for staging in case of nonvisualized sentinel nodes. Patients, methods: 61 patients with newly diagnosed, invasive breast cancer potentially eligible for NCTX were included in this substudy of a prospective trial on the monitoring of NCTX with 18F-FDG PET/CT. In all patients, lymphoscintigraphy was performed prior to sentinel lymph node biopsy (SLNB). 42 patients received neoadjuvant chemotherapy. 19 patients did not receive NCTX. After SLNB, mastectomy or lumpectomy (breast-conserving surgery) combined with level I and II axillary lymph node dissection were performed. Cases of nonvisualized sentinel nodes were analyzed with respect to tumour and patient characteristics and the results of ultrasonography and 18F-FDG-PET/CT before and after NCTX. Results: Lymphoscintigram successfully identified at least one sN in 55 patients (i.e. identification rate of 90%). The risk of failure to identify the sN was associated statistically with a positive clinical nodal status prior to NCTX (p = 0.021). There was no statistical difference between patients with visualized and nonvisualized sN with respect to age, tumour grade, tumour size, pathological lymph node status or tumour histology. In patients without NCTX the sN identification rate was 100% versus 86% in patients with NCTX (n.s.). The FNR of patients with NCTX was 9.1%. Post NCTX axillary ultrasonography or FDG-PET/CT did not provide accurate information about the lymph node status in case of failing lymphatic mapping. Conclusion: On the basis of our findings, SLNB can not yet be recommended as a reliable staging method in breast cancer patients undergoing neoadjuvant chemotherapy. Patients with clinically positive axillary lymph nodes have a higher chance of unsuccessful lymphatic mapping by lymphoscintigraphy. Performing SLNB before NCTX in clinically node-negative patients may identify the subset of patients in whom axillary lymph node dissection can be omitted. Post NCTX axillary ultrasonography and 18F-FDG-PET/CT can not be suggested as valid axillary staging methods in case of a failed lymphatic mapping.
La coordination européenne « à la bolognaise »
Authors: Ravinet Pauline
Published: February 2011

Résumé Cet article s’intéresse à la construction de l’Espace européen d’enseignement supérieur, ou processus de Bologne. Il s’appuie sur et discute l’approche des instruments d’action publique pour recomposer en détails la structuration et l’instrumentation d’un dispositif de coordination des politiques nationales d’enseignement supérieur. Cette approche permet de comprendre d’une part comment ce processus initialement souple et volontaire est piloté par son instrument transversal (le stocktaking ) et en vient à exercer une contrainte sur les États participants. Elle permet d’autre part de caractériser une forme de coordination « à la bolognaise » à la fois familière avec les « nouveaux modes de gouvernance européens » et particulière dans son mode de relation à l’Union européenne, puisqu’elle s’est développée et institutionnalisée à la marge du cadre institutionnel de l’UE.
Applying Participatory Methods to Address Motivational Aspects in Informal Workplace
Authors: Holocher Teresa , Kieslinger Barbara , Fabian Claudia Magdalena
Published: February 2011

Motivational aspects are core to successful knowledge sharing and collaborative learning experiences. However, it still remains one of the great challenges to overcome motivational barriers when it comes to introducing information systems for collaborative learning at the workplace. In the context of an international research project we have taken motivational aspects into account during the design phase and started a participatory process involving researchers, end-users, managers, designers and developers. As initial findings show, a continuous dialogue with end-users may contribute to creating a sense of ownership amongst them and become a motivational driver for the future use of the system.
A New Vision for Evaluating the Quality of E-Commerce Websites
Authors: Rababah Osama M. , Al-Shboul Muhannad , Al-Sayyed Rizik
Published: February 2011

Quality has been established as a key factor in ensuring the success of E-commerce in attracting and retaining customers. To help in this, numerous software metrics and website quality models have been developed, with a correspondingly large literature. We provide a critical review of this literature and the state-of-the-art. Most of the wide ranges of E-commerce website evaluation models give emphasis on the web applications of the system, using techniques like feature inspection and collecting data about end-usersâ?? opinion by questionnaires. However, this is in conflict with two fundamental pragmatic aspects of current websites. Web technologies evolve extremely fast, enabling sophisticated tools to be deployed and complex interactions to take place. Secondly, the life cycle of a website is also extremely fast: maintenance of a website is performed at a rate that is higher than that of other software products because of market pressure and lack of distribution barriers.
Bringing the Everyday Life into Engineering Education
Authors: Pasman Gert , Mulder Ingrid
Published: February 2011

Abstractâ?? To successfully design and engineer solutions for todayâ??s and tomorrowâ??s rapidly changing and expanding global contexts, in which people are confronted with new opportunities and challenges each day, engineering programs should be training their students to become broad based professionals, who are aware of the actual needs, values and behaviors of the people that use their solutions in their everyday life, work or play. This article argues that in order to built such an awareness, engineering students should acquire direct, first-hand experiences of real people in real contexts. It presents a number of techniques that can be used to gain such experiences. Each technique is briefly described and illustrated with examples from our Industrial Design Engineering program. Knowledge, skills and attitude that are acquired through the use of the techniques are listed and reflected upon. Finally, our experiences with implementing the techniques into our program are discussed in view of their relevance for other engineering programs.
A TRANSDERMAL DRUG DELIVERY SYSTEM CONTAINING DEFERIOXAMINE MESYLATE FOR THE TREATMENT OF BETA-THALASSAEMIA MAJOR
Authors: Hsieh Chin-Hsiung , Ku Yuan-An , Chiu Lien-Hua , Young Tai-Horng , Huang Yi-You
Published: February 2011

Patients with beta-thalassaemia major need blood transfusion frequently during their whole life. However, frequent transfusions will eventually lead to the accumulation of trivalent iron, resulting in iron overload. To reduce iron overload, patients are administered regularly with intravenous or subcutaneous infusion of deferioxamine mesylate (DFO). Nevertheless, high costs of medication, poor patient compliance, and side effects limit its use and patient's acceptance. To overcome such drawbacks, we developed a novel transdermal delivery system to administer the DFO instead of traditional injections. We assayed the feasibility of fabricating a transdermal DFO patch using the single-layer drug-in-adhesive drug delivery system. We used the pressure-sensitive adhesives and hydrogels as the drug reservoirs and studied the release profile of DFO from the transdermal patches in vitro. In order to enhance the transdermal delivery rate, chemical enhancers, polysorbate 80 and oleic acid, and physical enhancer, ultrasound, were incorporated into the monolith DFO patches. Experimental results showed that the combination of polysorbate 80 and oleic acid in the pressure-sensitive adhesives enhanced the penetration efficiency through nude mice skin. The pretreatment of nude mice skin with ultrasound temporally changed the diffusional resistance and facilitated DFO penetration through the skin. We expect that the new delivery system can enable the drug to penetrate through skin at a stable rate and reach the circulation system successfully, thus allowing the concentration of drug to achieve the therapeutic effect.
FATIGUE AND DURABILITY OF A NOVEL PERCUTANEOUS AORTIC VALVE STENT
Authors: Kumar Gideon Praveen , Mathew Lazar
Published: February 2011

To design against mechanical failure, most implants such as valve stents are assessed on the basis of survival on a long term. However, accurate investigation of the stress/strain distributions in such valve stents, which govern their deformation and fracture behavior, is essential for their prolonged, and safe use. With this background, an S–N type fatigue analysis was done on three stents with Von Mises stress component having the infinite life at 1.e + 006. The results of this study may aid a biomedical scientist to zero in on the material that could be used to analyze and fabricate percutaneous valve stents.