bluuebunny/crossref_metadata_2025 huggingface dataset:
Integrating Mechanical and Reduced Chemical Weed Control in Conservation Tillage Corn
Authors: Bates Ryan T. , Gallagher Robert S. , Curran William S. , Harper Jayson K.
Published: March 2012

Conservation tillage for corn (Zea mays L.) production has greatly reduced the soil erosion potential in these systems, but relies heavily on herbicides to manage weeds. Overreliance on herbicides can lead to the development of herbicide‐resistant weed communities and increase the risk of ground and surface water contamination by residual herbicides. This study evaluates the integration of various mechanical soil/weed management implements and herbicide programs for surface residue cover, weed control, corn productivity, and economic net returns. A pre‐plant vertical coulter/rotary harrow tended to control small annual weeds as well as a standard burn down herbicide program, but reduced surface residue cover by 15% compared to the no‐till check treatments. The high residue rotary hoe had little effect on surface residue cover, but provided inconsistent early‐season weed control. The high residue inter‐row cultivator resulted in 23% residue cover compared to 50% in the no‐till treatments, but reduced weed biomass by 53% without any supplemental residual herbicides and 88% with a banded residual herbicide compared to the weedy check treatment. Crop productivity and net return data suggest that integrating the vertical coulter/rotary harrow, high residue cultivator, and banded residual herbicide program could reduce herbicide ai rates by 70% and still achieve similar corn yields and economic returns as the herbicide intensive systems. Such integrated mechanical‐chemical systems will increase the crop management complexity for farmers, which may hinder adoption. Soil erosion potential of the integrated systems requires further in‐depth evaluation.
Evaluating the Contribution of Weather to Maize and Wheat Yield Trends in 12 U.S. Counties
Authors: Maltais‐Landry Gabriel , Lobell David B.
Published: March 2012

Evaluating the contribution of weather and its individual components to recent yield trends can be useful to predict the response of crop production to future climate change, but different modeling approaches can yield diverging results. We used two common approaches to evaluate the effect of weather trends on maize (Zea mays L.) and wheat (Triticum aestivum L.) production in 12 U.S. counties, and investigate sources of disparities between the two methods. We first used the Decision Support System for Agrotechnology Transfer (DSSAT) model from 1984 to 2008 to evaluate the contribution of weather changes to simulated yield trends in six counties for each crop, each county being located in one of the top 10 U.S. producing states for that crop. A parallel analysis was conducted by multiplying inter‐annual weather sensitivity of county‐level yields with observed weather trends to estimate weather contributions to empirical yield trends. Weather had a low (maize) to high (wheat) contribution to simulated yield trends, with rain having the largest effect. In contrast, weather and rain had lower contributions to empirical yield trends. Along with evidence from previous studies, this suggests that DSSAT may be too sensitive to water thus inflating the importance of rain. Moreover, the time period used to compute yield trends also had a large effect on the importance of weather and its individual components. Our results highlight the importance of using multiple computation approaches and different time periods when estimating weather‐related yield trends.
Swath‐Grazing Potential for Small‐Grain Species with a Delayed Planting Date
Authors: Baron Vern S. , Aasen Arvid , Oba Masahito , Dick A. Campbell , Salmon Don F. , Basarab John A. , Stevenson Craig F.
Published: March 2012

Grazing swathed, small‐grain crops can reduce costs of overwintering beef cows (Bos taurus) by 40%. However, the late planting required to target mid‐September harvest may be associated with low yield and carrying capacity. The objective was to compare whole‐plant yield, nutritive value, and potential carrying capacity in relation to beef cow requirements for spring barley (Hordeum vulgare L.), oat (Avena sativa L.), and triticale (X Triticosecale Wittmack) when planted on seven weekly intervals (10 May–23 June) over 3 yr at Lacombe, AB; whole‐plant material was harvested at soft dough (barley and triticale) or milk stages (oat). Data were analyzed relative to planting date delay as an independent variable. Barley matured more rapidly than oat and triticale, with the latest planting date harvested on 27 August for barley, 8 September for oat and 25 September for triticale. Nutritive value for barley and triticale was unaffected by planting date, but neutral (NDF) and acid detergent fiber (ADF) concentrations increased quadratically with delay in planting for oat. In vitro true digestibility (IVTD) was lower for oat than barley and triticale. Yield declined linearly with planting delay for barley (35–39%), but increased (quadratically) as planting was delayed from late May to early June for oat (8%) and triticale (10%). Consequently, the potential carrying capacity for triticale was 1.6 and 1.8 times greater than barley and oat, respectively when planted for swathing in late August or early September.
Hydrothermal Modeling of Seedling Emergence Timing across Topography and Soil Depth
Authors: Bullied W. John , Van Acker Rene C. , Bullock Paul R.
Published: March 2012

The soil environment is an essential determinant of microsite conditions required to model weed seedling emergence timing. An experiment was established across topography within an annually cropped field in south‐central Manitoba to determine the effect of hillslope position (summit, backslope, toeslope), soil residue (native, added) and soil depth (three 25‐mm layers) on the microsite environment and the emergence timing of spring wheat as a surrogate weed. Soil temperature decreased with soil depth whereas soil temperature fluctuation decreased with soil depth and lower hillslope position. Soil water potential was lowest at the summit hillslope position and the upper soil layer. Soil temperature and water potential were combined into hydrothermal time using water potential minimum thresholds (–2.1, –1.3, –0.7, and –0.1 MPa). Thermal accumulation was greatest at the soil surface, whereas hydrothermal accumulation using a water potential minimum threshold of –0.7 or –0.1 MPa was greatest in the 25‐ to 50‐mm and 50‐ to 75‐mm soil depths. Seedling emergence occurred earliest from the 0‐ to 25‐ and 25‐ to 50‐mm soil depths and latest from the soil surface. No differences occurred in seedling emergence timing across levels of hillslope or soil residue. This study identifies recruitment depth as an important microsite variable that influences seedling emergence timing. Weed seedling recruitment models should be based on hydrothermal time and depth of recruitment to reflect the spatial and temporal dynamics of the recruitment zone environment.
Winter Grain–Short Season Corn Double Crop Forage Production for New England
Authors: Jemison John M. , Darby Heather M. , Reberg‐Horton S. Chris
Published: March 2012

Alternative organic forage systems that provide high quality feed and low weed pressure are required to improve farm viability. Five site‐year locations of research were conducted in Stillwater, ME and Alburgh, VT to evaluate winter grain–short season corn (WGSSC) double crops compared to full season corn (FSC) (Zea mays L.) for dry matter yield (DMY), weed biomass, and forage quality. Small grains evaluated in the study included winter barley (WB) (Hordeum vulgare L.), triticale (TC) (X Triticosecale), and winter wheat (WW) (Triticum aestivum L.). Low degree‐day open‐pollinated and hybrid corns were planted following cereal boot or soft dough stage harvest and were evaluated relative to FSC. A moderately winterkilled WB stand reduced DMY by 33 to 50% relative to TC and WW, and WB was weakly competitive against weeds. In most measures, WB forage quality was significantly higher than TC or WW. Delaying harvest to soft dough stage nearly doubled small grain DMY and forage quality yield for most measures. Corn planted after boot stage grain harvest produced 1700 kg ha−1 greater DMY than later planted corn, but weed biomass was not significantly affected by planting date. Forage quality and forage quality yield were approximately 15% greater for corn planted after boot stage harvest. Dense TC and WW stands reduced weed biomass by 300% relative to WB‐corn double crop. Highest forage quality/yield was found with soft‐dough stage WB–corn double crop. Double crop forage systems can reduce environmental risk and lower organic dairy production costs, and provide high yielding, high quality feed.
Agricultural Reference Index for Drought (ARID)
Authors: Woli Prem , Jones James W. , Ingram Keith T. , Fraisse Clyde W.
Published: March 2012

Several drought indices are available to compute the degree of drought to which crops are exposed. They vary in complexity, generality, and the adequacy with which they represent processes in the soil, plant, and atmosphere. Agricultural Reference Index for Drought (ARID) was developed as a reference index to approximate the water stress factor that is used to affect growth and other physiological processes in crop simulation models. Using RMSE, Willmott d index, and modeling efficiency (ME) as performance measures, ARID was evaluated using soil water contents in the root zone measured daily in two grass fields in Florida. The ability of ARID was assessed through comparison with the water deficit index (WSPD) of the Decision Support System for Agrotechnology Transfer (DSSAT) CERES‐Maize model. Seven other drought indices were compared with WSPD to identify the most appropriate agricultural drought index. Values of each index were computed for full canopy cover periods of maize (Zea mays L.) crops for 16 locations in the U.S. Southeast. Using periodic values, the performance of each index was assessed in terms of its correlation (r) with and departure from WSPD. The ARID reasonably predicted soil water contents (RMSE = 0.01–0.019, d index = 0.92–0.94, ME = 0.66–0.73) and adequately approximated WSPD (r = 0.90, RMSE = 0.15). Among the indices compared, ARID mimicked WSPD the most closely (RMSE smaller by 1–83%, r larger by 1–630%) and captured weather fluctuation effects the most accurately. Results indicated that ARID may be used as a simple index for quantifying drought and its effects on crop yields.
Vegetative Propagation of Napiergrass and Energycane for Biomass Production in the Southeastern United States
Authors: Knoll Joseph E. , Anderson William F.
Published: March 2012

With renewed interest in planting large areas to bioenergy crops, improvements in establishment methods are needed. Our objectives were to evaluate propagation methods with stem cuttings of napiergrass (Pennisetum purpureum Schum.), and to determine the optimum planting date for napiergrass and energycane (Saccharum hybrid) in the southeastern Coastal Plain of the United States. A greenhouse study with ‘Merkeron’ napiergrass showed only minor differences between horizontal buried planting and vertical planting with one node exposed. However, cuttings taken from the lower portion of the parent stem were superior to younger material from the upper portion. The rooting hormone indole‐3‐butyric acid (IBA) did not affect propagation success. Nine napiergrass genotypes were compared for response to cutting length in the field (1, 2, 5, or 10 nodes cutting−1, with 10 nodes plot−1). Single‐node cuttings tended to produce more shoots plot−1 initially in the fall, but many of these did not survive the winter. Generally, higher emergence percentages were achieved with 5‐ and 10‐node cuttings. Seven genotypes of napiergrass and two of energycane were compared for response to planting date. Five biweekly plantings were made beginning 17 Sept. 2009, and six plantings beginning 2 Sept. 2010. In 2009 initial fall emergence was greater in earlier plantings, but the following spring, both early and late plantings had similar numbers of shoots cutting−1, while intermediate plantings had the least. In 2010 there was less variation in fall emergence among planting dates, but the following spring the earliest plantings had more shoots cutting−1 than later plantings.
The Effect of Solar Loading on Soil Temperatures and Developmental Variation in Greenhouse Studies
Authors: Gitz D. C. , Xin Z. , Baker J. T. , Lascano R. J. , Burke J. J.
Published: March 2012

Water is the single most limiting factor of crop yield. A high throughput method of screening sorghum for transpiration efficiency (TE) might allow selection for plants able to maintain production in semiarid regions having few irrigation resources. A high throughput TE assay was characterized. We hypothesized that variation in solar radiation absorbed by containers could introduce soil temperature variation and influence measured TE. To test our hypothesis, two sorghum lines, Liang Tang Ai (High TE) and TX‐7078 (Low TE), were grown in either conventional black plastic or in insulated containers and TE determined as biomass/water transpired. Soil temperatures in the sealed conventional thermoplastic containers exceeded 50°C and plants developed more slowly than those grown in insulated containers. Liang Tang Ai showed 30% greater TE as compared to TX‐7078 when grown in insulated containers, but any potential TE differences were masked by supra‐optimal temperatures in the conventional black plastic containers. Our results showed that the effects of solar radiation loading can lead to high soil temperatures and must be considered when designing TE screening experiments or other physiological studies.
Nitrogen Sources and Timing Effects on Nitrogen Loss and Uptake in Delayed Flood Rice
Authors: Dillon K. A. , Walker T. W. , Harrell D. L. , Krutz L. J. , Varco J. J. , Koger C. H. , Cox M. S.
Published: March 2012

Field experiments were conducted in 2009 and 2010 in Louisiana and Mississippi to evaluate ammonia volatilization loss and subsequent effects on apparent nitrogen recovery efficiency (ANRE) and grain yield for rice (Oryza sativa L.). A semi‐open static chamber approach was used to measure ammonia volatilization loss from multiple N sources applied 10 days before flood (dbf) at the rate of 168 kg N ha−1. Cumulative ammonia volatilization losses for urea for Louisiana environments were 19 and 33% compared to 7% for both Mississippi environments. Urea + [N‐(n‐butyl) thiophosphoric triamide] (NBPT), urea + NBPT + dicyandiamide (DCD), and ammonium sulfate (AS) all minimized volatilization losses over all environments (range of 1.9–4.9%). Additionally, ammonia volatilization data fitted to the Gompertz model demonstrated that urea + NBPT and urea + NBPT + DCD had longer lag phases (7.2–7.7 d) relative to urea, AS, and urea + ammonium sulfate (UAS) blend (3.6 d). The same N sources and rate of N was applied 10, 7, 4, and 1 dbf to determine the effects on ANRE and yield. Apparent N recovery efficiency ranged from 43 to 71%. Grain yield was influenced by application time for two environments. Nitrogen application 10 dbf resulted in the least grain yield and yields tended to increase with fewer days between application and permanent flood. In Louisiana, urea + NBPT and urea + NBPT + DCD resulted in yields greater than urea alone. Where volatilization potential is substantial, NBPT should be included with the urea application to protect yield potential.
Negative Impact of Employment on Engineering Student Time Management, Time to Degree, and Retention: Faculty, Administrator, and Staff Perspectives
Authors: Tyson Will
Published: March 2012

Interviews with faculty, administrators, staff, and students at four engineering programs reveal the role of undergraduate student employment on retention and timely degree completion among engineering students. Dueling narratives reveal how student approaches to earning an engineering degree differ greatly from faculty, administrator, and staff expectations. Faculty, administrators, and staff advise students on proper time management and are frustrated that student employment reflects a lack of commitment to engineering. Students acknowledge the challenges of balancing school and work yet consider employment important to student life. Some students adjust their course schedules to meet work demands, thus increasing time to degree. Faculty describe a seamless pathway to an engineering career through coursework, scholarships, undergraduate research opportunities, and internships. Students remain employed because scholarships do not sufficiently meet their financial needs and internships are not convenient for all students.
Learning as Liberation: How Liberal Arts Education Transforms First-Generation/Low Socio-Economic College Students
Authors: Morales Erik E.
Published: March 2012

Extensive qualitative interviews were conducted with 20 first-generation college students. Profound changes to the students resulting from exposure to academic liberal arts course content were documented. Specifically, this study explores evident thematic trends and specific examples of how liberal arts course work provided students with profound senses of freedom and liberation from emotional/psychological issues and ideological/political constraints. Exactly how exposure and learning resulted in these changes, and what these changes mean to the individual students, is explored in detail. What faculty can do to more effectively teach and retain these students is also discussed.
Modeling Racial Differences in the Effects of Racial Representation on 2-Year College Student Success
Authors: Museus Samuel D. , Jayakumar Uma M. , Robinson Thomas
Published: March 2012

The failure of many 2-year college students to persist and complete a postsecondary credential or degree remains a problem of paramount importance to higher education policymakers and practitioners. While racial representation—or the extent to which a student's racial group is represented on their respective campus—might be one factor that influences the success of students at 2–year colleges, this relationship has received little attention in the higher education literature. The current inquiry focuses on the direct and indirect influences of racial representation on the academic success of Black, Latino, and White students at 2–year institutions. Results indicate that racial representation exhibits both direct and indirect effects on 2–year students' academic success and that the nature of the relationship varies across racial groups. Implications for research and practice are discussed.
Development of difference spectrophotometric method for the estimation of leflunomide in tablet dosage form
Authors: Lakshmana Prabu , Prakash Suriya , Shanmugarathinam A.
Published: March 2012

A new simple, accurate, precise, highly sensitive and reproducible difference
spectrophotometric method for the determination of leflunomide in bulk and
pharmaceutical dosage form is described. Difference spectroscopic method is
based on the principle that leflunomide exhibit two different forms; in
acidic and basic medium which differs in their absorption spectra. The
difference spectra were obtained by reading the absorbance of leflunomide in
0.1N HCl in the reference cell and the absorbance of leflunomide in 0.1N NaOH
in the sample cell and vice versa; in the difference spectrum maxima and
minima were seen at 293.5nm and at 261.5nm respectively. The amplitude values
were calculated, which was plotted against concentration. The method is found
to be linear in the concentration range of 2-12 ?g/ml. The percentage
recovery was found to be between the ranges from 98.92 % to 99.08 %. The
proposed method was statistically validated and successfully applied for
analysis of tablet dosage forms.
Antioxidant activity, the content of total phenols and flavonoids in the ethanol extracts of Mentha longifolia (L.) Hudson dried by the use of different techniques
Authors: Stanisavljevic Dragana , Stojicevic Sasa , Djordjevic Sofija , Zlatkovic Branislav , Velickovic Dragan , Karabegovic Ivana , Lazic Miodrag
Published: March 2012

In this study, we have examined the yield of extracted substances obtained by
means of extraction using 70 % ethanol (v/v), the content of total phenols
and flavonoids, as well as the antioxidant activity of the extracts obtained
from the samples of the herbs dried by means of different techniques. Wild
mint Mentha longifolia (L.) Hudson was dried naturally in a laboratory oven
at a temperature of 45 ?C and in an absorptive low temperature condensation
oven at 35?C. The highest yield of extracts was obtained from the naturally
dried herbs and the lowest from the herbs dried in the low temperature
condensation drying oven. The content of total phenols and flavonoids was
determined by spectrophotometric methods with an FC reagent and by the
complexation reaction with aluminium-chloride, respectively. The extract of
the naturally dried herbs had the highest overall content of phenols
(113.8?2.0 mg of gallic acid/g of the dry extract) and flavonoids (106.7?0.3
mg of rutin/g of the dry extract). The highest antioxidant activity
determined by the FRAP and DPPH assay was determined in the extracts obtained
from naturally dried herbs (2.76?0.15 mmol Fe2+/mg of the dry extract and
EC50=0.022?0.001 mg/ml), while the lowest was obtained from the extracts of
herbs dried in the laboratory oven (1.13?0.11 mmol Fe2+/mg of the dry extract
and EC50=0.033?0.001 mg/ml). The HPLC-DAD analysis result show that the
greatest content of phenolic compounds show extract obtained from naturally
dried plant material. The dominant phenolic component in the all extracts is
Kaempferol 3-O-glucoside. The content of all phenolic compound strongly
depend on the drying conditions.
Lack of Gromov-hyperbolicity in small-world networks
Authors: Shang Yilun
Published: March 2012

The geometry of complex networks is closely related with their structure and function. In this paper, we investigate the Gromov-hyperbolicity of the Newman-Watts model of small-world networks. It is known that asymptotic Erdős-Rényi random graphs are not hyperbolic. We show that the Newman-Watts ones built on top of them by adding lattice-induced clustering are not hyperbolic as the network size goes to infinity. Numerical simulations are provided to illustrate the effects of various parameters on hyperbolicity in this model.
Curvatures of the diagonal lift from an affine manifold to the linear frame bundle
Authors: Kowalski Oldřich , Sekizawa Masami
Published: March 2012

We investigate the curvature of the so-called diagonal lift from an affine manifold to the linear frame bundle LM. This is an affine analogue (but not a direct generalization) of the Sasaki-Mok metric on LM investigated by L.A. Cordero and M. de León in 1986. The Sasaki-Mok metric is constructed over a Riemannian manifold as base manifold. We receive analogous and, surprisingly, even stronger results in our affine setting.
Antibiotic prophylaxis in low risk patients undergoing laparoscopic cholecystectomy
Authors: Kumar S , Lakhey PJ , Vaidya P , Patowary BN , Praveen CR , Shrestha P
Published: March 2012

Laparoscopic cholecystectomy is the 'gold standard' for benign diseases of gallbladder. It has rapidly gained popularity and it is one of the commonly performed operations in Nepal. The need for antibiotic prophylaxis when performing an elective laparoscopic cholecystectomy may not be as important as it is thought in low risk group. Despite, low postoperative infection rate in laparoscopic cholecystectomy in low risk group, the same criteria of antibiotic prophylaxis previously applied to conventional surgery are routinely used for laparoscopic surgery, even though its actual need has not been ascertained. Aim of this study was to assess the efficacy of antibiotic prophylaxis in elective laparoscopic cholecystectomy with respect to postoperative Surgical Site Infection (SSI) in low risk group. Study was carried out in The Department of Surgery, Tribhuvan University Teaching Hospital, Kathmandu, Nepal from May 2005 to June 2006 (14 months).This was a prospective randomized study done on 104 consecutive patients undergoing laparoscopic cholecystectomy. Patients were randomized into case group (group A) and control group (group B) with 52 patients in each group. Two and four patients from Group A and Group B respectively were excluded. In Group A, 50 patients received one gram ceftriaxone intravenously 30 minutes prior to induction of anesthesia and in Group B, all 48 patients received 10 milliliters (ml) of isotonic sodium chloride solution intravenously 30 minutes before induction. In both groups, age, sex, ultrasonogram findings, duration of surgery, American society of anesthesiologists patient classification score, antibiotic administration, bile spillage during surgery, length of postoperative hospital stay and postoperative SSI were recorded. Patients were advised to follow up in Surgical Out-patient Clinic if there was any evidence of SSI within 30 days. SSI was reported and classified as, superficial incisional, deep incisional or space / organ SSI. There were a total of 98 patients included in the study; 50 in Group A and 48 in Group B. In group A, three (6%) patients and in Group B, also three (6.3%) patients had superficial incisional SSI. None of them had deep or organ / space SSI. Comparison of data showed no statistically significant difference between two groups (P- 1.00). DOI: http://dx.doi.org/10.3126/jcmsn.v7i1.5962 JCMSN 2011; 7(1): 12-18
Tuberculin reactivity in bacille calmette-guerin vaccinated individuals with sputum positive pulmonary tuberculosis
Authors: Jha PK , Gurung R , Gyawali N , Nepal HP , Baral DD , Bhattacharya SK
Published: March 2012

The study was carried out to assess the value of tuberculin skin test for the diagnosis of Tuberculosis (TB) in BCG vaccinated individuals and to find out the sensitivity rate of tuberculin skin test (TST) in comparison to acid fast bacilli positive pulmonary TB. Similar population with high BCG vaccination coverage having both pulmonary TB patients (n=150) and apparently healthy individuals (n=150) in eastern Nepal were enrolled in this comparative study. Sputum from all the subjects was subjected to Z-N microscopy. TST was performed on these subjects by standard Mantoux method. Among the patients (mean age 36.18±14.15 yrs) and controls (mean age 35.61±13.44 yrs), 55.33 % and 47.33 % respectively have been found to be positive PPD reactors (>10mm) which is statistically not significant (P>0.05). About 23% of the patients & 27% of controls failed to react (anergic) to 5 TU PPD. PPD reactivity rate was high in the patients whose sputum smears were graded as 1+ in Z-N microscopy. The sensitivity of TST was highest for the induration of >5mm (77.3%). Specificity increased with increasing size of induration and was highest (73.3%) with induration of >15 mm. Tuberculin skin test is an all or none phenomenon. In Nepal, tuberculin test has a limited value in the diagnosis of pulmonary TB as both the apparently healthy individuals and patients with sputum smear positive pulmonary TB who had been immunized with BCG, showed almost similar rate of tuberculin reactivity. DOI: http://dx.doi.org/10.3126/jcmsn.v7i1.5970 JCMSN 2011; 7(1): 28-35
Evaluation of acute head injury by computed tomography scan in College of Medical Sciences-Teaching Hospital, Chitwan
Authors: Tayal A , Chhetri PK
Published: March 2012

This study was conducted to evaluate the computed tomography findings in patient with acute head injury and to emphasize the importance of computed tomography scan in head injury. One hundred consecutive patients presenting to the emergency department with head injury were evaluated by computed tomography scan of the head. Seventy five patients (75%) were male and twenty five (25%) were females. The age of the patients ranged from three to seventy years and the most affected age group was between thirty and forty (40%). The common causes of head injury were motor vehicle accident (70%), fall injury (25% ) and physical assault (5%). The most common computed tomographic findings were: cerebral contusions (52%), skull fractures (41%), intracerebral hematomas (24%), diffuse cerebral edema (23%), midline shift (18%), subdural hematomas (15%), subarachnoid hemorrhage (13%), diffuse axonal injury (8%), intraventricular hemorrhage (6%), extradural hemotomas (4%), pnemocephalus (2%) and normal scans were found in (5%). In conclusion, computed tomography is the mainstay in the imaging of head injury and helps in the patient management. DOI: http://dx.doi.org/10.3126/jcmsn.v7i1.5971 JCMSN 2011; 7(1): 36-39
Ultrasonography in infantile hypertrophic pyloric stenosis
Authors: Garg S , Deka PK , Chettri PK , Tayal A
Published: March 2012

Infantile hypertrophic pyloric stenosis (IHPS) is usually seen among the first born male infants. In recent time, ultrasonography has become the investigation of choice and has almost completely replaced the radiographic upper gastrointestinal series for the diagnosis of the disease. Here we report a case of 31 days infant with hypertrophic pyloric stenosis. Our purpose of reporting this case is to show the importance of ultrasonography in diagnosing infantile hypertrophic pyloric stenosis. DOI: http://dx.doi.org/10.3126/jcmsn.v7i1.5978 JCMSN 2011; 7(1): 73-76
Assessment of Wider Economic Impacts of High-Speed Rail for Great Britain
Authors: Graham Daniel J. , Melo Patricia C.
Published: March 2012

This paper considers the scope for wider economic impacts of agglomeration-based effects in the context of high-speed rail. The paper provides new evidence concerning the distance decay of long-distance travel and on the basis of such estimates assesses the potential order of magnitude of agglomeration benefits from improvements to high-speed rail transport in Great Britain. A new methodology assumed constancy of trip decay with respect to equal average travel times but variability with respect to distance. The expected outcome was that improvement in travel times would reduce the extent to which travelers perceived distance as an obstacle to interaction. Although urban economic theory did not preclude the existence of agglomeration benefits across interregional distances, the empirical evidence suggested that the order of magnitude of agglomeration benefits corresponding to 25% and 50% increases in travel speeds was small.
High-Speed Railways in Spain
Authors: Sánchez-Borràs M. , Robusté F. , Criado O.
Published: March 2012

The Spanish high-speed railway (HSR) network has developed swiftly over the past few years. In less than two decades, this network has already become the second longest in Europe and the third in the world ranking, and the network continues to grow. Given this situation and given that the Spanish HSR system is considered by several governments as an example to follow, the authors of this paper analyzed whether the Spanish case could be considered an example of success in terms of HSR and whether some Spanish practices could be improved on. A thorough analysis presents the Spanish HSR network in terms of its use, competitiveness with air travel, environmental and territorial impacts, and profitability and costs. The results of this analysis allowed conclusions to be drawn regarding the success of the Spanish HSR and some recommendations to be made for decision makers planning the construction of a high-speed line.
Installation of Railroad Wayside Defect Detectors
Authors: Peng Fan , Li Xiaopeng , Ouyang Yanfeng
Published: March 2012

Railroads use wayside inspection technologies to monitor the health of passing railcars. Because of resource constraints, an efficient and feasible installation plan should be integrated into a multiperiod decision–support framework to derive the maximum benefit over a long planning horizon. A large-scale network optimization framework was proposed to solve this problem. The problem was formulated into two equivalent mathematical models: a maximum coverage model and a K-median model. A set of solution algorithms including a greedy heuristic, a 1-interchange heuristic, and a Lagrangian relaxation method were developed for these models, and their computational performances were investigated. A numerical case study was developed to illustrate the use of these models in real-world settings, and insights into empirical applications of these models were drawn.
Track Maintenance of Heavy Haul Railways with Resilient versus Stiff Fastenings
Authors: Giannakos K.
Published: March 2012

The average stress on the tie–ballast contact surface is used to examine the stress on the seating of the track. According to AASHTO testing for road construction, increasing the pressure on the ballast by 10% results in a decrease that is 1.3 to 1.5 times more rapid in the geometry of the track and a corresponding increase in the maintenance cost. The type of fastening used, rigid or resilient, plays a major role in the magnitude of the stress at the seating surface of the tie on the ballast. Track maintenance and renewal are planned accordingly, always taking into consideration local conditions, on the basis of a combination of control data from measuring systems, visual observation, and economic data. This paper presents a parametric investigation of the influence of rigid versus resilient fastenings on track maintenance of heavy haul railroads.
Women, Educational Leadership and Societal Culture
Authors: Shah Saeeda , Shah Umbreen
Published: March 2012

This paper argues that women’s participation in the public and their access to senior leadership positions is defined by cultural and belief systems in a society. It draws upon a study of Women College heads of women-only colleges, in a region in Pakistan, to unveil the discursive dynamics in that societal context where complex factors interact to determine what is acceptable in that culture. This has implications for women’ roles and determines their practices as college heads. The study also unveiled the culturally-informed strategies adopted by these women professionals to exercise their role as college heads in the presence of multiple cultural constraints.
Using Submarine Heat Pumps for Efficient Gas Production from Seabed Hydrate Reservoirs
Authors: Mori Yasuhiko H. , Ochiai Jun-ichi , Ohmura Ryo
Published: March 2012

This article reports our novel idea about the thermal stimulation of seabed hydrate reservoirs for the purpose of natural gas production. Our idea is to use submarine heat pumps, which are to be placed near the hydrate reservoir and work to recover thermal energy from the surrounding seawater and supply it into the reservoir. Although the heat pumps need an electricity supply from the sea surface level, they can provide thermal energy which is several times that of the consumed electricity in quantity. As a consequence, the use of submarine heat pumps has a distinct thermodynamic advantage over other thermal stimulation techniques already proposed in the literature.
Selective Capture of Transcribed Sequences: A Promising Approach for Investigating Bacterium-Insect Interactions
Authors: An Ruisheng , Grewal Parwinder S.
Published: March 2012

Bacterial interactions with eukaryotic hosts are complex processes which vary from pathogenic to mutualistic. Identification of bacterial genes differentially expressed in the host, promises to unravel molecular mechanisms driving and maintaining such interactions. Several techniques have been developed in the past 20 years to investigate bacterial gene expression within their hosts. The most commonly used techniques include in-vivo expression technology, signature-tagged mutagenesis, differential fluorescence induction, and cDNA microarrays. However, the limitations of these techniques in analyzing bacterial in-vivo gene expression indicate the need to develop alternative tools. With many advantages over the other methods for analyzing bacterial in-vivo gene expression, selective capture of transcribed sequences (SCOTS) technique has the prospect of becoming an elegant tool for discovery of genes involved in the bacterium-host interaction. Here, we summarize the advances in SCOTS technique, including its current and potential applications in bacterial gene expression studies under a variety of conditions from in-vitro to in-vivo and from mammals to insects.
Activation of the Dormant Secondary Metabolite Production by Introducing Gentamicin-Resistance in a Marine-Derived Penicillium purpurogenum G59
Authors: Chai Yun-Jing , Cui Cheng-Bin , Li Chang-Wei , Wu Chang-Jing , Tian Cong-Kui , Hua Wei
Published: March 2012

A new approach to activate silent gene clusters for dormant secondary metabolite production has been developed by introducing gentamicin-resistance to an originally inactive, marine-derived fungal strain Penicillium purpurogenum G59. Upon treatment of the G59 spores with a high concentration of gentamicin in aqueous DMSO, a total of 181 mutants were obtained by single colony isolation. In contrast to the strain G59, the EtOAc extracts of nine mutant cultures showed inhibitory effects on K562 cells, indicating that the nine mutants had acquired capability to produce antitumor metabolites. This was evidenced by TLC and HPLC analysis of EtOAc extracts of G59 and the nine mutants. Further isolation and characterization demonstrated that four antitumor secondary metabolites, janthinone (1), fructigenine A (2), aspterric acid methyl ester (3) and citrinin (4), were newly produced by mutant 5-1-4 compared to the parent strain G59, and which were also not found in the secondary metabolites of other Penicillium purpurogenum strains. However, Compounds 1–4 inhibited the proliferation of K562 cells with inhibition rates of 34.6% (1), 60.8% (2), 31.7% (3) and 67.1% (4) at 100 μg/mL, respectively. The present study demonstrated the effectiveness of a simple, yet practical approach to activate the production of dormant fungal secondary metabolites by introducing acquired resistance to aminoglycoside antibiotics, which could be applied to the studies for eliciting dormant metabolic potential of fungi to obtain cryptic secondary metabolites.
Light Responsive Polymer Membranes: A Review
Authors: Nicoletta Fiore Pasquale , Cupelli Daniela , Formoso Patrizia , De Filpo Giovanni , Colella Valentina , Gugliuzza Annarosa
Published: March 2012

In recent years, stimuli responsive materials have gained significant attention in membrane separation processes due to their ability to change specific properties in response to small external stimuli, such as light, pH, temperature, ionic strength, pressure, magnetic field, antigen, chemical composition, and so on. In this review, we briefly report recent progresses in light-driven materials and membranes. Photo-switching mechanisms, valved-membrane fabrication and light-driven properties are examined. Advances and perspectives of light responsive polymer membranes in biotechnology, chemistry and biology areas are discussed.
Human Metabolic Network: Reconstruction, Simulation, and Applications in Systems Biology
Authors: Wu Ming , Chan Christina
Published: March 2012

Metabolism is crucial to cell growth and proliferation. Deficiency or alterations in metabolic functions are known to be involved in many human diseases. Therefore, understanding the human metabolic system is important for the study and treatment of complex diseases. Current reconstructions of the global human metabolic network provide a computational platform to integrate genome-scale information on metabolism. The platform enables a systematic study of the regulation and is applicable to a wide variety of cases, wherein one could rely on in silico perturbations to predict novel targets, interpret systemic effects, and identify alterations in the metabolic states to better understand the genotype-phenotype relationships. In this review, we describe the reconstruction of the human metabolic network, introduce the constraint based modeling approach to analyze metabolic networks, and discuss systems biology applications to study human physiology and pathology. We highlight the challenges and opportunities in network reconstruction and systems modeling of the human metabolic system.
Effects of Different Extraction Methods and Conditions on the Phenolic Composition of Mate Tea Extracts
Authors: Grujic Nevena , Lepojevic Zika , Srdjenovic Branislava , Vladic Jelena , Sudji Jan
Published: March 2012

A simple and rapid HPLC method for determination of chlorogenic acid (5-O-caffeoylquinic acid) in mate tea extracts was developed and validated. The chromatography used isocratic elution with a mobile phase of aqueous 1.5% acetic acid-methanol (85:15, v/v). The flow rate was 0.8 mL/min and detection by UV at 325 nm. The method showed good selectivity, accuracy, repeatability and robustness, with detection limit of 0.26 mg/L and recovery of 97.76%. The developed method was applied for the determination of chlorogenic acid in mate tea extracts obtained by ethanol extraction and liquid carbon dioxide extraction with ethanol as co-solvent. Different ethanol concentrations were used (40, 50 and 60%, v/v) and liquid CO2 extraction was performed at different pressures (50 and 100 bar) and constant temperature (27 ± 1 °C). Significant influence of extraction methods, conditions and solvent polarity on chlorogenic acid content, antioxidant activity and total phenolic and flavonoid content of mate tea extracts was established. The most efficient extraction solvent was liquid CO2 with aqueous ethanol (40%) as co-solvent using an extraction pressure of 100 bar.
An Icon-Based Synoptic Visualization of Fully Polarimetric Radar Data
Authors: Turner Dean , Woodhouse Iain H.
Published: March 2012

The visualization of fully polarimetric radar data is hindered by traditional remote sensing methodologies for displaying data due to the large number of parameters per pixel in such data, and the non-scalar nature of variables such as phase difference. In this paper, a new method is described that uses icons instead of image pixels to represent the image data so that polarimetric properties and geographic context can be visualized together. The icons are parameterized using the alpha-entropy decomposition of polarimetric data. The resulting image allows the following five variables to be displayed simultaneously: unpolarized power, alpha angle, polarimetric entropy, anisotropy and orientation angle. Examples are given for both airborne and laboratory-based imaging.
Ranging in an Underwater Medium with Multiple Isogradient Sound Speed Profile Layers
Authors: Ramezani Hamid , Leus Geert
Published: March 2012

In this paper, we analyze the problem of acoustic ranging between sensor nodes in an underwater environment. The underwater medium is assumed to be composed of multiple isogradient sound speed profile (SSP) layers where in each layer the sound speed is linearly related to the depth. Furthermore, each sensor node is able to measure its depth and can exchange this information with other nodes. Under these assumptions, we first show how the problem of underwater localization can be converted to the traditional range-based terrestrial localization problem when the depth information of the nodes is known a priori. Second, we relate the pair-wise time of flight (ToF) measurements between the nodes to their positions. Next, based on this relation, we propose a novel ranging algorithm for an underwater medium. The proposed ranging algorithm considers reflections from the seabed and sea surface. We will show that even without any reflections, the transmitted signal may travel through more than one path between two given nodes. The proposed algorithm analyzes them and selects the fastest one (first arrival path) based on the measured ToF and the nodes’ depth measurements. Finally, in order to evaluate the performance of the proposed algorithm we run several simulations and compare the results with other existing algorithms.
Histoire de la Centrale générale des syndicats libéraux de Belgique (CGSLB)
Authors: Faniel Jean , Vandaele Kurt
Published: March 2012

Résumé La Centrale générale des syndicats libéraux de Belgique s’apprête à fêter son 120e anniversaire. L’existence et la persistance d’un syndicat libéral restent pourtant des particularités belges peu connues. Pour combler cette lacune, le Courrier hebdomadaire se penche sur l’histoire de la CGSLB après avoir étudié les principales caractéristiques de ses membres dans un précédent numéro. Le tableau brossé ici permet de suivre l’évolution du syndicalisme libéral de sa naissance à l’époque actuelle. J. Faniel et K. Vandaele analysent la structuration du mouvement syndical libéral et son enracinement dans le paysage socio-politique belge. Ils s’intéressent à ses prises de position et fondements doctrinaux, à sa reconnaissance institutionnelle, à ses rapports avec les partis libéraux, à l’évolution du nombre de ses membres et de ses résultats aux élections sociales. Ils examinent également sa place dans les relations collectives du travail et dans certaines grandes mobilisations sociales, ainsi que son activité et sa reconnaissance au niveau international. En revenant sur les racines de la CGSLB, les auteurs soulignent l’importance de la pilarisation de la société belge dans l’apparition d’un syndicat se présentant ouvertement comme libéral. Ils montrent également comment cette pilarisation, de même que le développement de la sécurité sociale et l’institutionnalisation de la concertation sociale, ont contribué au maintien et à la croissance de la CGSLB. Certaines caractéristiques historiques du syndicalisme libéral expliquent aussi pourquoi la CGSLB est le syndicat belge le plus centralisé. En s’intéressant à l’histoire de la CGSLB et en l’examinant sur le long terme, J. Faniel et K. Vandaele éclairent une facette rarement abordée du libéralisme.
Keeping Ethnography in the Study of Communication
Authors: Irvine Judith T.
Published: March 2012

Maintenir l'ethnographie à l'étude de la communication Le programme proposé par Dell Hymes pour l’ethnographie de la communication est illustré dans ce texte par une étude de cas tirée d’une recherche menée en milieu rural wolof au Sénégal dans les années mille neuf cent soixante dix et quatre vingt. Comme le proposait Hymes, l’étude du langage comme action sociale devait aller au-delà de la linguistique. L’étude décrit ainsi les registres linguistiques wolofs ; elle les met en rapport plus largement avec l’organisation des conduites en tant qu’elles sont des pratiques communicationnelles – ceci pour illustrer ce sur quoi porte le terme de communication dans l’expression ethnographie de la communication. Pour ce qui en est du mot d’ethnographie, l’argument est méthodologique ; il montre qu’il faut aller au-delà des seuls entretiens. Les entretiens dans le cas étudié n’auraient pas révélé comment l’organisation des pratiques linguistiques wolof diverge des descriptions normatives et métapragmatiques des interlocuteurs consultés. De telles descriptions représentent des stéréotypes culturels, auxquels ils se réfèrent d’une façon ou d’une autre ; mais les stéréotypes ne sont pas un compte rendu (account) de la pratique. Une approche ethnographique impliquant un engagement prolongé est nécessaire pour découvrir les principes qui sous-tendent les pratiques réelles et la manière dont la conduite de quelqu’un, dans des circonstances concrètes, est interprétée par ses semblables. Ces arguments sont en accord avec le projet de Hymes ; mais le texte prend aussi en compte certains points problématiques (par exemple la notion de « communauté » chez Hymes), et les raisons pour dépasser l’étude « du langage en situation culturelle et sociale » (language in culture), ce qui caractérisait l’époque de Hymes, et se tourner vers les conceptualisations nouvelles de l’idéologie langagière.